Annotation of src/usr.bin/ssh/session.c, Revision 1.162
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"
1.162 ! markus 36: RCSID("$OpenBSD: session.c,v 1.161 2003/08/22 10:56:09 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:
1.161 markus 61: #ifdef GSSAPI
62: #include "ssh-gss.h"
63: #endif
64:
1.1 markus 65: /* func */
66:
67: Session *session_new(void);
1.94 itojun 68: void session_set_fds(Session *, int, int, int);
1.130 provos 69: void session_pty_cleanup(void *);
1.94 itojun 70: void session_proctitle(Session *);
71: int session_setup_x11fwd(Session *);
72: void do_exec_pty(Session *, const char *);
73: void do_exec_no_pty(Session *, const char *);
74: void do_exec(Session *, const char *);
75: void do_login(Session *, const char *);
76: void do_child(Session *, const char *);
1.73 djm 77: void do_motd(void);
1.94 itojun 78: int check_quietlogin(Session *, const char *);
1.1 markus 79:
1.94 itojun 80: static void do_authenticated1(Authctxt *);
81: static void do_authenticated2(Authctxt *);
82:
83: static int session_pty_req(Session *);
1.65 markus 84:
1.1 markus 85: /* import */
86: extern ServerOptions options;
87: extern char *__progname;
88: extern int log_stderr;
89: extern int debug_flag;
1.45 markus 90: extern u_int utmp_len;
1.21 markus 91: extern int startup_pipe;
1.74 markus 92: extern void destroy_sensitive_data(void);
1.21 markus 93:
1.34 markus 94: /* original command from peer. */
1.92 markus 95: const char *original_command = NULL;
1.34 markus 96:
1.1 markus 97: /* data */
98: #define MAX_SESSIONS 10
99: Session sessions[MAX_SESSIONS];
100:
1.28 millert 101: #ifdef HAVE_LOGIN_CAP
1.129 provos 102: login_cap_t *lc;
1.28 millert 103: #endif
104:
1.136 markus 105: /* Name and directory of socket for authentication agent forwarding. */
106: static char *auth_sock_name = NULL;
107: static char *auth_sock_dir = NULL;
108:
109: /* removes the agent forwarding socket */
110:
111: static void
112: auth_sock_cleanup_proc(void *_pw)
113: {
114: struct passwd *pw = _pw;
115:
116: if (auth_sock_name != NULL) {
117: temporarily_use_uid(pw);
118: unlink(auth_sock_name);
119: rmdir(auth_sock_dir);
120: auth_sock_name = NULL;
121: restore_uid();
122: }
123: }
124:
125: static int
126: auth_input_request_forwarding(struct passwd * pw)
127: {
128: Channel *nc;
129: int sock;
130: struct sockaddr_un sunaddr;
131:
132: if (auth_sock_name != NULL) {
133: error("authentication forwarding requested twice.");
134: return 0;
135: }
136:
137: /* Temporarily drop privileged uid for mkdir/bind. */
138: temporarily_use_uid(pw);
139:
140: /* Allocate a buffer for the socket name, and format the name. */
141: auth_sock_name = xmalloc(MAXPATHLEN);
142: auth_sock_dir = xmalloc(MAXPATHLEN);
143: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
144:
145: /* Create private directory for socket */
146: if (mkdtemp(auth_sock_dir) == NULL) {
147: packet_send_debug("Agent forwarding disabled: "
148: "mkdtemp() failed: %.100s", strerror(errno));
149: restore_uid();
150: xfree(auth_sock_name);
151: xfree(auth_sock_dir);
152: auth_sock_name = NULL;
153: auth_sock_dir = NULL;
154: return 0;
155: }
1.137 mpech 156: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
157: auth_sock_dir, (long) getpid());
1.136 markus 158:
159: /* delete agent socket on fatal() */
160: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
161:
162: /* Create the socket. */
163: sock = socket(AF_UNIX, SOCK_STREAM, 0);
164: if (sock < 0)
165: packet_disconnect("socket: %.100s", strerror(errno));
166:
167: /* Bind it to the name. */
168: memset(&sunaddr, 0, sizeof(sunaddr));
169: sunaddr.sun_family = AF_UNIX;
170: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
171:
172: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
173: packet_disconnect("bind: %.100s", strerror(errno));
174:
175: /* Restore the privileged uid. */
176: restore_uid();
177:
178: /* Start listening on the socket. */
179: if (listen(sock, 5) < 0)
180: packet_disconnect("listen: %.100s", strerror(errno));
181:
182: /* Allocate a channel for the authentication agent socket. */
183: nc = channel_new("auth socket",
184: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
185: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 186: 0, "auth socket", 1);
1.136 markus 187: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
188: return 1;
189: }
190:
191:
1.65 markus 192: void
193: do_authenticated(Authctxt *authctxt)
194: {
1.153 markus 195: setproctitle("%s", authctxt->pw->pw_name);
196:
1.65 markus 197: /*
198: * Cancel the alarm we set to limit the time taken for
199: * authentication.
200: */
201: alarm(0);
202: if (startup_pipe != -1) {
203: close(startup_pipe);
204: startup_pipe = -1;
205: }
206: /* setup the channel layer */
207: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
208: channel_permit_all_opens();
209:
210: if (compat20)
211: do_authenticated2(authctxt);
212: else
213: do_authenticated1(authctxt);
1.79 markus 214:
1.87 markus 215: /* remove agent socket */
1.136 markus 216: if (auth_sock_name != NULL)
1.80 markus 217: auth_sock_cleanup_proc(authctxt->pw);
1.96 dugsong 218: #ifdef KRB5
219: if (options.kerberos_ticket_cleanup)
220: krb5_cleanup_proc(authctxt);
221: #endif
1.65 markus 222: }
223:
1.1 markus 224: /*
225: * Prepares for an interactive session. This is called after the user has
226: * been successfully authenticated. During this message exchange, pseudo
227: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
228: * are requested, etc.
229: */
1.94 itojun 230: static void
1.65 markus 231: do_authenticated1(Authctxt *authctxt)
1.1 markus 232: {
233: Session *s;
1.65 markus 234: char *command;
1.117 markus 235: int success, type, screen_flag;
1.139 deraadt 236: int enable_compression_after_reply = 0;
237: u_int proto_len, data_len, dlen, compression_level = 0;
1.1 markus 238:
1.61 markus 239: s = session_new();
1.96 dugsong 240: s->authctxt = authctxt;
1.65 markus 241: s->pw = authctxt->pw;
1.28 millert 242:
1.1 markus 243: /*
244: * We stay in this loop until the client requests to execute a shell
245: * or a command.
246: */
247: for (;;) {
1.65 markus 248: success = 0;
1.1 markus 249:
250: /* Get a packet from the client. */
1.117 markus 251: type = packet_read();
1.1 markus 252:
253: /* Process the packet. */
254: switch (type) {
255: case SSH_CMSG_REQUEST_COMPRESSION:
256: compression_level = packet_get_int();
1.116 markus 257: packet_check_eom();
1.1 markus 258: if (compression_level < 1 || compression_level > 9) {
259: packet_send_debug("Received illegal compression level %d.",
1.112 deraadt 260: compression_level);
1.138 markus 261: break;
262: }
263: if (!options.compression) {
264: debug2("compression disabled");
1.1 markus 265: break;
266: }
267: /* Enable compression after we have responded with SUCCESS. */
268: enable_compression_after_reply = 1;
269: success = 1;
270: break;
271:
272: case SSH_CMSG_REQUEST_PTY:
1.86 markus 273: success = session_pty_req(s);
1.1 markus 274: break;
275:
276: case SSH_CMSG_X11_REQUEST_FORWARDING:
277: s->auth_proto = packet_get_string(&proto_len);
278: s->auth_data = packet_get_string(&data_len);
279:
1.57 markus 280: screen_flag = packet_get_protocol_flags() &
281: SSH_PROTOFLAG_SCREEN_NUMBER;
282: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
283:
284: if (packet_remaining() == 4) {
285: if (!screen_flag)
286: debug2("Buggy client: "
287: "X11 screen flag missing");
1.1 markus 288: s->screen = packet_get_int();
1.56 markus 289: } else {
1.1 markus 290: s->screen = 0;
1.56 markus 291: }
1.116 markus 292: packet_check_eom();
1.81 markus 293: success = session_setup_x11fwd(s);
294: if (!success) {
295: xfree(s->auth_proto);
296: xfree(s->auth_data);
1.84 markus 297: s->auth_proto = NULL;
298: s->auth_data = NULL;
1.1 markus 299: }
300: break;
301:
302: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
303: if (no_agent_forwarding_flag || compat13) {
304: debug("Authentication agent forwarding not permitted for this authentication.");
305: break;
306: }
307: debug("Received authentication agent forwarding request.");
1.65 markus 308: success = auth_input_request_forwarding(s->pw);
1.1 markus 309: break;
310:
311: case SSH_CMSG_PORT_FORWARD_REQUEST:
312: if (no_port_forwarding_flag) {
313: debug("Port forwarding not permitted for this authentication.");
1.39 markus 314: break;
315: }
316: if (!options.allow_tcp_forwarding) {
317: debug("Port forwarding not permitted.");
1.1 markus 318: break;
319: }
320: debug("Received TCP/IP port forwarding request.");
1.65 markus 321: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 322: success = 1;
323: break;
324:
325: case SSH_CMSG_MAX_PACKET_SIZE:
326: if (packet_set_maxsize(packet_get_int()) > 0)
327: success = 1;
328: break;
329:
330: case SSH_CMSG_EXEC_SHELL:
331: case SSH_CMSG_EXEC_CMD:
332: if (type == SSH_CMSG_EXEC_CMD) {
333: command = packet_get_string(&dlen);
334: debug("Exec command '%.500s'", command);
1.92 markus 335: do_exec(s, command);
336: xfree(command);
1.1 markus 337: } else {
1.92 markus 338: do_exec(s, NULL);
1.1 markus 339: }
1.116 markus 340: packet_check_eom();
1.82 markus 341: session_close(s);
1.1 markus 342: return;
343:
344: default:
345: /*
346: * Any unknown messages in this phase are ignored,
347: * and a failure message is returned.
348: */
1.155 itojun 349: logit("Unknown packet type received after authentication: %d", type);
1.1 markus 350: }
351: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
352: packet_send();
353: packet_write_wait();
354:
355: /* Enable compression now that we have replied if appropriate. */
356: if (enable_compression_after_reply) {
357: enable_compression_after_reply = 0;
358: packet_start_compression(compression_level);
359: }
360: }
361: }
362:
363: /*
364: * This is called to fork and execute a command when we have no tty. This
365: * will call do_child from the child, and server_loop from the parent after
366: * setting up file descriptors and such.
367: */
1.4 markus 368: void
1.63 markus 369: do_exec_no_pty(Session *s, const char *command)
1.1 markus 370: {
1.137 mpech 371: pid_t pid;
1.1 markus 372:
373: #ifdef USE_PIPES
374: int pin[2], pout[2], perr[2];
375: /* Allocate pipes for communicating with the program. */
376: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
377: packet_disconnect("Could not create pipes: %.100s",
378: strerror(errno));
379: #else /* USE_PIPES */
380: int inout[2], err[2];
381: /* Uses socket pairs to communicate with the program. */
382: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
383: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
384: packet_disconnect("Could not create socket pairs: %.100s",
385: strerror(errno));
386: #endif /* USE_PIPES */
387: if (s == NULL)
388: fatal("do_exec_no_pty: no session");
389:
1.9 markus 390: session_proctitle(s);
1.1 markus 391:
1.161 markus 392: #ifdef GSSAPI
393: temporarily_use_uid(s->pw);
394: ssh_gssapi_storecreds();
395: restore_uid();
396: #endif
397:
1.1 markus 398: /* Fork the child. */
399: if ((pid = fork()) == 0) {
1.144 markus 400: fatal_remove_all_cleanups();
401:
1.1 markus 402: /* Child. Reinitialize the log since the pid has changed. */
403: log_init(__progname, options.log_level, options.log_facility, log_stderr);
404:
405: /*
406: * Create a new session and process group since the 4.4BSD
407: * setlogin() affects the entire process group.
408: */
409: if (setsid() < 0)
410: error("setsid failed: %.100s", strerror(errno));
411:
412: #ifdef USE_PIPES
413: /*
414: * Redirect stdin. We close the parent side of the socket
415: * pair, and make the child side the standard input.
416: */
417: close(pin[1]);
418: if (dup2(pin[0], 0) < 0)
419: perror("dup2 stdin");
420: close(pin[0]);
421:
422: /* Redirect stdout. */
423: close(pout[0]);
424: if (dup2(pout[1], 1) < 0)
425: perror("dup2 stdout");
426: close(pout[1]);
427:
428: /* Redirect stderr. */
429: close(perr[0]);
430: if (dup2(perr[1], 2) < 0)
431: perror("dup2 stderr");
432: close(perr[1]);
433: #else /* USE_PIPES */
434: /*
435: * Redirect stdin, stdout, and stderr. Stdin and stdout will
436: * use the same socket, as some programs (particularly rdist)
437: * seem to depend on it.
438: */
439: close(inout[1]);
440: close(err[1]);
441: if (dup2(inout[0], 0) < 0) /* stdin */
442: perror("dup2 stdin");
443: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
444: perror("dup2 stdout");
445: if (dup2(err[0], 2) < 0) /* stderr */
446: perror("dup2 stderr");
447: #endif /* USE_PIPES */
448:
449: /* Do processing for the child (exec command etc). */
1.60 markus 450: do_child(s, command);
1.1 markus 451: /* NOTREACHED */
452: }
453: if (pid < 0)
454: packet_disconnect("fork failed: %.100s", strerror(errno));
455: s->pid = pid;
1.47 markus 456: /* Set interactive/non-interactive mode. */
1.48 markus 457: packet_set_interactive(s->display != NULL);
1.1 markus 458: #ifdef USE_PIPES
459: /* We are the parent. Close the child sides of the pipes. */
460: close(pin[0]);
461: close(pout[1]);
462: close(perr[1]);
463:
1.2 markus 464: if (compat20) {
1.64 markus 465: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 466: } else {
467: /* Enter the interactive session. */
468: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 469: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 470: }
1.1 markus 471: #else /* USE_PIPES */
472: /* We are the parent. Close the child sides of the socket pairs. */
473: close(inout[0]);
474: close(err[0]);
475:
476: /*
477: * Enter the interactive session. Note: server_loop must be able to
478: * handle the case that fdin and fdout are the same.
479: */
1.2 markus 480: if (compat20) {
1.64 markus 481: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 482: } else {
483: server_loop(pid, inout[1], inout[1], err[1]);
484: /* server_loop has closed inout[1] and err[1]. */
485: }
1.1 markus 486: #endif /* USE_PIPES */
487: }
488:
489: /*
490: * This is called to fork and execute a command when we have a tty. This
491: * will call do_child from the child, and server_loop from the parent after
492: * setting up file descriptors, controlling tty, updating wtmp, utmp,
493: * lastlog, and other such operations.
494: */
1.4 markus 495: void
1.63 markus 496: do_exec_pty(Session *s, const char *command)
1.1 markus 497: {
498: int fdout, ptyfd, ttyfd, ptymaster;
499: pid_t pid;
500:
501: if (s == NULL)
502: fatal("do_exec_pty: no session");
503: ptyfd = s->ptyfd;
504: ttyfd = s->ttyfd;
505:
1.161 markus 506: #ifdef GSSAPI
507: temporarily_use_uid(s->pw);
508: ssh_gssapi_storecreds();
509: restore_uid();
510: #endif
511:
1.1 markus 512: /* Fork the child. */
513: if ((pid = fork()) == 0) {
1.144 markus 514: fatal_remove_all_cleanups();
1.97 markus 515:
1.24 markus 516: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 517: log_init(__progname, options.log_level, options.log_facility, log_stderr);
518: /* Close the master side of the pseudo tty. */
519: close(ptyfd);
520:
521: /* Make the pseudo tty our controlling tty. */
522: pty_make_controlling_tty(&ttyfd, s->tty);
523:
1.103 markus 524: /* Redirect stdin/stdout/stderr from the pseudo tty. */
525: if (dup2(ttyfd, 0) < 0)
526: error("dup2 stdin: %s", strerror(errno));
527: if (dup2(ttyfd, 1) < 0)
528: error("dup2 stdout: %s", strerror(errno));
529: if (dup2(ttyfd, 2) < 0)
530: error("dup2 stderr: %s", strerror(errno));
1.1 markus 531:
532: /* Close the extra descriptor for the pseudo tty. */
533: close(ttyfd);
534:
1.24 markus 535: /* record login, etc. similar to login(1) */
1.41 markus 536: if (!(options.use_login && command == NULL))
537: do_login(s, command);
1.1 markus 538:
539: /* Do common processing for the child, such as execing the command. */
1.60 markus 540: do_child(s, command);
1.1 markus 541: /* NOTREACHED */
542: }
543: if (pid < 0)
544: packet_disconnect("fork failed: %.100s", strerror(errno));
545: s->pid = pid;
546:
547: /* Parent. Close the slave side of the pseudo tty. */
548: close(ttyfd);
549:
550: /*
551: * Create another descriptor of the pty master side for use as the
552: * standard input. We could use the original descriptor, but this
553: * simplifies code in server_loop. The descriptor is bidirectional.
554: */
555: fdout = dup(ptyfd);
556: if (fdout < 0)
557: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
558:
559: /* we keep a reference to the pty master */
560: ptymaster = dup(ptyfd);
561: if (ptymaster < 0)
562: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
563: s->ptymaster = ptymaster;
564:
565: /* Enter interactive session. */
1.47 markus 566: packet_set_interactive(1);
1.2 markus 567: if (compat20) {
568: session_set_fds(s, ptyfd, fdout, -1);
569: } else {
570: server_loop(pid, ptyfd, fdout, -1);
571: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 572: }
573: }
574:
1.90 markus 575: /*
576: * This is called to fork and execute a command. If another command is
577: * to be forced, execute that instead.
578: */
579: void
580: do_exec(Session *s, const char *command)
581: {
582: if (forced_command) {
583: original_command = command;
584: command = forced_command;
585: debug("Forced command '%.900s'", command);
586: }
587:
588: if (s->ttyfd != -1)
589: do_exec_pty(s, command);
590: else
591: do_exec_no_pty(s, command);
592:
1.92 markus 593: original_command = NULL;
1.90 markus 594: }
595:
596:
1.24 markus 597: /* administrative, login(1)-like work */
598: void
1.41 markus 599: do_login(Session *s, const char *command)
1.24 markus 600: {
601: char *time_string;
602: socklen_t fromlen;
603: struct sockaddr_storage from;
604: struct passwd * pw = s->pw;
605: pid_t pid = getpid();
606:
607: /*
608: * Get IP address of client. If the connection is not a socket, let
609: * the address be 0.0.0.0.
610: */
611: memset(&from, 0, sizeof(from));
1.148 stevesk 612: fromlen = sizeof(from);
1.24 markus 613: if (packet_connection_is_on_socket()) {
614: if (getpeername(packet_get_connection_in(),
1.112 deraadt 615: (struct sockaddr *) & from, &fromlen) < 0) {
1.24 markus 616: debug("getpeername: %.100s", strerror(errno));
617: fatal_cleanup();
618: }
619: }
1.25 markus 620:
1.24 markus 621: /* Record that there was a login on that tty from the remote host. */
1.133 markus 622: if (!use_privsep)
623: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
624: get_remote_name_or_ip(utmp_len,
1.158 markus 625: options.use_dns),
1.148 stevesk 626: (struct sockaddr *)&from, fromlen);
1.24 markus 627:
1.73 djm 628: if (check_quietlogin(s, command))
1.24 markus 629: return;
1.73 djm 630:
1.134 markus 631: if (options.print_lastlog && s->last_login_time != 0) {
632: time_string = ctime(&s->last_login_time);
1.24 markus 633: if (strchr(time_string, '\n'))
634: *strchr(time_string, '\n') = 0;
1.134 markus 635: if (strcmp(s->hostname, "") == 0)
1.24 markus 636: printf("Last login: %s\r\n", time_string);
637: else
1.134 markus 638: printf("Last login: %s from %s\r\n", time_string,
639: s->hostname);
1.24 markus 640: }
1.73 djm 641:
642: do_motd();
643: }
644:
645: /*
646: * Display the message of the day.
647: */
648: void
649: do_motd(void)
650: {
651: FILE *f;
652: char buf[256];
653:
1.24 markus 654: if (options.print_motd) {
1.28 millert 655: #ifdef HAVE_LOGIN_CAP
656: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
657: "/etc/motd"), "r");
658: #else
1.24 markus 659: f = fopen("/etc/motd", "r");
1.28 millert 660: #endif
1.24 markus 661: if (f) {
662: while (fgets(buf, sizeof(buf), f))
663: fputs(buf, stdout);
664: fclose(f);
665: }
1.2 markus 666: }
1.73 djm 667: }
668:
669:
670: /*
671: * Check for quiet login, either .hushlogin or command given.
672: */
673: int
674: check_quietlogin(Session *s, const char *command)
675: {
676: char buf[256];
1.96 dugsong 677: struct passwd *pw = s->pw;
1.73 djm 678: struct stat st;
679:
680: /* Return 1 if .hushlogin exists or a command given. */
681: if (command != NULL)
682: return 1;
683: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
684: #ifdef HAVE_LOGIN_CAP
685: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
686: return 1;
687: #else
688: if (stat(buf, &st) >= 0)
689: return 1;
690: #endif
691: return 0;
1.1 markus 692: }
693:
694: /*
695: * Sets the value of the given variable in the environment. If the variable
696: * already exists, its value is overriden.
697: */
1.161 markus 698: void
1.45 markus 699: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 700: const char *value)
1.1 markus 701: {
1.45 markus 702: u_int i, namelen;
1.1 markus 703: char **env;
704:
705: /*
706: * Find the slot where the value should be stored. If the variable
707: * already exists, we reuse the slot; otherwise we append a new slot
708: * at the end of the array, expanding if necessary.
709: */
710: env = *envp;
711: namelen = strlen(name);
712: for (i = 0; env[i]; i++)
713: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
714: break;
715: if (env[i]) {
716: /* Reuse the slot. */
717: xfree(env[i]);
718: } else {
719: /* New variable. Expand if necessary. */
720: if (i >= (*envsizep) - 1) {
1.141 markus 721: if (*envsizep >= 1000)
722: fatal("child_set_env: too many env vars,"
723: " skipping: %.100s", name);
1.1 markus 724: (*envsizep) += 50;
725: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
726: }
727: /* Need to set the NULL pointer at end of array beyond the new slot. */
728: env[i + 1] = NULL;
729: }
730:
731: /* Allocate space and format the variable in the appropriate slot. */
732: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
733: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
734: }
735:
736: /*
737: * Reads environment variables from the given file and adds/overrides them
738: * into the environment. If the file does not exist, this does nothing.
739: * Otherwise, it must consist of empty lines, comments (line starts with '#')
740: * and assignments of the form name=value. No other forms are allowed.
741: */
1.94 itojun 742: static void
1.45 markus 743: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 744: const char *filename)
1.1 markus 745: {
746: FILE *f;
747: char buf[4096];
748: char *cp, *value;
1.142 deraadt 749: u_int lineno = 0;
1.1 markus 750:
751: f = fopen(filename, "r");
752: if (!f)
753: return;
754:
755: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 756: if (++lineno > 1000)
757: fatal("Too many lines in environment file %s", filename);
1.1 markus 758: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
759: ;
760: if (!*cp || *cp == '#' || *cp == '\n')
761: continue;
762: if (strchr(cp, '\n'))
763: *strchr(cp, '\n') = '\0';
764: value = strchr(cp, '=');
765: if (value == NULL) {
1.142 deraadt 766: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
767: filename);
1.1 markus 768: continue;
769: }
1.14 deraadt 770: /*
771: * Replace the equals sign by nul, and advance value to
772: * the value string.
773: */
1.1 markus 774: *value = '\0';
775: value++;
776: child_set_env(env, envsize, cp, value);
777: }
778: fclose(f);
779: }
780:
1.127 markus 781: static char **
782: do_setup_env(Session *s, const char *shell)
1.1 markus 783: {
784: char buf[256];
1.127 markus 785: u_int i, envsize;
1.154 markus 786: char **env, *laddr;
1.127 markus 787: struct passwd *pw = s->pw;
1.1 markus 788:
789: /* Initialize the environment. */
790: envsize = 100;
791: env = xmalloc(envsize * sizeof(char *));
792: env[0] = NULL;
793:
1.161 markus 794: #ifdef GSSAPI
795: /* Allow any GSSAPI methods that we've used to alter
796: * the childs environment as they see fit
797: */
798: ssh_gssapi_do_child(&env, &envsize);
799: #endif
800:
1.1 markus 801: if (!options.use_login) {
802: /* Set basic environment. */
803: child_set_env(&env, &envsize, "USER", pw->pw_name);
804: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
805: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 806: #ifdef HAVE_LOGIN_CAP
1.145 markus 807: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
808: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
809: else
810: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 811: #else
1.29 millert 812: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 813: #endif
1.1 markus 814:
815: snprintf(buf, sizeof buf, "%.200s/%.50s",
816: _PATH_MAILDIR, pw->pw_name);
817: child_set_env(&env, &envsize, "MAIL", buf);
818:
819: /* Normal systems set SHELL by default. */
820: child_set_env(&env, &envsize, "SHELL", shell);
821: }
822: if (getenv("TZ"))
823: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
824:
825: /* Set custom environment options from RSA authentication. */
1.110 markus 826: if (!options.use_login) {
827: while (custom_environment) {
828: struct envstring *ce = custom_environment;
1.143 deraadt 829: char *str = ce->s;
1.127 markus 830:
1.143 deraadt 831: for (i = 0; str[i] != '=' && str[i]; i++)
1.110 markus 832: ;
1.143 deraadt 833: if (str[i] == '=') {
834: str[i] = 0;
835: child_set_env(&env, &envsize, str, str + i + 1);
1.110 markus 836: }
837: custom_environment = ce->next;
838: xfree(ce->s);
839: xfree(ce);
1.1 markus 840: }
841: }
842:
1.149 stevesk 843: /* SSH_CLIENT deprecated */
1.1 markus 844: snprintf(buf, sizeof buf, "%.50s %d %d",
1.127 markus 845: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 846: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 847:
1.154 markus 848: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 849: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.154 markus 850: get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
851: xfree(laddr);
1.149 stevesk 852: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 853:
1.60 markus 854: if (s->ttyfd != -1)
855: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
856: if (s->term)
857: child_set_env(&env, &envsize, "TERM", s->term);
858: if (s->display)
859: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 860: if (original_command)
861: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
862: original_command);
1.96 dugsong 863: #ifdef KRB5
864: if (s->authctxt->krb5_ticket_file)
865: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 866: s->authctxt->krb5_ticket_file);
1.96 dugsong 867: #endif
1.136 markus 868: if (auth_sock_name != NULL)
1.1 markus 869: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 870: auth_sock_name);
1.1 markus 871:
872: /* read $HOME/.ssh/environment. */
1.146 markus 873: if (options.permit_user_env && !options.use_login) {
1.14 deraadt 874: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
875: pw->pw_dir);
1.1 markus 876: read_environment_file(&env, &envsize, buf);
877: }
878: if (debug_flag) {
879: /* dump the environment */
880: fprintf(stderr, "Environment:\n");
881: for (i = 0; env[i]; i++)
882: fprintf(stderr, " %.200s\n", env[i]);
883: }
1.127 markus 884: return env;
885: }
886:
887: /*
888: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
889: * first in this order).
890: */
891: static void
892: do_rc_files(Session *s, const char *shell)
893: {
894: FILE *f = NULL;
895: char cmd[1024];
896: int do_xauth;
897: struct stat st;
898:
899: do_xauth =
900: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
901:
902: /* ignore _PATH_SSH_USER_RC for subsystems */
903: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
904: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
905: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
906: if (debug_flag)
907: fprintf(stderr, "Running %s\n", cmd);
908: f = popen(cmd, "w");
909: if (f) {
910: if (do_xauth)
911: fprintf(f, "%s %s\n", s->auth_proto,
912: s->auth_data);
913: pclose(f);
914: } else
915: fprintf(stderr, "Could not run %s\n",
916: _PATH_SSH_USER_RC);
917: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
918: if (debug_flag)
919: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
920: _PATH_SSH_SYSTEM_RC);
921: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
922: if (f) {
923: if (do_xauth)
924: fprintf(f, "%s %s\n", s->auth_proto,
925: s->auth_data);
926: pclose(f);
927: } else
928: fprintf(stderr, "Could not run %s\n",
929: _PATH_SSH_SYSTEM_RC);
930: } else if (do_xauth && options.xauth_location != NULL) {
931: /* Add authority data to .Xauthority if appropriate. */
932: if (debug_flag) {
933: fprintf(stderr,
1.151 stevesk 934: "Running %.500s remove %.100s\n",
935: options.xauth_location, s->auth_display);
936: fprintf(stderr,
937: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 938: options.xauth_location, s->auth_display,
939: s->auth_proto, s->auth_data);
940: }
941: snprintf(cmd, sizeof cmd, "%s -q -",
942: options.xauth_location);
943: f = popen(cmd, "w");
944: if (f) {
1.151 stevesk 945: fprintf(f, "remove %s\n",
946: s->auth_display);
1.127 markus 947: fprintf(f, "add %s %s %s\n",
948: s->auth_display, s->auth_proto,
949: s->auth_data);
950: pclose(f);
951: } else {
952: fprintf(stderr, "Could not run %s\n",
953: cmd);
954: }
955: }
956: }
957:
958: static void
959: do_nologin(struct passwd *pw)
960: {
961: FILE *f = NULL;
962: char buf[1024];
963:
964: #ifdef HAVE_LOGIN_CAP
965: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
966: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
967: _PATH_NOLOGIN), "r");
968: #else
969: if (pw->pw_uid)
970: f = fopen(_PATH_NOLOGIN, "r");
971: #endif
972: if (f) {
973: /* /etc/nologin exists. Print its contents and exit. */
1.155 itojun 974: logit("User %.100s not allowed because %s exists",
1.150 stevesk 975: pw->pw_name, _PATH_NOLOGIN);
1.127 markus 976: while (fgets(buf, sizeof(buf), f))
977: fputs(buf, stderr);
978: fclose(f);
979: exit(254);
980: }
981: }
982:
983: /* Set login name, uid, gid, and groups. */
1.130 provos 984: void
1.127 markus 985: do_setusercontext(struct passwd *pw)
986: {
987: if (getuid() == 0 || geteuid() == 0) {
988: #ifdef HAVE_LOGIN_CAP
989: if (setusercontext(lc, pw, pw->pw_uid,
990: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
991: perror("unable to set user context");
992: exit(1);
993: }
994: #else
995: if (setlogin(pw->pw_name) < 0)
996: error("setlogin failed: %s", strerror(errno));
997: if (setgid(pw->pw_gid) < 0) {
998: perror("setgid");
999: exit(1);
1000: }
1001: /* Initialize the group list. */
1002: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1003: perror("initgroups");
1004: exit(1);
1005: }
1006: endgrent();
1007:
1008: /* Permanently switch to the desired uid. */
1009: permanently_set_uid(pw);
1010: #endif
1011: }
1012: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1013: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1014: }
1015:
1.131 markus 1016: static void
1.130 provos 1017: launch_login(struct passwd *pw, const char *hostname)
1018: {
1019: /* Launch login(1). */
1020:
1021: execl("/usr/bin/login", "login", "-h", hostname,
1022: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1023:
1024: /* Login couldn't be executed, die. */
1025:
1026: perror("login");
1027: exit(1);
1028: }
1029:
1.127 markus 1030: /*
1031: * Performs common processing for the child, such as setting up the
1032: * environment, closing extra file descriptors, setting the user and group
1033: * ids, and executing the command or shell.
1034: */
1035: void
1036: do_child(Session *s, const char *command)
1037: {
1038: extern char **environ;
1039: char **env;
1040: char *argv[10];
1041: const char *shell, *shell0, *hostname = NULL;
1042: struct passwd *pw = s->pw;
1043: u_int i;
1044:
1045: /* remove hostkey from the child's memory */
1046: destroy_sensitive_data();
1047:
1048: /* login(1) is only called if we execute the login shell */
1049: if (options.use_login && command != NULL)
1050: options.use_login = 0;
1051:
1052: /*
1053: * Login(1) does this as well, and it needs uid 0 for the "-h"
1054: * switch, so we let login(1) to this for us.
1055: */
1056: if (!options.use_login) {
1057: do_nologin(pw);
1058: do_setusercontext(pw);
1059: }
1060:
1061: /*
1062: * Get the shell from the password data. An empty shell field is
1063: * legal, and means /bin/sh.
1064: */
1065: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1066:
1067: /*
1068: * Make sure $SHELL points to the shell from the password file,
1069: * even if shell is overridden from login.conf
1070: */
1071: env = do_setup_env(s, shell);
1072:
1.127 markus 1073: #ifdef HAVE_LOGIN_CAP
1074: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1075: #endif
1076:
1.26 millert 1077: /* we have to stash the hostname before we close our socket. */
1078: if (options.use_login)
1.70 stevesk 1079: hostname = get_remote_name_or_ip(utmp_len,
1.158 markus 1080: options.use_dns);
1.1 markus 1081: /*
1082: * Close the connection descriptors; note that this is the child, and
1083: * the server will still have the socket open, and it is important
1084: * that we do not shutdown it. Note that the descriptors cannot be
1085: * closed before building the environment, as we call
1086: * get_remote_ipaddr there.
1087: */
1088: if (packet_get_connection_in() == packet_get_connection_out())
1089: close(packet_get_connection_in());
1090: else {
1091: close(packet_get_connection_in());
1092: close(packet_get_connection_out());
1093: }
1094: /*
1095: * Close all descriptors related to channels. They will still remain
1096: * open in the parent.
1097: */
1098: /* XXX better use close-on-exec? -markus */
1099: channel_close_all();
1100:
1101: /*
1102: * Close any extra file descriptors. Note that there may still be
1103: * descriptors left by system functions. They will be closed later.
1104: */
1105: endpwent();
1106:
1107: /*
1108: * Close any extra open file descriptors so that we don\'t have them
1109: * hanging around in clients. Note that we want to do this after
1110: * initgroups, because at least on Solaris 2.3 it leaves file
1111: * descriptors open.
1112: */
1113: for (i = 3; i < 64; i++)
1114: close(i);
1115:
1116: /*
1.125 deraadt 1117: * Must take new environment into use so that .ssh/rc,
1118: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1119: */
1120: environ = env;
1.104 markus 1121:
1122: /* Change current directory to the user\'s home directory. */
1123: if (chdir(pw->pw_dir) < 0) {
1124: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1125: pw->pw_dir, strerror(errno));
1126: #ifdef HAVE_LOGIN_CAP
1127: if (login_getcapbool(lc, "requirehome", 0))
1128: exit(1);
1129: #endif
1130: }
1.1 markus 1131:
1.127 markus 1132: if (!options.use_login)
1133: do_rc_files(s, shell);
1.67 markus 1134:
1135: /* restore SIGPIPE for child */
1136: signal(SIGPIPE, SIG_DFL);
1137:
1.127 markus 1138: if (options.use_login) {
1.130 provos 1139: launch_login(pw, hostname);
1140: /* NEVERREACHED */
1.127 markus 1141: }
1142:
1143: /* Get the last component of the shell name. */
1144: if ((shell0 = strrchr(shell, '/')) != NULL)
1145: shell0++;
1146: else
1147: shell0 = shell;
1148:
1.1 markus 1149: /*
1150: * If we have no command, execute the shell. In this case, the shell
1151: * name to be passed in argv[0] is preceded by '-' to indicate that
1152: * this is a login shell.
1153: */
1154: if (!command) {
1.127 markus 1155: char argv0[256];
1.1 markus 1156:
1.127 markus 1157: /* Start the shell. Set initial character to '-'. */
1158: argv0[0] = '-';
1.1 markus 1159:
1.127 markus 1160: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1161: >= sizeof(argv0) - 1) {
1.127 markus 1162: errno = EINVAL;
1.1 markus 1163: perror(shell);
1164: exit(1);
1.127 markus 1165: }
1.1 markus 1166:
1.127 markus 1167: /* Execute the shell. */
1168: argv[0] = argv0;
1169: argv[1] = NULL;
1170: execve(shell, argv, env);
1171:
1172: /* Executing the shell failed. */
1173: perror(shell);
1174: exit(1);
1.1 markus 1175: }
1176: /*
1177: * Execute the command using the user's shell. This uses the -c
1178: * option to execute the command.
1179: */
1.127 markus 1180: argv[0] = (char *) shell0;
1.1 markus 1181: argv[1] = "-c";
1182: argv[2] = (char *) command;
1183: argv[3] = NULL;
1184: execve(shell, argv, env);
1185: perror(shell);
1186: exit(1);
1187: }
1188:
1189: Session *
1190: session_new(void)
1191: {
1192: int i;
1193: static int did_init = 0;
1194: if (!did_init) {
1195: debug("session_new: init");
1.112 deraadt 1196: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1197: sessions[i].used = 0;
1198: }
1199: did_init = 1;
1200: }
1.112 deraadt 1201: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1202: Session *s = &sessions[i];
1203: if (! s->used) {
1.68 djm 1204: memset(s, 0, sizeof(*s));
1.1 markus 1205: s->chanid = -1;
1206: s->ptyfd = -1;
1207: s->ttyfd = -1;
1208: s->used = 1;
1.85 markus 1209: s->self = i;
1.1 markus 1210: debug("session_new: session %d", i);
1211: return s;
1212: }
1213: }
1214: return NULL;
1215: }
1216:
1.94 itojun 1217: static void
1.1 markus 1218: session_dump(void)
1219: {
1220: int i;
1.112 deraadt 1221: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1222: Session *s = &sessions[i];
1.137 mpech 1223: debug("dump: used %d session %d %p channel %d pid %ld",
1.1 markus 1224: s->used,
1225: s->self,
1226: s,
1227: s->chanid,
1.137 mpech 1228: (long)s->pid);
1.1 markus 1229: }
1230: }
1231:
1.2 markus 1232: int
1.97 markus 1233: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1234: {
1235: Session *s = session_new();
1236: debug("session_open: channel %d", chanid);
1237: if (s == NULL) {
1238: error("no more sessions");
1239: return 0;
1240: }
1.97 markus 1241: s->authctxt = authctxt;
1242: s->pw = authctxt->pw;
1.7 markus 1243: if (s->pw == NULL)
1.54 stevesk 1244: fatal("no user for session %d", s->self);
1.2 markus 1245: debug("session_open: session %d: link with channel %d", s->self, chanid);
1246: s->chanid = chanid;
1247: return 1;
1248: }
1249:
1.130 provos 1250: Session *
1251: session_by_tty(char *tty)
1252: {
1253: int i;
1254: for (i = 0; i < MAX_SESSIONS; i++) {
1255: Session *s = &sessions[i];
1256: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1257: debug("session_by_tty: session %d tty %s", i, tty);
1258: return s;
1259: }
1260: }
1261: debug("session_by_tty: unknown tty %.100s", tty);
1262: session_dump();
1263: return NULL;
1264: }
1265:
1.94 itojun 1266: static Session *
1.2 markus 1267: session_by_channel(int id)
1268: {
1269: int i;
1.112 deraadt 1270: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1271: Session *s = &sessions[i];
1272: if (s->used && s->chanid == id) {
1273: debug("session_by_channel: session %d channel %d", i, id);
1274: return s;
1275: }
1276: }
1277: debug("session_by_channel: unknown channel %d", id);
1278: session_dump();
1279: return NULL;
1280: }
1281:
1.94 itojun 1282: static Session *
1.2 markus 1283: session_by_pid(pid_t pid)
1284: {
1285: int i;
1.137 mpech 1286: debug("session_by_pid: pid %ld", (long)pid);
1.112 deraadt 1287: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1288: Session *s = &sessions[i];
1289: if (s->used && s->pid == pid)
1290: return s;
1291: }
1.137 mpech 1292: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1293: session_dump();
1294: return NULL;
1295: }
1296:
1.94 itojun 1297: static int
1.2 markus 1298: session_window_change_req(Session *s)
1299: {
1300: s->col = packet_get_int();
1301: s->row = packet_get_int();
1302: s->xpixel = packet_get_int();
1303: s->ypixel = packet_get_int();
1.116 markus 1304: packet_check_eom();
1.2 markus 1305: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1306: return 1;
1307: }
1308:
1.94 itojun 1309: static int
1.2 markus 1310: session_pty_req(Session *s)
1311: {
1.45 markus 1312: u_int len;
1.72 stevesk 1313: int n_bytes;
1.132 markus 1314:
1.86 markus 1315: if (no_pty_flag) {
1316: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1317: return 0;
1.86 markus 1318: }
1319: if (s->ttyfd != -1) {
1320: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1321: return 0;
1.134 markus 1322: }
1323: /* Get the time and hostname when the user last logged in. */
1324: if (options.print_lastlog) {
1325: s->hostname[0] = '\0';
1326: s->last_login_time = get_last_login_time(s->pw->pw_uid,
1327: s->pw->pw_name, s->hostname, sizeof(s->hostname));
1.86 markus 1328: }
1329:
1.2 markus 1330: s->term = packet_get_string(&len);
1.86 markus 1331:
1332: if (compat20) {
1333: s->col = packet_get_int();
1334: s->row = packet_get_int();
1335: } else {
1336: s->row = packet_get_int();
1337: s->col = packet_get_int();
1338: }
1.2 markus 1339: s->xpixel = packet_get_int();
1340: s->ypixel = packet_get_int();
1341:
1342: if (strcmp(s->term, "") == 0) {
1343: xfree(s->term);
1344: s->term = NULL;
1345: }
1.86 markus 1346:
1.2 markus 1347: /* Allocate a pty and open it. */
1.86 markus 1348: debug("Allocating pty.");
1.130 provos 1349: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1.86 markus 1350: if (s->term)
1351: xfree(s->term);
1.2 markus 1352: s->term = NULL;
1353: s->ptyfd = -1;
1354: s->ttyfd = -1;
1355: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1356: return 0;
1.2 markus 1357: }
1358: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1359:
1360: /* for SSH1 the tty modes length is not given */
1361: if (!compat20)
1362: n_bytes = packet_remaining();
1363: tty_parse_modes(s->ttyfd, &n_bytes);
1364:
1.2 markus 1365: /*
1366: * Add a cleanup function to clear the utmp entry and record logout
1367: * time in case we call fatal() (e.g., the connection gets closed).
1368: */
1.85 markus 1369: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.130 provos 1370: if (!use_privsep)
1371: pty_setowner(s->pw, s->tty);
1.86 markus 1372:
1373: /* Set window size from the packet. */
1.2 markus 1374: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1375:
1.116 markus 1376: packet_check_eom();
1.9 markus 1377: session_proctitle(s);
1.2 markus 1378: return 1;
1379: }
1380:
1.94 itojun 1381: static int
1.7 markus 1382: session_subsystem_req(Session *s)
1383: {
1.105 markus 1384: struct stat st;
1.45 markus 1385: u_int len;
1.7 markus 1386: int success = 0;
1.105 markus 1387: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1388: int i;
1.7 markus 1389:
1.116 markus 1390: packet_check_eom();
1.155 itojun 1391: logit("subsystem request for %.100s", subsys);
1.18 jakob 1392:
1393: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1394: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1395: cmd = options.subsystem_command[i];
1396: if (stat(cmd, &st) < 0) {
1397: error("subsystem: cannot stat %s: %s", cmd,
1398: strerror(errno));
1399: break;
1400: }
1401: debug("subsystem: exec() %s", cmd);
1.64 markus 1402: s->is_subsystem = 1;
1.105 markus 1403: do_exec(s, cmd);
1.18 jakob 1404: success = 1;
1.122 markus 1405: break;
1.18 jakob 1406: }
1407: }
1408:
1409: if (!success)
1.155 itojun 1410: logit("subsystem request for %.100s failed, subsystem not found",
1.105 markus 1411: subsys);
1.7 markus 1412:
1413: xfree(subsys);
1414: return success;
1415: }
1416:
1.94 itojun 1417: static int
1.7 markus 1418: session_x11_req(Session *s)
1419: {
1.81 markus 1420: int success;
1.7 markus 1421:
1422: s->single_connection = packet_get_char();
1423: s->auth_proto = packet_get_string(NULL);
1424: s->auth_data = packet_get_string(NULL);
1425: s->screen = packet_get_int();
1.116 markus 1426: packet_check_eom();
1.7 markus 1427:
1.81 markus 1428: success = session_setup_x11fwd(s);
1429: if (!success) {
1.7 markus 1430: xfree(s->auth_proto);
1431: xfree(s->auth_data);
1.84 markus 1432: s->auth_proto = NULL;
1433: s->auth_data = NULL;
1.7 markus 1434: }
1.81 markus 1435: return success;
1.7 markus 1436: }
1437:
1.94 itojun 1438: static int
1.19 markus 1439: session_shell_req(Session *s)
1440: {
1.116 markus 1441: packet_check_eom();
1.90 markus 1442: do_exec(s, NULL);
1.19 markus 1443: return 1;
1444: }
1445:
1.94 itojun 1446: static int
1.19 markus 1447: session_exec_req(Session *s)
1448: {
1.45 markus 1449: u_int len;
1.19 markus 1450: char *command = packet_get_string(&len);
1.116 markus 1451: packet_check_eom();
1.90 markus 1452: do_exec(s, command);
1.92 markus 1453: xfree(command);
1.19 markus 1454: return 1;
1455: }
1456:
1.94 itojun 1457: static int
1.157 markus 1458: session_break_req(Session *s)
1459: {
1460: u_int break_length;
1461:
1.160 markus 1462: break_length = packet_get_int(); /* ignored */
1.157 markus 1463: packet_check_eom();
1464:
1.160 markus 1465: if (s->ttyfd == -1 ||
1466: tcsendbreak(s->ttyfd, 0) < 0)
1.157 markus 1467: return 0;
1468: return 1;
1469: }
1470:
1471: static int
1.43 markus 1472: session_auth_agent_req(Session *s)
1473: {
1474: static int called = 0;
1.116 markus 1475: packet_check_eom();
1.44 markus 1476: if (no_agent_forwarding_flag) {
1477: debug("session_auth_agent_req: no_agent_forwarding_flag");
1478: return 0;
1479: }
1.43 markus 1480: if (called) {
1481: return 0;
1482: } else {
1483: called = 1;
1484: return auth_input_request_forwarding(s->pw);
1485: }
1486: }
1487:
1.123 markus 1488: int
1489: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1490: {
1491: int success = 0;
1492: Session *s;
1493:
1.123 markus 1494: if ((s = session_by_channel(c->self)) == NULL) {
1.155 itojun 1495: logit("session_input_channel_req: no session %d req %.100s",
1.123 markus 1496: c->self, rtype);
1497: return 0;
1498: }
1499: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1500:
1501: /*
1.64 markus 1502: * a session is in LARVAL state until a shell, a command
1503: * or a subsystem is executed
1.2 markus 1504: */
1505: if (c->type == SSH_CHANNEL_LARVAL) {
1506: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1507: success = session_shell_req(s);
1.2 markus 1508: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1509: success = session_exec_req(s);
1.2 markus 1510: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1511: success = session_pty_req(s);
1.7 markus 1512: } else if (strcmp(rtype, "x11-req") == 0) {
1513: success = session_x11_req(s);
1.43 markus 1514: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1515: success = session_auth_agent_req(s);
1.7 markus 1516: } else if (strcmp(rtype, "subsystem") == 0) {
1517: success = session_subsystem_req(s);
1.157 markus 1518: } else if (strcmp(rtype, "break") == 0) {
1519: success = session_break_req(s);
1.2 markus 1520: }
1521: }
1522: if (strcmp(rtype, "window-change") == 0) {
1523: success = session_window_change_req(s);
1524: }
1.123 markus 1525: return success;
1.2 markus 1526: }
1527:
1528: void
1529: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1530: {
1531: if (!compat20)
1532: fatal("session_set_fds: called for proto != 2.0");
1533: /*
1534: * now that have a child and a pipe to the child,
1535: * we can activate our channel and register the fd's
1536: */
1537: if (s->chanid == -1)
1538: fatal("no channel for session %d", s->self);
1539: channel_set_fds(s->chanid,
1540: fdout, fdin, fderr,
1.42 markus 1541: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.126 markus 1542: 1,
1543: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1544: }
1545:
1.85 markus 1546: /*
1547: * Function to perform pty cleanup. Also called if we get aborted abnormally
1548: * (e.g., due to a dropped connection).
1549: */
1.130 provos 1550: void
1551: session_pty_cleanup2(void *session)
1.1 markus 1552: {
1.85 markus 1553: Session *s = session;
1554:
1555: if (s == NULL) {
1556: error("session_pty_cleanup: no session");
1557: return;
1558: }
1559: if (s->ttyfd == -1)
1.1 markus 1560: return;
1561:
1.54 stevesk 1562: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1563:
1564: /* Record that the user has logged out. */
1.85 markus 1565: if (s->pid != 0)
1566: record_logout(s->pid, s->tty);
1.1 markus 1567:
1568: /* Release the pseudo-tty. */
1.130 provos 1569: if (getuid() == 0)
1570: pty_release(s->tty);
1.1 markus 1571:
1572: /*
1573: * Close the server side of the socket pairs. We must do this after
1574: * the pty cleanup, so that another process doesn't get this pty
1575: * while we're still cleaning up.
1576: */
1577: if (close(s->ptymaster) < 0)
1.130 provos 1578: error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
1.108 markus 1579:
1580: /* unlink pty from session */
1581: s->ttyfd = -1;
1.2 markus 1582: }
1583:
1.130 provos 1584: void
1585: session_pty_cleanup(void *session)
1586: {
1587: PRIVSEP(session_pty_cleanup2(session));
1588: }
1589:
1.147 markus 1590: static char *
1591: sig2name(int sig)
1592: {
1593: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1594: SSH_SIG(ABRT);
1595: SSH_SIG(ALRM);
1596: SSH_SIG(FPE);
1597: SSH_SIG(HUP);
1598: SSH_SIG(ILL);
1599: SSH_SIG(INT);
1600: SSH_SIG(KILL);
1601: SSH_SIG(PIPE);
1602: SSH_SIG(QUIT);
1603: SSH_SIG(SEGV);
1604: SSH_SIG(TERM);
1605: SSH_SIG(USR1);
1606: SSH_SIG(USR2);
1607: #undef SSH_SIG
1608: return "SIG@openssh.com";
1609: }
1610:
1.94 itojun 1611: static void
1.2 markus 1612: session_exit_message(Session *s, int status)
1613: {
1614: Channel *c;
1.124 markus 1615:
1616: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 1617: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1618: s->self, s->chanid);
1.137 mpech 1619: debug("session_exit_message: session %d channel %d pid %ld",
1620: s->self, s->chanid, (long)s->pid);
1.2 markus 1621:
1622: if (WIFEXITED(status)) {
1.124 markus 1623: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1624: packet_put_int(WEXITSTATUS(status));
1625: packet_send();
1626: } else if (WIFSIGNALED(status)) {
1.124 markus 1627: channel_request_start(s->chanid, "exit-signal", 0);
1.147 markus 1628: packet_put_cstring(sig2name(WTERMSIG(status)));
1.2 markus 1629: packet_put_char(WCOREDUMP(status));
1630: packet_put_cstring("");
1631: packet_put_cstring("");
1632: packet_send();
1633: } else {
1634: /* Some weird exit cause. Just exit. */
1635: packet_disconnect("wait returned status %04x.", status);
1636: }
1637:
1638: /* disconnect channel */
1639: debug("session_exit_message: release channel %d", s->chanid);
1640: channel_cancel_cleanup(s->chanid);
1.5 markus 1641: /*
1642: * emulate a write failure with 'chan_write_failed', nobody will be
1643: * interested in data we write.
1644: * Note that we must not call 'chan_read_failed', since there could
1645: * be some more data waiting in the pipe.
1646: */
1.8 markus 1647: if (c->ostate != CHAN_OUTPUT_CLOSED)
1648: chan_write_failed(c);
1.2 markus 1649: s->chanid = -1;
1650: }
1651:
1.130 provos 1652: void
1.85 markus 1653: session_close(Session *s)
1.2 markus 1654: {
1.137 mpech 1655: debug("session_close: session %d pid %ld", s->self, (long)s->pid);
1.85 markus 1656: if (s->ttyfd != -1) {
1657: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1658: session_pty_cleanup(s);
1659: }
1.2 markus 1660: if (s->term)
1661: xfree(s->term);
1662: if (s->display)
1663: xfree(s->display);
1.118 stevesk 1664: if (s->auth_display)
1665: xfree(s->auth_display);
1.2 markus 1666: if (s->auth_data)
1667: xfree(s->auth_data);
1668: if (s->auth_proto)
1669: xfree(s->auth_proto);
1670: s->used = 0;
1.9 markus 1671: session_proctitle(s);
1.2 markus 1672: }
1673:
1674: void
1675: session_close_by_pid(pid_t pid, int status)
1676: {
1677: Session *s = session_by_pid(pid);
1678: if (s == NULL) {
1.137 mpech 1679: debug("session_close_by_pid: no session for pid %ld",
1680: (long)pid);
1.2 markus 1681: return;
1682: }
1683: if (s->chanid != -1)
1684: session_exit_message(s, status);
1685: session_close(s);
1.98 markus 1686: }
1687:
1.2 markus 1688: /*
1689: * this is called when a channel dies before
1690: * the session 'child' itself dies
1691: */
1692: void
1693: session_close_by_channel(int id, void *arg)
1694: {
1695: Session *s = session_by_channel(id);
1696: if (s == NULL) {
1.107 markus 1697: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1698: return;
1699: }
1.137 mpech 1700: debug("session_close_by_channel: channel %d child %ld",
1701: id, (long)s->pid);
1.107 markus 1702: if (s->pid != 0) {
1703: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 1704: /*
1705: * delay detach of session, but release pty, since
1706: * the fd's to the child are already closed
1707: */
1708: if (s->ttyfd != -1) {
1709: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1710: session_pty_cleanup(s);
1711: }
1.107 markus 1712: return;
1713: }
1714: /* detach by removing callback */
1.2 markus 1715: channel_cancel_cleanup(s->chanid);
1716: s->chanid = -1;
1.106 markus 1717: session_close(s);
1718: }
1719:
1720: void
1.130 provos 1721: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 1722: {
1723: int i;
1.112 deraadt 1724: for (i = 0; i < MAX_SESSIONS; i++) {
1.106 markus 1725: Session *s = &sessions[i];
1.130 provos 1726: if (s->used) {
1727: if (closefunc != NULL)
1728: closefunc(s);
1729: else
1730: session_close(s);
1731: }
1.2 markus 1732: }
1.9 markus 1733: }
1734:
1.94 itojun 1735: static char *
1.9 markus 1736: session_tty_list(void)
1737: {
1738: static char buf[1024];
1739: int i;
1740: buf[0] = '\0';
1.112 deraadt 1741: for (i = 0; i < MAX_SESSIONS; i++) {
1.9 markus 1742: Session *s = &sessions[i];
1743: if (s->used && s->ttyfd != -1) {
1744: if (buf[0] != '\0')
1745: strlcat(buf, ",", sizeof buf);
1746: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1747: }
1748: }
1749: if (buf[0] == '\0')
1750: strlcpy(buf, "notty", sizeof buf);
1751: return buf;
1752: }
1753:
1754: void
1755: session_proctitle(Session *s)
1756: {
1757: if (s->pw == NULL)
1758: error("no user for session %d", s->self);
1759: else
1760: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1761: }
1762:
1763: int
1764: session_setup_x11fwd(Session *s)
1765: {
1766: struct stat st;
1.109 stevesk 1767: char display[512], auth_display[512];
1768: char hostname[MAXHOSTNAMELEN];
1.81 markus 1769:
1770: if (no_x11_forwarding_flag) {
1771: packet_send_debug("X11 forwarding disabled in user configuration file.");
1772: return 0;
1773: }
1774: if (!options.x11_forwarding) {
1775: debug("X11 forwarding disabled in server configuration file.");
1776: return 0;
1777: }
1778: if (!options.xauth_location ||
1779: (stat(options.xauth_location, &st) == -1)) {
1780: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1781: return 0;
1782: }
1783: if (options.use_login) {
1784: packet_send_debug("X11 forwarding disabled; "
1785: "not compatible with UseLogin=yes.");
1.81 markus 1786: return 0;
1787: }
1.87 markus 1788: if (s->display != NULL) {
1.81 markus 1789: debug("X11 display already set.");
1790: return 0;
1791: }
1.140 deraadt 1792: if (x11_create_display_inet(options.x11_display_offset,
1793: options.x11_use_localhost, s->single_connection,
1794: &s->display_number) == -1) {
1.87 markus 1795: debug("x11_create_display_inet failed.");
1.81 markus 1796: return 0;
1797: }
1.109 stevesk 1798:
1799: /* Set up a suitable value for the DISPLAY variable. */
1800: if (gethostname(hostname, sizeof(hostname)) < 0)
1801: fatal("gethostname: %.100s", strerror(errno));
1802: /*
1803: * auth_display must be used as the displayname when the
1804: * authorization entry is added with xauth(1). This will be
1805: * different than the DISPLAY string for localhost displays.
1806: */
1.119 stevesk 1807: if (options.x11_use_localhost) {
1.140 deraadt 1808: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 1809: s->display_number, s->screen);
1.140 deraadt 1810: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 1811: s->display_number, s->screen);
1.109 stevesk 1812: s->display = xstrdup(display);
1.118 stevesk 1813: s->auth_display = xstrdup(auth_display);
1.109 stevesk 1814: } else {
1.140 deraadt 1815: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 1816: s->display_number, s->screen);
1817: s->display = xstrdup(display);
1.118 stevesk 1818: s->auth_display = xstrdup(display);
1.109 stevesk 1819: }
1820:
1.81 markus 1821: return 1;
1.2 markus 1822: }
1823:
1.94 itojun 1824: static void
1.49 markus 1825: do_authenticated2(Authctxt *authctxt)
1.2 markus 1826: {
1.97 markus 1827: server_loop2(authctxt);
1.161 markus 1828: #if defined(GSSAPI)
1829: if (options.gss_cleanup_creds)
1830: ssh_gssapi_cleanup_creds(NULL);
1831: #endif
1.1 markus 1832: }
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