Annotation of src/usr.bin/ssh/session.c, Revision 1.309
1.309 ! djm 1: /* $OpenBSD: session.c,v 1.308 2018/11/16 03:26:01 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
1.37 deraadt 5: *
6: * As far as I am concerned, the code I have written for this software
7: * can be used freely for any purpose. Any derived versions of this
8: * software must be clearly marked as such, and if the derived work is
9: * incompatible with the protocol description in the RFC file, it must be
10: * called by a name other than "ssh" or "Secure Shell".
11: *
1.2 markus 12: * SSH2 support by Markus Friedl.
1.95 markus 13: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.37 deraadt 14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2 markus 34: */
1.1 markus 35:
1.193 stevesk 36: #include <sys/types.h>
37: #include <sys/wait.h>
1.194 stevesk 38: #include <sys/un.h>
1.196 stevesk 39: #include <sys/stat.h>
1.207 stevesk 40: #include <sys/socket.h>
1.236 djm 41: #include <sys/queue.h>
1.192 stevesk 42:
1.282 djm 43: #include <ctype.h>
1.209 stevesk 44: #include <errno.h>
1.253 djm 45: #include <fcntl.h>
1.204 stevesk 46: #include <grp.h>
1.223 djm 47: #include <login_cap.h>
1.272 djm 48: #include <netdb.h>
1.192 stevesk 49: #include <paths.h>
1.206 stevesk 50: #include <pwd.h>
1.195 stevesk 51: #include <signal.h>
1.215 stevesk 52: #include <stdio.h>
1.214 stevesk 53: #include <stdlib.h>
1.212 stevesk 54: #include <string.h>
1.211 stevesk 55: #include <unistd.h>
1.277 deraadt 56: #include <limits.h>
1.1 markus 57:
1.216 deraadt 58: #include "xmalloc.h"
1.51 markus 59: #include "ssh.h"
60: #include "ssh2.h"
1.59 djm 61: #include "sshpty.h"
1.1 markus 62: #include "packet.h"
1.303 markus 63: #include "sshbuf.h"
64: #include "ssherr.h"
1.173 djm 65: #include "match.h"
1.1 markus 66: #include "uidswap.h"
67: #include "compat.h"
1.78 markus 68: #include "channels.h"
1.304 markus 69: #include "sshkey.h"
1.216 deraadt 70: #include "cipher.h"
71: #include "kex.h"
72: #include "hostfile.h"
1.2 markus 73: #include "auth.h"
1.19 markus 74: #include "auth-options.h"
1.266 markus 75: #include "authfd.h"
1.50 markus 76: #include "pathnames.h"
1.51 markus 77: #include "log.h"
1.274 millert 78: #include "misc.h"
1.51 markus 79: #include "servconf.h"
1.59 djm 80: #include "sshlogin.h"
1.51 markus 81: #include "serverloop.h"
82: #include "canohost.h"
1.55 itojun 83: #include "session.h"
1.216 deraadt 84: #ifdef GSSAPI
85: #include "ssh-gss.h"
86: #endif
1.130 provos 87: #include "monitor_wrap.h"
1.225 markus 88: #include "sftp.h"
1.290 djm 89: #include "atomicio.h"
1.171 markus 90:
91: #ifdef KRB5
92: #include <kafs.h>
1.161 markus 93: #endif
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;
1.309 ! djm 129: extern 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] != '_')
1.305 deraadt 363: return 0;
1.282 djm 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: }
1.306 djm 644: s->forced = 0;
1.267 djm 645: if (forced != NULL) {
1.306 djm 646: s->forced = 1;
1.248 djm 647: if (IS_INTERNAL_SFTP(command)) {
648: s->is_subsystem = s->is_subsystem ?
649: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
650: } else if (s->is_subsystem)
1.225 markus 651: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 652: snprintf(session_type, sizeof(session_type),
653: "forced-command %s '%.900s'", forced, command);
654: } else if (s->is_subsystem) {
655: snprintf(session_type, sizeof(session_type),
656: "subsystem '%.900s'", s->subsys);
657: } else if (command == NULL) {
658: snprintf(session_type, sizeof(session_type), "shell");
659: } else {
660: /* NB. we don't log unforced commands to preserve privacy */
661: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 662: }
1.163 markus 663:
1.267 djm 664: if (s->ttyfd != -1) {
665: tty = s->tty;
666: if (strncmp(tty, "/dev/", 5) == 0)
667: tty += 5;
668: }
669:
1.280 djm 670: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 671: session_type,
672: tty == NULL ? "" : " on ",
673: tty == NULL ? "" : tty,
674: s->pw->pw_name,
1.281 djm 675: ssh_remote_ipaddr(ssh),
676: ssh_remote_port(ssh),
1.280 djm 677: s->self);
1.267 djm 678:
1.163 markus 679: #ifdef GSSAPI
680: if (options.gss_authentication) {
681: temporarily_use_uid(s->pw);
682: ssh_gssapi_storecreds();
683: restore_uid();
684: }
685: #endif
1.90 markus 686: if (s->ttyfd != -1)
1.292 djm 687: ret = do_exec_pty(ssh, s, command);
1.90 markus 688: else
1.292 djm 689: ret = do_exec_no_pty(ssh, s, command);
1.90 markus 690:
1.92 markus 691: original_command = NULL;
1.179 dtucker 692:
693: /*
694: * Clear loginmsg: it's the child's responsibility to display
695: * it to the user, otherwise multiple sessions may accumulate
696: * multiple copies of the login messages.
697: */
1.303 markus 698: sshbuf_reset(loginmsg);
1.237 djm 699:
700: return ret;
1.90 markus 701: }
702:
703:
1.24 markus 704: /* administrative, login(1)-like work */
705: void
1.292 djm 706: do_login(struct ssh *ssh, Session *s, const char *command)
1.24 markus 707: {
708: socklen_t fromlen;
709: struct sockaddr_storage from;
710: struct passwd * pw = s->pw;
711: pid_t pid = getpid();
712:
713: /*
714: * Get IP address of client. If the connection is not a socket, let
715: * the address be 0.0.0.0.
716: */
717: memset(&from, 0, sizeof(from));
1.148 stevesk 718: fromlen = sizeof(from);
1.24 markus 719: if (packet_connection_is_on_socket()) {
720: if (getpeername(packet_get_connection_in(),
1.200 deraadt 721: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 722: debug("getpeername: %.100s", strerror(errno));
1.165 markus 723: cleanup_exit(255);
1.24 markus 724: }
725: }
1.25 markus 726:
1.24 markus 727: /* Record that there was a login on that tty from the remote host. */
1.133 markus 728: if (!use_privsep)
729: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 730: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 731: options.use_dns),
1.148 stevesk 732: (struct sockaddr *)&from, fromlen);
1.24 markus 733:
1.73 djm 734: if (check_quietlogin(s, command))
1.24 markus 735: return;
1.73 djm 736:
1.179 dtucker 737: display_loginmsg();
1.73 djm 738:
739: do_motd();
740: }
741:
742: /*
743: * Display the message of the day.
744: */
745: void
746: do_motd(void)
747: {
748: FILE *f;
749: char buf[256];
750:
1.24 markus 751: if (options.print_motd) {
1.28 millert 752: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
753: "/etc/motd"), "r");
1.24 markus 754: if (f) {
755: while (fgets(buf, sizeof(buf), f))
756: fputs(buf, stdout);
757: fclose(f);
758: }
1.2 markus 759: }
1.73 djm 760: }
761:
762:
763: /*
764: * Check for quiet login, either .hushlogin or command given.
765: */
766: int
767: check_quietlogin(Session *s, const char *command)
768: {
769: char buf[256];
1.96 dugsong 770: struct passwd *pw = s->pw;
1.73 djm 771: struct stat st;
772:
773: /* Return 1 if .hushlogin exists or a command given. */
774: if (command != NULL)
775: return 1;
776: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
777: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
778: return 1;
779: return 0;
1.1 markus 780: }
781:
782: /*
783: * Reads environment variables from the given file and adds/overrides them
784: * into the environment. If the file does not exist, this does nothing.
785: * Otherwise, it must consist of empty lines, comments (line starts with '#')
786: * and assignments of the form name=value. No other forms are allowed.
1.301 djm 787: * If whitelist is not NULL, then it is interpreted as a pattern list and
788: * only variable names that match it will be accepted.
1.1 markus 789: */
1.94 itojun 790: static void
1.45 markus 791: read_environment_file(char ***env, u_int *envsize,
1.301 djm 792: const char *filename, const char *whitelist)
1.1 markus 793: {
794: FILE *f;
1.298 markus 795: char *line = NULL, *cp, *value;
796: size_t linesize = 0;
1.142 deraadt 797: u_int lineno = 0;
1.1 markus 798:
799: f = fopen(filename, "r");
800: if (!f)
801: return;
802:
1.298 markus 803: while (getline(&line, &linesize, f) != -1) {
1.142 deraadt 804: if (++lineno > 1000)
805: fatal("Too many lines in environment file %s", filename);
1.298 markus 806: for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
1.1 markus 807: ;
808: if (!*cp || *cp == '#' || *cp == '\n')
809: continue;
1.224 gilles 810:
811: cp[strcspn(cp, "\n")] = '\0';
812:
1.1 markus 813: value = strchr(cp, '=');
814: if (value == NULL) {
1.142 deraadt 815: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
816: filename);
1.1 markus 817: continue;
818: }
1.14 deraadt 819: /*
820: * Replace the equals sign by nul, and advance value to
821: * the value string.
822: */
1.1 markus 823: *value = '\0';
824: value++;
1.301 djm 825: if (whitelist != NULL &&
826: match_pattern_list(cp, whitelist, 0) != 1)
827: continue;
1.1 markus 828: child_set_env(env, envsize, cp, value);
829: }
1.298 markus 830: free(line);
1.1 markus 831: fclose(f);
832: }
833:
1.127 markus 834: static char **
1.292 djm 835: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1 markus 836: {
837: char buf[256];
1.294 djm 838: size_t n;
1.127 markus 839: u_int i, envsize;
1.300 djm 840: char *ocp, *cp, *value, **env, *laddr;
1.127 markus 841: struct passwd *pw = s->pw;
1.1 markus 842:
843: /* Initialize the environment. */
844: envsize = 100;
1.220 djm 845: env = xcalloc(envsize, sizeof(char *));
1.1 markus 846: env[0] = NULL;
847:
1.161 markus 848: #ifdef GSSAPI
1.168 djm 849: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 850: * the childs environment as they see fit
851: */
852: ssh_gssapi_do_child(&env, &envsize);
853: #endif
854:
1.284 djm 855: /* Set basic environment. */
856: for (i = 0; i < s->num_env; i++)
857: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
858:
859: child_set_env(&env, &envsize, "USER", pw->pw_name);
860: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
861: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
862: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
863: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
864: else
865: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
866:
867: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
868: child_set_env(&env, &envsize, "MAIL", buf);
869:
870: /* Normal systems set SHELL by default. */
871: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 872:
873: if (getenv("TZ"))
874: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1.299 djm 875: if (s->term)
876: child_set_env(&env, &envsize, "TERM", s->term);
877: if (s->display)
878: child_set_env(&env, &envsize, "DISPLAY", s->display);
879: #ifdef KRB5
880: if (s->authctxt->krb5_ticket_file)
881: child_set_env(&env, &envsize, "KRB5CCNAME",
882: s->authctxt->krb5_ticket_file);
883: #endif
884: if (auth_sock_name != NULL)
885: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
886: auth_sock_name);
887:
1.1 markus 888:
1.294 djm 889: /* Set custom environment options from pubkey authentication. */
890: if (options.permit_user_env) {
891: for (n = 0 ; n < auth_opts->nenv; n++) {
892: ocp = xstrdup(auth_opts->env[n]);
893: cp = strchr(ocp, '=');
894: if (*cp == '=') {
895: *cp = '\0';
1.301 djm 896: /* Apply PermitUserEnvironment whitelist */
897: if (options.permit_user_env_whitelist == NULL ||
898: match_pattern_list(ocp,
899: options.permit_user_env_whitelist, 0) == 1)
900: child_set_env(&env, &envsize,
901: ocp, cp + 1);
1.294 djm 902: }
903: free(ocp);
904: }
1.1 markus 905: }
906:
1.299 djm 907: /* read $HOME/.ssh/environment. */
908: if (options.permit_user_env) {
909: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
910: pw->pw_dir);
1.301 djm 911: read_environment_file(&env, &envsize, buf,
912: options.permit_user_env_whitelist);
1.300 djm 913: }
914:
915: /* Environment specified by admin */
916: for (i = 0; i < options.num_setenv; i++) {
917: cp = xstrdup(options.setenv[i]);
918: if ((value = strchr(cp, '=')) == NULL) {
919: /* shouldn't happen; vars are checked in servconf.c */
920: fatal("Invalid config SetEnv: %s", options.setenv[i]);
921: }
922: *value++ = '\0';
923: child_set_env(&env, &envsize, cp, value);
1.299 djm 924: }
925:
1.149 stevesk 926: /* SSH_CLIENT deprecated */
1.1 markus 927: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 928: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
929: ssh_local_port(ssh));
1.1 markus 930: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 931:
1.154 markus 932: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 933: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 934: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
935: laddr, ssh_local_port(ssh));
1.265 djm 936: free(laddr);
1.149 stevesk 937: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 938:
1.293 djm 939: if (tun_fwd_ifnames != NULL)
940: child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
1.290 djm 941: if (auth_info_file != NULL)
942: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 943: if (s->ttyfd != -1)
944: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1.34 markus 945: if (original_command)
946: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
947: original_command);
1.1 markus 948:
949: if (debug_flag) {
950: /* dump the environment */
951: fprintf(stderr, "Environment:\n");
952: for (i = 0; env[i]; i++)
953: fprintf(stderr, " %.200s\n", env[i]);
954: }
1.127 markus 955: return env;
956: }
957:
958: /*
959: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
960: * first in this order).
961: */
962: static void
1.294 djm 963: do_rc_files(struct ssh *ssh, Session *s, const char *shell)
1.127 markus 964: {
965: FILE *f = NULL;
966: char cmd[1024];
967: int do_xauth;
968: struct stat st;
969:
970: do_xauth =
971: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
972:
1.231 djm 973: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 974: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.294 djm 975: auth_opts->permit_user_rc && options.permit_user_rc &&
1.273 djm 976: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 977: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
978: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
979: if (debug_flag)
980: fprintf(stderr, "Running %s\n", cmd);
981: f = popen(cmd, "w");
982: if (f) {
983: if (do_xauth)
984: fprintf(f, "%s %s\n", s->auth_proto,
985: s->auth_data);
986: pclose(f);
987: } else
988: fprintf(stderr, "Could not run %s\n",
989: _PATH_SSH_USER_RC);
990: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
991: if (debug_flag)
992: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
993: _PATH_SSH_SYSTEM_RC);
994: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
995: if (f) {
996: if (do_xauth)
997: fprintf(f, "%s %s\n", s->auth_proto,
998: s->auth_data);
999: pclose(f);
1000: } else
1001: fprintf(stderr, "Could not run %s\n",
1002: _PATH_SSH_SYSTEM_RC);
1003: } else if (do_xauth && options.xauth_location != NULL) {
1004: /* Add authority data to .Xauthority if appropriate. */
1005: if (debug_flag) {
1006: fprintf(stderr,
1.151 stevesk 1007: "Running %.500s remove %.100s\n",
1.165 markus 1008: options.xauth_location, s->auth_display);
1.151 stevesk 1009: fprintf(stderr,
1010: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 1011: options.xauth_location, s->auth_display,
1012: s->auth_proto, s->auth_data);
1013: }
1014: snprintf(cmd, sizeof cmd, "%s -q -",
1015: options.xauth_location);
1016: f = popen(cmd, "w");
1017: if (f) {
1.151 stevesk 1018: fprintf(f, "remove %s\n",
1019: s->auth_display);
1.127 markus 1020: fprintf(f, "add %s %s %s\n",
1021: s->auth_display, s->auth_proto,
1022: s->auth_data);
1023: pclose(f);
1024: } else {
1025: fprintf(stderr, "Could not run %s\n",
1026: cmd);
1027: }
1028: }
1029: }
1030:
1031: static void
1032: do_nologin(struct passwd *pw)
1033: {
1034: FILE *f = NULL;
1.251 dtucker 1035: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
1036: struct stat sb;
1.127 markus 1037:
1.260 guenther 1038: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 1039: return;
1040: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
1041:
1042: if (stat(nl, &sb) == -1) {
1043: if (nl != def_nl)
1.265 djm 1044: free(nl);
1.251 dtucker 1045: return;
1046: }
1047:
1048: /* /etc/nologin exists. Print its contents if we can and exit. */
1049: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1050: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 1051: while (fgets(buf, sizeof(buf), f))
1052: fputs(buf, stderr);
1053: fclose(f);
1054: }
1.251 dtucker 1055: exit(254);
1.127 markus 1056: }
1057:
1.226 djm 1058: /*
1059: * Chroot into a directory after checking it for safety: all path components
1060: * must be root-owned directories with strict permissions.
1061: */
1062: static void
1063: safely_chroot(const char *path, uid_t uid)
1064: {
1065: const char *cp;
1.277 deraadt 1066: char component[PATH_MAX];
1.226 djm 1067: struct stat st;
1068:
1.308 djm 1069: if (!path_absolute(path))
1.226 djm 1070: fatal("chroot path does not begin at root");
1071: if (strlen(path) >= sizeof(component))
1072: fatal("chroot path too long");
1073:
1074: /*
1075: * Descend the path, checking that each component is a
1076: * root-owned directory with strict permissions.
1077: */
1078: for (cp = path; cp != NULL;) {
1079: if ((cp = strchr(cp, '/')) == NULL)
1080: strlcpy(component, path, sizeof(component));
1081: else {
1082: cp++;
1083: memcpy(component, path, cp - path);
1084: component[cp - path] = '\0';
1085: }
1086:
1087: debug3("%s: checking '%s'", __func__, component);
1088:
1089: if (stat(component, &st) != 0)
1090: fatal("%s: stat(\"%s\"): %s", __func__,
1091: component, strerror(errno));
1092: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1093: fatal("bad ownership or modes for chroot "
1094: "directory %s\"%s\"",
1095: cp == NULL ? "" : "component ", component);
1096: if (!S_ISDIR(st.st_mode))
1097: fatal("chroot path %s\"%s\" is not a directory",
1098: cp == NULL ? "" : "component ", component);
1099:
1100: }
1101:
1102: if (chdir(path) == -1)
1103: fatal("Unable to chdir to chroot path \"%s\": "
1104: "%s", path, strerror(errno));
1105: if (chroot(path) == -1)
1106: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1107: if (chdir("/") == -1)
1108: fatal("%s: chdir(/) after chroot: %s",
1109: __func__, strerror(errno));
1110: verbose("Changed root directory to \"%s\"", path);
1111: }
1112:
1.127 markus 1113: /* Set login name, uid, gid, and groups. */
1.130 provos 1114: void
1.127 markus 1115: do_setusercontext(struct passwd *pw)
1116: {
1.295 djm 1117: char uidstr[32], *chroot_path, *tmp;
1.227 djm 1118:
1.127 markus 1119: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1120: /* Prepare groups */
1.127 markus 1121: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1122: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1123: perror("unable to set user context");
1124: exit(1);
1125: }
1.226 djm 1126:
1.279 djm 1127: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1128: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1129: tmp = tilde_expand_filename(options.chroot_directory,
1130: pw->pw_uid);
1.295 djm 1131: snprintf(uidstr, sizeof(uidstr), "%llu",
1132: (unsigned long long)pw->pw_uid);
1.227 djm 1133: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1.295 djm 1134: "u", pw->pw_name, "U", uidstr, (char *)NULL);
1.226 djm 1135: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1136: free(tmp);
1.226 djm 1137: free(chroot_path);
1.264 djm 1138: /* Make sure we don't attempt to chroot again */
1139: free(options.chroot_directory);
1140: options.chroot_directory = NULL;
1.279 djm 1141: in_chroot = 1;
1.226 djm 1142: }
1143:
1144: /* Set UID */
1145: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1146: perror("unable to set user context (setuser)");
1147: exit(1);
1148: }
1.264 djm 1149: } else if (options.chroot_directory != NULL &&
1150: strcasecmp(options.chroot_directory, "none") != 0) {
1151: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1152: }
1.264 djm 1153:
1.127 markus 1154: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1155: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1156: }
1157:
1.131 markus 1158: static void
1.172 markus 1159: do_pwchange(Session *s)
1160: {
1.179 dtucker 1161: fflush(NULL);
1.172 markus 1162: fprintf(stderr, "WARNING: Your password has expired.\n");
1163: if (s->ttyfd != -1) {
1.178 deraadt 1164: fprintf(stderr,
1.172 markus 1165: "You must change your password now and login again!\n");
1166: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1167: perror("passwd");
1168: } else {
1169: fprintf(stderr,
1170: "Password change required but no TTY available.\n");
1171: }
1172: exit(1);
1173: }
1174:
1175: static void
1.292 djm 1176: child_close_fds(struct ssh *ssh)
1.172 markus 1177: {
1.276 djm 1178: extern int auth_sock;
1.266 markus 1179:
1.276 djm 1180: if (auth_sock != -1) {
1181: close(auth_sock);
1182: auth_sock = -1;
1.266 markus 1183: }
1184:
1.172 markus 1185: if (packet_get_connection_in() == packet_get_connection_out())
1186: close(packet_get_connection_in());
1187: else {
1188: close(packet_get_connection_in());
1189: close(packet_get_connection_out());
1190: }
1191: /*
1192: * Close all descriptors related to channels. They will still remain
1193: * open in the parent.
1194: */
1195: /* XXX better use close-on-exec? -markus */
1.292 djm 1196: channel_close_all(ssh);
1.172 markus 1197:
1198: /*
1199: * Close any extra file descriptors. Note that there may still be
1200: * descriptors left by system functions. They will be closed later.
1201: */
1202: endpwent();
1203:
1204: /*
1.188 djm 1205: * Close any extra open file descriptors so that we don't have them
1.172 markus 1206: * hanging around in clients. Note that we want to do this after
1207: * initgroups, because at least on Solaris 2.3 it leaves file
1208: * descriptors open.
1209: */
1.258 djm 1210: closefrom(STDERR_FILENO + 1);
1.172 markus 1211: }
1212:
1.127 markus 1213: /*
1214: * Performs common processing for the child, such as setting up the
1215: * environment, closing extra file descriptors, setting the user and group
1216: * ids, and executing the command or shell.
1217: */
1.225 markus 1218: #define ARGV_MAX 10
1.127 markus 1219: void
1.292 djm 1220: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1221: {
1222: extern char **environ;
1223: char **env;
1.225 markus 1224: char *argv[ARGV_MAX];
1.284 djm 1225: const char *shell, *shell0;
1.127 markus 1226: struct passwd *pw = s->pw;
1.239 djm 1227: int r = 0;
1.127 markus 1228:
1229: /* remove hostkey from the child's memory */
1230: destroy_sensitive_data();
1.287 markus 1231: packet_clear_keys();
1.127 markus 1232:
1.172 markus 1233: /* Force a password change */
1234: if (s->authctxt->force_pwchange) {
1235: do_setusercontext(pw);
1.292 djm 1236: child_close_fds(ssh);
1.172 markus 1237: do_pwchange(s);
1238: exit(1);
1239: }
1240:
1.127 markus 1241: /*
1242: * Login(1) does this as well, and it needs uid 0 for the "-h"
1243: * switch, so we let login(1) to this for us.
1244: */
1.284 djm 1245: do_nologin(pw);
1246: do_setusercontext(pw);
1.127 markus 1247:
1248: /*
1249: * Get the shell from the password data. An empty shell field is
1250: * legal, and means /bin/sh.
1251: */
1252: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1253:
1254: /*
1255: * Make sure $SHELL points to the shell from the password file,
1256: * even if shell is overridden from login.conf
1257: */
1.292 djm 1258: env = do_setup_env(ssh, s, shell);
1.152 markus 1259:
1.127 markus 1260: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1261:
1.1 markus 1262: /*
1263: * Close the connection descriptors; note that this is the child, and
1264: * the server will still have the socket open, and it is important
1265: * that we do not shutdown it. Note that the descriptors cannot be
1266: * closed before building the environment, as we call
1.281 djm 1267: * ssh_remote_ipaddr there.
1.1 markus 1268: */
1.292 djm 1269: child_close_fds(ssh);
1.1 markus 1270:
1271: /*
1.125 deraadt 1272: * Must take new environment into use so that .ssh/rc,
1273: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1274: */
1275: environ = env;
1.170 jakob 1276:
1277: #ifdef KRB5
1278: /*
1279: * At this point, we check to see if AFS is active and if we have
1280: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1281: * if we can (and need to) extend the ticket into an AFS token. If
1282: * we don't do this, we run into potential problems if the user's
1283: * home directory is in AFS and it's not world-readable.
1284: */
1285:
1286: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1287: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1288: char cell[64];
1289:
1290: debug("Getting AFS token");
1291:
1292: k_setpag();
1293:
1294: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1295: krb5_afslog(s->authctxt->krb5_ctx,
1296: s->authctxt->krb5_fwd_ccache, cell, NULL);
1297:
1298: krb5_afslog_home(s->authctxt->krb5_ctx,
1299: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1300: }
1301: #endif
1.104 markus 1302:
1.188 djm 1303: /* Change current directory to the user's home directory. */
1.104 markus 1304: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1305: /* Suppress missing homedir warning for chroot case */
1306: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1307: if (r || !in_chroot) {
1.239 djm 1308: fprintf(stderr, "Could not chdir to home "
1309: "directory %s: %s\n", pw->pw_dir,
1310: strerror(errno));
1.279 djm 1311: }
1.239 djm 1312: if (r)
1.104 markus 1313: exit(1);
1314: }
1.230 djm 1315:
1316: closefrom(STDERR_FILENO + 1);
1.1 markus 1317:
1.294 djm 1318: do_rc_files(ssh, s, shell);
1.67 markus 1319:
1320: /* restore SIGPIPE for child */
1.217 stevesk 1321: signal(SIGPIPE, SIG_DFL);
1.67 markus 1322:
1.248 djm 1323: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1324: printf("This service allows sftp connections only.\n");
1325: fflush(NULL);
1326: exit(1);
1327: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1328: extern int optind, optreset;
1329: int i;
1330: char *p, *args;
1331:
1.246 stevesk 1332: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1333: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1334: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1335: if (i < ARGV_MAX - 1)
1336: argv[i++] = p;
1337: argv[i] = NULL;
1338: optind = optreset = 1;
1339: __progname = argv[0];
1.226 djm 1340: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1341: }
1.247 djm 1342:
1343: fflush(NULL);
1.225 markus 1344:
1.127 markus 1345: /* Get the last component of the shell name. */
1346: if ((shell0 = strrchr(shell, '/')) != NULL)
1347: shell0++;
1348: else
1349: shell0 = shell;
1350:
1.1 markus 1351: /*
1352: * If we have no command, execute the shell. In this case, the shell
1353: * name to be passed in argv[0] is preceded by '-' to indicate that
1354: * this is a login shell.
1355: */
1356: if (!command) {
1.127 markus 1357: char argv0[256];
1.1 markus 1358:
1.127 markus 1359: /* Start the shell. Set initial character to '-'. */
1360: argv0[0] = '-';
1.1 markus 1361:
1.127 markus 1362: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1363: >= sizeof(argv0) - 1) {
1.127 markus 1364: errno = EINVAL;
1.1 markus 1365: perror(shell);
1366: exit(1);
1.127 markus 1367: }
1.1 markus 1368:
1.127 markus 1369: /* Execute the shell. */
1370: argv[0] = argv0;
1371: argv[1] = NULL;
1372: execve(shell, argv, env);
1373:
1374: /* Executing the shell failed. */
1375: perror(shell);
1376: exit(1);
1.1 markus 1377: }
1378: /*
1379: * Execute the command using the user's shell. This uses the -c
1380: * option to execute the command.
1381: */
1.127 markus 1382: argv[0] = (char *) shell0;
1.1 markus 1383: argv[1] = "-c";
1384: argv[2] = (char *) command;
1385: argv[3] = NULL;
1386: execve(shell, argv, env);
1387: perror(shell);
1388: exit(1);
1389: }
1390:
1.237 djm 1391: void
1392: session_unused(int id)
1393: {
1394: debug3("%s: session id %d unused", __func__, id);
1395: if (id >= options.max_sessions ||
1396: id >= sessions_nalloc) {
1397: fatal("%s: insane session id %d (max %d nalloc %d)",
1398: __func__, id, options.max_sessions, sessions_nalloc);
1399: }
1.270 tedu 1400: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1401: sessions[id].self = id;
1402: sessions[id].used = 0;
1403: sessions[id].chanid = -1;
1404: sessions[id].ptyfd = -1;
1405: sessions[id].ttyfd = -1;
1406: sessions[id].ptymaster = -1;
1407: sessions[id].x11_chanids = NULL;
1408: sessions[id].next_unused = sessions_first_unused;
1409: sessions_first_unused = id;
1410: }
1411:
1.1 markus 1412: Session *
1413: session_new(void)
1414: {
1.237 djm 1415: Session *s, *tmp;
1416:
1417: if (sessions_first_unused == -1) {
1418: if (sessions_nalloc >= options.max_sessions)
1419: return NULL;
1420: debug2("%s: allocate (allocated %d max %d)",
1421: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1422: tmp = xrecallocarray(sessions, sessions_nalloc,
1423: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1424: if (tmp == NULL) {
1425: error("%s: cannot allocate %d sessions",
1426: __func__, sessions_nalloc + 1);
1427: return NULL;
1428: }
1429: sessions = tmp;
1430: session_unused(sessions_nalloc++);
1431: }
1432:
1433: if (sessions_first_unused >= sessions_nalloc ||
1434: sessions_first_unused < 0) {
1435: fatal("%s: insane first_unused %d max %d nalloc %d",
1436: __func__, sessions_first_unused, options.max_sessions,
1437: sessions_nalloc);
1438: }
1439:
1440: s = &sessions[sessions_first_unused];
1441: if (s->used) {
1442: fatal("%s: session %d already used",
1443: __func__, sessions_first_unused);
1444: }
1445: sessions_first_unused = s->next_unused;
1446: s->used = 1;
1447: s->next_unused = -1;
1448: debug("session_new: session %d", s->self);
1449:
1450: return s;
1.1 markus 1451: }
1452:
1.94 itojun 1453: static void
1.1 markus 1454: session_dump(void)
1455: {
1456: int i;
1.237 djm 1457: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1458: Session *s = &sessions[i];
1.237 djm 1459:
1460: debug("dump: used %d next_unused %d session %d %p "
1461: "channel %d pid %ld",
1.1 markus 1462: s->used,
1.237 djm 1463: s->next_unused,
1.1 markus 1464: s->self,
1465: s,
1466: s->chanid,
1.137 mpech 1467: (long)s->pid);
1.1 markus 1468: }
1469: }
1470:
1.2 markus 1471: int
1.97 markus 1472: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1473: {
1474: Session *s = session_new();
1475: debug("session_open: channel %d", chanid);
1476: if (s == NULL) {
1477: error("no more sessions");
1478: return 0;
1479: }
1.97 markus 1480: s->authctxt = authctxt;
1481: s->pw = authctxt->pw;
1.167 djm 1482: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1483: fatal("no user for session %d", s->self);
1.2 markus 1484: debug("session_open: session %d: link with channel %d", s->self, chanid);
1485: s->chanid = chanid;
1486: return 1;
1487: }
1488:
1.130 provos 1489: Session *
1490: session_by_tty(char *tty)
1491: {
1492: int i;
1.237 djm 1493: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1494: Session *s = &sessions[i];
1495: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1496: debug("session_by_tty: session %d tty %s", i, tty);
1497: return s;
1498: }
1499: }
1500: debug("session_by_tty: unknown tty %.100s", tty);
1501: session_dump();
1502: return NULL;
1503: }
1504:
1.94 itojun 1505: static Session *
1.2 markus 1506: session_by_channel(int id)
1507: {
1508: int i;
1.237 djm 1509: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1510: Session *s = &sessions[i];
1511: if (s->used && s->chanid == id) {
1.237 djm 1512: debug("session_by_channel: session %d channel %d",
1513: i, id);
1.2 markus 1514: return s;
1515: }
1516: }
1517: debug("session_by_channel: unknown channel %d", id);
1518: session_dump();
1519: return NULL;
1520: }
1521:
1.94 itojun 1522: static Session *
1.184 djm 1523: session_by_x11_channel(int id)
1524: {
1525: int i, j;
1526:
1.237 djm 1527: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1528: Session *s = &sessions[i];
1529:
1530: if (s->x11_chanids == NULL || !s->used)
1531: continue;
1532: for (j = 0; s->x11_chanids[j] != -1; j++) {
1533: if (s->x11_chanids[j] == id) {
1534: debug("session_by_x11_channel: session %d "
1535: "channel %d", s->self, id);
1536: return s;
1537: }
1538: }
1539: }
1540: debug("session_by_x11_channel: unknown channel %d", id);
1541: session_dump();
1542: return NULL;
1543: }
1544:
1545: static Session *
1.2 markus 1546: session_by_pid(pid_t pid)
1547: {
1548: int i;
1.137 mpech 1549: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1550: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1551: Session *s = &sessions[i];
1552: if (s->used && s->pid == pid)
1553: return s;
1554: }
1.137 mpech 1555: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1556: session_dump();
1557: return NULL;
1558: }
1559:
1.94 itojun 1560: static int
1.292 djm 1561: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1562: {
1563: s->col = packet_get_int();
1564: s->row = packet_get_int();
1565: s->xpixel = packet_get_int();
1566: s->ypixel = packet_get_int();
1.116 markus 1567: packet_check_eom();
1.2 markus 1568: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1569: return 1;
1570: }
1571:
1.94 itojun 1572: static int
1.292 djm 1573: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1574: {
1.45 markus 1575: u_int len;
1.132 markus 1576:
1.294 djm 1577: if (!auth_opts->permit_pty_flag || !options.permit_tty) {
1578: debug("Allocating a pty not permitted for this connection.");
1.19 markus 1579: return 0;
1.86 markus 1580: }
1581: if (s->ttyfd != -1) {
1582: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1583: return 0;
1.86 markus 1584: }
1585:
1.2 markus 1586: s->term = packet_get_string(&len);
1.283 markus 1587: s->col = packet_get_int();
1588: s->row = packet_get_int();
1.2 markus 1589: s->xpixel = packet_get_int();
1590: s->ypixel = packet_get_int();
1591:
1592: if (strcmp(s->term, "") == 0) {
1.265 djm 1593: free(s->term);
1.2 markus 1594: s->term = NULL;
1595: }
1.86 markus 1596:
1.2 markus 1597: /* Allocate a pty and open it. */
1.86 markus 1598: debug("Allocating pty.");
1.237 djm 1599: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1600: sizeof(s->tty)))) {
1.265 djm 1601: free(s->term);
1.2 markus 1602: s->term = NULL;
1603: s->ptyfd = -1;
1604: s->ttyfd = -1;
1605: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1606: return 0;
1.2 markus 1607: }
1608: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1609:
1.302 markus 1610: ssh_tty_parse_modes(ssh, s->ttyfd);
1.86 markus 1611:
1.130 provos 1612: if (!use_privsep)
1613: pty_setowner(s->pw, s->tty);
1.86 markus 1614:
1615: /* Set window size from the packet. */
1.2 markus 1616: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1617:
1.116 markus 1618: packet_check_eom();
1.9 markus 1619: session_proctitle(s);
1.2 markus 1620: return 1;
1621: }
1622:
1.94 itojun 1623: static int
1.292 djm 1624: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1625: {
1.105 markus 1626: struct stat st;
1.45 markus 1627: u_int len;
1.7 markus 1628: int success = 0;
1.267 djm 1629: char *prog, *cmd;
1.182 djm 1630: u_int i;
1.7 markus 1631:
1.267 djm 1632: s->subsys = packet_get_string(&len);
1.116 markus 1633: packet_check_eom();
1.267 djm 1634: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1635: s->pw->pw_name);
1.18 jakob 1636:
1637: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1638: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1639: prog = options.subsystem_command[i];
1640: cmd = options.subsystem_args[i];
1.249 dtucker 1641: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1642: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1643: debug("subsystem: %s", prog);
1.225 markus 1644: } else {
1.249 dtucker 1645: if (stat(prog, &st) < 0)
1646: debug("subsystem: cannot stat %s: %s",
1647: prog, strerror(errno));
1.225 markus 1648: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1649: debug("subsystem: exec() %s", cmd);
1.105 markus 1650: }
1.292 djm 1651: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1652: break;
1.18 jakob 1653: }
1654: }
1655:
1656: if (!success)
1.267 djm 1657: logit("subsystem request for %.100s by user %s failed, "
1658: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1659:
1660: return success;
1661: }
1662:
1.94 itojun 1663: static int
1.292 djm 1664: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1665: {
1.81 markus 1666: int success;
1.7 markus 1667:
1.184 djm 1668: if (s->auth_proto != NULL || s->auth_data != NULL) {
1669: error("session_x11_req: session %d: "
1.190 stevesk 1670: "x11 forwarding already active", s->self);
1.184 djm 1671: return 0;
1672: }
1.7 markus 1673: s->single_connection = packet_get_char();
1674: s->auth_proto = packet_get_string(NULL);
1675: s->auth_data = packet_get_string(NULL);
1676: s->screen = packet_get_int();
1.116 markus 1677: packet_check_eom();
1.7 markus 1678:
1.282 djm 1679: if (xauth_valid_string(s->auth_proto) &&
1680: xauth_valid_string(s->auth_data))
1.292 djm 1681: success = session_setup_x11fwd(ssh, s);
1.282 djm 1682: else {
1683: success = 0;
1684: error("Invalid X11 forwarding data");
1685: }
1.81 markus 1686: if (!success) {
1.265 djm 1687: free(s->auth_proto);
1688: free(s->auth_data);
1.84 markus 1689: s->auth_proto = NULL;
1690: s->auth_data = NULL;
1.7 markus 1691: }
1.81 markus 1692: return success;
1.7 markus 1693: }
1694:
1.94 itojun 1695: static int
1.292 djm 1696: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1697: {
1.116 markus 1698: packet_check_eom();
1.292 djm 1699: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1700: }
1701:
1.94 itojun 1702: static int
1.292 djm 1703: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1704: {
1.237 djm 1705: u_int len, success;
1706:
1.19 markus 1707: char *command = packet_get_string(&len);
1.116 markus 1708: packet_check_eom();
1.292 djm 1709: success = do_exec(ssh, s, command) == 0;
1.265 djm 1710: free(command);
1.237 djm 1711: return success;
1.19 markus 1712: }
1713:
1.94 itojun 1714: static int
1.292 djm 1715: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1716: {
1717:
1.175 deraadt 1718: packet_get_int(); /* ignored */
1.157 markus 1719: packet_check_eom();
1720:
1.259 djm 1721: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1722: return 0;
1723: return 1;
1724: }
1725:
1726: static int
1.292 djm 1727: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1728: {
1729: char *name, *val;
1730: u_int name_len, val_len, i;
1731:
1.271 djm 1732: name = packet_get_cstring(&name_len);
1733: val = packet_get_cstring(&val_len);
1.173 djm 1734: packet_check_eom();
1735:
1736: /* Don't set too many environment variables */
1737: if (s->num_env > 128) {
1738: debug2("Ignoring env request %s: too many env vars", name);
1739: goto fail;
1740: }
1741:
1742: for (i = 0; i < options.num_accept_env; i++) {
1743: if (match_pattern(name, options.accept_env[i])) {
1744: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1745: s->env = xrecallocarray(s->env, s->num_env,
1746: s->num_env + 1, sizeof(*s->env));
1.173 djm 1747: s->env[s->num_env].name = name;
1748: s->env[s->num_env].val = val;
1749: s->num_env++;
1750: return (1);
1751: }
1752: }
1753: debug2("Ignoring env request %s: disallowed name", name);
1754:
1755: fail:
1.265 djm 1756: free(name);
1757: free(val);
1.173 djm 1758: return (0);
1759: }
1760:
1.306 djm 1761: /*
1762: * Conversion of signals from ssh channel request names.
1763: * Subset of signals from RFC 4254 section 6.10C, with SIGINFO as
1764: * local extension.
1765: */
1766: static int
1767: name2sig(char *name)
1768: {
1769: #define SSH_SIG(x) if (strcmp(name, #x) == 0) return SIG ## x
1770: SSH_SIG(HUP);
1771: SSH_SIG(INT);
1772: SSH_SIG(KILL);
1773: SSH_SIG(QUIT);
1774: SSH_SIG(TERM);
1775: SSH_SIG(USR1);
1776: SSH_SIG(USR2);
1777: #undef SSH_SIG
1778: if (strcmp(name, "INFO@openssh.com") == 0)
1779: return SIGINFO;
1780: return -1;
1781: }
1782:
1783: static int
1784: session_signal_req(struct ssh *ssh, Session *s)
1785: {
1786: char *signame = NULL;
1787: int r, sig, success = 0;
1788:
1789: if ((r = sshpkt_get_cstring(ssh, &signame, NULL)) != 0 ||
1790: (r = sshpkt_get_end(ssh)) != 0) {
1791: error("%s: parse packet: %s", __func__, ssh_err(r));
1792: goto out;
1793: }
1794: if ((sig = name2sig(signame)) == -1) {
1795: error("%s: unsupported signal \"%s\"", __func__, signame);
1796: goto out;
1797: }
1798: if (s->pid <= 0) {
1799: error("%s: no pid for session %d", __func__, s->self);
1800: goto out;
1801: }
1802: if (s->forced || s->is_subsystem) {
1803: error("%s: refusing to send signal %s to %s session", __func__,
1804: signame, s->forced ? "forced-command" : "subsystem");
1805: goto out;
1806: }
1807: if (!use_privsep || mm_is_monitor()) {
1808: error("%s: session signalling requires privilege separation",
1809: __func__);
1810: goto out;
1811: }
1812:
1813: debug("%s: signal %s, killpg(%ld, %d)", __func__, signame,
1814: (long)s->pid, sig);
1815: temporarily_use_uid(s->pw);
1816: r = killpg(s->pid, sig);
1817: restore_uid();
1818: if (r != 0) {
1819: error("%s: killpg(%ld, %d): %s", __func__, (long)s->pid,
1820: sig, strerror(errno));
1821: goto out;
1822: }
1823:
1824: /* success */
1825: success = 1;
1826: out:
1827: free(signame);
1828: return success;
1829: }
1830:
1.173 djm 1831: static int
1.292 djm 1832: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1833: {
1834: static int called = 0;
1.294 djm 1835:
1.116 markus 1836: packet_check_eom();
1.294 djm 1837: if (!auth_opts->permit_agent_forwarding_flag ||
1838: !options.allow_agent_forwarding) {
1839: debug("%s: agent forwarding disabled", __func__);
1.44 markus 1840: return 0;
1841: }
1.43 markus 1842: if (called) {
1843: return 0;
1844: } else {
1845: called = 1;
1.292 djm 1846: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1847: }
1848: }
1849:
1.123 markus 1850: int
1.292 djm 1851: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1852: {
1853: int success = 0;
1854: Session *s;
1855:
1.123 markus 1856: if ((s = session_by_channel(c->self)) == NULL) {
1.292 djm 1857: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1858: return 0;
1859: }
1.292 djm 1860: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1861:
1862: /*
1.64 markus 1863: * a session is in LARVAL state until a shell, a command
1864: * or a subsystem is executed
1.2 markus 1865: */
1866: if (c->type == SSH_CHANNEL_LARVAL) {
1867: if (strcmp(rtype, "shell") == 0) {
1.292 djm 1868: success = session_shell_req(ssh, s);
1.2 markus 1869: } else if (strcmp(rtype, "exec") == 0) {
1.292 djm 1870: success = session_exec_req(ssh, s);
1.2 markus 1871: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 djm 1872: success = session_pty_req(ssh, s);
1.7 markus 1873: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 djm 1874: success = session_x11_req(ssh, s);
1.43 markus 1875: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 djm 1876: success = session_auth_agent_req(ssh, s);
1.7 markus 1877: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 djm 1878: success = session_subsystem_req(ssh, s);
1.173 djm 1879: } else if (strcmp(rtype, "env") == 0) {
1.292 djm 1880: success = session_env_req(ssh, s);
1.2 markus 1881: }
1882: }
1883: if (strcmp(rtype, "window-change") == 0) {
1.292 djm 1884: success = session_window_change_req(ssh, s);
1.177 djm 1885: } else if (strcmp(rtype, "break") == 0) {
1.292 djm 1886: success = session_break_req(ssh, s);
1.306 djm 1887: } else if (strcmp(rtype, "signal") == 0) {
1888: success = session_signal_req(ssh, s);
1.2 markus 1889: }
1.177 djm 1890:
1.123 markus 1891: return success;
1.2 markus 1892: }
1893:
1894: void
1.292 djm 1895: session_set_fds(struct ssh *ssh, Session *s,
1896: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1897: {
1898: /*
1899: * now that have a child and a pipe to the child,
1900: * we can activate our channel and register the fd's
1901: */
1902: if (s->chanid == -1)
1903: fatal("no channel for session %d", s->self);
1.292 djm 1904: channel_set_fds(ssh, s->chanid,
1.2 markus 1905: fdout, fdin, fderr,
1.256 djm 1906: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1907: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1908: }
1909:
1.85 markus 1910: /*
1911: * Function to perform pty cleanup. Also called if we get aborted abnormally
1912: * (e.g., due to a dropped connection).
1913: */
1.130 provos 1914: void
1.165 markus 1915: session_pty_cleanup2(Session *s)
1.1 markus 1916: {
1.85 markus 1917: if (s == NULL) {
1.307 djm 1918: error("%s: no session", __func__);
1.85 markus 1919: return;
1920: }
1921: if (s->ttyfd == -1)
1.1 markus 1922: return;
1923:
1.307 djm 1924: debug("%s: session %d release %s", __func__, s->self, s->tty);
1.1 markus 1925:
1926: /* Record that the user has logged out. */
1.85 markus 1927: if (s->pid != 0)
1928: record_logout(s->pid, s->tty);
1.1 markus 1929:
1930: /* Release the pseudo-tty. */
1.130 provos 1931: if (getuid() == 0)
1932: pty_release(s->tty);
1.1 markus 1933:
1934: /*
1935: * Close the server side of the socket pairs. We must do this after
1936: * the pty cleanup, so that another process doesn't get this pty
1937: * while we're still cleaning up.
1938: */
1.237 djm 1939: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1940: error("close(s->ptymaster/%d): %s",
1941: s->ptymaster, strerror(errno));
1.108 markus 1942:
1943: /* unlink pty from session */
1944: s->ttyfd = -1;
1.2 markus 1945: }
1946:
1.130 provos 1947: void
1.165 markus 1948: session_pty_cleanup(Session *s)
1.130 provos 1949: {
1.165 markus 1950: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1951: }
1952:
1.147 markus 1953: static char *
1954: sig2name(int sig)
1955: {
1956: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1957: SSH_SIG(ABRT);
1958: SSH_SIG(ALRM);
1959: SSH_SIG(FPE);
1960: SSH_SIG(HUP);
1961: SSH_SIG(ILL);
1962: SSH_SIG(INT);
1963: SSH_SIG(KILL);
1964: SSH_SIG(PIPE);
1965: SSH_SIG(QUIT);
1966: SSH_SIG(SEGV);
1967: SSH_SIG(TERM);
1968: SSH_SIG(USR1);
1969: SSH_SIG(USR2);
1970: #undef SSH_SIG
1971: return "SIG@openssh.com";
1972: }
1973:
1.94 itojun 1974: static void
1.292 djm 1975: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1976: {
1977: Channel *c;
1978:
1.292 djm 1979: if ((c = channel_by_id(ssh, id)) == NULL) {
1980: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1981: } else {
1982: /* Detach X11 listener */
1.292 djm 1983: debug("%s: detach x11 channel %d", __func__, id);
1984: channel_cancel_cleanup(ssh, id);
1.184 djm 1985: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1986: chan_mark_dead(ssh, c);
1.184 djm 1987: }
1988: }
1989:
1990: static void
1.292 djm 1991: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1992: {
1993: Session *s;
1994: u_int i;
1995:
1.292 djm 1996: debug3("%s: channel %d", __func__, id);
1997: channel_cancel_cleanup(ssh, id);
1.221 stevesk 1998: if ((s = session_by_x11_channel(id)) == NULL)
1.292 djm 1999: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 2000: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2001: debug("%s: session %d: closing channel %d",
2002: __func__, s->self, s->x11_chanids[i]);
1.184 djm 2003: /*
2004: * The channel "id" is already closing, but make sure we
2005: * close all of its siblings.
2006: */
2007: if (s->x11_chanids[i] != id)
1.292 djm 2008: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 2009: }
1.265 djm 2010: free(s->x11_chanids);
1.184 djm 2011: s->x11_chanids = NULL;
1.265 djm 2012: free(s->display);
2013: s->display = NULL;
2014: free(s->auth_proto);
2015: s->auth_proto = NULL;
2016: free(s->auth_data);
2017: s->auth_data = NULL;
2018: free(s->auth_display);
2019: s->auth_display = NULL;
1.184 djm 2020: }
2021:
2022: static void
1.292 djm 2023: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 2024: {
2025: Channel *c;
1.124 markus 2026:
1.292 djm 2027: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
2028: fatal("%s: session %d: no channel %d",
2029: __func__, s->self, s->chanid);
2030: debug("%s: session %d channel %d pid %ld",
2031: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 2032:
2033: if (WIFEXITED(status)) {
1.292 djm 2034: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 2035: packet_put_int(WEXITSTATUS(status));
2036: packet_send();
2037: } else if (WIFSIGNALED(status)) {
1.292 djm 2038: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 2039: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 2040: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 2041: packet_put_cstring("");
2042: packet_put_cstring("");
2043: packet_send();
2044: } else {
2045: /* Some weird exit cause. Just exit. */
2046: packet_disconnect("wait returned status %04x.", status);
2047: }
2048:
2049: /* disconnect channel */
1.292 djm 2050: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 2051:
2052: /*
2053: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 2054: * the channel gets EOF. The session will be then be closed
1.187 djm 2055: * by session_close_by_channel when the childs close their fds.
2056: */
1.292 djm 2057: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 2058:
1.5 markus 2059: /*
2060: * emulate a write failure with 'chan_write_failed', nobody will be
2061: * interested in data we write.
2062: * Note that we must not call 'chan_read_failed', since there could
2063: * be some more data waiting in the pipe.
2064: */
1.8 markus 2065: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 2066: chan_write_failed(ssh, c);
1.2 markus 2067: }
2068:
1.130 provos 2069: void
1.292 djm 2070: session_close(struct ssh *ssh, Session *s)
1.2 markus 2071: {
1.182 djm 2072: u_int i;
1.173 djm 2073:
1.280 djm 2074: verbose("Close session: user %s from %.200s port %d id %d",
2075: s->pw->pw_name,
1.281 djm 2076: ssh_remote_ipaddr(ssh),
2077: ssh_remote_port(ssh),
1.280 djm 2078: s->self);
2079:
1.165 markus 2080: if (s->ttyfd != -1)
1.85 markus 2081: session_pty_cleanup(s);
1.265 djm 2082: free(s->term);
2083: free(s->display);
2084: free(s->x11_chanids);
2085: free(s->auth_display);
2086: free(s->auth_data);
2087: free(s->auth_proto);
1.267 djm 2088: free(s->subsys);
1.219 djm 2089: if (s->env != NULL) {
2090: for (i = 0; i < s->num_env; i++) {
1.265 djm 2091: free(s->env[i].name);
2092: free(s->env[i].val);
1.219 djm 2093: }
1.265 djm 2094: free(s->env);
1.173 djm 2095: }
1.9 markus 2096: session_proctitle(s);
1.237 djm 2097: session_unused(s->self);
1.2 markus 2098: }
2099:
2100: void
1.292 djm 2101: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 2102: {
2103: Session *s = session_by_pid(pid);
2104: if (s == NULL) {
1.292 djm 2105: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 2106: return;
2107: }
2108: if (s->chanid != -1)
1.292 djm 2109: session_exit_message(ssh, s, status);
1.187 djm 2110: if (s->ttyfd != -1)
2111: session_pty_cleanup(s);
1.197 djm 2112: s->pid = 0;
1.98 markus 2113: }
2114:
1.2 markus 2115: /*
2116: * this is called when a channel dies before
2117: * the session 'child' itself dies
2118: */
2119: void
1.292 djm 2120: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 2121: {
2122: Session *s = session_by_channel(id);
1.187 djm 2123: u_int i;
1.184 djm 2124:
1.2 markus 2125: if (s == NULL) {
1.292 djm 2126: debug("%s: no session for id %d", __func__, id);
1.2 markus 2127: return;
2128: }
1.292 djm 2129: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 2130: if (s->pid != 0) {
1.307 djm 2131: debug("%s: channel %d: has child, ttyfd %d",
2132: __func__, id, s->ttyfd);
1.108 markus 2133: /*
2134: * delay detach of session, but release pty, since
2135: * the fd's to the child are already closed
2136: */
1.165 markus 2137: if (s->ttyfd != -1)
1.108 markus 2138: session_pty_cleanup(s);
1.107 markus 2139: return;
2140: }
2141: /* detach by removing callback */
1.292 djm 2142: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 2143:
2144: /* Close any X11 listeners associated with this session */
2145: if (s->x11_chanids != NULL) {
2146: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2147: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 2148: s->x11_chanids[i] = -1;
2149: }
2150: }
2151:
1.2 markus 2152: s->chanid = -1;
1.292 djm 2153: session_close(ssh, s);
1.106 markus 2154: }
2155:
2156: void
1.292 djm 2157: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 2158: {
2159: int i;
1.237 djm 2160: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2161: Session *s = &sessions[i];
1.130 provos 2162: if (s->used) {
2163: if (closefunc != NULL)
2164: closefunc(s);
2165: else
1.292 djm 2166: session_close(ssh, s);
1.130 provos 2167: }
1.2 markus 2168: }
1.9 markus 2169: }
2170:
1.94 itojun 2171: static char *
1.9 markus 2172: session_tty_list(void)
2173: {
2174: static char buf[1024];
2175: int i;
2176: buf[0] = '\0';
1.237 djm 2177: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2178: Session *s = &sessions[i];
2179: if (s->used && s->ttyfd != -1) {
2180: if (buf[0] != '\0')
2181: strlcat(buf, ",", sizeof buf);
2182: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2183: }
2184: }
2185: if (buf[0] == '\0')
2186: strlcpy(buf, "notty", sizeof buf);
2187: return buf;
2188: }
2189:
2190: void
2191: session_proctitle(Session *s)
2192: {
2193: if (s->pw == NULL)
2194: error("no user for session %d", s->self);
2195: else
2196: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2197: }
2198:
2199: int
1.292 djm 2200: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2201: {
2202: struct stat st;
1.109 stevesk 2203: char display[512], auth_display[512];
1.272 djm 2204: char hostname[NI_MAXHOST];
1.184 djm 2205: u_int i;
1.81 markus 2206:
1.294 djm 2207: if (!auth_opts->permit_x11_forwarding_flag) {
2208: packet_send_debug("X11 forwarding disabled by key options.");
1.81 markus 2209: return 0;
2210: }
2211: if (!options.x11_forwarding) {
2212: debug("X11 forwarding disabled in server configuration file.");
2213: return 0;
2214: }
1.275 djm 2215: if (options.xauth_location == NULL ||
1.81 markus 2216: (stat(options.xauth_location, &st) == -1)) {
1.294 djm 2217: packet_send_debug("No xauth program; cannot forward X11.");
1.81 markus 2218: return 0;
2219: }
1.87 markus 2220: if (s->display != NULL) {
1.81 markus 2221: debug("X11 display already set.");
2222: return 0;
2223: }
1.292 djm 2224: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2225: options.x11_use_localhost, s->single_connection,
1.184 djm 2226: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2227: debug("x11_create_display_inet failed.");
1.81 markus 2228: return 0;
1.184 djm 2229: }
2230: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2231: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2232: session_close_single_x11, 0);
1.81 markus 2233: }
1.109 stevesk 2234:
2235: /* Set up a suitable value for the DISPLAY variable. */
2236: if (gethostname(hostname, sizeof(hostname)) < 0)
2237: fatal("gethostname: %.100s", strerror(errno));
2238: /*
2239: * auth_display must be used as the displayname when the
2240: * authorization entry is added with xauth(1). This will be
2241: * different than the DISPLAY string for localhost displays.
2242: */
1.119 stevesk 2243: if (options.x11_use_localhost) {
1.140 deraadt 2244: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2245: s->display_number, s->screen);
1.140 deraadt 2246: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2247: s->display_number, s->screen);
1.109 stevesk 2248: s->display = xstrdup(display);
1.118 stevesk 2249: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2250: } else {
1.140 deraadt 2251: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2252: s->display_number, s->screen);
2253: s->display = xstrdup(display);
1.118 stevesk 2254: s->auth_display = xstrdup(display);
1.109 stevesk 2255: }
2256:
1.81 markus 2257: return 1;
1.2 markus 2258: }
2259:
1.94 itojun 2260: static void
1.292 djm 2261: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2262: {
1.292 djm 2263: server_loop2(ssh, authctxt);
1.165 markus 2264: }
2265:
2266: void
1.292 djm 2267: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2268: {
2269: static int called = 0;
2270:
2271: debug("do_cleanup");
2272:
2273: /* no cleanup if we're in the child for login shell */
2274: if (is_child)
2275: return;
2276:
2277: /* avoid double cleanup */
2278: if (called)
2279: return;
2280: called = 1;
2281:
1.218 markus 2282: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2283: return;
2284: #ifdef KRB5
2285: if (options.kerberos_ticket_cleanup &&
2286: authctxt->krb5_ctx)
2287: krb5_cleanup_proc(authctxt);
1.161 markus 2288: #endif
1.165 markus 2289:
2290: #ifdef GSSAPI
1.283 markus 2291: if (options.gss_cleanup_creds)
1.165 markus 2292: ssh_gssapi_cleanup_creds();
2293: #endif
2294:
2295: /* remove agent socket */
2296: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2297:
2298: /* remove userauth info */
2299: if (auth_info_file != NULL) {
2300: temporarily_use_uid(authctxt->pw);
2301: unlink(auth_info_file);
2302: restore_uid();
2303: free(auth_info_file);
2304: auth_info_file = NULL;
2305: }
1.165 markus 2306:
2307: /*
2308: * Cleanup ptys/utmp only if privsep is disabled,
2309: * or if running in monitor.
2310: */
2311: if (!use_privsep || mm_is_monitor())
1.292 djm 2312: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2313: }
1.281 djm 2314:
2315: /* Return a name for the remote host that fits inside utmp_size */
2316:
2317: const char *
2318: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2319: {
2320: const char *remote = "";
2321:
2322: if (utmp_size > 0)
2323: remote = auth_get_canonical_hostname(ssh, use_dns);
2324: if (utmp_size == 0 || strlen(remote) > utmp_size)
2325: remote = ssh_remote_ipaddr(ssh);
2326: return remote;
2327: }
2328: