Annotation of src/usr.bin/ssh/session.c, Revision 1.311
1.311 ! djm 1: /* $OpenBSD: session.c,v 1.310 2019/01/19 21:31:32 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"
1.303 markus 63: #include "sshbuf.h"
64: #include "ssherr.h"
1.173 djm 65: #include "match.h"
1.1 markus 66: #include "uidswap.h"
67: #include "compat.h"
1.78 markus 68: #include "channels.h"
1.304 markus 69: #include "sshkey.h"
1.216 deraadt 70: #include "cipher.h"
71: #include "kex.h"
72: #include "hostfile.h"
1.2 markus 73: #include "auth.h"
1.19 markus 74: #include "auth-options.h"
1.266 markus 75: #include "authfd.h"
1.50 markus 76: #include "pathnames.h"
1.51 markus 77: #include "log.h"
1.274 millert 78: #include "misc.h"
1.51 markus 79: #include "servconf.h"
1.59 djm 80: #include "sshlogin.h"
1.51 markus 81: #include "serverloop.h"
82: #include "canohost.h"
1.55 itojun 83: #include "session.h"
1.216 deraadt 84: #ifdef GSSAPI
85: #include "ssh-gss.h"
86: #endif
1.130 provos 87: #include "monitor_wrap.h"
1.225 markus 88: #include "sftp.h"
1.290 djm 89: #include "atomicio.h"
1.171 markus 90:
91: #ifdef KRB5
92: #include <kafs.h>
1.161 markus 93: #endif
1.310 djm 94:
95: #include "opacket.h" /* XXX */
96: extern struct ssh *active_state; /* XXX */
1.161 markus 97:
1.242 djm 98: #define IS_INTERNAL_SFTP(c) \
99: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
100: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
101: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
102: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
103:
1.1 markus 104: /* func */
105:
106: Session *session_new(void);
1.292 djm 107: void session_set_fds(struct ssh *, Session *, int, int, int, int, int);
1.165 markus 108: void session_pty_cleanup(Session *);
1.94 itojun 109: void session_proctitle(Session *);
1.292 djm 110: int session_setup_x11fwd(struct ssh *, Session *);
111: int do_exec_pty(struct ssh *, Session *, const char *);
112: int do_exec_no_pty(struct ssh *, Session *, const char *);
113: int do_exec(struct ssh *, Session *, const char *);
114: void do_login(struct ssh *, Session *, const char *);
115: void do_child(struct ssh *, Session *, const char *);
1.73 djm 116: void do_motd(void);
1.94 itojun 117: int check_quietlogin(Session *, const char *);
1.1 markus 118:
1.292 djm 119: static void do_authenticated2(struct ssh *, Authctxt *);
1.94 itojun 120:
1.292 djm 121: static int session_pty_req(struct ssh *, Session *);
1.65 markus 122:
1.1 markus 123: /* import */
124: extern ServerOptions options;
125: extern char *__progname;
126: extern int debug_flag;
1.45 markus 127: extern u_int utmp_len;
1.21 markus 128: extern int startup_pipe;
1.74 markus 129: extern void destroy_sensitive_data(void);
1.303 markus 130: extern struct sshbuf *loginmsg;
1.294 djm 131: extern struct sshauthopt *auth_opts;
1.309 djm 132: extern char *tun_fwd_ifnames; /* serverloop.c */
1.21 markus 133:
1.34 markus 134: /* original command from peer. */
1.92 markus 135: const char *original_command = NULL;
1.34 markus 136:
1.1 markus 137: /* data */
1.237 djm 138: static int sessions_first_unused = -1;
139: static int sessions_nalloc = 0;
140: static Session *sessions = NULL;
1.1 markus 141:
1.248 djm 142: #define SUBSYSTEM_NONE 0
143: #define SUBSYSTEM_EXT 1
144: #define SUBSYSTEM_INT_SFTP 2
145: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.225 markus 146:
1.129 provos 147: login_cap_t *lc;
1.28 millert 148:
1.165 markus 149: static int is_child = 0;
1.279 djm 150: static int in_chroot = 0;
1.165 markus 151:
1.290 djm 152: /* File containing userauth info, if ExposeAuthInfo set */
153: static char *auth_info_file = NULL;
154:
1.136 markus 155: /* Name and directory of socket for authentication agent forwarding. */
156: static char *auth_sock_name = NULL;
157: static char *auth_sock_dir = NULL;
158:
159: /* removes the agent forwarding socket */
160:
161: static void
1.165 markus 162: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 163: {
164: if (auth_sock_name != NULL) {
165: temporarily_use_uid(pw);
166: unlink(auth_sock_name);
167: rmdir(auth_sock_dir);
168: auth_sock_name = NULL;
169: restore_uid();
170: }
171: }
172:
173: static int
1.292 djm 174: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136 markus 175: {
176: Channel *nc;
1.237 djm 177: int sock = -1;
1.136 markus 178:
179: if (auth_sock_name != NULL) {
180: error("authentication forwarding requested twice.");
181: return 0;
182: }
183:
184: /* Temporarily drop privileged uid for mkdir/bind. */
185: temporarily_use_uid(pw);
186:
187: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 188: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 189:
190: /* Create private directory for socket */
191: if (mkdtemp(auth_sock_dir) == NULL) {
192: packet_send_debug("Agent forwarding disabled: "
193: "mkdtemp() failed: %.100s", strerror(errno));
194: restore_uid();
1.265 djm 195: free(auth_sock_dir);
1.136 markus 196: auth_sock_dir = NULL;
1.237 djm 197: goto authsock_err;
1.136 markus 198: }
1.237 djm 199:
200: xasprintf(&auth_sock_name, "%s/agent.%ld",
201: auth_sock_dir, (long) getpid());
1.136 markus 202:
1.274 millert 203: /* Start a Unix listener on auth_sock_name. */
204: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136 markus 205:
206: /* Restore the privileged uid. */
207: restore_uid();
208:
1.274 millert 209: /* Check for socket/bind/listen failure. */
210: if (sock < 0)
1.237 djm 211: goto authsock_err;
1.136 markus 212:
213: /* Allocate a channel for the authentication agent socket. */
1.292 djm 214: nc = channel_new(ssh, "auth socket",
1.136 markus 215: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
216: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 217: 0, "auth socket", 1);
1.245 djm 218: nc->path = xstrdup(auth_sock_name);
1.136 markus 219: return 1;
1.237 djm 220:
