Annotation of src/usr.bin/ssh/session.c, Revision 1.246
1.246 ! stevesk 1: /* $OpenBSD: session.c,v 1.245 2009/01/22 09:46:01 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>
1.213 stevesk 41: #include <sys/param.h>
1.236 djm 42: #include <sys/queue.h>
1.192 stevesk 43:
1.209 stevesk 44: #include <errno.h>
1.204 stevesk 45: #include <grp.h>
1.223 djm 46: #include <login_cap.h>
1.192 stevesk 47: #include <paths.h>
1.206 stevesk 48: #include <pwd.h>
1.195 stevesk 49: #include <signal.h>
1.215 stevesk 50: #include <stdio.h>
1.214 stevesk 51: #include <stdlib.h>
1.212 stevesk 52: #include <string.h>
1.211 stevesk 53: #include <unistd.h>
1.1 markus 54:
1.216 deraadt 55: #include "xmalloc.h"
1.51 markus 56: #include "ssh.h"
57: #include "ssh1.h"
58: #include "ssh2.h"
1.59 djm 59: #include "sshpty.h"
1.1 markus 60: #include "packet.h"
61: #include "buffer.h"
1.173 djm 62: #include "match.h"
1.1 markus 63: #include "uidswap.h"
64: #include "compat.h"
1.78 markus 65: #include "channels.h"
1.216 deraadt 66: #include "key.h"
67: #include "cipher.h"
68: #include "kex.h"
69: #include "hostfile.h"
1.2 markus 70: #include "auth.h"
1.19 markus 71: #include "auth-options.h"
1.50 markus 72: #include "pathnames.h"
1.51 markus 73: #include "log.h"
74: #include "servconf.h"
1.59 djm 75: #include "sshlogin.h"
1.51 markus 76: #include "serverloop.h"
77: #include "canohost.h"
1.226 djm 78: #include "misc.h"
1.55 itojun 79: #include "session.h"
1.216 deraadt 80: #ifdef GSSAPI
81: #include "ssh-gss.h"
82: #endif
1.130 provos 83: #include "monitor_wrap.h"
1.225 markus 84: #include "sftp.h"
1.171 markus 85:
86: #ifdef KRB5
87: #include <kafs.h>
1.161 markus 88: #endif
89:
1.242 djm 90: #define IS_INTERNAL_SFTP(c) \
91: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
92: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
93: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
94: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
95:
1.1 markus 96: /* func */
97:
98: Session *session_new(void);
1.240 djm 99: void session_set_fds(Session *, int, int, int, int);
1.165 markus 100: void session_pty_cleanup(Session *);
1.94 itojun 101: void session_proctitle(Session *);
102: int session_setup_x11fwd(Session *);
1.237 djm 103: int do_exec_pty(Session *, const char *);
104: int do_exec_no_pty(Session *, const char *);
105: int do_exec(Session *, const char *);
1.94 itojun 106: void do_login(Session *, const char *);
107: void do_child(Session *, const char *);
1.73 djm 108: void do_motd(void);
1.94 itojun 109: int check_quietlogin(Session *, const char *);
1.1 markus 110:
1.94 itojun 111: static void do_authenticated1(Authctxt *);
112: static void do_authenticated2(Authctxt *);
113:
114: static int session_pty_req(Session *);
1.65 markus 115:
1.1 markus 116: /* import */
117: extern ServerOptions options;
118: extern char *__progname;
119: extern int log_stderr;
120: extern int debug_flag;
1.45 markus 121: extern u_int utmp_len;
1.21 markus 122: extern int startup_pipe;
1.74 markus 123: extern void destroy_sensitive_data(void);
1.179 dtucker 124: extern Buffer loginmsg;
1.21 markus 125:
1.34 markus 126: /* original command from peer. */
1.92 markus 127: const char *original_command = NULL;
1.34 markus 128:
1.1 markus 129: /* data */
1.237 djm 130: static int sessions_first_unused = -1;
131: static int sessions_nalloc = 0;
132: static Session *sessions = NULL;
1.1 markus 133:
1.225 markus 134: #define SUBSYSTEM_NONE 0
135: #define SUBSYSTEM_EXT 1
136: #define SUBSYSTEM_INT_SFTP 2
137:
1.129 provos 138: login_cap_t *lc;
1.28 millert 139:
1.165 markus 140: static int is_child = 0;
141:
1.136 markus 142: /* Name and directory of socket for authentication agent forwarding. */
143: static char *auth_sock_name = NULL;
144: static char *auth_sock_dir = NULL;
145:
146: /* removes the agent forwarding socket */
147:
148: static void
1.165 markus 149: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 150: {
151: if (auth_sock_name != NULL) {
152: temporarily_use_uid(pw);
153: unlink(auth_sock_name);
154: rmdir(auth_sock_dir);
155: auth_sock_name = NULL;
156: restore_uid();
157: }
158: }
159:
160: static int
161: auth_input_request_forwarding(struct passwd * pw)
162: {
163: Channel *nc;
1.237 djm 164: int sock = -1;
1.136 markus 165: struct sockaddr_un sunaddr;
166:
167: if (auth_sock_name != NULL) {
168: error("authentication forwarding requested twice.");
169: return 0;
170: }
171:
172: /* Temporarily drop privileged uid for mkdir/bind. */
173: temporarily_use_uid(pw);
174:
175: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 176: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 177:
178: /* Create private directory for socket */
179: if (mkdtemp(auth_sock_dir) == NULL) {
180: packet_send_debug("Agent forwarding disabled: "
181: "mkdtemp() failed: %.100s", strerror(errno));
182: restore_uid();
183: xfree(auth_sock_dir);
184: auth_sock_dir = NULL;
1.237 djm 185: goto authsock_err;
1.136 markus 186: }
1.237 djm 187:
188: xasprintf(&auth_sock_name, "%s/agent.%ld",
189: auth_sock_dir, (long) getpid());
1.136 markus 190:
191: /* Create the socket. */
192: sock = socket(AF_UNIX, SOCK_STREAM, 0);
1.237 djm 193: if (sock < 0) {
194: error("socket: %.100s", strerror(errno));
195: restore_uid();
196: goto authsock_err;
197: }
1.136 markus 198:
199: /* Bind it to the name. */
200: memset(&sunaddr, 0, sizeof(sunaddr));
201: sunaddr.sun_family = AF_UNIX;
202: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
203:
1.237 djm 204: if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
205: error("bind: %.100s", strerror(errno));
206: restore_uid();
207: goto authsock_err;
208: }
1.136 markus 209:
210: /* Restore the privileged uid. */
211: restore_uid();
212:
213: /* Start listening on the socket. */
1.237 djm 214: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
215: error("listen: %.100s", strerror(errno));
216: goto authsock_err;
217: }
1.136 markus 218:
219: /* Allocate a channel for the authentication agent socket. */
220: nc = channel_new("auth socket",
221: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
222: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 223: 0, "auth socket", 1);
1.245 djm 224: nc->path = xstrdup(auth_sock_name);
1.136 markus 225: return 1;
1.237 djm 226:
227: authsock_err:
228: if (auth_sock_name != NULL)
229: xfree(auth_sock_name);
230: if (auth_sock_dir != NULL) {
231: rmdir(auth_sock_dir);
232: xfree(auth_sock_dir);
233: }
234: if (sock != -1)
235: close(sock);
236: auth_sock_name = NULL;
237: auth_sock_dir = NULL;
238: return 0;
1.136 markus 239: }
240:
1.179 dtucker 241: static void
242: display_loginmsg(void)
243: {
1.183 djm 244: if (buffer_len(&loginmsg) > 0) {
245: buffer_append(&loginmsg, "\0", 1);
246: printf("%s", (char *)buffer_ptr(&loginmsg));
247: buffer_clear(&loginmsg);
248: }
1.179 dtucker 249: }
1.136 markus 250:
1.65 markus 251: void
252: do_authenticated(Authctxt *authctxt)
253: {
1.153 markus 254: setproctitle("%s", authctxt->pw->pw_name);
255:
1.65 markus 256: /* setup the channel layer */
257: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
258: channel_permit_all_opens();
259:
260: if (compat20)
261: do_authenticated2(authctxt);
262: else
263: do_authenticated1(authctxt);
1.79 markus 264:
1.165 markus 265: do_cleanup(authctxt);
1.65 markus 266: }
267:
1.1 markus 268: /*
269: * Prepares for an interactive session. This is called after the user has
270: * been successfully authenticated. During this message exchange, pseudo
271: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
272: * are requested, etc.
273: */
1.94 itojun 274: static void
1.65 markus 275: do_authenticated1(Authctxt *authctxt)
1.1 markus 276: {
277: Session *s;
1.65 markus 278: char *command;
1.117 markus 279: int success, type, screen_flag;
1.139 deraadt 280: int enable_compression_after_reply = 0;
281: u_int proto_len, data_len, dlen, compression_level = 0;
1.1 markus 282:
1.61 markus 283: s = session_new();
1.181 markus 284: if (s == NULL) {
285: error("no more sessions");
286: return;
287: }
1.96 dugsong 288: s->authctxt = authctxt;
1.65 markus 289: s->pw = authctxt->pw;
1.28 millert 290:
1.1 markus 291: /*
292: * We stay in this loop until the client requests to execute a shell
293: * or a command.
294: */
295: for (;;) {
1.65 markus 296: success = 0;
1.1 markus 297:
298: /* Get a packet from the client. */
1.117 markus 299: type = packet_read();
1.1 markus 300:
301: /* Process the packet. */
302: switch (type) {
303: case SSH_CMSG_REQUEST_COMPRESSION:
304: compression_level = packet_get_int();
1.116 markus 305: packet_check_eom();
1.1 markus 306: if (compression_level < 1 || compression_level > 9) {
1.180 markus 307: packet_send_debug("Received invalid compression level %d.",
1.112 deraadt 308: compression_level);
1.138 markus 309: break;
310: }
1.186 markus 311: if (options.compression == COMP_NONE) {
1.138 markus 312: debug2("compression disabled");
1.1 markus 313: break;
314: }
315: /* Enable compression after we have responded with SUCCESS. */
316: enable_compression_after_reply = 1;
317: success = 1;
318: break;
319:
320: case SSH_CMSG_REQUEST_PTY:
1.86 markus 321: success = session_pty_req(s);
1.1 markus 322: break;
323:
324: case SSH_CMSG_X11_REQUEST_FORWARDING:
325: s->auth_proto = packet_get_string(&proto_len);
326: s->auth_data = packet_get_string(&data_len);
327:
1.57 markus 328: screen_flag = packet_get_protocol_flags() &
329: SSH_PROTOFLAG_SCREEN_NUMBER;
330: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
331:
332: if (packet_remaining() == 4) {
333: if (!screen_flag)
334: debug2("Buggy client: "
335: "X11 screen flag missing");
1.1 markus 336: s->screen = packet_get_int();
1.56 markus 337: } else {
1.1 markus 338: s->screen = 0;
1.56 markus 339: }
1.116 markus 340: packet_check_eom();
1.81 markus 341: success = session_setup_x11fwd(s);
342: if (!success) {
343: xfree(s->auth_proto);
344: xfree(s->auth_data);
1.84 markus 345: s->auth_proto = NULL;
346: s->auth_data = NULL;
1.1 markus 347: }
348: break;
349:
350: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
1.235 pyr 351: if (!options.allow_agent_forwarding ||
352: no_agent_forwarding_flag || compat13) {
1.1 markus 353: debug("Authentication agent forwarding not permitted for this authentication.");
354: break;
355: }
356: debug("Received authentication agent forwarding request.");
1.65 markus 357: success = auth_input_request_forwarding(s->pw);
1.1 markus 358: break;
359:
360: case SSH_CMSG_PORT_FORWARD_REQUEST:
361: if (no_port_forwarding_flag) {
362: debug("Port forwarding not permitted for this authentication.");
1.39 markus 363: break;
364: }
365: if (!options.allow_tcp_forwarding) {
366: debug("Port forwarding not permitted.");
1.1 markus 367: break;
368: }
369: debug("Received TCP/IP port forwarding request.");
1.208 markus 370: if (channel_input_port_forward_request(s->pw->pw_uid == 0,
371: options.gateway_ports) < 0) {
372: debug("Port forwarding failed.");
373: break;
374: }
1.1 markus 375: success = 1;
376: break;
377:
378: case SSH_CMSG_MAX_PACKET_SIZE:
379: if (packet_set_maxsize(packet_get_int()) > 0)
380: success = 1;
381: break;
382:
383: case SSH_CMSG_EXEC_SHELL:
384: case SSH_CMSG_EXEC_CMD:
385: if (type == SSH_CMSG_EXEC_CMD) {
386: command = packet_get_string(&dlen);
387: debug("Exec command '%.500s'", command);
1.237 djm 388: if (do_exec(s, command) != 0)
389: packet_disconnect(
390: "command execution failed");
1.92 markus 391: xfree(command);
1.1 markus 392: } else {
1.237 djm 393: if (do_exec(s, NULL) != 0)
394: packet_disconnect(
395: "shell execution failed");
1.1 markus 396: }
1.116 markus 397: packet_check_eom();
1.82 markus 398: session_close(s);
1.1 markus 399: return;
400:
401: default:
402: /*
403: * Any unknown messages in this phase are ignored,
404: * and a failure message is returned.
405: */
1.155 itojun 406: logit("Unknown packet type received after authentication: %d", type);
1.1 markus 407: }
408: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
409: packet_send();
410: packet_write_wait();
411:
412: /* Enable compression now that we have replied if appropriate. */
413: if (enable_compression_after_reply) {
414: enable_compression_after_reply = 0;
415: packet_start_compression(compression_level);
416: }
417: }
418: }
419:
1.238 markus 420: #define USE_PIPES
1.1 markus 421: /*
422: * This is called to fork and execute a command when we have no tty. This
423: * will call do_child from the child, and server_loop from the parent after
424: * setting up file descriptors and such.
425: */
1.237 djm 426: int
1.63 markus 427: do_exec_no_pty(Session *s, const char *command)
1.1 markus 428: {
1.137 mpech 429: pid_t pid;
1.238 markus 430: #ifdef USE_PIPES
431: int pin[2], pout[2], perr[2];
432:
433: /* Allocate pipes for communicating with the program. */
434: if (pipe(pin) < 0) {
435: error("%s: pipe in: %.100s", __func__, strerror(errno));
436: return -1;
437: }
438: if (pipe(pout) < 0) {
439: error("%s: pipe out: %.100s", __func__, strerror(errno));
440: close(pin[0]);
441: close(pin[1]);
442: return -1;
443: }
444: if (pipe(perr) < 0) {
445: error("%s: pipe err: %.100s", __func__, strerror(errno));
446: close(pin[0]);
447: close(pin[1]);
448: close(pout[0]);
449: close(pout[1]);
450: return -1;
451: }
452: #else
1.237 djm 453: int inout[2], err[2];
1.1 markus 454:
455: /* Uses socket pairs to communicate with the program. */
1.237 djm 456: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
457: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
458: return -1;
459: }
460: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
461: error("%s: socketpair #2: %.100s", __func__, strerror(errno));
462: close(inout[0]);
463: close(inout[1]);
464: return -1;
465: }
1.238 markus 466: #endif
1.237 djm 467:
1.1 markus 468: if (s == NULL)
469: fatal("do_exec_no_pty: no session");
470:
1.9 markus 471: session_proctitle(s);
1.1 markus 472:
473: /* Fork the child. */
1.237 djm 474: switch ((pid = fork())) {
475: case -1:
476: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 markus 477: #ifdef USE_PIPES
478: close(pin[0]);
479: close(pin[1]);
480: close(pout[0]);
481: close(pout[1]);
482: close(perr[0]);
483: close(perr[1]);
484: #else
1.237 djm 485: close(inout[0]);
486: close(inout[1]);
487: close(err[0]);
488: close(err[1]);
1.238 markus 489: #endif
1.237 djm 490: return -1;
491: case 0:
1.165 markus 492: is_child = 1;
1.144 markus 493:
1.1 markus 494: /* Child. Reinitialize the log since the pid has changed. */
1.237 djm 495: log_init(__progname, options.log_level,
496: options.log_facility, log_stderr);
1.1 markus 497:
498: /*
499: * Create a new session and process group since the 4.4BSD
500: * setlogin() affects the entire process group.
501: */
502: if (setsid() < 0)
503: error("setsid failed: %.100s", strerror(errno));
504:
1.238 markus 505: #ifdef USE_PIPES
506: /*
507: * Redirect stdin. We close the parent side of the socket
508: * pair, and make the child side the standard input.
509: */
510: close(pin[1]);
511: if (dup2(pin[0], 0) < 0)
512: perror("dup2 stdin");
513: close(pin[0]);
514:
515: /* Redirect stdout. */
516: close(pout[0]);
517: if (dup2(pout[1], 1) < 0)
518: perror("dup2 stdout");
519: close(pout[1]);
520:
521: /* Redirect stderr. */
522: close(perr[0]);
523: if (dup2(perr[1], 2) < 0)
524: perror("dup2 stderr");
525: close(perr[1]);
526: #else
1.1 markus 527: /*
528: * Redirect stdin, stdout, and stderr. Stdin and stdout will
529: * use the same socket, as some programs (particularly rdist)
530: * seem to depend on it.
531: */
532: close(inout[1]);
533: close(err[1]);
534: if (dup2(inout[0], 0) < 0) /* stdin */
535: perror("dup2 stdin");
1.237 djm 536: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 537: perror("dup2 stdout");
1.238 markus 538: close(inout[0]);
1.1 markus 539: if (dup2(err[0], 2) < 0) /* stderr */
540: perror("dup2 stderr");
1.238 markus 541: close(err[0]);
542: #endif
1.1 markus 543:
544: /* Do processing for the child (exec command etc). */
1.60 markus 545: do_child(s, command);
1.1 markus 546: /* NOTREACHED */
1.237 djm 547: default:
548: break;
1.1 markus 549: }
1.237 djm 550:
1.1 markus 551: s->pid = pid;
1.47 markus 552: /* Set interactive/non-interactive mode. */
1.48 markus 553: packet_set_interactive(s->display != NULL);
1.1 markus 554:
1.238 markus 555: #ifdef USE_PIPES
556: /* We are the parent. Close the child sides of the pipes. */
557: close(pin[0]);
558: close(pout[1]);
559: close(perr[1]);
560:
561: if (compat20) {
562: if (s->is_subsystem) {
563: close(perr[0]);
564: perr[0] = -1;
565: }
1.240 djm 566: session_set_fds(s, pin[1], pout[0], perr[0], 0);
1.238 markus 567: } else {
568: /* Enter the interactive session. */
569: server_loop(pid, pin[1], pout[0], perr[0]);
570: /* server_loop has closed pin[1], pout[0], and perr[0]. */
571: }
572: #else
1.1 markus 573: /* We are the parent. Close the child sides of the socket pairs. */
574: close(inout[0]);
575: close(err[0]);
576:
577: /*
578: * Enter the interactive session. Note: server_loop must be able to
579: * handle the case that fdin and fdout are the same.
580: */
1.2 markus 581: if (compat20) {
1.237 djm 582: session_set_fds(s, inout[1], inout[1],
1.240 djm 583: s->is_subsystem ? -1 : err[1], 0);
1.237 djm 584: if (s->is_subsystem)
585: close(err[1]);
1.2 markus 586: } else {
587: server_loop(pid, inout[1], inout[1], err[1]);
588: /* server_loop has closed inout[1] and err[1]. */
589: }
1.238 markus 590: #endif
1.237 djm 591: return 0;
1.1 markus 592: }
593:
594: /*
595: * This is called to fork and execute a command when we have a tty. This
596: * will call do_child from the child, and server_loop from the parent after
597: * setting up file descriptors, controlling tty, updating wtmp, utmp,
598: * lastlog, and other such operations.
599: */
1.237 djm 600: int
1.63 markus 601: do_exec_pty(Session *s, const char *command)
1.1 markus 602: {
603: int fdout, ptyfd, ttyfd, ptymaster;
604: pid_t pid;
605:
606: if (s == NULL)
607: fatal("do_exec_pty: no session");
608: ptyfd = s->ptyfd;
609: ttyfd = s->ttyfd;
610:
1.237 djm 611: /*
612: * Create another descriptor of the pty master side for use as the
613: * standard input. We could use the original descriptor, but this
614: * simplifies code in server_loop. The descriptor is bidirectional.
615: * Do this before forking (and cleanup in the child) so as to
616: * detect and gracefully fail out-of-fd conditions.
617: */
618: if ((fdout = dup(ptyfd)) < 0) {
619: error("%s: dup #1: %s", __func__, strerror(errno));
620: close(ttyfd);
621: close(ptyfd);
622: return -1;
623: }
624: /* we keep a reference to the pty master */
625: if ((ptymaster = dup(ptyfd)) < 0) {
626: error("%s: dup #2: %s", __func__, strerror(errno));
627: close(ttyfd);
628: close(ptyfd);
629: close(fdout);
630: return -1;
631: }
632:
1.1 markus 633: /* Fork the child. */
1.237 djm 634: switch ((pid = fork())) {
635: case -1:
636: error("%s: fork: %.100s", __func__, strerror(errno));
637: close(fdout);
638: close(ptymaster);
639: close(ttyfd);
640: close(ptyfd);
641: return -1;
642: case 0:
1.165 markus 643: is_child = 1;
1.97 markus 644:
1.237 djm 645: close(fdout);
646: close(ptymaster);
647:
1.24 markus 648: /* Child. Reinitialize the log because the pid has changed. */
1.237 djm 649: log_init(__progname, options.log_level,
650: options.log_facility, log_stderr);
1.1 markus 651: /* Close the master side of the pseudo tty. */
652: close(ptyfd);
653:
654: /* Make the pseudo tty our controlling tty. */
655: pty_make_controlling_tty(&ttyfd, s->tty);
656:
1.103 markus 657: /* Redirect stdin/stdout/stderr from the pseudo tty. */
658: if (dup2(ttyfd, 0) < 0)
659: error("dup2 stdin: %s", strerror(errno));
660: if (dup2(ttyfd, 1) < 0)
661: error("dup2 stdout: %s", strerror(errno));
662: if (dup2(ttyfd, 2) < 0)
663: error("dup2 stderr: %s", strerror(errno));
1.1 markus 664:
665: /* Close the extra descriptor for the pseudo tty. */
666: close(ttyfd);
667:
1.24 markus 668: /* record login, etc. similar to login(1) */
1.41 markus 669: if (!(options.use_login && command == NULL))
670: do_login(s, command);
1.228 djm 671:
1.237 djm 672: /*
673: * Do common processing for the child, such as execing
674: * the command.
675: */
1.60 markus 676: do_child(s, command);
1.1 markus 677: /* NOTREACHED */
1.237 djm 678: default:
679: break;
1.1 markus 680: }
681: s->pid = pid;
682:
683: /* Parent. Close the slave side of the pseudo tty. */
684: close(ttyfd);
685:
1.237 djm 686: /* Enter interactive session. */
1.1 markus 687: s->ptymaster = ptymaster;
1.47 markus 688: packet_set_interactive(1);
1.2 markus 689: if (compat20) {
1.240 djm 690: session_set_fds(s, ptyfd, fdout, -1, 1);
1.2 markus 691: } else {
692: server_loop(pid, ptyfd, fdout, -1);
693: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 694: }
1.237 djm 695: return 0;
1.24 markus 696: }
697:
1.90 markus 698: /*
699: * This is called to fork and execute a command. If another command is
700: * to be forced, execute that instead.
701: */
1.237 djm 702: int
1.90 markus 703: do_exec(Session *s, const char *command)
704: {
1.237 djm 705: int ret;
706:
1.210 dtucker 707: if (options.adm_forced_command) {
708: original_command = command;
709: command = options.adm_forced_command;
1.242 djm 710: if (IS_INTERNAL_SFTP(command))
1.226 djm 711: s->is_subsystem = SUBSYSTEM_INT_SFTP;
712: else if (s->is_subsystem)
1.225 markus 713: s->is_subsystem = SUBSYSTEM_EXT;
1.210 dtucker 714: debug("Forced command (config) '%.900s'", command);
715: } else if (forced_command) {
1.90 markus 716: original_command = command;
717: command = forced_command;
1.242 djm 718: if (IS_INTERNAL_SFTP(command))
1.226 djm 719: s->is_subsystem = SUBSYSTEM_INT_SFTP;
720: else if (s->is_subsystem)
1.225 markus 721: s->is_subsystem = SUBSYSTEM_EXT;
1.210 dtucker 722: debug("Forced command (key option) '%.900s'", command);
1.90 markus 723: }
1.163 markus 724:
725: #ifdef GSSAPI
726: if (options.gss_authentication) {
727: temporarily_use_uid(s->pw);
728: ssh_gssapi_storecreds();
729: restore_uid();
730: }
731: #endif
1.90 markus 732: if (s->ttyfd != -1)
1.237 djm 733: ret = do_exec_pty(s, command);
1.90 markus 734: else
1.237 djm 735: ret = do_exec_no_pty(s, command);
1.90 markus 736:
1.92 markus 737: original_command = NULL;
1.179 dtucker 738:
739: /*
740: * Clear loginmsg: it's the child's responsibility to display
741: * it to the user, otherwise multiple sessions may accumulate
742: * multiple copies of the login messages.
743: */
744: buffer_clear(&loginmsg);
1.237 djm 745:
746: return ret;
1.90 markus 747: }
748:
749:
1.24 markus 750: /* administrative, login(1)-like work */
751: void
1.41 markus 752: do_login(Session *s, const char *command)
1.24 markus 753: {
754: socklen_t fromlen;
755: struct sockaddr_storage from;
756: struct passwd * pw = s->pw;
757: pid_t pid = getpid();
758:
759: /*
760: * Get IP address of client. If the connection is not a socket, let
761: * the address be 0.0.0.0.
762: */
763: memset(&from, 0, sizeof(from));
1.148 stevesk 764: fromlen = sizeof(from);
1.24 markus 765: if (packet_connection_is_on_socket()) {
766: if (getpeername(packet_get_connection_in(),
1.200 deraadt 767: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 768: debug("getpeername: %.100s", strerror(errno));
1.165 markus 769: cleanup_exit(255);
1.24 markus 770: }
771: }
1.25 markus 772:
1.24 markus 773: /* Record that there was a login on that tty from the remote host. */
1.133 markus 774: if (!use_privsep)
775: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
776: get_remote_name_or_ip(utmp_len,
1.158 markus 777: options.use_dns),
1.148 stevesk 778: (struct sockaddr *)&from, fromlen);
1.24 markus 779:
1.73 djm 780: if (check_quietlogin(s, command))
1.24 markus 781: return;
1.73 djm 782:
1.179 dtucker 783: display_loginmsg();
1.73 djm 784:
785: do_motd();
786: }
787:
788: /*
789: * Display the message of the day.
790: */
791: void
792: do_motd(void)
793: {
794: FILE *f;
795: char buf[256];
796:
1.24 markus 797: if (options.print_motd) {
1.28 millert 798: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
799: "/etc/motd"), "r");
1.24 markus 800: if (f) {
801: while (fgets(buf, sizeof(buf), f))
802: fputs(buf, stdout);
803: fclose(f);
804: }
1.2 markus 805: }
1.73 djm 806: }
807:
808:
809: /*
810: * Check for quiet login, either .hushlogin or command given.
811: */
812: int
813: check_quietlogin(Session *s, const char *command)
814: {
815: char buf[256];
1.96 dugsong 816: struct passwd *pw = s->pw;
1.73 djm 817: struct stat st;
818:
819: /* Return 1 if .hushlogin exists or a command given. */
820: if (command != NULL)
821: return 1;
822: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
823: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
824: return 1;
825: return 0;
1.1 markus 826: }
827:
828: /*
829: * Sets the value of the given variable in the environment. If the variable
1.244 tobias 830: * already exists, its value is overridden.
1.1 markus 831: */
1.161 markus 832: void
1.45 markus 833: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 834: const char *value)
1.1 markus 835: {
1.164 markus 836: char **env;
837: u_int envsize;
1.45 markus 838: u_int i, namelen;
1.1 markus 839:
840: /*
841: * Find the slot where the value should be stored. If the variable
842: * already exists, we reuse the slot; otherwise we append a new slot
843: * at the end of the array, expanding if necessary.
844: */
845: env = *envp;
846: namelen = strlen(name);
847: for (i = 0; env[i]; i++)
848: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
849: break;
850: if (env[i]) {
851: /* Reuse the slot. */
852: xfree(env[i]);
853: } else {
854: /* New variable. Expand if necessary. */
1.164 markus 855: envsize = *envsizep;
856: if (i >= envsize - 1) {
857: if (envsize >= 1000)
858: fatal("child_set_env: too many env vars");
859: envsize += 50;
1.201 djm 860: env = (*envp) = xrealloc(env, envsize, sizeof(char *));
1.164 markus 861: *envsizep = envsize;
1.1 markus 862: }
863: /* Need to set the NULL pointer at end of array beyond the new slot. */
864: env[i + 1] = NULL;
865: }
866:
867: /* Allocate space and format the variable in the appropriate slot. */
868: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
869: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
870: }
871:
872: /*
873: * Reads environment variables from the given file and adds/overrides them
874: * into the environment. If the file does not exist, this does nothing.
875: * Otherwise, it must consist of empty lines, comments (line starts with '#')
876: * and assignments of the form name=value. No other forms are allowed.
877: */
1.94 itojun 878: static void
1.45 markus 879: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 880: const char *filename)
1.1 markus 881: {
882: FILE *f;
883: char buf[4096];
884: char *cp, *value;
1.142 deraadt 885: u_int lineno = 0;
1.1 markus 886:
887: f = fopen(filename, "r");
888: if (!f)
889: return;
890:
891: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 892: if (++lineno > 1000)
893: fatal("Too many lines in environment file %s", filename);
1.1 markus 894: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
895: ;
896: if (!*cp || *cp == '#' || *cp == '\n')
897: continue;
1.224 gilles 898:
899: cp[strcspn(cp, "\n")] = '\0';
900:
1.1 markus 901: value = strchr(cp, '=');
902: if (value == NULL) {
1.142 deraadt 903: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
904: filename);
1.1 markus 905: continue;
906: }
1.14 deraadt 907: /*
908: * Replace the equals sign by nul, and advance value to
909: * the value string.
910: */
1.1 markus 911: *value = '\0';
912: value++;
913: child_set_env(env, envsize, cp, value);
914: }
915: fclose(f);
916: }
917:
1.127 markus 918: static char **
919: do_setup_env(Session *s, const char *shell)
1.1 markus 920: {
921: char buf[256];
1.127 markus 922: u_int i, envsize;
1.154 markus 923: char **env, *laddr;
1.127 markus 924: struct passwd *pw = s->pw;
1.1 markus 925:
926: /* Initialize the environment. */
927: envsize = 100;
1.220 djm 928: env = xcalloc(envsize, sizeof(char *));
1.1 markus 929: env[0] = NULL;
930:
1.161 markus 931: #ifdef GSSAPI
1.168 djm 932: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 933: * the childs environment as they see fit
934: */
935: ssh_gssapi_do_child(&env, &envsize);
936: #endif
937:
1.1 markus 938: if (!options.use_login) {
939: /* Set basic environment. */
1.173 djm 940: for (i = 0; i < s->num_env; i++)
1.178 deraadt 941: child_set_env(&env, &envsize, s->env[i].name,
1.173 djm 942: s->env[i].val);
943:
1.1 markus 944: child_set_env(&env, &envsize, "USER", pw->pw_name);
945: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
946: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.145 markus 947: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
948: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
949: else
950: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.1 markus 951:
952: snprintf(buf, sizeof buf, "%.200s/%.50s",
953: _PATH_MAILDIR, pw->pw_name);
954: child_set_env(&env, &envsize, "MAIL", buf);
955:
956: /* Normal systems set SHELL by default. */
957: child_set_env(&env, &envsize, "SHELL", shell);
958: }
959: if (getenv("TZ"))
960: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
961:
962: /* Set custom environment options from RSA authentication. */
1.110 markus 963: if (!options.use_login) {
964: while (custom_environment) {
965: struct envstring *ce = custom_environment;
1.143 deraadt 966: char *str = ce->s;
1.127 markus 967:
1.143 deraadt 968: for (i = 0; str[i] != '=' && str[i]; i++)
1.110 markus 969: ;
1.143 deraadt 970: if (str[i] == '=') {
971: str[i] = 0;
972: child_set_env(&env, &envsize, str, str + i + 1);
1.110 markus 973: }
974: custom_environment = ce->next;
975: xfree(ce->s);
976: xfree(ce);
1.1 markus 977: }
978: }
979:
1.149 stevesk 980: /* SSH_CLIENT deprecated */
1.1 markus 981: snprintf(buf, sizeof buf, "%.50s %d %d",
1.127 markus 982: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 983: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 984:
1.154 markus 985: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 986: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.154 markus 987: get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
988: xfree(laddr);
1.149 stevesk 989: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 990:
1.60 markus 991: if (s->ttyfd != -1)
992: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
993: if (s->term)
994: child_set_env(&env, &envsize, "TERM", s->term);
995: if (s->display)
996: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 997: if (original_command)
998: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
999: original_command);
1.96 dugsong 1000: #ifdef KRB5
1001: if (s->authctxt->krb5_ticket_file)
1002: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 1003: s->authctxt->krb5_ticket_file);
1.96 dugsong 1004: #endif
1.136 markus 1005: if (auth_sock_name != NULL)
1.1 markus 1006: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 1007: auth_sock_name);
1.1 markus 1008:
1009: /* read $HOME/.ssh/environment. */
1.146 markus 1010: if (options.permit_user_env && !options.use_login) {
1.14 deraadt 1011: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1012: pw->pw_dir);
1.1 markus 1013: read_environment_file(&env, &envsize, buf);
1014: }
1015: if (debug_flag) {
1016: /* dump the environment */
1017: fprintf(stderr, "Environment:\n");
1018: for (i = 0; env[i]; i++)
1019: fprintf(stderr, " %.200s\n", env[i]);
1020: }
1.127 markus 1021: return env;
1022: }
1023:
1024: /*
1025: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1026: * first in this order).
1027: */
1028: static void
1029: do_rc_files(Session *s, const char *shell)
1030: {
1031: FILE *f = NULL;
1032: char cmd[1024];
1033: int do_xauth;
1034: struct stat st;
1035:
1036: do_xauth =
1037: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1038:
1.231 djm 1039: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 1040: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.234 djm 1041: !no_user_rc && stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 1042: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1043: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1044: if (debug_flag)
1045: fprintf(stderr, "Running %s\n", cmd);
1046: f = popen(cmd, "w");
1047: if (f) {
1048: if (do_xauth)
1049: fprintf(f, "%s %s\n", s->auth_proto,
1050: s->auth_data);
1051: pclose(f);
1052: } else
1053: fprintf(stderr, "Could not run %s\n",
1054: _PATH_SSH_USER_RC);
1055: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1056: if (debug_flag)
1057: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1058: _PATH_SSH_SYSTEM_RC);
1059: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1060: if (f) {
1061: if (do_xauth)
1062: fprintf(f, "%s %s\n", s->auth_proto,
1063: s->auth_data);
1064: pclose(f);
1065: } else
1066: fprintf(stderr, "Could not run %s\n",
1067: _PATH_SSH_SYSTEM_RC);
1068: } else if (do_xauth && options.xauth_location != NULL) {
1069: /* Add authority data to .Xauthority if appropriate. */
1070: if (debug_flag) {
1071: fprintf(stderr,
1.151 stevesk 1072: "Running %.500s remove %.100s\n",
1.165 markus 1073: options.xauth_location, s->auth_display);
1.151 stevesk 1074: fprintf(stderr,
1075: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 1076: options.xauth_location, s->auth_display,
1077: s->auth_proto, s->auth_data);
1078: }
1079: snprintf(cmd, sizeof cmd, "%s -q -",
1080: options.xauth_location);
1081: f = popen(cmd, "w");
1082: if (f) {
1.151 stevesk 1083: fprintf(f, "remove %s\n",
1084: s->auth_display);
1.127 markus 1085: fprintf(f, "add %s %s %s\n",
1086: s->auth_display, s->auth_proto,
1087: s->auth_data);
1088: pclose(f);
1089: } else {
1090: fprintf(stderr, "Could not run %s\n",
1091: cmd);
1092: }
1093: }
1094: }
1095:
1096: static void
1097: do_nologin(struct passwd *pw)
1098: {
1099: FILE *f = NULL;
1100: char buf[1024];
1101:
1102: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1103: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1104: _PATH_NOLOGIN), "r");
1105: if (f) {
1106: /* /etc/nologin exists. Print its contents and exit. */
1.155 itojun 1107: logit("User %.100s not allowed because %s exists",
1.150 stevesk 1108: pw->pw_name, _PATH_NOLOGIN);
1.127 markus 1109: while (fgets(buf, sizeof(buf), f))
1110: fputs(buf, stderr);
1111: fclose(f);
1112: exit(254);
1113: }
1114: }
1115:
1.226 djm 1116: /*
1117: * Chroot into a directory after checking it for safety: all path components
1118: * must be root-owned directories with strict permissions.
1119: */
1120: static void
1121: safely_chroot(const char *path, uid_t uid)
1122: {
1123: const char *cp;
1124: char component[MAXPATHLEN];
1125: struct stat st;
1126:
1127: if (*path != '/')
1128: fatal("chroot path does not begin at root");
1129: if (strlen(path) >= sizeof(component))
1130: fatal("chroot path too long");
1131:
1132: /*
1133: * Descend the path, checking that each component is a
1134: * root-owned directory with strict permissions.
1135: */
1136: for (cp = path; cp != NULL;) {
1137: if ((cp = strchr(cp, '/')) == NULL)
1138: strlcpy(component, path, sizeof(component));
1139: else {
1140: cp++;
1141: memcpy(component, path, cp - path);
1142: component[cp - path] = '\0';
1143: }
1144:
1145: debug3("%s: checking '%s'", __func__, component);
1146:
1147: if (stat(component, &st) != 0)
1148: fatal("%s: stat(\"%s\"): %s", __func__,
1149: component, strerror(errno));
1150: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1151: fatal("bad ownership or modes for chroot "
1152: "directory %s\"%s\"",
1153: cp == NULL ? "" : "component ", component);
1154: if (!S_ISDIR(st.st_mode))
1155: fatal("chroot path %s\"%s\" is not a directory",
1156: cp == NULL ? "" : "component ", component);
1157:
1158: }
1159:
1160: if (chdir(path) == -1)
1161: fatal("Unable to chdir to chroot path \"%s\": "
1162: "%s", path, strerror(errno));
1163: if (chroot(path) == -1)
1164: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1165: if (chdir("/") == -1)
1166: fatal("%s: chdir(/) after chroot: %s",
1167: __func__, strerror(errno));
1168: verbose("Changed root directory to \"%s\"", path);
1169: }
1170:
1.127 markus 1171: /* Set login name, uid, gid, and groups. */
1.130 provos 1172: void
1.127 markus 1173: do_setusercontext(struct passwd *pw)
1174: {
1.227 djm 1175: char *chroot_path, *tmp;
1176:
1.127 markus 1177: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1178: /* Prepare groups */
1.127 markus 1179: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1180: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1181: perror("unable to set user context");
1182: exit(1);
1183: }
1.226 djm 1184:
1185: if (options.chroot_directory != NULL &&
1186: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1187: tmp = tilde_expand_filename(options.chroot_directory,
1188: pw->pw_uid);
1189: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1190: "u", pw->pw_name, (char *)NULL);
1.226 djm 1191: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1192: free(tmp);
1.226 djm 1193: free(chroot_path);
1194: }
1195:
1196: /* Set UID */
1197: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1198: perror("unable to set user context (setuser)");
1199: exit(1);
1200: }
1.127 markus 1201: }
1202: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1203: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1204: }
1205:
1.131 markus 1206: static void
1.172 markus 1207: do_pwchange(Session *s)
1208: {
1.179 dtucker 1209: fflush(NULL);
1.172 markus 1210: fprintf(stderr, "WARNING: Your password has expired.\n");
1211: if (s->ttyfd != -1) {
1.178 deraadt 1212: fprintf(stderr,
1.172 markus 1213: "You must change your password now and login again!\n");
1214: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1215: perror("passwd");
1216: } else {
1217: fprintf(stderr,
1218: "Password change required but no TTY available.\n");
1219: }
1220: exit(1);
1221: }
1222:
1223: static void
1.130 provos 1224: launch_login(struct passwd *pw, const char *hostname)
1225: {
1226: /* Launch login(1). */
1227:
1228: execl("/usr/bin/login", "login", "-h", hostname,
1229: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1230:
1231: /* Login couldn't be executed, die. */
1232:
1233: perror("login");
1234: exit(1);
1235: }
1236:
1.172 markus 1237: static void
1238: child_close_fds(void)
1239: {
1240: int i;
1241:
1242: if (packet_get_connection_in() == packet_get_connection_out())
1243: close(packet_get_connection_in());
1244: else {
1245: close(packet_get_connection_in());
1246: close(packet_get_connection_out());
1247: }
1248: /*
1249: * Close all descriptors related to channels. They will still remain
1250: * open in the parent.
1251: */
1252: /* XXX better use close-on-exec? -markus */
1253: channel_close_all();
1254:
1255: /*
1256: * Close any extra file descriptors. Note that there may still be
1257: * descriptors left by system functions. They will be closed later.
1258: */
1259: endpwent();
1260:
1261: /*
1.188 djm 1262: * Close any extra open file descriptors so that we don't have them
1.172 markus 1263: * hanging around in clients. Note that we want to do this after
1264: * initgroups, because at least on Solaris 2.3 it leaves file
1265: * descriptors open.
1266: */
1267: for (i = 3; i < 64; i++)
1268: close(i);
1269: }
1270:
1.127 markus 1271: /*
1272: * Performs common processing for the child, such as setting up the
1273: * environment, closing extra file descriptors, setting the user and group
1274: * ids, and executing the command or shell.
1275: */
1.225 markus 1276: #define ARGV_MAX 10
1.127 markus 1277: void
1278: do_child(Session *s, const char *command)
1279: {
1280: extern char **environ;
1281: char **env;
1.225 markus 1282: char *argv[ARGV_MAX];
1.127 markus 1283: const char *shell, *shell0, *hostname = NULL;
1284: struct passwd *pw = s->pw;
1.239 djm 1285: int r = 0;
1.127 markus 1286:
1287: /* remove hostkey from the child's memory */
1288: destroy_sensitive_data();
1289:
1.172 markus 1290: /* Force a password change */
1291: if (s->authctxt->force_pwchange) {
1292: do_setusercontext(pw);
1293: child_close_fds();
1294: do_pwchange(s);
1295: exit(1);
1296: }
1297:
1.127 markus 1298: /* login(1) is only called if we execute the login shell */
1299: if (options.use_login && command != NULL)
1300: options.use_login = 0;
1301:
1302: /*
1303: * Login(1) does this as well, and it needs uid 0 for the "-h"
1304: * switch, so we let login(1) to this for us.
1305: */
1306: if (!options.use_login) {
1307: do_nologin(pw);
1308: do_setusercontext(pw);
1309: }
1310:
1311: /*
1312: * Get the shell from the password data. An empty shell field is
1313: * legal, and means /bin/sh.
1314: */
1315: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1316:
1317: /*
1318: * Make sure $SHELL points to the shell from the password file,
1319: * even if shell is overridden from login.conf
1320: */
1321: env = do_setup_env(s, shell);
1322:
1.127 markus 1323: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1324:
1.26 millert 1325: /* we have to stash the hostname before we close our socket. */
1326: if (options.use_login)
1.70 stevesk 1327: hostname = get_remote_name_or_ip(utmp_len,
1.158 markus 1328: options.use_dns);
1.1 markus 1329: /*
1330: * Close the connection descriptors; note that this is the child, and
1331: * the server will still have the socket open, and it is important
1332: * that we do not shutdown it. Note that the descriptors cannot be
1333: * closed before building the environment, as we call
1334: * get_remote_ipaddr there.
1335: */
1.172 markus 1336: child_close_fds();
1.1 markus 1337:
1338: /*
1.125 deraadt 1339: * Must take new environment into use so that .ssh/rc,
1340: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1341: */
1342: environ = env;
1.170 jakob 1343:
1344: #ifdef KRB5
1345: /*
1346: * At this point, we check to see if AFS is active and if we have
1347: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1348: * if we can (and need to) extend the ticket into an AFS token. If
1349: * we don't do this, we run into potential problems if the user's
1350: * home directory is in AFS and it's not world-readable.
1351: */
1352:
1353: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1354: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1355: char cell[64];
1356:
1357: debug("Getting AFS token");
1358:
1359: k_setpag();
1360:
1361: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1362: krb5_afslog(s->authctxt->krb5_ctx,
1363: s->authctxt->krb5_fwd_ccache, cell, NULL);
1364:
1365: krb5_afslog_home(s->authctxt->krb5_ctx,
1366: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1367: }
1368: #endif
1.104 markus 1369:
1.188 djm 1370: /* Change current directory to the user's home directory. */
1.104 markus 1371: if (chdir(pw->pw_dir) < 0) {
1.239 djm 1372: /* Suppress missing homedir warning for chroot case */
1373: r = login_getcapbool(lc, "requirehome", 0);
1374: if (r || options.chroot_directory == NULL)
1375: fprintf(stderr, "Could not chdir to home "
1376: "directory %s: %s\n", pw->pw_dir,
1377: strerror(errno));
1378: if (r)
1.104 markus 1379: exit(1);
1380: }
1.230 djm 1381:
1382: closefrom(STDERR_FILENO + 1);
1.1 markus 1383:
1.127 markus 1384: if (!options.use_login)
1385: do_rc_files(s, shell);
1.67 markus 1386:
1387: /* restore SIGPIPE for child */
1.217 stevesk 1388: signal(SIGPIPE, SIG_DFL);
1.67 markus 1389:
1.225 markus 1390: if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1391: extern int optind, optreset;
1392: int i;
1393: char *p, *args;
1394:
1.246 ! stevesk 1395: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.243 millert 1396: args = xstrdup(command ? command : "sftp-server");
1.225 markus 1397: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1398: if (i < ARGV_MAX - 1)
1399: argv[i++] = p;
1400: argv[i] = NULL;
1401: optind = optreset = 1;
1402: __progname = argv[0];
1.226 djm 1403: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1404: }
1405:
1.127 markus 1406: if (options.use_login) {
1.130 provos 1407: launch_login(pw, hostname);
1408: /* NEVERREACHED */
1.127 markus 1409: }
1410:
1411: /* Get the last component of the shell name. */
1412: if ((shell0 = strrchr(shell, '/')) != NULL)
1413: shell0++;
1414: else
1415: shell0 = shell;
1416:
1.1 markus 1417: /*
1418: * If we have no command, execute the shell. In this case, the shell
1419: * name to be passed in argv[0] is preceded by '-' to indicate that
1420: * this is a login shell.
1421: */
1422: if (!command) {
1.127 markus 1423: char argv0[256];
1.1 markus 1424:
1.127 markus 1425: /* Start the shell. Set initial character to '-'. */
1426: argv0[0] = '-';
1.1 markus 1427:
1.127 markus 1428: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1429: >= sizeof(argv0) - 1) {
1.127 markus 1430: errno = EINVAL;
1.1 markus 1431: perror(shell);
1432: exit(1);
1.127 markus 1433: }
1.1 markus 1434:
1.127 markus 1435: /* Execute the shell. */
1436: argv[0] = argv0;
1437: argv[1] = NULL;
1438: execve(shell, argv, env);
1439:
1440: /* Executing the shell failed. */
1441: perror(shell);
1442: exit(1);
1.1 markus 1443: }
1444: /*
1445: * Execute the command using the user's shell. This uses the -c
1446: * option to execute the command.
1447: */
1.127 markus 1448: argv[0] = (char *) shell0;
1.1 markus 1449: argv[1] = "-c";
1450: argv[2] = (char *) command;
1451: argv[3] = NULL;
1452: execve(shell, argv, env);
1453: perror(shell);
1454: exit(1);
1455: }
1456:
1.237 djm 1457: void
1458: session_unused(int id)
1459: {
1460: debug3("%s: session id %d unused", __func__, id);
1461: if (id >= options.max_sessions ||
1462: id >= sessions_nalloc) {
1463: fatal("%s: insane session id %d (max %d nalloc %d)",
1464: __func__, id, options.max_sessions, sessions_nalloc);
1465: }
1466: bzero(&sessions[id], sizeof(*sessions));
1467: sessions[id].self = id;
1468: sessions[id].used = 0;
1469: sessions[id].chanid = -1;
1470: sessions[id].ptyfd = -1;
1471: sessions[id].ttyfd = -1;
1472: sessions[id].ptymaster = -1;
1473: sessions[id].x11_chanids = NULL;
1474: sessions[id].next_unused = sessions_first_unused;
1475: sessions_first_unused = id;
1476: }
1477:
1.1 markus 1478: Session *
1479: session_new(void)
1480: {
1.237 djm 1481: Session *s, *tmp;
1482:
1483: if (sessions_first_unused == -1) {
1484: if (sessions_nalloc >= options.max_sessions)
1485: return NULL;
1486: debug2("%s: allocate (allocated %d max %d)",
1487: __func__, sessions_nalloc, options.max_sessions);
1488: tmp = xrealloc(sessions, sessions_nalloc + 1,
1489: sizeof(*sessions));
1490: if (tmp == NULL) {
1491: error("%s: cannot allocate %d sessions",
1492: __func__, sessions_nalloc + 1);
1493: return NULL;
1494: }
1495: sessions = tmp;
1496: session_unused(sessions_nalloc++);
1497: }
1498:
1499: if (sessions_first_unused >= sessions_nalloc ||
1500: sessions_first_unused < 0) {
1501: fatal("%s: insane first_unused %d max %d nalloc %d",
1502: __func__, sessions_first_unused, options.max_sessions,
1503: sessions_nalloc);
1504: }
1505:
1506: s = &sessions[sessions_first_unused];
1507: if (s->used) {
1508: fatal("%s: session %d already used",
1509: __func__, sessions_first_unused);
1510: }
1511: sessions_first_unused = s->next_unused;
1512: s->used = 1;
1513: s->next_unused = -1;
1514: debug("session_new: session %d", s->self);
1515:
1516: return s;
1.1 markus 1517: }
1518:
1.94 itojun 1519: static void
1.1 markus 1520: session_dump(void)
1521: {
1522: int i;
1.237 djm 1523: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1524: Session *s = &sessions[i];
1.237 djm 1525:
1526: debug("dump: used %d next_unused %d session %d %p "
1527: "channel %d pid %ld",
1.1 markus 1528: s->used,
1.237 djm 1529: s->next_unused,
1.1 markus 1530: s->self,
1531: s,
1532: s->chanid,
1.137 mpech 1533: (long)s->pid);
1.1 markus 1534: }
1535: }
1536:
1.2 markus 1537: int
1.97 markus 1538: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1539: {
1540: Session *s = session_new();
1541: debug("session_open: channel %d", chanid);
1542: if (s == NULL) {
1543: error("no more sessions");
1544: return 0;
1545: }
1.97 markus 1546: s->authctxt = authctxt;
1547: s->pw = authctxt->pw;
1.167 djm 1548: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1549: fatal("no user for session %d", s->self);
1.2 markus 1550: debug("session_open: session %d: link with channel %d", s->self, chanid);
1551: s->chanid = chanid;
1552: return 1;
1553: }
1554:
1.130 provos 1555: Session *
1556: session_by_tty(char *tty)
1557: {
1558: int i;
1.237 djm 1559: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1560: Session *s = &sessions[i];
1561: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1562: debug("session_by_tty: session %d tty %s", i, tty);
1563: return s;
1564: }
1565: }
1566: debug("session_by_tty: unknown tty %.100s", tty);
1567: session_dump();
1568: return NULL;
1569: }
1570:
1.94 itojun 1571: static Session *
1.2 markus 1572: session_by_channel(int id)
1573: {
1574: int i;
1.237 djm 1575: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1576: Session *s = &sessions[i];
1577: if (s->used && s->chanid == id) {
1.237 djm 1578: debug("session_by_channel: session %d channel %d",
1579: i, id);
1.2 markus 1580: return s;
1581: }
1582: }
1583: debug("session_by_channel: unknown channel %d", id);
1584: session_dump();
1585: return NULL;
1586: }
1587:
1.94 itojun 1588: static Session *
1.184 djm 1589: session_by_x11_channel(int id)
1590: {
1591: int i, j;
1592:
1.237 djm 1593: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1594: Session *s = &sessions[i];
1595:
1596: if (s->x11_chanids == NULL || !s->used)
1597: continue;
1598: for (j = 0; s->x11_chanids[j] != -1; j++) {
1599: if (s->x11_chanids[j] == id) {
1600: debug("session_by_x11_channel: session %d "
1601: "channel %d", s->self, id);
1602: return s;
1603: }
1604: }
1605: }
1606: debug("session_by_x11_channel: unknown channel %d", id);
1607: session_dump();
1608: return NULL;
1609: }
1610:
1611: static Session *
1.2 markus 1612: session_by_pid(pid_t pid)
1613: {
1614: int i;
1.137 mpech 1615: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1616: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1617: Session *s = &sessions[i];
1618: if (s->used && s->pid == pid)
1619: return s;
1620: }
1.137 mpech 1621: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1622: session_dump();
1623: return NULL;
1624: }
1625:
1.94 itojun 1626: static int
1.2 markus 1627: session_window_change_req(Session *s)
1628: {
1629: s->col = packet_get_int();
1630: s->row = packet_get_int();
1631: s->xpixel = packet_get_int();
1632: s->ypixel = packet_get_int();
1.116 markus 1633: packet_check_eom();
1.2 markus 1634: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1635: return 1;
1636: }
1637:
1.94 itojun 1638: static int
1.2 markus 1639: session_pty_req(Session *s)
1640: {
1.45 markus 1641: u_int len;
1.72 stevesk 1642: int n_bytes;
1.132 markus 1643:
1.86 markus 1644: if (no_pty_flag) {
1645: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1646: return 0;
1.86 markus 1647: }
1648: if (s->ttyfd != -1) {
1649: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1650: return 0;
1.86 markus 1651: }
1652:
1.2 markus 1653: s->term = packet_get_string(&len);
1.86 markus 1654:
1655: if (compat20) {
1656: s->col = packet_get_int();
1657: s->row = packet_get_int();
1658: } else {
1659: s->row = packet_get_int();
1660: s->col = packet_get_int();
1661: }
1.2 markus 1662: s->xpixel = packet_get_int();
1663: s->ypixel = packet_get_int();
1664:
1665: if (strcmp(s->term, "") == 0) {
1666: xfree(s->term);
1667: s->term = NULL;
1668: }
1.86 markus 1669:
1.2 markus 1670: /* Allocate a pty and open it. */
1.86 markus 1671: debug("Allocating pty.");
1.237 djm 1672: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1673: sizeof(s->tty)))) {
1.86 markus 1674: if (s->term)
1675: xfree(s->term);
1.2 markus 1676: s->term = NULL;
1677: s->ptyfd = -1;
1678: s->ttyfd = -1;
1679: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1680: return 0;
1.2 markus 1681: }
1682: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1683:
1684: /* for SSH1 the tty modes length is not given */
1685: if (!compat20)
1686: n_bytes = packet_remaining();
1687: tty_parse_modes(s->ttyfd, &n_bytes);
1688:
1.130 provos 1689: if (!use_privsep)
1690: pty_setowner(s->pw, s->tty);
1.86 markus 1691:
1692: /* Set window size from the packet. */
1.2 markus 1693: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1694:
1.116 markus 1695: packet_check_eom();
1.9 markus 1696: session_proctitle(s);
1.2 markus 1697: return 1;
1698: }
1699:
1.94 itojun 1700: static int
1.7 markus 1701: session_subsystem_req(Session *s)
1702: {
1.105 markus 1703: struct stat st;
1.45 markus 1704: u_int len;
1.7 markus 1705: int success = 0;
1.205 djm 1706: char *prog, *cmd, *subsys = packet_get_string(&len);
1.182 djm 1707: u_int i;
1.7 markus 1708:
1.116 markus 1709: packet_check_eom();
1.155 itojun 1710: logit("subsystem request for %.100s", subsys);
1.18 jakob 1711:
1712: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1713: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1714: prog = options.subsystem_command[i];
1715: cmd = options.subsystem_args[i];
1.226 djm 1716: if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
1.225 markus 1717: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1718: } else if (stat(prog, &st) < 0) {
1.205 djm 1719: error("subsystem: cannot stat %s: %s", prog,
1.105 markus 1720: strerror(errno));
1721: break;
1.225 markus 1722: } else {
1723: s->is_subsystem = SUBSYSTEM_EXT;
1.105 markus 1724: }
1725: debug("subsystem: exec() %s", cmd);
1.237 djm 1726: success = do_exec(s, cmd) == 0;
1.122 markus 1727: break;
1.18 jakob 1728: }
1729: }
1730:
1731: if (!success)
1.155 itojun 1732: logit("subsystem request for %.100s failed, subsystem not found",
1.105 markus 1733: subsys);
1.7 markus 1734:
1735: xfree(subsys);
1736: return success;
1737: }
1738:
1.94 itojun 1739: static int
1.7 markus 1740: session_x11_req(Session *s)
1741: {
1.81 markus 1742: int success;
1.7 markus 1743:
1.184 djm 1744: if (s->auth_proto != NULL || s->auth_data != NULL) {
1745: error("session_x11_req: session %d: "
1.190 stevesk 1746: "x11 forwarding already active", s->self);
1.184 djm 1747: return 0;
1748: }
1.7 markus 1749: s->single_connection = packet_get_char();
1750: s->auth_proto = packet_get_string(NULL);
1751: s->auth_data = packet_get_string(NULL);
1752: s->screen = packet_get_int();
1.116 markus 1753: packet_check_eom();
1.7 markus 1754:
1.81 markus 1755: success = session_setup_x11fwd(s);
1756: if (!success) {
1.7 markus 1757: xfree(s->auth_proto);
1758: xfree(s->auth_data);
1.84 markus 1759: s->auth_proto = NULL;
1760: s->auth_data = NULL;
1.7 markus 1761: }
1.81 markus 1762: return success;
1.7 markus 1763: }
1764:
1.94 itojun 1765: static int
1.19 markus 1766: session_shell_req(Session *s)
1767: {
1.116 markus 1768: packet_check_eom();
1.237 djm 1769: return do_exec(s, NULL) == 0;
1.19 markus 1770: }
1771:
1.94 itojun 1772: static int
1.19 markus 1773: session_exec_req(Session *s)
1774: {
1.237 djm 1775: u_int len, success;
1776:
1.19 markus 1777: char *command = packet_get_string(&len);
1.116 markus 1778: packet_check_eom();
1.237 djm 1779: success = do_exec(s, command) == 0;
1.92 markus 1780: xfree(command);
1.237 djm 1781: return success;
1.19 markus 1782: }
1783:
1.94 itojun 1784: static int
1.157 markus 1785: session_break_req(Session *s)
1786: {
1787:
1.175 deraadt 1788: packet_get_int(); /* ignored */
1.157 markus 1789: packet_check_eom();
1790:
1.237 djm 1791: if (s->ttyfd == -1 || tcsendbreak(s->ttyfd, 0) < 0)
1.157 markus 1792: return 0;
1793: return 1;
1794: }
1795:
1796: static int
1.173 djm 1797: session_env_req(Session *s)
1798: {
1799: char *name, *val;
1800: u_int name_len, val_len, i;
1801:
1802: name = packet_get_string(&name_len);
1803: val = packet_get_string(&val_len);
1804: packet_check_eom();
1805:
1806: /* Don't set too many environment variables */
1807: if (s->num_env > 128) {
1808: debug2("Ignoring env request %s: too many env vars", name);
1809: goto fail;
1810: }
1811:
1812: for (i = 0; i < options.num_accept_env; i++) {
1813: if (match_pattern(name, options.accept_env[i])) {
1814: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.201 djm 1815: s->env = xrealloc(s->env, s->num_env + 1,
1816: sizeof(*s->env));
1.173 djm 1817: s->env[s->num_env].name = name;
1818: s->env[s->num_env].val = val;
1819: s->num_env++;
1820: return (1);
1821: }
1822: }
1823: debug2("Ignoring env request %s: disallowed name", name);
1824:
1825: fail:
1826: xfree(name);
1827: xfree(val);
1828: return (0);
1829: }
1830:
1831: static int
1.43 markus 1832: session_auth_agent_req(Session *s)
1833: {
1834: static int called = 0;
1.116 markus 1835: packet_check_eom();
1.235 pyr 1836: if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
1.44 markus 1837: debug("session_auth_agent_req: no_agent_forwarding_flag");
1838: return 0;
1839: }
1.43 markus 1840: if (called) {
1841: return 0;
1842: } else {
1843: called = 1;
1844: return auth_input_request_forwarding(s->pw);
1845: }
1846: }
1847:
1.123 markus 1848: int
1849: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1850: {
1851: int success = 0;
1852: Session *s;
1853:
1.123 markus 1854: if ((s = session_by_channel(c->self)) == NULL) {
1.155 itojun 1855: logit("session_input_channel_req: no session %d req %.100s",
1.123 markus 1856: c->self, rtype);
1857: return 0;
1858: }
1859: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1860:
1861: /*
1.64 markus 1862: * a session is in LARVAL state until a shell, a command
1863: * or a subsystem is executed
1.2 markus 1864: */
1865: if (c->type == SSH_CHANNEL_LARVAL) {
1866: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1867: success = session_shell_req(s);
1.2 markus 1868: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1869: success = session_exec_req(s);
1.2 markus 1870: } else if (strcmp(rtype, "pty-req") == 0) {
1.221 stevesk 1871: success = session_pty_req(s);
1.7 markus 1872: } else if (strcmp(rtype, "x11-req") == 0) {
1873: success = session_x11_req(s);
1.43 markus 1874: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1875: success = session_auth_agent_req(s);
1.7 markus 1876: } else if (strcmp(rtype, "subsystem") == 0) {
1877: success = session_subsystem_req(s);
1.173 djm 1878: } else if (strcmp(rtype, "env") == 0) {
1879: success = session_env_req(s);
1.2 markus 1880: }
1881: }
1882: if (strcmp(rtype, "window-change") == 0) {
1883: success = session_window_change_req(s);
1.177 djm 1884: } else if (strcmp(rtype, "break") == 0) {
1885: success = session_break_req(s);
1.2 markus 1886: }
1.177 djm 1887:
1.123 markus 1888: return success;
1.2 markus 1889: }
1890:
1891: void
1.241 dtucker 1892: session_set_fds(Session *s, int fdin, int fdout, int fderr, int is_tty)
1.2 markus 1893: {
1894: if (!compat20)
1895: fatal("session_set_fds: called for proto != 2.0");
1896: /*
1897: * now that have a child and a pipe to the child,
1898: * we can activate our channel and register the fd's
1899: */
1900: if (s->chanid == -1)
1901: fatal("no channel for session %d", s->self);
1902: channel_set_fds(s->chanid,
1903: fdout, fdin, fderr,
1.42 markus 1904: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.241 dtucker 1905: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1906: }
1907:
1.85 markus 1908: /*
1909: * Function to perform pty cleanup. Also called if we get aborted abnormally
1910: * (e.g., due to a dropped connection).
1911: */
1.130 provos 1912: void
1.165 markus 1913: session_pty_cleanup2(Session *s)
1.1 markus 1914: {
1.85 markus 1915: if (s == NULL) {
1916: error("session_pty_cleanup: no session");
1917: return;
1918: }
1919: if (s->ttyfd == -1)
1.1 markus 1920: return;
1921:
1.54 stevesk 1922: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1923:
1924: /* Record that the user has logged out. */
1.85 markus 1925: if (s->pid != 0)
1926: record_logout(s->pid, s->tty);
1.1 markus 1927:
1928: /* Release the pseudo-tty. */
1.130 provos 1929: if (getuid() == 0)
1930: pty_release(s->tty);
1.1 markus 1931:
1932: /*
1933: * Close the server side of the socket pairs. We must do this after
1934: * the pty cleanup, so that another process doesn't get this pty
1935: * while we're still cleaning up.
1936: */
1.237 djm 1937: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1938: error("close(s->ptymaster/%d): %s",
1939: s->ptymaster, strerror(errno));
1.108 markus 1940:
1941: /* unlink pty from session */
1942: s->ttyfd = -1;
1.2 markus 1943: }
1944:
1.130 provos 1945: void
1.165 markus 1946: session_pty_cleanup(Session *s)
1.130 provos 1947: {
1.165 markus 1948: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1949: }
1950:
1.147 markus 1951: static char *
1952: sig2name(int sig)
1953: {
1954: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1955: SSH_SIG(ABRT);
1956: SSH_SIG(ALRM);
1957: SSH_SIG(FPE);
1958: SSH_SIG(HUP);
1959: SSH_SIG(ILL);
1960: SSH_SIG(INT);
1961: SSH_SIG(KILL);
1962: SSH_SIG(PIPE);
1963: SSH_SIG(QUIT);
1964: SSH_SIG(SEGV);
1965: SSH_SIG(TERM);
1966: SSH_SIG(USR1);
1967: SSH_SIG(USR2);
1968: #undef SSH_SIG
1969: return "SIG@openssh.com";
1970: }
1971:
1.94 itojun 1972: static void
1.184 djm 1973: session_close_x11(int id)
1974: {
1975: Channel *c;
1976:
1.189 markus 1977: if ((c = channel_by_id(id)) == NULL) {
1.184 djm 1978: debug("session_close_x11: x11 channel %d missing", id);
1979: } else {
1980: /* Detach X11 listener */
1981: debug("session_close_x11: detach x11 channel %d", id);
1982: channel_cancel_cleanup(id);
1983: if (c->ostate != CHAN_OUTPUT_CLOSED)
1984: chan_mark_dead(c);
1985: }
1986: }
1987:
1988: static void
1989: session_close_single_x11(int id, void *arg)
1990: {
1991: Session *s;
1992: u_int i;
1993:
1994: debug3("session_close_single_x11: channel %d", id);
1995: channel_cancel_cleanup(id);
1.221 stevesk 1996: if ((s = session_by_x11_channel(id)) == NULL)
1.184 djm 1997: fatal("session_close_single_x11: no x11 channel %d", id);
1998: for (i = 0; s->x11_chanids[i] != -1; i++) {
1999: debug("session_close_single_x11: session %d: "
2000: "closing channel %d", s->self, s->x11_chanids[i]);
2001: /*
2002: * The channel "id" is already closing, but make sure we
2003: * close all of its siblings.
2004: */
2005: if (s->x11_chanids[i] != id)
2006: session_close_x11(s->x11_chanids[i]);
2007: }
2008: xfree(s->x11_chanids);
2009: s->x11_chanids = NULL;
2010: if (s->display) {
2011: xfree(s->display);
2012: s->display = NULL;
2013: }
2014: if (s->auth_proto) {
2015: xfree(s->auth_proto);
2016: s->auth_proto = NULL;
2017: }
2018: if (s->auth_data) {
2019: xfree(s->auth_data);
2020: s->auth_data = NULL;
2021: }
2022: if (s->auth_display) {
2023: xfree(s->auth_display);
2024: s->auth_display = NULL;
2025: }
2026: }
2027:
2028: static void
1.2 markus 2029: session_exit_message(Session *s, int status)
2030: {
2031: Channel *c;
1.124 markus 2032:
2033: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 2034: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 2035: s->self, s->chanid);
1.137 mpech 2036: debug("session_exit_message: session %d channel %d pid %ld",
2037: s->self, s->chanid, (long)s->pid);
1.2 markus 2038:
2039: if (WIFEXITED(status)) {
1.124 markus 2040: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 2041: packet_put_int(WEXITSTATUS(status));
2042: packet_send();
2043: } else if (WIFSIGNALED(status)) {
1.124 markus 2044: channel_request_start(s->chanid, "exit-signal", 0);
1.147 markus 2045: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 2046: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 2047: packet_put_cstring("");
2048: packet_put_cstring("");
2049: packet_send();
2050: } else {
2051: /* Some weird exit cause. Just exit. */
2052: packet_disconnect("wait returned status %04x.", status);
2053: }
2054:
2055: /* disconnect channel */
2056: debug("session_exit_message: release channel %d", s->chanid);
1.187 djm 2057:
2058: /*
2059: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 2060: * the channel gets EOF. The session will be then be closed
1.187 djm 2061: * by session_close_by_channel when the childs close their fds.
2062: */
2063: channel_register_cleanup(c->self, session_close_by_channel, 1);
2064:
1.5 markus 2065: /*
2066: * emulate a write failure with 'chan_write_failed', nobody will be
2067: * interested in data we write.
2068: * Note that we must not call 'chan_read_failed', since there could
2069: * be some more data waiting in the pipe.
2070: */
1.8 markus 2071: if (c->ostate != CHAN_OUTPUT_CLOSED)
2072: chan_write_failed(c);
1.2 markus 2073: }
2074:
1.130 provos 2075: void
1.85 markus 2076: session_close(Session *s)
1.2 markus 2077: {
1.182 djm 2078: u_int i;
1.173 djm 2079:
1.137 mpech 2080: debug("session_close: session %d pid %ld", s->self, (long)s->pid);
1.165 markus 2081: if (s->ttyfd != -1)
1.85 markus 2082: session_pty_cleanup(s);
1.2 markus 2083: if (s->term)
2084: xfree(s->term);
2085: if (s->display)
2086: xfree(s->display);
1.184 djm 2087: if (s->x11_chanids)
2088: xfree(s->x11_chanids);
1.118 stevesk 2089: if (s->auth_display)
2090: xfree(s->auth_display);
1.2 markus 2091: if (s->auth_data)
2092: xfree(s->auth_data);
2093: if (s->auth_proto)
2094: xfree(s->auth_proto);
1.219 djm 2095: if (s->env != NULL) {
2096: for (i = 0; i < s->num_env; i++) {
2097: xfree(s->env[i].name);
2098: xfree(s->env[i].val);
2099: }
2100: xfree(s->env);
1.173 djm 2101: }
1.9 markus 2102: session_proctitle(s);
1.237 djm 2103: session_unused(s->self);
1.2 markus 2104: }
2105:
2106: void
2107: session_close_by_pid(pid_t pid, int status)
2108: {
2109: Session *s = session_by_pid(pid);
2110: if (s == NULL) {
1.137 mpech 2111: debug("session_close_by_pid: no session for pid %ld",
2112: (long)pid);
1.2 markus 2113: return;
2114: }
2115: if (s->chanid != -1)
2116: session_exit_message(s, status);
1.187 djm 2117: if (s->ttyfd != -1)
2118: session_pty_cleanup(s);
1.197 djm 2119: s->pid = 0;
1.98 markus 2120: }
2121:
1.2 markus 2122: /*
2123: * this is called when a channel dies before
2124: * the session 'child' itself dies
2125: */
2126: void
2127: session_close_by_channel(int id, void *arg)
2128: {
2129: Session *s = session_by_channel(id);
1.187 djm 2130: u_int i;
1.184 djm 2131:
1.2 markus 2132: if (s == NULL) {
1.107 markus 2133: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 2134: return;
2135: }
1.137 mpech 2136: debug("session_close_by_channel: channel %d child %ld",
2137: id, (long)s->pid);
1.107 markus 2138: if (s->pid != 0) {
2139: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 2140: /*
2141: * delay detach of session, but release pty, since
2142: * the fd's to the child are already closed
2143: */
1.165 markus 2144: if (s->ttyfd != -1)
1.108 markus 2145: session_pty_cleanup(s);
1.107 markus 2146: return;
2147: }
2148: /* detach by removing callback */
1.2 markus 2149: channel_cancel_cleanup(s->chanid);
1.187 djm 2150:
2151: /* Close any X11 listeners associated with this session */
2152: if (s->x11_chanids != NULL) {
2153: for (i = 0; s->x11_chanids[i] != -1; i++) {
2154: session_close_x11(s->x11_chanids[i]);
2155: s->x11_chanids[i] = -1;
2156: }
2157: }
2158:
1.2 markus 2159: s->chanid = -1;
1.106 markus 2160: session_close(s);
2161: }
2162:
2163: void
1.130 provos 2164: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 2165: {
2166: int i;
1.237 djm 2167: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2168: Session *s = &sessions[i];
1.130 provos 2169: if (s->used) {
2170: if (closefunc != NULL)
2171: closefunc(s);
2172: else
2173: session_close(s);
2174: }
1.2 markus 2175: }
1.9 markus 2176: }
2177:
1.94 itojun 2178: static char *
1.9 markus 2179: session_tty_list(void)
2180: {
2181: static char buf[1024];
2182: int i;
2183: buf[0] = '\0';
1.237 djm 2184: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2185: Session *s = &sessions[i];
2186: if (s->used && s->ttyfd != -1) {
2187: if (buf[0] != '\0')
2188: strlcat(buf, ",", sizeof buf);
2189: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2190: }
2191: }
2192: if (buf[0] == '\0')
2193: strlcpy(buf, "notty", sizeof buf);
2194: return buf;
2195: }
2196:
2197: void
2198: session_proctitle(Session *s)
2199: {
2200: if (s->pw == NULL)
2201: error("no user for session %d", s->self);
2202: else
2203: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2204: }
2205:
2206: int
2207: session_setup_x11fwd(Session *s)
2208: {
2209: struct stat st;
1.109 stevesk 2210: char display[512], auth_display[512];
2211: char hostname[MAXHOSTNAMELEN];
1.184 djm 2212: u_int i;
1.81 markus 2213:
2214: if (no_x11_forwarding_flag) {
2215: packet_send_debug("X11 forwarding disabled in user configuration file.");
2216: return 0;
2217: }
2218: if (!options.x11_forwarding) {
2219: debug("X11 forwarding disabled in server configuration file.");
2220: return 0;
2221: }
2222: if (!options.xauth_location ||
2223: (stat(options.xauth_location, &st) == -1)) {
2224: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 2225: return 0;
2226: }
2227: if (options.use_login) {
2228: packet_send_debug("X11 forwarding disabled; "
2229: "not compatible with UseLogin=yes.");
1.81 markus 2230: return 0;
2231: }
1.87 markus 2232: if (s->display != NULL) {
1.81 markus 2233: debug("X11 display already set.");
2234: return 0;
2235: }
1.140 deraadt 2236: if (x11_create_display_inet(options.x11_display_offset,
2237: options.x11_use_localhost, s->single_connection,
1.184 djm 2238: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2239: debug("x11_create_display_inet failed.");
1.81 markus 2240: return 0;
1.184 djm 2241: }
2242: for (i = 0; s->x11_chanids[i] != -1; i++) {
2243: channel_register_cleanup(s->x11_chanids[i],
1.187 djm 2244: session_close_single_x11, 0);
1.81 markus 2245: }
1.109 stevesk 2246:
2247: /* Set up a suitable value for the DISPLAY variable. */
2248: if (gethostname(hostname, sizeof(hostname)) < 0)
2249: fatal("gethostname: %.100s", strerror(errno));
2250: /*
2251: * auth_display must be used as the displayname when the
2252: * authorization entry is added with xauth(1). This will be
2253: * different than the DISPLAY string for localhost displays.
2254: */
1.119 stevesk 2255: if (options.x11_use_localhost) {
1.140 deraadt 2256: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2257: s->display_number, s->screen);
1.140 deraadt 2258: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2259: s->display_number, s->screen);
1.109 stevesk 2260: s->display = xstrdup(display);
1.118 stevesk 2261: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2262: } else {
1.140 deraadt 2263: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2264: s->display_number, s->screen);
2265: s->display = xstrdup(display);
1.118 stevesk 2266: s->auth_display = xstrdup(display);
1.109 stevesk 2267: }
2268:
1.81 markus 2269: return 1;
1.2 markus 2270: }
2271:
1.94 itojun 2272: static void
1.49 markus 2273: do_authenticated2(Authctxt *authctxt)
1.2 markus 2274: {
1.97 markus 2275: server_loop2(authctxt);
1.165 markus 2276: }
2277:
2278: void
2279: do_cleanup(Authctxt *authctxt)
2280: {
2281: static int called = 0;
2282:
2283: debug("do_cleanup");
2284:
2285: /* no cleanup if we're in the child for login shell */
2286: if (is_child)
2287: return;
2288:
2289: /* avoid double cleanup */
2290: if (called)
2291: return;
2292: called = 1;
2293:
1.218 markus 2294: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2295: return;
2296: #ifdef KRB5
2297: if (options.kerberos_ticket_cleanup &&
2298: authctxt->krb5_ctx)
2299: krb5_cleanup_proc(authctxt);
1.161 markus 2300: #endif
1.165 markus 2301:
2302: #ifdef GSSAPI
2303: if (compat20 && options.gss_cleanup_creds)
2304: ssh_gssapi_cleanup_creds();
2305: #endif
2306:
2307: /* remove agent socket */
2308: auth_sock_cleanup_proc(authctxt->pw);
2309:
2310: /*
2311: * Cleanup ptys/utmp only if privsep is disabled,
2312: * or if running in monitor.
2313: */
2314: if (!use_privsep || mm_is_monitor())
2315: session_destroy_all(session_pty_cleanup2);
1.1 markus 2316: }
![[BACK]](/icons/back.gif){kind=icon}
Return to session.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh