Annotation of src/usr.bin/ssh/session.c, Revision 1.292
1.292 ! djm 1: /* $OpenBSD: session.c,v 1.291 2017/08/18 05:36:45 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;
1.21 markus 127:
1.34 markus 128: /* original command from peer. */
1.92 markus 129: const char *original_command = NULL;
1.34 markus 130:
1.1 markus 131: /* data */
1.237 djm 132: static int sessions_first_unused = -1;
133: static int sessions_nalloc = 0;
134: static Session *sessions = NULL;
1.1 markus 135:
1.248 djm 136: #define SUBSYSTEM_NONE 0
137: #define SUBSYSTEM_EXT 1
138: #define SUBSYSTEM_INT_SFTP 2
139: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.225 markus 140:
1.129 provos 141: login_cap_t *lc;
1.28 millert 142:
1.165 markus 143: static int is_child = 0;
1.279 djm 144: static int in_chroot = 0;
1.165 markus 145:
1.290 djm 146: /* File containing userauth info, if ExposeAuthInfo set */
147: static char *auth_info_file = NULL;
148:
1.136 markus 149: /* Name and directory of socket for authentication agent forwarding. */
150: static char *auth_sock_name = NULL;
151: static char *auth_sock_dir = NULL;
152:
153: /* removes the agent forwarding socket */
154:
155: static void
1.165 markus 156: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 157: {
158: if (auth_sock_name != NULL) {
159: temporarily_use_uid(pw);
160: unlink(auth_sock_name);
161: rmdir(auth_sock_dir);
162: auth_sock_name = NULL;
163: restore_uid();
164: }
165: }
166:
167: static int
1.292 ! djm 168: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136 markus 169: {
170: Channel *nc;
1.237 djm 171: int sock = -1;
1.136 markus 172:
173: if (auth_sock_name != NULL) {
174: error("authentication forwarding requested twice.");
175: return 0;
176: }
177:
178: /* Temporarily drop privileged uid for mkdir/bind. */
179: temporarily_use_uid(pw);
180:
181: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 182: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 183:
184: /* Create private directory for socket */
185: if (mkdtemp(auth_sock_dir) == NULL) {
186: packet_send_debug("Agent forwarding disabled: "
187: "mkdtemp() failed: %.100s", strerror(errno));
188: restore_uid();
1.265 djm 189: free(auth_sock_dir);
1.136 markus 190: auth_sock_dir = NULL;
1.237 djm 191: goto authsock_err;
1.136 markus 192: }
1.237 djm 193:
194: xasprintf(&auth_sock_name, "%s/agent.%ld",
195: auth_sock_dir, (long) getpid());
1.136 markus 196:
1.274 millert 197: /* Start a Unix listener on auth_sock_name. */
198: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136 markus 199:
200: /* Restore the privileged uid. */
201: restore_uid();
202:
1.274 millert 203: /* Check for socket/bind/listen failure. */
204: if (sock < 0)
1.237 djm 205: goto authsock_err;
1.136 markus 206:
207: /* Allocate a channel for the authentication agent socket. */
1.292 ! djm 208: nc = channel_new(ssh, "auth socket",
1.136 markus 209: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
210: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 211: 0, "auth socket", 1);
1.245 djm 212: nc->path = xstrdup(auth_sock_name);
1.136 markus 213: return 1;
1.237 djm 214:
215: authsock_err:
1.265 djm 216: free(auth_sock_name);
1.237 djm 217: if (auth_sock_dir != NULL) {
218: rmdir(auth_sock_dir);
1.265 djm 219: free(auth_sock_dir);
1.237 djm 220: }
221: if (sock != -1)
222: close(sock);
223: auth_sock_name = NULL;
224: auth_sock_dir = NULL;
225: return 0;
1.136 markus 226: }
227:
1.179 dtucker 228: static void
229: display_loginmsg(void)
230: {
1.183 djm 231: if (buffer_len(&loginmsg) > 0) {
232: buffer_append(&loginmsg, "\0", 1);
233: printf("%s", (char *)buffer_ptr(&loginmsg));
234: buffer_clear(&loginmsg);
235: }
1.179 dtucker 236: }
1.136 markus 237:
1.290 djm 238: static void
239: prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
240: {
241: int fd = -1, success = 0;
242:
243: if (!options.expose_userauth_info || info == NULL)
244: return;
245:
246: temporarily_use_uid(pw);
247: auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
248: if ((fd = mkstemp(auth_info_file)) == -1) {
249: error("%s: mkstemp: %s", __func__, strerror(errno));
250: goto out;
251: }
252: if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
253: sshbuf_len(info)) != sshbuf_len(info)) {
254: error("%s: write: %s", __func__, strerror(errno));
255: goto out;
256: }
257: if (close(fd) != 0) {
258: error("%s: close: %s", __func__, strerror(errno));
259: goto out;
260: }
261: success = 1;
262: out:
263: if (!success) {
264: if (fd != -1)
265: close(fd);
266: free(auth_info_file);
267: auth_info_file = NULL;
268: }
269: restore_uid();
270: }
271:
1.65 markus 272: void
1.292 ! djm 273: do_authenticated(struct ssh *ssh, Authctxt *authctxt)
1.65 markus 274: {
1.153 markus 275: setproctitle("%s", authctxt->pw->pw_name);
276:
1.65 markus 277: /* setup the channel layer */
1.274 millert 278: /* XXX - streamlocal? */
1.286 djm 279: if (no_port_forwarding_flag || options.disable_forwarding ||
1.261 djm 280: (options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
1.292 ! djm 281: channel_disable_adm_local_opens(ssh);
1.261 djm 282: else
1.292 ! djm 283: channel_permit_all_opens(ssh);
1.252 dtucker 284:
285: auth_debug_send();
1.65 markus 286:
1.290 djm 287: prepare_auth_info_file(authctxt->pw, authctxt->session_info);
288:
1.292 ! djm 289: do_authenticated2(ssh, authctxt);
1.290 djm 290:
1.292 ! djm 291: do_cleanup(ssh, authctxt);
1.65 markus 292: }
293:
1.282 djm 294: /* Check untrusted xauth strings for metacharacters */
295: static int
296: xauth_valid_string(const char *s)
297: {
298: size_t i;
299:
300: for (i = 0; s[i] != '\0'; i++) {
301: if (!isalnum((u_char)s[i]) &&
302: s[i] != '.' && s[i] != ':' && s[i] != '/' &&
303: s[i] != '-' && s[i] != '_')
304: return 0;
305: }
306: return 1;
307: }
308:
1.269 dtucker 309: #define USE_PIPES 1
1.1 markus 310: /*
311: * This is called to fork and execute a command when we have no tty. This
312: * will call do_child from the child, and server_loop from the parent after
313: * setting up file descriptors and such.
314: */
1.237 djm 315: int
1.292 ! djm 316: do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 317: {
1.137 mpech 318: pid_t pid;
1.238 markus 319: #ifdef USE_PIPES
320: int pin[2], pout[2], perr[2];
321:
1.253 djm 322: if (s == NULL)
323: fatal("do_exec_no_pty: no session");
324:
1.238 markus 325: /* Allocate pipes for communicating with the program. */
326: if (pipe(pin) < 0) {
327: error("%s: pipe in: %.100s", __func__, strerror(errno));
328: return -1;
329: }
330: if (pipe(pout) < 0) {
331: error("%s: pipe out: %.100s", __func__, strerror(errno));
332: close(pin[0]);
333: close(pin[1]);
334: return -1;
335: }
1.256 djm 336: if (pipe(perr) < 0) {
337: error("%s: pipe err: %.100s", __func__,
338: strerror(errno));
339: close(pin[0]);
340: close(pin[1]);
341: close(pout[0]);
342: close(pout[1]);
343: return -1;
1.238 markus 344: }
345: #else
1.237 djm 346: int inout[2], err[2];
1.1 markus 347:
1.253 djm 348: if (s == NULL)
349: fatal("do_exec_no_pty: no session");
350:
1.1 markus 351: /* Uses socket pairs to communicate with the program. */
1.237 djm 352: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
353: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
354: return -1;
355: }
1.256 djm 356: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
357: error("%s: socketpair #2: %.100s", __func__,
358: strerror(errno));
359: close(inout[0]);
360: close(inout[1]);
361: return -1;
1.237 djm 362: }
1.238 markus 363: #endif
1.237 djm 364:
1.9 markus 365: session_proctitle(s);
1.1 markus 366:
367: /* Fork the child. */
1.237 djm 368: switch ((pid = fork())) {
369: case -1:
370: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 markus 371: #ifdef USE_PIPES
372: close(pin[0]);
373: close(pin[1]);
374: close(pout[0]);
375: close(pout[1]);
1.256 djm 376: close(perr[0]);
1.238 markus 377: close(perr[1]);
378: #else
1.237 djm 379: close(inout[0]);
380: close(inout[1]);
381: close(err[0]);
1.256 djm 382: close(err[1]);
1.238 markus 383: #endif
1.237 djm 384: return -1;
385: case 0:
1.165 markus 386: is_child = 1;
1.144 markus 387:
1.1 markus 388: /*
389: * Create a new session and process group since the 4.4BSD
390: * setlogin() affects the entire process group.
