Annotation of src/usr.bin/ssh/session.c, Revision 1.98
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"
1.98 ! markus 36: RCSID("$OpenBSD: session.c,v 1.97 2001/06/27 02:12:53 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:
506: /* Redirect stdin from the pseudo tty. */
507: if (dup2(ttyfd, fileno(stdin)) < 0)
508: error("dup2 stdin failed: %.100s", strerror(errno));
509:
510: /* Redirect stdout to the pseudo tty. */
511: if (dup2(ttyfd, fileno(stdout)) < 0)
512: error("dup2 stdin failed: %.100s", strerror(errno));
513:
514: /* Redirect stderr to the pseudo tty. */
515: if (dup2(ttyfd, fileno(stderr)) < 0)
516: error("dup2 stdin failed: %.100s", strerror(errno));
517:
518: /* Close the extra descriptor for the pseudo tty. */
519: close(ttyfd);
520:
1.24 markus 521: /* record login, etc. similar to login(1) */
1.41 markus 522: if (!(options.use_login && command == NULL))
523: do_login(s, command);
1.1 markus 524:
525: /* Do common processing for the child, such as execing the command. */
1.60 markus 526: do_child(s, command);
1.1 markus 527: /* NOTREACHED */
528: }
529: if (pid < 0)
530: packet_disconnect("fork failed: %.100s", strerror(errno));
531: s->pid = pid;
532:
533: /* Parent. Close the slave side of the pseudo tty. */
534: close(ttyfd);
535:
536: /*
537: * Create another descriptor of the pty master side for use as the
538: * standard input. We could use the original descriptor, but this
539: * simplifies code in server_loop. The descriptor is bidirectional.
540: */
541: fdout = dup(ptyfd);
542: if (fdout < 0)
543: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
544:
545: /* we keep a reference to the pty master */
546: ptymaster = dup(ptyfd);
547: if (ptymaster < 0)
548: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
549: s->ptymaster = ptymaster;
550:
551: /* Enter interactive session. */
1.47 markus 552: packet_set_interactive(1);
1.2 markus 553: if (compat20) {
554: session_set_fds(s, ptyfd, fdout, -1);
555: } else {
556: server_loop(pid, ptyfd, fdout, -1);
557: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 558: }
559: }
560:
1.90 markus 561: /*
562: * This is called to fork and execute a command. If another command is
563: * to be forced, execute that instead.
564: */
565: void
566: do_exec(Session *s, const char *command)
567: {
568: if (forced_command) {
569: original_command = command;
570: command = forced_command;
571: debug("Forced command '%.900s'", command);
572: }
573:
574: if (s->ttyfd != -1)
575: do_exec_pty(s, command);
576: else
577: do_exec_no_pty(s, command);
578:
1.92 markus 579: original_command = NULL;
1.90 markus 580: }
581:
582:
1.24 markus 583: /* administrative, login(1)-like work */
584: void
1.41 markus 585: do_login(Session *s, const char *command)
1.24 markus 586: {
587: char *time_string;
1.35 markus 588: char hostname[MAXHOSTNAMELEN];
1.24 markus 589: socklen_t fromlen;
590: struct sockaddr_storage from;
591: time_t last_login_time;
592: struct passwd * pw = s->pw;
593: pid_t pid = getpid();
594:
595: /*
596: * Get IP address of client. If the connection is not a socket, let
597: * the address be 0.0.0.0.
598: */
599: memset(&from, 0, sizeof(from));
600: if (packet_connection_is_on_socket()) {
601: fromlen = sizeof(from);
602: if (getpeername(packet_get_connection_in(),
603: (struct sockaddr *) & from, &fromlen) < 0) {
604: debug("getpeername: %.100s", strerror(errno));
605: fatal_cleanup();
606: }
607: }
1.25 markus 608:
1.35 markus 609: /* Get the time and hostname when the user last logged in. */
1.69 stevesk 610: if (options.print_lastlog) {
611: hostname[0] = '\0';
612: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
613: hostname, sizeof(hostname));
614: }
1.35 markus 615:
1.24 markus 616: /* Record that there was a login on that tty from the remote host. */
617: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.70 stevesk 618: get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
619: (struct sockaddr *)&from);
1.24 markus 620:
1.73 djm 621: if (check_quietlogin(s, command))
1.24 markus 622: return;
1.73 djm 623:
1.69 stevesk 624: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 625: time_string = ctime(&last_login_time);
626: if (strchr(time_string, '\n'))
627: *strchr(time_string, '\n') = 0;
1.40 markus 628: if (strcmp(hostname, "") == 0)
1.24 markus 629: printf("Last login: %s\r\n", time_string);
630: else
1.36 markus 631: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 632: }
1.73 djm 633:
634: do_motd();
635: }
636:
637: /*
638: * Display the message of the day.
639: */
640: void
641: do_motd(void)
642: {
643: FILE *f;
644: char buf[256];
645:
1.24 markus 646: if (options.print_motd) {
1.28 millert 647: #ifdef HAVE_LOGIN_CAP
648: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
649: "/etc/motd"), "r");
650: #else
1.24 markus 651: f = fopen("/etc/motd", "r");
1.28 millert 652: #endif
1.24 markus 653: if (f) {
654: while (fgets(buf, sizeof(buf), f))
655: fputs(buf, stdout);
656: fclose(f);
657: }
1.2 markus 658: }
1.73 djm 659: }
660:
661:
662: /*
663: * Check for quiet login, either .hushlogin or command given.
664: */
665: int
666: check_quietlogin(Session *s, const char *command)
667: {
668: char buf[256];
1.96 dugsong 669: struct passwd *pw = s->pw;
1.73 djm 670: struct stat st;
671:
672: /* Return 1 if .hushlogin exists or a command given. */
673: if (command != NULL)
674: return 1;
675: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
676: #ifdef HAVE_LOGIN_CAP
677: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
678: return 1;
679: #else
680: if (stat(buf, &st) >= 0)
681: return 1;
682: #endif
683: return 0;
1.1 markus 684: }
685:
686: /*
687: * Sets the value of the given variable in the environment. If the variable
688: * already exists, its value is overriden.
689: */
1.94 itojun 690: static void
1.45 markus 691: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 692: const char *value)
693: {
1.45 markus 694: u_int i, namelen;
1.1 markus 695: char **env;
696:
697: /*
698: * Find the slot where the value should be stored. If the variable
699: * already exists, we reuse the slot; otherwise we append a new slot
700: * at the end of the array, expanding if necessary.
701: */
702: env = *envp;
703: namelen = strlen(name);
704: for (i = 0; env[i]; i++)
705: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
706: break;
707: if (env[i]) {
708: /* Reuse the slot. */
709: xfree(env[i]);
710: } else {
711: /* New variable. Expand if necessary. */
712: if (i >= (*envsizep) - 1) {
713: (*envsizep) += 50;
714: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
715: }
716: /* Need to set the NULL pointer at end of array beyond the new slot. */
717: env[i + 1] = NULL;
718: }
719:
720: /* Allocate space and format the variable in the appropriate slot. */
721: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
722: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
723: }
724:
725: /*
726: * Reads environment variables from the given file and adds/overrides them
727: * into the environment. If the file does not exist, this does nothing.
728: * Otherwise, it must consist of empty lines, comments (line starts with '#')
729: * and assignments of the form name=value. No other forms are allowed.
730: */
1.94 itojun 731: static void
1.45 markus 732: read_environment_file(char ***env, u_int *envsize,
1.1 markus 733: const char *filename)
734: {
735: FILE *f;
736: char buf[4096];
737: char *cp, *value;
738:
739: f = fopen(filename, "r");
740: if (!f)
741: return;
742:
743: while (fgets(buf, sizeof(buf), f)) {
744: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
745: ;
746: if (!*cp || *cp == '#' || *cp == '\n')
747: continue;
748: if (strchr(cp, '\n'))
749: *strchr(cp, '\n') = '\0';
750: value = strchr(cp, '=');
751: if (value == NULL) {
752: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
753: continue;
754: }
1.14 deraadt 755: /*
756: * Replace the equals sign by nul, and advance value to
757: * the value string.
758: */
1.1 markus 759: *value = '\0';
760: value++;
761: child_set_env(env, envsize, cp, value);
762: }
763: fclose(f);
764: }
765:
766: /*
767: * Performs common processing for the child, such as setting up the
768: * environment, closing extra file descriptors, setting the user and group
769: * ids, and executing the command or shell.
770: */
1.4 markus 771: void
1.60 markus 772: do_child(Session *s, const char *command)
1.1 markus 773: {
1.32 markus 774: const char *shell, *hostname = NULL, *cp = NULL;
1.96 dugsong 775: struct passwd *pw = s->pw;
1.1 markus 776: char buf[256];
1.16 markus 777: char cmd[1024];
1.27 millert 778: FILE *f = NULL;
1.45 markus 779: u_int envsize, i;
1.1 markus 780: char **env;
781: extern char **environ;
782: struct stat st;
783: char *argv[10];
1.84 markus 784: int do_xauth;
785:
786: do_xauth =
787: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 788:
1.74 markus 789: /* remove hostkey from the child's memory */
790: destroy_sensitive_data();
791:
1.17 markus 792: /* login(1) is only called if we execute the login shell */
793: if (options.use_login && command != NULL)
794: options.use_login = 0;
1.1 markus 795:
1.27 millert 796: if (!options.use_login) {
1.28 millert 797: #ifdef HAVE_LOGIN_CAP
798: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
799: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
800: _PATH_NOLOGIN), "r");
801: #else
1.27 millert 802: if (pw->pw_uid)
803: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 804: #endif
1.27 millert 805: if (f) {
806: /* /etc/nologin exists. Print its contents and exit. */
807: while (fgets(buf, sizeof(buf), f))
808: fputs(buf, stderr);
809: fclose(f);
1.1 markus 810: exit(254);
1.27 millert 811: }
1.1 markus 812: }
1.28 millert 813: /* Set login name, uid, gid, and groups. */
1.1 markus 814: /* Login(1) does this as well, and it needs uid 0 for the "-h"
815: switch, so we let login(1) to this for us. */
816: if (!options.use_login) {
817: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 818: #ifdef HAVE_LOGIN_CAP
819: if (setusercontext(lc, pw, pw->pw_uid,
820: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
821: perror("unable to set user context");
822: exit(1);
823: }
824: #else
825: if (setlogin(pw->pw_name) < 0)
826: error("setlogin failed: %s", strerror(errno));
1.1 markus 827: if (setgid(pw->pw_gid) < 0) {
828: perror("setgid");
829: exit(1);
830: }
831: /* Initialize the group list. */
832: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
833: perror("initgroups");
834: exit(1);
835: }
836: endgrent();
837:
838: /* Permanently switch to the desired uid. */
1.71 markus 839: permanently_set_uid(pw);
1.28 millert 840: #endif
1.1 markus 841: }
842: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 843: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 844: }
845: /*
846: * Get the shell from the password data. An empty shell field is
847: * legal, and means /bin/sh.
848: */
849: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 850: #ifdef HAVE_LOGIN_CAP
851: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
852: #endif
1.1 markus 853:
854: #ifdef AFS
855: /* Try to get AFS tokens for the local cell. */
856: if (k_hasafs()) {
857: char cell[64];
1.96 dugsong 858:
1.1 markus 859: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
860: krb_afslog(cell, 0);
1.96 dugsong 861:
1.1 markus 862: krb_afslog(0, 0);
863: }
864: #endif /* AFS */
865:
866: /* Initialize the environment. */
867: envsize = 100;
868: env = xmalloc(envsize * sizeof(char *));
869: env[0] = NULL;
870:
871: if (!options.use_login) {
872: /* Set basic environment. */
873: child_set_env(&env, &envsize, "USER", pw->pw_name);
874: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
875: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 876: #ifdef HAVE_LOGIN_CAP
1.29 millert 877: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
878: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 879: #else
1.29 millert 880: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 881: #endif
1.1 markus 882:
883: snprintf(buf, sizeof buf, "%.200s/%.50s",
884: _PATH_MAILDIR, pw->pw_name);
885: child_set_env(&env, &envsize, "MAIL", buf);
886:
887: /* Normal systems set SHELL by default. */
888: child_set_env(&env, &envsize, "SHELL", shell);
889: }
890: if (getenv("TZ"))
891: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
892:
893: /* Set custom environment options from RSA authentication. */
894: while (custom_environment) {
895: struct envstring *ce = custom_environment;
896: char *s = ce->s;
897: int i;
898: for (i = 0; s[i] != '=' && s[i]; i++);
899: if (s[i] == '=') {
900: s[i] = 0;
901: child_set_env(&env, &envsize, s, s + i + 1);
902: }
903: custom_environment = ce->next;
904: xfree(ce->s);
905: xfree(ce);
906: }
907:
908: snprintf(buf, sizeof buf, "%.50s %d %d",
909: get_remote_ipaddr(), get_remote_port(), get_local_port());
910: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
911:
1.60 markus 912: if (s->ttyfd != -1)
913: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
914: if (s->term)
915: child_set_env(&env, &envsize, "TERM", s->term);
916: if (s->display)
917: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 918: if (original_command)
919: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
920: original_command);
1.1 markus 921: #ifdef KRB4
1.96 dugsong 922: if (s->authctxt->krb4_ticket_file)
923: child_set_env(&env, &envsize, "KRBTKFILE",
924: s->authctxt->krb4_ticket_file);
925: #endif
926: #ifdef KRB5
927: if (s->authctxt->krb5_ticket_file)
928: child_set_env(&env, &envsize, "KRB5CCNAME",
929: s->authctxt->krb5_ticket_file);
930: #endif
1.1 markus 931: if (auth_get_socket_name() != NULL)
932: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
933: auth_get_socket_name());
934:
935: /* read $HOME/.ssh/environment. */
936: if (!options.use_login) {
1.14 deraadt 937: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
938: pw->pw_dir);
1.1 markus 939: read_environment_file(&env, &envsize, buf);
940: }
941: if (debug_flag) {
942: /* dump the environment */
943: fprintf(stderr, "Environment:\n");
944: for (i = 0; env[i]; i++)
945: fprintf(stderr, " %.200s\n", env[i]);
946: }
1.26 millert 947: /* we have to stash the hostname before we close our socket. */
948: if (options.use_login)
1.70 stevesk 949: hostname = get_remote_name_or_ip(utmp_len,
950: options.reverse_mapping_check);
1.1 markus 951: /*
952: * Close the connection descriptors; note that this is the child, and
953: * the server will still have the socket open, and it is important
954: * that we do not shutdown it. Note that the descriptors cannot be
955: * closed before building the environment, as we call
956: * get_remote_ipaddr there.
957: */
958: if (packet_get_connection_in() == packet_get_connection_out())
959: close(packet_get_connection_in());
960: else {
961: close(packet_get_connection_in());
962: close(packet_get_connection_out());
963: }
964: /*
965: * Close all descriptors related to channels. They will still remain
966: * open in the parent.
967: */
968: /* XXX better use close-on-exec? -markus */
969: channel_close_all();
970:
971: /*
972: * Close any extra file descriptors. Note that there may still be
973: * descriptors left by system functions. They will be closed later.
974: */
975: endpwent();
976:
977: /*
978: * Close any extra open file descriptors so that we don\'t have them
979: * hanging around in clients. Note that we want to do this after
980: * initgroups, because at least on Solaris 2.3 it leaves file
981: * descriptors open.
982: */
983: for (i = 3; i < 64; i++)
984: close(i);
985:
986: /* Change current directory to the user\'s home directory. */
1.28 millert 987: if (chdir(pw->pw_dir) < 0) {
1.1 markus 988: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
989: pw->pw_dir, strerror(errno));
1.28 millert 990: #ifdef HAVE_LOGIN_CAP
991: if (login_getcapbool(lc, "requirehome", 0))
992: exit(1);
993: #endif
994: }
1.1 markus 995:
996: /*
997: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
998: * xauth are run in the proper environment.
999: */
1000: environ = env;
1001:
1002: /*
1003: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1004: * in this order).
1005: */
1006: if (!options.use_login) {
1.74 markus 1007: /* ignore _PATH_SSH_USER_RC for subsystems */
1008: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.75 markus 1009: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1010: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 1011: if (debug_flag)
1.75 markus 1012: fprintf(stderr, "Running %s\n", cmd);
1013: f = popen(cmd, "w");
1.1 markus 1014: if (f) {
1.60 markus 1015: if (do_xauth)
1016: fprintf(f, "%s %s\n", s->auth_proto,
1017: s->auth_data);
1.1 markus 1018: pclose(f);
1019: } else
1.60 markus 1020: fprintf(stderr, "Could not run %s\n",
1021: _PATH_SSH_USER_RC);
1.50 markus 1022: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1023: if (debug_flag)
1.60 markus 1024: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1025: _PATH_SSH_SYSTEM_RC);
1.50 markus 1026: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1027: if (f) {
1.60 markus 1028: if (do_xauth)
1029: fprintf(f, "%s %s\n", s->auth_proto,
1030: s->auth_data);
1.1 markus 1031: pclose(f);
1032: } else
1.60 markus 1033: fprintf(stderr, "Could not run %s\n",
1034: _PATH_SSH_SYSTEM_RC);
1035: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 1036: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 1037: char *screen = strchr(s->display, ':');
1038:
1039: if (debug_flag) {
1040: fprintf(stderr,
1041: "Running %.100s add "
1042: "%.100s %.100s %.100s\n",
1043: options.xauth_location, s->display,
1044: s->auth_proto, s->auth_data);
1045: if (screen != NULL)
1.14 deraadt 1046: fprintf(stderr,
1.60 markus 1047: "Adding %.*s/unix%s %s %s\n",
1048: (int)(screen - s->display),
1049: s->display, screen,
1050: s->auth_proto, s->auth_data);
1051: }
1052: snprintf(cmd, sizeof cmd, "%s -q -",
1053: options.xauth_location);
1054: f = popen(cmd, "w");
1055: if (f) {
1056: fprintf(f, "add %s %s %s\n", s->display,
1057: s->auth_proto, s->auth_data);
1058: if (screen != NULL)
1059: fprintf(f, "add %.*s/unix%s %s %s\n",
1060: (int)(screen - s->display),
1061: s->display, screen,
1062: s->auth_proto,
1063: s->auth_data);
1064: pclose(f);
1065: } else {
1066: fprintf(stderr, "Could not run %s\n",
1067: cmd);
1.1 markus 1068: }
1069: }
1070: /* Get the last component of the shell name. */
1071: cp = strrchr(shell, '/');
1072: if (cp)
1073: cp++;
1074: else
1075: cp = shell;
1076: }
1.67 markus 1077:
1078: /* restore SIGPIPE for child */
1079: signal(SIGPIPE, SIG_DFL);
1080:
1.1 markus 1081: /*
1082: * If we have no command, execute the shell. In this case, the shell
1083: * name to be passed in argv[0] is preceded by '-' to indicate that
1084: * this is a login shell.
1085: */
1086: if (!command) {
1087: if (!options.use_login) {
1088: char buf[256];
1089:
1090: /*
1091: * Check for mail if we have a tty and it was enabled
1092: * in server options.
1093: */
1.60 markus 1094: if (s->ttyfd != -1 && options.check_mail) {
1.1 markus 1095: char *mailbox;
1096: struct stat mailstat;
1.60 markus 1097:
1.1 markus 1098: mailbox = getenv("MAIL");
1099: if (mailbox != NULL) {
1.14 deraadt 1100: if (stat(mailbox, &mailstat) != 0 ||
1101: mailstat.st_size == 0)
1.1 markus 1102: printf("No mail.\n");
1103: else if (mailstat.st_mtime < mailstat.st_atime)
1104: printf("You have mail.\n");
1105: else
1106: printf("You have new mail.\n");
1107: }
1108: }
1109: /* Start the shell. Set initial character to '-'. */
1110: buf[0] = '-';
1111: strncpy(buf + 1, cp, sizeof(buf) - 1);
1112: buf[sizeof(buf) - 1] = 0;
1113:
1114: /* Execute the shell. */
1115: argv[0] = buf;
1116: argv[1] = NULL;
1117: execve(shell, argv, env);
1118:
1119: /* Executing the shell failed. */
1120: perror(shell);
1121: exit(1);
1122:
1123: } else {
1124: /* Launch login(1). */
1125:
1.26 millert 1126: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1127: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1128:
1129: /* Login couldn't be executed, die. */
1130:
1131: perror("login");
1132: exit(1);
1133: }
1134: }
1135: /*
1136: * Execute the command using the user's shell. This uses the -c
1137: * option to execute the command.
1138: */
1139: argv[0] = (char *) cp;
1140: argv[1] = "-c";
1141: argv[2] = (char *) command;
1142: argv[3] = NULL;
1143: execve(shell, argv, env);
1144: perror(shell);
1145: exit(1);
1146: }
1147:
1148: Session *
1149: session_new(void)
1150: {
1151: int i;
1152: static int did_init = 0;
1153: if (!did_init) {
1154: debug("session_new: init");
1155: for(i = 0; i < MAX_SESSIONS; i++) {
1156: sessions[i].used = 0;
1157: }
1158: did_init = 1;
1159: }
1160: for(i = 0; i < MAX_SESSIONS; i++) {
1161: Session *s = &sessions[i];
1162: if (! s->used) {
1.68 djm 1163: memset(s, 0, sizeof(*s));
1.1 markus 1164: s->chanid = -1;
1165: s->ptyfd = -1;
1166: s->ttyfd = -1;
1167: s->used = 1;
1.85 markus 1168: s->self = i;
1.1 markus 1169: debug("session_new: session %d", i);
1170: return s;
1171: }
1172: }
1173: return NULL;
1174: }
1175:
1.94 itojun 1176: static void
1.1 markus 1177: session_dump(void)
1178: {
1179: int i;
1180: for(i = 0; i < MAX_SESSIONS; i++) {
1181: Session *s = &sessions[i];
1182: debug("dump: used %d session %d %p channel %d pid %d",
1183: s->used,
1184: s->self,
1185: s,
1186: s->chanid,
1187: s->pid);
1188: }
1189: }
1190:
1.2 markus 1191: int
1.97 markus 1192: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1193: {
1194: Session *s = session_new();
1195: debug("session_open: channel %d", chanid);
1196: if (s == NULL) {
1197: error("no more sessions");
1198: return 0;
1199: }
1.97 markus 1200: s->authctxt = authctxt;
1201: s->pw = authctxt->pw;
1.7 markus 1202: if (s->pw == NULL)
1.54 stevesk 1203: fatal("no user for session %d", s->self);
1.2 markus 1204: debug("session_open: session %d: link with channel %d", s->self, chanid);
1205: s->chanid = chanid;
1206: return 1;
1207: }
1208:
1.94 itojun 1209: static Session *
1.2 markus 1210: session_by_channel(int id)
1211: {
1212: int i;
1213: for(i = 0; i < MAX_SESSIONS; i++) {
1214: Session *s = &sessions[i];
1215: if (s->used && s->chanid == id) {
1216: debug("session_by_channel: session %d channel %d", i, id);
1217: return s;
1218: }
1219: }
1220: debug("session_by_channel: unknown channel %d", id);
1221: session_dump();
1222: return NULL;
1223: }
1224:
1.94 itojun 1225: static Session *
1.2 markus 1226: session_by_pid(pid_t pid)
1227: {
1228: int i;
1229: debug("session_by_pid: pid %d", pid);
1230: for(i = 0; i < MAX_SESSIONS; i++) {
1231: Session *s = &sessions[i];
1232: if (s->used && s->pid == pid)
1233: return s;
1234: }
1235: error("session_by_pid: unknown pid %d", pid);
1236: session_dump();
1237: return NULL;
1238: }
1239:
1.94 itojun 1240: static int
1.2 markus 1241: session_window_change_req(Session *s)
1242: {
1243: s->col = packet_get_int();
1244: s->row = packet_get_int();
1245: s->xpixel = packet_get_int();
1246: s->ypixel = packet_get_int();
1.3 markus 1247: packet_done();
1.2 markus 1248: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1249: return 1;
1250: }
1251:
1.94 itojun 1252: static int
1.2 markus 1253: session_pty_req(Session *s)
1254: {
1.45 markus 1255: u_int len;
1.72 stevesk 1256: int n_bytes;
1.2 markus 1257:
1.86 markus 1258: if (no_pty_flag) {
1259: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1260: return 0;
1.86 markus 1261: }
1262: if (s->ttyfd != -1) {
1263: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1264: return 0;
1.86 markus 1265: }
1266:
1.2 markus 1267: s->term = packet_get_string(&len);
1.86 markus 1268:
1269: if (compat20) {
1270: s->col = packet_get_int();
1271: s->row = packet_get_int();
1272: } else {
1273: s->row = packet_get_int();
1274: s->col = packet_get_int();
1275: }
1.2 markus 1276: s->xpixel = packet_get_int();
1277: s->ypixel = packet_get_int();
1278:
1279: if (strcmp(s->term, "") == 0) {
1280: xfree(s->term);
1281: s->term = NULL;
1282: }
1.86 markus 1283:
1.2 markus 1284: /* Allocate a pty and open it. */
1.86 markus 1285: debug("Allocating pty.");
1.2 markus 1286: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.86 markus 1287: if (s->term)
1288: xfree(s->term);
1.2 markus 1289: s->term = NULL;
1290: s->ptyfd = -1;
1291: s->ttyfd = -1;
1292: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1293: return 0;
1.2 markus 1294: }
1295: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1296:
1297: /* for SSH1 the tty modes length is not given */
1298: if (!compat20)
1299: n_bytes = packet_remaining();
1300: tty_parse_modes(s->ttyfd, &n_bytes);
1301:
1.2 markus 1302: /*
1303: * Add a cleanup function to clear the utmp entry and record logout
1304: * time in case we call fatal() (e.g., the connection gets closed).
1305: */
1.85 markus 1306: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1307: pty_setowner(s->pw, s->tty);
1.86 markus 1308:
1309: /* Set window size from the packet. */
1.2 markus 1310: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1311:
1.72 stevesk 1312: packet_done();
1.9 markus 1313: session_proctitle(s);
1.2 markus 1314: return 1;
1315: }
1316:
1.94 itojun 1317: static int
1.7 markus 1318: session_subsystem_req(Session *s)
1319: {
1.45 markus 1320: u_int len;
1.7 markus 1321: int success = 0;
1322: char *subsys = packet_get_string(&len);
1.18 jakob 1323: int i;
1.7 markus 1324:
1325: packet_done();
1326: log("subsystem request for %s", subsys);
1.18 jakob 1327:
1328: for (i = 0; i < options.num_subsystems; i++) {
1329: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1330: debug("subsystem: exec() %s", options.subsystem_command[i]);
1.64 markus 1331: s->is_subsystem = 1;
1.63 markus 1332: do_exec_no_pty(s, options.subsystem_command[i]);
1.18 jakob 1333: success = 1;
1334: }
1335: }
1336:
1337: if (!success)
1338: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1339:
1340: xfree(subsys);
1341: return success;
1342: }
1343:
1.94 itojun 1344: static int
1.7 markus 1345: session_x11_req(Session *s)
1346: {
1.81 markus 1347: int success;
1.7 markus 1348:
1349: s->single_connection = packet_get_char();
1350: s->auth_proto = packet_get_string(NULL);
1351: s->auth_data = packet_get_string(NULL);
1352: s->screen = packet_get_int();
1353: packet_done();
1354:
1.81 markus 1355: success = session_setup_x11fwd(s);
1356: if (!success) {
1.7 markus 1357: xfree(s->auth_proto);
1358: xfree(s->auth_data);
1.84 markus 1359: s->auth_proto = NULL;
1360: s->auth_data = NULL;
1.7 markus 1361: }
1.81 markus 1362: return success;
1.7 markus 1363: }
1364:
1.94 itojun 1365: static int
1.19 markus 1366: session_shell_req(Session *s)
1367: {
1368: packet_done();
1.90 markus 1369: do_exec(s, NULL);
1.19 markus 1370: return 1;
1371: }
1372:
1.94 itojun 1373: static int
1.19 markus 1374: session_exec_req(Session *s)
1375: {
1.45 markus 1376: u_int len;
1.19 markus 1377: char *command = packet_get_string(&len);
1378: packet_done();
1.90 markus 1379: do_exec(s, command);
1.92 markus 1380: xfree(command);
1.19 markus 1381: return 1;
1382: }
1383:
1.94 itojun 1384: static int
1.43 markus 1385: session_auth_agent_req(Session *s)
1386: {
1387: static int called = 0;
1388: packet_done();
1.44 markus 1389: if (no_agent_forwarding_flag) {
1390: debug("session_auth_agent_req: no_agent_forwarding_flag");
1391: return 0;
1392: }
1.43 markus 1393: if (called) {
1394: return 0;
1395: } else {
1396: called = 1;
1397: return auth_input_request_forwarding(s->pw);
1398: }
1399: }
1400:
1.2 markus 1401: void
1402: session_input_channel_req(int id, void *arg)
1403: {
1.45 markus 1404: u_int len;
1.2 markus 1405: int reply;
1406: int success = 0;
1407: char *rtype;
1408: Session *s;
1409: Channel *c;
1410:
1411: rtype = packet_get_string(&len);
1412: reply = packet_get_char();
1413:
1414: s = session_by_channel(id);
1415: if (s == NULL)
1416: fatal("session_input_channel_req: channel %d: no session", id);
1417: c = channel_lookup(id);
1418: if (c == NULL)
1419: fatal("session_input_channel_req: channel %d: bad channel", id);
1420:
1421: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1422: s->self, id, rtype, reply);
1423:
1424: /*
1.64 markus 1425: * a session is in LARVAL state until a shell, a command
1426: * or a subsystem is executed
1.2 markus 1427: */
1428: if (c->type == SSH_CHANNEL_LARVAL) {
1429: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1430: success = session_shell_req(s);
1.2 markus 1431: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1432: success = session_exec_req(s);
1.2 markus 1433: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1434: success = session_pty_req(s);
1.7 markus 1435: } else if (strcmp(rtype, "x11-req") == 0) {
1436: success = session_x11_req(s);
1.43 markus 1437: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1438: success = session_auth_agent_req(s);
1.7 markus 1439: } else if (strcmp(rtype, "subsystem") == 0) {
1440: success = session_subsystem_req(s);
1.2 markus 1441: }
1442: }
1443: if (strcmp(rtype, "window-change") == 0) {
1444: success = session_window_change_req(s);
1445: }
1446:
1447: if (reply) {
1448: packet_start(success ?
1449: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1450: packet_put_int(c->remote_id);
1451: packet_send();
1452: }
1453: xfree(rtype);
1454: }
1455:
1456: void
1457: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1458: {
1459: if (!compat20)
1460: fatal("session_set_fds: called for proto != 2.0");
1461: /*
1462: * now that have a child and a pipe to the child,
1463: * we can activate our channel and register the fd's
1464: */
1465: if (s->chanid == -1)
1466: fatal("no channel for session %d", s->self);
1467: channel_set_fds(s->chanid,
1468: fdout, fdin, fderr,
1.42 markus 1469: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1470: 1);
1.2 markus 1471: }
1472:
1.85 markus 1473: /*
1474: * Function to perform pty cleanup. Also called if we get aborted abnormally
1475: * (e.g., due to a dropped connection).
1476: */
1.94 itojun 1477: static void
1.85 markus 1478: session_pty_cleanup(void *session)
1.1 markus 1479: {
1.85 markus 1480: Session *s = session;
1481:
1482: if (s == NULL) {
1483: error("session_pty_cleanup: no session");
1484: return;
1485: }
1486: if (s->ttyfd == -1)
1.1 markus 1487: return;
1488:
1.54 stevesk 1489: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1490:
1491: /* Record that the user has logged out. */
1.85 markus 1492: if (s->pid != 0)
1493: record_logout(s->pid, s->tty);
1.1 markus 1494:
1495: /* Release the pseudo-tty. */
1496: pty_release(s->tty);
1497:
1498: /*
1499: * Close the server side of the socket pairs. We must do this after
1500: * the pty cleanup, so that another process doesn't get this pty
1501: * while we're still cleaning up.
1502: */
1503: if (close(s->ptymaster) < 0)
1504: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1505: }
1506:
1.94 itojun 1507: static void
1.2 markus 1508: session_exit_message(Session *s, int status)
1509: {
1510: Channel *c;
1511: if (s == NULL)
1512: fatal("session_close: no session");
1513: c = channel_lookup(s->chanid);
1514: if (c == NULL)
1.85 markus 1515: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1516: s->self, s->chanid);
1517: debug("session_exit_message: session %d channel %d pid %d",
1518: s->self, s->chanid, s->pid);
1519:
1520: if (WIFEXITED(status)) {
1521: channel_request_start(s->chanid,
1522: "exit-status", 0);
1523: packet_put_int(WEXITSTATUS(status));
1524: packet_send();
1525: } else if (WIFSIGNALED(status)) {
1526: channel_request_start(s->chanid,
1527: "exit-signal", 0);
1528: packet_put_int(WTERMSIG(status));
1529: packet_put_char(WCOREDUMP(status));
1530: packet_put_cstring("");
1531: packet_put_cstring("");
1532: packet_send();
1533: } else {
1534: /* Some weird exit cause. Just exit. */
1535: packet_disconnect("wait returned status %04x.", status);
1536: }
1537:
1538: /* disconnect channel */
1539: debug("session_exit_message: release channel %d", s->chanid);
1540: channel_cancel_cleanup(s->chanid);
1.5 markus 1541: /*
1542: * emulate a write failure with 'chan_write_failed', nobody will be
1543: * interested in data we write.
1544: * Note that we must not call 'chan_read_failed', since there could
1545: * be some more data waiting in the pipe.
1546: */
1.8 markus 1547: if (c->ostate != CHAN_OUTPUT_CLOSED)
1548: chan_write_failed(c);
1.2 markus 1549: s->chanid = -1;
1550: }
1551:
1.94 itojun 1552: static void
1.85 markus 1553: session_close(Session *s)
1.2 markus 1554: {
1.85 markus 1555: debug("session_close: session %d pid %d", s->self, s->pid);
1556: if (s->ttyfd != -1) {
1557: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1558: session_pty_cleanup(s);
1559: }
1.2 markus 1560: if (s->term)
1561: xfree(s->term);
1562: if (s->display)
1563: xfree(s->display);
1564: if (s->auth_data)
1565: xfree(s->auth_data);
1566: if (s->auth_proto)
1567: xfree(s->auth_proto);
1568: s->used = 0;
1.9 markus 1569: session_proctitle(s);
1.2 markus 1570: }
1571:
1572: void
1573: session_close_by_pid(pid_t pid, int status)
1574: {
1575: Session *s = session_by_pid(pid);
1576: if (s == NULL) {
1.89 markus 1577: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1578: return;
1579: }
1580: if (s->chanid != -1)
1581: session_exit_message(s, status);
1582: session_close(s);
1.98 ! markus 1583: }
! 1584:
! 1585: int
! 1586: session_have_children(void)
! 1587: {
! 1588: int i;
! 1589:
! 1590: for(i = 0; i < MAX_SESSIONS; i++) {
! 1591: Session *s = &sessions[i];
! 1592: if (s->used && s->pid != -1) {
! 1593: debug("session_have_children: id %d pid %d", i, s->pid);
! 1594: return 1;
! 1595: }
! 1596: }
! 1597: debug("session_have_children: no more children");
! 1598: return 0;
1.2 markus 1599: }
1600:
1601: /*
1602: * this is called when a channel dies before
1603: * the session 'child' itself dies
1604: */
1605: void
1606: session_close_by_channel(int id, void *arg)
1607: {
1608: Session *s = session_by_channel(id);
1609: if (s == NULL) {
1610: debug("session_close_by_channel: no session for channel %d", id);
1611: return;
1612: }
1613: /* disconnect channel */
1614: channel_cancel_cleanup(s->chanid);
1615: s->chanid = -1;
1616:
1617: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1618: if (s->pid == 0) {
1619: /* close session immediately */
1620: session_close(s);
1621: } else {
1622: /* notify child, delay session cleanup */
1623: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1624: error("session_close_by_channel: kill %d: %s",
1625: s->pid, strerror(errno));
1626: }
1.9 markus 1627: }
1628:
1.94 itojun 1629: static char *
1.9 markus 1630: session_tty_list(void)
1631: {
1632: static char buf[1024];
1633: int i;
1634: buf[0] = '\0';
1635: for(i = 0; i < MAX_SESSIONS; i++) {
1636: Session *s = &sessions[i];
1637: if (s->used && s->ttyfd != -1) {
1638: if (buf[0] != '\0')
1639: strlcat(buf, ",", sizeof buf);
1640: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1641: }
1642: }
1643: if (buf[0] == '\0')
1644: strlcpy(buf, "notty", sizeof buf);
1645: return buf;
1646: }
1647:
1648: void
1649: session_proctitle(Session *s)
1650: {
1651: if (s->pw == NULL)
1652: error("no user for session %d", s->self);
1653: else
1654: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1655: }
1656:
1657: int
1658: session_setup_x11fwd(Session *s)
1659: {
1660: struct stat st;
1661:
1662: if (no_x11_forwarding_flag) {
1663: packet_send_debug("X11 forwarding disabled in user configuration file.");
1664: return 0;
1665: }
1666: if (!options.x11_forwarding) {
1667: debug("X11 forwarding disabled in server configuration file.");
1668: return 0;
1669: }
1670: if (!options.xauth_location ||
1671: (stat(options.xauth_location, &st) == -1)) {
1672: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1673: return 0;
1674: }
1675: if (options.use_login) {
1676: packet_send_debug("X11 forwarding disabled; "
1677: "not compatible with UseLogin=yes.");
1.81 markus 1678: return 0;
1679: }
1.87 markus 1680: if (s->display != NULL) {
1.81 markus 1681: debug("X11 display already set.");
1682: return 0;
1683: }
1684: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1685: if (s->display == NULL) {
1.87 markus 1686: debug("x11_create_display_inet failed.");
1.81 markus 1687: return 0;
1688: }
1689: return 1;
1.2 markus 1690: }
1691:
1.94 itojun 1692: static void
1.49 markus 1693: do_authenticated2(Authctxt *authctxt)
1.2 markus 1694: {
1.97 markus 1695: server_loop2(authctxt);
1.1 markus 1696: }
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