Annotation of src/usr.bin/ssh/session.c, Revision 1.295
1.295 ! djm 1: /* $OpenBSD: session.c,v 1.294 2018/03/03 03:15:51 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
1.37 deraadt 5: *
6: * As far as I am concerned, the code I have written for this software
7: * can be used freely for any purpose. Any derived versions of this
8: * software must be clearly marked as such, and if the derived work is
9: * incompatible with the protocol description in the RFC file, it must be
10: * called by a name other than "ssh" or "Secure Shell".
11: *
1.2 markus 12: * SSH2 support by Markus Friedl.
1.95 markus 13: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.37 deraadt 14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2 markus 34: */
1.1 markus 35:
1.193 stevesk 36: #include <sys/types.h>
37: #include <sys/wait.h>
1.194 stevesk 38: #include <sys/un.h>
1.196 stevesk 39: #include <sys/stat.h>
1.207 stevesk 40: #include <sys/socket.h>
1.236 djm 41: #include <sys/queue.h>
1.192 stevesk 42:
1.282 djm 43: #include <ctype.h>
1.209 stevesk 44: #include <errno.h>
1.253 djm 45: #include <fcntl.h>
1.204 stevesk 46: #include <grp.h>
1.223 djm 47: #include <login_cap.h>
1.272 djm 48: #include <netdb.h>
1.192 stevesk 49: #include <paths.h>
1.206 stevesk 50: #include <pwd.h>
1.195 stevesk 51: #include <signal.h>
1.215 stevesk 52: #include <stdio.h>
1.214 stevesk 53: #include <stdlib.h>
1.212 stevesk 54: #include <string.h>
1.211 stevesk 55: #include <unistd.h>
1.277 deraadt 56: #include <limits.h>
1.1 markus 57:
1.216 deraadt 58: #include "xmalloc.h"
1.51 markus 59: #include "ssh.h"
60: #include "ssh2.h"
1.59 djm 61: #include "sshpty.h"
1.1 markus 62: #include "packet.h"
63: #include "buffer.h"
1.173 djm 64: #include "match.h"
1.1 markus 65: #include "uidswap.h"
66: #include "compat.h"
1.78 markus 67: #include "channels.h"
1.216 deraadt 68: #include "key.h"
69: #include "cipher.h"
70: #include "kex.h"
71: #include "hostfile.h"
1.2 markus 72: #include "auth.h"
1.19 markus 73: #include "auth-options.h"
1.266 markus 74: #include "authfd.h"
1.50 markus 75: #include "pathnames.h"
1.51 markus 76: #include "log.h"
1.274 millert 77: #include "misc.h"
1.51 markus 78: #include "servconf.h"
1.59 djm 79: #include "sshlogin.h"
1.51 markus 80: #include "serverloop.h"
81: #include "canohost.h"
1.55 itojun 82: #include "session.h"
1.216 deraadt 83: #ifdef GSSAPI
84: #include "ssh-gss.h"
85: #endif
1.130 provos 86: #include "monitor_wrap.h"
1.225 markus 87: #include "sftp.h"
1.290 djm 88: #include "atomicio.h"
1.171 markus 89:
90: #ifdef KRB5
91: #include <kafs.h>
1.161 markus 92: #endif
93:
1.242 djm 94: #define IS_INTERNAL_SFTP(c) \
95: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
96: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
97: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
98: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
99:
1.1 markus 100: /* func */
101:
102: Session *session_new(void);
1.292 djm 103: void session_set_fds(struct ssh *, Session *, int, int, int, int, int);
1.165 markus 104: void session_pty_cleanup(Session *);
1.94 itojun 105: void session_proctitle(Session *);
1.292 djm 106: int session_setup_x11fwd(struct ssh *, Session *);
107: int do_exec_pty(struct ssh *, Session *, const char *);
108: int do_exec_no_pty(struct ssh *, Session *, const char *);
109: int do_exec(struct ssh *, Session *, const char *);
110: void do_login(struct ssh *, Session *, const char *);
111: void do_child(struct ssh *, Session *, const char *);
1.73 djm 112: void do_motd(void);
1.94 itojun 113: int check_quietlogin(Session *, const char *);
1.1 markus 114:
1.292 djm 115: static void do_authenticated2(struct ssh *, Authctxt *);
1.94 itojun 116:
1.292 djm 117: static int session_pty_req(struct ssh *, Session *);
1.65 markus 118:
1.1 markus 119: /* import */
120: extern ServerOptions options;
121: extern char *__progname;
122: extern int debug_flag;
1.45 markus 123: extern u_int utmp_len;
1.21 markus 124: extern int startup_pipe;
1.74 markus 125: extern void destroy_sensitive_data(void);
1.179 dtucker 126: extern Buffer loginmsg;
1.294 djm 127: extern struct sshauthopt *auth_opts;
1.293 djm 128: char *tun_fwd_ifnames; /* serverloop.c */
1.21 markus 129:
1.34 markus 130: /* original command from peer. */
1.92 markus 131: const char *original_command = NULL;
1.34 markus 132:
1.1 markus 133: /* data */
1.237 djm 134: static int sessions_first_unused = -1;
135: static int sessions_nalloc = 0;
136: static Session *sessions = NULL;
1.1 markus 137:
1.248 djm 138: #define SUBSYSTEM_NONE 0
139: #define SUBSYSTEM_EXT 1
140: #define SUBSYSTEM_INT_SFTP 2
141: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.225 markus 142:
1.129 provos 143: login_cap_t *lc;
1.28 millert 144:
1.165 markus 145: static int is_child = 0;
1.279 djm 146: static int in_chroot = 0;
1.165 markus 147:
1.290 djm 148: /* File containing userauth info, if ExposeAuthInfo set */
149: static char *auth_info_file = NULL;
150:
1.136 markus 151: /* Name and directory of socket for authentication agent forwarding. */
152: static char *auth_sock_name = NULL;
153: static char *auth_sock_dir = NULL;
154:
155: /* removes the agent forwarding socket */
156:
157: static void
1.165 markus 158: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 159: {
160: if (auth_sock_name != NULL) {
161: temporarily_use_uid(pw);
162: unlink(auth_sock_name);
163: rmdir(auth_sock_dir);
164: auth_sock_name = NULL;
165: restore_uid();
166: }
167: }
168:
169: static int
1.292 djm 170: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136 markus 171: {
172: Channel *nc;
1.237 djm 173: int sock = -1;
1.136 markus 174:
175: if (auth_sock_name != NULL) {
176: error("authentication forwarding requested twice.");
177: return 0;
178: }
179:
180: /* Temporarily drop privileged uid for mkdir/bind. */
181: temporarily_use_uid(pw);
182:
183: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 184: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 185:
186: /* Create private directory for socket */
187: if (mkdtemp(auth_sock_dir) == NULL) {
188: packet_send_debug("Agent forwarding disabled: "
189: "mkdtemp() failed: %.100s", strerror(errno));
190: restore_uid();
1.265 djm 191: free(auth_sock_dir);
1.136 markus 192: auth_sock_dir = NULL;
1.237 djm 193: goto authsock_err;
1.136 markus 194: }
1.237 djm 195:
196: xasprintf(&auth_sock_name, "%s/agent.%ld",
197: auth_sock_dir, (long) getpid());
1.136 markus 198:
1.274 millert 199: /* Start a Unix listener on auth_sock_name. */
200: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136 markus 201:
202: /* Restore the privileged uid. */
203: restore_uid();
204:
1.274 millert 205: /* Check for socket/bind/listen failure. */
206: if (sock < 0)
1.237 djm 207: goto authsock_err;
1.136 markus 208:
209: /* Allocate a channel for the authentication agent socket. */
1.292 djm 210: nc = channel_new(ssh, "auth socket",
1.136 markus 211: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
212: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 213: 0, "auth socket", 1);
1.245 djm 214: nc->path = xstrdup(auth_sock_name);
1.136 markus 215: return 1;
1.237 djm 216:
217: authsock_err:
1.265 djm 218: free(auth_sock_name);
1.237 djm 219: if (auth_sock_dir != NULL) {
220: rmdir(auth_sock_dir);
1.265 djm 221: free(auth_sock_dir);
1.237 djm 222: }
223: if (sock != -1)
224: close(sock);
225: auth_sock_name = NULL;
226: auth_sock_dir = NULL;
227: return 0;
1.136 markus 228: }
229:
1.179 dtucker 230: static void
231: display_loginmsg(void)
232: {
1.183 djm 233: if (buffer_len(&loginmsg) > 0) {
234: buffer_append(&loginmsg, "\0", 1);
235: printf("%s", (char *)buffer_ptr(&loginmsg));
236: buffer_clear(&loginmsg);
237: }
1.179 dtucker 238: }
1.136 markus 239:
1.290 djm 240: static void
241: prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
242: {
243: int fd = -1, success = 0;
244:
245: if (!options.expose_userauth_info || info == NULL)
246: return;
247:
248: temporarily_use_uid(pw);
249: auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
250: if ((fd = mkstemp(auth_info_file)) == -1) {
251: error("%s: mkstemp: %s", __func__, strerror(errno));
252: goto out;
253: }
254: if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
255: sshbuf_len(info)) != sshbuf_len(info)) {
256: error("%s: write: %s", __func__, strerror(errno));
257: goto out;
258: }
259: if (close(fd) != 0) {
260: error("%s: close: %s", __func__, strerror(errno));
261: goto out;
262: }
263: success = 1;
264: out:
265: if (!success) {
266: if (fd != -1)
267: close(fd);
268: free(auth_info_file);
269: auth_info_file = NULL;
270: }
271: restore_uid();
272: }
273:
1.294 djm 274: static void
275: set_permitopen_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
276: {
277: char *tmp, *cp, *host;
278: int port;
279: size_t i;
280:
281: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
282: return;
283: channel_clear_permitted_opens(ssh);
284: for (i = 0; i < auth_opts->npermitopen; i++) {
285: tmp = cp = xstrdup(auth_opts->permitopen[i]);
286: /* This shouldn't fail as it has already been checked */
287: if ((host = hpdelim(&cp)) == NULL)
288: fatal("%s: internal error: hpdelim", __func__);
289: host = cleanhostname(host);
290: if (cp == NULL || (port = permitopen_port(cp)) < 0)
291: fatal("%s: internal error: permitopen port",
292: __func__);
293: channel_add_permitted_opens(ssh, host, port);
294: free(tmp);
295: }
296: }
297:
1.65 markus 298: void
1.292 djm 299: do_authenticated(struct ssh *ssh, Authctxt *authctxt)
1.65 markus 300: {
1.153 markus 301: setproctitle("%s", authctxt->pw->pw_name);
302:
1.294 djm 303: auth_log_authopts("active", auth_opts, 0);
304:
1.65 markus 305: /* setup the channel layer */
1.274 millert 306: /* XXX - streamlocal? */
1.294 djm 307: set_permitopen_from_authopts(ssh, auth_opts);
308: if (!auth_opts->permit_port_forwarding_flag ||
309: options.disable_forwarding ||
1.261 djm 310: (options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
1.292 djm 311: channel_disable_adm_local_opens(ssh);
1.261 djm 312: else
1.292 djm 313: channel_permit_all_opens(ssh);
1.252 dtucker 314:
315: auth_debug_send();
1.65 markus 316:
1.290 djm 317: prepare_auth_info_file(authctxt->pw, authctxt->session_info);
318:
1.292 djm 319: do_authenticated2(ssh, authctxt);
1.290 djm 320:
1.292 djm 321: do_cleanup(ssh, authctxt);
1.65 markus 322: }
323:
1.282 djm 324: /* Check untrusted xauth strings for metacharacters */
325: static int
326: xauth_valid_string(const char *s)
327: {
328: size_t i;
329:
330: for (i = 0; s[i] != '\0'; i++) {
331: if (!isalnum((u_char)s[i]) &&
332: s[i] != '.' && s[i] != ':' && s[i] != '/' &&
333: s[i] != '-' && s[i] != '_')
334: return 0;
335: }
336: return 1;
337: }
338:
1.269 dtucker 339: #define USE_PIPES 1
1.1 markus 340: /*
341: * This is called to fork and execute a command when we have no tty. This
342: * will call do_child from the child, and server_loop from the parent after
343: * setting up file descriptors and such.
344: */
1.237 djm 345: int
1.292 djm 346: do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 347: {
1.137 mpech 348: pid_t pid;
1.238 markus 349: #ifdef USE_PIPES
350: int pin[2], pout[2], perr[2];
351:
1.253 djm 352: if (s == NULL)
353: fatal("do_exec_no_pty: no session");
354:
1.238 markus 355: /* Allocate pipes for communicating with the program. */
356: if (pipe(pin) < 0) {
357: error("%s: pipe in: %.100s", __func__, strerror(errno));
358: return -1;
359: }
360: if (pipe(pout) < 0) {
361: error("%s: pipe out: %.100s", __func__, strerror(errno));
362: close(pin[0]);
363: close(pin[1]);
364: return -1;
365: }
1.256 djm 366: if (pipe(perr) < 0) {
367: error("%s: pipe err: %.100s", __func__,
368: strerror(errno));
369: close(pin[0]);
370: close(pin[1]);
371: close(pout[0]);
372: close(pout[1]);
373: return -1;
1.238 markus 374: }
375: #else
1.237 djm 376: int inout[2], err[2];
1.1 markus 377:
1.253 djm 378: if (s == NULL)
379: fatal("do_exec_no_pty: no session");
380:
1.1 markus 381: /* Uses socket pairs to communicate with the program. */
1.237 djm 382: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
383: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
384: return -1;
385: }
1.256 djm 386: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
387: error("%s: socketpair #2: %.100s", __func__,
388: strerror(errno));
389: close(inout[0]);
390: close(inout[1]);
391: return -1;
1.237 djm 392: }
1.238 markus 393: #endif
1.237 djm 394:
1.9 markus 395: session_proctitle(s);
1.1 markus 396:
397: /* Fork the child. */
1.237 djm 398: switch ((pid = fork())) {
399: case -1:
400: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 markus 401: #ifdef USE_PIPES
402: close(pin[0]);
403: close(pin[1]);
404: close(pout[0]);
405: close(pout[1]);
1.256 djm 406: close(perr[0]);
1.238 markus 407: close(perr[1]);
408: #else
1.237 djm 409: close(inout[0]);
410: close(inout[1]);
411: close(err[0]);
1.256 djm 412: close(err[1]);
1.238 markus 413: #endif
1.237 djm 414: return -1;
415: case 0:
1.165 markus 416: is_child = 1;
1.144 markus 417:
1.1 markus 418: /*
419: * Create a new session and process group since the 4.4BSD
420: * setlogin() affects the entire process group.
421: */
422: if (setsid() < 0)
423: error("setsid failed: %.100s", strerror(errno));
424:
1.238 markus 425: #ifdef USE_PIPES
426: /*
427: * Redirect stdin. We close the parent side of the socket
428: * pair, and make the child side the standard input.
429: */
430: close(pin[1]);
431: if (dup2(pin[0], 0) < 0)
432: perror("dup2 stdin");
433: close(pin[0]);
434:
435: /* Redirect stdout. */
436: close(pout[0]);
437: if (dup2(pout[1], 1) < 0)
438: perror("dup2 stdout");
439: close(pout[1]);
440:
441: /* Redirect stderr. */
1.256 djm 442: close(perr[0]);
1.238 markus 443: if (dup2(perr[1], 2) < 0)
444: perror("dup2 stderr");
445: close(perr[1]);
446: #else
1.1 markus 447: /*
448: * Redirect stdin, stdout, and stderr. Stdin and stdout will
449: * use the same socket, as some programs (particularly rdist)
450: * seem to depend on it.
451: */
452: close(inout[1]);
1.256 djm 453: close(err[1]);
1.1 markus 454: if (dup2(inout[0], 0) < 0) /* stdin */
455: perror("dup2 stdin");
1.237 djm 456: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 457: perror("dup2 stdout");
1.238 markus 458: close(inout[0]);
1.1 markus 459: if (dup2(err[0], 2) < 0) /* stderr */
460: perror("dup2 stderr");
1.238 markus 461: close(err[0]);
462: #endif
1.1 markus 463:
464: /* Do processing for the child (exec command etc). */
1.292 djm 465: do_child(ssh, s, command);
1.1 markus 466: /* NOTREACHED */
1.237 djm 467: default:
468: break;
1.1 markus 469: }
1.237 djm 470:
1.1 markus 471: s->pid = pid;
1.47 markus 472: /* Set interactive/non-interactive mode. */
1.257 djm 473: packet_set_interactive(s->display != NULL,
474: options.ip_qos_interactive, options.ip_qos_bulk);
1.1 markus 475:
1.238 markus 476: #ifdef USE_PIPES
477: /* We are the parent. Close the child sides of the pipes. */
478: close(pin[0]);
479: close(pout[1]);
480: close(perr[1]);
481:
1.292 djm 482: session_set_fds(ssh, s, pin[1], pout[0], perr[0],
1.283 markus 483: s->is_subsystem, 0);
1.238 markus 484: #else
1.1 markus 485: /* We are the parent. Close the child sides of the socket pairs. */
486: close(inout[0]);
487: close(err[0]);
488:
489: /*
490: * Enter the interactive session. Note: server_loop must be able to
491: * handle the case that fdin and fdout are the same.
492: */
1.283 markus 493: session_set_fds(s, inout[1], inout[1], err[1],
494: s->is_subsystem, 0);
1.238 markus 495: #endif
1.237 djm 496: return 0;
1.1 markus 497: }
498:
499: /*
500: * This is called to fork and execute a command when we have a tty. This
501: * will call do_child from the child, and server_loop from the parent after
502: * setting up file descriptors, controlling tty, updating wtmp, utmp,
503: * lastlog, and other such operations.
504: */
1.237 djm 505: int
1.292 djm 506: do_exec_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 507: {
508: int fdout, ptyfd, ttyfd, ptymaster;
509: pid_t pid;
510:
511: if (s == NULL)
512: fatal("do_exec_pty: no session");
513: ptyfd = s->ptyfd;
514: ttyfd = s->ttyfd;
515:
1.237 djm 516: /*
517: * Create another descriptor of the pty master side for use as the
518: * standard input. We could use the original descriptor, but this
519: * simplifies code in server_loop. The descriptor is bidirectional.
520: * Do this before forking (and cleanup in the child) so as to
521: * detect and gracefully fail out-of-fd conditions.
522: */
523: if ((fdout = dup(ptyfd)) < 0) {
524: error("%s: dup #1: %s", __func__, strerror(errno));
525: close(ttyfd);
526: close(ptyfd);
527: return -1;
528: }
529: /* we keep a reference to the pty master */
530: if ((ptymaster = dup(ptyfd)) < 0) {
531: error("%s: dup #2: %s", __func__, strerror(errno));
532: close(ttyfd);
533: close(ptyfd);
534: close(fdout);
535: return -1;
536: }
537:
1.1 markus 538: /* Fork the child. */
1.237 djm 539: switch ((pid = fork())) {
540: case -1:
541: error("%s: fork: %.100s", __func__, strerror(errno));
542: close(fdout);
543: close(ptymaster);
544: close(ttyfd);
545: close(ptyfd);
546: return -1;
547: case 0:
1.165 markus 548: is_child = 1;
1.97 markus 549:
1.237 djm 550: close(fdout);
551: close(ptymaster);
552:
1.1 markus 553: /* Close the master side of the pseudo tty. */
554: close(ptyfd);
555:
556: /* Make the pseudo tty our controlling tty. */
557: pty_make_controlling_tty(&ttyfd, s->tty);
558:
1.103 markus 559: /* Redirect stdin/stdout/stderr from the pseudo tty. */
560: if (dup2(ttyfd, 0) < 0)
561: error("dup2 stdin: %s", strerror(errno));
562: if (dup2(ttyfd, 1) < 0)
563: error("dup2 stdout: %s", strerror(errno));
564: if (dup2(ttyfd, 2) < 0)
565: error("dup2 stderr: %s", strerror(errno));
1.1 markus 566:
567: /* Close the extra descriptor for the pseudo tty. */
568: close(ttyfd);
569:
1.24 markus 570: /* record login, etc. similar to login(1) */
1.292 djm 571: do_login(ssh, s, command);
1.228 djm 572:
1.237 djm 573: /*
574: * Do common processing for the child, such as execing
575: * the command.
576: */
1.292 djm 577: do_child(ssh, s, command);
1.1 markus 578: /* NOTREACHED */
1.237 djm 579: default:
580: break;
1.1 markus 581: }
582: s->pid = pid;
583:
584: /* Parent. Close the slave side of the pseudo tty. */
585: close(ttyfd);
586:
1.237 djm 587: /* Enter interactive session. */
1.1 markus 588: s->ptymaster = ptymaster;
1.257 djm 589: packet_set_interactive(1,
590: options.ip_qos_interactive, options.ip_qos_bulk);
1.292 djm 591: session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
1.237 djm 592: return 0;
1.24 markus 593: }
594:
1.90 markus 595: /*
596: * This is called to fork and execute a command. If another command is
597: * to be forced, execute that instead.
598: */
1.237 djm 599: int
1.292 djm 600: do_exec(struct ssh *ssh, Session *s, const char *command)
1.90 markus 601: {
1.237 djm 602: int ret;
1.280 djm 603: const char *forced = NULL, *tty = NULL;
604: char session_type[1024];
1.237 djm 605:
1.210 dtucker 606: if (options.adm_forced_command) {
607: original_command = command;
608: command = options.adm_forced_command;
1.267 djm 609: forced = "(config)";
1.294 djm 610: } else if (auth_opts->force_command != NULL) {
1.90 markus 611: original_command = command;
1.294 djm 612: command = auth_opts->force_command;
1.267 djm 613: forced = "(key-option)";
614: }
615: if (forced != NULL) {
1.248 djm 616: if (IS_INTERNAL_SFTP(command)) {
617: s->is_subsystem = s->is_subsystem ?
618: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
619: } else if (s->is_subsystem)
1.225 markus 620: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 621: snprintf(session_type, sizeof(session_type),
622: "forced-command %s '%.900s'", forced, command);
623: } else if (s->is_subsystem) {
624: snprintf(session_type, sizeof(session_type),
625: "subsystem '%.900s'", s->subsys);
626: } else if (command == NULL) {
627: snprintf(session_type, sizeof(session_type), "shell");
628: } else {
629: /* NB. we don't log unforced commands to preserve privacy */
630: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 631: }
1.163 markus 632:
1.267 djm 633: if (s->ttyfd != -1) {
634: tty = s->tty;
635: if (strncmp(tty, "/dev/", 5) == 0)
636: tty += 5;
637: }
638:
1.280 djm 639: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 640: session_type,
641: tty == NULL ? "" : " on ",
642: tty == NULL ? "" : tty,
643: s->pw->pw_name,
1.281 djm 644: ssh_remote_ipaddr(ssh),
645: ssh_remote_port(ssh),
1.280 djm 646: s->self);
1.267 djm 647:
1.163 markus 648: #ifdef GSSAPI
649: if (options.gss_authentication) {
650: temporarily_use_uid(s->pw);
651: ssh_gssapi_storecreds();
652: restore_uid();
653: }
654: #endif
1.90 markus 655: if (s->ttyfd != -1)
1.292 djm 656: ret = do_exec_pty(ssh, s, command);
1.90 markus 657: else
1.292 djm 658: ret = do_exec_no_pty(ssh, s, command);
1.90 markus 659:
1.92 markus 660: original_command = NULL;
1.179 dtucker 661:
662: /*
663: * Clear loginmsg: it's the child's responsibility to display
664: * it to the user, otherwise multiple sessions may accumulate
665: * multiple copies of the login messages.
666: */
667: buffer_clear(&loginmsg);
1.237 djm 668:
669: return ret;
1.90 markus 670: }
671:
672:
1.24 markus 673: /* administrative, login(1)-like work */
674: void
1.292 djm 675: do_login(struct ssh *ssh, Session *s, const char *command)
1.24 markus 676: {
677: socklen_t fromlen;
678: struct sockaddr_storage from;
679: struct passwd * pw = s->pw;
680: pid_t pid = getpid();
681:
682: /*
683: * Get IP address of client. If the connection is not a socket, let
684: * the address be 0.0.0.0.
685: */
686: memset(&from, 0, sizeof(from));
1.148 stevesk 687: fromlen = sizeof(from);
1.24 markus 688: if (packet_connection_is_on_socket()) {
689: if (getpeername(packet_get_connection_in(),
1.200 deraadt 690: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 691: debug("getpeername: %.100s", strerror(errno));
1.165 markus 692: cleanup_exit(255);
1.24 markus 693: }
694: }
1.25 markus 695:
1.24 markus 696: /* Record that there was a login on that tty from the remote host. */
1.133 markus 697: if (!use_privsep)
698: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 699: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 700: options.use_dns),
1.148 stevesk 701: (struct sockaddr *)&from, fromlen);
1.24 markus 702:
1.73 djm 703: if (check_quietlogin(s, command))
1.24 markus 704: return;
1.73 djm 705:
1.179 dtucker 706: display_loginmsg();
1.73 djm 707:
708: do_motd();
709: }
710:
711: /*
712: * Display the message of the day.
713: */
714: void
715: do_motd(void)
716: {
717: FILE *f;
718: char buf[256];
719:
1.24 markus 720: if (options.print_motd) {
1.28 millert 721: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
722: "/etc/motd"), "r");
1.24 markus 723: if (f) {
724: while (fgets(buf, sizeof(buf), f))
725: fputs(buf, stdout);
726: fclose(f);
727: }
1.2 markus 728: }
1.73 djm 729: }
730:
731:
732: /*
733: * Check for quiet login, either .hushlogin or command given.
734: */
735: int
736: check_quietlogin(Session *s, const char *command)
737: {
738: char buf[256];
1.96 dugsong 739: struct passwd *pw = s->pw;
1.73 djm 740: struct stat st;
741:
742: /* Return 1 if .hushlogin exists or a command given. */
743: if (command != NULL)
744: return 1;
745: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
746: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
747: return 1;
748: return 0;
1.1 markus 749: }
750:
751: /*
752: * Reads environment variables from the given file and adds/overrides them
753: * into the environment. If the file does not exist, this does nothing.
754: * Otherwise, it must consist of empty lines, comments (line starts with '#')
755: * and assignments of the form name=value. No other forms are allowed.
756: */
1.94 itojun 757: static void
1.45 markus 758: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 759: const char *filename)
1.1 markus 760: {
761: FILE *f;
762: char buf[4096];
763: char *cp, *value;
1.142 deraadt 764: u_int lineno = 0;
1.1 markus 765:
766: f = fopen(filename, "r");
767: if (!f)
768: return;
769:
770: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 771: if (++lineno > 1000)
772: fatal("Too many lines in environment file %s", filename);
1.1 markus 773: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
774: ;
775: if (!*cp || *cp == '#' || *cp == '\n')
776: continue;
1.224 gilles 777:
778: cp[strcspn(cp, "\n")] = '\0';
779:
1.1 markus 780: value = strchr(cp, '=');
781: if (value == NULL) {
1.142 deraadt 782: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
783: filename);
1.1 markus 784: continue;
785: }
1.14 deraadt 786: /*
787: * Replace the equals sign by nul, and advance value to
788: * the value string.
789: */
1.1 markus 790: *value = '\0';
791: value++;
792: child_set_env(env, envsize, cp, value);
793: }
794: fclose(f);
795: }
796:
1.127 markus 797: static char **
1.292 djm 798: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1 markus 799: {
800: char buf[256];
1.294 djm 801: size_t n;
1.127 markus 802: u_int i, envsize;
1.294 djm 803: char *ocp, *cp, **env, *laddr;
1.127 markus 804: struct passwd *pw = s->pw;
1.1 markus 805:
806: /* Initialize the environment. */
807: envsize = 100;
1.220 djm 808: env = xcalloc(envsize, sizeof(char *));
1.1 markus 809: env[0] = NULL;
810:
1.161 markus 811: #ifdef GSSAPI
1.168 djm 812: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 813: * the childs environment as they see fit
814: */
815: ssh_gssapi_do_child(&env, &envsize);
816: #endif
817:
1.284 djm 818: /* Set basic environment. */
819: for (i = 0; i < s->num_env; i++)
820: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
821:
822: child_set_env(&env, &envsize, "USER", pw->pw_name);
823: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
824: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
825: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
826: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
827: else
828: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
829:
830: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
831: child_set_env(&env, &envsize, "MAIL", buf);
832:
833: /* Normal systems set SHELL by default. */
834: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 835:
836: if (getenv("TZ"))
837: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
838:
1.294 djm 839: /* Set custom environment options from pubkey authentication. */
840: if (options.permit_user_env) {
841: for (n = 0 ; n < auth_opts->nenv; n++) {
842: ocp = xstrdup(auth_opts->env[n]);
843: cp = strchr(ocp, '=');
844: if (*cp == '=') {
845: *cp = '\0';
846: child_set_env(&env, &envsize, ocp, cp + 1);
847: }
848: free(ocp);
849: }
1.1 markus 850: }
851:
1.149 stevesk 852: /* SSH_CLIENT deprecated */
1.1 markus 853: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 854: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
855: ssh_local_port(ssh));
1.1 markus 856: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 857:
1.154 markus 858: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 859: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 860: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
861: laddr, ssh_local_port(ssh));
1.265 djm 862: free(laddr);
1.149 stevesk 863: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 864:
1.293 djm 865: if (tun_fwd_ifnames != NULL)
866: child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
1.290 djm 867: if (auth_info_file != NULL)
868: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 869: if (s->ttyfd != -1)
870: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
871: if (s->term)
872: child_set_env(&env, &envsize, "TERM", s->term);
873: if (s->display)
874: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 875: if (original_command)
876: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
877: original_command);
1.96 dugsong 878: #ifdef KRB5
879: if (s->authctxt->krb5_ticket_file)
880: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 881: s->authctxt->krb5_ticket_file);
1.96 dugsong 882: #endif
1.136 markus 883: if (auth_sock_name != NULL)
1.1 markus 884: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 885: auth_sock_name);
1.1 markus 886:
887: /* read $HOME/.ssh/environment. */
1.284 djm 888: if (options.permit_user_env) {
1.14 deraadt 889: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
890: pw->pw_dir);
1.1 markus 891: read_environment_file(&env, &envsize, buf);
892: }
893: if (debug_flag) {
894: /* dump the environment */
895: fprintf(stderr, "Environment:\n");
896: for (i = 0; env[i]; i++)
897: fprintf(stderr, " %.200s\n", env[i]);
898: }
1.127 markus 899: return env;
900: }
901:
902: /*
903: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
904: * first in this order).
905: */
906: static void
1.294 djm 907: do_rc_files(struct ssh *ssh, Session *s, const char *shell)
1.127 markus 908: {
909: FILE *f = NULL;
910: char cmd[1024];
911: int do_xauth;
912: struct stat st;
913:
914: do_xauth =
915: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
916:
1.231 djm 917: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 918: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.294 djm 919: auth_opts->permit_user_rc && options.permit_user_rc &&
1.273 djm 920: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 921: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
922: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
923: if (debug_flag)
924: fprintf(stderr, "Running %s\n", cmd);
925: f = popen(cmd, "w");
926: if (f) {
927: if (do_xauth)
928: fprintf(f, "%s %s\n", s->auth_proto,
929: s->auth_data);
930: pclose(f);
931: } else
932: fprintf(stderr, "Could not run %s\n",
933: _PATH_SSH_USER_RC);
934: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
935: if (debug_flag)
936: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
937: _PATH_SSH_SYSTEM_RC);
938: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
939: if (f) {
940: if (do_xauth)
941: fprintf(f, "%s %s\n", s->auth_proto,
942: s->auth_data);
943: pclose(f);
944: } else
945: fprintf(stderr, "Could not run %s\n",
946: _PATH_SSH_SYSTEM_RC);
947: } else if (do_xauth && options.xauth_location != NULL) {
948: /* Add authority data to .Xauthority if appropriate. */
949: if (debug_flag) {
950: fprintf(stderr,
1.151 stevesk 951: "Running %.500s remove %.100s\n",
1.165 markus 952: options.xauth_location, s->auth_display);
1.151 stevesk 953: fprintf(stderr,
954: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 955: options.xauth_location, s->auth_display,
956: s->auth_proto, s->auth_data);
957: }
958: snprintf(cmd, sizeof cmd, "%s -q -",
959: options.xauth_location);
960: f = popen(cmd, "w");
961: if (f) {
1.151 stevesk 962: fprintf(f, "remove %s\n",
963: s->auth_display);
1.127 markus 964: fprintf(f, "add %s %s %s\n",
965: s->auth_display, s->auth_proto,
966: s->auth_data);
967: pclose(f);
968: } else {
969: fprintf(stderr, "Could not run %s\n",
970: cmd);
971: }
972: }
973: }
974:
975: static void
976: do_nologin(struct passwd *pw)
977: {
978: FILE *f = NULL;
1.251 dtucker 979: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
980: struct stat sb;
1.127 markus 981:
1.260 guenther 982: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 983: return;
984: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
985:
986: if (stat(nl, &sb) == -1) {
987: if (nl != def_nl)
1.265 djm 988: free(nl);
1.251 dtucker 989: return;
990: }
991:
992: /* /etc/nologin exists. Print its contents if we can and exit. */
993: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
994: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 995: while (fgets(buf, sizeof(buf), f))
996: fputs(buf, stderr);
997: fclose(f);
998: }
1.251 dtucker 999: exit(254);
1.127 markus 1000: }
1001:
1.226 djm 1002: /*
1003: * Chroot into a directory after checking it for safety: all path components
1004: * must be root-owned directories with strict permissions.
1005: */
1006: static void
1007: safely_chroot(const char *path, uid_t uid)
1008: {
1009: const char *cp;
1.277 deraadt 1010: char component[PATH_MAX];
1.226 djm 1011: struct stat st;
1012:
1013: if (*path != '/')
1014: fatal("chroot path does not begin at root");
1015: if (strlen(path) >= sizeof(component))
1016: fatal("chroot path too long");
1017:
1018: /*
1019: * Descend the path, checking that each component is a
1020: * root-owned directory with strict permissions.
1021: */
1022: for (cp = path; cp != NULL;) {
1023: if ((cp = strchr(cp, '/')) == NULL)
1024: strlcpy(component, path, sizeof(component));
1025: else {
1026: cp++;
1027: memcpy(component, path, cp - path);
1028: component[cp - path] = '\0';
1029: }
1030:
1031: debug3("%s: checking '%s'", __func__, component);
1032:
1033: if (stat(component, &st) != 0)
1034: fatal("%s: stat(\"%s\"): %s", __func__,
1035: component, strerror(errno));
1036: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1037: fatal("bad ownership or modes for chroot "
1038: "directory %s\"%s\"",
1039: cp == NULL ? "" : "component ", component);
1040: if (!S_ISDIR(st.st_mode))
1041: fatal("chroot path %s\"%s\" is not a directory",
1042: cp == NULL ? "" : "component ", component);
1043:
1044: }
1045:
1046: if (chdir(path) == -1)
1047: fatal("Unable to chdir to chroot path \"%s\": "
1048: "%s", path, strerror(errno));
1049: if (chroot(path) == -1)
1050: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1051: if (chdir("/") == -1)
1052: fatal("%s: chdir(/) after chroot: %s",
1053: __func__, strerror(errno));
1054: verbose("Changed root directory to \"%s\"", path);
1055: }
1056:
1.127 markus 1057: /* Set login name, uid, gid, and groups. */
1.130 provos 1058: void
1.127 markus 1059: do_setusercontext(struct passwd *pw)
1060: {
1.295 ! djm 1061: char uidstr[32], *chroot_path, *tmp;
1.227 djm 1062:
1.127 markus 1063: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1064: /* Prepare groups */
1.127 markus 1065: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1066: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1067: perror("unable to set user context");
1068: exit(1);
1069: }
1.226 djm 1070:
1.279 djm 1071: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1072: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1073: tmp = tilde_expand_filename(options.chroot_directory,
1074: pw->pw_uid);
1.295 ! djm 1075: snprintf(uidstr, sizeof(uidstr), "%llu",
! 1076: (unsigned long long)pw->pw_uid);
1.227 djm 1077: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1.295 ! djm 1078: "u", pw->pw_name, "U", uidstr, (char *)NULL);
1.226 djm 1079: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1080: free(tmp);
1.226 djm 1081: free(chroot_path);
1.264 djm 1082: /* Make sure we don't attempt to chroot again */
1083: free(options.chroot_directory);
1084: options.chroot_directory = NULL;
1.279 djm 1085: in_chroot = 1;
1.226 djm 1086: }
1087:
1088: /* Set UID */
1089: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1090: perror("unable to set user context (setuser)");
1091: exit(1);
1092: }
1.264 djm 1093: } else if (options.chroot_directory != NULL &&
1094: strcasecmp(options.chroot_directory, "none") != 0) {
1095: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1096: }
1.264 djm 1097:
1.127 markus 1098: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1099: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1100: }
1101:
1.131 markus 1102: static void
1.172 markus 1103: do_pwchange(Session *s)
1104: {
1.179 dtucker 1105: fflush(NULL);
1.172 markus 1106: fprintf(stderr, "WARNING: Your password has expired.\n");
1107: if (s->ttyfd != -1) {
1.178 deraadt 1108: fprintf(stderr,
1.172 markus 1109: "You must change your password now and login again!\n");
1110: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1111: perror("passwd");
1112: } else {
1113: fprintf(stderr,
1114: "Password change required but no TTY available.\n");
1115: }
1116: exit(1);
1117: }
1118:
1119: static void
1.292 djm 1120: child_close_fds(struct ssh *ssh)
1.172 markus 1121: {
1.276 djm 1122: extern int auth_sock;
1.266 markus 1123:
1.276 djm 1124: if (auth_sock != -1) {
1125: close(auth_sock);
1126: auth_sock = -1;
1.266 markus 1127: }
1128:
1.172 markus 1129: if (packet_get_connection_in() == packet_get_connection_out())
1130: close(packet_get_connection_in());
1131: else {
1132: close(packet_get_connection_in());
1133: close(packet_get_connection_out());
1134: }
1135: /*
1136: * Close all descriptors related to channels. They will still remain
1137: * open in the parent.
1138: */
1139: /* XXX better use close-on-exec? -markus */
1.292 djm 1140: channel_close_all(ssh);
1.172 markus 1141:
1142: /*
1143: * Close any extra file descriptors. Note that there may still be
1144: * descriptors left by system functions. They will be closed later.
1145: */
1146: endpwent();
1147:
1148: /*
1.188 djm 1149: * Close any extra open file descriptors so that we don't have them
1.172 markus 1150: * hanging around in clients. Note that we want to do this after
1151: * initgroups, because at least on Solaris 2.3 it leaves file
1152: * descriptors open.
1153: */
1.258 djm 1154: closefrom(STDERR_FILENO + 1);
1.172 markus 1155: }
1156:
1.127 markus 1157: /*
1158: * Performs common processing for the child, such as setting up the
1159: * environment, closing extra file descriptors, setting the user and group
1160: * ids, and executing the command or shell.
1161: */
1.225 markus 1162: #define ARGV_MAX 10
1.127 markus 1163: void
1.292 djm 1164: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1165: {
1166: extern char **environ;
1167: char **env;
1.225 markus 1168: char *argv[ARGV_MAX];
1.284 djm 1169: const char *shell, *shell0;
1.127 markus 1170: struct passwd *pw = s->pw;
1.239 djm 1171: int r = 0;
1.127 markus 1172:
1173: /* remove hostkey from the child's memory */
1174: destroy_sensitive_data();
1.287 markus 1175: packet_clear_keys();
1.127 markus 1176:
1.172 markus 1177: /* Force a password change */
1178: if (s->authctxt->force_pwchange) {
1179: do_setusercontext(pw);
1.292 djm 1180: child_close_fds(ssh);
1.172 markus 1181: do_pwchange(s);
1182: exit(1);
1183: }
1184:
1.127 markus 1185: /*
1186: * Login(1) does this as well, and it needs uid 0 for the "-h"
1187: * switch, so we let login(1) to this for us.
1188: */
1.284 djm 1189: do_nologin(pw);
1190: do_setusercontext(pw);
1.127 markus 1191:
1192: /*
1193: * Get the shell from the password data. An empty shell field is
1194: * legal, and means /bin/sh.
1195: */
1196: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1197:
1198: /*
1199: * Make sure $SHELL points to the shell from the password file,
1200: * even if shell is overridden from login.conf
1201: */
1.292 djm 1202: env = do_setup_env(ssh, s, shell);
1.152 markus 1203:
1.127 markus 1204: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1205:
1.1 markus 1206: /*
1207: * Close the connection descriptors; note that this is the child, and
1208: * the server will still have the socket open, and it is important
1209: * that we do not shutdown it. Note that the descriptors cannot be
1210: * closed before building the environment, as we call
1.281 djm 1211: * ssh_remote_ipaddr there.
1.1 markus 1212: */
1.292 djm 1213: child_close_fds(ssh);
1.1 markus 1214:
1215: /*
1.125 deraadt 1216: * Must take new environment into use so that .ssh/rc,
1217: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1218: */
1219: environ = env;
1.170 jakob 1220:
1221: #ifdef KRB5
1222: /*
1223: * At this point, we check to see if AFS is active and if we have
1224: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1225: * if we can (and need to) extend the ticket into an AFS token. If
1226: * we don't do this, we run into potential problems if the user's
1227: * home directory is in AFS and it's not world-readable.
1228: */
1229:
1230: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1231: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1232: char cell[64];
1233:
1234: debug("Getting AFS token");
1235:
1236: k_setpag();
1237:
1238: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1239: krb5_afslog(s->authctxt->krb5_ctx,
1240: s->authctxt->krb5_fwd_ccache, cell, NULL);
1241:
1242: krb5_afslog_home(s->authctxt->krb5_ctx,
1243: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1244: }
1245: #endif
1.104 markus 1246:
1.188 djm 1247: /* Change current directory to the user's home directory. */
1.104 markus 1248: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1249: /* Suppress missing homedir warning for chroot case */
1250: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1251: if (r || !in_chroot) {
1.239 djm 1252: fprintf(stderr, "Could not chdir to home "
1253: "directory %s: %s\n", pw->pw_dir,
1254: strerror(errno));
1.279 djm 1255: }
1.239 djm 1256: if (r)
1.104 markus 1257: exit(1);
1258: }
1.230 djm 1259:
1260: closefrom(STDERR_FILENO + 1);
1.1 markus 1261:
1.294 djm 1262: do_rc_files(ssh, s, shell);
1.67 markus 1263:
1264: /* restore SIGPIPE for child */
1.217 stevesk 1265: signal(SIGPIPE, SIG_DFL);
1.67 markus 1266:
1.248 djm 1267: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1268: printf("This service allows sftp connections only.\n");
1269: fflush(NULL);
1270: exit(1);
1271: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1272: extern int optind, optreset;
1273: int i;
1274: char *p, *args;
1275:
1.246 stevesk 1276: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1277: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1278: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1279: if (i < ARGV_MAX - 1)
1280: argv[i++] = p;
1281: argv[i] = NULL;
1282: optind = optreset = 1;
1283: __progname = argv[0];
1.226 djm 1284: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1285: }
1.247 djm 1286:
1287: fflush(NULL);
1.225 markus 1288:
1.127 markus 1289: /* Get the last component of the shell name. */
1290: if ((shell0 = strrchr(shell, '/')) != NULL)
1291: shell0++;
1292: else
1293: shell0 = shell;
1294:
1.1 markus 1295: /*
1296: * If we have no command, execute the shell. In this case, the shell
1297: * name to be passed in argv[0] is preceded by '-' to indicate that
1298: * this is a login shell.
1299: */
1300: if (!command) {
1.127 markus 1301: char argv0[256];
1.1 markus 1302:
1.127 markus 1303: /* Start the shell. Set initial character to '-'. */
1304: argv0[0] = '-';
1.1 markus 1305:
1.127 markus 1306: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1307: >= sizeof(argv0) - 1) {
1.127 markus 1308: errno = EINVAL;
1.1 markus 1309: perror(shell);
1310: exit(1);
1.127 markus 1311: }
1.1 markus 1312:
1.127 markus 1313: /* Execute the shell. */
1314: argv[0] = argv0;
1315: argv[1] = NULL;
1316: execve(shell, argv, env);
1317:
1318: /* Executing the shell failed. */
1319: perror(shell);
1320: exit(1);
1.1 markus 1321: }
1322: /*
1323: * Execute the command using the user's shell. This uses the -c
1324: * option to execute the command.
