Annotation of src/usr.bin/ssh/session.c, Revision 1.290
1.290 ! djm 1: /* $OpenBSD: session.c,v 1.289 2017/06/24 05:24:11 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);
1.256 djm 103: void session_set_fds(Session *, int, int, int, int, int);
1.165 markus 104: void session_pty_cleanup(Session *);
1.94 itojun 105: void session_proctitle(Session *);
106: int session_setup_x11fwd(Session *);
1.237 djm 107: int do_exec_pty(Session *, const char *);
108: int do_exec_no_pty(Session *, const char *);
109: int do_exec(Session *, const char *);
1.94 itojun 110: void do_login(Session *, const char *);
111: void do_child(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:
1.94 itojun 115: static void do_authenticated2(Authctxt *);
116:
117: static int session_pty_req(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
168: auth_input_request_forwarding(struct passwd * pw)
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. */
208: nc = channel_new("auth socket",
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
273: do_authenticated(Authctxt *authctxt)
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)
281: channel_disable_adm_local_opens();
282: else
1.65 markus 283: channel_permit_all_opens();
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:
1.283 markus 289: do_authenticated2(authctxt);
1.290 ! djm 290:
1.165 markus 291: do_cleanup(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
1.63 markus 316: do_exec_no_pty(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). */
1.60 markus 435: do_child(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:
1.283 markus 452: session_set_fds(s, pin[1], pout[0], perr[0],
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
1.63 markus 476: do_exec_pty(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) */
1.285 otto 541: do_login(s, command);
1.228 djm 542:
1.237 djm 543: /*
544: * Do common processing for the child, such as execing
545: * the command.
546: */
1.60 markus 547: do_child(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);
1.283 markus 561: session_set_fds(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
1.90 markus 570: do_exec(Session *s, const char *command)
571: {
1.281 djm 572: struct ssh *ssh = active_state; /* XXX */
1.237 djm 573: int ret;
1.280 djm 574: const char *forced = NULL, *tty = NULL;
575: char session_type[1024];
1.237 djm 576:
1.210 dtucker 577: if (options.adm_forced_command) {
578: original_command = command;
579: command = options.adm_forced_command;
1.267 djm 580: forced = "(config)";
1.210 dtucker 581: } else if (forced_command) {
1.90 markus 582: original_command = command;
583: command = forced_command;
1.267 djm 584: forced = "(key-option)";
585: }
586: if (forced != NULL) {
1.248 djm 587: if (IS_INTERNAL_SFTP(command)) {
588: s->is_subsystem = s->is_subsystem ?
589: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
590: } else if (s->is_subsystem)
1.225 markus 591: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 592: snprintf(session_type, sizeof(session_type),
593: "forced-command %s '%.900s'", forced, command);
594: } else if (s->is_subsystem) {
595: snprintf(session_type, sizeof(session_type),
596: "subsystem '%.900s'", s->subsys);
597: } else if (command == NULL) {
598: snprintf(session_type, sizeof(session_type), "shell");
599: } else {
600: /* NB. we don't log unforced commands to preserve privacy */
601: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 602: }
1.163 markus 603:
1.267 djm 604: if (s->ttyfd != -1) {
605: tty = s->tty;
606: if (strncmp(tty, "/dev/", 5) == 0)
607: tty += 5;
608: }
609:
1.280 djm 610: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 611: session_type,
612: tty == NULL ? "" : " on ",
613: tty == NULL ? "" : tty,
614: s->pw->pw_name,
1.281 djm 615: ssh_remote_ipaddr(ssh),
616: ssh_remote_port(ssh),
1.280 djm 617: s->self);
1.267 djm 618:
1.163 markus 619: #ifdef GSSAPI
620: if (options.gss_authentication) {
621: temporarily_use_uid(s->pw);
622: ssh_gssapi_storecreds();
623: restore_uid();
624: }
625: #endif
1.90 markus 626: if (s->ttyfd != -1)
1.237 djm 627: ret = do_exec_pty(s, command);
1.90 markus 628: else
1.237 djm 629: ret = do_exec_no_pty(s, command);
1.90 markus 630:
1.92 markus 631: original_command = NULL;
1.179 dtucker 632:
633: /*
634: * Clear loginmsg: it's the child's responsibility to display
635: * it to the user, otherwise multiple sessions may accumulate
636: * multiple copies of the login messages.
637: */
638: buffer_clear(&loginmsg);
1.237 djm 639:
640: return ret;
1.90 markus 641: }
642:
643:
1.24 markus 644: /* administrative, login(1)-like work */
645: void
1.41 markus 646: do_login(Session *s, const char *command)
1.24 markus 647: {
1.281 djm 648: struct ssh *ssh = active_state; /* XXX */
1.24 markus 649: socklen_t fromlen;
650: struct sockaddr_storage from;
651: struct passwd * pw = s->pw;
652: pid_t pid = getpid();
653:
654: /*
655: * Get IP address of client. If the connection is not a socket, let
656: * the address be 0.0.0.0.
657: */
658: memset(&from, 0, sizeof(from));
1.148 stevesk 659: fromlen = sizeof(from);
1.24 markus 660: if (packet_connection_is_on_socket()) {
661: if (getpeername(packet_get_connection_in(),
1.200 deraadt 662: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 663: debug("getpeername: %.100s", strerror(errno));
1.165 markus 664: cleanup_exit(255);
1.24 markus 665: }
666: }
1.25 markus 667:
1.24 markus 668: /* Record that there was a login on that tty from the remote host. */
1.133 markus 669: if (!use_privsep)
670: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 671: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 672: options.use_dns),
1.148 stevesk 673: (struct sockaddr *)&from, fromlen);
1.24 markus 674:
1.73 djm 675: if (check_quietlogin(s, command))
1.24 markus 676: return;
1.73 djm 677:
1.179 dtucker 678: display_loginmsg();
1.73 djm 679:
680: do_motd();
681: }
682:
683: /*
684: * Display the message of the day.
685: */
686: void
687: do_motd(void)
688: {
689: FILE *f;
690: char buf[256];
691:
1.24 markus 692: if (options.print_motd) {
1.28 millert 693: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
694: "/etc/motd"), "r");
1.24 markus 695: if (f) {
696: while (fgets(buf, sizeof(buf), f))
697: fputs(buf, stdout);
698: fclose(f);
699: }
1.2 markus 700: }
1.73 djm 701: }
702:
703:
704: /*
705: * Check for quiet login, either .hushlogin or command given.
706: */
707: int
708: check_quietlogin(Session *s, const char *command)
709: {
710: char buf[256];
1.96 dugsong 711: struct passwd *pw = s->pw;
1.73 djm 712: struct stat st;
713:
714: /* Return 1 if .hushlogin exists or a command given. */
715: if (command != NULL)
716: return 1;
717: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
718: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
719: return 1;
720: return 0;
1.1 markus 721: }
722:
723: /*
724: * Sets the value of the given variable in the environment. If the variable
1.244 tobias 725: * already exists, its value is overridden.
1.1 markus 726: */
1.161 markus 727: void
1.45 markus 728: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 729: const char *value)
1.1 markus 730: {
1.164 markus 731: char **env;
732: u_int envsize;
1.45 markus 733: u_int i, namelen;
1.1 markus 734:
1.271 djm 735: if (strchr(name, '=') != NULL) {
736: error("Invalid environment variable \"%.100s\"", name);
737: return;
738: }
739:
1.1 markus 740: /*
741: * Find the slot where the value should be stored. If the variable
742: * already exists, we reuse the slot; otherwise we append a new slot
743: * at the end of the array, expanding if necessary.
744: */
745: env = *envp;
746: namelen = strlen(name);
747: for (i = 0; env[i]; i++)
748: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
749: break;
750: if (env[i]) {
751: /* Reuse the slot. */
1.265 djm 752: free(env[i]);
1.1 markus 753: } else {
754: /* New variable. Expand if necessary. */
1.164 markus 755: envsize = *envsizep;
756: if (i >= envsize - 1) {
757: if (envsize >= 1000)
758: fatal("child_set_env: too many env vars");
759: envsize += 50;
1.278 deraadt 760: env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
1.164 markus 761: *envsizep = envsize;
1.1 markus 762: }
763: /* Need to set the NULL pointer at end of array beyond the new slot. */
764: env[i + 1] = NULL;
765: }
766:
767: /* Allocate space and format the variable in the appropriate slot. */
768: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
769: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
770: }
771:
772: /*
773: * Reads environment variables from the given file and adds/overrides them
774: * into the environment. If the file does not exist, this does nothing.
775: * Otherwise, it must consist of empty lines, comments (line starts with '#')
776: * and assignments of the form name=value. No other forms are allowed.
777: */
1.94 itojun 778: static void
1.45 markus 779: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 780: const char *filename)
1.1 markus 781: {
782: FILE *f;
783: char buf[4096];
784: char *cp, *value;
1.142 deraadt 785: u_int lineno = 0;
1.1 markus 786:
787: f = fopen(filename, "r");
788: if (!f)
789: return;
790:
791: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 792: if (++lineno > 1000)
793: fatal("Too many lines in environment file %s", filename);
1.1 markus 794: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
795: ;
796: if (!*cp || *cp == '#' || *cp == '\n')
797: continue;
1.224 gilles 798:
799: cp[strcspn(cp, "\n")] = '\0';
800:
1.1 markus 801: value = strchr(cp, '=');
802: if (value == NULL) {
1.142 deraadt 803: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
804: filename);
1.1 markus 805: continue;
806: }
1.14 deraadt 807: /*
808: * Replace the equals sign by nul, and advance value to
809: * the value string.
810: */
1.1 markus 811: *value = '\0';
812: value++;
813: child_set_env(env, envsize, cp, value);
814: }
815: fclose(f);
816: }
817:
1.127 markus 818: static char **
819: do_setup_env(Session *s, const char *shell)
1.1 markus 820: {
1.281 djm 821: struct ssh *ssh = active_state; /* XXX */
1.1 markus 822: char buf[256];
1.127 markus 823: u_int i, envsize;
1.154 markus 824: char **env, *laddr;
1.127 markus 825: struct passwd *pw = s->pw;
1.1 markus 826:
827: /* Initialize the environment. */
828: envsize = 100;
1.220 djm 829: env = xcalloc(envsize, sizeof(char *));
1.1 markus 830: env[0] = NULL;
831:
1.161 markus 832: #ifdef GSSAPI
1.168 djm 833: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 834: * the childs environment as they see fit
835: */
836: ssh_gssapi_do_child(&env, &envsize);
837: #endif
838:
1.284 djm 839: /* Set basic environment. */
840: for (i = 0; i < s->num_env; i++)
841: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
842:
843: child_set_env(&env, &envsize, "USER", pw->pw_name);
844: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
845: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
846: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
847: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
848: else
849: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
850:
851: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
852: child_set_env(&env, &envsize, "MAIL", buf);
853:
854: /* Normal systems set SHELL by default. */
855: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 856:
857: if (getenv("TZ"))
858: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
859:
860: /* Set custom environment options from RSA authentication. */
1.284 djm 861: while (custom_environment) {
862: struct envstring *ce = custom_environment;
863: char *str = ce->s;
864:
865: for (i = 0; str[i] != '=' && str[i]; i++)
866: ;
867: if (str[i] == '=') {
868: str[i] = 0;
869: child_set_env(&env, &envsize, str, str + i + 1);
870: }
871: custom_environment = ce->next;
872: free(ce->s);
873: free(ce);
1.1 markus 874: }
875:
1.149 stevesk 876: /* SSH_CLIENT deprecated */
1.1 markus 877: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 878: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
879: ssh_local_port(ssh));
1.1 markus 880: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 881:
1.154 markus 882: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 883: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 884: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
885: laddr, ssh_local_port(ssh));
1.265 djm 886: free(laddr);
1.149 stevesk 887: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 888:
1.290 ! djm 889: if (auth_info_file != NULL)
! 890: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 891: if (s->ttyfd != -1)
892: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
893: if (s->term)
894: child_set_env(&env, &envsize, "TERM", s->term);
895: if (s->display)
896: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 897: if (original_command)
898: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
899: original_command);
1.96 dugsong 900: #ifdef KRB5
901: if (s->authctxt->krb5_ticket_file)
902: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 903: s->authctxt->krb5_ticket_file);
1.96 dugsong 904: #endif
1.136 markus 905: if (auth_sock_name != NULL)
1.1 markus 906: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 907: auth_sock_name);
1.1 markus 908:
909: /* read $HOME/.ssh/environment. */
1.284 djm 910: if (options.permit_user_env) {
1.14 deraadt 911: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
912: pw->pw_dir);
1.1 markus 913: read_environment_file(&env, &envsize, buf);
914: }
915: if (debug_flag) {
916: /* dump the environment */
917: fprintf(stderr, "Environment:\n");
918: for (i = 0; env[i]; i++)
919: fprintf(stderr, " %.200s\n", env[i]);
920: }
1.127 markus 921: return env;
922: }
923:
924: /*
925: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
926: * first in this order).
