Annotation of src/usr.bin/ssh/session.c, Revision 1.159
1.1 markus 1: /*
2: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
3: * All rights reserved
1.37 deraadt 4: *
5: * As far as I am concerned, the code I have written for this software
6: * can be used freely for any purpose. Any derived versions of this
7: * software must be clearly marked as such, and if the derived work is
8: * incompatible with the protocol description in the RFC file, it must be
9: * called by a name other than "ssh" or "Secure Shell".
10: *
1.2 markus 11: * SSH2 support by Markus Friedl.
1.95 markus 12: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.37 deraadt 13: *
14: * Redistribution and use in source and binary forms, with or without
15: * modification, are permitted provided that the following conditions
16: * are met:
17: * 1. Redistributions of source code must retain the above copyright
18: * notice, this list of conditions and the following disclaimer.
19: * 2. Redistributions in binary form must reproduce the above copyright
20: * notice, this list of conditions and the following disclaimer in the
21: * documentation and/or other materials provided with the distribution.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2 markus 33: */
1.1 markus 34:
35: #include "includes.h"
1.159 ! markus 36: RCSID("$OpenBSD: session.c,v 1.158 2003/06/02 09:17:34 markus Exp $");
1.1 markus 37:
1.51 markus 38: #include "ssh.h"
39: #include "ssh1.h"
40: #include "ssh2.h"
1.1 markus 41: #include "xmalloc.h"
1.59 djm 42: #include "sshpty.h"
1.1 markus 43: #include "packet.h"
44: #include "buffer.h"
45: #include "mpaux.h"
46: #include "uidswap.h"
47: #include "compat.h"
1.78 markus 48: #include "channels.h"
1.2 markus 49: #include "bufaux.h"
50: #include "auth.h"
1.19 markus 51: #include "auth-options.h"
1.50 markus 52: #include "pathnames.h"
1.51 markus 53: #include "log.h"
54: #include "servconf.h"
1.59 djm 55: #include "sshlogin.h"
1.51 markus 56: #include "serverloop.h"
57: #include "canohost.h"
1.55 itojun 58: #include "session.h"
1.130 provos 59: #include "monitor_wrap.h"
1.1 markus 60:
61: /* func */
62:
63: Session *session_new(void);
1.94 itojun 64: void session_set_fds(Session *, int, int, int);
1.130 provos 65: void session_pty_cleanup(void *);
1.94 itojun 66: void session_proctitle(Session *);
67: int session_setup_x11fwd(Session *);
68: void do_exec_pty(Session *, const char *);
69: void do_exec_no_pty(Session *, const char *);
70: void do_exec(Session *, const char *);
71: void do_login(Session *, const char *);
72: void do_child(Session *, const char *);
1.73 djm 73: void do_motd(void);
1.94 itojun 74: int check_quietlogin(Session *, const char *);
1.1 markus 75:
1.94 itojun 76: static void do_authenticated1(Authctxt *);
77: static void do_authenticated2(Authctxt *);
78:
79: static int session_pty_req(Session *);
1.65 markus 80:
1.1 markus 81: /* import */
82: extern ServerOptions options;
83: extern char *__progname;
84: extern int log_stderr;
85: extern int debug_flag;
1.45 markus 86: extern u_int utmp_len;
1.21 markus 87: extern int startup_pipe;
1.74 markus 88: extern void destroy_sensitive_data(void);
1.21 markus 89:
1.34 markus 90: /* original command from peer. */
1.92 markus 91: const char *original_command = NULL;
1.34 markus 92:
1.1 markus 93: /* data */
94: #define MAX_SESSIONS 10
95: Session sessions[MAX_SESSIONS];
96:
1.28 millert 97: #ifdef HAVE_LOGIN_CAP
1.129 provos 98: login_cap_t *lc;
1.28 millert 99: #endif
100:
1.136 markus 101: /* Name and directory of socket for authentication agent forwarding. */
102: static char *auth_sock_name = NULL;
103: static char *auth_sock_dir = NULL;
104:
105: /* removes the agent forwarding socket */
106:
107: static void
108: auth_sock_cleanup_proc(void *_pw)
109: {
110: struct passwd *pw = _pw;
111:
112: if (auth_sock_name != NULL) {
113: temporarily_use_uid(pw);
114: unlink(auth_sock_name);
115: rmdir(auth_sock_dir);
116: auth_sock_name = NULL;
117: restore_uid();
118: }
119: }
120:
121: static int
122: auth_input_request_forwarding(struct passwd * pw)
123: {
124: Channel *nc;
125: int sock;
126: struct sockaddr_un sunaddr;
127:
128: if (auth_sock_name != NULL) {
129: error("authentication forwarding requested twice.");
130: return 0;
131: }
132:
133: /* Temporarily drop privileged uid for mkdir/bind. */
134: temporarily_use_uid(pw);
135:
136: /* Allocate a buffer for the socket name, and format the name. */
137: auth_sock_name = xmalloc(MAXPATHLEN);
138: auth_sock_dir = xmalloc(MAXPATHLEN);
139: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
140:
141: /* Create private directory for socket */
142: if (mkdtemp(auth_sock_dir) == NULL) {
143: packet_send_debug("Agent forwarding disabled: "
144: "mkdtemp() failed: %.100s", strerror(errno));
145: restore_uid();
146: xfree(auth_sock_name);
147: xfree(auth_sock_dir);
148: auth_sock_name = NULL;
149: auth_sock_dir = NULL;
150: return 0;
151: }
1.137 mpech 152: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
153: auth_sock_dir, (long) getpid());
1.136 markus 154:
155: /* delete agent socket on fatal() */
156: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
157:
158: /* Create the socket. */
159: sock = socket(AF_UNIX, SOCK_STREAM, 0);
160: if (sock < 0)
161: packet_disconnect("socket: %.100s", strerror(errno));
162:
163: /* Bind it to the name. */
164: memset(&sunaddr, 0, sizeof(sunaddr));
165: sunaddr.sun_family = AF_UNIX;
166: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
167:
168: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
169: packet_disconnect("bind: %.100s", strerror(errno));
170:
171: /* Restore the privileged uid. */
172: restore_uid();
173:
174: /* Start listening on the socket. */
175: if (listen(sock, 5) < 0)
176: packet_disconnect("listen: %.100s", strerror(errno));
177:
178: /* Allocate a channel for the authentication agent socket. */
179: nc = channel_new("auth socket",
180: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
181: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 182: 0, "auth socket", 1);
1.136 markus 183: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
184: return 1;
185: }
186:
187:
1.65 markus 188: void
189: do_authenticated(Authctxt *authctxt)
190: {
1.153 markus 191: setproctitle("%s", authctxt->pw->pw_name);
192:
1.65 markus 193: /*
194: * Cancel the alarm we set to limit the time taken for
195: * authentication.
196: */
197: alarm(0);
198: if (startup_pipe != -1) {
199: close(startup_pipe);
200: startup_pipe = -1;
201: }
202: /* setup the channel layer */
203: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
204: channel_permit_all_opens();
205:
206: if (compat20)
207: do_authenticated2(authctxt);
208: else
209: do_authenticated1(authctxt);
1.79 markus 210:
1.87 markus 211: /* remove agent socket */
1.136 markus 212: if (auth_sock_name != NULL)
1.80 markus 213: auth_sock_cleanup_proc(authctxt->pw);
1.96 dugsong 214: #ifdef KRB5
215: if (options.kerberos_ticket_cleanup)
216: krb5_cleanup_proc(authctxt);
217: #endif
1.65 markus 218: }
219:
1.1 markus 220: /*
221: * Prepares for an interactive session. This is called after the user has
222: * been successfully authenticated. During this message exchange, pseudo
223: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
224: * are requested, etc.
225: */
1.94 itojun 226: static void
1.65 markus 227: do_authenticated1(Authctxt *authctxt)
1.1 markus 228: {
229: Session *s;
1.65 markus 230: char *command;
1.117 markus 231: int success, type, screen_flag;
1.139 deraadt 232: int enable_compression_after_reply = 0;
233: u_int proto_len, data_len, dlen, compression_level = 0;
1.1 markus 234:
1.61 markus 235: s = session_new();
1.96 dugsong 236: s->authctxt = authctxt;
1.65 markus 237: s->pw = authctxt->pw;
1.28 millert 238:
1.1 markus 239: /*
240: * We stay in this loop until the client requests to execute a shell
241: * or a command.
242: */
243: for (;;) {
1.65 markus 244: success = 0;
1.1 markus 245:
246: /* Get a packet from the client. */
1.117 markus 247: type = packet_read();
1.1 markus 248:
249: /* Process the packet. */
250: switch (type) {
251: case SSH_CMSG_REQUEST_COMPRESSION:
252: compression_level = packet_get_int();
1.116 markus 253: packet_check_eom();
1.1 markus 254: if (compression_level < 1 || compression_level > 9) {
255: packet_send_debug("Received illegal compression level %d.",
1.112 deraadt 256: compression_level);
1.138 markus 257: break;
258: }
259: if (!options.compression) {
260: debug2("compression disabled");
1.1 markus 261: break;
262: }
263: /* Enable compression after we have responded with SUCCESS. */
264: enable_compression_after_reply = 1;
265: success = 1;
266: break;
267:
268: case SSH_CMSG_REQUEST_PTY:
1.86 markus 269: success = session_pty_req(s);
1.1 markus 270: break;
271:
272: case SSH_CMSG_X11_REQUEST_FORWARDING:
273: s->auth_proto = packet_get_string(&proto_len);
274: s->auth_data = packet_get_string(&data_len);
275:
1.57 markus 276: screen_flag = packet_get_protocol_flags() &
277: SSH_PROTOFLAG_SCREEN_NUMBER;
278: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
279:
280: if (packet_remaining() == 4) {
281: if (!screen_flag)
282: debug2("Buggy client: "
283: "X11 screen flag missing");
1.1 markus 284: s->screen = packet_get_int();
1.56 markus 285: } else {
1.1 markus 286: s->screen = 0;
1.56 markus 287: }
1.116 markus 288: packet_check_eom();
1.81 markus 289: success = session_setup_x11fwd(s);
290: if (!success) {
291: xfree(s->auth_proto);
292: xfree(s->auth_data);
1.84 markus 293: s->auth_proto = NULL;
294: s->auth_data = NULL;
1.1 markus 295: }
296: break;
297:
298: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
299: if (no_agent_forwarding_flag || compat13) {
300: debug("Authentication agent forwarding not permitted for this authentication.");
301: break;
302: }
303: debug("Received authentication agent forwarding request.");
1.65 markus 304: success = auth_input_request_forwarding(s->pw);
1.1 markus 305: break;
306:
307: case SSH_CMSG_PORT_FORWARD_REQUEST:
308: if (no_port_forwarding_flag) {
309: debug("Port forwarding not permitted for this authentication.");
1.39 markus 310: break;
311: }
312: if (!options.allow_tcp_forwarding) {
313: debug("Port forwarding not permitted.");
1.1 markus 314: break;
315: }
316: debug("Received TCP/IP port forwarding request.");
1.65 markus 317: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 318: success = 1;
319: break;
320:
321: case SSH_CMSG_MAX_PACKET_SIZE:
322: if (packet_set_maxsize(packet_get_int()) > 0)
323: success = 1;
324: break;
1.112 deraadt 325:
1.159 ! markus 326: #ifdef KRB5
1.96 dugsong 327: case SSH_CMSG_HAVE_KERBEROS_TGT:
328: if (!options.kerberos_tgt_passing) {
329: verbose("Kerberos TGT passing disabled.");
330: } else {
331: char *kdata = packet_get_string(&dlen);
1.116 markus 332: packet_check_eom();
1.112 deraadt 333:
1.159 ! markus 334: /* XXX - 0x41, used for AFS */
1.96 dugsong 335: if (kdata[0] != 0x41) {
336: krb5_data tgt;
337: tgt.data = kdata;
338: tgt.length = dlen;
1.112 deraadt 339:
1.96 dugsong 340: if (auth_krb5_tgt(s->authctxt, &tgt))
341: success = 1;
342: else
343: verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
344: }
345: xfree(kdata);
346: }
347: break;
1.159 ! markus 348: #endif
1.1 markus 349:
350: case SSH_CMSG_EXEC_SHELL:
351: case SSH_CMSG_EXEC_CMD:
352: if (type == SSH_CMSG_EXEC_CMD) {
353: command = packet_get_string(&dlen);
354: debug("Exec command '%.500s'", command);
1.92 markus 355: do_exec(s, command);
356: xfree(command);
1.1 markus 357: } else {
1.92 markus 358: do_exec(s, NULL);
1.1 markus 359: }
1.116 markus 360: packet_check_eom();
1.82 markus 361: session_close(s);
1.1 markus 362: return;
363:
364: default:
365: /*
366: * Any unknown messages in this phase are ignored,
367: * and a failure message is returned.
368: */
1.155 itojun 369: logit("Unknown packet type received after authentication: %d", type);
1.1 markus 370: }
371: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
372: packet_send();
373: packet_write_wait();
374:
375: /* Enable compression now that we have replied if appropriate. */
376: if (enable_compression_after_reply) {
377: enable_compression_after_reply = 0;
378: packet_start_compression(compression_level);
379: }
380: }
381: }
382:
383: /*
384: * This is called to fork and execute a command when we have no tty. This
385: * will call do_child from the child, and server_loop from the parent after
386: * setting up file descriptors and such.
387: */
1.4 markus 388: void
1.63 markus 389: do_exec_no_pty(Session *s, const char *command)
1.1 markus 390: {
1.137 mpech 391: pid_t pid;
1.1 markus 392:
393: #ifdef USE_PIPES
394: int pin[2], pout[2], perr[2];
395: /* Allocate pipes for communicating with the program. */
396: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
397: packet_disconnect("Could not create pipes: %.100s",
398: strerror(errno));
399: #else /* USE_PIPES */
400: int inout[2], err[2];
401: /* Uses socket pairs to communicate with the program. */
402: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
403: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
404: packet_disconnect("Could not create socket pairs: %.100s",
405: strerror(errno));
406: #endif /* USE_PIPES */
407: if (s == NULL)
408: fatal("do_exec_no_pty: no session");
409:
1.9 markus 410: session_proctitle(s);
1.1 markus 411:
412: /* Fork the child. */
413: if ((pid = fork()) == 0) {
1.144 markus 414: fatal_remove_all_cleanups();
415:
1.1 markus 416: /* Child. Reinitialize the log since the pid has changed. */
417: log_init(__progname, options.log_level, options.log_facility, log_stderr);
418:
419: /*
420: * Create a new session and process group since the 4.4BSD
421: * setlogin() affects the entire process group.
422: */
423: if (setsid() < 0)
424: error("setsid failed: %.100s", strerror(errno));
425:
426: #ifdef USE_PIPES
427: /*
428: * Redirect stdin. We close the parent side of the socket
429: * pair, and make the child side the standard input.
430: */
431: close(pin[1]);
432: if (dup2(pin[0], 0) < 0)
433: perror("dup2 stdin");
434: close(pin[0]);
435:
436: /* Redirect stdout. */
437: close(pout[0]);
438: if (dup2(pout[1], 1) < 0)
439: perror("dup2 stdout");
440: close(pout[1]);
441:
442: /* Redirect stderr. */
443: close(perr[0]);
444: if (dup2(perr[1], 2) < 0)
445: perror("dup2 stderr");
446: close(perr[1]);
447: #else /* USE_PIPES */
448: /*
449: * Redirect stdin, stdout, and stderr. Stdin and stdout will
450: * use the same socket, as some programs (particularly rdist)
451: * seem to depend on it.
452: */
453: close(inout[1]);
454: close(err[1]);
455: if (dup2(inout[0], 0) < 0) /* stdin */
456: perror("dup2 stdin");
457: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
458: perror("dup2 stdout");
459: if (dup2(err[0], 2) < 0) /* stderr */
460: perror("dup2 stderr");
461: #endif /* USE_PIPES */
462:
463: /* Do processing for the child (exec command etc). */
1.60 markus 464: do_child(s, command);
1.1 markus 465: /* NOTREACHED */
466: }
467: if (pid < 0)
468: packet_disconnect("fork failed: %.100s", strerror(errno));
469: s->pid = pid;
1.47 markus 470: /* Set interactive/non-interactive mode. */
1.48 markus 471: packet_set_interactive(s->display != NULL);
1.1 markus 472: #ifdef USE_PIPES
473: /* We are the parent. Close the child sides of the pipes. */
474: close(pin[0]);
475: close(pout[1]);
476: close(perr[1]);
477:
1.2 markus 478: if (compat20) {
1.64 markus 479: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 480: } else {
481: /* Enter the interactive session. */
482: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 483: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 484: }
1.1 markus 485: #else /* USE_PIPES */
486: /* We are the parent. Close the child sides of the socket pairs. */
487: close(inout[0]);
488: close(err[0]);
489:
490: /*
491: * Enter the interactive session. Note: server_loop must be able to
492: * handle the case that fdin and fdout are the same.
493: */
1.2 markus 494: if (compat20) {
1.64 markus 495: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 496: } else {
497: server_loop(pid, inout[1], inout[1], err[1]);
498: /* server_loop has closed inout[1] and err[1]. */
499: }
1.1 markus 500: #endif /* USE_PIPES */
501: }
502:
503: /*
504: * This is called to fork and execute a command when we have a tty. This
505: * will call do_child from the child, and server_loop from the parent after
506: * setting up file descriptors, controlling tty, updating wtmp, utmp,
507: * lastlog, and other such operations.
508: */
1.4 markus 509: void
1.63 markus 510: do_exec_pty(Session *s, const char *command)
1.1 markus 511: {
512: int fdout, ptyfd, ttyfd, ptymaster;
513: pid_t pid;
514:
515: if (s == NULL)
516: fatal("do_exec_pty: no session");
517: ptyfd = s->ptyfd;
518: ttyfd = s->ttyfd;
519:
520: /* Fork the child. */
521: if ((pid = fork()) == 0) {
1.144 markus 522: fatal_remove_all_cleanups();
1.97 markus 523:
1.24 markus 524: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 525: log_init(__progname, options.log_level, options.log_facility, log_stderr);
526: /* Close the master side of the pseudo tty. */
527: close(ptyfd);
528:
529: /* Make the pseudo tty our controlling tty. */
530: pty_make_controlling_tty(&ttyfd, s->tty);
531:
1.103 markus 532: /* Redirect stdin/stdout/stderr from the pseudo tty. */
533: if (dup2(ttyfd, 0) < 0)
534: error("dup2 stdin: %s", strerror(errno));
535: if (dup2(ttyfd, 1) < 0)
536: error("dup2 stdout: %s", strerror(errno));
537: if (dup2(ttyfd, 2) < 0)
538: error("dup2 stderr: %s", strerror(errno));
1.1 markus 539:
540: /* Close the extra descriptor for the pseudo tty. */
541: close(ttyfd);
542:
1.24 markus 543: /* record login, etc. similar to login(1) */
1.41 markus 544: if (!(options.use_login && command == NULL))
545: do_login(s, command);
1.1 markus 546:
547: /* Do common processing for the child, such as execing the command. */
1.60 markus 548: do_child(s, command);
1.1 markus 549: /* NOTREACHED */
550: }
551: if (pid < 0)
552: packet_disconnect("fork failed: %.100s", strerror(errno));
553: s->pid = pid;
554:
555: /* Parent. Close the slave side of the pseudo tty. */
556: close(ttyfd);
557:
558: /*
559: * Create another descriptor of the pty master side for use as the
560: * standard input. We could use the original descriptor, but this
561: * simplifies code in server_loop. The descriptor is bidirectional.
562: */
563: fdout = dup(ptyfd);
564: if (fdout < 0)
565: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
566:
567: /* we keep a reference to the pty master */
568: ptymaster = dup(ptyfd);
569: if (ptymaster < 0)
570: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
571: s->ptymaster = ptymaster;
572:
573: /* Enter interactive session. */
1.47 markus 574: packet_set_interactive(1);
1.2 markus 575: if (compat20) {
576: session_set_fds(s, ptyfd, fdout, -1);
577: } else {
578: server_loop(pid, ptyfd, fdout, -1);
579: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 580: }
581: }
582:
1.90 markus 583: /*
584: * This is called to fork and execute a command. If another command is
585: * to be forced, execute that instead.
586: */
587: void
588: do_exec(Session *s, const char *command)
589: {
590: if (forced_command) {
591: original_command = command;
592: command = forced_command;
593: debug("Forced command '%.900s'", command);
594: }
595:
596: if (s->ttyfd != -1)
597: do_exec_pty(s, command);
598: else
599: do_exec_no_pty(s, command);
600:
1.92 markus 601: original_command = NULL;
1.90 markus 602: }
603:
604:
1.24 markus 605: /* administrative, login(1)-like work */
606: void
1.41 markus 607: do_login(Session *s, const char *command)
1.24 markus 608: {
609: char *time_string;
610: socklen_t fromlen;
611: struct sockaddr_storage from;
612: struct passwd * pw = s->pw;
613: pid_t pid = getpid();
614:
615: /*
616: * Get IP address of client. If the connection is not a socket, let
617: * the address be 0.0.0.0.
618: */
619: memset(&from, 0, sizeof(from));
1.148 stevesk 620: fromlen = sizeof(from);
1.24 markus 621: if (packet_connection_is_on_socket()) {
622: if (getpeername(packet_get_connection_in(),
1.112 deraadt 623: (struct sockaddr *) & from, &fromlen) < 0) {
1.24 markus 624: debug("getpeername: %.100s", strerror(errno));
625: fatal_cleanup();
626: }
627: }
1.25 markus 628:
1.24 markus 629: /* Record that there was a login on that tty from the remote host. */
1.133 markus 630: if (!use_privsep)
631: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
632: get_remote_name_or_ip(utmp_len,
1.158 markus 633: options.use_dns),
1.148 stevesk 634: (struct sockaddr *)&from, fromlen);
1.24 markus 635:
1.73 djm 636: if (check_quietlogin(s, command))
1.24 markus 637: return;
1.73 djm 638:
1.134 markus 639: if (options.print_lastlog && s->last_login_time != 0) {
640: time_string = ctime(&s->last_login_time);
1.24 markus 641: if (strchr(time_string, '\n'))
642: *strchr(time_string, '\n') = 0;
1.134 markus 643: if (strcmp(s->hostname, "") == 0)
1.24 markus 644: printf("Last login: %s\r\n", time_string);
645: else
1.134 markus 646: printf("Last login: %s from %s\r\n", time_string,
647: s->hostname);
1.24 markus 648: }
1.73 djm 649:
650: do_motd();
651: }
652:
653: /*
654: * Display the message of the day.
655: */
656: void
657: do_motd(void)
658: {
659: FILE *f;
660: char buf[256];
661:
1.24 markus 662: if (options.print_motd) {
1.28 millert 663: #ifdef HAVE_LOGIN_CAP
664: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
665: "/etc/motd"), "r");
666: #else
1.24 markus 667: f = fopen("/etc/motd", "r");
1.28 millert 668: #endif
1.24 markus 669: if (f) {
670: while (fgets(buf, sizeof(buf), f))
671: fputs(buf, stdout);
672: fclose(f);
673: }
1.2 markus 674: }
1.73 djm 675: }
676:
677:
678: /*
679: * Check for quiet login, either .hushlogin or command given.
680: */
681: int
682: check_quietlogin(Session *s, const char *command)
683: {
684: char buf[256];
1.96 dugsong 685: struct passwd *pw = s->pw;
1.73 djm 686: struct stat st;
687:
688: /* Return 1 if .hushlogin exists or a command given. */
689: if (command != NULL)
690: return 1;
691: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
692: #ifdef HAVE_LOGIN_CAP
693: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
694: return 1;
695: #else
696: if (stat(buf, &st) >= 0)
697: return 1;
698: #endif
699: return 0;
1.1 markus 700: }
701:
702: /*
703: * Sets the value of the given variable in the environment. If the variable
704: * already exists, its value is overriden.
705: */
1.94 itojun 706: static void
1.45 markus 707: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 708: const char *value)
1.1 markus 709: {
1.45 markus 710: u_int i, namelen;
1.1 markus 711: char **env;
712:
713: /*
714: * Find the slot where the value should be stored. If the variable
715: * already exists, we reuse the slot; otherwise we append a new slot
716: * at the end of the array, expanding if necessary.
717: */
718: env = *envp;
719: namelen = strlen(name);
720: for (i = 0; env[i]; i++)
721: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
722: break;
723: if (env[i]) {
724: /* Reuse the slot. */
725: xfree(env[i]);
726: } else {
727: /* New variable. Expand if necessary. */
728: if (i >= (*envsizep) - 1) {
1.141 markus 729: if (*envsizep >= 1000)
730: fatal("child_set_env: too many env vars,"
731: " skipping: %.100s", name);
1.1 markus 732: (*envsizep) += 50;
733: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
734: }
735: /* Need to set the NULL pointer at end of array beyond the new slot. */
736: env[i + 1] = NULL;
737: }
738:
739: /* Allocate space and format the variable in the appropriate slot. */
740: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
741: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
742: }
743:
744: /*
745: * Reads environment variables from the given file and adds/overrides them
746: * into the environment. If the file does not exist, this does nothing.
747: * Otherwise, it must consist of empty lines, comments (line starts with '#')
748: * and assignments of the form name=value. No other forms are allowed.
749: */
1.94 itojun 750: static void
1.45 markus 751: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 752: const char *filename)
1.1 markus 753: {
754: FILE *f;
755: char buf[4096];
756: char *cp, *value;
1.142 deraadt 757: u_int lineno = 0;
1.1 markus 758:
759: f = fopen(filename, "r");
760: if (!f)
761: return;
762:
763: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 764: if (++lineno > 1000)
765: fatal("Too many lines in environment file %s", filename);
1.1 markus 766: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
767: ;
768: if (!*cp || *cp == '#' || *cp == '\n')
769: continue;
770: if (strchr(cp, '\n'))
771: *strchr(cp, '\n') = '\0';
772: value = strchr(cp, '=');
773: if (value == NULL) {
1.142 deraadt 774: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
775: filename);
1.1 markus 776: continue;
777: }
1.14 deraadt 778: /*
779: * Replace the equals sign by nul, and advance value to
780: * the value string.
781: */
1.1 markus 782: *value = '\0';
783: value++;
784: child_set_env(env, envsize, cp, value);
785: }
786: fclose(f);
787: }
788:
1.127 markus 789: static char **
790: do_setup_env(Session *s, const char *shell)
1.1 markus 791: {
792: char buf[256];
1.127 markus 793: u_int i, envsize;
1.154 markus 794: char **env, *laddr;
1.127 markus 795: struct passwd *pw = s->pw;
1.1 markus 796:
797: /* Initialize the environment. */
798: envsize = 100;
799: env = xmalloc(envsize * sizeof(char *));
800: env[0] = NULL;
801:
802: if (!options.use_login) {
803: /* Set basic environment. */
804: child_set_env(&env, &envsize, "USER", pw->pw_name);
805: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
806: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 807: #ifdef HAVE_LOGIN_CAP
1.145 markus 808: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
809: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
810: else
811: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 812: #else
1.29 millert 813: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 814: #endif
1.1 markus 815:
816: snprintf(buf, sizeof buf, "%.200s/%.50s",
817: _PATH_MAILDIR, pw->pw_name);
818: child_set_env(&env, &envsize, "MAIL", buf);
819:
820: /* Normal systems set SHELL by default. */
821: child_set_env(&env, &envsize, "SHELL", shell);
822: }
823: if (getenv("TZ"))
824: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
825:
826: /* Set custom environment options from RSA authentication. */
1.110 markus 827: if (!options.use_login) {
828: while (custom_environment) {
829: struct envstring *ce = custom_environment;
1.143 deraadt 830: char *str = ce->s;
1.127 markus 831:
1.143 deraadt 832: for (i = 0; str[i] != '=' && str[i]; i++)
1.110 markus 833: ;
1.143 deraadt 834: if (str[i] == '=') {
835: str[i] = 0;
836: child_set_env(&env, &envsize, str, str + i + 1);
1.110 markus 837: }
838: custom_environment = ce->next;
839: xfree(ce->s);
840: xfree(ce);
1.1 markus 841: }
842: }
843:
1.149 stevesk 844: /* SSH_CLIENT deprecated */
1.1 markus 845: snprintf(buf, sizeof buf, "%.50s %d %d",
1.127 markus 846: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 847: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 848:
1.154 markus 849: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 850: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.154 markus 851: get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
852: xfree(laddr);
1.149 stevesk 853: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 854:
1.60 markus 855: if (s->ttyfd != -1)
856: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
857: if (s->term)
858: child_set_env(&env, &envsize, "TERM", s->term);
859: if (s->display)
860: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 861: if (original_command)
862: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
863: original_command);
1.96 dugsong 864: #ifdef KRB5
865: if (s->authctxt->krb5_ticket_file)
866: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 867: s->authctxt->krb5_ticket_file);
1.96 dugsong 868: #endif
1.136 markus 869: if (auth_sock_name != NULL)
1.1 markus 870: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 871: auth_sock_name);
1.1 markus 872:
873: /* read $HOME/.ssh/environment. */
1.146 markus 874: if (options.permit_user_env && !options.use_login) {
1.14 deraadt 875: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
876: pw->pw_dir);
1.1 markus 877: read_environment_file(&env, &envsize, buf);
878: }
879: if (debug_flag) {
880: /* dump the environment */
881: fprintf(stderr, "Environment:\n");
882: for (i = 0; env[i]; i++)
883: fprintf(stderr, " %.200s\n", env[i]);
884: }
1.127 markus 885: return env;
886: }
887:
888: /*
889: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
890: * first in this order).
891: */
892: static void
893: do_rc_files(Session *s, const char *shell)
894: {
895: FILE *f = NULL;
896: char cmd[1024];
897: int do_xauth;
898: struct stat st;
899:
900: do_xauth =
901: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
902:
903: /* ignore _PATH_SSH_USER_RC for subsystems */
904: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
905: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
906: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
907: if (debug_flag)
908: fprintf(stderr, "Running %s\n", cmd);
909: f = popen(cmd, "w");
910: if (f) {
911: if (do_xauth)
912: fprintf(f, "%s %s\n", s->auth_proto,
913: s->auth_data);
914: pclose(f);
915: } else
916: fprintf(stderr, "Could not run %s\n",
917: _PATH_SSH_USER_RC);
918: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
919: if (debug_flag)
920: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
921: _PATH_SSH_SYSTEM_RC);
922: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
923: if (f) {
924: if (do_xauth)
925: fprintf(f, "%s %s\n", s->auth_proto,
926: s->auth_data);
927: pclose(f);
928: } else
929: fprintf(stderr, "Could not run %s\n",
930: _PATH_SSH_SYSTEM_RC);
931: } else if (do_xauth && options.xauth_location != NULL) {
932: /* Add authority data to .Xauthority if appropriate. */
933: if (debug_flag) {
934: fprintf(stderr,
1.151 stevesk 935: "Running %.500s remove %.100s\n",
936: options.xauth_location, s->auth_display);
937: fprintf(stderr,
938: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 939: options.xauth_location, s->auth_display,
940: s->auth_proto, s->auth_data);
941: }
942: snprintf(cmd, sizeof cmd, "%s -q -",
943: options.xauth_location);
944: f = popen(cmd, "w");
945: if (f) {
1.151 stevesk 946: fprintf(f, "remove %s\n",
947: s->auth_display);
1.127 markus 948: fprintf(f, "add %s %s %s\n",
949: s->auth_display, s->auth_proto,
950: s->auth_data);
951: pclose(f);
952: } else {
953: fprintf(stderr, "Could not run %s\n",
954: cmd);
955: }
956: }
957: }
958:
959: static void
960: do_nologin(struct passwd *pw)
961: {
962: FILE *f = NULL;
963: char buf[1024];
964:
965: #ifdef HAVE_LOGIN_CAP
966: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
967: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
968: _PATH_NOLOGIN), "r");
969: #else
970: if (pw->pw_uid)
971: f = fopen(_PATH_NOLOGIN, "r");
972: #endif
973: if (f) {
974: /* /etc/nologin exists. Print its contents and exit. */
1.155 itojun 975: logit("User %.100s not allowed because %s exists",
1.150 stevesk 976: pw->pw_name, _PATH_NOLOGIN);
1.127 markus 977: while (fgets(buf, sizeof(buf), f))
978: fputs(buf, stderr);
979: fclose(f);
980: exit(254);
981: }
982: }
983:
984: /* Set login name, uid, gid, and groups. */
1.130 provos 985: void
1.127 markus 986: do_setusercontext(struct passwd *pw)
987: {
988: if (getuid() == 0 || geteuid() == 0) {
989: #ifdef HAVE_LOGIN_CAP
990: if (setusercontext(lc, pw, pw->pw_uid,
991: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
992: perror("unable to set user context");
993: exit(1);
994: }
995: #else
996: if (setlogin(pw->pw_name) < 0)
997: error("setlogin failed: %s", strerror(errno));
998: if (setgid(pw->pw_gid) < 0) {
999: perror("setgid");
1000: exit(1);
1001: }
1002: /* Initialize the group list. */
1003: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1004: perror("initgroups");
1005: exit(1);
1006: }
1007: endgrent();
1008:
1009: /* Permanently switch to the desired uid. */
1010: permanently_set_uid(pw);
1011: #endif
1012: }
1013: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1014: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1015: }
1016:
1.131 markus 1017: static void
1.130 provos 1018: launch_login(struct passwd *pw, const char *hostname)
1019: {
1020: /* Launch login(1). */
1021:
1022: execl("/usr/bin/login", "login", "-h", hostname,
1023: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1024:
1025: /* Login couldn't be executed, die. */
1026:
1027: perror("login");
1028: exit(1);
1029: }
1030:
1.127 markus 1031: /*
1032: * Performs common processing for the child, such as setting up the
1033: * environment, closing extra file descriptors, setting the user and group
1034: * ids, and executing the command or shell.
1035: */
1036: void
1037: do_child(Session *s, const char *command)
1038: {
1039: extern char **environ;
1040: char **env;
1041: char *argv[10];
1042: const char *shell, *shell0, *hostname = NULL;
1043: struct passwd *pw = s->pw;
1044: u_int i;
1045:
1046: /* remove hostkey from the child's memory */
1047: destroy_sensitive_data();
1048:
1049: /* login(1) is only called if we execute the login shell */
1050: if (options.use_login && command != NULL)
1051: options.use_login = 0;
1052:
1053: /*
1054: * Login(1) does this as well, and it needs uid 0 for the "-h"
1055: * switch, so we let login(1) to this for us.
1056: */
1057: if (!options.use_login) {
1058: do_nologin(pw);
1059: do_setusercontext(pw);
1060: }
1061:
1062: /*
1063: * Get the shell from the password data. An empty shell field is
1064: * legal, and means /bin/sh.
1065: */
1066: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1067:
1068: /*
1069: * Make sure $SHELL points to the shell from the password file,
1070: * even if shell is overridden from login.conf
1071: */
1072: env = do_setup_env(s, shell);
1073:
1.127 markus 1074: #ifdef HAVE_LOGIN_CAP
1075: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1076: #endif
1077:
1.26 millert 1078: /* we have to stash the hostname before we close our socket. */
1079: if (options.use_login)
1.70 stevesk 1080: hostname = get_remote_name_or_ip(utmp_len,
1.158 markus 1081: options.use_dns);
1.1 markus 1082: /*
1083: * Close the connection descriptors; note that this is the child, and
1084: * the server will still have the socket open, and it is important
1085: * that we do not shutdown it. Note that the descriptors cannot be
1086: * closed before building the environment, as we call
1087: * get_remote_ipaddr there.
1088: */
1089: if (packet_get_connection_in() == packet_get_connection_out())
1090: close(packet_get_connection_in());
1091: else {
1092: close(packet_get_connection_in());
1093: close(packet_get_connection_out());
1094: }
1095: /*
1096: * Close all descriptors related to channels. They will still remain
1097: * open in the parent.
1098: */
1099: /* XXX better use close-on-exec? -markus */
1100: channel_close_all();
1101:
1102: /*
1103: * Close any extra file descriptors. Note that there may still be
1104: * descriptors left by system functions. They will be closed later.
1105: */
1106: endpwent();
1107:
1108: /*
1109: * Close any extra open file descriptors so that we don\'t have them
1110: * hanging around in clients. Note that we want to do this after
1111: * initgroups, because at least on Solaris 2.3 it leaves file
1112: * descriptors open.
1113: */
1114: for (i = 3; i < 64; i++)
1115: close(i);
1116:
1117: /*
1.125 deraadt 1118: * Must take new environment into use so that .ssh/rc,
1119: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1120: */
1121: environ = env;
1.104 markus 1122:
1123: /* Change current directory to the user\'s home directory. */
1124: if (chdir(pw->pw_dir) < 0) {
1125: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1126: pw->pw_dir, strerror(errno));
1127: #ifdef HAVE_LOGIN_CAP
1128: if (login_getcapbool(lc, "requirehome", 0))
1129: exit(1);
1130: #endif
1131: }
1.1 markus 1132:
1.127 markus 1133: if (!options.use_login)
1134: do_rc_files(s, shell);
1.67 markus 1135:
1136: /* restore SIGPIPE for child */
1137: signal(SIGPIPE, SIG_DFL);
1138:
1.127 markus 1139: if (options.use_login) {
1.130 provos 1140: launch_login(pw, hostname);
1141: /* NEVERREACHED */
1.127 markus 1142: }
1143:
1144: /* Get the last component of the shell name. */
1145: if ((shell0 = strrchr(shell, '/')) != NULL)
1146: shell0++;
1147: else
1148: shell0 = shell;
1149:
1.1 markus 1150: /*
1151: * If we have no command, execute the shell. In this case, the shell
1152: * name to be passed in argv[0] is preceded by '-' to indicate that
1153: * this is a login shell.
1154: */
1155: if (!command) {
1.127 markus 1156: char argv0[256];
1.1 markus 1157:
1.127 markus 1158: /* Start the shell. Set initial character to '-'. */
1159: argv0[0] = '-';
1.1 markus 1160:
1.127 markus 1161: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1162: >= sizeof(argv0) - 1) {
1.127 markus 1163: errno = EINVAL;
1.1 markus 1164: perror(shell);
1165: exit(1);
1.127 markus 1166: }
1.1 markus 1167:
1.127 markus 1168: /* Execute the shell. */
1169: argv[0] = argv0;
1170: argv[1] = NULL;
1171: execve(shell, argv, env);
1172:
1173: /* Executing the shell failed. */
1174: perror(shell);
1175: exit(1);
1.1 markus 1176: }
1177: /*
1178: * Execute the command using the user's shell. This uses the -c
1179: * option to execute the command.
1180: */
1.127 markus 1181: argv[0] = (char *) shell0;
1.1 markus 1182: argv[1] = "-c";
1183: argv[2] = (char *) command;
1184: argv[3] = NULL;
1185: execve(shell, argv, env);
1186: perror(shell);
1187: exit(1);
1188: }
1189:
1190: Session *
1191: session_new(void)
1192: {
1193: int i;
1194: static int did_init = 0;
1195: if (!did_init) {
1196: debug("session_new: init");
1.112 deraadt 1197: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1198: sessions[i].used = 0;
1199: }
1200: did_init = 1;
1201: }
1.112 deraadt 1202: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1203: Session *s = &sessions[i];
1204: if (! s->used) {
1.68 djm 1205: memset(s, 0, sizeof(*s));
1.1 markus 1206: s->chanid = -1;
1207: s->ptyfd = -1;
1208: s->ttyfd = -1;
1209: s->used = 1;
1.85 markus 1210: s->self = i;
1.1 markus 1211: debug("session_new: session %d", i);
1212: return s;
1213: }
1214: }
1215: return NULL;
1216: }
1217:
1.94 itojun 1218: static void
1.1 markus 1219: session_dump(void)
1220: {
1221: int i;
1.112 deraadt 1222: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1223: Session *s = &sessions[i];
1.137 mpech 1224: debug("dump: used %d session %d %p channel %d pid %ld",
1.1 markus 1225: s->used,
1226: s->self,
1227: s,
1228: s->chanid,
1.137 mpech 1229: (long)s->pid);
1.1 markus 1230: }
1231: }
1232:
1.2 markus 1233: int
1.97 markus 1234: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1235: {
1236: Session *s = session_new();
1237: debug("session_open: channel %d", chanid);
1238: if (s == NULL) {
1239: error("no more sessions");
1240: return 0;
1241: }
1.97 markus 1242: s->authctxt = authctxt;
1243: s->pw = authctxt->pw;
1.7 markus 1244: if (s->pw == NULL)
1.54 stevesk 1245: fatal("no user for session %d", s->self);
1.2 markus 1246: debug("session_open: session %d: link with channel %d", s->self, chanid);
1247: s->chanid = chanid;
1248: return 1;
1249: }
1250:
1.130 provos 1251: Session *
1252: session_by_tty(char *tty)
1253: {
1254: int i;
1255: for (i = 0; i < MAX_SESSIONS; i++) {
1256: Session *s = &sessions[i];
1257: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1258: debug("session_by_tty: session %d tty %s", i, tty);
1259: return s;
1260: }
1261: }
1262: debug("session_by_tty: unknown tty %.100s", tty);
1263: session_dump();
1264: return NULL;
1265: }
1266:
1.94 itojun 1267: static Session *
1.2 markus 1268: session_by_channel(int id)
1269: {
1270: int i;
1.112 deraadt 1271: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1272: Session *s = &sessions[i];
1273: if (s->used && s->chanid == id) {
1274: debug("session_by_channel: session %d channel %d", i, id);
1275: return s;
1276: }
1277: }
1278: debug("session_by_channel: unknown channel %d", id);
1279: session_dump();
1280: return NULL;
1281: }
1282:
1.94 itojun 1283: static Session *
1.2 markus 1284: session_by_pid(pid_t pid)
1285: {
1286: int i;
1.137 mpech 1287: debug("session_by_pid: pid %ld", (long)pid);
1.112 deraadt 1288: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1289: Session *s = &sessions[i];
1290: if (s->used && s->pid == pid)
1291: return s;
1292: }
1.137 mpech 1293: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1294: session_dump();
1295: return NULL;
1296: }
1297:
1.94 itojun 1298: static int
1.2 markus 1299: session_window_change_req(Session *s)
1300: {
1301: s->col = packet_get_int();
1302: s->row = packet_get_int();
1303: s->xpixel = packet_get_int();
1304: s->ypixel = packet_get_int();
1.116 markus 1305: packet_check_eom();
1.2 markus 1306: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1307: return 1;
1308: }
1309:
1.94 itojun 1310: static int
1.2 markus 1311: session_pty_req(Session *s)
1312: {
1.45 markus 1313: u_int len;
1.72 stevesk 1314: int n_bytes;
1.132 markus 1315:
1.86 markus 1316: if (no_pty_flag) {
1317: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1318: return 0;
1.86 markus 1319: }
1320: if (s->ttyfd != -1) {
1321: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1322: return 0;
1.134 markus 1323: }
1324: /* Get the time and hostname when the user last logged in. */
1325: if (options.print_lastlog) {
1326: s->hostname[0] = '\0';
1327: s->last_login_time = get_last_login_time(s->pw->pw_uid,
1328: s->pw->pw_name, s->hostname, sizeof(s->hostname));
1.86 markus 1329: }
1330:
1.2 markus 1331: s->term = packet_get_string(&len);
1.86 markus 1332:
1333: if (compat20) {
1334: s->col = packet_get_int();
1335: s->row = packet_get_int();
1336: } else {
1337: s->row = packet_get_int();
1338: s->col = packet_get_int();
1339: }
1.2 markus 1340: s->xpixel = packet_get_int();
1341: s->ypixel = packet_get_int();
1342:
1343: if (strcmp(s->term, "") == 0) {
1344: xfree(s->term);
1345: s->term = NULL;
1346: }
1.86 markus 1347:
1.2 markus 1348: /* Allocate a pty and open it. */
1.86 markus 1349: debug("Allocating pty.");
1.130 provos 1350: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1.86 markus 1351: if (s->term)
1352: xfree(s->term);
1.2 markus 1353: s->term = NULL;
1354: s->ptyfd = -1;
1355: s->ttyfd = -1;
1356: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1357: return 0;
1.2 markus 1358: }
1359: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1360:
1361: /* for SSH1 the tty modes length is not given */
1362: if (!compat20)
1363: n_bytes = packet_remaining();
1364: tty_parse_modes(s->ttyfd, &n_bytes);
1365:
1.2 markus 1366: /*
1367: * Add a cleanup function to clear the utmp entry and record logout
1368: * time in case we call fatal() (e.g., the connection gets closed).
1369: */
1.85 markus 1370: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.130 provos 1371: if (!use_privsep)
1372: pty_setowner(s->pw, s->tty);
1.86 markus 1373:
1374: /* Set window size from the packet. */
1.2 markus 1375: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1376:
1.116 markus 1377: packet_check_eom();
1.9 markus 1378: session_proctitle(s);
1.2 markus 1379: return 1;
1380: }
1381:
1.94 itojun 1382: static int
1.7 markus 1383: session_subsystem_req(Session *s)
1384: {
1.105 markus 1385: struct stat st;
1.45 markus 1386: u_int len;
1.7 markus 1387: int success = 0;
1.105 markus 1388: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1389: int i;
1.7 markus 1390:
1.116 markus 1391: packet_check_eom();
1.155 itojun 1392: logit("subsystem request for %.100s", subsys);
1.18 jakob 1393:
1394: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1395: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1396: cmd = options.subsystem_command[i];
1397: if (stat(cmd, &st) < 0) {
1398: error("subsystem: cannot stat %s: %s", cmd,
1399: strerror(errno));
1400: break;
1401: }
1402: debug("subsystem: exec() %s", cmd);
1.64 markus 1403: s->is_subsystem = 1;
1.105 markus 1404: do_exec(s, cmd);
1.18 jakob 1405: success = 1;
1.122 markus 1406: break;
1.18 jakob 1407: }
1408: }
1409:
1410: if (!success)
1.155 itojun 1411: logit("subsystem request for %.100s failed, subsystem not found",
1.105 markus 1412: subsys);
1.7 markus 1413:
1414: xfree(subsys);
1415: return success;
1416: }
1417:
1.94 itojun 1418: static int
1.7 markus 1419: session_x11_req(Session *s)
1420: {
1.81 markus 1421: int success;
1.7 markus 1422:
1423: s->single_connection = packet_get_char();
1424: s->auth_proto = packet_get_string(NULL);
1425: s->auth_data = packet_get_string(NULL);
1426: s->screen = packet_get_int();
1.116 markus 1427: packet_check_eom();
1.7 markus 1428:
1.81 markus 1429: success = session_setup_x11fwd(s);
1430: if (!success) {
1.7 markus 1431: xfree(s->auth_proto);
1432: xfree(s->auth_data);
1.84 markus 1433: s->auth_proto = NULL;
1434: s->auth_data = NULL;
1.7 markus 1435: }
1.81 markus 1436: return success;
1.7 markus 1437: }
1438:
1.94 itojun 1439: static int
1.19 markus 1440: session_shell_req(Session *s)
1441: {
1.116 markus 1442: packet_check_eom();
1.90 markus 1443: do_exec(s, NULL);
1.19 markus 1444: return 1;
1445: }
1446:
1.94 itojun 1447: static int
1.19 markus 1448: session_exec_req(Session *s)
1449: {
1.45 markus 1450: u_int len;
1.19 markus 1451: char *command = packet_get_string(&len);
1.116 markus 1452: packet_check_eom();
1.90 markus 1453: do_exec(s, command);
1.92 markus 1454: xfree(command);
1.19 markus 1455: return 1;
1456: }
1457:
1.94 itojun 1458: static int
1.157 markus 1459: session_break_req(Session *s)
1460: {
1461: u_int break_length;
1462:
1463: break_length = packet_get_int();
1464: packet_check_eom();
1465:
1466: if (s->ttyfd == -1)
1467: return 0;
1468: /* we will sleep from 500ms to 3000ms */
1469: break_length = MIN(break_length, 3000);
1470: break_length = MAX(break_length, 500);
1471: ioctl(s->ttyfd, TIOCSBRK, NULL);
1472: /* should we care about EINTR? */
1473: usleep(break_length * 1000);
1474: ioctl(s->ttyfd, TIOCCBRK, NULL);
1475: return 1;
1476: }
1477:
1478: static int
1.43 markus 1479: session_auth_agent_req(Session *s)
1480: {
1481: static int called = 0;
1.116 markus 1482: packet_check_eom();
1.44 markus 1483: if (no_agent_forwarding_flag) {
1484: debug("session_auth_agent_req: no_agent_forwarding_flag");
1485: return 0;
1486: }
1.43 markus 1487: if (called) {
1488: return 0;
1489: } else {
1490: called = 1;
1491: return auth_input_request_forwarding(s->pw);
1492: }
1493: }
1494:
1.123 markus 1495: int
1496: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1497: {
1498: int success = 0;
1499: Session *s;
1500:
1.123 markus 1501: if ((s = session_by_channel(c->self)) == NULL) {
1.155 itojun 1502: logit("session_input_channel_req: no session %d req %.100s",
1.123 markus 1503: c->self, rtype);
1504: return 0;
1505: }
1506: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1507:
1508: /*
1.64 markus 1509: * a session is in LARVAL state until a shell, a command
1510: * or a subsystem is executed
1.2 markus 1511: */
1512: if (c->type == SSH_CHANNEL_LARVAL) {
1513: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1514: success = session_shell_req(s);
1.2 markus 1515: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1516: success = session_exec_req(s);
1.2 markus 1517: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1518: success = session_pty_req(s);
1.7 markus 1519: } else if (strcmp(rtype, "x11-req") == 0) {
1520: success = session_x11_req(s);
1.43 markus 1521: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1522: success = session_auth_agent_req(s);
1.7 markus 1523: } else if (strcmp(rtype, "subsystem") == 0) {
1524: success = session_subsystem_req(s);
1.157 markus 1525: } else if (strcmp(rtype, "break") == 0) {
1526: success = session_break_req(s);
1.2 markus 1527: }
1528: }
1529: if (strcmp(rtype, "window-change") == 0) {
1530: success = session_window_change_req(s);
1531: }
1.123 markus 1532: return success;
1.2 markus 1533: }
1534:
1535: void
1536: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1537: {
1538: if (!compat20)
1539: fatal("session_set_fds: called for proto != 2.0");
1540: /*
1541: * now that have a child and a pipe to the child,
1542: * we can activate our channel and register the fd's
1543: */
1544: if (s->chanid == -1)
1545: fatal("no channel for session %d", s->self);
1546: channel_set_fds(s->chanid,
1547: fdout, fdin, fderr,
1.42 markus 1548: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.126 markus 1549: 1,
1550: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1551: }
1552:
1.85 markus 1553: /*
1554: * Function to perform pty cleanup. Also called if we get aborted abnormally
1555: * (e.g., due to a dropped connection).
1556: */
1.130 provos 1557: void
1558: session_pty_cleanup2(void *session)
1.1 markus 1559: {
1.85 markus 1560: Session *s = session;
1561:
1562: if (s == NULL) {
1563: error("session_pty_cleanup: no session");
1564: return;
1565: }
1566: if (s->ttyfd == -1)
1.1 markus 1567: return;
1568:
1.54 stevesk 1569: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1570:
1571: /* Record that the user has logged out. */
1.85 markus 1572: if (s->pid != 0)
1573: record_logout(s->pid, s->tty);
1.1 markus 1574:
1575: /* Release the pseudo-tty. */
1.130 provos 1576: if (getuid() == 0)
1577: pty_release(s->tty);
1.1 markus 1578:
1579: /*
1580: * Close the server side of the socket pairs. We must do this after
1581: * the pty cleanup, so that another process doesn't get this pty
1582: * while we're still cleaning up.
1583: */
1584: if (close(s->ptymaster) < 0)
1.130 provos 1585: error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
1.108 markus 1586:
1587: /* unlink pty from session */
1588: s->ttyfd = -1;
1.2 markus 1589: }
1590:
1.130 provos 1591: void
1592: session_pty_cleanup(void *session)
1593: {
1594: PRIVSEP(session_pty_cleanup2(session));
1595: }
1596:
1.147 markus 1597: static char *
1598: sig2name(int sig)
1599: {
1600: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1601: SSH_SIG(ABRT);
1602: SSH_SIG(ALRM);
1603: SSH_SIG(FPE);
1604: SSH_SIG(HUP);
1605: SSH_SIG(ILL);
1606: SSH_SIG(INT);
1607: SSH_SIG(KILL);
1608: SSH_SIG(PIPE);
1609: SSH_SIG(QUIT);
1610: SSH_SIG(SEGV);
1611: SSH_SIG(TERM);
1612: SSH_SIG(USR1);
1613: SSH_SIG(USR2);
1614: #undef SSH_SIG
1615: return "SIG@openssh.com";
1616: }
1617:
1.94 itojun 1618: static void
1.2 markus 1619: session_exit_message(Session *s, int status)
1620: {
1621: Channel *c;
1.124 markus 1622:
1623: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 1624: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1625: s->self, s->chanid);
1.137 mpech 1626: debug("session_exit_message: session %d channel %d pid %ld",
1627: s->self, s->chanid, (long)s->pid);
1.2 markus 1628:
1629: if (WIFEXITED(status)) {
1.124 markus 1630: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1631: packet_put_int(WEXITSTATUS(status));
1632: packet_send();
1633: } else if (WIFSIGNALED(status)) {
1.124 markus 1634: channel_request_start(s->chanid, "exit-signal", 0);
1.147 markus 1635: packet_put_cstring(sig2name(WTERMSIG(status)));
1.2 markus 1636: packet_put_char(WCOREDUMP(status));
1637: packet_put_cstring("");
1638: packet_put_cstring("");
1639: packet_send();
1640: } else {
1641: /* Some weird exit cause. Just exit. */
1642: packet_disconnect("wait returned status %04x.", status);
1643: }
1644:
1645: /* disconnect channel */
1646: debug("session_exit_message: release channel %d", s->chanid);
1647: channel_cancel_cleanup(s->chanid);
1.5 markus 1648: /*
1649: * emulate a write failure with 'chan_write_failed', nobody will be
1650: * interested in data we write.
1651: * Note that we must not call 'chan_read_failed', since there could
1652: * be some more data waiting in the pipe.
1653: */
1.8 markus 1654: if (c->ostate != CHAN_OUTPUT_CLOSED)
1655: chan_write_failed(c);
1.2 markus 1656: s->chanid = -1;
1657: }
1658:
1.130 provos 1659: void
1.85 markus 1660: session_close(Session *s)
1.2 markus 1661: {
1.137 mpech 1662: debug("session_close: session %d pid %ld", s->self, (long)s->pid);
1.85 markus 1663: if (s->ttyfd != -1) {
1664: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1665: session_pty_cleanup(s);
1666: }
1.2 markus 1667: if (s->term)
1668: xfree(s->term);
1669: if (s->display)
1670: xfree(s->display);
1.118 stevesk 1671: if (s->auth_display)
1672: xfree(s->auth_display);
1.2 markus 1673: if (s->auth_data)
1674: xfree(s->auth_data);
1675: if (s->auth_proto)
1676: xfree(s->auth_proto);
1677: s->used = 0;
1.9 markus 1678: session_proctitle(s);
1.2 markus 1679: }
1680:
1681: void
1682: session_close_by_pid(pid_t pid, int status)
1683: {
1684: Session *s = session_by_pid(pid);
1685: if (s == NULL) {
1.137 mpech 1686: debug("session_close_by_pid: no session for pid %ld",
1687: (long)pid);
1.2 markus 1688: return;
1689: }
1690: if (s->chanid != -1)
1691: session_exit_message(s, status);
1692: session_close(s);
1.98 markus 1693: }
1694:
1.2 markus 1695: /*
1696: * this is called when a channel dies before
1697: * the session 'child' itself dies
1698: */
1699: void
1700: session_close_by_channel(int id, void *arg)
1701: {
1702: Session *s = session_by_channel(id);
1703: if (s == NULL) {
1.107 markus 1704: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1705: return;
1706: }
1.137 mpech 1707: debug("session_close_by_channel: channel %d child %ld",
1708: id, (long)s->pid);
1.107 markus 1709: if (s->pid != 0) {
1710: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 1711: /*
1712: * delay detach of session, but release pty, since
1713: * the fd's to the child are already closed
1714: */
1715: if (s->ttyfd != -1) {
1716: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1717: session_pty_cleanup(s);
1718: }
1.107 markus 1719: return;
1720: }
1721: /* detach by removing callback */
1.2 markus 1722: channel_cancel_cleanup(s->chanid);
1723: s->chanid = -1;
1.106 markus 1724: session_close(s);
1725: }
1726:
1727: void
1.130 provos 1728: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 1729: {
1730: int i;
1.112 deraadt 1731: for (i = 0; i < MAX_SESSIONS; i++) {
1.106 markus 1732: Session *s = &sessions[i];
1.130 provos 1733: if (s->used) {
1734: if (closefunc != NULL)
1735: closefunc(s);
1736: else
1737: session_close(s);
1738: }
1.2 markus 1739: }
1.9 markus 1740: }
1741:
1.94 itojun 1742: static char *
1.9 markus 1743: session_tty_list(void)
1744: {
1745: static char buf[1024];
1746: int i;
1747: buf[0] = '\0';
1.112 deraadt 1748: for (i = 0; i < MAX_SESSIONS; i++) {
1.9 markus 1749: Session *s = &sessions[i];
1750: if (s->used && s->ttyfd != -1) {
1751: if (buf[0] != '\0')
1752: strlcat(buf, ",", sizeof buf);
1753: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1754: }
1755: }
1756: if (buf[0] == '\0')
1757: strlcpy(buf, "notty", sizeof buf);
1758: return buf;
1759: }
1760:
1761: void
1762: session_proctitle(Session *s)
1763: {
1764: if (s->pw == NULL)
1765: error("no user for session %d", s->self);
1766: else
1767: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1768: }
1769:
1770: int
1771: session_setup_x11fwd(Session *s)
1772: {
1773: struct stat st;
1.109 stevesk 1774: char display[512], auth_display[512];
1775: char hostname[MAXHOSTNAMELEN];
1.81 markus 1776:
1777: if (no_x11_forwarding_flag) {
1778: packet_send_debug("X11 forwarding disabled in user configuration file.");
1779: return 0;
1780: }
1781: if (!options.x11_forwarding) {
1782: debug("X11 forwarding disabled in server configuration file.");
1783: return 0;
1784: }
1785: if (!options.xauth_location ||
1786: (stat(options.xauth_location, &st) == -1)) {
1787: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1788: return 0;
1789: }
1790: if (options.use_login) {
1791: packet_send_debug("X11 forwarding disabled; "
1792: "not compatible with UseLogin=yes.");
1.81 markus 1793: return 0;
1794: }
1.87 markus 1795: if (s->display != NULL) {
1.81 markus 1796: debug("X11 display already set.");
1797: return 0;
1798: }
1.140 deraadt 1799: if (x11_create_display_inet(options.x11_display_offset,
1800: options.x11_use_localhost, s->single_connection,
1801: &s->display_number) == -1) {
1.87 markus 1802: debug("x11_create_display_inet failed.");
1.81 markus 1803: return 0;
1804: }
1.109 stevesk 1805:
1806: /* Set up a suitable value for the DISPLAY variable. */
1807: if (gethostname(hostname, sizeof(hostname)) < 0)
1808: fatal("gethostname: %.100s", strerror(errno));
1809: /*
1810: * auth_display must be used as the displayname when the
1811: * authorization entry is added with xauth(1). This will be
1812: * different than the DISPLAY string for localhost displays.
1813: */
1.119 stevesk 1814: if (options.x11_use_localhost) {
1.140 deraadt 1815: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 1816: s->display_number, s->screen);
1.140 deraadt 1817: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 1818: s->display_number, s->screen);
1.109 stevesk 1819: s->display = xstrdup(display);
1.118 stevesk 1820: s->auth_display = xstrdup(auth_display);
1.109 stevesk 1821: } else {
1.140 deraadt 1822: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 1823: s->display_number, s->screen);
1824: s->display = xstrdup(display);
1.118 stevesk 1825: s->auth_display = xstrdup(display);
1.109 stevesk 1826: }
1827:
1.81 markus 1828: return 1;
1.2 markus 1829: }
1830:
1.94 itojun 1831: static void
1.49 markus 1832: do_authenticated2(Authctxt *authctxt)
1.2 markus 1833: {
1.97 markus 1834: server_loop2(authctxt);
1.1 markus 1835: }
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