| /* |
| * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| * All rights reserved |
| * |
| * As far as I am concerned, the code I have written for this software |
| * can be used freely for any purpose. Any derived versions of this |
| * software must be clearly marked as such, and if the derived work is |
| * incompatible with the protocol description in the RFC file, it must be |
| * called by a name other than "ssh" or "Secure Shell". |
| * |
| * SSH2 support by Markus Friedl. |
| * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "includes.h" |
| RCSID("$OpenBSD: session.c,v 1.152 2002/12/10 08:56:00 markus Exp $"); |
| |
| #include "ssh.h" |
| #include "ssh1.h" |
| #include "ssh2.h" |
| #include "xmalloc.h" |
| #include "sshpty.h" |
| #include "packet.h" |
| #include "buffer.h" |
| #include "mpaux.h" |
| #include "uidswap.h" |
| #include "compat.h" |
| #include "channels.h" |
| #include "bufaux.h" |
| #include "auth.h" |
| #include "auth-options.h" |
| #include "pathnames.h" |
| #include "log.h" |
| #include "servconf.h" |
| #include "sshlogin.h" |
| #include "serverloop.h" |
| #include "canohost.h" |
| #include "session.h" |
| #include "monitor_wrap.h" |
| |
| #ifdef HAVE_CYGWIN |
| #include <windows.h> |
| #include <sys/cygwin.h> |
| #define is_winnt (GetVersion() < 0x80000000) |
| #endif |
| |
| /* func */ |
| |
| Session *session_new(void); |
| void session_set_fds(Session *, int, int, int); |
| void session_pty_cleanup(void *); |
| void session_proctitle(Session *); |
| int session_setup_x11fwd(Session *); |
| void do_exec_pty(Session *, const char *); |
| void do_exec_no_pty(Session *, const char *); |
| void do_exec(Session *, const char *); |
| void do_login(Session *, const char *); |
| #ifdef LOGIN_NEEDS_UTMPX |
| static void do_pre_login(Session *s); |
| #endif |
| void do_child(Session *, const char *); |
| void do_motd(void); |
| int check_quietlogin(Session *, const char *); |
| |
| static void do_authenticated1(Authctxt *); |
| static void do_authenticated2(Authctxt *); |
| |
| static int session_pty_req(Session *); |
| |
| /* import */ |
| extern ServerOptions options; |
| extern char *__progname; |
| extern int log_stderr; |
| extern int debug_flag; |
| extern u_int utmp_len; |
| extern int startup_pipe; |
| extern void destroy_sensitive_data(void); |
| |
| /* original command from peer. */ |
| const char *original_command = NULL; |
| |
| /* data */ |
| #define MAX_SESSIONS 10 |
| Session sessions[MAX_SESSIONS]; |
| |
| #ifdef WITH_AIXAUTHENTICATE |
| char *aixloginmsg; |
| #endif /* WITH_AIXAUTHENTICATE */ |
| |
| #ifdef HAVE_LOGIN_CAP |
| login_cap_t *lc; |
| #endif |
| |
| /* Name and directory of socket for authentication agent forwarding. */ |
| static char *auth_sock_name = NULL; |
| static char *auth_sock_dir = NULL; |
| |
| /* removes the agent forwarding socket */ |
| |
| static void |
| auth_sock_cleanup_proc(void *_pw) |
| { |
| struct passwd *pw = _pw; |
| |
| if (auth_sock_name != NULL) { |
| temporarily_use_uid(pw); |
| unlink(auth_sock_name); |
| rmdir(auth_sock_dir); |
| auth_sock_name = NULL; |
| restore_uid(); |
| } |
| } |
| |
| static int |
| auth_input_request_forwarding(struct passwd * pw) |
| { |
| Channel *nc; |
| int sock; |
| struct sockaddr_un sunaddr; |
| |
| if (auth_sock_name != NULL) { |
| error("authentication forwarding requested twice."); |
| return 0; |
| } |
| |
| /* Temporarily drop privileged uid for mkdir/bind. */ |
| temporarily_use_uid(pw); |
| |
| /* Allocate a buffer for the socket name, and format the name. */ |
| auth_sock_name = xmalloc(MAXPATHLEN); |
| auth_sock_dir = xmalloc(MAXPATHLEN); |
| strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); |
| |
| /* Create private directory for socket */ |
| if (mkdtemp(auth_sock_dir) == NULL) { |
| packet_send_debug("Agent forwarding disabled: " |
| "mkdtemp() failed: %.100s", strerror(errno)); |
| restore_uid(); |
| xfree(auth_sock_name); |
| xfree(auth_sock_dir); |
| auth_sock_name = NULL; |
| auth_sock_dir = NULL; |
| return 0; |
| } |
| snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", |
| auth_sock_dir, (long) getpid()); |
| |
| /* delete agent socket on fatal() */ |
| fatal_add_cleanup(auth_sock_cleanup_proc, pw); |
| |
| /* Create the socket. */ |
| sock = socket(AF_UNIX, SOCK_STREAM, 0); |
| if (sock < 0) |
| packet_disconnect("socket: %.100s", strerror(errno)); |
| |
| /* Bind it to the name. */ |
| memset(&sunaddr, 0, sizeof(sunaddr)); |
| sunaddr.sun_family = AF_UNIX; |
| strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); |
| |
| if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) |
| packet_disconnect("bind: %.100s", strerror(errno)); |
| |
| /* Restore the privileged uid. */ |
| restore_uid(); |
| |
| /* Start listening on the socket. */ |
| if (listen(sock, 5) < 0) |
| packet_disconnect("listen: %.100s", strerror(errno)); |
| |
| /* Allocate a channel for the authentication agent socket. */ |
| nc = channel_new("auth socket", |
| SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, |
| CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, |
| 0, xstrdup("auth socket"), 1); |
| strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); |
| return 1; |
| } |
| |
| |
| void |
| do_authenticated(Authctxt *authctxt) |
| { |
| /* |
| * Cancel the alarm we set to limit the time taken for |
| * authentication. |
| */ |
| alarm(0); |
| if (startup_pipe != -1) { |
| close(startup_pipe); |
| startup_pipe = -1; |
| } |
| |
| /* setup the channel layer */ |
| if (!no_port_forwarding_flag && options.allow_tcp_forwarding) |
| channel_permit_all_opens(); |
| |
| if (compat20) |
| do_authenticated2(authctxt); |
| else |
| do_authenticated1(authctxt); |
| |
| /* remove agent socket */ |
| if (auth_sock_name != NULL) |
| auth_sock_cleanup_proc(authctxt->pw); |
| #ifdef KRB4 |
| if (options.kerberos_ticket_cleanup) |
| krb4_cleanup_proc(authctxt); |
| #endif |
| #ifdef KRB5 |
| if (options.kerberos_ticket_cleanup) |
| krb5_cleanup_proc(authctxt); |
| #endif |
| } |
| |
| /* |
| * Prepares for an interactive session. This is called after the user has |
| * been successfully authenticated. During this message exchange, pseudo |
| * terminals are allocated, X11, TCP/IP, and authentication agent forwardings |
| * are requested, etc. |
| */ |
| static void |
| do_authenticated1(Authctxt *authctxt) |
| { |
| Session *s; |
| char *command; |
| int success, type, screen_flag; |
| int enable_compression_after_reply = 0; |
| u_int proto_len, data_len, dlen, compression_level = 0; |
| |
| s = session_new(); |
| s->authctxt = authctxt; |
| s->pw = authctxt->pw; |
| |
| /* |
| * We stay in this loop until the client requests to execute a shell |
| * or a command. |
| */ |
| for (;;) { |
| success = 0; |
| |
| /* Get a packet from the client. */ |
| type = packet_read(); |
| |
| /* Process the packet. */ |
| switch (type) { |
| case SSH_CMSG_REQUEST_COMPRESSION: |
| compression_level = packet_get_int(); |
| packet_check_eom(); |
| if (compression_level < 1 || compression_level > 9) { |