391: */
392: if (setsid() < 0)
393: error("setsid failed: %.100s", strerror(errno));
394:
1.238 markus 395: #ifdef USE_PIPES
396: /*
397: * Redirect stdin. We close the parent side of the socket
398: * pair, and make the child side the standard input.
399: */
400: close(pin[1]);
401: if (dup2(pin[0], 0) < 0)
402: perror("dup2 stdin");
403: close(pin[0]);
404:
405: /* Redirect stdout. */
406: close(pout[0]);
407: if (dup2(pout[1], 1) < 0)
408: perror("dup2 stdout");
409: close(pout[1]);
410:
411: /* Redirect stderr. */
1.256 djm 412: close(perr[0]);
1.238 markus 413: if (dup2(perr[1], 2) < 0)
414: perror("dup2 stderr");
415: close(perr[1]);
416: #else
1.1 markus 417: /*
418: * Redirect stdin, stdout, and stderr. Stdin and stdout will
419: * use the same socket, as some programs (particularly rdist)
420: * seem to depend on it.
421: */
422: close(inout[1]);
1.256 djm 423: close(err[1]);
1.1 markus 424: if (dup2(inout[0], 0) < 0) /* stdin */
425: perror("dup2 stdin");
1.237 djm 426: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 427: perror("dup2 stdout");
1.238 markus 428: close(inout[0]);
1.1 markus 429: if (dup2(err[0], 2) < 0) /* stderr */
430: perror("dup2 stderr");
1.238 markus 431: close(err[0]);
432: #endif
1.1 markus 433:
434: /* Do processing for the child (exec command etc). */
1.292 ! djm 435: do_child(ssh, s, command);
1.1 markus 436: /* NOTREACHED */
1.237 djm 437: default:
438: break;
1.1 markus 439: }
1.237 djm 440:
1.1 markus 441: s->pid = pid;
1.47 markus 442: /* Set interactive/non-interactive mode. */
1.257 djm 443: packet_set_interactive(s->display != NULL,
444: options.ip_qos_interactive, options.ip_qos_bulk);
1.1 markus 445:
1.238 markus 446: #ifdef USE_PIPES
447: /* We are the parent. Close the child sides of the pipes. */
448: close(pin[0]);
449: close(pout[1]);
450: close(perr[1]);
451:
1.292 ! djm 452: session_set_fds(ssh, s, pin[1], pout[0], perr[0],
1.283 markus 453: s->is_subsystem, 0);
1.238 markus 454: #else
1.1 markus 455: /* We are the parent. Close the child sides of the socket pairs. */
456: close(inout[0]);
457: close(err[0]);
458:
459: /*
460: * Enter the interactive session. Note: server_loop must be able to
461: * handle the case that fdin and fdout are the same.
462: */
1.283 markus 463: session_set_fds(s, inout[1], inout[1], err[1],
464: s->is_subsystem, 0);
1.238 markus 465: #endif
1.237 djm 466: return 0;
1.1 markus 467: }
468:
469: /*
470: * This is called to fork and execute a command when we have a tty. This
471: * will call do_child from the child, and server_loop from the parent after
472: * setting up file descriptors, controlling tty, updating wtmp, utmp,
473: * lastlog, and other such operations.
474: */
1.237 djm 475: int
1.292 ! djm 476: do_exec_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 477: {
478: int fdout, ptyfd, ttyfd, ptymaster;
479: pid_t pid;
480:
481: if (s == NULL)
482: fatal("do_exec_pty: no session");
483: ptyfd = s->ptyfd;
484: ttyfd = s->ttyfd;
485:
1.237 djm 486: /*
487: * Create another descriptor of the pty master side for use as the
488: * standard input. We could use the original descriptor, but this
489: * simplifies code in server_loop. The descriptor is bidirectional.
490: * Do this before forking (and cleanup in the child) so as to
491: * detect and gracefully fail out-of-fd conditions.
492: */
493: if ((fdout = dup(ptyfd)) < 0) {
494: error("%s: dup #1: %s", __func__, strerror(errno));
495: close(ttyfd);
496: close(ptyfd);
497: return -1;
498: }
499: /* we keep a reference to the pty master */
500: if ((ptymaster = dup(ptyfd)) < 0) {
501: error("%s: dup #2: %s", __func__, strerror(errno));
502: close(ttyfd);
503: close(ptyfd);
504: close(fdout);
505: return -1;
506: }
507:
1.1 markus 508: /* Fork the child. */
1.237 djm 509: switch ((pid = fork())) {
510: case -1:
511: error("%s: fork: %.100s", __func__, strerror(errno));
512: close(fdout);
513: close(ptymaster);
514: close(ttyfd);
515: close(ptyfd);
516: return -1;
517: case 0:
1.165 markus 518: is_child = 1;
1.97 markus 519:
1.237 djm 520: close(fdout);
521: close(ptymaster);
522:
1.1 markus 523: /* Close the master side of the pseudo tty. */
524: close(ptyfd);
525:
526: /* Make the pseudo tty our controlling tty. */
527: pty_make_controlling_tty(&ttyfd, s->tty);
528:
1.103 markus 529: /* Redirect stdin/stdout/stderr from the pseudo tty. */
530: if (dup2(ttyfd, 0) < 0)
531: error("dup2 stdin: %s", strerror(errno));
532: if (dup2(ttyfd, 1) < 0)
533: error("dup2 stdout: %s", strerror(errno));
534: if (dup2(ttyfd, 2) < 0)
535: error("dup2 stderr: %s", strerror(errno));
1.1 markus 536:
537: /* Close the extra descriptor for the pseudo tty. */
538: close(ttyfd);
539:
1.24 markus 540: /* record login, etc. similar to login(1) */
1.292 ! djm 541: do_login(ssh, s, command);
1.228 djm 542:
1.237 djm 543: /*
544: * Do common processing for the child, such as execing
545: * the command.
546: */
1.292 ! djm 547: do_child(ssh, s, command);
1.1 markus 548: /* NOTREACHED */
1.237 djm 549: default:
550: break;
1.1 markus 551: }
552: s->pid = pid;
553:
554: /* Parent. Close the slave side of the pseudo tty. */
555: close(ttyfd);
556:
1.237 djm 557: /* Enter interactive session. */
1.1 markus 558: s->ptymaster = ptymaster;
1.257 djm 559: packet_set_interactive(1,
560: options.ip_qos_interactive, options.ip_qos_bulk);
1.292 ! djm 561: session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
1.237 djm 562: return 0;
1.24 markus 563: }
564:
1.90 markus 565: /*
566: * This is called to fork and execute a command. If another command is
567: * to be forced, execute that instead.
568: */
1.237 djm 569: int
1.292 ! djm 570: do_exec(struct ssh *ssh, Session *s, const char *command)
1.90 markus 571: {
1.237 djm 572: int ret;
1.280 djm 573: const char *forced = NULL, *tty = NULL;
574: char session_type[1024];
1.237 djm 575:
1.210 dtucker 576: if (options.adm_forced_command) {
577: original_command = command;
578: command = options.adm_forced_command;
1.267 djm 579: forced = "(config)";
1.210 dtucker 580: } else if (forced_command) {
1.90 markus 581: original_command = command;
582: command = forced_command;
1.267 djm 583: forced = "(key-option)";
584: }
585: if (forced != NULL) {
1.248 djm 586: if (IS_INTERNAL_SFTP(command)) {
587: s->is_subsystem = s->is_subsystem ?
588: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
589: } else if (s->is_subsystem)
1.225 markus 590: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 591: snprintf(session_type, sizeof(session_type),
592: "forced-command %s '%.900s'", forced, command);
593: } else if (s->is_subsystem) {
594: snprintf(session_type, sizeof(session_type),
595: "subsystem '%.900s'", s->subsys);
596: } else if (command == NULL) {
597: snprintf(session_type, sizeof(session_type), "shell");
598: } else {
599: /* NB. we don't log unforced commands to preserve privacy */
600: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 601: }
1.163 markus 602:
1.267 djm 603: if (s->ttyfd != -1) {
604: tty = s->tty;
605: if (strncmp(tty, "/dev/", 5) == 0)
606: tty += 5;
607: }
608:
1.280 djm 609: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 610: session_type,
611: tty == NULL ? "" : " on ",
612: tty == NULL ? "" : tty,
613: s->pw->pw_name,
1.281 djm 614: ssh_remote_ipaddr(ssh),
615: ssh_remote_port(ssh),
1.280 djm 616: s->self);
1.267 djm 617:
1.163 markus 618: #ifdef GSSAPI
619: if (options.gss_authentication) {
620: temporarily_use_uid(s->pw);
621: ssh_gssapi_storecreds();
622: restore_uid();
623: }
624: #endif
1.90 markus 625: if (s->ttyfd != -1)
1.292 ! djm 626: ret = do_exec_pty(ssh, s, command);
1.90 markus 627: else
1.292 ! djm 628: ret = do_exec_no_pty(ssh, s, command);
1.90 markus 629:
1.92 markus 630: original_command = NULL;
1.179 dtucker 631:
632: /*
633: * Clear loginmsg: it's the child's responsibility to display
634: * it to the user, otherwise multiple sessions may accumulate
635: * multiple copies of the login messages.
636: */
637: buffer_clear(&loginmsg);
1.237 djm 638:
639: return ret;
1.90 markus 640: }
641:
642:
1.24 markus 643: /* administrative, login(1)-like work */
644: void
1.292 ! djm 645: do_login(struct ssh *ssh, Session *s, const char *command)
1.24 markus 646: {
647: socklen_t fromlen;
648: struct sockaddr_storage from;
649: struct passwd * pw = s->pw;
650: pid_t pid = getpid();
651:
652: /*
653: * Get IP address of client. If the connection is not a socket, let
654: * the address be 0.0.0.0.
655: */
656: memset(&from, 0, sizeof(from));
1.148 stevesk 657: fromlen = sizeof(from);
1.24 markus 658: if (packet_connection_is_on_socket()) {
659: if (getpeername(packet_get_connection_in(),
1.200 deraadt 660: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 661: debug("getpeername: %.100s", strerror(errno));
1.165 markus 662: cleanup_exit(255);
1.24 markus 663: }
664: }
1.25 markus 665:
1.24 markus 666: /* Record that there was a login on that tty from the remote host. */
1.133 markus 667: if (!use_privsep)
668: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 669: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 670: options.use_dns),
1.148 stevesk 671: (struct sockaddr *)&from, fromlen);
1.24 markus 672:
1.73 djm 673: if (check_quietlogin(s, command))
1.24 markus 674: return;
1.73 djm 675:
1.179 dtucker 676: display_loginmsg();
1.73 djm 677:
678: do_motd();
679: }
680:
681: /*
682: * Display the message of the day.
683: */
684: void
685: do_motd(void)
686: {
687: FILE *f;
688: char buf[256];
689:
1.24 markus 690: if (options.print_motd) {
1.28 millert 691: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
692: "/etc/motd"), "r");
1.24 markus 693: if (f) {
694: while (fgets(buf, sizeof(buf), f))
695: fputs(buf, stdout);
696: fclose(f);
697: }
1.2 markus 698: }
1.73 djm 699: }
700:
701:
702: /*
703: * Check for quiet login, either .hushlogin or command given.
704: */
705: int
706: check_quietlogin(Session *s, const char *command)
707: {
708: char buf[256];
1.96 dugsong 709: struct passwd *pw = s->pw;
1.73 djm 710: struct stat st;
711:
712: /* Return 1 if .hushlogin exists or a command given. */
713: if (command != NULL)
714: return 1;
715: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
716: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
717: return 1;
718: return 0;
1.1 markus 719: }
720:
721: /*
722: * Reads environment variables from the given file and adds/overrides them
723: * into the environment. If the file does not exist, this does nothing.
724: * Otherwise, it must consist of empty lines, comments (line starts with '#')
725: * and assignments of the form name=value. No other forms are allowed.
726: */
1.94 itojun 727: static void
1.45 markus 728: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 729: const char *filename)
1.1 markus 730: {
731: FILE *f;
732: char buf[4096];
733: char *cp, *value;
1.142 deraadt 734: u_int lineno = 0;
1.1 markus 735:
736: f = fopen(filename, "r");
737: if (!f)
738: return;
739:
740: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 741: if (++lineno > 1000)
742: fatal("Too many lines in environment file %s", filename);
1.1 markus 743: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
744: ;
745: if (!*cp || *cp == '#' || *cp == '\n')
746: continue;
1.224 gilles 747:
748: cp[strcspn(cp, "\n")] = '\0';
749:
1.1 markus 750: value = strchr(cp, '=');
751: if (value == NULL) {
1.142 deraadt 752: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
753: filename);
1.1 markus 754: continue;
755: }
1.14 deraadt 756: /*
757: * Replace the equals sign by nul, and advance value to
758: * the value string.
759: */
1.1 markus 760: *value = '\0';
761: value++;
762: child_set_env(env, envsize, cp, value);
763: }
764: fclose(f);
765: }
766:
1.127 markus 767: static char **
1.292 ! djm 768: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1 markus 769: {
770: char buf[256];
1.127 markus 771: u_int i, envsize;
1.154 markus 772: char **env, *laddr;
1.127 markus 773: struct passwd *pw = s->pw;
1.1 markus 774:
775: /* Initialize the environment. */
776: envsize = 100;
1.220 djm 777: env = xcalloc(envsize, sizeof(char *));
1.1 markus 778: env[0] = NULL;
779:
1.161 markus 780: #ifdef GSSAPI
1.168 djm 781: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 782: * the childs environment as they see fit
783: */
784: ssh_gssapi_do_child(&env, &envsize);
785: #endif
786:
1.284 djm 787: /* Set basic environment. */
788: for (i = 0; i < s->num_env; i++)
789: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
790:
791: child_set_env(&env, &envsize, "USER", pw->pw_name);
792: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
793: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
794: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
795: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
796: else
797: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
798:
799: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
800: child_set_env(&env, &envsize, "MAIL", buf);
801:
802: /* Normal systems set SHELL by default. */
803: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 804:
805: if (getenv("TZ"))
806: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
807:
808: /* Set custom environment options from RSA authentication. */
1.284 djm 809: while (custom_environment) {
810: struct envstring *ce = custom_environment;
811: char *str = ce->s;
812:
813: for (i = 0; str[i] != '=' && str[i]; i++)
814: ;
815: if (str[i] == '=') {
816: str[i] = 0;
817: child_set_env(&env, &envsize, str, str + i + 1);
818: }
819: custom_environment = ce->next;
820: free(ce->s);
821: free(ce);
1.1 markus 822: }
823:
1.149 stevesk 824: /* SSH_CLIENT deprecated */
1.1 markus 825: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 826: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
827: ssh_local_port(ssh));
1.1 markus 828: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 829:
1.154 markus 830: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 831: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 832: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
833: laddr, ssh_local_port(ssh));
1.265 djm 834: free(laddr);
1.149 stevesk 835: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 836:
1.290 djm 837: if (auth_info_file != NULL)
838: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 839: if (s->ttyfd != -1)
840: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
841: if (s->term)
842: child_set_env(&env, &envsize, "TERM", s->term);
843: if (s->display)
844: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 845: if (original_command)
846: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
847: original_command);
1.96 dugsong 848: #ifdef KRB5
849: if (s->authctxt->krb5_ticket_file)
850: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 851: s->authctxt->krb5_ticket_file);
1.96 dugsong 852: #endif
1.136 markus 853: if (auth_sock_name != NULL)
1.1 markus 854: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 855: auth_sock_name);
1.1 markus 856:
857: /* read $HOME/.ssh/environment. */
1.284 djm 858: if (options.permit_user_env) {
1.14 deraadt 859: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
860: pw->pw_dir);
1.1 markus 861: read_environment_file(&env, &envsize, buf);
862: }
863: if (debug_flag) {
864: /* dump the environment */
865: fprintf(stderr, "Environment:\n");
866: for (i = 0; env[i]; i++)
867: fprintf(stderr, " %.200s\n", env[i]);
868: }
1.127 markus 869: return env;
870: }
871:
872: /*
873: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
874: * first in this order).
875: */
876: static void
877: do_rc_files(Session *s, const char *shell)
878: {
879: FILE *f = NULL;
880: char cmd[1024];
881: int do_xauth;
882: struct stat st;
883:
884: do_xauth =
885: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
886:
1.231 djm 887: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 888: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.273 djm 889: !no_user_rc && options.permit_user_rc &&
890: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 891: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
892: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
893: if (debug_flag)
894: fprintf(stderr, "Running %s\n", cmd);
895: f = popen(cmd, "w");
896: if (f) {
897: if (do_xauth)
898: fprintf(f, "%s %s\n", s->auth_proto,
899: s->auth_data);
900: pclose(f);
901: } else
902: fprintf(stderr, "Could not run %s\n",
903: _PATH_SSH_USER_RC);
904: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
905: if (debug_flag)
906: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
907: _PATH_SSH_SYSTEM_RC);
908: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
909: if (f) {
910: if (do_xauth)
911: fprintf(f, "%s %s\n", s->auth_proto,
912: s->auth_data);
913: pclose(f);
914: } else
915: fprintf(stderr, "Could not run %s\n",
916: _PATH_SSH_SYSTEM_RC);
917: } else if (do_xauth && options.xauth_location != NULL) {
918: /* Add authority data to .Xauthority if appropriate. */
919: if (debug_flag) {
920: fprintf(stderr,
1.151 stevesk 921: "Running %.500s remove %.100s\n",
1.165 markus 922: options.xauth_location, s->auth_display);
1.151 stevesk 923: fprintf(stderr,
924: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 925: options.xauth_location, s->auth_display,
926: s->auth_proto, s->auth_data);
927: }
928: snprintf(cmd, sizeof cmd, "%s -q -",
929: options.xauth_location);
930: f = popen(cmd, "w");
931: if (f) {
1.151 stevesk 932: fprintf(f, "remove %s\n",
933: s->auth_display);
1.127 markus 934: fprintf(f, "add %s %s %s\n",
935: s->auth_display, s->auth_proto,
936: s->auth_data);
937: pclose(f);
938: } else {
939: fprintf(stderr, "Could not run %s\n",
940: cmd);
941: }
942: }
943: }
944:
945: static void
946: do_nologin(struct passwd *pw)
947: {
948: FILE *f = NULL;
1.251 dtucker 949: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
950: struct stat sb;
1.127 markus 951:
1.260 guenther 952: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 953: return;
954: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
955:
956: if (stat(nl, &sb) == -1) {
957: if (nl != def_nl)
1.265 djm 958: free(nl);
1.251 dtucker 959: return;
960: }
961:
962: /* /etc/nologin exists. Print its contents if we can and exit. */
963: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
964: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 965: while (fgets(buf, sizeof(buf), f))
966: fputs(buf, stderr);
967: fclose(f);
968: }
1.251 dtucker 969: exit(254);
1.127 markus 970: }
971:
1.226 djm 972: /*
973: * Chroot into a directory after checking it for safety: all path components
974: * must be root-owned directories with strict permissions.
975: */
976: static void
977: safely_chroot(const char *path, uid_t uid)
978: {
979: const char *cp;
1.277 deraadt 980: char component[PATH_MAX];
1.226 djm 981: struct stat st;
982:
983: if (*path != '/')
984: fatal("chroot path does not begin at root");
985: if (strlen(path) >= sizeof(component))
986: fatal("chroot path too long");
987:
988: /*
989: * Descend the path, checking that each component is a
990: * root-owned directory with strict permissions.
991: */
992: for (cp = path; cp != NULL;) {
993: if ((cp = strchr(cp, '/')) == NULL)
994: strlcpy(component, path, sizeof(component));
995: else {
996: cp++;
997: memcpy(component, path, cp - path);
998: component[cp - path] = '\0';
999: }
1000:
1001: debug3("%s: checking '%s'", __func__, component);
1002:
1003: if (stat(component, &st) != 0)
1004: fatal("%s: stat(\"%s\"): %s", __func__,
1005: component, strerror(errno));
1006: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1007: fatal("bad ownership or modes for chroot "
1008: "directory %s\"%s\"",
1009: cp == NULL ? "" : "component ", component);
1010: if (!S_ISDIR(st.st_mode))
1011: fatal("chroot path %s\"%s\" is not a directory",
1012: cp == NULL ? "" : "component ", component);
1013:
1014: }
1015:
1016: if (chdir(path) == -1)
1017: fatal("Unable to chdir to chroot path \"%s\": "
1018: "%s", path, strerror(errno));
1019: if (chroot(path) == -1)
1020: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1021: if (chdir("/") == -1)
1022: fatal("%s: chdir(/) after chroot: %s",
1023: __func__, strerror(errno));
1024: verbose("Changed root directory to \"%s\"", path);
1025: }
1026:
1.127 markus 1027: /* Set login name, uid, gid, and groups. */
1.130 provos 1028: void
1.127 markus 1029: do_setusercontext(struct passwd *pw)
1030: {
1.227 djm 1031: char *chroot_path, *tmp;
1032:
1.127 markus 1033: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1034: /* Prepare groups */
1.127 markus 1035: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1036: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1037: perror("unable to set user context");
1038: exit(1);
1039: }
1.226 djm 1040:
1.279 djm 1041: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1042: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1043: tmp = tilde_expand_filename(options.chroot_directory,
1044: pw->pw_uid);
1045: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1046: "u", pw->pw_name, (char *)NULL);
1.226 djm 1047: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1048: free(tmp);
1.226 djm 1049: free(chroot_path);
1.264 djm 1050: /* Make sure we don't attempt to chroot again */
1051: free(options.chroot_directory);
1052: options.chroot_directory = NULL;
1.279 djm 1053: in_chroot = 1;
1.226 djm 1054: }
1055:
1056: /* Set UID */
1057: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1058: perror("unable to set user context (setuser)");
1059: exit(1);
1060: }
1.264 djm 1061: } else if (options.chroot_directory != NULL &&
1062: strcasecmp(options.chroot_directory, "none") != 0) {
1063: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1064: }
1.264 djm 1065:
1.127 markus 1066: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1067: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1068: }
1069:
1.131 markus 1070: static void
1.172 markus 1071: do_pwchange(Session *s)
1072: {
1.179 dtucker 1073: fflush(NULL);
1.172 markus 1074: fprintf(stderr, "WARNING: Your password has expired.\n");
1075: if (s->ttyfd != -1) {
1.178 deraadt 1076: fprintf(stderr,
1.172 markus 1077: "You must change your password now and login again!\n");
1078: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1079: perror("passwd");
1080: } else {
1081: fprintf(stderr,
1082: "Password change required but no TTY available.\n");
1083: }
1084: exit(1);
1085: }
1086:
1087: static void
1.292 ! djm 1088: child_close_fds(struct ssh *ssh)
1.172 markus 1089: {
1.276 djm 1090: extern int auth_sock;
1.266 markus 1091:
1.276 djm 1092: if (auth_sock != -1) {
1093: close(auth_sock);
1094: auth_sock = -1;
1.266 markus 1095: }
1096:
1.172 markus 1097: if (packet_get_connection_in() == packet_get_connection_out())
1098: close(packet_get_connection_in());
1099: else {
1100: close(packet_get_connection_in());
1101: close(packet_get_connection_out());
1102: }
1103: /*
1104: * Close all descriptors related to channels. They will still remain
1105: * open in the parent.
1106: */
1107: /* XXX better use close-on-exec? -markus */
1.292 ! djm 1108: channel_close_all(ssh);
1.172 markus 1109:
1110: /*
1111: * Close any extra file descriptors. Note that there may still be
1112: * descriptors left by system functions. They will be closed later.
1113: */
1114: endpwent();
1115:
1116: /*
1.188 djm 1117: * Close any extra open file descriptors so that we don't have them
1.172 markus 1118: * hanging around in clients. Note that we want to do this after
1119: * initgroups, because at least on Solaris 2.3 it leaves file
1120: * descriptors open.
1121: */
1.258 djm 1122: closefrom(STDERR_FILENO + 1);
1.172 markus 1123: }
1124:
1.127 markus 1125: /*
1126: * Performs common processing for the child, such as setting up the
1127: * environment, closing extra file descriptors, setting the user and group
1128: * ids, and executing the command or shell.
1129: */
1.225 markus 1130: #define ARGV_MAX 10
1.127 markus 1131: void
1.292 ! djm 1132: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1133: {
1134: extern char **environ;
1135: char **env;
1.225 markus 1136: char *argv[ARGV_MAX];
1.284 djm 1137: const char *shell, *shell0;
1.127 markus 1138: struct passwd *pw = s->pw;
1.239 djm 1139: int r = 0;
1.127 markus 1140:
1141: /* remove hostkey from the child's memory */
1142: destroy_sensitive_data();
1.287 markus 1143: packet_clear_keys();
1.127 markus 1144:
1.172 markus 1145: /* Force a password change */
1146: if (s->authctxt->force_pwchange) {
1147: do_setusercontext(pw);
1.292 ! djm 1148: child_close_fds(ssh);
1.172 markus 1149: do_pwchange(s);
1150: exit(1);
1151: }
1152:
1.127 markus 1153: /*
1154: * Login(1) does this as well, and it needs uid 0 for the "-h"
1155: * switch, so we let login(1) to this for us.
1156: */
1.284 djm 1157: do_nologin(pw);
1158: do_setusercontext(pw);
1.127 markus 1159:
1160: /*
1161: * Get the shell from the password data. An empty shell field is
1162: * legal, and means /bin/sh.
1163: */
1164: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1165:
1166: /*
1167: * Make sure $SHELL points to the shell from the password file,
1168: * even if shell is overridden from login.conf
1169: */
1.292 ! djm 1170: env = do_setup_env(ssh, s, shell);
1.152 markus 1171:
1.127 markus 1172: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1173:
1.1 markus 1174: /*
1175: * Close the connection descriptors; note that this is the child, and
1176: * the server will still have the socket open, and it is important
1177: * that we do not shutdown it. Note that the descriptors cannot be
1178: * closed before building the environment, as we call
1.281 djm 1179: * ssh_remote_ipaddr there.
1.1 markus 1180: */
1.292 ! djm 1181: child_close_fds(ssh);
1.1 markus 1182:
1183: /*
1.125 deraadt 1184: * Must take new environment into use so that .ssh/rc,
1185: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1186: */
1187: environ = env;
1.170 jakob 1188:
1189: #ifdef KRB5
1190: /*
1191: * At this point, we check to see if AFS is active and if we have
1192: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1193: * if we can (and need to) extend the ticket into an AFS token. If
1194: * we don't do this, we run into potential problems if the user's
1195: * home directory is in AFS and it's not world-readable.
1196: */
1197:
1198: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1199: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1200: char cell[64];
1201:
1202: debug("Getting AFS token");
1203:
1204: k_setpag();
1205:
1206: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1207: krb5_afslog(s->authctxt->krb5_ctx,
1208: s->authctxt->krb5_fwd_ccache, cell, NULL);
1209:
1210: krb5_afslog_home(s->authctxt->krb5_ctx,
1211: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1212: }
1213: #endif
1.104 markus 1214:
1.188 djm 1215: /* Change current directory to the user's home directory. */
1.104 markus 1216: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1217: /* Suppress missing homedir warning for chroot case */
1218: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1219: if (r || !in_chroot) {
1.239 djm 1220: fprintf(stderr, "Could not chdir to home "
1221: "directory %s: %s\n", pw->pw_dir,
1222: strerror(errno));
1.279 djm 1223: }
1.239 djm 1224: if (r)
1.104 markus 1225: exit(1);
1226: }
1.230 djm 1227:
1228: closefrom(STDERR_FILENO + 1);
1.1 markus 1229:
1.284 djm 1230: do_rc_files(s, shell);
1.67 markus 1231:
1232: /* restore SIGPIPE for child */
1.217 stevesk 1233: signal(SIGPIPE, SIG_DFL);
1.67 markus 1234:
1.248 djm 1235: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1236: printf("This service allows sftp connections only.\n");
1237: fflush(NULL);
1238: exit(1);
1239: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1240: extern int optind, optreset;
1241: int i;
1242: char *p, *args;
1243:
1.246 stevesk 1244: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1245: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1246: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1247: if (i < ARGV_MAX - 1)
1248: argv[i++] = p;
1249: argv[i] = NULL;
1250: optind = optreset = 1;
1251: __progname = argv[0];
1.226 djm 1252: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1253: }
1.247 djm 1254:
1255: fflush(NULL);
1.225 markus 1256:
1.127 markus 1257: /* Get the last component of the shell name. */
1258: if ((shell0 = strrchr(shell, '/')) != NULL)
1259: shell0++;
1260: else
1261: shell0 = shell;
1262:
1.1 markus 1263: /*
1264: * If we have no command, execute the shell. In this case, the shell
1265: * name to be passed in argv[0] is preceded by '-' to indicate that
1266: * this is a login shell.
1267: */
1268: if (!command) {
1.127 markus 1269: char argv0[256];
1.1 markus 1270:
1.127 markus 1271: /* Start the shell. Set initial character to '-'. */
1272: argv0[0] = '-';
1.1 markus 1273:
1.127 markus 1274: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1275: >= sizeof(argv0) - 1) {
1.127 markus 1276: errno = EINVAL;
1.1 markus 1277: perror(shell);
1278: exit(1);
1.127 markus 1279: }
1.1 markus 1280:
1.127 markus 1281: /* Execute the shell. */
1282: argv[0] = argv0;
1283: argv[1] = NULL;
1284: execve(shell, argv, env);
1285:
1286: /* Executing the shell failed. */
1287: perror(shell);
1288: exit(1);
1.1 markus 1289: }
1290: /*
1291: * Execute the command using the user's shell. This uses the -c
1292: * option to execute the command.
1293: */
1.127 markus 1294: argv[0] = (char *) shell0;
1.1 markus 1295: argv[1] = "-c";
1296: argv[2] = (char *) command;
1297: argv[3] = NULL;
1298: execve(shell, argv, env);
1299: perror(shell);
1300: exit(1);
1301: }
1302:
1.237 djm 1303: void
1304: session_unused(int id)
1305: {
1306: debug3("%s: session id %d unused", __func__, id);
1307: if (id >= options.max_sessions ||
1308: id >= sessions_nalloc) {
1309: fatal("%s: insane session id %d (max %d nalloc %d)",
1310: __func__, id, options.max_sessions, sessions_nalloc);
1311: }
1.270 tedu 1312: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1313: sessions[id].self = id;
1314: sessions[id].used = 0;
1315: sessions[id].chanid = -1;
1316: sessions[id].ptyfd = -1;
1317: sessions[id].ttyfd = -1;
1318: sessions[id].ptymaster = -1;
1319: sessions[id].x11_chanids = NULL;
1320: sessions[id].next_unused = sessions_first_unused;
1321: sessions_first_unused = id;
1322: }
1323:
1.1 markus 1324: Session *
1325: session_new(void)
1326: {
1.237 djm 1327: Session *s, *tmp;
1328:
1329: if (sessions_first_unused == -1) {
1330: if (sessions_nalloc >= options.max_sessions)
1331: return NULL;
1332: debug2("%s: allocate (allocated %d max %d)",
1333: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1334: tmp = xrecallocarray(sessions, sessions_nalloc,
1335: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1336: if (tmp == NULL) {
1337: error("%s: cannot allocate %d sessions",
1338: __func__, sessions_nalloc + 1);
1339: return NULL;
1340: }
1341: sessions = tmp;
1342: session_unused(sessions_nalloc++);
1343: }
1344:
1345: if (sessions_first_unused >= sessions_nalloc ||
1346: sessions_first_unused < 0) {
1347: fatal("%s: insane first_unused %d max %d nalloc %d",
1348: __func__, sessions_first_unused, options.max_sessions,
1349: sessions_nalloc);
1350: }
1351:
1352: s = &sessions[sessions_first_unused];
1353: if (s->used) {
1354: fatal("%s: session %d already used",
1355: __func__, sessions_first_unused);
1356: }
1357: sessions_first_unused = s->next_unused;
1358: s->used = 1;
1359: s->next_unused = -1;
1360: debug("session_new: session %d", s->self);
1361:
1362: return s;
1.1 markus 1363: }
1364:
1.94 itojun 1365: static void
1.1 markus 1366: session_dump(void)
1367: {
1368: int i;
1.237 djm 1369: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1370: Session *s = &sessions[i];
1.237 djm 1371:
1372: debug("dump: used %d next_unused %d session %d %p "
1373: "channel %d pid %ld",
1.1 markus 1374: s->used,
1.237 djm 1375: s->next_unused,
1.1 markus 1376: s->self,
1377: s,
1378: s->chanid,
1.137 mpech 1379: (long)s->pid);
1.1 markus 1380: }
1381: }
1382:
1.2 markus 1383: int
1.97 markus 1384: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1385: {
1386: Session *s = session_new();
1387: debug("session_open: channel %d", chanid);
1388: if (s == NULL) {
1389: error("no more sessions");
1390: return 0;
1391: }
1.97 markus 1392: s->authctxt = authctxt;
1393: s->pw = authctxt->pw;
1.167 djm 1394: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1395: fatal("no user for session %d", s->self);
1.2 markus 1396: debug("session_open: session %d: link with channel %d", s->self, chanid);
1397: s->chanid = chanid;
1398: return 1;
1399: }
1400:
1.130 provos 1401: Session *
1402: session_by_tty(char *tty)
1403: {
1404: int i;
1.237 djm 1405: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1406: Session *s = &sessions[i];
1407: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1408: debug("session_by_tty: session %d tty %s", i, tty);
1409: return s;
1410: }
1411: }
1412: debug("session_by_tty: unknown tty %.100s", tty);
1413: session_dump();
1414: return NULL;
1415: }
1416:
1.94 itojun 1417: static Session *
1.2 markus 1418: session_by_channel(int id)
1419: {
1420: int i;
1.237 djm 1421: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1422: Session *s = &sessions[i];
1423: if (s->used && s->chanid == id) {
1.237 djm 1424: debug("session_by_channel: session %d channel %d",
1425: i, id);
1.2 markus 1426: return s;
1427: }
1428: }
1429: debug("session_by_channel: unknown channel %d", id);
1430: session_dump();
1431: return NULL;
1432: }
1433:
1.94 itojun 1434: static Session *
1.184 djm 1435: session_by_x11_channel(int id)
1436: {
1437: int i, j;
1438:
1.237 djm 1439: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1440: Session *s = &sessions[i];
1441:
1442: if (s->x11_chanids == NULL || !s->used)
1443: continue;
1444: for (j = 0; s->x11_chanids[j] != -1; j++) {
1445: if (s->x11_chanids[j] == id) {
1446: debug("session_by_x11_channel: session %d "
1447: "channel %d", s->self, id);
1448: return s;
1449: }
1450: }
1451: }
1452: debug("session_by_x11_channel: unknown channel %d", id);
1453: session_dump();
1454: return NULL;
1455: }
1456:
1457: static Session *
1.2 markus 1458: session_by_pid(pid_t pid)
1459: {
1460: int i;
1.137 mpech 1461: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1462: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1463: Session *s = &sessions[i];
1464: if (s->used && s->pid == pid)
1465: return s;
1466: }
1.137 mpech 1467: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1468: session_dump();
1469: return NULL;
1470: }
1471:
1.94 itojun 1472: static int
1.292 ! djm 1473: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1474: {
1475: s->col = packet_get_int();
1476: s->row = packet_get_int();
1477: s->xpixel = packet_get_int();
1478: s->ypixel = packet_get_int();
1.116 markus 1479: packet_check_eom();
1.2 markus 1480: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1481: return 1;
1482: }
1483:
1.94 itojun 1484: static int
1.292 ! djm 1485: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1486: {
1.45 markus 1487: u_int len;
1.72 stevesk 1488: int n_bytes;
1.132 markus 1489:
1.268 djm 1490: if (no_pty_flag || !options.permit_tty) {
1.86 markus 1491: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1492: return 0;
1.86 markus 1493: }
1494: if (s->ttyfd != -1) {
1495: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1496: return 0;
1.86 markus 1497: }
1498:
1.2 markus 1499: s->term = packet_get_string(&len);
1.283 markus 1500: s->col = packet_get_int();
1501: s->row = packet_get_int();
1.2 markus 1502: s->xpixel = packet_get_int();
1503: s->ypixel = packet_get_int();
1504:
1505: if (strcmp(s->term, "") == 0) {
1.265 djm 1506: free(s->term);
1.2 markus 1507: s->term = NULL;
1508: }
1.86 markus 1509:
1.2 markus 1510: /* Allocate a pty and open it. */
1.86 markus 1511: debug("Allocating pty.");
1.237 djm 1512: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1513: sizeof(s->tty)))) {
1.265 djm 1514: free(s->term);
1.2 markus 1515: s->term = NULL;
1516: s->ptyfd = -1;
1517: s->ttyfd = -1;
1518: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1519: return 0;
1.2 markus 1520: }
1521: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1522:
1.283 markus 1523: n_bytes = packet_remaining();
1.86 markus 1524: tty_parse_modes(s->ttyfd, &n_bytes);
1525:
1.130 provos 1526: if (!use_privsep)
1527: pty_setowner(s->pw, s->tty);
1.86 markus 1528:
1529: /* Set window size from the packet. */
1.2 markus 1530: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1531:
1.116 markus 1532: packet_check_eom();
1.9 markus 1533: session_proctitle(s);
1.2 markus 1534: return 1;
1535: }
1536:
1.94 itojun 1537: static int
1.292 ! djm 1538: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1539: {
1.105 markus 1540: struct stat st;
1.45 markus 1541: u_int len;
1.7 markus 1542: int success = 0;
1.267 djm 1543: char *prog, *cmd;
1.182 djm 1544: u_int i;
1.7 markus 1545:
1.267 djm 1546: s->subsys = packet_get_string(&len);
1.116 markus 1547: packet_check_eom();
1.267 djm 1548: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1549: s->pw->pw_name);
1.18 jakob 1550:
1551: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1552: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1553: prog = options.subsystem_command[i];
1554: cmd = options.subsystem_args[i];
1.249 dtucker 1555: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1556: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1557: debug("subsystem: %s", prog);
1.225 markus 1558: } else {
1.249 dtucker 1559: if (stat(prog, &st) < 0)
1560: debug("subsystem: cannot stat %s: %s",
1561: prog, strerror(errno));
1.225 markus 1562: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1563: debug("subsystem: exec() %s", cmd);
1.105 markus 1564: }
1.292 ! djm 1565: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1566: break;
1.18 jakob 1567: }
1568: }
1569:
1570: if (!success)
1.267 djm 1571: logit("subsystem request for %.100s by user %s failed, "
1572: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1573:
1574: return success;
1575: }
1576:
1.94 itojun 1577: static int
1.292 ! djm 1578: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1579: {
1.81 markus 1580: int success;
1.7 markus 1581:
1.184 djm 1582: if (s->auth_proto != NULL || s->auth_data != NULL) {
1583: error("session_x11_req: session %d: "
1.190 stevesk 1584: "x11 forwarding already active", s->self);
1.184 djm 1585: return 0;
1586: }
1.7 markus 1587: s->single_connection = packet_get_char();
1588: s->auth_proto = packet_get_string(NULL);
1589: s->auth_data = packet_get_string(NULL);
1590: s->screen = packet_get_int();
1.116 markus 1591: packet_check_eom();
1.7 markus 1592:
1.282 djm 1593: if (xauth_valid_string(s->auth_proto) &&
1594: xauth_valid_string(s->auth_data))
1.292 ! djm 1595: success = session_setup_x11fwd(ssh, s);
1.282 djm 1596: else {
1597: success = 0;
1598: error("Invalid X11 forwarding data");
1599: }
1.81 markus 1600: if (!success) {
1.265 djm 1601: free(s->auth_proto);
1602: free(s->auth_data);
1.84 markus 1603: s->auth_proto = NULL;
1604: s->auth_data = NULL;
1.7 markus 1605: }
1.81 markus 1606: return success;
1.7 markus 1607: }
1608:
1.94 itojun 1609: static int
1.292 ! djm 1610: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1611: {
1.116 markus 1612: packet_check_eom();
1.292 ! djm 1613: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1614: }
1615:
1.94 itojun 1616: static int
1.292 ! djm 1617: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1618: {
1.237 djm 1619: u_int len, success;
1620:
1.19 markus 1621: char *command = packet_get_string(&len);
1.116 markus 1622: packet_check_eom();
1.292 ! djm 1623: success = do_exec(ssh, s, command) == 0;
1.265 djm 1624: free(command);
1.237 djm 1625: return success;
1.19 markus 1626: }
1627:
1.94 itojun 1628: static int
1.292 ! djm 1629: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1630: {
1631:
1.175 deraadt 1632: packet_get_int(); /* ignored */
1.157 markus 1633: packet_check_eom();
1634:
1.259 djm 1635: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1636: return 0;
1637: return 1;
1638: }
1639:
1640: static int
1.292 ! djm 1641: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1642: {
1643: char *name, *val;
1644: u_int name_len, val_len, i;
1645:
1.271 djm 1646: name = packet_get_cstring(&name_len);
1647: val = packet_get_cstring(&val_len);
1.173 djm 1648: packet_check_eom();
1649:
1650: /* Don't set too many environment variables */
1651: if (s->num_env > 128) {
1652: debug2("Ignoring env request %s: too many env vars", name);
1653: goto fail;
1654: }
1655:
1656: for (i = 0; i < options.num_accept_env; i++) {
1657: if (match_pattern(name, options.accept_env[i])) {
1658: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1659: s->env = xrecallocarray(s->env, s->num_env,
1660: s->num_env + 1, sizeof(*s->env));
1.173 djm 1661: s->env[s->num_env].name = name;
1662: s->env[s->num_env].val = val;
1663: s->num_env++;
1664: return (1);
1665: }
1666: }
1667: debug2("Ignoring env request %s: disallowed name", name);
1668:
1669: fail:
1.265 djm 1670: free(name);
1671: free(val);
1.173 djm 1672: return (0);
1673: }
1674:
1675: static int
1.292 ! djm 1676: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1677: {
1678: static int called = 0;
1.116 markus 1679: packet_check_eom();
1.235 pyr 1680: if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
1.44 markus 1681: debug("session_auth_agent_req: no_agent_forwarding_flag");
1682: return 0;
1683: }
1.43 markus 1684: if (called) {
1685: return 0;
1686: } else {
1687: called = 1;
1.292 ! djm 1688: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1689: }
1690: }
1691:
1.123 markus 1692: int
1.292 ! djm 1693: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1694: {
1695: int success = 0;
1696: Session *s;
1697:
1.123 markus 1698: if ((s = session_by_channel(c->self)) == NULL) {
1.292 ! djm 1699: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1700: return 0;
1701: }
1.292 ! djm 1702: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1703:
1704: /*
1.64 markus 1705: * a session is in LARVAL state until a shell, a command
1706: * or a subsystem is executed
1.2 markus 1707: */
1708: if (c->type == SSH_CHANNEL_LARVAL) {
1709: if (strcmp(rtype, "shell") == 0) {
1.292 ! djm 1710: success = session_shell_req(ssh, s);
1.2 markus 1711: } else if (strcmp(rtype, "exec") == 0) {
1.292 ! djm 1712: success = session_exec_req(ssh, s);
1.2 markus 1713: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 ! djm 1714: success = session_pty_req(ssh, s);
1.7 markus 1715: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 ! djm 1716: success = session_x11_req(ssh, s);
1.43 markus 1717: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 ! djm 1718: success = session_auth_agent_req(ssh, s);
1.7 markus 1719: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 ! djm 1720: success = session_subsystem_req(ssh, s);
1.173 djm 1721: } else if (strcmp(rtype, "env") == 0) {
1.292 ! djm 1722: success = session_env_req(ssh, s);
1.2 markus 1723: }
1724: }
1725: if (strcmp(rtype, "window-change") == 0) {
1.292 ! djm 1726: success = session_window_change_req(ssh, s);
1.177 djm 1727: } else if (strcmp(rtype, "break") == 0) {
1.292 ! djm 1728: success = session_break_req(ssh, s);
1.2 markus 1729: }
1.177 djm 1730:
1.123 markus 1731: return success;
1.2 markus 1732: }
1733:
1734: void
1.292 ! djm 1735: session_set_fds(struct ssh *ssh, Session *s,
! 1736: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1737: {
1738: /*
1739: * now that have a child and a pipe to the child,
1740: * we can activate our channel and register the fd's
1741: */
1742: if (s->chanid == -1)
1743: fatal("no channel for session %d", s->self);
1.292 ! djm 1744: channel_set_fds(ssh, s->chanid,
1.2 markus 1745: fdout, fdin, fderr,
1.256 djm 1746: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1747: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1748: }
1749:
1.85 markus 1750: /*
1751: * Function to perform pty cleanup. Also called if we get aborted abnormally
1752: * (e.g., due to a dropped connection).
1753: */
1.130 provos 1754: void
1.165 markus 1755: session_pty_cleanup2(Session *s)
1.1 markus 1756: {
1.85 markus 1757: if (s == NULL) {
1758: error("session_pty_cleanup: no session");
1759: return;
1760: }
1761: if (s->ttyfd == -1)
1.1 markus 1762: return;
1763:
1.54 stevesk 1764: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1765:
1766: /* Record that the user has logged out. */
1.85 markus 1767: if (s->pid != 0)
1768: record_logout(s->pid, s->tty);
1.1 markus 1769:
1770: /* Release the pseudo-tty. */
1.130 provos 1771: if (getuid() == 0)
1772: pty_release(s->tty);
1.1 markus 1773:
1774: /*
1775: * Close the server side of the socket pairs. We must do this after
1776: * the pty cleanup, so that another process doesn't get this pty
1777: * while we're still cleaning up.
1778: */
1.237 djm 1779: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1780: error("close(s->ptymaster/%d): %s",
1781: s->ptymaster, strerror(errno));
1.108 markus 1782:
1783: /* unlink pty from session */
1784: s->ttyfd = -1;
1.2 markus 1785: }
1786:
1.130 provos 1787: void
1.165 markus 1788: session_pty_cleanup(Session *s)
1.130 provos 1789: {
1.165 markus 1790: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1791: }
1792:
1.147 markus 1793: static char *
1794: sig2name(int sig)
1795: {
1796: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1797: SSH_SIG(ABRT);
1798: SSH_SIG(ALRM);
1799: SSH_SIG(FPE);
1800: SSH_SIG(HUP);
1801: SSH_SIG(ILL);
1802: SSH_SIG(INT);
1803: SSH_SIG(KILL);
1804: SSH_SIG(PIPE);
1805: SSH_SIG(QUIT);
1806: SSH_SIG(SEGV);
1807: SSH_SIG(TERM);
1808: SSH_SIG(USR1);
1809: SSH_SIG(USR2);
1810: #undef SSH_SIG
1811: return "SIG@openssh.com";
1812: }
1813:
1.94 itojun 1814: static void
1.292 ! djm 1815: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1816: {
1817: Channel *c;
1818:
1.292 ! djm 1819: if ((c = channel_by_id(ssh, id)) == NULL) {
! 1820: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1821: } else {
1822: /* Detach X11 listener */
1.292 ! djm 1823: debug("%s: detach x11 channel %d", __func__, id);
! 1824: channel_cancel_cleanup(ssh, id);
1.184 djm 1825: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 ! djm 1826: chan_mark_dead(ssh, c);
1.184 djm 1827: }
1828: }
1829:
1830: static void
1.292 ! djm 1831: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1832: {
1833: Session *s;
1834: u_int i;
1835:
1.292 ! djm 1836: debug3("%s: channel %d", __func__, id);
! 1837: channel_cancel_cleanup(ssh, id);
1.221 stevesk 1838: if ((s = session_by_x11_channel(id)) == NULL)
1.292 ! djm 1839: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 1840: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 ! djm 1841: debug("%s: session %d: closing channel %d",
! 1842: __func__, s->self, s->x11_chanids[i]);
1.184 djm 1843: /*
1844: * The channel "id" is already closing, but make sure we
1845: * close all of its siblings.
1846: */
1847: if (s->x11_chanids[i] != id)
1.292 ! djm 1848: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 1849: }
1.265 djm 1850: free(s->x11_chanids);
1.184 djm 1851: s->x11_chanids = NULL;
1.265 djm 1852: free(s->display);
1853: s->display = NULL;
1854: free(s->auth_proto);
1855: s->auth_proto = NULL;
1856: free(s->auth_data);
1857: s->auth_data = NULL;
1858: free(s->auth_display);
1859: s->auth_display = NULL;
1.184 djm 1860: }
1861:
1862: static void
1.292 ! djm 1863: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 1864: {
1865: Channel *c;
1.124 markus 1866:
1.292 ! djm 1867: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
! 1868: fatal("%s: session %d: no channel %d",
! 1869: __func__, s->self, s->chanid);
! 1870: debug("%s: session %d channel %d pid %ld",
! 1871: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 1872:
1873: if (WIFEXITED(status)) {
1.292 ! djm 1874: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 1875: packet_put_int(WEXITSTATUS(status));
1876: packet_send();
1877: } else if (WIFSIGNALED(status)) {
1.292 ! djm 1878: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 1879: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 1880: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 1881: packet_put_cstring("");
1882: packet_put_cstring("");
1883: packet_send();
1884: } else {
1885: /* Some weird exit cause. Just exit. */
1886: packet_disconnect("wait returned status %04x.", status);
1887: }
1888:
1889: /* disconnect channel */
1.292 ! djm 1890: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 1891:
1892: /*
1893: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 1894: * the channel gets EOF. The session will be then be closed
1.187 djm 1895: * by session_close_by_channel when the childs close their fds.
1896: */
1.292 ! djm 1897: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 1898:
1.5 markus 1899: /*
1900: * emulate a write failure with 'chan_write_failed', nobody will be
1901: * interested in data we write.
1902: * Note that we must not call 'chan_read_failed', since there could
1903: * be some more data waiting in the pipe.
1904: */
1.8 markus 1905: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 ! djm 1906: chan_write_failed(ssh, c);
1.2 markus 1907: }
1908:
1.130 provos 1909: void
1.292 ! djm 1910: session_close(struct ssh *ssh, Session *s)
1.2 markus 1911: {
1.182 djm 1912: u_int i;
1.173 djm 1913:
1.280 djm 1914: verbose("Close session: user %s from %.200s port %d id %d",
1915: s->pw->pw_name,
1.281 djm 1916: ssh_remote_ipaddr(ssh),
1917: ssh_remote_port(ssh),
1.280 djm 1918: s->self);
1919:
1.165 markus 1920: if (s->ttyfd != -1)
1.85 markus 1921: session_pty_cleanup(s);
1.265 djm 1922: free(s->term);
1923: free(s->display);
1924: free(s->x11_chanids);
1925: free(s->auth_display);
1926: free(s->auth_data);
1927: free(s->auth_proto);
1.267 djm 1928: free(s->subsys);
1.219 djm 1929: if (s->env != NULL) {
1930: for (i = 0; i < s->num_env; i++) {
1.265 djm 1931: free(s->env[i].name);
1932: free(s->env[i].val);
1.219 djm 1933: }
1.265 djm 1934: free(s->env);
1.173 djm 1935: }
1.9 markus 1936: session_proctitle(s);
1.237 djm 1937: session_unused(s->self);
1.2 markus 1938: }
1939:
1940: void
1.292 ! djm 1941: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 1942: {
1943: Session *s = session_by_pid(pid);
1944: if (s == NULL) {
1.292 ! djm 1945: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 1946: return;
1947: }
1948: if (s->chanid != -1)
1.292 ! djm 1949: session_exit_message(ssh, s, status);
1.187 djm 1950: if (s->ttyfd != -1)
1951: session_pty_cleanup(s);
1.197 djm 1952: s->pid = 0;
1.98 markus 1953: }
1954:
1.2 markus 1955: /*
1956: * this is called when a channel dies before
1957: * the session 'child' itself dies
1958: */
1959: void
1.292 ! djm 1960: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 1961: {
1962: Session *s = session_by_channel(id);
1.187 djm 1963: u_int i;
1.184 djm 1964:
1.2 markus 1965: if (s == NULL) {
1.292 ! djm 1966: debug("%s: no session for id %d", __func__, id);
1.2 markus 1967: return;
1968: }
1.292 ! djm 1969: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 1970: if (s->pid != 0) {
1.292 ! djm 1971: debug("%s: channel %d: has child", __func__, id);
1.108 markus 1972: /*
1973: * delay detach of session, but release pty, since
1974: * the fd's to the child are already closed
1975: */
1.165 markus 1976: if (s->ttyfd != -1)
1.108 markus 1977: session_pty_cleanup(s);
1.107 markus 1978: return;
1979: }
1980: /* detach by removing callback */
1.292 ! djm 1981: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 1982:
1983: /* Close any X11 listeners associated with this session */
1984: if (s->x11_chanids != NULL) {
1985: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 ! djm 1986: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 1987: s->x11_chanids[i] = -1;
1988: }
1989: }
1990:
1.2 markus 1991: s->chanid = -1;
1.292 ! djm 1992: session_close(ssh, s);
1.106 markus 1993: }
1994:
1995: void
1.292 ! djm 1996: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 1997: {
1998: int i;
1.237 djm 1999: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2000: Session *s = &sessions[i];
1.130 provos 2001: if (s->used) {
2002: if (closefunc != NULL)
2003: closefunc(s);
2004: else
1.292 ! djm 2005: session_close(ssh, s);
1.130 provos 2006: }
1.2 markus 2007: }
1.9 markus 2008: }
2009:
1.94 itojun 2010: static char *
1.9 markus 2011: session_tty_list(void)
2012: {
2013: static char buf[1024];
2014: int i;
2015: buf[0] = '\0';
1.237 djm 2016: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2017: Session *s = &sessions[i];
2018: if (s->used && s->ttyfd != -1) {
2019: if (buf[0] != '\0')
2020: strlcat(buf, ",", sizeof buf);
2021: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2022: }
2023: }
2024: if (buf[0] == '\0')
2025: strlcpy(buf, "notty", sizeof buf);
2026: return buf;
2027: }
2028:
2029: void
2030: session_proctitle(Session *s)
2031: {
2032: if (s->pw == NULL)
2033: error("no user for session %d", s->self);
2034: else
2035: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2036: }
2037:
2038: int
1.292 ! djm 2039: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2040: {
2041: struct stat st;
1.109 stevesk 2042: char display[512], auth_display[512];
1.272 djm 2043: char hostname[NI_MAXHOST];
1.184 djm 2044: u_int i;
1.81 markus 2045:
2046: if (no_x11_forwarding_flag) {
2047: packet_send_debug("X11 forwarding disabled in user configuration file.");
2048: return 0;
2049: }
2050: if (!options.x11_forwarding) {
2051: debug("X11 forwarding disabled in server configuration file.");
2052: return 0;
2053: }
1.275 djm 2054: if (options.xauth_location == NULL ||
1.81 markus 2055: (stat(options.xauth_location, &st) == -1)) {
2056: packet_send_debug("No xauth program; cannot forward with spoofing.");
2057: return 0;
2058: }
1.87 markus 2059: if (s->display != NULL) {
1.81 markus 2060: debug("X11 display already set.");
2061: return 0;
2062: }
1.292 ! djm 2063: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2064: options.x11_use_localhost, s->single_connection,
1.184 djm 2065: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2066: debug("x11_create_display_inet failed.");
1.81 markus 2067: return 0;
1.184 djm 2068: }
2069: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 ! djm 2070: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2071: session_close_single_x11, 0);
1.81 markus 2072: }
1.109 stevesk 2073:
2074: /* Set up a suitable value for the DISPLAY variable. */
2075: if (gethostname(hostname, sizeof(hostname)) < 0)
2076: fatal("gethostname: %.100s", strerror(errno));
2077: /*
2078: * auth_display must be used as the displayname when the
2079: * authorization entry is added with xauth(1). This will be
2080: * different than the DISPLAY string for localhost displays.
2081: */
1.119 stevesk 2082: if (options.x11_use_localhost) {
1.140 deraadt 2083: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2084: s->display_number, s->screen);
1.140 deraadt 2085: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2086: s->display_number, s->screen);
1.109 stevesk 2087: s->display = xstrdup(display);
1.118 stevesk 2088: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2089: } else {
1.140 deraadt 2090: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2091: s->display_number, s->screen);
2092: s->display = xstrdup(display);
1.118 stevesk 2093: s->auth_display = xstrdup(display);
1.109 stevesk 2094: }
2095:
1.81 markus 2096: return 1;
1.2 markus 2097: }
2098:
1.94 itojun 2099: static void
1.292 ! djm 2100: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2101: {
1.292 ! djm 2102: server_loop2(ssh, authctxt);
1.165 markus 2103: }
2104:
2105: void
1.292 ! djm 2106: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2107: {
2108: static int called = 0;
2109:
2110: debug("do_cleanup");
2111:
2112: /* no cleanup if we're in the child for login shell */
2113: if (is_child)
2114: return;
2115:
2116: /* avoid double cleanup */
2117: if (called)
2118: return;
2119: called = 1;
2120:
1.218 markus 2121: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2122: return;
2123: #ifdef KRB5
2124: if (options.kerberos_ticket_cleanup &&
2125: authctxt->krb5_ctx)
2126: krb5_cleanup_proc(authctxt);
1.161 markus 2127: #endif
1.165 markus 2128:
2129: #ifdef GSSAPI
1.283 markus 2130: if (options.gss_cleanup_creds)
1.165 markus 2131: ssh_gssapi_cleanup_creds();
2132: #endif
2133:
2134: /* remove agent socket */
2135: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2136:
2137: /* remove userauth info */
2138: if (auth_info_file != NULL) {
2139: temporarily_use_uid(authctxt->pw);
2140: unlink(auth_info_file);
2141: restore_uid();
2142: free(auth_info_file);
2143: auth_info_file = NULL;
2144: }
1.165 markus 2145:
2146: /*
2147: * Cleanup ptys/utmp only if privsep is disabled,
2148: * or if running in monitor.
2149: */
2150: if (!use_privsep || mm_is_monitor())
1.292 ! djm 2151: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2152: }
1.281 djm 2153:
2154: /* Return a name for the remote host that fits inside utmp_size */
2155:
2156: const char *
2157: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2158: {
2159: const char *remote = "";
2160:
2161: if (utmp_size > 0)
2162: remote = auth_get_canonical_hostname(ssh, use_dns);
2163: if (utmp_size == 0 || strlen(remote) > utmp_size)
2164: remote = ssh_remote_ipaddr(ssh);
2165: return remote;
2166: }
2167:
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