Annotation of src/usr.bin/ssh/session.c, Revision 1.296
1.296 ! djm 1: /* $OpenBSD: session.c,v 1.295 2018/06/01 03:33:53 djm 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>
1.211 stevesk 55: #include <unistd.h>
1.277 deraadt 56: #include <limits.h>
1.1 markus 57:
1.216 deraadt 58: #include "xmalloc.h"
1.51 markus 59: #include "ssh.h"
60: #include "ssh2.h"
1.59 djm 61: #include "sshpty.h"
1.1 markus 62: #include "packet.h"
63: #include "buffer.h"
1.173 djm 64: #include "match.h"
1.1 markus 65: #include "uidswap.h"
66: #include "compat.h"
1.78 markus 67: #include "channels.h"
1.216 deraadt 68: #include "key.h"
69: #include "cipher.h"
70: #include "kex.h"
71: #include "hostfile.h"
1.2 markus 72: #include "auth.h"
1.19 markus 73: #include "auth-options.h"
1.266 markus 74: #include "authfd.h"
1.50 markus 75: #include "pathnames.h"
1.51 markus 76: #include "log.h"
1.274 millert 77: #include "misc.h"
1.51 markus 78: #include "servconf.h"
1.59 djm 79: #include "sshlogin.h"
1.51 markus 80: #include "serverloop.h"
81: #include "canohost.h"
1.55 itojun 82: #include "session.h"
1.216 deraadt 83: #ifdef GSSAPI
84: #include "ssh-gss.h"
85: #endif
1.130 provos 86: #include "monitor_wrap.h"
1.225 markus 87: #include "sftp.h"
1.290 djm 88: #include "atomicio.h"
1.171 markus 89:
90: #ifdef KRB5
91: #include <kafs.h>
1.161 markus 92: #endif
93:
1.242 djm 94: #define IS_INTERNAL_SFTP(c) \
95: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
96: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
97: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
98: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
99:
1.1 markus 100: /* func */
101:
102: Session *session_new(void);
1.292 djm 103: void session_set_fds(struct ssh *, Session *, int, int, int, int, int);
1.165 markus 104: void session_pty_cleanup(Session *);
1.94 itojun 105: void session_proctitle(Session *);
1.292 djm 106: int session_setup_x11fwd(struct ssh *, Session *);
107: int do_exec_pty(struct ssh *, Session *, const char *);
108: int do_exec_no_pty(struct ssh *, Session *, const char *);
109: int do_exec(struct ssh *, Session *, const char *);
110: void do_login(struct ssh *, Session *, const char *);
111: void do_child(struct ssh *, Session *, const char *);
1.73 djm 112: void do_motd(void);
1.94 itojun 113: int check_quietlogin(Session *, const char *);
1.1 markus 114:
1.292 djm 115: static void do_authenticated2(struct ssh *, Authctxt *);
1.94 itojun 116:
1.292 djm 117: static int session_pty_req(struct ssh *, Session *);
1.65 markus 118:
1.1 markus 119: /* import */
120: extern ServerOptions options;
121: extern char *__progname;
122: extern int debug_flag;
1.45 markus 123: extern u_int utmp_len;
1.21 markus 124: extern int startup_pipe;
1.74 markus 125: extern void destroy_sensitive_data(void);
1.179 dtucker 126: extern Buffer loginmsg;
1.294 djm 127: extern struct sshauthopt *auth_opts;
1.293 djm 128: char *tun_fwd_ifnames; /* serverloop.c */
1.21 markus 129:
1.34 markus 130: /* original command from peer. */
1.92 markus 131: const char *original_command = NULL;
1.34 markus 132:
1.1 markus 133: /* data */
1.237 djm 134: static int sessions_first_unused = -1;
135: static int sessions_nalloc = 0;
136: static Session *sessions = NULL;
1.1 markus 137:
1.248 djm 138: #define SUBSYSTEM_NONE 0
139: #define SUBSYSTEM_EXT 1
140: #define SUBSYSTEM_INT_SFTP 2
141: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.225 markus 142:
1.129 provos 143: login_cap_t *lc;
1.28 millert 144:
1.165 markus 145: static int is_child = 0;
1.279 djm 146: static int in_chroot = 0;
1.165 markus 147:
1.290 djm 148: /* File containing userauth info, if ExposeAuthInfo set */
149: static char *auth_info_file = NULL;
150:
1.136 markus 151: /* Name and directory of socket for authentication agent forwarding. */
152: static char *auth_sock_name = NULL;
153: static char *auth_sock_dir = NULL;
154:
155: /* removes the agent forwarding socket */
156:
157: static void
1.165 markus 158: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 159: {
160: if (auth_sock_name != NULL) {
161: temporarily_use_uid(pw);
162: unlink(auth_sock_name);
163: rmdir(auth_sock_dir);
164: auth_sock_name = NULL;
165: restore_uid();
166: }
167: }
168:
169: static int
1.292 djm 170: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136 markus 171: {
172: Channel *nc;
1.237 djm 173: int sock = -1;
1.136 markus 174:
175: if (auth_sock_name != NULL) {
176: error("authentication forwarding requested twice.");
177: return 0;
178: }
179:
180: /* Temporarily drop privileged uid for mkdir/bind. */
181: temporarily_use_uid(pw);
182:
183: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 184: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 185:
186: /* Create private directory for socket */
187: if (mkdtemp(auth_sock_dir) == NULL) {
188: packet_send_debug("Agent forwarding disabled: "
189: "mkdtemp() failed: %.100s", strerror(errno));
190: restore_uid();
1.265 djm 191: free(auth_sock_dir);
1.136 markus 192: auth_sock_dir = NULL;
1.237 djm 193: goto authsock_err;
1.136 markus 194: }
1.237 djm 195:
196: xasprintf(&auth_sock_name, "%s/agent.%ld",
197: auth_sock_dir, (long) getpid());
1.136 markus 198:
1.274 millert 199: /* Start a Unix listener on auth_sock_name. */
200: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136 markus 201:
202: /* Restore the privileged uid. */
203: restore_uid();
204:
1.274 millert 205: /* Check for socket/bind/listen failure. */
206: if (sock < 0)
1.237 djm 207: goto authsock_err;
1.136 markus 208:
209: /* Allocate a channel for the authentication agent socket. */
1.292 djm 210: nc = channel_new(ssh, "auth socket",
1.136 markus 211: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
212: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 213: 0, "auth socket", 1);
1.245 djm 214: nc->path = xstrdup(auth_sock_name);
1.136 markus 215: return 1;
1.237 djm 216:
217: authsock_err:
1.265 djm 218: free(auth_sock_name);
1.237 djm 219: if (auth_sock_dir != NULL) {
220: rmdir(auth_sock_dir);
1.265 djm 221: free(auth_sock_dir);
1.237 djm 222: }
223: if (sock != -1)
224: close(sock);
225: auth_sock_name = NULL;
226: auth_sock_dir = NULL;
227: return 0;
1.136 markus 228: }
229:
1.179 dtucker 230: static void
231: display_loginmsg(void)
232: {
1.183 djm 233: if (buffer_len(&loginmsg) > 0) {
234: buffer_append(&loginmsg, "\0", 1);
235: printf("%s", (char *)buffer_ptr(&loginmsg));
236: buffer_clear(&loginmsg);
237: }
1.179 dtucker 238: }
1.136 markus 239:
1.290 djm 240: static void
241: prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
242: {
243: int fd = -1, success = 0;
244:
245: if (!options.expose_userauth_info || info == NULL)
246: return;
247:
248: temporarily_use_uid(pw);
249: auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
250: if ((fd = mkstemp(auth_info_file)) == -1) {
251: error("%s: mkstemp: %s", __func__, strerror(errno));
252: goto out;
253: }
254: if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
255: sshbuf_len(info)) != sshbuf_len(info)) {
256: error("%s: write: %s", __func__, strerror(errno));
257: goto out;
258: }
259: if (close(fd) != 0) {
260: error("%s: close: %s", __func__, strerror(errno));
261: goto out;
262: }
263: success = 1;
264: out:
265: if (!success) {
266: if (fd != -1)
267: close(fd);
268: free(auth_info_file);
269: auth_info_file = NULL;
270: }
271: restore_uid();
272: }
273:
1.294 djm 274: static void
275: set_permitopen_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
276: {
277: char *tmp, *cp, *host;
278: int port;
279: size_t i;
280:
281: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
282: return;
1.296 ! djm 283: channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL);
1.294 djm 284: for (i = 0; i < auth_opts->npermitopen; i++) {
285: tmp = cp = xstrdup(auth_opts->permitopen[i]);
286: /* This shouldn't fail as it has already been checked */
287: if ((host = hpdelim(&cp)) == NULL)
288: fatal("%s: internal error: hpdelim", __func__);
289: host = cleanhostname(host);
290: if (cp == NULL || (port = permitopen_port(cp)) < 0)
291: fatal("%s: internal error: permitopen port",
292: __func__);
1.296 ! djm 293: channel_add_permission(ssh, FORWARD_USER, FORWARD_LOCAL,
! 294: host, port);
1.294 djm 295: free(tmp);
296: }
297: }
298:
1.65 markus 299: void
1.292 djm 300: do_authenticated(struct ssh *ssh, Authctxt *authctxt)
1.65 markus 301: {
1.153 markus 302: setproctitle("%s", authctxt->pw->pw_name);
303:
1.294 djm 304: auth_log_authopts("active", auth_opts, 0);
305:
1.65 markus 306: /* setup the channel layer */
1.274 millert 307: /* XXX - streamlocal? */
1.294 djm 308: set_permitopen_from_authopts(ssh, auth_opts);
1.296 ! djm 309:
1.294 djm 310: if (!auth_opts->permit_port_forwarding_flag ||
1.296 ! djm 311: options.disable_forwarding) {
! 312: channel_disable_admin(ssh, FORWARD_LOCAL);
! 313: channel_disable_admin(ssh, FORWARD_REMOTE);
! 314: } else {
! 315: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
! 316: channel_disable_admin(ssh, FORWARD_LOCAL);
! 317: else
! 318: channel_permit_all(ssh, FORWARD_LOCAL);
! 319: if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0)
! 320: channel_disable_admin(ssh, FORWARD_REMOTE);
! 321: else
! 322: channel_permit_all(ssh, FORWARD_REMOTE);
! 323: }
1.252 dtucker 324: auth_debug_send();
1.65 markus 325:
1.290 djm 326: prepare_auth_info_file(authctxt->pw, authctxt->session_info);
327:
1.292 djm 328: do_authenticated2(ssh, authctxt);
1.290 djm 329:
1.292 djm 330: do_cleanup(ssh, authctxt);
1.65 markus 331: }
332:
1.282 djm 333: /* Check untrusted xauth strings for metacharacters */
334: static int
335: xauth_valid_string(const char *s)
336: {
337: size_t i;
338:
339: for (i = 0; s[i] != '\0'; i++) {
340: if (!isalnum((u_char)s[i]) &&
341: s[i] != '.' && s[i] != ':' && s[i] != '/' &&
342: s[i] != '-' && s[i] != '_')
343: return 0;
344: }
345: return 1;
346: }
347:
1.269 dtucker 348: #define USE_PIPES 1
1.1 markus 349: /*
350: * This is called to fork and execute a command when we have no tty. This
351: * will call do_child from the child, and server_loop from the parent after
352: * setting up file descriptors and such.
353: */
1.237 djm 354: int
1.292 djm 355: do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 356: {
1.137 mpech 357: pid_t pid;
1.238 markus 358: #ifdef USE_PIPES
359: int pin[2], pout[2], perr[2];
360:
1.253 djm 361: if (s == NULL)
362: fatal("do_exec_no_pty: no session");
363:
1.238 markus 364: /* Allocate pipes for communicating with the program. */
365: if (pipe(pin) < 0) {
366: error("%s: pipe in: %.100s", __func__, strerror(errno));
367: return -1;
368: }
369: if (pipe(pout) < 0) {
370: error("%s: pipe out: %.100s", __func__, strerror(errno));
371: close(pin[0]);
372: close(pin[1]);
373: return -1;
374: }
1.256 djm 375: if (pipe(perr) < 0) {
376: error("%s: pipe err: %.100s", __func__,
377: strerror(errno));
378: close(pin[0]);
379: close(pin[1]);
380: close(pout[0]);
381: close(pout[1]);
382: return -1;
1.238 markus 383: }
384: #else
1.237 djm 385: int inout[2], err[2];
1.1 markus 386:
1.253 djm 387: if (s == NULL)
388: fatal("do_exec_no_pty: no session");
389:
1.1 markus 390: /* Uses socket pairs to communicate with the program. */
1.237 djm 391: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
392: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
393: return -1;
394: }
1.256 djm 395: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
396: error("%s: socketpair #2: %.100s", __func__,
397: strerror(errno));
398: close(inout[0]);
399: close(inout[1]);
400: return -1;
1.237 djm 401: }
1.238 markus 402: #endif
1.237 djm 403:
1.9 markus 404: session_proctitle(s);
1.1 markus 405:
406: /* Fork the child. */
1.237 djm 407: switch ((pid = fork())) {
408: case -1:
409: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 markus 410: #ifdef USE_PIPES
411: close(pin[0]);
412: close(pin[1]);
413: close(pout[0]);
414: close(pout[1]);
1.256 djm 415: close(perr[0]);
1.238 markus 416: close(perr[1]);
417: #else
1.237 djm 418: close(inout[0]);
419: close(inout[1]);
420: close(err[0]);
1.256 djm 421: close(err[1]);
1.238 markus 422: #endif
1.237 djm 423: return -1;
424: case 0:
1.165 markus 425: is_child = 1;
1.144 markus 426:
1.1 markus 427: /*
428: * Create a new session and process group since the 4.4BSD
429: * setlogin() affects the entire process group.
430: */
431: if (setsid() < 0)
432: error("setsid failed: %.100s", strerror(errno));
433:
1.238 markus 434: #ifdef USE_PIPES
435: /*
436: * Redirect stdin. We close the parent side of the socket
437: * pair, and make the child side the standard input.
438: */
439: close(pin[1]);
440: if (dup2(pin[0], 0) < 0)
441: perror("dup2 stdin");
442: close(pin[0]);
443:
444: /* Redirect stdout. */
445: close(pout[0]);
446: if (dup2(pout[1], 1) < 0)
447: perror("dup2 stdout");
448: close(pout[1]);
449:
450: /* Redirect stderr. */
1.256 djm 451: close(perr[0]);
1.238 markus 452: if (dup2(perr[1], 2) < 0)
453: perror("dup2 stderr");
454: close(perr[1]);
455: #else
1.1 markus 456: /*
457: * Redirect stdin, stdout, and stderr. Stdin and stdout will
458: * use the same socket, as some programs (particularly rdist)
459: * seem to depend on it.
460: */
461: close(inout[1]);
1.256 djm 462: close(err[1]);
1.1 markus 463: if (dup2(inout[0], 0) < 0) /* stdin */
464: perror("dup2 stdin");
1.237 djm 465: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 466: perror("dup2 stdout");
1.238 markus 467: close(inout[0]);
1.1 markus 468: if (dup2(err[0], 2) < 0) /* stderr */
469: perror("dup2 stderr");
1.238 markus 470: close(err[0]);
471: #endif
1.1 markus 472:
473: /* Do processing for the child (exec command etc). */
1.292 djm 474: do_child(ssh, s, command);
1.1 markus 475: /* NOTREACHED */
1.237 djm 476: default:
477: break;
1.1 markus 478: }
1.237 djm 479:
1.1 markus 480: s->pid = pid;
1.47 markus 481: /* Set interactive/non-interactive mode. */
1.257 djm 482: packet_set_interactive(s->display != NULL,
483: options.ip_qos_interactive, options.ip_qos_bulk);
1.1 markus 484:
1.238 markus 485: #ifdef USE_PIPES
486: /* We are the parent. Close the child sides of the pipes. */
487: close(pin[0]);
488: close(pout[1]);
489: close(perr[1]);
490:
1.292 djm 491: session_set_fds(ssh, s, pin[1], pout[0], perr[0],
1.283 markus 492: s->is_subsystem, 0);
1.238 markus 493: #else
1.1 markus 494: /* We are the parent. Close the child sides of the socket pairs. */
495: close(inout[0]);
496: close(err[0]);
497:
498: /*
499: * Enter the interactive session. Note: server_loop must be able to
500: * handle the case that fdin and fdout are the same.
501: */
1.283 markus 502: session_set_fds(s, inout[1], inout[1], err[1],
503: s->is_subsystem, 0);
1.238 markus 504: #endif
1.237 djm 505: return 0;
1.1 markus 506: }
507:
508: /*
509: * This is called to fork and execute a command when we have a tty. This
510: * will call do_child from the child, and server_loop from the parent after
511: * setting up file descriptors, controlling tty, updating wtmp, utmp,
512: * lastlog, and other such operations.
513: */
1.237 djm 514: int
1.292 djm 515: do_exec_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 516: {
517: int fdout, ptyfd, ttyfd, ptymaster;
518: pid_t pid;
519:
520: if (s == NULL)
521: fatal("do_exec_pty: no session");
522: ptyfd = s->ptyfd;
523: ttyfd = s->ttyfd;
524:
1.237 djm 525: /*
526: * Create another descriptor of the pty master side for use as the
527: * standard input. We could use the original descriptor, but this
528: * simplifies code in server_loop. The descriptor is bidirectional.
529: * Do this before forking (and cleanup in the child) so as to
530: * detect and gracefully fail out-of-fd conditions.