| packet_send_debug("Received illegal compression level %d.", |
| compression_level); |
| break; |
| } |
| if (!options.compression) { |
| debug2("compression disabled"); |
| break; |
| } |
| /* Enable compression after we have responded with SUCCESS. */ |
| enable_compression_after_reply = 1; |
| success = 1; |
| break; |
| |
| case SSH_CMSG_REQUEST_PTY: |
| success = session_pty_req(s); |
| break; |
| |
| case SSH_CMSG_X11_REQUEST_FORWARDING: |
| s->auth_proto = packet_get_string(&proto_len); |
| s->auth_data = packet_get_string(&data_len); |
| |
| screen_flag = packet_get_protocol_flags() & |
| SSH_PROTOFLAG_SCREEN_NUMBER; |
| debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); |
| |
| if (packet_remaining() == 4) { |
| if (!screen_flag) |
| debug2("Buggy client: " |
| "X11 screen flag missing"); |
| s->screen = packet_get_int(); |
| } else { |
| s->screen = 0; |
| } |
| packet_check_eom(); |
| success = session_setup_x11fwd(s); |
| if (!success) { |
| xfree(s->auth_proto); |
| xfree(s->auth_data); |
| s->auth_proto = NULL; |
| s->auth_data = NULL; |
| } |
| break; |
| |
| case SSH_CMSG_AGENT_REQUEST_FORWARDING: |
| if (no_agent_forwarding_flag || compat13) { |
| debug("Authentication agent forwarding not permitted for this authentication."); |
| break; |
| } |
| debug("Received authentication agent forwarding request."); |
| success = auth_input_request_forwarding(s->pw); |
| break; |
| |
| case SSH_CMSG_PORT_FORWARD_REQUEST: |
| if (no_port_forwarding_flag) { |
| debug("Port forwarding not permitted for this authentication."); |
| break; |
| } |
| if (!options.allow_tcp_forwarding) { |
| debug("Port forwarding not permitted."); |
| break; |
| } |
| debug("Received TCP/IP port forwarding request."); |
| channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); |
| success = 1; |
| break; |
| |
| case SSH_CMSG_MAX_PACKET_SIZE: |
| if (packet_set_maxsize(packet_get_int()) > 0) |
| success = 1; |
| break; |
| |
| #if defined(AFS) || defined(KRB5) |
| case SSH_CMSG_HAVE_KERBEROS_TGT: |
| if (!options.kerberos_tgt_passing) { |
| verbose("Kerberos TGT passing disabled."); |
| } else { |
| char *kdata = packet_get_string(&dlen); |
| packet_check_eom(); |
| |
| /* XXX - 0x41, see creds_to_radix version */ |
| if (kdata[0] != 0x41) { |
| #ifdef KRB5 |
| krb5_data tgt; |
| tgt.data = kdata; |
| tgt.length = dlen; |
| |
| if (auth_krb5_tgt(s->authctxt, &tgt)) |
| success = 1; |
| else |
| verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user); |
| #endif /* KRB5 */ |
| } else { |
| #ifdef AFS |
| if (auth_krb4_tgt(s->authctxt, kdata)) |
| success = 1; |
| else |
| verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user); |
| #endif /* AFS */ |
| } |
| xfree(kdata); |
| } |
| break; |
| #endif /* AFS || KRB5 */ |
| |
| #ifdef AFS |
| case SSH_CMSG_HAVE_AFS_TOKEN: |
| if (!options.afs_token_passing || !k_hasafs()) { |
| verbose("AFS token passing disabled."); |
| } else { |
| /* Accept AFS token. */ |
| char *token = packet_get_string(&dlen); |
| packet_check_eom(); |
| |
| if (auth_afs_token(s->authctxt, token)) |
| success = 1; |
| else |
| verbose("AFS token refused for %.100s", |
| s->authctxt->user); |
| xfree(token); |
| } |
| break; |
| #endif /* AFS */ |
| |
| case SSH_CMSG_EXEC_SHELL: |
| case SSH_CMSG_EXEC_CMD: |
| if (type == SSH_CMSG_EXEC_CMD) { |
| command = packet_get_string(&dlen); |
| debug("Exec command '%.500s'", command); |
| do_exec(s, command); |
| xfree(command); |
| } else { |
| do_exec(s, NULL); |
| } |
| packet_check_eom(); |
| session_close(s); |
| return; |
| |
| default: |
| /* |
| * Any unknown messages in this phase are ignored, |
| * and a failure message is returned. |
| */ |
| log("Unknown packet type received after authentication: %d", type); |
| } |
| packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); |
| packet_send(); |
| packet_write_wait(); |
| |
| /* Enable compression now that we have replied if appropriate. */ |
| if (enable_compression_after_reply) { |
| enable_compression_after_reply = 0; |
| packet_start_compression(compression_level); |
| } |
| } |
| } |
| |
| /* |
| * This is called to fork and execute a command when we have no tty. This |
| * will call do_child from the child, and server_loop from the parent after |
| * setting up file descriptors and such. |
| */ |
| void |
| do_exec_no_pty(Session *s, const char *command) |
| { |
| pid_t pid; |
| |
| #ifdef USE_PIPES |
| int pin[2], pout[2], perr[2]; |
| /* Allocate pipes for communicating with the program. */ |
| if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) |
| packet_disconnect("Could not create pipes: %.100s", |
| strerror(errno)); |
| #else /* USE_PIPES */ |
| int inout[2], err[2]; |
| /* Uses socket pairs to communicate with the program. */ |
| if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || |
| socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) |
| packet_disconnect("Could not create socket pairs: %.100s", |
| strerror(errno)); |
| #endif /* USE_PIPES */ |
| if (s == NULL) |
| fatal("do_exec_no_pty: no session"); |
| |
| session_proctitle(s); |
| |
| #if defined(USE_PAM) |
| do_pam_session(s->pw->pw_name, NULL); |
| do_pam_setcred(1); |
| if (is_pam_password_change_required()) |
| packet_disconnect("Password change required but no " |
| "TTY available"); |
| #endif /* USE_PAM */ |
| |
| /* Fork the child. */ |
| if ((pid = fork()) == 0) { |
| fatal_remove_all_cleanups(); |
| |
| /* Child. Reinitialize the log since the pid has changed. */ |
| log_init(__progname, options.log_level, options.log_facility, log_stderr); |
| |
| /* |
| * Create a new session and process group since the 4.4BSD |
| * setlogin() affects the entire process group. |
| */ |
| if (setsid() < 0) |
| error("setsid failed: %.100s", strerror(errno)); |
| |
| #ifdef USE_PIPES |
| /* |
| * Redirect stdin. We close the parent side of the socket |
| * pair, and make the child side the standard input. |
| */ |
| close(pin[1]); |
| if (dup2(pin[0], 0) < 0) |
| perror("dup2 stdin"); |
| close(pin[0]); |
| |
| /* Redirect stdout. */ |
| close(pout[0]); |
| if (dup2(pout[1], 1) < 0) |
| perror("dup2 stdout"); |
| close(pout[1]); |
| |
| /* Redirect stderr. */ |
| close(perr[0]); |
| if (dup2(perr[1], 2) < 0) |
| perror("dup2 stderr"); |
| close(perr[1]); |
| #else /* USE_PIPES */ |
| /* |
| * Redirect stdin, stdout, and stderr. Stdin and stdout will |
| * use the same socket, as some programs (particularly rdist) |
| * seem to depend on it. |
| */ |
| close(inout[1]); |
| close(err[1]); |
| if (dup2(inout[0], 0) < 0) /* stdin */ |
| perror("dup2 stdin"); |
| if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ |
| perror("dup2 stdout"); |
| if (dup2(err[0], 2) < 0) /* stderr */ |
| perror("dup2 stderr"); |
| #endif /* USE_PIPES */ |
| |
| #ifdef _UNICOS |
| cray_init_job(s->pw); /* set up cray jid and tmpdir */ |
| #endif |
| |
| /* Do processing for the child (exec command etc). */ |
| do_child(s, command); |
| /* NOTREACHED */ |
| } |
| #ifdef _UNICOS |
| signal(WJSIGNAL, cray_job_termination_handler); |
| #endif /* _UNICOS */ |
| #ifdef HAVE_CYGWIN |
| if (is_winnt) |
| cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); |
| #endif |
| if (pid < 0) |
| packet_disconnect("fork failed: %.100s", strerror(errno)); |
| s->pid = pid; |
| /* Set interactive/non-interactive mode. */ |
| packet_set_interactive(s->display != NULL); |
| #ifdef USE_PIPES |
| /* We are the parent. Close the child sides of the pipes. */ |
| close(pin[0]); |
| close(pout[1]); |
| close(perr[1]); |
| |
| if (compat20) { |
| session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); |
| } else { |
| /* Enter the interactive session. */ |
| server_loop(pid, pin[1], pout[0], perr[0]); |
| /* server_loop has closed pin[1], pout[0], and perr[0]. */ |
| } |
| #else /* USE_PIPES */ |
| /* We are the parent. Close the child sides of the socket pairs. */ |
| close(inout[0]); |
| close(err[0]); |
| |
| /* |
| * Enter the interactive session. Note: server_loop must be able to |
| * handle the case that fdin and fdout are the same. |
| */ |
| if (compat20) { |
| session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); |
| } else { |
| server_loop(pid, inout[1], inout[1], err[1]); |
| /* server_loop has closed inout[1] and err[1]. */ |
| } |
| #endif /* USE_PIPES */ |
| } |
| |
| /* |
| * This is called to fork and execute a command when we have a tty. This |
| * will call do_child from the child, and server_loop from the parent after |
| * setting up file descriptors, controlling tty, updating wtmp, utmp, |
| * lastlog, and other such operations. |
| */ |
| void |
| do_exec_pty(Session *s, const char *command) |
| { |
| int fdout, ptyfd, ttyfd, ptymaster; |
| pid_t pid; |
| |
| if (s == NULL) |
| fatal("do_exec_pty: no session"); |
| ptyfd = s->ptyfd; |
| ttyfd = s->ttyfd; |
| |
| #if defined(USE_PAM) |
| do_pam_session(s->pw->pw_name, s->tty); |
| do_pam_setcred(1); |
| #endif |
| |
| /* Fork the child. */ |
| if ((pid = fork()) == 0) { |
| fatal_remove_all_cleanups(); |
| |
| /* Child. Reinitialize the log because the pid has changed. */ |
| log_init(__progname, options.log_level, options.log_facility, log_stderr); |
| /* Close the master side of the pseudo tty. */ |
| close(ptyfd); |
| |
| /* Make the pseudo tty our controlling tty. */ |
| pty_make_controlling_tty(&ttyfd, s->tty); |
| |
| /* Redirect stdin/stdout/stderr from the pseudo tty. */ |
| if (dup2(ttyfd, 0) < 0) |
| error("dup2 stdin: %s", strerror(errno)); |
| if (dup2(ttyfd, 1) < 0) |
| error("dup2 stdout: %s", strerror(errno)); |
| if (dup2(ttyfd, 2) < 0) |
| error("dup2 stderr: %s", strerror(errno)); |
| |
| /* Close the extra descriptor for the pseudo tty. */ |
| close(ttyfd); |
| |
| /* record login, etc. similar to login(1) */ |
| #ifndef HAVE_OSF_SIA |
| if (!(options.use_login && command == NULL)) { |
| #ifdef _UNICOS |
| cray_init_job(s->pw); /* set up cray jid and tmpdir */ |
| #endif /* _UNICOS */ |
| do_login(s, command); |
| } |
| # ifdef LOGIN_NEEDS_UTMPX |
| else |
| do_pre_login(s); |
| # endif |
| #endif |
| |
| /* Do common processing for the child, such as execing the command. */ |
| do_child(s, command); |
| /* NOTREACHED */ |
| } |
| #ifdef _UNICOS |
| signal(WJSIGNAL, cray_job_termination_handler); |
| #endif /* _UNICOS */ |
| #ifdef HAVE_CYGWIN |
| if (is_winnt) |
| cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); |
| #endif |
| if (pid < 0) |
| packet_disconnect("fork failed: %.100s", strerror(errno)); |
| s->pid = pid; |
| |
| /* Parent. Close the slave side of the pseudo tty. */ |
| close(ttyfd); |
| |
| /* |
| * Create another descriptor of the pty master side for use as the |
| * standard input. We could use the original descriptor, but this |
| * simplifies code in server_loop. The descriptor is bidirectional. |
| */ |
| fdout = dup(ptyfd); |
| if (fdout < 0) |
| packet_disconnect("dup #1 failed: %.100s", strerror(errno)); |
| |
| /* we keep a reference to the pty master */ |
| ptymaster = dup(ptyfd); |
| if (ptymaster < 0) |
| packet_disconnect("dup #2 failed: %.100s", strerror(errno)); |
| s->ptymaster = ptymaster; |
| |
| /* Enter interactive session. */ |
| packet_set_interactive(1); |
| if (compat20) { |
| session_set_fds(s, ptyfd, fdout, -1); |
| } else { |
| server_loop(pid, ptyfd, fdout, -1); |
| /* server_loop _has_ closed ptyfd and fdout. */ |
| } |
| } |
| |
| #ifdef LOGIN_NEEDS_UTMPX |
| static void |
| do_pre_login(Session *s) |
| { |
| socklen_t fromlen; |
| struct sockaddr_storage from; |
| pid_t pid = getpid(); |
| |
| /* |
| * Get IP address of client. If the connection is not a socket, let |
| * the address be 0.0.0.0. |
| */ |
| memset(&from, 0, sizeof(from)); |
| fromlen = sizeof(from); |
| if (packet_connection_is_on_socket()) { |
| if (getpeername(packet_get_connection_in(), |
| (struct sockaddr *) & from, &fromlen) < 0) { |
| debug("getpeername: %.100s", strerror(errno)); |
| fatal_cleanup(); |
| } |
| } |
| |
| record_utmp_only(pid, s->tty, s->pw->pw_name, |
| get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), |
| (struct sockaddr *)&from); |
| } |
| #endif |
| |
| /* |
| * This is called to fork and execute a command. If another command is |
| * to be forced, execute that instead. |
| */ |
| void |
| do_exec(Session *s, const char *command) |
| { |
| if (forced_command) { |
| original_command = command; |
| command = forced_command; |
| debug("Forced command '%.900s'", command); |
| } |
| |
| if (s->ttyfd != -1) |
| do_exec_pty(s, command); |
| else |
| do_exec_no_pty(s, command); |
| |
| original_command = NULL; |
| } |
| |
| |
| /* administrative, login(1)-like work */ |
| void |
| do_login(Session *s, const char *command) |
| { |
| char *time_string; |
| socklen_t fromlen; |
| struct sockaddr_storage from; |
| struct passwd * pw = s->pw; |
| pid_t pid = getpid(); |
| |
| /* |
| * Get IP address of client. If the connection is not a socket, let |
| * the address be 0.0.0.0. |
| */ |
| memset(&from, 0, sizeof(from)); |
| if (packet_connection_is_on_socket()) { |
| fromlen = sizeof(from); |
| if (getpeername(packet_get_connection_in(), |
| (struct sockaddr *) & from, &fromlen) < 0) { |
| debug("getpeername: %.100s", strerror(errno)); |
| fatal_cleanup(); |
| } |
| } |
| |
| /* Record that there was a login on that tty from the remote host. */ |
| if (!use_privsep) |
| record_login(pid, s->tty, pw->pw_name, pw->pw_uid, |
| get_remote_name_or_ip(utmp_len, |
| options.verify_reverse_mapping), |
| (struct sockaddr *)&from, fromlen); |
| |
| #ifdef USE_PAM |
| /* |
| * If password change is needed, do it now. |
| * This needs to occur before the ~/.hushlogin check. |
| */ |
| if (is_pam_password_change_required()) { |
| print_pam_messages(); |
| do_pam_chauthtok(); |
| } |
| #endif |
| |
| if (check_quietlogin(s, command)) |
| return; |
| |
| #ifdef USE_PAM |
| if (!is_pam_password_change_required()) |
| print_pam_messages(); |
| #endif /* USE_PAM */ |
| #ifdef WITH_AIXAUTHENTICATE |
| if (aixloginmsg && *aixloginmsg) |
| printf("%s\n", aixloginmsg); |
