Annotation of src/usr.bin/ssh/session.c, Revision 1.42.2.6
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.
1.42.2.6! miod 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"
1.42.2.6! miod 36: RCSID("$OpenBSD: session.c,v 1.102 2001/09/16 14:46:54 markus Exp $");
1.1 markus 37:
38: #include "ssh.h"
1.42.2.1 jason 39: #include "ssh1.h"
40: #include "ssh2.h"
41: #include "xmalloc.h"
1.42.2.3 jason 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"
48: #include "channels.h"
1.2 markus 49: #include "bufaux.h"
50: #include "auth.h"
1.19 markus 51: #include "auth-options.h"
1.42.2.1 jason 52: #include "pathnames.h"
53: #include "log.h"
54: #include "servconf.h"
1.42.2.3 jason 55: #include "sshlogin.h"
1.42.2.1 jason 56: #include "serverloop.h"
57: #include "canohost.h"
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;
1.42.2.6! miod 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;
1.42.2.4 jason 83: int is_subsystem;
1.1 markus 84: };
85:
86: /* func */
87:
88: Session *session_new(void);
1.42.2.6! miod 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 *);
1.42.2.4 jason 98: void do_motd(void);
1.42.2.6! miod 99: int check_quietlogin(Session *, const char *);
1.42.2.4 jason 100:
1.42.2.6! miod 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 *);
1.1 markus 106:
107: /* import */
108: extern ServerOptions options;
109: extern char *__progname;
110: extern int log_stderr;
111: extern int debug_flag;
1.42.2.1 jason 112: extern u_int utmp_len;
1.21 markus 113: extern int startup_pipe;
1.42.2.4 jason 114: extern void destroy_sensitive_data(void);
1.21 markus 115:
1.34 markus 116: /* original command from peer. */
1.42.2.6! miod 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:
1.42.2.4 jason 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: }
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
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);
159:
1.42.2.5 miod 160: /* remove agent socket */
161: if (auth_get_socket_name())
162: auth_sock_cleanup_proc(authctxt->pw);
1.42.2.6! miod 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
1.1 markus 171: }
172:
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: */
1.42.2.6! miod 179: static void
1.42.2.4 jason 180: do_authenticated1(Authctxt *authctxt)
1.1 markus 181: {
182: Session *s;
183: char *command;
1.42.2.6! miod 184: int success, type, plen, screen_flag;
1.42.2.4 jason 185: int compression_level = 0, enable_compression_after_reply = 0;
1.42.2.1 jason 186: u_int proto_len, data_len, dlen;
1.1 markus 187:
188: s = session_new();
1.42.2.6! miod 189: s->authctxt = authctxt;
1.42.2.4 jason 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 (;;) {
1.42.2.4 jason 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:
1.42.2.6! miod 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:
1.42.2.3 jason 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();
1.42.2.1 jason 234: } else {
1.1 markus 235: s->screen = 0;
1.42.2.1 jason 236: }
1.42.2.6! miod 237: packet_done();
! 238: success = session_setup_x11fwd(s);
! 239: if (!success) {
! 240: xfree(s->auth_proto);
! 241: xfree(s->auth_data);
! 242: s->auth_proto = NULL;
! 243: s->auth_data = NULL;
! 244: }
1.1 markus 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.");
1.42.2.4 jason 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.");
1.42.2.4 jason 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;
1.42.2.6! miod 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);
1.42.2.6! miod 332: do_exec(s, command);
! 333: xfree(command);
1.1 markus 334: } else {
1.42.2.6! miod 335: do_exec(s, NULL);
1.1 markus 336: }
1.42.2.6! miod 337: packet_done();
! 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
1.42.2.4 jason 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). */
1.42.2.3 jason 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;
1.42.2.1 jason 445: /* Set interactive/non-interactive mode. */
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) {
1.42.2.4 jason 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]);
1.42.2.4 jason 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) {
1.42.2.4 jason 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
1.42.2.4 jason 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) {
1.42.2.6! miod 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. */
1.42.2.3 jason 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. */
1.42.2.1 jason 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:
1.42.2.6! miod 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:
! 579: original_command = NULL;
! 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. */
1.42.2.4 jason 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,
1.42.2.4 jason 618: get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
619: (struct sockaddr *)&from);
1.24 markus 620:
1.42.2.4 jason 621: if (check_quietlogin(s, command))
1.24 markus 622: return;
1.42.2.4 jason 623:
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: }
1.42.2.4 jason 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: }
1.1 markus 659: }
660:
1.42.2.4 jason 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];
1.42.2.6! miod 669: struct passwd *pw = s->pw;
1.42.2.4 jason 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;
684: }
685:
1.1 markus 686: /*
687: * Sets the value of the given variable in the environment. If the variable
688: * already exists, its value is overriden.
689: */
1.42.2.6! miod 690: static void
1.42.2.1 jason 691: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 692: const char *value)
693: {
1.42.2.1 jason 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: */
1.42.2.6! miod 731: static void
1.42.2.1 jason 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
1.42.2.3 jason 772: do_child(Session *s, const char *command)
1.1 markus 773: {
1.32 markus 774: const char *shell, *hostname = NULL, *cp = NULL;
1.42.2.6! miod 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;
1.42.2.1 jason 779: u_int envsize, i;
1.1 markus 780: char **env;
781: extern char **environ;
782: struct stat st;
783: char *argv[10];
1.42.2.6! miod 784: int do_xauth;
! 785:
! 786: do_xauth =
! 787: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 788:
1.42.2.4 jason 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. */
1.42.2.4 jason 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: /* Initialize the environment. */
855: envsize = 100;
856: env = xmalloc(envsize * sizeof(char *));
857: env[0] = NULL;
858:
859: if (!options.use_login) {
860: /* Set basic environment. */
861: child_set_env(&env, &envsize, "USER", pw->pw_name);
862: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
863: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 864: #ifdef HAVE_LOGIN_CAP
1.29 millert 865: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
866: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 867: #else
1.29 millert 868: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 869: #endif
1.1 markus 870:
871: snprintf(buf, sizeof buf, "%.200s/%.50s",
872: _PATH_MAILDIR, pw->pw_name);
873: child_set_env(&env, &envsize, "MAIL", buf);
874:
875: /* Normal systems set SHELL by default. */
876: child_set_env(&env, &envsize, "SHELL", shell);
877: }
878: if (getenv("TZ"))
879: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
880:
881: /* Set custom environment options from RSA authentication. */
882: while (custom_environment) {
883: struct envstring *ce = custom_environment;
884: char *s = ce->s;
885: int i;
886: for (i = 0; s[i] != '=' && s[i]; i++);
887: if (s[i] == '=') {
888: s[i] = 0;
889: child_set_env(&env, &envsize, s, s + i + 1);
890: }
891: custom_environment = ce->next;
892: xfree(ce->s);
893: xfree(ce);
894: }
895:
896: snprintf(buf, sizeof buf, "%.50s %d %d",
897: get_remote_ipaddr(), get_remote_port(), get_local_port());
898: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
899:
1.42.2.3 jason 900: if (s->ttyfd != -1)
901: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
902: if (s->term)
903: child_set_env(&env, &envsize, "TERM", s->term);
904: if (s->display)
905: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 906: if (original_command)
907: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
908: original_command);
1.1 markus 909: #ifdef KRB4
1.42.2.6! miod 910: if (s->authctxt->krb4_ticket_file)
! 911: child_set_env(&env, &envsize, "KRBTKFILE",
! 912: s->authctxt->krb4_ticket_file);
! 913: #endif
! 914: #ifdef KRB5
! 915: if (s->authctxt->krb5_ticket_file)
! 916: child_set_env(&env, &envsize, "KRB5CCNAME",
! 917: s->authctxt->krb5_ticket_file);
! 918: #endif
1.1 markus 919: if (auth_get_socket_name() != NULL)
920: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
921: auth_get_socket_name());
922:
923: /* read $HOME/.ssh/environment. */
924: if (!options.use_login) {
1.14 deraadt 925: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
926: pw->pw_dir);
1.1 markus 927: read_environment_file(&env, &envsize, buf);
928: }
929: if (debug_flag) {
930: /* dump the environment */
931: fprintf(stderr, "Environment:\n");
932: for (i = 0; env[i]; i++)
933: fprintf(stderr, " %.200s\n", env[i]);
934: }
1.26 millert 935: /* we have to stash the hostname before we close our socket. */
936: if (options.use_login)
1.42.2.4 jason 937: hostname = get_remote_name_or_ip(utmp_len,
938: options.reverse_mapping_check);
1.1 markus 939: /*
940: * Close the connection descriptors; note that this is the child, and
941: * the server will still have the socket open, and it is important
942: * that we do not shutdown it. Note that the descriptors cannot be
943: * closed before building the environment, as we call
944: * get_remote_ipaddr there.
945: */
946: if (packet_get_connection_in() == packet_get_connection_out())
947: close(packet_get_connection_in());
948: else {
949: close(packet_get_connection_in());
950: close(packet_get_connection_out());
951: }
952: /*
953: * Close all descriptors related to channels. They will still remain
954: * open in the parent.
955: */
956: /* XXX better use close-on-exec? -markus */
957: channel_close_all();
958:
959: /*
960: * Close any extra file descriptors. Note that there may still be
961: * descriptors left by system functions. They will be closed later.
962: */
963: endpwent();
964:
965: /*
966: * Close any extra open file descriptors so that we don\'t have them
967: * hanging around in clients. Note that we want to do this after
968: * initgroups, because at least on Solaris 2.3 it leaves file
969: * descriptors open.
970: */
971: for (i = 3; i < 64; i++)
972: close(i);
973:
974: /* Change current directory to the user\'s home directory. */
1.28 millert 975: if (chdir(pw->pw_dir) < 0) {
1.1 markus 976: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
977: pw->pw_dir, strerror(errno));
1.28 millert 978: #ifdef HAVE_LOGIN_CAP
979: if (login_getcapbool(lc, "requirehome", 0))
980: exit(1);
981: #endif
982: }
1.1 markus 983:
984: /*
985: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
986: * xauth are run in the proper environment.
987: */
988: environ = env;
989:
1.42.2.6! miod 990: #ifdef AFS
! 991: /* Try to get AFS tokens for the local cell. */
! 992: if (k_hasafs()) {
! 993: char cell[64];
! 994:
! 995: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
! 996: krb_afslog(cell, 0);
! 997:
! 998: krb_afslog(0, 0);
! 999: }
! 1000: #endif /* AFS */
! 1001:
1.1 markus 1002: /*
1003: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1004: * in this order).
1005: */
1006: if (!options.use_login) {
1.42.2.4 jason 1007: /* ignore _PATH_SSH_USER_RC for subsystems */
1008: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.42.2.6! miod 1009: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
! 1010: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 1011: if (debug_flag)
1.42.2.6! miod 1012: fprintf(stderr, "Running %s\n", cmd);
! 1013: f = popen(cmd, "w");
1.1 markus 1014: if (f) {
1.42.2.3 jason 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
1.42.2.3 jason 1020: fprintf(stderr, "Could not run %s\n",
1021: _PATH_SSH_USER_RC);
1.42.2.1 jason 1022: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1023: if (debug_flag)
1.42.2.3 jason 1024: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1025: _PATH_SSH_SYSTEM_RC);
1.42.2.1 jason 1026: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1027: if (f) {
1.42.2.3 jason 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
1.42.2.3 jason 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. */
1.42.2.3 jason 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,
1.42.2.3 jason 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: }
1.42.2.4 jason 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: /* Start the shell. Set initial character to '-'. */
1091: buf[0] = '-';
1092: strncpy(buf + 1, cp, sizeof(buf) - 1);
1093: buf[sizeof(buf) - 1] = 0;
1094:
1095: /* Execute the shell. */
1096: argv[0] = buf;
1097: argv[1] = NULL;
1098: execve(shell, argv, env);
1099:
1100: /* Executing the shell failed. */
1101: perror(shell);
1102: exit(1);
1103:
1104: } else {
1105: /* Launch login(1). */
1106:
1.26 millert 1107: execl("/usr/bin/login", "login", "-h", hostname,
1.42.2.6! miod 1108: "-p", "-f", "--", pw->pw_name, (char *)NULL);
1.1 markus 1109:
1110: /* Login couldn't be executed, die. */
1111:
1112: perror("login");
1113: exit(1);
1114: }
1115: }
1116: /*
1117: * Execute the command using the user's shell. This uses the -c
1118: * option to execute the command.
1119: */
1120: argv[0] = (char *) cp;
1121: argv[1] = "-c";
1122: argv[2] = (char *) command;
1123: argv[3] = NULL;
1124: execve(shell, argv, env);
1125: perror(shell);
1126: exit(1);
1127: }
1128:
1129: Session *
1130: session_new(void)
1131: {
1132: int i;
1133: static int did_init = 0;
1134: if (!did_init) {
1135: debug("session_new: init");
1136: for(i = 0; i < MAX_SESSIONS; i++) {
1137: sessions[i].used = 0;
1138: }
1139: did_init = 1;
1140: }
1141: for(i = 0; i < MAX_SESSIONS; i++) {
1142: Session *s = &sessions[i];
1143: if (! s->used) {
1.42.2.4 jason 1144: memset(s, 0, sizeof(*s));
1.1 markus 1145: s->chanid = -1;
1146: s->ptyfd = -1;
1147: s->ttyfd = -1;
1148: s->used = 1;
1.42.2.6! miod 1149: s->self = i;
1.1 markus 1150: debug("session_new: session %d", i);
1151: return s;
1152: }
1153: }
1154: return NULL;
1155: }
1156:
1.42.2.6! miod 1157: static void
1.1 markus 1158: session_dump(void)
1159: {
1160: int i;
1161: for(i = 0; i < MAX_SESSIONS; i++) {
1162: Session *s = &sessions[i];
1163: debug("dump: used %d session %d %p channel %d pid %d",
1164: s->used,
1165: s->self,
1166: s,
1167: s->chanid,
1168: s->pid);
1169: }
1170: }
1171:
1.2 markus 1172: int
1.42.2.6! miod 1173: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1174: {
1175: Session *s = session_new();
1176: debug("session_open: channel %d", chanid);
1177: if (s == NULL) {
1178: error("no more sessions");
1179: return 0;
1180: }
1.42.2.6! miod 1181: s->authctxt = authctxt;
! 1182: s->pw = authctxt->pw;
1.7 markus 1183: if (s->pw == NULL)
1.42.2.1 jason 1184: fatal("no user for session %d", s->self);
1.2 markus 1185: debug("session_open: session %d: link with channel %d", s->self, chanid);
1186: s->chanid = chanid;
1187: return 1;
1188: }
1189:
1.42.2.6! miod 1190: static Session *
1.2 markus 1191: session_by_channel(int id)
1192: {
1193: int i;
1194: for(i = 0; i < MAX_SESSIONS; i++) {
1195: Session *s = &sessions[i];
1196: if (s->used && s->chanid == id) {
1197: debug("session_by_channel: session %d channel %d", i, id);
1198: return s;
1199: }
1200: }
1201: debug("session_by_channel: unknown channel %d", id);
1202: session_dump();
1203: return NULL;
1204: }
1205:
1.42.2.6! miod 1206: static Session *
1.2 markus 1207: session_by_pid(pid_t pid)
1208: {
1209: int i;
1210: debug("session_by_pid: pid %d", pid);
1211: for(i = 0; i < MAX_SESSIONS; i++) {
1212: Session *s = &sessions[i];
1213: if (s->used && s->pid == pid)
1214: return s;
1215: }
1216: error("session_by_pid: unknown pid %d", pid);
1217: session_dump();
1218: return NULL;
1219: }
1220:
1.42.2.6! miod 1221: static int
1.2 markus 1222: session_window_change_req(Session *s)
1223: {
1224: s->col = packet_get_int();
1225: s->row = packet_get_int();
1226: s->xpixel = packet_get_int();
1227: s->ypixel = packet_get_int();
1.3 markus 1228: packet_done();
1.2 markus 1229: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1230: return 1;
1231: }
1232:
1.42.2.6! miod 1233: static int
1.2 markus 1234: session_pty_req(Session *s)
1235: {
1.42.2.1 jason 1236: u_int len;
1.42.2.4 jason 1237: int n_bytes;
1.2 markus 1238:
1.42.2.6! miod 1239: if (no_pty_flag) {
! 1240: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1241: return 0;
1.42.2.6! miod 1242: }
! 1243: if (s->ttyfd != -1) {
! 1244: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1245: return 0;
1.42.2.6! miod 1246: }
! 1247:
1.2 markus 1248: s->term = packet_get_string(&len);
1.42.2.6! miod 1249:
! 1250: if (compat20) {
! 1251: s->col = packet_get_int();
! 1252: s->row = packet_get_int();
! 1253: } else {
! 1254: s->row = packet_get_int();
! 1255: s->col = packet_get_int();
! 1256: }
1.2 markus 1257: s->xpixel = packet_get_int();
1258: s->ypixel = packet_get_int();
1259:
1260: if (strcmp(s->term, "") == 0) {
1261: xfree(s->term);
1262: s->term = NULL;
1263: }
1.42.2.6! miod 1264:
1.2 markus 1265: /* Allocate a pty and open it. */
1.42.2.6! miod 1266: debug("Allocating pty.");
1.2 markus 1267: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.42.2.6! miod 1268: if (s->term)
! 1269: xfree(s->term);
1.2 markus 1270: s->term = NULL;
1271: s->ptyfd = -1;
1272: s->ttyfd = -1;
1273: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1274: return 0;
1.2 markus 1275: }
1276: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.42.2.6! miod 1277:
! 1278: /* for SSH1 the tty modes length is not given */
! 1279: if (!compat20)
! 1280: n_bytes = packet_remaining();
! 1281: tty_parse_modes(s->ttyfd, &n_bytes);
! 1282:
1.2 markus 1283: /*
1284: * Add a cleanup function to clear the utmp entry and record logout
1285: * time in case we call fatal() (e.g., the connection gets closed).
1286: */
1.42.2.6! miod 1287: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1288: pty_setowner(s->pw, s->tty);
1.42.2.6! miod 1289:
! 1290: /* Set window size from the packet. */
1.2 markus 1291: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1292:
1.42.2.4 jason 1293: packet_done();
1.9 markus 1294: session_proctitle(s);
1.2 markus 1295: return 1;
1296: }
1297:
1.42.2.6! miod 1298: static int
1.7 markus 1299: session_subsystem_req(Session *s)
1300: {
1.42.2.1 jason 1301: u_int len;
1.7 markus 1302: int success = 0;
1303: char *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++) {
1310: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1311: debug("subsystem: exec() %s", options.subsystem_command[i]);
1.42.2.4 jason 1312: s->is_subsystem = 1;
1.42.2.6! miod 1313: do_exec(s, options.subsystem_command[i]);
1.18 jakob 1314: success = 1;
1315: }
1316: }
1317:
1318: if (!success)
1319: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1320:
1321: xfree(subsys);
1322: return success;
1323: }
1324:
1.42.2.6! miod 1325: static int
1.7 markus 1326: session_x11_req(Session *s)
1327: {
1.42.2.6! miod 1328: int success;
1.7 markus 1329:
1330: s->single_connection = packet_get_char();
1331: s->auth_proto = packet_get_string(NULL);
1332: s->auth_data = packet_get_string(NULL);
1333: s->screen = packet_get_int();
1334: packet_done();
1335:
1.42.2.6! miod 1336: success = session_setup_x11fwd(s);
! 1337: if (!success) {
1.7 markus 1338: xfree(s->auth_proto);
1339: xfree(s->auth_data);
1.42.2.6! miod 1340: s->auth_proto = NULL;
! 1341: s->auth_data = NULL;
1.7 markus 1342: }
1.42.2.6! miod 1343: return success;
1.7 markus 1344: }
1345:
1.42.2.6! miod 1346: static int
1.19 markus 1347: session_shell_req(Session *s)
1348: {
1349: packet_done();
1.42.2.6! miod 1350: do_exec(s, NULL);
1.19 markus 1351: return 1;
1352: }
1353:
1.42.2.6! miod 1354: static int
1.19 markus 1355: session_exec_req(Session *s)
1356: {
1.42.2.1 jason 1357: u_int len;
1.19 markus 1358: char *command = packet_get_string(&len);
1359: packet_done();
1.42.2.6! miod 1360: do_exec(s, command);
! 1361: xfree(command);
1.19 markus 1362: return 1;
1363: }
1364:
1.42.2.6! miod 1365: static int
1.42.2.1 jason 1366: session_auth_agent_req(Session *s)
1367: {
1368: static int called = 0;
1369: packet_done();
1370: if (no_agent_forwarding_flag) {
1371: debug("session_auth_agent_req: no_agent_forwarding_flag");
1372: return 0;
1373: }
1374: if (called) {
1375: return 0;
1376: } else {
1377: called = 1;
1378: return auth_input_request_forwarding(s->pw);
1379: }
1380: }
1381:
1.2 markus 1382: void
1383: session_input_channel_req(int id, void *arg)
1384: {
1.42.2.1 jason 1385: u_int len;
1.2 markus 1386: int reply;
1387: int success = 0;
1388: char *rtype;
1389: Session *s;
1390: Channel *c;
1391:
1392: rtype = packet_get_string(&len);
1393: reply = packet_get_char();
1394:
1395: s = session_by_channel(id);
1396: if (s == NULL)
1397: fatal("session_input_channel_req: channel %d: no session", id);
1398: c = channel_lookup(id);
1399: if (c == NULL)
1400: fatal("session_input_channel_req: channel %d: bad channel", id);
1401:
1402: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1403: s->self, id, rtype, reply);
1404:
1405: /*
1.42.2.4 jason 1406: * a session is in LARVAL state until a shell, a command
1407: * or a subsystem is executed
1.2 markus 1408: */
1409: if (c->type == SSH_CHANNEL_LARVAL) {
1410: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1411: success = session_shell_req(s);
1.2 markus 1412: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1413: success = session_exec_req(s);
1.2 markus 1414: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1415: success = session_pty_req(s);
1.7 markus 1416: } else if (strcmp(rtype, "x11-req") == 0) {
1417: success = session_x11_req(s);
1.42.2.1 jason 1418: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1419: success = session_auth_agent_req(s);
1.7 markus 1420: } else if (strcmp(rtype, "subsystem") == 0) {
1421: success = session_subsystem_req(s);
1.2 markus 1422: }
1423: }
1424: if (strcmp(rtype, "window-change") == 0) {
1425: success = session_window_change_req(s);
1426: }
1427:
1428: if (reply) {
1429: packet_start(success ?
1430: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1431: packet_put_int(c->remote_id);
1432: packet_send();
1433: }
1434: xfree(rtype);
1435: }
1436:
1437: void
1438: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1439: {
1440: if (!compat20)
1441: fatal("session_set_fds: called for proto != 2.0");
1442: /*
1443: * now that have a child and a pipe to the child,
1444: * we can activate our channel and register the fd's
1445: */
1446: if (s->chanid == -1)
1447: fatal("no channel for session %d", s->self);
1448: channel_set_fds(s->chanid,
1449: fdout, fdin, fderr,
1.42 markus 1450: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1451: 1);
1.2 markus 1452: }
1453:
1.42.2.6! miod 1454: /*
! 1455: * Function to perform pty cleanup. Also called if we get aborted abnormally
! 1456: * (e.g., due to a dropped connection).
! 1457: */
! 1458: static void
! 1459: session_pty_cleanup(void *session)
1.1 markus 1460: {
1.42.2.6! miod 1461: Session *s = session;
! 1462:
! 1463: if (s == NULL) {
! 1464: error("session_pty_cleanup: no session");
! 1465: return;
! 1466: }
! 1467: if (s->ttyfd == -1)
1.1 markus 1468: return;
1469:
1.42.2.1 jason 1470: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1471:
1472: /* Record that the user has logged out. */
1.42.2.6! miod 1473: if (s->pid != 0)
! 1474: record_logout(s->pid, s->tty);
1.1 markus 1475:
1476: /* Release the pseudo-tty. */
1477: pty_release(s->tty);
1478:
1479: /*
1480: * Close the server side of the socket pairs. We must do this after
1481: * the pty cleanup, so that another process doesn't get this pty
1482: * while we're still cleaning up.
1483: */
1484: if (close(s->ptymaster) < 0)
1485: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1486: }
1487:
1.42.2.6! miod 1488: static void
1.2 markus 1489: session_exit_message(Session *s, int status)
1490: {
1491: Channel *c;
1492: if (s == NULL)
1493: fatal("session_close: no session");
1494: c = channel_lookup(s->chanid);
1495: if (c == NULL)
1.42.2.6! miod 1496: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1497: s->self, s->chanid);
1498: debug("session_exit_message: session %d channel %d pid %d",
1499: s->self, s->chanid, s->pid);
1500:
1501: if (WIFEXITED(status)) {
1502: channel_request_start(s->chanid,
1503: "exit-status", 0);
1504: packet_put_int(WEXITSTATUS(status));
1505: packet_send();
1506: } else if (WIFSIGNALED(status)) {
1507: channel_request_start(s->chanid,
1508: "exit-signal", 0);
1509: packet_put_int(WTERMSIG(status));
1510: packet_put_char(WCOREDUMP(status));
1511: packet_put_cstring("");
1512: packet_put_cstring("");
1513: packet_send();
1514: } else {
1515: /* Some weird exit cause. Just exit. */
1516: packet_disconnect("wait returned status %04x.", status);
1517: }
1518:
1519: /* disconnect channel */
1520: debug("session_exit_message: release channel %d", s->chanid);
1521: channel_cancel_cleanup(s->chanid);
1.5 markus 1522: /*
1523: * emulate a write failure with 'chan_write_failed', nobody will be
1524: * interested in data we write.
1525: * Note that we must not call 'chan_read_failed', since there could
1526: * be some more data waiting in the pipe.
1527: */
1.8 markus 1528: if (c->ostate != CHAN_OUTPUT_CLOSED)
1529: chan_write_failed(c);
1.2 markus 1530: s->chanid = -1;
1531: }
1532:
1.42.2.6! miod 1533: static void
! 1534: session_close(Session *s)
1.2 markus 1535: {
1.42.2.6! miod 1536: debug("session_close: session %d pid %d", s->self, s->pid);
! 1537: if (s->ttyfd != -1) {
! 1538: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
! 1539: session_pty_cleanup(s);
! 1540: }
1.2 markus 1541: if (s->term)
1542: xfree(s->term);
1543: if (s->display)
1544: xfree(s->display);
1545: if (s->auth_data)
1546: xfree(s->auth_data);
1547: if (s->auth_proto)
1548: xfree(s->auth_proto);
1549: s->used = 0;
1.9 markus 1550: session_proctitle(s);
1.2 markus 1551: }
1552:
1553: void
1554: session_close_by_pid(pid_t pid, int status)
1555: {
1556: Session *s = session_by_pid(pid);
1557: if (s == NULL) {
1.42.2.6! miod 1558: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1559: return;
1560: }
1561: if (s->chanid != -1)
1562: session_exit_message(s, status);
1563: session_close(s);
1564: }
1565:
1.42.2.6! miod 1566: int
! 1567: session_have_children(void)
! 1568: {
! 1569: int i;
! 1570:
! 1571: for(i = 0; i < MAX_SESSIONS; i++) {
! 1572: Session *s = &sessions[i];
! 1573: if (s->used && s->pid != -1) {
! 1574: debug("session_have_children: id %d pid %d", i, s->pid);
! 1575: return 1;
! 1576: }
! 1577: }
! 1578: debug("session_have_children: no more children");
! 1579: return 0;
! 1580: }
! 1581:
1.2 markus 1582: /*
1583: * this is called when a channel dies before
1584: * the session 'child' itself dies
1585: */
1586: void
1587: session_close_by_channel(int id, void *arg)
1588: {
1589: Session *s = session_by_channel(id);
1590: if (s == NULL) {
1591: debug("session_close_by_channel: no session for channel %d", id);
1592: return;
1593: }
1594: /* disconnect channel */
1595: channel_cancel_cleanup(s->chanid);
1596: s->chanid = -1;
1597:
1598: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1599: if (s->pid == 0) {
1600: /* close session immediately */
1601: session_close(s);
1602: } else {
1603: /* notify child, delay session cleanup */
1604: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1605: error("session_close_by_channel: kill %d: %s",
1606: s->pid, strerror(errno));
1607: }
1.9 markus 1608: }
1609:
1.42.2.6! miod 1610: static char *
1.9 markus 1611: session_tty_list(void)
1612: {
1613: static char buf[1024];
1614: int i;
1615: buf[0] = '\0';
1616: for(i = 0; i < MAX_SESSIONS; i++) {
1617: Session *s = &sessions[i];
1618: if (s->used && s->ttyfd != -1) {
1619: if (buf[0] != '\0')
1620: strlcat(buf, ",", sizeof buf);
1621: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1622: }
1623: }
1624: if (buf[0] == '\0')
1625: strlcpy(buf, "notty", sizeof buf);
1626: return buf;
1627: }
1628:
1629: void
1630: session_proctitle(Session *s)
1631: {
1632: if (s->pw == NULL)
1633: error("no user for session %d", s->self);
1634: else
1635: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1636: }
1637:
1.42.2.6! miod 1638: int
! 1639: session_setup_x11fwd(Session *s)
1.2 markus 1640: {
1.42.2.6! miod 1641: struct stat st;
1.42.2.4 jason 1642:
1.42.2.6! miod 1643: if (no_x11_forwarding_flag) {
! 1644: packet_send_debug("X11 forwarding disabled in user configuration file.");
! 1645: return 0;
! 1646: }
! 1647: if (!options.x11_forwarding) {
! 1648: debug("X11 forwarding disabled in server configuration file.");
! 1649: return 0;
! 1650: }
! 1651: if (!options.xauth_location ||
! 1652: (stat(options.xauth_location, &st) == -1)) {
! 1653: packet_send_debug("No xauth program; cannot forward with spoofing.");
! 1654: return 0;
! 1655: }
! 1656: if (options.use_login) {
! 1657: packet_send_debug("X11 forwarding disabled; "
! 1658: "not compatible with UseLogin=yes.");
! 1659: return 0;
! 1660: }
! 1661: if (s->display != NULL) {
! 1662: debug("X11 display already set.");
! 1663: return 0;
! 1664: }
! 1665: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
! 1666: if (s->display == NULL) {
! 1667: debug("x11_create_display_inet failed.");
! 1668: return 0;
! 1669: }
! 1670: return 1;
! 1671: }
! 1672:
! 1673: static void
! 1674: do_authenticated2(Authctxt *authctxt)
! 1675: {
! 1676: server_loop2(authctxt);
1.1 markus 1677: }
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