221: authsock_err:
1.265 djm 222: free(auth_sock_name);
1.237 djm 223: if (auth_sock_dir != NULL) {
224: rmdir(auth_sock_dir);
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. */
388: if (pipe(pin) < 0) {
389: error("%s: pipe in: %.100s", __func__, strerror(errno));
390: return -1;
391: }
392: if (pipe(pout) < 0) {
393: error("%s: pipe out: %.100s", __func__, strerror(errno));
394: close(pin[0]);
395: close(pin[1]);
396: return -1;
397: }
1.256 djm 398: if (pipe(perr) < 0) {
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. */
1.237 djm 414: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
415: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
416: return -1;
417: }
1.256 djm 418: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
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: */
454: if (setsid() < 0)
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]);
463: if (dup2(pin[0], 0) < 0)
464: perror("dup2 stdin");
465: close(pin[0]);
466:
467: /* Redirect stdout. */
468: close(pout[0]);
469: if (dup2(pout[1], 1) < 0)
470: perror("dup2 stdout");
471: close(pout[1]);
472:
473: /* Redirect stderr. */
1.256 djm 474: close(perr[0]);
1.238 markus 475: if (dup2(perr[1], 2) < 0)
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]);
1.1 markus 486: if (dup2(inout[0], 0) < 0) /* stdin */
487: perror("dup2 stdin");
1.237 djm 488: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 489: perror("dup2 stdout");
1.238 markus 490: close(inout[0]);
1.1 markus 491: if (dup2(err[0], 2) < 0) /* stderr */
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. */
1.257 djm 505: packet_set_interactive(s->display != NULL,
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: */
1.283 markus 525: session_set_fds(s, inout[1], inout[1], err[1],
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: */
555: if ((fdout = dup(ptyfd)) < 0) {
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 */
562: if ((ptymaster = dup(ptyfd)) < 0) {
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. */
592: if (dup2(ttyfd, 0) < 0)
593: error("dup2 stdin: %s", strerror(errno));
594: if (dup2(ttyfd, 1) < 0)
595: error("dup2 stdout: %s", strerror(errno));
596: if (dup2(ttyfd, 2) < 0)
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;
1.257 djm 621: packet_set_interactive(1,
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);
1.24 markus 722: if (packet_connection_is_on_socket()) {
723: if (getpeername(packet_get_connection_in(),
1.200 deraadt 724: (struct sockaddr *)&from, &fromlen) < 0) {
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
1.161 markus 853: * the childs environment as they see fit
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:
1.154 markus 935: laddr = get_local_ipaddr(packet_get_connection_in());
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 "
1097: "directory %s\"%s\"",
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:
1.172 markus 1188: if (packet_get_connection_in() == packet_get_connection_out())
1189: close(packet_get_connection_in());
1190: else {
1191: close(packet_get_connection_in());
1192: close(packet_get_connection_out());
1193: }
1194: /*
1195: * Close all descriptors related to channels. They will still remain
1196: * open in the parent.
1197: */
1198: /* XXX better use close-on-exec? -markus */
1.292 djm 1199: channel_close_all(ssh);
1.172 markus 1200:
1201: /*
1202: * Close any extra file descriptors. Note that there may still be
1203: * descriptors left by system functions. They will be closed later.
1204: */
1205: endpwent();
1206:
1207: /*
1.188 djm 1208: * Close any extra open file descriptors so that we don't have them
1.172 markus 1209: * hanging around in clients. Note that we want to do this after
1210: * initgroups, because at least on Solaris 2.3 it leaves file
1211: * descriptors open.
1212: */
1.258 djm 1213: closefrom(STDERR_FILENO + 1);
1.172 markus 1214: }
1215:
1.127 markus 1216: /*
1217: * Performs common processing for the child, such as setting up the
1218: * environment, closing extra file descriptors, setting the user and group
1219: * ids, and executing the command or shell.
1220: */
1.225 markus 1221: #define ARGV_MAX 10
1.127 markus 1222: void
1.292 djm 1223: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1224: {
1225: extern char **environ;
1226: char **env;
1.225 markus 1227: char *argv[ARGV_MAX];
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:
1232: /* remove hostkey from the child's memory */
1233: destroy_sensitive_data();
1.287 markus 1234: packet_clear_keys();
1.127 markus 1235:
1.172 markus 1236: /* Force a password change */
1237: if (s->authctxt->force_pwchange) {
1238: do_setusercontext(pw);
1.292 djm 1239: child_close_fds(ssh);
1.172 markus 1240: do_pwchange(s);
1241: exit(1);
1242: }
1243:
1.127 markus 1244: /*
1245: * Login(1) does this as well, and it needs uid 0 for the "-h"
1246: * switch, so we let login(1) to this for us.
1247: */
1.284 djm 1248: do_nologin(pw);
1249: do_setusercontext(pw);
1.127 markus 1250:
1251: /*
1252: * Get the shell from the password data. An empty shell field is
1253: * legal, and means /bin/sh.
1254: */
1255: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1256:
1257: /*
1258: * Make sure $SHELL points to the shell from the password file,
1259: * even if shell is overridden from login.conf
1260: */
1.292 djm 1261: env = do_setup_env(ssh, s, shell);
1.152 markus 1262:
1.127 markus 1263: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1264:
1.1 markus 1265: /*
1266: * Close the connection descriptors; note that this is the child, and
1267: * the server will still have the socket open, and it is important
1268: * that we do not shutdown it. Note that the descriptors cannot be
1269: * closed before building the environment, as we call
1.281 djm 1270: * ssh_remote_ipaddr there.
