Annotation of src/usr.bin/ssh/session.c, Revision 1.105
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"
1.105 ! markus 36: RCSID("$OpenBSD: session.c,v 1.104 2001/10/09 10:12:08 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"
1.2 markus 59:
1.1 markus 60: /* types */
61:
62: #define TTYSZ 64
63: typedef struct Session Session;
64: struct Session {
65: int used;
66: int self;
1.96 dugsong 67: struct passwd *pw;
68: Authctxt *authctxt;
1.1 markus 69: pid_t pid;
70: /* tty */
71: char *term;
72: int ptyfd, ttyfd, ptymaster;
73: int row, col, xpixel, ypixel;
74: char tty[TTYSZ];
75: /* X11 */
76: char *display;
77: int screen;
78: char *auth_proto;
79: char *auth_data;
1.7 markus 80: int single_connection;
1.1 markus 81: /* proto 2 */
82: int chanid;
1.64 markus 83: int is_subsystem;
1.1 markus 84: };
85:
86: /* func */
87:
88: Session *session_new(void);
1.94 itojun 89: void session_set_fds(Session *, int, int, int);
90: static void session_pty_cleanup(void *);
91: void session_proctitle(Session *);
92: int session_setup_x11fwd(Session *);
93: void do_exec_pty(Session *, const char *);
94: void do_exec_no_pty(Session *, const char *);
95: void do_exec(Session *, const char *);
96: void do_login(Session *, const char *);
97: void do_child(Session *, const char *);
1.73 djm 98: void do_motd(void);
1.94 itojun 99: int check_quietlogin(Session *, const char *);
1.1 markus 100:
1.94 itojun 101: static void do_authenticated1(Authctxt *);
102: static void do_authenticated2(Authctxt *);
103:
104: static void session_close(Session *);
105: static int session_pty_req(Session *);
1.65 markus 106:
1.1 markus 107: /* import */
108: extern ServerOptions options;
109: extern char *__progname;
110: extern int log_stderr;
111: extern int debug_flag;
1.45 markus 112: extern u_int utmp_len;
1.21 markus 113: extern int startup_pipe;
1.74 markus 114: extern void destroy_sensitive_data(void);
1.21 markus 115:
1.34 markus 116: /* original command from peer. */
1.92 markus 117: const char *original_command = NULL;
1.34 markus 118:
1.1 markus 119: /* data */
120: #define MAX_SESSIONS 10
121: Session sessions[MAX_SESSIONS];
122:
1.28 millert 123: #ifdef HAVE_LOGIN_CAP
124: static login_cap_t *lc;
125: #endif
126:
1.65 markus 127: void
128: do_authenticated(Authctxt *authctxt)
129: {
130: /*
131: * Cancel the alarm we set to limit the time taken for
132: * authentication.
133: */
134: alarm(0);
135: if (startup_pipe != -1) {
136: close(startup_pipe);
137: startup_pipe = -1;
138: }
139: #ifdef HAVE_LOGIN_CAP
140: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
141: error("unable to get login class");
142: return;
143: }
1.74 markus 144: #ifdef BSD_AUTH
145: if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
146: packet_disconnect("Approval failure for %s",
147: authctxt->pw->pw_name);
148: }
149: #endif
1.65 markus 150: #endif
151: /* setup the channel layer */
152: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
153: channel_permit_all_opens();
154:
155: if (compat20)
156: do_authenticated2(authctxt);
157: else
158: do_authenticated1(authctxt);
1.79 markus 159:
1.87 markus 160: /* remove agent socket */
1.79 markus 161: if (auth_get_socket_name())
1.80 markus 162: auth_sock_cleanup_proc(authctxt->pw);
1.96 dugsong 163: #ifdef KRB4
164: if (options.kerberos_ticket_cleanup)
165: krb4_cleanup_proc(authctxt);
166: #endif
167: #ifdef KRB5
168: if (options.kerberos_ticket_cleanup)
169: krb5_cleanup_proc(authctxt);
170: #endif
1.65 markus 171: }
172:
1.1 markus 173: /*
174: * Prepares for an interactive session. This is called after the user has
175: * been successfully authenticated. During this message exchange, pseudo
176: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
177: * are requested, etc.
178: */
1.94 itojun 179: static void
1.65 markus 180: do_authenticated1(Authctxt *authctxt)
1.1 markus 181: {
182: Session *s;
1.65 markus 183: char *command;
1.86 markus 184: int success, type, plen, screen_flag;
1.1 markus 185: int compression_level = 0, enable_compression_after_reply = 0;
1.45 markus 186: u_int proto_len, data_len, dlen;
1.1 markus 187:
1.61 markus 188: s = session_new();
1.96 dugsong 189: s->authctxt = authctxt;
1.65 markus 190: s->pw = authctxt->pw;
1.28 millert 191:
1.1 markus 192: /*
193: * We stay in this loop until the client requests to execute a shell
194: * or a command.
195: */
196: for (;;) {
1.65 markus 197: success = 0;
1.1 markus 198:
199: /* Get a packet from the client. */
200: type = packet_read(&plen);
201:
202: /* Process the packet. */
203: switch (type) {
204: case SSH_CMSG_REQUEST_COMPRESSION:
205: packet_integrity_check(plen, 4, type);
206: compression_level = packet_get_int();
207: if (compression_level < 1 || compression_level > 9) {
208: packet_send_debug("Received illegal compression level %d.",
209: compression_level);
210: break;
211: }
212: /* Enable compression after we have responded with SUCCESS. */
213: enable_compression_after_reply = 1;
214: success = 1;
215: break;
216:
217: case SSH_CMSG_REQUEST_PTY:
1.86 markus 218: success = session_pty_req(s);
1.1 markus 219: break;
220:
221: case SSH_CMSG_X11_REQUEST_FORWARDING:
222: s->auth_proto = packet_get_string(&proto_len);
223: s->auth_data = packet_get_string(&data_len);
224:
1.57 markus 225: screen_flag = packet_get_protocol_flags() &
226: SSH_PROTOFLAG_SCREEN_NUMBER;
227: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
228:
229: if (packet_remaining() == 4) {
230: if (!screen_flag)
231: debug2("Buggy client: "
232: "X11 screen flag missing");
1.1 markus 233: s->screen = packet_get_int();
1.56 markus 234: } else {
1.1 markus 235: s->screen = 0;
1.56 markus 236: }
1.81 markus 237: packet_done();
238: success = session_setup_x11fwd(s);
239: if (!success) {
240: xfree(s->auth_proto);
241: xfree(s->auth_data);
1.84 markus 242: s->auth_proto = NULL;
243: s->auth_data = NULL;
1.1 markus 244: }
245: break;
246:
247: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
248: if (no_agent_forwarding_flag || compat13) {
249: debug("Authentication agent forwarding not permitted for this authentication.");
250: break;
251: }
252: debug("Received authentication agent forwarding request.");
1.65 markus 253: success = auth_input_request_forwarding(s->pw);
1.1 markus 254: break;
255:
256: case SSH_CMSG_PORT_FORWARD_REQUEST:
257: if (no_port_forwarding_flag) {
258: debug("Port forwarding not permitted for this authentication.");
1.39 markus 259: break;
260: }
261: if (!options.allow_tcp_forwarding) {
262: debug("Port forwarding not permitted.");
1.1 markus 263: break;
264: }
265: debug("Received TCP/IP port forwarding request.");
1.65 markus 266: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 267: success = 1;
268: break;
269:
270: case SSH_CMSG_MAX_PACKET_SIZE:
271: if (packet_set_maxsize(packet_get_int()) > 0)
272: success = 1;
273: break;
1.96 dugsong 274:
275: #if defined(AFS) || defined(KRB5)
276: case SSH_CMSG_HAVE_KERBEROS_TGT:
277: if (!options.kerberos_tgt_passing) {
278: verbose("Kerberos TGT passing disabled.");
279: } else {
280: char *kdata = packet_get_string(&dlen);
281: packet_integrity_check(plen, 4 + dlen, type);
282:
283: /* XXX - 0x41, see creds_to_radix version */
284: if (kdata[0] != 0x41) {
285: #ifdef KRB5
286: krb5_data tgt;
287: tgt.data = kdata;
288: tgt.length = dlen;
289:
290: if (auth_krb5_tgt(s->authctxt, &tgt))
291: success = 1;
292: else
293: verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
294: #endif /* KRB5 */
295: } else {
296: #ifdef AFS
297: if (auth_krb4_tgt(s->authctxt, kdata))
298: success = 1;
299: else
300: verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
301: #endif /* AFS */
302: }
303: xfree(kdata);
304: }
305: break;
306: #endif /* AFS || KRB5 */
307:
308: #ifdef AFS
309: case SSH_CMSG_HAVE_AFS_TOKEN:
310: if (!options.afs_token_passing || !k_hasafs()) {
311: verbose("AFS token passing disabled.");
312: } else {
313: /* Accept AFS token. */
314: char *token = packet_get_string(&dlen);
315: packet_integrity_check(plen, 4 + dlen, type);
316:
317: if (auth_afs_token(s->authctxt, token))
318: success = 1;
319: else
320: verbose("AFS token refused for %.100s",
321: s->authctxt->user);
322: xfree(token);
323: }
324: break;
325: #endif /* AFS */
1.1 markus 326:
327: case SSH_CMSG_EXEC_SHELL:
328: case SSH_CMSG_EXEC_CMD:
329: if (type == SSH_CMSG_EXEC_CMD) {
330: command = packet_get_string(&dlen);
331: debug("Exec command '%.500s'", command);
1.92 markus 332: do_exec(s, command);
333: xfree(command);
1.1 markus 334: } else {
1.92 markus 335: do_exec(s, NULL);
1.1 markus 336: }
1.92 markus 337: packet_done();
1.82 markus 338: session_close(s);
1.1 markus 339: return;
340:
341: default:
342: /*
343: * Any unknown messages in this phase are ignored,
344: * and a failure message is returned.
345: */
346: log("Unknown packet type received after authentication: %d", type);
347: }
348: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
349: packet_send();
350: packet_write_wait();
351:
352: /* Enable compression now that we have replied if appropriate. */
353: if (enable_compression_after_reply) {
354: enable_compression_after_reply = 0;
355: packet_start_compression(compression_level);
356: }
357: }
358: }
359:
360: /*
361: * This is called to fork and execute a command when we have no tty. This
362: * will call do_child from the child, and server_loop from the parent after
363: * setting up file descriptors and such.
364: */
1.4 markus 365: void
1.63 markus 366: do_exec_no_pty(Session *s, const char *command)
1.1 markus 367: {
368: int pid;
369:
370: #ifdef USE_PIPES
371: int pin[2], pout[2], perr[2];
372: /* Allocate pipes for communicating with the program. */
373: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
374: packet_disconnect("Could not create pipes: %.100s",
375: strerror(errno));
376: #else /* USE_PIPES */
377: int inout[2], err[2];
378: /* Uses socket pairs to communicate with the program. */
379: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
380: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
381: packet_disconnect("Could not create socket pairs: %.100s",
382: strerror(errno));
383: #endif /* USE_PIPES */
384: if (s == NULL)
385: fatal("do_exec_no_pty: no session");
386:
1.9 markus 387: session_proctitle(s);
1.1 markus 388:
389: /* Fork the child. */
390: if ((pid = fork()) == 0) {
391: /* Child. Reinitialize the log since the pid has changed. */
392: log_init(__progname, options.log_level, options.log_facility, log_stderr);
393:
394: /*
395: * Create a new session and process group since the 4.4BSD
396: * setlogin() affects the entire process group.
397: */
398: if (setsid() < 0)
399: error("setsid failed: %.100s", strerror(errno));
400:
401: #ifdef USE_PIPES
402: /*
403: * Redirect stdin. We close the parent side of the socket
404: * pair, and make the child side the standard input.
405: */
406: close(pin[1]);
407: if (dup2(pin[0], 0) < 0)
408: perror("dup2 stdin");
409: close(pin[0]);
410:
411: /* Redirect stdout. */
412: close(pout[0]);
413: if (dup2(pout[1], 1) < 0)
414: perror("dup2 stdout");
415: close(pout[1]);
416:
417: /* Redirect stderr. */
418: close(perr[0]);
419: if (dup2(perr[1], 2) < 0)
420: perror("dup2 stderr");
421: close(perr[1]);
422: #else /* USE_PIPES */
423: /*
424: * Redirect stdin, stdout, and stderr. Stdin and stdout will
425: * use the same socket, as some programs (particularly rdist)
426: * seem to depend on it.
427: */
428: close(inout[1]);
429: close(err[1]);
430: if (dup2(inout[0], 0) < 0) /* stdin */
431: perror("dup2 stdin");
432: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
433: perror("dup2 stdout");
434: if (dup2(err[0], 2) < 0) /* stderr */
435: perror("dup2 stderr");
436: #endif /* USE_PIPES */
437:
438: /* Do processing for the child (exec command etc). */
1.60 markus 439: do_child(s, command);
1.1 markus 440: /* NOTREACHED */
441: }
442: if (pid < 0)
443: packet_disconnect("fork failed: %.100s", strerror(errno));
444: s->pid = pid;
1.47 markus 445: /* Set interactive/non-interactive mode. */
1.48 markus 446: packet_set_interactive(s->display != NULL);
1.1 markus 447: #ifdef USE_PIPES
448: /* We are the parent. Close the child sides of the pipes. */
449: close(pin[0]);
450: close(pout[1]);
451: close(perr[1]);
452:
1.2 markus 453: if (compat20) {
1.64 markus 454: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 455: } else {
456: /* Enter the interactive session. */
457: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 458: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 459: }
1.1 markus 460: #else /* USE_PIPES */
461: /* We are the parent. Close the child sides of the socket pairs. */
462: close(inout[0]);
463: close(err[0]);
464:
465: /*
466: * Enter the interactive session. Note: server_loop must be able to
467: * handle the case that fdin and fdout are the same.
468: */
1.2 markus 469: if (compat20) {
1.64 markus 470: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 471: } else {
472: server_loop(pid, inout[1], inout[1], err[1]);
473: /* server_loop has closed inout[1] and err[1]. */
474: }
1.1 markus 475: #endif /* USE_PIPES */
476: }
477:
478: /*
479: * This is called to fork and execute a command when we have a tty. This
480: * will call do_child from the child, and server_loop from the parent after
481: * setting up file descriptors, controlling tty, updating wtmp, utmp,
482: * lastlog, and other such operations.
483: */
1.4 markus 484: void
1.63 markus 485: do_exec_pty(Session *s, const char *command)
1.1 markus 486: {
487: int fdout, ptyfd, ttyfd, ptymaster;
488: pid_t pid;
489:
490: if (s == NULL)
491: fatal("do_exec_pty: no session");
492: ptyfd = s->ptyfd;
493: ttyfd = s->ttyfd;
494:
495: /* Fork the child. */
496: if ((pid = fork()) == 0) {
1.97 markus 497:
1.24 markus 498: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 499: log_init(__progname, options.log_level, options.log_facility, log_stderr);
500: /* Close the master side of the pseudo tty. */
501: close(ptyfd);
502:
503: /* Make the pseudo tty our controlling tty. */
504: pty_make_controlling_tty(&ttyfd, s->tty);
505:
1.103 markus 506: /* Redirect stdin/stdout/stderr from the pseudo tty. */
507: if (dup2(ttyfd, 0) < 0)
508: error("dup2 stdin: %s", strerror(errno));
509: if (dup2(ttyfd, 1) < 0)
510: error("dup2 stdout: %s", strerror(errno));
511: if (dup2(ttyfd, 2) < 0)
512: error("dup2 stderr: %s", strerror(errno));
1.1 markus 513:
514: /* Close the extra descriptor for the pseudo tty. */
515: close(ttyfd);
516:
1.24 markus 517: /* record login, etc. similar to login(1) */
1.41 markus 518: if (!(options.use_login && command == NULL))
519: do_login(s, command);
1.1 markus 520:
521: /* Do common processing for the child, such as execing the command. */
1.60 markus 522: do_child(s, command);
1.1 markus 523: /* NOTREACHED */
524: }
525: if (pid < 0)
526: packet_disconnect("fork failed: %.100s", strerror(errno));
527: s->pid = pid;
528:
529: /* Parent. Close the slave side of the pseudo tty. */
530: close(ttyfd);
531:
532: /*
533: * Create another descriptor of the pty master side for use as the
534: * standard input. We could use the original descriptor, but this
535: * simplifies code in server_loop. The descriptor is bidirectional.
536: */
537: fdout = dup(ptyfd);
538: if (fdout < 0)
539: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
540:
541: /* we keep a reference to the pty master */
542: ptymaster = dup(ptyfd);
543: if (ptymaster < 0)
544: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
545: s->ptymaster = ptymaster;
546:
547: /* Enter interactive session. */
1.47 markus 548: packet_set_interactive(1);
1.2 markus 549: if (compat20) {
550: session_set_fds(s, ptyfd, fdout, -1);
551: } else {
552: server_loop(pid, ptyfd, fdout, -1);
553: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 554: }
555: }
556:
1.90 markus 557: /*
558: * This is called to fork and execute a command. If another command is
559: * to be forced, execute that instead.
560: */
561: void
562: do_exec(Session *s, const char *command)
563: {
564: if (forced_command) {
565: original_command = command;
566: command = forced_command;
567: debug("Forced command '%.900s'", command);
568: }
569:
570: if (s->ttyfd != -1)
571: do_exec_pty(s, command);
572: else
573: do_exec_no_pty(s, command);
574:
1.92 markus 575: original_command = NULL;
1.90 markus 576: }
577:
578:
1.24 markus 579: /* administrative, login(1)-like work */
580: void
1.41 markus 581: do_login(Session *s, const char *command)
1.24 markus 582: {
583: char *time_string;
1.35 markus 584: char hostname[MAXHOSTNAMELEN];
1.24 markus 585: socklen_t fromlen;
586: struct sockaddr_storage from;
587: time_t last_login_time;
588: struct passwd * pw = s->pw;
589: pid_t pid = getpid();
590:
591: /*
592: * Get IP address of client. If the connection is not a socket, let
593: * the address be 0.0.0.0.
594: */
595: memset(&from, 0, sizeof(from));
596: if (packet_connection_is_on_socket()) {
597: fromlen = sizeof(from);
598: if (getpeername(packet_get_connection_in(),
599: (struct sockaddr *) & from, &fromlen) < 0) {
600: debug("getpeername: %.100s", strerror(errno));
601: fatal_cleanup();
602: }
603: }
1.25 markus 604:
1.35 markus 605: /* Get the time and hostname when the user last logged in. */
1.69 stevesk 606: if (options.print_lastlog) {
607: hostname[0] = '\0';
608: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
609: hostname, sizeof(hostname));
610: }
1.35 markus 611:
1.24 markus 612: /* Record that there was a login on that tty from the remote host. */
613: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.70 stevesk 614: get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
615: (struct sockaddr *)&from);
1.24 markus 616:
1.73 djm 617: if (check_quietlogin(s, command))
1.24 markus 618: return;
1.73 djm 619:
1.69 stevesk 620: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 621: time_string = ctime(&last_login_time);
622: if (strchr(time_string, '\n'))
623: *strchr(time_string, '\n') = 0;
1.40 markus 624: if (strcmp(hostname, "") == 0)
1.24 markus 625: printf("Last login: %s\r\n", time_string);
626: else
1.36 markus 627: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 628: }
1.73 djm 629:
630: do_motd();
631: }
632:
633: /*
634: * Display the message of the day.
635: */
636: void
637: do_motd(void)
638: {
639: FILE *f;
640: char buf[256];
641:
1.24 markus 642: if (options.print_motd) {
1.28 millert 643: #ifdef HAVE_LOGIN_CAP
644: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
645: "/etc/motd"), "r");
646: #else
1.24 markus 647: f = fopen("/etc/motd", "r");
1.28 millert 648: #endif
1.24 markus 649: if (f) {
650: while (fgets(buf, sizeof(buf), f))
651: fputs(buf, stdout);
652: fclose(f);
653: }
1.2 markus 654: }
1.73 djm 655: }
656:
657:
658: /*
659: * Check for quiet login, either .hushlogin or command given.
660: */
661: int
662: check_quietlogin(Session *s, const char *command)
663: {
664: char buf[256];
1.96 dugsong 665: struct passwd *pw = s->pw;
1.73 djm 666: struct stat st;
667:
668: /* Return 1 if .hushlogin exists or a command given. */
669: if (command != NULL)
670: return 1;
671: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
672: #ifdef HAVE_LOGIN_CAP
673: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
674: return 1;
675: #else
676: if (stat(buf, &st) >= 0)
677: return 1;
678: #endif
679: return 0;
1.1 markus 680: }
681:
682: /*
683: * Sets the value of the given variable in the environment. If the variable
684: * already exists, its value is overriden.
685: */
1.94 itojun 686: static void
1.45 markus 687: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 688: const char *value)
689: {
1.45 markus 690: u_int i, namelen;
1.1 markus 691: char **env;
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. */
708: if (i >= (*envsizep) - 1) {
709: (*envsizep) += 50;
710: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
711: }
712: /* Need to set the NULL pointer at end of array beyond the new slot. */
713: env[i + 1] = NULL;
714: }
715:
716: /* Allocate space and format the variable in the appropriate slot. */
717: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
718: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
719: }
720:
721: /*
722: * Reads environment variables from the given file and adds/overrides them
723: * into the environment. If the file does not exist, this does nothing.
724: * Otherwise, it must consist of empty lines, comments (line starts with '#')
725: * and assignments of the form name=value. No other forms are allowed.
726: */
1.94 itojun 727: static void
1.45 markus 728: read_environment_file(char ***env, u_int *envsize,
1.1 markus 729: const char *filename)
730: {
731: FILE *f;
732: char buf[4096];
733: char *cp, *value;
734:
735: f = fopen(filename, "r");
736: if (!f)
737: return;
738:
739: while (fgets(buf, sizeof(buf), f)) {
740: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
741: ;
742: if (!*cp || *cp == '#' || *cp == '\n')
743: continue;
744: if (strchr(cp, '\n'))
745: *strchr(cp, '\n') = '\0';
746: value = strchr(cp, '=');
747: if (value == NULL) {
748: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
749: continue;
750: }
1.14 deraadt 751: /*
752: * Replace the equals sign by nul, and advance value to
753: * the value string.
754: */
1.1 markus 755: *value = '\0';
756: value++;
757: child_set_env(env, envsize, cp, value);
758: }
759: fclose(f);
760: }
761:
762: /*
763: * Performs common processing for the child, such as setting up the
764: * environment, closing extra file descriptors, setting the user and group
765: * ids, and executing the command or shell.
766: */
1.4 markus 767: void
1.60 markus 768: do_child(Session *s, const char *command)
1.1 markus 769: {
1.32 markus 770: const char *shell, *hostname = NULL, *cp = NULL;
1.96 dugsong 771: struct passwd *pw = s->pw;
1.1 markus 772: char buf[256];
1.16 markus 773: char cmd[1024];
1.27 millert 774: FILE *f = NULL;
1.45 markus 775: u_int envsize, i;
1.1 markus 776: char **env;
777: extern char **environ;
778: struct stat st;
779: char *argv[10];
1.84 markus 780: int do_xauth;
781:
782: do_xauth =
783: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 784:
1.74 markus 785: /* remove hostkey from the child's memory */
786: destroy_sensitive_data();
787:
1.17 markus 788: /* login(1) is only called if we execute the login shell */
789: if (options.use_login && command != NULL)
790: options.use_login = 0;
1.1 markus 791:
1.27 millert 792: if (!options.use_login) {
1.28 millert 793: #ifdef HAVE_LOGIN_CAP
794: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
795: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
796: _PATH_NOLOGIN), "r");
797: #else
1.27 millert 798: if (pw->pw_uid)
799: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 800: #endif
1.27 millert 801: if (f) {
802: /* /etc/nologin exists. Print its contents and exit. */
803: while (fgets(buf, sizeof(buf), f))
804: fputs(buf, stderr);
805: fclose(f);
1.1 markus 806: exit(254);
1.27 millert 807: }
1.1 markus 808: }
1.28 millert 809: /* Set login name, uid, gid, and groups. */
1.1 markus 810: /* Login(1) does this as well, and it needs uid 0 for the "-h"
811: switch, so we let login(1) to this for us. */
812: if (!options.use_login) {
813: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 814: #ifdef HAVE_LOGIN_CAP
815: if (setusercontext(lc, pw, pw->pw_uid,
816: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
817: perror("unable to set user context");
818: exit(1);
819: }
820: #else
821: if (setlogin(pw->pw_name) < 0)
822: error("setlogin failed: %s", strerror(errno));
1.1 markus 823: if (setgid(pw->pw_gid) < 0) {
824: perror("setgid");
825: exit(1);
826: }
827: /* Initialize the group list. */
828: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
829: perror("initgroups");
830: exit(1);
831: }
832: endgrent();
833:
834: /* Permanently switch to the desired uid. */
1.71 markus 835: permanently_set_uid(pw);
1.28 millert 836: #endif
1.1 markus 837: }
838: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 839: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 840: }
841: /*
842: * Get the shell from the password data. An empty shell field is
843: * legal, and means /bin/sh.
844: */
845: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 846: #ifdef HAVE_LOGIN_CAP
847: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
848: #endif
1.1 markus 849:
850: /* Initialize the environment. */
851: envsize = 100;
852: env = xmalloc(envsize * sizeof(char *));
853: env[0] = NULL;
854:
855: if (!options.use_login) {
856: /* Set basic environment. */
857: child_set_env(&env, &envsize, "USER", pw->pw_name);
858: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
859: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 860: #ifdef HAVE_LOGIN_CAP
1.29 millert 861: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
862: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 863: #else
1.29 millert 864: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 865: #endif
1.1 markus 866:
867: snprintf(buf, sizeof buf, "%.200s/%.50s",
868: _PATH_MAILDIR, pw->pw_name);
869: child_set_env(&env, &envsize, "MAIL", buf);
870:
871: /* Normal systems set SHELL by default. */
872: child_set_env(&env, &envsize, "SHELL", shell);
873: }
874: if (getenv("TZ"))
875: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
876:
877: /* Set custom environment options from RSA authentication. */
878: while (custom_environment) {
879: struct envstring *ce = custom_environment;
880: char *s = ce->s;
881: int i;
882: for (i = 0; s[i] != '=' && s[i]; i++);
883: if (s[i] == '=') {
884: s[i] = 0;
885: child_set_env(&env, &envsize, s, s + i + 1);
886: }
887: custom_environment = ce->next;
888: xfree(ce->s);
889: xfree(ce);
890: }
891:
892: snprintf(buf, sizeof buf, "%.50s %d %d",
893: get_remote_ipaddr(), get_remote_port(), get_local_port());
894: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
895:
1.60 markus 896: if (s->ttyfd != -1)
897: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
898: if (s->term)
899: child_set_env(&env, &envsize, "TERM", s->term);
900: if (s->display)
901: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 902: if (original_command)
903: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
904: original_command);
1.1 markus 905: #ifdef KRB4
1.96 dugsong 906: if (s->authctxt->krb4_ticket_file)
907: child_set_env(&env, &envsize, "KRBTKFILE",
908: s->authctxt->krb4_ticket_file);
909: #endif
910: #ifdef KRB5
911: if (s->authctxt->krb5_ticket_file)
912: child_set_env(&env, &envsize, "KRB5CCNAME",
913: s->authctxt->krb5_ticket_file);
914: #endif
1.1 markus 915: if (auth_get_socket_name() != NULL)
916: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
917: auth_get_socket_name());
918:
919: /* read $HOME/.ssh/environment. */
920: if (!options.use_login) {
1.14 deraadt 921: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
922: pw->pw_dir);
1.1 markus 923: read_environment_file(&env, &envsize, buf);
924: }
925: if (debug_flag) {
926: /* dump the environment */
927: fprintf(stderr, "Environment:\n");
928: for (i = 0; env[i]; i++)
929: fprintf(stderr, " %.200s\n", env[i]);
930: }
1.26 millert 931: /* we have to stash the hostname before we close our socket. */
932: if (options.use_login)
1.70 stevesk 933: hostname = get_remote_name_or_ip(utmp_len,
934: options.reverse_mapping_check);
1.1 markus 935: /*
936: * Close the connection descriptors; note that this is the child, and
937: * the server will still have the socket open, and it is important
938: * that we do not shutdown it. Note that the descriptors cannot be
939: * closed before building the environment, as we call
940: * get_remote_ipaddr there.
941: */
942: if (packet_get_connection_in() == packet_get_connection_out())
943: close(packet_get_connection_in());
944: else {
945: close(packet_get_connection_in());
946: close(packet_get_connection_out());
947: }
948: /*
949: * Close all descriptors related to channels. They will still remain
950: * open in the parent.
951: */
952: /* XXX better use close-on-exec? -markus */
953: channel_close_all();
954:
955: /*
956: * Close any extra file descriptors. Note that there may still be
957: * descriptors left by system functions. They will be closed later.
958: */
959: endpwent();
960:
961: /*
962: * Close any extra open file descriptors so that we don\'t have them
963: * hanging around in clients. Note that we want to do this after
964: * initgroups, because at least on Solaris 2.3 it leaves file
965: * descriptors open.
966: */
967: for (i = 3; i < 64; i++)
968: close(i);
969:
970: /*
971: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
972: * xauth are run in the proper environment.
973: */
974: environ = env;
1.102 markus 975:
976: #ifdef AFS
977: /* Try to get AFS tokens for the local cell. */
978: if (k_hasafs()) {
979: char cell[64];
980:
981: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
982: krb_afslog(cell, 0);
983:
984: krb_afslog(0, 0);
985: }
986: #endif /* AFS */
1.104 markus 987:
988: /* Change current directory to the user\'s home directory. */
989: if (chdir(pw->pw_dir) < 0) {
990: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
991: pw->pw_dir, strerror(errno));
992: #ifdef HAVE_LOGIN_CAP
993: if (login_getcapbool(lc, "requirehome", 0))
994: exit(1);
995: #endif
996: }
1.1 markus 997:
998: /*
999: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1000: * in this order).
1001: */
1002: if (!options.use_login) {
1.74 markus 1003: /* ignore _PATH_SSH_USER_RC for subsystems */
1004: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.75 markus 1005: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1006: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 1007: if (debug_flag)
1.75 markus 1008: fprintf(stderr, "Running %s\n", cmd);
1009: f = popen(cmd, "w");
1.1 markus 1010: if (f) {
1.60 markus 1011: if (do_xauth)
1012: fprintf(f, "%s %s\n", s->auth_proto,
1013: s->auth_data);
1.1 markus 1014: pclose(f);
1015: } else
1.60 markus 1016: fprintf(stderr, "Could not run %s\n",
1017: _PATH_SSH_USER_RC);
1.50 markus 1018: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1019: if (debug_flag)
1.60 markus 1020: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1021: _PATH_SSH_SYSTEM_RC);
1.50 markus 1022: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1023: if (f) {
1.60 markus 1024: if (do_xauth)
1025: fprintf(f, "%s %s\n", s->auth_proto,
1026: s->auth_data);
1.1 markus 1027: pclose(f);
1028: } else
1.60 markus 1029: fprintf(stderr, "Could not run %s\n",
1030: _PATH_SSH_SYSTEM_RC);
1031: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 1032: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 1033: char *screen = strchr(s->display, ':');
1034:
1035: if (debug_flag) {
1036: fprintf(stderr,
1037: "Running %.100s add "
1038: "%.100s %.100s %.100s\n",
1039: options.xauth_location, s->display,
1040: s->auth_proto, s->auth_data);
1041: if (screen != NULL)
1.14 deraadt 1042: fprintf(stderr,
1.60 markus 1043: "Adding %.*s/unix%s %s %s\n",
1044: (int)(screen - s->display),
1045: s->display, screen,
1046: s->auth_proto, s->auth_data);
1047: }
1048: snprintf(cmd, sizeof cmd, "%s -q -",
1049: options.xauth_location);
1050: f = popen(cmd, "w");
1051: if (f) {
1052: fprintf(f, "add %s %s %s\n", s->display,
1053: s->auth_proto, s->auth_data);
1054: if (screen != NULL)
1055: fprintf(f, "add %.*s/unix%s %s %s\n",
1056: (int)(screen - s->display),
1057: s->display, screen,
1058: s->auth_proto,
1059: s->auth_data);
1060: pclose(f);
1061: } else {
1062: fprintf(stderr, "Could not run %s\n",
1063: cmd);
1.1 markus 1064: }
1065: }
1066: /* Get the last component of the shell name. */
1067: cp = strrchr(shell, '/');
1068: if (cp)
1069: cp++;
1070: else
1071: cp = shell;
1072: }
1.67 markus 1073:
1074: /* restore SIGPIPE for child */
1075: signal(SIGPIPE, SIG_DFL);
1076:
1.1 markus 1077: /*
1078: * If we have no command, execute the shell. In this case, the shell
1079: * name to be passed in argv[0] is preceded by '-' to indicate that
1080: * this is a login shell.
1081: */
1082: if (!command) {
1083: if (!options.use_login) {
1084: char buf[256];
1085:
1086: /* Start the shell. Set initial character to '-'. */
1087: buf[0] = '-';
1088: strncpy(buf + 1, cp, sizeof(buf) - 1);
1089: buf[sizeof(buf) - 1] = 0;
1090:
1091: /* Execute the shell. */
1092: argv[0] = buf;
1093: argv[1] = NULL;
1094: execve(shell, argv, env);
1095:
1096: /* Executing the shell failed. */
1097: perror(shell);
1098: exit(1);
1099:
1100: } else {
1101: /* Launch login(1). */
1102:
1.26 millert 1103: execl("/usr/bin/login", "login", "-h", hostname,
1.99 deraadt 1104: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1.1 markus 1105:
1106: /* Login couldn't be executed, die. */
1107:
1108: perror("login");
1109: exit(1);
1110: }
1111: }
1112: /*
1113: * Execute the command using the user's shell. This uses the -c
1114: * option to execute the command.
1115: */
1116: argv[0] = (char *) cp;
1117: argv[1] = "-c";
1118: argv[2] = (char *) command;
1119: argv[3] = NULL;
1120: execve(shell, argv, env);
1121: perror(shell);
1122: exit(1);
1123: }
1124:
1125: Session *
1126: session_new(void)
1127: {
1128: int i;
1129: static int did_init = 0;
1130: if (!did_init) {
1131: debug("session_new: init");
1132: for(i = 0; i < MAX_SESSIONS; i++) {
1133: sessions[i].used = 0;
1134: }
1135: did_init = 1;
1136: }
1137: for(i = 0; i < MAX_SESSIONS; i++) {
1138: Session *s = &sessions[i];
1139: if (! s->used) {
1.68 djm 1140: memset(s, 0, sizeof(*s));
1.1 markus 1141: s->chanid = -1;
1142: s->ptyfd = -1;
1143: s->ttyfd = -1;
1144: s->used = 1;
1.85 markus 1145: s->self = i;
1.1 markus 1146: debug("session_new: session %d", i);
1147: return s;
1148: }
1149: }
1150: return NULL;
1151: }
1152:
1.94 itojun 1153: static void
1.1 markus 1154: session_dump(void)
1155: {
1156: int i;
1157: for(i = 0; i < MAX_SESSIONS; i++) {
1158: Session *s = &sessions[i];
1159: debug("dump: used %d session %d %p channel %d pid %d",
1160: s->used,
1161: s->self,
1162: s,
1163: s->chanid,
1164: s->pid);
1165: }
1166: }
1167:
1.2 markus 1168: int
1.97 markus 1169: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1170: {
1171: Session *s = session_new();
1172: debug("session_open: channel %d", chanid);
1173: if (s == NULL) {
1174: error("no more sessions");
1175: return 0;
1176: }
1.97 markus 1177: s->authctxt = authctxt;
1178: s->pw = authctxt->pw;
1.7 markus 1179: if (s->pw == NULL)
1.54 stevesk 1180: fatal("no user for session %d", s->self);
1.2 markus 1181: debug("session_open: session %d: link with channel %d", s->self, chanid);
1182: s->chanid = chanid;
1183: return 1;
1184: }
1185:
1.94 itojun 1186: static Session *
1.2 markus 1187: session_by_channel(int id)
1188: {
1189: int i;
1190: for(i = 0; i < MAX_SESSIONS; i++) {
1191: Session *s = &sessions[i];
1192: if (s->used && s->chanid == id) {
1193: debug("session_by_channel: session %d channel %d", i, id);
1194: return s;
1195: }
1196: }
1197: debug("session_by_channel: unknown channel %d", id);
1198: session_dump();
1199: return NULL;
1200: }
1201:
1.94 itojun 1202: static Session *
1.2 markus 1203: session_by_pid(pid_t pid)
1204: {
1205: int i;
1206: debug("session_by_pid: pid %d", pid);
1207: for(i = 0; i < MAX_SESSIONS; i++) {
1208: Session *s = &sessions[i];
1209: if (s->used && s->pid == pid)
1210: return s;
1211: }
1212: error("session_by_pid: unknown pid %d", pid);
1213: session_dump();
1214: return NULL;
1215: }
1216:
1.94 itojun 1217: static int
1.2 markus 1218: session_window_change_req(Session *s)
1219: {
1220: s->col = packet_get_int();
1221: s->row = packet_get_int();
1222: s->xpixel = packet_get_int();
1223: s->ypixel = packet_get_int();
1.3 markus 1224: packet_done();
1.2 markus 1225: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1226: return 1;
1227: }
1228:
1.94 itojun 1229: static int
1.2 markus 1230: session_pty_req(Session *s)
1231: {
1.45 markus 1232: u_int len;
1.72 stevesk 1233: int n_bytes;
1.2 markus 1234:
1.86 markus 1235: if (no_pty_flag) {
1236: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1237: return 0;
1.86 markus 1238: }
1239: if (s->ttyfd != -1) {
1240: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1241: return 0;
1.86 markus 1242: }
1243:
1.2 markus 1244: s->term = packet_get_string(&len);
1.86 markus 1245:
1246: if (compat20) {
1247: s->col = packet_get_int();
1248: s->row = packet_get_int();
1249: } else {
1250: s->row = packet_get_int();
1251: s->col = packet_get_int();
1252: }
1.2 markus 1253: s->xpixel = packet_get_int();
1254: s->ypixel = packet_get_int();
1255:
1256: if (strcmp(s->term, "") == 0) {
1257: xfree(s->term);
1258: s->term = NULL;
1259: }
1.86 markus 1260:
1.2 markus 1261: /* Allocate a pty and open it. */
1.86 markus 1262: debug("Allocating pty.");
1.2 markus 1263: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.86 markus 1264: if (s->term)
1265: xfree(s->term);
1.2 markus 1266: s->term = NULL;
1267: s->ptyfd = -1;
1268: s->ttyfd = -1;
1269: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1270: return 0;
1.2 markus 1271: }
1272: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1273:
1274: /* for SSH1 the tty modes length is not given */
1275: if (!compat20)
1276: n_bytes = packet_remaining();
1277: tty_parse_modes(s->ttyfd, &n_bytes);
1278:
1.2 markus 1279: /*
1280: * Add a cleanup function to clear the utmp entry and record logout
1281: * time in case we call fatal() (e.g., the connection gets closed).
1282: */
1.85 markus 1283: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1284: pty_setowner(s->pw, s->tty);
1.86 markus 1285:
1286: /* Set window size from the packet. */
1.2 markus 1287: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1288:
1.72 stevesk 1289: packet_done();
1.9 markus 1290: session_proctitle(s);
1.2 markus 1291: return 1;
1292: }
1293:
1.94 itojun 1294: static int
1.7 markus 1295: session_subsystem_req(Session *s)
1296: {
1.105 ! markus 1297: struct stat st;
1.45 markus 1298: u_int len;
1.7 markus 1299: int success = 0;
1.105 ! markus 1300: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1301: int i;
1.7 markus 1302:
1303: packet_done();
1304: log("subsystem request for %s", subsys);
1.18 jakob 1305:
1306: for (i = 0; i < options.num_subsystems; i++) {
1.105 ! markus 1307: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
! 1308: cmd = options.subsystem_command[i];
! 1309: if (stat(cmd, &st) < 0) {
! 1310: error("subsystem: cannot stat %s: %s", cmd,
! 1311: strerror(errno));
! 1312: break;
! 1313: }
! 1314: debug("subsystem: exec() %s", cmd);
1.64 markus 1315: s->is_subsystem = 1;
1.105 ! markus 1316: do_exec(s, cmd);
1.18 jakob 1317: success = 1;
1318: }
1319: }
1320:
1321: if (!success)
1.105 ! markus 1322: log("subsystem request for %s failed, subsystem not found",
! 1323: subsys);
1.7 markus 1324:
1325: xfree(subsys);
1326: return success;
1327: }
1328:
1.94 itojun 1329: static int
1.7 markus 1330: session_x11_req(Session *s)
1331: {
1.81 markus 1332: int success;
1.7 markus 1333:
1334: s->single_connection = packet_get_char();
1335: s->auth_proto = packet_get_string(NULL);
1336: s->auth_data = packet_get_string(NULL);
1337: s->screen = packet_get_int();
1338: packet_done();
1339:
1.81 markus 1340: success = session_setup_x11fwd(s);
1341: if (!success) {
1.7 markus 1342: xfree(s->auth_proto);
1343: xfree(s->auth_data);
1.84 markus 1344: s->auth_proto = NULL;
1345: s->auth_data = NULL;
1.7 markus 1346: }
1.81 markus 1347: return success;
1.7 markus 1348: }
1349:
1.94 itojun 1350: static int
1.19 markus 1351: session_shell_req(Session *s)
1352: {
1353: packet_done();
1.90 markus 1354: do_exec(s, NULL);
1.19 markus 1355: return 1;
1356: }
1357:
1.94 itojun 1358: static int
1.19 markus 1359: session_exec_req(Session *s)
1360: {
1.45 markus 1361: u_int len;
1.19 markus 1362: char *command = packet_get_string(&len);
1363: packet_done();
1.90 markus 1364: do_exec(s, command);
1.92 markus 1365: xfree(command);
1.19 markus 1366: return 1;
1367: }
1368:
1.94 itojun 1369: static int
1.43 markus 1370: session_auth_agent_req(Session *s)
1371: {
1372: static int called = 0;
1373: packet_done();
1.44 markus 1374: if (no_agent_forwarding_flag) {
1375: debug("session_auth_agent_req: no_agent_forwarding_flag");
1376: return 0;
1377: }
1.43 markus 1378: if (called) {
1379: return 0;
1380: } else {
1381: called = 1;
1382: return auth_input_request_forwarding(s->pw);
1383: }
1384: }
1385:
1.2 markus 1386: void
1387: session_input_channel_req(int id, void *arg)
1388: {
1.45 markus 1389: u_int len;
1.2 markus 1390: int reply;
1391: int success = 0;
1392: char *rtype;
1393: Session *s;
1394: Channel *c;
1395:
1396: rtype = packet_get_string(&len);
1397: reply = packet_get_char();
1398:
1399: s = session_by_channel(id);
1400: if (s == NULL)
1401: fatal("session_input_channel_req: channel %d: no session", id);
1402: c = channel_lookup(id);
1403: if (c == NULL)
1404: fatal("session_input_channel_req: channel %d: bad channel", id);
1405:
1406: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1407: s->self, id, rtype, reply);
1408:
1409: /*
1.64 markus 1410: * a session is in LARVAL state until a shell, a command
1411: * or a subsystem is executed
1.2 markus 1412: */
1413: if (c->type == SSH_CHANNEL_LARVAL) {
1414: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1415: success = session_shell_req(s);
1.2 markus 1416: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1417: success = session_exec_req(s);
1.2 markus 1418: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1419: success = session_pty_req(s);
1.7 markus 1420: } else if (strcmp(rtype, "x11-req") == 0) {
1421: success = session_x11_req(s);
1.43 markus 1422: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1423: success = session_auth_agent_req(s);
1.7 markus 1424: } else if (strcmp(rtype, "subsystem") == 0) {
1425: success = session_subsystem_req(s);
1.2 markus 1426: }
1427: }
1428: if (strcmp(rtype, "window-change") == 0) {
1429: success = session_window_change_req(s);
1430: }
1431:
1432: if (reply) {
1433: packet_start(success ?
1434: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1435: packet_put_int(c->remote_id);
1436: packet_send();
1437: }
1438: xfree(rtype);
1439: }
1440:
1441: void
1442: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1443: {
1444: if (!compat20)
1445: fatal("session_set_fds: called for proto != 2.0");
1446: /*
1447: * now that have a child and a pipe to the child,
1448: * we can activate our channel and register the fd's
1449: */
1450: if (s->chanid == -1)
1451: fatal("no channel for session %d", s->self);
1452: channel_set_fds(s->chanid,
1453: fdout, fdin, fderr,
1.42 markus 1454: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1455: 1);
1.2 markus 1456: }
1457:
1.85 markus 1458: /*
1459: * Function to perform pty cleanup. Also called if we get aborted abnormally
1460: * (e.g., due to a dropped connection).
1461: */
1.94 itojun 1462: static void
1.85 markus 1463: session_pty_cleanup(void *session)
1.1 markus 1464: {
1.85 markus 1465: Session *s = session;
1466:
1467: if (s == NULL) {
1468: error("session_pty_cleanup: no session");
1469: return;
1470: }
1471: if (s->ttyfd == -1)
1.1 markus 1472: return;
1473:
1.54 stevesk 1474: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1475:
1476: /* Record that the user has logged out. */
1.85 markus 1477: if (s->pid != 0)
1478: record_logout(s->pid, s->tty);
1.1 markus 1479:
1480: /* Release the pseudo-tty. */
1481: pty_release(s->tty);
1482:
1483: /*
1484: * Close the server side of the socket pairs. We must do this after
1485: * the pty cleanup, so that another process doesn't get this pty
1486: * while we're still cleaning up.
1487: */
1488: if (close(s->ptymaster) < 0)
1489: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1490: }
1491:
1.94 itojun 1492: static void
1.2 markus 1493: session_exit_message(Session *s, int status)
1494: {
1495: Channel *c;
1496: if (s == NULL)
1497: fatal("session_close: no session");
1498: c = channel_lookup(s->chanid);
1499: if (c == NULL)
1.85 markus 1500: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1501: s->self, s->chanid);
1502: debug("session_exit_message: session %d channel %d pid %d",
1503: s->self, s->chanid, s->pid);
1504:
1505: if (WIFEXITED(status)) {
1506: channel_request_start(s->chanid,
1507: "exit-status", 0);
1508: packet_put_int(WEXITSTATUS(status));
1509: packet_send();
1510: } else if (WIFSIGNALED(status)) {
1511: channel_request_start(s->chanid,
1512: "exit-signal", 0);
1513: packet_put_int(WTERMSIG(status));
1514: packet_put_char(WCOREDUMP(status));
1515: packet_put_cstring("");
1516: packet_put_cstring("");
1517: packet_send();
1518: } else {
1519: /* Some weird exit cause. Just exit. */
1520: packet_disconnect("wait returned status %04x.", status);
1521: }
1522:
1523: /* disconnect channel */
1524: debug("session_exit_message: release channel %d", s->chanid);
1525: channel_cancel_cleanup(s->chanid);
1.5 markus 1526: /*
1527: * emulate a write failure with 'chan_write_failed', nobody will be
1528: * interested in data we write.
1529: * Note that we must not call 'chan_read_failed', since there could
1530: * be some more data waiting in the pipe.
1531: */
1.8 markus 1532: if (c->ostate != CHAN_OUTPUT_CLOSED)
1533: chan_write_failed(c);
1.2 markus 1534: s->chanid = -1;
1535: }
1536:
1.94 itojun 1537: static void
1.85 markus 1538: session_close(Session *s)
1.2 markus 1539: {
1.85 markus 1540: debug("session_close: session %d pid %d", s->self, s->pid);
1541: if (s->ttyfd != -1) {
1542: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1543: session_pty_cleanup(s);
1544: }
1.2 markus 1545: if (s->term)
1546: xfree(s->term);
1547: if (s->display)
1548: xfree(s->display);
1549: if (s->auth_data)
1550: xfree(s->auth_data);
1551: if (s->auth_proto)
1552: xfree(s->auth_proto);
1553: s->used = 0;
1.9 markus 1554: session_proctitle(s);
1.2 markus 1555: }
1556:
1557: void
1558: session_close_by_pid(pid_t pid, int status)
1559: {
1560: Session *s = session_by_pid(pid);
1561: if (s == NULL) {
1.89 markus 1562: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1563: return;
1564: }
1565: if (s->chanid != -1)
1566: session_exit_message(s, status);
1567: session_close(s);
1.98 markus 1568: }
1569:
1570: int
1571: session_have_children(void)
1572: {
1573: int i;
1574:
1575: for(i = 0; i < MAX_SESSIONS; i++) {
1576: Session *s = &sessions[i];
1577: if (s->used && s->pid != -1) {
1578: debug("session_have_children: id %d pid %d", i, s->pid);
1579: return 1;
1580: }
1581: }
1582: debug("session_have_children: no more children");
1583: return 0;
1.2 markus 1584: }
1585:
1586: /*
1587: * this is called when a channel dies before
1588: * the session 'child' itself dies
1589: */
1590: void
1591: session_close_by_channel(int id, void *arg)
1592: {
1593: Session *s = session_by_channel(id);
1594: if (s == NULL) {
1595: debug("session_close_by_channel: no session for channel %d", id);
1596: return;
1597: }
1598: /* disconnect channel */
1599: channel_cancel_cleanup(s->chanid);
1600: s->chanid = -1;
1601:
1602: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1603: if (s->pid == 0) {
1604: /* close session immediately */
1605: session_close(s);
1606: } else {
1607: /* notify child, delay session cleanup */
1608: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1609: error("session_close_by_channel: kill %d: %s",
1610: s->pid, strerror(errno));
1611: }
1.9 markus 1612: }
1613:
1.94 itojun 1614: static char *
1.9 markus 1615: session_tty_list(void)
1616: {
1617: static char buf[1024];
1618: int i;
1619: buf[0] = '\0';
1620: for(i = 0; i < MAX_SESSIONS; i++) {
1621: Session *s = &sessions[i];
1622: if (s->used && s->ttyfd != -1) {
1623: if (buf[0] != '\0')
1624: strlcat(buf, ",", sizeof buf);
1625: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1626: }
1627: }
1628: if (buf[0] == '\0')
1629: strlcpy(buf, "notty", sizeof buf);
1630: return buf;
1631: }
1632:
1633: void
1634: session_proctitle(Session *s)
1635: {
1636: if (s->pw == NULL)
1637: error("no user for session %d", s->self);
1638: else
1639: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1640: }
1641:
1642: int
1643: session_setup_x11fwd(Session *s)
1644: {
1645: struct stat st;
1646:
1647: if (no_x11_forwarding_flag) {
1648: packet_send_debug("X11 forwarding disabled in user configuration file.");
1649: return 0;
1650: }
1651: if (!options.x11_forwarding) {
1652: debug("X11 forwarding disabled in server configuration file.");
1653: return 0;
1654: }
1655: if (!options.xauth_location ||
1656: (stat(options.xauth_location, &st) == -1)) {
1657: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1658: return 0;
1659: }
1660: if (options.use_login) {
1661: packet_send_debug("X11 forwarding disabled; "
1662: "not compatible with UseLogin=yes.");
1.81 markus 1663: return 0;
1664: }
1.87 markus 1665: if (s->display != NULL) {
1.81 markus 1666: debug("X11 display already set.");
1667: return 0;
1668: }
1669: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1670: if (s->display == NULL) {
1.87 markus 1671: debug("x11_create_display_inet failed.");
1.81 markus 1672: return 0;
1673: }
1674: return 1;
1.2 markus 1675: }
1676:
1.94 itojun 1677: static void
1.49 markus 1678: do_authenticated2(Authctxt *authctxt)
1.2 markus 1679: {
1.97 markus 1680: server_loop2(authctxt);
1.1 markus 1681: }
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