session.c

   1 /*
   2  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   3  *                    All rights reserved
   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  *
  11  * SSH2 support by Markus Friedl.
  12  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  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.
  33  */
  34
  35 #include "includes.h"
  36 RCSID("$OpenBSD: session.c,v 1.113 2001/12/19 15:43:11 stevesk Exp $");
  37
  38 #include "ssh.h"
  39 #include "ssh1.h"
  40 #include "ssh2.h"
  41 #include "xmalloc.h"
  42 #include "sshpty.h"
  43 #include "packet.h"
  44 #include "buffer.h"
  45 #include "mpaux.h"
  46 #include "uidswap.h"
  47 #include "compat.h"
  48 #include "channels.h"
  49 #include "bufaux.h"
  50 #include "auth.h"
  51 #include "auth-options.h"
  52 #include "pathnames.h"
  53 #include "log.h"
  54 #include "servconf.h"
  55 #include "sshlogin.h"
  56 #include "serverloop.h"
  57 #include "canohost.h"
  58 #include "session.h"
  59
  60 #ifdef WITH_IRIX_PROJECT
  61 #include <proj.h>
  62 #endif /* WITH_IRIX_PROJECT */
  63 #ifdef WITH_IRIX_JOBS
  64 #include <sys/resource.h>
  65 #endif
  66 #ifdef WITH_IRIX_AUDIT
  67 #include <sat.h>
  68 #endif /* WITH_IRIX_AUDIT */
  69
  70 #if defined(HAVE_USERSEC_H)
  71 #include <usersec.h>
  72 #endif
  73
  74 #ifdef HAVE_CYGWIN
  75 #include <windows.h>
  76 #include <sys/cygwin.h>
  77 #define is_winnt       (GetVersion() < 0x80000000)
  78 #endif
  79
  80 /* AIX limits */
  81 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  82 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  83 # define S_UCPU_HARD  S_UCPU "_hard"
  84 # define S_UDATA_HARD  S_UDATA "_hard"
  85 # define S_USTACK_HARD  S_USTACK "_hard"
  86 # define S_URSS_HARD  S_URSS "_hard"
  87 # define S_UCORE_HARD  S_UCORE "_hard"
  88 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  89 #endif
  90
  91 #ifdef _AIX
  92 # include <uinfo.h>
  93 #endif
  94
  95 /* types */
  96
  97 #define TTYSZ 64
  98 typedef struct Session Session;
  99 struct Session {
 100         int     used;
 101         int     self;
 102         struct passwd *pw;
 103         Authctxt *authctxt;
 104         pid_t   pid;
 105         /* tty */
 106         char    *term;
 107         int     ptyfd, ttyfd, ptymaster;
 108         int     row, col, xpixel, ypixel;
 109         char    tty[TTYSZ];
 110         /* X11 */
 111         int     display_number;
 112         char    *display;
 113         int     screen;
 114         char    *auth_display[2];
 115         char    *auth_proto;
 116         char    *auth_data;
 117         int     single_connection;
 118         /* proto 2 */
 119         int     chanid;
 120         int     is_subsystem;
 121 };
 122
 123 /* func */
 124
 125 Session *session_new(void);
 126 void    session_set_fds(Session *, int, int, int);
 127 static void     session_pty_cleanup(void *);
 128 void    session_proctitle(Session *);
 129 int     session_setup_x11fwd(Session *);
 130 void    do_exec_pty(Session *, const char *);
 131 void    do_exec_no_pty(Session *, const char *);
 132 void    do_exec(Session *, const char *);
 133 void    do_login(Session *, const char *);
 134 #ifdef LOGIN_NEEDS_UTMPX
 135 static void     do_pre_login(Session *s);
 136 #endif
 137 void    do_child(Session *, const char *);
 138 void    do_motd(void);
 139 int     check_quietlogin(Session *, const char *);
 140
 141 static void do_authenticated1(Authctxt *);
 142 static void do_authenticated2(Authctxt *);
 143
 144 static void session_close(Session *);
 145 static int session_pty_req(Session *);
 146
 147 /* import */
 148 extern ServerOptions options;
 149 extern char *__progname;
 150 extern int log_stderr;
 151 extern int debug_flag;
 152 extern u_int utmp_len;
 153 extern int startup_pipe;
 154 extern void destroy_sensitive_data(void);
 155
 156 /* original command from peer. */
 157 const char *original_command = NULL;
 158
 159 /* data */
 160 #define MAX_SESSIONS 10
 161 Session sessions[MAX_SESSIONS];
 162
 163 #ifdef WITH_AIXAUTHENTICATE
 164 char *aixloginmsg;
 165 #endif /* WITH_AIXAUTHENTICATE */
 166
 167 #ifdef HAVE_LOGIN_CAP
 168 static login_cap_t *lc;
 169 #endif
 170
 171 void
 172 do_authenticated(Authctxt *authctxt)
 173 {
 174         /*
 175          * Cancel the alarm we set to limit the time taken for
 176          * authentication.
 177          */
 178         alarm(0);
 179         if (startup_pipe != -1) {
 180                 close(startup_pipe);
 181                 startup_pipe = -1;
 182         }
 183 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 184         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
 185                 error("unable to get login class");
 186                 return;
 187         }
 188 #ifdef BSD_AUTH
 189         if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
 190                 packet_disconnect("Approval failure for %s",
 191                     authctxt->pw->pw_name);
 192         }
 193 #endif
 194 #endif
 195 #ifdef WITH_AIXAUTHENTICATE
 196         /* We don't have a pty yet, so just label the line as "ssh" */
 197         if (loginsuccess(authctxt->user,
 198             get_canonical_hostname(options.reverse_mapping_check),
 199             "ssh", &aixloginmsg) < 0)
 200                 aixloginmsg = NULL;
 201 #endif /* WITH_AIXAUTHENTICATE */
 202
 203         /* setup the channel layer */
 204         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 205                 channel_permit_all_opens();
 206
 207         if (compat20)
 208                 do_authenticated2(authctxt);
 209         else
 210                 do_authenticated1(authctxt);
 211
 212         /* remove agent socket */
 213         if (auth_get_socket_name())
 214                 auth_sock_cleanup_proc(authctxt->pw);
 215 #ifdef KRB4
 216         if (options.kerberos_ticket_cleanup)
 217                 krb4_cleanup_proc(authctxt);
 218 #endif
 219 #ifdef KRB5
 220         if (options.kerberos_ticket_cleanup)
 221                 krb5_cleanup_proc(authctxt);
 222 #endif
 223 }
 224
 225 /*
 226  * Prepares for an interactive session.  This is called after the user has
 227  * been successfully authenticated.  During this message exchange, pseudo
 228  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 229  * are requested, etc.
 230  */
 231 static void
 232 do_authenticated1(Authctxt *authctxt)
 233 {
 234         Session *s;
 235         char *command;
 236         int success, type, plen, screen_flag;
 237         int compression_level = 0, enable_compression_after_reply = 0;
 238         u_int proto_len, data_len, dlen;
 239
 240         s = session_new();
 241         s->authctxt = authctxt;
 242         s->pw = authctxt->pw;
 243
 244         /*
 245          * We stay in this loop until the client requests to execute a shell
 246          * or a command.
 247          */
 248         for (;;) {
 249                 success = 0;
 250
 251                 /* Get a packet from the client. */
 252                 type = packet_read(&plen);
 253
 254                 /* Process the packet. */
 255                 switch (type) {
 256                 case SSH_CMSG_REQUEST_COMPRESSION:
 257                         packet_integrity_check(plen, 4, type);
 258                         compression_level = packet_get_int();
 259                         if (compression_level < 1 || compression_level > 9) {
 260                                 packet_send_debug("Received illegal compression level %d.",
 261                                     compression_level);
 262                                 break;
 263                         }
 264                         /* Enable compression after we have responded with SUCCESS. */
 265                         enable_compression_after_reply = 1;
 266                         success = 1;
 267                         break;
 268
 269                 case SSH_CMSG_REQUEST_PTY:
 270                         success = session_pty_req(s);
 271                         break;
 272
 273                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 274                         s->auth_proto = packet_get_string(&proto_len);
 275                         s->auth_data = packet_get_string(&data_len);
 276
 277                         screen_flag = packet_get_protocol_flags() &
 278                             SSH_PROTOFLAG_SCREEN_NUMBER;
 279                         debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
 280
 281                         if (packet_remaining() == 4) {
 282                                 if (!screen_flag)
 283                                         debug2("Buggy client: "
 284                                             "X11 screen flag missing");
 285                                 s->screen = packet_get_int();
 286                         } else {
 287                                 s->screen = 0;
 288                         }
 289                         packet_done();
 290                         success = session_setup_x11fwd(s);
 291                         if (!success) {
 292                                 xfree(s->auth_proto);
 293                                 xfree(s->auth_data);
 294                                 s->auth_proto = NULL;
 295                                 s->auth_data = NULL;
 296                         }
 297                         break;
 298
 299                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 300                         if (no_agent_forwarding_flag || compat13) {
 301                                 debug("Authentication agent forwarding not permitted for this authentication.");
 302                                 break;
 303                         }
 304                         debug("Received authentication agent forwarding request.");
 305                         success = auth_input_request_forwarding(s->pw);
 306                         break;
 307
 308                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 309                         if (no_port_forwarding_flag) {
 310                                 debug("Port forwarding not permitted for this authentication.");
 311                                 break;
 312                         }
 313                         if (!options.allow_tcp_forwarding) {
 314                                 debug("Port forwarding not permitted.");
 315                                 break;
 316                         }
 317                         debug("Received TCP/IP port forwarding request.");
 318                         channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
 319                         success = 1;
 320                         break;
 321
 322                 case SSH_CMSG_MAX_PACKET_SIZE:
 323                         if (packet_set_maxsize(packet_get_int()) > 0)
 324                                 success = 1;
 325                         break;
 326
 327 #if defined(AFS) || defined(KRB5)
 328                 case SSH_CMSG_HAVE_KERBEROS_TGT:
 329                         if (!options.kerberos_tgt_passing) {
 330                                 verbose("Kerberos TGT passing disabled.");
 331                         } else {
 332                                 char *kdata = packet_get_string(&dlen);
 333                                 packet_integrity_check(plen, 4 + dlen, type);
 334
 335                                 /* XXX - 0x41, see creds_to_radix version */
 336                                 if (kdata[0] != 0x41) {
 337 #ifdef KRB5
 338                                         krb5_data tgt;
 339                                         tgt.data = kdata;
 340                                         tgt.length = dlen;
 341
 342                                         if (auth_krb5_tgt(s->authctxt, &tgt))
 343                                                 success = 1;
 344                                         else
 345                                                 verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
 346 #endif /* KRB5 */
 347                                 } else {
 348 #ifdef AFS
 349                                         if (auth_krb4_tgt(s->authctxt, kdata))
 350                                                 success = 1;
 351                                         else
 352                                                 verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
 353 #endif /* AFS */
 354                                 }
 355                                 xfree(kdata);
 356                         }
 357                         break;
 358 #endif /* AFS || KRB5 */
 359
 360 #ifdef AFS
 361                 case SSH_CMSG_HAVE_AFS_TOKEN:
 362                         if (!options.afs_token_passing || !k_hasafs()) {
 363                                 verbose("AFS token passing disabled.");
 364                         } else {
 365                                 /* Accept AFS token. */
 366                                 char *token = packet_get_string(&dlen);
 367                                 packet_integrity_check(plen, 4 + dlen, type);
 368
 369                                 if (auth_afs_token(s->authctxt, token))
 370                                         success = 1;
 371                                 else
 372                                         verbose("AFS token refused for %.100s",
 373                                             s->authctxt->user);
 374                                 xfree(token);
 375                         }
 376                         break;
 377 #endif /* AFS */
 378
 379                 case SSH_CMSG_EXEC_SHELL:
 380                 case SSH_CMSG_EXEC_CMD:
 381                         if (type == SSH_CMSG_EXEC_CMD) {
 382                                 command = packet_get_string(&dlen);
 383                                 debug("Exec command '%.500s'", command);
 384                                 do_exec(s, command);
 385                                 xfree(command);
 386                         } else {
 387                                 do_exec(s, NULL);
 388                         }
 389                         packet_done();
 390                         session_close(s);
 391                         return;
 392
 393                 default:
 394                         /*
 395                          * Any unknown messages in this phase are ignored,
 396                          * and a failure message is returned.
 397                          */
 398                         log("Unknown packet type received after authentication: %d", type);
 399                 }
 400                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 401                 packet_send();
 402                 packet_write_wait();
 403
 404                 /* Enable compression now that we have replied if appropriate. */
 405                 if (enable_compression_after_reply) {
 406                         enable_compression_after_reply = 0;
 407                         packet_start_compression(compression_level);
 408                 }
 409         }
 410 }
 411
 412 /*
 413  * This is called to fork and execute a command when we have no tty.  This
 414  * will call do_child from the child, and server_loop from the parent after
 415  * setting up file descriptors and such.
 416  */
 417 void
 418 do_exec_no_pty(Session *s, const char *command)
 419 {
 420         int pid;
 421
 422 #ifdef USE_PIPES
 423         int pin[2], pout[2], perr[2];
 424         /* Allocate pipes for communicating with the program. */
 425         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 426                 packet_disconnect("Could not create pipes: %.100s",
 427                                   strerror(errno));
 428 #else /* USE_PIPES */
 429         int inout[2], err[2];
 430         /* Uses socket pairs to communicate with the program. */
 431         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 432             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 433                 packet_disconnect("Could not create socket pairs: %.100s",
 434                                   strerror(errno));
 435 #endif /* USE_PIPES */
 436         if (s == NULL)
 437                 fatal("do_exec_no_pty: no session");
 438
 439         session_proctitle(s);
 440
 441 #if defined(USE_PAM)
 442         do_pam_session(s->pw->pw_name, NULL);
 443         do_pam_setcred(1);
 444         if (is_pam_password_change_required())
 445                 packet_disconnect("Password change required but no "
 446                     "TTY available");
 447 #endif /* USE_PAM */
 448
 449         /* Fork the child. */
 450         if ((pid = fork()) == 0) {
 451                 /* Child.  Reinitialize the log since the pid has changed. */
 452                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 453
 454                 /*
 455                  * Create a new session and process group since the 4.4BSD
 456                  * setlogin() affects the entire process group.
 457                  */
 458                 if (setsid() < 0)
 459                         error("setsid failed: %.100s", strerror(errno));
 460
 461 #ifdef USE_PIPES
 462                 /*
 463                  * Redirect stdin.  We close the parent side of the socket
 464                  * pair, and make the child side the standard input.
 465                  */
 466                 close(pin[1]);
 467                 if (dup2(pin[0], 0) < 0)
 468                         perror("dup2 stdin");
 469                 close(pin[0]);
 470
 471                 /* Redirect stdout. */
 472                 close(pout[0]);
 473                 if (dup2(pout[1], 1) < 0)
 474                         perror("dup2 stdout");
 475                 close(pout[1]);
 476
 477                 /* Redirect stderr. */
 478                 close(perr[0]);
 479                 if (dup2(perr[1], 2) < 0)
 480                         perror("dup2 stderr");
 481                 close(perr[1]);
 482 #else /* USE_PIPES */
 483                 /*
 484                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 485                  * use the same socket, as some programs (particularly rdist)
 486                  * seem to depend on it.
 487                  */
 488                 close(inout[1]);
 489                 close(err[1]);
 490                 if (dup2(inout[0], 0) < 0)      /* stdin */
 491                         perror("dup2 stdin");
 492                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 493                         perror("dup2 stdout");
 494                 if (dup2(err[0], 2) < 0)        /* stderr */
 495                         perror("dup2 stderr");
 496 #endif /* USE_PIPES */
 497
 498                 /* Do processing for the child (exec command etc). */
 499                 do_child(s, command);
 500                 /* NOTREACHED */
 501         }
 502 #ifdef HAVE_CYGWIN
 503         if (is_winnt)
 504                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 505 #endif
 506         if (pid < 0)
 507                 packet_disconnect("fork failed: %.100s", strerror(errno));
 508         s->pid = pid;
 509         /* Set interactive/non-interactive mode. */
 510         packet_set_interactive(s->display != NULL);
 511 #ifdef USE_PIPES
 512         /* We are the parent.  Close the child sides of the pipes. */
 513         close(pin[0]);
 514         close(pout[1]);
 515         close(perr[1]);
 516
 517         if (compat20) {
 518                 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
 519         } else {
 520                 /* Enter the interactive session. */
 521                 server_loop(pid, pin[1], pout[0], perr[0]);
 522                 /* server_loop has closed pin[1], pout[0], and perr[0]. */
 523         }
 524 #else /* USE_PIPES */
 525         /* We are the parent.  Close the child sides of the socket pairs. */
 526         close(inout[0]);
 527         close(err[0]);
 528
 529         /*
 530          * Enter the interactive session.  Note: server_loop must be able to
 531          * handle the case that fdin and fdout are the same.
 532          */
 533         if (compat20) {
 534                 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
 535         } else {
 536                 server_loop(pid, inout[1], inout[1], err[1]);
 537                 /* server_loop has closed inout[1] and err[1]. */
 538         }
 539 #endif /* USE_PIPES */
 540 }
 541
 542 /*
 543  * This is called to fork and execute a command when we have a tty.  This
 544  * will call do_child from the child, and server_loop from the parent after
 545  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 546  * lastlog, and other such operations.
 547  */
 548 void
 549 do_exec_pty(Session *s, const char *command)
 550 {
 551         int fdout, ptyfd, ttyfd, ptymaster;
 552         pid_t pid;
 553
 554         if (s == NULL)
 555                 fatal("do_exec_pty: no session");
 556         ptyfd = s->ptyfd;
 557         ttyfd = s->ttyfd;
 558
 559 #if defined(USE_PAM)
 560         do_pam_session(s->pw->pw_name, s->tty);
 561         do_pam_setcred(1);
 562 #endif
 563
 564         /* Fork the child. */
 565         if ((pid = fork()) == 0) {
 566
 567                 /* Child.  Reinitialize the log because the pid has changed. */
 568                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 569                 /* Close the master side of the pseudo tty. */
 570                 close(ptyfd);
 571
 572                 /* Make the pseudo tty our controlling tty. */
 573                 pty_make_controlling_tty(&ttyfd, s->tty);
 574
 575                 /* Redirect stdin/stdout/stderr from the pseudo tty. */
 576                 if (dup2(ttyfd, 0) < 0)
 577                         error("dup2 stdin: %s", strerror(errno));
 578                 if (dup2(ttyfd, 1) < 0)
 579                         error("dup2 stdout: %s", strerror(errno));
 580                 if (dup2(ttyfd, 2) < 0)
 581                         error("dup2 stderr: %s", strerror(errno));
 582
 583                 /* Close the extra descriptor for the pseudo tty. */
 584                 close(ttyfd);
 585
 586                 /* record login, etc. similar to login(1) */
 587 #ifndef HAVE_OSF_SIA
 588                 if (!(options.use_login && command == NULL))
 589                         do_login(s, command);
 590 # ifdef LOGIN_NEEDS_UTMPX
 591                 else
 592                         do_pre_login(s);
 593 # endif
 594 #endif
 595
 596                 /* Do common processing for the child, such as execing the command. */
 597                 do_child(s, command);
 598                 /* NOTREACHED */
 599         }
 600 #ifdef HAVE_CYGWIN
 601         if (is_winnt)
 602                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 603 #endif
 604         if (pid < 0)
 605                 packet_disconnect("fork failed: %.100s", strerror(errno));
 606         s->pid = pid;
 607
 608         /* Parent.  Close the slave side of the pseudo tty. */
 609         close(ttyfd);
 610
 611         /*
 612          * Create another descriptor of the pty master side for use as the
 613          * standard input.  We could use the original descriptor, but this
 614          * simplifies code in server_loop.  The descriptor is bidirectional.
 615          */
 616         fdout = dup(ptyfd);
 617         if (fdout < 0)
 618                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 619
 620         /* we keep a reference to the pty master */
 621         ptymaster = dup(ptyfd);
 622         if (ptymaster < 0)
 623                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 624         s->ptymaster = ptymaster;
 625
 626         /* Enter interactive session. */
 627         packet_set_interactive(1);
 628         if (compat20) {
 629                 session_set_fds(s, ptyfd, fdout, -1);
 630         } else {
 631                 server_loop(pid, ptyfd, fdout, -1);
 632                 /* server_loop _has_ closed ptyfd and fdout. */
 633         }
 634 }
 635
 636 #ifdef LOGIN_NEEDS_UTMPX
 637 static void
 638 do_pre_login(Session *s)
 639 {
 640         socklen_t fromlen;
 641         struct sockaddr_storage from;
 642         pid_t pid = getpid();
 643
 644         /*
 645          * Get IP address of client. If the connection is not a socket, let
 646          * the address be 0.0.0.0.
 647          */
 648         memset(&from, 0, sizeof(from));
 649         if (packet_connection_is_on_socket()) {
 650                 fromlen = sizeof(from);
 651                 if (getpeername(packet_get_connection_in(),
 652                     (struct sockaddr *) & from, &fromlen) < 0) {
 653                         debug("getpeername: %.100s", strerror(errno));
 654                         fatal_cleanup();
 655                 }
 656         }
 657
 658         record_utmp_only(pid, s->tty, s->pw->pw_name,
 659             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 660             (struct sockaddr *)&from);
 661 }
 662 #endif
 663
 664 /*
 665  * This is called to fork and execute a command.  If another command is
 666  * to be forced, execute that instead.
 667  */
 668 void
 669 do_exec(Session *s, const char *command)
 670 {
 671         if (forced_command) {
 672                 original_command = command;
 673                 command = forced_command;
 674                 debug("Forced command '%.900s'", command);
 675         }
 676
 677         if (s->ttyfd != -1)
 678                 do_exec_pty(s, command);
 679         else
 680                 do_exec_no_pty(s, command);
 681
 682         original_command = NULL;
 683 }
 684
 685 /* administrative, login(1)-like work */
 686 void
 687 do_login(Session *s, const char *command)
 688 {
 689         char *time_string;
 690         char hostname[MAXHOSTNAMELEN];
 691         socklen_t fromlen;
 692         struct sockaddr_storage from;
 693         time_t last_login_time;
 694         struct passwd * pw = s->pw;
 695         pid_t pid = getpid();
 696
 697         /*
 698          * Get IP address of client. If the connection is not a socket, let
 699          * the address be 0.0.0.0.
 700          */
 701         memset(&from, 0, sizeof(from));
 702         if (packet_connection_is_on_socket()) {
 703                 fromlen = sizeof(from);
 704                 if (getpeername(packet_get_connection_in(),
 705                      (struct sockaddr *) & from, &fromlen) < 0) {
 706                         debug("getpeername: %.100s", strerror(errno));
 707                         fatal_cleanup();
 708                 }
 709         }
 710
 711         /* Get the time and hostname when the user last logged in. */
 712         if (options.print_lastlog) {
 713                 hostname[0] = '\0';
 714                 last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 715                     hostname, sizeof(hostname));
 716         }
 717
 718         /* Record that there was a login on that tty from the remote host. */
 719         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 720             get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
 721             (struct sockaddr *)&from);
 722
 723 #ifdef USE_PAM
 724         /*
 725          * If password change is needed, do it now.
 726          * This needs to occur before the ~/.hushlogin check.
 727          */
 728         if (is_pam_password_change_required()) {
 729                 print_pam_messages();
 730                 do_pam_chauthtok();
 731         }
 732 #endif
 733
 734         if (check_quietlogin(s, command))
 735                 return;
 736
 737 #ifdef USE_PAM
 738         if (!is_pam_password_change_required())
 739                 print_pam_messages();
 740 #endif /* USE_PAM */
 741 #ifdef WITH_AIXAUTHENTICATE
 742         if (aixloginmsg && *aixloginmsg)
 743                 printf("%s\n", aixloginmsg);
 744 #endif /* WITH_AIXAUTHENTICATE */
 745
 746         if (options.print_lastlog && last_login_time != 0) {
 747                 time_string = ctime(&last_login_time);
 748                 if (strchr(time_string, '\n'))
 749                         *strchr(time_string, '\n') = 0;
 750                 if (strcmp(hostname, "") == 0)
 751                         printf("Last login: %s\r\n", time_string);
 752                 else
 753                         printf("Last login: %s from %s\r\n", time_string, hostname);
 754         }
 755
 756         do_motd();
 757 }
 758
 759 /*
 760  * Display the message of the day.
 761  */
 762 void
 763 do_motd(void)
 764 {
 765         FILE *f;
 766         char buf[256];
 767
 768         if (options.print_motd) {
 769 #ifdef HAVE_LOGIN_CAP
 770                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 771                     "/etc/motd"), "r");
 772 #else
 773                 f = fopen("/etc/motd", "r");
 774 #endif
 775                 if (f) {
 776                         while (fgets(buf, sizeof(buf), f))
 777                                 fputs(buf, stdout);
 778                         fclose(f);
 779                 }
 780         }
 781 }
 782
 783
 784 /*
 785  * Check for quiet login, either .hushlogin or command given.
 786  */
 787 int
 788 check_quietlogin(Session *s, const char *command)
 789 {
 790         char buf[256];
 791         struct passwd *pw = s->pw;
 792         struct stat st;
 793
 794         /* Return 1 if .hushlogin exists or a command given. */
 795         if (command != NULL)
 796                 return 1;
 797         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 798 #ifdef HAVE_LOGIN_CAP
 799         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 800                 return 1;
 801 #else
 802         if (stat(buf, &st) >= 0)
 803                 return 1;
 804 #endif
 805         return 0;
 806 }
 807
 808 /*
 809  * Sets the value of the given variable in the environment.  If the variable
 810  * already exists, its value is overriden.
 811  */
 812 static void
 813 child_set_env(char ***envp, u_int *envsizep, const char *name,
 814         const char *value)
 815 {
 816         u_int i, namelen;
 817         char **env;
 818
 819         /*
 820          * Find the slot where the value should be stored.  If the variable
 821          * already exists, we reuse the slot; otherwise we append a new slot
 822          * at the end of the array, expanding if necessary.
 823          */
 824         env = *envp;
 825         namelen = strlen(name);
 826         for (i = 0; env[i]; i++)
 827                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 828                         break;
 829         if (env[i]) {
 830                 /* Reuse the slot. */
 831                 xfree(env[i]);
 832         } else {
 833                 /* New variable.  Expand if necessary. */
 834                 if (i >= (*envsizep) - 1) {
 835                         (*envsizep) += 50;
 836                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 837                 }
 838                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 839                 env[i + 1] = NULL;
 840         }
 841
 842         /* Allocate space and format the variable in the appropriate slot. */
 843         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 844         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 845 }
 846
 847 /*
 848  * Reads environment variables from the given file and adds/overrides them
 849  * into the environment.  If the file does not exist, this does nothing.
 850  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 851  * and assignments of the form name=value.  No other forms are allowed.
 852  */
 853 static void
 854 read_environment_file(char ***env, u_int *envsize,
 855         const char *filename)
 856 {
 857         FILE *f;
 858         char buf[4096];
 859         char *cp, *value;
 860
 861         f = fopen(filename, "r");
 862         if (!f)
 863                 return;
 864
 865         while (fgets(buf, sizeof(buf), f)) {
 866                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 867                         ;
 868                 if (!*cp || *cp == '#' || *cp == '\n')
 869                         continue;
 870                 if (strchr(cp, '\n'))
 871                         *strchr(cp, '\n') = '\0';
 872                 value = strchr(cp, '=');
 873                 if (value == NULL) {
 874                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 875                         continue;
 876                 }
 877                 /*
 878                  * Replace the equals sign by nul, and advance value to
 879                  * the value string.
 880                  */
 881                 *value = '\0';
 882                 value++;
 883                 child_set_env(env, envsize, cp, value);
 884         }
 885         fclose(f);
 886 }
 887
 888 #ifdef USE_PAM
 889 /*
 890  * Sets any environment variables which have been specified by PAM
 891  */
 892 void do_pam_environment(char ***env, u_int *envsize)
 893 {
 894         char *equals, var_name[512], var_val[512];
 895         char **pam_env;
 896         int i;
 897
 898         if ((pam_env = fetch_pam_environment()) == NULL)
 899                 return;
 900
 901         for(i = 0; pam_env[i] != NULL; i++) {
 902                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 903                         continue;
 904
 905                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 906                         memset(var_name, '\0', sizeof(var_name));
 907                         memset(var_val, '\0', sizeof(var_val));
 908
 909                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 910                         strcpy(var_val, equals + 1);
 911
 912                         debug3("PAM environment: %s=%s", var_name, var_val);
 913
 914                         child_set_env(env, envsize, var_name, var_val);
 915                 }
 916         }
 917 }
 918 #endif /* USE_PAM */
 919
 920 #ifdef HAVE_CYGWIN
 921 void copy_environment(char ***env, u_int *envsize)
 922 {
 923         char *equals, var_name[512], var_val[512];
 924         int i;
 925
 926         for(i = 0; environ[i] != NULL; i++) {
 927                 if ((equals = strstr(environ[i], "=")) == NULL)
 928                         continue;
 929
 930                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 931                         memset(var_name, '\0', sizeof(var_name));
 932                         memset(var_val, '\0', sizeof(var_val));
 933
 934                         strncpy(var_name, environ[i], equals - environ[i]);
 935                         strcpy(var_val, equals + 1);
 936
 937                         debug3("Copy environment: %s=%s", var_name, var_val);
 938
 939                         child_set_env(env, envsize, var_name, var_val);
 940                 }
 941         }
 942 }
 943 #endif
 944
 945 #if defined(HAVE_GETUSERATTR)
 946 /*
 947  * AIX-specific login initialisation
 948  */
 949 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 950 {
 951         struct rlimit rlim;
 952         int slim, hlim;
 953
 954         getrlimit(resource, &rlim);
 955
 956         slim = 0;
 957         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 958                 if (slim < 0) {
 959                         rlim.rlim_cur = RLIM_INFINITY;
 960                 } else if (slim != 0) {
 961                         /* See the wackiness below */
 962                         if (rlim.rlim_cur == slim * mult)
 963                                 slim = 0;
 964                         else
 965                                 rlim.rlim_cur = slim * mult;
 966                 }
 967         }
 968
 969         hlim = 0;
 970         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 971                 if (hlim < 0) {
 972                         rlim.rlim_max = RLIM_INFINITY;
 973                 } else if (hlim != 0) {
 974                         rlim.rlim_max = hlim * mult;
 975                 }
 976         }
 977
 978         /*
 979          * XXX For cpu and fsize the soft limit is set to the hard limit
 980          * if the hard limit is left at its default value and the soft limit
 981          * is changed from its default value, either by requesting it
 982          * (slim == 0) or by setting it to the current default.  At least
 983          * that's how rlogind does it.  If you're confused you're not alone.
 984          * Bug or feature? AIX 4.3.1.2
 985          */
 986         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 987             && hlim == 0 && slim != 0)
 988                 rlim.rlim_max = rlim.rlim_cur;
 989         /* A specified hard limit limits the soft limit */
 990         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 991                 rlim.rlim_cur = rlim.rlim_max;
 992         /* A soft limit can increase a hard limit */
 993         else if (rlim.rlim_cur > rlim.rlim_max)
 994                 rlim.rlim_max = rlim.rlim_cur;
 995
 996         if (setrlimit(resource, &rlim) != 0)
 997                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 998 }
 999
1000 void set_limits_from_userattr(char *user)
1001 {
1002         int mask;
1003         char buf[16];
1004
1005         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
1006         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
1007         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
1008         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
1009         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
1010         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
1011 #if defined(S_UNOFILE)
1012         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
1013 #endif
1014
1015         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
1016                 /* Convert decimal to octal */
1017                 (void) snprintf(buf, sizeof(buf), "%d", mask);
1018                 if (sscanf(buf, "%o", &mask) == 1)
1019                         umask(mask);
1020         }
1021 }
1022 #endif /* defined(HAVE_GETUSERATTR) */
1023
1024 /*
1025  * Performs common processing for the child, such as setting up the
1026  * environment, closing extra file descriptors, setting the user and group
1027  * ids, and executing the command or shell.
1028  */
1029 void
1030 do_child(Session *s, const char *command)
1031 {
1032         const char *shell, *hostname = NULL, *cp = NULL;
1033         struct passwd *pw = s->pw;
1034         char buf[256];
1035         char cmd[1024];
1036         FILE *f = NULL;
1037         u_int envsize, i;
1038         char **env;
1039         extern char **environ;
1040         struct stat st;
1041         char *argv[10];
1042         int do_xauth;
1043 #ifdef WITH_IRIX_PROJECT
1044         prid_t projid;
1045 #endif /* WITH_IRIX_PROJECT */
1046 #ifdef WITH_IRIX_JOBS
1047         jid_t jid = 0;
1048 #else
1049 #ifdef WITH_IRIX_ARRAY
1050         int jid = 0;
1051 #endif /* WITH_IRIX_ARRAY */
1052 #endif /* WITH_IRIX_JOBS */
1053
1054         do_xauth =
1055             s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1056
1057         /* remove hostkey from the child's memory */
1058         destroy_sensitive_data();
1059
1060         /* login(1) is only called if we execute the login shell */
1061         if (options.use_login && command != NULL)
1062                 options.use_login = 0;
1063
1064 #if !defined(HAVE_OSF_SIA)
1065         if (!options.use_login) {
1066 # ifdef HAVE_LOGIN_CAP
1067                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1068                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1069                             _PATH_NOLOGIN), "r");
1070 # else /* HAVE_LOGIN_CAP */
1071                 if (pw->pw_uid)
1072                         f = fopen(_PATH_NOLOGIN, "r");
1073 # endif /* HAVE_LOGIN_CAP */
1074                 if (f) {
1075                         /* /etc/nologin exists.  Print its contents and exit. */
1076                         while (fgets(buf, sizeof(buf), f))
1077                                 fputs(buf, stderr);
1078                         fclose(f);
1079                         exit(254);
1080                 }
1081         }
1082 #endif /* HAVE_OSF_SIA */
1083
1084         /* Set login name, uid, gid, and groups. */
1085         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1086            switch, so we let login(1) to this for us. */
1087         if (!options.use_login) {
1088 #ifdef HAVE_OSF_SIA
1089                 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1090                 if (!check_quietlogin(s, command))
1091                         do_motd();
1092 #else /* HAVE_OSF_SIA */
1093 #ifdef HAVE_CYGWIN
1094                 if (is_winnt) {
1095 #else
1096                 if (getuid() == 0 || geteuid() == 0) {
1097 #endif
1098 # ifdef HAVE_GETUSERATTR
1099                         set_limits_from_userattr(pw->pw_name);
1100 # endif /* HAVE_GETUSERATTR */
1101 # ifdef HAVE_LOGIN_CAP
1102                         if (setusercontext(lc, pw, pw->pw_uid,
1103                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1104                                 perror("unable to set user context");
1105                                 exit(1);
1106                         }
1107 # else /* HAVE_LOGIN_CAP */
1108 #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1109                         /* Sets login uid for accounting */
1110                         if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1111                                 error("setluid: %s", strerror(errno));
1112 #endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1113
1114                         if (setlogin(pw->pw_name) < 0)
1115                                 error("setlogin failed: %s", strerror(errno));
1116                         if (setgid(pw->pw_gid) < 0) {
1117                                 perror("setgid");
1118                                 exit(1);
1119                         }
1120                         /* Initialize the group list. */
1121                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1122                                 perror("initgroups");
1123                                 exit(1);
1124                         }
1125                         endgrent();
1126 #  ifdef USE_PAM
1127                         /*
1128                          * PAM credentials may take the form of
1129                          * supplementary groups. These will have been
1130                          * wiped by the above initgroups() call.
1131                          * Reestablish them here.
1132                          */
1133                         do_pam_setcred(0);
1134 #  endif /* USE_PAM */
1135 #  ifdef WITH_IRIX_JOBS
1136                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1137                         if (jid == -1) {
1138                                 fatal("Failed to create job container: %.100s",
1139                                       strerror(errno));
1140                         }
1141 #  endif /* WITH_IRIX_JOBS */
1142 #  ifdef WITH_IRIX_ARRAY
1143                         /* initialize array session */
1144                         if (jid == 0) {
1145                                 if (newarraysess() != 0)
1146                                         fatal("Failed to set up new array session: %.100s",
1147                                               strerror(errno));
1148                         }
1149 #  endif /* WITH_IRIX_ARRAY */
1150 #  ifdef WITH_IRIX_PROJECT
1151                         /* initialize irix project info */
1152                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1153                           debug("Failed to get project id, using projid 0");
1154                           projid = 0;
1155                         }
1156                         if (setprid(projid))
1157                           fatal("Failed to initialize project %d for %s: %.100s",
1158                                 (int)projid, pw->pw_name, strerror(errno));
1159 #  endif /* WITH_IRIX_PROJECT */
1160 #ifdef WITH_IRIX_AUDIT
1161                         if (sysconf(_SC_AUDIT)) {
1162                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1163                                 if (satsetid(pw->pw_uid))
1164                                         debug("error setting satid: %.100s", strerror(errno));
1165                         }
1166 #endif /* WITH_IRIX_AUDIT */
1167
1168 #ifdef _AIX
1169                         /*
1170                          * AIX has a "usrinfo" area where logname and
1171                          * other stuff is stored - a few applications
1172                          * actually use this and die if it's not set
1173                          */
1174                         if (s->ttyfd == -1)
1175                                 s->tty[0] = '\0';
1176                         cp = xmalloc(22 + strlen(s->tty) +
1177                             2 * strlen(pw->pw_name));
1178                         i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c",
1179                             pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0);
1180                         if (usrinfo(SETUINFO, cp, i) == -1)
1181                                 fatal("Couldn't set usrinfo: %s",
1182                                     strerror(errno));
1183                         debug3("AIX/UsrInfo: set len %d", i);
1184                         xfree(cp);
1185 #endif
1186
1187                         /* Permanently switch to the desired uid. */
1188                         permanently_set_uid(pw);
1189 # endif /* HAVE_LOGIN_CAP */
1190                 }
1191 #endif /* HAVE_OSF_SIA */
1192
1193 #ifdef HAVE_CYGWIN
1194                 if (is_winnt)
1195 #endif
1196                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1197                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1198         }
1199         /*
1200          * Get the shell from the password data.  An empty shell field is
1201          * legal, and means /bin/sh.
1202          */
1203         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1204 #ifdef HAVE_LOGIN_CAP
1205         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1206 #endif
1207
1208         /* Initialize the environment. */
1209         envsize = 100;
1210         env = xmalloc(envsize * sizeof(char *));
1211         env[0] = NULL;
1212
1213 #ifdef HAVE_CYGWIN
1214         /*
1215          * The Windows environment contains some setting which are
1216          * important for a running system. They must not be dropped.
1217          */
1218         copy_environment(&env, &envsize);
1219 #endif
1220
1221         if (!options.use_login) {
1222                 /* Set basic environment. */
1223                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1224                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1225                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1226 #ifdef HAVE_LOGIN_CAP
1227                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1228                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1229 #else /* HAVE_LOGIN_CAP */
1230 # ifndef HAVE_CYGWIN
1231                 /*
1232                  * There's no standard path on Windows. The path contains
1233                  * important components pointing to the system directories,
1234                  * needed for loading shared libraries. So the path better
1235                  * remains intact here.
1236                  */
1237                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1238 # endif /* HAVE_CYGWIN */
1239 #endif /* HAVE_LOGIN_CAP */
1240
1241                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1242                          _PATH_MAILDIR, pw->pw_name);
1243                 child_set_env(&env, &envsize, "MAIL", buf);
1244
1245                 /* Normal systems set SHELL by default. */
1246                 child_set_env(&env, &envsize, "SHELL", shell);
1247         }
1248         if (getenv("TZ"))
1249                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1250
1251         /* Set custom environment options from RSA authentication. */
1252         if (!options.use_login) {
1253                 while (custom_environment) {
1254                         struct envstring *ce = custom_environment;
1255                         char *s = ce->s;
1256                         int i;
1257                         for (i = 0; s[i] != '=' && s[i]; i++)
1258                                 ;
1259                         if (s[i] == '=') {
1260                                 s[i] = 0;
1261                                 child_set_env(&env, &envsize, s, s + i + 1);
1262                         }
1263                         custom_environment = ce->next;
1264                         xfree(ce->s);
1265                         xfree(ce);
1266                 }
1267         }
1268
1269         snprintf(buf, sizeof buf, "%.50s %d %d",
1270                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1271         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1272
1273         if (s->ttyfd != -1)
1274                 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1275         if (s->term)
1276                 child_set_env(&env, &envsize, "TERM", s->term);
1277         if (s->display)
1278                 child_set_env(&env, &envsize, "DISPLAY", s->display);
1279         if (original_command)
1280                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1281                     original_command);
1282
1283 #ifdef _AIX
1284         if ((cp = getenv("AUTHSTATE")) != NULL)
1285                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1286         if ((cp = getenv("KRB5CCNAME")) != NULL)
1287                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1288         read_environment_file(&env, &envsize, "/etc/environment");
1289 #endif
1290 #ifdef KRB4
1291         if (s->authctxt->krb4_ticket_file)
1292                 child_set_env(&env, &envsize, "KRBTKFILE",
1293                     s->authctxt->krb4_ticket_file);
1294 #endif
1295 #ifdef KRB5
1296         if (s->authctxt->krb5_ticket_file)
1297                 child_set_env(&env, &envsize, "KRB5CCNAME",
1298                     s->authctxt->krb5_ticket_file);
1299 #endif
1300 #ifdef USE_PAM
1301         /* Pull in any environment variables that may have been set by PAM. */
1302         do_pam_environment(&env, &envsize);
1303 #endif /* USE_PAM */
1304
1305         if (auth_get_socket_name() != NULL)
1306                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1307                     auth_get_socket_name());
1308
1309         /* read $HOME/.ssh/environment. */
1310         if (!options.use_login) {
1311                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1312                     pw->pw_dir);
1313                 read_environment_file(&env, &envsize, buf);
1314         }
1315         if (debug_flag) {
1316                 /* dump the environment */
1317                 fprintf(stderr, "Environment:\n");
1318                 for (i = 0; env[i]; i++)
1319                         fprintf(stderr, "  %.200s\n", env[i]);
1320         }
1321         /* we have to stash the hostname before we close our socket. */
1322         if (options.use_login)
1323                 hostname = get_remote_name_or_ip(utmp_len,
1324                     options.reverse_mapping_check);
1325         /*
1326          * Close the connection descriptors; note that this is the child, and
1327          * the server will still have the socket open, and it is important
1328          * that we do not shutdown it.  Note that the descriptors cannot be
1329          * closed before building the environment, as we call
1330          * get_remote_ipaddr there.
1331          */
1332         if (packet_get_connection_in() == packet_get_connection_out())
1333                 close(packet_get_connection_in());
1334         else {
1335                 close(packet_get_connection_in());
1336                 close(packet_get_connection_out());
1337         }
1338         /*
1339          * Close all descriptors related to channels.  They will still remain
1340          * open in the parent.
1341          */
1342         /* XXX better use close-on-exec? -markus */
1343         channel_close_all();
1344
1345         /*
1346          * Close any extra file descriptors.  Note that there may still be
1347          * descriptors left by system functions.  They will be closed later.
1348          */
1349         endpwent();
1350
1351         /*
1352          * Close any extra open file descriptors so that we don\'t have them
1353          * hanging around in clients.  Note that we want to do this after
1354          * initgroups, because at least on Solaris 2.3 it leaves file
1355          * descriptors open.
1356          */
1357         for (i = 3; i < 64; i++)
1358                 close(i);
1359
1360         /*
1361          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1362          * xauth are run in the proper environment.
1363          */
1364         environ = env;
1365
1366 #ifdef AFS
1367         /* Try to get AFS tokens for the local cell. */
1368         if (k_hasafs()) {
1369                 char cell[64];
1370
1371                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1372                         krb_afslog(cell, 0);
1373
1374                 krb_afslog(0, 0);
1375         }
1376 #endif /* AFS */
1377
1378         /* Change current directory to the user\'s home directory. */
1379         if (chdir(pw->pw_dir) < 0) {
1380                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1381                     pw->pw_dir, strerror(errno));
1382 #ifdef HAVE_LOGIN_CAP
1383                 if (login_getcapbool(lc, "requirehome", 0))
1384                         exit(1);
1385 #endif
1386         }
1387
1388         /*
1389          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1390          * in this order).
1391          */
1392         if (!options.use_login) {
1393                 /* ignore _PATH_SSH_USER_RC for subsystems */
1394                 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1395                         snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1396                             shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1397                         if (debug_flag)
1398                                 fprintf(stderr, "Running %s\n", cmd);
1399                         f = popen(cmd, "w");
1400                         if (f) {
1401                                 if (do_xauth)
1402                                         fprintf(f, "%s %s\n", s->auth_proto,
1403                                             s->auth_data);
1404                                 pclose(f);
1405                         } else
1406                                 fprintf(stderr, "Could not run %s\n",
1407                                     _PATH_SSH_USER_RC);
1408                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1409                         if (debug_flag)
1410                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1411                                     _PATH_SSH_SYSTEM_RC);
1412                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1413                         if (f) {
1414                                 if (do_xauth)
1415                                         fprintf(f, "%s %s\n", s->auth_proto,
1416                                             s->auth_data);
1417                                 pclose(f);
1418                         } else
1419                                 fprintf(stderr, "Could not run %s\n",
1420                                     _PATH_SSH_SYSTEM_RC);
1421                 } else if (do_xauth && options.xauth_location != NULL) {
1422                         /* Add authority data to .Xauthority if appropriate. */
1423                         if (debug_flag) {
1424                                 fprintf(stderr,
1425                                     "Running %.100s add "
1426                                     "%.100s %.100s %.100s\n",
1427                                     options.xauth_location, s->auth_display[0],
1428                                     s->auth_proto, s->auth_data);
1429                                 if (s->auth_display[1])
1430                                         fprintf(stderr,
1431                                             "add %.100s %.100s %.100s\n",
1432                                             s->auth_display[1],
1433                                             s->auth_proto, s->auth_data);
1434                         }
1435                         snprintf(cmd, sizeof cmd, "%s -q -",
1436                             options.xauth_location);
1437                         f = popen(cmd, "w");
1438                         if (f) {
1439                                 fprintf(f, "add %s %s %s\n",
1440                                     s->auth_display[0], s->auth_proto,
1441                                     s->auth_data);
1442                                 if (s->auth_display[1])
1443                                         fprintf(f, "add %s %s %s\n",
1444                                             s->auth_display[1], s->auth_proto,
1445                                             s->auth_data);
1446                                 pclose(f);
1447                         } else {
1448                                 fprintf(stderr, "Could not run %s\n",
1449                                     cmd);
1450                         }
1451                 }
1452                 /* Get the last component of the shell name. */
1453                 cp = strrchr(shell, '/');
1454                 if (cp)
1455                         cp++;
1456                 else
1457                         cp = shell;
1458         }
1459
1460         /* restore SIGPIPE for child */
1461         signal(SIGPIPE,  SIG_DFL);
1462
1463         /*
1464          * If we have no command, execute the shell.  In this case, the shell
1465          * name to be passed in argv[0] is preceded by '-' to indicate that
1466          * this is a login shell.
1467          */
1468         if (!command) {
1469                 if (!options.use_login) {
1470                         char buf[256];
1471
1472                         /* Start the shell.  Set initial character to '-'. */
1473                         buf[0] = '-';
1474                         strlcpy(buf + 1, cp, sizeof(buf) - 1);
1475
1476                         /* Execute the shell. */
1477                         argv[0] = buf;
1478                         argv[1] = NULL;
1479                         execve(shell, argv, env);
1480
1481                         /* Executing the shell failed. */
1482                         perror(shell);
1483                         exit(1);
1484
1485                 } else {
1486                         /* Launch login(1). */
1487
1488                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1489 #ifdef LOGIN_NEEDS_TERM
1490                             s->term? s->term : "unknown",
1491 #endif
1492                             "-p", "-f", "--", pw->pw_name, (char *)NULL);
1493
1494                         /* Login couldn't be executed, die. */
1495
1496                         perror("login");
1497                         exit(1);
1498                 }
1499         }
1500         /*
1501          * Execute the command using the user's shell.  This uses the -c
1502          * option to execute the command.
1503          */
1504         argv[0] = (char *) cp;
1505         argv[1] = "-c";
1506         argv[2] = (char *) command;
1507         argv[3] = NULL;
1508         execve(shell, argv, env);
1509         perror(shell);
1510         exit(1);
1511 }
1512
1513 Session *
1514 session_new(void)
1515 {
1516         int i;
1517         static int did_init = 0;
1518         if (!did_init) {
1519                 debug("session_new: init");
1520                 for (i = 0; i < MAX_SESSIONS; i++) {
1521                         sessions[i].used = 0;
1522                 }
1523                 did_init = 1;
1524         }
1525         for (i = 0; i < MAX_SESSIONS; i++) {
1526                 Session *s = &sessions[i];
1527                 if (! s->used) {
1528                         memset(s, 0, sizeof(*s));
1529                         s->chanid = -1;
1530                         s->ptyfd = -1;
1531                         s->ttyfd = -1;
1532                         s->used = 1;
1533                         s->self = i;
1534                         debug("session_new: session %d", i);
1535                         return s;
1536                 }
1537         }
1538         return NULL;
1539 }
1540
1541 static void
1542 session_dump(void)
1543 {
1544         int i;
1545         for (i = 0; i < MAX_SESSIONS; i++) {
1546                 Session *s = &sessions[i];
1547                 debug("dump: used %d session %d %p channel %d pid %d",
1548                     s->used,
1549                     s->self,
1550                     s,
1551                     s->chanid,
1552                     s->pid);
1553         }
1554 }
1555
1556 int
1557 session_open(Authctxt *authctxt, int chanid)
1558 {
1559         Session *s = session_new();
1560         debug("session_open: channel %d", chanid);
1561         if (s == NULL) {
1562                 error("no more sessions");
1563                 return 0;
1564         }
1565         s->authctxt = authctxt;
1566         s->pw = authctxt->pw;
1567         if (s->pw == NULL)
1568                 fatal("no user for session %d", s->self);
1569         debug("session_open: session %d: link with channel %d", s->self, chanid);
1570         s->chanid = chanid;
1571         return 1;
1572 }
1573
1574 static Session *
1575 session_by_channel(int id)
1576 {
1577         int i;
1578         for (i = 0; i < MAX_SESSIONS; i++) {
1579                 Session *s = &sessions[i];
1580                 if (s->used && s->chanid == id) {
1581                         debug("session_by_channel: session %d channel %d", i, id);
1582                         return s;
1583                 }
1584         }
1585         debug("session_by_channel: unknown channel %d", id);
1586         session_dump();
1587         return NULL;
1588 }
1589
1590 static Session *
1591 session_by_pid(pid_t pid)
1592 {
1593         int i;
1594         debug("session_by_pid: pid %d", pid);
1595         for (i = 0; i < MAX_SESSIONS; i++) {
1596                 Session *s = &sessions[i];
1597                 if (s->used && s->pid == pid)
1598                         return s;
1599         }
1600         error("session_by_pid: unknown pid %d", pid);
1601         session_dump();
1602         return NULL;
1603 }
1604
1605 static int
1606 session_window_change_req(Session *s)
1607 {
1608         s->col = packet_get_int();
1609         s->row = packet_get_int();
1610         s->xpixel = packet_get_int();
1611         s->ypixel = packet_get_int();
1612         packet_done();
1613         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1614         return 1;
1615 }
1616
1617 static int
1618 session_pty_req(Session *s)
1619 {
1620         u_int len;
1621         int n_bytes;
1622
1623         if (no_pty_flag) {
1624                 debug("Allocating a pty not permitted for this authentication.");
1625                 return 0;
1626         }
1627         if (s->ttyfd != -1) {
1628                 packet_disconnect("Protocol error: you already have a pty.");
1629                 return 0;
1630         }
1631
1632         s->term = packet_get_string(&len);
1633
1634         if (compat20) {
1635                 s->col = packet_get_int();
1636                 s->row = packet_get_int();
1637         } else {
1638                 s->row = packet_get_int();
1639                 s->col = packet_get_int();
1640         }
1641         s->xpixel = packet_get_int();
1642         s->ypixel = packet_get_int();
1643
1644         if (strcmp(s->term, "") == 0) {
1645                 xfree(s->term);
1646                 s->term = NULL;
1647         }
1648
1649         /* Allocate a pty and open it. */
1650         debug("Allocating pty.");
1651         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1652                 if (s->term)
1653                         xfree(s->term);
1654                 s->term = NULL;
1655                 s->ptyfd = -1;
1656                 s->ttyfd = -1;
1657                 error("session_pty_req: session %d alloc failed", s->self);
1658                 return 0;
1659         }
1660         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1661
1662         /* for SSH1 the tty modes length is not given */
1663         if (!compat20)
1664                 n_bytes = packet_remaining();
1665         tty_parse_modes(s->ttyfd, &n_bytes);
1666
1667         /*
1668          * Add a cleanup function to clear the utmp entry and record logout
1669          * time in case we call fatal() (e.g., the connection gets closed).
1670          */
1671         fatal_add_cleanup(session_pty_cleanup, (void *)s);
1672         pty_setowner(s->pw, s->tty);
1673
1674         /* Set window size from the packet. */
1675         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1676
1677         packet_done();
1678         session_proctitle(s);
1679         return 1;
1680 }
1681
1682 static int
1683 session_subsystem_req(Session *s)
1684 {
1685         struct stat st;
1686         u_int len;
1687         int success = 0;
1688         char *cmd, *subsys = packet_get_string(&len);
1689         int i;
1690
1691         packet_done();
1692         log("subsystem request for %s", subsys);
1693
1694         for (i = 0; i < options.num_subsystems; i++) {
1695                 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1696                         cmd = options.subsystem_command[i];
1697                         if (stat(cmd, &st) < 0) {
1698                                 error("subsystem: cannot stat %s: %s", cmd,
1699                                     strerror(errno));
1700                                 break;
1701                         }
1702                         debug("subsystem: exec() %s", cmd);
1703                         s->is_subsystem = 1;
1704                         do_exec(s, cmd);
1705                         success = 1;
1706                 }
1707         }
1708
1709         if (!success)
1710                 log("subsystem request for %s failed, subsystem not found",
1711                     subsys);
1712
1713         xfree(subsys);
1714         return success;
1715 }
1716
1717 static int
1718 session_x11_req(Session *s)
1719 {
1720         int success;
1721
1722         s->single_connection = packet_get_char();
1723         s->auth_proto = packet_get_string(NULL);
1724         s->auth_data = packet_get_string(NULL);
1725         s->screen = packet_get_int();
1726         packet_done();
1727
1728         success = session_setup_x11fwd(s);
1729         if (!success) {
1730                 xfree(s->auth_proto);
1731                 xfree(s->auth_data);
1732                 s->auth_proto = NULL;
1733                 s->auth_data = NULL;
1734         }
1735         return success;
1736 }
1737
1738 static int
1739 session_shell_req(Session *s)
1740 {
1741         packet_done();
1742         do_exec(s, NULL);
1743         return 1;
1744 }
1745
1746 static int
1747 session_exec_req(Session *s)
1748 {
1749         u_int len;
1750         char *command = packet_get_string(&len);
1751         packet_done();
1752         do_exec(s, command);
1753         xfree(command);
1754         return 1;
1755 }
1756
1757 static int
1758 session_auth_agent_req(Session *s)
1759 {
1760         static int called = 0;
1761         packet_done();
1762         if (no_agent_forwarding_flag) {
1763                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1764                 return 0;
1765         }
1766         if (called) {
1767                 return 0;
1768         } else {
1769                 called = 1;
1770                 return auth_input_request_forwarding(s->pw);
1771         }
1772 }
1773
1774 void
1775 session_input_channel_req(int id, void *arg)
1776 {
1777         u_int len;
1778         int reply;
1779         int success = 0;
1780         char *rtype;
1781         Session *s;
1782         Channel *c;
1783
1784         rtype = packet_get_string(&len);
1785         reply = packet_get_char();
1786
1787         s = session_by_channel(id);
1788         if (s == NULL)
1789                 fatal("session_input_channel_req: channel %d: no session", id);
1790         c = channel_lookup(id);
1791         if (c == NULL)
1792                 fatal("session_input_channel_req: channel %d: bad channel", id);
1793
1794         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1795             s->self, id, rtype, reply);
1796
1797         /*
1798          * a session is in LARVAL state until a shell, a command
1799          * or a subsystem is executed
1800          */
1801         if (c->type == SSH_CHANNEL_LARVAL) {
1802                 if (strcmp(rtype, "shell") == 0) {
1803                         success = session_shell_req(s);
1804                 } else if (strcmp(rtype, "exec") == 0) {
1805                         success = session_exec_req(s);
1806                 } else if (strcmp(rtype, "pty-req") == 0) {
1807                         success =  session_pty_req(s);
1808                 } else if (strcmp(rtype, "x11-req") == 0) {
1809                         success = session_x11_req(s);
1810                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1811                         success = session_auth_agent_req(s);
1812                 } else if (strcmp(rtype, "subsystem") == 0) {
1813                         success = session_subsystem_req(s);
1814                 }
1815         }
1816         if (strcmp(rtype, "window-change") == 0) {
1817                 success = session_window_change_req(s);
1818         }
1819
1820         if (reply) {
1821                 packet_start(success ?
1822                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1823                 packet_put_int(c->remote_id);
1824                 packet_send();
1825         }
1826         xfree(rtype);
1827 }
1828
1829 void
1830 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1831 {
1832         if (!compat20)
1833                 fatal("session_set_fds: called for proto != 2.0");
1834         /*
1835          * now that have a child and a pipe to the child,
1836          * we can activate our channel and register the fd's
1837          */
1838         if (s->chanid == -1)
1839                 fatal("no channel for session %d", s->self);
1840         channel_set_fds(s->chanid,
1841             fdout, fdin, fderr,
1842             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1843             1);
1844 }
1845
1846 /*
1847  * Function to perform pty cleanup. Also called if we get aborted abnormally
1848  * (e.g., due to a dropped connection).
1849  */
1850 static void
1851 session_pty_cleanup(void *session)
1852 {
1853         Session *s = session;
1854
1855         if (s == NULL) {
1856                 error("session_pty_cleanup: no session");
1857                 return;
1858         }
1859         if (s->ttyfd == -1)
1860                 return;
1861
1862         debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1863
1864         /* Record that the user has logged out. */
1865         if (s->pid != 0)
1866                 record_logout(s->pid, s->tty);
1867
1868         /* Release the pseudo-tty. */
1869         pty_release(s->tty);
1870
1871         /*
1872          * Close the server side of the socket pairs.  We must do this after
1873          * the pty cleanup, so that another process doesn't get this pty
1874          * while we're still cleaning up.
1875          */
1876         if (close(s->ptymaster) < 0)
1877                 error("close(s->ptymaster): %s", strerror(errno));
1878
1879         /* unlink pty from session */
1880         s->ttyfd = -1;
1881 }
1882
1883 static void
1884 session_exit_message(Session *s, int status)
1885 {
1886         Channel *c;
1887         if (s == NULL)
1888                 fatal("session_close: no session");
1889         c = channel_lookup(s->chanid);
1890         if (c == NULL)
1891                 fatal("session_exit_message: session %d: no channel %d",
1892                     s->self, s->chanid);
1893         debug("session_exit_message: session %d channel %d pid %d",
1894             s->self, s->chanid, s->pid);
1895
1896         if (WIFEXITED(status)) {
1897                 channel_request_start(s->chanid,
1898                     "exit-status", 0);
1899                 packet_put_int(WEXITSTATUS(status));
1900                 packet_send();
1901         } else if (WIFSIGNALED(status)) {
1902                 channel_request_start(s->chanid,
1903                     "exit-signal", 0);
1904                 packet_put_int(WTERMSIG(status));
1905 #ifdef WCOREDUMP
1906                 packet_put_char(WCOREDUMP(status));
1907 #else /* WCOREDUMP */
1908                 packet_put_char(0);
1909 #endif /* WCOREDUMP */
1910                 packet_put_cstring("");
1911                 packet_put_cstring("");
1912                 packet_send();
1913         } else {
1914                 /* Some weird exit cause.  Just exit. */
1915                 packet_disconnect("wait returned status %04x.", status);
1916         }
1917
1918         /* disconnect channel */
1919         debug("session_exit_message: release channel %d", s->chanid);
1920         channel_cancel_cleanup(s->chanid);
1921         /*
1922          * emulate a write failure with 'chan_write_failed', nobody will be
1923          * interested in data we write.
1924          * Note that we must not call 'chan_read_failed', since there could
1925          * be some more data waiting in the pipe.
1926          */
1927         if (c->ostate != CHAN_OUTPUT_CLOSED)
1928                 chan_write_failed(c);
1929         s->chanid = -1;
1930 }
1931
1932 static void
1933 session_close(Session *s)
1934 {
1935         debug("session_close: session %d pid %d", s->self, s->pid);
1936         if (s->ttyfd != -1) {
1937                 fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1938                 session_pty_cleanup(s);
1939         }
1940         if (s->term)
1941                 xfree(s->term);
1942         if (s->display)
1943                 xfree(s->display);
1944         if (s->auth_display[0])
1945                 xfree(s->auth_display[0]);
1946         if (s->auth_display[1])
1947                 xfree(s->auth_display[1]);
1948         if (s->auth_data)
1949                 xfree(s->auth_data);
1950         if (s->auth_proto)
1951                 xfree(s->auth_proto);
1952         s->used = 0;
1953         session_proctitle(s);
1954 }
1955
1956 void
1957 session_close_by_pid(pid_t pid, int status)
1958 {
1959         Session *s = session_by_pid(pid);
1960         if (s == NULL) {
1961                 debug("session_close_by_pid: no session for pid %d", pid);
1962                 return;
1963         }
1964         if (s->chanid != -1)
1965                 session_exit_message(s, status);
1966         session_close(s);
1967 }
1968
1969 /*
1970  * this is called when a channel dies before
1971  * the session 'child' itself dies
1972  */
1973 void
1974 session_close_by_channel(int id, void *arg)
1975 {
1976         Session *s = session_by_channel(id);
1977         if (s == NULL) {
1978                 debug("session_close_by_channel: no session for id %d", id);
1979                 return;
1980         }
1981         debug("session_close_by_channel: channel %d child %d", id, s->pid);
1982         if (s->pid != 0) {
1983                 debug("session_close_by_channel: channel %d: has child", id);
1984                 /*
1985                  * delay detach of session, but release pty, since
1986                  * the fd's to the child are already closed
1987                  */
1988                 if (s->ttyfd != -1) {
1989                         fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1990                         session_pty_cleanup(s);
1991                 }
1992                 return;
1993         }
1994         /* detach by removing callback */
1995         channel_cancel_cleanup(s->chanid);
1996         s->chanid = -1;
1997         session_close(s);
1998 }
1999
2000 void
2001 session_destroy_all(void)
2002 {
2003         int i;
2004         for (i = 0; i < MAX_SESSIONS; i++) {
2005                 Session *s = &sessions[i];
2006                 if (s->used)
2007                         session_close(s);
2008         }
2009 }
2010
2011 static char *
2012 session_tty_list(void)
2013 {
2014         static char buf[1024];
2015         int i;
2016         buf[0] = '\0';
2017         for (i = 0; i < MAX_SESSIONS; i++) {
2018                 Session *s = &sessions[i];
2019                 if (s->used && s->ttyfd != -1) {
2020                         if (buf[0] != '\0')
2021                                 strlcat(buf, ",", sizeof buf);
2022                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
2023                 }
2024         }
2025         if (buf[0] == '\0')
2026                 strlcpy(buf, "notty", sizeof buf);
2027         return buf;
2028 }
2029
2030 void
2031 session_proctitle(Session *s)
2032 {
2033         if (s->pw == NULL)
2034                 error("no user for session %d", s->self);
2035         else
2036                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2037 }
2038
2039 int
2040 session_setup_x11fwd(Session *s)
2041 {
2042         struct stat st;
2043         char display[512], auth_display[512];
2044         char hostname[MAXHOSTNAMELEN];
2045
2046         if (no_x11_forwarding_flag) {
2047                 packet_send_debug("X11 forwarding disabled in user configuration file.");
2048                 return 0;
2049         }
2050         if (!options.x11_forwarding) {
2051                 debug("X11 forwarding disabled in server configuration file.");
2052                 return 0;
2053         }
2054         if (!options.xauth_location ||
2055             (stat(options.xauth_location, &st) == -1)) {
2056                 packet_send_debug("No xauth program; cannot forward with spoofing.");
2057                 return 0;
2058         }
2059         if (options.use_login) {
2060                 packet_send_debug("X11 forwarding disabled; "
2061                     "not compatible with UseLogin=yes.");
2062                 return 0;
2063         }
2064         if (s->display != NULL) {
2065                 debug("X11 display already set.");
2066                 return 0;
2067         }
2068         s->display_number = x11_create_display_inet(options.x11_display_offset,
2069             options.gateway_ports);
2070         if (s->display_number == -1) {
2071                 debug("x11_create_display_inet failed.");
2072                 return 0;
2073         }
2074
2075         /* Set up a suitable value for the DISPLAY variable. */
2076         if (gethostname(hostname, sizeof(hostname)) < 0)
2077                 fatal("gethostname: %.100s", strerror(errno));
2078         /*
2079          * auth_display must be used as the displayname when the
2080          * authorization entry is added with xauth(1).  This will be
2081          * different than the DISPLAY string for localhost displays.
2082          */
2083         s->auth_display[1] = NULL;
2084         if (!options.gateway_ports) {
2085                 struct utsname uts;
2086
2087                 snprintf(display, sizeof display, "localhost:%d.%d",
2088                     s->display_number, s->screen);
2089                 snprintf(auth_display, sizeof auth_display, "%.400s/unix:%d.%d",
2090                     hostname, s->display_number, s->screen);
2091                 s->display = xstrdup(display);
2092                 s->auth_display[0] = xstrdup(auth_display);
2093                 /*
2094                  * Xlib may use gethostbyname() or uname() hostname to
2095                  * look up authorization data for FamilyLocal; see:
2096                  * xc/lib/xtrans/Xtrans.c:TRANS(GetHostname)
2097                  * We just add authorization entries with both
2098                  * hostname and nodename if they are different.
2099                  */
2100                 if (uname(&uts) == -1)
2101                         fatal("uname: %.100s", strerror(errno));
2102                 if (strcmp(hostname, uts.nodename) != 0) {
2103                         snprintf(auth_display, sizeof auth_display,
2104                             "%.400s/unix:%d.%d", uts.nodename,
2105                             s->display_number, s->screen);
2106                         s->auth_display[1] = xstrdup(auth_display);
2107                 }
2108         } else {
2109 #ifdef IPADDR_IN_DISPLAY
2110                 struct hostent *he;
2111                 struct in_addr my_addr;
2112
2113                 he = gethostbyname(hostname);
2114                 if (he == NULL) {
2115                         error("Can't get IP address for X11 DISPLAY.");
2116                         packet_send_debug("Can't get IP address for X11 DISPLAY.");
2117                         return 0;
2118                 }
2119                 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2120                 snprintf(display, sizeof display, "%.50s:%d.%d", inet_ntoa(my_addr),
2121                     s->display_number, s->screen);
2122 #else
2123                 snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
2124                     s->display_number, s->screen);
2125 #endif
2126                 s->display = xstrdup(display);
2127                 s->auth_display[0] = xstrdup(display);
2128         }
2129
2130         return 1;
2131 }
2132
2133 static void
2134 do_authenticated2(Authctxt *authctxt)
2135 {
2136         server_loop2(authctxt);
2137 }