1.1 markus 1271: */
1.292 djm 1272: child_close_fds(ssh);
1.1 markus 1273:
1274: /*
1.125 deraadt 1275: * Must take new environment into use so that .ssh/rc,
1276: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1277: */
1278: environ = env;
1.170 jakob 1279:
1280: #ifdef KRB5
1281: /*
1282: * At this point, we check to see if AFS is active and if we have
1283: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1284: * if we can (and need to) extend the ticket into an AFS token. If
1285: * we don't do this, we run into potential problems if the user's
1286: * home directory is in AFS and it's not world-readable.
1287: */
1288:
1289: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1290: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1291: char cell[64];
1292:
1293: debug("Getting AFS token");
1294:
1295: k_setpag();
1296:
1297: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1298: krb5_afslog(s->authctxt->krb5_ctx,
1299: s->authctxt->krb5_fwd_ccache, cell, NULL);
1300:
1301: krb5_afslog_home(s->authctxt->krb5_ctx,
1302: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1303: }
1304: #endif
1.104 markus 1305:
1.188 djm 1306: /* Change current directory to the user's home directory. */
1.104 markus 1307: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1308: /* Suppress missing homedir warning for chroot case */
1309: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1310: if (r || !in_chroot) {
1.239 djm 1311: fprintf(stderr, "Could not chdir to home "
1312: "directory %s: %s\n", pw->pw_dir,
1313: strerror(errno));
1.279 djm 1314: }
1.239 djm 1315: if (r)
1.104 markus 1316: exit(1);
1317: }
1.230 djm 1318:
1319: closefrom(STDERR_FILENO + 1);
1.1 markus 1320:
1.294 djm 1321: do_rc_files(ssh, s, shell);
1.67 markus 1322:
1323: /* restore SIGPIPE for child */
1.217 stevesk 1324: signal(SIGPIPE, SIG_DFL);
1.67 markus 1325:
1.248 djm 1326: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1327: printf("This service allows sftp connections only.\n");
1328: fflush(NULL);
1329: exit(1);
1330: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1331: extern int optind, optreset;
1332: int i;
1333: char *p, *args;
1334:
1.246 stevesk 1335: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1336: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1337: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1338: if (i < ARGV_MAX - 1)
1339: argv[i++] = p;
1340: argv[i] = NULL;
1341: optind = optreset = 1;
1342: __progname = argv[0];
1.226 djm 1343: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1344: }
1.247 djm 1345:
1346: fflush(NULL);
1.225 markus 1347:
1.127 markus 1348: /* Get the last component of the shell name. */
1349: if ((shell0 = strrchr(shell, '/')) != NULL)
1350: shell0++;
1351: else
1352: shell0 = shell;
1353:
1.1 markus 1354: /*
1355: * If we have no command, execute the shell. In this case, the shell
1356: * name to be passed in argv[0] is preceded by '-' to indicate that
1357: * this is a login shell.
1358: */
1359: if (!command) {
1.127 markus 1360: char argv0[256];
1.1 markus 1361:
1.127 markus 1362: /* Start the shell. Set initial character to '-'. */
1363: argv0[0] = '-';
1.1 markus 1364:
1.127 markus 1365: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1366: >= sizeof(argv0) - 1) {
1.127 markus 1367: errno = EINVAL;
1.1 markus 1368: perror(shell);
1369: exit(1);
1.127 markus 1370: }
1.1 markus 1371:
1.127 markus 1372: /* Execute the shell. */
1373: argv[0] = argv0;
1374: argv[1] = NULL;
1375: execve(shell, argv, env);
1376:
1377: /* Executing the shell failed. */
1378: perror(shell);
1379: exit(1);
1.1 markus 1380: }
1381: /*
1382: * Execute the command using the user's shell. This uses the -c
1383: * option to execute the command.
1384: */
1.127 markus 1385: argv[0] = (char *) shell0;
1.1 markus 1386: argv[1] = "-c";
1387: argv[2] = (char *) command;
1388: argv[3] = NULL;
1389: execve(shell, argv, env);
1390: perror(shell);
1391: exit(1);
1392: }
1393:
1.237 djm 1394: void
1395: session_unused(int id)
1396: {
1397: debug3("%s: session id %d unused", __func__, id);
1398: if (id >= options.max_sessions ||
1399: id >= sessions_nalloc) {
1400: fatal("%s: insane session id %d (max %d nalloc %d)",
1401: __func__, id, options.max_sessions, sessions_nalloc);
1402: }
1.270 tedu 1403: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1404: sessions[id].self = id;
1405: sessions[id].used = 0;
1406: sessions[id].chanid = -1;
1407: sessions[id].ptyfd = -1;
1408: sessions[id].ttyfd = -1;
1409: sessions[id].ptymaster = -1;
1410: sessions[id].x11_chanids = NULL;
1411: sessions[id].next_unused = sessions_first_unused;
1412: sessions_first_unused = id;
1413: }
1414:
1.1 markus 1415: Session *
1416: session_new(void)
1417: {
1.237 djm 1418: Session *s, *tmp;
1419:
1420: if (sessions_first_unused == -1) {
1421: if (sessions_nalloc >= options.max_sessions)
1422: return NULL;
1423: debug2("%s: allocate (allocated %d max %d)",
1424: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1425: tmp = xrecallocarray(sessions, sessions_nalloc,
1426: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1427: if (tmp == NULL) {
1428: error("%s: cannot allocate %d sessions",
1429: __func__, sessions_nalloc + 1);
