Annotation of src/usr.bin/ssh/session.c, Revision 1.93
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.
1.58 deraadt 12: * Copyright (c) 2000 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"
1.93 ! markus 36: RCSID("$OpenBSD: session.c,v 1.92 2001/06/19 15:40:45 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;
67: struct passwd *pw;
68: pid_t pid;
69: /* tty */
70: char *term;
71: int ptyfd, ttyfd, ptymaster;
72: int row, col, xpixel, ypixel;
73: char tty[TTYSZ];
74: /* X11 */
75: char *display;
76: int screen;
77: char *auth_proto;
78: char *auth_data;
1.7 markus 79: int single_connection;
1.1 markus 80: /* proto 2 */
81: int chanid;
1.64 markus 82: int is_subsystem;
1.1 markus 83: };
84:
85: /* func */
86:
87: Session *session_new(void);
88: void session_set_fds(Session *s, int fdin, int fdout, int fderr);
1.85 markus 89: void session_pty_cleanup(void *session);
1.86 markus 90: int session_pty_req(Session *s);
1.9 markus 91: void session_proctitle(Session *s);
1.81 markus 92: int session_setup_x11fwd(Session *s);
1.82 markus 93: void session_close(Session *s);
1.63 markus 94: void do_exec_pty(Session *s, const char *command);
95: void do_exec_no_pty(Session *s, const char *command);
1.90 markus 96: void do_exec(Session *s, const char *command);
1.41 markus 97: void do_login(Session *s, const char *command);
1.60 markus 98: void do_child(Session *s, const char *command);
1.73 djm 99: void do_motd(void);
100: int check_quietlogin(Session *s, const char *command);
1.1 markus 101:
1.65 markus 102: void do_authenticated1(Authctxt *authctxt);
103: void do_authenticated2(Authctxt *authctxt);
104:
1.1 markus 105: /* import */
106: extern ServerOptions options;
107: extern char *__progname;
108: extern int log_stderr;
109: extern int debug_flag;
1.45 markus 110: extern u_int utmp_len;
1.21 markus 111: extern int startup_pipe;
1.74 markus 112: extern void destroy_sensitive_data(void);
1.21 markus 113:
1.34 markus 114: /* original command from peer. */
1.92 markus 115: const char *original_command = NULL;
1.34 markus 116:
1.1 markus 117: /* data */
118: #define MAX_SESSIONS 10
119: Session sessions[MAX_SESSIONS];
120:
1.28 millert 121: #ifdef HAVE_LOGIN_CAP
122: static login_cap_t *lc;
123: #endif
124:
1.65 markus 125: void
126: do_authenticated(Authctxt *authctxt)
127: {
128: /*
129: * Cancel the alarm we set to limit the time taken for
130: * authentication.
131: */
132: alarm(0);
133: if (startup_pipe != -1) {
134: close(startup_pipe);
135: startup_pipe = -1;
136: }
137: #ifdef HAVE_LOGIN_CAP
138: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
139: error("unable to get login class");
140: return;
141: }
1.74 markus 142: #ifdef BSD_AUTH
143: if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
144: packet_disconnect("Approval failure for %s",
145: authctxt->pw->pw_name);
146: }
147: #endif
1.65 markus 148: #endif
149: /* setup the channel layer */
150: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
151: channel_permit_all_opens();
152:
153: if (compat20)
154: do_authenticated2(authctxt);
155: else
156: do_authenticated1(authctxt);
1.79 markus 157:
1.87 markus 158: /* remove agent socket */
1.79 markus 159: if (auth_get_socket_name())
1.80 markus 160: auth_sock_cleanup_proc(authctxt->pw);
1.65 markus 161: }
162:
1.1 markus 163: /*
164: * Prepares for an interactive session. This is called after the user has
165: * been successfully authenticated. During this message exchange, pseudo
166: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
167: * are requested, etc.
168: */
1.4 markus 169: void
1.65 markus 170: do_authenticated1(Authctxt *authctxt)
1.1 markus 171: {
172: Session *s;
1.65 markus 173: char *command;
1.86 markus 174: int success, type, plen, screen_flag;
1.1 markus 175: int compression_level = 0, enable_compression_after_reply = 0;
1.45 markus 176: u_int proto_len, data_len, dlen;
1.1 markus 177:
1.61 markus 178: s = session_new();
1.65 markus 179: s->pw = authctxt->pw;
1.28 millert 180:
1.1 markus 181: /*
182: * We stay in this loop until the client requests to execute a shell
183: * or a command.
184: */
185: for (;;) {
1.65 markus 186: success = 0;
1.1 markus 187:
188: /* Get a packet from the client. */
189: type = packet_read(&plen);
190:
191: /* Process the packet. */
192: switch (type) {
193: case SSH_CMSG_REQUEST_COMPRESSION:
194: packet_integrity_check(plen, 4, type);
195: compression_level = packet_get_int();
196: if (compression_level < 1 || compression_level > 9) {
197: packet_send_debug("Received illegal compression level %d.",
198: compression_level);
199: break;
200: }
201: /* Enable compression after we have responded with SUCCESS. */
202: enable_compression_after_reply = 1;
203: success = 1;
204: break;
205:
206: case SSH_CMSG_REQUEST_PTY:
1.86 markus 207: success = session_pty_req(s);
1.1 markus 208: break;
209:
210: case SSH_CMSG_X11_REQUEST_FORWARDING:
211: s->auth_proto = packet_get_string(&proto_len);
212: s->auth_data = packet_get_string(&data_len);
213:
1.57 markus 214: screen_flag = packet_get_protocol_flags() &
215: SSH_PROTOFLAG_SCREEN_NUMBER;
216: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
217:
218: if (packet_remaining() == 4) {
219: if (!screen_flag)
220: debug2("Buggy client: "
221: "X11 screen flag missing");
1.1 markus 222: s->screen = packet_get_int();
1.56 markus 223: } else {
1.1 markus 224: s->screen = 0;
1.56 markus 225: }
1.81 markus 226: packet_done();
227: success = session_setup_x11fwd(s);
228: if (!success) {
229: xfree(s->auth_proto);
230: xfree(s->auth_data);
1.84 markus 231: s->auth_proto = NULL;
232: s->auth_data = NULL;
1.1 markus 233: }
234: break;
235:
236: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
237: if (no_agent_forwarding_flag || compat13) {
238: debug("Authentication agent forwarding not permitted for this authentication.");
239: break;
240: }
241: debug("Received authentication agent forwarding request.");
1.65 markus 242: success = auth_input_request_forwarding(s->pw);
1.1 markus 243: break;
244:
245: case SSH_CMSG_PORT_FORWARD_REQUEST:
246: if (no_port_forwarding_flag) {
247: debug("Port forwarding not permitted for this authentication.");
1.39 markus 248: break;
249: }
250: if (!options.allow_tcp_forwarding) {
251: debug("Port forwarding not permitted.");
1.1 markus 252: break;
253: }
254: debug("Received TCP/IP port forwarding request.");
1.65 markus 255: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 256: success = 1;
257: break;
258:
259: case SSH_CMSG_MAX_PACKET_SIZE:
260: if (packet_set_maxsize(packet_get_int()) > 0)
261: success = 1;
262: break;
263:
264: case SSH_CMSG_EXEC_SHELL:
265: case SSH_CMSG_EXEC_CMD:
266: if (type == SSH_CMSG_EXEC_CMD) {
267: command = packet_get_string(&dlen);
268: debug("Exec command '%.500s'", command);
1.92 markus 269: do_exec(s, command);
270: xfree(command);
1.1 markus 271: } else {
1.92 markus 272: do_exec(s, NULL);
1.1 markus 273: }
1.92 markus 274: packet_done();
1.82 markus 275: session_close(s);
1.1 markus 276: return;
277:
278: default:
279: /*
280: * Any unknown messages in this phase are ignored,
281: * and a failure message is returned.
282: */
283: log("Unknown packet type received after authentication: %d", type);
284: }
285: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
286: packet_send();
287: packet_write_wait();
288:
289: /* Enable compression now that we have replied if appropriate. */
290: if (enable_compression_after_reply) {
291: enable_compression_after_reply = 0;
292: packet_start_compression(compression_level);
293: }
294: }
295: }
296:
297: /*
298: * This is called to fork and execute a command when we have no tty. This
299: * will call do_child from the child, and server_loop from the parent after
300: * setting up file descriptors and such.
301: */
1.4 markus 302: void
1.63 markus 303: do_exec_no_pty(Session *s, const char *command)
1.1 markus 304: {
305: int pid;
306:
307: #ifdef USE_PIPES
308: int pin[2], pout[2], perr[2];
309: /* Allocate pipes for communicating with the program. */
310: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
311: packet_disconnect("Could not create pipes: %.100s",
312: strerror(errno));
313: #else /* USE_PIPES */
314: int inout[2], err[2];
315: /* Uses socket pairs to communicate with the program. */
316: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
317: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
318: packet_disconnect("Could not create socket pairs: %.100s",
319: strerror(errno));
320: #endif /* USE_PIPES */
321: if (s == NULL)
322: fatal("do_exec_no_pty: no session");
323:
1.9 markus 324: session_proctitle(s);
1.1 markus 325:
326: /* Fork the child. */
327: if ((pid = fork()) == 0) {
328: /* Child. Reinitialize the log since the pid has changed. */
329: log_init(__progname, options.log_level, options.log_facility, log_stderr);
330:
331: /*
332: * Create a new session and process group since the 4.4BSD
333: * setlogin() affects the entire process group.
334: */
335: if (setsid() < 0)
336: error("setsid failed: %.100s", strerror(errno));
337:
338: #ifdef USE_PIPES
339: /*
340: * Redirect stdin. We close the parent side of the socket
341: * pair, and make the child side the standard input.
342: */
343: close(pin[1]);
344: if (dup2(pin[0], 0) < 0)
345: perror("dup2 stdin");
346: close(pin[0]);
347:
348: /* Redirect stdout. */
349: close(pout[0]);
350: if (dup2(pout[1], 1) < 0)
351: perror("dup2 stdout");
352: close(pout[1]);
353:
354: /* Redirect stderr. */
355: close(perr[0]);
356: if (dup2(perr[1], 2) < 0)
357: perror("dup2 stderr");
358: close(perr[1]);
359: #else /* USE_PIPES */
360: /*
361: * Redirect stdin, stdout, and stderr. Stdin and stdout will
362: * use the same socket, as some programs (particularly rdist)
363: * seem to depend on it.
364: */
365: close(inout[1]);
366: close(err[1]);
367: if (dup2(inout[0], 0) < 0) /* stdin */
368: perror("dup2 stdin");
369: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
370: perror("dup2 stdout");
371: if (dup2(err[0], 2) < 0) /* stderr */
372: perror("dup2 stderr");
373: #endif /* USE_PIPES */
374:
375: /* Do processing for the child (exec command etc). */
1.60 markus 376: do_child(s, command);
1.1 markus 377: /* NOTREACHED */
378: }
379: if (pid < 0)
380: packet_disconnect("fork failed: %.100s", strerror(errno));
381: s->pid = pid;
1.47 markus 382: /* Set interactive/non-interactive mode. */
1.48 markus 383: packet_set_interactive(s->display != NULL);
1.1 markus 384: #ifdef USE_PIPES
385: /* We are the parent. Close the child sides of the pipes. */
386: close(pin[0]);
387: close(pout[1]);
388: close(perr[1]);
389:
1.2 markus 390: if (compat20) {
1.64 markus 391: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 392: } else {
393: /* Enter the interactive session. */
394: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 395: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 396: }
1.1 markus 397: #else /* USE_PIPES */
398: /* We are the parent. Close the child sides of the socket pairs. */
399: close(inout[0]);
400: close(err[0]);
401:
402: /*
403: * Enter the interactive session. Note: server_loop must be able to
404: * handle the case that fdin and fdout are the same.
405: */
1.2 markus 406: if (compat20) {
1.64 markus 407: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 408: } else {
409: server_loop(pid, inout[1], inout[1], err[1]);
410: /* server_loop has closed inout[1] and err[1]. */
411: }
1.1 markus 412: #endif /* USE_PIPES */
413: }
414:
415: /*
416: * This is called to fork and execute a command when we have a tty. This
417: * will call do_child from the child, and server_loop from the parent after
418: * setting up file descriptors, controlling tty, updating wtmp, utmp,
419: * lastlog, and other such operations.
420: */
1.4 markus 421: void
1.63 markus 422: do_exec_pty(Session *s, const char *command)
1.1 markus 423: {
424: int fdout, ptyfd, ttyfd, ptymaster;
425: pid_t pid;
426:
427: if (s == NULL)
428: fatal("do_exec_pty: no session");
429: ptyfd = s->ptyfd;
430: ttyfd = s->ttyfd;
431:
432: /* Fork the child. */
433: if ((pid = fork()) == 0) {
1.24 markus 434: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 435: log_init(__progname, options.log_level, options.log_facility, log_stderr);
436:
437: /* Close the master side of the pseudo tty. */
438: close(ptyfd);
439:
440: /* Make the pseudo tty our controlling tty. */
441: pty_make_controlling_tty(&ttyfd, s->tty);
442:
443: /* Redirect stdin from the pseudo tty. */
444: if (dup2(ttyfd, fileno(stdin)) < 0)
445: error("dup2 stdin failed: %.100s", strerror(errno));
446:
447: /* Redirect stdout to the pseudo tty. */
448: if (dup2(ttyfd, fileno(stdout)) < 0)
449: error("dup2 stdin failed: %.100s", strerror(errno));
450:
451: /* Redirect stderr to the pseudo tty. */
452: if (dup2(ttyfd, fileno(stderr)) < 0)
453: error("dup2 stdin failed: %.100s", strerror(errno));
454:
455: /* Close the extra descriptor for the pseudo tty. */
456: close(ttyfd);
457:
1.24 markus 458: /* record login, etc. similar to login(1) */
1.41 markus 459: if (!(options.use_login && command == NULL))
460: do_login(s, command);
1.1 markus 461:
462: /* Do common processing for the child, such as execing the command. */
1.60 markus 463: do_child(s, command);
1.1 markus 464: /* NOTREACHED */
465: }
466: if (pid < 0)
467: packet_disconnect("fork failed: %.100s", strerror(errno));
468: s->pid = pid;
469:
470: /* Parent. Close the slave side of the pseudo tty. */
471: close(ttyfd);
472:
473: /*
474: * Create another descriptor of the pty master side for use as the
475: * standard input. We could use the original descriptor, but this
476: * simplifies code in server_loop. The descriptor is bidirectional.
477: */
478: fdout = dup(ptyfd);
479: if (fdout < 0)
480: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
481:
482: /* we keep a reference to the pty master */
483: ptymaster = dup(ptyfd);
484: if (ptymaster < 0)
485: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
486: s->ptymaster = ptymaster;
487:
488: /* Enter interactive session. */
1.47 markus 489: packet_set_interactive(1);
1.2 markus 490: if (compat20) {
491: session_set_fds(s, ptyfd, fdout, -1);
492: } else {
493: server_loop(pid, ptyfd, fdout, -1);
494: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 495: }
496: }
497:
1.90 markus 498: /*
499: * This is called to fork and execute a command. If another command is
500: * to be forced, execute that instead.
501: */
502: void
503: do_exec(Session *s, const char *command)
504: {
505: if (forced_command) {
506: original_command = command;
507: command = forced_command;
508: debug("Forced command '%.900s'", command);
509: }
510:
511: if (s->ttyfd != -1)
512: do_exec_pty(s, command);
513: else
514: do_exec_no_pty(s, command);
515:
1.92 markus 516: original_command = NULL;
1.90 markus 517: }
518:
519:
1.24 markus 520: /* administrative, login(1)-like work */
521: void
1.41 markus 522: do_login(Session *s, const char *command)
1.24 markus 523: {
524: char *time_string;
1.35 markus 525: char hostname[MAXHOSTNAMELEN];
1.24 markus 526: socklen_t fromlen;
527: struct sockaddr_storage from;
528: time_t last_login_time;
529: struct passwd * pw = s->pw;
530: pid_t pid = getpid();
531:
532: /*
533: * Get IP address of client. If the connection is not a socket, let
534: * the address be 0.0.0.0.
535: */
536: memset(&from, 0, sizeof(from));
537: if (packet_connection_is_on_socket()) {
538: fromlen = sizeof(from);
539: if (getpeername(packet_get_connection_in(),
540: (struct sockaddr *) & from, &fromlen) < 0) {
541: debug("getpeername: %.100s", strerror(errno));
542: fatal_cleanup();
543: }
544: }
1.25 markus 545:
1.35 markus 546: /* Get the time and hostname when the user last logged in. */
1.69 stevesk 547: if (options.print_lastlog) {
548: hostname[0] = '\0';
549: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
550: hostname, sizeof(hostname));
551: }
1.35 markus 552:
1.24 markus 553: /* Record that there was a login on that tty from the remote host. */
554: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.70 stevesk 555: get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
556: (struct sockaddr *)&from);
1.24 markus 557:
1.73 djm 558: if (check_quietlogin(s, command))
1.24 markus 559: return;
1.73 djm 560:
1.69 stevesk 561: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 562: time_string = ctime(&last_login_time);
563: if (strchr(time_string, '\n'))
564: *strchr(time_string, '\n') = 0;
1.40 markus 565: if (strcmp(hostname, "") == 0)
1.24 markus 566: printf("Last login: %s\r\n", time_string);
567: else
1.36 markus 568: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 569: }
1.73 djm 570:
571: do_motd();
572: }
573:
574: /*
575: * Display the message of the day.
576: */
577: void
578: do_motd(void)
579: {
580: FILE *f;
581: char buf[256];
582:
1.24 markus 583: if (options.print_motd) {
1.28 millert 584: #ifdef HAVE_LOGIN_CAP
585: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
586: "/etc/motd"), "r");
587: #else
1.24 markus 588: f = fopen("/etc/motd", "r");
1.28 millert 589: #endif
1.24 markus 590: if (f) {
591: while (fgets(buf, sizeof(buf), f))
592: fputs(buf, stdout);
593: fclose(f);
594: }
1.2 markus 595: }
1.73 djm 596: }
597:
598:
599: /*
600: * Check for quiet login, either .hushlogin or command given.
601: */
602: int
603: check_quietlogin(Session *s, const char *command)
604: {
605: char buf[256];
606: struct passwd * pw = s->pw;
607: struct stat st;
608:
609: /* Return 1 if .hushlogin exists or a command given. */
610: if (command != NULL)
611: return 1;
612: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
613: #ifdef HAVE_LOGIN_CAP
614: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
615: return 1;
616: #else
617: if (stat(buf, &st) >= 0)
618: return 1;
619: #endif
620: return 0;
1.1 markus 621: }
622:
623: /*
624: * Sets the value of the given variable in the environment. If the variable
625: * already exists, its value is overriden.
626: */
1.4 markus 627: void
1.45 markus 628: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 629: const char *value)
630: {
1.45 markus 631: u_int i, namelen;
1.1 markus 632: char **env;
633:
634: /*
635: * Find the slot where the value should be stored. If the variable
636: * already exists, we reuse the slot; otherwise we append a new slot
637: * at the end of the array, expanding if necessary.
638: */
639: env = *envp;
640: namelen = strlen(name);
641: for (i = 0; env[i]; i++)
642: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
643: break;
644: if (env[i]) {
645: /* Reuse the slot. */
646: xfree(env[i]);
647: } else {
648: /* New variable. Expand if necessary. */
649: if (i >= (*envsizep) - 1) {
650: (*envsizep) += 50;
651: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
652: }
653: /* Need to set the NULL pointer at end of array beyond the new slot. */
654: env[i + 1] = NULL;
655: }
656:
657: /* Allocate space and format the variable in the appropriate slot. */
658: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
659: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
660: }
661:
662: /*
663: * Reads environment variables from the given file and adds/overrides them
664: * into the environment. If the file does not exist, this does nothing.
665: * Otherwise, it must consist of empty lines, comments (line starts with '#')
666: * and assignments of the form name=value. No other forms are allowed.
667: */
1.4 markus 668: void
1.45 markus 669: read_environment_file(char ***env, u_int *envsize,
1.1 markus 670: const char *filename)
671: {
672: FILE *f;
673: char buf[4096];
674: char *cp, *value;
675:
676: f = fopen(filename, "r");
677: if (!f)
678: return;
679:
680: while (fgets(buf, sizeof(buf), f)) {
681: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
682: ;
683: if (!*cp || *cp == '#' || *cp == '\n')
684: continue;
685: if (strchr(cp, '\n'))
686: *strchr(cp, '\n') = '\0';
687: value = strchr(cp, '=');
688: if (value == NULL) {
689: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
690: continue;
691: }
1.14 deraadt 692: /*
693: * Replace the equals sign by nul, and advance value to
694: * the value string.
695: */
1.1 markus 696: *value = '\0';
697: value++;
698: child_set_env(env, envsize, cp, value);
699: }
700: fclose(f);
701: }
702:
703: /*
704: * Performs common processing for the child, such as setting up the
705: * environment, closing extra file descriptors, setting the user and group
706: * ids, and executing the command or shell.
707: */
1.4 markus 708: void
1.60 markus 709: do_child(Session *s, const char *command)
1.1 markus 710: {
1.32 markus 711: const char *shell, *hostname = NULL, *cp = NULL;
1.60 markus 712: struct passwd * pw = s->pw;
1.1 markus 713: char buf[256];
1.16 markus 714: char cmd[1024];
1.27 millert 715: FILE *f = NULL;
1.45 markus 716: u_int envsize, i;
1.1 markus 717: char **env;
718: extern char **environ;
719: struct stat st;
720: char *argv[10];
1.84 markus 721: int do_xauth;
722:
723: do_xauth =
724: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 725:
1.74 markus 726: /* remove hostkey from the child's memory */
727: destroy_sensitive_data();
728:
1.17 markus 729: /* login(1) is only called if we execute the login shell */
730: if (options.use_login && command != NULL)
731: options.use_login = 0;
1.1 markus 732:
1.27 millert 733: if (!options.use_login) {
1.28 millert 734: #ifdef HAVE_LOGIN_CAP
735: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
736: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
737: _PATH_NOLOGIN), "r");
738: #else
1.27 millert 739: if (pw->pw_uid)
740: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 741: #endif
1.27 millert 742: if (f) {
743: /* /etc/nologin exists. Print its contents and exit. */
744: while (fgets(buf, sizeof(buf), f))
745: fputs(buf, stderr);
746: fclose(f);
1.1 markus 747: exit(254);
1.27 millert 748: }
1.1 markus 749: }
1.28 millert 750: /* Set login name, uid, gid, and groups. */
1.1 markus 751: /* Login(1) does this as well, and it needs uid 0 for the "-h"
752: switch, so we let login(1) to this for us. */
753: if (!options.use_login) {
754: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 755: #ifdef HAVE_LOGIN_CAP
756: if (setusercontext(lc, pw, pw->pw_uid,
757: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
758: perror("unable to set user context");
759: exit(1);
760: }
761: #else
762: if (setlogin(pw->pw_name) < 0)
763: error("setlogin failed: %s", strerror(errno));
1.1 markus 764: if (setgid(pw->pw_gid) < 0) {
765: perror("setgid");
766: exit(1);
767: }
768: /* Initialize the group list. */
769: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
770: perror("initgroups");
771: exit(1);
772: }
773: endgrent();
774:
775: /* Permanently switch to the desired uid. */
1.71 markus 776: permanently_set_uid(pw);
1.28 millert 777: #endif
1.1 markus 778: }
779: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 780: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 781: }
782: /*
783: * Get the shell from the password data. An empty shell field is
784: * legal, and means /bin/sh.
785: */
786: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 787: #ifdef HAVE_LOGIN_CAP
788: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
789: #endif
1.1 markus 790:
791: #ifdef AFS
792: /* Try to get AFS tokens for the local cell. */
793: if (k_hasafs()) {
794: char cell[64];
795:
796: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
797: krb_afslog(cell, 0);
798:
799: krb_afslog(0, 0);
800: }
801: #endif /* AFS */
802:
803: /* Initialize the environment. */
804: envsize = 100;
805: env = xmalloc(envsize * sizeof(char *));
806: env[0] = NULL;
807:
808: if (!options.use_login) {
809: /* Set basic environment. */
810: child_set_env(&env, &envsize, "USER", pw->pw_name);
811: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
812: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 813: #ifdef HAVE_LOGIN_CAP
1.29 millert 814: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
815: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 816: #else
1.29 millert 817: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 818: #endif
1.1 markus 819:
820: snprintf(buf, sizeof buf, "%.200s/%.50s",
821: _PATH_MAILDIR, pw->pw_name);
822: child_set_env(&env, &envsize, "MAIL", buf);
823:
824: /* Normal systems set SHELL by default. */
825: child_set_env(&env, &envsize, "SHELL", shell);
826: }
827: if (getenv("TZ"))
828: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
829:
830: /* Set custom environment options from RSA authentication. */
831: while (custom_environment) {
832: struct envstring *ce = custom_environment;
833: char *s = ce->s;
834: int i;
835: for (i = 0; s[i] != '=' && s[i]; i++);
836: if (s[i] == '=') {
837: s[i] = 0;
838: child_set_env(&env, &envsize, s, s + i + 1);
839: }
840: custom_environment = ce->next;
841: xfree(ce->s);
842: xfree(ce);
843: }
844:
845: snprintf(buf, sizeof buf, "%.50s %d %d",
846: get_remote_ipaddr(), get_remote_port(), get_local_port());
847: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
848:
1.60 markus 849: if (s->ttyfd != -1)
850: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
851: if (s->term)
852: child_set_env(&env, &envsize, "TERM", s->term);
853: if (s->display)
854: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 855: if (original_command)
856: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
857: original_command);
1.1 markus 858:
859: #ifdef KRB4
860: {
861: extern char *ticket;
862:
863: if (ticket)
864: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
865: }
866: #endif /* KRB4 */
867:
868: if (auth_get_socket_name() != NULL)
869: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
870: auth_get_socket_name());
871:
872: /* read $HOME/.ssh/environment. */
873: if (!options.use_login) {
1.14 deraadt 874: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
875: pw->pw_dir);
1.1 markus 876: read_environment_file(&env, &envsize, buf);
877: }
878: if (debug_flag) {
879: /* dump the environment */
880: fprintf(stderr, "Environment:\n");
881: for (i = 0; env[i]; i++)
882: fprintf(stderr, " %.200s\n", env[i]);
883: }
1.26 millert 884: /* we have to stash the hostname before we close our socket. */
885: if (options.use_login)
1.70 stevesk 886: hostname = get_remote_name_or_ip(utmp_len,
887: options.reverse_mapping_check);
1.1 markus 888: /*
889: * Close the connection descriptors; note that this is the child, and
890: * the server will still have the socket open, and it is important
891: * that we do not shutdown it. Note that the descriptors cannot be
892: * closed before building the environment, as we call
893: * get_remote_ipaddr there.
894: */
895: if (packet_get_connection_in() == packet_get_connection_out())
896: close(packet_get_connection_in());
897: else {
898: close(packet_get_connection_in());
899: close(packet_get_connection_out());
900: }
901: /*
902: * Close all descriptors related to channels. They will still remain
903: * open in the parent.
904: */
905: /* XXX better use close-on-exec? -markus */
906: channel_close_all();
907:
908: /*
909: * Close any extra file descriptors. Note that there may still be
910: * descriptors left by system functions. They will be closed later.
911: */
912: endpwent();
913:
914: /*
915: * Close any extra open file descriptors so that we don\'t have them
916: * hanging around in clients. Note that we want to do this after
917: * initgroups, because at least on Solaris 2.3 it leaves file
918: * descriptors open.
919: */
920: for (i = 3; i < 64; i++)
921: close(i);
922:
923: /* Change current directory to the user\'s home directory. */
1.28 millert 924: if (chdir(pw->pw_dir) < 0) {
1.1 markus 925: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
926: pw->pw_dir, strerror(errno));
1.28 millert 927: #ifdef HAVE_LOGIN_CAP
928: if (login_getcapbool(lc, "requirehome", 0))
929: exit(1);
930: #endif
931: }
1.1 markus 932:
933: /*
934: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
935: * xauth are run in the proper environment.
936: */
937: environ = env;
938:
939: /*
940: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
941: * in this order).
942: */
943: if (!options.use_login) {
1.74 markus 944: /* ignore _PATH_SSH_USER_RC for subsystems */
945: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.75 markus 946: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
947: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 948: if (debug_flag)
1.75 markus 949: fprintf(stderr, "Running %s\n", cmd);
950: f = popen(cmd, "w");
1.1 markus 951: if (f) {
1.60 markus 952: if (do_xauth)
953: fprintf(f, "%s %s\n", s->auth_proto,
954: s->auth_data);
1.1 markus 955: pclose(f);
956: } else
1.60 markus 957: fprintf(stderr, "Could not run %s\n",
958: _PATH_SSH_USER_RC);
1.50 markus 959: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 960: if (debug_flag)
1.60 markus 961: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
962: _PATH_SSH_SYSTEM_RC);
1.50 markus 963: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 964: if (f) {
1.60 markus 965: if (do_xauth)
966: fprintf(f, "%s %s\n", s->auth_proto,
967: s->auth_data);
1.1 markus 968: pclose(f);
969: } else
1.60 markus 970: fprintf(stderr, "Could not run %s\n",
971: _PATH_SSH_SYSTEM_RC);
972: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 973: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 974: char *screen = strchr(s->display, ':');
975:
976: if (debug_flag) {
977: fprintf(stderr,
978: "Running %.100s add "
979: "%.100s %.100s %.100s\n",
980: options.xauth_location, s->display,
981: s->auth_proto, s->auth_data);
982: if (screen != NULL)
1.14 deraadt 983: fprintf(stderr,
1.60 markus 984: "Adding %.*s/unix%s %s %s\n",
985: (int)(screen - s->display),
986: s->display, screen,
987: s->auth_proto, s->auth_data);
988: }
989: snprintf(cmd, sizeof cmd, "%s -q -",
990: options.xauth_location);
991: f = popen(cmd, "w");
992: if (f) {
993: fprintf(f, "add %s %s %s\n", s->display,
994: s->auth_proto, s->auth_data);
995: if (screen != NULL)
996: fprintf(f, "add %.*s/unix%s %s %s\n",
997: (int)(screen - s->display),
998: s->display, screen,
999: s->auth_proto,
1000: s->auth_data);
1001: pclose(f);
1002: } else {
1003: fprintf(stderr, "Could not run %s\n",
1004: cmd);
1.1 markus 1005: }
1006: }
1007: /* Get the last component of the shell name. */
1008: cp = strrchr(shell, '/');
1009: if (cp)
1010: cp++;
1011: else
1012: cp = shell;
1013: }
1.67 markus 1014:
1015: /* restore SIGPIPE for child */
1016: signal(SIGPIPE, SIG_DFL);
1017:
1.1 markus 1018: /*
1019: * If we have no command, execute the shell. In this case, the shell
1020: * name to be passed in argv[0] is preceded by '-' to indicate that
1021: * this is a login shell.
1022: */
1023: if (!command) {
1024: if (!options.use_login) {
1025: char buf[256];
1026:
1027: /*
1028: * Check for mail if we have a tty and it was enabled
1029: * in server options.
1030: */
1.60 markus 1031: if (s->ttyfd != -1 && options.check_mail) {
1.1 markus 1032: char *mailbox;
1033: struct stat mailstat;
1.60 markus 1034:
1.1 markus 1035: mailbox = getenv("MAIL");
1036: if (mailbox != NULL) {
1.14 deraadt 1037: if (stat(mailbox, &mailstat) != 0 ||
1038: mailstat.st_size == 0)
1.1 markus 1039: printf("No mail.\n");
1040: else if (mailstat.st_mtime < mailstat.st_atime)
1041: printf("You have mail.\n");
1042: else
1043: printf("You have new mail.\n");
1044: }
1045: }
1046: /* Start the shell. Set initial character to '-'. */
1047: buf[0] = '-';
1048: strncpy(buf + 1, cp, sizeof(buf) - 1);
1049: buf[sizeof(buf) - 1] = 0;
1050:
1051: /* Execute the shell. */
1052: argv[0] = buf;
1053: argv[1] = NULL;
1054: execve(shell, argv, env);
1055:
1056: /* Executing the shell failed. */
1057: perror(shell);
1058: exit(1);
1059:
1060: } else {
1061: /* Launch login(1). */
1062:
1.26 millert 1063: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1064: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1065:
1066: /* Login couldn't be executed, die. */
1067:
1068: perror("login");
1069: exit(1);
1070: }
1071: }
1072: /*
1073: * Execute the command using the user's shell. This uses the -c
1074: * option to execute the command.
1075: */
1076: argv[0] = (char *) cp;
1077: argv[1] = "-c";
1078: argv[2] = (char *) command;
1079: argv[3] = NULL;
1080: execve(shell, argv, env);
1081: perror(shell);
1082: exit(1);
1083: }
1084:
1085: Session *
1086: session_new(void)
1087: {
1088: int i;
1089: static int did_init = 0;
1090: if (!did_init) {
1091: debug("session_new: init");
1092: for(i = 0; i < MAX_SESSIONS; i++) {
1093: sessions[i].used = 0;
1094: }
1095: did_init = 1;
1096: }
1097: for(i = 0; i < MAX_SESSIONS; i++) {
1098: Session *s = &sessions[i];
1099: if (! s->used) {
1.68 djm 1100: memset(s, 0, sizeof(*s));
1.1 markus 1101: s->chanid = -1;
1102: s->ptyfd = -1;
1103: s->ttyfd = -1;
1104: s->used = 1;
1.85 markus 1105: s->self = i;
1.1 markus 1106: debug("session_new: session %d", i);
1107: return s;
1108: }
1109: }
1110: return NULL;
1111: }
1112:
1113: void
1114: session_dump(void)
1115: {
1116: int i;
1117: for(i = 0; i < MAX_SESSIONS; i++) {
1118: Session *s = &sessions[i];
1119: debug("dump: used %d session %d %p channel %d pid %d",
1120: s->used,
1121: s->self,
1122: s,
1123: s->chanid,
1124: s->pid);
1125: }
1126: }
1127:
1.2 markus 1128: int
1129: session_open(int chanid)
1130: {
1131: Session *s = session_new();
1132: debug("session_open: channel %d", chanid);
1133: if (s == NULL) {
1134: error("no more sessions");
1135: return 0;
1136: }
1.7 markus 1137: s->pw = auth_get_user();
1138: if (s->pw == NULL)
1.54 stevesk 1139: fatal("no user for session %d", s->self);
1.2 markus 1140: debug("session_open: session %d: link with channel %d", s->self, chanid);
1141: s->chanid = chanid;
1142: return 1;
1143: }
1144:
1145: Session *
1146: session_by_channel(int id)
1147: {
1148: int i;
1149: for(i = 0; i < MAX_SESSIONS; i++) {
1150: Session *s = &sessions[i];
1151: if (s->used && s->chanid == id) {
1152: debug("session_by_channel: session %d channel %d", i, id);
1153: return s;
1154: }
1155: }
1156: debug("session_by_channel: unknown channel %d", id);
1157: session_dump();
1158: return NULL;
1159: }
1160:
1161: Session *
1162: session_by_pid(pid_t pid)
1163: {
1164: int i;
1165: debug("session_by_pid: pid %d", pid);
1166: for(i = 0; i < MAX_SESSIONS; i++) {
1167: Session *s = &sessions[i];
1168: if (s->used && s->pid == pid)
1169: return s;
1170: }
1171: error("session_by_pid: unknown pid %d", pid);
1172: session_dump();
1173: return NULL;
1174: }
1175:
1176: int
1177: session_window_change_req(Session *s)
1178: {
1179: s->col = packet_get_int();
1180: s->row = packet_get_int();
1181: s->xpixel = packet_get_int();
1182: s->ypixel = packet_get_int();
1.3 markus 1183: packet_done();
1.2 markus 1184: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1185: return 1;
1186: }
1187:
1188: int
1189: session_pty_req(Session *s)
1190: {
1.45 markus 1191: u_int len;
1.72 stevesk 1192: int n_bytes;
1.2 markus 1193:
1.86 markus 1194: if (no_pty_flag) {
1195: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1196: return 0;
1.86 markus 1197: }
1198: if (s->ttyfd != -1) {
1199: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1200: return 0;
1.86 markus 1201: }
1202:
1.2 markus 1203: s->term = packet_get_string(&len);
1.86 markus 1204:
1205: if (compat20) {
1206: s->col = packet_get_int();
1207: s->row = packet_get_int();
1208: } else {
1209: s->row = packet_get_int();
1210: s->col = packet_get_int();
1211: }
1.2 markus 1212: s->xpixel = packet_get_int();
1213: s->ypixel = packet_get_int();
1214:
1215: if (strcmp(s->term, "") == 0) {
1216: xfree(s->term);
1217: s->term = NULL;
1218: }
1.86 markus 1219:
1.2 markus 1220: /* Allocate a pty and open it. */
1.86 markus 1221: debug("Allocating pty.");
1.2 markus 1222: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.86 markus 1223: if (s->term)
1224: xfree(s->term);
1.2 markus 1225: s->term = NULL;
1226: s->ptyfd = -1;
1227: s->ttyfd = -1;
1228: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1229: return 0;
1.2 markus 1230: }
1231: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1232:
1233: /* for SSH1 the tty modes length is not given */
1234: if (!compat20)
1235: n_bytes = packet_remaining();
1236: tty_parse_modes(s->ttyfd, &n_bytes);
1237:
1.2 markus 1238: /*
1239: * Add a cleanup function to clear the utmp entry and record logout
1240: * time in case we call fatal() (e.g., the connection gets closed).
1241: */
1.85 markus 1242: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1243: pty_setowner(s->pw, s->tty);
1.86 markus 1244:
1245: /* Set window size from the packet. */
1.2 markus 1246: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1247:
1.72 stevesk 1248: packet_done();
1.9 markus 1249: session_proctitle(s);
1.2 markus 1250: return 1;
1251: }
1252:
1.7 markus 1253: int
1254: session_subsystem_req(Session *s)
1255: {
1.45 markus 1256: u_int len;
1.7 markus 1257: int success = 0;
1258: char *subsys = packet_get_string(&len);
1.18 jakob 1259: int i;
1.7 markus 1260:
1261: packet_done();
1262: log("subsystem request for %s", subsys);
1.18 jakob 1263:
1264: for (i = 0; i < options.num_subsystems; i++) {
1265: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1266: debug("subsystem: exec() %s", options.subsystem_command[i]);
1.64 markus 1267: s->is_subsystem = 1;
1.63 markus 1268: do_exec_no_pty(s, options.subsystem_command[i]);
1.18 jakob 1269: success = 1;
1270: }
1271: }
1272:
1273: if (!success)
1274: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1275:
1276: xfree(subsys);
1277: return success;
1278: }
1279:
1280: int
1281: session_x11_req(Session *s)
1282: {
1.81 markus 1283: int success;
1.7 markus 1284:
1285: s->single_connection = packet_get_char();
1286: s->auth_proto = packet_get_string(NULL);
1287: s->auth_data = packet_get_string(NULL);
1288: s->screen = packet_get_int();
1289: packet_done();
1290:
1.81 markus 1291: success = session_setup_x11fwd(s);
1292: if (!success) {
1.7 markus 1293: xfree(s->auth_proto);
1294: xfree(s->auth_data);
1.84 markus 1295: s->auth_proto = NULL;
1296: s->auth_data = NULL;
1.7 markus 1297: }
1.81 markus 1298: return success;
1.7 markus 1299: }
1300:
1.19 markus 1301: int
1302: session_shell_req(Session *s)
1303: {
1304: packet_done();
1.90 markus 1305: do_exec(s, NULL);
1.19 markus 1306: return 1;
1307: }
1308:
1309: int
1310: session_exec_req(Session *s)
1311: {
1.45 markus 1312: u_int len;
1.19 markus 1313: char *command = packet_get_string(&len);
1314: packet_done();
1.90 markus 1315: do_exec(s, command);
1.92 markus 1316: xfree(command);
1.19 markus 1317: return 1;
1318: }
1319:
1.43 markus 1320: int
1321: session_auth_agent_req(Session *s)
1322: {
1323: static int called = 0;
1324: packet_done();
1.44 markus 1325: if (no_agent_forwarding_flag) {
1326: debug("session_auth_agent_req: no_agent_forwarding_flag");
1327: return 0;
1328: }
1.43 markus 1329: if (called) {
1330: return 0;
1331: } else {
1332: called = 1;
1333: return auth_input_request_forwarding(s->pw);
1334: }
1335: }
1336:
1.2 markus 1337: void
1338: session_input_channel_req(int id, void *arg)
1339: {
1.45 markus 1340: u_int len;
1.2 markus 1341: int reply;
1342: int success = 0;
1343: char *rtype;
1344: Session *s;
1345: Channel *c;
1346:
1347: rtype = packet_get_string(&len);
1348: reply = packet_get_char();
1349:
1350: s = session_by_channel(id);
1351: if (s == NULL)
1352: fatal("session_input_channel_req: channel %d: no session", id);
1353: c = channel_lookup(id);
1354: if (c == NULL)
1355: fatal("session_input_channel_req: channel %d: bad channel", id);
1356:
1357: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1358: s->self, id, rtype, reply);
1359:
1360: /*
1.64 markus 1361: * a session is in LARVAL state until a shell, a command
1362: * or a subsystem is executed
1.2 markus 1363: */
1364: if (c->type == SSH_CHANNEL_LARVAL) {
1365: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1366: success = session_shell_req(s);
1.2 markus 1367: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1368: success = session_exec_req(s);
1.2 markus 1369: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1370: success = session_pty_req(s);
1.7 markus 1371: } else if (strcmp(rtype, "x11-req") == 0) {
1372: success = session_x11_req(s);
1.43 markus 1373: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1374: success = session_auth_agent_req(s);
1.7 markus 1375: } else if (strcmp(rtype, "subsystem") == 0) {
1376: success = session_subsystem_req(s);
1.2 markus 1377: }
1378: }
1379: if (strcmp(rtype, "window-change") == 0) {
1380: success = session_window_change_req(s);
1381: }
1382:
1383: if (reply) {
1384: packet_start(success ?
1385: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1386: packet_put_int(c->remote_id);
1387: packet_send();
1388: }
1389: xfree(rtype);
1390: }
1391:
1392: void
1393: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1394: {
1395: if (!compat20)
1396: fatal("session_set_fds: called for proto != 2.0");
1397: /*
1398: * now that have a child and a pipe to the child,
1399: * we can activate our channel and register the fd's
1400: */
1401: if (s->chanid == -1)
1402: fatal("no channel for session %d", s->self);
1403: channel_set_fds(s->chanid,
1404: fdout, fdin, fderr,
1.42 markus 1405: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1406: 1);
1.2 markus 1407: }
1408:
1.85 markus 1409: /*
1410: * Function to perform pty cleanup. Also called if we get aborted abnormally
1411: * (e.g., due to a dropped connection).
1412: */
1.1 markus 1413: void
1.85 markus 1414: session_pty_cleanup(void *session)
1.1 markus 1415: {
1.85 markus 1416: Session *s = session;
1417:
1418: if (s == NULL) {
1419: error("session_pty_cleanup: no session");
1420: return;
1421: }
1422: if (s->ttyfd == -1)
1.1 markus 1423: return;
1424:
1.54 stevesk 1425: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1426:
1427: /* Record that the user has logged out. */
1.85 markus 1428: if (s->pid != 0)
1429: record_logout(s->pid, s->tty);
1.1 markus 1430:
1431: /* Release the pseudo-tty. */
1432: pty_release(s->tty);
1433:
1434: /*
1435: * Close the server side of the socket pairs. We must do this after
1436: * the pty cleanup, so that another process doesn't get this pty
1437: * while we're still cleaning up.
1438: */
1439: if (close(s->ptymaster) < 0)
1440: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1441: }
1442:
1443: void
1444: session_exit_message(Session *s, int status)
1445: {
1446: Channel *c;
1447: if (s == NULL)
1448: fatal("session_close: no session");
1449: c = channel_lookup(s->chanid);
1450: if (c == NULL)
1.85 markus 1451: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1452: s->self, s->chanid);
1453: debug("session_exit_message: session %d channel %d pid %d",
1454: s->self, s->chanid, s->pid);
1455:
1456: if (WIFEXITED(status)) {
1457: channel_request_start(s->chanid,
1458: "exit-status", 0);
1459: packet_put_int(WEXITSTATUS(status));
1460: packet_send();
1461: } else if (WIFSIGNALED(status)) {
1462: channel_request_start(s->chanid,
1463: "exit-signal", 0);
1464: packet_put_int(WTERMSIG(status));
1465: packet_put_char(WCOREDUMP(status));
1466: packet_put_cstring("");
1467: packet_put_cstring("");
1468: packet_send();
1469: } else {
1470: /* Some weird exit cause. Just exit. */
1471: packet_disconnect("wait returned status %04x.", status);
1472: }
1473:
1474: /* disconnect channel */
1475: debug("session_exit_message: release channel %d", s->chanid);
1476: channel_cancel_cleanup(s->chanid);
1.5 markus 1477: /*
1478: * emulate a write failure with 'chan_write_failed', nobody will be
1479: * interested in data we write.
1480: * Note that we must not call 'chan_read_failed', since there could
1481: * be some more data waiting in the pipe.
1482: */
1.8 markus 1483: if (c->ostate != CHAN_OUTPUT_CLOSED)
1484: chan_write_failed(c);
1.2 markus 1485: s->chanid = -1;
1486: }
1487:
1488: void
1.85 markus 1489: session_close(Session *s)
1.2 markus 1490: {
1.85 markus 1491: debug("session_close: session %d pid %d", s->self, s->pid);
1492: if (s->ttyfd != -1) {
1493: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1494: session_pty_cleanup(s);
1495: }
1.2 markus 1496: if (s->term)
1497: xfree(s->term);
1498: if (s->display)
1499: xfree(s->display);
1500: if (s->auth_data)
1501: xfree(s->auth_data);
1502: if (s->auth_proto)
1503: xfree(s->auth_proto);
1504: s->used = 0;
1.9 markus 1505: session_proctitle(s);
1.2 markus 1506: }
1507:
1508: void
1509: session_close_by_pid(pid_t pid, int status)
1510: {
1511: Session *s = session_by_pid(pid);
1512: if (s == NULL) {
1.89 markus 1513: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1514: return;
1515: }
1516: if (s->chanid != -1)
1517: session_exit_message(s, status);
1518: session_close(s);
1519: }
1520:
1521: /*
1522: * this is called when a channel dies before
1523: * the session 'child' itself dies
1524: */
1525: void
1526: session_close_by_channel(int id, void *arg)
1527: {
1528: Session *s = session_by_channel(id);
1529: if (s == NULL) {
1530: debug("session_close_by_channel: no session for channel %d", id);
1531: return;
1532: }
1533: /* disconnect channel */
1534: channel_cancel_cleanup(s->chanid);
1535: s->chanid = -1;
1536:
1537: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1538: if (s->pid == 0) {
1539: /* close session immediately */
1540: session_close(s);
1541: } else {
1542: /* notify child, delay session cleanup */
1543: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1544: error("session_close_by_channel: kill %d: %s",
1545: s->pid, strerror(errno));
1546: }
1.9 markus 1547: }
1548:
1549: char *
1550: session_tty_list(void)
1551: {
1552: static char buf[1024];
1553: int i;
1554: buf[0] = '\0';
1555: for(i = 0; i < MAX_SESSIONS; i++) {
1556: Session *s = &sessions[i];
1557: if (s->used && s->ttyfd != -1) {
1558: if (buf[0] != '\0')
1559: strlcat(buf, ",", sizeof buf);
1560: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1561: }
1562: }
1563: if (buf[0] == '\0')
1564: strlcpy(buf, "notty", sizeof buf);
1565: return buf;
1566: }
1567:
1568: void
1569: session_proctitle(Session *s)
1570: {
1571: if (s->pw == NULL)
1572: error("no user for session %d", s->self);
1573: else
1574: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1575: }
1576:
1577: int
1578: session_setup_x11fwd(Session *s)
1579: {
1580: struct stat st;
1581:
1582: if (no_x11_forwarding_flag) {
1583: packet_send_debug("X11 forwarding disabled in user configuration file.");
1584: return 0;
1585: }
1586: if (!options.x11_forwarding) {
1587: debug("X11 forwarding disabled in server configuration file.");
1588: return 0;
1589: }
1590: if (!options.xauth_location ||
1591: (stat(options.xauth_location, &st) == -1)) {
1592: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1593: return 0;
1594: }
1595: if (options.use_login) {
1596: packet_send_debug("X11 forwarding disabled; "
1597: "not compatible with UseLogin=yes.");
1.81 markus 1598: return 0;
1599: }
1.87 markus 1600: if (s->display != NULL) {
1.81 markus 1601: debug("X11 display already set.");
1602: return 0;
1603: }
1604: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1605: if (s->display == NULL) {
1.87 markus 1606: debug("x11_create_display_inet failed.");
1.81 markus 1607: return 0;
1608: }
1609: return 1;
1.2 markus 1610: }
1611:
1612: void
1.49 markus 1613: do_authenticated2(Authctxt *authctxt)
1.2 markus 1614: {
1615: server_loop2();
1.1 markus 1616: }
![[BACK]](/icons/back.gif){kind=icon}
Return to session.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh