Annotation of src/usr.bin/ssh/session.c, Revision 1.108.2.1
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"
1.108.2.1! jason 36: RCSID("$OpenBSD: session.c,v 1.108 2001/10/11 13:45:21 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. */
1.108.2.1! jason 878: if (!options.use_login) {
! 879: while (custom_environment) {
! 880: struct envstring *ce = custom_environment;
! 881: char *s = ce->s;
! 882: int i;
! 883: for (i = 0; s[i] != '=' && s[i]; i++)
! 884: ;
! 885: if (s[i] == '=') {
! 886: s[i] = 0;
! 887: child_set_env(&env, &envsize, s, s + i + 1);
! 888: }
! 889: custom_environment = ce->next;
! 890: xfree(ce->s);
! 891: xfree(ce);
1.1 markus 892: }
893: }
894:
895: snprintf(buf, sizeof buf, "%.50s %d %d",
896: get_remote_ipaddr(), get_remote_port(), get_local_port());
897: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
898:
1.60 markus 899: if (s->ttyfd != -1)
900: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
901: if (s->term)
902: child_set_env(&env, &envsize, "TERM", s->term);
903: if (s->display)
904: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 905: if (original_command)
906: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
907: original_command);
1.1 markus 908: #ifdef KRB4
1.96 dugsong 909: if (s->authctxt->krb4_ticket_file)
910: child_set_env(&env, &envsize, "KRBTKFILE",
911: s->authctxt->krb4_ticket_file);
912: #endif
913: #ifdef KRB5
914: if (s->authctxt->krb5_ticket_file)
915: child_set_env(&env, &envsize, "KRB5CCNAME",
916: s->authctxt->krb5_ticket_file);
917: #endif
1.1 markus 918: if (auth_get_socket_name() != NULL)
919: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
920: auth_get_socket_name());
921:
922: /* read $HOME/.ssh/environment. */
923: if (!options.use_login) {
1.14 deraadt 924: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
925: pw->pw_dir);
1.1 markus 926: read_environment_file(&env, &envsize, buf);
927: }
928: if (debug_flag) {
929: /* dump the environment */
930: fprintf(stderr, "Environment:\n");
931: for (i = 0; env[i]; i++)
932: fprintf(stderr, " %.200s\n", env[i]);
933: }
1.26 millert 934: /* we have to stash the hostname before we close our socket. */
935: if (options.use_login)
1.70 stevesk 936: hostname = get_remote_name_or_ip(utmp_len,
937: options.reverse_mapping_check);
1.1 markus 938: /*
939: * Close the connection descriptors; note that this is the child, and
940: * the server will still have the socket open, and it is important
941: * that we do not shutdown it. Note that the descriptors cannot be
942: * closed before building the environment, as we call
943: * get_remote_ipaddr there.
944: */
945: if (packet_get_connection_in() == packet_get_connection_out())
946: close(packet_get_connection_in());
947: else {
948: close(packet_get_connection_in());
949: close(packet_get_connection_out());
950: }
951: /*
952: * Close all descriptors related to channels. They will still remain
953: * open in the parent.
954: */
955: /* XXX better use close-on-exec? -markus */
956: channel_close_all();
957:
958: /*
959: * Close any extra file descriptors. Note that there may still be
960: * descriptors left by system functions. They will be closed later.
961: */
962: endpwent();
963:
964: /*
965: * Close any extra open file descriptors so that we don\'t have them
966: * hanging around in clients. Note that we want to do this after
967: * initgroups, because at least on Solaris 2.3 it leaves file
968: * descriptors open.
969: */
970: for (i = 3; i < 64; i++)
971: close(i);
972:
973: /*
974: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
975: * xauth are run in the proper environment.
976: */
977: environ = env;
1.102 markus 978:
979: #ifdef AFS
980: /* Try to get AFS tokens for the local cell. */
981: if (k_hasafs()) {
982: char cell[64];
983:
984: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
985: krb_afslog(cell, 0);
986:
987: krb_afslog(0, 0);
988: }
989: #endif /* AFS */
1.104 markus 990:
991: /* Change current directory to the user\'s home directory. */
992: if (chdir(pw->pw_dir) < 0) {
993: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
994: pw->pw_dir, strerror(errno));
995: #ifdef HAVE_LOGIN_CAP
996: if (login_getcapbool(lc, "requirehome", 0))
997: exit(1);
998: #endif
999: }
1.1 markus 1000:
1001: /*
1002: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1003: * in this order).
1004: */
1005: if (!options.use_login) {
1.74 markus 1006: /* ignore _PATH_SSH_USER_RC for subsystems */
1007: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.75 markus 1008: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1009: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 1010: if (debug_flag)
1.75 markus 1011: fprintf(stderr, "Running %s\n", cmd);
1012: f = popen(cmd, "w");
1.1 markus 1013: if (f) {
1.60 markus 1014: if (do_xauth)
1015: fprintf(f, "%s %s\n", s->auth_proto,
1016: s->auth_data);
1.1 markus 1017: pclose(f);
1018: } else
1.60 markus 1019: fprintf(stderr, "Could not run %s\n",
1020: _PATH_SSH_USER_RC);
1.50 markus 1021: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1022: if (debug_flag)
1.60 markus 1023: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1024: _PATH_SSH_SYSTEM_RC);
1.50 markus 1025: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1026: if (f) {
1.60 markus 1027: if (do_xauth)
1028: fprintf(f, "%s %s\n", s->auth_proto,
1029: s->auth_data);
1.1 markus 1030: pclose(f);
1031: } else
1.60 markus 1032: fprintf(stderr, "Could not run %s\n",
1033: _PATH_SSH_SYSTEM_RC);
1034: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 1035: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 1036: char *screen = strchr(s->display, ':');
1037:
1038: if (debug_flag) {
1039: fprintf(stderr,
1040: "Running %.100s add "
1041: "%.100s %.100s %.100s\n",
1042: options.xauth_location, s->display,
1043: s->auth_proto, s->auth_data);
1044: if (screen != NULL)
1.14 deraadt 1045: fprintf(stderr,
1.60 markus 1046: "Adding %.*s/unix%s %s %s\n",
1047: (int)(screen - s->display),
1048: s->display, screen,
1049: s->auth_proto, s->auth_data);
1050: }
1051: snprintf(cmd, sizeof cmd, "%s -q -",
1052: options.xauth_location);
1053: f = popen(cmd, "w");
1054: if (f) {
1055: fprintf(f, "add %s %s %s\n", s->display,
1056: s->auth_proto, s->auth_data);
1057: if (screen != NULL)
1058: fprintf(f, "add %.*s/unix%s %s %s\n",
1059: (int)(screen - s->display),
1060: s->display, screen,
1061: s->auth_proto,
1062: s->auth_data);
1063: pclose(f);
1064: } else {
1065: fprintf(stderr, "Could not run %s\n",
1066: cmd);
1.1 markus 1067: }
1068: }
1069: /* Get the last component of the shell name. */
1070: cp = strrchr(shell, '/');
1071: if (cp)
1072: cp++;
1073: else
1074: cp = shell;
1075: }
1.67 markus 1076:
1077: /* restore SIGPIPE for child */
1078: signal(SIGPIPE, SIG_DFL);
1079:
1.1 markus 1080: /*
1081: * If we have no command, execute the shell. In this case, the shell
1082: * name to be passed in argv[0] is preceded by '-' to indicate that
1083: * this is a login shell.
1084: */
1085: if (!command) {
1086: if (!options.use_login) {
1087: char buf[256];
1088:
1089: /* Start the shell. Set initial character to '-'. */
1090: buf[0] = '-';
1091: strncpy(buf + 1, cp, sizeof(buf) - 1);
1092: buf[sizeof(buf) - 1] = 0;
1093:
1094: /* Execute the shell. */
1095: argv[0] = buf;
1096: argv[1] = NULL;
1097: execve(shell, argv, env);
1098:
1099: /* Executing the shell failed. */
1100: perror(shell);
1101: exit(1);
1102:
1103: } else {
1104: /* Launch login(1). */
1105:
1.26 millert 1106: execl("/usr/bin/login", "login", "-h", hostname,
1.99 deraadt 1107: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1.1 markus 1108:
1109: /* Login couldn't be executed, die. */
1110:
1111: perror("login");
1112: exit(1);
1113: }
1114: }
1115: /*
1116: * Execute the command using the user's shell. This uses the -c
1117: * option to execute the command.
1118: */
1119: argv[0] = (char *) cp;
1120: argv[1] = "-c";
1121: argv[2] = (char *) command;
1122: argv[3] = NULL;
1123: execve(shell, argv, env);
1124: perror(shell);
1125: exit(1);
1126: }
1127:
1128: Session *
1129: session_new(void)
1130: {
1131: int i;
1132: static int did_init = 0;
1133: if (!did_init) {
1134: debug("session_new: init");
1135: for(i = 0; i < MAX_SESSIONS; i++) {
1136: sessions[i].used = 0;
1137: }
1138: did_init = 1;
1139: }
1140: for(i = 0; i < MAX_SESSIONS; i++) {
1141: Session *s = &sessions[i];
1142: if (! s->used) {
1.68 djm 1143: memset(s, 0, sizeof(*s));
1.1 markus 1144: s->chanid = -1;
1145: s->ptyfd = -1;
1146: s->ttyfd = -1;
1147: s->used = 1;
1.85 markus 1148: s->self = i;
1.1 markus 1149: debug("session_new: session %d", i);
1150: return s;
1151: }
1152: }
1153: return NULL;
1154: }
1155:
1.94 itojun 1156: static void
1.1 markus 1157: session_dump(void)
1158: {
1159: int i;
1160: for(i = 0; i < MAX_SESSIONS; i++) {
1161: Session *s = &sessions[i];
1162: debug("dump: used %d session %d %p channel %d pid %d",
1163: s->used,
1164: s->self,
1165: s,
1166: s->chanid,
1167: s->pid);
1168: }
1169: }
1170:
1.2 markus 1171: int
1.97 markus 1172: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1173: {
1174: Session *s = session_new();
1175: debug("session_open: channel %d", chanid);
1176: if (s == NULL) {
1177: error("no more sessions");
1178: return 0;
1179: }
1.97 markus 1180: s->authctxt = authctxt;
1181: s->pw = authctxt->pw;
1.7 markus 1182: if (s->pw == NULL)
1.54 stevesk 1183: fatal("no user for session %d", s->self);
1.2 markus 1184: debug("session_open: session %d: link with channel %d", s->self, chanid);
1185: s->chanid = chanid;
1186: return 1;
1187: }
1188:
1.94 itojun 1189: static Session *
1.2 markus 1190: session_by_channel(int id)
1191: {
1192: int i;
1193: for(i = 0; i < MAX_SESSIONS; i++) {
1194: Session *s = &sessions[i];
1195: if (s->used && s->chanid == id) {
1196: debug("session_by_channel: session %d channel %d", i, id);
1197: return s;
1198: }
1199: }
1200: debug("session_by_channel: unknown channel %d", id);
1201: session_dump();
1202: return NULL;
1203: }
1204:
1.94 itojun 1205: static Session *
1.2 markus 1206: session_by_pid(pid_t pid)
1207: {
1208: int i;
1209: debug("session_by_pid: pid %d", pid);
1210: for(i = 0; i < MAX_SESSIONS; i++) {
1211: Session *s = &sessions[i];
1212: if (s->used && s->pid == pid)
1213: return s;
1214: }
1215: error("session_by_pid: unknown pid %d", pid);
1216: session_dump();
1217: return NULL;
1218: }
1219:
1.94 itojun 1220: static int
1.2 markus 1221: session_window_change_req(Session *s)
1222: {
1223: s->col = packet_get_int();
1224: s->row = packet_get_int();
1225: s->xpixel = packet_get_int();
1226: s->ypixel = packet_get_int();
1.3 markus 1227: packet_done();
1.2 markus 1228: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1229: return 1;
1230: }
1231:
1.94 itojun 1232: static int
1.2 markus 1233: session_pty_req(Session *s)
1234: {
1.45 markus 1235: u_int len;
1.72 stevesk 1236: int n_bytes;
1.2 markus 1237:
1.86 markus 1238: if (no_pty_flag) {
1239: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1240: return 0;
1.86 markus 1241: }
1242: if (s->ttyfd != -1) {
1243: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1244: return 0;
1.86 markus 1245: }
1246:
1.2 markus 1247: s->term = packet_get_string(&len);
1.86 markus 1248:
1249: if (compat20) {
1250: s->col = packet_get_int();
1251: s->row = packet_get_int();
1252: } else {
1253: s->row = packet_get_int();
1254: s->col = packet_get_int();
1255: }
1.2 markus 1256: s->xpixel = packet_get_int();
1257: s->ypixel = packet_get_int();
1258:
1259: if (strcmp(s->term, "") == 0) {
1260: xfree(s->term);
1261: s->term = NULL;
1262: }
1.86 markus 1263:
1.2 markus 1264: /* Allocate a pty and open it. */
1.86 markus 1265: debug("Allocating pty.");
1.2 markus 1266: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.86 markus 1267: if (s->term)
1268: xfree(s->term);
1.2 markus 1269: s->term = NULL;
1270: s->ptyfd = -1;
1271: s->ttyfd = -1;
1272: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1273: return 0;
1.2 markus 1274: }
1275: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1276:
1277: /* for SSH1 the tty modes length is not given */
1278: if (!compat20)
1279: n_bytes = packet_remaining();
1280: tty_parse_modes(s->ttyfd, &n_bytes);
1281:
1.2 markus 1282: /*
1283: * Add a cleanup function to clear the utmp entry and record logout
1284: * time in case we call fatal() (e.g., the connection gets closed).
1285: */
1.85 markus 1286: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1287: pty_setowner(s->pw, s->tty);
1.86 markus 1288:
1289: /* Set window size from the packet. */
1.2 markus 1290: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1291:
1.72 stevesk 1292: packet_done();
1.9 markus 1293: session_proctitle(s);
1.2 markus 1294: return 1;
1295: }
1296:
1.94 itojun 1297: static int
1.7 markus 1298: session_subsystem_req(Session *s)
1299: {
1.105 markus 1300: struct stat st;
1.45 markus 1301: u_int len;
1.7 markus 1302: int success = 0;
1.105 markus 1303: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1304: int i;
1.7 markus 1305:
1306: packet_done();
1307: log("subsystem request for %s", subsys);
1.18 jakob 1308:
1309: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1310: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1311: cmd = options.subsystem_command[i];
1312: if (stat(cmd, &st) < 0) {
1313: error("subsystem: cannot stat %s: %s", cmd,
1314: strerror(errno));
1315: break;
1316: }
1317: debug("subsystem: exec() %s", cmd);
1.64 markus 1318: s->is_subsystem = 1;
1.105 markus 1319: do_exec(s, cmd);
1.18 jakob 1320: success = 1;
1321: }
1322: }
1323:
1324: if (!success)
1.105 markus 1325: log("subsystem request for %s failed, subsystem not found",
1326: subsys);
1.7 markus 1327:
1328: xfree(subsys);
1329: return success;
1330: }
1331:
1.94 itojun 1332: static int
1.7 markus 1333: session_x11_req(Session *s)
1334: {
1.81 markus 1335: int success;
1.7 markus 1336:
1337: s->single_connection = packet_get_char();
1338: s->auth_proto = packet_get_string(NULL);
1339: s->auth_data = packet_get_string(NULL);
1340: s->screen = packet_get_int();
1341: packet_done();
1342:
1.81 markus 1343: success = session_setup_x11fwd(s);
1344: if (!success) {
1.7 markus 1345: xfree(s->auth_proto);
1346: xfree(s->auth_data);
1.84 markus 1347: s->auth_proto = NULL;
1348: s->auth_data = NULL;
1.7 markus 1349: }
1.81 markus 1350: return success;
1.7 markus 1351: }
1352:
1.94 itojun 1353: static int
1.19 markus 1354: session_shell_req(Session *s)
1355: {
1356: packet_done();
1.90 markus 1357: do_exec(s, NULL);
1.19 markus 1358: return 1;
1359: }
1360:
1.94 itojun 1361: static int
1.19 markus 1362: session_exec_req(Session *s)
1363: {
1.45 markus 1364: u_int len;
1.19 markus 1365: char *command = packet_get_string(&len);
1366: packet_done();
1.90 markus 1367: do_exec(s, command);
1.92 markus 1368: xfree(command);
1.19 markus 1369: return 1;
1370: }
1371:
1.94 itojun 1372: static int
1.43 markus 1373: session_auth_agent_req(Session *s)
1374: {
1375: static int called = 0;
1376: packet_done();
1.44 markus 1377: if (no_agent_forwarding_flag) {
1378: debug("session_auth_agent_req: no_agent_forwarding_flag");
1379: return 0;
1380: }
1.43 markus 1381: if (called) {
1382: return 0;
1383: } else {
1384: called = 1;
1385: return auth_input_request_forwarding(s->pw);
1386: }
1387: }
1388:
1.2 markus 1389: void
1390: session_input_channel_req(int id, void *arg)
1391: {
1.45 markus 1392: u_int len;
1.2 markus 1393: int reply;
1394: int success = 0;
1395: char *rtype;
1396: Session *s;
1397: Channel *c;
1398:
1399: rtype = packet_get_string(&len);
1400: reply = packet_get_char();
1401:
1402: s = session_by_channel(id);
1403: if (s == NULL)
1404: fatal("session_input_channel_req: channel %d: no session", id);
1405: c = channel_lookup(id);
1406: if (c == NULL)
1407: fatal("session_input_channel_req: channel %d: bad channel", id);
1408:
1409: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1410: s->self, id, rtype, reply);
1411:
1412: /*
1.64 markus 1413: * a session is in LARVAL state until a shell, a command
1414: * or a subsystem is executed
1.2 markus 1415: */
1416: if (c->type == SSH_CHANNEL_LARVAL) {
1417: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1418: success = session_shell_req(s);
1.2 markus 1419: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1420: success = session_exec_req(s);
1.2 markus 1421: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1422: success = session_pty_req(s);
1.7 markus 1423: } else if (strcmp(rtype, "x11-req") == 0) {
1424: success = session_x11_req(s);
1.43 markus 1425: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1426: success = session_auth_agent_req(s);
1.7 markus 1427: } else if (strcmp(rtype, "subsystem") == 0) {
1428: success = session_subsystem_req(s);
1.2 markus 1429: }
1430: }
1431: if (strcmp(rtype, "window-change") == 0) {
1432: success = session_window_change_req(s);
1433: }
1434:
1435: if (reply) {
1436: packet_start(success ?
1437: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1438: packet_put_int(c->remote_id);
1439: packet_send();
1440: }
1441: xfree(rtype);
1442: }
1443:
1444: void
1445: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1446: {
1447: if (!compat20)
1448: fatal("session_set_fds: called for proto != 2.0");
1449: /*
1450: * now that have a child and a pipe to the child,
1451: * we can activate our channel and register the fd's
1452: */
1453: if (s->chanid == -1)
1454: fatal("no channel for session %d", s->self);
1455: channel_set_fds(s->chanid,
1456: fdout, fdin, fderr,
1.42 markus 1457: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1458: 1);
1.2 markus 1459: }
1460:
1.85 markus 1461: /*
1462: * Function to perform pty cleanup. Also called if we get aborted abnormally
1463: * (e.g., due to a dropped connection).
1464: */
1.94 itojun 1465: static void
1.85 markus 1466: session_pty_cleanup(void *session)
1.1 markus 1467: {
1.85 markus 1468: Session *s = session;
1469:
1470: if (s == NULL) {
1471: error("session_pty_cleanup: no session");
1472: return;
1473: }
1474: if (s->ttyfd == -1)
1.1 markus 1475: return;
1476:
1.54 stevesk 1477: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1478:
1479: /* Record that the user has logged out. */
1.85 markus 1480: if (s->pid != 0)
1481: record_logout(s->pid, s->tty);
1.1 markus 1482:
1483: /* Release the pseudo-tty. */
1484: pty_release(s->tty);
1485:
1486: /*
1487: * Close the server side of the socket pairs. We must do this after
1488: * the pty cleanup, so that another process doesn't get this pty
1489: * while we're still cleaning up.
1490: */
1491: if (close(s->ptymaster) < 0)
1492: error("close(s->ptymaster): %s", strerror(errno));
1.108 markus 1493:
1494: /* unlink pty from session */
1495: s->ttyfd = -1;
1.2 markus 1496: }
1497:
1.94 itojun 1498: static void
1.2 markus 1499: session_exit_message(Session *s, int status)
1500: {
1501: Channel *c;
1502: if (s == NULL)
1503: fatal("session_close: no session");
1504: c = channel_lookup(s->chanid);
1505: if (c == NULL)
1.85 markus 1506: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1507: s->self, s->chanid);
1508: debug("session_exit_message: session %d channel %d pid %d",
1509: s->self, s->chanid, s->pid);
1510:
1511: if (WIFEXITED(status)) {
1512: channel_request_start(s->chanid,
1513: "exit-status", 0);
1514: packet_put_int(WEXITSTATUS(status));
1515: packet_send();
1516: } else if (WIFSIGNALED(status)) {
1517: channel_request_start(s->chanid,
1518: "exit-signal", 0);
1519: packet_put_int(WTERMSIG(status));
1520: packet_put_char(WCOREDUMP(status));
1521: packet_put_cstring("");
1522: packet_put_cstring("");
1523: packet_send();
1524: } else {
1525: /* Some weird exit cause. Just exit. */
1526: packet_disconnect("wait returned status %04x.", status);
1527: }
1528:
1529: /* disconnect channel */
1530: debug("session_exit_message: release channel %d", s->chanid);
1531: channel_cancel_cleanup(s->chanid);
1.5 markus 1532: /*
1533: * emulate a write failure with 'chan_write_failed', nobody will be
1534: * interested in data we write.
1535: * Note that we must not call 'chan_read_failed', since there could
1536: * be some more data waiting in the pipe.
1537: */
1.8 markus 1538: if (c->ostate != CHAN_OUTPUT_CLOSED)
1539: chan_write_failed(c);
1.2 markus 1540: s->chanid = -1;
1541: }
1542:
1.94 itojun 1543: static void
1.85 markus 1544: session_close(Session *s)
1.2 markus 1545: {
1.85 markus 1546: debug("session_close: session %d pid %d", s->self, s->pid);
1547: if (s->ttyfd != -1) {
1548: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1549: session_pty_cleanup(s);
1550: }
1.2 markus 1551: if (s->term)
1552: xfree(s->term);
1553: if (s->display)
1554: xfree(s->display);
1555: if (s->auth_data)
1556: xfree(s->auth_data);
1557: if (s->auth_proto)
1558: xfree(s->auth_proto);
1559: s->used = 0;
1.9 markus 1560: session_proctitle(s);
1.2 markus 1561: }
1562:
1563: void
1564: session_close_by_pid(pid_t pid, int status)
1565: {
1566: Session *s = session_by_pid(pid);
1567: if (s == NULL) {
1.89 markus 1568: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1569: return;
1570: }
1571: if (s->chanid != -1)
1572: session_exit_message(s, status);
1573: session_close(s);
1.98 markus 1574: }
1575:
1.2 markus 1576: /*
1577: * this is called when a channel dies before
1578: * the session 'child' itself dies
1579: */
1580: void
1581: session_close_by_channel(int id, void *arg)
1582: {
1583: Session *s = session_by_channel(id);
1584: if (s == NULL) {
1.107 markus 1585: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1586: return;
1587: }
1.107 markus 1588: debug("session_close_by_channel: channel %d child %d", id, s->pid);
1589: if (s->pid != 0) {
1590: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 1591: /*
1592: * delay detach of session, but release pty, since
1593: * the fd's to the child are already closed
1594: */
1595: if (s->ttyfd != -1) {
1596: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1597: session_pty_cleanup(s);
1598: }
1.107 markus 1599: return;
1600: }
1601: /* detach by removing callback */
1.2 markus 1602: channel_cancel_cleanup(s->chanid);
1603: s->chanid = -1;
1.106 markus 1604: session_close(s);
1605: }
1606:
1607: void
1.107 markus 1608: session_destroy_all(void)
1.106 markus 1609: {
1610: int i;
1611: for(i = 0; i < MAX_SESSIONS; i++) {
1612: Session *s = &sessions[i];
1.107 markus 1613: if (s->used)
1.106 markus 1614: session_close(s);
1.2 markus 1615: }
1.9 markus 1616: }
1617:
1.94 itojun 1618: static char *
1.9 markus 1619: session_tty_list(void)
1620: {
1621: static char buf[1024];
1622: int i;
1623: buf[0] = '\0';
1624: for(i = 0; i < MAX_SESSIONS; i++) {
1625: Session *s = &sessions[i];
1626: if (s->used && s->ttyfd != -1) {
1627: if (buf[0] != '\0')
1628: strlcat(buf, ",", sizeof buf);
1629: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1630: }
1631: }
1632: if (buf[0] == '\0')
1633: strlcpy(buf, "notty", sizeof buf);
1634: return buf;
1635: }
1636:
1637: void
1638: session_proctitle(Session *s)
1639: {
1640: if (s->pw == NULL)
1641: error("no user for session %d", s->self);
1642: else
1643: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1644: }
1645:
1646: int
1647: session_setup_x11fwd(Session *s)
1648: {
1649: struct stat st;
1650:
1651: if (no_x11_forwarding_flag) {
1652: packet_send_debug("X11 forwarding disabled in user configuration file.");
1653: return 0;
1654: }
1655: if (!options.x11_forwarding) {
1656: debug("X11 forwarding disabled in server configuration file.");
1657: return 0;
1658: }
1659: if (!options.xauth_location ||
1660: (stat(options.xauth_location, &st) == -1)) {
1661: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1662: return 0;
1663: }
1664: if (options.use_login) {
1665: packet_send_debug("X11 forwarding disabled; "
1666: "not compatible with UseLogin=yes.");
1.81 markus 1667: return 0;
1668: }
1.87 markus 1669: if (s->display != NULL) {
1.81 markus 1670: debug("X11 display already set.");
1671: return 0;
1672: }
1673: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1674: if (s->display == NULL) {
1.87 markus 1675: debug("x11_create_display_inet failed.");
1.81 markus 1676: return 0;
1677: }
1678: return 1;
1.2 markus 1679: }
1680:
1.94 itojun 1681: static void
1.49 markus 1682: do_authenticated2(Authctxt *authctxt)
1.2 markus 1683: {
1.97 markus 1684: server_loop2(authctxt);
1.1 markus 1685: }