1430: return NULL;
1431: }
1432: sessions = tmp;
1433: session_unused(sessions_nalloc++);
1434: }
1435:
1436: if (sessions_first_unused >= sessions_nalloc ||
1437: sessions_first_unused < 0) {
1438: fatal("%s: insane first_unused %d max %d nalloc %d",
1439: __func__, sessions_first_unused, options.max_sessions,
1440: sessions_nalloc);
1441: }
1442:
1443: s = &sessions[sessions_first_unused];
1444: if (s->used) {
1445: fatal("%s: session %d already used",
1446: __func__, sessions_first_unused);
1447: }
1448: sessions_first_unused = s->next_unused;
1449: s->used = 1;
1450: s->next_unused = -1;
1451: debug("session_new: session %d", s->self);
1452:
1453: return s;
1.1 markus 1454: }
1455:
1.94 itojun 1456: static void
1.1 markus 1457: session_dump(void)
1458: {
1459: int i;
1.237 djm 1460: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1461: Session *s = &sessions[i];
1.237 djm 1462:
1463: debug("dump: used %d next_unused %d session %d %p "
1464: "channel %d pid %ld",
1.1 markus 1465: s->used,
1.237 djm 1466: s->next_unused,
1.1 markus 1467: s->self,
1468: s,
1469: s->chanid,
1.137 mpech 1470: (long)s->pid);
1.1 markus 1471: }
1472: }
1473:
1.2 markus 1474: int
1.97 markus 1475: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1476: {
1477: Session *s = session_new();
1478: debug("session_open: channel %d", chanid);
1479: if (s == NULL) {
1480: error("no more sessions");
1481: return 0;
1482: }
1.97 markus 1483: s->authctxt = authctxt;
1484: s->pw = authctxt->pw;
1.167 djm 1485: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1486: fatal("no user for session %d", s->self);
1.2 markus 1487: debug("session_open: session %d: link with channel %d", s->self, chanid);
1488: s->chanid = chanid;
1489: return 1;
1490: }
1491:
1.130 provos 1492: Session *
1493: session_by_tty(char *tty)
1494: {
1495: int i;
1.237 djm 1496: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1497: Session *s = &sessions[i];
1498: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1499: debug("session_by_tty: session %d tty %s", i, tty);
1500: return s;
1501: }
1502: }
1503: debug("session_by_tty: unknown tty %.100s", tty);
1504: session_dump();
1505: return NULL;
1506: }
1507:
1.94 itojun 1508: static Session *
1.2 markus 1509: session_by_channel(int id)
1510: {
1511: int i;
1.237 djm 1512: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1513: Session *s = &sessions[i];
1514: if (s->used && s->chanid == id) {
1.237 djm 1515: debug("session_by_channel: session %d channel %d",
1516: i, id);
1.2 markus 1517: return s;
1518: }
1519: }
1520: debug("session_by_channel: unknown channel %d", id);
1521: session_dump();
1522: return NULL;
1523: }
1524:
1.94 itojun 1525: static Session *
1.184 djm 1526: session_by_x11_channel(int id)
1527: {
1528: int i, j;
1529:
1.237 djm 1530: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1531: Session *s = &sessions[i];
1532:
1533: if (s->x11_chanids == NULL || !s->used)
1534: continue;
1535: for (j = 0; s->x11_chanids[j] != -1; j++) {
1536: if (s->x11_chanids[j] == id) {
1537: debug("session_by_x11_channel: session %d "
1538: "channel %d", s->self, id);
1539: return s;
1540: }
1541: }
1542: }
1543: debug("session_by_x11_channel: unknown channel %d", id);
1544: session_dump();
1545: return NULL;
1546: }
1547:
1548: static Session *
1.2 markus 1549: session_by_pid(pid_t pid)
1550: {
1551: int i;
1.137 mpech 1552: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1553: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1554: Session *s = &sessions[i];
1555: if (s->used && s->pid == pid)
1556: return s;
1557: }
1.137 mpech 1558: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1559: session_dump();
1560: return NULL;
1561: }
1562:
1.94 itojun 1563: static int
1.292 djm 1564: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1565: {
1566: s->col = packet_get_int();
1567: s->row = packet_get_int();
1568: s->xpixel = packet_get_int();
1569: s->ypixel = packet_get_int();
1.116 markus 1570: packet_check_eom();
1.2 markus 1571: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1572: return 1;
1573: }
1574:
1.94 itojun 1575: static int
1.292 djm 1576: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1577: {
1.45 markus 1578: u_int len;
1.132 markus 1579:
1.294 djm 1580: if (!auth_opts->permit_pty_flag || !options.permit_tty) {
1581: debug("Allocating a pty not permitted for this connection.");
1.19 markus 1582: return 0;
1.86 markus 1583: }
1584: if (s->ttyfd != -1) {
1585: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1586: return 0;
1.86 markus 1587: }
1588:
1.2 markus 1589: s->term = packet_get_string(&len);
1.283 markus 1590: s->col = packet_get_int();
1591: s->row = packet_get_int();
1.2 markus 1592: s->xpixel = packet_get_int();
1593: s->ypixel = packet_get_int();
1594:
1595: if (strcmp(s->term, "") == 0) {
1.265 djm 1596: free(s->term);
1.2 markus 1597: s->term = NULL;
1598: }
1.86 markus 1599:
1.2 markus 1600: /* Allocate a pty and open it. */
1.86 markus 1601: debug("Allocating pty.");
1.237 djm 1602: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1603: sizeof(s->tty)))) {
1.265 djm 1604: free(s->term);
1.2 markus 1605: s->term = NULL;
1606: s->ptyfd = -1;
1607: s->ttyfd = -1;
