Annotation of src/usr.bin/ssh/session.c, Revision 1.304
1.304 ! markus 1: /* $OpenBSD: session.c,v 1.303 2018/07/09 21:26:02 markus Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
1.37 deraadt 5: *
6: * As far as I am concerned, the code I have written for this software
7: * can be used freely for any purpose. Any derived versions of this
8: * software must be clearly marked as such, and if the derived work is
9: * incompatible with the protocol description in the RFC file, it must be
10: * called by a name other than "ssh" or "Secure Shell".
11: *
1.2 markus 12: * SSH2 support by Markus Friedl.
1.95 markus 13: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.37 deraadt 14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2 markus 34: */
1.1 markus 35:
1.193 stevesk 36: #include <sys/types.h>
37: #include <sys/wait.h>
1.194 stevesk 38: #include <sys/un.h>
1.196 stevesk 39: #include <sys/stat.h>
1.207 stevesk 40: #include <sys/socket.h>
1.236 djm 41: #include <sys/queue.h>
1.192 stevesk 42:
1.282 djm 43: #include <ctype.h>
1.209 stevesk 44: #include <errno.h>
1.253 djm 45: #include <fcntl.h>
1.204 stevesk 46: #include <grp.h>
1.223 djm 47: #include <login_cap.h>
1.272 djm 48: #include <netdb.h>
1.192 stevesk 49: #include <paths.h>
1.206 stevesk 50: #include <pwd.h>
1.195 stevesk 51: #include <signal.h>
1.215 stevesk 52: #include <stdio.h>
1.214 stevesk 53: #include <stdlib.h>
1.212 stevesk 54: #include <string.h>
1.211 stevesk 55: #include <unistd.h>
1.277 deraadt 56: #include <limits.h>
1.1 markus 57:
1.216 deraadt 58: #include "xmalloc.h"
1.51 markus 59: #include "ssh.h"
60: #include "ssh2.h"
1.59 djm 61: #include "sshpty.h"
1.1 markus 62: #include "packet.h"
1.303 markus 63: #include "sshbuf.h"
64: #include "ssherr.h"
1.173 djm 65: #include "match.h"
1.1 markus 66: #include "uidswap.h"
67: #include "compat.h"
1.78 markus 68: #include "channels.h"
1.304 ! markus 69: #include "sshkey.h"
1.216 deraadt 70: #include "cipher.h"
71: #include "kex.h"
72: #include "hostfile.h"
1.2 markus 73: #include "auth.h"
1.19 markus 74: #include "auth-options.h"
1.266 markus 75: #include "authfd.h"
1.50 markus 76: #include "pathnames.h"
1.51 markus 77: #include "log.h"
1.274 millert 78: #include "misc.h"
1.51 markus 79: #include "servconf.h"
1.59 djm 80: #include "sshlogin.h"
1.51 markus 81: #include "serverloop.h"
82: #include "canohost.h"
1.55 itojun 83: #include "session.h"
1.216 deraadt 84: #ifdef GSSAPI
85: #include "ssh-gss.h"
86: #endif
1.130 provos 87: #include "monitor_wrap.h"
1.225 markus 88: #include "sftp.h"
1.290 djm 89: #include "atomicio.h"
1.171 markus 90:
91: #ifdef KRB5
92: #include <kafs.h>
1.161 markus 93: #endif
94:
1.242 djm 95: #define IS_INTERNAL_SFTP(c) \
96: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
97: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
98: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
99: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
100:
1.1 markus 101: /* func */
102:
103: Session *session_new(void);
1.292 djm 104: void session_set_fds(struct ssh *, Session *, int, int, int, int, int);
1.165 markus 105: void session_pty_cleanup(Session *);
1.94 itojun 106: void session_proctitle(Session *);
1.292 djm 107: int session_setup_x11fwd(struct ssh *, Session *);
108: int do_exec_pty(struct ssh *, Session *, const char *);
109: int do_exec_no_pty(struct ssh *, Session *, const char *);
110: int do_exec(struct ssh *, Session *, const char *);
111: void do_login(struct ssh *, Session *, const char *);
112: void do_child(struct ssh *, Session *, const char *);
1.73 djm 113: void do_motd(void);
1.94 itojun 114: int check_quietlogin(Session *, const char *);
1.1 markus 115:
1.292 djm 116: static void do_authenticated2(struct ssh *, Authctxt *);
1.94 itojun 117:
1.292 djm 118: static int session_pty_req(struct ssh *, Session *);
1.65 markus 119:
1.1 markus 120: /* import */
121: extern ServerOptions options;
122: extern char *__progname;
123: extern int debug_flag;
1.45 markus 124: extern u_int utmp_len;
1.21 markus 125: extern int startup_pipe;
1.74 markus 126: extern void destroy_sensitive_data(void);
1.303 markus 127: extern struct sshbuf *loginmsg;
1.294 djm 128: extern struct sshauthopt *auth_opts;
1.293 djm 129: char *tun_fwd_ifnames; /* serverloop.c */
1.21 markus 130:
1.34 markus 131: /* original command from peer. */
1.92 markus 132: const char *original_command = NULL;
1.34 markus 133:
1.1 markus 134: /* data */
1.237 djm 135: static int sessions_first_unused = -1;
136: static int sessions_nalloc = 0;
137: static Session *sessions = NULL;
1.1 markus 138:
1.248 djm 139: #define SUBSYSTEM_NONE 0
140: #define SUBSYSTEM_EXT 1
141: #define SUBSYSTEM_INT_SFTP 2
142: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.225 markus 143:
1.129 provos 144: login_cap_t *lc;
1.28 millert 145:
1.165 markus 146: static int is_child = 0;
1.279 djm 147: static int in_chroot = 0;
1.165 markus 148:
1.290 djm 149: /* File containing userauth info, if ExposeAuthInfo set */
150: static char *auth_info_file = NULL;
151:
1.136 markus 152: /* Name and directory of socket for authentication agent forwarding. */
153: static char *auth_sock_name = NULL;
154: static char *auth_sock_dir = NULL;
155:
156: /* removes the agent forwarding socket */
157:
158: static void
1.165 markus 159: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 160: {
161: if (auth_sock_name != NULL) {
162: temporarily_use_uid(pw);
163: unlink(auth_sock_name);
164: rmdir(auth_sock_dir);
165: auth_sock_name = NULL;
166: restore_uid();
167: }
168: }
169:
170: static int
1.292 djm 171: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136 markus 172: {
173: Channel *nc;
1.237 djm 174: int sock = -1;
1.136 markus 175:
176: if (auth_sock_name != NULL) {
177: error("authentication forwarding requested twice.");
178: return 0;
179: }
180:
181: /* Temporarily drop privileged uid for mkdir/bind. */
182: temporarily_use_uid(pw);
183:
184: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 185: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 186:
187: /* Create private directory for socket */
188: if (mkdtemp(auth_sock_dir) == NULL) {
189: packet_send_debug("Agent forwarding disabled: "
190: "mkdtemp() failed: %.100s", strerror(errno));
191: restore_uid();
1.265 djm 192: free(auth_sock_dir);
1.136 markus 193: auth_sock_dir = NULL;
1.237 djm 194: goto authsock_err;
1.136 markus 195: }
1.237 djm 196:
197: xasprintf(&auth_sock_name, "%s/agent.%ld",
198: auth_sock_dir, (long) getpid());
1.136 markus 199:
1.274 millert 200: /* Start a Unix listener on auth_sock_name. */
201: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136 markus 202:
203: /* Restore the privileged uid. */
204: restore_uid();
205:
1.274 millert 206: /* Check for socket/bind/listen failure. */
207: if (sock < 0)
1.237 djm 208: goto authsock_err;
1.136 markus 209:
210: /* Allocate a channel for the authentication agent socket. */
1.292 djm 211: nc = channel_new(ssh, "auth socket",
1.136 markus 212: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
213: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 214: 0, "auth socket", 1);
1.245 djm 215: nc->path = xstrdup(auth_sock_name);
1.136 markus 216: return 1;
1.237 djm 217:
218: authsock_err:
1.265 djm 219: free(auth_sock_name);
1.237 djm 220: if (auth_sock_dir != NULL) {
221: rmdir(auth_sock_dir);
1.265 djm 222: free(auth_sock_dir);
1.237 djm 223: }
224: if (sock != -1)
225: close(sock);
226: auth_sock_name = NULL;
227: auth_sock_dir = NULL;
228: return 0;
1.136 markus 229: }
230:
1.179 dtucker 231: static void
232: display_loginmsg(void)
233: {
1.303 markus 234: int r;
235:
236: if (sshbuf_len(loginmsg) == 0)
237: return;
238: if ((r = sshbuf_put_u8(loginmsg, 0)) != 0)
239: fatal("%s: buffer error: %s", __func__, ssh_err(r));
240: printf("%s", (char *)sshbuf_ptr(loginmsg));
241: sshbuf_reset(loginmsg);
1.179 dtucker 242: }
1.136 markus 243:
1.290 djm 244: static void
245: prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
246: {
247: int fd = -1, success = 0;
248:
249: if (!options.expose_userauth_info || info == NULL)
250: return;
251:
252: temporarily_use_uid(pw);
253: auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
254: if ((fd = mkstemp(auth_info_file)) == -1) {
255: error("%s: mkstemp: %s", __func__, strerror(errno));
256: goto out;
257: }
258: if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
259: sshbuf_len(info)) != sshbuf_len(info)) {
260: error("%s: write: %s", __func__, strerror(errno));
261: goto out;
262: }
263: if (close(fd) != 0) {
264: error("%s: close: %s", __func__, strerror(errno));
265: goto out;
266: }
267: success = 1;
268: out:
269: if (!success) {
270: if (fd != -1)
271: close(fd);
272: free(auth_info_file);
273: auth_info_file = NULL;
274: }
275: restore_uid();
276: }
277:
1.294 djm 278: static void
1.297 djm 279: set_fwdpermit_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
1.294 djm 280: {
281: char *tmp, *cp, *host;
282: int port;
283: size_t i;
284:
1.297 djm 285: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0) {
286: channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL);
287: for (i = 0; i < auth_opts->npermitopen; i++) {
288: tmp = cp = xstrdup(auth_opts->permitopen[i]);
289: /* This shouldn't fail as it has already been checked */
290: if ((host = hpdelim(&cp)) == NULL)
291: fatal("%s: internal error: hpdelim", __func__);
292: host = cleanhostname(host);
293: if (cp == NULL || (port = permitopen_port(cp)) < 0)
294: fatal("%s: internal error: permitopen port",
295: __func__);
296: channel_add_permission(ssh,
297: FORWARD_USER, FORWARD_LOCAL, host, port);
298: free(tmp);
299: }
300: }
301: if ((options.allow_tcp_forwarding & FORWARD_REMOTE) != 0) {
302: channel_clear_permission(ssh, FORWARD_USER, FORWARD_REMOTE);
303: for (i = 0; i < auth_opts->npermitlisten; i++) {
304: tmp = cp = xstrdup(auth_opts->permitlisten[i]);
305: /* This shouldn't fail as it has already been checked */
306: if ((host = hpdelim(&cp)) == NULL)
307: fatal("%s: internal error: hpdelim", __func__);
308: host = cleanhostname(host);
309: if (cp == NULL || (port = permitopen_port(cp)) < 0)
310: fatal("%s: internal error: permitlisten port",
311: __func__);
312: channel_add_permission(ssh,
313: FORWARD_USER, FORWARD_REMOTE, host, port);
314: free(tmp);
315: }
1.294 djm 316: }
317: }
318:
1.65 markus 319: void
1.292 djm 320: do_authenticated(struct ssh *ssh, Authctxt *authctxt)
1.65 markus 321: {
1.153 markus 322: setproctitle("%s", authctxt->pw->pw_name);
323:
1.294 djm 324: auth_log_authopts("active", auth_opts, 0);
325:
1.65 markus 326: /* setup the channel layer */
1.274 millert 327: /* XXX - streamlocal? */
1.297 djm 328: set_fwdpermit_from_authopts(ssh, auth_opts);
1.296 djm 329:
1.294 djm 330: if (!auth_opts->permit_port_forwarding_flag ||
1.296 djm 331: options.disable_forwarding) {
332: channel_disable_admin(ssh, FORWARD_LOCAL);
333: channel_disable_admin(ssh, FORWARD_REMOTE);
334: } else {
335: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
336: channel_disable_admin(ssh, FORWARD_LOCAL);
337: else
338: channel_permit_all(ssh, FORWARD_LOCAL);
339: if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0)
340: channel_disable_admin(ssh, FORWARD_REMOTE);
341: else
342: channel_permit_all(ssh, FORWARD_REMOTE);
343: }
1.252 dtucker 344: auth_debug_send();
1.65 markus 345:
1.290 djm 346: prepare_auth_info_file(authctxt->pw, authctxt->session_info);
347:
1.292 djm 348: do_authenticated2(ssh, authctxt);
1.290 djm 349:
1.292 djm 350: do_cleanup(ssh, authctxt);
1.65 markus 351: }
352:
1.282 djm 353: /* Check untrusted xauth strings for metacharacters */
354: static int
355: xauth_valid_string(const char *s)
356: {
357: size_t i;
358:
359: for (i = 0; s[i] != '\0'; i++) {
360: if (!isalnum((u_char)s[i]) &&
361: s[i] != '.' && s[i] != ':' && s[i] != '/' &&
362: s[i] != '-' && s[i] != '_')
363: return 0;
364: }
365: return 1;
366: }
367:
1.269 dtucker 368: #define USE_PIPES 1
1.1 markus 369: /*
370: * This is called to fork and execute a command when we have no tty. This
371: * will call do_child from the child, and server_loop from the parent after
372: * setting up file descriptors and such.
373: */
1.237 djm 374: int
1.292 djm 375: do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 376: {
1.137 mpech 377: pid_t pid;
1.238 markus 378: #ifdef USE_PIPES
379: int pin[2], pout[2], perr[2];
380:
1.253 djm 381: if (s == NULL)
382: fatal("do_exec_no_pty: no session");
383:
1.238 markus 384: /* Allocate pipes for communicating with the program. */
385: if (pipe(pin) < 0) {
386: error("%s: pipe in: %.100s", __func__, strerror(errno));
387: return -1;
388: }
389: if (pipe(pout) < 0) {
390: error("%s: pipe out: %.100s", __func__, strerror(errno));
391: close(pin[0]);
392: close(pin[1]);
393: return -1;
394: }
1.256 djm 395: if (pipe(perr) < 0) {
396: error("%s: pipe err: %.100s", __func__,
397: strerror(errno));
398: close(pin[0]);
399: close(pin[1]);
400: close(pout[0]);
401: close(pout[1]);
402: return -1;
1.238 markus 403: }
404: #else
1.237 djm 405: int inout[2], err[2];
1.1 markus 406:
1.253 djm 407: if (s == NULL)
408: fatal("do_exec_no_pty: no session");
409:
1.1 markus 410: /* Uses socket pairs to communicate with the program. */
1.237 djm 411: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
412: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
413: return -1;
414: }
1.256 djm 415: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
416: error("%s: socketpair #2: %.100s", __func__,
417: strerror(errno));
418: close(inout[0]);
419: close(inout[1]);
420: return -1;
1.237 djm 421: }
1.238 markus 422: #endif
1.237 djm 423:
1.9 markus 424: session_proctitle(s);
1.1 markus 425:
426: /* Fork the child. */
1.237 djm 427: switch ((pid = fork())) {
428: case -1:
429: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 markus 430: #ifdef USE_PIPES
431: close(pin[0]);
432: close(pin[1]);
433: close(pout[0]);
434: close(pout[1]);
1.256 djm 435: close(perr[0]);
1.238 markus 436: close(perr[1]);
437: #else
1.237 djm 438: close(inout[0]);
439: close(inout[1]);
440: close(err[0]);
1.256 djm 441: close(err[1]);
1.238 markus 442: #endif
1.237 djm 443: return -1;
444: case 0:
1.165 markus 445: is_child = 1;
1.144 markus 446:
1.1 markus 447: /*
448: * Create a new session and process group since the 4.4BSD
449: * setlogin() affects the entire process group.
450: */
451: if (setsid() < 0)
452: error("setsid failed: %.100s", strerror(errno));
453:
1.238 markus 454: #ifdef USE_PIPES
455: /*
456: * Redirect stdin. We close the parent side of the socket
457: * pair, and make the child side the standard input.
458: */
459: close(pin[1]);
460: if (dup2(pin[0], 0) < 0)
461: perror("dup2 stdin");
462: close(pin[0]);
463:
464: /* Redirect stdout. */
465: close(pout[0]);
466: if (dup2(pout[1], 1) < 0)
467: perror("dup2 stdout");
468: close(pout[1]);
469:
470: /* Redirect stderr. */
1.256 djm 471: close(perr[0]);
1.238 markus 472: if (dup2(perr[1], 2) < 0)
473: perror("dup2 stderr");
474: close(perr[1]);
475: #else
1.1 markus 476: /*
477: * Redirect stdin, stdout, and stderr. Stdin and stdout will
478: * use the same socket, as some programs (particularly rdist)
479: * seem to depend on it.
480: */
481: close(inout[1]);
1.256 djm 482: close(err[1]);
1.1 markus 483: if (dup2(inout[0], 0) < 0) /* stdin */
484: perror("dup2 stdin");
1.237 djm 485: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 486: perror("dup2 stdout");
1.238 markus 487: close(inout[0]);
1.1 markus 488: if (dup2(err[0], 2) < 0) /* stderr */
489: perror("dup2 stderr");
1.238 markus 490: close(err[0]);
491: #endif
1.1 markus 492:
493: /* Do processing for the child (exec command etc). */
1.292 djm 494: do_child(ssh, s, command);
1.1 markus 495: /* NOTREACHED */
1.237 djm 496: default:
497: break;
1.1 markus 498: }
1.237 djm 499:
1.1 markus 500: s->pid = pid;
1.47 markus 501: /* Set interactive/non-interactive mode. */
1.257 djm 502: packet_set_interactive(s->display != NULL,
503: options.ip_qos_interactive, options.ip_qos_bulk);
1.1 markus 504:
1.238 markus 505: #ifdef USE_PIPES
506: /* We are the parent. Close the child sides of the pipes. */
507: close(pin[0]);
508: close(pout[1]);
509: close(perr[1]);
510:
1.292 djm 511: session_set_fds(ssh, s, pin[1], pout[0], perr[0],
1.283 markus 512: s->is_subsystem, 0);
1.238 markus 513: #else
1.1 markus 514: /* We are the parent. Close the child sides of the socket pairs. */
515: close(inout[0]);
516: close(err[0]);
517:
518: /*
519: * Enter the interactive session. Note: server_loop must be able to
520: * handle the case that fdin and fdout are the same.
521: */
1.283 markus 522: session_set_fds(s, inout[1], inout[1], err[1],
523: s->is_subsystem, 0);
1.238 markus 524: #endif
1.237 djm 525: return 0;
1.1 markus 526: }
527:
528: /*
529: * This is called to fork and execute a command when we have a tty. This
530: * will call do_child from the child, and server_loop from the parent after
531: * setting up file descriptors, controlling tty, updating wtmp, utmp,
532: * lastlog, and other such operations.
533: */
1.237 djm 534: int
1.292 djm 535: do_exec_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 536: {
537: int fdout, ptyfd, ttyfd, ptymaster;
538: pid_t pid;
539:
540: if (s == NULL)
541: fatal("do_exec_pty: no session");
542: ptyfd = s->ptyfd;
543: ttyfd = s->ttyfd;
544:
1.237 djm 545: /*
546: * Create another descriptor of the pty master side for use as the
547: * standard input. We could use the original descriptor, but this
548: * simplifies code in server_loop. The descriptor is bidirectional.
549: * Do this before forking (and cleanup in the child) so as to
550: * detect and gracefully fail out-of-fd conditions.
551: */
552: if ((fdout = dup(ptyfd)) < 0) {
553: error("%s: dup #1: %s", __func__, strerror(errno));
554: close(ttyfd);
555: close(ptyfd);
556: return -1;
557: }
558: /* we keep a reference to the pty master */
559: if ((ptymaster = dup(ptyfd)) < 0) {
560: error("%s: dup #2: %s", __func__, strerror(errno));
561: close(ttyfd);
562: close(ptyfd);
563: close(fdout);
564: return -1;
565: }
566:
1.1 markus 567: /* Fork the child. */
1.237 djm 568: switch ((pid = fork())) {
569: case -1:
570: error("%s: fork: %.100s", __func__, strerror(errno));
571: close(fdout);
572: close(ptymaster);
573: close(ttyfd);
574: close(ptyfd);
575: return -1;
576: case 0:
1.165 markus 577: is_child = 1;
1.97 markus 578:
1.237 djm 579: close(fdout);
580: close(ptymaster);
581:
1.1 markus 582: /* Close the master side of the pseudo tty. */
583: close(ptyfd);
584:
585: /* Make the pseudo tty our controlling tty. */
586: pty_make_controlling_tty(&ttyfd, s->tty);
587:
1.103 markus 588: /* Redirect stdin/stdout/stderr from the pseudo tty. */
589: if (dup2(ttyfd, 0) < 0)
590: error("dup2 stdin: %s", strerror(errno));
591: if (dup2(ttyfd, 1) < 0)
592: error("dup2 stdout: %s", strerror(errno));
593: if (dup2(ttyfd, 2) < 0)
594: error("dup2 stderr: %s", strerror(errno));
1.1 markus 595:
596: /* Close the extra descriptor for the pseudo tty. */
597: close(ttyfd);
598:
1.24 markus 599: /* record login, etc. similar to login(1) */
1.292 djm 600: do_login(ssh, s, command);
1.228 djm 601:
1.237 djm 602: /*
603: * Do common processing for the child, such as execing
604: * the command.
605: */
1.292 djm 606: do_child(ssh, s, command);
1.1 markus 607: /* NOTREACHED */
1.237 djm 608: default:
609: break;
1.1 markus 610: }
611: s->pid = pid;
612:
613: /* Parent. Close the slave side of the pseudo tty. */
614: close(ttyfd);
615:
1.237 djm 616: /* Enter interactive session. */
1.1 markus 617: s->ptymaster = ptymaster;
1.257 djm 618: packet_set_interactive(1,
619: options.ip_qos_interactive, options.ip_qos_bulk);
1.292 djm 620: session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
1.237 djm 621: return 0;
1.24 markus 622: }
623:
1.90 markus 624: /*
625: * This is called to fork and execute a command. If another command is
626: * to be forced, execute that instead.
627: */
1.237 djm 628: int
1.292 djm 629: do_exec(struct ssh *ssh, Session *s, const char *command)
1.90 markus 630: {
1.237 djm 631: int ret;
1.280 djm 632: const char *forced = NULL, *tty = NULL;
633: char session_type[1024];
1.237 djm 634:
1.210 dtucker 635: if (options.adm_forced_command) {
636: original_command = command;
637: command = options.adm_forced_command;
1.267 djm 638: forced = "(config)";
1.294 djm 639: } else if (auth_opts->force_command != NULL) {
1.90 markus 640: original_command = command;
1.294 djm 641: command = auth_opts->force_command;
1.267 djm 642: forced = "(key-option)";
643: }
644: if (forced != NULL) {
1.248 djm 645: if (IS_INTERNAL_SFTP(command)) {
646: s->is_subsystem = s->is_subsystem ?
647: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
648: } else if (s->is_subsystem)
1.225 markus 649: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 650: snprintf(session_type, sizeof(session_type),
651: "forced-command %s '%.900s'", forced, command);
652: } else if (s->is_subsystem) {
653: snprintf(session_type, sizeof(session_type),
654: "subsystem '%.900s'", s->subsys);
655: } else if (command == NULL) {
656: snprintf(session_type, sizeof(session_type), "shell");
657: } else {
658: /* NB. we don't log unforced commands to preserve privacy */
659: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 660: }
1.163 markus 661:
1.267 djm 662: if (s->ttyfd != -1) {
663: tty = s->tty;
664: if (strncmp(tty, "/dev/", 5) == 0)
665: tty += 5;
666: }
667:
1.280 djm 668: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 669: session_type,
670: tty == NULL ? "" : " on ",
671: tty == NULL ? "" : tty,
672: s->pw->pw_name,
1.281 djm 673: ssh_remote_ipaddr(ssh),
674: ssh_remote_port(ssh),
1.280 djm 675: s->self);
1.267 djm 676:
1.163 markus 677: #ifdef GSSAPI
678: if (options.gss_authentication) {
679: temporarily_use_uid(s->pw);
680: ssh_gssapi_storecreds();
681: restore_uid();
682: }
683: #endif
1.90 markus 684: if (s->ttyfd != -1)
1.292 djm 685: ret = do_exec_pty(ssh, s, command);
1.90 markus 686: else
1.292 djm 687: ret = do_exec_no_pty(ssh, s, command);
1.90 markus 688:
1.92 markus 689: original_command = NULL;
1.179 dtucker 690:
691: /*
692: * Clear loginmsg: it's the child's responsibility to display
693: * it to the user, otherwise multiple sessions may accumulate
694: * multiple copies of the login messages.
695: */
1.303 markus 696: sshbuf_reset(loginmsg);
1.237 djm 697:
698: return ret;
1.90 markus 699: }
700:
701:
1.24 markus 702: /* administrative, login(1)-like work */
703: void
1.292 djm 704: do_login(struct ssh *ssh, Session *s, const char *command)
1.24 markus 705: {
706: socklen_t fromlen;
707: struct sockaddr_storage from;
708: struct passwd * pw = s->pw;
709: pid_t pid = getpid();
710:
711: /*
712: * Get IP address of client. If the connection is not a socket, let
713: * the address be 0.0.0.0.
714: */
715: memset(&from, 0, sizeof(from));
1.148 stevesk 716: fromlen = sizeof(from);
1.24 markus 717: if (packet_connection_is_on_socket()) {
718: if (getpeername(packet_get_connection_in(),
1.200 deraadt 719: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 720: debug("getpeername: %.100s", strerror(errno));
1.165 markus 721: cleanup_exit(255);
1.24 markus 722: }
723: }
1.25 markus 724:
1.24 markus 725: /* Record that there was a login on that tty from the remote host. */
1.133 markus 726: if (!use_privsep)
727: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 728: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 729: options.use_dns),
1.148 stevesk 730: (struct sockaddr *)&from, fromlen);
1.24 markus 731:
1.73 djm 732: if (check_quietlogin(s, command))
1.24 markus 733: return;
1.73 djm 734:
1.179 dtucker 735: display_loginmsg();
1.73 djm 736:
737: do_motd();
738: }
739:
740: /*
741: * Display the message of the day.
742: */
743: void
744: do_motd(void)
745: {
746: FILE *f;
747: char buf[256];
748:
1.24 markus 749: if (options.print_motd) {
1.28 millert 750: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
751: "/etc/motd"), "r");
1.24 markus 752: if (f) {
753: while (fgets(buf, sizeof(buf), f))
754: fputs(buf, stdout);
755: fclose(f);
756: }
1.2 markus 757: }
1.73 djm 758: }
759:
760:
761: /*
762: * Check for quiet login, either .hushlogin or command given.
763: */
764: int
765: check_quietlogin(Session *s, const char *command)
766: {
767: char buf[256];
1.96 dugsong 768: struct passwd *pw = s->pw;
1.73 djm 769: struct stat st;
770:
771: /* Return 1 if .hushlogin exists or a command given. */
772: if (command != NULL)
773: return 1;
774: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
775: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
776: return 1;
777: return 0;
1.1 markus 778: }
779:
780: /*
781: * Reads environment variables from the given file and adds/overrides them
782: * into the environment. If the file does not exist, this does nothing.
783: * Otherwise, it must consist of empty lines, comments (line starts with '#')
784: * and assignments of the form name=value. No other forms are allowed.
1.301 djm 785: * If whitelist is not NULL, then it is interpreted as a pattern list and
786: * only variable names that match it will be accepted.
1.1 markus 787: */
1.94 itojun 788: static void
1.45 markus 789: read_environment_file(char ***env, u_int *envsize,
1.301 djm 790: const char *filename, const char *whitelist)
1.1 markus 791: {
792: FILE *f;
1.298 markus 793: char *line = NULL, *cp, *value;
794: size_t linesize = 0;
1.142 deraadt 795: u_int lineno = 0;
1.1 markus 796:
797: f = fopen(filename, "r");
798: if (!f)
799: return;
800:
1.298 markus 801: while (getline(&line, &linesize, f) != -1) {
1.142 deraadt 802: if (++lineno > 1000)
803: fatal("Too many lines in environment file %s", filename);
1.298 markus 804: for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
1.1 markus 805: ;
806: if (!*cp || *cp == '#' || *cp == '\n')
807: continue;
1.224 gilles 808:
809: cp[strcspn(cp, "\n")] = '\0';
810:
1.1 markus 811: value = strchr(cp, '=');
812: if (value == NULL) {
1.142 deraadt 813: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
814: filename);
1.1 markus 815: continue;
816: }
1.14 deraadt 817: /*
818: * Replace the equals sign by nul, and advance value to
819: * the value string.
820: */
1.1 markus 821: *value = '\0';
822: value++;
1.301 djm 823: if (whitelist != NULL &&
824: match_pattern_list(cp, whitelist, 0) != 1)
825: continue;
1.1 markus 826: child_set_env(env, envsize, cp, value);
827: }
1.298 markus 828: free(line);
1.1 markus 829: fclose(f);
830: }
831:
1.127 markus 832: static char **
1.292 djm 833: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1 markus 834: {
835: char buf[256];
1.294 djm 836: size_t n;
1.127 markus 837: u_int i, envsize;
1.300 djm 838: char *ocp, *cp, *value, **env, *laddr;
1.127 markus 839: struct passwd *pw = s->pw;
1.1 markus 840:
841: /* Initialize the environment. */
842: envsize = 100;
1.220 djm 843: env = xcalloc(envsize, sizeof(char *));
1.1 markus 844: env[0] = NULL;
845:
1.161 markus 846: #ifdef GSSAPI
1.168 djm 847: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 848: * the childs environment as they see fit
849: */
850: ssh_gssapi_do_child(&env, &envsize);
851: #endif
852:
1.284 djm 853: /* Set basic environment. */
854: for (i = 0; i < s->num_env; i++)
855: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
856:
857: child_set_env(&env, &envsize, "USER", pw->pw_name);
858: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
859: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
860: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
861: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
862: else
863: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
864:
865: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
866: child_set_env(&env, &envsize, "MAIL", buf);
867:
868: /* Normal systems set SHELL by default. */
869: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 870:
871: if (getenv("TZ"))
872: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1.299 djm 873: if (s->term)
874: child_set_env(&env, &envsize, "TERM", s->term);
875: if (s->display)
876: child_set_env(&env, &envsize, "DISPLAY", s->display);
877: #ifdef KRB5
878: if (s->authctxt->krb5_ticket_file)
879: child_set_env(&env, &envsize, "KRB5CCNAME",
880: s->authctxt->krb5_ticket_file);
881: #endif
882: if (auth_sock_name != NULL)
883: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
884: auth_sock_name);
885:
1.1 markus 886:
1.294 djm 887: /* Set custom environment options from pubkey authentication. */
888: if (options.permit_user_env) {
889: for (n = 0 ; n < auth_opts->nenv; n++) {
890: ocp = xstrdup(auth_opts->env[n]);
891: cp = strchr(ocp, '=');
892: if (*cp == '=') {
893: *cp = '\0';
1.301 djm 894: /* Apply PermitUserEnvironment whitelist */
895: if (options.permit_user_env_whitelist == NULL ||
896: match_pattern_list(ocp,
897: options.permit_user_env_whitelist, 0) == 1)
898: child_set_env(&env, &envsize,
899: ocp, cp + 1);
1.294 djm 900: }
901: free(ocp);
902: }
1.1 markus 903: }
904:
1.299 djm 905: /* read $HOME/.ssh/environment. */
906: if (options.permit_user_env) {
907: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
908: pw->pw_dir);
1.301 djm 909: read_environment_file(&env, &envsize, buf,
910: options.permit_user_env_whitelist);
1.300 djm 911: }
912:
913: /* Environment specified by admin */
914: for (i = 0; i < options.num_setenv; i++) {
915: cp = xstrdup(options.setenv[i]);
916: if ((value = strchr(cp, '=')) == NULL) {
917: /* shouldn't happen; vars are checked in servconf.c */
918: fatal("Invalid config SetEnv: %s", options.setenv[i]);
919: }
920: *value++ = '\0';
921: child_set_env(&env, &envsize, cp, value);
1.299 djm 922: }
923:
1.149 stevesk 924: /* SSH_CLIENT deprecated */
1.1 markus 925: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 926: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
927: ssh_local_port(ssh));
1.1 markus 928: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 929:
1.154 markus 930: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 931: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 932: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
933: laddr, ssh_local_port(ssh));
1.265 djm 934: free(laddr);
1.149 stevesk 935: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 936:
1.293 djm 937: if (tun_fwd_ifnames != NULL)
938: child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
1.290 djm 939: if (auth_info_file != NULL)
940: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 941: if (s->ttyfd != -1)
942: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1.34 markus 943: if (original_command)
944: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
945: original_command);
1.1 markus 946:
947: if (debug_flag) {
948: /* dump the environment */
949: fprintf(stderr, "Environment:\n");
950: for (i = 0; env[i]; i++)
951: fprintf(stderr, " %.200s\n", env[i]);
952: }
1.127 markus 953: return env;
954: }
955:
956: /*
957: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
958: * first in this order).
959: */
960: static void
1.294 djm 961: do_rc_files(struct ssh *ssh, Session *s, const char *shell)
1.127 markus 962: {
963: FILE *f = NULL;
964: char cmd[1024];
965: int do_xauth;
966: struct stat st;
967:
968: do_xauth =
969: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
970:
1.231 djm 971: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 972: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.294 djm 973: auth_opts->permit_user_rc && options.permit_user_rc &&
1.273 djm 974: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 975: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
976: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
977: if (debug_flag)
978: fprintf(stderr, "Running %s\n", cmd);
979: f = popen(cmd, "w");
980: if (f) {
981: if (do_xauth)
982: fprintf(f, "%s %s\n", s->auth_proto,
983: s->auth_data);
984: pclose(f);
985: } else
986: fprintf(stderr, "Could not run %s\n",
987: _PATH_SSH_USER_RC);
988: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
989: if (debug_flag)
990: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
991: _PATH_SSH_SYSTEM_RC);
992: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
993: if (f) {
994: if (do_xauth)
995: fprintf(f, "%s %s\n", s->auth_proto,
996: s->auth_data);
997: pclose(f);
998: } else
999: fprintf(stderr, "Could not run %s\n",
1000: _PATH_SSH_SYSTEM_RC);
1001: } else if (do_xauth && options.xauth_location != NULL) {
1002: /* Add authority data to .Xauthority if appropriate. */
1003: if (debug_flag) {
1004: fprintf(stderr,
1.151 stevesk 1005: "Running %.500s remove %.100s\n",
1.165 markus 1006: options.xauth_location, s->auth_display);
1.151 stevesk 1007: fprintf(stderr,
1008: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 1009: options.xauth_location, s->auth_display,
1010: s->auth_proto, s->auth_data);
1011: }
1012: snprintf(cmd, sizeof cmd, "%s -q -",
1013: options.xauth_location);
1014: f = popen(cmd, "w");
1015: if (f) {
1.151 stevesk 1016: fprintf(f, "remove %s\n",
1017: s->auth_display);
1.127 markus 1018: fprintf(f, "add %s %s %s\n",
1019: s->auth_display, s->auth_proto,
1020: s->auth_data);
1021: pclose(f);
1022: } else {
1023: fprintf(stderr, "Could not run %s\n",
1024: cmd);
1025: }
1026: }
1027: }
1028:
1029: static void
1030: do_nologin(struct passwd *pw)
1031: {
1032: FILE *f = NULL;
1.251 dtucker 1033: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
1034: struct stat sb;
1.127 markus 1035:
1.260 guenther 1036: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 1037: return;
1038: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
1039:
1040: if (stat(nl, &sb) == -1) {
1041: if (nl != def_nl)
1.265 djm 1042: free(nl);
1.251 dtucker 1043: return;
1044: }
1045:
1046: /* /etc/nologin exists. Print its contents if we can and exit. */
1047: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1048: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 1049: while (fgets(buf, sizeof(buf), f))
1050: fputs(buf, stderr);
1051: fclose(f);
1052: }
1.251 dtucker 1053: exit(254);
1.127 markus 1054: }
1055:
1.226 djm 1056: /*
1057: * Chroot into a directory after checking it for safety: all path components
1058: * must be root-owned directories with strict permissions.
1059: */
1060: static void
1061: safely_chroot(const char *path, uid_t uid)
1062: {
1063: const char *cp;
1.277 deraadt 1064: char component[PATH_MAX];
1.226 djm 1065: struct stat st;
1066:
1067: if (*path != '/')
1068: fatal("chroot path does not begin at root");
1069: if (strlen(path) >= sizeof(component))
1070: fatal("chroot path too long");
1071:
1072: /*
1073: * Descend the path, checking that each component is a
1074: * root-owned directory with strict permissions.
1075: */
1076: for (cp = path; cp != NULL;) {
1077: if ((cp = strchr(cp, '/')) == NULL)
1078: strlcpy(component, path, sizeof(component));
1079: else {
1080: cp++;
1081: memcpy(component, path, cp - path);
1082: component[cp - path] = '\0';
1083: }
1084:
1085: debug3("%s: checking '%s'", __func__, component);
1086:
1087: if (stat(component, &st) != 0)
1088: fatal("%s: stat(\"%s\"): %s", __func__,
1089: component, strerror(errno));
1090: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1091: fatal("bad ownership or modes for chroot "
1092: "directory %s\"%s\"",
1093: cp == NULL ? "" : "component ", component);
1094: if (!S_ISDIR(st.st_mode))
1095: fatal("chroot path %s\"%s\" is not a directory",
1096: cp == NULL ? "" : "component ", component);
1097:
1098: }
1099:
1100: if (chdir(path) == -1)
1101: fatal("Unable to chdir to chroot path \"%s\": "
1102: "%s", path, strerror(errno));
1103: if (chroot(path) == -1)
1104: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1105: if (chdir("/") == -1)
1106: fatal("%s: chdir(/) after chroot: %s",
1107: __func__, strerror(errno));
1108: verbose("Changed root directory to \"%s\"", path);
1109: }
1110:
1.127 markus 1111: /* Set login name, uid, gid, and groups. */
1.130 provos 1112: void
1.127 markus 1113: do_setusercontext(struct passwd *pw)
1114: {
1.295 djm 1115: char uidstr[32], *chroot_path, *tmp;
1.227 djm 1116:
1.127 markus 1117: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1118: /* Prepare groups */
1.127 markus 1119: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1120: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1121: perror("unable to set user context");
1122: exit(1);
1123: }
1.226 djm 1124:
1.279 djm 1125: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1126: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1127: tmp = tilde_expand_filename(options.chroot_directory,
1128: pw->pw_uid);
1.295 djm 1129: snprintf(uidstr, sizeof(uidstr), "%llu",
1130: (unsigned long long)pw->pw_uid);
1.227 djm 1131: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1.295 djm 1132: "u", pw->pw_name, "U", uidstr, (char *)NULL);
1.226 djm 1133: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1134: free(tmp);
1.226 djm 1135: free(chroot_path);
1.264 djm 1136: /* Make sure we don't attempt to chroot again */
1137: free(options.chroot_directory);
1138: options.chroot_directory = NULL;
1.279 djm 1139: in_chroot = 1;
1.226 djm 1140: }
1141:
1142: /* Set UID */
1143: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1144: perror("unable to set user context (setuser)");
1145: exit(1);
1146: }
1.264 djm 1147: } else if (options.chroot_directory != NULL &&
1148: strcasecmp(options.chroot_directory, "none") != 0) {
1149: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1150: }
1.264 djm 1151:
1.127 markus 1152: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1153: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1154: }
1155:
1.131 markus 1156: static void
1.172 markus 1157: do_pwchange(Session *s)
1158: {
1.179 dtucker 1159: fflush(NULL);
1.172 markus 1160: fprintf(stderr, "WARNING: Your password has expired.\n");
1161: if (s->ttyfd != -1) {
1.178 deraadt 1162: fprintf(stderr,
1.172 markus 1163: "You must change your password now and login again!\n");
1164: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1165: perror("passwd");
1166: } else {
1167: fprintf(stderr,
1168: "Password change required but no TTY available.\n");
1169: }
1170: exit(1);
1171: }
1172:
1173: static void
1.292 djm 1174: child_close_fds(struct ssh *ssh)
1.172 markus 1175: {
1.276 djm 1176: extern int auth_sock;
1.266 markus 1177:
1.276 djm 1178: if (auth_sock != -1) {
1179: close(auth_sock);
1180: auth_sock = -1;
1.266 markus 1181: }
1182:
1.172 markus 1183: if (packet_get_connection_in() == packet_get_connection_out())
1184: close(packet_get_connection_in());
1185: else {
1186: close(packet_get_connection_in());
1187: close(packet_get_connection_out());
1188: }
1189: /*
1190: * Close all descriptors related to channels. They will still remain
1191: * open in the parent.
1192: */
1193: /* XXX better use close-on-exec? -markus */
1.292 djm 1194: channel_close_all(ssh);
1.172 markus 1195:
1196: /*
1197: * Close any extra file descriptors. Note that there may still be
1198: * descriptors left by system functions. They will be closed later.
1199: */
1200: endpwent();
1201:
1202: /*
1.188 djm 1203: * Close any extra open file descriptors so that we don't have them
1.172 markus 1204: * hanging around in clients. Note that we want to do this after
1205: * initgroups, because at least on Solaris 2.3 it leaves file
1206: * descriptors open.
1207: */
1.258 djm 1208: closefrom(STDERR_FILENO + 1);
1.172 markus 1209: }
1210:
1.127 markus 1211: /*
1212: * Performs common processing for the child, such as setting up the
1213: * environment, closing extra file descriptors, setting the user and group
1214: * ids, and executing the command or shell.
1215: */
1.225 markus 1216: #define ARGV_MAX 10
1.127 markus 1217: void
1.292 djm 1218: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1219: {
1220: extern char **environ;
1221: char **env;
1.225 markus 1222: char *argv[ARGV_MAX];
1.284 djm 1223: const char *shell, *shell0;
1.127 markus 1224: struct passwd *pw = s->pw;
1.239 djm 1225: int r = 0;
1.127 markus 1226:
1227: /* remove hostkey from the child's memory */
1228: destroy_sensitive_data();
1.287 markus 1229: packet_clear_keys();
1.127 markus 1230:
1.172 markus 1231: /* Force a password change */
1232: if (s->authctxt->force_pwchange) {
1233: do_setusercontext(pw);
1.292 djm 1234: child_close_fds(ssh);
1.172 markus 1235: do_pwchange(s);
1236: exit(1);
1237: }
1238:
1.127 markus 1239: /*
1240: * Login(1) does this as well, and it needs uid 0 for the "-h"
1241: * switch, so we let login(1) to this for us.
1242: */
1.284 djm 1243: do_nologin(pw);
1244: do_setusercontext(pw);
1.127 markus 1245:
1246: /*
1247: * Get the shell from the password data. An empty shell field is
1248: * legal, and means /bin/sh.
1249: */
1250: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1251:
1252: /*
1253: * Make sure $SHELL points to the shell from the password file,
1254: * even if shell is overridden from login.conf
1255: */
1.292 djm 1256: env = do_setup_env(ssh, s, shell);
1.152 markus 1257:
1.127 markus 1258: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1259:
1.1 markus 1260: /*
1261: * Close the connection descriptors; note that this is the child, and
1262: * the server will still have the socket open, and it is important
1263: * that we do not shutdown it. Note that the descriptors cannot be
1264: * closed before building the environment, as we call
1.281 djm 1265: * ssh_remote_ipaddr there.
1.1 markus 1266: */
1.292 djm 1267: child_close_fds(ssh);
1.1 markus 1268:
1269: /*
1.125 deraadt 1270: * Must take new environment into use so that .ssh/rc,
1271: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1272: */
1273: environ = env;
1.170 jakob 1274:
1275: #ifdef KRB5
1276: /*
1277: * At this point, we check to see if AFS is active and if we have
1278: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1279: * if we can (and need to) extend the ticket into an AFS token. If
1280: * we don't do this, we run into potential problems if the user's
1281: * home directory is in AFS and it's not world-readable.
1282: */
1283:
1284: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1285: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1286: char cell[64];
1287:
1288: debug("Getting AFS token");
1289:
1290: k_setpag();
1291:
1292: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1293: krb5_afslog(s->authctxt->krb5_ctx,
1294: s->authctxt->krb5_fwd_ccache, cell, NULL);
1295:
1296: krb5_afslog_home(s->authctxt->krb5_ctx,
1297: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1298: }
1299: #endif
1.104 markus 1300:
1.188 djm 1301: /* Change current directory to the user's home directory. */
1.104 markus 1302: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1303: /* Suppress missing homedir warning for chroot case */
1304: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1305: if (r || !in_chroot) {
1.239 djm 1306: fprintf(stderr, "Could not chdir to home "
1307: "directory %s: %s\n", pw->pw_dir,
1308: strerror(errno));
1.279 djm 1309: }
1.239 djm 1310: if (r)
1.104 markus 1311: exit(1);
1312: }
1.230 djm 1313:
1314: closefrom(STDERR_FILENO + 1);
1.1 markus 1315:
1.294 djm 1316: do_rc_files(ssh, s, shell);
1.67 markus 1317:
1318: /* restore SIGPIPE for child */
1.217 stevesk 1319: signal(SIGPIPE, SIG_DFL);
1.67 markus 1320:
1.248 djm 1321: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1322: printf("This service allows sftp connections only.\n");
1323: fflush(NULL);
1324: exit(1);
1325: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1326: extern int optind, optreset;
1327: int i;
1328: char *p, *args;
1329:
1.246 stevesk 1330: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1331: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1332: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1333: if (i < ARGV_MAX - 1)
1334: argv[i++] = p;
1335: argv[i] = NULL;
1336: optind = optreset = 1;
1337: __progname = argv[0];
1.226 djm 1338: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1339: }
1.247 djm 1340:
1341: fflush(NULL);
1.225 markus 1342:
1.127 markus 1343: /* Get the last component of the shell name. */
1344: if ((shell0 = strrchr(shell, '/')) != NULL)
1345: shell0++;
1346: else
1347: shell0 = shell;
1348:
1.1 markus 1349: /*
1350: * If we have no command, execute the shell. In this case, the shell
1351: * name to be passed in argv[0] is preceded by '-' to indicate that
1352: * this is a login shell.
1353: */
1354: if (!command) {
1.127 markus 1355: char argv0[256];
1.1 markus 1356:
1.127 markus 1357: /* Start the shell. Set initial character to '-'. */
1358: argv0[0] = '-';
1.1 markus 1359:
1.127 markus 1360: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1361: >= sizeof(argv0) - 1) {
1.127 markus 1362: errno = EINVAL;
1.1 markus 1363: perror(shell);
1364: exit(1);
1.127 markus 1365: }
1.1 markus 1366:
1.127 markus 1367: /* Execute the shell. */
1368: argv[0] = argv0;
1369: argv[1] = NULL;
1370: execve(shell, argv, env);
1371:
1372: /* Executing the shell failed. */
1373: perror(shell);
1374: exit(1);
1.1 markus 1375: }
1376: /*
1377: * Execute the command using the user's shell. This uses the -c
1378: * option to execute the command.
1379: */
1.127 markus 1380: argv[0] = (char *) shell0;
1.1 markus 1381: argv[1] = "-c";
1382: argv[2] = (char *) command;
1383: argv[3] = NULL;
1384: execve(shell, argv, env);
1385: perror(shell);
1386: exit(1);
1387: }
1388:
1.237 djm 1389: void
1390: session_unused(int id)
1391: {
1392: debug3("%s: session id %d unused", __func__, id);
1393: if (id >= options.max_sessions ||
1394: id >= sessions_nalloc) {
1395: fatal("%s: insane session id %d (max %d nalloc %d)",
1396: __func__, id, options.max_sessions, sessions_nalloc);
1397: }
1.270 tedu 1398: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1399: sessions[id].self = id;
1400: sessions[id].used = 0;
1401: sessions[id].chanid = -1;
1402: sessions[id].ptyfd = -1;
1403: sessions[id].ttyfd = -1;
1404: sessions[id].ptymaster = -1;
1405: sessions[id].x11_chanids = NULL;
1406: sessions[id].next_unused = sessions_first_unused;
1407: sessions_first_unused = id;
1408: }
1409:
1.1 markus 1410: Session *
1411: session_new(void)
1412: {
1.237 djm 1413: Session *s, *tmp;
1414:
1415: if (sessions_first_unused == -1) {
1416: if (sessions_nalloc >= options.max_sessions)
1417: return NULL;
1418: debug2("%s: allocate (allocated %d max %d)",
1419: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1420: tmp = xrecallocarray(sessions, sessions_nalloc,
1421: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1422: if (tmp == NULL) {
1423: error("%s: cannot allocate %d sessions",
1424: __func__, sessions_nalloc + 1);
1425: return NULL;
1426: }
1427: sessions = tmp;
1428: session_unused(sessions_nalloc++);
1429: }
1430:
1431: if (sessions_first_unused >= sessions_nalloc ||
1432: sessions_first_unused < 0) {
1433: fatal("%s: insane first_unused %d max %d nalloc %d",
1434: __func__, sessions_first_unused, options.max_sessions,
1435: sessions_nalloc);
1436: }
1437:
1438: s = &sessions[sessions_first_unused];
1439: if (s->used) {
1440: fatal("%s: session %d already used",
1441: __func__, sessions_first_unused);
1442: }
1443: sessions_first_unused = s->next_unused;
1444: s->used = 1;
1445: s->next_unused = -1;
1446: debug("session_new: session %d", s->self);
1447:
1448: return s;
1.1 markus 1449: }
1450:
1.94 itojun 1451: static void
1.1 markus 1452: session_dump(void)
1453: {
1454: int i;
1.237 djm 1455: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1456: Session *s = &sessions[i];
1.237 djm 1457:
1458: debug("dump: used %d next_unused %d session %d %p "
1459: "channel %d pid %ld",
1.1 markus 1460: s->used,
1.237 djm 1461: s->next_unused,
1.1 markus 1462: s->self,
1463: s,
1464: s->chanid,
1.137 mpech 1465: (long)s->pid);
1.1 markus 1466: }
1467: }
1468:
1.2 markus 1469: int
1.97 markus 1470: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1471: {
1472: Session *s = session_new();
1473: debug("session_open: channel %d", chanid);
1474: if (s == NULL) {
1475: error("no more sessions");
1476: return 0;
1477: }
1.97 markus 1478: s->authctxt = authctxt;
1479: s->pw = authctxt->pw;
1.167 djm 1480: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1481: fatal("no user for session %d", s->self);
1.2 markus 1482: debug("session_open: session %d: link with channel %d", s->self, chanid);
1483: s->chanid = chanid;
1484: return 1;
1485: }
1486:
1.130 provos 1487: Session *
1488: session_by_tty(char *tty)
1489: {
1490: int i;
1.237 djm 1491: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1492: Session *s = &sessions[i];
1493: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1494: debug("session_by_tty: session %d tty %s", i, tty);
1495: return s;
1496: }
1497: }
1498: debug("session_by_tty: unknown tty %.100s", tty);
1499: session_dump();
1500: return NULL;
1501: }
1502:
1.94 itojun 1503: static Session *
1.2 markus 1504: session_by_channel(int id)
1505: {
1506: int i;
1.237 djm 1507: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1508: Session *s = &sessions[i];
1509: if (s->used && s->chanid == id) {
1.237 djm 1510: debug("session_by_channel: session %d channel %d",
1511: i, id);
1.2 markus 1512: return s;
1513: }
1514: }
1515: debug("session_by_channel: unknown channel %d", id);
1516: session_dump();
1517: return NULL;
1518: }
1519:
1.94 itojun 1520: static Session *
1.184 djm 1521: session_by_x11_channel(int id)
1522: {
1523: int i, j;
1524:
1.237 djm 1525: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1526: Session *s = &sessions[i];
1527:
1528: if (s->x11_chanids == NULL || !s->used)
1529: continue;
1530: for (j = 0; s->x11_chanids[j] != -1; j++) {
1531: if (s->x11_chanids[j] == id) {
1532: debug("session_by_x11_channel: session %d "
1533: "channel %d", s->self, id);
1534: return s;
1535: }
1536: }
1537: }
1538: debug("session_by_x11_channel: unknown channel %d", id);
1539: session_dump();
1540: return NULL;
1541: }
1542:
1543: static Session *
1.2 markus 1544: session_by_pid(pid_t pid)
1545: {
1546: int i;
1.137 mpech 1547: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1548: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1549: Session *s = &sessions[i];
1550: if (s->used && s->pid == pid)
1551: return s;
1552: }
1.137 mpech 1553: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1554: session_dump();
1555: return NULL;
1556: }
1557:
1.94 itojun 1558: static int
1.292 djm 1559: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1560: {
1561: s->col = packet_get_int();
1562: s->row = packet_get_int();
1563: s->xpixel = packet_get_int();
1564: s->ypixel = packet_get_int();
1.116 markus 1565: packet_check_eom();
1.2 markus 1566: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1567: return 1;
1568: }
1569:
1.94 itojun 1570: static int
1.292 djm 1571: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1572: {
1.45 markus 1573: u_int len;
1.132 markus 1574:
1.294 djm 1575: if (!auth_opts->permit_pty_flag || !options.permit_tty) {
1576: debug("Allocating a pty not permitted for this connection.");
1.19 markus 1577: return 0;
1.86 markus 1578: }
1579: if (s->ttyfd != -1) {
1580: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1581: return 0;
1.86 markus 1582: }
1583:
1.2 markus 1584: s->term = packet_get_string(&len);
1.283 markus 1585: s->col = packet_get_int();
1586: s->row = packet_get_int();
1.2 markus 1587: s->xpixel = packet_get_int();
1588: s->ypixel = packet_get_int();
1589:
1590: if (strcmp(s->term, "") == 0) {
1.265 djm 1591: free(s->term);
1.2 markus 1592: s->term = NULL;
1593: }
1.86 markus 1594:
1.2 markus 1595: /* Allocate a pty and open it. */
1.86 markus 1596: debug("Allocating pty.");
1.237 djm 1597: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1598: sizeof(s->tty)))) {
1.265 djm 1599: free(s->term);
1.2 markus 1600: s->term = NULL;
1601: s->ptyfd = -1;
1602: s->ttyfd = -1;
1603: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1604: return 0;
1.2 markus 1605: }
1606: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1607:
1.302 markus 1608: ssh_tty_parse_modes(ssh, s->ttyfd);
1.86 markus 1609:
1.130 provos 1610: if (!use_privsep)
1611: pty_setowner(s->pw, s->tty);
1.86 markus 1612:
1613: /* Set window size from the packet. */
1.2 markus 1614: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1615:
1.116 markus 1616: packet_check_eom();
1.9 markus 1617: session_proctitle(s);
1.2 markus 1618: return 1;
1619: }
1620:
1.94 itojun 1621: static int
1.292 djm 1622: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1623: {
1.105 markus 1624: struct stat st;
1.45 markus 1625: u_int len;
1.7 markus 1626: int success = 0;
1.267 djm 1627: char *prog, *cmd;
1.182 djm 1628: u_int i;
1.7 markus 1629:
1.267 djm 1630: s->subsys = packet_get_string(&len);
1.116 markus 1631: packet_check_eom();
1.267 djm 1632: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1633: s->pw->pw_name);
1.18 jakob 1634:
1635: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1636: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1637: prog = options.subsystem_command[i];
1638: cmd = options.subsystem_args[i];
1.249 dtucker 1639: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1640: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1641: debug("subsystem: %s", prog);
1.225 markus 1642: } else {
1.249 dtucker 1643: if (stat(prog, &st) < 0)
1644: debug("subsystem: cannot stat %s: %s",
1645: prog, strerror(errno));
1.225 markus 1646: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1647: debug("subsystem: exec() %s", cmd);
1.105 markus 1648: }
1.292 djm 1649: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1650: break;
1.18 jakob 1651: }
1652: }
1653:
1654: if (!success)
1.267 djm 1655: logit("subsystem request for %.100s by user %s failed, "
1656: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1657:
1658: return success;
1659: }
1660:
1.94 itojun 1661: static int
1.292 djm 1662: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1663: {
1.81 markus 1664: int success;
1.7 markus 1665:
1.184 djm 1666: if (s->auth_proto != NULL || s->auth_data != NULL) {
1667: error("session_x11_req: session %d: "
1.190 stevesk 1668: "x11 forwarding already active", s->self);
1.184 djm 1669: return 0;
1670: }
1.7 markus 1671: s->single_connection = packet_get_char();
1672: s->auth_proto = packet_get_string(NULL);
1673: s->auth_data = packet_get_string(NULL);
1674: s->screen = packet_get_int();
1.116 markus 1675: packet_check_eom();
1.7 markus 1676:
1.282 djm 1677: if (xauth_valid_string(s->auth_proto) &&
1678: xauth_valid_string(s->auth_data))
1.292 djm 1679: success = session_setup_x11fwd(ssh, s);
1.282 djm 1680: else {
1681: success = 0;
1682: error("Invalid X11 forwarding data");
1683: }
1.81 markus 1684: if (!success) {
1.265 djm 1685: free(s->auth_proto);
1686: free(s->auth_data);
1.84 markus 1687: s->auth_proto = NULL;
1688: s->auth_data = NULL;
1.7 markus 1689: }
1.81 markus 1690: return success;
1.7 markus 1691: }
1692:
1.94 itojun 1693: static int
1.292 djm 1694: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1695: {
1.116 markus 1696: packet_check_eom();
1.292 djm 1697: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1698: }
1699:
1.94 itojun 1700: static int
1.292 djm 1701: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1702: {
1.237 djm 1703: u_int len, success;
1704:
1.19 markus 1705: char *command = packet_get_string(&len);
1.116 markus 1706: packet_check_eom();
1.292 djm 1707: success = do_exec(ssh, s, command) == 0;
1.265 djm 1708: free(command);
1.237 djm 1709: return success;
1.19 markus 1710: }
1711:
1.94 itojun 1712: static int
1.292 djm 1713: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1714: {
1715:
1.175 deraadt 1716: packet_get_int(); /* ignored */
1.157 markus 1717: packet_check_eom();
1718:
1.259 djm 1719: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1720: return 0;
1721: return 1;
1722: }
1723:
1724: static int
1.292 djm 1725: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1726: {
1727: char *name, *val;
1728: u_int name_len, val_len, i;
1729:
1.271 djm 1730: name = packet_get_cstring(&name_len);
1731: val = packet_get_cstring(&val_len);
1.173 djm 1732: packet_check_eom();
1733:
1734: /* Don't set too many environment variables */
1735: if (s->num_env > 128) {
1736: debug2("Ignoring env request %s: too many env vars", name);
1737: goto fail;
1738: }
1739:
1740: for (i = 0; i < options.num_accept_env; i++) {
1741: if (match_pattern(name, options.accept_env[i])) {
1742: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1743: s->env = xrecallocarray(s->env, s->num_env,
1744: s->num_env + 1, sizeof(*s->env));
1.173 djm 1745: s->env[s->num_env].name = name;
1746: s->env[s->num_env].val = val;
1747: s->num_env++;
1748: return (1);
1749: }
1750: }
1751: debug2("Ignoring env request %s: disallowed name", name);
1752:
1753: fail:
1.265 djm 1754: free(name);
1755: free(val);
1.173 djm 1756: return (0);
1757: }
1758:
1759: static int
1.292 djm 1760: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1761: {
1762: static int called = 0;
1.294 djm 1763:
1.116 markus 1764: packet_check_eom();
1.294 djm 1765: if (!auth_opts->permit_agent_forwarding_flag ||
1766: !options.allow_agent_forwarding) {
1767: debug("%s: agent forwarding disabled", __func__);
1.44 markus 1768: return 0;
1769: }
1.43 markus 1770: if (called) {
1771: return 0;
1772: } else {
1773: called = 1;
1.292 djm 1774: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1775: }
1776: }
1777:
1.123 markus 1778: int
1.292 djm 1779: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1780: {
1781: int success = 0;
1782: Session *s;
1783:
1.123 markus 1784: if ((s = session_by_channel(c->self)) == NULL) {
1.292 djm 1785: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1786: return 0;
1787: }
1.292 djm 1788: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1789:
1790: /*
1.64 markus 1791: * a session is in LARVAL state until a shell, a command
1792: * or a subsystem is executed
1.2 markus 1793: */
1794: if (c->type == SSH_CHANNEL_LARVAL) {
1795: if (strcmp(rtype, "shell") == 0) {
1.292 djm 1796: success = session_shell_req(ssh, s);
1.2 markus 1797: } else if (strcmp(rtype, "exec") == 0) {
1.292 djm 1798: success = session_exec_req(ssh, s);
1.2 markus 1799: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 djm 1800: success = session_pty_req(ssh, s);
1.7 markus 1801: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 djm 1802: success = session_x11_req(ssh, s);
1.43 markus 1803: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 djm 1804: success = session_auth_agent_req(ssh, s);
1.7 markus 1805: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 djm 1806: success = session_subsystem_req(ssh, s);
1.173 djm 1807: } else if (strcmp(rtype, "env") == 0) {
1.292 djm 1808: success = session_env_req(ssh, s);
1.2 markus 1809: }
1810: }
1811: if (strcmp(rtype, "window-change") == 0) {
1.292 djm 1812: success = session_window_change_req(ssh, s);
1.177 djm 1813: } else if (strcmp(rtype, "break") == 0) {
1.292 djm 1814: success = session_break_req(ssh, s);
1.2 markus 1815: }
1.177 djm 1816:
1.123 markus 1817: return success;
1.2 markus 1818: }
1819:
1820: void
1.292 djm 1821: session_set_fds(struct ssh *ssh, Session *s,
1822: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1823: {
1824: /*
1825: * now that have a child and a pipe to the child,
1826: * we can activate our channel and register the fd's
1827: */
1828: if (s->chanid == -1)
1829: fatal("no channel for session %d", s->self);
1.292 djm 1830: channel_set_fds(ssh, s->chanid,
1.2 markus 1831: fdout, fdin, fderr,
1.256 djm 1832: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1833: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1834: }
1835:
1.85 markus 1836: /*
1837: * Function to perform pty cleanup. Also called if we get aborted abnormally
1838: * (e.g., due to a dropped connection).
1839: */
1.130 provos 1840: void
1.165 markus 1841: session_pty_cleanup2(Session *s)
1.1 markus 1842: {
1.85 markus 1843: if (s == NULL) {
1844: error("session_pty_cleanup: no session");
1845: return;
1846: }
1847: if (s->ttyfd == -1)
1.1 markus 1848: return;
1849:
1.54 stevesk 1850: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1851:
1852: /* Record that the user has logged out. */
1.85 markus 1853: if (s->pid != 0)
1854: record_logout(s->pid, s->tty);
1.1 markus 1855:
1856: /* Release the pseudo-tty. */
1.130 provos 1857: if (getuid() == 0)
1858: pty_release(s->tty);
1.1 markus 1859:
1860: /*
1861: * Close the server side of the socket pairs. We must do this after
1862: * the pty cleanup, so that another process doesn't get this pty
1863: * while we're still cleaning up.
1864: */
1.237 djm 1865: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1866: error("close(s->ptymaster/%d): %s",
1867: s->ptymaster, strerror(errno));
1.108 markus 1868:
1869: /* unlink pty from session */
1870: s->ttyfd = -1;
1.2 markus 1871: }
1872:
1.130 provos 1873: void
1.165 markus 1874: session_pty_cleanup(Session *s)
1.130 provos 1875: {
1.165 markus 1876: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1877: }
1878:
1.147 markus 1879: static char *
1880: sig2name(int sig)
1881: {
1882: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1883: SSH_SIG(ABRT);
1884: SSH_SIG(ALRM);
1885: SSH_SIG(FPE);
1886: SSH_SIG(HUP);
1887: SSH_SIG(ILL);
1888: SSH_SIG(INT);
1889: SSH_SIG(KILL);
1890: SSH_SIG(PIPE);
1891: SSH_SIG(QUIT);
1892: SSH_SIG(SEGV);
1893: SSH_SIG(TERM);
1894: SSH_SIG(USR1);
1895: SSH_SIG(USR2);
1896: #undef SSH_SIG
1897: return "SIG@openssh.com";
1898: }
1899:
1.94 itojun 1900: static void
1.292 djm 1901: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1902: {
1903: Channel *c;
1904:
1.292 djm 1905: if ((c = channel_by_id(ssh, id)) == NULL) {
1906: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1907: } else {
1908: /* Detach X11 listener */
1.292 djm 1909: debug("%s: detach x11 channel %d", __func__, id);
1910: channel_cancel_cleanup(ssh, id);
1.184 djm 1911: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1912: chan_mark_dead(ssh, c);
1.184 djm 1913: }
1914: }
1915:
1916: static void
1.292 djm 1917: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1918: {
1919: Session *s;
1920: u_int i;
1921:
1.292 djm 1922: debug3("%s: channel %d", __func__, id);
1923: channel_cancel_cleanup(ssh, id);
1.221 stevesk 1924: if ((s = session_by_x11_channel(id)) == NULL)
1.292 djm 1925: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 1926: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 1927: debug("%s: session %d: closing channel %d",
1928: __func__, s->self, s->x11_chanids[i]);
1.184 djm 1929: /*
1930: * The channel "id" is already closing, but make sure we
1931: * close all of its siblings.
1932: */
1933: if (s->x11_chanids[i] != id)
1.292 djm 1934: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 1935: }
1.265 djm 1936: free(s->x11_chanids);
1.184 djm 1937: s->x11_chanids = NULL;
1.265 djm 1938: free(s->display);
1939: s->display = NULL;
1940: free(s->auth_proto);
1941: s->auth_proto = NULL;
1942: free(s->auth_data);
1943: s->auth_data = NULL;
1944: free(s->auth_display);
1945: s->auth_display = NULL;
1.184 djm 1946: }
1947:
1948: static void
1.292 djm 1949: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 1950: {
1951: Channel *c;
1.124 markus 1952:
1.292 djm 1953: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
1954: fatal("%s: session %d: no channel %d",
1955: __func__, s->self, s->chanid);
1956: debug("%s: session %d channel %d pid %ld",
1957: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 1958:
1959: if (WIFEXITED(status)) {
1.292 djm 1960: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 1961: packet_put_int(WEXITSTATUS(status));
1962: packet_send();
1963: } else if (WIFSIGNALED(status)) {
1.292 djm 1964: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 1965: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 1966: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 1967: packet_put_cstring("");
1968: packet_put_cstring("");
1969: packet_send();
1970: } else {
1971: /* Some weird exit cause. Just exit. */
1972: packet_disconnect("wait returned status %04x.", status);
1973: }
1974:
1975: /* disconnect channel */
1.292 djm 1976: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 1977:
1978: /*
1979: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 1980: * the channel gets EOF. The session will be then be closed
1.187 djm 1981: * by session_close_by_channel when the childs close their fds.
1982: */
1.292 djm 1983: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 1984:
1.5 markus 1985: /*
1986: * emulate a write failure with 'chan_write_failed', nobody will be
1987: * interested in data we write.
1988: * Note that we must not call 'chan_read_failed', since there could
1989: * be some more data waiting in the pipe.
1990: */
1.8 markus 1991: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1992: chan_write_failed(ssh, c);
1.2 markus 1993: }
1994:
1.130 provos 1995: void
1.292 djm 1996: session_close(struct ssh *ssh, Session *s)
1.2 markus 1997: {
1.182 djm 1998: u_int i;
1.173 djm 1999:
1.280 djm 2000: verbose("Close session: user %s from %.200s port %d id %d",
2001: s->pw->pw_name,
1.281 djm 2002: ssh_remote_ipaddr(ssh),
2003: ssh_remote_port(ssh),
1.280 djm 2004: s->self);
2005:
1.165 markus 2006: if (s->ttyfd != -1)
1.85 markus 2007: session_pty_cleanup(s);
1.265 djm 2008: free(s->term);
2009: free(s->display);
2010: free(s->x11_chanids);
2011: free(s->auth_display);
2012: free(s->auth_data);
2013: free(s->auth_proto);
1.267 djm 2014: free(s->subsys);
1.219 djm 2015: if (s->env != NULL) {
2016: for (i = 0; i < s->num_env; i++) {
1.265 djm 2017: free(s->env[i].name);
2018: free(s->env[i].val);
1.219 djm 2019: }
1.265 djm 2020: free(s->env);
1.173 djm 2021: }
1.9 markus 2022: session_proctitle(s);
1.237 djm 2023: session_unused(s->self);
1.2 markus 2024: }
2025:
2026: void
1.292 djm 2027: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 2028: {
2029: Session *s = session_by_pid(pid);
2030: if (s == NULL) {
1.292 djm 2031: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 2032: return;
2033: }
2034: if (s->chanid != -1)
1.292 djm 2035: session_exit_message(ssh, s, status);
1.187 djm 2036: if (s->ttyfd != -1)
2037: session_pty_cleanup(s);
1.197 djm 2038: s->pid = 0;
1.98 markus 2039: }
2040:
1.2 markus 2041: /*
2042: * this is called when a channel dies before
2043: * the session 'child' itself dies
2044: */
2045: void
1.292 djm 2046: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 2047: {
2048: Session *s = session_by_channel(id);
1.187 djm 2049: u_int i;
1.184 djm 2050:
1.2 markus 2051: if (s == NULL) {
1.292 djm 2052: debug("%s: no session for id %d", __func__, id);
1.2 markus 2053: return;
2054: }
1.292 djm 2055: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 2056: if (s->pid != 0) {
1.292 djm 2057: debug("%s: channel %d: has child", __func__, id);
1.108 markus 2058: /*
2059: * delay detach of session, but release pty, since
2060: * the fd's to the child are already closed
2061: */
1.165 markus 2062: if (s->ttyfd != -1)
1.108 markus 2063: session_pty_cleanup(s);
1.107 markus 2064: return;
2065: }
2066: /* detach by removing callback */
1.292 djm 2067: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 2068:
2069: /* Close any X11 listeners associated with this session */
2070: if (s->x11_chanids != NULL) {
2071: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2072: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 2073: s->x11_chanids[i] = -1;
2074: }
2075: }
2076:
1.2 markus 2077: s->chanid = -1;
1.292 djm 2078: session_close(ssh, s);
1.106 markus 2079: }
2080:
2081: void
1.292 djm 2082: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 2083: {
2084: int i;
1.237 djm 2085: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2086: Session *s = &sessions[i];
1.130 provos 2087: if (s->used) {
2088: if (closefunc != NULL)
2089: closefunc(s);
2090: else
1.292 djm 2091: session_close(ssh, s);
1.130 provos 2092: }
1.2 markus 2093: }
1.9 markus 2094: }
2095:
1.94 itojun 2096: static char *
1.9 markus 2097: session_tty_list(void)
2098: {
2099: static char buf[1024];
2100: int i;
2101: buf[0] = '\0';
1.237 djm 2102: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2103: Session *s = &sessions[i];
2104: if (s->used && s->ttyfd != -1) {
2105: if (buf[0] != '\0')
2106: strlcat(buf, ",", sizeof buf);
2107: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2108: }
2109: }
2110: if (buf[0] == '\0')
2111: strlcpy(buf, "notty", sizeof buf);
2112: return buf;
2113: }
2114:
2115: void
2116: session_proctitle(Session *s)
2117: {
2118: if (s->pw == NULL)
2119: error("no user for session %d", s->self);
2120: else
2121: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2122: }
2123:
2124: int
1.292 djm 2125: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2126: {
2127: struct stat st;
1.109 stevesk 2128: char display[512], auth_display[512];
1.272 djm 2129: char hostname[NI_MAXHOST];
1.184 djm 2130: u_int i;
1.81 markus 2131:
1.294 djm 2132: if (!auth_opts->permit_x11_forwarding_flag) {
2133: packet_send_debug("X11 forwarding disabled by key options.");
1.81 markus 2134: return 0;
2135: }
2136: if (!options.x11_forwarding) {
2137: debug("X11 forwarding disabled in server configuration file.");
2138: return 0;
2139: }
1.275 djm 2140: if (options.xauth_location == NULL ||
1.81 markus 2141: (stat(options.xauth_location, &st) == -1)) {
1.294 djm 2142: packet_send_debug("No xauth program; cannot forward X11.");
1.81 markus 2143: return 0;
2144: }
1.87 markus 2145: if (s->display != NULL) {
1.81 markus 2146: debug("X11 display already set.");
2147: return 0;
2148: }
1.292 djm 2149: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2150: options.x11_use_localhost, s->single_connection,
1.184 djm 2151: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2152: debug("x11_create_display_inet failed.");
1.81 markus 2153: return 0;
1.184 djm 2154: }
2155: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2156: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2157: session_close_single_x11, 0);
1.81 markus 2158: }
1.109 stevesk 2159:
2160: /* Set up a suitable value for the DISPLAY variable. */
2161: if (gethostname(hostname, sizeof(hostname)) < 0)
2162: fatal("gethostname: %.100s", strerror(errno));
2163: /*
2164: * auth_display must be used as the displayname when the
2165: * authorization entry is added with xauth(1). This will be
2166: * different than the DISPLAY string for localhost displays.
2167: */
1.119 stevesk 2168: if (options.x11_use_localhost) {
1.140 deraadt 2169: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2170: s->display_number, s->screen);
1.140 deraadt 2171: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2172: s->display_number, s->screen);
1.109 stevesk 2173: s->display = xstrdup(display);
1.118 stevesk 2174: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2175: } else {
1.140 deraadt 2176: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2177: s->display_number, s->screen);
2178: s->display = xstrdup(display);
1.118 stevesk 2179: s->auth_display = xstrdup(display);
1.109 stevesk 2180: }
2181:
1.81 markus 2182: return 1;
1.2 markus 2183: }
2184:
1.94 itojun 2185: static void
1.292 djm 2186: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2187: {
1.292 djm 2188: server_loop2(ssh, authctxt);
1.165 markus 2189: }
2190:
2191: void
1.292 djm 2192: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2193: {
2194: static int called = 0;
2195:
2196: debug("do_cleanup");
2197:
2198: /* no cleanup if we're in the child for login shell */
2199: if (is_child)
2200: return;
2201:
2202: /* avoid double cleanup */
2203: if (called)
2204: return;
2205: called = 1;
2206:
1.218 markus 2207: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2208: return;
2209: #ifdef KRB5
2210: if (options.kerberos_ticket_cleanup &&
2211: authctxt->krb5_ctx)
2212: krb5_cleanup_proc(authctxt);
1.161 markus 2213: #endif
1.165 markus 2214:
2215: #ifdef GSSAPI
1.283 markus 2216: if (options.gss_cleanup_creds)
1.165 markus 2217: ssh_gssapi_cleanup_creds();
2218: #endif
2219:
2220: /* remove agent socket */
2221: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2222:
2223: /* remove userauth info */
2224: if (auth_info_file != NULL) {
2225: temporarily_use_uid(authctxt->pw);
2226: unlink(auth_info_file);
2227: restore_uid();
2228: free(auth_info_file);
2229: auth_info_file = NULL;
2230: }
1.165 markus 2231:
2232: /*
2233: * Cleanup ptys/utmp only if privsep is disabled,
2234: * or if running in monitor.
2235: */
2236: if (!use_privsep || mm_is_monitor())
1.292 djm 2237: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2238: }
1.281 djm 2239:
2240: /* Return a name for the remote host that fits inside utmp_size */
2241:
2242: const char *
2243: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2244: {
2245: const char *remote = "";
2246:
2247: if (utmp_size > 0)
2248: remote = auth_get_canonical_hostname(ssh, use_dns);
2249: if (utmp_size == 0 || strlen(remote) > utmp_size)
2250: remote = ssh_remote_ipaddr(ssh);
2251: return remote;
2252: }
2253:
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