927: */
928: static void
929: do_rc_files(Session *s, const char *shell)
930: {
931: FILE *f = NULL;
932: char cmd[1024];
933: int do_xauth;
934: struct stat st;
935:
936: do_xauth =
937: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
938:
1.231 djm 939: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 940: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.273 djm 941: !no_user_rc && options.permit_user_rc &&
942: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 943: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
944: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
945: if (debug_flag)
946: fprintf(stderr, "Running %s\n", cmd);
947: f = popen(cmd, "w");
948: if (f) {
949: if (do_xauth)
950: fprintf(f, "%s %s\n", s->auth_proto,
951: s->auth_data);
952: pclose(f);
953: } else
954: fprintf(stderr, "Could not run %s\n",
955: _PATH_SSH_USER_RC);
956: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
957: if (debug_flag)
958: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
959: _PATH_SSH_SYSTEM_RC);
960: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
961: if (f) {
962: if (do_xauth)
963: fprintf(f, "%s %s\n", s->auth_proto,
964: s->auth_data);
965: pclose(f);
966: } else
967: fprintf(stderr, "Could not run %s\n",
968: _PATH_SSH_SYSTEM_RC);
969: } else if (do_xauth && options.xauth_location != NULL) {
970: /* Add authority data to .Xauthority if appropriate. */
971: if (debug_flag) {
972: fprintf(stderr,
1.151 stevesk 973: "Running %.500s remove %.100s\n",
1.165 markus 974: options.xauth_location, s->auth_display);
1.151 stevesk 975: fprintf(stderr,
976: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 977: options.xauth_location, s->auth_display,
978: s->auth_proto, s->auth_data);
979: }
980: snprintf(cmd, sizeof cmd, "%s -q -",
981: options.xauth_location);
982: f = popen(cmd, "w");
983: if (f) {
1.151 stevesk 984: fprintf(f, "remove %s\n",
985: s->auth_display);
1.127 markus 986: fprintf(f, "add %s %s %s\n",
987: s->auth_display, s->auth_proto,
988: s->auth_data);
989: pclose(f);
990: } else {
991: fprintf(stderr, "Could not run %s\n",
992: cmd);
993: }
994: }
995: }
996:
997: static void
998: do_nologin(struct passwd *pw)
999: {
1000: FILE *f = NULL;
1.251 dtucker 1001: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
1002: struct stat sb;
1.127 markus 1003:
1.260 guenther 1004: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 1005: return;
1006: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
1007:
1008: if (stat(nl, &sb) == -1) {
1009: if (nl != def_nl)
1.265 djm 1010: free(nl);
1.251 dtucker 1011: return;
1012: }
1013:
1014: /* /etc/nologin exists. Print its contents if we can and exit. */
1015: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1016: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 1017: while (fgets(buf, sizeof(buf), f))
1018: fputs(buf, stderr);
1019: fclose(f);
1020: }
1.251 dtucker 1021: exit(254);
1.127 markus 1022: }
1023:
1.226 djm 1024: /*
1025: * Chroot into a directory after checking it for safety: all path components
1026: * must be root-owned directories with strict permissions.
1027: */
1028: static void
1029: safely_chroot(const char *path, uid_t uid)
1030: {
1031: const char *cp;
1.277 deraadt 1032: char component[PATH_MAX];
1.226 djm 1033: struct stat st;
1034:
1035: if (*path != '/')
1036: fatal("chroot path does not begin at root");
1037: if (strlen(path) >= sizeof(component))
1038: fatal("chroot path too long");
1039:
1040: /*
1041: * Descend the path, checking that each component is a
1042: * root-owned directory with strict permissions.
1043: */
1044: for (cp = path; cp != NULL;) {
1045: if ((cp = strchr(cp, '/')) == NULL)
1046: strlcpy(component, path, sizeof(component));
1047: else {
1048: cp++;
1049: memcpy(component, path, cp - path);
1050: component[cp - path] = '\0';
1051: }
1052:
1053: debug3("%s: checking '%s'", __func__, component);
1054:
1055: if (stat(component, &st) != 0)
1056: fatal("%s: stat(\"%s\"): %s", __func__,
1057: component, strerror(errno));
1058: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1059: fatal("bad ownership or modes for chroot "
1060: "directory %s\"%s\"",
1061: cp == NULL ? "" : "component ", component);
1062: if (!S_ISDIR(st.st_mode))
1063: fatal("chroot path %s\"%s\" is not a directory",
1064: cp == NULL ? "" : "component ", component);
1065:
1066: }
1067:
1068: if (chdir(path) == -1)
1069: fatal("Unable to chdir to chroot path \"%s\": "
1070: "%s", path, strerror(errno));
1071: if (chroot(path) == -1)
1072: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1073: if (chdir("/") == -1)
1074: fatal("%s: chdir(/) after chroot: %s",
1075: __func__, strerror(errno));
1076: verbose("Changed root directory to \"%s\"", path);
1077: }
1078:
1.127 markus 1079: /* Set login name, uid, gid, and groups. */
1.130 provos 1080: void
1.127 markus 1081: do_setusercontext(struct passwd *pw)
1082: {
1.227 djm 1083: char *chroot_path, *tmp;
1084:
1.127 markus 1085: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1086: /* Prepare groups */
1.127 markus 1087: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1088: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1089: perror("unable to set user context");
1090: exit(1);
1091: }
1.226 djm 1092:
1.279 djm 1093: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1094: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1095: tmp = tilde_expand_filename(options.chroot_directory,
1096: pw->pw_uid);
1097: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1098: "u", pw->pw_name, (char *)NULL);
1.226 djm 1099: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1100: free(tmp);
1.226 djm 1101: free(chroot_path);
1.264 djm 1102: /* Make sure we don't attempt to chroot again */
1103: free(options.chroot_directory);
1104: options.chroot_directory = NULL;
1.279 djm 1105: in_chroot = 1;
1.226 djm 1106: }
1107:
1108: /* Set UID */
1109: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1110: perror("unable to set user context (setuser)");
1111: exit(1);
1112: }
1.264 djm 1113: } else if (options.chroot_directory != NULL &&
1114: strcasecmp(options.chroot_directory, "none") != 0) {
1115: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1116: }
1.264 djm 1117:
1.127 markus 1118: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1119: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1120: }
1121:
1.131 markus 1122: static void
1.172 markus 1123: do_pwchange(Session *s)
1124: {
1.179 dtucker 1125: fflush(NULL);
1.172 markus 1126: fprintf(stderr, "WARNING: Your password has expired.\n");
1127: if (s->ttyfd != -1) {
1.178 deraadt 1128: fprintf(stderr,
1.172 markus 1129: "You must change your password now and login again!\n");
1130: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1131: perror("passwd");
1132: } else {
1133: fprintf(stderr,
1134: "Password change required but no TTY available.\n");
1135: }
1136: exit(1);
1137: }
1138:
1139: static void
1140: child_close_fds(void)
1141: {
1.276 djm 1142: extern int auth_sock;
1.266 markus 1143:
1.276 djm 1144: if (auth_sock != -1) {
1145: close(auth_sock);
1146: auth_sock = -1;
1.266 markus 1147: }
1148:
1.172 markus 1149: if (packet_get_connection_in() == packet_get_connection_out())
1150: close(packet_get_connection_in());
1151: else {
1152: close(packet_get_connection_in());
1153: close(packet_get_connection_out());
1154: }
1155: /*
1156: * Close all descriptors related to channels. They will still remain
1157: * open in the parent.
1158: */
1159: /* XXX better use close-on-exec? -markus */
1160: channel_close_all();
1161:
1162: /*
1163: * Close any extra file descriptors. Note that there may still be
1164: * descriptors left by system functions. They will be closed later.
1165: */
1166: endpwent();
1167:
1168: /*
1.188 djm 1169: * Close any extra open file descriptors so that we don't have them
1.172 markus 1170: * hanging around in clients. Note that we want to do this after
1171: * initgroups, because at least on Solaris 2.3 it leaves file
1172: * descriptors open.
1173: */
1.258 djm 1174: closefrom(STDERR_FILENO + 1);
1.172 markus 1175: }
1176:
1.127 markus 1177: /*
1178: * Performs common processing for the child, such as setting up the
1179: * environment, closing extra file descriptors, setting the user and group
1180: * ids, and executing the command or shell.
1181: */
1.225 markus 1182: #define ARGV_MAX 10
1.127 markus 1183: void
1184: do_child(Session *s, const char *command)
1185: {
1186: extern char **environ;
1187: char **env;
1.225 markus 1188: char *argv[ARGV_MAX];
1.284 djm 1189: const char *shell, *shell0;
1.127 markus 1190: struct passwd *pw = s->pw;
1.239 djm 1191: int r = 0;
1.127 markus 1192:
1193: /* remove hostkey from the child's memory */
1194: destroy_sensitive_data();
1.287 markus 1195: packet_clear_keys();
1.127 markus 1196:
1.172 markus 1197: /* Force a password change */
1198: if (s->authctxt->force_pwchange) {
1199: do_setusercontext(pw);
1200: child_close_fds();
1201: do_pwchange(s);
1202: exit(1);
1203: }
1204:
1.127 markus 1205: /*
1206: * Login(1) does this as well, and it needs uid 0 for the "-h"
1207: * switch, so we let login(1) to this for us.
1208: */
1.284 djm 1209: do_nologin(pw);
1210: do_setusercontext(pw);
1.127 markus 1211:
1212: /*
1213: * Get the shell from the password data. An empty shell field is
1214: * legal, and means /bin/sh.
1215: */
1216: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1217:
1218: /*
1219: * Make sure $SHELL points to the shell from the password file,
1220: * even if shell is overridden from login.conf
1221: */
1222: env = do_setup_env(s, shell);
1223:
1.127 markus 1224: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1225:
1.1 markus 1226: /*
1227: * Close the connection descriptors; note that this is the child, and
1228: * the server will still have the socket open, and it is important
1229: * that we do not shutdown it. Note that the descriptors cannot be
1230: * closed before building the environment, as we call
1.281 djm 1231: * ssh_remote_ipaddr there.
1.1 markus 1232: */
1.172 markus 1233: child_close_fds();
1.1 markus 1234:
1235: /*
1.125 deraadt 1236: * Must take new environment into use so that .ssh/rc,
1237: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1238: */
1239: environ = env;
1.170 jakob 1240:
1241: #ifdef KRB5
1242: /*
1243: * At this point, we check to see if AFS is active and if we have
1244: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1245: * if we can (and need to) extend the ticket into an AFS token. If
1246: * we don't do this, we run into potential problems if the user's
1247: * home directory is in AFS and it's not world-readable.
1248: */
1249:
1250: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1251: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1252: char cell[64];
1253:
1254: debug("Getting AFS token");
1255:
1256: k_setpag();
1257:
1258: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1259: krb5_afslog(s->authctxt->krb5_ctx,
1260: s->authctxt->krb5_fwd_ccache, cell, NULL);
1261:
1262: krb5_afslog_home(s->authctxt->krb5_ctx,
1263: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1264: }
1265: #endif
1.104 markus 1266:
1.188 djm 1267: /* Change current directory to the user's home directory. */
1.104 markus 1268: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1269: /* Suppress missing homedir warning for chroot case */
1270: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1271: if (r || !in_chroot) {
1.239 djm 1272: fprintf(stderr, "Could not chdir to home "
1273: "directory %s: %s\n", pw->pw_dir,
1274: strerror(errno));
1.279 djm 1275: }
1.239 djm 1276: if (r)
1.104 markus 1277: exit(1);
1278: }
1.230 djm 1279:
1280: closefrom(STDERR_FILENO + 1);
1.1 markus 1281:
1.284 djm 1282: do_rc_files(s, shell);
1.67 markus 1283:
1284: /* restore SIGPIPE for child */
1.217 stevesk 1285: signal(SIGPIPE, SIG_DFL);
1.67 markus 1286:
1.248 djm 1287: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1288: printf("This service allows sftp connections only.\n");
1289: fflush(NULL);
1290: exit(1);
1291: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1292: extern int optind, optreset;
1293: int i;
1294: char *p, *args;
1295:
1.246 stevesk 1296: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1297: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1298: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1299: if (i < ARGV_MAX - 1)
1300: argv[i++] = p;
1301: argv[i] = NULL;
1302: optind = optreset = 1;
1303: __progname = argv[0];
1.226 djm 1304: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1305: }
1.247 djm 1306:
1307: fflush(NULL);
1.225 markus 1308:
1.127 markus 1309: /* Get the last component of the shell name. */
1310: if ((shell0 = strrchr(shell, '/')) != NULL)
1311: shell0++;
1312: else
1313: shell0 = shell;
1314:
1.1 markus 1315: /*
1316: * If we have no command, execute the shell. In this case, the shell
1317: * name to be passed in argv[0] is preceded by '-' to indicate that
1318: * this is a login shell.
1319: */
1320: if (!command) {
1.127 markus 1321: char argv0[256];
1.1 markus 1322:
1.127 markus 1323: /* Start the shell. Set initial character to '-'. */
1324: argv0[0] = '-';
1.1 markus 1325:
1.127 markus 1326: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1327: >= sizeof(argv0) - 1) {
1.127 markus 1328: errno = EINVAL;
1.1 markus 1329: perror(shell);
1330: exit(1);
1.127 markus 1331: }
1.1 markus 1332:
1.127 markus 1333: /* Execute the shell. */
1334: argv[0] = argv0;
1335: argv[1] = NULL;
1336: execve(shell, argv, env);
1337:
1338: /* Executing the shell failed. */
1339: perror(shell);
1340: exit(1);
1.1 markus 1341: }
1342: /*
1343: * Execute the command using the user's shell. This uses the -c
1344: * option to execute the command.
1345: */
1.127 markus 1346: argv[0] = (char *) shell0;
1.1 markus 1347: argv[1] = "-c";
1348: argv[2] = (char *) command;
1349: argv[3] = NULL;
1350: execve(shell, argv, env);
1351: perror(shell);
1352: exit(1);
1353: }
1354:
1.237 djm 1355: void
1356: session_unused(int id)
1357: {
1358: debug3("%s: session id %d unused", __func__, id);
1359: if (id >= options.max_sessions ||
1360: id >= sessions_nalloc) {
1361: fatal("%s: insane session id %d (max %d nalloc %d)",
1362: __func__, id, options.max_sessions, sessions_nalloc);
1363: }
1.270 tedu 1364: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1365: sessions[id].self = id;
1366: sessions[id].used = 0;
1367: sessions[id].chanid = -1;
1368: sessions[id].ptyfd = -1;
1369: sessions[id].ttyfd = -1;
1370: sessions[id].ptymaster = -1;
1371: sessions[id].x11_chanids = NULL;
1372: sessions[id].next_unused = sessions_first_unused;
1373: sessions_first_unused = id;
1374: }
1375:
1.1 markus 1376: Session *
1377: session_new(void)
1378: {
1.237 djm 1379: Session *s, *tmp;
1380:
1381: if (sessions_first_unused == -1) {
1382: if (sessions_nalloc >= options.max_sessions)
1383: return NULL;
1384: debug2("%s: allocate (allocated %d max %d)",
1385: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1386: tmp = xrecallocarray(sessions, sessions_nalloc,
1387: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1388: if (tmp == NULL) {
1389: error("%s: cannot allocate %d sessions",
1390: __func__, sessions_nalloc + 1);
1391: return NULL;
1392: }
1393: sessions = tmp;
1394: session_unused(sessions_nalloc++);
1395: }
1396:
1397: if (sessions_first_unused >= sessions_nalloc ||
1398: sessions_first_unused < 0) {
1399: fatal("%s: insane first_unused %d max %d nalloc %d",
1400: __func__, sessions_first_unused, options.max_sessions,
1401: sessions_nalloc);
1402: }
1403:
1404: s = &sessions[sessions_first_unused];
1405: if (s->used) {
1406: fatal("%s: session %d already used",
1407: __func__, sessions_first_unused);
1408: }
1409: sessions_first_unused = s->next_unused;
1410: s->used = 1;
1411: s->next_unused = -1;
1412: debug("session_new: session %d", s->self);
1413:
1414: return s;
1.1 markus 1415: }
1416:
1.94 itojun 1417: static void
1.1 markus 1418: session_dump(void)
1419: {
1420: int i;
1.237 djm 1421: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1422: Session *s = &sessions[i];
1.237 djm 1423:
1424: debug("dump: used %d next_unused %d session %d %p "
1425: "channel %d pid %ld",
1.1 markus 1426: s->used,
1.237 djm 1427: s->next_unused,
1.1 markus 1428: s->self,
1429: s,
1430: s->chanid,
1.137 mpech 1431: (long)s->pid);
1.1 markus 1432: }
1433: }
1434:
1.2 markus 1435: int
1.97 markus 1436: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1437: {
1438: Session *s = session_new();
1439: debug("session_open: channel %d", chanid);
1440: if (s == NULL) {
1441: error("no more sessions");
1442: return 0;
1443: }
1.97 markus 1444: s->authctxt = authctxt;
1445: s->pw = authctxt->pw;
1.167 djm 1446: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1447: fatal("no user for session %d", s->self);
1.2 markus 1448: debug("session_open: session %d: link with channel %d", s->self, chanid);
1449: s->chanid = chanid;
1450: return 1;
1451: }
1452:
1.130 provos 1453: Session *
1454: session_by_tty(char *tty)
1455: {
1456: int i;
1.237 djm 1457: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1458: Session *s = &sessions[i];
1459: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1460: debug("session_by_tty: session %d tty %s", i, tty);
1461: return s;
1462: }
1463: }
1464: debug("session_by_tty: unknown tty %.100s", tty);
1465: session_dump();
1466: return NULL;
1467: }
1468:
1.94 itojun 1469: static Session *
1.2 markus 1470: session_by_channel(int id)
1471: {
1472: int i;
1.237 djm 1473: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1474: Session *s = &sessions[i];
1475: if (s->used && s->chanid == id) {
1.237 djm 1476: debug("session_by_channel: session %d channel %d",
1477: i, id);
1.2 markus 1478: return s;
1479: }
1480: }
1481: debug("session_by_channel: unknown channel %d", id);
1482: session_dump();
1483: return NULL;
1484: }
1485:
1.94 itojun 1486: static Session *
1.184 djm 1487: session_by_x11_channel(int id)
1488: {
1489: int i, j;
1490:
1.237 djm 1491: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1492: Session *s = &sessions[i];
1493:
1494: if (s->x11_chanids == NULL || !s->used)
1495: continue;
1496: for (j = 0; s->x11_chanids[j] != -1; j++) {
1497: if (s->x11_chanids[j] == id) {
1498: debug("session_by_x11_channel: session %d "
1499: "channel %d", s->self, id);
1500: return s;
1501: }
1502: }
1503: }
1504: debug("session_by_x11_channel: unknown channel %d", id);
1505: session_dump();
1506: return NULL;
1507: }
1508:
1509: static Session *
1.2 markus 1510: session_by_pid(pid_t pid)
1511: {
1512: int i;
1.137 mpech 1513: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1514: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1515: Session *s = &sessions[i];
1516: if (s->used && s->pid == pid)
1517: return s;
1518: }
1.137 mpech 1519: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1520: session_dump();
1521: return NULL;
1522: }
1523:
1.94 itojun 1524: static int
1.2 markus 1525: session_window_change_req(Session *s)
1526: {
1527: s->col = packet_get_int();
1528: s->row = packet_get_int();
1529: s->xpixel = packet_get_int();
1530: s->ypixel = packet_get_int();
1.116 markus 1531: packet_check_eom();
1.2 markus 1532: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1533: return 1;
1534: }
1535:
1.94 itojun 1536: static int
1.2 markus 1537: session_pty_req(Session *s)
1538: {
1.45 markus 1539: u_int len;
1.72 stevesk 1540: int n_bytes;
1.132 markus 1541:
1.268 djm 1542: if (no_pty_flag || !options.permit_tty) {
1.86 markus 1543: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1544: return 0;
1.86 markus 1545: }
1546: if (s->ttyfd != -1) {
1547: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1548: return 0;
1.86 markus 1549: }
1550:
1.2 markus 1551: s->term = packet_get_string(&len);
1.283 markus 1552: s->col = packet_get_int();
1553: s->row = packet_get_int();
1.2 markus 1554: s->xpixel = packet_get_int();
1555: s->ypixel = packet_get_int();
1556:
1557: if (strcmp(s->term, "") == 0) {
1.265 djm 1558: free(s->term);
1.2 markus 1559: s->term = NULL;
1560: }
1.86 markus 1561:
1.2 markus 1562: /* Allocate a pty and open it. */
1.86 markus 1563: debug("Allocating pty.");
1.237 djm 1564: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1565: sizeof(s->tty)))) {
1.265 djm 1566: free(s->term);
1.2 markus 1567: s->term = NULL;
1568: s->ptyfd = -1;
1569: s->ttyfd = -1;
1570: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1571: return 0;
1.2 markus 1572: }
1573: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1574:
1.283 markus 1575: n_bytes = packet_remaining();
1.86 markus 1576: tty_parse_modes(s->ttyfd, &n_bytes);
1577:
1.130 provos 1578: if (!use_privsep)
1579: pty_setowner(s->pw, s->tty);
1.86 markus 1580:
1581: /* Set window size from the packet. */
1.2 markus 1582: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1583:
1.116 markus 1584: packet_check_eom();
1.9 markus 1585: session_proctitle(s);
1.2 markus 1586: return 1;
1587: }
1588:
1.94 itojun 1589: static int
1.7 markus 1590: session_subsystem_req(Session *s)
1591: {
1.105 markus 1592: struct stat st;
1.45 markus 1593: u_int len;
1.7 markus 1594: int success = 0;
1.267 djm 1595: char *prog, *cmd;
1.182 djm 1596: u_int i;
1.7 markus 1597:
1.267 djm 1598: s->subsys = packet_get_string(&len);
1.116 markus 1599: packet_check_eom();
1.267 djm 1600: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1601: s->pw->pw_name);
1.18 jakob 1602:
1603: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1604: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1605: prog = options.subsystem_command[i];
1606: cmd = options.subsystem_args[i];
1.249 dtucker 1607: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1608: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1609: debug("subsystem: %s", prog);
1.225 markus 1610: } else {
1.249 dtucker 1611: if (stat(prog, &st) < 0)
1612: debug("subsystem: cannot stat %s: %s",
1613: prog, strerror(errno));
1.225 markus 1614: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1615: debug("subsystem: exec() %s", cmd);
1.105 markus 1616: }
1.237 djm 1617: success = do_exec(s, cmd) == 0;
1.122 markus 1618: break;
1.18 jakob 1619: }
1620: }
1621:
1622: if (!success)
1.267 djm 1623: logit("subsystem request for %.100s by user %s failed, "
1624: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1625:
1626: return success;
1627: }
1628:
1.94 itojun 1629: static int
1.7 markus 1630: session_x11_req(Session *s)
1631: {
1.81 markus 1632: int success;
1.7 markus 1633:
1.184 djm 1634: if (s->auth_proto != NULL || s->auth_data != NULL) {
1635: error("session_x11_req: session %d: "
1.190 stevesk 1636: "x11 forwarding already active", s->self);
1.184 djm 1637: return 0;
1638: }
1.7 markus 1639: s->single_connection = packet_get_char();
1640: s->auth_proto = packet_get_string(NULL);
1641: s->auth_data = packet_get_string(NULL);
1642: s->screen = packet_get_int();
1.116 markus 1643: packet_check_eom();
1.7 markus 1644:
1.282 djm 1645: if (xauth_valid_string(s->auth_proto) &&
1646: xauth_valid_string(s->auth_data))
1647: success = session_setup_x11fwd(s);
1648: else {
1649: success = 0;
1650: error("Invalid X11 forwarding data");
1651: }
1.81 markus 1652: if (!success) {
1.265 djm 1653: free(s->auth_proto);
1654: free(s->auth_data);
1.84 markus 1655: s->auth_proto = NULL;
1656: s->auth_data = NULL;
1.7 markus 1657: }
1.81 markus 1658: return success;
1.7 markus 1659: }
1660:
1.94 itojun 1661: static int
1.19 markus 1662: session_shell_req(Session *s)
1663: {
1.116 markus 1664: packet_check_eom();
1.237 djm 1665: return do_exec(s, NULL) == 0;
1.19 markus 1666: }
1667:
1.94 itojun 1668: static int
1.19 markus 1669: session_exec_req(Session *s)
1670: {
1.237 djm 1671: u_int len, success;
1672:
1.19 markus 1673: char *command = packet_get_string(&len);
1.116 markus 1674: packet_check_eom();
1.237 djm 1675: success = do_exec(s, command) == 0;
1.265 djm 1676: free(command);
1.237 djm 1677: return success;
1.19 markus 1678: }
1679:
1.94 itojun 1680: static int
1.157 markus 1681: session_break_req(Session *s)
1682: {
1683:
1.175 deraadt 1684: packet_get_int(); /* ignored */
1.157 markus 1685: packet_check_eom();
1686:
1.259 djm 1687: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1688: return 0;
1689: return 1;
1690: }
1691:
1692: static int
1.173 djm 1693: session_env_req(Session *s)
1694: {
1695: char *name, *val;
1696: u_int name_len, val_len, i;
1697:
1.271 djm 1698: name = packet_get_cstring(&name_len);
1699: val = packet_get_cstring(&val_len);
1.173 djm 1700: packet_check_eom();
1701:
1702: /* Don't set too many environment variables */
1703: if (s->num_env > 128) {
1704: debug2("Ignoring env request %s: too many env vars", name);
1705: goto fail;
1706: }
1707:
1708: for (i = 0; i < options.num_accept_env; i++) {
1709: if (match_pattern(name, options.accept_env[i])) {
1710: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1711: s->env = xrecallocarray(s->env, s->num_env,
1712: s->num_env + 1, sizeof(*s->env));
1.173 djm 1713: s->env[s->num_env].name = name;
1714: s->env[s->num_env].val = val;
1715: s->num_env++;
1716: return (1);
1717: }
1718: }
1719: debug2("Ignoring env request %s: disallowed name", name);
1720:
1721: fail:
1.265 djm 1722: free(name);
1723: free(val);
1.173 djm 1724: return (0);
1725: }
1726:
1727: static int
1.43 markus 1728: session_auth_agent_req(Session *s)
1729: {
1730: static int called = 0;
1.116 markus 1731: packet_check_eom();
1.235 pyr 1732: if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
1.44 markus 1733: debug("session_auth_agent_req: no_agent_forwarding_flag");
1734: return 0;
1735: }
1.43 markus 1736: if (called) {
1737: return 0;
1738: } else {
1739: called = 1;
1740: return auth_input_request_forwarding(s->pw);
1741: }
1742: }
1743:
1.123 markus 1744: int
1745: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1746: {
1747: int success = 0;
1748: Session *s;
1749:
1.123 markus 1750: if ((s = session_by_channel(c->self)) == NULL) {
1.155 itojun 1751: logit("session_input_channel_req: no session %d req %.100s",
1.123 markus 1752: c->self, rtype);
1753: return 0;
1754: }
1755: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1756:
1757: /*
1.64 markus 1758: * a session is in LARVAL state until a shell, a command
1759: * or a subsystem is executed
1.2 markus 1760: */
1761: if (c->type == SSH_CHANNEL_LARVAL) {
1762: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1763: success = session_shell_req(s);
1.2 markus 1764: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1765: success = session_exec_req(s);
1.2 markus 1766: } else if (strcmp(rtype, "pty-req") == 0) {
1.221 stevesk 1767: success = session_pty_req(s);
1.7 markus 1768: } else if (strcmp(rtype, "x11-req") == 0) {
1769: success = session_x11_req(s);
1.43 markus 1770: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1771: success = session_auth_agent_req(s);
1.7 markus 1772: } else if (strcmp(rtype, "subsystem") == 0) {
1773: success = session_subsystem_req(s);
1.173 djm 1774: } else if (strcmp(rtype, "env") == 0) {
1775: success = session_env_req(s);
1.2 markus 1776: }
1777: }
1778: if (strcmp(rtype, "window-change") == 0) {
1779: success = session_window_change_req(s);
1.177 djm 1780: } else if (strcmp(rtype, "break") == 0) {
1781: success = session_break_req(s);
1.2 markus 1782: }
1.177 djm 1783:
1.123 markus 1784: return success;
1.2 markus 1785: }
1786:
1787: void
1.256 djm 1788: session_set_fds(Session *s, int fdin, int fdout, int fderr, int ignore_fderr,
1789: int is_tty)
1.2 markus 1790: {
1791: /*
1792: * now that have a child and a pipe to the child,
1793: * we can activate our channel and register the fd's
1794: */
1795: if (s->chanid == -1)
1796: fatal("no channel for session %d", s->self);
1797: channel_set_fds(s->chanid,
1798: fdout, fdin, fderr,
1.256 djm 1799: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1800: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1801: }
1802:
1.85 markus 1803: /*
1804: * Function to perform pty cleanup. Also called if we get aborted abnormally
1805: * (e.g., due to a dropped connection).
1806: */
1.130 provos 1807: void
1.165 markus 1808: session_pty_cleanup2(Session *s)
1.1 markus 1809: {
1.85 markus 1810: if (s == NULL) {
1811: error("session_pty_cleanup: no session");
1812: return;
1813: }
1814: if (s->ttyfd == -1)
1.1 markus 1815: return;
1816:
1.54 stevesk 1817: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1818:
1819: /* Record that the user has logged out. */
1.85 markus 1820: if (s->pid != 0)
1821: record_logout(s->pid, s->tty);
1.1 markus 1822:
1823: /* Release the pseudo-tty. */
1.130 provos 1824: if (getuid() == 0)
1825: pty_release(s->tty);
1.1 markus 1826:
1827: /*
1828: * Close the server side of the socket pairs. We must do this after
1829: * the pty cleanup, so that another process doesn't get this pty
1830: * while we're still cleaning up.
1831: */
1.237 djm 1832: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1833: error("close(s->ptymaster/%d): %s",
1834: s->ptymaster, strerror(errno));
1.108 markus 1835:
1836: /* unlink pty from session */
1837: s->ttyfd = -1;
1.2 markus 1838: }
1839:
1.130 provos 1840: void
1.165 markus 1841: session_pty_cleanup(Session *s)
1.130 provos 1842: {
1.165 markus 1843: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1844: }
1845:
1.147 markus 1846: static char *
1847: sig2name(int sig)
1848: {
1849: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1850: SSH_SIG(ABRT);
1851: SSH_SIG(ALRM);
1852: SSH_SIG(FPE);
1853: SSH_SIG(HUP);
1854: SSH_SIG(ILL);
1855: SSH_SIG(INT);
1856: SSH_SIG(KILL);
1857: SSH_SIG(PIPE);
1858: SSH_SIG(QUIT);
1859: SSH_SIG(SEGV);
1860: SSH_SIG(TERM);
1861: SSH_SIG(USR1);
1862: SSH_SIG(USR2);
1863: #undef SSH_SIG
1864: return "SIG@openssh.com";
1865: }
1866:
1.94 itojun 1867: static void
1.184 djm 1868: session_close_x11(int id)
1869: {
1870: Channel *c;
1871:
1.189 markus 1872: if ((c = channel_by_id(id)) == NULL) {
1.184 djm 1873: debug("session_close_x11: x11 channel %d missing", id);
1874: } else {
1875: /* Detach X11 listener */
1876: debug("session_close_x11: detach x11 channel %d", id);
1877: channel_cancel_cleanup(id);
1878: if (c->ostate != CHAN_OUTPUT_CLOSED)
1879: chan_mark_dead(c);
1880: }
1881: }
1882:
1883: static void
1884: session_close_single_x11(int id, void *arg)
1885: {
1886: Session *s;
1887: u_int i;
1888:
1889: debug3("session_close_single_x11: channel %d", id);
1890: channel_cancel_cleanup(id);
1.221 stevesk 1891: if ((s = session_by_x11_channel(id)) == NULL)
1.184 djm 1892: fatal("session_close_single_x11: no x11 channel %d", id);
1893: for (i = 0; s->x11_chanids[i] != -1; i++) {
1894: debug("session_close_single_x11: session %d: "
1895: "closing channel %d", s->self, s->x11_chanids[i]);
1896: /*
1897: * The channel "id" is already closing, but make sure we
1898: * close all of its siblings.
1899: */
1900: if (s->x11_chanids[i] != id)
1901: session_close_x11(s->x11_chanids[i]);
1902: }
1.265 djm 1903: free(s->x11_chanids);
1.184 djm 1904: s->x11_chanids = NULL;
1.265 djm 1905: free(s->display);
1906: s->display = NULL;
1907: free(s->auth_proto);
1908: s->auth_proto = NULL;
1909: free(s->auth_data);
1910: s->auth_data = NULL;
1911: free(s->auth_display);
1912: s->auth_display = NULL;
1.184 djm 1913: }
1914:
1915: static void
1.2 markus 1916: session_exit_message(Session *s, int status)
1917: {
1918: Channel *c;
1.124 markus 1919:
1920: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 1921: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1922: s->self, s->chanid);
1.137 mpech 1923: debug("session_exit_message: session %d channel %d pid %ld",
1924: s->self, s->chanid, (long)s->pid);
1.2 markus 1925:
1926: if (WIFEXITED(status)) {
1.124 markus 1927: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1928: packet_put_int(WEXITSTATUS(status));
1929: packet_send();
1930: } else if (WIFSIGNALED(status)) {
1.124 markus 1931: channel_request_start(s->chanid, "exit-signal", 0);
1.147 markus 1932: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 1933: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 1934: packet_put_cstring("");
1935: packet_put_cstring("");
1936: packet_send();
1937: } else {
1938: /* Some weird exit cause. Just exit. */
1939: packet_disconnect("wait returned status %04x.", status);
1940: }
1941:
1942: /* disconnect channel */
1943: debug("session_exit_message: release channel %d", s->chanid);
1.187 djm 1944:
1945: /*
1946: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 1947: * the channel gets EOF. The session will be then be closed
1.187 djm 1948: * by session_close_by_channel when the childs close their fds.
1949: */
1950: channel_register_cleanup(c->self, session_close_by_channel, 1);
1951:
1.5 markus 1952: /*
1953: * emulate a write failure with 'chan_write_failed', nobody will be
1954: * interested in data we write.
1955: * Note that we must not call 'chan_read_failed', since there could
1956: * be some more data waiting in the pipe.
1957: */
1.8 markus 1958: if (c->ostate != CHAN_OUTPUT_CLOSED)
1959: chan_write_failed(c);
1.2 markus 1960: }
1961:
1.130 provos 1962: void
1.85 markus 1963: session_close(Session *s)
1.2 markus 1964: {
1.281 djm 1965: struct ssh *ssh = active_state; /* XXX */
1.182 djm 1966: u_int i;
1.173 djm 1967:
1.280 djm 1968: verbose("Close session: user %s from %.200s port %d id %d",
1969: s->pw->pw_name,
1.281 djm 1970: ssh_remote_ipaddr(ssh),
1971: ssh_remote_port(ssh),
1.280 djm 1972: s->self);
1973:
1.165 markus 1974: if (s->ttyfd != -1)
1.85 markus 1975: session_pty_cleanup(s);
1.265 djm 1976: free(s->term);
1977: free(s->display);
1978: free(s->x11_chanids);
1979: free(s->auth_display);
1980: free(s->auth_data);
1981: free(s->auth_proto);
1.267 djm 1982: free(s->subsys);
1.219 djm 1983: if (s->env != NULL) {
1984: for (i = 0; i < s->num_env; i++) {
1.265 djm 1985: free(s->env[i].name);
1986: free(s->env[i].val);
1.219 djm 1987: }
1.265 djm 1988: free(s->env);
1.173 djm 1989: }
1.9 markus 1990: session_proctitle(s);
1.237 djm 1991: session_unused(s->self);
1.2 markus 1992: }
1993:
1994: void
1995: session_close_by_pid(pid_t pid, int status)
1996: {
1997: Session *s = session_by_pid(pid);
1998: if (s == NULL) {
1.137 mpech 1999: debug("session_close_by_pid: no session for pid %ld",
2000: (long)pid);
1.2 markus 2001: return;
2002: }
2003: if (s->chanid != -1)
2004: session_exit_message(s, status);
1.187 djm 2005: if (s->ttyfd != -1)
2006: session_pty_cleanup(s);
1.197 djm 2007: s->pid = 0;
1.98 markus 2008: }
2009:
1.2 markus 2010: /*
2011: * this is called when a channel dies before
2012: * the session 'child' itself dies
2013: */
2014: void
2015: session_close_by_channel(int id, void *arg)
2016: {
2017: Session *s = session_by_channel(id);
1.187 djm 2018: u_int i;
1.184 djm 2019:
1.2 markus 2020: if (s == NULL) {
1.107 markus 2021: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 2022: return;
2023: }
1.137 mpech 2024: debug("session_close_by_channel: channel %d child %ld",
2025: id, (long)s->pid);
1.107 markus 2026: if (s->pid != 0) {
2027: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 2028: /*
2029: * delay detach of session, but release pty, since
2030: * the fd's to the child are already closed
2031: */
1.165 markus 2032: if (s->ttyfd != -1)
1.108 markus 2033: session_pty_cleanup(s);
1.107 markus 2034: return;
2035: }
2036: /* detach by removing callback */
1.2 markus 2037: channel_cancel_cleanup(s->chanid);
1.187 djm 2038:
2039: /* Close any X11 listeners associated with this session */
2040: if (s->x11_chanids != NULL) {
2041: for (i = 0; s->x11_chanids[i] != -1; i++) {
2042: session_close_x11(s->x11_chanids[i]);
2043: s->x11_chanids[i] = -1;
2044: }
2045: }
2046:
1.2 markus 2047: s->chanid = -1;
1.106 markus 2048: session_close(s);
2049: }
2050:
2051: void
1.130 provos 2052: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 2053: {
2054: int i;
1.237 djm 2055: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2056: Session *s = &sessions[i];
1.130 provos 2057: if (s->used) {
2058: if (closefunc != NULL)
2059: closefunc(s);
2060: else
2061: session_close(s);
2062: }
1.2 markus 2063: }
1.9 markus 2064: }
2065:
1.94 itojun 2066: static char *
1.9 markus 2067: session_tty_list(void)
2068: {
2069: static char buf[1024];
2070: int i;
2071: buf[0] = '\0';
1.237 djm 2072: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2073: Session *s = &sessions[i];
2074: if (s->used && s->ttyfd != -1) {
2075: if (buf[0] != '\0')
2076: strlcat(buf, ",", sizeof buf);
2077: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2078: }
2079: }
2080: if (buf[0] == '\0')
2081: strlcpy(buf, "notty", sizeof buf);
2082: return buf;
2083: }
2084:
2085: void
2086: session_proctitle(Session *s)
2087: {
2088: if (s->pw == NULL)
2089: error("no user for session %d", s->self);
2090: else
2091: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2092: }
2093:
2094: int
2095: session_setup_x11fwd(Session *s)
2096: {
2097: struct stat st;
1.109 stevesk 2098: char display[512], auth_display[512];
1.272 djm 2099: char hostname[NI_MAXHOST];
1.184 djm 2100: u_int i;
1.81 markus 2101:
2102: if (no_x11_forwarding_flag) {
2103: packet_send_debug("X11 forwarding disabled in user configuration file.");
2104: return 0;
2105: }
2106: if (!options.x11_forwarding) {
2107: debug("X11 forwarding disabled in server configuration file.");
2108: return 0;
2109: }
1.275 djm 2110: if (options.xauth_location == NULL ||
1.81 markus 2111: (stat(options.xauth_location, &st) == -1)) {
2112: packet_send_debug("No xauth program; cannot forward with spoofing.");
2113: return 0;
2114: }
1.87 markus 2115: if (s->display != NULL) {
1.81 markus 2116: debug("X11 display already set.");
2117: return 0;
2118: }
1.140 deraadt 2119: if (x11_create_display_inet(options.x11_display_offset,
2120: options.x11_use_localhost, s->single_connection,
1.184 djm 2121: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2122: debug("x11_create_display_inet failed.");
1.81 markus 2123: return 0;
1.184 djm 2124: }
2125: for (i = 0; s->x11_chanids[i] != -1; i++) {
2126: channel_register_cleanup(s->x11_chanids[i],
1.187 djm 2127: session_close_single_x11, 0);
1.81 markus 2128: }
1.109 stevesk 2129:
2130: /* Set up a suitable value for the DISPLAY variable. */
2131: if (gethostname(hostname, sizeof(hostname)) < 0)
2132: fatal("gethostname: %.100s", strerror(errno));
2133: /*
2134: * auth_display must be used as the displayname when the
2135: * authorization entry is added with xauth(1). This will be
2136: * different than the DISPLAY string for localhost displays.
2137: */
1.119 stevesk 2138: if (options.x11_use_localhost) {
1.140 deraadt 2139: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2140: s->display_number, s->screen);
1.140 deraadt 2141: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2142: s->display_number, s->screen);
1.109 stevesk 2143: s->display = xstrdup(display);
1.118 stevesk 2144: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2145: } else {
1.140 deraadt 2146: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2147: s->display_number, s->screen);
2148: s->display = xstrdup(display);
1.118 stevesk 2149: s->auth_display = xstrdup(display);
1.109 stevesk 2150: }
2151:
1.81 markus 2152: return 1;
1.2 markus 2153: }
2154:
1.94 itojun 2155: static void
1.49 markus 2156: do_authenticated2(Authctxt *authctxt)
1.2 markus 2157: {
1.97 markus 2158: server_loop2(authctxt);
1.165 markus 2159: }
2160:
2161: void
2162: do_cleanup(Authctxt *authctxt)
2163: {
2164: static int called = 0;
2165:
2166: debug("do_cleanup");
2167:
2168: /* no cleanup if we're in the child for login shell */
2169: if (is_child)
2170: return;
2171:
2172: /* avoid double cleanup */
2173: if (called)
2174: return;
2175: called = 1;
2176:
1.218 markus 2177: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2178: return;
2179: #ifdef KRB5
2180: if (options.kerberos_ticket_cleanup &&
2181: authctxt->krb5_ctx)
2182: krb5_cleanup_proc(authctxt);
1.161 markus 2183: #endif
1.165 markus 2184:
2185: #ifdef GSSAPI
1.283 markus 2186: if (options.gss_cleanup_creds)
1.165 markus 2187: ssh_gssapi_cleanup_creds();
2188: #endif
2189:
2190: /* remove agent socket */
2191: auth_sock_cleanup_proc(authctxt->pw);
1.290 ! djm 2192:
! 2193: /* remove userauth info */
! 2194: if (auth_info_file != NULL) {
! 2195: temporarily_use_uid(authctxt->pw);
! 2196: unlink(auth_info_file);
! 2197: restore_uid();
! 2198: free(auth_info_file);
! 2199: auth_info_file = NULL;
! 2200: }
1.165 markus 2201:
2202: /*
2203: * Cleanup ptys/utmp only if privsep is disabled,
2204: * or if running in monitor.
2205: */
2206: if (!use_privsep || mm_is_monitor())
2207: session_destroy_all(session_pty_cleanup2);
1.1 markus 2208: }
1.281 djm 2209:
2210: /* Return a name for the remote host that fits inside utmp_size */
2211:
2212: const char *
2213: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2214: {
2215: const char *remote = "";
2216:
2217: if (utmp_size > 0)
2218: remote = auth_get_canonical_hostname(ssh, use_dns);
2219: if (utmp_size == 0 || strlen(remote) > utmp_size)
2220: remote = ssh_remote_ipaddr(ssh);
2221: return remote;
2222: }
2223:
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