1608: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1609: return 0;
1.2 markus 1610: }
1611: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1612:
1.302 markus 1613: ssh_tty_parse_modes(ssh, s->ttyfd);
1.86 markus 1614:
1.130 provos 1615: if (!use_privsep)
1616: pty_setowner(s->pw, s->tty);
1.86 markus 1617:
1618: /* Set window size from the packet. */
1.2 markus 1619: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1620:
1.116 markus 1621: packet_check_eom();
1.9 markus 1622: session_proctitle(s);
1.2 markus 1623: return 1;
1624: }
1625:
1.94 itojun 1626: static int
1.292 djm 1627: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1628: {
1.105 markus 1629: struct stat st;
1.45 markus 1630: u_int len;
1.7 markus 1631: int success = 0;
1.267 djm 1632: char *prog, *cmd;
1.182 djm 1633: u_int i;
1.7 markus 1634:
1.267 djm 1635: s->subsys = packet_get_string(&len);
1.116 markus 1636: packet_check_eom();
1.267 djm 1637: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1638: s->pw->pw_name);
1.18 jakob 1639:
1640: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1641: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1642: prog = options.subsystem_command[i];
1643: cmd = options.subsystem_args[i];
1.249 dtucker 1644: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1645: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1646: debug("subsystem: %s", prog);
1.225 markus 1647: } else {
1.249 dtucker 1648: if (stat(prog, &st) < 0)
1649: debug("subsystem: cannot stat %s: %s",
1650: prog, strerror(errno));
1.225 markus 1651: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1652: debug("subsystem: exec() %s", cmd);
1.105 markus 1653: }
1.292 djm 1654: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1655: break;
1.18 jakob 1656: }
1657: }
1658:
1659: if (!success)
1.267 djm 1660: logit("subsystem request for %.100s by user %s failed, "
1661: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1662:
1663: return success;
1664: }
1665:
1.94 itojun 1666: static int
1.292 djm 1667: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1668: {
1.81 markus 1669: int success;
1.7 markus 1670:
1.184 djm 1671: if (s->auth_proto != NULL || s->auth_data != NULL) {
1672: error("session_x11_req: session %d: "
1.190 stevesk 1673: "x11 forwarding already active", s->self);
1.184 djm 1674: return 0;
1675: }
1.7 markus 1676: s->single_connection = packet_get_char();
1677: s->auth_proto = packet_get_string(NULL);
1678: s->auth_data = packet_get_string(NULL);
1679: s->screen = packet_get_int();
1.116 markus 1680: packet_check_eom();
1.7 markus 1681:
1.282 djm 1682: if (xauth_valid_string(s->auth_proto) &&
1683: xauth_valid_string(s->auth_data))
1.292 djm 1684: success = session_setup_x11fwd(ssh, s);
1.282 djm 1685: else {
1686: success = 0;
1687: error("Invalid X11 forwarding data");
1688: }
1.81 markus 1689: if (!success) {
1.265 djm 1690: free(s->auth_proto);
1691: free(s->auth_data);
1.84 markus 1692: s->auth_proto = NULL;
1693: s->auth_data = NULL;
1.7 markus 1694: }
1.81 markus 1695: return success;
1.7 markus 1696: }
1697:
1.94 itojun 1698: static int
1.292 djm 1699: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1700: {
1.116 markus 1701: packet_check_eom();
1.292 djm 1702: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1703: }
1704:
1.94 itojun 1705: static int
1.292 djm 1706: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1707: {
1.237 djm 1708: u_int len, success;
1709:
1.19 markus 1710: char *command = packet_get_string(&len);
1.116 markus 1711: packet_check_eom();
1.292 djm 1712: success = do_exec(ssh, s, command) == 0;
1.265 djm 1713: free(command);
1.237 djm 1714: return success;
1.19 markus 1715: }
1716:
1.94 itojun 1717: static int
1.292 djm 1718: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1719: {
1720:
1.175 deraadt 1721: packet_get_int(); /* ignored */
1.157 markus 1722: packet_check_eom();
1723:
1.259 djm 1724: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1725: return 0;
1726: return 1;
1727: }
1728:
1729: static int
1.292 djm 1730: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1731: {
1732: char *name, *val;
1733: u_int name_len, val_len, i;
1734:
1.271 djm 1735: name = packet_get_cstring(&name_len);
1736: val = packet_get_cstring(&val_len);
1.173 djm 1737: packet_check_eom();
1738:
1739: /* Don't set too many environment variables */
1740: if (s->num_env > 128) {
1741: debug2("Ignoring env request %s: too many env vars", name);
1742: goto fail;
1743: }
1744:
1745: for (i = 0; i < options.num_accept_env; i++) {
1746: if (match_pattern(name, options.accept_env[i])) {
1747: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1748: s->env = xrecallocarray(s->env, s->num_env,
1749: s->num_env + 1, sizeof(*s->env));
1.173 djm 1750: s->env[s->num_env].name = name;
1751: s->env[s->num_env].val = val;
1752: s->num_env++;
1753: return (1);
1754: }
1755: }
1756: debug2("Ignoring env request %s: disallowed name", name);
1757:
1758: fail:
1.265 djm 1759: free(name);
1760: free(val);
1.173 djm 1761: return (0);
1762: }
1763:
1.306 djm 1764: /*
1765: * Conversion of signals from ssh channel request names.
1766: * Subset of signals from RFC 4254 section 6.10C, with SIGINFO as
1767: * local extension.
1768: */
1769: static int
1770: name2sig(char *name)
1771: {
1772: #define SSH_SIG(x) if (strcmp(name, #x) == 0) return SIG ## x
1773: SSH_SIG(HUP);
1774: SSH_SIG(INT);
1775: SSH_SIG(KILL);
1776: SSH_SIG(QUIT);
1777: SSH_SIG(TERM);
1778: SSH_SIG(USR1);
1779: SSH_SIG(USR2);
1780: #undef SSH_SIG
1781: if (strcmp(name, "INFO@openssh.com") == 0)
1782: return SIGINFO;
1783: return -1;
1784: }
1785:
1786: static int
1787: session_signal_req(struct ssh *ssh, Session *s)
1788: {
1789: char *signame = NULL;
1790: int r, sig, success = 0;
1791:
1792: if ((r = sshpkt_get_cstring(ssh, &signame, NULL)) != 0 ||
1793: (r = sshpkt_get_end(ssh)) != 0) {
1794: error("%s: parse packet: %s", __func__, ssh_err(r));
1795: goto out;
1796: }
1797: if ((sig = name2sig(signame)) == -1) {
1798: error("%s: unsupported signal \"%s\"", __func__, signame);
1799: goto out;
1800: }
1801: if (s->pid <= 0) {
1802: error("%s: no pid for session %d", __func__, s->self);
1803: goto out;
1804: }
1805: if (s->forced || s->is_subsystem) {
1806: error("%s: refusing to send signal %s to %s session", __func__,
1807: signame, s->forced ? "forced-command" : "subsystem");
1808: goto out;
1809: }
1810: if (!use_privsep || mm_is_monitor()) {
1811: error("%s: session signalling requires privilege separation",
1812: __func__);
1813: goto out;
1814: }
1815:
1816: debug("%s: signal %s, killpg(%ld, %d)", __func__, signame,
1817: (long)s->pid, sig);
1818: temporarily_use_uid(s->pw);
1819: r = killpg(s->pid, sig);
1820: restore_uid();
1821: if (r != 0) {
1822: error("%s: killpg(%ld, %d): %s", __func__, (long)s->pid,
1823: sig, strerror(errno));
1824: goto out;
1825: }
1826:
1827: /* success */
1828: success = 1;
1829: out:
1830: free(signame);
1831: return success;
1832: }
1833:
1.173 djm 1834: static int
1.292 djm 1835: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1836: {
1837: static int called = 0;
1.294 djm 1838:
1.116 markus 1839: packet_check_eom();
1.294 djm 1840: if (!auth_opts->permit_agent_forwarding_flag ||
1841: !options.allow_agent_forwarding) {
1842: debug("%s: agent forwarding disabled", __func__);
1.44 markus 1843: return 0;
1844: }
1.43 markus 1845: if (called) {
1846: return 0;
1847: } else {
1848: called = 1;
1.292 djm 1849: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1850: }
1851: }
1852:
1.123 markus 1853: int
1.292 djm 1854: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1855: {
1856: int success = 0;
1857: Session *s;
1858:
1.123 markus 1859: if ((s = session_by_channel(c->self)) == NULL) {
1.292 djm 1860: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1861: return 0;
1862: }
1.292 djm 1863: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1864:
1865: /*
1.64 markus 1866: * a session is in LARVAL state until a shell, a command
1867: * or a subsystem is executed
1.2 markus 1868: */
1869: if (c->type == SSH_CHANNEL_LARVAL) {
1870: if (strcmp(rtype, "shell") == 0) {
1.292 djm 1871: success = session_shell_req(ssh, s);
1.2 markus 1872: } else if (strcmp(rtype, "exec") == 0) {
1.292 djm 1873: success = session_exec_req(ssh, s);
1.2 markus 1874: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 djm 1875: success = session_pty_req(ssh, s);
1.7 markus 1876: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 djm 1877: success = session_x11_req(ssh, s);
1.43 markus 1878: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 djm 1879: success = session_auth_agent_req(ssh, s);
1.7 markus 1880: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 djm 1881: success = session_subsystem_req(ssh, s);
1.173 djm 1882: } else if (strcmp(rtype, "env") == 0) {
1.292 djm 1883: success = session_env_req(ssh, s);
1.2 markus 1884: }
1885: }
1886: if (strcmp(rtype, "window-change") == 0) {
1.292 djm 1887: success = session_window_change_req(ssh, s);
1.177 djm 1888: } else if (strcmp(rtype, "break") == 0) {
1.292 djm 1889: success = session_break_req(ssh, s);
1.306 djm 1890: } else if (strcmp(rtype, "signal") == 0) {
1891: success = session_signal_req(ssh, s);
1.2 markus 1892: }
1.177 djm 1893:
1.123 markus 1894: return success;
1.2 markus 1895: }
1896:
1897: void
1.292 djm 1898: session_set_fds(struct ssh *ssh, Session *s,
1899: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1900: {
1901: /*
1902: * now that have a child and a pipe to the child,
1903: * we can activate our channel and register the fd's
1904: */
1905: if (s->chanid == -1)
1906: fatal("no channel for session %d", s->self);
1.292 djm 1907: channel_set_fds(ssh, s->chanid,
1.2 markus 1908: fdout, fdin, fderr,
1.256 djm 1909: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1910: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1911: }
1912:
1.85 markus 1913: /*
1914: * Function to perform pty cleanup. Also called if we get aborted abnormally
1915: * (e.g., due to a dropped connection).
1916: */
1.130 provos 1917: void
1.165 markus 1918: session_pty_cleanup2(Session *s)
1.1 markus 1919: {
1.85 markus 1920: if (s == NULL) {
1.307 djm 1921: error("%s: no session", __func__);
1.85 markus 1922: return;
1923: }
1924: if (s->ttyfd == -1)
1.1 markus 1925: return;
1926:
1.307 djm 1927: debug("%s: session %d release %s", __func__, s->self, s->tty);
1.1 markus 1928:
1929: /* Record that the user has logged out. */
1.85 markus 1930: if (s->pid != 0)
1931: record_logout(s->pid, s->tty);
1.1 markus 1932:
1933: /* Release the pseudo-tty. */
1.130 provos 1934: if (getuid() == 0)
1935: pty_release(s->tty);
1.1 markus 1936:
1937: /*
1938: * Close the server side of the socket pairs. We must do this after
1939: * the pty cleanup, so that another process doesn't get this pty
1940: * while we're still cleaning up.
1941: */
1.237 djm 1942: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1943: error("close(s->ptymaster/%d): %s",
1944: s->ptymaster, strerror(errno));
1.108 markus 1945:
1946: /* unlink pty from session */
1947: s->ttyfd = -1;
1.2 markus 1948: }
1949:
1.130 provos 1950: void
1.165 markus 1951: session_pty_cleanup(Session *s)
1.130 provos 1952: {
1.165 markus 1953: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1954: }
1955:
1.147 markus 1956: static char *
1957: sig2name(int sig)
1958: {
1959: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1960: SSH_SIG(ABRT);
1961: SSH_SIG(ALRM);
1962: SSH_SIG(FPE);
1963: SSH_SIG(HUP);
1964: SSH_SIG(ILL);
1965: SSH_SIG(INT);
1966: SSH_SIG(KILL);
1967: SSH_SIG(PIPE);
1968: SSH_SIG(QUIT);
1969: SSH_SIG(SEGV);
1970: SSH_SIG(TERM);
1971: SSH_SIG(USR1);
1972: SSH_SIG(USR2);
1973: #undef SSH_SIG
1974: return "SIG@openssh.com";
1975: }
1976:
1.94 itojun 1977: static void
1.292 djm 1978: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1979: {
1980: Channel *c;
1981:
1.292 djm 1982: if ((c = channel_by_id(ssh, id)) == NULL) {
1983: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1984: } else {
1985: /* Detach X11 listener */
1.292 djm 1986: debug("%s: detach x11 channel %d", __func__, id);
1987: channel_cancel_cleanup(ssh, id);
1.184 djm 1988: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1989: chan_mark_dead(ssh, c);
1.184 djm 1990: }
1991: }
1992:
1993: static void
1.292 djm 1994: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1995: {
1996: Session *s;
1997: u_int i;
1998:
1.292 djm 1999: debug3("%s: channel %d", __func__, id);
2000: channel_cancel_cleanup(ssh, id);
1.221 stevesk 2001: if ((s = session_by_x11_channel(id)) == NULL)
1.292 djm 2002: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 2003: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2004: debug("%s: session %d: closing channel %d",
2005: __func__, s->self, s->x11_chanids[i]);
1.184 djm 2006: /*
2007: * The channel "id" is already closing, but make sure we
2008: * close all of its siblings.
2009: */
2010: if (s->x11_chanids[i] != id)
1.292 djm 2011: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 2012: }
1.265 djm 2013: free(s->x11_chanids);
1.184 djm 2014: s->x11_chanids = NULL;
1.265 djm 2015: free(s->display);
2016: s->display = NULL;
2017: free(s->auth_proto);
2018: s->auth_proto = NULL;
2019: free(s->auth_data);
2020: s->auth_data = NULL;
2021: free(s->auth_display);
2022: s->auth_display = NULL;
1.184 djm 2023: }
2024:
2025: static void
1.292 djm 2026: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 2027: {
2028: Channel *c;
1.124 markus 2029:
1.292 djm 2030: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
2031: fatal("%s: session %d: no channel %d",
2032: __func__, s->self, s->chanid);
2033: debug("%s: session %d channel %d pid %ld",
2034: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 2035:
2036: if (WIFEXITED(status)) {
1.292 djm 2037: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 2038: packet_put_int(WEXITSTATUS(status));
2039: packet_send();
2040: } else if (WIFSIGNALED(status)) {
1.292 djm 2041: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 2042: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 2043: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 2044: packet_put_cstring("");
2045: packet_put_cstring("");
2046: packet_send();
2047: } else {
2048: /* Some weird exit cause. Just exit. */
2049: packet_disconnect("wait returned status %04x.", status);
2050: }
2051:
2052: /* disconnect channel */
1.292 djm 2053: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 2054:
2055: /*
2056: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 2057: * the channel gets EOF. The session will be then be closed
1.187 djm 2058: * by session_close_by_channel when the childs close their fds.
2059: */
1.292 djm 2060: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 2061:
1.5 markus 2062: /*
2063: * emulate a write failure with 'chan_write_failed', nobody will be
2064: * interested in data we write.
2065: * Note that we must not call 'chan_read_failed', since there could
2066: * be some more data waiting in the pipe.
2067: */
1.8 markus 2068: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 2069: chan_write_failed(ssh, c);
1.2 markus 2070: }
2071:
1.130 provos 2072: void
1.292 djm 2073: session_close(struct ssh *ssh, Session *s)
1.2 markus 2074: {
1.182 djm 2075: u_int i;
1.173 djm 2076:
1.280 djm 2077: verbose("Close session: user %s from %.200s port %d id %d",
2078: s->pw->pw_name,
1.281 djm 2079: ssh_remote_ipaddr(ssh),
2080: ssh_remote_port(ssh),
1.280 djm 2081: s->self);
2082:
1.165 markus 2083: if (s->ttyfd != -1)
1.85 markus 2084: session_pty_cleanup(s);
1.265 djm 2085: free(s->term);
2086: free(s->display);
2087: free(s->x11_chanids);
2088: free(s->auth_display);
2089: free(s->auth_data);
2090: free(s->auth_proto);
1.267 djm 2091: free(s->subsys);
1.219 djm 2092: if (s->env != NULL) {
2093: for (i = 0; i < s->num_env; i++) {
1.265 djm 2094: free(s->env[i].name);
2095: free(s->env[i].val);
1.219 djm 2096: }
1.265 djm 2097: free(s->env);
1.173 djm 2098: }
1.9 markus 2099: session_proctitle(s);
1.237 djm 2100: session_unused(s->self);
1.2 markus 2101: }
2102:
2103: void
1.292 djm 2104: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 2105: {
2106: Session *s = session_by_pid(pid);
2107: if (s == NULL) {
1.292 djm 2108: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 2109: return;
2110: }
2111: if (s->chanid != -1)
1.292 djm 2112: session_exit_message(ssh, s, status);
1.187 djm 2113: if (s->ttyfd != -1)
2114: session_pty_cleanup(s);
1.197 djm 2115: s->pid = 0;
1.98 markus 2116: }
2117:
1.2 markus 2118: /*
2119: * this is called when a channel dies before
2120: * the session 'child' itself dies
2121: */
2122: void
1.292 djm 2123: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 2124: {
2125: Session *s = session_by_channel(id);
1.187 djm 2126: u_int i;
1.184 djm 2127:
1.2 markus 2128: if (s == NULL) {
1.292 djm 2129: debug("%s: no session for id %d", __func__, id);
1.2 markus 2130: return;
2131: }
1.292 djm 2132: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 2133: if (s->pid != 0) {
1.307 djm 2134: debug("%s: channel %d: has child, ttyfd %d",
2135: __func__, id, s->ttyfd);
1.108 markus 2136: /*
2137: * delay detach of session, but release pty, since
2138: * the fd's to the child are already closed
2139: */
1.165 markus 2140: if (s->ttyfd != -1)
1.108 markus 2141: session_pty_cleanup(s);
1.107 markus 2142: return;
2143: }
2144: /* detach by removing callback */
1.292 djm 2145: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 2146:
2147: /* Close any X11 listeners associated with this session */
2148: if (s->x11_chanids != NULL) {
2149: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2150: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 2151: s->x11_chanids[i] = -1;
2152: }
2153: }
2154:
1.2 markus 2155: s->chanid = -1;
1.292 djm 2156: session_close(ssh, s);
1.106 markus 2157: }
2158:
2159: void
1.292 djm 2160: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 2161: {
2162: int i;
1.237 djm 2163: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2164: Session *s = &sessions[i];
1.130 provos 2165: if (s->used) {
2166: if (closefunc != NULL)
2167: closefunc(s);
2168: else
1.292 djm 2169: session_close(ssh, s);
1.130 provos 2170: }
1.2 markus 2171: }
1.9 markus 2172: }
2173:
1.94 itojun 2174: static char *
1.9 markus 2175: session_tty_list(void)
2176: {
2177: static char buf[1024];
2178: int i;
2179: buf[0] = '\0';
1.237 djm 2180: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2181: Session *s = &sessions[i];
2182: if (s->used && s->ttyfd != -1) {
2183: if (buf[0] != '\0')
2184: strlcat(buf, ",", sizeof buf);
2185: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2186: }
2187: }
2188: if (buf[0] == '\0')
2189: strlcpy(buf, "notty", sizeof buf);
2190: return buf;
2191: }
2192:
2193: void
2194: session_proctitle(Session *s)
2195: {
2196: if (s->pw == NULL)
2197: error("no user for session %d", s->self);
2198: else
2199: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2200: }
2201:
2202: int
1.292 djm 2203: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2204: {
2205: struct stat st;
1.109 stevesk 2206: char display[512], auth_display[512];
1.272 djm 2207: char hostname[NI_MAXHOST];
1.184 djm 2208: u_int i;
1.81 markus 2209:
1.294 djm 2210: if (!auth_opts->permit_x11_forwarding_flag) {
2211: packet_send_debug("X11 forwarding disabled by key options.");
1.81 markus 2212: return 0;
2213: }
2214: if (!options.x11_forwarding) {
2215: debug("X11 forwarding disabled in server configuration file.");
2216: return 0;
2217: }
1.275 djm 2218: if (options.xauth_location == NULL ||
1.81 markus 2219: (stat(options.xauth_location, &st) == -1)) {
1.294 djm 2220: packet_send_debug("No xauth program; cannot forward X11.");
1.81 markus 2221: return 0;
2222: }
1.87 markus 2223: if (s->display != NULL) {
1.81 markus 2224: debug("X11 display already set.");
2225: return 0;
2226: }
1.292 djm 2227: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2228: options.x11_use_localhost, s->single_connection,
1.184 djm 2229: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2230: debug("x11_create_display_inet failed.");
1.81 markus 2231: return 0;
1.184 djm 2232: }
2233: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2234: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2235: session_close_single_x11, 0);
1.81 markus 2236: }
1.109 stevesk 2237:
2238: /* Set up a suitable value for the DISPLAY variable. */
2239: if (gethostname(hostname, sizeof(hostname)) < 0)
2240: fatal("gethostname: %.100s", strerror(errno));
2241: /*
2242: * auth_display must be used as the displayname when the
2243: * authorization entry is added with xauth(1). This will be
2244: * different than the DISPLAY string for localhost displays.
2245: */
1.119 stevesk 2246: if (options.x11_use_localhost) {
1.140 deraadt 2247: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2248: s->display_number, s->screen);
1.140 deraadt 2249: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2250: s->display_number, s->screen);
1.109 stevesk 2251: s->display = xstrdup(display);
1.118 stevesk 2252: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2253: } else {
1.140 deraadt 2254: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2255: s->display_number, s->screen);
2256: s->display = xstrdup(display);
1.118 stevesk 2257: s->auth_display = xstrdup(display);
1.109 stevesk 2258: }
2259:
1.81 markus 2260: return 1;
1.2 markus 2261: }
2262:
1.94 itojun 2263: static void
1.292 djm 2264: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2265: {
1.292 djm 2266: server_loop2(ssh, authctxt);
1.165 markus 2267: }
2268:
2269: void
1.292 djm 2270: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2271: {
2272: static int called = 0;
2273:
2274: debug("do_cleanup");
2275:
2276: /* no cleanup if we're in the child for login shell */
2277: if (is_child)
2278: return;
2279:
2280: /* avoid double cleanup */
2281: if (called)
2282: return;
2283: called = 1;
2284:
1.218 markus 2285: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2286: return;
2287: #ifdef KRB5
2288: if (options.kerberos_ticket_cleanup &&
2289: authctxt->krb5_ctx)
2290: krb5_cleanup_proc(authctxt);
1.161 markus 2291: #endif
1.165 markus 2292:
2293: #ifdef GSSAPI
1.283 markus 2294: if (options.gss_cleanup_creds)
1.165 markus 2295: ssh_gssapi_cleanup_creds();
2296: #endif
2297:
2298: /* remove agent socket */
2299: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2300:
2301: /* remove userauth info */
2302: if (auth_info_file != NULL) {
2303: temporarily_use_uid(authctxt->pw);
2304: unlink(auth_info_file);
2305: restore_uid();
2306: free(auth_info_file);
2307: auth_info_file = NULL;
2308: }
1.165 markus 2309:
2310: /*
2311: * Cleanup ptys/utmp only if privsep is disabled,
2312: * or if running in monitor.
2313: */
2314: if (!use_privsep || mm_is_monitor())
1.292 djm 2315: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2316: }
1.281 djm 2317:
2318: /* Return a name for the remote host that fits inside utmp_size */
2319:
2320: const char *
2321: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2322: {
2323: const char *remote = "";
2324:
2325: if (utmp_size > 0)
2326: remote = auth_get_canonical_hostname(ssh, use_dns);
2327: if (utmp_size == 0 || strlen(remote) > utmp_size)
2328: remote = ssh_remote_ipaddr(ssh);
2329: return remote;
2330: }
2331:
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