531: */
532: if ((fdout = dup(ptyfd)) < 0) {
533: error("%s: dup #1: %s", __func__, strerror(errno));
534: close(ttyfd);
535: close(ptyfd);
536: return -1;
537: }
538: /* we keep a reference to the pty master */
539: if ((ptymaster = dup(ptyfd)) < 0) {
540: error("%s: dup #2: %s", __func__, strerror(errno));
541: close(ttyfd);
542: close(ptyfd);
543: close(fdout);
544: return -1;
545: }
546:
1.1 markus 547: /* Fork the child. */
1.237 djm 548: switch ((pid = fork())) {
549: case -1:
550: error("%s: fork: %.100s", __func__, strerror(errno));
551: close(fdout);
552: close(ptymaster);
553: close(ttyfd);
554: close(ptyfd);
555: return -1;
556: case 0:
1.165 markus 557: is_child = 1;
1.97 markus 558:
1.237 djm 559: close(fdout);
560: close(ptymaster);
561:
1.1 markus 562: /* Close the master side of the pseudo tty. */
563: close(ptyfd);
564:
565: /* Make the pseudo tty our controlling tty. */
566: pty_make_controlling_tty(&ttyfd, s->tty);
567:
1.103 markus 568: /* Redirect stdin/stdout/stderr from the pseudo tty. */
569: if (dup2(ttyfd, 0) < 0)
570: error("dup2 stdin: %s", strerror(errno));
571: if (dup2(ttyfd, 1) < 0)
572: error("dup2 stdout: %s", strerror(errno));
573: if (dup2(ttyfd, 2) < 0)
574: error("dup2 stderr: %s", strerror(errno));
1.1 markus 575:
576: /* Close the extra descriptor for the pseudo tty. */
577: close(ttyfd);
578:
1.24 markus 579: /* record login, etc. similar to login(1) */
1.292 djm 580: do_login(ssh, s, command);
1.228 djm 581:
1.237 djm 582: /*
583: * Do common processing for the child, such as execing
584: * the command.
585: */
1.292 djm 586: do_child(ssh, s, command);
1.1 markus 587: /* NOTREACHED */
1.237 djm 588: default:
589: break;
1.1 markus 590: }
591: s->pid = pid;
592:
593: /* Parent. Close the slave side of the pseudo tty. */
594: close(ttyfd);
595:
1.237 djm 596: /* Enter interactive session. */
1.1 markus 597: s->ptymaster = ptymaster;
1.257 djm 598: packet_set_interactive(1,
599: options.ip_qos_interactive, options.ip_qos_bulk);
1.292 djm 600: session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
1.237 djm 601: return 0;
1.24 markus 602: }
603:
1.90 markus 604: /*
605: * This is called to fork and execute a command. If another command is
606: * to be forced, execute that instead.
607: */
1.237 djm 608: int
1.292 djm 609: do_exec(struct ssh *ssh, Session *s, const char *command)
1.90 markus 610: {
1.237 djm 611: int ret;
1.280 djm 612: const char *forced = NULL, *tty = NULL;
613: char session_type[1024];
1.237 djm 614:
1.210 dtucker 615: if (options.adm_forced_command) {
616: original_command = command;
617: command = options.adm_forced_command;
1.267 djm 618: forced = "(config)";
1.294 djm 619: } else if (auth_opts->force_command != NULL) {
1.90 markus 620: original_command = command;
1.294 djm 621: command = auth_opts->force_command;
1.267 djm 622: forced = "(key-option)";
623: }
624: if (forced != NULL) {
1.248 djm 625: if (IS_INTERNAL_SFTP(command)) {
626: s->is_subsystem = s->is_subsystem ?
627: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
628: } else if (s->is_subsystem)
1.225 markus 629: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 630: snprintf(session_type, sizeof(session_type),
631: "forced-command %s '%.900s'", forced, command);
632: } else if (s->is_subsystem) {
633: snprintf(session_type, sizeof(session_type),
634: "subsystem '%.900s'", s->subsys);
635: } else if (command == NULL) {
636: snprintf(session_type, sizeof(session_type), "shell");
637: } else {
638: /* NB. we don't log unforced commands to preserve privacy */
639: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 640: }
1.163 markus 641:
1.267 djm 642: if (s->ttyfd != -1) {
643: tty = s->tty;
644: if (strncmp(tty, "/dev/", 5) == 0)
645: tty += 5;
646: }
647:
1.280 djm 648: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 649: session_type,
650: tty == NULL ? "" : " on ",
651: tty == NULL ? "" : tty,
652: s->pw->pw_name,
1.281 djm 653: ssh_remote_ipaddr(ssh),
654: ssh_remote_port(ssh),
1.280 djm 655: s->self);
1.267 djm 656:
1.163 markus 657: #ifdef GSSAPI
658: if (options.gss_authentication) {
659: temporarily_use_uid(s->pw);
660: ssh_gssapi_storecreds();
661: restore_uid();
662: }
663: #endif
1.90 markus 664: if (s->ttyfd != -1)
1.292 djm 665: ret = do_exec_pty(ssh, s, command);
1.90 markus 666: else
1.292 djm 667: ret = do_exec_no_pty(ssh, s, command);
1.90 markus 668:
1.92 markus 669: original_command = NULL;
1.179 dtucker 670:
671: /*
672: * Clear loginmsg: it's the child's responsibility to display
673: * it to the user, otherwise multiple sessions may accumulate
674: * multiple copies of the login messages.
675: */
676: buffer_clear(&loginmsg);
1.237 djm 677:
678: return ret;
1.90 markus 679: }
680:
681:
1.24 markus 682: /* administrative, login(1)-like work */
683: void
1.292 djm 684: do_login(struct ssh *ssh, Session *s, const char *command)
1.24 markus 685: {
686: socklen_t fromlen;
687: struct sockaddr_storage from;
688: struct passwd * pw = s->pw;
689: pid_t pid = getpid();
690:
691: /*
692: * Get IP address of client. If the connection is not a socket, let
693: * the address be 0.0.0.0.
694: */
695: memset(&from, 0, sizeof(from));
1.148 stevesk 696: fromlen = sizeof(from);
1.24 markus 697: if (packet_connection_is_on_socket()) {
698: if (getpeername(packet_get_connection_in(),
1.200 deraadt 699: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 700: debug("getpeername: %.100s", strerror(errno));
1.165 markus 701: cleanup_exit(255);
1.24 markus 702: }
703: }
1.25 markus 704:
1.24 markus 705: /* Record that there was a login on that tty from the remote host. */
1.133 markus 706: if (!use_privsep)
707: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 708: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 709: options.use_dns),
1.148 stevesk 710: (struct sockaddr *)&from, fromlen);
1.24 markus 711:
1.73 djm 712: if (check_quietlogin(s, command))
1.24 markus 713: return;
1.73 djm 714:
1.179 dtucker 715: display_loginmsg();
1.73 djm 716:
717: do_motd();
718: }
719:
720: /*
721: * Display the message of the day.
722: */
723: void
724: do_motd(void)
725: {
726: FILE *f;
727: char buf[256];
728:
1.24 markus 729: if (options.print_motd) {
1.28 millert 730: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
731: "/etc/motd"), "r");
1.24 markus 732: if (f) {
733: while (fgets(buf, sizeof(buf), f))
734: fputs(buf, stdout);
735: fclose(f);
736: }
1.2 markus 737: }
1.73 djm 738: }
739:
740:
741: /*
742: * Check for quiet login, either .hushlogin or command given.
743: */
744: int
745: check_quietlogin(Session *s, const char *command)
746: {
747: char buf[256];
1.96 dugsong 748: struct passwd *pw = s->pw;
1.73 djm 749: struct stat st;
750:
751: /* Return 1 if .hushlogin exists or a command given. */
752: if (command != NULL)
753: return 1;
754: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
755: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
756: return 1;
757: return 0;
1.1 markus 758: }
759:
760: /*
761: * Reads environment variables from the given file and adds/overrides them
762: * into the environment. If the file does not exist, this does nothing.
763: * Otherwise, it must consist of empty lines, comments (line starts with '#')
764: * and assignments of the form name=value. No other forms are allowed.
765: */
1.94 itojun 766: static void
1.45 markus 767: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 768: const char *filename)
1.1 markus 769: {
770: FILE *f;
771: char buf[4096];
772: char *cp, *value;
1.142 deraadt 773: u_int lineno = 0;
1.1 markus 774:
775: f = fopen(filename, "r");
776: if (!f)
777: return;
778:
779: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 780: if (++lineno > 1000)
781: fatal("Too many lines in environment file %s", filename);
1.1 markus 782: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
783: ;
784: if (!*cp || *cp == '#' || *cp == '\n')
785: continue;
1.224 gilles 786:
787: cp[strcspn(cp, "\n")] = '\0';
788:
1.1 markus 789: value = strchr(cp, '=');
790: if (value == NULL) {
1.142 deraadt 791: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
792: filename);
1.1 markus 793: continue;
794: }
1.14 deraadt 795: /*
796: * Replace the equals sign by nul, and advance value to
797: * the value string.
798: */
1.1 markus 799: *value = '\0';
800: value++;
801: child_set_env(env, envsize, cp, value);
802: }
803: fclose(f);
804: }
805:
1.127 markus 806: static char **
1.292 djm 807: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1 markus 808: {
809: char buf[256];
1.294 djm 810: size_t n;
1.127 markus 811: u_int i, envsize;
1.294 djm 812: char *ocp, *cp, **env, *laddr;
1.127 markus 813: struct passwd *pw = s->pw;
1.1 markus 814:
815: /* Initialize the environment. */
816: envsize = 100;
1.220 djm 817: env = xcalloc(envsize, sizeof(char *));
1.1 markus 818: env[0] = NULL;
819:
1.161 markus 820: #ifdef GSSAPI
1.168 djm 821: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 822: * the childs environment as they see fit
823: */
824: ssh_gssapi_do_child(&env, &envsize);
825: #endif
826:
1.284 djm 827: /* Set basic environment. */
828: for (i = 0; i < s->num_env; i++)
829: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
830:
831: child_set_env(&env, &envsize, "USER", pw->pw_name);
832: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
833: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
834: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
835: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
836: else
837: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
838:
839: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
840: child_set_env(&env, &envsize, "MAIL", buf);
841:
842: /* Normal systems set SHELL by default. */
843: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 844:
845: if (getenv("TZ"))
846: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
847:
1.294 djm 848: /* Set custom environment options from pubkey authentication. */
849: if (options.permit_user_env) {
850: for (n = 0 ; n < auth_opts->nenv; n++) {
851: ocp = xstrdup(auth_opts->env[n]);
852: cp = strchr(ocp, '=');
853: if (*cp == '=') {
854: *cp = '\0';
855: child_set_env(&env, &envsize, ocp, cp + 1);
856: }
857: free(ocp);
858: }
1.1 markus 859: }
860:
1.149 stevesk 861: /* SSH_CLIENT deprecated */
1.1 markus 862: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 863: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
864: ssh_local_port(ssh));
1.1 markus 865: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 866:
1.154 markus 867: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 868: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 869: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
870: laddr, ssh_local_port(ssh));
1.265 djm 871: free(laddr);
1.149 stevesk 872: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 873:
1.293 djm 874: if (tun_fwd_ifnames != NULL)
875: child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
1.290 djm 876: if (auth_info_file != NULL)
877: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 878: if (s->ttyfd != -1)
879: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
880: if (s->term)
881: child_set_env(&env, &envsize, "TERM", s->term);
882: if (s->display)
883: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 884: if (original_command)
885: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
886: original_command);
1.96 dugsong 887: #ifdef KRB5
888: if (s->authctxt->krb5_ticket_file)
889: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 890: s->authctxt->krb5_ticket_file);
1.96 dugsong 891: #endif
1.136 markus 892: if (auth_sock_name != NULL)
1.1 markus 893: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 894: auth_sock_name);
1.1 markus 895:
896: /* read $HOME/.ssh/environment. */
1.284 djm 897: if (options.permit_user_env) {
1.14 deraadt 898: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
899: pw->pw_dir);
1.1 markus 900: read_environment_file(&env, &envsize, buf);
901: }
902: if (debug_flag) {
903: /* dump the environment */
904: fprintf(stderr, "Environment:\n");
905: for (i = 0; env[i]; i++)
906: fprintf(stderr, " %.200s\n", env[i]);
907: }
1.127 markus 908: return env;
909: }
910:
911: /*
912: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
913: * first in this order).
914: */
915: static void
1.294 djm 916: do_rc_files(struct ssh *ssh, Session *s, const char *shell)
1.127 markus 917: {
918: FILE *f = NULL;
919: char cmd[1024];
920: int do_xauth;
921: struct stat st;
922:
923: do_xauth =
924: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
925:
1.231 djm 926: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 927: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.294 djm 928: auth_opts->permit_user_rc && options.permit_user_rc &&
1.273 djm 929: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 930: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
931: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
932: if (debug_flag)
933: fprintf(stderr, "Running %s\n", cmd);
934: f = popen(cmd, "w");
935: if (f) {
936: if (do_xauth)
937: fprintf(f, "%s %s\n", s->auth_proto,
938: s->auth_data);
939: pclose(f);
940: } else
941: fprintf(stderr, "Could not run %s\n",
942: _PATH_SSH_USER_RC);
943: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
944: if (debug_flag)
945: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
946: _PATH_SSH_SYSTEM_RC);
947: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
948: if (f) {
949: if (do_xauth)
950: fprintf(f, "%s %s\n", s->auth_proto,
951: s->auth_data);
952: pclose(f);
953: } else
954: fprintf(stderr, "Could not run %s\n",
955: _PATH_SSH_SYSTEM_RC);
956: } else if (do_xauth && options.xauth_location != NULL) {
957: /* Add authority data to .Xauthority if appropriate. */
958: if (debug_flag) {
959: fprintf(stderr,
1.151 stevesk 960: "Running %.500s remove %.100s\n",
1.165 markus 961: options.xauth_location, s->auth_display);
1.151 stevesk 962: fprintf(stderr,
963: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 964: options.xauth_location, s->auth_display,
965: s->auth_proto, s->auth_data);
966: }
967: snprintf(cmd, sizeof cmd, "%s -q -",
968: options.xauth_location);
969: f = popen(cmd, "w");
970: if (f) {
1.151 stevesk 971: fprintf(f, "remove %s\n",
972: s->auth_display);
1.127 markus 973: fprintf(f, "add %s %s %s\n",
974: s->auth_display, s->auth_proto,
975: s->auth_data);
976: pclose(f);
977: } else {
978: fprintf(stderr, "Could not run %s\n",
979: cmd);
980: }
981: }
982: }
983:
984: static void
985: do_nologin(struct passwd *pw)
986: {
987: FILE *f = NULL;
1.251 dtucker 988: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
989: struct stat sb;
1.127 markus 990:
1.260 guenther 991: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 992: return;
993: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
994:
995: if (stat(nl, &sb) == -1) {
996: if (nl != def_nl)
1.265 djm 997: free(nl);
1.251 dtucker 998: return;
999: }
1000:
1001: /* /etc/nologin exists. Print its contents if we can and exit. */
1002: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1003: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 1004: while (fgets(buf, sizeof(buf), f))
1005: fputs(buf, stderr);
1006: fclose(f);
1007: }
1.251 dtucker 1008: exit(254);
1.127 markus 1009: }
1010:
1.226 djm 1011: /*
1012: * Chroot into a directory after checking it for safety: all path components
1013: * must be root-owned directories with strict permissions.
1014: */
1015: static void
1016: safely_chroot(const char *path, uid_t uid)
1017: {
1018: const char *cp;
1.277 deraadt 1019: char component[PATH_MAX];
1.226 djm 1020: struct stat st;
1021:
1022: if (*path != '/')
1023: fatal("chroot path does not begin at root");
1024: if (strlen(path) >= sizeof(component))
1025: fatal("chroot path too long");
1026:
1027: /*
1028: * Descend the path, checking that each component is a
1029: * root-owned directory with strict permissions.
1030: */
1031: for (cp = path; cp != NULL;) {
1032: if ((cp = strchr(cp, '/')) == NULL)
1033: strlcpy(component, path, sizeof(component));
1034: else {
1035: cp++;
1036: memcpy(component, path, cp - path);
1037: component[cp - path] = '\0';
1038: }
1039:
1040: debug3("%s: checking '%s'", __func__, component);
1041:
1042: if (stat(component, &st) != 0)
1043: fatal("%s: stat(\"%s\"): %s", __func__,
1044: component, strerror(errno));
1045: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1046: fatal("bad ownership or modes for chroot "
1047: "directory %s\"%s\"",
1048: cp == NULL ? "" : "component ", component);
1049: if (!S_ISDIR(st.st_mode))
1050: fatal("chroot path %s\"%s\" is not a directory",
1051: cp == NULL ? "" : "component ", component);
1052:
1053: }
1054:
1055: if (chdir(path) == -1)
1056: fatal("Unable to chdir to chroot path \"%s\": "
1057: "%s", path, strerror(errno));
1058: if (chroot(path) == -1)
1059: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1060: if (chdir("/") == -1)
1061: fatal("%s: chdir(/) after chroot: %s",
1062: __func__, strerror(errno));
1063: verbose("Changed root directory to \"%s\"", path);
1064: }
1065:
1.127 markus 1066: /* Set login name, uid, gid, and groups. */
1.130 provos 1067: void
1.127 markus 1068: do_setusercontext(struct passwd *pw)
1069: {
1.295 djm 1070: char uidstr[32], *chroot_path, *tmp;
1.227 djm 1071:
1.127 markus 1072: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1073: /* Prepare groups */
1.127 markus 1074: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1075: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1076: perror("unable to set user context");
1077: exit(1);
1078: }
1.226 djm 1079:
1.279 djm 1080: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1081: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1082: tmp = tilde_expand_filename(options.chroot_directory,
1083: pw->pw_uid);
1.295 djm 1084: snprintf(uidstr, sizeof(uidstr), "%llu",
1085: (unsigned long long)pw->pw_uid);
1.227 djm 1086: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1.295 djm 1087: "u", pw->pw_name, "U", uidstr, (char *)NULL);
1.226 djm 1088: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1089: free(tmp);
1.226 djm 1090: free(chroot_path);
1.264 djm 1091: /* Make sure we don't attempt to chroot again */
1092: free(options.chroot_directory);
1093: options.chroot_directory = NULL;
1.279 djm 1094: in_chroot = 1;
1.226 djm 1095: }
1096:
1097: /* Set UID */
1098: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1099: perror("unable to set user context (setuser)");
1100: exit(1);
1101: }
1.264 djm 1102: } else if (options.chroot_directory != NULL &&
1103: strcasecmp(options.chroot_directory, "none") != 0) {
1104: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1105: }
1.264 djm 1106:
1.127 markus 1107: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1108: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1109: }
1110:
1.131 markus 1111: static void
1.172 markus 1112: do_pwchange(Session *s)
1113: {
1.179 dtucker 1114: fflush(NULL);
1.172 markus 1115: fprintf(stderr, "WARNING: Your password has expired.\n");
1116: if (s->ttyfd != -1) {
1.178 deraadt 1117: fprintf(stderr,
1.172 markus 1118: "You must change your password now and login again!\n");
1119: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1120: perror("passwd");
1121: } else {
1122: fprintf(stderr,
1123: "Password change required but no TTY available.\n");
1124: }
1125: exit(1);
1126: }
1127:
1128: static void
1.292 djm 1129: child_close_fds(struct ssh *ssh)
1.172 markus 1130: {
1.276 djm 1131: extern int auth_sock;
1.266 markus 1132:
1.276 djm 1133: if (auth_sock != -1) {
1134: close(auth_sock);
1135: auth_sock = -1;
1.266 markus 1136: }
1137:
1.172 markus 1138: if (packet_get_connection_in() == packet_get_connection_out())
1139: close(packet_get_connection_in());
1140: else {
1141: close(packet_get_connection_in());
1142: close(packet_get_connection_out());
1143: }
1144: /*
1145: * Close all descriptors related to channels. They will still remain
1146: * open in the parent.
1147: */
1148: /* XXX better use close-on-exec? -markus */
1.292 djm 1149: channel_close_all(ssh);
1.172 markus 1150:
1151: /*
1152: * Close any extra file descriptors. Note that there may still be
1153: * descriptors left by system functions. They will be closed later.
1154: */
1155: endpwent();
1156:
1157: /*
1.188 djm 1158: * Close any extra open file descriptors so that we don't have them
1.172 markus 1159: * hanging around in clients. Note that we want to do this after
1160: * initgroups, because at least on Solaris 2.3 it leaves file
1161: * descriptors open.
1162: */
1.258 djm 1163: closefrom(STDERR_FILENO + 1);
1.172 markus 1164: }
1165:
1.127 markus 1166: /*
1167: * Performs common processing for the child, such as setting up the
1168: * environment, closing extra file descriptors, setting the user and group
1169: * ids, and executing the command or shell.
1170: */
1.225 markus 1171: #define ARGV_MAX 10
1.127 markus 1172: void
1.292 djm 1173: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1174: {
1175: extern char **environ;
1176: char **env;
1.225 markus 1177: char *argv[ARGV_MAX];
1.284 djm 1178: const char *shell, *shell0;
1.127 markus 1179: struct passwd *pw = s->pw;
1.239 djm 1180: int r = 0;
1.127 markus 1181:
1182: /* remove hostkey from the child's memory */
1183: destroy_sensitive_data();
1.287 markus 1184: packet_clear_keys();
1.127 markus 1185:
1.172 markus 1186: /* Force a password change */
1187: if (s->authctxt->force_pwchange) {
1188: do_setusercontext(pw);
1.292 djm 1189: child_close_fds(ssh);
1.172 markus 1190: do_pwchange(s);
1191: exit(1);
1192: }
1193:
1.127 markus 1194: /*
1195: * Login(1) does this as well, and it needs uid 0 for the "-h"
1196: * switch, so we let login(1) to this for us.
1197: */
1.284 djm 1198: do_nologin(pw);
1199: do_setusercontext(pw);
1.127 markus 1200:
1201: /*
1202: * Get the shell from the password data. An empty shell field is
1203: * legal, and means /bin/sh.
1204: */
1205: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1206:
1207: /*
1208: * Make sure $SHELL points to the shell from the password file,
1209: * even if shell is overridden from login.conf
1210: */
1.292 djm 1211: env = do_setup_env(ssh, s, shell);
1.152 markus 1212:
1.127 markus 1213: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1214:
1.1 markus 1215: /*
1216: * Close the connection descriptors; note that this is the child, and
1217: * the server will still have the socket open, and it is important
1218: * that we do not shutdown it. Note that the descriptors cannot be
1219: * closed before building the environment, as we call
1.281 djm 1220: * ssh_remote_ipaddr there.
1.1 markus 1221: */
1.292 djm 1222: child_close_fds(ssh);
1.1 markus 1223:
1224: /*
1.125 deraadt 1225: * Must take new environment into use so that .ssh/rc,
1226: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1227: */
1228: environ = env;
1.170 jakob 1229:
1230: #ifdef KRB5
1231: /*
1232: * At this point, we check to see if AFS is active and if we have
1233: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1234: * if we can (and need to) extend the ticket into an AFS token. If
1235: * we don't do this, we run into potential problems if the user's
1236: * home directory is in AFS and it's not world-readable.
1237: */
1238:
1239: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1240: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1241: char cell[64];
1242:
1243: debug("Getting AFS token");
1244:
1245: k_setpag();
1246:
1247: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1248: krb5_afslog(s->authctxt->krb5_ctx,
1249: s->authctxt->krb5_fwd_ccache, cell, NULL);
1250:
1251: krb5_afslog_home(s->authctxt->krb5_ctx,
1252: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1253: }
1254: #endif
1.104 markus 1255:
1.188 djm 1256: /* Change current directory to the user's home directory. */
1.104 markus 1257: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1258: /* Suppress missing homedir warning for chroot case */
1259: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1260: if (r || !in_chroot) {
1.239 djm 1261: fprintf(stderr, "Could not chdir to home "
1262: "directory %s: %s\n", pw->pw_dir,
1263: strerror(errno));
1.279 djm 1264: }
1.239 djm 1265: if (r)
1.104 markus 1266: exit(1);
1267: }
1.230 djm 1268:
1269: closefrom(STDERR_FILENO + 1);
1.1 markus 1270:
1.294 djm 1271: do_rc_files(ssh, s, shell);
1.67 markus 1272:
1273: /* restore SIGPIPE for child */
1.217 stevesk 1274: signal(SIGPIPE, SIG_DFL);
1.67 markus 1275:
1.248 djm 1276: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1277: printf("This service allows sftp connections only.\n");
1278: fflush(NULL);
1279: exit(1);
1280: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1281: extern int optind, optreset;
1282: int i;
1283: char *p, *args;
1284:
1.246 stevesk 1285: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1286: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1287: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1288: if (i < ARGV_MAX - 1)
1289: argv[i++] = p;
1290: argv[i] = NULL;
1291: optind = optreset = 1;
1292: __progname = argv[0];
1.226 djm 1293: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1294: }
1.247 djm 1295:
1296: fflush(NULL);
1.225 markus 1297:
1.127 markus 1298: /* Get the last component of the shell name. */
1299: if ((shell0 = strrchr(shell, '/')) != NULL)
1300: shell0++;
1301: else
1302: shell0 = shell;
1303:
1.1 markus 1304: /*
1305: * If we have no command, execute the shell. In this case, the shell
1306: * name to be passed in argv[0] is preceded by '-' to indicate that
1307: * this is a login shell.
1308: */
1309: if (!command) {
1.127 markus 1310: char argv0[256];
1.1 markus 1311:
1.127 markus 1312: /* Start the shell. Set initial character to '-'. */
1313: argv0[0] = '-';
1.1 markus 1314:
1.127 markus 1315: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1316: >= sizeof(argv0) - 1) {
1.127 markus 1317: errno = EINVAL;
1.1 markus 1318: perror(shell);
1319: exit(1);
1.127 markus 1320: }
1.1 markus 1321:
1.127 markus 1322: /* Execute the shell. */
1323: argv[0] = argv0;
1324: argv[1] = NULL;
1325: execve(shell, argv, env);
1326:
1327: /* Executing the shell failed. */
1328: perror(shell);
1329: exit(1);
1.1 markus 1330: }
1331: /*
1332: * Execute the command using the user's shell. This uses the -c
1333: * option to execute the command.
1334: */
1.127 markus 1335: argv[0] = (char *) shell0;
1.1 markus 1336: argv[1] = "-c";
1337: argv[2] = (char *) command;
1338: argv[3] = NULL;
1339: execve(shell, argv, env);
1340: perror(shell);
1341: exit(1);
1342: }
1343:
1.237 djm 1344: void
1345: session_unused(int id)
1346: {
1347: debug3("%s: session id %d unused", __func__, id);
1348: if (id >= options.max_sessions ||
1349: id >= sessions_nalloc) {
1350: fatal("%s: insane session id %d (max %d nalloc %d)",
1351: __func__, id, options.max_sessions, sessions_nalloc);
1352: }
1.270 tedu 1353: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1354: sessions[id].self = id;
1355: sessions[id].used = 0;
1356: sessions[id].chanid = -1;
1357: sessions[id].ptyfd = -1;
1358: sessions[id].ttyfd = -1;
1359: sessions[id].ptymaster = -1;
1360: sessions[id].x11_chanids = NULL;
1361: sessions[id].next_unused = sessions_first_unused;
1362: sessions_first_unused = id;
1363: }
1364:
1.1 markus 1365: Session *
1366: session_new(void)
1367: {
1.237 djm 1368: Session *s, *tmp;
1369:
1370: if (sessions_first_unused == -1) {
1371: if (sessions_nalloc >= options.max_sessions)
1372: return NULL;
1373: debug2("%s: allocate (allocated %d max %d)",
1374: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1375: tmp = xrecallocarray(sessions, sessions_nalloc,
1376: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1377: if (tmp == NULL) {
1378: error("%s: cannot allocate %d sessions",
1379: __func__, sessions_nalloc + 1);
1380: return NULL;
1381: }
1382: sessions = tmp;
1383: session_unused(sessions_nalloc++);
1384: }
1385:
1386: if (sessions_first_unused >= sessions_nalloc ||
1387: sessions_first_unused < 0) {
1388: fatal("%s: insane first_unused %d max %d nalloc %d",
1389: __func__, sessions_first_unused, options.max_sessions,
1390: sessions_nalloc);
1391: }
1392:
1393: s = &sessions[sessions_first_unused];
1394: if (s->used) {
1395: fatal("%s: session %d already used",
1396: __func__, sessions_first_unused);
1397: }
1398: sessions_first_unused = s->next_unused;
1399: s->used = 1;
1400: s->next_unused = -1;
1401: debug("session_new: session %d", s->self);
1402:
1403: return s;
1.1 markus 1404: }
1405:
1.94 itojun 1406: static void
1.1 markus 1407: session_dump(void)
1408: {
1409: int i;
1.237 djm 1410: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1411: Session *s = &sessions[i];
1.237 djm 1412:
1413: debug("dump: used %d next_unused %d session %d %p "
1414: "channel %d pid %ld",
1.1 markus 1415: s->used,
1.237 djm 1416: s->next_unused,
1.1 markus 1417: s->self,
1418: s,
1419: s->chanid,
1.137 mpech 1420: (long)s->pid);
1.1 markus 1421: }
1422: }
1423:
1.2 markus 1424: int
1.97 markus 1425: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1426: {
1427: Session *s = session_new();
1428: debug("session_open: channel %d", chanid);
1429: if (s == NULL) {
1430: error("no more sessions");
1431: return 0;
1432: }
1.97 markus 1433: s->authctxt = authctxt;
1434: s->pw = authctxt->pw;
1.167 djm 1435: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1436: fatal("no user for session %d", s->self);
1.2 markus 1437: debug("session_open: session %d: link with channel %d", s->self, chanid);
1438: s->chanid = chanid;
1439: return 1;
1440: }
1441:
1.130 provos 1442: Session *
1443: session_by_tty(char *tty)
1444: {
1445: int i;
1.237 djm 1446: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1447: Session *s = &sessions[i];
1448: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1449: debug("session_by_tty: session %d tty %s", i, tty);
1450: return s;
1451: }
1452: }
1453: debug("session_by_tty: unknown tty %.100s", tty);
1454: session_dump();
1455: return NULL;
1456: }
1457:
1.94 itojun 1458: static Session *
1.2 markus 1459: session_by_channel(int id)
1460: {
1461: int i;
1.237 djm 1462: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1463: Session *s = &sessions[i];
1464: if (s->used && s->chanid == id) {
1.237 djm 1465: debug("session_by_channel: session %d channel %d",
1466: i, id);
1.2 markus 1467: return s;
1468: }
1469: }
1470: debug("session_by_channel: unknown channel %d", id);
1471: session_dump();
1472: return NULL;
1473: }
1474:
1.94 itojun 1475: static Session *
1.184 djm 1476: session_by_x11_channel(int id)
1477: {
1478: int i, j;
1479:
1.237 djm 1480: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1481: Session *s = &sessions[i];
1482:
1483: if (s->x11_chanids == NULL || !s->used)
1484: continue;
1485: for (j = 0; s->x11_chanids[j] != -1; j++) {
1486: if (s->x11_chanids[j] == id) {
1487: debug("session_by_x11_channel: session %d "
1488: "channel %d", s->self, id);
1489: return s;
1490: }
1491: }
1492: }
1493: debug("session_by_x11_channel: unknown channel %d", id);
1494: session_dump();
1495: return NULL;
1496: }
1497:
1498: static Session *
1.2 markus 1499: session_by_pid(pid_t pid)
1500: {
1501: int i;
1.137 mpech 1502: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1503: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1504: Session *s = &sessions[i];
1505: if (s->used && s->pid == pid)
1506: return s;
1507: }
1.137 mpech 1508: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1509: session_dump();
1510: return NULL;
1511: }
1512:
1.94 itojun 1513: static int
1.292 djm 1514: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1515: {
1516: s->col = packet_get_int();
1517: s->row = packet_get_int();
1518: s->xpixel = packet_get_int();
1519: s->ypixel = packet_get_int();
1.116 markus 1520: packet_check_eom();
1.2 markus 1521: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1522: return 1;
1523: }
1524:
1.94 itojun 1525: static int
1.292 djm 1526: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1527: {
1.45 markus 1528: u_int len;
1.72 stevesk 1529: int n_bytes;
1.132 markus 1530:
1.294 djm 1531: if (!auth_opts->permit_pty_flag || !options.permit_tty) {
1532: debug("Allocating a pty not permitted for this connection.");
1.19 markus 1533: return 0;
1.86 markus 1534: }
1535: if (s->ttyfd != -1) {
1536: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1537: return 0;
1.86 markus 1538: }
1539:
1.2 markus 1540: s->term = packet_get_string(&len);
1.283 markus 1541: s->col = packet_get_int();
1542: s->row = packet_get_int();
1.2 markus 1543: s->xpixel = packet_get_int();
1544: s->ypixel = packet_get_int();
1545:
1546: if (strcmp(s->term, "") == 0) {
1.265 djm 1547: free(s->term);
1.2 markus 1548: s->term = NULL;
1549: }
1.86 markus 1550:
1.2 markus 1551: /* Allocate a pty and open it. */
1.86 markus 1552: debug("Allocating pty.");
1.237 djm 1553: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1554: sizeof(s->tty)))) {
1.265 djm 1555: free(s->term);
1.2 markus 1556: s->term = NULL;
1557: s->ptyfd = -1;
1558: s->ttyfd = -1;
1559: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1560: return 0;
1.2 markus 1561: }
1562: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1563:
1.283 markus 1564: n_bytes = packet_remaining();
1.86 markus 1565: tty_parse_modes(s->ttyfd, &n_bytes);
1566:
1.130 provos 1567: if (!use_privsep)
1568: pty_setowner(s->pw, s->tty);
1.86 markus 1569:
1570: /* Set window size from the packet. */
1.2 markus 1571: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1572:
1.116 markus 1573: packet_check_eom();
1.9 markus 1574: session_proctitle(s);
1.2 markus 1575: return 1;
1576: }
1577:
1.94 itojun 1578: static int
1.292 djm 1579: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1580: {
1.105 markus 1581: struct stat st;
1.45 markus 1582: u_int len;
1.7 markus 1583: int success = 0;
1.267 djm 1584: char *prog, *cmd;
1.182 djm 1585: u_int i;
1.7 markus 1586:
1.267 djm 1587: s->subsys = packet_get_string(&len);
1.116 markus 1588: packet_check_eom();
1.267 djm 1589: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1590: s->pw->pw_name);
1.18 jakob 1591:
1592: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1593: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1594: prog = options.subsystem_command[i];
1595: cmd = options.subsystem_args[i];
1.249 dtucker 1596: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1597: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1598: debug("subsystem: %s", prog);
1.225 markus 1599: } else {
1.249 dtucker 1600: if (stat(prog, &st) < 0)
1601: debug("subsystem: cannot stat %s: %s",
1602: prog, strerror(errno));
1.225 markus 1603: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1604: debug("subsystem: exec() %s", cmd);
1.105 markus 1605: }
1.292 djm 1606: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1607: break;
1.18 jakob 1608: }
1609: }
1610:
1611: if (!success)
1.267 djm 1612: logit("subsystem request for %.100s by user %s failed, "
1613: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1614:
1615: return success;
1616: }
1617:
1.94 itojun 1618: static int
1.292 djm 1619: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1620: {
1.81 markus 1621: int success;
1.7 markus 1622:
1.184 djm 1623: if (s->auth_proto != NULL || s->auth_data != NULL) {
1624: error("session_x11_req: session %d: "
1.190 stevesk 1625: "x11 forwarding already active", s->self);
1.184 djm 1626: return 0;
1627: }
1.7 markus 1628: s->single_connection = packet_get_char();
1629: s->auth_proto = packet_get_string(NULL);
1630: s->auth_data = packet_get_string(NULL);
1631: s->screen = packet_get_int();
1.116 markus 1632: packet_check_eom();
1.7 markus 1633:
1.282 djm 1634: if (xauth_valid_string(s->auth_proto) &&
1635: xauth_valid_string(s->auth_data))
1.292 djm 1636: success = session_setup_x11fwd(ssh, s);
1.282 djm 1637: else {
1638: success = 0;
1639: error("Invalid X11 forwarding data");
1640: }
1.81 markus 1641: if (!success) {
1.265 djm 1642: free(s->auth_proto);
1643: free(s->auth_data);
1.84 markus 1644: s->auth_proto = NULL;
1645: s->auth_data = NULL;
1.7 markus 1646: }
1.81 markus 1647: return success;
1.7 markus 1648: }
1649:
1.94 itojun 1650: static int
1.292 djm 1651: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1652: {
1.116 markus 1653: packet_check_eom();
1.292 djm 1654: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1655: }
1656:
1.94 itojun 1657: static int
1.292 djm 1658: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1659: {
1.237 djm 1660: u_int len, success;
1661:
1.19 markus 1662: char *command = packet_get_string(&len);
1.116 markus 1663: packet_check_eom();
1.292 djm 1664: success = do_exec(ssh, s, command) == 0;
1.265 djm 1665: free(command);
1.237 djm 1666: return success;
1.19 markus 1667: }
1668:
1.94 itojun 1669: static int
1.292 djm 1670: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1671: {
1672:
1.175 deraadt 1673: packet_get_int(); /* ignored */
1.157 markus 1674: packet_check_eom();
1675:
1.259 djm 1676: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1677: return 0;
1678: return 1;
1679: }
1680:
1681: static int
1.292 djm 1682: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1683: {
1684: char *name, *val;
1685: u_int name_len, val_len, i;
1686:
1.271 djm 1687: name = packet_get_cstring(&name_len);
1688: val = packet_get_cstring(&val_len);
1.173 djm 1689: packet_check_eom();
1690:
1691: /* Don't set too many environment variables */
1692: if (s->num_env > 128) {
1693: debug2("Ignoring env request %s: too many env vars", name);
1694: goto fail;
1695: }
1696:
1697: for (i = 0; i < options.num_accept_env; i++) {
1698: if (match_pattern(name, options.accept_env[i])) {
1699: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1700: s->env = xrecallocarray(s->env, s->num_env,
1701: s->num_env + 1, sizeof(*s->env));
1.173 djm 1702: s->env[s->num_env].name = name;
1703: s->env[s->num_env].val = val;
1704: s->num_env++;
1705: return (1);
1706: }
1707: }
1708: debug2("Ignoring env request %s: disallowed name", name);
1709:
1710: fail:
1.265 djm 1711: free(name);
1712: free(val);
1.173 djm 1713: return (0);
1714: }
1715:
1716: static int
1.292 djm 1717: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1718: {
1719: static int called = 0;
1.294 djm 1720:
1.116 markus 1721: packet_check_eom();
1.294 djm 1722: if (!auth_opts->permit_agent_forwarding_flag ||
1723: !options.allow_agent_forwarding) {
1724: debug("%s: agent forwarding disabled", __func__);
1.44 markus 1725: return 0;
1726: }
1.43 markus 1727: if (called) {
1728: return 0;
1729: } else {
1730: called = 1;
1.292 djm 1731: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1732: }
1733: }
1734:
1.123 markus 1735: int
1.292 djm 1736: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1737: {
1738: int success = 0;
1739: Session *s;
1740:
1.123 markus 1741: if ((s = session_by_channel(c->self)) == NULL) {
1.292 djm 1742: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1743: return 0;
1744: }
1.292 djm 1745: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1746:
1747: /*
1.64 markus 1748: * a session is in LARVAL state until a shell, a command
1749: * or a subsystem is executed
1.2 markus 1750: */
1751: if (c->type == SSH_CHANNEL_LARVAL) {
1752: if (strcmp(rtype, "shell") == 0) {
1.292 djm 1753: success = session_shell_req(ssh, s);
1.2 markus 1754: } else if (strcmp(rtype, "exec") == 0) {
1.292 djm 1755: success = session_exec_req(ssh, s);
1.2 markus 1756: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 djm 1757: success = session_pty_req(ssh, s);
1.7 markus 1758: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 djm 1759: success = session_x11_req(ssh, s);
1.43 markus 1760: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 djm 1761: success = session_auth_agent_req(ssh, s);
1.7 markus 1762: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 djm 1763: success = session_subsystem_req(ssh, s);
1.173 djm 1764: } else if (strcmp(rtype, "env") == 0) {
1.292 djm 1765: success = session_env_req(ssh, s);
1.2 markus 1766: }
1767: }
1768: if (strcmp(rtype, "window-change") == 0) {
1.292 djm 1769: success = session_window_change_req(ssh, s);
1.177 djm 1770: } else if (strcmp(rtype, "break") == 0) {
1.292 djm 1771: success = session_break_req(ssh, s);
1.2 markus 1772: }
1.177 djm 1773:
1.123 markus 1774: return success;
1.2 markus 1775: }
1776:
1777: void
1.292 djm 1778: session_set_fds(struct ssh *ssh, Session *s,
1779: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1780: {
1781: /*
1782: * now that have a child and a pipe to the child,
1783: * we can activate our channel and register the fd's
1784: */
1785: if (s->chanid == -1)
1786: fatal("no channel for session %d", s->self);
1.292 djm 1787: channel_set_fds(ssh, s->chanid,
1.2 markus 1788: fdout, fdin, fderr,
1.256 djm 1789: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1790: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1791: }
1792:
1.85 markus 1793: /*
1794: * Function to perform pty cleanup. Also called if we get aborted abnormally
1795: * (e.g., due to a dropped connection).
1796: */
1.130 provos 1797: void
1.165 markus 1798: session_pty_cleanup2(Session *s)
1.1 markus 1799: {
1.85 markus 1800: if (s == NULL) {
1801: error("session_pty_cleanup: no session");
1802: return;
1803: }
1804: if (s->ttyfd == -1)
1.1 markus 1805: return;
1806:
1.54 stevesk 1807: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1808:
1809: /* Record that the user has logged out. */
1.85 markus 1810: if (s->pid != 0)
1811: record_logout(s->pid, s->tty);
1.1 markus 1812:
1813: /* Release the pseudo-tty. */
1.130 provos 1814: if (getuid() == 0)
1815: pty_release(s->tty);
1.1 markus 1816:
1817: /*
1818: * Close the server side of the socket pairs. We must do this after
1819: * the pty cleanup, so that another process doesn't get this pty
1820: * while we're still cleaning up.
1821: */
1.237 djm 1822: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1823: error("close(s->ptymaster/%d): %s",
1824: s->ptymaster, strerror(errno));
1.108 markus 1825:
1826: /* unlink pty from session */
1827: s->ttyfd = -1;
1.2 markus 1828: }
1829:
1.130 provos 1830: void
1.165 markus 1831: session_pty_cleanup(Session *s)
1.130 provos 1832: {
1.165 markus 1833: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1834: }
1835:
1.147 markus 1836: static char *
1837: sig2name(int sig)
1838: {
1839: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1840: SSH_SIG(ABRT);
1841: SSH_SIG(ALRM);
1842: SSH_SIG(FPE);
1843: SSH_SIG(HUP);
1844: SSH_SIG(ILL);
1845: SSH_SIG(INT);
1846: SSH_SIG(KILL);
1847: SSH_SIG(PIPE);
1848: SSH_SIG(QUIT);
1849: SSH_SIG(SEGV);
1850: SSH_SIG(TERM);
1851: SSH_SIG(USR1);
1852: SSH_SIG(USR2);
1853: #undef SSH_SIG
1854: return "SIG@openssh.com";
1855: }
1856:
1.94 itojun 1857: static void
1.292 djm 1858: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1859: {
1860: Channel *c;
1861:
1.292 djm 1862: if ((c = channel_by_id(ssh, id)) == NULL) {
1863: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1864: } else {
1865: /* Detach X11 listener */
1.292 djm 1866: debug("%s: detach x11 channel %d", __func__, id);
1867: channel_cancel_cleanup(ssh, id);
1.184 djm 1868: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1869: chan_mark_dead(ssh, c);
1.184 djm 1870: }
1871: }
1872:
1873: static void
1.292 djm 1874: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1875: {
1876: Session *s;
1877: u_int i;
1878:
1.292 djm 1879: debug3("%s: channel %d", __func__, id);
1880: channel_cancel_cleanup(ssh, id);
1.221 stevesk 1881: if ((s = session_by_x11_channel(id)) == NULL)
1.292 djm 1882: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 1883: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 1884: debug("%s: session %d: closing channel %d",
1885: __func__, s->self, s->x11_chanids[i]);
1.184 djm 1886: /*
1887: * The channel "id" is already closing, but make sure we
1888: * close all of its siblings.
1889: */
1890: if (s->x11_chanids[i] != id)
1.292 djm 1891: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 1892: }
1.265 djm 1893: free(s->x11_chanids);
1.184 djm 1894: s->x11_chanids = NULL;
1.265 djm 1895: free(s->display);
1896: s->display = NULL;
1897: free(s->auth_proto);
1898: s->auth_proto = NULL;
1899: free(s->auth_data);
1900: s->auth_data = NULL;
1901: free(s->auth_display);
1902: s->auth_display = NULL;
1.184 djm 1903: }
1904:
1905: static void
1.292 djm 1906: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 1907: {
1908: Channel *c;
1.124 markus 1909:
1.292 djm 1910: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
1911: fatal("%s: session %d: no channel %d",
1912: __func__, s->self, s->chanid);
1913: debug("%s: session %d channel %d pid %ld",
1914: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 1915:
1916: if (WIFEXITED(status)) {
1.292 djm 1917: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 1918: packet_put_int(WEXITSTATUS(status));
1919: packet_send();
1920: } else if (WIFSIGNALED(status)) {
1.292 djm 1921: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 1922: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 1923: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 1924: packet_put_cstring("");
1925: packet_put_cstring("");
1926: packet_send();
1927: } else {
1928: /* Some weird exit cause. Just exit. */
1929: packet_disconnect("wait returned status %04x.", status);
1930: }
1931:
1932: /* disconnect channel */
1.292 djm 1933: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 1934:
1935: /*
1936: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 1937: * the channel gets EOF. The session will be then be closed
1.187 djm 1938: * by session_close_by_channel when the childs close their fds.
1939: */
1.292 djm 1940: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 1941:
1.5 markus 1942: /*
1943: * emulate a write failure with 'chan_write_failed', nobody will be
1944: * interested in data we write.
1945: * Note that we must not call 'chan_read_failed', since there could
1946: * be some more data waiting in the pipe.
1947: */
1.8 markus 1948: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1949: chan_write_failed(ssh, c);
1.2 markus 1950: }
1951:
1.130 provos 1952: void
1.292 djm 1953: session_close(struct ssh *ssh, Session *s)
1.2 markus 1954: {
1.182 djm 1955: u_int i;
1.173 djm 1956:
1.280 djm 1957: verbose("Close session: user %s from %.200s port %d id %d",
1958: s->pw->pw_name,
1.281 djm 1959: ssh_remote_ipaddr(ssh),
1960: ssh_remote_port(ssh),
1.280 djm 1961: s->self);
1962:
1.165 markus 1963: if (s->ttyfd != -1)
1.85 markus 1964: session_pty_cleanup(s);
1.265 djm 1965: free(s->term);
1966: free(s->display);
1967: free(s->x11_chanids);
1968: free(s->auth_display);
1969: free(s->auth_data);
1970: free(s->auth_proto);
1.267 djm 1971: free(s->subsys);
1.219 djm 1972: if (s->env != NULL) {
1973: for (i = 0; i < s->num_env; i++) {
1.265 djm 1974: free(s->env[i].name);
1975: free(s->env[i].val);
1.219 djm 1976: }
1.265 djm 1977: free(s->env);
1.173 djm 1978: }
1.9 markus 1979: session_proctitle(s);
1.237 djm 1980: session_unused(s->self);
1.2 markus 1981: }
1982:
1983: void
1.292 djm 1984: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 1985: {
1986: Session *s = session_by_pid(pid);
1987: if (s == NULL) {
1.292 djm 1988: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 1989: return;
1990: }
1991: if (s->chanid != -1)
1.292 djm 1992: session_exit_message(ssh, s, status);
1.187 djm 1993: if (s->ttyfd != -1)
1994: session_pty_cleanup(s);
1.197 djm 1995: s->pid = 0;
1.98 markus 1996: }
1997:
1.2 markus 1998: /*
1999: * this is called when a channel dies before
2000: * the session 'child' itself dies
2001: */
2002: void
1.292 djm 2003: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 2004: {
2005: Session *s = session_by_channel(id);
1.187 djm 2006: u_int i;
1.184 djm 2007:
1.2 markus 2008: if (s == NULL) {
1.292 djm 2009: debug("%s: no session for id %d", __func__, id);
1.2 markus 2010: return;
2011: }
1.292 djm 2012: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 2013: if (s->pid != 0) {
1.292 djm 2014: debug("%s: channel %d: has child", __func__, id);
1.108 markus 2015: /*
2016: * delay detach of session, but release pty, since
2017: * the fd's to the child are already closed
2018: */
1.165 markus 2019: if (s->ttyfd != -1)
1.108 markus 2020: session_pty_cleanup(s);
1.107 markus 2021: return;
2022: }
2023: /* detach by removing callback */
1.292 djm 2024: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 2025:
2026: /* Close any X11 listeners associated with this session */
2027: if (s->x11_chanids != NULL) {
2028: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2029: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 2030: s->x11_chanids[i] = -1;
2031: }
2032: }
2033:
1.2 markus 2034: s->chanid = -1;
1.292 djm 2035: session_close(ssh, s);
1.106 markus 2036: }
2037:
2038: void
1.292 djm 2039: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 2040: {
2041: int i;
1.237 djm 2042: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2043: Session *s = &sessions[i];
1.130 provos 2044: if (s->used) {
2045: if (closefunc != NULL)
2046: closefunc(s);
2047: else
1.292 djm 2048: session_close(ssh, s);
1.130 provos 2049: }
1.2 markus 2050: }
1.9 markus 2051: }
2052:
1.94 itojun 2053: static char *
1.9 markus 2054: session_tty_list(void)
2055: {
2056: static char buf[1024];
2057: int i;
2058: buf[0] = '\0';
1.237 djm 2059: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2060: Session *s = &sessions[i];
2061: if (s->used && s->ttyfd != -1) {
2062: if (buf[0] != '\0')
2063: strlcat(buf, ",", sizeof buf);
2064: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2065: }
2066: }
2067: if (buf[0] == '\0')
2068: strlcpy(buf, "notty", sizeof buf);
2069: return buf;
2070: }
2071:
2072: void
2073: session_proctitle(Session *s)
2074: {
2075: if (s->pw == NULL)
2076: error("no user for session %d", s->self);
2077: else
2078: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2079: }
2080:
2081: int
1.292 djm 2082: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2083: {
2084: struct stat st;
1.109 stevesk 2085: char display[512], auth_display[512];
1.272 djm 2086: char hostname[NI_MAXHOST];
1.184 djm 2087: u_int i;
1.81 markus 2088:
1.294 djm 2089: if (!auth_opts->permit_x11_forwarding_flag) {
2090: packet_send_debug("X11 forwarding disabled by key options.");
1.81 markus 2091: return 0;
2092: }
2093: if (!options.x11_forwarding) {
2094: debug("X11 forwarding disabled in server configuration file.");
2095: return 0;
2096: }
1.275 djm 2097: if (options.xauth_location == NULL ||
1.81 markus 2098: (stat(options.xauth_location, &st) == -1)) {
1.294 djm 2099: packet_send_debug("No xauth program; cannot forward X11.");
1.81 markus 2100: return 0;
2101: }
1.87 markus 2102: if (s->display != NULL) {
1.81 markus 2103: debug("X11 display already set.");
2104: return 0;
2105: }
1.292 djm 2106: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2107: options.x11_use_localhost, s->single_connection,
1.184 djm 2108: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2109: debug("x11_create_display_inet failed.");
1.81 markus 2110: return 0;
1.184 djm 2111: }
2112: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2113: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2114: session_close_single_x11, 0);
1.81 markus 2115: }
1.109 stevesk 2116:
2117: /* Set up a suitable value for the DISPLAY variable. */
2118: if (gethostname(hostname, sizeof(hostname)) < 0)
2119: fatal("gethostname: %.100s", strerror(errno));
2120: /*
2121: * auth_display must be used as the displayname when the
2122: * authorization entry is added with xauth(1). This will be
2123: * different than the DISPLAY string for localhost displays.
2124: */
1.119 stevesk 2125: if (options.x11_use_localhost) {
1.140 deraadt 2126: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2127: s->display_number, s->screen);
1.140 deraadt 2128: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2129: s->display_number, s->screen);
1.109 stevesk 2130: s->display = xstrdup(display);
1.118 stevesk 2131: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2132: } else {
1.140 deraadt 2133: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2134: s->display_number, s->screen);
2135: s->display = xstrdup(display);
1.118 stevesk 2136: s->auth_display = xstrdup(display);
1.109 stevesk 2137: }
2138:
1.81 markus 2139: return 1;
1.2 markus 2140: }
2141:
1.94 itojun 2142: static void
1.292 djm 2143: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2144: {
1.292 djm 2145: server_loop2(ssh, authctxt);
1.165 markus 2146: }
2147:
2148: void
1.292 djm 2149: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2150: {
2151: static int called = 0;
2152:
2153: debug("do_cleanup");
2154:
2155: /* no cleanup if we're in the child for login shell */
2156: if (is_child)
2157: return;
2158:
2159: /* avoid double cleanup */
2160: if (called)
2161: return;
2162: called = 1;
2163:
1.218 markus 2164: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2165: return;
2166: #ifdef KRB5
2167: if (options.kerberos_ticket_cleanup &&
2168: authctxt->krb5_ctx)
2169: krb5_cleanup_proc(authctxt);
1.161 markus 2170: #endif
1.165 markus 2171:
2172: #ifdef GSSAPI
1.283 markus 2173: if (options.gss_cleanup_creds)
1.165 markus 2174: ssh_gssapi_cleanup_creds();
2175: #endif
2176:
2177: /* remove agent socket */
2178: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2179:
2180: /* remove userauth info */
2181: if (auth_info_file != NULL) {
2182: temporarily_use_uid(authctxt->pw);
2183: unlink(auth_info_file);
2184: restore_uid();
2185: free(auth_info_file);
2186: auth_info_file = NULL;
2187: }
1.165 markus 2188:
2189: /*
2190: * Cleanup ptys/utmp only if privsep is disabled,
2191: * or if running in monitor.
2192: */
2193: if (!use_privsep || mm_is_monitor())
1.292 djm 2194: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2195: }
1.281 djm 2196:
2197: /* Return a name for the remote host that fits inside utmp_size */
2198:
2199: const char *
2200: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2201: {
2202: const char *remote = "";
2203:
2204: if (utmp_size > 0)
2205: remote = auth_get_canonical_hostname(ssh, use_dns);
2206: if (utmp_size == 0 || strlen(remote) > utmp_size)
2207: remote = ssh_remote_ipaddr(ssh);
2208: return remote;
2209: }
2210: