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Annotation of src/usr.bin/ssh/session.c, Revision 1.319

1.319   ! djm         1: /* $OpenBSD: session.c,v 1.318 2020/01/23 07:10:22 dtucker Exp $ */
1.1       markus      2: /*
                      3:  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
                      4:  *                    All rights reserved
1.37      deraadt     5:  *
                      6:  * As far as I am concerned, the code I have written for this software
                      7:  * can be used freely for any purpose.  Any derived versions of this
                      8:  * software must be clearly marked as such, and if the derived work is
                      9:  * incompatible with the protocol description in the RFC file, it must be
                     10:  * called by a name other than "ssh" or "Secure Shell".
                     11:  *
1.2       markus     12:  * SSH2 support by Markus Friedl.
1.95      markus     13:  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
1.37      deraadt    14:  *
                     15:  * Redistribution and use in source and binary forms, with or without
                     16:  * modification, are permitted provided that the following conditions
                     17:  * are met:
                     18:  * 1. Redistributions of source code must retain the above copyright
                     19:  *    notice, this list of conditions and the following disclaimer.
                     20:  * 2. Redistributions in binary form must reproduce the above copyright
                     21:  *    notice, this list of conditions and the following disclaimer in the
                     22:  *    documentation and/or other materials provided with the distribution.
                     23:  *
                     24:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
                     25:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
                     26:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
                     27:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
                     28:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
                     29:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
                     30:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
                     31:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
                     32:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
                     33:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2       markus     34:  */
1.1       markus     35:
1.193     stevesk    36: #include <sys/types.h>
                     37: #include <sys/wait.h>
1.194     stevesk    38: #include <sys/un.h>
1.196     stevesk    39: #include <sys/stat.h>
1.207     stevesk    40: #include <sys/socket.h>
1.236     djm        41: #include <sys/queue.h>
1.192     stevesk    42:
1.282     djm        43: #include <ctype.h>
1.209     stevesk    44: #include <errno.h>
1.253     djm        45: #include <fcntl.h>
1.204     stevesk    46: #include <grp.h>
1.223     djm        47: #include <login_cap.h>
1.272     djm        48: #include <netdb.h>
1.192     stevesk    49: #include <paths.h>
1.206     stevesk    50: #include <pwd.h>
1.195     stevesk    51: #include <signal.h>
1.215     stevesk    52: #include <stdio.h>
1.214     stevesk    53: #include <stdlib.h>
1.212     stevesk    54: #include <string.h>
1.317     deraadt    55: #include <stdarg.h>
1.211     stevesk    56: #include <unistd.h>
1.277     deraadt    57: #include <limits.h>
1.1       markus     58:
1.216     deraadt    59: #include "xmalloc.h"
1.51      markus     60: #include "ssh.h"
                     61: #include "ssh2.h"
1.59      djm        62: #include "sshpty.h"
1.1       markus     63: #include "packet.h"
1.303     markus     64: #include "sshbuf.h"
                     65: #include "ssherr.h"
1.173     djm        66: #include "match.h"
1.1       markus     67: #include "uidswap.h"
                     68: #include "compat.h"
1.78      markus     69: #include "channels.h"
1.304     markus     70: #include "sshkey.h"
1.216     deraadt    71: #include "cipher.h"
                     72: #include "kex.h"
                     73: #include "hostfile.h"
1.2       markus     74: #include "auth.h"
1.19      markus     75: #include "auth-options.h"
1.266     markus     76: #include "authfd.h"
1.50      markus     77: #include "pathnames.h"
1.51      markus     78: #include "log.h"
1.274     millert    79: #include "misc.h"
1.51      markus     80: #include "servconf.h"
1.59      djm        81: #include "sshlogin.h"
1.51      markus     82: #include "serverloop.h"
                     83: #include "canohost.h"
1.55      itojun     84: #include "session.h"
1.216     deraadt    85: #ifdef GSSAPI
                     86: #include "ssh-gss.h"
                     87: #endif
1.130     provos     88: #include "monitor_wrap.h"
1.225     markus     89: #include "sftp.h"
1.290     djm        90: #include "atomicio.h"
1.171     markus     91:
                     92: #ifdef KRB5
                     93: #include <kafs.h>
1.161     markus     94: #endif
1.310     djm        95:
1.242     djm        96: #define IS_INTERNAL_SFTP(c) \
                     97:        (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
                     98:         (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
                     99:          c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
                    100:          c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
                    101:
1.1       markus    102: /* func */
                    103:
                    104: Session *session_new(void);
1.292     djm       105: void   session_set_fds(struct ssh *, Session *, int, int, int, int, int);
1.165     markus    106: void   session_pty_cleanup(Session *);
1.94      itojun    107: void   session_proctitle(Session *);
1.292     djm       108: int    session_setup_x11fwd(struct ssh *, Session *);
                    109: int    do_exec_pty(struct ssh *, Session *, const char *);
                    110: int    do_exec_no_pty(struct ssh *, Session *, const char *);
                    111: int    do_exec(struct ssh *, Session *, const char *);
                    112: void   do_login(struct ssh *, Session *, const char *);
                    113: void   do_child(struct ssh *, Session *, const char *);
1.73      djm       114: void   do_motd(void);
1.94      itojun    115: int    check_quietlogin(Session *, const char *);
1.1       markus    116:
1.292     djm       117: static void do_authenticated2(struct ssh *, Authctxt *);
1.94      itojun    118:
1.292     djm       119: static int session_pty_req(struct ssh *, Session *);
1.65      markus    120:
1.1       markus    121: /* import */
                    122: extern ServerOptions options;
                    123: extern char *__progname;
                    124: extern int debug_flag;
1.45      markus    125: extern u_int utmp_len;
1.21      markus    126: extern int startup_pipe;
1.74      markus    127: extern void destroy_sensitive_data(void);
1.303     markus    128: extern struct sshbuf *loginmsg;
1.294     djm       129: extern struct sshauthopt *auth_opts;
1.309     djm       130: extern char *tun_fwd_ifnames; /* serverloop.c */
1.21      markus    131:
1.34      markus    132: /* original command from peer. */
1.92      markus    133: const char *original_command = NULL;
1.34      markus    134:
1.1       markus    135: /* data */
1.237     djm       136: static int sessions_first_unused = -1;
                    137: static int sessions_nalloc = 0;
                    138: static Session *sessions = NULL;
1.1       markus    139:
1.248     djm       140: #define SUBSYSTEM_NONE                 0
                    141: #define SUBSYSTEM_EXT                  1
                    142: #define SUBSYSTEM_INT_SFTP             2
                    143: #define SUBSYSTEM_INT_SFTP_ERROR       3
1.225     markus    144:
1.129     provos    145: login_cap_t *lc;
1.28      millert   146:
1.165     markus    147: static int is_child = 0;
1.279     djm       148: static int in_chroot = 0;
1.165     markus    149:
1.290     djm       150: /* File containing userauth info, if ExposeAuthInfo set */
                    151: static char *auth_info_file = NULL;
                    152:
1.136     markus    153: /* Name and directory of socket for authentication agent forwarding. */
                    154: static char *auth_sock_name = NULL;
                    155: static char *auth_sock_dir = NULL;
                    156:
                    157: /* removes the agent forwarding socket */
                    158:
                    159: static void
1.165     markus    160: auth_sock_cleanup_proc(struct passwd *pw)
1.136     markus    161: {
                    162:        if (auth_sock_name != NULL) {
                    163:                temporarily_use_uid(pw);
                    164:                unlink(auth_sock_name);
                    165:                rmdir(auth_sock_dir);
                    166:                auth_sock_name = NULL;
                    167:                restore_uid();
                    168:        }
                    169: }
                    170:
                    171: static int
1.292     djm       172: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136     markus    173: {
                    174:        Channel *nc;
1.237     djm       175:        int sock = -1;
1.136     markus    176:
                    177:        if (auth_sock_name != NULL) {
                    178:                error("authentication forwarding requested twice.");
                    179:                return 0;
                    180:        }
                    181:
                    182:        /* Temporarily drop privileged uid for mkdir/bind. */
                    183:        temporarily_use_uid(pw);
                    184:
                    185:        /* Allocate a buffer for the socket name, and format the name. */
1.237     djm       186:        auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136     markus    187:
                    188:        /* Create private directory for socket */
                    189:        if (mkdtemp(auth_sock_dir) == NULL) {
1.312     djm       190:                ssh_packet_send_debug(ssh, "Agent forwarding disabled: "
1.136     markus    191:                    "mkdtemp() failed: %.100s", strerror(errno));
                    192:                restore_uid();
1.265     djm       193:                free(auth_sock_dir);
1.136     markus    194:                auth_sock_dir = NULL;
1.237     djm       195:                goto authsock_err;
1.136     markus    196:        }
1.237     djm       197:
                    198:        xasprintf(&auth_sock_name, "%s/agent.%ld",
                    199:            auth_sock_dir, (long) getpid());
1.136     markus    200:
1.274     millert   201:        /* Start a Unix listener on auth_sock_name. */
                    202:        sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136     markus    203:
                    204:        /* Restore the privileged uid. */
                    205:        restore_uid();
                    206:
1.274     millert   207:        /* Check for socket/bind/listen failure. */
                    208:        if (sock < 0)
1.237     djm       209:                goto authsock_err;
1.136     markus    210:
                    211:        /* Allocate a channel for the authentication agent socket. */
1.292     djm       212:        nc = channel_new(ssh, "auth socket",
1.136     markus    213:            SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
                    214:            CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156     markus    215:            0, "auth socket", 1);
1.245     djm       216:        nc->path = xstrdup(auth_sock_name);
1.136     markus    217:        return 1;
1.237     djm       218:
                    219:  authsock_err:
1.265     djm       220:        free(auth_sock_name);
1.237     djm       221:        if (auth_sock_dir != NULL) {
1.315     djm       222:                temporarily_use_uid(pw);
1.237     djm       223:                rmdir(auth_sock_dir);
1.315     djm       224:                restore_uid();
1.265     djm       225:                free(auth_sock_dir);
1.237     djm       226:        }
                    227:        if (sock != -1)
                    228:                close(sock);
                    229:        auth_sock_name = NULL;
                    230:        auth_sock_dir = NULL;
                    231:        return 0;
1.136     markus    232: }
                    233:
1.179     dtucker   234: static void
                    235: display_loginmsg(void)
                    236: {
1.303     markus    237:        int r;
                    238:
                    239:        if (sshbuf_len(loginmsg) == 0)
                    240:                return;
                    241:        if ((r = sshbuf_put_u8(loginmsg, 0)) != 0)
                    242:                fatal("%s: buffer error: %s", __func__, ssh_err(r));
                    243:        printf("%s", (char *)sshbuf_ptr(loginmsg));
                    244:        sshbuf_reset(loginmsg);
1.179     dtucker   245: }
1.136     markus    246:
1.290     djm       247: static void
                    248: prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
                    249: {
                    250:        int fd = -1, success = 0;
                    251:
                    252:        if (!options.expose_userauth_info || info == NULL)
                    253:                return;
                    254:
                    255:        temporarily_use_uid(pw);
                    256:        auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
                    257:        if ((fd = mkstemp(auth_info_file)) == -1) {
                    258:                error("%s: mkstemp: %s", __func__, strerror(errno));
                    259:                goto out;
                    260:        }
                    261:        if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
                    262:            sshbuf_len(info)) != sshbuf_len(info)) {
                    263:                error("%s: write: %s", __func__, strerror(errno));
                    264:                goto out;
                    265:        }
                    266:        if (close(fd) != 0) {
                    267:                error("%s: close: %s", __func__, strerror(errno));
                    268:                goto out;
                    269:        }
                    270:        success = 1;
                    271:  out:
                    272:        if (!success) {
                    273:                if (fd != -1)
                    274:                        close(fd);
                    275:                free(auth_info_file);
                    276:                auth_info_file = NULL;
                    277:        }
                    278:        restore_uid();
                    279: }
                    280:
1.294     djm       281: static void
1.297     djm       282: set_fwdpermit_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
1.294     djm       283: {
                    284:        char *tmp, *cp, *host;
                    285:        int port;
                    286:        size_t i;
                    287:
1.297     djm       288:        if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0) {
                    289:                channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL);
                    290:                for (i = 0; i < auth_opts->npermitopen; i++) {
                    291:                        tmp = cp = xstrdup(auth_opts->permitopen[i]);
                    292:                        /* This shouldn't fail as it has already been checked */
                    293:                        if ((host = hpdelim(&cp)) == NULL)
                    294:                                fatal("%s: internal error: hpdelim", __func__);
                    295:                        host = cleanhostname(host);
                    296:                        if (cp == NULL || (port = permitopen_port(cp)) < 0)
                    297:                                fatal("%s: internal error: permitopen port",
                    298:                                    __func__);
                    299:                        channel_add_permission(ssh,
                    300:                            FORWARD_USER, FORWARD_LOCAL, host, port);
                    301:                        free(tmp);
                    302:                }
                    303:        }
                    304:        if ((options.allow_tcp_forwarding & FORWARD_REMOTE) != 0) {
                    305:                channel_clear_permission(ssh, FORWARD_USER, FORWARD_REMOTE);
                    306:                for (i = 0; i < auth_opts->npermitlisten; i++) {
                    307:                        tmp = cp = xstrdup(auth_opts->permitlisten[i]);
                    308:                        /* This shouldn't fail as it has already been checked */
                    309:                        if ((host = hpdelim(&cp)) == NULL)
                    310:                                fatal("%s: internal error: hpdelim", __func__);
                    311:                        host = cleanhostname(host);
                    312:                        if (cp == NULL || (port = permitopen_port(cp)) < 0)
                    313:                                fatal("%s: internal error: permitlisten port",
                    314:                                    __func__);
                    315:                        channel_add_permission(ssh,
                    316:                            FORWARD_USER, FORWARD_REMOTE, host, port);
                    317:                        free(tmp);
                    318:                }
1.294     djm       319:        }
                    320: }
                    321:
1.65      markus    322: void
1.292     djm       323: do_authenticated(struct ssh *ssh, Authctxt *authctxt)
1.65      markus    324: {
1.153     markus    325:        setproctitle("%s", authctxt->pw->pw_name);
                    326:
1.294     djm       327:        auth_log_authopts("active", auth_opts, 0);
                    328:
1.65      markus    329:        /* setup the channel layer */
1.274     millert   330:        /* XXX - streamlocal? */
1.297     djm       331:        set_fwdpermit_from_authopts(ssh, auth_opts);
1.296     djm       332:
1.294     djm       333:        if (!auth_opts->permit_port_forwarding_flag ||
1.296     djm       334:            options.disable_forwarding) {
                    335:                channel_disable_admin(ssh, FORWARD_LOCAL);
                    336:                channel_disable_admin(ssh, FORWARD_REMOTE);
                    337:        } else {
                    338:                if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
                    339:                        channel_disable_admin(ssh, FORWARD_LOCAL);
                    340:                else
                    341:                        channel_permit_all(ssh, FORWARD_LOCAL);
                    342:                if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0)
                    343:                        channel_disable_admin(ssh, FORWARD_REMOTE);
                    344:                else
                    345:                        channel_permit_all(ssh, FORWARD_REMOTE);
                    346:        }
1.311     djm       347:        auth_debug_send(ssh);
1.65      markus    348:
1.290     djm       349:        prepare_auth_info_file(authctxt->pw, authctxt->session_info);
                    350:
1.292     djm       351:        do_authenticated2(ssh, authctxt);
1.290     djm       352:
1.292     djm       353:        do_cleanup(ssh, authctxt);
1.65      markus    354: }
                    355:
1.282     djm       356: /* Check untrusted xauth strings for metacharacters */
                    357: static int
                    358: xauth_valid_string(const char *s)
                    359: {
                    360:        size_t i;
                    361:
                    362:        for (i = 0; s[i] != '\0'; i++) {
                    363:                if (!isalnum((u_char)s[i]) &&
                    364:                    s[i] != '.' && s[i] != ':' && s[i] != '/' &&
                    365:                    s[i] != '-' && s[i] != '_')
1.305     deraadt   366:                        return 0;
1.282     djm       367:        }
                    368:        return 1;
                    369: }
                    370:
1.269     dtucker   371: #define USE_PIPES 1
1.1       markus    372: /*
                    373:  * This is called to fork and execute a command when we have no tty.  This
                    374:  * will call do_child from the child, and server_loop from the parent after
                    375:  * setting up file descriptors and such.
                    376:  */
1.237     djm       377: int
1.292     djm       378: do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
1.1       markus    379: {
1.137     mpech     380:        pid_t pid;
1.238     markus    381: #ifdef USE_PIPES
                    382:        int pin[2], pout[2], perr[2];
                    383:
1.253     djm       384:        if (s == NULL)
                    385:                fatal("do_exec_no_pty: no session");
                    386:
1.238     markus    387:        /* Allocate pipes for communicating with the program. */
1.316     deraadt   388:        if (pipe(pin) == -1) {
1.238     markus    389:                error("%s: pipe in: %.100s", __func__, strerror(errno));
                    390:                return -1;
                    391:        }
1.316     deraadt   392:        if (pipe(pout) == -1) {
1.238     markus    393:                error("%s: pipe out: %.100s", __func__, strerror(errno));
                    394:                close(pin[0]);
                    395:                close(pin[1]);
                    396:                return -1;
                    397:        }
1.316     deraadt   398:        if (pipe(perr) == -1) {
1.256     djm       399:                error("%s: pipe err: %.100s", __func__,
                    400:                    strerror(errno));
                    401:                close(pin[0]);
                    402:                close(pin[1]);
                    403:                close(pout[0]);
                    404:                close(pout[1]);
                    405:                return -1;
1.238     markus    406:        }
                    407: #else
1.237     djm       408:        int inout[2], err[2];
1.1       markus    409:
1.253     djm       410:        if (s == NULL)
                    411:                fatal("do_exec_no_pty: no session");
                    412:
1.1       markus    413:        /* Uses socket pairs to communicate with the program. */
1.316     deraadt   414:        if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) == -1) {
1.237     djm       415:                error("%s: socketpair #1: %.100s", __func__, strerror(errno));
                    416:                return -1;
                    417:        }
1.316     deraadt   418:        if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) == -1) {
1.256     djm       419:                error("%s: socketpair #2: %.100s", __func__,
                    420:                    strerror(errno));
                    421:                close(inout[0]);
                    422:                close(inout[1]);
                    423:                return -1;
1.237     djm       424:        }
1.238     markus    425: #endif
1.237     djm       426:
1.9       markus    427:        session_proctitle(s);
1.1       markus    428:
                    429:        /* Fork the child. */
1.237     djm       430:        switch ((pid = fork())) {
                    431:        case -1:
                    432:                error("%s: fork: %.100s", __func__, strerror(errno));
1.238     markus    433: #ifdef USE_PIPES
                    434:                close(pin[0]);
                    435:                close(pin[1]);
                    436:                close(pout[0]);
                    437:                close(pout[1]);
1.256     djm       438:                close(perr[0]);
1.238     markus    439:                close(perr[1]);
                    440: #else
1.237     djm       441:                close(inout[0]);
                    442:                close(inout[1]);
                    443:                close(err[0]);
1.256     djm       444:                close(err[1]);
1.238     markus    445: #endif
1.237     djm       446:                return -1;
                    447:        case 0:
1.165     markus    448:                is_child = 1;
1.144     markus    449:
1.1       markus    450:                /*
                    451:                 * Create a new session and process group since the 4.4BSD
                    452:                 * setlogin() affects the entire process group.
                    453:                 */
1.316     deraadt   454:                if (setsid() == -1)
1.1       markus    455:                        error("setsid failed: %.100s", strerror(errno));
                    456:
1.238     markus    457: #ifdef USE_PIPES
                    458:                /*
                    459:                 * Redirect stdin.  We close the parent side of the socket
                    460:                 * pair, and make the child side the standard input.
                    461:                 */
                    462:                close(pin[1]);
1.316     deraadt   463:                if (dup2(pin[0], 0) == -1)
1.238     markus    464:                        perror("dup2 stdin");
                    465:                close(pin[0]);
                    466:
                    467:                /* Redirect stdout. */
                    468:                close(pout[0]);
1.316     deraadt   469:                if (dup2(pout[1], 1) == -1)
1.238     markus    470:                        perror("dup2 stdout");
                    471:                close(pout[1]);
                    472:
                    473:                /* Redirect stderr. */
1.256     djm       474:                close(perr[0]);
1.316     deraadt   475:                if (dup2(perr[1], 2) == -1)
1.238     markus    476:                        perror("dup2 stderr");
                    477:                close(perr[1]);
                    478: #else
1.1       markus    479:                /*
                    480:                 * Redirect stdin, stdout, and stderr.  Stdin and stdout will
                    481:                 * use the same socket, as some programs (particularly rdist)
                    482:                 * seem to depend on it.
                    483:                 */
                    484:                close(inout[1]);
1.256     djm       485:                close(err[1]);
1.316     deraadt   486:                if (dup2(inout[0], 0) == -1)    /* stdin */
1.1       markus    487:                        perror("dup2 stdin");
1.316     deraadt   488:                if (dup2(inout[0], 1) == -1)    /* stdout (same as stdin) */
1.1       markus    489:                        perror("dup2 stdout");
1.238     markus    490:                close(inout[0]);
1.316     deraadt   491:                if (dup2(err[0], 2) == -1)      /* stderr */
1.1       markus    492:                        perror("dup2 stderr");
1.238     markus    493:                close(err[0]);
                    494: #endif
1.1       markus    495:
                    496:                /* Do processing for the child (exec command etc). */
1.292     djm       497:                do_child(ssh, s, command);
1.1       markus    498:                /* NOTREACHED */
1.237     djm       499:        default:
                    500:                break;
1.1       markus    501:        }
1.237     djm       502:
1.1       markus    503:        s->pid = pid;
1.47      markus    504:        /* Set interactive/non-interactive mode. */
1.312     djm       505:        ssh_packet_set_interactive(ssh, s->display != NULL,
1.257     djm       506:            options.ip_qos_interactive, options.ip_qos_bulk);
1.1       markus    507:
1.238     markus    508: #ifdef USE_PIPES
                    509:        /* We are the parent.  Close the child sides of the pipes. */
                    510:        close(pin[0]);
                    511:        close(pout[1]);
                    512:        close(perr[1]);
                    513:
1.292     djm       514:        session_set_fds(ssh, s, pin[1], pout[0], perr[0],
1.283     markus    515:            s->is_subsystem, 0);
1.238     markus    516: #else
1.1       markus    517:        /* We are the parent.  Close the child sides of the socket pairs. */
                    518:        close(inout[0]);
                    519:        close(err[0]);
                    520:
                    521:        /*
                    522:         * Enter the interactive session.  Note: server_loop must be able to
                    523:         * handle the case that fdin and fdout are the same.
                    524:         */
1.313     dtucker   525:        session_set_fds(ssh, s, inout[1], inout[1], err[1],
1.283     markus    526:            s->is_subsystem, 0);
1.238     markus    527: #endif
1.237     djm       528:        return 0;
1.1       markus    529: }
                    530:
                    531: /*
                    532:  * This is called to fork and execute a command when we have a tty.  This
                    533:  * will call do_child from the child, and server_loop from the parent after
                    534:  * setting up file descriptors, controlling tty, updating wtmp, utmp,
                    535:  * lastlog, and other such operations.
                    536:  */
1.237     djm       537: int
1.292     djm       538: do_exec_pty(struct ssh *ssh, Session *s, const char *command)
1.1       markus    539: {
                    540:        int fdout, ptyfd, ttyfd, ptymaster;
                    541:        pid_t pid;
                    542:
                    543:        if (s == NULL)
                    544:                fatal("do_exec_pty: no session");
                    545:        ptyfd = s->ptyfd;
                    546:        ttyfd = s->ttyfd;
                    547:
1.237     djm       548:        /*
                    549:         * Create another descriptor of the pty master side for use as the
                    550:         * standard input.  We could use the original descriptor, but this
                    551:         * simplifies code in server_loop.  The descriptor is bidirectional.
                    552:         * Do this before forking (and cleanup in the child) so as to
                    553:         * detect and gracefully fail out-of-fd conditions.
                    554:         */
1.316     deraadt   555:        if ((fdout = dup(ptyfd)) == -1) {
1.237     djm       556:                error("%s: dup #1: %s", __func__, strerror(errno));
                    557:                close(ttyfd);
                    558:                close(ptyfd);
                    559:                return -1;
                    560:        }
                    561:        /* we keep a reference to the pty master */
1.316     deraadt   562:        if ((ptymaster = dup(ptyfd)) == -1) {
1.237     djm       563:                error("%s: dup #2: %s", __func__, strerror(errno));
                    564:                close(ttyfd);
                    565:                close(ptyfd);
                    566:                close(fdout);
                    567:                return -1;
                    568:        }
                    569:
1.1       markus    570:        /* Fork the child. */
1.237     djm       571:        switch ((pid = fork())) {
                    572:        case -1:
                    573:                error("%s: fork: %.100s", __func__, strerror(errno));
                    574:                close(fdout);
                    575:                close(ptymaster);
                    576:                close(ttyfd);
                    577:                close(ptyfd);
                    578:                return -1;
                    579:        case 0:
1.165     markus    580:                is_child = 1;
1.97      markus    581:
1.237     djm       582:                close(fdout);
                    583:                close(ptymaster);
                    584:
1.1       markus    585:                /* Close the master side of the pseudo tty. */
                    586:                close(ptyfd);
                    587:
                    588:                /* Make the pseudo tty our controlling tty. */
                    589:                pty_make_controlling_tty(&ttyfd, s->tty);
                    590:
1.103     markus    591:                /* Redirect stdin/stdout/stderr from the pseudo tty. */
1.316     deraadt   592:                if (dup2(ttyfd, 0) == -1)
1.103     markus    593:                        error("dup2 stdin: %s", strerror(errno));
1.316     deraadt   594:                if (dup2(ttyfd, 1) == -1)
1.103     markus    595:                        error("dup2 stdout: %s", strerror(errno));
1.316     deraadt   596:                if (dup2(ttyfd, 2) == -1)
1.103     markus    597:                        error("dup2 stderr: %s", strerror(errno));
1.1       markus    598:
                    599:                /* Close the extra descriptor for the pseudo tty. */
                    600:                close(ttyfd);
                    601:
1.24      markus    602:                /* record login, etc. similar to login(1) */
1.292     djm       603:                do_login(ssh, s, command);
1.228     djm       604:
1.237     djm       605:                /*
                    606:                 * Do common processing for the child, such as execing
                    607:                 * the command.
                    608:                 */
1.292     djm       609:                do_child(ssh, s, command);
1.1       markus    610:                /* NOTREACHED */
1.237     djm       611:        default:
                    612:                break;
1.1       markus    613:        }
                    614:        s->pid = pid;
                    615:
                    616:        /* Parent.  Close the slave side of the pseudo tty. */
                    617:        close(ttyfd);
                    618:
1.237     djm       619:        /* Enter interactive session. */
1.1       markus    620:        s->ptymaster = ptymaster;
1.312     djm       621:        ssh_packet_set_interactive(ssh, 1,
1.257     djm       622:            options.ip_qos_interactive, options.ip_qos_bulk);
1.292     djm       623:        session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
1.237     djm       624:        return 0;
1.24      markus    625: }
                    626:
1.90      markus    627: /*
                    628:  * This is called to fork and execute a command.  If another command is
                    629:  * to be forced, execute that instead.
                    630:  */
1.237     djm       631: int
1.292     djm       632: do_exec(struct ssh *ssh, Session *s, const char *command)
1.90      markus    633: {
1.237     djm       634:        int ret;
1.280     djm       635:        const char *forced = NULL, *tty = NULL;
                    636:        char session_type[1024];
1.237     djm       637:
1.210     dtucker   638:        if (options.adm_forced_command) {
                    639:                original_command = command;
                    640:                command = options.adm_forced_command;
1.267     djm       641:                forced = "(config)";
1.294     djm       642:        } else if (auth_opts->force_command != NULL) {
1.90      markus    643:                original_command = command;
1.294     djm       644:                command = auth_opts->force_command;
1.267     djm       645:                forced = "(key-option)";
                    646:        }
1.306     djm       647:        s->forced = 0;
1.267     djm       648:        if (forced != NULL) {
1.306     djm       649:                s->forced = 1;
1.248     djm       650:                if (IS_INTERNAL_SFTP(command)) {
                    651:                        s->is_subsystem = s->is_subsystem ?
                    652:                            SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
                    653:                } else if (s->is_subsystem)
1.225     markus    654:                        s->is_subsystem = SUBSYSTEM_EXT;
1.267     djm       655:                snprintf(session_type, sizeof(session_type),
                    656:                    "forced-command %s '%.900s'", forced, command);
                    657:        } else if (s->is_subsystem) {
                    658:                snprintf(session_type, sizeof(session_type),
                    659:                    "subsystem '%.900s'", s->subsys);
                    660:        } else if (command == NULL) {
                    661:                snprintf(session_type, sizeof(session_type), "shell");
                    662:        } else {
                    663:                /* NB. we don't log unforced commands to preserve privacy */
                    664:                snprintf(session_type, sizeof(session_type), "command");
1.90      markus    665:        }
1.163     markus    666:
1.267     djm       667:        if (s->ttyfd != -1) {
                    668:                tty = s->tty;
                    669:                if (strncmp(tty, "/dev/", 5) == 0)
                    670:                        tty += 5;
                    671:        }
                    672:
1.280     djm       673:        verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267     djm       674:            session_type,
                    675:            tty == NULL ? "" : " on ",
                    676:            tty == NULL ? "" : tty,
                    677:            s->pw->pw_name,
1.281     djm       678:            ssh_remote_ipaddr(ssh),
                    679:            ssh_remote_port(ssh),
1.280     djm       680:            s->self);
1.267     djm       681:
1.163     markus    682: #ifdef GSSAPI
                    683:        if (options.gss_authentication) {
                    684:                temporarily_use_uid(s->pw);
                    685:                ssh_gssapi_storecreds();
                    686:                restore_uid();
                    687:        }
                    688: #endif
1.90      markus    689:        if (s->ttyfd != -1)
1.292     djm       690:                ret = do_exec_pty(ssh, s, command);
1.90      markus    691:        else
1.292     djm       692:                ret = do_exec_no_pty(ssh, s, command);
1.90      markus    693:
1.92      markus    694:        original_command = NULL;
1.179     dtucker   695:
                    696:        /*
                    697:         * Clear loginmsg: it's the child's responsibility to display
                    698:         * it to the user, otherwise multiple sessions may accumulate
                    699:         * multiple copies of the login messages.
                    700:         */
1.303     markus    701:        sshbuf_reset(loginmsg);
1.237     djm       702:
                    703:        return ret;
1.90      markus    704: }
                    705:
                    706:
1.24      markus    707: /* administrative, login(1)-like work */
                    708: void
1.292     djm       709: do_login(struct ssh *ssh, Session *s, const char *command)
1.24      markus    710: {
                    711:        socklen_t fromlen;
                    712:        struct sockaddr_storage from;
                    713:        struct passwd * pw = s->pw;
                    714:        pid_t pid = getpid();
                    715:
                    716:        /*
                    717:         * Get IP address of client. If the connection is not a socket, let
                    718:         * the address be 0.0.0.0.
                    719:         */
                    720:        memset(&from, 0, sizeof(from));
1.148     stevesk   721:        fromlen = sizeof(from);
1.312     djm       722:        if (ssh_packet_connection_is_on_socket(ssh)) {
                    723:                if (getpeername(ssh_packet_get_connection_in(ssh),
1.316     deraadt   724:                    (struct sockaddr *)&from, &fromlen) == -1) {
1.24      markus    725:                        debug("getpeername: %.100s", strerror(errno));
1.165     markus    726:                        cleanup_exit(255);
1.24      markus    727:                }
                    728:        }
1.25      markus    729:
1.24      markus    730:        /* Record that there was a login on that tty from the remote host. */
1.133     markus    731:        if (!use_privsep)
                    732:                record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281     djm       733:                    session_get_remote_name_or_ip(ssh, utmp_len,
1.158     markus    734:                    options.use_dns),
1.148     stevesk   735:                    (struct sockaddr *)&from, fromlen);
1.24      markus    736:
1.73      djm       737:        if (check_quietlogin(s, command))
1.24      markus    738:                return;
1.73      djm       739:
1.179     dtucker   740:        display_loginmsg();
1.73      djm       741:
                    742:        do_motd();
                    743: }
                    744:
                    745: /*
                    746:  * Display the message of the day.
                    747:  */
                    748: void
                    749: do_motd(void)
                    750: {
                    751:        FILE *f;
                    752:        char buf[256];
                    753:
1.24      markus    754:        if (options.print_motd) {
1.28      millert   755:                f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
                    756:                    "/etc/motd"), "r");
1.24      markus    757:                if (f) {
                    758:                        while (fgets(buf, sizeof(buf), f))
                    759:                                fputs(buf, stdout);
                    760:                        fclose(f);
                    761:                }
1.2       markus    762:        }
1.73      djm       763: }
                    764:
                    765:
                    766: /*
                    767:  * Check for quiet login, either .hushlogin or command given.
                    768:  */
                    769: int
                    770: check_quietlogin(Session *s, const char *command)
                    771: {
                    772:        char buf[256];
1.96      dugsong   773:        struct passwd *pw = s->pw;
1.73      djm       774:        struct stat st;
                    775:
                    776:        /* Return 1 if .hushlogin exists or a command given. */
                    777:        if (command != NULL)
                    778:                return 1;
                    779:        snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
                    780:        if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
                    781:                return 1;
                    782:        return 0;
1.1       markus    783: }
                    784:
                    785: /*
                    786:  * Reads environment variables from the given file and adds/overrides them
                    787:  * into the environment.  If the file does not exist, this does nothing.
                    788:  * Otherwise, it must consist of empty lines, comments (line starts with '#')
                    789:  * and assignments of the form name=value.  No other forms are allowed.
1.301     djm       790:  * If whitelist is not NULL, then it is interpreted as a pattern list and
                    791:  * only variable names that match it will be accepted.
1.1       markus    792:  */
1.94      itojun    793: static void
1.45      markus    794: read_environment_file(char ***env, u_int *envsize,
1.301     djm       795:        const char *filename, const char *whitelist)
1.1       markus    796: {
                    797:        FILE *f;
1.298     markus    798:        char *line = NULL, *cp, *value;
                    799:        size_t linesize = 0;
1.142     deraadt   800:        u_int lineno = 0;
1.1       markus    801:
                    802:        f = fopen(filename, "r");
                    803:        if (!f)
                    804:                return;
                    805:
1.298     markus    806:        while (getline(&line, &linesize, f) != -1) {
1.142     deraadt   807:                if (++lineno > 1000)
                    808:                        fatal("Too many lines in environment file %s", filename);
1.298     markus    809:                for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
1.1       markus    810:                        ;
                    811:                if (!*cp || *cp == '#' || *cp == '\n')
                    812:                        continue;
1.224     gilles    813:
                    814:                cp[strcspn(cp, "\n")] = '\0';
                    815:
1.1       markus    816:                value = strchr(cp, '=');
                    817:                if (value == NULL) {
1.142     deraadt   818:                        fprintf(stderr, "Bad line %u in %.100s\n", lineno,
                    819:                            filename);
1.1       markus    820:                        continue;
                    821:                }
1.14      deraadt   822:                /*
                    823:                 * Replace the equals sign by nul, and advance value to
                    824:                 * the value string.
                    825:                 */
1.1       markus    826:                *value = '\0';
                    827:                value++;
1.301     djm       828:                if (whitelist != NULL &&
                    829:                    match_pattern_list(cp, whitelist, 0) != 1)
                    830:                        continue;
1.1       markus    831:                child_set_env(env, envsize, cp, value);
                    832:        }
1.298     markus    833:        free(line);
1.1       markus    834:        fclose(f);
                    835: }
                    836:
1.127     markus    837: static char **
1.292     djm       838: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1       markus    839: {
                    840:        char buf[256];
1.294     djm       841:        size_t n;
1.127     markus    842:        u_int i, envsize;
1.300     djm       843:        char *ocp, *cp, *value, **env, *laddr;
1.127     markus    844:        struct passwd *pw = s->pw;
1.1       markus    845:
                    846:        /* Initialize the environment. */
                    847:        envsize = 100;
1.220     djm       848:        env = xcalloc(envsize, sizeof(char *));
1.1       markus    849:        env[0] = NULL;
                    850:
1.161     markus    851: #ifdef GSSAPI
1.168     djm       852:        /* Allow any GSSAPI methods that we've used to alter
1.319   ! djm       853:         * the child's environment as they see fit
1.161     markus    854:         */
                    855:        ssh_gssapi_do_child(&env, &envsize);
                    856: #endif
                    857:
1.284     djm       858:        /* Set basic environment. */
                    859:        for (i = 0; i < s->num_env; i++)
                    860:                child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
                    861:
                    862:        child_set_env(&env, &envsize, "USER", pw->pw_name);
                    863:        child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
                    864:        child_set_env(&env, &envsize, "HOME", pw->pw_dir);
                    865:        if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
                    866:                child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
                    867:        else
                    868:                child_set_env(&env, &envsize, "PATH", getenv("PATH"));
                    869:
                    870:        snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
                    871:        child_set_env(&env, &envsize, "MAIL", buf);
                    872:
                    873:        /* Normal systems set SHELL by default. */
                    874:        child_set_env(&env, &envsize, "SHELL", shell);
1.1       markus    875:
                    876:        if (getenv("TZ"))
                    877:                child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1.299     djm       878:        if (s->term)
                    879:                child_set_env(&env, &envsize, "TERM", s->term);
                    880:        if (s->display)
                    881:                child_set_env(&env, &envsize, "DISPLAY", s->display);
                    882: #ifdef KRB5
                    883:        if (s->authctxt->krb5_ticket_file)
                    884:                child_set_env(&env, &envsize, "KRB5CCNAME",
                    885:                    s->authctxt->krb5_ticket_file);
                    886: #endif
                    887:        if (auth_sock_name != NULL)
                    888:                child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
                    889:                    auth_sock_name);
                    890:
1.1       markus    891:
1.294     djm       892:        /* Set custom environment options from pubkey authentication. */
                    893:        if (options.permit_user_env) {
                    894:                for (n = 0 ; n < auth_opts->nenv; n++) {
                    895:                        ocp = xstrdup(auth_opts->env[n]);
                    896:                        cp = strchr(ocp, '=');
                    897:                        if (*cp == '=') {
                    898:                                *cp = '\0';
1.301     djm       899:                                /* Apply PermitUserEnvironment whitelist */
                    900:                                if (options.permit_user_env_whitelist == NULL ||
                    901:                                    match_pattern_list(ocp,
                    902:                                    options.permit_user_env_whitelist, 0) == 1)
                    903:                                        child_set_env(&env, &envsize,
                    904:                                            ocp, cp + 1);
1.294     djm       905:                        }
                    906:                        free(ocp);
                    907:                }
1.1       markus    908:        }
                    909:
1.299     djm       910:        /* read $HOME/.ssh/environment. */
                    911:        if (options.permit_user_env) {
                    912:                snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
                    913:                    pw->pw_dir);
1.301     djm       914:                read_environment_file(&env, &envsize, buf,
                    915:                    options.permit_user_env_whitelist);
1.300     djm       916:        }
                    917:
                    918:        /* Environment specified by admin */
                    919:        for (i = 0; i < options.num_setenv; i++) {
                    920:                cp = xstrdup(options.setenv[i]);
                    921:                if ((value = strchr(cp, '=')) == NULL) {
                    922:                        /* shouldn't happen; vars are checked in servconf.c */
                    923:                        fatal("Invalid config SetEnv: %s", options.setenv[i]);
                    924:                }
                    925:                *value++ = '\0';
                    926:                child_set_env(&env, &envsize, cp, value);
1.299     djm       927:        }
                    928:
1.149     stevesk   929:        /* SSH_CLIENT deprecated */
1.1       markus    930:        snprintf(buf, sizeof buf, "%.50s %d %d",
1.281     djm       931:            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
                    932:            ssh_local_port(ssh));
1.1       markus    933:        child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149     stevesk   934:
1.312     djm       935:        laddr = get_local_ipaddr(ssh_packet_get_connection_in(ssh));
1.149     stevesk   936:        snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281     djm       937:            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
                    938:            laddr, ssh_local_port(ssh));
1.265     djm       939:        free(laddr);
1.149     stevesk   940:        child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1       markus    941:
1.293     djm       942:        if (tun_fwd_ifnames != NULL)
                    943:                child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
1.290     djm       944:        if (auth_info_file != NULL)
                    945:                child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60      markus    946:        if (s->ttyfd != -1)
                    947:                child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1.34      markus    948:        if (original_command)
                    949:                child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
                    950:                    original_command);
1.1       markus    951:
                    952:        if (debug_flag) {
                    953:                /* dump the environment */
                    954:                fprintf(stderr, "Environment:\n");
                    955:                for (i = 0; env[i]; i++)
                    956:                        fprintf(stderr, "  %.200s\n", env[i]);
                    957:        }
1.127     markus    958:        return env;
                    959: }
                    960:
                    961: /*
                    962:  * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
                    963:  * first in this order).
                    964:  */
                    965: static void
1.294     djm       966: do_rc_files(struct ssh *ssh, Session *s, const char *shell)
1.127     markus    967: {
                    968:        FILE *f = NULL;
                    969:        char cmd[1024];
                    970:        int do_xauth;
                    971:        struct stat st;
                    972:
                    973:        do_xauth =
                    974:            s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
                    975:
1.231     djm       976:        /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232     djm       977:        if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.294     djm       978:            auth_opts->permit_user_rc && options.permit_user_rc &&
1.273     djm       979:            stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127     markus    980:                snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
                    981:                    shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
                    982:                if (debug_flag)
                    983:                        fprintf(stderr, "Running %s\n", cmd);
                    984:                f = popen(cmd, "w");
                    985:                if (f) {
                    986:                        if (do_xauth)
                    987:                                fprintf(f, "%s %s\n", s->auth_proto,
                    988:                                    s->auth_data);
                    989:                        pclose(f);
                    990:                } else
                    991:                        fprintf(stderr, "Could not run %s\n",
                    992:                            _PATH_SSH_USER_RC);
                    993:        } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
                    994:                if (debug_flag)
                    995:                        fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
                    996:                            _PATH_SSH_SYSTEM_RC);
                    997:                f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
                    998:                if (f) {
                    999:                        if (do_xauth)
                   1000:                                fprintf(f, "%s %s\n", s->auth_proto,
                   1001:                                    s->auth_data);
                   1002:                        pclose(f);
                   1003:                } else
                   1004:                        fprintf(stderr, "Could not run %s\n",
                   1005:                            _PATH_SSH_SYSTEM_RC);
                   1006:        } else if (do_xauth && options.xauth_location != NULL) {
                   1007:                /* Add authority data to .Xauthority if appropriate. */
                   1008:                if (debug_flag) {
                   1009:                        fprintf(stderr,
1.151     stevesk  1010:                            "Running %.500s remove %.100s\n",
1.165     markus   1011:                            options.xauth_location, s->auth_display);
1.151     stevesk  1012:                        fprintf(stderr,
                   1013:                            "%.500s add %.100s %.100s %.100s\n",
1.127     markus   1014:                            options.xauth_location, s->auth_display,
                   1015:                            s->auth_proto, s->auth_data);
                   1016:                }
                   1017:                snprintf(cmd, sizeof cmd, "%s -q -",
                   1018:                    options.xauth_location);
                   1019:                f = popen(cmd, "w");
                   1020:                if (f) {
1.151     stevesk  1021:                        fprintf(f, "remove %s\n",
                   1022:                            s->auth_display);
1.127     markus   1023:                        fprintf(f, "add %s %s %s\n",
                   1024:                            s->auth_display, s->auth_proto,
                   1025:                            s->auth_data);
                   1026:                        pclose(f);
                   1027:                } else {
                   1028:                        fprintf(stderr, "Could not run %s\n",
                   1029:                            cmd);
                   1030:                }
                   1031:        }
                   1032: }
                   1033:
                   1034: static void
                   1035: do_nologin(struct passwd *pw)
                   1036: {
                   1037:        FILE *f = NULL;
1.251     dtucker  1038:        char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
                   1039:        struct stat sb;
1.127     markus   1040:
1.260     guenther 1041:        if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251     dtucker  1042:                return;
                   1043:        nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
                   1044:
                   1045:        if (stat(nl, &sb) == -1) {
                   1046:                if (nl != def_nl)
1.265     djm      1047:                        free(nl);
1.251     dtucker  1048:                return;
                   1049:        }
                   1050:
                   1051:        /* /etc/nologin exists.  Print its contents if we can and exit. */
                   1052:        logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
                   1053:        if ((f = fopen(nl, "r")) != NULL) {
1.127     markus   1054:                while (fgets(buf, sizeof(buf), f))
                   1055:                        fputs(buf, stderr);
                   1056:                fclose(f);
                   1057:        }
1.251     dtucker  1058:        exit(254);
1.127     markus   1059: }
                   1060:
1.226     djm      1061: /*
                   1062:  * Chroot into a directory after checking it for safety: all path components
                   1063:  * must be root-owned directories with strict permissions.
                   1064:  */
                   1065: static void
                   1066: safely_chroot(const char *path, uid_t uid)
                   1067: {
                   1068:        const char *cp;
1.277     deraadt  1069:        char component[PATH_MAX];
1.226     djm      1070:        struct stat st;
                   1071:
1.308     djm      1072:        if (!path_absolute(path))
1.226     djm      1073:                fatal("chroot path does not begin at root");
                   1074:        if (strlen(path) >= sizeof(component))
                   1075:                fatal("chroot path too long");
                   1076:
                   1077:        /*
                   1078:         * Descend the path, checking that each component is a
                   1079:         * root-owned directory with strict permissions.
                   1080:         */
                   1081:        for (cp = path; cp != NULL;) {
                   1082:                if ((cp = strchr(cp, '/')) == NULL)
                   1083:                        strlcpy(component, path, sizeof(component));
                   1084:                else {
                   1085:                        cp++;
                   1086:                        memcpy(component, path, cp - path);
                   1087:                        component[cp - path] = '\0';
                   1088:                }
                   1089:
                   1090:                debug3("%s: checking '%s'", __func__, component);
                   1091:
                   1092:                if (stat(component, &st) != 0)
                   1093:                        fatal("%s: stat(\"%s\"): %s", __func__,
                   1094:                            component, strerror(errno));
                   1095:                if (st.st_uid != 0 || (st.st_mode & 022) != 0)
                   1096:                        fatal("bad ownership or modes for chroot "
1.312     djm      1097:                            "directory %s\"%s\"",
1.226     djm      1098:                            cp == NULL ? "" : "component ", component);
                   1099:                if (!S_ISDIR(st.st_mode))
                   1100:                        fatal("chroot path %s\"%s\" is not a directory",
                   1101:                            cp == NULL ? "" : "component ", component);
                   1102:
                   1103:        }
                   1104:
                   1105:        if (chdir(path) == -1)
                   1106:                fatal("Unable to chdir to chroot path \"%s\": "
                   1107:                    "%s", path, strerror(errno));
                   1108:        if (chroot(path) == -1)
                   1109:                fatal("chroot(\"%s\"): %s", path, strerror(errno));
                   1110:        if (chdir("/") == -1)
                   1111:                fatal("%s: chdir(/) after chroot: %s",
                   1112:                    __func__, strerror(errno));
                   1113:        verbose("Changed root directory to \"%s\"", path);
                   1114: }
                   1115:
1.127     markus   1116: /* Set login name, uid, gid, and groups. */
1.130     provos   1117: void
1.127     markus   1118: do_setusercontext(struct passwd *pw)
                   1119: {
1.295     djm      1120:        char uidstr[32], *chroot_path, *tmp;
1.227     djm      1121:
1.127     markus   1122:        if (getuid() == 0 || geteuid() == 0) {
1.226     djm      1123:                /* Prepare groups */
1.127     markus   1124:                if (setusercontext(lc, pw, pw->pw_uid,
1.226     djm      1125:                    (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127     markus   1126:                        perror("unable to set user context");
                   1127:                        exit(1);
                   1128:                }
1.226     djm      1129:
1.279     djm      1130:                if (!in_chroot && options.chroot_directory != NULL &&
1.226     djm      1131:                    strcasecmp(options.chroot_directory, "none") != 0) {
1.227     djm      1132:                         tmp = tilde_expand_filename(options.chroot_directory,
                   1133:                            pw->pw_uid);
1.295     djm      1134:                        snprintf(uidstr, sizeof(uidstr), "%llu",
                   1135:                            (unsigned long long)pw->pw_uid);
1.227     djm      1136:                        chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1.295     djm      1137:                            "u", pw->pw_name, "U", uidstr, (char *)NULL);
1.226     djm      1138:                        safely_chroot(chroot_path, pw->pw_uid);
1.227     djm      1139:                        free(tmp);
1.226     djm      1140:                        free(chroot_path);
1.264     djm      1141:                        /* Make sure we don't attempt to chroot again */
                   1142:                        free(options.chroot_directory);
                   1143:                        options.chroot_directory = NULL;
1.279     djm      1144:                        in_chroot = 1;
1.226     djm      1145:                }
                   1146:
                   1147:                /* Set UID */
                   1148:                if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
                   1149:                        perror("unable to set user context (setuser)");
                   1150:                        exit(1);
                   1151:                }
1.264     djm      1152:        } else if (options.chroot_directory != NULL &&
                   1153:            strcasecmp(options.chroot_directory, "none") != 0) {
                   1154:                fatal("server lacks privileges to chroot to ChrootDirectory");
1.263     dtucker  1155:        }
1.264     djm      1156:
1.127     markus   1157:        if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
                   1158:                fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
                   1159: }
                   1160:
1.131     markus   1161: static void
1.172     markus   1162: do_pwchange(Session *s)
                   1163: {
1.179     dtucker  1164:        fflush(NULL);
1.172     markus   1165:        fprintf(stderr, "WARNING: Your password has expired.\n");
                   1166:        if (s->ttyfd != -1) {
1.178     deraadt  1167:                fprintf(stderr,
1.172     markus   1168:                    "You must change your password now and login again!\n");
                   1169:                execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
                   1170:                perror("passwd");
                   1171:        } else {
                   1172:                fprintf(stderr,
                   1173:                    "Password change required but no TTY available.\n");
                   1174:        }
                   1175:        exit(1);
                   1176: }
                   1177:
                   1178: static void
1.292     djm      1179: child_close_fds(struct ssh *ssh)
1.172     markus   1180: {
1.276     djm      1181:        extern int auth_sock;
1.266     markus   1182:
1.276     djm      1183:        if (auth_sock != -1) {
                   1184:                close(auth_sock);
                   1185:                auth_sock = -1;
1.266     markus   1186:        }
                   1187:
1.312     djm      1188:        if (ssh_packet_get_connection_in(ssh) ==
                   1189:            ssh_packet_get_connection_out(ssh))
                   1190:                close(ssh_packet_get_connection_in(ssh));
1.172     markus   1191:        else {
1.312     djm      1192:                close(ssh_packet_get_connection_in(ssh));
                   1193:                close(ssh_packet_get_connection_out(ssh));
1.172     markus   1194:        }
                   1195:        /*
                   1196:         * Close all descriptors related to channels.  They will still remain
                   1197:         * open in the parent.
                   1198:         */
                   1199:        /* XXX better use close-on-exec? -markus */
1.292     djm      1200:        channel_close_all(ssh);
1.172     markus   1201:
                   1202:        /*
                   1203:         * Close any extra file descriptors.  Note that there may still be
                   1204:         * descriptors left by system functions.  They will be closed later.
                   1205:         */
                   1206:        endpwent();
                   1207:
                   1208:        /*
1.188     djm      1209:         * Close any extra open file descriptors so that we don't have them
1.172     markus   1210:         * hanging around in clients.  Note that we want to do this after
                   1211:         * initgroups, because at least on Solaris 2.3 it leaves file
                   1212:         * descriptors open.
                   1213:         */
1.258     djm      1214:        closefrom(STDERR_FILENO + 1);
1.172     markus   1215: }
                   1216:
1.127     markus   1217: /*
                   1218:  * Performs common processing for the child, such as setting up the
                   1219:  * environment, closing extra file descriptors, setting the user and group
                   1220:  * ids, and executing the command or shell.
                   1221:  */
1.225     markus   1222: #define ARGV_MAX 10
1.127     markus   1223: void
1.292     djm      1224: do_child(struct ssh *ssh, Session *s, const char *command)
1.127     markus   1225: {
                   1226:        extern char **environ;
1.314     djm      1227:        char **env, *argv[ARGV_MAX], remote_id[512];
1.284     djm      1228:        const char *shell, *shell0;
1.127     markus   1229:        struct passwd *pw = s->pw;
1.239     djm      1230:        int r = 0;
1.127     markus   1231:
1.314     djm      1232:        sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
                   1233:
1.127     markus   1234:        /* remove hostkey from the child's memory */
                   1235:        destroy_sensitive_data();
1.312     djm      1236:        ssh_packet_clear_keys(ssh);
1.127     markus   1237:
1.172     markus   1238:        /* Force a password change */
                   1239:        if (s->authctxt->force_pwchange) {
                   1240:                do_setusercontext(pw);
1.292     djm      1241:                child_close_fds(ssh);
1.172     markus   1242:                do_pwchange(s);
                   1243:                exit(1);
                   1244:        }
                   1245:
1.127     markus   1246:        /*
                   1247:         * Login(1) does this as well, and it needs uid 0 for the "-h"
                   1248:         * switch, so we let login(1) to this for us.
                   1249:         */
1.284     djm      1250:        do_nologin(pw);
                   1251:        do_setusercontext(pw);
1.127     markus   1252:
                   1253:        /*
                   1254:         * Get the shell from the password data.  An empty shell field is
                   1255:         * legal, and means /bin/sh.
                   1256:         */
                   1257:        shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152     markus   1258:
                   1259:        /*
                   1260:         * Make sure $SHELL points to the shell from the password file,
                   1261:         * even if shell is overridden from login.conf
                   1262:         */
1.292     djm      1263:        env = do_setup_env(ssh, s, shell);
1.152     markus   1264:
1.127     markus   1265:        shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
                   1266:
1.1       markus   1267:        /*
                   1268:         * Close the connection descriptors; note that this is the child, and
                   1269:         * the server will still have the socket open, and it is important
                   1270:         * that we do not shutdown it.  Note that the descriptors cannot be
                   1271:         * closed before building the environment, as we call
1.281     djm      1272:         * ssh_remote_ipaddr there.
1.1       markus   1273:         */
1.292     djm      1274:        child_close_fds(ssh);
1.1       markus   1275:
                   1276:        /*
1.125     deraadt  1277:         * Must take new environment into use so that .ssh/rc,
                   1278:         * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1       markus   1279:         */
                   1280:        environ = env;
1.170     jakob    1281:
                   1282: #ifdef KRB5
                   1283:        /*
                   1284:         * At this point, we check to see if AFS is active and if we have
                   1285:         * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
                   1286:         * if we can (and need to) extend the ticket into an AFS token. If
                   1287:         * we don't do this, we run into potential problems if the user's
                   1288:         * home directory is in AFS and it's not world-readable.
                   1289:         */
                   1290:
                   1291:        if (options.kerberos_get_afs_token && k_hasafs() &&
1.185     djm      1292:            (s->authctxt->krb5_ctx != NULL)) {
1.170     jakob    1293:                char cell[64];
                   1294:
                   1295:                debug("Getting AFS token");
                   1296:
                   1297:                k_setpag();
                   1298:
                   1299:                if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
                   1300:                        krb5_afslog(s->authctxt->krb5_ctx,
                   1301:                            s->authctxt->krb5_fwd_ccache, cell, NULL);
                   1302:
                   1303:                krb5_afslog_home(s->authctxt->krb5_ctx,
                   1304:                    s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
                   1305:        }
                   1306: #endif
1.104     markus   1307:
1.188     djm      1308:        /* Change current directory to the user's home directory. */
1.316     deraadt  1309:        if (chdir(pw->pw_dir) == -1) {
1.239     djm      1310:                /* Suppress missing homedir warning for chroot case */
                   1311:                r = login_getcapbool(lc, "requirehome", 0);
1.279     djm      1312:                if (r || !in_chroot) {
1.239     djm      1313:                        fprintf(stderr, "Could not chdir to home "
                   1314:                            "directory %s: %s\n", pw->pw_dir,
                   1315:                            strerror(errno));
1.279     djm      1316:                }
1.239     djm      1317:                if (r)
1.104     markus   1318:                        exit(1);
                   1319:        }
1.230     djm      1320:
                   1321:        closefrom(STDERR_FILENO + 1);
1.1       markus   1322:
1.294     djm      1323:        do_rc_files(ssh, s, shell);
1.67      markus   1324:
                   1325:        /* restore SIGPIPE for child */
1.318     dtucker  1326:        ssh_signal(SIGPIPE, SIG_DFL);
1.67      markus   1327:
1.248     djm      1328:        if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1.314     djm      1329:                error("Connection from %s: refusing non-sftp session",
                   1330:                    remote_id);
1.248     djm      1331:                printf("This service allows sftp connections only.\n");
                   1332:                fflush(NULL);
                   1333:                exit(1);
                   1334:        } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225     markus   1335:                extern int optind, optreset;
                   1336:                int i;
                   1337:                char *p, *args;
                   1338:
1.246     stevesk  1339:                setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243     millert  1340:                args = xstrdup(command ? command : "sftp-server");
1.225     markus   1341:                for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
                   1342:                        if (i < ARGV_MAX - 1)
                   1343:                                argv[i++] = p;
                   1344:                argv[i] = NULL;
                   1345:                optind = optreset = 1;
                   1346:                __progname = argv[0];
1.226     djm      1347:                exit(sftp_server_main(i, argv, s->pw));
1.225     markus   1348:        }
1.247     djm      1349:
                   1350:        fflush(NULL);
1.225     markus   1351:
1.127     markus   1352:        /* Get the last component of the shell name. */
                   1353:        if ((shell0 = strrchr(shell, '/')) != NULL)
                   1354:                shell0++;
                   1355:        else
                   1356:                shell0 = shell;
                   1357:
1.1       markus   1358:        /*
                   1359:         * If we have no command, execute the shell.  In this case, the shell
                   1360:         * name to be passed in argv[0] is preceded by '-' to indicate that
                   1361:         * this is a login shell.
                   1362:         */
                   1363:        if (!command) {
1.127     markus   1364:                char argv0[256];
1.1       markus   1365:
1.127     markus   1366:                /* Start the shell.  Set initial character to '-'. */
                   1367:                argv0[0] = '-';
1.1       markus   1368:
1.127     markus   1369:                if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128     markus   1370:                    >= sizeof(argv0) - 1) {
1.127     markus   1371:                        errno = EINVAL;
1.1       markus   1372:                        perror(shell);
                   1373:                        exit(1);
1.127     markus   1374:                }
1.1       markus   1375:
1.127     markus   1376:                /* Execute the shell. */
                   1377:                argv[0] = argv0;
                   1378:                argv[1] = NULL;
                   1379:                execve(shell, argv, env);
                   1380:
                   1381:                /* Executing the shell failed. */
                   1382:                perror(shell);
                   1383:                exit(1);
1.1       markus   1384:        }
                   1385:        /*
                   1386:         * Execute the command using the user's shell.  This uses the -c
                   1387:         * option to execute the command.
                   1388:         */
1.127     markus   1389:        argv[0] = (char *) shell0;
1.1       markus   1390:        argv[1] = "-c";
                   1391:        argv[2] = (char *) command;
                   1392:        argv[3] = NULL;
                   1393:        execve(shell, argv, env);
                   1394:        perror(shell);
                   1395:        exit(1);
                   1396: }
                   1397:
1.237     djm      1398: void
                   1399: session_unused(int id)
                   1400: {
                   1401:        debug3("%s: session id %d unused", __func__, id);
                   1402:        if (id >= options.max_sessions ||
                   1403:            id >= sessions_nalloc) {
                   1404:                fatal("%s: insane session id %d (max %d nalloc %d)",
                   1405:                    __func__, id, options.max_sessions, sessions_nalloc);
                   1406:        }
1.270     tedu     1407:        memset(&sessions[id], 0, sizeof(*sessions));
1.237     djm      1408:        sessions[id].self = id;
                   1409:        sessions[id].used = 0;
                   1410:        sessions[id].chanid = -1;
                   1411:        sessions[id].ptyfd = -1;
                   1412:        sessions[id].ttyfd = -1;
                   1413:        sessions[id].ptymaster = -1;
                   1414:        sessions[id].x11_chanids = NULL;
                   1415:        sessions[id].next_unused = sessions_first_unused;
                   1416:        sessions_first_unused = id;
                   1417: }
                   1418:
1.1       markus   1419: Session *
                   1420: session_new(void)
                   1421: {
1.237     djm      1422:        Session *s, *tmp;
                   1423:
                   1424:        if (sessions_first_unused == -1) {
                   1425:                if (sessions_nalloc >= options.max_sessions)
                   1426:                        return NULL;
                   1427:                debug2("%s: allocate (allocated %d max %d)",
                   1428:                    __func__, sessions_nalloc, options.max_sessions);
1.288     deraadt  1429:                tmp = xrecallocarray(sessions, sessions_nalloc,
                   1430:                    sessions_nalloc + 1, sizeof(*sessions));
1.237     djm      1431:                if (tmp == NULL) {
                   1432:                        error("%s: cannot allocate %d sessions",
                   1433:                            __func__, sessions_nalloc + 1);
                   1434:                        return NULL;
                   1435:                }
                   1436:                sessions = tmp;
                   1437:                session_unused(sessions_nalloc++);
                   1438:        }
                   1439:
                   1440:        if (sessions_first_unused >= sessions_nalloc ||
                   1441:            sessions_first_unused < 0) {
                   1442:                fatal("%s: insane first_unused %d max %d nalloc %d",
                   1443:                    __func__, sessions_first_unused, options.max_sessions,
                   1444:                    sessions_nalloc);
                   1445:        }
                   1446:
                   1447:        s = &sessions[sessions_first_unused];
                   1448:        if (s->used) {
                   1449:                fatal("%s: session %d already used",
                   1450:                    __func__, sessions_first_unused);
                   1451:        }
                   1452:        sessions_first_unused = s->next_unused;
                   1453:        s->used = 1;
                   1454:        s->next_unused = -1;
                   1455:        debug("session_new: session %d", s->self);
                   1456:
                   1457:        return s;
1.1       markus   1458: }
                   1459:
1.94      itojun   1460: static void
1.1       markus   1461: session_dump(void)
                   1462: {
                   1463:        int i;
1.237     djm      1464:        for (i = 0; i < sessions_nalloc; i++) {
1.1       markus   1465:                Session *s = &sessions[i];
1.237     djm      1466:
                   1467:                debug("dump: used %d next_unused %d session %d %p "
                   1468:                    "channel %d pid %ld",
1.1       markus   1469:                    s->used,
1.237     djm      1470:                    s->next_unused,
1.1       markus   1471:                    s->self,
                   1472:                    s,
                   1473:                    s->chanid,
1.137     mpech    1474:                    (long)s->pid);
1.1       markus   1475:        }
                   1476: }
                   1477:
1.2       markus   1478: int
1.97      markus   1479: session_open(Authctxt *authctxt, int chanid)
1.2       markus   1480: {
                   1481:        Session *s = session_new();
                   1482:        debug("session_open: channel %d", chanid);
                   1483:        if (s == NULL) {
                   1484:                error("no more sessions");
                   1485:                return 0;
                   1486:        }
1.97      markus   1487:        s->authctxt = authctxt;
                   1488:        s->pw = authctxt->pw;
1.167     djm      1489:        if (s->pw == NULL || !authctxt->valid)
1.54      stevesk  1490:                fatal("no user for session %d", s->self);
1.2       markus   1491:        debug("session_open: session %d: link with channel %d", s->self, chanid);
                   1492:        s->chanid = chanid;
                   1493:        return 1;
                   1494: }
                   1495:
1.130     provos   1496: Session *
                   1497: session_by_tty(char *tty)
                   1498: {
                   1499:        int i;
1.237     djm      1500:        for (i = 0; i < sessions_nalloc; i++) {
1.130     provos   1501:                Session *s = &sessions[i];
                   1502:                if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
                   1503:                        debug("session_by_tty: session %d tty %s", i, tty);
                   1504:                        return s;
                   1505:                }
                   1506:        }
                   1507:        debug("session_by_tty: unknown tty %.100s", tty);
                   1508:        session_dump();
                   1509:        return NULL;
                   1510: }
                   1511:
1.94      itojun   1512: static Session *
1.2       markus   1513: session_by_channel(int id)
                   1514: {
                   1515:        int i;
1.237     djm      1516:        for (i = 0; i < sessions_nalloc; i++) {
1.2       markus   1517:                Session *s = &sessions[i];
                   1518:                if (s->used && s->chanid == id) {
1.237     djm      1519:                        debug("session_by_channel: session %d channel %d",
                   1520:                            i, id);
1.2       markus   1521:                        return s;
                   1522:                }
                   1523:        }
                   1524:        debug("session_by_channel: unknown channel %d", id);
                   1525:        session_dump();
                   1526:        return NULL;
                   1527: }
                   1528:
1.94      itojun   1529: static Session *
1.184     djm      1530: session_by_x11_channel(int id)
                   1531: {
                   1532:        int i, j;
                   1533:
1.237     djm      1534:        for (i = 0; i < sessions_nalloc; i++) {
1.184     djm      1535:                Session *s = &sessions[i];
                   1536:
                   1537:                if (s->x11_chanids == NULL || !s->used)
                   1538:                        continue;
                   1539:                for (j = 0; s->x11_chanids[j] != -1; j++) {
                   1540:                        if (s->x11_chanids[j] == id) {
                   1541:                                debug("session_by_x11_channel: session %d "
                   1542:                                    "channel %d", s->self, id);
                   1543:                                return s;
                   1544:                        }
                   1545:                }
                   1546:        }
                   1547:        debug("session_by_x11_channel: unknown channel %d", id);
                   1548:        session_dump();
                   1549:        return NULL;
                   1550: }
                   1551:
                   1552: static Session *
1.2       markus   1553: session_by_pid(pid_t pid)
                   1554: {
                   1555:        int i;
1.137     mpech    1556:        debug("session_by_pid: pid %ld", (long)pid);
1.237     djm      1557:        for (i = 0; i < sessions_nalloc; i++) {
1.2       markus   1558:                Session *s = &sessions[i];
                   1559:                if (s->used && s->pid == pid)
                   1560:                        return s;
                   1561:        }
1.137     mpech    1562:        error("session_by_pid: unknown pid %ld", (long)pid);
1.2       markus   1563:        session_dump();
                   1564:        return NULL;
                   1565: }
                   1566:
1.94      itojun   1567: static int
1.292     djm      1568: session_window_change_req(struct ssh *ssh, Session *s)
1.2       markus   1569: {
1.312     djm      1570:        int r;
                   1571:
                   1572:        if ((r = sshpkt_get_u32(ssh, &s->col)) != 0 ||
                   1573:            (r = sshpkt_get_u32(ssh, &s->row)) != 0 ||
                   1574:            (r = sshpkt_get_u32(ssh, &s->xpixel)) != 0 ||
                   1575:            (r = sshpkt_get_u32(ssh, &s->ypixel)) != 0 ||
                   1576:            (r = sshpkt_get_end(ssh)) != 0)
                   1577:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.2       markus   1578:        pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
                   1579:        return 1;
                   1580: }
                   1581:
1.94      itojun   1582: static int
1.292     djm      1583: session_pty_req(struct ssh *ssh, Session *s)
1.2       markus   1584: {
1.312     djm      1585:        int r;
1.132     markus   1586:
1.294     djm      1587:        if (!auth_opts->permit_pty_flag || !options.permit_tty) {
                   1588:                debug("Allocating a pty not permitted for this connection.");
1.19      markus   1589:                return 0;
1.86      markus   1590:        }
                   1591:        if (s->ttyfd != -1) {
1.312     djm      1592:                ssh_packet_disconnect(ssh, "Protocol error: you already have a pty.");
1.3       markus   1593:                return 0;
1.86      markus   1594:        }
                   1595:
1.312     djm      1596:        if ((r = sshpkt_get_cstring(ssh, &s->term, NULL)) != 0 ||
                   1597:            (r = sshpkt_get_u32(ssh, &s->col)) != 0 ||
                   1598:            (r = sshpkt_get_u32(ssh, &s->row)) != 0 ||
                   1599:            (r = sshpkt_get_u32(ssh, &s->xpixel)) != 0 ||
                   1600:            (r = sshpkt_get_u32(ssh, &s->ypixel)) != 0)
                   1601:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.2       markus   1602:
                   1603:        if (strcmp(s->term, "") == 0) {
1.265     djm      1604:                free(s->term);
1.2       markus   1605:                s->term = NULL;
                   1606:        }
1.86      markus   1607:
1.2       markus   1608:        /* Allocate a pty and open it. */
1.86      markus   1609:        debug("Allocating pty.");
1.237     djm      1610:        if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
                   1611:            sizeof(s->tty)))) {
1.265     djm      1612:                free(s->term);
1.2       markus   1613:                s->term = NULL;
                   1614:                s->ptyfd = -1;
                   1615:                s->ttyfd = -1;
                   1616:                error("session_pty_req: session %d alloc failed", s->self);
1.3       markus   1617:                return 0;
1.2       markus   1618:        }
                   1619:        debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86      markus   1620:
1.302     markus   1621:        ssh_tty_parse_modes(ssh, s->ttyfd);
1.86      markus   1622:
1.312     djm      1623:        if ((r = sshpkt_get_end(ssh)) != 0)
                   1624:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
                   1625:
1.130     provos   1626:        if (!use_privsep)
                   1627:                pty_setowner(s->pw, s->tty);
1.86      markus   1628:
                   1629:        /* Set window size from the packet. */
1.2       markus   1630:        pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
                   1631:
1.9       markus   1632:        session_proctitle(s);
1.2       markus   1633:        return 1;
                   1634: }
                   1635:
1.94      itojun   1636: static int
1.292     djm      1637: session_subsystem_req(struct ssh *ssh, Session *s)
1.7       markus   1638: {
1.105     markus   1639:        struct stat st;
1.312     djm      1640:        int r, success = 0;
1.267     djm      1641:        char *prog, *cmd;
1.182     djm      1642:        u_int i;
1.7       markus   1643:
1.312     djm      1644:        if ((r = sshpkt_get_cstring(ssh, &s->subsys, NULL)) != 0 ||
                   1645:            (r = sshpkt_get_end(ssh)) != 0)
                   1646:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.267     djm      1647:        debug2("subsystem request for %.100s by user %s", s->subsys,
1.255     djm      1648:            s->pw->pw_name);
1.18      jakob    1649:
                   1650:        for (i = 0; i < options.num_subsystems; i++) {
1.267     djm      1651:                if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205     djm      1652:                        prog = options.subsystem_command[i];
                   1653:                        cmd = options.subsystem_args[i];
1.249     dtucker  1654:                        if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225     markus   1655:                                s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249     dtucker  1656:                                debug("subsystem: %s", prog);
1.225     markus   1657:                        } else {
1.316     deraadt  1658:                                if (stat(prog, &st) == -1)
1.249     dtucker  1659:                                        debug("subsystem: cannot stat %s: %s",
                   1660:                                            prog, strerror(errno));
1.225     markus   1661:                                s->is_subsystem = SUBSYSTEM_EXT;
1.249     dtucker  1662:                                debug("subsystem: exec() %s", cmd);
1.105     markus   1663:                        }
1.292     djm      1664:                        success = do_exec(ssh, s, cmd) == 0;
1.122     markus   1665:                        break;
1.18      jakob    1666:                }
                   1667:        }
                   1668:
                   1669:        if (!success)
1.267     djm      1670:                logit("subsystem request for %.100s by user %s failed, "
                   1671:                    "subsystem not found", s->subsys, s->pw->pw_name);
1.7       markus   1672:
                   1673:        return success;
                   1674: }
                   1675:
1.94      itojun   1676: static int
1.292     djm      1677: session_x11_req(struct ssh *ssh, Session *s)
1.7       markus   1678: {
1.312     djm      1679:        int r, success;
                   1680:        u_char single_connection = 0;
1.7       markus   1681:
1.184     djm      1682:        if (s->auth_proto != NULL || s->auth_data != NULL) {
                   1683:                error("session_x11_req: session %d: "
1.190     stevesk  1684:                    "x11 forwarding already active", s->self);
1.184     djm      1685:                return 0;
                   1686:        }
1.312     djm      1687:        if ((r = sshpkt_get_u8(ssh, &single_connection)) != 0 ||
                   1688:            (r = sshpkt_get_cstring(ssh, &s->auth_proto, NULL)) != 0 ||
                   1689:            (r = sshpkt_get_cstring(ssh, &s->auth_data, NULL)) != 0 ||
                   1690:            (r = sshpkt_get_u32(ssh, &s->screen)) != 0 ||
                   1691:            (r = sshpkt_get_end(ssh)) != 0)
                   1692:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
                   1693:
                   1694:        s->single_connection = single_connection;
1.7       markus   1695:
1.282     djm      1696:        if (xauth_valid_string(s->auth_proto) &&
                   1697:            xauth_valid_string(s->auth_data))
1.292     djm      1698:                success = session_setup_x11fwd(ssh, s);
1.282     djm      1699:        else {
                   1700:                success = 0;
                   1701:                error("Invalid X11 forwarding data");
                   1702:        }
1.81      markus   1703:        if (!success) {
1.265     djm      1704:                free(s->auth_proto);
                   1705:                free(s->auth_data);
1.84      markus   1706:                s->auth_proto = NULL;
                   1707:                s->auth_data = NULL;
1.7       markus   1708:        }
1.81      markus   1709:        return success;
1.7       markus   1710: }
                   1711:
1.94      itojun   1712: static int
1.292     djm      1713: session_shell_req(struct ssh *ssh, Session *s)
1.19      markus   1714: {
1.312     djm      1715:        int r;
                   1716:
                   1717:        if ((r = sshpkt_get_end(ssh)) != 0)
                   1718:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.292     djm      1719:        return do_exec(ssh, s, NULL) == 0;
1.19      markus   1720: }
                   1721:
1.94      itojun   1722: static int
1.292     djm      1723: session_exec_req(struct ssh *ssh, Session *s)
1.19      markus   1724: {
1.312     djm      1725:        u_int success;
                   1726:        int r;
                   1727:        char *command = NULL;
                   1728:
                   1729:        if ((r = sshpkt_get_cstring(ssh, &command, NULL)) != 0 ||
                   1730:            (r = sshpkt_get_end(ssh)) != 0)
                   1731:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.237     djm      1732:
1.292     djm      1733:        success = do_exec(ssh, s, command) == 0;
1.265     djm      1734:        free(command);
1.237     djm      1735:        return success;
1.19      markus   1736: }
                   1737:
1.94      itojun   1738: static int
1.292     djm      1739: session_break_req(struct ssh *ssh, Session *s)
1.157     markus   1740: {
1.312     djm      1741:        int r;
1.157     markus   1742:
1.312     djm      1743:        if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* ignore */
                   1744:            (r = sshpkt_get_end(ssh)) != 0)
                   1745:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.157     markus   1746:
1.316     deraadt  1747:        if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) == -1)
1.157     markus   1748:                return 0;
                   1749:        return 1;
                   1750: }
                   1751:
                   1752: static int
1.292     djm      1753: session_env_req(struct ssh *ssh, Session *s)
1.173     djm      1754: {
                   1755:        char *name, *val;
1.312     djm      1756:        u_int i;
                   1757:        int r;
1.173     djm      1758:
1.312     djm      1759:        if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
                   1760:            (r = sshpkt_get_cstring(ssh, &val, NULL)) != 0 ||
                   1761:            (r = sshpkt_get_end(ssh)) != 0)
                   1762:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.173     djm      1763:
                   1764:        /* Don't set too many environment variables */
                   1765:        if (s->num_env > 128) {
                   1766:                debug2("Ignoring env request %s: too many env vars", name);
                   1767:                goto fail;
                   1768:        }
                   1769:
                   1770:        for (i = 0; i < options.num_accept_env; i++) {
                   1771:                if (match_pattern(name, options.accept_env[i])) {
                   1772:                        debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288     deraadt  1773:                        s->env = xrecallocarray(s->env, s->num_env,
                   1774:                            s->num_env + 1, sizeof(*s->env));
1.173     djm      1775:                        s->env[s->num_env].name = name;
                   1776:                        s->env[s->num_env].val = val;
                   1777:                        s->num_env++;
                   1778:                        return (1);
                   1779:                }
                   1780:        }
                   1781:        debug2("Ignoring env request %s: disallowed name", name);
                   1782:
                   1783:  fail:
1.265     djm      1784:        free(name);
                   1785:        free(val);
1.173     djm      1786:        return (0);
                   1787: }
                   1788:
1.306     djm      1789: /*
                   1790:  * Conversion of signals from ssh channel request names.
                   1791:  * Subset of signals from RFC 4254 section 6.10C, with SIGINFO as
                   1792:  * local extension.
                   1793:  */
                   1794: static int
                   1795: name2sig(char *name)
                   1796: {
                   1797: #define SSH_SIG(x) if (strcmp(name, #x) == 0) return SIG ## x
                   1798:        SSH_SIG(HUP);
                   1799:        SSH_SIG(INT);
                   1800:        SSH_SIG(KILL);
                   1801:        SSH_SIG(QUIT);
                   1802:        SSH_SIG(TERM);
                   1803:        SSH_SIG(USR1);
                   1804:        SSH_SIG(USR2);
                   1805: #undef SSH_SIG
                   1806:        if (strcmp(name, "INFO@openssh.com") == 0)
                   1807:                return SIGINFO;
                   1808:        return -1;
                   1809: }
                   1810:
                   1811: static int
                   1812: session_signal_req(struct ssh *ssh, Session *s)
                   1813: {
                   1814:        char *signame = NULL;
                   1815:        int r, sig, success = 0;
                   1816:
                   1817:        if ((r = sshpkt_get_cstring(ssh, &signame, NULL)) != 0 ||
                   1818:            (r = sshpkt_get_end(ssh)) != 0) {
                   1819:                error("%s: parse packet: %s", __func__, ssh_err(r));
                   1820:                goto out;
                   1821:        }
                   1822:        if ((sig = name2sig(signame)) == -1) {
                   1823:                error("%s: unsupported signal \"%s\"", __func__, signame);
                   1824:                goto out;
                   1825:        }
                   1826:        if (s->pid <= 0) {
                   1827:                error("%s: no pid for session %d", __func__, s->self);
                   1828:                goto out;
                   1829:        }
                   1830:        if (s->forced || s->is_subsystem) {
                   1831:                error("%s: refusing to send signal %s to %s session", __func__,
                   1832:                    signame, s->forced ? "forced-command" : "subsystem");
                   1833:                goto out;
                   1834:        }
                   1835:        if (!use_privsep || mm_is_monitor()) {
                   1836:                error("%s: session signalling requires privilege separation",
                   1837:                    __func__);
                   1838:                goto out;
                   1839:        }
                   1840:
                   1841:        debug("%s: signal %s, killpg(%ld, %d)", __func__, signame,
                   1842:            (long)s->pid, sig);
                   1843:        temporarily_use_uid(s->pw);
                   1844:        r = killpg(s->pid, sig);
                   1845:        restore_uid();
                   1846:        if (r != 0) {
                   1847:                error("%s: killpg(%ld, %d): %s", __func__, (long)s->pid,
                   1848:                    sig, strerror(errno));
                   1849:                goto out;
                   1850:        }
                   1851:
                   1852:        /* success */
                   1853:        success = 1;
                   1854:  out:
                   1855:        free(signame);
                   1856:        return success;
                   1857: }
                   1858:
1.173     djm      1859: static int
1.292     djm      1860: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43      markus   1861: {
                   1862:        static int called = 0;
1.312     djm      1863:        int r;
1.294     djm      1864:
1.312     djm      1865:        if ((r = sshpkt_get_end(ssh)) != 0)
                   1866:                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.294     djm      1867:        if (!auth_opts->permit_agent_forwarding_flag ||
                   1868:            !options.allow_agent_forwarding) {
                   1869:                debug("%s: agent forwarding disabled", __func__);
1.44      markus   1870:                return 0;
                   1871:        }
1.43      markus   1872:        if (called) {
                   1873:                return 0;
                   1874:        } else {
                   1875:                called = 1;
1.292     djm      1876:                return auth_input_request_forwarding(ssh, s->pw);
1.43      markus   1877:        }
                   1878: }
                   1879:
1.123     markus   1880: int
1.292     djm      1881: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2       markus   1882: {
                   1883:        int success = 0;
                   1884:        Session *s;
                   1885:
1.123     markus   1886:        if ((s = session_by_channel(c->self)) == NULL) {
1.292     djm      1887:                logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123     markus   1888:                return 0;
                   1889:        }
1.292     djm      1890:        debug("%s: session %d req %s", __func__, s->self, rtype);
1.2       markus   1891:
                   1892:        /*
1.64      markus   1893:         * a session is in LARVAL state until a shell, a command
                   1894:         * or a subsystem is executed
1.2       markus   1895:         */
                   1896:        if (c->type == SSH_CHANNEL_LARVAL) {
                   1897:                if (strcmp(rtype, "shell") == 0) {
1.292     djm      1898:                        success = session_shell_req(ssh, s);
1.2       markus   1899:                } else if (strcmp(rtype, "exec") == 0) {
1.292     djm      1900:                        success = session_exec_req(ssh, s);
1.2       markus   1901:                } else if (strcmp(rtype, "pty-req") == 0) {
1.292     djm      1902:                        success = session_pty_req(ssh, s);
1.7       markus   1903:                } else if (strcmp(rtype, "x11-req") == 0) {
1.292     djm      1904:                        success = session_x11_req(ssh, s);
1.43      markus   1905:                } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292     djm      1906:                        success = session_auth_agent_req(ssh, s);
1.7       markus   1907:                } else if (strcmp(rtype, "subsystem") == 0) {
1.292     djm      1908:                        success = session_subsystem_req(ssh, s);
1.173     djm      1909:                } else if (strcmp(rtype, "env") == 0) {
1.292     djm      1910:                        success = session_env_req(ssh, s);
1.2       markus   1911:                }
                   1912:        }
                   1913:        if (strcmp(rtype, "window-change") == 0) {
1.292     djm      1914:                success = session_window_change_req(ssh, s);
1.177     djm      1915:        } else if (strcmp(rtype, "break") == 0) {
1.292     djm      1916:                success = session_break_req(ssh, s);
1.306     djm      1917:        } else if (strcmp(rtype, "signal") == 0) {
                   1918:                success = session_signal_req(ssh, s);
1.2       markus   1919:        }
1.177     djm      1920:
1.123     markus   1921:        return success;
1.2       markus   1922: }
                   1923:
                   1924: void
1.292     djm      1925: session_set_fds(struct ssh *ssh, Session *s,
                   1926:     int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2       markus   1927: {
                   1928:        /*
                   1929:         * now that have a child and a pipe to the child,
                   1930:         * we can activate our channel and register the fd's
                   1931:         */
                   1932:        if (s->chanid == -1)
                   1933:                fatal("no channel for session %d", s->self);
1.292     djm      1934:        channel_set_fds(ssh, s->chanid,
1.2       markus   1935:            fdout, fdin, fderr,
1.256     djm      1936:            ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241     dtucker  1937:            1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2       markus   1938: }
                   1939:
1.85      markus   1940: /*
                   1941:  * Function to perform pty cleanup. Also called if we get aborted abnormally
                   1942:  * (e.g., due to a dropped connection).
                   1943:  */
1.130     provos   1944: void
1.165     markus   1945: session_pty_cleanup2(Session *s)
1.1       markus   1946: {
1.85      markus   1947:        if (s == NULL) {
1.307     djm      1948:                error("%s: no session", __func__);
1.85      markus   1949:                return;
                   1950:        }
                   1951:        if (s->ttyfd == -1)
1.1       markus   1952:                return;
                   1953:
1.307     djm      1954:        debug("%s: session %d release %s", __func__, s->self, s->tty);
1.1       markus   1955:
                   1956:        /* Record that the user has logged out. */
1.85      markus   1957:        if (s->pid != 0)
                   1958:                record_logout(s->pid, s->tty);
1.1       markus   1959:
                   1960:        /* Release the pseudo-tty. */
1.130     provos   1961:        if (getuid() == 0)
                   1962:                pty_release(s->tty);
1.1       markus   1963:
                   1964:        /*
                   1965:         * Close the server side of the socket pairs.  We must do this after
                   1966:         * the pty cleanup, so that another process doesn't get this pty
                   1967:         * while we're still cleaning up.
                   1968:         */
1.316     deraadt  1969:        if (s->ptymaster != -1 && close(s->ptymaster) == -1)
1.237     djm      1970:                error("close(s->ptymaster/%d): %s",
                   1971:                    s->ptymaster, strerror(errno));
1.108     markus   1972:
                   1973:        /* unlink pty from session */
                   1974:        s->ttyfd = -1;
1.2       markus   1975: }
                   1976:
1.130     provos   1977: void
1.165     markus   1978: session_pty_cleanup(Session *s)
1.130     provos   1979: {
1.165     markus   1980:        PRIVSEP(session_pty_cleanup2(s));
1.130     provos   1981: }
                   1982:
1.147     markus   1983: static char *
                   1984: sig2name(int sig)
                   1985: {
                   1986: #define SSH_SIG(x) if (sig == SIG ## x) return #x
                   1987:        SSH_SIG(ABRT);
                   1988:        SSH_SIG(ALRM);
                   1989:        SSH_SIG(FPE);
                   1990:        SSH_SIG(HUP);
                   1991:        SSH_SIG(ILL);
                   1992:        SSH_SIG(INT);
                   1993:        SSH_SIG(KILL);
                   1994:        SSH_SIG(PIPE);
                   1995:        SSH_SIG(QUIT);
                   1996:        SSH_SIG(SEGV);
                   1997:        SSH_SIG(TERM);
                   1998:        SSH_SIG(USR1);
                   1999:        SSH_SIG(USR2);
                   2000: #undef SSH_SIG
                   2001:        return "SIG@openssh.com";
                   2002: }
                   2003:
1.94      itojun   2004: static void
1.292     djm      2005: session_close_x11(struct ssh *ssh, int id)
1.184     djm      2006: {
                   2007:        Channel *c;
                   2008:
1.292     djm      2009:        if ((c = channel_by_id(ssh, id)) == NULL) {
                   2010:                debug("%s: x11 channel %d missing", __func__, id);
1.184     djm      2011:        } else {
                   2012:                /* Detach X11 listener */
1.292     djm      2013:                debug("%s: detach x11 channel %d", __func__, id);
                   2014:                channel_cancel_cleanup(ssh, id);
1.184     djm      2015:                if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292     djm      2016:                        chan_mark_dead(ssh, c);
1.184     djm      2017:        }
                   2018: }
                   2019:
                   2020: static void
1.292     djm      2021: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184     djm      2022: {
                   2023:        Session *s;
                   2024:        u_int i;
                   2025:
1.292     djm      2026:        debug3("%s: channel %d", __func__, id);
                   2027:        channel_cancel_cleanup(ssh, id);
1.221     stevesk  2028:        if ((s = session_by_x11_channel(id)) == NULL)
1.292     djm      2029:                fatal("%s: no x11 channel %d", __func__, id);
1.184     djm      2030:        for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292     djm      2031:                debug("%s: session %d: closing channel %d",
                   2032:                    __func__, s->self, s->x11_chanids[i]);
1.184     djm      2033:                /*
                   2034:                 * The channel "id" is already closing, but make sure we
                   2035:                 * close all of its siblings.
                   2036:                 */
                   2037:                if (s->x11_chanids[i] != id)
1.292     djm      2038:                        session_close_x11(ssh, s->x11_chanids[i]);
1.184     djm      2039:        }
1.265     djm      2040:        free(s->x11_chanids);
1.184     djm      2041:        s->x11_chanids = NULL;
1.265     djm      2042:        free(s->display);
                   2043:        s->display = NULL;
                   2044:        free(s->auth_proto);
                   2045:        s->auth_proto = NULL;
                   2046:        free(s->auth_data);
                   2047:        s->auth_data = NULL;
                   2048:        free(s->auth_display);
                   2049:        s->auth_display = NULL;
1.184     djm      2050: }
                   2051:
                   2052: static void
1.292     djm      2053: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2       markus   2054: {
                   2055:        Channel *c;
1.312     djm      2056:        int r;
1.124     markus   2057:
1.292     djm      2058:        if ((c = channel_lookup(ssh, s->chanid)) == NULL)
                   2059:                fatal("%s: session %d: no channel %d",
                   2060:                    __func__, s->self, s->chanid);
                   2061:        debug("%s: session %d channel %d pid %ld",
                   2062:            __func__, s->self, s->chanid, (long)s->pid);
1.2       markus   2063:
                   2064:        if (WIFEXITED(status)) {
1.292     djm      2065:                channel_request_start(ssh, s->chanid, "exit-status", 0);
1.312     djm      2066:                if ((r = sshpkt_put_u32(ssh, WEXITSTATUS(status))) != 0 ||
                   2067:                    (r = sshpkt_send(ssh)) != 0)
                   2068:                        sshpkt_fatal(ssh, r, "%s: exit reply", __func__);
1.2       markus   2069:        } else if (WIFSIGNALED(status)) {
1.292     djm      2070:                channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.312     djm      2071:                if ((r = sshpkt_put_cstring(ssh, sig2name(WTERMSIG(status)))) != 0 ||
                   2072:                    (r = sshpkt_put_u8(ssh, WCOREDUMP(status)? 1 : 0)) != 0 ||
                   2073:                    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
                   2074:                    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
                   2075:                    (r = sshpkt_send(ssh)) != 0)
                   2076:                        sshpkt_fatal(ssh, r, "%s: exit reply", __func__);
1.2       markus   2077:        } else {
                   2078:                /* Some weird exit cause.  Just exit. */
1.312     djm      2079:                ssh_packet_disconnect(ssh, "wait returned status %04x.", status);
1.2       markus   2080:        }
                   2081:
                   2082:        /* disconnect channel */
1.292     djm      2083:        debug("%s: release channel %d", __func__, s->chanid);
1.187     djm      2084:
                   2085:        /*
                   2086:         * Adjust cleanup callback attachment to send close messages when
1.199     deraadt  2087:         * the channel gets EOF. The session will be then be closed
1.319   ! djm      2088:         * by session_close_by_channel when the child sessions close their fds.
1.187     djm      2089:         */
1.292     djm      2090:        channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187     djm      2091:
1.5       markus   2092:        /*
                   2093:         * emulate a write failure with 'chan_write_failed', nobody will be
                   2094:         * interested in data we write.
                   2095:         * Note that we must not call 'chan_read_failed', since there could
                   2096:         * be some more data waiting in the pipe.
                   2097:         */
1.8       markus   2098:        if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292     djm      2099:                chan_write_failed(ssh, c);
1.2       markus   2100: }
                   2101:
1.130     provos   2102: void
1.292     djm      2103: session_close(struct ssh *ssh, Session *s)
1.2       markus   2104: {
1.182     djm      2105:        u_int i;
1.173     djm      2106:
1.280     djm      2107:        verbose("Close session: user %s from %.200s port %d id %d",
                   2108:            s->pw->pw_name,
1.281     djm      2109:            ssh_remote_ipaddr(ssh),
                   2110:            ssh_remote_port(ssh),
1.280     djm      2111:            s->self);
                   2112:
1.165     markus   2113:        if (s->ttyfd != -1)
1.85      markus   2114:                session_pty_cleanup(s);
1.265     djm      2115:        free(s->term);
                   2116:        free(s->display);
                   2117:        free(s->x11_chanids);
                   2118:        free(s->auth_display);
                   2119:        free(s->auth_data);
                   2120:        free(s->auth_proto);
1.267     djm      2121:        free(s->subsys);
1.219     djm      2122:        if (s->env != NULL) {
                   2123:                for (i = 0; i < s->num_env; i++) {
1.265     djm      2124:                        free(s->env[i].name);
                   2125:                        free(s->env[i].val);
1.219     djm      2126:                }
1.265     djm      2127:                free(s->env);
1.173     djm      2128:        }
1.9       markus   2129:        session_proctitle(s);
1.237     djm      2130:        session_unused(s->self);
1.2       markus   2131: }
                   2132:
                   2133: void
1.292     djm      2134: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2       markus   2135: {
                   2136:        Session *s = session_by_pid(pid);
                   2137:        if (s == NULL) {
1.292     djm      2138:                debug("%s: no session for pid %ld", __func__, (long)pid);
1.2       markus   2139:                return;
                   2140:        }
                   2141:        if (s->chanid != -1)
1.292     djm      2142:                session_exit_message(ssh, s, status);
1.187     djm      2143:        if (s->ttyfd != -1)
                   2144:                session_pty_cleanup(s);
1.197     djm      2145:        s->pid = 0;
1.98      markus   2146: }
                   2147:
1.2       markus   2148: /*
                   2149:  * this is called when a channel dies before
                   2150:  * the session 'child' itself dies
                   2151:  */
                   2152: void
1.292     djm      2153: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2       markus   2154: {
                   2155:        Session *s = session_by_channel(id);
1.187     djm      2156:        u_int i;
1.184     djm      2157:
1.2       markus   2158:        if (s == NULL) {
1.292     djm      2159:                debug("%s: no session for id %d", __func__, id);
1.2       markus   2160:                return;
                   2161:        }
1.292     djm      2162:        debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107     markus   2163:        if (s->pid != 0) {
1.307     djm      2164:                debug("%s: channel %d: has child, ttyfd %d",
                   2165:                    __func__, id, s->ttyfd);
1.108     markus   2166:                /*
                   2167:                 * delay detach of session, but release pty, since
                   2168:                 * the fd's to the child are already closed
                   2169:                 */
1.165     markus   2170:                if (s->ttyfd != -1)
1.108     markus   2171:                        session_pty_cleanup(s);
1.107     markus   2172:                return;
                   2173:        }
                   2174:        /* detach by removing callback */
1.292     djm      2175:        channel_cancel_cleanup(ssh, s->chanid);
1.187     djm      2176:
                   2177:        /* Close any X11 listeners associated with this session */
                   2178:        if (s->x11_chanids != NULL) {
                   2179:                for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292     djm      2180:                        session_close_x11(ssh, s->x11_chanids[i]);
1.187     djm      2181:                        s->x11_chanids[i] = -1;
                   2182:                }
                   2183:        }
                   2184:
1.2       markus   2185:        s->chanid = -1;
1.292     djm      2186:        session_close(ssh, s);
1.106     markus   2187: }
                   2188:
                   2189: void
1.292     djm      2190: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106     markus   2191: {
                   2192:        int i;
1.237     djm      2193:        for (i = 0; i < sessions_nalloc; i++) {
1.106     markus   2194:                Session *s = &sessions[i];
1.130     provos   2195:                if (s->used) {
                   2196:                        if (closefunc != NULL)
                   2197:                                closefunc(s);
                   2198:                        else
1.292     djm      2199:                                session_close(ssh, s);
1.130     provos   2200:                }
1.2       markus   2201:        }
1.9       markus   2202: }
                   2203:
1.94      itojun   2204: static char *
1.9       markus   2205: session_tty_list(void)
                   2206: {
                   2207:        static char buf[1024];
                   2208:        int i;
                   2209:        buf[0] = '\0';
1.237     djm      2210:        for (i = 0; i < sessions_nalloc; i++) {
1.9       markus   2211:                Session *s = &sessions[i];
                   2212:                if (s->used && s->ttyfd != -1) {
                   2213:                        if (buf[0] != '\0')
                   2214:                                strlcat(buf, ",", sizeof buf);
                   2215:                        strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
                   2216:                }
                   2217:        }
                   2218:        if (buf[0] == '\0')
                   2219:                strlcpy(buf, "notty", sizeof buf);
                   2220:        return buf;
                   2221: }
                   2222:
                   2223: void
                   2224: session_proctitle(Session *s)
                   2225: {
                   2226:        if (s->pw == NULL)
                   2227:                error("no user for session %d", s->self);
                   2228:        else
                   2229:                setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81      markus   2230: }
                   2231:
                   2232: int
1.292     djm      2233: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81      markus   2234: {
                   2235:        struct stat st;
1.109     stevesk  2236:        char display[512], auth_display[512];
1.272     djm      2237:        char hostname[NI_MAXHOST];
1.184     djm      2238:        u_int i;
1.81      markus   2239:
1.294     djm      2240:        if (!auth_opts->permit_x11_forwarding_flag) {
1.312     djm      2241:                ssh_packet_send_debug(ssh, "X11 forwarding disabled by key options.");
1.81      markus   2242:                return 0;
                   2243:        }
                   2244:        if (!options.x11_forwarding) {
                   2245:                debug("X11 forwarding disabled in server configuration file.");
                   2246:                return 0;
                   2247:        }
1.275     djm      2248:        if (options.xauth_location == NULL ||
1.81      markus   2249:            (stat(options.xauth_location, &st) == -1)) {
1.312     djm      2250:                ssh_packet_send_debug(ssh, "No xauth program; cannot forward X11.");
1.81      markus   2251:                return 0;
                   2252:        }
1.87      markus   2253:        if (s->display != NULL) {
1.81      markus   2254:                debug("X11 display already set.");
                   2255:                return 0;
                   2256:        }
1.292     djm      2257:        if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140     deraadt  2258:            options.x11_use_localhost, s->single_connection,
1.184     djm      2259:            &s->display_number, &s->x11_chanids) == -1) {
1.87      markus   2260:                debug("x11_create_display_inet failed.");
1.81      markus   2261:                return 0;
1.184     djm      2262:        }
                   2263:        for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292     djm      2264:                channel_register_cleanup(ssh, s->x11_chanids[i],
1.187     djm      2265:                    session_close_single_x11, 0);
1.81      markus   2266:        }
1.109     stevesk  2267:
                   2268:        /* Set up a suitable value for the DISPLAY variable. */
1.316     deraadt  2269:        if (gethostname(hostname, sizeof(hostname)) == -1)
1.109     stevesk  2270:                fatal("gethostname: %.100s", strerror(errno));
                   2271:        /*
                   2272:         * auth_display must be used as the displayname when the
                   2273:         * authorization entry is added with xauth(1).  This will be
                   2274:         * different than the DISPLAY string for localhost displays.
                   2275:         */
1.119     stevesk  2276:        if (options.x11_use_localhost) {
1.140     deraadt  2277:                snprintf(display, sizeof display, "localhost:%u.%u",
1.109     stevesk  2278:                    s->display_number, s->screen);
1.140     deraadt  2279:                snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118     stevesk  2280:                    s->display_number, s->screen);
1.109     stevesk  2281:                s->display = xstrdup(display);
1.118     stevesk  2282:                s->auth_display = xstrdup(auth_display);
1.109     stevesk  2283:        } else {
1.140     deraadt  2284:                snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109     stevesk  2285:                    s->display_number, s->screen);
                   2286:                s->display = xstrdup(display);
1.118     stevesk  2287:                s->auth_display = xstrdup(display);
1.109     stevesk  2288:        }
                   2289:
1.81      markus   2290:        return 1;
1.2       markus   2291: }
                   2292:
1.94      itojun   2293: static void
1.292     djm      2294: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2       markus   2295: {
1.292     djm      2296:        server_loop2(ssh, authctxt);
1.165     markus   2297: }
                   2298:
                   2299: void
1.292     djm      2300: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165     markus   2301: {
                   2302:        static int called = 0;
                   2303:
                   2304:        debug("do_cleanup");
                   2305:
                   2306:        /* no cleanup if we're in the child for login shell */
                   2307:        if (is_child)
                   2308:                return;
                   2309:
                   2310:        /* avoid double cleanup */
                   2311:        if (called)
                   2312:                return;
                   2313:        called = 1;
                   2314:
1.218     markus   2315:        if (authctxt == NULL || !authctxt->authenticated)
1.165     markus   2316:                return;
                   2317: #ifdef KRB5
                   2318:        if (options.kerberos_ticket_cleanup &&
                   2319:            authctxt->krb5_ctx)
                   2320:                krb5_cleanup_proc(authctxt);
1.161     markus   2321: #endif
1.165     markus   2322:
                   2323: #ifdef GSSAPI
1.283     markus   2324:        if (options.gss_cleanup_creds)
1.165     markus   2325:                ssh_gssapi_cleanup_creds();
                   2326: #endif
                   2327:
                   2328:        /* remove agent socket */
                   2329:        auth_sock_cleanup_proc(authctxt->pw);
1.290     djm      2330:
                   2331:        /* remove userauth info */
                   2332:        if (auth_info_file != NULL) {
                   2333:                temporarily_use_uid(authctxt->pw);
                   2334:                unlink(auth_info_file);
                   2335:                restore_uid();
                   2336:                free(auth_info_file);
                   2337:                auth_info_file = NULL;
                   2338:        }
1.165     markus   2339:
                   2340:        /*
                   2341:         * Cleanup ptys/utmp only if privsep is disabled,
                   2342:         * or if running in monitor.
                   2343:         */
                   2344:        if (!use_privsep || mm_is_monitor())
1.292     djm      2345:                session_destroy_all(ssh, session_pty_cleanup2);
1.1       markus   2346: }
1.281     djm      2347:
                   2348: /* Return a name for the remote host that fits inside utmp_size */
                   2349:
                   2350: const char *
                   2351: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
                   2352: {
                   2353:        const char *remote = "";
                   2354:
                   2355:        if (utmp_size > 0)
                   2356:                remote = auth_get_canonical_hostname(ssh, use_dns);
                   2357:        if (utmp_size == 0 || strlen(remote) > utmp_size)
                   2358:                remote = ssh_remote_ipaddr(ssh);
                   2359:        return remote;
                   2360: }
                   2361: