diff options
Diffstat (limited to 'crypto/openssh/session.c')
| -rw-r--r-- | crypto/openssh/session.c | 2124 |
1 files changed, 0 insertions, 2124 deletions
diff --git a/crypto/openssh/session.c b/crypto/openssh/session.c deleted file mode 100644 index c75fea9669330..0000000000000 --- a/crypto/openssh/session.c +++ /dev/null @@ -1,2124 +0,0 @@ -/* - * 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 1.154 2003/03/05 22:33:43 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) -{ - setproctitle("%s", authctxt->pw->pw_name); - - /* - * 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, fromlen); -} -#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)); - 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 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, *laddr; - 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); -#ifdef _AIX - child_set_env(&env, &envsize, "LOGIN", pw->pw_name); -#endif - 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); - - laddr = get_local_ipaddr(packet_get_connection_in()); - snprintf(buf, sizeof buf, "%.50s %d %.50s %d", - get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); - xfree(laddr); - 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); - fflush(NULL); - exit(254); - } -} - -/* Set login name, uid, gid, and groups. */ -void -do_setusercontext(struct passwd *pw) -{ -#ifndef 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 - } - -#ifdef HAVE_CYGWIN - if (is_winnt) -#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, 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; - char *cp; - - buf[0] = '\0'; - for (i = 0; i < MAX_SESSIONS; i++) { - Session *s = &sessions[i]; - if (s->used && s->ttyfd != -1) { - - if (strncmp(s->tty, "/dev/", 5) != 0) { - cp = strrchr(s->tty, '/'); - cp = (cp == NULL) ? s->tty : cp + 1; - } else - cp = s->tty + 5; - - if (buf[0] != '\0') - strlcat(buf, ",", sizeof buf); - strlcat(buf, cp, 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); -} |