1325: */
1.127 markus 1326: argv[0] = (char *) shell0;
1.1 markus 1327: argv[1] = "-c";
1328: argv[2] = (char *) command;
1329: argv[3] = NULL;
1330: execve(shell, argv, env);
1331: perror(shell);
1332: exit(1);
1333: }
1334:
1.237 djm 1335: void
1336: session_unused(int id)
1337: {
1338: debug3("%s: session id %d unused", __func__, id);
1339: if (id >= options.max_sessions ||
1340: id >= sessions_nalloc) {
1341: fatal("%s: insane session id %d (max %d nalloc %d)",
1342: __func__, id, options.max_sessions, sessions_nalloc);
1343: }
1.270 tedu 1344: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1345: sessions[id].self = id;
1346: sessions[id].used = 0;
1347: sessions[id].chanid = -1;
1348: sessions[id].ptyfd = -1;
1349: sessions[id].ttyfd = -1;
1350: sessions[id].ptymaster = -1;
1351: sessions[id].x11_chanids = NULL;
1352: sessions[id].next_unused = sessions_first_unused;
1353: sessions_first_unused = id;
1354: }
1355:
1.1 markus 1356: Session *
1357: session_new(void)
1358: {
1.237 djm 1359: Session *s, *tmp;
1360:
1361: if (sessions_first_unused == -1) {
1362: if (sessions_nalloc >= options.max_sessions)
1363: return NULL;
1364: debug2("%s: allocate (allocated %d max %d)",
1365: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1366: tmp = xrecallocarray(sessions, sessions_nalloc,
1367: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1368: if (tmp == NULL) {
1369: error("%s: cannot allocate %d sessions",
1370: __func__, sessions_nalloc + 1);
1371: return NULL;
1372: }
1373: sessions = tmp;
1374: session_unused(sessions_nalloc++);
1375: }
1376:
1377: if (sessions_first_unused >= sessions_nalloc ||
1378: sessions_first_unused < 0) {
1379: fatal("%s: insane first_unused %d max %d nalloc %d",
1380: __func__, sessions_first_unused, options.max_sessions,
1381: sessions_nalloc);
1382: }
1383:
1384: s = &sessions[sessions_first_unused];
1385: if (s->used) {
1386: fatal("%s: session %d already used",
1387: __func__, sessions_first_unused);
1388: }
1389: sessions_first_unused = s->next_unused;
1390: s->used = 1;
1391: s->next_unused = -1;
1392: debug("session_new: session %d", s->self);
1393:
1394: return s;
1.1 markus 1395: }
1396:
1.94 itojun 1397: static void
1.1 markus 1398: session_dump(void)
1399: {
1400: int i;
1.237 djm 1401: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1402: Session *s = &sessions[i];
1.237 djm 1403:
1404: debug("dump: used %d next_unused %d session %d %p "
1405: "channel %d pid %ld",
1.1 markus 1406: s->used,
1.237 djm 1407: s->next_unused,
1.1 markus 1408: s->self,
1409: s,
1410: s->chanid,
1.137 mpech 1411: (long)s->pid);
1.1 markus 1412: }
1413: }
1414:
1.2 markus 1415: int
1.97 markus 1416: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1417: {
1418: Session *s = session_new();
1419: debug("session_open: channel %d", chanid);
1420: if (s == NULL) {
1421: error("no more sessions");
1422: return 0;
1423: }
1.97 markus 1424: s->authctxt = authctxt;
1425: s->pw = authctxt->pw;
1.167 djm 1426: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1427: fatal("no user for session %d", s->self);
1.2 markus 1428: debug("session_open: session %d: link with channel %d", s->self, chanid);
1429: s->chanid = chanid;
1430: return 1;
1431: }
1432:
1.130 provos 1433: Session *
1434: session_by_tty(char *tty)
1435: {
1436: int i;
1.237 djm 1437: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1438: Session *s = &sessions[i];
1439: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1440: debug("session_by_tty: session %d tty %s", i, tty);
1441: return s;
1442: }
1443: }
1444: debug("session_by_tty: unknown tty %.100s", tty);
1445: session_dump();
1446: return NULL;
1447: }
1448:
1.94 itojun 1449: static Session *
1.2 markus 1450: session_by_channel(int id)
1451: {
1452: int i;
1.237 djm 1453: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1454: Session *s = &sessions[i];
1455: if (s->used && s->chanid == id) {
1.237 djm 1456: debug("session_by_channel: session %d channel %d",
1457: i, id);
1.2 markus 1458: return s;
1459: }
1460: }
1461: debug("session_by_channel: unknown channel %d", id);
1462: session_dump();
1463: return NULL;
1464: }
1465:
1.94 itojun 1466: static Session *
1.184 djm 1467: session_by_x11_channel(int id)
1468: {
1469: int i, j;
1470:
1.237 djm 1471: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1472: Session *s = &sessions[i];
1473:
1474: if (s->x11_chanids == NULL || !s->used)
1475: continue;
1476: for (j = 0; s->x11_chanids[j] != -1; j++) {
1477: if (s->x11_chanids[j] == id) {
1478: debug("session_by_x11_channel: session %d "
1479: "channel %d", s->self, id);
1480: return s;
1481: }
1482: }
1483: }
1484: debug("session_by_x11_channel: unknown channel %d", id);
1485: session_dump();
1486: return NULL;
1487: }
1488:
1489: static Session *
1.2 markus 1490: session_by_pid(pid_t pid)
1491: {
1492: int i;
1.137 mpech 1493: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1494: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1495: Session *s = &sessions[i];
1496: if (s->used && s->pid == pid)
1497: return s;
1498: }
1.137 mpech 1499: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1500: session_dump();
1501: return NULL;
1502: }
1503:
1.94 itojun 1504: static int
1.292 djm 1505: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1506: {
1507: s->col = packet_get_int();
1508: s->row = packet_get_int();
1509: s->xpixel = packet_get_int();
1510: s->ypixel = packet_get_int();
1.116 markus 1511: packet_check_eom();
1.2 markus 1512: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1513: return 1;
1514: }
1515:
1.94 itojun 1516: static int
1.292 djm 1517: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1518: {
1.45 markus 1519: u_int len;
1.72 stevesk 1520: int n_bytes;
1.132 markus 1521:
1.294 djm 1522: if (!auth_opts->permit_pty_flag || !options.permit_tty) {
1523: debug("Allocating a pty not permitted for this connection.");
1.19 markus 1524: return 0;
1.86 markus 1525: }
1526: if (s->ttyfd != -1) {
1527: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1528: return 0;
1.86 markus 1529: }
1530:
1.2 markus 1531: s->term = packet_get_string(&len);
1.283 markus 1532: s->col = packet_get_int();
1533: s->row = packet_get_int();
1.2 markus 1534: s->xpixel = packet_get_int();
1535: s->ypixel = packet_get_int();
1536:
1537: if (strcmp(s->term, "") == 0) {
1.265 djm 1538: free(s->term);
1.2 markus 1539: s->term = NULL;
1540: }
1.86 markus 1541:
1.2 markus 1542: /* Allocate a pty and open it. */
1.86 markus 1543: debug("Allocating pty.");
1.237 djm 1544: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1545: sizeof(s->tty)))) {
1.265 djm 1546: free(s->term);
1.2 markus 1547: s->term = NULL;
1548: s->ptyfd = -1;
1549: s->ttyfd = -1;
1550: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1551: return 0;
1.2 markus 1552: }
1553: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1554:
1.283 markus 1555: n_bytes = packet_remaining();
1.86 markus 1556: tty_parse_modes(s->ttyfd, &n_bytes);
1557:
1.130 provos 1558: if (!use_privsep)
1559: pty_setowner(s->pw, s->tty);
1.86 markus 1560:
1561: /* Set window size from the packet. */
1.2 markus 1562: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1563:
1.116 markus 1564: packet_check_eom();
1.9 markus 1565: session_proctitle(s);
1.2 markus 1566: return 1;
1567: }
1568:
1.94 itojun 1569: static int
1.292 djm 1570: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1571: {
1.105 markus 1572: struct stat st;
1.45 markus 1573: u_int len;
1.7 markus 1574: int success = 0;
1.267 djm 1575: char *prog, *cmd;
1.182 djm 1576: u_int i;
1.7 markus 1577:
1.267 djm 1578: s->subsys = packet_get_string(&len);
1.116 markus 1579: packet_check_eom();
1.267 djm 1580: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1581: s->pw->pw_name);
1.18 jakob 1582:
1583: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1584: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1585: prog = options.subsystem_command[i];
1586: cmd = options.subsystem_args[i];
1.249 dtucker 1587: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1588: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1589: debug("subsystem: %s", prog);
1.225 markus 1590: } else {
1.249 dtucker 1591: if (stat(prog, &st) < 0)
1592: debug("subsystem: cannot stat %s: %s",
1593: prog, strerror(errno));
1.225 markus 1594: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1595: debug("subsystem: exec() %s", cmd);
1.105 markus 1596: }
1.292 djm 1597: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1598: break;
1.18 jakob 1599: }
1600: }
1601:
1602: if (!success)
1.267 djm 1603: logit("subsystem request for %.100s by user %s failed, "
1604: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1605:
1606: return success;
1607: }
1608:
1.94 itojun 1609: static int
1.292 djm 1610: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1611: {
1.81 markus 1612: int success;
1.7 markus 1613:
1.184 djm 1614: if (s->auth_proto != NULL || s->auth_data != NULL) {
1615: error("session_x11_req: session %d: "
1.190 stevesk 1616: "x11 forwarding already active", s->self);
1.184 djm 1617: return 0;
1618: }
1.7 markus 1619: s->single_connection = packet_get_char();
1620: s->auth_proto = packet_get_string(NULL);
1621: s->auth_data = packet_get_string(NULL);
1622: s->screen = packet_get_int();
1.116 markus 1623: packet_check_eom();
1.7 markus 1624:
1.282 djm 1625: if (xauth_valid_string(s->auth_proto) &&
1626: xauth_valid_string(s->auth_data))
1.292 djm 1627: success = session_setup_x11fwd(ssh, s);
1.282 djm 1628: else {
1629: success = 0;
1630: error("Invalid X11 forwarding data");
1631: }
1.81 markus 1632: if (!success) {
1.265 djm 1633: free(s->auth_proto);
1634: free(s->auth_data);
1.84 markus 1635: s->auth_proto = NULL;
1636: s->auth_data = NULL;
1.7 markus 1637: }
1.81 markus 1638: return success;
1.7 markus 1639: }
1640:
1.94 itojun 1641: static int
1.292 djm 1642: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1643: {
1.116 markus 1644: packet_check_eom();
1.292 djm 1645: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1646: }
1647:
1.94 itojun 1648: static int
1.292 djm 1649: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1650: {
1.237 djm 1651: u_int len, success;
1652:
1.19 markus 1653: char *command = packet_get_string(&len);
1.116 markus 1654: packet_check_eom();
1.292 djm 1655: success = do_exec(ssh, s, command) == 0;
1.265 djm 1656: free(command);
1.237 djm 1657: return success;
1.19 markus 1658: }
1659:
1.94 itojun 1660: static int
1.292 djm 1661: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1662: {
1663:
1.175 deraadt 1664: packet_get_int(); /* ignored */
1.157 markus 1665: packet_check_eom();
1666:
1.259 djm 1667: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1668: return 0;
1669: return 1;
1670: }
1671:
1672: static int
1.292 djm 1673: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1674: {
1675: char *name, *val;
1676: u_int name_len, val_len, i;
1677:
1.271 djm 1678: name = packet_get_cstring(&name_len);
1679: val = packet_get_cstring(&val_len);
1.173 djm 1680: packet_check_eom();
1681:
1682: /* Don't set too many environment variables */
1683: if (s->num_env > 128) {
1684: debug2("Ignoring env request %s: too many env vars", name);
1685: goto fail;
1686: }
1687:
1688: for (i = 0; i < options.num_accept_env; i++) {
1689: if (match_pattern(name, options.accept_env[i])) {
1690: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1691: s->env = xrecallocarray(s->env, s->num_env,
1692: s->num_env + 1, sizeof(*s->env));
1.173 djm 1693: s->env[s->num_env].name = name;
1694: s->env[s->num_env].val = val;
1695: s->num_env++;
1696: return (1);
1697: }
1698: }
1699: debug2("Ignoring env request %s: disallowed name", name);
1700:
1701: fail:
1.265 djm 1702: free(name);
1703: free(val);
1.173 djm 1704: return (0);
1705: }
1706:
1707: static int
1.292 djm 1708: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1709: {
1710: static int called = 0;
1.294 djm 1711:
1.116 markus 1712: packet_check_eom();
1.294 djm 1713: if (!auth_opts->permit_agent_forwarding_flag ||
1714: !options.allow_agent_forwarding) {
1715: debug("%s: agent forwarding disabled", __func__);
1.44 markus 1716: return 0;
1717: }
1.43 markus 1718: if (called) {
1719: return 0;
1720: } else {
1721: called = 1;
1.292 djm 1722: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1723: }
1724: }
1725:
1.123 markus 1726: int
1.292 djm 1727: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1728: {
1729: int success = 0;
1730: Session *s;
1731:
1.123 markus 1732: if ((s = session_by_channel(c->self)) == NULL) {
1.292 djm 1733: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1734: return 0;
1735: }
1.292 djm 1736: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1737:
1738: /*
1.64 markus 1739: * a session is in LARVAL state until a shell, a command
1740: * or a subsystem is executed
1.2 markus 1741: */
1742: if (c->type == SSH_CHANNEL_LARVAL) {
1743: if (strcmp(rtype, "shell") == 0) {
1.292 djm 1744: success = session_shell_req(ssh, s);
1.2 markus 1745: } else if (strcmp(rtype, "exec") == 0) {
1.292 djm 1746: success = session_exec_req(ssh, s);
1.2 markus 1747: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 djm 1748: success = session_pty_req(ssh, s);
1.7 markus 1749: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 djm 1750: success = session_x11_req(ssh, s);
1.43 markus 1751: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 djm 1752: success = session_auth_agent_req(ssh, s);
1.7 markus 1753: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 djm 1754: success = session_subsystem_req(ssh, s);
1.173 djm 1755: } else if (strcmp(rtype, "env") == 0) {
1.292 djm 1756: success = session_env_req(ssh, s);
1.2 markus 1757: }
1758: }
1759: if (strcmp(rtype, "window-change") == 0) {
1.292 djm 1760: success = session_window_change_req(ssh, s);
1.177 djm 1761: } else if (strcmp(rtype, "break") == 0) {
1.292 djm 1762: success = session_break_req(ssh, s);
1.2 markus 1763: }
1.177 djm 1764:
1.123 markus 1765: return success;
1.2 markus 1766: }
1767:
1768: void
1.292 djm 1769: session_set_fds(struct ssh *ssh, Session *s,
1770: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1771: {
1772: /*
1773: * now that have a child and a pipe to the child,
1774: * we can activate our channel and register the fd's
1775: */
1776: if (s->chanid == -1)
1777: fatal("no channel for session %d", s->self);
1.292 djm 1778: channel_set_fds(ssh, s->chanid,
1.2 markus 1779: fdout, fdin, fderr,
1.256 djm 1780: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1781: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1782: }
1783:
1.85 markus 1784: /*
1785: * Function to perform pty cleanup. Also called if we get aborted abnormally
1786: * (e.g., due to a dropped connection).
1787: */
1.130 provos 1788: void
1.165 markus 1789: session_pty_cleanup2(Session *s)
1.1 markus 1790: {
1.85 markus 1791: if (s == NULL) {
1792: error("session_pty_cleanup: no session");
1793: return;
1794: }
1795: if (s->ttyfd == -1)
1.1 markus 1796: return;
1797:
1.54 stevesk 1798: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1799:
1800: /* Record that the user has logged out. */
1.85 markus 1801: if (s->pid != 0)
1802: record_logout(s->pid, s->tty);
1.1 markus 1803:
1804: /* Release the pseudo-tty. */
1.130 provos 1805: if (getuid() == 0)
1806: pty_release(s->tty);
1.1 markus 1807:
1808: /*
1809: * Close the server side of the socket pairs. We must do this after
1810: * the pty cleanup, so that another process doesn't get this pty
1811: * while we're still cleaning up.
1812: */
1.237 djm 1813: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1814: error("close(s->ptymaster/%d): %s",
1815: s->ptymaster, strerror(errno));
1.108 markus 1816:
1817: /* unlink pty from session */
1818: s->ttyfd = -1;
1.2 markus 1819: }
1820:
1.130 provos 1821: void
1.165 markus 1822: session_pty_cleanup(Session *s)
1.130 provos 1823: {
1.165 markus 1824: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1825: }
1826:
1.147 markus 1827: static char *
1828: sig2name(int sig)
1829: {
1830: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1831: SSH_SIG(ABRT);
1832: SSH_SIG(ALRM);
1833: SSH_SIG(FPE);
1834: SSH_SIG(HUP);
1835: SSH_SIG(ILL);
1836: SSH_SIG(INT);
1837: SSH_SIG(KILL);
1838: SSH_SIG(PIPE);
1839: SSH_SIG(QUIT);
1840: SSH_SIG(SEGV);
1841: SSH_SIG(TERM);
1842: SSH_SIG(USR1);
1843: SSH_SIG(USR2);
1844: #undef SSH_SIG
1845: return "SIG@openssh.com";
1846: }
1847:
1.94 itojun 1848: static void
1.292 djm 1849: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1850: {
1851: Channel *c;
1852:
1.292 djm 1853: if ((c = channel_by_id(ssh, id)) == NULL) {
1854: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1855: } else {
1856: /* Detach X11 listener */
1.292 djm 1857: debug("%s: detach x11 channel %d", __func__, id);
1858: channel_cancel_cleanup(ssh, id);
1.184 djm 1859: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1860: chan_mark_dead(ssh, c);
1.184 djm 1861: }
1862: }
1863:
1864: static void
1.292 djm 1865: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1866: {
1867: Session *s;
1868: u_int i;
1869:
1.292 djm 1870: debug3("%s: channel %d", __func__, id);
1871: channel_cancel_cleanup(ssh, id);
1.221 stevesk 1872: if ((s = session_by_x11_channel(id)) == NULL)
1.292 djm 1873: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 1874: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 1875: debug("%s: session %d: closing channel %d",
1876: __func__, s->self, s->x11_chanids[i]);
1.184 djm 1877: /*
1878: * The channel "id" is already closing, but make sure we
1879: * close all of its siblings.
1880: */
1881: if (s->x11_chanids[i] != id)
1.292 djm 1882: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 1883: }
1.265 djm 1884: free(s->x11_chanids);
1.184 djm 1885: s->x11_chanids = NULL;
1.265 djm 1886: free(s->display);
1887: s->display = NULL;
1888: free(s->auth_proto);
1889: s->auth_proto = NULL;
1890: free(s->auth_data);
1891: s->auth_data = NULL;
1892: free(s->auth_display);
1893: s->auth_display = NULL;
1.184 djm 1894: }
1895:
1896: static void
1.292 djm 1897: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 1898: {
1899: Channel *c;
1.124 markus 1900:
1.292 djm 1901: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
1902: fatal("%s: session %d: no channel %d",
1903: __func__, s->self, s->chanid);
1904: debug("%s: session %d channel %d pid %ld",
1905: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 1906:
1907: if (WIFEXITED(status)) {
1.292 djm 1908: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 1909: packet_put_int(WEXITSTATUS(status));
1910: packet_send();
1911: } else if (WIFSIGNALED(status)) {
1.292 djm 1912: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 1913: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 1914: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 1915: packet_put_cstring("");
1916: packet_put_cstring("");
1917: packet_send();
1918: } else {
1919: /* Some weird exit cause. Just exit. */
1920: packet_disconnect("wait returned status %04x.", status);
1921: }
1922:
1923: /* disconnect channel */
1.292 djm 1924: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 1925:
1926: /*
1927: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 1928: * the channel gets EOF. The session will be then be closed
1.187 djm 1929: * by session_close_by_channel when the childs close their fds.
1930: */
1.292 djm 1931: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 1932:
1.5 markus 1933: /*
1934: * emulate a write failure with 'chan_write_failed', nobody will be
1935: * interested in data we write.
1936: * Note that we must not call 'chan_read_failed', since there could
1937: * be some more data waiting in the pipe.
1938: */
1.8 markus 1939: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1940: chan_write_failed(ssh, c);
1.2 markus 1941: }
1942:
1.130 provos 1943: void
1.292 djm 1944: session_close(struct ssh *ssh, Session *s)
1.2 markus 1945: {
1.182 djm 1946: u_int i;
1.173 djm 1947:
1.280 djm 1948: verbose("Close session: user %s from %.200s port %d id %d",
1949: s->pw->pw_name,
1.281 djm 1950: ssh_remote_ipaddr(ssh),
1951: ssh_remote_port(ssh),
1.280 djm 1952: s->self);
1953:
1.165 markus 1954: if (s->ttyfd != -1)
1.85 markus 1955: session_pty_cleanup(s);
1.265 djm 1956: free(s->term);
1957: free(s->display);
1958: free(s->x11_chanids);
1959: free(s->auth_display);
1960: free(s->auth_data);
1961: free(s->auth_proto);
1.267 djm 1962: free(s->subsys);
1.219 djm 1963: if (s->env != NULL) {
1964: for (i = 0; i < s->num_env; i++) {
1.265 djm 1965: free(s->env[i].name);
1966: free(s->env[i].val);
1.219 djm 1967: }
1.265 djm 1968: free(s->env);
1.173 djm 1969: }
1.9 markus 1970: session_proctitle(s);
1.237 djm 1971: session_unused(s->self);
1.2 markus 1972: }
1973:
1974: void
1.292 djm 1975: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 1976: {
1977: Session *s = session_by_pid(pid);
1978: if (s == NULL) {
1.292 djm 1979: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 1980: return;
1981: }
1982: if (s->chanid != -1)
1.292 djm 1983: session_exit_message(ssh, s, status);
1.187 djm 1984: if (s->ttyfd != -1)
1985: session_pty_cleanup(s);
1.197 djm 1986: s->pid = 0;
1.98 markus 1987: }
1988:
1.2 markus 1989: /*
1990: * this is called when a channel dies before
1991: * the session 'child' itself dies
1992: */
1993: void
1.292 djm 1994: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 1995: {
1996: Session *s = session_by_channel(id);
1.187 djm 1997: u_int i;
1.184 djm 1998:
1.2 markus 1999: if (s == NULL) {
1.292 djm 2000: debug("%s: no session for id %d", __func__, id);
1.2 markus 2001: return;
2002: }
1.292 djm 2003: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 2004: if (s->pid != 0) {
1.292 djm 2005: debug("%s: channel %d: has child", __func__, id);
1.108 markus 2006: /*
2007: * delay detach of session, but release pty, since
2008: * the fd's to the child are already closed
2009: */
1.165 markus 2010: if (s->ttyfd != -1)
1.108 markus 2011: session_pty_cleanup(s);
1.107 markus 2012: return;
2013: }
2014: /* detach by removing callback */
1.292 djm 2015: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 2016:
2017: /* Close any X11 listeners associated with this session */
2018: if (s->x11_chanids != NULL) {
2019: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2020: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 2021: s->x11_chanids[i] = -1;
2022: }
2023: }
2024:
1.2 markus 2025: s->chanid = -1;
1.292 djm 2026: session_close(ssh, s);
1.106 markus 2027: }
2028:
2029: void
1.292 djm 2030: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 2031: {
2032: int i;
1.237 djm 2033: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2034: Session *s = &sessions[i];
1.130 provos 2035: if (s->used) {
2036: if (closefunc != NULL)
2037: closefunc(s);
2038: else
1.292 djm 2039: session_close(ssh, s);
1.130 provos 2040: }
1.2 markus 2041: }
1.9 markus 2042: }
2043:
1.94 itojun 2044: static char *
1.9 markus 2045: session_tty_list(void)
2046: {
2047: static char buf[1024];
2048: int i;
2049: buf[0] = '\0';
1.237 djm 2050: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2051: Session *s = &sessions[i];
2052: if (s->used && s->ttyfd != -1) {
2053: if (buf[0] != '\0')
2054: strlcat(buf, ",", sizeof buf);
2055: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2056: }
2057: }
2058: if (buf[0] == '\0')
2059: strlcpy(buf, "notty", sizeof buf);
2060: return buf;
2061: }
2062:
2063: void
2064: session_proctitle(Session *s)
2065: {
2066: if (s->pw == NULL)
2067: error("no user for session %d", s->self);
2068: else
2069: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2070: }
2071:
2072: int
1.292 djm 2073: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2074: {
2075: struct stat st;
1.109 stevesk 2076: char display[512], auth_display[512];
1.272 djm 2077: char hostname[NI_MAXHOST];
1.184 djm 2078: u_int i;
1.81 markus 2079:
1.294 djm 2080: if (!auth_opts->permit_x11_forwarding_flag) {
2081: packet_send_debug("X11 forwarding disabled by key options.");
1.81 markus 2082: return 0;
2083: }
2084: if (!options.x11_forwarding) {
2085: debug("X11 forwarding disabled in server configuration file.");
2086: return 0;
2087: }
1.275 djm 2088: if (options.xauth_location == NULL ||
1.81 markus 2089: (stat(options.xauth_location, &st) == -1)) {
1.294 djm 2090: packet_send_debug("No xauth program; cannot forward X11.");
1.81 markus 2091: return 0;
2092: }
1.87 markus 2093: if (s->display != NULL) {
1.81 markus 2094: debug("X11 display already set.");
2095: return 0;
2096: }
1.292 djm 2097: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2098: options.x11_use_localhost, s->single_connection,
1.184 djm 2099: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2100: debug("x11_create_display_inet failed.");
1.81 markus 2101: return 0;
1.184 djm 2102: }
2103: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2104: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2105: session_close_single_x11, 0);
1.81 markus 2106: }
1.109 stevesk 2107:
2108: /* Set up a suitable value for the DISPLAY variable. */
2109: if (gethostname(hostname, sizeof(hostname)) < 0)
2110: fatal("gethostname: %.100s", strerror(errno));
2111: /*
2112: * auth_display must be used as the displayname when the
2113: * authorization entry is added with xauth(1). This will be
2114: * different than the DISPLAY string for localhost displays.
2115: */
1.119 stevesk 2116: if (options.x11_use_localhost) {
1.140 deraadt 2117: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2118: s->display_number, s->screen);
1.140 deraadt 2119: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2120: s->display_number, s->screen);
1.109 stevesk 2121: s->display = xstrdup(display);
1.118 stevesk 2122: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2123: } else {
1.140 deraadt 2124: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2125: s->display_number, s->screen);
2126: s->display = xstrdup(display);
1.118 stevesk 2127: s->auth_display = xstrdup(display);
1.109 stevesk 2128: }
2129:
1.81 markus 2130: return 1;
1.2 markus 2131: }
2132:
1.94 itojun 2133: static void
1.292 djm 2134: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2135: {
1.292 djm 2136: server_loop2(ssh, authctxt);
1.165 markus 2137: }
2138:
2139: void
1.292 djm 2140: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2141: {
2142: static int called = 0;
2143:
2144: debug("do_cleanup");
2145:
2146: /* no cleanup if we're in the child for login shell */
2147: if (is_child)
2148: return;
2149:
2150: /* avoid double cleanup */
2151: if (called)
2152: return;
2153: called = 1;
2154:
1.218 markus 2155: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2156: return;
2157: #ifdef KRB5
2158: if (options.kerberos_ticket_cleanup &&
2159: authctxt->krb5_ctx)
2160: krb5_cleanup_proc(authctxt);
1.161 markus 2161: #endif
1.165 markus 2162:
2163: #ifdef GSSAPI
1.283 markus 2164: if (options.gss_cleanup_creds)
1.165 markus 2165: ssh_gssapi_cleanup_creds();
2166: #endif
2167:
2168: /* remove agent socket */
2169: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2170:
2171: /* remove userauth info */
2172: if (auth_info_file != NULL) {
2173: temporarily_use_uid(authctxt->pw);
2174: unlink(auth_info_file);
2175: restore_uid();
2176: free(auth_info_file);
2177: auth_info_file = NULL;
2178: }
1.165 markus 2179:
2180: /*
2181: * Cleanup ptys/utmp only if privsep is disabled,
2182: * or if running in monitor.
2183: */
2184: if (!use_privsep || mm_is_monitor())
1.292 djm 2185: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2186: }
1.281 djm 2187:
2188: /* Return a name for the remote host that fits inside utmp_size */
2189:
2190: const char *
2191: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2192: {
2193: const char *remote = "";
2194:
2195: if (utmp_size > 0)
2196: remote = auth_get_canonical_hostname(ssh, use_dns);
2197: if (utmp_size == 0 || strlen(remote) > utmp_size)
2198: remote = ssh_remote_ipaddr(ssh);
2199: return remote;
2200: }
2201:
![[BACK]](/icons/back.gif){kind=icon}
Return to session.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh