Annotation of src/usr.bin/ssh/session.c, Revision 1.167
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"
1.167 ! djm 36: RCSID("$OpenBSD: session.c,v 1.166 2003/10/14 19:54:39 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);
1.165 markus 69: void session_pty_cleanup(Session *);
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:
1.165 markus 105: static int is_child = 0;
106:
1.136 markus 107: /* Name and directory of socket for authentication agent forwarding. */
108: static char *auth_sock_name = NULL;
109: static char *auth_sock_dir = NULL;
110:
111: /* removes the agent forwarding socket */
112:
113: static void
1.165 markus 114: auth_sock_cleanup_proc(struct passwd *pw)
1.136 markus 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);
1.166 markus 143: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
1.136 markus 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: /* Create the socket. */
160: sock = socket(AF_UNIX, SOCK_STREAM, 0);
161: if (sock < 0)
162: packet_disconnect("socket: %.100s", strerror(errno));
163:
164: /* Bind it to the name. */
165: memset(&sunaddr, 0, sizeof(sunaddr));
166: sunaddr.sun_family = AF_UNIX;
167: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
168:
169: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
170: packet_disconnect("bind: %.100s", strerror(errno));
171:
172: /* Restore the privileged uid. */
173: restore_uid();
174:
175: /* Start listening on the socket. */
176: if (listen(sock, 5) < 0)
177: packet_disconnect("listen: %.100s", strerror(errno));
178:
179: /* Allocate a channel for the authentication agent socket. */
180: nc = channel_new("auth socket",
181: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
182: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.156 markus 183: 0, "auth socket", 1);
1.136 markus 184: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
185: return 1;
186: }
187:
188:
1.65 markus 189: void
190: do_authenticated(Authctxt *authctxt)
191: {
1.153 markus 192: setproctitle("%s", authctxt->pw->pw_name);
193:
1.65 markus 194: /*
195: * Cancel the alarm we set to limit the time taken for
196: * authentication.
197: */
198: alarm(0);
199: if (startup_pipe != -1) {
200: close(startup_pipe);
201: startup_pipe = -1;
202: }
203: /* setup the channel layer */
204: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
205: channel_permit_all_opens();
206:
207: if (compat20)
208: do_authenticated2(authctxt);
209: else
210: do_authenticated1(authctxt);
1.79 markus 211:
1.165 markus 212: do_cleanup(authctxt);
1.65 markus 213: }
214:
1.1 markus 215: /*
216: * Prepares for an interactive session. This is called after the user has
217: * been successfully authenticated. During this message exchange, pseudo
218: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
219: * are requested, etc.
220: */
1.94 itojun 221: static void
1.65 markus 222: do_authenticated1(Authctxt *authctxt)
1.1 markus 223: {
224: Session *s;
1.65 markus 225: char *command;
1.117 markus 226: int success, type, screen_flag;
1.139 deraadt 227: int enable_compression_after_reply = 0;
228: u_int proto_len, data_len, dlen, compression_level = 0;
1.1 markus 229:
1.61 markus 230: s = session_new();
1.96 dugsong 231: s->authctxt = authctxt;
1.65 markus 232: s->pw = authctxt->pw;
1.28 millert 233:
1.1 markus 234: /*
235: * We stay in this loop until the client requests to execute a shell
236: * or a command.
237: */
238: for (;;) {
1.65 markus 239: success = 0;
1.1 markus 240:
241: /* Get a packet from the client. */
1.117 markus 242: type = packet_read();
1.1 markus 243:
244: /* Process the packet. */
245: switch (type) {
246: case SSH_CMSG_REQUEST_COMPRESSION:
247: compression_level = packet_get_int();
1.116 markus 248: packet_check_eom();
1.1 markus 249: if (compression_level < 1 || compression_level > 9) {
250: packet_send_debug("Received illegal compression level %d.",
1.112 deraadt 251: compression_level);
1.138 markus 252: break;
253: }
254: if (!options.compression) {
255: debug2("compression disabled");
1.1 markus 256: break;
257: }
258: /* Enable compression after we have responded with SUCCESS. */
259: enable_compression_after_reply = 1;
260: success = 1;
261: break;
262:
263: case SSH_CMSG_REQUEST_PTY:
1.86 markus 264: success = session_pty_req(s);
1.1 markus 265: break;
266:
267: case SSH_CMSG_X11_REQUEST_FORWARDING:
268: s->auth_proto = packet_get_string(&proto_len);
269: s->auth_data = packet_get_string(&data_len);
270:
1.57 markus 271: screen_flag = packet_get_protocol_flags() &
272: SSH_PROTOFLAG_SCREEN_NUMBER;
273: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
274:
275: if (packet_remaining() == 4) {
276: if (!screen_flag)
277: debug2("Buggy client: "
278: "X11 screen flag missing");
1.1 markus 279: s->screen = packet_get_int();
1.56 markus 280: } else {
1.1 markus 281: s->screen = 0;
1.56 markus 282: }
1.116 markus 283: packet_check_eom();
1.81 markus 284: success = session_setup_x11fwd(s);
285: if (!success) {
286: xfree(s->auth_proto);
287: xfree(s->auth_data);
1.84 markus 288: s->auth_proto = NULL;
289: s->auth_data = NULL;
1.1 markus 290: }
291: break;
292:
293: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
294: if (no_agent_forwarding_flag || compat13) {
295: debug("Authentication agent forwarding not permitted for this authentication.");
296: break;
297: }
298: debug("Received authentication agent forwarding request.");
1.65 markus 299: success = auth_input_request_forwarding(s->pw);
1.1 markus 300: break;
301:
302: case SSH_CMSG_PORT_FORWARD_REQUEST:
303: if (no_port_forwarding_flag) {
304: debug("Port forwarding not permitted for this authentication.");
1.39 markus 305: break;
306: }
307: if (!options.allow_tcp_forwarding) {
308: debug("Port forwarding not permitted.");
1.1 markus 309: break;
310: }
311: debug("Received TCP/IP port forwarding request.");
1.65 markus 312: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 313: success = 1;
314: break;
315:
316: case SSH_CMSG_MAX_PACKET_SIZE:
317: if (packet_set_maxsize(packet_get_int()) > 0)
318: success = 1;
319: break;
320:
321: case SSH_CMSG_EXEC_SHELL:
322: case SSH_CMSG_EXEC_CMD:
323: if (type == SSH_CMSG_EXEC_CMD) {
324: command = packet_get_string(&dlen);
325: debug("Exec command '%.500s'", command);
1.92 markus 326: do_exec(s, command);
327: xfree(command);
1.1 markus 328: } else {
1.92 markus 329: do_exec(s, NULL);
1.1 markus 330: }
1.116 markus 331: packet_check_eom();
1.82 markus 332: session_close(s);
1.1 markus 333: return;
334:
335: default:
336: /*
337: * Any unknown messages in this phase are ignored,
338: * and a failure message is returned.
339: */
1.155 itojun 340: logit("Unknown packet type received after authentication: %d", type);
1.1 markus 341: }
342: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
343: packet_send();
344: packet_write_wait();
345:
346: /* Enable compression now that we have replied if appropriate. */
347: if (enable_compression_after_reply) {
348: enable_compression_after_reply = 0;
349: packet_start_compression(compression_level);
350: }
351: }
352: }
353:
354: /*
355: * This is called to fork and execute a command when we have no tty. This
356: * will call do_child from the child, and server_loop from the parent after
357: * setting up file descriptors and such.
358: */
1.4 markus 359: void
1.63 markus 360: do_exec_no_pty(Session *s, const char *command)
1.1 markus 361: {
1.137 mpech 362: pid_t pid;
1.1 markus 363:
364: #ifdef USE_PIPES
365: int pin[2], pout[2], perr[2];
366: /* Allocate pipes for communicating with the program. */
367: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
368: packet_disconnect("Could not create pipes: %.100s",
369: strerror(errno));
370: #else /* USE_PIPES */
371: int inout[2], err[2];
372: /* Uses socket pairs to communicate with the program. */
373: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
374: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
375: packet_disconnect("Could not create socket pairs: %.100s",
376: strerror(errno));
377: #endif /* USE_PIPES */
378: if (s == NULL)
379: fatal("do_exec_no_pty: no session");
380:
1.9 markus 381: session_proctitle(s);
1.1 markus 382:
383: /* Fork the child. */
384: if ((pid = fork()) == 0) {
1.165 markus 385: is_child = 1;
1.144 markus 386:
1.1 markus 387: /* Child. Reinitialize the log since the pid has changed. */
388: log_init(__progname, options.log_level, options.log_facility, log_stderr);
389:
390: /*
391: * Create a new session and process group since the 4.4BSD
392: * setlogin() affects the entire process group.
393: */
394: if (setsid() < 0)
395: error("setsid failed: %.100s", strerror(errno));
396:
397: #ifdef USE_PIPES
398: /*
399: * Redirect stdin. We close the parent side of the socket
400: * pair, and make the child side the standard input.
401: */
402: close(pin[1]);
403: if (dup2(pin[0], 0) < 0)
404: perror("dup2 stdin");
405: close(pin[0]);
406:
407: /* Redirect stdout. */
408: close(pout[0]);
409: if (dup2(pout[1], 1) < 0)
410: perror("dup2 stdout");
411: close(pout[1]);
412:
413: /* Redirect stderr. */
414: close(perr[0]);
415: if (dup2(perr[1], 2) < 0)
416: perror("dup2 stderr");
417: close(perr[1]);
418: #else /* USE_PIPES */
419: /*
420: * Redirect stdin, stdout, and stderr. Stdin and stdout will
421: * use the same socket, as some programs (particularly rdist)
422: * seem to depend on it.
423: */
424: close(inout[1]);
425: close(err[1]);
426: if (dup2(inout[0], 0) < 0) /* stdin */
427: perror("dup2 stdin");
428: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
429: perror("dup2 stdout");
430: if (dup2(err[0], 2) < 0) /* stderr */
431: perror("dup2 stderr");
432: #endif /* USE_PIPES */
433:
434: /* Do processing for the child (exec command etc). */
1.60 markus 435: do_child(s, command);
1.1 markus 436: /* NOTREACHED */
437: }
438: if (pid < 0)
439: packet_disconnect("fork failed: %.100s", strerror(errno));
440: s->pid = pid;
1.47 markus 441: /* Set interactive/non-interactive mode. */
1.48 markus 442: packet_set_interactive(s->display != NULL);
1.1 markus 443: #ifdef USE_PIPES
444: /* We are the parent. Close the child sides of the pipes. */
445: close(pin[0]);
446: close(pout[1]);
447: close(perr[1]);
448:
1.2 markus 449: if (compat20) {
1.64 markus 450: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 451: } else {
452: /* Enter the interactive session. */
453: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 454: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 455: }
1.1 markus 456: #else /* USE_PIPES */
457: /* We are the parent. Close the child sides of the socket pairs. */
458: close(inout[0]);
459: close(err[0]);
460:
461: /*
462: * Enter the interactive session. Note: server_loop must be able to
463: * handle the case that fdin and fdout are the same.
464: */
1.2 markus 465: if (compat20) {
1.64 markus 466: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 467: } else {
468: server_loop(pid, inout[1], inout[1], err[1]);
469: /* server_loop has closed inout[1] and err[1]. */
470: }
1.1 markus 471: #endif /* USE_PIPES */
472: }
473:
474: /*
475: * This is called to fork and execute a command when we have a tty. This
476: * will call do_child from the child, and server_loop from the parent after
477: * setting up file descriptors, controlling tty, updating wtmp, utmp,
478: * lastlog, and other such operations.
479: */
1.4 markus 480: void
1.63 markus 481: do_exec_pty(Session *s, const char *command)
1.1 markus 482: {
483: int fdout, ptyfd, ttyfd, ptymaster;
484: pid_t pid;
485:
486: if (s == NULL)
487: fatal("do_exec_pty: no session");
488: ptyfd = s->ptyfd;
489: ttyfd = s->ttyfd;
490:
491: /* Fork the child. */
492: if ((pid = fork()) == 0) {
1.165 markus 493: is_child = 1;
1.97 markus 494:
1.24 markus 495: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 496: log_init(__progname, options.log_level, options.log_facility, log_stderr);
497: /* Close the master side of the pseudo tty. */
498: close(ptyfd);
499:
500: /* Make the pseudo tty our controlling tty. */
501: pty_make_controlling_tty(&ttyfd, s->tty);
502:
1.103 markus 503: /* Redirect stdin/stdout/stderr from the pseudo tty. */
504: if (dup2(ttyfd, 0) < 0)
505: error("dup2 stdin: %s", strerror(errno));
506: if (dup2(ttyfd, 1) < 0)
507: error("dup2 stdout: %s", strerror(errno));
508: if (dup2(ttyfd, 2) < 0)
509: error("dup2 stderr: %s", strerror(errno));
1.1 markus 510:
511: /* Close the extra descriptor for the pseudo tty. */
512: close(ttyfd);
513:
1.24 markus 514: /* record login, etc. similar to login(1) */
1.41 markus 515: if (!(options.use_login && command == NULL))
516: do_login(s, command);
1.1 markus 517:
518: /* Do common processing for the child, such as execing the command. */
1.60 markus 519: do_child(s, command);
1.1 markus 520: /* NOTREACHED */
521: }
522: if (pid < 0)
523: packet_disconnect("fork failed: %.100s", strerror(errno));
524: s->pid = pid;
525:
526: /* Parent. Close the slave side of the pseudo tty. */
527: close(ttyfd);
528:
529: /*
530: * Create another descriptor of the pty master side for use as the
531: * standard input. We could use the original descriptor, but this
532: * simplifies code in server_loop. The descriptor is bidirectional.
533: */
534: fdout = dup(ptyfd);
535: if (fdout < 0)
536: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
537:
538: /* we keep a reference to the pty master */
539: ptymaster = dup(ptyfd);
540: if (ptymaster < 0)
541: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
542: s->ptymaster = ptymaster;
543:
544: /* Enter interactive session. */
1.47 markus 545: packet_set_interactive(1);
1.2 markus 546: if (compat20) {
547: session_set_fds(s, ptyfd, fdout, -1);
548: } else {
549: server_loop(pid, ptyfd, fdout, -1);
550: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 551: }
552: }
553:
1.90 markus 554: /*
555: * This is called to fork and execute a command. If another command is
556: * to be forced, execute that instead.
557: */
558: void
559: do_exec(Session *s, const char *command)
560: {
561: if (forced_command) {
562: original_command = command;
563: command = forced_command;
564: debug("Forced command '%.900s'", command);
565: }
1.163 markus 566:
567: #ifdef GSSAPI
568: if (options.gss_authentication) {
569: temporarily_use_uid(s->pw);
570: ssh_gssapi_storecreds();
571: restore_uid();
572: }
573: #endif
1.90 markus 574:
575: if (s->ttyfd != -1)
576: do_exec_pty(s, command);
577: else
578: do_exec_no_pty(s, command);
579:
1.92 markus 580: original_command = NULL;
1.90 markus 581: }
582:
583:
1.24 markus 584: /* administrative, login(1)-like work */
585: void
1.41 markus 586: do_login(Session *s, const char *command)
1.24 markus 587: {
588: char *time_string;
589: socklen_t fromlen;
590: struct sockaddr_storage from;
591: struct passwd * pw = s->pw;
592: pid_t pid = getpid();
593:
594: /*
595: * Get IP address of client. If the connection is not a socket, let
596: * the address be 0.0.0.0.
597: */
598: memset(&from, 0, sizeof(from));
1.148 stevesk 599: fromlen = sizeof(from);
1.24 markus 600: if (packet_connection_is_on_socket()) {
601: if (getpeername(packet_get_connection_in(),
1.112 deraadt 602: (struct sockaddr *) & from, &fromlen) < 0) {
1.24 markus 603: debug("getpeername: %.100s", strerror(errno));
1.165 markus 604: cleanup_exit(255);
1.24 markus 605: }
606: }
1.25 markus 607:
1.24 markus 608: /* Record that there was a login on that tty from the remote host. */
1.133 markus 609: if (!use_privsep)
610: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
611: get_remote_name_or_ip(utmp_len,
1.158 markus 612: options.use_dns),
1.148 stevesk 613: (struct sockaddr *)&from, fromlen);
1.24 markus 614:
1.73 djm 615: if (check_quietlogin(s, command))
1.24 markus 616: return;
1.73 djm 617:
1.134 markus 618: if (options.print_lastlog && s->last_login_time != 0) {
619: time_string = ctime(&s->last_login_time);
1.24 markus 620: if (strchr(time_string, '\n'))
621: *strchr(time_string, '\n') = 0;
1.134 markus 622: if (strcmp(s->hostname, "") == 0)
1.24 markus 623: printf("Last login: %s\r\n", time_string);
624: else
1.134 markus 625: printf("Last login: %s from %s\r\n", time_string,
626: s->hostname);
1.24 markus 627: }
1.73 djm 628:
629: do_motd();
630: }
631:
632: /*
633: * Display the message of the day.
634: */
635: void
636: do_motd(void)
637: {
638: FILE *f;
639: char buf[256];
640:
1.24 markus 641: if (options.print_motd) {
1.28 millert 642: #ifdef HAVE_LOGIN_CAP
643: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
644: "/etc/motd"), "r");
645: #else
1.24 markus 646: f = fopen("/etc/motd", "r");
1.28 millert 647: #endif
1.24 markus 648: if (f) {
649: while (fgets(buf, sizeof(buf), f))
650: fputs(buf, stdout);
651: fclose(f);
652: }
1.2 markus 653: }
1.73 djm 654: }
655:
656:
657: /*
658: * Check for quiet login, either .hushlogin or command given.
659: */
660: int
661: check_quietlogin(Session *s, const char *command)
662: {
663: char buf[256];
1.96 dugsong 664: struct passwd *pw = s->pw;
1.73 djm 665: struct stat st;
666:
667: /* Return 1 if .hushlogin exists or a command given. */
668: if (command != NULL)
669: return 1;
670: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
671: #ifdef HAVE_LOGIN_CAP
672: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
673: return 1;
674: #else
675: if (stat(buf, &st) >= 0)
676: return 1;
677: #endif
678: return 0;
1.1 markus 679: }
680:
681: /*
682: * Sets the value of the given variable in the environment. If the variable
683: * already exists, its value is overriden.
684: */
1.161 markus 685: void
1.45 markus 686: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 687: const char *value)
1.1 markus 688: {
1.164 markus 689: char **env;
690: u_int envsize;
1.45 markus 691: u_int i, namelen;
1.1 markus 692:
693: /*
694: * Find the slot where the value should be stored. If the variable
695: * already exists, we reuse the slot; otherwise we append a new slot
696: * at the end of the array, expanding if necessary.
697: */
698: env = *envp;
699: namelen = strlen(name);
700: for (i = 0; env[i]; i++)
701: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
702: break;
703: if (env[i]) {
704: /* Reuse the slot. */
705: xfree(env[i]);
706: } else {
707: /* New variable. Expand if necessary. */
1.164 markus 708: envsize = *envsizep;
709: if (i >= envsize - 1) {
710: if (envsize >= 1000)
711: fatal("child_set_env: too many env vars");
712: envsize += 50;
713: env = (*envp) = xrealloc(env, envsize * sizeof(char *));
714: *envsizep = envsize;
1.1 markus 715: }
716: /* Need to set the NULL pointer at end of array beyond the new slot. */
717: env[i + 1] = NULL;
718: }
719:
720: /* Allocate space and format the variable in the appropriate slot. */
721: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
722: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
723: }
724:
725: /*
726: * Reads environment variables from the given file and adds/overrides them
727: * into the environment. If the file does not exist, this does nothing.
728: * Otherwise, it must consist of empty lines, comments (line starts with '#')
729: * and assignments of the form name=value. No other forms are allowed.
730: */
1.94 itojun 731: static void
1.45 markus 732: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 733: const char *filename)
1.1 markus 734: {
735: FILE *f;
736: char buf[4096];
737: char *cp, *value;
1.142 deraadt 738: u_int lineno = 0;
1.1 markus 739:
740: f = fopen(filename, "r");
741: if (!f)
742: return;
743:
744: while (fgets(buf, sizeof(buf), f)) {
1.142 deraadt 745: if (++lineno > 1000)
746: fatal("Too many lines in environment file %s", filename);
1.1 markus 747: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
748: ;
749: if (!*cp || *cp == '#' || *cp == '\n')
750: continue;
751: if (strchr(cp, '\n'))
752: *strchr(cp, '\n') = '\0';
753: value = strchr(cp, '=');
754: if (value == NULL) {
1.142 deraadt 755: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
756: filename);
1.1 markus 757: continue;
758: }
1.14 deraadt 759: /*
760: * Replace the equals sign by nul, and advance value to
761: * the value string.
762: */
1.1 markus 763: *value = '\0';
764: value++;
765: child_set_env(env, envsize, cp, value);
766: }
767: fclose(f);
768: }
769:
1.127 markus 770: static char **
771: do_setup_env(Session *s, const char *shell)
1.1 markus 772: {
773: char buf[256];
1.127 markus 774: u_int i, envsize;
1.154 markus 775: char **env, *laddr;
1.127 markus 776: struct passwd *pw = s->pw;
1.1 markus 777:
778: /* Initialize the environment. */
779: envsize = 100;
780: env = xmalloc(envsize * sizeof(char *));
781: env[0] = NULL;
782:
1.161 markus 783: #ifdef GSSAPI
784: /* Allow any GSSAPI methods that we've used to alter
785: * the childs environment as they see fit
786: */
787: ssh_gssapi_do_child(&env, &envsize);
788: #endif
789:
1.1 markus 790: if (!options.use_login) {
791: /* Set basic environment. */
792: child_set_env(&env, &envsize, "USER", pw->pw_name);
793: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
794: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 795: #ifdef HAVE_LOGIN_CAP
1.145 markus 796: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
797: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
798: else
799: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 800: #else
1.29 millert 801: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 802: #endif
1.1 markus 803:
804: snprintf(buf, sizeof buf, "%.200s/%.50s",
805: _PATH_MAILDIR, pw->pw_name);
806: child_set_env(&env, &envsize, "MAIL", buf);
807:
808: /* Normal systems set SHELL by default. */
809: child_set_env(&env, &envsize, "SHELL", shell);
810: }
811: if (getenv("TZ"))
812: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
813:
814: /* Set custom environment options from RSA authentication. */
1.110 markus 815: if (!options.use_login) {
816: while (custom_environment) {
817: struct envstring *ce = custom_environment;
1.143 deraadt 818: char *str = ce->s;
1.127 markus 819:
1.143 deraadt 820: for (i = 0; str[i] != '=' && str[i]; i++)
1.110 markus 821: ;
1.143 deraadt 822: if (str[i] == '=') {
823: str[i] = 0;
824: child_set_env(&env, &envsize, str, str + i + 1);
1.110 markus 825: }
826: custom_environment = ce->next;
827: xfree(ce->s);
828: xfree(ce);
1.1 markus 829: }
830: }
831:
1.149 stevesk 832: /* SSH_CLIENT deprecated */
1.1 markus 833: snprintf(buf, sizeof buf, "%.50s %d %d",
1.127 markus 834: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 835: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1.149 stevesk 836:
1.154 markus 837: laddr = get_local_ipaddr(packet_get_connection_in());
1.149 stevesk 838: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.154 markus 839: get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
840: xfree(laddr);
1.149 stevesk 841: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1.1 markus 842:
1.60 markus 843: if (s->ttyfd != -1)
844: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
845: if (s->term)
846: child_set_env(&env, &envsize, "TERM", s->term);
847: if (s->display)
848: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 849: if (original_command)
850: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
851: original_command);
1.96 dugsong 852: #ifdef KRB5
853: if (s->authctxt->krb5_ticket_file)
854: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 855: s->authctxt->krb5_ticket_file);
1.96 dugsong 856: #endif
1.136 markus 857: if (auth_sock_name != NULL)
1.1 markus 858: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.136 markus 859: auth_sock_name);
1.1 markus 860:
861: /* read $HOME/.ssh/environment. */
1.146 markus 862: if (options.permit_user_env && !options.use_login) {
1.14 deraadt 863: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
864: pw->pw_dir);
1.1 markus 865: read_environment_file(&env, &envsize, buf);
866: }
867: if (debug_flag) {
868: /* dump the environment */
869: fprintf(stderr, "Environment:\n");
870: for (i = 0; env[i]; i++)
871: fprintf(stderr, " %.200s\n", env[i]);
872: }
1.127 markus 873: return env;
874: }
875:
876: /*
877: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
878: * first in this order).
879: */
880: static void
881: do_rc_files(Session *s, const char *shell)
882: {
883: FILE *f = NULL;
884: char cmd[1024];
885: int do_xauth;
886: struct stat st;
887:
888: do_xauth =
889: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
890:
891: /* ignore _PATH_SSH_USER_RC for subsystems */
892: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
893: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
894: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
895: if (debug_flag)
896: fprintf(stderr, "Running %s\n", cmd);
897: f = popen(cmd, "w");
898: if (f) {
899: if (do_xauth)
900: fprintf(f, "%s %s\n", s->auth_proto,
901: s->auth_data);
902: pclose(f);
903: } else
904: fprintf(stderr, "Could not run %s\n",
905: _PATH_SSH_USER_RC);
906: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
907: if (debug_flag)
908: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
909: _PATH_SSH_SYSTEM_RC);
910: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
911: if (f) {
912: if (do_xauth)
913: fprintf(f, "%s %s\n", s->auth_proto,
914: s->auth_data);
915: pclose(f);
916: } else
917: fprintf(stderr, "Could not run %s\n",
918: _PATH_SSH_SYSTEM_RC);
919: } else if (do_xauth && options.xauth_location != NULL) {
920: /* Add authority data to .Xauthority if appropriate. */
921: if (debug_flag) {
922: fprintf(stderr,
1.151 stevesk 923: "Running %.500s remove %.100s\n",
1.165 markus 924: options.xauth_location, s->auth_display);
1.151 stevesk 925: fprintf(stderr,
926: "%.500s add %.100s %.100s %.100s\n",
1.127 markus 927: options.xauth_location, s->auth_display,
928: s->auth_proto, s->auth_data);
929: }
930: snprintf(cmd, sizeof cmd, "%s -q -",
931: options.xauth_location);
932: f = popen(cmd, "w");
933: if (f) {
1.151 stevesk 934: fprintf(f, "remove %s\n",
935: s->auth_display);
1.127 markus 936: fprintf(f, "add %s %s %s\n",
937: s->auth_display, s->auth_proto,
938: s->auth_data);
939: pclose(f);
940: } else {
941: fprintf(stderr, "Could not run %s\n",
942: cmd);
943: }
944: }
945: }
946:
947: static void
948: do_nologin(struct passwd *pw)
949: {
950: FILE *f = NULL;
951: char buf[1024];
952:
953: #ifdef HAVE_LOGIN_CAP
954: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
955: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
956: _PATH_NOLOGIN), "r");
957: #else
958: if (pw->pw_uid)
959: f = fopen(_PATH_NOLOGIN, "r");
960: #endif
961: if (f) {
962: /* /etc/nologin exists. Print its contents and exit. */
1.155 itojun 963: logit("User %.100s not allowed because %s exists",
1.150 stevesk 964: pw->pw_name, _PATH_NOLOGIN);
1.127 markus 965: while (fgets(buf, sizeof(buf), f))
966: fputs(buf, stderr);
967: fclose(f);
968: exit(254);
969: }
970: }
971:
972: /* Set login name, uid, gid, and groups. */
1.130 provos 973: void
1.127 markus 974: do_setusercontext(struct passwd *pw)
975: {
976: if (getuid() == 0 || geteuid() == 0) {
977: #ifdef HAVE_LOGIN_CAP
978: if (setusercontext(lc, pw, pw->pw_uid,
979: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
980: perror("unable to set user context");
981: exit(1);
982: }
983: #else
984: if (setlogin(pw->pw_name) < 0)
985: error("setlogin failed: %s", strerror(errno));
986: if (setgid(pw->pw_gid) < 0) {
987: perror("setgid");
988: exit(1);
989: }
990: /* Initialize the group list. */
991: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
992: perror("initgroups");
993: exit(1);
994: }
995: endgrent();
996:
997: /* Permanently switch to the desired uid. */
998: permanently_set_uid(pw);
999: #endif
1000: }
1001: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1002: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1003: }
1004:
1.131 markus 1005: static void
1.130 provos 1006: launch_login(struct passwd *pw, const char *hostname)
1007: {
1008: /* Launch login(1). */
1009:
1010: execl("/usr/bin/login", "login", "-h", hostname,
1011: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1012:
1013: /* Login couldn't be executed, die. */
1014:
1015: perror("login");
1016: exit(1);
1017: }
1018:
1.127 markus 1019: /*
1020: * Performs common processing for the child, such as setting up the
1021: * environment, closing extra file descriptors, setting the user and group
1022: * ids, and executing the command or shell.
1023: */
1024: void
1025: do_child(Session *s, const char *command)
1026: {
1027: extern char **environ;
1028: char **env;
1029: char *argv[10];
1030: const char *shell, *shell0, *hostname = NULL;
1031: struct passwd *pw = s->pw;
1032: u_int i;
1033:
1034: /* remove hostkey from the child's memory */
1035: destroy_sensitive_data();
1036:
1037: /* login(1) is only called if we execute the login shell */
1038: if (options.use_login && command != NULL)
1039: options.use_login = 0;
1040:
1041: /*
1042: * Login(1) does this as well, and it needs uid 0 for the "-h"
1043: * switch, so we let login(1) to this for us.
1044: */
1045: if (!options.use_login) {
1046: do_nologin(pw);
1047: do_setusercontext(pw);
1048: }
1049:
1050: /*
1051: * Get the shell from the password data. An empty shell field is
1052: * legal, and means /bin/sh.
1053: */
1054: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.152 markus 1055:
1056: /*
1057: * Make sure $SHELL points to the shell from the password file,
1058: * even if shell is overridden from login.conf
1059: */
1060: env = do_setup_env(s, shell);
1061:
1.127 markus 1062: #ifdef HAVE_LOGIN_CAP
1063: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1064: #endif
1065:
1.26 millert 1066: /* we have to stash the hostname before we close our socket. */
1067: if (options.use_login)
1.70 stevesk 1068: hostname = get_remote_name_or_ip(utmp_len,
1.158 markus 1069: options.use_dns);
1.1 markus 1070: /*
1071: * Close the connection descriptors; note that this is the child, and
1072: * the server will still have the socket open, and it is important
1073: * that we do not shutdown it. Note that the descriptors cannot be
1074: * closed before building the environment, as we call
1075: * get_remote_ipaddr there.
1076: */
1077: if (packet_get_connection_in() == packet_get_connection_out())
1078: close(packet_get_connection_in());
1079: else {
1080: close(packet_get_connection_in());
1081: close(packet_get_connection_out());
1082: }
1083: /*
1084: * Close all descriptors related to channels. They will still remain
1085: * open in the parent.
1086: */
1087: /* XXX better use close-on-exec? -markus */
1088: channel_close_all();
1089:
1090: /*
1091: * Close any extra file descriptors. Note that there may still be
1092: * descriptors left by system functions. They will be closed later.
1093: */
1094: endpwent();
1095:
1096: /*
1097: * Close any extra open file descriptors so that we don\'t have them
1098: * hanging around in clients. Note that we want to do this after
1099: * initgroups, because at least on Solaris 2.3 it leaves file
1100: * descriptors open.
1101: */
1102: for (i = 3; i < 64; i++)
1103: close(i);
1104:
1105: /*
1.125 deraadt 1106: * Must take new environment into use so that .ssh/rc,
1107: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1108: */
1109: environ = env;
1.104 markus 1110:
1111: /* Change current directory to the user\'s home directory. */
1112: if (chdir(pw->pw_dir) < 0) {
1113: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1114: pw->pw_dir, strerror(errno));
1115: #ifdef HAVE_LOGIN_CAP
1116: if (login_getcapbool(lc, "requirehome", 0))
1117: exit(1);
1118: #endif
1119: }
1.1 markus 1120:
1.127 markus 1121: if (!options.use_login)
1122: do_rc_files(s, shell);
1.67 markus 1123:
1124: /* restore SIGPIPE for child */
1125: signal(SIGPIPE, SIG_DFL);
1126:
1.127 markus 1127: if (options.use_login) {
1.130 provos 1128: launch_login(pw, hostname);
1129: /* NEVERREACHED */
1.127 markus 1130: }
1131:
1132: /* Get the last component of the shell name. */
1133: if ((shell0 = strrchr(shell, '/')) != NULL)
1134: shell0++;
1135: else
1136: shell0 = shell;
1137:
1.1 markus 1138: /*
1139: * If we have no command, execute the shell. In this case, the shell
1140: * name to be passed in argv[0] is preceded by '-' to indicate that
1141: * this is a login shell.
1142: */
1143: if (!command) {
1.127 markus 1144: char argv0[256];
1.1 markus 1145:
1.127 markus 1146: /* Start the shell. Set initial character to '-'. */
1147: argv0[0] = '-';
1.1 markus 1148:
1.127 markus 1149: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1150: >= sizeof(argv0) - 1) {
1.127 markus 1151: errno = EINVAL;
1.1 markus 1152: perror(shell);
1153: exit(1);
1.127 markus 1154: }
1.1 markus 1155:
1.127 markus 1156: /* Execute the shell. */
1157: argv[0] = argv0;
1158: argv[1] = NULL;
1159: execve(shell, argv, env);
1160:
1161: /* Executing the shell failed. */
1162: perror(shell);
1163: exit(1);
1.1 markus 1164: }
1165: /*
1166: * Execute the command using the user's shell. This uses the -c
1167: * option to execute the command.
1168: */
1.127 markus 1169: argv[0] = (char *) shell0;
1.1 markus 1170: argv[1] = "-c";
1171: argv[2] = (char *) command;
1172: argv[3] = NULL;
1173: execve(shell, argv, env);
1174: perror(shell);
1175: exit(1);
1176: }
1177:
1178: Session *
1179: session_new(void)
1180: {
1181: int i;
1182: static int did_init = 0;
1183: if (!did_init) {
1184: debug("session_new: init");
1.112 deraadt 1185: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1186: sessions[i].used = 0;
1187: }
1188: did_init = 1;
1189: }
1.112 deraadt 1190: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1191: Session *s = &sessions[i];
1192: if (! s->used) {
1.68 djm 1193: memset(s, 0, sizeof(*s));
1.1 markus 1194: s->chanid = -1;
1195: s->ptyfd = -1;
1196: s->ttyfd = -1;
1197: s->used = 1;
1.85 markus 1198: s->self = i;
1.1 markus 1199: debug("session_new: session %d", i);
1200: return s;
1201: }
1202: }
1203: return NULL;
1204: }
1205:
1.94 itojun 1206: static void
1.1 markus 1207: session_dump(void)
1208: {
1209: int i;
1.112 deraadt 1210: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1211: Session *s = &sessions[i];
1.137 mpech 1212: debug("dump: used %d session %d %p channel %d pid %ld",
1.1 markus 1213: s->used,
1214: s->self,
1215: s,
1216: s->chanid,
1.137 mpech 1217: (long)s->pid);
1.1 markus 1218: }
1219: }
1220:
1.2 markus 1221: int
1.97 markus 1222: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1223: {
1224: Session *s = session_new();
1225: debug("session_open: channel %d", chanid);
1226: if (s == NULL) {
1227: error("no more sessions");
1228: return 0;
1229: }
1.97 markus 1230: s->authctxt = authctxt;
1231: s->pw = authctxt->pw;
1.167 ! djm 1232: if (s->pw == NULL || !authctxt->valid)
1.54 stevesk 1233: fatal("no user for session %d", s->self);
1.2 markus 1234: debug("session_open: session %d: link with channel %d", s->self, chanid);
1235: s->chanid = chanid;
1236: return 1;
1237: }
1238:
1.130 provos 1239: Session *
1240: session_by_tty(char *tty)
1241: {
1242: int i;
1243: for (i = 0; i < MAX_SESSIONS; i++) {
1244: Session *s = &sessions[i];
1245: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1246: debug("session_by_tty: session %d tty %s", i, tty);
1247: return s;
1248: }
1249: }
1250: debug("session_by_tty: unknown tty %.100s", tty);
1251: session_dump();
1252: return NULL;
1253: }
1254:
1.94 itojun 1255: static Session *
1.2 markus 1256: session_by_channel(int id)
1257: {
1258: int i;
1.112 deraadt 1259: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1260: Session *s = &sessions[i];
1261: if (s->used && s->chanid == id) {
1262: debug("session_by_channel: session %d channel %d", i, id);
1263: return s;
1264: }
1265: }
1266: debug("session_by_channel: unknown channel %d", id);
1267: session_dump();
1268: return NULL;
1269: }
1270:
1.94 itojun 1271: static Session *
1.2 markus 1272: session_by_pid(pid_t pid)
1273: {
1274: int i;
1.137 mpech 1275: debug("session_by_pid: pid %ld", (long)pid);
1.112 deraadt 1276: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1277: Session *s = &sessions[i];
1278: if (s->used && s->pid == pid)
1279: return s;
1280: }
1.137 mpech 1281: error("session_by_pid: unknown pid %ld", (long)pid);
1.2 markus 1282: session_dump();
1283: return NULL;
1284: }
1285:
1.94 itojun 1286: static int
1.2 markus 1287: session_window_change_req(Session *s)
1288: {
1289: s->col = packet_get_int();
1290: s->row = packet_get_int();
1291: s->xpixel = packet_get_int();
1292: s->ypixel = packet_get_int();
1.116 markus 1293: packet_check_eom();
1.2 markus 1294: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1295: return 1;
1296: }
1297:
1.94 itojun 1298: static int
1.2 markus 1299: session_pty_req(Session *s)
1300: {
1.45 markus 1301: u_int len;
1.72 stevesk 1302: int n_bytes;
1.132 markus 1303:
1.86 markus 1304: if (no_pty_flag) {
1305: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1306: return 0;
1.86 markus 1307: }
1308: if (s->ttyfd != -1) {
1309: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1310: return 0;
1.134 markus 1311: }
1312: /* Get the time and hostname when the user last logged in. */
1313: if (options.print_lastlog) {
1314: s->hostname[0] = '\0';
1315: s->last_login_time = get_last_login_time(s->pw->pw_uid,
1316: s->pw->pw_name, s->hostname, sizeof(s->hostname));
1.86 markus 1317: }
1318:
1.2 markus 1319: s->term = packet_get_string(&len);
1.86 markus 1320:
1321: if (compat20) {
1322: s->col = packet_get_int();
1323: s->row = packet_get_int();
1324: } else {
1325: s->row = packet_get_int();
1326: s->col = packet_get_int();
1327: }
1.2 markus 1328: s->xpixel = packet_get_int();
1329: s->ypixel = packet_get_int();
1330:
1331: if (strcmp(s->term, "") == 0) {
1332: xfree(s->term);
1333: s->term = NULL;
1334: }
1.86 markus 1335:
1.2 markus 1336: /* Allocate a pty and open it. */
1.86 markus 1337: debug("Allocating pty.");
1.130 provos 1338: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1.86 markus 1339: if (s->term)
1340: xfree(s->term);
1.2 markus 1341: s->term = NULL;
1342: s->ptyfd = -1;
1343: s->ttyfd = -1;
1344: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1345: return 0;
1.2 markus 1346: }
1347: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1348:
1349: /* for SSH1 the tty modes length is not given */
1350: if (!compat20)
1351: n_bytes = packet_remaining();
1352: tty_parse_modes(s->ttyfd, &n_bytes);
1353:
1.130 provos 1354: if (!use_privsep)
1355: pty_setowner(s->pw, s->tty);
1.86 markus 1356:
1357: /* Set window size from the packet. */
1.2 markus 1358: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1359:
1.116 markus 1360: packet_check_eom();
1.9 markus 1361: session_proctitle(s);
1.2 markus 1362: return 1;
1363: }
1364:
1.94 itojun 1365: static int
1.7 markus 1366: session_subsystem_req(Session *s)
1367: {
1.105 markus 1368: struct stat st;
1.45 markus 1369: u_int len;
1.7 markus 1370: int success = 0;
1.105 markus 1371: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1372: int i;
1.7 markus 1373:
1.116 markus 1374: packet_check_eom();
1.155 itojun 1375: logit("subsystem request for %.100s", subsys);
1.18 jakob 1376:
1377: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1378: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1379: cmd = options.subsystem_command[i];
1380: if (stat(cmd, &st) < 0) {
1381: error("subsystem: cannot stat %s: %s", cmd,
1382: strerror(errno));
1383: break;
1384: }
1385: debug("subsystem: exec() %s", cmd);
1.64 markus 1386: s->is_subsystem = 1;
1.105 markus 1387: do_exec(s, cmd);
1.18 jakob 1388: success = 1;
1.122 markus 1389: break;
1.18 jakob 1390: }
1391: }
1392:
1393: if (!success)
1.155 itojun 1394: logit("subsystem request for %.100s failed, subsystem not found",
1.105 markus 1395: subsys);
1.7 markus 1396:
1397: xfree(subsys);
1398: return success;
1399: }
1400:
1.94 itojun 1401: static int
1.7 markus 1402: session_x11_req(Session *s)
1403: {
1.81 markus 1404: int success;
1.7 markus 1405:
1406: s->single_connection = packet_get_char();
1407: s->auth_proto = packet_get_string(NULL);
1408: s->auth_data = packet_get_string(NULL);
1409: s->screen = packet_get_int();
1.116 markus 1410: packet_check_eom();
1.7 markus 1411:
1.81 markus 1412: success = session_setup_x11fwd(s);
1413: if (!success) {
1.7 markus 1414: xfree(s->auth_proto);
1415: xfree(s->auth_data);
1.84 markus 1416: s->auth_proto = NULL;
1417: s->auth_data = NULL;
1.7 markus 1418: }
1.81 markus 1419: return success;
1.7 markus 1420: }
1421:
1.94 itojun 1422: static int
1.19 markus 1423: session_shell_req(Session *s)
1424: {
1.116 markus 1425: packet_check_eom();
1.90 markus 1426: do_exec(s, NULL);
1.19 markus 1427: return 1;
1428: }
1429:
1.94 itojun 1430: static int
1.19 markus 1431: session_exec_req(Session *s)
1432: {
1.45 markus 1433: u_int len;
1.19 markus 1434: char *command = packet_get_string(&len);
1.116 markus 1435: packet_check_eom();
1.90 markus 1436: do_exec(s, command);
1.92 markus 1437: xfree(command);
1.19 markus 1438: return 1;
1439: }
1440:
1.94 itojun 1441: static int
1.157 markus 1442: session_break_req(Session *s)
1443: {
1444: u_int break_length;
1445:
1.160 markus 1446: break_length = packet_get_int(); /* ignored */
1.157 markus 1447: packet_check_eom();
1448:
1.160 markus 1449: if (s->ttyfd == -1 ||
1450: tcsendbreak(s->ttyfd, 0) < 0)
1.157 markus 1451: return 0;
1452: return 1;
1453: }
1454:
1455: static int
1.43 markus 1456: session_auth_agent_req(Session *s)
1457: {
1458: static int called = 0;
1.116 markus 1459: packet_check_eom();
1.44 markus 1460: if (no_agent_forwarding_flag) {
1461: debug("session_auth_agent_req: no_agent_forwarding_flag");
1462: return 0;
1463: }
1.43 markus 1464: if (called) {
1465: return 0;
1466: } else {
1467: called = 1;
1468: return auth_input_request_forwarding(s->pw);
1469: }
1470: }
1471:
1.123 markus 1472: int
1473: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1474: {
1475: int success = 0;
1476: Session *s;
1477:
1.123 markus 1478: if ((s = session_by_channel(c->self)) == NULL) {
1.155 itojun 1479: logit("session_input_channel_req: no session %d req %.100s",
1.123 markus 1480: c->self, rtype);
1481: return 0;
1482: }
1483: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1484:
1485: /*
1.64 markus 1486: * a session is in LARVAL state until a shell, a command
1487: * or a subsystem is executed
1.2 markus 1488: */
1489: if (c->type == SSH_CHANNEL_LARVAL) {
1490: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1491: success = session_shell_req(s);
1.2 markus 1492: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1493: success = session_exec_req(s);
1.2 markus 1494: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1495: success = session_pty_req(s);
1.7 markus 1496: } else if (strcmp(rtype, "x11-req") == 0) {
1497: success = session_x11_req(s);
1.43 markus 1498: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1499: success = session_auth_agent_req(s);
1.7 markus 1500: } else if (strcmp(rtype, "subsystem") == 0) {
1501: success = session_subsystem_req(s);
1.157 markus 1502: } else if (strcmp(rtype, "break") == 0) {
1503: success = session_break_req(s);
1.2 markus 1504: }
1505: }
1506: if (strcmp(rtype, "window-change") == 0) {
1507: success = session_window_change_req(s);
1508: }
1.123 markus 1509: return success;
1.2 markus 1510: }
1511:
1512: void
1513: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1514: {
1515: if (!compat20)
1516: fatal("session_set_fds: called for proto != 2.0");
1517: /*
1518: * now that have a child and a pipe to the child,
1519: * we can activate our channel and register the fd's
1520: */
1521: if (s->chanid == -1)
1522: fatal("no channel for session %d", s->self);
1523: channel_set_fds(s->chanid,
1524: fdout, fdin, fderr,
1.42 markus 1525: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.126 markus 1526: 1,
1527: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1528: }
1529:
1.85 markus 1530: /*
1531: * Function to perform pty cleanup. Also called if we get aborted abnormally
1532: * (e.g., due to a dropped connection).
1533: */
1.130 provos 1534: void
1.165 markus 1535: session_pty_cleanup2(Session *s)
1.1 markus 1536: {
1.85 markus 1537: if (s == NULL) {
1538: error("session_pty_cleanup: no session");
1539: return;
1540: }
1541: if (s->ttyfd == -1)
1.1 markus 1542: return;
1543:
1.54 stevesk 1544: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1545:
1546: /* Record that the user has logged out. */
1.85 markus 1547: if (s->pid != 0)
1548: record_logout(s->pid, s->tty);
1.1 markus 1549:
1550: /* Release the pseudo-tty. */
1.130 provos 1551: if (getuid() == 0)
1552: pty_release(s->tty);
1.1 markus 1553:
1554: /*
1555: * Close the server side of the socket pairs. We must do this after
1556: * the pty cleanup, so that another process doesn't get this pty
1557: * while we're still cleaning up.
1558: */
1559: if (close(s->ptymaster) < 0)
1.130 provos 1560: error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
1.108 markus 1561:
1562: /* unlink pty from session */
1563: s->ttyfd = -1;
1.2 markus 1564: }
1565:
1.130 provos 1566: void
1.165 markus 1567: session_pty_cleanup(Session *s)
1.130 provos 1568: {
1.165 markus 1569: PRIVSEP(session_pty_cleanup2(s));
1.130 provos 1570: }
1571:
1.147 markus 1572: static char *
1573: sig2name(int sig)
1574: {
1575: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1576: SSH_SIG(ABRT);
1577: SSH_SIG(ALRM);
1578: SSH_SIG(FPE);
1579: SSH_SIG(HUP);
1580: SSH_SIG(ILL);
1581: SSH_SIG(INT);
1582: SSH_SIG(KILL);
1583: SSH_SIG(PIPE);
1584: SSH_SIG(QUIT);
1585: SSH_SIG(SEGV);
1586: SSH_SIG(TERM);
1587: SSH_SIG(USR1);
1588: SSH_SIG(USR2);
1589: #undef SSH_SIG
1590: return "SIG@openssh.com";
1591: }
1592:
1.94 itojun 1593: static void
1.2 markus 1594: session_exit_message(Session *s, int status)
1595: {
1596: Channel *c;
1.124 markus 1597:
1598: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 1599: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1600: s->self, s->chanid);
1.137 mpech 1601: debug("session_exit_message: session %d channel %d pid %ld",
1602: s->self, s->chanid, (long)s->pid);
1.2 markus 1603:
1604: if (WIFEXITED(status)) {
1.124 markus 1605: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1606: packet_put_int(WEXITSTATUS(status));
1607: packet_send();
1608: } else if (WIFSIGNALED(status)) {
1.124 markus 1609: channel_request_start(s->chanid, "exit-signal", 0);
1.147 markus 1610: packet_put_cstring(sig2name(WTERMSIG(status)));
1.2 markus 1611: packet_put_char(WCOREDUMP(status));
1612: packet_put_cstring("");
1613: packet_put_cstring("");
1614: packet_send();
1615: } else {
1616: /* Some weird exit cause. Just exit. */
1617: packet_disconnect("wait returned status %04x.", status);
1618: }
1619:
1620: /* disconnect channel */
1621: debug("session_exit_message: release channel %d", s->chanid);
1622: channel_cancel_cleanup(s->chanid);
1.5 markus 1623: /*
1624: * emulate a write failure with 'chan_write_failed', nobody will be
1625: * interested in data we write.
1626: * Note that we must not call 'chan_read_failed', since there could
1627: * be some more data waiting in the pipe.
1628: */
1.8 markus 1629: if (c->ostate != CHAN_OUTPUT_CLOSED)
1630: chan_write_failed(c);
1.2 markus 1631: s->chanid = -1;
1632: }
1633:
1.130 provos 1634: void
1.85 markus 1635: session_close(Session *s)
1.2 markus 1636: {
1.137 mpech 1637: debug("session_close: session %d pid %ld", s->self, (long)s->pid);
1.165 markus 1638: if (s->ttyfd != -1)
1.85 markus 1639: session_pty_cleanup(s);
1.2 markus 1640: if (s->term)
1641: xfree(s->term);
1642: if (s->display)
1643: xfree(s->display);
1.118 stevesk 1644: if (s->auth_display)
1645: xfree(s->auth_display);
1.2 markus 1646: if (s->auth_data)
1647: xfree(s->auth_data);
1648: if (s->auth_proto)
1649: xfree(s->auth_proto);
1650: s->used = 0;
1.9 markus 1651: session_proctitle(s);
1.2 markus 1652: }
1653:
1654: void
1655: session_close_by_pid(pid_t pid, int status)
1656: {
1657: Session *s = session_by_pid(pid);
1658: if (s == NULL) {
1.137 mpech 1659: debug("session_close_by_pid: no session for pid %ld",
1660: (long)pid);
1.2 markus 1661: return;
1662: }
1663: if (s->chanid != -1)
1664: session_exit_message(s, status);
1665: session_close(s);
1.98 markus 1666: }
1667:
1.2 markus 1668: /*
1669: * this is called when a channel dies before
1670: * the session 'child' itself dies
1671: */
1672: void
1673: session_close_by_channel(int id, void *arg)
1674: {
1675: Session *s = session_by_channel(id);
1676: if (s == NULL) {
1.107 markus 1677: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1678: return;
1679: }
1.137 mpech 1680: debug("session_close_by_channel: channel %d child %ld",
1681: id, (long)s->pid);
1.107 markus 1682: if (s->pid != 0) {
1683: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 1684: /*
1685: * delay detach of session, but release pty, since
1686: * the fd's to the child are already closed
1687: */
1.165 markus 1688: if (s->ttyfd != -1)
1.108 markus 1689: session_pty_cleanup(s);
1.107 markus 1690: return;
1691: }
1692: /* detach by removing callback */
1.2 markus 1693: channel_cancel_cleanup(s->chanid);
1694: s->chanid = -1;
1.106 markus 1695: session_close(s);
1696: }
1697:
1698: void
1.130 provos 1699: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 1700: {
1701: int i;
1.112 deraadt 1702: for (i = 0; i < MAX_SESSIONS; i++) {
1.106 markus 1703: Session *s = &sessions[i];
1.130 provos 1704: if (s->used) {
1705: if (closefunc != NULL)
1706: closefunc(s);
1707: else
1708: session_close(s);
1709: }
1.2 markus 1710: }
1.9 markus 1711: }
1712:
1.94 itojun 1713: static char *
1.9 markus 1714: session_tty_list(void)
1715: {
1716: static char buf[1024];
1717: int i;
1718: buf[0] = '\0';
1.112 deraadt 1719: for (i = 0; i < MAX_SESSIONS; i++) {
1.9 markus 1720: Session *s = &sessions[i];
1721: if (s->used && s->ttyfd != -1) {
1722: if (buf[0] != '\0')
1723: strlcat(buf, ",", sizeof buf);
1724: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1725: }
1726: }
1727: if (buf[0] == '\0')
1728: strlcpy(buf, "notty", sizeof buf);
1729: return buf;
1730: }
1731:
1732: void
1733: session_proctitle(Session *s)
1734: {
1735: if (s->pw == NULL)
1736: error("no user for session %d", s->self);
1737: else
1738: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1739: }
1740:
1741: int
1742: session_setup_x11fwd(Session *s)
1743: {
1744: struct stat st;
1.109 stevesk 1745: char display[512], auth_display[512];
1746: char hostname[MAXHOSTNAMELEN];
1.81 markus 1747:
1748: if (no_x11_forwarding_flag) {
1749: packet_send_debug("X11 forwarding disabled in user configuration file.");
1750: return 0;
1751: }
1752: if (!options.x11_forwarding) {
1753: debug("X11 forwarding disabled in server configuration file.");
1754: return 0;
1755: }
1756: if (!options.xauth_location ||
1757: (stat(options.xauth_location, &st) == -1)) {
1758: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1759: return 0;
1760: }
1761: if (options.use_login) {
1762: packet_send_debug("X11 forwarding disabled; "
1763: "not compatible with UseLogin=yes.");
1.81 markus 1764: return 0;
1765: }
1.87 markus 1766: if (s->display != NULL) {
1.81 markus 1767: debug("X11 display already set.");
1768: return 0;
1769: }
1.140 deraadt 1770: if (x11_create_display_inet(options.x11_display_offset,
1771: options.x11_use_localhost, s->single_connection,
1772: &s->display_number) == -1) {
1.87 markus 1773: debug("x11_create_display_inet failed.");
1.81 markus 1774: return 0;
1775: }
1.109 stevesk 1776:
1777: /* Set up a suitable value for the DISPLAY variable. */
1778: if (gethostname(hostname, sizeof(hostname)) < 0)
1779: fatal("gethostname: %.100s", strerror(errno));
1780: /*
1781: * auth_display must be used as the displayname when the
1782: * authorization entry is added with xauth(1). This will be
1783: * different than the DISPLAY string for localhost displays.
1784: */
1.119 stevesk 1785: if (options.x11_use_localhost) {
1.140 deraadt 1786: snprintf(display, sizeof display, "localhost:%u.%u",
1.109 stevesk 1787: s->display_number, s->screen);
1.140 deraadt 1788: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
1.118 stevesk 1789: s->display_number, s->screen);
1.109 stevesk 1790: s->display = xstrdup(display);
1.118 stevesk 1791: s->auth_display = xstrdup(auth_display);
1.109 stevesk 1792: } else {
1.140 deraadt 1793: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
1.109 stevesk 1794: s->display_number, s->screen);
1795: s->display = xstrdup(display);
1.118 stevesk 1796: s->auth_display = xstrdup(display);
1.109 stevesk 1797: }
1798:
1.81 markus 1799: return 1;
1.2 markus 1800: }
1801:
1.94 itojun 1802: static void
1.49 markus 1803: do_authenticated2(Authctxt *authctxt)
1.2 markus 1804: {
1.97 markus 1805: server_loop2(authctxt);
1.165 markus 1806: }
1807:
1808: void
1809: do_cleanup(Authctxt *authctxt)
1810: {
1811: static int called = 0;
1812:
1813: debug("do_cleanup");
1814:
1815: /* no cleanup if we're in the child for login shell */
1816: if (is_child)
1817: return;
1818:
1819: /* avoid double cleanup */
1820: if (called)
1821: return;
1822: called = 1;
1823:
1824: if (authctxt == NULL)
1825: return;
1826: #ifdef KRB5
1827: if (options.kerberos_ticket_cleanup &&
1828: authctxt->krb5_ctx)
1829: krb5_cleanup_proc(authctxt);
1.161 markus 1830: #endif
1.165 markus 1831:
1832: #ifdef GSSAPI
1833: if (compat20 && options.gss_cleanup_creds)
1834: ssh_gssapi_cleanup_creds();
1835: #endif
1836:
1837: /* remove agent socket */
1838: auth_sock_cleanup_proc(authctxt->pw);
1839:
1840: /*
1841: * Cleanup ptys/utmp only if privsep is disabled,
1842: * or if running in monitor.
1843: */
1844: if (!use_privsep || mm_is_monitor())
1845: session_destroy_all(session_pty_cleanup2);
1.1 markus 1846: }
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