Annotation of src/usr.bin/ssh/session.c, Revision 1.300
1.300 ! djm 1: /* $OpenBSD: session.c,v 1.299 2018/06/09 02:58:02 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
1.37 deraadt 5: *
6: * As far as I am concerned, the code I have written for this software
7: * can be used freely for any purpose. Any derived versions of this
8: * software must be clearly marked as such, and if the derived work is
9: * incompatible with the protocol description in the RFC file, it must be
10: * called by a name other than "ssh" or "Secure Shell".
11: *
1.2 markus 12: * SSH2 support by Markus Friedl.
1.95 markus 13: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.37 deraadt 14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2 markus 34: */
1.1 markus 35:
1.193 stevesk 36: #include <sys/types.h>
37: #include <sys/wait.h>
1.194 stevesk 38: #include <sys/un.h>
1.196 stevesk 39: #include <sys/stat.h>
1.207 stevesk 40: #include <sys/socket.h>
1.236 djm 41: #include <sys/queue.h>
1.192 stevesk 42:
1.282 djm 43: #include <ctype.h>
1.209 stevesk 44: #include <errno.h>
1.253 djm 45: #include <fcntl.h>
1.204 stevesk 46: #include <grp.h>
1.223 djm 47: #include <login_cap.h>
1.272 djm 48: #include <netdb.h>
1.192 stevesk 49: #include <paths.h>
1.206 stevesk 50: #include <pwd.h>
1.195 stevesk 51: #include <signal.h>
1.215 stevesk 52: #include <stdio.h>
1.214 stevesk 53: #include <stdlib.h>
1.212 stevesk 54: #include <string.h>
1.211 stevesk 55: #include <unistd.h>
1.277 deraadt 56: #include <limits.h>
1.1 markus 57:
1.216 deraadt 58: #include "xmalloc.h"
1.51 markus 59: #include "ssh.h"
60: #include "ssh2.h"
1.59 djm 61: #include "sshpty.h"
1.1 markus 62: #include "packet.h"
63: #include "buffer.h"
1.173 djm 64: #include "match.h"
1.1 markus 65: #include "uidswap.h"
66: #include "compat.h"
1.78 markus 67: #include "channels.h"
1.216 deraadt 68: #include "key.h"
69: #include "cipher.h"
70: #include "kex.h"
71: #include "hostfile.h"
1.2 markus 72: #include "auth.h"
1.19 markus 73: #include "auth-options.h"
1.266 markus 74: #include "authfd.h"
1.50 markus 75: #include "pathnames.h"
1.51 markus 76: #include "log.h"
1.274 millert 77: #include "misc.h"
1.51 markus 78: #include "servconf.h"
1.59 djm 79: #include "sshlogin.h"
1.51 markus 80: #include "serverloop.h"
81: #include "canohost.h"
1.55 itojun 82: #include "session.h"
1.216 deraadt 83: #ifdef GSSAPI
84: #include "ssh-gss.h"
85: #endif
1.130 provos 86: #include "monitor_wrap.h"
1.225 markus 87: #include "sftp.h"
1.290 djm 88: #include "atomicio.h"
1.171 markus 89:
90: #ifdef KRB5
91: #include <kafs.h>
1.161 markus 92: #endif
93:
1.242 djm 94: #define IS_INTERNAL_SFTP(c) \
95: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
96: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
97: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
98: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
99:
1.1 markus 100: /* func */
101:
102: Session *session_new(void);
1.292 djm 103: void session_set_fds(struct ssh *, Session *, int, int, int, int, int);
1.165 markus 104: void session_pty_cleanup(Session *);
1.94 itojun 105: void session_proctitle(Session *);
1.292 djm 106: int session_setup_x11fwd(struct ssh *, Session *);
107: int do_exec_pty(struct ssh *, Session *, const char *);
108: int do_exec_no_pty(struct ssh *, Session *, const char *);
109: int do_exec(struct ssh *, Session *, const char *);
110: void do_login(struct ssh *, Session *, const char *);
111: void do_child(struct ssh *, Session *, const char *);
1.73 djm 112: void do_motd(void);
1.94 itojun 113: int check_quietlogin(Session *, const char *);
1.1 markus 114:
1.292 djm 115: static void do_authenticated2(struct ssh *, Authctxt *);
1.94 itojun 116:
1.292 djm 117: static int session_pty_req(struct ssh *, Session *);
1.65 markus 118:
1.1 markus 119: /* import */
120: extern ServerOptions options;
121: extern char *__progname;
122: extern int debug_flag;
1.45 markus 123: extern u_int utmp_len;
1.21 markus 124: extern int startup_pipe;
1.74 markus 125: extern void destroy_sensitive_data(void);
1.179 dtucker 126: extern Buffer loginmsg;
1.294 djm 127: extern struct sshauthopt *auth_opts;
1.293 djm 128: char *tun_fwd_ifnames; /* serverloop.c */
1.21 markus 129:
1.34 markus 130: /* original command from peer. */
1.92 markus 131: const char *original_command = NULL;
1.34 markus 132:
1.1 markus 133: /* data */
1.237 djm 134: static int sessions_first_unused = -1;
135: static int sessions_nalloc = 0;
136: static Session *sessions = NULL;
1.1 markus 137:
1.248 djm 138: #define SUBSYSTEM_NONE 0
139: #define SUBSYSTEM_EXT 1
140: #define SUBSYSTEM_INT_SFTP 2
141: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.225 markus 142:
1.129 provos 143: login_cap_t *lc;
1.28 millert 144:
1.165 markus 145: static int is_child = 0;
1.279 djm 146: static int in_chroot = 0;
1.165 markus 147:
1.290 djm 148: /* File containing userauth info, if ExposeAuthInfo set */
149: static char *auth_info_file = NULL;
150:
1.136 markus 151: /* Name and directory of socket for authentication agent forwarding. */
152: static char *auth_sock_name = NULL;
153: static char *auth_sock_dir = NULL;
154:
155: /* removes the agent forwarding socket */
156:
157: static void
1.165 markus 158: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 159: {
160: if (auth_sock_name != NULL) {
161: temporarily_use_uid(pw);
162: unlink(auth_sock_name);
163: rmdir(auth_sock_dir);
164: auth_sock_name = NULL;
165: restore_uid();
166: }
167: }
168:
169: static int
1.292 djm 170: auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
1.136 markus 171: {
172: Channel *nc;
1.237 djm 173: int sock = -1;
1.136 markus 174:
175: if (auth_sock_name != NULL) {
176: error("authentication forwarding requested twice.");
177: return 0;
178: }
179:
180: /* Temporarily drop privileged uid for mkdir/bind. */
181: temporarily_use_uid(pw);
182:
183: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 184: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 185:
186: /* Create private directory for socket */
187: if (mkdtemp(auth_sock_dir) == NULL) {
188: packet_send_debug("Agent forwarding disabled: "
189: "mkdtemp() failed: %.100s", strerror(errno));
190: restore_uid();
1.265 djm 191: free(auth_sock_dir);
1.136 markus 192: auth_sock_dir = NULL;
1.237 djm 193: goto authsock_err;
1.136 markus 194: }
1.237 djm 195:
196: xasprintf(&auth_sock_name, "%s/agent.%ld",
197: auth_sock_dir, (long) getpid());
1.136 markus 198:
1.274 millert 199: /* Start a Unix listener on auth_sock_name. */
200: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.136 markus 201:
202: /* Restore the privileged uid. */
203: restore_uid();
204:
1.274 millert 205: /* Check for socket/bind/listen failure. */
206: if (sock < 0)
1.237 djm 207: goto authsock_err;
1.136 markus 208:
209: /* Allocate a channel for the authentication agent socket. */
1.292 djm 210: nc = channel_new(ssh, "auth socket",
1.136 markus 211: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
212: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 213: 0, "auth socket", 1);
1.245 djm 214: nc->path = xstrdup(auth_sock_name);
1.136 markus 215: return 1;
1.237 djm 216:
217: authsock_err:
1.265 djm 218: free(auth_sock_name);
1.237 djm 219: if (auth_sock_dir != NULL) {
220: rmdir(auth_sock_dir);
1.265 djm 221: free(auth_sock_dir);
1.237 djm 222: }
223: if (sock != -1)
224: close(sock);
225: auth_sock_name = NULL;
226: auth_sock_dir = NULL;
227: return 0;
1.136 markus 228: }
229:
1.179 dtucker 230: static void
231: display_loginmsg(void)
232: {
1.183 djm 233: if (buffer_len(&loginmsg) > 0) {
234: buffer_append(&loginmsg, "\0", 1);
235: printf("%s", (char *)buffer_ptr(&loginmsg));
236: buffer_clear(&loginmsg);
237: }
1.179 dtucker 238: }
1.136 markus 239:
1.290 djm 240: static void
241: prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
242: {
243: int fd = -1, success = 0;
244:
245: if (!options.expose_userauth_info || info == NULL)
246: return;
247:
248: temporarily_use_uid(pw);
249: auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
250: if ((fd = mkstemp(auth_info_file)) == -1) {
251: error("%s: mkstemp: %s", __func__, strerror(errno));
252: goto out;
253: }
254: if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
255: sshbuf_len(info)) != sshbuf_len(info)) {
256: error("%s: write: %s", __func__, strerror(errno));
257: goto out;
258: }
259: if (close(fd) != 0) {
260: error("%s: close: %s", __func__, strerror(errno));
261: goto out;
262: }
263: success = 1;
264: out:
265: if (!success) {
266: if (fd != -1)
267: close(fd);
268: free(auth_info_file);
269: auth_info_file = NULL;
270: }
271: restore_uid();
272: }
273:
1.294 djm 274: static void
1.297 djm 275: set_fwdpermit_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
1.294 djm 276: {
