Annotation of src/usr.bin/ssh/session.c, Revision 1.238
1.238 ! markus 1: /* $OpenBSD: session.c,v 1.237 2008/05/08 12:21:16 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:
1.1 markus 90: /* func */
91:
92: Session *session_new(void);
1.94 itojun 93: void session_set_fds(Session *, int, int, int);
1.165 markus 94: void session_pty_cleanup(Session *);
1.94 itojun 95: void session_proctitle(Session *);
96: int session_setup_x11fwd(Session *);
1.237 djm 97: int do_exec_pty(Session *, const char *);
98: int do_exec_no_pty(Session *, const char *);
99: int do_exec(Session *, const char *);
1.94 itojun 100: void do_login(Session *, const char *);
101: void do_child(Session *, const char *);
1.73 djm 102: void do_motd(void);
1.94 itojun 103: int check_quietlogin(Session *, const char *);
1.1 markus 104:
1.94 itojun 105: static void do_authenticated1(Authctxt *);
106: static void do_authenticated2(Authctxt *);
107:
108: static int session_pty_req(Session *);
1.65 markus 109:
1.1 markus 110: /* import */
111: extern ServerOptions options;
112: extern char *__progname;
113: extern int log_stderr;
114: extern int debug_flag;
1.45 markus 115: extern u_int utmp_len;
1.21 markus 116: extern int startup_pipe;
1.74 markus 117: extern void destroy_sensitive_data(void);
1.179 dtucker 118: extern Buffer loginmsg;
1.21 markus 119:
1.34 markus 120: /* original command from peer. */
1.92 markus 121: const char *original_command = NULL;
1.34 markus 122:
1.1 markus 123: /* data */
1.237 djm 124: static int sessions_first_unused = -1;
125: static int sessions_nalloc = 0;
126: static Session *sessions = NULL;
1.1 markus 127:
1.225 markus 128: #define SUBSYSTEM_NONE 0
129: #define SUBSYSTEM_EXT 1
130: #define SUBSYSTEM_INT_SFTP 2
131:
1.129 provos 132: login_cap_t *lc;
1.28 millert 133:
1.165 markus 134: static int is_child = 0;
135:
1.136 markus 136: /* Name and directory of socket for authentication agent forwarding. */
137: static char *auth_sock_name = NULL;
138: static char *auth_sock_dir = NULL;
139:
140: /* removes the agent forwarding socket */
141:
142: static void
1.165 markus 143: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 144: {
145: if (auth_sock_name != NULL) {
146: temporarily_use_uid(pw);
147: unlink(auth_sock_name);
148: rmdir(auth_sock_dir);
149: auth_sock_name = NULL;
150: restore_uid();
151: }
152: }
153:
154: static int
155: auth_input_request_forwarding(struct passwd * pw)
156: {
157: Channel *nc;
1.237 djm 158: int sock = -1;
1.136 markus 159: struct sockaddr_un sunaddr;
160:
161: if (auth_sock_name != NULL) {
162: error("authentication forwarding requested twice.");
163: return 0;
164: }
165:
166: /* Temporarily drop privileged uid for mkdir/bind. */
167: temporarily_use_uid(pw);
168:
169: /* Allocate a buffer for the socket name, and format the name. */
1.237 djm 170: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
1.136 markus 171:
172: /* Create private directory for socket */
173: if (mkdtemp(auth_sock_dir) == NULL) {
174: packet_send_debug("Agent forwarding disabled: "
175: "mkdtemp() failed: %.100s", strerror(errno));
176: restore_uid();
177: xfree(auth_sock_dir);
178: auth_sock_dir = NULL;
1.237 djm 179: goto authsock_err;
1.136 markus 180: }
1.237 djm 181:
182: xasprintf(&auth_sock_name, "%s/agent.%ld",
183: auth_sock_dir, (long) getpid());
1.136 markus 184:
185: /* Create the socket. */
186: sock = socket(AF_UNIX, SOCK_STREAM, 0);
1.237 djm 187: if (sock < 0) {
188: error("socket: %.100s", strerror(errno));
189: restore_uid();
190: goto authsock_err;
191: }
1.136 markus 192:
193: /* Bind it to the name. */
194: memset(&sunaddr, 0, sizeof(sunaddr));
195: sunaddr.sun_family = AF_UNIX;
196: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
197:
1.237 djm 198: if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
199: error("bind: %.100s", strerror(errno));
200: restore_uid();
201: goto authsock_err;
202: }
1.136 markus 203:
204: /* Restore the privileged uid. */
205: restore_uid();
206:
207: /* Start listening on the socket. */
1.237 djm 208: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
209: error("listen: %.100s", strerror(errno));
210: goto authsock_err;
211: }
1.136 markus 212:
213: /* Allocate a channel for the authentication agent socket. */
214: nc = channel_new("auth socket",
215: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
216: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 217: 0, "auth socket", 1);
1.136 markus 218: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
219: return 1;
1.237 djm 220:
221: authsock_err:
222: if (auth_sock_name != NULL)
223: xfree(auth_sock_name);
224: if (auth_sock_dir != NULL) {
225: rmdir(auth_sock_dir);
226: xfree(auth_sock_dir);
227: }
228: if (sock != -1)
229: close(sock);
230: auth_sock_name = NULL;
231: auth_sock_dir = NULL;
232: return 0;
1.136 markus 233: }
234:
1.179 dtucker 235: static void
236: display_loginmsg(void)
237: {
1.183 djm 238: if (buffer_len(&loginmsg) > 0) {
239: buffer_append(&loginmsg, "\0", 1);
240: printf("%s", (char *)buffer_ptr(&loginmsg));
241: buffer_clear(&loginmsg);
242: }
1.179 dtucker 243: }
1.136 markus 244:
1.65 markus 245: void
246: do_authenticated(Authctxt *authctxt)
247: {
1.153 markus 248: setproctitle("%s", authctxt->pw->pw_name);
249:
1.65 markus 250: /* setup the channel layer */
251: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
252: channel_permit_all_opens();
253:
254: if (compat20)
255: do_authenticated2(authctxt);
256: else
257: do_authenticated1(authctxt);
1.79 markus 258:
1.165 markus 259: do_cleanup(authctxt);
1.65 markus 260: }
261:
1.1 markus 262: /*
263: * Prepares for an interactive session. This is called after the user has
264: * been successfully authenticated. During this message exchange, pseudo
265: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
266: * are requested, etc.
267: */
1.94 itojun 268: static void
1.65 markus 269: do_authenticated1(Authctxt *authctxt)
1.1 markus 270: {
271: Session *s;
1.65 markus 272: char *command;
1.117 markus 273: int success, type, screen_flag;
1.139 deraadt 274: int enable_compression_after_reply = 0;
275: u_int proto_len, data_len, dlen, compression_level = 0;
1.1 markus 276:
1.61 markus 277: s = session_new();
1.181 markus 278: if (s == NULL) {
279: error("no more sessions");
280: return;
281: }
1.96 dugsong 282: s->authctxt = authctxt;
1.65 markus 283: s->pw = authctxt->pw;
1.28 millert 284:
1.1 markus 285: /*
286: * We stay in this loop until the client requests to execute a shell
287: * or a command.
288: */
289: for (;;) {
1.65 markus 290: success = 0;
1.1 markus 291:
292: /* Get a packet from the client. */
1.117 markus 293: type = packet_read();
1.1 markus 294:
295: /* Process the packet. */
296: switch (type) {
297: case SSH_CMSG_REQUEST_COMPRESSION:
298: compression_level = packet_get_int();
1.116 markus 299: packet_check_eom();
1.1 markus 300: if (compression_level < 1 || compression_level > 9) {
1.180 markus 301: packet_send_debug("Received invalid compression level %d.",
1.112 deraadt 302: compression_level);
1.138 markus 303: break;
304: }
1.186 markus 305: if (options.compression == COMP_NONE) {
1.138 markus 306: debug2("compression disabled");
1.1 markus 307: break;
308: }
309: /* Enable compression after we have responded with SUCCESS. */
310: enable_compression_after_reply = 1;
311: success = 1;
312: break;
313:
314: case SSH_CMSG_REQUEST_PTY:
1.86 markus 315: success = session_pty_req(s);
1.1 markus 316: break;
317:
318: case SSH_CMSG_X11_REQUEST_FORWARDING:
319: s->auth_proto = packet_get_string(&proto_len);
320: s->auth_data = packet_get_string(&data_len);
321:
1.57 markus 322: screen_flag = packet_get_protocol_flags() &
323: SSH_PROTOFLAG_SCREEN_NUMBER;
324: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
325:
326: if (packet_remaining() == 4) {
327: if (!screen_flag)
328: debug2("Buggy client: "
329: "X11 screen flag missing");
1.1 markus 330: s->screen = packet_get_int();
1.56 markus 331: } else {
1.1 markus 332: s->screen = 0;
1.56 markus 333: }
1.116 markus 334: packet_check_eom();
1.81 markus 335: success = session_setup_x11fwd(s);
336: if (!success) {
337: xfree(s->auth_proto);
338: xfree(s->auth_data);
1.84 markus 339: s->auth_proto = NULL;
340: s->auth_data = NULL;
1.1 markus 341: }
342: break;
343:
344: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
1.235 pyr 345: if (!options.allow_agent_forwarding ||
346: no_agent_forwarding_flag || compat13) {
1.1 markus 347: debug("Authentication agent forwarding not permitted for this authentication.");
348: break;
349: }
350: debug("Received authentication agent forwarding request.");
1.65 markus 351: success = auth_input_request_forwarding(s->pw);
1.1 markus 352: break;
353:
354: case SSH_CMSG_PORT_FORWARD_REQUEST:
355: if (no_port_forwarding_flag) {
356: debug("Port forwarding not permitted for this authentication.");
1.39 markus 357: break;
358: }
359: if (!options.allow_tcp_forwarding) {
360: debug("Port forwarding not permitted.");
1.1 markus 361: break;
362: }
363: debug("Received TCP/IP port forwarding request.");
1.208 markus 364: if (channel_input_port_forward_request(s->pw->pw_uid == 0,
365: options.gateway_ports) < 0) {
366: debug("Port forwarding failed.");
367: break;
368: }
1.1 markus 369: success = 1;
370: break;
371:
372: case SSH_CMSG_MAX_PACKET_SIZE:
373: if (packet_set_maxsize(packet_get_int()) > 0)
374: success = 1;
375: break;
376:
377: case SSH_CMSG_EXEC_SHELL:
378: case SSH_CMSG_EXEC_CMD:
379: if (type == SSH_CMSG_EXEC_CMD) {
380: command = packet_get_string(&dlen);
381: debug("Exec command '%.500s'", command);
1.237 djm 382: if (do_exec(s, command) != 0)
383: packet_disconnect(
384: "command execution failed");
1.92 markus 385: xfree(command);
1.1 markus 386: } else {
1.237 djm 387: if (do_exec(s, NULL) != 0)
388: packet_disconnect(
389: "shell execution failed");
1.1 markus 390: }
1.116 markus 391: packet_check_eom();
1.82 markus 392: session_close(s);
1.1 markus 393: return;
394:
395: default:
396: /*
397: * Any unknown messages in this phase are ignored,
398: * and a failure message is returned.
399: */
1.155 itojun 400: logit("Unknown packet type received after authentication: %d", type);
1.1 markus 401: }
402: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
403: packet_send();
404: packet_write_wait();
405:
406: /* Enable compression now that we have replied if appropriate. */
407: if (enable_compression_after_reply) {
408: enable_compression_after_reply = 0;
409: packet_start_compression(compression_level);
410: }
411: }
412: }
413:
1.238 ! markus 414: #define USE_PIPES
1.1 markus 415: /*
416: * This is called to fork and execute a command when we have no tty. This
417: * will call do_child from the child, and server_loop from the parent after
418: * setting up file descriptors and such.
419: */
1.237 djm 420: int
1.63 markus 421: do_exec_no_pty(Session *s, const char *command)
1.1 markus 422: {
1.137 mpech 423: pid_t pid;
1.238 ! markus 424: #ifdef USE_PIPES
! 425: int pin[2], pout[2], perr[2];
! 426:
! 427: /* Allocate pipes for communicating with the program. */
! 428: if (pipe(pin) < 0) {
! 429: error("%s: pipe in: %.100s", __func__, strerror(errno));
! 430: return -1;
! 431: }
! 432: if (pipe(pout) < 0) {
! 433: error("%s: pipe out: %.100s", __func__, strerror(errno));
! 434: close(pin[0]);
! 435: close(pin[1]);
! 436: return -1;
! 437: }
! 438: if (pipe(perr) < 0) {
! 439: error("%s: pipe err: %.100s", __func__, strerror(errno));
! 440: close(pin[0]);
! 441: close(pin[1]);
! 442: close(pout[0]);
! 443: close(pout[1]);
! 444: return -1;
! 445: }
! 446: #else
1.237 djm 447: int inout[2], err[2];
1.1 markus 448:
449: /* Uses socket pairs to communicate with the program. */
1.237 djm 450: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
451: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
452: return -1;
453: }
454: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
455: error("%s: socketpair #2: %.100s", __func__, strerror(errno));
456: close(inout[0]);
457: close(inout[1]);
458: return -1;
459: }
1.238 ! markus 460: #endif
1.237 djm 461:
1.1 markus 462: if (s == NULL)
463: fatal("do_exec_no_pty: no session");
464:
1.9 markus 465: session_proctitle(s);
1.1 markus 466:
467: /* Fork the child. */
1.237 djm 468: switch ((pid = fork())) {
469: case -1:
470: error("%s: fork: %.100s", __func__, strerror(errno));
1.238 ! markus 471: #ifdef USE_PIPES
! 472: close(pin[0]);
! 473: close(pin[1]);
! 474: close(pout[0]);
! 475: close(pout[1]);
! 476: close(perr[0]);
! 477: close(perr[1]);
! 478: #else
1.237 djm 479: close(inout[0]);
480: close(inout[1]);
481: close(err[0]);
482: close(err[1]);
1.238 ! markus 483: #endif
1.237 djm 484: return -1;
485: case 0:
1.165 markus 486: is_child = 1;
1.144 markus 487:
1.1 markus 488: /* Child. Reinitialize the log since the pid has changed. */
1.237 djm 489: log_init(__progname, options.log_level,
490: options.log_facility, log_stderr);
1.1 markus 491:
492: /*
493: * Create a new session and process group since the 4.4BSD
494: * setlogin() affects the entire process group.
495: */
496: if (setsid() < 0)
497: error("setsid failed: %.100s", strerror(errno));
498:
1.238 ! markus 499: #ifdef USE_PIPES
! 500: /*
! 501: * Redirect stdin. We close the parent side of the socket
! 502: * pair, and make the child side the standard input.
! 503: */
! 504: close(pin[1]);
! 505: if (dup2(pin[0], 0) < 0)
! 506: perror("dup2 stdin");
! 507: close(pin[0]);
! 508:
! 509: /* Redirect stdout. */
! 510: close(pout[0]);
! 511: if (dup2(pout[1], 1) < 0)
! 512: perror("dup2 stdout");
! 513: close(pout[1]);
! 514:
! 515: /* Redirect stderr. */
! 516: close(perr[0]);
! 517: if (dup2(perr[1], 2) < 0)
! 518: perror("dup2 stderr");
! 519: close(perr[1]);
! 520: #else
1.1 markus 521: /*
522: * Redirect stdin, stdout, and stderr. Stdin and stdout will
523: * use the same socket, as some programs (particularly rdist)
524: * seem to depend on it.
525: */
526: close(inout[1]);
527: close(err[1]);
528: if (dup2(inout[0], 0) < 0) /* stdin */
529: perror("dup2 stdin");
1.237 djm 530: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
1.1 markus 531: perror("dup2 stdout");
1.238 ! markus 532: close(inout[0]);
1.1 markus 533: if (dup2(err[0], 2) < 0) /* stderr */
534: perror("dup2 stderr");
1.238 ! markus 535: close(err[0]);
! 536: #endif
1.1 markus 537:
538: /* Do processing for the child (exec command etc). */
1.60 markus 539: do_child(s, command);
1.1 markus 540: /* NOTREACHED */
1.237 djm 541: default:
542: break;
1.1 markus 543: }
1.237 djm 544:
1.1 markus 545: s->pid = pid;
1.47 markus 546: /* Set interactive/non-interactive mode. */
1.48 markus 547: packet_set_interactive(s->display != NULL);
1.1 markus 548:
1.238 ! markus 549: #ifdef USE_PIPES
! 550: /* We are the parent. Close the child sides of the pipes. */
! 551: close(pin[0]);
! 552: close(pout[1]);
! 553: close(perr[1]);
! 554:
! 555: if (compat20) {
! 556: if (s->is_subsystem) {
! 557: close(perr[0]);
! 558: perr[0] = -1;
! 559: }
! 560: session_set_fds(s, pin[1], pout[0], perr[0]);
! 561: } else {
! 562: /* Enter the interactive session. */
! 563: server_loop(pid, pin[1], pout[0], perr[0]);
! 564: /* server_loop has closed pin[1], pout[0], and perr[0]. */
! 565: }
! 566: #else
1.1 markus 567: /* We are the parent. Close the child sides of the socket pairs. */
568: close(inout[0]);
569: close(err[0]);
570:
571: /*
572: * Enter the interactive session. Note: server_loop must be able to
573: * handle the case that fdin and fdout are the same.
574: */
1.2 markus 575: if (compat20) {
1.237 djm 576: session_set_fds(s, inout[1], inout[1],
577: s->is_subsystem ? -1 : err[1]);
578: if (s->is_subsystem)
579: close(err[1]);
1.2 markus 580: } else {
581: server_loop(pid, inout[1], inout[1], err[1]);
582: /* server_loop has closed inout[1] and err[1]. */
583: }
1.238 ! markus 584: #endif
1.237 djm 585: return 0;
1.1 markus 586: }
587:
588: /*
589: * This is called to fork and execute a command when we have a tty. This
590: * will call do_child from the child, and server_loop from the parent after
591: * setting up file descriptors, controlling tty, updating wtmp, utmp,
592: * lastlog, and other such operations.
593: */
1.237 djm 594: int
1.63 markus 595: do_exec_pty(Session *s, const char *command)
1.1 markus 596: {
597: int fdout, ptyfd, ttyfd, ptymaster;
598: pid_t pid;
599:
600: if (s == NULL)
601: fatal("do_exec_pty: no session");
602: ptyfd = s->ptyfd;
603: ttyfd = s->ttyfd;
604:
1.237 djm 605: /*
606: * Create another descriptor of the pty master side for use as the
607: * standard input. We could use the original descriptor, but this
608: * simplifies code in server_loop. The descriptor is bidirectional.
609: * Do this before forking (and cleanup in the child) so as to
610: * detect and gracefully fail out-of-fd conditions.
611: */
612: if ((fdout = dup(ptyfd)) < 0) {
613: error("%s: dup #1: %s", __func__, strerror(errno));
614: close(ttyfd);
615: close(ptyfd);
616: return -1;
617: }
618: /* we keep a reference to the pty master */
619: if ((ptymaster = dup(ptyfd)) < 0) {
620: error("%s: dup #2: %s", __func__, strerror(errno));
621: close(ttyfd);
622: close(ptyfd);
623: close(fdout);
624: return -1;
625: }
626:
1.1 markus 627: /* Fork the child. */
1.237 djm 628: switch ((pid = fork())) {
629: case -1:
630: error("%s: fork: %.100s", __func__, strerror(errno));
631: close(fdout);
632: close(ptymaster);
633: close(ttyfd);
634: close(ptyfd);
635: return -1;
636: case 0:
1.165 markus 637: is_child = 1;
1.97 markus 638:
1.237 djm 639: close(fdout);
640: close(ptymaster);
641:
1.24 markus 642: /* Child. Reinitialize the log because the pid has changed. */
1.237 djm 643: log_init(__progname, options.log_level,
644: options.log_facility, log_stderr);
1.1 markus 645: /* Close the master side of the pseudo tty. */
646: close(ptyfd);
647:
648: /* Make the pseudo tty our controlling tty. */
649: pty_make_controlling_tty(&ttyfd, s->tty);
650:
1.103 markus 651: /* Redirect stdin/stdout/stderr from the pseudo tty. */
652: if (dup2(ttyfd, 0) < 0)
653: error("dup2 stdin: %s", strerror(errno));
654: if (dup2(ttyfd, 1) < 0)
655: error("dup2 stdout: %s", strerror(errno));
656: if (dup2(ttyfd, 2) < 0)
657: error("dup2 stderr: %s", strerror(errno));
1.1 markus 658:
659: /* Close the extra descriptor for the pseudo tty. */
660: close(ttyfd);
661:
1.24 markus 662: /* record login, etc. similar to login(1) */
1.41 markus 663: if (!(options.use_login && command == NULL))
664: do_login(s, command);
1.228 djm 665:
1.237 djm 666: /*
667: * Do common processing for the child, such as execing
668: * the command.
669: */
1.60 markus 670: do_child(s, command);
1.1 markus 671: /* NOTREACHED */
1.237 djm 672: default:
673: break;
1.1 markus 674: }
675: s->pid = pid;
676:
677: /* Parent. Close the slave side of the pseudo tty. */
678: close(ttyfd);
679:
1.237 djm 680: /* Enter interactive session. */
1.1 markus 681: s->ptymaster = ptymaster;
1.47 markus 682: packet_set_interactive(1);
1.2 markus 683: if (compat20) {
684: session_set_fds(s, ptyfd, fdout, -1);
685: } else {
686: server_loop(pid, ptyfd, fdout, -1);
687: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 688: }
1.237 djm 689: return 0;
1.24 markus 690: }
691:
1.90 markus 692: /*
693: * This is called to fork and execute a command. If another command is
694: * to be forced, execute that instead.
695: */
1.237 djm 696: int
1.90 markus 697: do_exec(Session *s, const char *command)
698: {
1.237 djm 699: int ret;
700:
1.210 dtucker 701: if (options.adm_forced_command) {
702: original_command = command;
703: command = options.adm_forced_command;
1.226 djm 704: if (strcmp(INTERNAL_SFTP_NAME, command) == 0)
705: s->is_subsystem = SUBSYSTEM_INT_SFTP;
706: else if (s->is_subsystem)
1.225 markus 707: s->is_subsystem = SUBSYSTEM_EXT;
1.210 dtucker 708: debug("Forced command (config) '%.900s'", command);
709: } else if (forced_command) {
1.90 markus 710: original_command = command;
711: command = forced_command;
1.226 djm 712: if (strcmp(INTERNAL_SFTP_NAME, command) == 0)
713: s->is_subsystem = SUBSYSTEM_INT_SFTP;
714: else if (s->is_subsystem)
1.225 markus 715: s->is_subsystem = SUBSYSTEM_EXT;
1.210 dtucker 716: debug("Forced command (key option) '%.900s'", command);
1.90 markus 717: }
1.163 markus 718:
719: #ifdef GSSAPI
720: if (options.gss_authentication) {
721: temporarily_use_uid(s->pw);
722: ssh_gssapi_storecreds();
723: restore_uid();
724: }
725: #endif
1.90 markus 726: if (s->ttyfd != -1)
1.237 djm 727: ret = do_exec_pty(s, command);
1.90 markus 728: else
1.237 djm 729: ret = do_exec_no_pty(s, command);
1.90 markus 730:
1.92 markus 731: original_command = NULL;
1.179 dtucker 732:
733: /*
734: * Clear loginmsg: it's the child's responsibility to display
735: * it to the user, otherwise multiple sessions may accumulate
736: * multiple copies of the login messages.
737: */
738: buffer_clear(&loginmsg);
1.237 djm 739:
740: return ret;
1.90 markus 741: }
742:
743:
1.24 markus 744: /* administrative, login(1)-like work */
745: void
1.41 markus 746: do_login(Session *s, const char *command)
1.24 markus 747: {
748: socklen_t fromlen;
749: struct sockaddr_storage from;
750: struct passwd * pw = s->pw;
751: pid_t pid = getpid();
752:
753: /*
754: * Get IP address of client. If the connection is not a socket, let
755: * the address be 0.0.0.0.
756: */
757: memset(&from, 0, sizeof(from));
1.148 stevesk 758: fromlen = sizeof(from);
1.24 markus 759: if (packet_connection_is_on_socket()) {
760: if (getpeername(packet_get_connection_in(),
1.200 deraadt 761: (struct sockaddr *)&from, &fromlen) < 0) {
1.24 markus 762: debug("getpeername: %.100s", strerror(errno));
1.165 markus 763: cleanup_exit(255);
1.24 markus 764: }
765: }
1.25 markus 766:
1.24 markus 767: /* Record that there was a login on that tty from the remote host. */
1.133 markus 768: if (!use_privsep)
769: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
770: get_remote_name_or_ip(utmp_len,
1.158 markus 771: options.use_dns),
1.148 stevesk 772: (struct sockaddr *)&from, fromlen);
1.24 markus 773:
1.73 djm 774: if (check_quietlogin(s, command))
1.24 markus 775: return;
1.73 djm 776:
1.179 dtucker 777: display_loginmsg();
1.73 djm 778:
779: do_motd();
780: }
781:
782: /*
783: * Display the message of the day.
784: */
785: void
786: do_motd(void)
787: {
788: FILE *f;
789: char buf[256];
790:
1.24 markus 791: if (options.print_motd) {
1.28 millert 792: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
793: "/etc/motd"), "r");
1.24 markus 794: if (f) {
795: while (fgets(buf, sizeof(buf), f))
796: fputs(buf, stdout);
797: fclose(f);
798: }
1.2 markus 799: }
1.73 djm 800: }
801:
802:
803: /*
804: * Check for quiet login, either .hushlogin or command given.
805: */
806: int
807: check_quietlogin(Session *s, const char *command)
808: {
809: char buf[256];
1.96 dugsong 810: struct passwd *pw = s->pw;
1.73 djm 811: struct stat st;
812:
813: /* Return 1 if .hushlogin exists or a command given. */
814: if (command != NULL)
815: return 1;
816: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
817: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
818: return 1;
819: return 0;
1.1 markus 820: }
821:
822: /*
823: * Sets the value of the given variable in the environment. If the variable
824: * already exists, its value is overriden.
825: */
1.161 markus 826: void
1.45 markus 827: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 828: const char *value)
1.1 markus 829: {
1.164 markus 830: char **env;
831: u_int envsize;
1.45 markus 832: u_int i, namelen;
1.1 markus 833:
834: /*
835: * Find the slot where the value should be stored. If the variable
836: * already exists, we reuse the slot; otherwise we append a new slot
837: * at the end of the array, expanding if necessary.
838: */
839: env = *envp;
840: namelen = strlen(name);
841: for (i = 0; env[i]; i++)
842: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
843: break;
844: if (env[i]) {
845: /* Reuse the slot. */
846: xfree(env[i]);
847: } else {
848: /* New variable. Expand if necessary. */
1.164 markus 849: envsize = *envsizep;
850: if (i >= envsize - 1) {
851: if (envsize >= 1000)
852: fatal("child_set_env: too many env vars");
853: envsize += 50;
1.201 djm 854: env = (*envp) = xrealloc(env, envsize, sizeof(char *));
1.164 markus 855: *envsizep = envsize;
1.1 markus 856: }
857: /* Need to set the NULL pointer at end of array beyond the new slot. */
858: env[i + 1] = NULL;
859: }
860:
861: /* Allocate space and format the variable in the appropriate slot. */
862: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
863: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
864: }
865:
866: /*
867: * Reads environment variables from the given file and adds/overrides them
868: * into the environment. If the file does not exist, this does nothing.
869: * Otherwise, it must consist of empty lines, comments (line starts with '#')
870: * and assignments of the form name=value. No other forms are allowed.
871: */
1.94 itojun 872: static void
1.45 markus 873: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 874: const char *filename)
1.1 markus 875: {
876: FILE *f;
877: char buf[4096];
878: char *cp, *value;
1.142 deraadt 879: u_int lineno = 0;
1.1 markus 880:
881: f = fopen(filename, "r");
882: if (!f)
883: return;
884:
885: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 886: if (++lineno > 1000)
887: fatal("Too many lines in environment file %s", filename);
1.1 markus 888: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
889: ;
890: if (!*cp || *cp == '#' || *cp == '\n')
891: continue;
1.224 gilles 892:
893: cp[strcspn(cp, "\n")] = '\0';
894:
1.1 markus 895: value = strchr(cp, '=');
896: if (value == NULL) {
1.142 deraadt 897: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
898: filename);
1.1 markus 899: continue;
900: }
1.14 deraadt 901: /*
902: * Replace the equals sign by nul, and advance value to
903: * the value string.
904: */
1.1 markus 905: *value = '\0';
906: value++;
907: child_set_env(env, envsize, cp, value);
908: }
909: fclose(f);
910: }
911:
1.127 markus 912: static char **
913: do_setup_env(Session *s, const char *shell)
1.1 markus 914: {
915: char buf[256];
1.127 markus 916: u_int i, envsize;
1.154 markus 917: char **env, *laddr;
1.127 markus 918: struct passwd *pw = s->pw;
1.1 markus 919:
920: /* Initialize the environment. */
921: envsize = 100;
1.220 djm 922: env = xcalloc(envsize, sizeof(char *));
1.1 markus 923: env[0] = NULL;
924:
1.161 markus 925: #ifdef GSSAPI
1.168 djm 926: /* Allow any GSSAPI methods that we've used to alter
1.161 markus 927: * the childs environment as they see fit
928: */
929: ssh_gssapi_do_child(&env, &envsize);
930: #endif
931:
1.1 markus 932: if (!options.use_login) {
933: /* Set basic environment. */
1.173 djm 934: for (i = 0; i < s->num_env; i++)
1.178 deraadt 935: child_set_env(&env, &envsize, s->env[i].name,
1.173 djm 936: s->env[i].val);
937:
1.1 markus 938: child_set_env(&env, &envsize, "USER", pw->pw_name);
939: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
940: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.145 markus 941: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
942: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
943: else
944: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.1 markus 945:
946: snprintf(buf, sizeof buf, "%.200s/%.50s",
947: _PATH_MAILDIR, pw->pw_name);
948: child_set_env(&env, &envsize, "MAIL", buf);
949:
950: /* Normal systems set SHELL by default. */
951: child_set_env(&env, &envsize, "SHELL", shell);
952: }
953: if (getenv("TZ"))
954: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
955:
956: /* Set custom environment options from RSA authentication. */
1.110 markus 957: if (!options.use_login) {
958: while (custom_environment) {
959: struct envstring *ce = custom_environment;
1.143 deraadt 960: char *str = ce->s;
1.127 markus 961:
1.143 deraadt 962: for (i = 0; str[i] != '=' && str[i]; i++)
1.110 markus 963: ;
1.143 deraadt 964: if (str[i] == '=') {
965: str[i] = 0;
966: child_set_env(&env, &envsize, str, str + i + 1);
1.110 markus 967: }
968: custom_environment = ce->next;
969: xfree(ce->s);
970: xfree(ce);
1.1 markus 971: }
972: }
973:
1.149 stevesk 974: /* SSH_CLIENT deprecated */
1.1 markus 975: snprintf(buf, sizeof buf, "%.50s %d %d",
1.127 markus 976: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 977: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 978:
1.154 markus 979: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 980: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.154 markus 981: get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
982: xfree(laddr);
1.149 stevesk 983: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 984:
1.60 markus 985: if (s->ttyfd != -1)
986: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
987: if (s->term)
988: child_set_env(&env, &envsize, "TERM", s->term);
989: if (s->display)
990: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 991: if (original_command)
992: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
993: original_command);
1.96 dugsong 994: #ifdef KRB5
995: if (s->authctxt->krb5_ticket_file)
996: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 997: s->authctxt->krb5_ticket_file);
1.96 dugsong 998: #endif
1.136 markus 999: if (auth_sock_name != NULL)
1.1 markus 1000: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 1001: auth_sock_name);
1.1 markus 1002:
1003: /* read $HOME/.ssh/environment. */
1.146 markus 1004: if (options.permit_user_env && !options.use_login) {
1.14 deraadt 1005: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1006: pw->pw_dir);
1.1 markus 1007: read_environment_file(&env, &envsize, buf);
1008: }
1009: if (debug_flag) {
1010: /* dump the environment */
1011: fprintf(stderr, "Environment:\n");
1012: for (i = 0; env[i]; i++)
1013: fprintf(stderr, " %.200s\n", env[i]);
1014: }
1.127 markus 1015: return env;
1016: }
1017:
1018: /*
1019: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1020: * first in this order).
1021: */
1022: static void
1023: do_rc_files(Session *s, const char *shell)
1024: {
1025: FILE *f = NULL;
1026: char cmd[1024];
1027: int do_xauth;
1028: struct stat st;
1029:
1030: do_xauth =
1031: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1032:
1.231 djm 1033: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1.232 djm 1034: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.234 djm 1035: !no_user_rc && stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.127 markus 1036: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1037: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1038: if (debug_flag)
1039: fprintf(stderr, "Running %s\n", cmd);
1040: f = popen(cmd, "w");
1041: if (f) {
1042: if (do_xauth)
1043: fprintf(f, "%s %s\n", s->auth_proto,
1044: s->auth_data);
1045: pclose(f);
1046: } else
1047: fprintf(stderr, "Could not run %s\n",
1048: _PATH_SSH_USER_RC);
1049: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1050: if (debug_flag)
1051: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1052: _PATH_SSH_SYSTEM_RC);
1053: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1054: if (f) {
1055: if (do_xauth)
1056: fprintf(f, "%s %s\n", s->auth_proto,
1057: s->auth_data);
1058: pclose(f);
1059: } else
1060: fprintf(stderr, "Could not run %s\n",
1061: _PATH_SSH_SYSTEM_RC);
1062: } else if (do_xauth && options.xauth_location != NULL) {
1063: /* Add authority data to .Xauthority if appropriate. */
1064: if (debug_flag) {
1065: fprintf(stderr,
1.151 stevesk 1066: "Running %.500s remove %.100s\n",
1.165 markus 1067: options.xauth_location, s->auth_display);
1.151 stevesk 1068: fprintf(stderr,
1069: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 1070: options.xauth_location, s->auth_display,
1071: s->auth_proto, s->auth_data);
1072: }
1073: snprintf(cmd, sizeof cmd, "%s -q -",
1074: options.xauth_location);
1075: f = popen(cmd, "w");
1076: if (f) {
1.151 stevesk 1077: fprintf(f, "remove %s\n",
1078: s->auth_display);
1.127 markus 1079: fprintf(f, "add %s %s %s\n",
1080: s->auth_display, s->auth_proto,
1081: s->auth_data);
1082: pclose(f);
1083: } else {
1084: fprintf(stderr, "Could not run %s\n",
1085: cmd);
1086: }
1087: }
1088: }
1089:
1090: static void
1091: do_nologin(struct passwd *pw)
1092: {
1093: FILE *f = NULL;
1094: char buf[1024];
1095:
1096: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1097: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1098: _PATH_NOLOGIN), "r");
1099: if (f) {
1100: /* /etc/nologin exists. Print its contents and exit. */
1.155 itojun 1101: logit("User %.100s not allowed because %s exists",
1.150 stevesk 1102: pw->pw_name, _PATH_NOLOGIN);
1.127 markus 1103: while (fgets(buf, sizeof(buf), f))
1104: fputs(buf, stderr);
1105: fclose(f);
1106: exit(254);
1107: }
1108: }
1109:
1.226 djm 1110: /*
1111: * Chroot into a directory after checking it for safety: all path components
1112: * must be root-owned directories with strict permissions.
1113: */
1114: static void
1115: safely_chroot(const char *path, uid_t uid)
1116: {
1117: const char *cp;
1118: char component[MAXPATHLEN];
1119: struct stat st;
1120:
1121: if (*path != '/')
1122: fatal("chroot path does not begin at root");
1123: if (strlen(path) >= sizeof(component))
1124: fatal("chroot path too long");
1125:
1126: /*
1127: * Descend the path, checking that each component is a
1128: * root-owned directory with strict permissions.
1129: */
1130: for (cp = path; cp != NULL;) {
1131: if ((cp = strchr(cp, '/')) == NULL)
1132: strlcpy(component, path, sizeof(component));
1133: else {
1134: cp++;
1135: memcpy(component, path, cp - path);
1136: component[cp - path] = '\0';
1137: }
1138:
1139: debug3("%s: checking '%s'", __func__, component);
1140:
1141: if (stat(component, &st) != 0)
1142: fatal("%s: stat(\"%s\"): %s", __func__,
1143: component, strerror(errno));
1144: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1145: fatal("bad ownership or modes for chroot "
1146: "directory %s\"%s\"",
1147: cp == NULL ? "" : "component ", component);
1148: if (!S_ISDIR(st.st_mode))
1149: fatal("chroot path %s\"%s\" is not a directory",
1150: cp == NULL ? "" : "component ", component);
1151:
1152: }
1153:
1154: if (chdir(path) == -1)
1155: fatal("Unable to chdir to chroot path \"%s\": "
1156: "%s", path, strerror(errno));
1157: if (chroot(path) == -1)
1158: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1159: if (chdir("/") == -1)
1160: fatal("%s: chdir(/) after chroot: %s",
1161: __func__, strerror(errno));
1162: verbose("Changed root directory to \"%s\"", path);
1163: }
1164:
1.127 markus 1165: /* Set login name, uid, gid, and groups. */
1.130 provos 1166: void
1.127 markus 1167: do_setusercontext(struct passwd *pw)
1168: {
1.227 djm 1169: char *chroot_path, *tmp;
1170:
1.127 markus 1171: if (getuid() == 0 || geteuid() == 0) {
1.226 djm 1172: /* Prepare groups */
1.127 markus 1173: if (setusercontext(lc, pw, pw->pw_uid,
1.226 djm 1174: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1.127 markus 1175: perror("unable to set user context");
1176: exit(1);
1177: }
1.226 djm 1178:
1179: if (options.chroot_directory != NULL &&
1180: strcasecmp(options.chroot_directory, "none") != 0) {
1.227 djm 1181: tmp = tilde_expand_filename(options.chroot_directory,
1182: pw->pw_uid);
1183: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1184: "u", pw->pw_name, (char *)NULL);
1.226 djm 1185: safely_chroot(chroot_path, pw->pw_uid);
1.227 djm 1186: free(tmp);
1.226 djm 1187: free(chroot_path);
1188: }
1189:
1190: /* Set UID */
1191: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1192: perror("unable to set user context (setuser)");
1193: exit(1);
1194: }
1.127 markus 1195: }
1196: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1197: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1198: }
1199:
1.131 markus 1200: static void
1.172 markus 1201: do_pwchange(Session *s)
1202: {
1.179 dtucker 1203: fflush(NULL);
1.172 markus 1204: fprintf(stderr, "WARNING: Your password has expired.\n");
1205: if (s->ttyfd != -1) {
1.178 deraadt 1206: fprintf(stderr,
1.172 markus 1207: "You must change your password now and login again!\n");
1208: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1209: perror("passwd");
1210: } else {
1211: fprintf(stderr,
1212: "Password change required but no TTY available.\n");
1213: }
1214: exit(1);
1215: }
1216:
1217: static void
1.130 provos 1218: launch_login(struct passwd *pw, const char *hostname)
1219: {
1220: /* Launch login(1). */
1221:
1222: execl("/usr/bin/login", "login", "-h", hostname,
1223: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1224:
1225: /* Login couldn't be executed, die. */
1226:
1227: perror("login");
1228: exit(1);
1229: }
1230:
1.172 markus 1231: static void
1232: child_close_fds(void)
1233: {
1234: int i;
1235:
1236: if (packet_get_connection_in() == packet_get_connection_out())
1237: close(packet_get_connection_in());
1238: else {
1239: close(packet_get_connection_in());
1240: close(packet_get_connection_out());
1241: }
1242: /*
1243: * Close all descriptors related to channels. They will still remain
1244: * open in the parent.
1245: */
1246: /* XXX better use close-on-exec? -markus */
1247: channel_close_all();
1248:
1249: /*
1250: * Close any extra file descriptors. Note that there may still be
1251: * descriptors left by system functions. They will be closed later.
1252: */
1253: endpwent();
1254:
1255: /*
1.188 djm 1256: * Close any extra open file descriptors so that we don't have them
1.172 markus 1257: * hanging around in clients. Note that we want to do this after
1258: * initgroups, because at least on Solaris 2.3 it leaves file
1259: * descriptors open.
1260: */
1261: for (i = 3; i < 64; i++)
1262: close(i);
1263: }
1264:
1.127 markus 1265: /*
1266: * Performs common processing for the child, such as setting up the
1267: * environment, closing extra file descriptors, setting the user and group
1268: * ids, and executing the command or shell.
1269: */
1.225 markus 1270: #define ARGV_MAX 10
1.127 markus 1271: void
1272: do_child(Session *s, const char *command)
1273: {
1274: extern char **environ;
1275: char **env;
1.225 markus 1276: char *argv[ARGV_MAX];
1.127 markus 1277: const char *shell, *shell0, *hostname = NULL;
1278: struct passwd *pw = s->pw;
1279:
1280: /* remove hostkey from the child's memory */
1281: destroy_sensitive_data();
1282:
1.172 markus 1283: /* Force a password change */
1284: if (s->authctxt->force_pwchange) {
1285: do_setusercontext(pw);
1286: child_close_fds();
1287: do_pwchange(s);
1288: exit(1);
1289: }
1290:
1.127 markus 1291: /* login(1) is only called if we execute the login shell */
1292: if (options.use_login && command != NULL)
1293: options.use_login = 0;
1294:
1295: /*
1296: * Login(1) does this as well, and it needs uid 0 for the "-h"
1297: * switch, so we let login(1) to this for us.
1298: */
1299: if (!options.use_login) {
1300: do_nologin(pw);
1301: do_setusercontext(pw);
1302: }
1303:
1304: /*
1305: * Get the shell from the password data. An empty shell field is
1306: * legal, and means /bin/sh.
1307: */
1308: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1309:
1310: /*
1311: * Make sure $SHELL points to the shell from the password file,
1312: * even if shell is overridden from login.conf
1313: */
1314: env = do_setup_env(s, shell);
1315:
1.127 markus 1316: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1317:
1.26 millert 1318: /* we have to stash the hostname before we close our socket. */
1319: if (options.use_login)
1.70 stevesk 1320: hostname = get_remote_name_or_ip(utmp_len,
1.158 markus 1321: options.use_dns);
1.1 markus 1322: /*
1323: * Close the connection descriptors; note that this is the child, and
1324: * the server will still have the socket open, and it is important
1325: * that we do not shutdown it. Note that the descriptors cannot be
1326: * closed before building the environment, as we call
1327: * get_remote_ipaddr there.
1328: */
1.172 markus 1329: child_close_fds();
1.1 markus 1330:
1331: /*
1.125 deraadt 1332: * Must take new environment into use so that .ssh/rc,
1333: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1334: */
1335: environ = env;
1.170 jakob 1336:
1337: #ifdef KRB5
1338: /*
1339: * At this point, we check to see if AFS is active and if we have
1340: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1341: * if we can (and need to) extend the ticket into an AFS token. If
1342: * we don't do this, we run into potential problems if the user's
1343: * home directory is in AFS and it's not world-readable.
1344: */
1345:
1346: if (options.kerberos_get_afs_token && k_hasafs() &&
1.185 djm 1347: (s->authctxt->krb5_ctx != NULL)) {
1.170 jakob 1348: char cell[64];
1349:
1350: debug("Getting AFS token");
1351:
1352: k_setpag();
1353:
1354: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1355: krb5_afslog(s->authctxt->krb5_ctx,
1356: s->authctxt->krb5_fwd_ccache, cell, NULL);
1357:
1358: krb5_afslog_home(s->authctxt->krb5_ctx,
1359: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1360: }
1361: #endif
1.104 markus 1362:
1.188 djm 1363: /* Change current directory to the user's home directory. */
1.104 markus 1364: if (chdir(pw->pw_dir) < 0) {
1365: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1366: pw->pw_dir, strerror(errno));
1367: if (login_getcapbool(lc, "requirehome", 0))
1368: exit(1);
1369: }
1.230 djm 1370:
1371: closefrom(STDERR_FILENO + 1);
1.1 markus 1372:
1.127 markus 1373: if (!options.use_login)
1374: do_rc_files(s, shell);
1.67 markus 1375:
1376: /* restore SIGPIPE for child */
1.217 stevesk 1377: signal(SIGPIPE, SIG_DFL);
1.67 markus 1378:
1.225 markus 1379: if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1380: extern int optind, optreset;
1381: int i;
1382: char *p, *args;
1383:
1384: setproctitle("%s@internal-sftp-server", s->pw->pw_name);
1385: args = strdup(command ? command : "sftp-server");
1386: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1387: if (i < ARGV_MAX - 1)
1388: argv[i++] = p;
1389: argv[i] = NULL;
1390: optind = optreset = 1;
1391: __progname = argv[0];
1.226 djm 1392: exit(sftp_server_main(i, argv, s->pw));
1.225 markus 1393: }
1394:
1.127 markus 1395: if (options.use_login) {
1.130 provos 1396: launch_login(pw, hostname);
1397: /* NEVERREACHED */
1.127 markus 1398: }
1399:
1400: /* Get the last component of the shell name. */
1401: if ((shell0 = strrchr(shell, '/')) != NULL)
1402: shell0++;
1403: else
1404: shell0 = shell;
1405:
1.1 markus 1406: /*
1407: * If we have no command, execute the shell. In this case, the shell
1408: * name to be passed in argv[0] is preceded by '-' to indicate that
1409: * this is a login shell.
1410: */
1411: if (!command) {
1.127 markus 1412: char argv0[256];
1.1 markus 1413:
1.127 markus 1414: /* Start the shell. Set initial character to '-'. */
1415: argv0[0] = '-';
1.1 markus 1416:
1.127 markus 1417: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1418: >= sizeof(argv0) - 1) {
1.127 markus 1419: errno = EINVAL;
1.1 markus 1420: perror(shell);
1421: exit(1);
1.127 markus 1422: }
1.1 markus 1423:
1.127 markus 1424: /* Execute the shell. */
1425: argv[0] = argv0;
1426: argv[1] = NULL;
1427: execve(shell, argv, env);
1428:
1429: /* Executing the shell failed. */
1430: perror(shell);
1431: exit(1);
1.1 markus 1432: }
1433: /*
1434: * Execute the command using the user's shell. This uses the -c
1435: * option to execute the command.
1436: */
1.127 markus 1437: argv[0] = (char *) shell0;
1.1 markus 1438: argv[1] = "-c";
1439: argv[2] = (char *) command;
1440: argv[3] = NULL;
1441: execve(shell, argv, env);
1442: perror(shell);
1443: exit(1);
1444: }
1445:
1.237 djm 1446: void
1447: session_unused(int id)
1448: {
1449: debug3("%s: session id %d unused", __func__, id);
1450: if (id >= options.max_sessions ||
1451: id >= sessions_nalloc) {
1452: fatal("%s: insane session id %d (max %d nalloc %d)",
1453: __func__, id, options.max_sessions, sessions_nalloc);
1454: }
1455: bzero(&sessions[id], sizeof(*sessions));
1456: sessions[id].self = id;
1457: sessions[id].used = 0;
1458: sessions[id].chanid = -1;
1459: sessions[id].ptyfd = -1;
1460: sessions[id].ttyfd = -1;
1461: sessions[id].ptymaster = -1;
1462: sessions[id].x11_chanids = NULL;
1463: sessions[id].next_unused = sessions_first_unused;
1464: sessions_first_unused = id;
1465: }
1466:
1.1 markus 1467: Session *
1468: session_new(void)
1469: {
1.237 djm 1470: Session *s, *tmp;
1471:
1472: if (sessions_first_unused == -1) {
1473: if (sessions_nalloc >= options.max_sessions)
1474: return NULL;
1475: debug2("%s: allocate (allocated %d max %d)",
1476: __func__, sessions_nalloc, options.max_sessions);
1477: tmp = xrealloc(sessions, sessions_nalloc + 1,
1478: sizeof(*sessions));
1479: if (tmp == NULL) {
1480: error("%s: cannot allocate %d sessions",
1481: __func__, sessions_nalloc + 1);
1482: return NULL;
1483: }
1484: sessions = tmp;
1485: session_unused(sessions_nalloc++);
1486: }
1487:
1488: if (sessions_first_unused >= sessions_nalloc ||
1489: sessions_first_unused < 0) {
1490: fatal("%s: insane first_unused %d max %d nalloc %d",
1491: __func__, sessions_first_unused, options.max_sessions,
1492: sessions_nalloc);
1493: }
1494:
1495: s = &sessions[sessions_first_unused];
1496: if (s->used) {
1497: fatal("%s: session %d already used",
1498: __func__, sessions_first_unused);
1499: }
1500: sessions_first_unused = s->next_unused;
1501: s->used = 1;
1502: s->next_unused = -1;
1503: debug("session_new: session %d", s->self);
1504:
1505: return s;
1.1 markus 1506: }
1507:
1.94 itojun 1508: static void
1.1 markus 1509: session_dump(void)
1510: {
1511: int i;
1.237 djm 1512: for (i = 0; i < sessions_nalloc; i++) {
1.1 markus 1513: Session *s = &sessions[i];
1.237 djm 1514:
1515: debug("dump: used %d next_unused %d session %d %p "
1516: "channel %d pid %ld",
1.1 markus 1517: s->used,
1.237 djm 1518: s->next_unused,
1.1 markus 1519: s->self,
1520: s,
1521: s->chanid,
1.137 mpech 1522: (long)s->pid);
1.1 markus 1523: }
1524: }
1525:
1.2 markus 1526: int
1.97 markus 1527: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1528: {
1529: Session *s = session_new();
1530: debug("session_open: channel %d", chanid);
1531: if (s == NULL) {
1532: error("no more sessions");
1533: return 0;
1534: }
1.97 markus 1535: s->authctxt = authctxt;
1536: s->pw = authctxt->pw;
1.167 djm 1537: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1538: fatal("no user for session %d", s->self);
1.2 markus 1539: debug("session_open: session %d: link with channel %d", s->self, chanid);
1540: s->chanid = chanid;
1541: return 1;
1542: }
1543:
1.130 provos 1544: Session *
1545: session_by_tty(char *tty)
1546: {
1547: int i;
1.237 djm 1548: for (i = 0; i < sessions_nalloc; i++) {
1.130 provos 1549: Session *s = &sessions[i];
1550: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1551: debug("session_by_tty: session %d tty %s", i, tty);
1552: return s;
1553: }
1554: }
1555: debug("session_by_tty: unknown tty %.100s", tty);
1556: session_dump();
1557: return NULL;
1558: }
1559:
1.94 itojun 1560: static Session *
1.2 markus 1561: session_by_channel(int id)
1562: {
1563: int i;
1.237 djm 1564: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1565: Session *s = &sessions[i];
1566: if (s->used && s->chanid == id) {
1.237 djm 1567: debug("session_by_channel: session %d channel %d",
1568: i, id);
1.2 markus 1569: return s;
1570: }
1571: }
1572: debug("session_by_channel: unknown channel %d", id);
1573: session_dump();
1574: return NULL;
1575: }
1576:
1.94 itojun 1577: static Session *
1.184 djm 1578: session_by_x11_channel(int id)
1579: {
1580: int i, j;
1581:
1.237 djm 1582: for (i = 0; i < sessions_nalloc; i++) {
1.184 djm 1583: Session *s = &sessions[i];
1584:
1585: if (s->x11_chanids == NULL || !s->used)
1586: continue;
1587: for (j = 0; s->x11_chanids[j] != -1; j++) {
1588: if (s->x11_chanids[j] == id) {
1589: debug("session_by_x11_channel: session %d "
1590: "channel %d", s->self, id);
1591: return s;
1592: }
1593: }
1594: }
1595: debug("session_by_x11_channel: unknown channel %d", id);
1596: session_dump();
1597: return NULL;
1598: }
1599:
1600: static Session *
1.2 markus 1601: session_by_pid(pid_t pid)
1602: {
1603: int i;
1.137 mpech 1604: debug("session_by_pid: pid %ld", (long)pid);
1.237 djm 1605: for (i = 0; i < sessions_nalloc; i++) {
1.2 markus 1606: Session *s = &sessions[i];
1607: if (s->used && s->pid == pid)
1608: return s;
1609: }
1.137 mpech 1610: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1611: session_dump();
1612: return NULL;
1613: }
1614:
1.94 itojun 1615: static int
1.2 markus 1616: session_window_change_req(Session *s)
1617: {
1618: s->col = packet_get_int();
1619: s->row = packet_get_int();
1620: s->xpixel = packet_get_int();
1621: s->ypixel = packet_get_int();
1.116 markus 1622: packet_check_eom();
1.2 markus 1623: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1624: return 1;
1625: }
1626:
1.94 itojun 1627: static int
1.2 markus 1628: session_pty_req(Session *s)
1629: {
1.45 markus 1630: u_int len;
1.72 stevesk 1631: int n_bytes;
1.132 markus 1632:
1.86 markus 1633: if (no_pty_flag) {
1634: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1635: return 0;
1.86 markus 1636: }
1637: if (s->ttyfd != -1) {
1638: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1639: return 0;
1.86 markus 1640: }
1641:
1.2 markus 1642: s->term = packet_get_string(&len);
1.86 markus 1643:
1644: if (compat20) {
1645: s->col = packet_get_int();
1646: s->row = packet_get_int();
1647: } else {
1648: s->row = packet_get_int();
1649: s->col = packet_get_int();
1650: }
1.2 markus 1651: s->xpixel = packet_get_int();
1652: s->ypixel = packet_get_int();
1653:
1654: if (strcmp(s->term, "") == 0) {
1655: xfree(s->term);
1656: s->term = NULL;
1657: }
1.86 markus 1658:
1.2 markus 1659: /* Allocate a pty and open it. */
1.86 markus 1660: debug("Allocating pty.");
1.237 djm 1661: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1662: sizeof(s->tty)))) {
1.86 markus 1663: if (s->term)
1664: xfree(s->term);
1.2 markus 1665: s->term = NULL;
1666: s->ptyfd = -1;
1667: s->ttyfd = -1;
1668: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1669: return 0;
1.2 markus 1670: }
1671: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1672:
1673: /* for SSH1 the tty modes length is not given */
1674: if (!compat20)
1675: n_bytes = packet_remaining();
1676: tty_parse_modes(s->ttyfd, &n_bytes);
1677:
1.130 provos 1678: if (!use_privsep)
1679: pty_setowner(s->pw, s->tty);
1.86 markus 1680:
1681: /* Set window size from the packet. */
1.2 markus 1682: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1683:
1.116 markus 1684: packet_check_eom();
1.9 markus 1685: session_proctitle(s);
1.2 markus 1686: return 1;
1687: }
1688:
1.94 itojun 1689: static int
1.7 markus 1690: session_subsystem_req(Session *s)
1691: {
1.105 markus 1692: struct stat st;
1.45 markus 1693: u_int len;
1.7 markus 1694: int success = 0;
1.205 djm 1695: char *prog, *cmd, *subsys = packet_get_string(&len);
1.182 djm 1696: u_int i;
1.7 markus 1697:
1.116 markus 1698: packet_check_eom();
1.155 itojun 1699: logit("subsystem request for %.100s", subsys);
1.18 jakob 1700:
1701: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1702: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1.205 djm 1703: prog = options.subsystem_command[i];
1704: cmd = options.subsystem_args[i];
1.226 djm 1705: if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
1.225 markus 1706: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1707: } else if (stat(prog, &st) < 0) {
1.205 djm 1708: error("subsystem: cannot stat %s: %s", prog,
1.105 markus 1709: strerror(errno));
1710: break;
1.225 markus 1711: } else {
1712: s->is_subsystem = SUBSYSTEM_EXT;
1.105 markus 1713: }
1714: debug("subsystem: exec() %s", cmd);
1.237 djm 1715: success = do_exec(s, cmd) == 0;
1.122 markus 1716: break;
1.18 jakob 1717: }
1718: }
1719:
1720: if (!success)
1.155 itojun 1721: logit("subsystem request for %.100s failed, subsystem not found",
1.105 markus 1722: subsys);
1.7 markus 1723:
1724: xfree(subsys);
1725: return success;
1726: }
1727:
1.94 itojun 1728: static int
1.7 markus 1729: session_x11_req(Session *s)
1730: {
1.81 markus 1731: int success;
1.7 markus 1732:
1.184 djm 1733: if (s->auth_proto != NULL || s->auth_data != NULL) {
1734: error("session_x11_req: session %d: "
1.190 stevesk 1735: "x11 forwarding already active", s->self);
1.184 djm 1736: return 0;
1737: }
1.7 markus 1738: s->single_connection = packet_get_char();
1739: s->auth_proto = packet_get_string(NULL);
1740: s->auth_data = packet_get_string(NULL);
1741: s->screen = packet_get_int();
1.116 markus 1742: packet_check_eom();
1.7 markus 1743:
1.81 markus 1744: success = session_setup_x11fwd(s);
1745: if (!success) {
1.7 markus 1746: xfree(s->auth_proto);
1747: xfree(s->auth_data);
1.84 markus 1748: s->auth_proto = NULL;
1749: s->auth_data = NULL;
1.7 markus 1750: }
1.81 markus 1751: return success;
1.7 markus 1752: }
1753:
1.94 itojun 1754: static int
1.19 markus 1755: session_shell_req(Session *s)
1756: {
1.116 markus 1757: packet_check_eom();
1.237 djm 1758: return do_exec(s, NULL) == 0;
1.19 markus 1759: }
1760:
1.94 itojun 1761: static int
1.19 markus 1762: session_exec_req(Session *s)
1763: {
1.237 djm 1764: u_int len, success;
1765:
1.19 markus 1766: char *command = packet_get_string(&len);
1.116 markus 1767: packet_check_eom();
1.237 djm 1768: success = do_exec(s, command) == 0;
1.92 markus 1769: xfree(command);
1.237 djm 1770: return success;
1.19 markus 1771: }
1772:
1.94 itojun 1773: static int
1.157 markus 1774: session_break_req(Session *s)
1775: {
1776:
1.175 deraadt 1777: packet_get_int(); /* ignored */
1.157 markus 1778: packet_check_eom();
1779:
1.237 djm 1780: if (s->ttyfd == -1 || tcsendbreak(s->ttyfd, 0) < 0)
1.157 markus 1781: return 0;
1782: return 1;
1783: }
1784:
1785: static int
1.173 djm 1786: session_env_req(Session *s)
1787: {
1788: char *name, *val;
1789: u_int name_len, val_len, i;
1790:
1791: name = packet_get_string(&name_len);
1792: val = packet_get_string(&val_len);
1793: packet_check_eom();
1794:
1795: /* Don't set too many environment variables */
1796: if (s->num_env > 128) {
1797: debug2("Ignoring env request %s: too many env vars", name);
1798: goto fail;
1799: }
1800:
1801: for (i = 0; i < options.num_accept_env; i++) {
1802: if (match_pattern(name, options.accept_env[i])) {
1803: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.201 djm 1804: s->env = xrealloc(s->env, s->num_env + 1,
1805: sizeof(*s->env));
1.173 djm 1806: s->env[s->num_env].name = name;
1807: s->env[s->num_env].val = val;
1808: s->num_env++;
1809: return (1);
1810: }
1811: }
1812: debug2("Ignoring env request %s: disallowed name", name);
1813:
1814: fail:
1815: xfree(name);
1816: xfree(val);
1817: return (0);
1818: }
1819:
1820: static int
1.43 markus 1821: session_auth_agent_req(Session *s)
1822: {
1823: static int called = 0;
1.116 markus 1824: packet_check_eom();
1.235 pyr 1825: if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
1.44 markus 1826: debug("session_auth_agent_req: no_agent_forwarding_flag");
1827: return 0;
1828: }
1.43 markus 1829: if (called) {
1830: return 0;
1831: } else {
1832: called = 1;
1833: return auth_input_request_forwarding(s->pw);
1834: }
1835: }
1836:
1.123 markus 1837: int
1838: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1839: {
1840: int success = 0;
1841: Session *s;
1842:
1.123 markus 1843: if ((s = session_by_channel(c->self)) == NULL) {
1.155 itojun 1844: logit("session_input_channel_req: no session %d req %.100s",
1.123 markus 1845: c->self, rtype);
1846: return 0;
1847: }
1848: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1849:
1850: /*
1.64 markus 1851: * a session is in LARVAL state until a shell, a command
1852: * or a subsystem is executed
1.2 markus 1853: */
1854: if (c->type == SSH_CHANNEL_LARVAL) {
1855: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1856: success = session_shell_req(s);
1.2 markus 1857: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1858: success = session_exec_req(s);
1.2 markus 1859: } else if (strcmp(rtype, "pty-req") == 0) {
1.221 stevesk 1860: success = session_pty_req(s);
1.7 markus 1861: } else if (strcmp(rtype, "x11-req") == 0) {
1862: success = session_x11_req(s);
1.43 markus 1863: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1864: success = session_auth_agent_req(s);
1.7 markus 1865: } else if (strcmp(rtype, "subsystem") == 0) {
1866: success = session_subsystem_req(s);
1.173 djm 1867: } else if (strcmp(rtype, "env") == 0) {
1868: success = session_env_req(s);
1.2 markus 1869: }
1870: }
1871: if (strcmp(rtype, "window-change") == 0) {
1872: success = session_window_change_req(s);
1.177 djm 1873: } else if (strcmp(rtype, "break") == 0) {
1874: success = session_break_req(s);
1.2 markus 1875: }
1.177 djm 1876:
1.123 markus 1877: return success;
1.2 markus 1878: }
1879:
1880: void
1881: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1882: {
1883: if (!compat20)
1884: fatal("session_set_fds: called for proto != 2.0");
1885: /*
1886: * now that have a child and a pipe to the child,
1887: * we can activate our channel and register the fd's
1888: */
1889: if (s->chanid == -1)
1890: fatal("no channel for session %d", s->self);
1891: channel_set_fds(s->chanid,
1892: fdout, fdin, fderr,
1.42 markus 1893: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.126 markus 1894: 1,
1895: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1896: }
1897:
1.85 markus 1898: /*
1899: * Function to perform pty cleanup. Also called if we get aborted abnormally
1900: * (e.g., due to a dropped connection).
1901: */
1.130 provos 1902: void
1.165 markus 1903: session_pty_cleanup2(Session *s)
1.1 markus 1904: {
1.85 markus 1905: if (s == NULL) {
1906: error("session_pty_cleanup: no session");
1907: return;
1908: }
1909: if (s->ttyfd == -1)
1.1 markus 1910: return;
1911:
1.54 stevesk 1912: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1913:
1914: /* Record that the user has logged out. */
1.85 markus 1915: if (s->pid != 0)
1916: record_logout(s->pid, s->tty);
1.1 markus 1917:
1918: /* Release the pseudo-tty. */
1.130 provos 1919: if (getuid() == 0)
1920: pty_release(s->tty);
1.1 markus 1921:
1922: /*
1923: * Close the server side of the socket pairs. We must do this after
1924: * the pty cleanup, so that another process doesn't get this pty
1925: * while we're still cleaning up.
1926: */
1.237 djm 1927: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1928: error("close(s->ptymaster/%d): %s",
1929: s->ptymaster, strerror(errno));
1.108 markus 1930:
1931: /* unlink pty from session */
1932: s->ttyfd = -1;
1.2 markus 1933: }
1934:
1.130 provos 1935: void
1.165 markus 1936: session_pty_cleanup(Session *s)
1.130 provos 1937: {
1.165 markus 1938: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1939: }
1940:
1.147 markus 1941: static char *
1942: sig2name(int sig)
1943: {
1944: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1945: SSH_SIG(ABRT);
1946: SSH_SIG(ALRM);
1947: SSH_SIG(FPE);
1948: SSH_SIG(HUP);
1949: SSH_SIG(ILL);
1950: SSH_SIG(INT);
1951: SSH_SIG(KILL);
1952: SSH_SIG(PIPE);
1953: SSH_SIG(QUIT);
1954: SSH_SIG(SEGV);
1955: SSH_SIG(TERM);
1956: SSH_SIG(USR1);
1957: SSH_SIG(USR2);
1958: #undef SSH_SIG
1959: return "SIG@openssh.com";
1960: }
1961:
1.94 itojun 1962: static void
1.184 djm 1963: session_close_x11(int id)
1964: {
1965: Channel *c;
1966:
1.189 markus 1967: if ((c = channel_by_id(id)) == NULL) {
1.184 djm 1968: debug("session_close_x11: x11 channel %d missing", id);
1969: } else {
1970: /* Detach X11 listener */
1971: debug("session_close_x11: detach x11 channel %d", id);
1972: channel_cancel_cleanup(id);
1973: if (c->ostate != CHAN_OUTPUT_CLOSED)
1974: chan_mark_dead(c);
1975: }
1976: }
1977:
1978: static void
1979: session_close_single_x11(int id, void *arg)
1980: {
1981: Session *s;
1982: u_int i;
1983:
1984: debug3("session_close_single_x11: channel %d", id);
1985: channel_cancel_cleanup(id);
1.221 stevesk 1986: if ((s = session_by_x11_channel(id)) == NULL)
1.184 djm 1987: fatal("session_close_single_x11: no x11 channel %d", id);
1988: for (i = 0; s->x11_chanids[i] != -1; i++) {
1989: debug("session_close_single_x11: session %d: "
1990: "closing channel %d", s->self, s->x11_chanids[i]);
1991: /*
1992: * The channel "id" is already closing, but make sure we
1993: * close all of its siblings.
1994: */
1995: if (s->x11_chanids[i] != id)
1996: session_close_x11(s->x11_chanids[i]);
1997: }
1998: xfree(s->x11_chanids);
1999: s->x11_chanids = NULL;
2000: if (s->display) {
2001: xfree(s->display);
2002: s->display = NULL;
2003: }
2004: if (s->auth_proto) {
2005: xfree(s->auth_proto);
2006: s->auth_proto = NULL;
2007: }
2008: if (s->auth_data) {
2009: xfree(s->auth_data);
2010: s->auth_data = NULL;
2011: }
2012: if (s->auth_display) {
2013: xfree(s->auth_display);
2014: s->auth_display = NULL;
2015: }
2016: }
2017:
2018: static void
1.2 markus 2019: session_exit_message(Session *s, int status)
2020: {
2021: Channel *c;
1.124 markus 2022:
2023: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 2024: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 2025: s->self, s->chanid);
1.137 mpech 2026: debug("session_exit_message: session %d channel %d pid %ld",
2027: s->self, s->chanid, (long)s->pid);
1.2 markus 2028:
2029: if (WIFEXITED(status)) {
1.124 markus 2030: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 2031: packet_put_int(WEXITSTATUS(status));
2032: packet_send();
2033: } else if (WIFSIGNALED(status)) {
1.124 markus 2034: channel_request_start(s->chanid, "exit-signal", 0);
1.147 markus 2035: packet_put_cstring(sig2name(WTERMSIG(status)));
1.229 markus 2036: packet_put_char(WCOREDUMP(status)? 1 : 0);
1.2 markus 2037: packet_put_cstring("");
2038: packet_put_cstring("");
2039: packet_send();
2040: } else {
2041: /* Some weird exit cause. Just exit. */
2042: packet_disconnect("wait returned status %04x.", status);
2043: }
2044:
2045: /* disconnect channel */
2046: debug("session_exit_message: release channel %d", s->chanid);
1.187 djm 2047:
2048: /*
2049: * Adjust cleanup callback attachment to send close messages when
1.199 deraadt 2050: * the channel gets EOF. The session will be then be closed
1.187 djm 2051: * by session_close_by_channel when the childs close their fds.
2052: */
2053: channel_register_cleanup(c->self, session_close_by_channel, 1);
2054:
1.5 markus 2055: /*
2056: * emulate a write failure with 'chan_write_failed', nobody will be
2057: * interested in data we write.
2058: * Note that we must not call 'chan_read_failed', since there could
2059: * be some more data waiting in the pipe.
2060: */
1.8 markus 2061: if (c->ostate != CHAN_OUTPUT_CLOSED)
2062: chan_write_failed(c);
1.2 markus 2063: }
2064:
1.130 provos 2065: void
1.85 markus 2066: session_close(Session *s)
1.2 markus 2067: {
1.182 djm 2068: u_int i;
1.173 djm 2069:
1.137 mpech 2070: debug("session_close: session %d pid %ld", s->self, (long)s->pid);
1.165 markus 2071: if (s->ttyfd != -1)
1.85 markus 2072: session_pty_cleanup(s);
1.2 markus 2073: if (s->term)
2074: xfree(s->term);
2075: if (s->display)
2076: xfree(s->display);
1.184 djm 2077: if (s->x11_chanids)
2078: xfree(s->x11_chanids);
1.118 stevesk 2079: if (s->auth_display)
2080: xfree(s->auth_display);
1.2 markus 2081: if (s->auth_data)
2082: xfree(s->auth_data);
2083: if (s->auth_proto)
2084: xfree(s->auth_proto);
1.219 djm 2085: if (s->env != NULL) {
2086: for (i = 0; i < s->num_env; i++) {
2087: xfree(s->env[i].name);
2088: xfree(s->env[i].val);
2089: }
2090: xfree(s->env);
1.173 djm 2091: }
1.9 markus 2092: session_proctitle(s);
1.237 djm 2093: session_unused(s->self);
1.2 markus 2094: }
2095:
2096: void
2097: session_close_by_pid(pid_t pid, int status)
2098: {
2099: Session *s = session_by_pid(pid);
2100: if (s == NULL) {
1.137 mpech 2101: debug("session_close_by_pid: no session for pid %ld",
2102: (long)pid);
1.2 markus 2103: return;
2104: }
2105: if (s->chanid != -1)
2106: session_exit_message(s, status);
1.187 djm 2107: if (s->ttyfd != -1)
2108: session_pty_cleanup(s);
1.197 djm 2109: s->pid = 0;
1.98 markus 2110: }
2111:
1.2 markus 2112: /*
2113: * this is called when a channel dies before
2114: * the session 'child' itself dies
2115: */
2116: void
2117: session_close_by_channel(int id, void *arg)
2118: {
2119: Session *s = session_by_channel(id);
1.187 djm 2120: u_int i;
1.184 djm 2121:
1.2 markus 2122: if (s == NULL) {
1.107 markus 2123: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 2124: return;
2125: }
1.137 mpech 2126: debug("session_close_by_channel: channel %d child %ld",
2127: id, (long)s->pid);
1.107 markus 2128: if (s->pid != 0) {
2129: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 2130: /*
2131: * delay detach of session, but release pty, since
2132: * the fd's to the child are already closed
2133: */
1.165 markus 2134: if (s->ttyfd != -1)
1.108 markus 2135: session_pty_cleanup(s);
1.107 markus 2136: return;
2137: }
2138: /* detach by removing callback */
1.2 markus 2139: channel_cancel_cleanup(s->chanid);
1.187 djm 2140:
2141: /* Close any X11 listeners associated with this session */
2142: if (s->x11_chanids != NULL) {
2143: for (i = 0; s->x11_chanids[i] != -1; i++) {
2144: session_close_x11(s->x11_chanids[i]);
2145: s->x11_chanids[i] = -1;
2146: }
2147: }
2148:
1.2 markus 2149: s->chanid = -1;
1.106 markus 2150: session_close(s);
2151: }
2152:
2153: void
1.130 provos 2154: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 2155: {
2156: int i;
1.237 djm 2157: for (i = 0; i < sessions_nalloc; i++) {
1.106 markus 2158: Session *s = &sessions[i];
1.130 provos 2159: if (s->used) {
2160: if (closefunc != NULL)
2161: closefunc(s);
2162: else
2163: session_close(s);
2164: }
1.2 markus 2165: }
1.9 markus 2166: }
2167:
1.94 itojun 2168: static char *
1.9 markus 2169: session_tty_list(void)
2170: {
2171: static char buf[1024];
2172: int i;
2173: buf[0] = '\0';
1.237 djm 2174: for (i = 0; i < sessions_nalloc; i++) {
1.9 markus 2175: Session *s = &sessions[i];
2176: if (s->used && s->ttyfd != -1) {
2177: if (buf[0] != '\0')
2178: strlcat(buf, ",", sizeof buf);
2179: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2180: }
2181: }
2182: if (buf[0] == '\0')
2183: strlcpy(buf, "notty", sizeof buf);
2184: return buf;
2185: }
2186:
2187: void
2188: session_proctitle(Session *s)
2189: {
2190: if (s->pw == NULL)
2191: error("no user for session %d", s->self);
2192: else
2193: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 2194: }
2195:
2196: int
2197: session_setup_x11fwd(Session *s)
2198: {
2199: struct stat st;
1.109 stevesk 2200: char display[512], auth_display[512];
2201: char hostname[MAXHOSTNAMELEN];
1.184 djm 2202: u_int i;
1.81 markus 2203:
2204: if (no_x11_forwarding_flag) {
2205: packet_send_debug("X11 forwarding disabled in user configuration file.");
2206: return 0;
2207: }
2208: if (!options.x11_forwarding) {
2209: debug("X11 forwarding disabled in server configuration file.");
2210: return 0;
2211: }
2212: if (!options.xauth_location ||
2213: (stat(options.xauth_location, &st) == -1)) {
2214: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 2215: return 0;
2216: }
2217: if (options.use_login) {
2218: packet_send_debug("X11 forwarding disabled; "
2219: "not compatible with UseLogin=yes.");
1.81 markus 2220: return 0;
2221: }
1.87 markus 2222: if (s->display != NULL) {
1.81 markus 2223: debug("X11 display already set.");
2224: return 0;
2225: }
1.140 deraadt 2226: if (x11_create_display_inet(options.x11_display_offset,
2227: options.x11_use_localhost, s->single_connection,
1.184 djm 2228: &s->display_number, &s->x11_chanids) == -1) {
1.87 markus 2229: debug("x11_create_display_inet failed.");
1.81 markus 2230: return 0;
1.184 djm 2231: }
2232: for (i = 0; s->x11_chanids[i] != -1; i++) {
2233: channel_register_cleanup(s->x11_chanids[i],
1.187 djm 2234: session_close_single_x11, 0);
1.81 markus 2235: }
1.109 stevesk 2236:
2237: /* Set up a suitable value for the DISPLAY variable. */
2238: if (gethostname(hostname, sizeof(hostname)) < 0)
2239: fatal("gethostname: %.100s", strerror(errno));
2240: /*
2241: * auth_display must be used as the displayname when the
2242: * authorization entry is added with xauth(1). This will be
2243: * different than the DISPLAY string for localhost displays.
2244: */
1.119 stevesk 2245: if (options.x11_use_localhost) {
1.140 deraadt 2246: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 2247: s->display_number, s->screen);
1.140 deraadt 2248: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 2249: s->display_number, s->screen);
1.109 stevesk 2250: s->display = xstrdup(display);
1.118 stevesk 2251: s->auth_display = xstrdup(auth_display);
1.109 stevesk 2252: } else {
1.140 deraadt 2253: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 2254: s->display_number, s->screen);
2255: s->display = xstrdup(display);
1.118 stevesk 2256: s->auth_display = xstrdup(display);
1.109 stevesk 2257: }
2258:
1.81 markus 2259: return 1;
1.2 markus 2260: }
2261:
1.94 itojun 2262: static void
1.49 markus 2263: do_authenticated2(Authctxt *authctxt)
1.2 markus 2264: {
1.97 markus 2265: server_loop2(authctxt);
1.165 markus 2266: }
2267:
2268: void
2269: do_cleanup(Authctxt *authctxt)
2270: {
2271: static int called = 0;
2272:
2273: debug("do_cleanup");
2274:
2275: /* no cleanup if we're in the child for login shell */
2276: if (is_child)
2277: return;
2278:
2279: /* avoid double cleanup */
2280: if (called)
2281: return;
2282: called = 1;
2283:
1.218 markus 2284: if (authctxt == NULL || !authctxt->authenticated)
1.165 markus 2285: return;
2286: #ifdef KRB5
2287: if (options.kerberos_ticket_cleanup &&
2288: authctxt->krb5_ctx)
2289: krb5_cleanup_proc(authctxt);
1.161 markus 2290: #endif
1.165 markus 2291:
2292: #ifdef GSSAPI
2293: if (compat20 && options.gss_cleanup_creds)
2294: ssh_gssapi_cleanup_creds();
2295: #endif
2296:
2297: /* remove agent socket */
2298: auth_sock_cleanup_proc(authctxt->pw);
2299:
2300: /*
2301: * Cleanup ptys/utmp only if privsep is disabled,
2302: * or if running in monitor.
2303: */
2304: if (!use_privsep || mm_is_monitor())
2305: session_destroy_all(session_pty_cleanup2);
1.1 markus 2306: }
![[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