| #endif /* WITH_AIXAUTHENTICATE */ |
| |
| #ifndef NO_SSH_LASTLOG |
| if (options.print_lastlog && s->last_login_time != 0) { |
| time_string = ctime(&s->last_login_time); |
| if (strchr(time_string, '\n')) |
| *strchr(time_string, '\n') = 0; |
| if (strcmp(s->hostname, "") == 0) |
| printf("Last login: %s\r\n", time_string); |
| else |
| printf("Last login: %s from %s\r\n", time_string, |
| s->hostname); |
| } |
| #endif /* NO_SSH_LASTLOG */ |
| |
| do_motd(); |
| } |
| |
| /* |
| * Display the message of the day. |
| */ |
| void |
| do_motd(void) |
| { |
| FILE *f; |
| char buf[256]; |
| |
| if (options.print_motd) { |
| #ifdef HAVE_LOGIN_CAP |
| f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", |
| "/etc/motd"), "r"); |
| #else |
| f = fopen("/etc/motd", "r"); |
| #endif |
| if (f) { |
| while (fgets(buf, sizeof(buf), f)) |
| fputs(buf, stdout); |
| fclose(f); |
| } |
| } |
| } |
| |
| |
| /* |
| * Check for quiet login, either .hushlogin or command given. |
| */ |
| int |
| check_quietlogin(Session *s, const char *command) |
| { |
| char buf[256]; |
| struct passwd *pw = s->pw; |
| struct stat st; |
| |
| /* Return 1 if .hushlogin exists or a command given. */ |
| if (command != NULL) |
| return 1; |
| snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); |
| #ifdef HAVE_LOGIN_CAP |
| if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) |
| return 1; |
| #else |
| if (stat(buf, &st) >= 0) |
| return 1; |
| #endif |
| return 0; |
| } |
| |
| /* |
| * Sets the value of the given variable in the environment. If the variable |
| * already exists, its value is overriden. |
| */ |
| static void |
| child_set_env(char ***envp, u_int *envsizep, const char *name, |
| const char *value) |
| { |
| u_int i, namelen; |
| char **env; |
| |
| /* |
| * Find the slot where the value should be stored. If the variable |
| * already exists, we reuse the slot; otherwise we append a new slot |
| * at the end of the array, expanding if necessary. |
| */ |
| env = *envp; |
| namelen = strlen(name); |
| for (i = 0; env[i]; i++) |
| if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') |
| break; |
| if (env[i]) { |
| /* Reuse the slot. */ |
| xfree(env[i]); |
| } else { |
| /* New variable. Expand if necessary. */ |
| if (i >= (*envsizep) - 1) { |
| if (*envsizep >= 1000) |
| fatal("child_set_env: too many env vars," |
| " skipping: %.100s", name); |
| (*envsizep) += 50; |
| env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); |
| } |
| /* Need to set the NULL pointer at end of array beyond the new slot. */ |
| env[i + 1] = NULL; |
| } |
| |
| /* Allocate space and format the variable in the appropriate slot. */ |
| env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); |
| snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); |
| } |
| |
| /* |
| * Reads environment variables from the given file and adds/overrides them |
| * into the environment. If the file does not exist, this does nothing. |
| * Otherwise, it must consist of empty lines, comments (line starts with '#') |
| * and assignments of the form name=value. No other forms are allowed. |
| */ |
| static void |
| read_environment_file(char ***env, u_int *envsize, |
| const char *filename) |
| { |
| FILE *f; |
| char buf[4096]; |
| char *cp, *value; |
| u_int lineno = 0; |
| |
| f = fopen(filename, "r"); |
| if (!f) |
| return; |
| |
| while (fgets(buf, sizeof(buf), f)) { |
| if (++lineno > 1000) |
| fatal("Too many lines in environment file %s", filename); |
| for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) |
| ; |
| if (!*cp || *cp == '#' || *cp == '\n') |
| continue; |
| if (strchr(cp, '\n')) |
| *strchr(cp, '\n') = '\0'; |
| value = strchr(cp, '='); |
| if (value == NULL) { |
| fprintf(stderr, "Bad line %u in %.100s\n", lineno, |
| filename); |
| continue; |
| } |
| /* |
| * Replace the equals sign by nul, and advance value to |
| * the value string. |
| */ |
| *value = '\0'; |
| value++; |
| child_set_env(env, envsize, cp, value); |
| } |
| fclose(f); |
| } |
| |
| void copy_environment(char **source, char ***env, u_int *envsize) |
| { |
| char *var_name, *var_val; |
| int i; |
| |
| if (source == NULL) |
| return; |
| |
| for(i = 0; source[i] != NULL; i++) { |
| var_name = xstrdup(source[i]); |
| if ((var_val = strstr(var_name, "=")) == NULL) { |
| xfree(var_name); |
| continue; |
| } |
| *var_val++ = '\0'; |
| |
| debug3("Copy environment: %s=%s", var_name, var_val); |
| child_set_env(env, envsize, var_name, var_val); |
| |
| xfree(var_name); |
| } |
| } |
| |
| static char ** |
| do_setup_env(Session *s, const char *shell) |
| { |
| char buf[256]; |
| u_int i, envsize; |
| char **env; |
| struct passwd *pw = s->pw; |
| |
| /* Initialize the environment. */ |
| envsize = 100; |
| env = xmalloc(envsize * sizeof(char *)); |
| env[0] = NULL; |
| |
| #ifdef HAVE_CYGWIN |
| /* |
| * The Windows environment contains some setting which are |
| * important for a running system. They must not be dropped. |
| */ |
| copy_environment(environ, &env, &envsize); |
| #endif |
| |
| if (!options.use_login) { |
| /* Set basic environment. */ |
| child_set_env(&env, &envsize, "USER", pw->pw_name); |
| child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); |
| child_set_env(&env, &envsize, "HOME", pw->pw_dir); |
| #ifdef HAVE_LOGIN_CAP |
| if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) |
| child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); |
| else |
| child_set_env(&env, &envsize, "PATH", getenv("PATH")); |
| #else /* HAVE_LOGIN_CAP */ |
| # ifndef HAVE_CYGWIN |
| /* |
| * There's no standard path on Windows. The path contains |
| * important components pointing to the system directories, |
| * needed for loading shared libraries. So the path better |
| * remains intact here. |
| */ |
| # ifdef SUPERUSER_PATH |
| child_set_env(&env, &envsize, "PATH", |
| s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); |
| # else |
| child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); |
| # endif /* SUPERUSER_PATH */ |
| # endif /* HAVE_CYGWIN */ |
| #endif /* HAVE_LOGIN_CAP */ |
| |
| snprintf(buf, sizeof buf, "%.200s/%.50s", |
| _PATH_MAILDIR, pw->pw_name); |
| child_set_env(&env, &envsize, "MAIL", buf); |
| |
| /* Normal systems set SHELL by default. */ |
| child_set_env(&env, &envsize, "SHELL", shell); |
| } |
| if (getenv("TZ")) |
| child_set_env(&env, &envsize, "TZ", getenv("TZ")); |
| |
| /* Set custom environment options from RSA authentication. */ |
| if (!options.use_login) { |
| while (custom_environment) { |
| struct envstring *ce = custom_environment; |
| char *str = ce->s; |
| |
| for (i = 0; str[i] != '=' && str[i]; i++) |
| ; |
| if (str[i] == '=') { |
| str[i] = 0; |
| child_set_env(&env, &envsize, str, str + i + 1); |
| } |
| custom_environment = ce->next; |
| xfree(ce->s); |
| xfree(ce); |
| } |
| } |
| |
| /* SSH_CLIENT deprecated */ |
| snprintf(buf, sizeof buf, "%.50s %d %d", |
| get_remote_ipaddr(), get_remote_port(), get_local_port()); |
| child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
| |
| snprintf(buf, sizeof buf, "%.50s %d %.50s %d", |
| get_remote_ipaddr(), get_remote_port(), |
| get_local_ipaddr(packet_get_connection_in()), get_local_port()); |
| child_set_env(&env, &envsize, "SSH_CONNECTION", buf); |
| |
| if (s->ttyfd != -1) |
| child_set_env(&env, &envsize, "SSH_TTY", s->tty); |
| if (s->term) |
| child_set_env(&env, &envsize, "TERM", s->term); |
| if (s->display) |
| child_set_env(&env, &envsize, "DISPLAY", s->display); |
| if (original_command) |
| child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", |
| original_command); |
| |
| #ifdef _UNICOS |
| if (cray_tmpdir[0] != '\0') |
| child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); |
| #endif /* _UNICOS */ |
| |
| #ifdef _AIX |
| { |
| char *cp; |
| |
| if ((cp = getenv("AUTHSTATE")) != NULL) |
| child_set_env(&env, &envsize, "AUTHSTATE", cp); |
| if ((cp = getenv("KRB5CCNAME")) != NULL) |
| child_set_env(&env, &envsize, "KRB5CCNAME", cp); |
| read_environment_file(&env, &envsize, "/etc/environment"); |
| } |
| #endif |
| #ifdef KRB4 |
| if (s->authctxt->krb4_ticket_file) |
| child_set_env(&env, &envsize, "KRBTKFILE", |
| s->authctxt->krb4_ticket_file); |
| #endif |
| #ifdef KRB5 |
| if (s->authctxt->krb5_ticket_file) |
| child_set_env(&env, &envsize, "KRB5CCNAME", |
| s->authctxt->krb5_ticket_file); |
| #endif |
| #ifdef USE_PAM |
| /* |
| * Pull in any environment variables that may have |
| * been set by PAM. |
| */ |
| { |
| char **p; |
| |
| p = fetch_pam_environment(); |
| copy_environment(p, &env, &envsize); |
| free_pam_environment(p); |
| } |
| #endif /* USE_PAM */ |
| |
| if (auth_sock_name != NULL) |
| child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, |
| auth_sock_name); |
| |
| /* read $HOME/.ssh/environment. */ |
| if (options.permit_user_env && !options.use_login) { |
| snprintf(buf, sizeof buf, "%.200s/.ssh/environment", |
| strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); |
| read_environment_file(&env, &envsize, buf); |
| } |
| if (debug_flag) { |
| /* dump the environment */ |
| fprintf(stderr, "Environment:\n"); |
| for (i = 0; env[i]; i++) |
| fprintf(stderr, " %.200s\n", env[i]); |
| } |
| return env; |
| } |
| |
| /* |
| * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found |
| * first in this order). |
| */ |
| static void |
| do_rc_files(Session *s, const char *shell) |
| { |
| FILE *f = NULL; |
| char cmd[1024]; |
| int do_xauth; |
| struct stat st; |
| |
| do_xauth = |
| s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; |
| |
| /* ignore _PATH_SSH_USER_RC for subsystems */ |
| if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { |
| snprintf(cmd, sizeof cmd, "%s -c '%s %s'", |
| shell, _PATH_BSHELL, _PATH_SSH_USER_RC); |
| if (debug_flag) |
| fprintf(stderr, "Running %s\n", cmd); |
| f = popen(cmd, "w"); |
| if (f) { |
| if (do_xauth) |
| fprintf(f, "%s %s\n", s->auth_proto, |
| s->auth_data); |
| pclose(f); |
| } else |
| fprintf(stderr, "Could not run %s\n", |
| _PATH_SSH_USER_RC); |
| } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { |
| if (debug_flag) |
| fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, |
| _PATH_SSH_SYSTEM_RC); |
| f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); |
| if (f) { |
| if (do_xauth) |
| fprintf(f, "%s %s\n", s->auth_proto, |
| s->auth_data); |
| pclose(f); |
| } else |
| fprintf(stderr, "Could not run %s\n", |
| _PATH_SSH_SYSTEM_RC); |
| } else if (do_xauth && options.xauth_location != NULL) { |
| /* Add authority data to .Xauthority if appropriate. */ |
| if (debug_flag) { |
| fprintf(stderr, |
| "Running %.500s remove %.100s\n", |
| options.xauth_location, s->auth_display); |
| fprintf(stderr, |
| "%.500s add %.100s %.100s %.100s\n", |
| options.xauth_location, s->auth_display, |
| s->auth_proto, s->auth_data); |
| } |
| snprintf(cmd, sizeof cmd, "%s -q -", |
| options.xauth_location); |
| f = popen(cmd, "w"); |
| if (f) { |
| fprintf(f, "remove %s\n", |
| s->auth_display); |
| fprintf(f, "add %s %s %s\n", |
| s->auth_display, s->auth_proto, |
| s->auth_data); |
| pclose(f); |
| } else { |
| fprintf(stderr, "Could not run %s\n", |
| cmd); |
| } |
| } |
| } |
| |
| static void |
| do_nologin(struct passwd *pw) |
| { |
| FILE *f = NULL; |
| char buf[1024]; |
| |
| #ifdef HAVE_LOGIN_CAP |
| if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) |
| f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, |
| _PATH_NOLOGIN), "r"); |
| #else |
| if (pw->pw_uid) |
| f = fopen(_PATH_NOLOGIN, "r"); |
| #endif |
| if (f) { |
| /* /etc/nologin exists. Print its contents and exit. */ |
| log("User %.100s not allowed because %s exists", |
| pw->pw_name, _PATH_NOLOGIN); |
| while (fgets(buf, sizeof(buf), f)) |
| fputs(buf, stderr); |
| fclose(f); |
| exit(254); |
| } |
| } |
| |
| /* Set login name, uid, gid, and groups. */ |
| void |
| do_setusercontext(struct passwd *pw) |
| { |
| #ifdef HAVE_CYGWIN |
| if (is_winnt) { |
| #else /* HAVE_CYGWIN */ |
| if (getuid() == 0 || geteuid() == 0) { |
| #endif /* HAVE_CYGWIN */ |
| #ifdef HAVE_SETPCRED |
| setpcred(pw->pw_name); |
| #endif /* HAVE_SETPCRED */ |
| #ifdef HAVE_LOGIN_CAP |
| # ifdef __bsdi__ |
| setpgid(0, 0); |
| # endif |
| if (setusercontext(lc, pw, pw->pw_uid, |
| (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { |
| perror("unable to set user context"); |
| exit(1); |
| } |
| #else |
| # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) |
| /* Sets login uid for accounting */ |
| if (getluid() == -1 && setluid(pw->pw_uid) == -1) |
| error("setluid: %s", strerror(errno)); |
| # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ |
| |
| if (setlogin(pw->pw_name) < 0) |
| error("setlogin failed: %s", strerror(errno)); |
| if (setgid(pw->pw_gid) < 0) { |
| perror("setgid"); |
| exit(1); |
| } |
| /* Initialize the group list. */ |
| if (initgroups(pw->pw_name, pw->pw_gid) < 0) { |
| perror("initgroups"); |
| exit(1); |
| } |
| endgrent(); |
| # ifdef USE_PAM |
| /* |
| * PAM credentials may take the form of supplementary groups. |
| * These will have been wiped by the above initgroups() call. |
| * Reestablish them here. |
| */ |
| do_pam_setcred(0); |
| # endif /* USE_PAM */ |
| # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) |
| irix_setusercontext(pw); |
| # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ |
| # ifdef _AIX |
| aix_usrinfo(pw); |
| # endif /* _AIX */ |
| /* Permanently switch to the desired uid. */ |
| permanently_set_uid(pw); |
| #endif |
| } |
| if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) |
| fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); |
| } |
| |
| static void |
| launch_login(struct passwd *pw, const char *hostname) |
| { |
| /* Launch login(1). */ |
| |
| execl(LOGIN_PROGRAM, "login", "-h", hostname, |
| #ifdef xxxLOGIN_NEEDS_TERM |
| (s->term ? s->term : "unknown"), |
| #endif /* LOGIN_NEEDS_TERM */ |
| #ifdef LOGIN_NO_ENDOPT |
| "-p", "-f", pw->pw_name, (char *)NULL); |
| #else |
| "-p", "-f", "--", pw->pw_name, (char *)NULL); |
| #endif |
| |
| /* Login couldn't be executed, die. */ |
| |
| perror("login"); |
| exit(1); |
| } |
| |
| /* |
| * Performs common processing for the child, such as setting up the |
| * environment, closing extra file descriptors, setting the user and group |
| * ids, and executing the command or shell. |
| */ |
| void |
| do_child(Session *s, const char *command) |
| { |
| extern char **environ; |
| char **env; |
| char *argv[10]; |
| const char *shell, *shell0, *hostname = NULL; |
| struct passwd *pw = s->pw; |
| u_int i; |
| |
| /* remove hostkey from the child's memory */ |
| destroy_sensitive_data(); |
| |
| /* login(1) is only called if we execute the login shell */ |
| if (options.use_login && command != NULL) |
| options.use_login = 0; |
| |
| #ifdef _UNICOS |
| cray_setup(pw->pw_uid, pw->pw_name, command); |
| #endif /* _UNICOS */ |
| |
| /* |
| * Login(1) does this as well, and it needs uid 0 for the "-h" |
| * switch, so we let login(1) to this for us. |
| */ |
| if (!options.use_login) { |
| #ifdef HAVE_OSF_SIA |
| session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); |
| if (!check_quietlogin(s, command)) |
| do_motd(); |
| #else /* HAVE_OSF_SIA */ |
| do_nologin(pw); |
| do_setusercontext(pw); |
| #endif /* HAVE_OSF_SIA */ |
| } |
| |
| /* |
| * Get the shell from the password data. An empty shell field is |
| * legal, and means /bin/sh. |
| */ |
| shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; |
| |
| /* |
| * Make sure $SHELL points to the shell from the password file, |
| * even if shell is overridden from login.conf |
| */ |
| env = do_setup_env(s, shell); |
| |
| #ifdef HAVE_LOGIN_CAP |
| shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); |
| #endif |
| |
| /* we have to stash the hostname before we close our socket. */ |
| if (options.use_login) |
| hostname = get_remote_name_or_ip(utmp_len, |
| options.verify_reverse_mapping); |
| /* |
| * Close the connection descriptors; note that this is the child, and |
| * the server will still have the socket open, and it is important |
| * that we do not shutdown it. Note that the descriptors cannot be |
| * closed before building the environment, as we call |
| * get_remote_ipaddr there. |
| */ |
| if (packet_get_connection_in() == packet_get_connection_out()) |
| close(packet_get_connection_in()); |
| else { |
| close(packet_get_connection_in()); |
| close(packet_get_connection_out()); |
| } |
| /* |
| * Close all descriptors related to channels. They will still remain |
| * open in the parent. |
| */ |
| /* XXX better use close-on-exec? -markus */ |
| channel_close_all(); |
| |
| /* |
| * Close any extra file descriptors. Note that there may still be |
| * descriptors left by system functions. They will be closed later. |
| */ |
| endpwent(); |
| |
| /* |
| * Close any extra open file descriptors so that we don\'t have them |
| * hanging around in clients. Note that we want to do this after |
| * initgroups, because at least on Solaris 2.3 it leaves file |
| * descriptors open. |
| */ |
| for (i = 3; i < 64; i++) |
| close(i); |
| |
| /* |
| * Must take new environment into use so that .ssh/rc, |
| * /etc/ssh/sshrc and xauth are run in the proper environment. |
| */ |
| environ = env; |
| |
| #ifdef AFS |
| /* Try to get AFS tokens for the local cell. */ |
| if (k_hasafs()) { |
| char cell[64]; |
| |
| if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) |
| krb_afslog(cell, 0); |
| |
| krb_afslog(0, 0); |
| } |
| #endif /* AFS */ |
| |
| /* Change current directory to the user\'s home directory. */ |
| if (chdir(pw->pw_dir) < 0) { |
| fprintf(stderr, "Could not chdir to home directory %s: %s\n", |
| pw->pw_dir, strerror(errno)); |
| #ifdef HAVE_LOGIN_CAP |
| if (login_getcapbool(lc, "requirehome", 0)) |
| exit(1); |
| #endif |
| } |
| |
| if (!options.use_login) |
| do_rc_files(s, shell); |
| |
| /* restore SIGPIPE for child */ |
| signal(SIGPIPE, SIG_DFL); |
| |
| if (options.use_login) { |
| launch_login(pw, hostname); |
| /* NEVERREACHED */ |
| } |
| |
| /* Get the last component of the shell name. */ |
| if ((shell0 = strrchr(shell, '/')) != NULL) |
| shell0++; |
| else |
| shell0 = shell; |
| |
| /* |
| * If we have no command, execute the shell. In this case, the shell |
| * name to be passed in argv[0] is preceded by '-' to indicate that |
| * this is a login shell. |
| */ |
| if (!command) { |
| char argv0[256]; |
| |
| /* Start the shell. Set initial character to '-'. */ |
| argv0[0] = '-'; |
| |
| if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) |
| >= sizeof(argv0) - 1) { |
| errno = EINVAL; |
| perror(shell); |
| exit(1); |
| } |
| |
| /* Execute the shell. */ |
| argv[0] = argv0; |
| argv[1] = NULL; |
| execve(shell, argv, env); |
| |
| /* Executing the shell failed. */ |
| perror(shell); |
| exit(1); |
| } |
| /* |
| * Execute the command using the user's shell. This uses the -c |
| * option to execute the command. |
| */ |
| argv[0] = (char *) shell0; |
| argv[1] = "-c"; |
| argv[2] = (char *) command; |
| argv[3] = NULL; |
| execve(shell, argv, env); |
| perror(shell); |
| exit(1); |
| } |
| |
| Session * |
| session_new(void) |
| { |
| int i; |
| static int did_init = 0; |
| if (!did_init) { |
| debug("session_new: init"); |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| sessions[i].used = 0; |
| } |
| did_init = 1; |
| } |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| if (! s->used) { |
| memset(s, 0, sizeof(*s)); |
| s->chanid = -1; |
| s->ptyfd = -1; |
| s->ttyfd = -1; |
| s->used = 1; |
| s->self = i; |
| debug("session_new: session %d", i); |
| return s; |
| } |
| } |
| return NULL; |
| } |
| |
| static void |
| session_dump(void) |
| { |
| int i; |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| debug("dump: used %d session %d %p channel %d pid %ld", |
| s->used, |
| s->self, |
| s, |
| s->chanid, |
| (long)s->pid); |
| } |
| } |
| |
| int |
| session_open(Authctxt *authctxt, int chanid) |
| { |
| Session *s = session_new(); |
| debug("session_open: channel %d", chanid); |
| if (s == NULL) { |
| error("no more sessions"); |
| return 0; |
| } |
| s->authctxt = authctxt; |
| s->pw = authctxt->pw; |
| if (s->pw == NULL) |
| fatal("no user for session %d", s->self); |
| debug("session_open: session %d: link with channel %d", s->self, chanid); |
| s->chanid = chanid; |
| return 1; |
| } |
| |
| Session * |
| session_by_tty(char *tty) |
| { |
| int i; |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { |
| debug("session_by_tty: session %d tty %s", i, tty); |
| return s; |
| } |
| } |
| debug("session_by_tty: unknown tty %.100s", tty); |
| session_dump(); |
| return NULL; |
| } |
| |
| static Session * |
| session_by_channel(int id) |
| { |
| int i; |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| if (s->used && s->chanid == id) { |
| debug("session_by_channel: session %d channel %d", i, id); |
| return s; |
| } |
| } |
| debug("session_by_channel: unknown channel %d", id); |
| session_dump(); |
| return NULL; |
| } |
| |
| static Session * |
| session_by_pid(pid_t pid) |
| { |
| int i; |
| debug("session_by_pid: pid %ld", (long)pid); |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| if (s->used && s->pid == pid) |
| return s; |
| } |
| error("session_by_pid: unknown pid %ld", (long)pid); |
| session_dump(); |
| return NULL; |
| } |
| |
| static int |
| session_window_change_req(Session *s) |
| { |
| s->col = packet_get_int(); |
| s->row = packet_get_int(); |
| s->xpixel = packet_get_int(); |
| s->ypixel = packet_get_int(); |
| packet_check_eom(); |
| pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
| return 1; |
| } |
| |
| static int |
| session_pty_req(Session *s) |
| { |
| u_int len; |
| int n_bytes; |
| |
| if (no_pty_flag) { |
| debug("Allocating a pty not permitted for this authentication."); |
| return 0; |
| } |
| if (s->ttyfd != -1) { |
| packet_disconnect("Protocol error: you already have a pty."); |
| return 0; |
| } |
| /* Get the time and hostname when the user last logged in. */ |
| if (options.print_lastlog) { |
| s->hostname[0] = '\0'; |
| s->last_login_time = get_last_login_time(s->pw->pw_uid, |
| s->pw->pw_name, s->hostname, sizeof(s->hostname)); |
| } |
| |
| s->term = packet_get_string(&len); |
| |
| if (compat20) { |
| s->col = packet_get_int(); |
| s->row = packet_get_int(); |
| } else { |
| s->row = packet_get_int(); |
| s->col = packet_get_int(); |
| } |
| s->xpixel = packet_get_int(); |
| s->ypixel = packet_get_int(); |
| |
| if (strcmp(s->term, "") == 0) { |
| xfree(s->term); |
| s->term = NULL; |
| } |
| |
| /* Allocate a pty and open it. */ |
| debug("Allocating pty."); |
| if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { |
| if (s->term) |
| xfree(s->term); |
| s->term = NULL; |
| s->ptyfd = -1; |
| s->ttyfd = -1; |
| error("session_pty_req: session %d alloc failed", s->self); |
| return 0; |
| } |
| debug("session_pty_req: session %d alloc %s", s->self, s->tty); |
| |
| /* for SSH1 the tty modes length is not given */ |
| if (!compat20) |
| n_bytes = packet_remaining(); |
| tty_parse_modes(s->ttyfd, &n_bytes); |
| |
| /* |
| * Add a cleanup function to clear the utmp entry and record logout |
| * time in case we call fatal() (e.g., the connection gets closed). |
| */ |
| fatal_add_cleanup(session_pty_cleanup, (void *)s); |
| if (!use_privsep) |
| pty_setowner(s->pw, s->tty); |
| |
| /* Set window size from the packet. */ |
| pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); |
| |
| packet_check_eom(); |
| session_proctitle(s); |
| return 1; |
| } |
| |
| static int |
| session_subsystem_req(Session *s) |
| { |
| struct stat st; |
| u_int len; |
| int success = 0; |
| char *cmd, *subsys = packet_get_string(&len); |
| int i; |
| |
| packet_check_eom(); |
| log("subsystem request for %.100s", subsys); |
| |
| for (i = 0; i < options.num_subsystems; i++) { |
| if (strcmp(subsys, options.subsystem_name[i]) == 0) { |
| cmd = options.subsystem_command[i]; |
| if (stat(cmd, &st) < 0) { |
| error("subsystem: cannot stat %s: %s", cmd, |
| strerror(errno)); |
| break; |
| } |
| debug("subsystem: exec() %s", cmd); |
| s->is_subsystem = 1; |
| do_exec(s, cmd); |
| success = 1; |
| break; |
| } |
| } |
| |
| if (!success) |
| log("subsystem request for %.100s failed, subsystem not found", |
| subsys); |
| |
| xfree(subsys); |
| return success; |
| } |
| |
| static int |
| session_x11_req(Session *s) |
| { |
| int success; |
| |
| s->single_connection = packet_get_char(); |
| s->auth_proto = packet_get_string(NULL); |
| s->auth_data = packet_get_string(NULL); |
| s->screen = packet_get_int(); |
| packet_check_eom(); |
| |
| success = session_setup_x11fwd(s); |
| if (!success) { |
| xfree(s->auth_proto); |
| xfree(s->auth_data); |
| s->auth_proto = NULL; |
| s->auth_data = NULL; |
| } |
| return success; |
| } |
| |
| static int |
| session_shell_req(Session *s) |
| { |
| packet_check_eom(); |
| do_exec(s, NULL); |
| return 1; |
| } |
| |
| static int |
| session_exec_req(Session *s) |
| { |
| u_int len; |
| char *command = packet_get_string(&len); |
| packet_check_eom(); |
| do_exec(s, command); |
| xfree(command); |
| return 1; |
| } |
| |
| static int |
| session_auth_agent_req(Session *s) |
| { |
| static int called = 0; |
| packet_check_eom(); |
| if (no_agent_forwarding_flag) { |
| debug("session_auth_agent_req: no_agent_forwarding_flag"); |
| return 0; |
| } |
| if (called) { |
| return 0; |
| } else { |
| called = 1; |
| return auth_input_request_forwarding(s->pw); |
| } |
| } |
| |
| int |
| session_input_channel_req(Channel *c, const char *rtype) |
| { |
| int success = 0; |
| Session *s; |
| |
| if ((s = session_by_channel(c->self)) == NULL) { |
| log("session_input_channel_req: no session %d req %.100s", |
| c->self, rtype); |
| return 0; |
| } |
| debug("session_input_channel_req: session %d req %s", s->self, rtype); |
| |
| /* |
| * a session is in LARVAL state until a shell, a command |
| * or a subsystem is executed |
| */ |
| if (c->type == SSH_CHANNEL_LARVAL) { |
| if (strcmp(rtype, "shell") == 0) { |
| success = session_shell_req(s); |
| } else if (strcmp(rtype, "exec") == 0) { |
| success = session_exec_req(s); |
| } else if (strcmp(rtype, "pty-req") == 0) { |
| success = session_pty_req(s); |
| } else if (strcmp(rtype, "x11-req") == 0) { |
| success = session_x11_req(s); |
| } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { |
| success = session_auth_agent_req(s); |
| } else if (strcmp(rtype, "subsystem") == 0) { |
| success = session_subsystem_req(s); |
| } |
| } |
| if (strcmp(rtype, "window-change") == 0) { |
| success = session_window_change_req(s); |
| } |
| return success; |
| } |
| |
| void |
| session_set_fds(Session *s, int fdin, int fdout, int fderr) |
| { |
| if (!compat20) |
| fatal("session_set_fds: called for proto != 2.0"); |
| /* |
| * now that have a child and a pipe to the child, |
| * we can activate our channel and register the fd's |
| */ |
| if (s->chanid == -1) |
| fatal("no channel for session %d", s->self); |
| channel_set_fds(s->chanid, |
| fdout, fdin, fderr, |
| fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, |
| 1, |
| CHAN_SES_WINDOW_DEFAULT); |
| } |
| |
| /* |
| * Function to perform pty cleanup. Also called if we get aborted abnormally |
| * (e.g., due to a dropped connection). |
| */ |
| void |
| session_pty_cleanup2(void *session) |
| { |
| Session *s = session; |
| |
| if (s == NULL) { |
| error("session_pty_cleanup: no session"); |
| return; |
| } |
| if (s->ttyfd == -1) |
| return; |
| |
| debug("session_pty_cleanup: session %d release %s", s->self, s->tty); |
| |
| /* Record that the user has logged out. */ |
| if (s->pid != 0) |
| record_logout(s->pid, s->tty, s->pw->pw_name); |
| |
| /* Release the pseudo-tty. */ |
| if (getuid() == 0) |
| pty_release(s->tty); |
| |
| /* |
| * Close the server side of the socket pairs. We must do this after |
| * the pty cleanup, so that another process doesn't get this pty |
| * while we're still cleaning up. |
| */ |
| if (close(s->ptymaster) < 0) |
| error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); |
| |
| /* unlink pty from session */ |
| s->ttyfd = -1; |
| } |
| |
| void |
| session_pty_cleanup(void *session) |
| { |
| PRIVSEP(session_pty_cleanup2(session)); |
| } |
| |
| static char * |
| sig2name(int sig) |
| { |
| #define SSH_SIG(x) if (sig == SIG ## x) return #x |
| SSH_SIG(ABRT); |
| SSH_SIG(ALRM); |
| SSH_SIG(FPE); |
| SSH_SIG(HUP); |
| SSH_SIG(ILL); |
| SSH_SIG(INT); |
| SSH_SIG(KILL); |
| SSH_SIG(PIPE); |
| SSH_SIG(QUIT); |
| SSH_SIG(SEGV); |
| SSH_SIG(TERM); |
| SSH_SIG(USR1); |
| SSH_SIG(USR2); |
| #undef SSH_SIG |
| return "SIG@openssh.com"; |
| } |
| |
| static void |
| session_exit_message(Session *s, int status) |
| { |
| Channel *c; |
| |
| if ((c = channel_lookup(s->chanid)) == NULL) |
| fatal("session_exit_message: session %d: no channel %d", |
| s->self, s->chanid); |
| debug("session_exit_message: session %d channel %d pid %ld", |
| s->self, s->chanid, (long)s->pid); |
| |
| if (WIFEXITED(status)) { |
| channel_request_start(s->chanid, "exit-status", 0); |
| packet_put_int(WEXITSTATUS(status)); |
| packet_send(); |
| } else if (WIFSIGNALED(status)) { |
| channel_request_start(s->chanid, "exit-signal", 0); |
| packet_put_cstring(sig2name(WTERMSIG(status))); |
| #ifdef WCOREDUMP |
| packet_put_char(WCOREDUMP(status)); |
| #else /* WCOREDUMP */ |
| packet_put_char(0); |
| #endif /* WCOREDUMP */ |
| packet_put_cstring(""); |
| packet_put_cstring(""); |
| packet_send(); |
| } else { |
| /* Some weird exit cause. Just exit. */ |
| packet_disconnect("wait returned status %04x.", status); |
| } |
| |
| /* disconnect channel */ |
| debug("session_exit_message: release channel %d", s->chanid); |
| channel_cancel_cleanup(s->chanid); |
| /* |
| * emulate a write failure with 'chan_write_failed', nobody will be |
| * interested in data we write. |
| * Note that we must not call 'chan_read_failed', since there could |
| * be some more data waiting in the pipe. |
| */ |
| if (c->ostate != CHAN_OUTPUT_CLOSED) |
| chan_write_failed(c); |
| s->chanid = -1; |
| } |
| |
| void |
| session_close(Session *s) |
| { |
| debug("session_close: session %d pid %ld", s->self, (long)s->pid); |
| if (s->ttyfd != -1) { |
| fatal_remove_cleanup(session_pty_cleanup, (void *)s); |
| session_pty_cleanup(s); |
| } |
| if (s->term) |
| xfree(s->term); |
| if (s->display) |
| xfree(s->display); |
| if (s->auth_display) |
| xfree(s->auth_display); |
| if (s->auth_data) |
| xfree(s->auth_data); |
| if (s->auth_proto) |
| xfree(s->auth_proto); |
| s->used = 0; |
| session_proctitle(s); |
| } |
| |
| void |
| session_close_by_pid(pid_t pid, int status) |
| { |
| Session *s = session_by_pid(pid); |
| if (s == NULL) { |
| debug("session_close_by_pid: no session for pid %ld", |
| (long)pid); |
| return; |
| } |
| if (s->chanid != -1) |
| session_exit_message(s, status); |
| session_close(s); |
| } |
| |
| /* |
| * this is called when a channel dies before |
| * the session 'child' itself dies |
| */ |
| void |
| session_close_by_channel(int id, void *arg) |
| { |
| Session *s = session_by_channel(id); |
| if (s == NULL) { |
| debug("session_close_by_channel: no session for id %d", id); |
| return; |
| } |
| debug("session_close_by_channel: channel %d child %ld", |
| id, (long)s->pid); |
| if (s->pid != 0) { |
| debug("session_close_by_channel: channel %d: has child", id); |
| /* |
| * delay detach of session, but release pty, since |
| * the fd's to the child are already closed |
| */ |
| if (s->ttyfd != -1) { |
| fatal_remove_cleanup(session_pty_cleanup, (void *)s); |
| session_pty_cleanup(s); |
| } |
| return; |
| } |
| /* detach by removing callback */ |
| channel_cancel_cleanup(s->chanid); |
| s->chanid = -1; |
| session_close(s); |
| } |
| |
| void |
| session_destroy_all(void (*closefunc)(Session *)) |
| { |
| int i; |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| if (s->used) { |
| if (closefunc != NULL) |
| closefunc(s); |
| else |
| session_close(s); |
| } |
| } |
| } |
| |
| static char * |
| session_tty_list(void) |
| { |
| static char buf[1024]; |
| int i; |
| buf[0] = '\0'; |
| for (i = 0; i < MAX_SESSIONS; i++) { |
| Session *s = &sessions[i]; |
| if (s->used && s->ttyfd != -1) { |
| if (buf[0] != '\0') |
| strlcat(buf, ",", sizeof buf); |
| strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); |
| } |
| } |
| if (buf[0] == '\0') |
| strlcpy(buf, "notty", sizeof buf); |
| return buf; |
| } |
| |
| void |
| session_proctitle(Session *s) |
| { |
| if (s->pw == NULL) |
| error("no user for session %d", s->self); |
| else |
| setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); |
| } |
| |
| int |
| session_setup_x11fwd(Session *s) |
| { |
| struct stat st; |
| char display[512], auth_display[512]; |
| char hostname[MAXHOSTNAMELEN]; |
| |
| if (no_x11_forwarding_flag) { |
| packet_send_debug("X11 forwarding disabled in user configuration file."); |
| return 0; |
| } |
| if (!options.x11_forwarding) { |
| debug("X11 forwarding disabled in server configuration file."); |
| return 0; |
| } |
| if (!options.xauth_location || |
| (stat(options.xauth_location, &st) == -1)) { |
| packet_send_debug("No xauth program; cannot forward with spoofing."); |
| return 0; |
| } |
| if (options.use_login) { |
| packet_send_debug("X11 forwarding disabled; " |
| "not compatible with UseLogin=yes."); |
| return 0; |
| } |
| if (s->display != NULL) { |
| debug("X11 display already set."); |
| return 0; |
| } |
| if (x11_create_display_inet(options.x11_display_offset, |
| options.x11_use_localhost, s->single_connection, |
| &s->display_number) == -1) { |
| debug("x11_create_display_inet failed."); |
| return 0; |
| } |
| |
| /* Set up a suitable value for the DISPLAY variable. */ |
| if (gethostname(hostname, sizeof(hostname)) < 0) |
| fatal("gethostname: %.100s", strerror(errno)); |
| /* |
| * auth_display must be used as the displayname when the |
| * authorization entry is added with xauth(1). This will be |
| * different than the DISPLAY string for localhost displays. |
| */ |
| if (options.x11_use_localhost) { |
| snprintf(display, sizeof display, "localhost:%u.%u", |
| s->display_number, s->screen); |
| snprintf(auth_display, sizeof auth_display, "unix:%u.%u", |
| s->display_number, s->screen); |
| s->display = xstrdup(display); |
| s->auth_display = xstrdup(auth_display); |
| } else { |
| #ifdef IPADDR_IN_DISPLAY |
| struct hostent *he; |
| struct in_addr my_addr; |
| |
| he = gethostbyname(hostname); |
| if (he == NULL) { |
| error("Can't get IP address for X11 DISPLAY."); |
| packet_send_debug("Can't get IP address for X11 DISPLAY."); |
| return 0; |
| } |
| memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); |
| snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), |
| s->display_number, s->screen); |
| #else |
| snprintf(display, sizeof display, "%.400s:%u.%u", hostname, |
| s->display_number, s->screen); |
| #endif |
| s->display = xstrdup(display); |
| s->auth_display = xstrdup(display); |
| } |
| |
| return 1; |
| } |
| |
| static void |
| do_authenticated2(Authctxt *authctxt) |
| { |
| server_loop2(authctxt); |
| } |