277: char *tmp, *cp, *host;
278: int port;
279: size_t i;
280:
1.297 djm 281: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0) {
282: channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL);
283: for (i = 0; i < auth_opts->npermitopen; i++) {
284: tmp = cp = xstrdup(auth_opts->permitopen[i]);
285: /* This shouldn't fail as it has already been checked */
286: if ((host = hpdelim(&cp)) == NULL)
287: fatal("%s: internal error: hpdelim", __func__);
288: host = cleanhostname(host);
289: if (cp == NULL || (port = permitopen_port(cp)) < 0)
290: fatal("%s: internal error: permitopen port",
291: __func__);
292: channel_add_permission(ssh,
293: FORWARD_USER, FORWARD_LOCAL, host, port);
294: free(tmp);
295: }
296: }
297: if ((options.allow_tcp_forwarding & FORWARD_REMOTE) != 0) {
298: channel_clear_permission(ssh, FORWARD_USER, FORWARD_REMOTE);
299: for (i = 0; i < auth_opts->npermitlisten; i++) {
300: tmp = cp = xstrdup(auth_opts->permitlisten[i]);
301: /* This shouldn't fail as it has already been checked */
302: if ((host = hpdelim(&cp)) == NULL)
303: fatal("%s: internal error: hpdelim", __func__);
304: host = cleanhostname(host);
305: if (cp == NULL || (port = permitopen_port(cp)) < 0)
306: fatal("%s: internal error: permitlisten port",
307: __func__);
308: channel_add_permission(ssh,
309: FORWARD_USER, FORWARD_REMOTE, host, port);
310: free(tmp);
311: }
1.294 djm 312: }
313: }
314:
1.65 markus 315: void
1.292 djm 316: do_authenticated(struct ssh *ssh, Authctxt *authctxt)
1.65 markus 317: {
1.153 markus 318: setproctitle("%s", authctxt->pw->pw_name);
319:
1.294 djm 320: auth_log_authopts("active", auth_opts, 0);
321:
1.65 markus 322: /* setup the channel layer */
1.274 millert 323: /* XXX - streamlocal? */
1.297 djm 324: set_fwdpermit_from_authopts(ssh, auth_opts);
1.296 djm 325:
1.294 djm 326: if (!auth_opts->permit_port_forwarding_flag ||
1.296 djm 327: options.disable_forwarding) {
328: channel_disable_admin(ssh, FORWARD_LOCAL);
329: channel_disable_admin(ssh, FORWARD_REMOTE);
330: } else {
331: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
332: channel_disable_admin(ssh, FORWARD_LOCAL);
333: else
334: channel_permit_all(ssh, FORWARD_LOCAL);
335: if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0)
336: channel_disable_admin(ssh, FORWARD_REMOTE);
337: else
338: channel_permit_all(ssh, FORWARD_REMOTE);
339: }
1.252 dtucker 340: auth_debug_send();
1.65 markus 341:
1.290 djm 342: prepare_auth_info_file(authctxt->pw, authctxt->session_info);
343:
1.292 djm 344: do_authenticated2(ssh, authctxt);
1.290 djm 345:
1.292 djm 346: do_cleanup(ssh, authctxt);
1.65 markus 347: }
348:
1.282 djm 349: /* Check untrusted xauth strings for metacharacters */
350: static int
351: xauth_valid_string(const char *s)
352: {
353: size_t i;
354:
355: for (i = 0; s[i] != '\0'; i++) {
356: if (!isalnum((u_char)s[i]) &&
357: s[i] != '.' && s[i] != ':' && s[i] != '/' &&
358: s[i] != '-' && s[i] != '_')
359: return 0;
360: }
361: return 1;
362: }
363:
1.269 dtucker 364: #define USE_PIPES 1
1.1 markus 365: /*
366: * This is called to fork and execute a command when we have no tty. This
367: * will call do_child from the child, and server_loop from the parent after
368: * setting up file descriptors and such.
369: */
1.237 djm 370: int
1.292 djm 371: do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 372: {
1.137 mpech 373: pid_t pid;
1.238 markus 374: #ifdef USE_PIPES
375: int pin[2], pout[2], perr[2];
376:
1.253 djm 377: if (s == NULL)
378: fatal("do_exec_no_pty: no session");
379:
1.238 markus 380: /* Allocate pipes for communicating with the program. */
381: if (pipe(pin) < 0) {
382: error("%s: pipe in: %.100s", __func__, strerror(errno));
383: return -1;
384: }
385: if (pipe(pout) < 0) {
386: error("%s: pipe out: %.100s", __func__, strerror(errno));
387: close(pin[0]);
388: close(pin[1]);
389: return -1;
390: }
1.256 djm 391: if (pipe(perr) < 0) {
392: error("%s: pipe err: %.100s", __func__,
393: strerror(errno));
394: close(pin[0]);
395: close(pin[1]);
396: close(pout[0]);
397: close(pout[1]);
398: return -1;
1.238 markus 399: }
400: #else
1.237 djm 401: int inout[2], err[2];
1.1 markus 402:
1.253 djm 403: if (s == NULL)
404: fatal("do_exec_no_pty: no session");
405:
1.1 markus 406: /* Uses socket pairs to communicate with the program. */
1.237 djm 407: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
408: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
409: return -1;
410: }
1.256 djm 411: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
412: error("%s: socketpair #2: %.100s", __func__,
413: strerror(errno));
414: close(inout[0]);
415: close(inout[1]);
416: return -1;
1.237 djm 417: }
1.238 markus 418: #endif
1.237 djm 419:
1.9 markus 420: session_proctitle(s);
1.1 markus 421:
422: /* Fork the child. */
1.237 djm 423: switch ((pid = fork())) {
424: case -1:
425: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 markus 426: #ifdef USE_PIPES
427: close(pin[0]);
428: close(pin[1]);
429: close(pout[0]);
430: close(pout[1]);
1.256 djm 431: close(perr[0]);
1.238 markus 432: close(perr[1]);
433: #else
1.237 djm 434: close(inout[0]);
435: close(inout[1]);
436: close(err[0]);
1.256 djm 437: close(err[1]);
1.238 markus 438: #endif
1.237 djm 439: return -1;
440: case 0:
1.165 markus 441: is_child = 1;
1.144 markus 442:
1.1 markus 443: /*
444: * Create a new session and process group since the 4.4BSD
445: * setlogin() affects the entire process group.
446: */
447: if (setsid() < 0)
448: error("setsid failed: %.100s", strerror(errno));
449:
1.238 markus 450: #ifdef USE_PIPES
451: /*
452: * Redirect stdin. We close the parent side of the socket
453: * pair, and make the child side the standard input.
454: */
455: close(pin[1]);
456: if (dup2(pin[0], 0) < 0)
457: perror("dup2 stdin");
458: close(pin[0]);
459:
460: /* Redirect stdout. */
461: close(pout[0]);
462: if (dup2(pout[1], 1) < 0)
463: perror("dup2 stdout");
464: close(pout[1]);
465:
466: /* Redirect stderr. */
1.256 djm 467: close(perr[0]);
1.238 markus 468: if (dup2(perr[1], 2) < 0)
469: perror("dup2 stderr");
470: close(perr[1]);
471: #else
1.1 markus 472: /*
473: * Redirect stdin, stdout, and stderr. Stdin and stdout will
474: * use the same socket, as some programs (particularly rdist)
475: * seem to depend on it.
476: */
477: close(inout[1]);
1.256 djm 478: close(err[1]);
1.1 markus 479: if (dup2(inout[0], 0) < 0) /* stdin */
480: perror("dup2 stdin");
1.237 djm 481: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 482: perror("dup2 stdout");
1.238 markus 483: close(inout[0]);
1.1 markus 484: if (dup2(err[0], 2) < 0) /* stderr */
485: perror("dup2 stderr");
1.238 markus 486: close(err[0]);
487: #endif
1.1 markus 488:
489: /* Do processing for the child (exec command etc). */
1.292 djm 490: do_child(ssh, s, command);
1.1 markus 491: /* NOTREACHED */
1.237 djm 492: default:
493: break;
1.1 markus 494: }
1.237 djm 495:
1.1 markus 496: s->pid = pid;
1.47 markus 497: /* Set interactive/non-interactive mode. */
1.257 djm 498: packet_set_interactive(s->display != NULL,
499: options.ip_qos_interactive, options.ip_qos_bulk);
1.1 markus 500:
1.238 markus 501: #ifdef USE_PIPES
502: /* We are the parent. Close the child sides of the pipes. */
503: close(pin[0]);
504: close(pout[1]);
505: close(perr[1]);
506:
1.292 djm 507: session_set_fds(ssh, s, pin[1], pout[0], perr[0],
1.283 markus 508: s->is_subsystem, 0);
1.238 markus 509: #else
1.1 markus 510: /* We are the parent. Close the child sides of the socket pairs. */
511: close(inout[0]);
512: close(err[0]);
513:
514: /*
515: * Enter the interactive session. Note: server_loop must be able to
516: * handle the case that fdin and fdout are the same.
517: */
1.283 markus 518: session_set_fds(s, inout[1], inout[1], err[1],
519: s->is_subsystem, 0);
1.238 markus 520: #endif
1.237 djm 521: return 0;
1.1 markus 522: }
523:
524: /*
525: * This is called to fork and execute a command when we have a tty. This
526: * will call do_child from the child, and server_loop from the parent after
527: * setting up file descriptors, controlling tty, updating wtmp, utmp,
528: * lastlog, and other such operations.
529: */
1.237 djm 530: int
1.292 djm 531: do_exec_pty(struct ssh *ssh, Session *s, const char *command)
1.1 markus 532: {
533: int fdout, ptyfd, ttyfd, ptymaster;
534: pid_t pid;
535:
536: if (s == NULL)
537: fatal("do_exec_pty: no session");
538: ptyfd = s->ptyfd;
539: ttyfd = s->ttyfd;
540:
1.237 djm 541: /*
542: * Create another descriptor of the pty master side for use as the
543: * standard input. We could use the original descriptor, but this
544: * simplifies code in server_loop. The descriptor is bidirectional.
545: * Do this before forking (and cleanup in the child) so as to
546: * detect and gracefully fail out-of-fd conditions.
547: */
548: if ((fdout = dup(ptyfd)) < 0) {
549: error("%s: dup #1: %s", __func__, strerror(errno));
550: close(ttyfd);
551: close(ptyfd);
552: return -1;
553: }
554: /* we keep a reference to the pty master */
555: if ((ptymaster = dup(ptyfd)) < 0) {
556: error("%s: dup #2: %s", __func__, strerror(errno));
557: close(ttyfd);
558: close(ptyfd);
559: close(fdout);
560: return -1;
561: }
562:
1.1 markus 563: /* Fork the child. */
1.237 djm 564: switch ((pid = fork())) {
565: case -1:
566: error("%s: fork: %.100s", __func__, strerror(errno));
567: close(fdout);
568: close(ptymaster);
569: close(ttyfd);
570: close(ptyfd);
571: return -1;
572: case 0:
1.165 markus 573: is_child = 1;
1.97 markus 574:
1.237 djm 575: close(fdout);
576: close(ptymaster);
577:
1.1 markus 578: /* Close the master side of the pseudo tty. */
579: close(ptyfd);
580:
581: /* Make the pseudo tty our controlling tty. */
582: pty_make_controlling_tty(&ttyfd, s->tty);
583:
1.103 markus 584: /* Redirect stdin/stdout/stderr from the pseudo tty. */
585: if (dup2(ttyfd, 0) < 0)
586: error("dup2 stdin: %s", strerror(errno));
587: if (dup2(ttyfd, 1) < 0)
588: error("dup2 stdout: %s", strerror(errno));
589: if (dup2(ttyfd, 2) < 0)
590: error("dup2 stderr: %s", strerror(errno));
1.1 markus 591:
592: /* Close the extra descriptor for the pseudo tty. */
593: close(ttyfd);
594:
1.24 markus 595: /* record login, etc. similar to login(1) */
1.292 djm 596: do_login(ssh, s, command);
1.228 djm 597:
1.237 djm 598: /*
599: * Do common processing for the child, such as execing
600: * the command.
601: */
1.292 djm 602: do_child(ssh, s, command);
1.1 markus 603: /* NOTREACHED */
1.237 djm 604: default:
605: break;
1.1 markus 606: }
607: s->pid = pid;
608:
609: /* Parent. Close the slave side of the pseudo tty. */
610: close(ttyfd);
611:
1.237 djm 612: /* Enter interactive session. */
1.1 markus 613: s->ptymaster = ptymaster;
1.257 djm 614: packet_set_interactive(1,
615: options.ip_qos_interactive, options.ip_qos_bulk);
1.292 djm 616: session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
1.237 djm 617: return 0;
1.24 markus 618: }
619:
1.90 markus 620: /*
621: * This is called to fork and execute a command. If another command is
622: * to be forced, execute that instead.
623: */
1.237 djm 624: int
1.292 djm 625: do_exec(struct ssh *ssh, Session *s, const char *command)
1.90 markus 626: {
1.237 djm 627: int ret;
1.280 djm 628: const char *forced = NULL, *tty = NULL;
629: char session_type[1024];
1.237 djm 630:
1.210 dtucker 631: if (options.adm_forced_command) {
632: original_command = command;
633: command = options.adm_forced_command;
1.267 djm 634: forced = "(config)";
1.294 djm 635: } else if (auth_opts->force_command != NULL) {
1.90 markus 636: original_command = command;
1.294 djm 637: command = auth_opts->force_command;
1.267 djm 638: forced = "(key-option)";
639: }
640: if (forced != NULL) {
1.248 djm 641: if (IS_INTERNAL_SFTP(command)) {
642: s->is_subsystem = s->is_subsystem ?
643: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
644: } else if (s->is_subsystem)
1.225 markus 645: s->is_subsystem = SUBSYSTEM_EXT;
1.267 djm 646: snprintf(session_type, sizeof(session_type),
647: "forced-command %s '%.900s'", forced, command);
648: } else if (s->is_subsystem) {
649: snprintf(session_type, sizeof(session_type),
650: "subsystem '%.900s'", s->subsys);
651: } else if (command == NULL) {
652: snprintf(session_type, sizeof(session_type), "shell");
653: } else {
654: /* NB. we don't log unforced commands to preserve privacy */
655: snprintf(session_type, sizeof(session_type), "command");
1.90 markus 656: }
1.163 markus 657:
1.267 djm 658: if (s->ttyfd != -1) {
659: tty = s->tty;
660: if (strncmp(tty, "/dev/", 5) == 0)
661: tty += 5;
662: }
663:
1.280 djm 664: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
1.267 djm 665: session_type,
666: tty == NULL ? "" : " on ",
667: tty == NULL ? "" : tty,
668: s->pw->pw_name,
1.281 djm 669: ssh_remote_ipaddr(ssh),
670: ssh_remote_port(ssh),
1.280 djm 671: s->self);
1.267 djm 672:
1.163 markus 673: #ifdef GSSAPI
674: if (options.gss_authentication) {
675: temporarily_use_uid(s->pw);
676: ssh_gssapi_storecreds();
677: restore_uid();
678: }
679: #endif
1.90 markus 680: if (s->ttyfd != -1)
1.292 djm 681: ret = do_exec_pty(ssh, s, command);
1.90 markus 682: else
1.292 djm 683: ret = do_exec_no_pty(ssh, s, command);
1.90 markus 684:
1.92 markus 685: original_command = NULL;
1.179 dtucker 686:
687: /*
688: * Clear loginmsg: it's the child's responsibility to display
689: * it to the user, otherwise multiple sessions may accumulate
690: * multiple copies of the login messages.
691: */
692: buffer_clear(&loginmsg);
1.237 djm 693:
694: return ret;
1.90 markus 695: }
696:
697:
1.24 markus 698: /* administrative, login(1)-like work */
699: void
1.292 djm 700: do_login(struct ssh *ssh, Session *s, const char *command)
1.24 markus 701: {
702: socklen_t fromlen;
703: struct sockaddr_storage from;
704: struct passwd * pw = s->pw;
705: pid_t pid = getpid();
706:
707: /*
708: * Get IP address of client. If the connection is not a socket, let
709: * the address be 0.0.0.0.
710: */
711: memset(&from, 0, sizeof(from));
1.148 stevesk 712: fromlen = sizeof(from);
1.24 markus 713: if (packet_connection_is_on_socket()) {
714: if (getpeername(packet_get_connection_in(),
1.200 deraadt 715: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 716: debug("getpeername: %.100s", strerror(errno));
1.165 markus 717: cleanup_exit(255);
1.24 markus 718: }
719: }
1.25 markus 720:
1.24 markus 721: /* Record that there was a login on that tty from the remote host. */
1.133 markus 722: if (!use_privsep)
723: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.281 djm 724: session_get_remote_name_or_ip(ssh, utmp_len,
1.158 markus 725: options.use_dns),
1.148 stevesk 726: (struct sockaddr *)&from, fromlen);
1.24 markus 727:
1.73 djm 728: if (check_quietlogin(s, command))
1.24 markus 729: return;
1.73 djm 730:
1.179 dtucker 731: display_loginmsg();
1.73 djm 732:
733: do_motd();
734: }
735:
736: /*
737: * Display the message of the day.
738: */
739: void
740: do_motd(void)
741: {
742: FILE *f;
743: char buf[256];
744:
1.24 markus 745: if (options.print_motd) {
1.28 millert 746: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
747: "/etc/motd"), "r");
1.24 markus 748: if (f) {
749: while (fgets(buf, sizeof(buf), f))
750: fputs(buf, stdout);
751: fclose(f);
752: }
1.2 markus 753: }
1.73 djm 754: }
755:
756:
757: /*
758: * Check for quiet login, either .hushlogin or command given.
759: */
760: int
761: check_quietlogin(Session *s, const char *command)
762: {
763: char buf[256];
1.96 dugsong 764: struct passwd *pw = s->pw;
1.73 djm 765: struct stat st;
766:
767: /* Return 1 if .hushlogin exists or a command given. */
768: if (command != NULL)
769: return 1;
770: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
771: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
772: return 1;
773: return 0;
1.1 markus 774: }
775:
776: /*
777: * Reads environment variables from the given file and adds/overrides them
778: * into the environment. If the file does not exist, this does nothing.
779: * Otherwise, it must consist of empty lines, comments (line starts with '#')
780: * and assignments of the form name=value. No other forms are allowed.
781: */
1.94 itojun 782: static void
1.45 markus 783: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 784: const char *filename)
1.1 markus 785: {
786: FILE *f;
1.298 markus 787: char *line = NULL, *cp, *value;
788: size_t linesize = 0;
1.142 deraadt 789: u_int lineno = 0;
1.1 markus 790:
791: f = fopen(filename, "r");
792: if (!f)
793: return;
794:
1.298 markus 795: while (getline(&line, &linesize, f) != -1) {
1.142 deraadt 796: if (++lineno > 1000)
797: fatal("Too many lines in environment file %s", filename);
1.298 markus 798: for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
1.1 markus 799: ;
800: if (!*cp || *cp == '#' || *cp == '\n')
801: continue;
1.224 gilles 802:
803: cp[strcspn(cp, "\n")] = '\0';
804:
1.1 markus 805: value = strchr(cp, '=');
806: if (value == NULL) {
1.142 deraadt 807: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
808: filename);
1.1 markus 809: continue;
810: }
1.14 deraadt 811: /*
812: * Replace the equals sign by nul, and advance value to
813: * the value string.
814: */
1.1 markus 815: *value = '\0';
816: value++;
817: child_set_env(env, envsize, cp, value);
818: }
1.298 markus 819: free(line);
1.1 markus 820: fclose(f);
821: }
822:
1.127 markus 823: static char **
1.292 djm 824: do_setup_env(struct ssh *ssh, Session *s, const char *shell)
1.1 markus 825: {
826: char buf[256];
1.294 djm 827: size_t n;
1.127 markus 828: u_int i, envsize;
1.300 ! djm 829: char *ocp, *cp, *value, **env, *laddr;
1.127 markus 830: struct passwd *pw = s->pw;
1.1 markus 831:
832: /* Initialize the environment. */
833: envsize = 100;
1.220 djm 834: env = xcalloc(envsize, sizeof(char *));
1.1 markus 835: env[0] = NULL;
836:
1.161 markus 837: #ifdef GSSAPI
1.168 djm 838: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 839: * the childs environment as they see fit
840: */
841: ssh_gssapi_do_child(&env, &envsize);
842: #endif
843:
1.284 djm 844: /* Set basic environment. */
845: for (i = 0; i < s->num_env; i++)
846: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
847:
848: child_set_env(&env, &envsize, "USER", pw->pw_name);
849: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
850: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
851: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
852: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
853: else
854: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
855:
856: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
857: child_set_env(&env, &envsize, "MAIL", buf);
858:
859: /* Normal systems set SHELL by default. */
860: child_set_env(&env, &envsize, "SHELL", shell);
1.1 markus 861:
862: if (getenv("TZ"))
863: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1.299 djm 864: if (s->term)
865: child_set_env(&env, &envsize, "TERM", s->term);
866: if (s->display)
867: child_set_env(&env, &envsize, "DISPLAY", s->display);
868: #ifdef KRB5
869: if (s->authctxt->krb5_ticket_file)
870: child_set_env(&env, &envsize, "KRB5CCNAME",
871: s->authctxt->krb5_ticket_file);
872: #endif
873: if (auth_sock_name != NULL)
874: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
875: auth_sock_name);
876:
1.1 markus 877:
1.294 djm 878: /* Set custom environment options from pubkey authentication. */
879: if (options.permit_user_env) {
880: for (n = 0 ; n < auth_opts->nenv; n++) {
881: ocp = xstrdup(auth_opts->env[n]);
882: cp = strchr(ocp, '=');
883: if (*cp == '=') {
884: *cp = '\0';
885: child_set_env(&env, &envsize, ocp, cp + 1);
886: }
887: free(ocp);
888: }
1.1 markus 889: }
890:
1.299 djm 891: /* read $HOME/.ssh/environment. */
892: if (options.permit_user_env) {
893: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
894: pw->pw_dir);
895: read_environment_file(&env, &envsize, buf);
1.300 ! djm 896: }
! 897:
! 898: /* Environment specified by admin */
! 899: for (i = 0; i < options.num_setenv; i++) {
! 900: cp = xstrdup(options.setenv[i]);
! 901: if ((value = strchr(cp, '=')) == NULL) {
! 902: /* shouldn't happen; vars are checked in servconf.c */
! 903: fatal("Invalid config SetEnv: %s", options.setenv[i]);
! 904: }
! 905: *value++ = '\0';
! 906: child_set_env(&env, &envsize, cp, value);
1.299 djm 907: }
908:
1.149 stevesk 909: /* SSH_CLIENT deprecated */
1.1 markus 910: snprintf(buf, sizeof buf, "%.50s %d %d",
1.281 djm 911: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
912: ssh_local_port(ssh));
1.1 markus 913: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 914:
1.154 markus 915: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 916: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.281 djm 917: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
918: laddr, ssh_local_port(ssh));
1.265 djm 919: free(laddr);
1.149 stevesk 920: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 921:
1.293 djm 922: if (tun_fwd_ifnames != NULL)
923: child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
1.290 djm 924: if (auth_info_file != NULL)
925: child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
1.60 markus 926: if (s->ttyfd != -1)
927: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1.34 markus 928: if (original_command)
929: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
930: original_command);
1.1 markus 931:
932: if (debug_flag) {
933: /* dump the environment */
934: fprintf(stderr, "Environment:\n");
935: for (i = 0; env[i]; i++)
936: fprintf(stderr, " %.200s\n", env[i]);
937: }
1.127 markus 938: return env;
939: }
940:
941: /*
942: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
943: * first in this order).
944: */
945: static void
1.294 djm 946: do_rc_files(struct ssh *ssh, Session *s, const char *shell)
1.127 markus 947: {
948: FILE *f = NULL;
949: char cmd[1024];
950: int do_xauth;
951: struct stat st;
952:
953: do_xauth =
954: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
955:
1.231 djm 956: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 957: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.294 djm 958: auth_opts->permit_user_rc && options.permit_user_rc &&
1.273 djm 959: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 960: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
961: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
962: if (debug_flag)
963: fprintf(stderr, "Running %s\n", cmd);
964: f = popen(cmd, "w");
965: if (f) {
966: if (do_xauth)
967: fprintf(f, "%s %s\n", s->auth_proto,
968: s->auth_data);
969: pclose(f);
970: } else
971: fprintf(stderr, "Could not run %s\n",
972: _PATH_SSH_USER_RC);
973: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
974: if (debug_flag)
975: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
976: _PATH_SSH_SYSTEM_RC);
977: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
978: if (f) {
979: if (do_xauth)
980: fprintf(f, "%s %s\n", s->auth_proto,
981: s->auth_data);
982: pclose(f);
983: } else
984: fprintf(stderr, "Could not run %s\n",
985: _PATH_SSH_SYSTEM_RC);
986: } else if (do_xauth && options.xauth_location != NULL) {
987: /* Add authority data to .Xauthority if appropriate. */
988: if (debug_flag) {
989: fprintf(stderr,
1.151 stevesk 990: "Running %.500s remove %.100s\n",
1.165 markus 991: options.xauth_location, s->auth_display);
1.151 stevesk 992: fprintf(stderr,
993: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 994: options.xauth_location, s->auth_display,
995: s->auth_proto, s->auth_data);
996: }
997: snprintf(cmd, sizeof cmd, "%s -q -",
998: options.xauth_location);
999: f = popen(cmd, "w");
1000: if (f) {
1.151 stevesk 1001: fprintf(f, "remove %s\n",
1002: s->auth_display);
1.127 markus 1003: fprintf(f, "add %s %s %s\n",
1004: s->auth_display, s->auth_proto,
1005: s->auth_data);
1006: pclose(f);
1007: } else {
1008: fprintf(stderr, "Could not run %s\n",
1009: cmd);
1010: }
1011: }
1012: }
1013:
1014: static void
1015: do_nologin(struct passwd *pw)
1016: {
1017: FILE *f = NULL;
1.251 dtucker 1018: char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
1019: struct stat sb;
1.127 markus 1020:
1.260 guenther 1021: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.251 dtucker 1022: return;
1023: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
1024:
1025: if (stat(nl, &sb) == -1) {
1026: if (nl != def_nl)
1.265 djm 1027: free(nl);
1.251 dtucker 1028: return;
1029: }
1030:
1031: /* /etc/nologin exists. Print its contents if we can and exit. */
1032: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1033: if ((f = fopen(nl, "r")) != NULL) {
1.127 markus 1034: while (fgets(buf, sizeof(buf), f))
1035: fputs(buf, stderr);
1036: fclose(f);
1037: }
1.251 dtucker 1038: exit(254);
1.127 markus 1039: }
1040:
1.226 djm 1041: /*
1042: * Chroot into a directory after checking it for safety: all path components
1043: * must be root-owned directories with strict permissions.
1044: */
1045: static void
1046: safely_chroot(const char *path, uid_t uid)
1047: {
1048: const char *cp;
1.277 deraadt 1049: char component[PATH_MAX];
1.226 djm 1050: struct stat st;
1051:
1052: if (*path != '/')
1053: fatal("chroot path does not begin at root");
1054: if (strlen(path) >= sizeof(component))
1055: fatal("chroot path too long");
1056:
1057: /*
1058: * Descend the path, checking that each component is a
1059: * root-owned directory with strict permissions.
1060: */
1061: for (cp = path; cp != NULL;) {
1062: if ((cp = strchr(cp, '/')) == NULL)
1063: strlcpy(component, path, sizeof(component));
1064: else {
1065: cp++;
1066: memcpy(component, path, cp - path);
1067: component[cp - path] = '\0';
1068: }
1069:
1070: debug3("%s: checking '%s'", __func__, component);
1071:
1072: if (stat(component, &st) != 0)
1073: fatal("%s: stat(\"%s\"): %s", __func__,
1074: component, strerror(errno));
1075: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1076: fatal("bad ownership or modes for chroot "
1077: "directory %s\"%s\"",
1078: cp == NULL ? "" : "component ", component);
1079: if (!S_ISDIR(st.st_mode))
1080: fatal("chroot path %s\"%s\" is not a directory",
1081: cp == NULL ? "" : "component ", component);
1082:
1083: }
1084:
1085: if (chdir(path) == -1)
1086: fatal("Unable to chdir to chroot path \"%s\": "
1087: "%s", path, strerror(errno));
1088: if (chroot(path) == -1)
1089: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1090: if (chdir("/") == -1)
1091: fatal("%s: chdir(/) after chroot: %s",
1092: __func__, strerror(errno));
1093: verbose("Changed root directory to \"%s\"", path);
1094: }
1095:
1.127 markus 1096: /* Set login name, uid, gid, and groups. */
1.130 provos 1097: void
1.127 markus 1098: do_setusercontext(struct passwd *pw)
1099: {
1.295 djm 1100: char uidstr[32], *chroot_path, *tmp;
1.227 djm 1101:
1.127 markus 1102: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1103: /* Prepare groups */
1.127 markus 1104: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1105: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1106: perror("unable to set user context");
1107: exit(1);
1108: }
1.226 djm 1109:
1.279 djm 1110: if (!in_chroot && options.chroot_directory != NULL &&
1.226 djm 1111: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1112: tmp = tilde_expand_filename(options.chroot_directory,
1113: pw->pw_uid);
1.295 djm 1114: snprintf(uidstr, sizeof(uidstr), "%llu",
1115: (unsigned long long)pw->pw_uid);
1.227 djm 1116: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1.295 djm 1117: "u", pw->pw_name, "U", uidstr, (char *)NULL);
1.226 djm 1118: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1119: free(tmp);
1.226 djm 1120: free(chroot_path);
1.264 djm 1121: /* Make sure we don't attempt to chroot again */
1122: free(options.chroot_directory);
1123: options.chroot_directory = NULL;
1.279 djm 1124: in_chroot = 1;
1.226 djm 1125: }
1126:
1127: /* Set UID */
1128: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1129: perror("unable to set user context (setuser)");
1130: exit(1);
1131: }
1.264 djm 1132: } else if (options.chroot_directory != NULL &&
1133: strcasecmp(options.chroot_directory, "none") != 0) {
1134: fatal("server lacks privileges to chroot to ChrootDirectory");
1.263 dtucker 1135: }
1.264 djm 1136:
1.127 markus 1137: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1138: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1139: }
1140:
1.131 markus 1141: static void
1.172 markus 1142: do_pwchange(Session *s)
1143: {
1.179 dtucker 1144: fflush(NULL);
1.172 markus 1145: fprintf(stderr, "WARNING: Your password has expired.\n");
1146: if (s->ttyfd != -1) {
1.178 deraadt 1147: fprintf(stderr,
1.172 markus 1148: "You must change your password now and login again!\n");
1149: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1150: perror("passwd");
1151: } else {
1152: fprintf(stderr,
1153: "Password change required but no TTY available.\n");
1154: }
1155: exit(1);
1156: }
1157:
1158: static void
1.292 djm 1159: child_close_fds(struct ssh *ssh)
1.172 markus 1160: {
1.276 djm 1161: extern int auth_sock;
1.266 markus 1162:
1.276 djm 1163: if (auth_sock != -1) {
1164: close(auth_sock);
1165: auth_sock = -1;
1.266 markus 1166: }
1167:
1.172 markus 1168: if (packet_get_connection_in() == packet_get_connection_out())
1169: close(packet_get_connection_in());
1170: else {
1171: close(packet_get_connection_in());
1172: close(packet_get_connection_out());
1173: }
1174: /*
1175: * Close all descriptors related to channels. They will still remain
1176: * open in the parent.
1177: */
1178: /* XXX better use close-on-exec? -markus */
1.292 djm 1179: channel_close_all(ssh);
1.172 markus 1180:
1181: /*
1182: * Close any extra file descriptors. Note that there may still be
1183: * descriptors left by system functions. They will be closed later.
1184: */
1185: endpwent();
1186:
1187: /*
1.188 djm 1188: * Close any extra open file descriptors so that we don't have them
1.172 markus 1189: * hanging around in clients. Note that we want to do this after
1190: * initgroups, because at least on Solaris 2.3 it leaves file
1191: * descriptors open.
1192: */
1.258 djm 1193: closefrom(STDERR_FILENO + 1);
1.172 markus 1194: }
1195:
1.127 markus 1196: /*
1197: * Performs common processing for the child, such as setting up the
1198: * environment, closing extra file descriptors, setting the user and group
1199: * ids, and executing the command or shell.
1200: */
1.225 markus 1201: #define ARGV_MAX 10
1.127 markus 1202: void
1.292 djm 1203: do_child(struct ssh *ssh, Session *s, const char *command)
1.127 markus 1204: {
1205: extern char **environ;
1206: char **env;
1.225 markus 1207: char *argv[ARGV_MAX];
1.284 djm 1208: const char *shell, *shell0;
1.127 markus 1209: struct passwd *pw = s->pw;
1.239 djm 1210: int r = 0;
1.127 markus 1211:
1212: /* remove hostkey from the child's memory */
1213: destroy_sensitive_data();
1.287 markus 1214: packet_clear_keys();
1.127 markus 1215:
1.172 markus 1216: /* Force a password change */
1217: if (s->authctxt->force_pwchange) {
1218: do_setusercontext(pw);
1.292 djm 1219: child_close_fds(ssh);
1.172 markus 1220: do_pwchange(s);
1221: exit(1);
1222: }
1223:
1.127 markus 1224: /*
1225: * Login(1) does this as well, and it needs uid 0 for the "-h"
1226: * switch, so we let login(1) to this for us.
1227: */
1.284 djm 1228: do_nologin(pw);
1229: do_setusercontext(pw);
1.127 markus 1230:
1231: /*
1232: * Get the shell from the password data. An empty shell field is
1233: * legal, and means /bin/sh.
1234: */
1235: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1236:
1237: /*
1238: * Make sure $SHELL points to the shell from the password file,
1239: * even if shell is overridden from login.conf
1240: */
1.292 djm 1241: env = do_setup_env(ssh, s, shell);
1.152 markus 1242:
1.127 markus 1243: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1244:
1.1 markus 1245: /*
1246: * Close the connection descriptors; note that this is the child, and
1247: * the server will still have the socket open, and it is important
1248: * that we do not shutdown it. Note that the descriptors cannot be
1249: * closed before building the environment, as we call
1.281 djm 1250: * ssh_remote_ipaddr there.
1.1 markus 1251: */
1.292 djm 1252: child_close_fds(ssh);
1.1 markus 1253:
1254: /*
1.125 deraadt 1255: * Must take new environment into use so that .ssh/rc,
1256: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1257: */
1258: environ = env;
1.170 jakob 1259:
1260: #ifdef KRB5
1261: /*
1262: * At this point, we check to see if AFS is active and if we have
1263: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1264: * if we can (and need to) extend the ticket into an AFS token. If
1265: * we don't do this, we run into potential problems if the user's
1266: * home directory is in AFS and it's not world-readable.
1267: */
1268:
1269: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1270: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1271: char cell[64];
1272:
1273: debug("Getting AFS token");
1274:
1275: k_setpag();
1276:
1277: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1278: krb5_afslog(s->authctxt->krb5_ctx,
1279: s->authctxt->krb5_fwd_ccache, cell, NULL);
1280:
1281: krb5_afslog_home(s->authctxt->krb5_ctx,
1282: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1283: }
1284: #endif
1.104 markus 1285:
1.188 djm 1286: /* Change current directory to the user's home directory. */
1.104 markus 1287: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1288: /* Suppress missing homedir warning for chroot case */
1289: r = login_getcapbool(lc, "requirehome", 0);
1.279 djm 1290: if (r || !in_chroot) {
1.239 djm 1291: fprintf(stderr, "Could not chdir to home "
1292: "directory %s: %s\n", pw->pw_dir,
1293: strerror(errno));
1.279 djm 1294: }
1.239 djm 1295: if (r)
1.104 markus 1296: exit(1);
1297: }
1.230 djm 1298:
1299: closefrom(STDERR_FILENO + 1);
1.1 markus 1300:
1.294 djm 1301: do_rc_files(ssh, s, shell);
1.67 markus 1302:
1303: /* restore SIGPIPE for child */
1.217 stevesk 1304: signal(SIGPIPE, SIG_DFL);
1.67 markus 1305:
1.248 djm 1306: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1307: printf("This service allows sftp connections only.\n");
1308: fflush(NULL);
1309: exit(1);
1310: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.225 markus 1311: extern int optind, optreset;
1312: int i;
1313: char *p, *args;
1314:
1.246 stevesk 1315: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1316: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1317: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1318: if (i < ARGV_MAX - 1)
1319: argv[i++] = p;
1320: argv[i] = NULL;
1321: optind = optreset = 1;
1322: __progname = argv[0];
1.226 djm 1323: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1324: }
1.247 djm 1325:
1326: fflush(NULL);
1.225 markus 1327:
1.127 markus 1328: /* Get the last component of the shell name. */
1329: if ((shell0 = strrchr(shell, '/')) != NULL)
1330: shell0++;
1331: else
1332: shell0 = shell;
1333:
1.1 markus 1334: /*
1335: * If we have no command, execute the shell. In this case, the shell
1336: * name to be passed in argv[0] is preceded by '-' to indicate that
1337: * this is a login shell.
1338: */
1339: if (!command) {
1.127 markus 1340: char argv0[256];
1.1 markus 1341:
1.127 markus 1342: /* Start the shell. Set initial character to '-'. */
1343: argv0[0] = '-';
1.1 markus 1344:
1.127 markus 1345: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1346: >= sizeof(argv0) - 1) {
1.127 markus 1347: errno = EINVAL;
1.1 markus 1348: perror(shell);
1349: exit(1);
1.127 markus 1350: }
1.1 markus 1351:
1.127 markus 1352: /* Execute the shell. */
1353: argv[0] = argv0;
1354: argv[1] = NULL;
1355: execve(shell, argv, env);
1356:
1357: /* Executing the shell failed. */
1358: perror(shell);
1359: exit(1);
1.1 markus 1360: }
1361: /*
1362: * Execute the command using the user's shell. This uses the -c
1363: * option to execute the command.
1364: */
1.127 markus 1365: argv[0] = (char *) shell0;
1.1 markus 1366: argv[1] = "-c";
1367: argv[2] = (char *) command;
1368: argv[3] = NULL;
1369: execve(shell, argv, env);
1370: perror(shell);
1371: exit(1);
1372: }
1373:
1.237 djm 1374: void
1375: session_unused(int id)
1376: {
1377: debug3("%s: session id %d unused", __func__, id);
1378: if (id >= options.max_sessions ||
1379: id >= sessions_nalloc) {
1380: fatal("%s: insane session id %d (max %d nalloc %d)",
1381: __func__, id, options.max_sessions, sessions_nalloc);
1382: }
1.270 tedu 1383: memset(&sessions[id], 0, sizeof(*sessions));
1.237 djm 1384: sessions[id].self = id;
1385: sessions[id].used = 0;
1386: sessions[id].chanid = -1;
1387: sessions[id].ptyfd = -1;
1388: sessions[id].ttyfd = -1;
1389: sessions[id].ptymaster = -1;
1390: sessions[id].x11_chanids = NULL;
1391: sessions[id].next_unused = sessions_first_unused;
1392: sessions_first_unused = id;
1393: }
1394:
1.1 markus 1395: Session *
1396: session_new(void)
1397: {
1.237 djm 1398: Session *s, *tmp;
1399:
1400: if (sessions_first_unused == -1) {
1401: if (sessions_nalloc >= options.max_sessions)
1402: return NULL;
1403: debug2("%s: allocate (allocated %d max %d)",
1404: __func__, sessions_nalloc, options.max_sessions);
1.288 deraadt 1405: tmp = xrecallocarray(sessions, sessions_nalloc,
1406: sessions_nalloc + 1, sizeof(*sessions));
1.237 djm 1407: if (tmp == NULL) {
1408: error("%s: cannot allocate %d sessions",
1409: __func__, sessions_nalloc + 1);
1410: return NULL;
1411: }
1412: sessions = tmp;
1413: session_unused(sessions_nalloc++);
1414: }
1415:
1416: if (sessions_first_unused >= sessions_nalloc ||
1417: sessions_first_unused < 0) {
1418: fatal("%s: insane first_unused %d max %d nalloc %d",
1419: __func__, sessions_first_unused, options.max_sessions,
1420: sessions_nalloc);
1421: }
1422:
1423: s = &sessions[sessions_first_unused];
1424: if (s->used) {
1425: fatal("%s: session %d already used",
1426: __func__, sessions_first_unused);
1427: }
1428: sessions_first_unused = s->next_unused;
1429: s->used = 1;
1430: s->next_unused = -1;
1431: debug("session_new: session %d", s->self);
1432:
1433: return s;
1.1 markus 1434: }
1435:
1.94 itojun 1436: static void
1.1 markus 1437: session_dump(void)
1438: {
1439: int i;
1.237 djm 1440: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1441: Session *s = &sessions[i];
1.237 djm 1442:
1443: debug("dump: used %d next_unused %d session %d %p "
1444: "channel %d pid %ld",
1.1 markus 1445: s->used,
1.237 djm 1446: s->next_unused,
1.1 markus 1447: s->self,
1448: s,
1449: s->chanid,
1.137 mpech 1450: (long)s->pid);
1.1 markus 1451: }
1452: }
1453:
1.2 markus 1454: int
1.97 markus 1455: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1456: {
1457: Session *s = session_new();
1458: debug("session_open: channel %d", chanid);
1459: if (s == NULL) {
1460: error("no more sessions");
1461: return 0;
1462: }
1.97 markus 1463: s->authctxt = authctxt;
1464: s->pw = authctxt->pw;
1.167 djm 1465: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1466: fatal("no user for session %d", s->self);
1.2 markus 1467: debug("session_open: session %d: link with channel %d", s->self, chanid);
1468: s->chanid = chanid;
1469: return 1;
1470: }
1471:
1.130 provos 1472: Session *
1473: session_by_tty(char *tty)
1474: {
1475: int i;
1.237 djm 1476: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1477: Session *s = &sessions[i];
1478: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1479: debug("session_by_tty: session %d tty %s", i, tty);
1480: return s;
1481: }
1482: }
1483: debug("session_by_tty: unknown tty %.100s", tty);
1484: session_dump();
1485: return NULL;
1486: }
1487:
1.94 itojun 1488: static Session *
1.2 markus 1489: session_by_channel(int id)
1490: {
1491: int i;
1.237 djm 1492: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1493: Session *s = &sessions[i];
1494: if (s->used && s->chanid == id) {
1.237 djm 1495: debug("session_by_channel: session %d channel %d",
1496: i, id);
1.2 markus 1497: return s;
1498: }
1499: }
1500: debug("session_by_channel: unknown channel %d", id);
1501: session_dump();
1502: return NULL;
1503: }
1504:
1.94 itojun 1505: static Session *
1.184 djm 1506: session_by_x11_channel(int id)
1507: {
1508: int i, j;
1509:
1.237 djm 1510: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1511: Session *s = &sessions[i];
1512:
1513: if (s->x11_chanids == NULL || !s->used)
1514: continue;
1515: for (j = 0; s->x11_chanids[j] != -1; j++) {
1516: if (s->x11_chanids[j] == id) {
1517: debug("session_by_x11_channel: session %d "
1518: "channel %d", s->self, id);
1519: return s;
1520: }
1521: }
1522: }
1523: debug("session_by_x11_channel: unknown channel %d", id);
1524: session_dump();
1525: return NULL;
1526: }
1527:
1528: static Session *
1.2 markus 1529: session_by_pid(pid_t pid)
1530: {
1531: int i;
1.137 mpech 1532: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1533: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1534: Session *s = &sessions[i];
1535: if (s->used && s->pid == pid)
1536: return s;
1537: }
1.137 mpech 1538: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1539: session_dump();
1540: return NULL;
1541: }
1542:
1.94 itojun 1543: static int
1.292 djm 1544: session_window_change_req(struct ssh *ssh, Session *s)
1.2 markus 1545: {
1546: s->col = packet_get_int();
1547: s->row = packet_get_int();
1548: s->xpixel = packet_get_int();
1549: s->ypixel = packet_get_int();
1.116 markus 1550: packet_check_eom();
1.2 markus 1551: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1552: return 1;
1553: }
1554:
1.94 itojun 1555: static int
1.292 djm 1556: session_pty_req(struct ssh *ssh, Session *s)
1.2 markus 1557: {
1.45 markus 1558: u_int len;
1.72 stevesk 1559: int n_bytes;
1.132 markus 1560:
1.294 djm 1561: if (!auth_opts->permit_pty_flag || !options.permit_tty) {
1562: debug("Allocating a pty not permitted for this connection.");
1.19 markus 1563: return 0;
1.86 markus 1564: }
1565: if (s->ttyfd != -1) {
1566: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1567: return 0;
1.86 markus 1568: }
1569:
1.2 markus 1570: s->term = packet_get_string(&len);
1.283 markus 1571: s->col = packet_get_int();
1572: s->row = packet_get_int();
1.2 markus 1573: s->xpixel = packet_get_int();
1574: s->ypixel = packet_get_int();
1575:
1576: if (strcmp(s->term, "") == 0) {
1.265 djm 1577: free(s->term);
1.2 markus 1578: s->term = NULL;
1579: }
1.86 markus 1580:
1.2 markus 1581: /* Allocate a pty and open it. */
1.86 markus 1582: debug("Allocating pty.");
1.237 djm 1583: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1584: sizeof(s->tty)))) {
1.265 djm 1585: free(s->term);
1.2 markus 1586: s->term = NULL;
1587: s->ptyfd = -1;
1588: s->ttyfd = -1;
1589: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1590: return 0;
1.2 markus 1591: }
1592: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1593:
1.283 markus 1594: n_bytes = packet_remaining();
1.86 markus 1595: tty_parse_modes(s->ttyfd, &n_bytes);
1596:
1.130 provos 1597: if (!use_privsep)
1598: pty_setowner(s->pw, s->tty);
1.86 markus 1599:
1600: /* Set window size from the packet. */
1.2 markus 1601: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1602:
1.116 markus 1603: packet_check_eom();
1.9 markus 1604: session_proctitle(s);
1.2 markus 1605: return 1;
1606: }
1607:
1.94 itojun 1608: static int
1.292 djm 1609: session_subsystem_req(struct ssh *ssh, Session *s)
1.7 markus 1610: {
1.105 markus 1611: struct stat st;
1.45 markus 1612: u_int len;
1.7 markus 1613: int success = 0;
1.267 djm 1614: char *prog, *cmd;
1.182 djm 1615: u_int i;
1.7 markus 1616:
1.267 djm 1617: s->subsys = packet_get_string(&len);
1.116 markus 1618: packet_check_eom();
1.267 djm 1619: debug2("subsystem request for %.100s by user %s", s->subsys,
1.255 djm 1620: s->pw->pw_name);
1.18 jakob 1621:
1622: for (i = 0; i < options.num_subsystems; i++) {
1.267 djm 1623: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1624: prog = options.subsystem_command[i];
1625: cmd = options.subsystem_args[i];
1.249 dtucker 1626: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.225 markus 1627: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.249 dtucker 1628: debug("subsystem: %s", prog);
1.225 markus 1629: } else {
1.249 dtucker 1630: if (stat(prog, &st) < 0)
1631: debug("subsystem: cannot stat %s: %s",
1632: prog, strerror(errno));
1.225 markus 1633: s->is_subsystem = SUBSYSTEM_EXT;
1.249 dtucker 1634: debug("subsystem: exec() %s", cmd);
1.105 markus 1635: }
1.292 djm 1636: success = do_exec(ssh, s, cmd) == 0;
1.122 markus 1637: break;
1.18 jakob 1638: }
1639: }
1640:
1641: if (!success)
1.267 djm 1642: logit("subsystem request for %.100s by user %s failed, "
1643: "subsystem not found", s->subsys, s->pw->pw_name);
1.7 markus 1644:
1645: return success;
1646: }
1647:
1.94 itojun 1648: static int
1.292 djm 1649: session_x11_req(struct ssh *ssh, Session *s)
1.7 markus 1650: {
1.81 markus 1651: int success;
1.7 markus 1652:
1.184 djm 1653: if (s->auth_proto != NULL || s->auth_data != NULL) {
1654: error("session_x11_req: session %d: "
1.190 stevesk 1655: "x11 forwarding already active", s->self);
1.184 djm 1656: return 0;
1657: }
1.7 markus 1658: s->single_connection = packet_get_char();
1659: s->auth_proto = packet_get_string(NULL);
1660: s->auth_data = packet_get_string(NULL);
1661: s->screen = packet_get_int();
1.116 markus 1662: packet_check_eom();
1.7 markus 1663:
1.282 djm 1664: if (xauth_valid_string(s->auth_proto) &&
1665: xauth_valid_string(s->auth_data))
1.292 djm 1666: success = session_setup_x11fwd(ssh, s);
1.282 djm 1667: else {
1668: success = 0;
1669: error("Invalid X11 forwarding data");
1670: }
1.81 markus 1671: if (!success) {
1.265 djm 1672: free(s->auth_proto);
1673: free(s->auth_data);
1.84 markus 1674: s->auth_proto = NULL;
1675: s->auth_data = NULL;
1.7 markus 1676: }
1.81 markus 1677: return success;
1.7 markus 1678: }
1679:
1.94 itojun 1680: static int
1.292 djm 1681: session_shell_req(struct ssh *ssh, Session *s)
1.19 markus 1682: {
1.116 markus 1683: packet_check_eom();
1.292 djm 1684: return do_exec(ssh, s, NULL) == 0;
1.19 markus 1685: }
1686:
1.94 itojun 1687: static int
1.292 djm 1688: session_exec_req(struct ssh *ssh, Session *s)
1.19 markus 1689: {
1.237 djm 1690: u_int len, success;
1691:
1.19 markus 1692: char *command = packet_get_string(&len);
1.116 markus 1693: packet_check_eom();
1.292 djm 1694: success = do_exec(ssh, s, command) == 0;
1.265 djm 1695: free(command);
1.237 djm 1696: return success;
1.19 markus 1697: }
1698:
1.94 itojun 1699: static int
1.292 djm 1700: session_break_req(struct ssh *ssh, Session *s)
1.157 markus 1701: {
1702:
1.175 deraadt 1703: packet_get_int(); /* ignored */
1.157 markus 1704: packet_check_eom();
1705:
1.259 djm 1706: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.157 markus 1707: return 0;
1708: return 1;
1709: }
1710:
1711: static int
1.292 djm 1712: session_env_req(struct ssh *ssh, Session *s)
1.173 djm 1713: {
1714: char *name, *val;
1715: u_int name_len, val_len, i;
1716:
1.271 djm 1717: name = packet_get_cstring(&name_len);
1718: val = packet_get_cstring(&val_len);
1.173 djm 1719: packet_check_eom();
1720:
1721: /* Don't set too many environment variables */
1722: if (s->num_env > 128) {
1723: debug2("Ignoring env request %s: too many env vars", name);
1724: goto fail;
1725: }
1726:
1727: for (i = 0; i < options.num_accept_env; i++) {
1728: if (match_pattern(name, options.accept_env[i])) {
1729: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.288 deraadt 1730: s->env = xrecallocarray(s->env, s->num_env,
1731: s->num_env + 1, sizeof(*s->env));
1.173 djm 1732: s->env[s->num_env].name = name;
1733: s->env[s->num_env].val = val;
1734: s->num_env++;
1735: return (1);
1736: }
1737: }
1738: debug2("Ignoring env request %s: disallowed name", name);
1739:
1740: fail:
1.265 djm 1741: free(name);
1742: free(val);
1.173 djm 1743: return (0);
1744: }
1745:
1746: static int
1.292 djm 1747: session_auth_agent_req(struct ssh *ssh, Session *s)
1.43 markus 1748: {
1749: static int called = 0;
1.294 djm 1750:
1.116 markus 1751: packet_check_eom();
1.294 djm 1752: if (!auth_opts->permit_agent_forwarding_flag ||
1753: !options.allow_agent_forwarding) {
1754: debug("%s: agent forwarding disabled", __func__);
1.44 markus 1755: return 0;
1756: }
1.43 markus 1757: if (called) {
1758: return 0;
1759: } else {
1760: called = 1;
1.292 djm 1761: return auth_input_request_forwarding(ssh, s->pw);
1.43 markus 1762: }
1763: }
1764:
1.123 markus 1765: int
1.292 djm 1766: session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
1.2 markus 1767: {
1768: int success = 0;
1769: Session *s;
1770:
1.123 markus 1771: if ((s = session_by_channel(c->self)) == NULL) {
1.292 djm 1772: logit("%s: no session %d req %.100s", __func__, c->self, rtype);
1.123 markus 1773: return 0;
1774: }
1.292 djm 1775: debug("%s: session %d req %s", __func__, s->self, rtype);
1.2 markus 1776:
1777: /*
1.64 markus 1778: * a session is in LARVAL state until a shell, a command
1779: * or a subsystem is executed
1.2 markus 1780: */
1781: if (c->type == SSH_CHANNEL_LARVAL) {
1782: if (strcmp(rtype, "shell") == 0) {
1.292 djm 1783: success = session_shell_req(ssh, s);
1.2 markus 1784: } else if (strcmp(rtype, "exec") == 0) {
1.292 djm 1785: success = session_exec_req(ssh, s);
1.2 markus 1786: } else if (strcmp(rtype, "pty-req") == 0) {
1.292 djm 1787: success = session_pty_req(ssh, s);
1.7 markus 1788: } else if (strcmp(rtype, "x11-req") == 0) {
1.292 djm 1789: success = session_x11_req(ssh, s);
1.43 markus 1790: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1.292 djm 1791: success = session_auth_agent_req(ssh, s);
1.7 markus 1792: } else if (strcmp(rtype, "subsystem") == 0) {
1.292 djm 1793: success = session_subsystem_req(ssh, s);
1.173 djm 1794: } else if (strcmp(rtype, "env") == 0) {
1.292 djm 1795: success = session_env_req(ssh, s);
1.2 markus 1796: }
1797: }
1798: if (strcmp(rtype, "window-change") == 0) {
1.292 djm 1799: success = session_window_change_req(ssh, s);
1.177 djm 1800: } else if (strcmp(rtype, "break") == 0) {
1.292 djm 1801: success = session_break_req(ssh, s);
1.2 markus 1802: }
1.177 djm 1803:
1.123 markus 1804: return success;
1.2 markus 1805: }
1806:
1807: void
1.292 djm 1808: session_set_fds(struct ssh *ssh, Session *s,
1809: int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
1.2 markus 1810: {
1811: /*
1812: * now that have a child and a pipe to the child,
1813: * we can activate our channel and register the fd's
1814: */
1815: if (s->chanid == -1)
1816: fatal("no channel for session %d", s->self);
1.292 djm 1817: channel_set_fds(ssh, s->chanid,
1.2 markus 1818: fdout, fdin, fderr,
1.256 djm 1819: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1820: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1821: }
1822:
1.85 markus 1823: /*
1824: * Function to perform pty cleanup. Also called if we get aborted abnormally
1825: * (e.g., due to a dropped connection).
1826: */
1.130 provos 1827: void
1.165 markus 1828: session_pty_cleanup2(Session *s)
1.1 markus 1829: {
1.85 markus 1830: if (s == NULL) {
1831: error("session_pty_cleanup: no session");
1832: return;
1833: }
1834: if (s->ttyfd == -1)
1.1 markus 1835: return;
1836:
1.54 stevesk 1837: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1838:
1839: /* Record that the user has logged out. */
1.85 markus 1840: if (s->pid != 0)
1841: record_logout(s->pid, s->tty);
1.1 markus 1842:
1843: /* Release the pseudo-tty. */
1.130 provos 1844: if (getuid() == 0)
1845: pty_release(s->tty);
1.1 markus 1846:
1847: /*
1848: * Close the server side of the socket pairs. We must do this after
1849: * the pty cleanup, so that another process doesn't get this pty
1850: * while we're still cleaning up.
1851: */
1.237 djm 1852: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1853: error("close(s->ptymaster/%d): %s",
1854: s->ptymaster, strerror(errno));
1.108 markus 1855:
1856: /* unlink pty from session */
1857: s->ttyfd = -1;
1.2 markus 1858: }
1859:
1.130 provos 1860: void
1.165 markus 1861: session_pty_cleanup(Session *s)
1.130 provos 1862: {
1.165 markus 1863: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1864: }
1865:
1.147 markus 1866: static char *
1867: sig2name(int sig)
1868: {
1869: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1870: SSH_SIG(ABRT);
1871: SSH_SIG(ALRM);
1872: SSH_SIG(FPE);
1873: SSH_SIG(HUP);
1874: SSH_SIG(ILL);
1875: SSH_SIG(INT);
1876: SSH_SIG(KILL);
1877: SSH_SIG(PIPE);
1878: SSH_SIG(QUIT);
1879: SSH_SIG(SEGV);
1880: SSH_SIG(TERM);
1881: SSH_SIG(USR1);
1882: SSH_SIG(USR2);
1883: #undef SSH_SIG
1884: return "SIG@openssh.com";
1885: }
1886:
1.94 itojun 1887: static void
1.292 djm 1888: session_close_x11(struct ssh *ssh, int id)
1.184 djm 1889: {
1890: Channel *c;
1891:
1.292 djm 1892: if ((c = channel_by_id(ssh, id)) == NULL) {
1893: debug("%s: x11 channel %d missing", __func__, id);
1.184 djm 1894: } else {
1895: /* Detach X11 listener */
1.292 djm 1896: debug("%s: detach x11 channel %d", __func__, id);
1897: channel_cancel_cleanup(ssh, id);
1.184 djm 1898: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1899: chan_mark_dead(ssh, c);
1.184 djm 1900: }
1901: }
1902:
1903: static void
1.292 djm 1904: session_close_single_x11(struct ssh *ssh, int id, void *arg)
1.184 djm 1905: {
1906: Session *s;
1907: u_int i;
1908:
1.292 djm 1909: debug3("%s: channel %d", __func__, id);
1910: channel_cancel_cleanup(ssh, id);
1.221 stevesk 1911: if ((s = session_by_x11_channel(id)) == NULL)
1.292 djm 1912: fatal("%s: no x11 channel %d", __func__, id);
1.184 djm 1913: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 1914: debug("%s: session %d: closing channel %d",
1915: __func__, s->self, s->x11_chanids[i]);
1.184 djm 1916: /*
1917: * The channel "id" is already closing, but make sure we
1918: * close all of its siblings.
1919: */
1920: if (s->x11_chanids[i] != id)
1.292 djm 1921: session_close_x11(ssh, s->x11_chanids[i]);
1.184 djm 1922: }
1.265 djm 1923: free(s->x11_chanids);
1.184 djm 1924: s->x11_chanids = NULL;
1.265 djm 1925: free(s->display);
1926: s->display = NULL;
1927: free(s->auth_proto);
1928: s->auth_proto = NULL;
1929: free(s->auth_data);
1930: s->auth_data = NULL;
1931: free(s->auth_display);
1932: s->auth_display = NULL;
1.184 djm 1933: }
1934:
1935: static void
1.292 djm 1936: session_exit_message(struct ssh *ssh, Session *s, int status)
1.2 markus 1937: {
1938: Channel *c;
1.124 markus 1939:
1.292 djm 1940: if ((c = channel_lookup(ssh, s->chanid)) == NULL)
1941: fatal("%s: session %d: no channel %d",
1942: __func__, s->self, s->chanid);
1943: debug("%s: session %d channel %d pid %ld",
1944: __func__, s->self, s->chanid, (long)s->pid);
1.2 markus 1945:
1946: if (WIFEXITED(status)) {
1.292 djm 1947: channel_request_start(ssh, s->chanid, "exit-status", 0);
1.2 markus 1948: packet_put_int(WEXITSTATUS(status));
1949: packet_send();
1950: } else if (WIFSIGNALED(status)) {
1.292 djm 1951: channel_request_start(ssh, s->chanid, "exit-signal", 0);
1.147 markus 1952: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 1953: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 1954: packet_put_cstring("");
1955: packet_put_cstring("");
1956: packet_send();
1957: } else {
1958: /* Some weird exit cause. Just exit. */
1959: packet_disconnect("wait returned status %04x.", status);
1960: }
1961:
1962: /* disconnect channel */
1.292 djm 1963: debug("%s: release channel %d", __func__, s->chanid);
1.187 djm 1964:
1965: /*
1966: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 1967: * the channel gets EOF. The session will be then be closed
1.187 djm 1968: * by session_close_by_channel when the childs close their fds.
1969: */
1.292 djm 1970: channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
1.187 djm 1971:
1.5 markus 1972: /*
1973: * emulate a write failure with 'chan_write_failed', nobody will be
1974: * interested in data we write.
1975: * Note that we must not call 'chan_read_failed', since there could
1976: * be some more data waiting in the pipe.
1977: */
1.8 markus 1978: if (c->ostate != CHAN_OUTPUT_CLOSED)
1.292 djm 1979: chan_write_failed(ssh, c);
1.2 markus 1980: }
1981:
1.130 provos 1982: void
1.292 djm 1983: session_close(struct ssh *ssh, Session *s)
1.2 markus 1984: {
1.182 djm 1985: u_int i;
1.173 djm 1986:
1.280 djm 1987: verbose("Close session: user %s from %.200s port %d id %d",
1988: s->pw->pw_name,
1.281 djm 1989: ssh_remote_ipaddr(ssh),
1990: ssh_remote_port(ssh),
1.280 djm 1991: s->self);
1992:
1.165 markus 1993: if (s->ttyfd != -1)
1.85 markus 1994: session_pty_cleanup(s);
1.265 djm 1995: free(s->term);
1996: free(s->display);
1997: free(s->x11_chanids);
1998: free(s->auth_display);
1999: free(s->auth_data);
2000: free(s->auth_proto);
1.267 djm 2001: free(s->subsys);
1.219 djm 2002: if (s->env != NULL) {
2003: for (i = 0; i < s->num_env; i++) {
1.265 djm 2004: free(s->env[i].name);
2005: free(s->env[i].val);
1.219 djm 2006: }
1.265 djm 2007: free(s->env);
1.173 djm 2008: }
1.9 markus 2009: session_proctitle(s);
1.237 djm 2010: session_unused(s->self);
1.2 markus 2011: }
2012:
2013: void
1.292 djm 2014: session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
1.2 markus 2015: {
2016: Session *s = session_by_pid(pid);
2017: if (s == NULL) {
1.292 djm 2018: debug("%s: no session for pid %ld", __func__, (long)pid);
1.2 markus 2019: return;
2020: }
2021: if (s->chanid != -1)
1.292 djm 2022: session_exit_message(ssh, s, status);
1.187 djm 2023: if (s->ttyfd != -1)
2024: session_pty_cleanup(s);
1.197 djm 2025: s->pid = 0;
1.98 markus 2026: }
2027:
1.2 markus 2028: /*
2029: * this is called when a channel dies before
2030: * the session 'child' itself dies
2031: */
2032: void
1.292 djm 2033: session_close_by_channel(struct ssh *ssh, int id, void *arg)
1.2 markus 2034: {
2035: Session *s = session_by_channel(id);
1.187 djm 2036: u_int i;
1.184 djm 2037:
1.2 markus 2038: if (s == NULL) {
1.292 djm 2039: debug("%s: no session for id %d", __func__, id);
1.2 markus 2040: return;
2041: }
1.292 djm 2042: debug("%s: channel %d child %ld", __func__, id, (long)s->pid);
1.107 markus 2043: if (s->pid != 0) {
1.292 djm 2044: debug("%s: channel %d: has child", __func__, id);
1.108 markus 2045: /*
2046: * delay detach of session, but release pty, since
2047: * the fd's to the child are already closed
2048: */
1.165 markus 2049: if (s->ttyfd != -1)
1.108 markus 2050: session_pty_cleanup(s);
1.107 markus 2051: return;
2052: }
2053: /* detach by removing callback */
1.292 djm 2054: channel_cancel_cleanup(ssh, s->chanid);
1.187 djm 2055:
2056: /* Close any X11 listeners associated with this session */
2057: if (s->x11_chanids != NULL) {
2058: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2059: session_close_x11(ssh, s->x11_chanids[i]);
1.187 djm 2060: s->x11_chanids[i] = -1;
2061: }
2062: }
2063:
1.2 markus 2064: s->chanid = -1;
1.292 djm 2065: session_close(ssh, s);
1.106 markus 2066: }
2067:
2068: void
1.292 djm 2069: session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
1.106 markus 2070: {
2071: int i;
1.237 djm 2072: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2073: Session *s = &sessions[i];
1.130 provos 2074: if (s->used) {
2075: if (closefunc != NULL)
2076: closefunc(s);
2077: else
1.292 djm 2078: session_close(ssh, s);
1.130 provos 2079: }
1.2 markus 2080: }
1.9 markus 2081: }
2082:
1.94 itojun 2083: static char *
1.9 markus 2084: session_tty_list(void)
2085: {
2086: static char buf[1024];
2087: int i;
2088: buf[0] = '\0';
1.237 djm 2089: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2090: Session *s = &sessions[i];
2091: if (s->used && s->ttyfd != -1) {
2092: if (buf[0] != '\0')
2093: strlcat(buf, ",", sizeof buf);
2094: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2095: }
2096: }
2097: if (buf[0] == '\0')
2098: strlcpy(buf, "notty", sizeof buf);
2099: return buf;
2100: }
2101:
2102: void
2103: session_proctitle(Session *s)
2104: {
2105: if (s->pw == NULL)
2106: error("no user for session %d", s->self);
2107: else
2108: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2109: }
2110:
2111: int
1.292 djm 2112: session_setup_x11fwd(struct ssh *ssh, Session *s)
1.81 markus 2113: {
2114: struct stat st;
1.109 stevesk 2115: char display[512], auth_display[512];
1.272 djm 2116: char hostname[NI_MAXHOST];
1.184 djm 2117: u_int i;
1.81 markus 2118:
1.294 djm 2119: if (!auth_opts->permit_x11_forwarding_flag) {
2120: packet_send_debug("X11 forwarding disabled by key options.");
1.81 markus 2121: return 0;
2122: }
2123: if (!options.x11_forwarding) {
2124: debug("X11 forwarding disabled in server configuration file.");
2125: return 0;
2126: }
1.275 djm 2127: if (options.xauth_location == NULL ||
1.81 markus 2128: (stat(options.xauth_location, &st) == -1)) {
1.294 djm 2129: packet_send_debug("No xauth program; cannot forward X11.");
1.81 markus 2130: return 0;
2131: }
1.87 markus 2132: if (s->display != NULL) {
1.81 markus 2133: debug("X11 display already set.");
2134: return 0;
2135: }
1.292 djm 2136: if (x11_create_display_inet(ssh, options.x11_display_offset,
1.140 deraadt 2137: options.x11_use_localhost, s->single_connection,
1.184 djm 2138: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2139: debug("x11_create_display_inet failed.");
1.81 markus 2140: return 0;
1.184 djm 2141: }
2142: for (i = 0; s->x11_chanids[i] != -1; i++) {
1.292 djm 2143: channel_register_cleanup(ssh, s->x11_chanids[i],
1.187 djm 2144: session_close_single_x11, 0);
1.81 markus 2145: }
1.109 stevesk 2146:
2147: /* Set up a suitable value for the DISPLAY variable. */
2148: if (gethostname(hostname, sizeof(hostname)) < 0)
2149: fatal("gethostname: %.100s", strerror(errno));
2150: /*
2151: * auth_display must be used as the displayname when the
2152: * authorization entry is added with xauth(1). This will be
2153: * different than the DISPLAY string for localhost displays.
2154: */
1.119 stevesk 2155: if (options.x11_use_localhost) {
1.140 deraadt 2156: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2157: s->display_number, s->screen);
1.140 deraadt 2158: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2159: s->display_number, s->screen);
1.109 stevesk 2160: s->display = xstrdup(display);
1.118 stevesk 2161: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2162: } else {
1.140 deraadt 2163: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2164: s->display_number, s->screen);
2165: s->display = xstrdup(display);
1.118 stevesk 2166: s->auth_display = xstrdup(display);
1.109 stevesk 2167: }
2168:
1.81 markus 2169: return 1;
1.2 markus 2170: }
2171:
1.94 itojun 2172: static void
1.292 djm 2173: do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
1.2 markus 2174: {
1.292 djm 2175: server_loop2(ssh, authctxt);
1.165 markus 2176: }
2177:
2178: void
1.292 djm 2179: do_cleanup(struct ssh *ssh, Authctxt *authctxt)
1.165 markus 2180: {
2181: static int called = 0;
2182:
2183: debug("do_cleanup");
2184:
2185: /* no cleanup if we're in the child for login shell */
2186: if (is_child)
2187: return;
2188:
2189: /* avoid double cleanup */
2190: if (called)
2191: return;
2192: called = 1;
2193:
1.218 markus 2194: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2195: return;
2196: #ifdef KRB5
2197: if (options.kerberos_ticket_cleanup &&
2198: authctxt->krb5_ctx)
2199: krb5_cleanup_proc(authctxt);
1.161 markus 2200: #endif
1.165 markus 2201:
2202: #ifdef GSSAPI
1.283 markus 2203: if (options.gss_cleanup_creds)
1.165 markus 2204: ssh_gssapi_cleanup_creds();
2205: #endif
2206:
2207: /* remove agent socket */
2208: auth_sock_cleanup_proc(authctxt->pw);
1.290 djm 2209:
2210: /* remove userauth info */
2211: if (auth_info_file != NULL) {
2212: temporarily_use_uid(authctxt->pw);
2213: unlink(auth_info_file);
2214: restore_uid();
2215: free(auth_info_file);
2216: auth_info_file = NULL;
2217: }
1.165 markus 2218:
2219: /*
2220: * Cleanup ptys/utmp only if privsep is disabled,
2221: * or if running in monitor.
2222: */
2223: if (!use_privsep || mm_is_monitor())
1.292 djm 2224: session_destroy_all(ssh, session_pty_cleanup2);
1.1 markus 2225: }
1.281 djm 2226:
2227: /* Return a name for the remote host that fits inside utmp_size */
2228:
2229: const char *
2230: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
2231: {
2232: const char *remote = "";
2233:
2234: if (utmp_size > 0)
2235: remote = auth_get_canonical_hostname(ssh, use_dns);
2236: if (utmp_size == 0 || strlen(remote) > utmp_size)
2237: remote = ssh_remote_ipaddr(ssh);
2238: return remote;
2239: }
2240:
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