| /* $OpenBSD: session.c,v 1.290 2017/06/24 06:34:38 djm Exp $ */ |
| /* |
| * 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" |
| |
| #include <sys/types.h> |
| #include <sys/param.h> |
| #ifdef HAVE_SYS_STAT_H |
| # include <sys/stat.h> |
| #endif |
| #include <sys/socket.h> |
| #include <sys/un.h> |
| #include <sys/wait.h> |
| |
| #include <arpa/inet.h> |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <grp.h> |
| #include <netdb.h> |
| #ifdef HAVE_PATHS_H |
| #include <paths.h> |
| #endif |
| #include <pwd.h> |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <limits.h> |
| |
| #include "openbsd-compat/sys-queue.h" |
| #include "xmalloc.h" |
| #include "ssh.h" |
| #include "ssh2.h" |
| #include "sshpty.h" |
| #include "packet.h" |
| #include "buffer.h" |
| #include "match.h" |
| #include "uidswap.h" |
| #include "compat.h" |
| #include "channels.h" |
| #include "key.h" |
| #include "cipher.h" |
| #ifdef GSSAPI |
| #include "ssh-gss.h" |
| #endif |
| #include "hostfile.h" |
| #include "auth.h" |
| #include "auth-options.h" |
| #include "authfd.h" |
| #include "pathnames.h" |
| #include "log.h" |
| #include "misc.h" |
| #include "servconf.h" |
| #include "sshlogin.h" |
| #include "serverloop.h" |
| #include "canohost.h" |
| #include "session.h" |
| #include "kex.h" |
| #include "monitor_wrap.h" |
| #include "sftp.h" |
| #include "atomicio.h" |
| |
| #if defined(KRB5) && defined(USE_AFS) |
| #include <kafs.h> |
| #endif |
| |
| #ifdef WITH_SELINUX |
| #include <selinux/selinux.h> |
| #endif |
| |
| #define IS_INTERNAL_SFTP(c) \ |
| (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \ |
| (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \ |
| c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \ |
| c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t')) |
| |
| /* func */ |
| |
| Session *session_new(void); |
| void session_set_fds(Session *, int, int, int, int, int); |
| void session_pty_cleanup(Session *); |
| void session_proctitle(Session *); |
| int session_setup_x11fwd(Session *); |
| int do_exec_pty(Session *, const char *); |
| int do_exec_no_pty(Session *, const char *); |
| int 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_authenticated2(Authctxt *); |
| |
| static int session_pty_req(Session *); |
| |
| /* import */ |
| extern ServerOptions options; |
| extern char *__progname; |
| extern int debug_flag; |
| extern u_int utmp_len; |
| extern int startup_pipe; |
| extern void destroy_sensitive_data(void); |
| extern Buffer loginmsg; |
| |
| /* original command from peer. */ |
| const char *original_command = NULL; |
| |
| /* data */ |
| static int sessions_first_unused = -1; |
| static int sessions_nalloc = 0; |
| static Session *sessions = NULL; |
| |
| #define SUBSYSTEM_NONE 0 |
| #define SUBSYSTEM_EXT 1 |
| #define SUBSYSTEM_INT_SFTP 2 |
| #define SUBSYSTEM_INT_SFTP_ERROR 3 |
| |
| #ifdef HAVE_LOGIN_CAP |
| login_cap_t *lc; |
| #endif |
| |
| static int is_child = 0; |
| static int in_chroot = 0; |
| |
| /* File containing userauth info, if ExposeAuthInfo set */ |
| static char *auth_info_file = NULL; |
| |
| /* 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(struct passwd *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 = -1; |
| |
| 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_dir = xstrdup("/tmp/ssh-XXXXXXXXXX"); |
| |
| /* Create private directory for socket */ |
| if (mkdtemp(auth_sock_dir) == NULL) { |
| packet_send_debug("Agent forwarding disabled: " |
| "mkdtemp() failed: %.100s", strerror(errno)); |
| restore_uid(); |
| free(auth_sock_dir); |
| auth_sock_dir = NULL; |
| goto authsock_err; |
| } |
| |
| xasprintf(&auth_sock_name, "%s/agent.%ld", |
| auth_sock_dir, (long) getpid()); |
| |
| /* Start a Unix listener on auth_sock_name. */ |
| sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0); |
| |
| /* Restore the privileged uid. */ |
| restore_uid(); |
| |
| /* Check for socket/bind/listen failure. */ |
| if (sock < 0) |
| goto authsock_err; |
| |
| /* 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, "auth socket", 1); |
| nc->path = xstrdup(auth_sock_name); |
| return 1; |
| |
| authsock_err: |
| free(auth_sock_name); |
| if (auth_sock_dir != NULL) { |
| rmdir(auth_sock_dir); |
| free(auth_sock_dir); |
| } |
| if (sock != -1) |
| close(sock); |
| auth_sock_name = NULL; |
| auth_sock_dir = NULL; |
| return 0; |
| } |
| |
| static void |
| display_loginmsg(void) |
| { |
| if (buffer_len(&loginmsg) > 0) { |
| buffer_append(&loginmsg, "\0", 1); |
| printf("%s", (char *)buffer_ptr(&loginmsg)); |
| buffer_clear(&loginmsg); |
| } |
| } |
| |
| static void |
| prepare_auth_info_file(struct passwd *pw, struct sshbuf *info) |
| { |
| int fd = -1, success = 0; |
| |
| if (!options.expose_userauth_info || info == NULL) |
| return; |
| |
| temporarily_use_uid(pw); |
| auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX"); |
| if ((fd = mkstemp(auth_info_file)) == -1) { |
| error("%s: mkstemp: %s", __func__, strerror(errno)); |
| goto out; |
| } |
| if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info), |
| sshbuf_len(info)) != sshbuf_len(info)) { |
| error("%s: write: %s", __func__, strerror(errno)); |
| goto out; |
| } |
| if (close(fd) != 0) { |
| error("%s: close: %s", __func__, strerror(errno)); |
| goto out; |
| } |
| success = 1; |
| out: |
| if (!success) { |
| if (fd != -1) |
| close(fd); |
| free(auth_info_file); |
| auth_info_file = NULL; |
| } |
| restore_uid(); |
| } |
| |
| void |
| do_authenticated(Authctxt *authctxt) |
| { |
| setproctitle("%s", authctxt->pw->pw_name); |
| |
| /* setup the channel layer */ |
| /* XXX - streamlocal? */ |
| if (no_port_forwarding_flag || options.disable_forwarding || |
| (options.allow_tcp_forwarding & FORWARD_LOCAL) == 0) |
| channel_disable_adm_local_opens(); |
| else |
| channel_permit_all_opens(); |
| |
| auth_debug_send(); |
| |
| prepare_auth_info_file(authctxt->pw, authctxt->session_info); |
| |
| do_authenticated2(authctxt); |
| |
| do_cleanup(authctxt); |
| } |
| |
| /* Check untrusted xauth strings for metacharacters */ |
| static int |
| xauth_valid_string(const char *s) |
| { |
| size_t i; |
| |
| for (i = 0; s[i] != '\0'; i++) { |
| if (!isalnum((u_char)s[i]) && |
| s[i] != '.' && s[i] != ':' && s[i] != '/' && |
| s[i] != '-' && s[i] != '_') |
| return 0; |
| } |
| return 1; |
| } |
| |
| #define USE_PIPES 1 |
| /* |
| * 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. |
| */ |
| int |
| do_exec_no_pty(Session *s, const char *command) |
| { |
| pid_t pid; |
| |
| #ifdef USE_PIPES |
| int pin[2], pout[2], perr[2]; |
| |
| if (s == NULL) |
| fatal("do_exec_no_pty: no session"); |
| |
| /* Allocate pipes for communicating with the program. */ |
| if (pipe(pin) < 0) { |
| error("%s: pipe in: %.100s", __func__, strerror(errno)); |
| return -1; |
| } |
| if (pipe(pout) < 0) { |
| error("%s: pipe out: %.100s", __func__, strerror(errno)); |
| close(pin[0]); |
| close(pin[1]); |
| return -1; |
| } |
| if (pipe(perr) < 0) { |
| error("%s: pipe err: %.100s", __func__, |
| strerror(errno)); |
| close(pin[0]); |
| close(pin[1]); |
| close(pout[0]); |
| close(pout[1]); |
| return -1; |
| } |
| #else |
| int inout[2], err[2]; |
| |
| if (s == NULL) |
| fatal("do_exec_no_pty: no session"); |
| |
| /* Uses socket pairs to communicate with the program. */ |
| if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) { |
| error("%s: socketpair #1: %.100s", __func__, strerror(errno)); |
| return -1; |
| } |
| if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) { |
| error("%s: socketpair #2: %.100s", __func__, |
| strerror(errno)); |
| close(inout[0]); |
| close(inout[1]); |
| return -1; |
| } |
| #endif |
| |
| session_proctitle(s); |
| |
| /* Fork the child. */ |
| switch ((pid = fork())) { |
| case -1: |
| error("%s: fork: %.100s", __func__, strerror(errno)); |
| #ifdef USE_PIPES |
| close(pin[0]); |
| close(pin[1]); |
| close(pout[0]); |
| close(pout[1]); |
| close(perr[0]); |
| close(perr[1]); |
| #else |
| close(inout[0]); |
| close(inout[1]); |
| close(err[0]); |
| close(err[1]); |
| #endif |
| return -1; |
| case 0: |
| is_child = 1; |
| |
| /* |
| * 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 |
| /* |
| * 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 (same as stdin) */ |
| perror("dup2 stdout"); |
| close(inout[0]); |
| if (dup2(err[0], 2) < 0) /* stderr */ |
| perror("dup2 stderr"); |
| close(err[0]); |
| #endif |
| |
| |
| #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 */ |
| default: |
| break; |
| } |
| |
| #ifdef _UNICOS |
| signal(WJSIGNAL, cray_job_termination_handler); |
| #endif /* _UNICOS */ |
| #ifdef HAVE_CYGWIN |
| cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); |
| #endif |
| |
| s->pid = pid; |
| /* Set interactive/non-interactive mode. */ |
| packet_set_interactive(s->display != NULL, |
| options.ip_qos_interactive, options.ip_qos_bulk); |
| |
| /* |
| * Clear loginmsg, since it's the child's responsibility to display |
| * it to the user, otherwise multiple sessions may accumulate |
| * multiple copies of the login messages. |
| */ |
| buffer_clear(&loginmsg); |
| |
| #ifdef USE_PIPES |
| /* We are the parent. Close the child sides of the pipes. */ |
| close(pin[0]); |
| close(pout[1]); |
| close(perr[1]); |
| |
| session_set_fds(s, pin[1], pout[0], perr[0], |
| s->is_subsystem, 0); |
| #else |
| /* 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. |
| */ |
| session_set_fds(s, inout[1], inout[1], err[1], |
| s->is_subsystem, 0); |
| #endif |
| return 0; |
| } |
| |
| /* |
| * 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. |
| */ |
| int |
| 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; |
| |
| /* |
| * 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. |
| * Do this before forking (and cleanup in the child) so as to |
| * detect and gracefully fail out-of-fd conditions. |
| */ |
| if ((fdout = dup(ptyfd)) < 0) { |
| error("%s: dup #1: %s", __func__, strerror(errno)); |
| close(ttyfd); |
| close(ptyfd); |
| return -1; |
| } |
| /* we keep a reference to the pty master */ |
| if ((ptymaster = dup(ptyfd)) < 0) { |
| error("%s: dup #2: %s", __func__, strerror(errno)); |
| close(ttyfd); |
| close(ptyfd); |
| close(fdout); |
| return -1; |
| } |
| |
| /* Fork the child. */ |
| switch ((pid = fork())) { |
| case -1: |
| error("%s: fork: %.100s", __func__, strerror(errno)); |
| close(fdout); |
| close(ptymaster); |
| close(ttyfd); |
| close(ptyfd); |
| return -1; |
| case 0: |
| is_child = 1; |
| |
| close(fdout); |
| close(ptymaster); |
| |
| /* 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) */ |
| #ifdef _UNICOS |
| cray_init_job(s->pw); /* set up cray jid and tmpdir */ |
| #endif /* _UNICOS */ |
| #ifndef HAVE_OSF_SIA |
| do_login(s, command); |
| #endif |
| /* |
| * Do common processing for the child, such as execing |
| * the command. |
| */ |
| do_child(s, command); |
| /* NOTREACHED */ |
| default: |
| break; |
| } |
| |
| #ifdef _UNICOS |
| signal(WJSIGNAL, cray_job_termination_handler); |
| #endif /* _UNICOS */ |
| #ifdef HAVE_CYGWIN |
| cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); |
| #endif |
| |
| s->pid = pid; |
| |
| /* Parent. Close the slave side of the pseudo tty. */ |
| close(ttyfd); |
| |
| /* Enter interactive session. */ |
| s->ptymaster = ptymaster; |
| packet_set_interactive(1, |
| options.ip_qos_interactive, options.ip_qos_bulk); |
| session_set_fds(s, ptyfd, fdout, -1, 1, 1); |
| return 0; |
| } |
| |
| #ifdef LOGIN_NEEDS_UTMPX |
| static void |
| do_pre_login(Session *s) |
| { |
| struct ssh *ssh = active_state; /* XXX */ |
| 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)); |
| cleanup_exit(255); |
| } |
| } |
| |
| record_utmp_only(pid, s->tty, s->pw->pw_name, |
| session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns), |
| (struct sockaddr *)&from, fromlen); |
| } |
| #endif |
| |
| /* |
| * This is called to fork and execute a command. If another command is |
| * to be forced, execute that instead. |
| */ |
| int |
| do_exec(Session *s, const char *command) |
| { |
| struct ssh *ssh = active_state; /* XXX */ |
| int ret; |
| const char *forced = NULL, *tty = NULL; |
| char session_type[1024]; |
| |
| if (options.adm_forced_command) { |
| original_command = command; |
| command = options.adm_forced_command; |
| forced = "(config)"; |
| } else if (forced_command) { |
| original_command = command; |
| command = forced_command; |
| forced = "(key-option)"; |
| } |
| if (forced != NULL) { |
| if (IS_INTERNAL_SFTP(command)) { |
| s->is_subsystem = s->is_subsystem ? |
| SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR; |
| } else if (s->is_subsystem) |
| s->is_subsystem = SUBSYSTEM_EXT; |
| snprintf(session_type, sizeof(session_type), |
| "forced-command %s '%.900s'", forced, command); |
| } else if (s->is_subsystem) { |
| snprintf(session_type, sizeof(session_type), |
| "subsystem '%.900s'", s->subsys); |
| } else if (command == NULL) { |
| snprintf(session_type, sizeof(session_type), "shell"); |
| } else { |
| /* NB. we don't log unforced commands to preserve privacy */ |
| snprintf(session_type, sizeof(session_type), "command"); |
| } |
| |
| if (s->ttyfd != -1) { |
| tty = s->tty; |
| if (strncmp(tty, "/dev/", 5) == 0) |
| tty += 5; |
| } |
| |
| verbose("Starting session: %s%s%s for %s from %.200s port %d id %d", |
| session_type, |
| tty == NULL ? "" : " on ", |
| tty == NULL ? "" : tty, |
| s->pw->pw_name, |
| ssh_remote_ipaddr(ssh), |
| ssh_remote_port(ssh), |
| s->self); |
| |
| #ifdef SSH_AUDIT_EVENTS |
| if (command != NULL) |
| PRIVSEP(audit_run_command(command)); |
| else if (s->ttyfd == -1) { |
| char *shell = s->pw->pw_shell; |
| |
| if (shell[0] == '\0') /* empty shell means /bin/sh */ |
| shell =_PATH_BSHELL; |
| PRIVSEP(audit_run_command(shell)); |
| } |
| #endif |
| if (s->ttyfd != -1) |
| ret = do_exec_pty(s, command); |
| else |
| ret = do_exec_no_pty(s, command); |
| |
| original_command = NULL; |
| |
| /* |
| * Clear loginmsg: it's the child's responsibility to display |
| * it to the user, otherwise multiple sessions may accumulate |
| * multiple copies of the login messages. |
| */ |
| buffer_clear(&loginmsg); |
| |
| return ret; |
| } |
| |
| /* administrative, login(1)-like work */ |
| void |
| do_login(Session *s, const char *command) |
| { |
| struct ssh *ssh = active_state; /* XXX */ |
| 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)); |
| cleanup_exit(255); |
| } |
| } |
| |
| /* 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, |
| session_get_remote_name_or_ip(ssh, utmp_len, |
| options.use_dns), |
| (struct sockaddr *)&from, fromlen); |
| |
| #ifdef USE_PAM |
| /* |
| * If password change is needed, do it now. |
| * This needs to occur before the ~/.hushlogin check. |
| */ |
| if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { |
| display_loginmsg(); |
| do_pam_chauthtok(); |
| s->authctxt->force_pwchange = 0; |
| /* XXX - signal [net] parent to enable forwardings */ |
| } |
| #endif |
| |
| if (check_quietlogin(s, command)) |
| return; |
| |
| display_loginmsg(); |
| |
| 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 overridden. |
| */ |
| void |
| child_set_env(char ***envp, u_int *envsizep, const char *name, |
| const char *value) |
| { |
| char **env; |
| u_int envsize; |
| u_int i, namelen; |
| |
| if (strchr(name, '=') != NULL) { |
| error("Invalid environment variable \"%.100s\"", name); |
| return; |
| } |
| |
| /* |
| * If we're passed an uninitialized list, allocate a single null |
| * entry before continuing. |
| */ |
| if (*envp == NULL && *envsizep == 0) { |
| *envp = xmalloc(sizeof(char *)); |
| *envp[0] = NULL; |
| *envsizep = 1; |
| } |
| |
| /* |
| * 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. */ |
| free(env[i]); |
| } else { |
| /* New variable. Expand if necessary. */ |
| envsize = *envsizep; |
| if (i >= envsize - 1) { |
| if (envsize >= 1000) |
| fatal("child_set_env: too many env vars"); |
| envsize += 50; |
| env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); |
| *envsizep = envsize; |
| } |
| /* 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; |
| |
| cp[strcspn(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); |
| } |
| |
| #ifdef HAVE_ETC_DEFAULT_LOGIN |
| /* |
| * Return named variable from specified environment, or NULL if not present. |
| */ |
| static char * |
| child_get_env(char **env, const char *name) |
| { |
| int i; |
| size_t len; |
| |
| len = strlen(name); |
| for (i=0; env[i] != NULL; i++) |
| if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') |
| return(env[i] + len + 1); |
| return NULL; |
| } |
| |
| /* |
| * Read /etc/default/login. |
| * We pick up the PATH (or SUPATH for root) and UMASK. |
| */ |
| static void |
| read_etc_default_login(char ***env, u_int *envsize, uid_t uid) |
| { |
| char **tmpenv = NULL, *var; |
| u_int i, tmpenvsize = 0; |
| u_long mask; |
| |
| /* |
| * We don't want to copy the whole file to the child's environment, |
| * so we use a temporary environment and copy the variables we're |
| * interested in. |
| */ |
| read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); |
| |
| if (tmpenv == NULL) |
| return; |
| |
| if (uid == 0) |
| var = child_get_env(tmpenv, "SUPATH"); |
| else |
| var = child_get_env(tmpenv, "PATH"); |
| if (var != NULL) |
| child_set_env(env, envsize, "PATH", var); |
| |
| if ((var = child_get_env(tmpenv, "UMASK")) != NULL) |
| if (sscanf(var, "%5lo", &mask) == 1) |
| umask((mode_t)mask); |
| |
| for (i = 0; tmpenv[i] != NULL; i++) |
| free(tmpenv[i]); |
| free(tmpenv); |
| } |
| #endif /* HAVE_ETC_DEFAULT_LOGIN */ |
| |
| 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) { |
| free(var_name); |
| continue; |
| } |
| *var_val++ = '\0'; |
| |
| debug3("Copy environment: %s=%s", var_name, var_val); |
| child_set_env(env, envsize, var_name, var_val); |
| |
| free(var_name); |
| } |
| } |
| |
| static char ** |
| do_setup_env(Session *s, const char *shell) |
| { |
| struct ssh *ssh = active_state; /* XXX */ |
| char buf[256]; |
| u_int i, envsize; |
| char **env, *laddr; |
| struct passwd *pw = s->pw; |
| #if !defined (HAVE_LOGIN_CAP) && !defined (HAVE_CYGWIN) |
| char *path = NULL; |
| #endif |
| |
| /* Initialize the environment. */ |
| envsize = 100; |
| env = xcalloc(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. |
| */ |
| { |
| char **p; |
| |
| p = fetch_windows_environment(); |
| copy_environment(p, &env, &envsize); |
| free_windows_environment(p); |
| } |
| #endif |
| |
| #ifdef GSSAPI |
| /* Allow any GSSAPI methods that we've used to alter |
| * the childs environment as they see fit |
| */ |
| ssh_gssapi_do_child(&env, &envsize); |
| #endif |
| |
| /* Set basic environment. */ |
| for (i = 0; i < s->num_env; i++) |
| child_set_env(&env, &envsize, s->env[i].name, s->env[i].val); |
| |
| 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 HAVE_ETC_DEFAULT_LOGIN |
| read_etc_default_login(&env, &envsize, pw->pw_uid); |
| path = child_get_env(env, "PATH"); |
| # endif /* HAVE_ETC_DEFAULT_LOGIN */ |
| if (path == NULL || *path == '\0') { |
| child_set_env(&env, &envsize, "PATH", |
| s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); |
| } |
| # 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. */ |
| 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; |
| free(ce->s); |
| free(ce); |
| } |
| |
| /* SSH_CLIENT deprecated */ |
| snprintf(buf, sizeof buf, "%.50s %d %d", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), |
| ssh_local_port(ssh)); |
| child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
| |
| laddr = get_local_ipaddr(packet_get_connection_in()); |
| snprintf(buf, sizeof buf, "%.50s %d %.50s %d", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), |
| laddr, ssh_local_port(ssh)); |
| free(laddr); |
| child_set_env(&env, &envsize, "SSH_CONNECTION", buf); |
| |
| if (auth_info_file != NULL) |
| child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file); |
| 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 */ |
| |
| /* |
| * Since we clear KRB5CCNAME at startup, if it's set now then it |
| * must have been set by a native authentication method (eg AIX or |
| * SIA), so copy it to the child. |
| */ |
| { |
| char *cp; |
| |
| if ((cp = getenv("KRB5CCNAME")) != NULL) |
| child_set_env(&env, &envsize, "KRB5CCNAME", cp); |
| } |
| |
| #ifdef _AIX |
| { |
| char *cp; |
| |
| if ((cp = getenv("AUTHSTATE")) != NULL) |
| child_set_env(&env, &envsize, "AUTHSTATE", cp); |
| read_environment_file(&env, &envsize, "/etc/environment"); |
| } |
| #endif |
| #ifdef KRB5 |
| if (s->authctxt->krb5_ccname) |
| child_set_env(&env, &envsize, "KRB5CCNAME", |
| s->authctxt->krb5_ccname); |
| #endif |
| #ifdef USE_PAM |
| /* |
| * Pull in any environment variables that may have |
| * been set by PAM. |
| */ |
| if (options.use_pam) { |
| char **p; |
| |
| p = fetch_pam_child_environment(); |
| copy_environment(p, &env, &envsize); |
| free_pam_environment(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) { |
| 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 and admin forced commands */ |
| if (!s->is_subsystem && options.adm_forced_command == NULL && |
| !no_user_rc && options.permit_user_rc && |
| 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], *nl, *def_nl = _PATH_NOLOGIN; |
| struct stat sb; |
| |
| #ifdef HAVE_LOGIN_CAP |
| if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0) |
| return; |
| nl = login_getcapstr(lc, "nologin", def_nl, def_nl); |
| #else |
| if (pw->pw_uid == 0) |
| return; |
| nl = def_nl; |
| #endif |
| if (stat(nl, &sb) == -1) { |
| if (nl != def_nl) |
| free(nl); |
| return; |
| } |
| |
| /* /etc/nologin exists. Print its contents if we can and exit. */ |
| logit("User %.100s not allowed because %s exists", pw->pw_name, nl); |
| if ((f = fopen(nl, "r")) != NULL) { |
| while (fgets(buf, sizeof(buf), f)) |
| fputs(buf, stderr); |
| fclose(f); |
| } |
| exit(254); |
| } |
| |
| /* |
| * Chroot into a directory after checking it for safety: all path components |
| * must be root-owned directories with strict permissions. |
| */ |
| static void |
| safely_chroot(const char *path, uid_t uid) |
| { |
| const char *cp; |
| char component[PATH_MAX]; |
| struct stat st; |
| |
| if (*path != '/') |
| fatal("chroot path does not begin at root"); |
| if (strlen(path) >= sizeof(component)) |
| fatal("chroot path too long"); |
| |
| /* |
| * Descend the path, checking that each component is a |
| * root-owned directory with strict permissions. |
| */ |
| for (cp = path; cp != NULL;) { |
| if ((cp = strchr(cp, '/')) == NULL) |
| strlcpy(component, path, sizeof(component)); |
| else { |
| cp++; |
| memcpy(component, path, cp - path); |
| component[cp - path] = '\0'; |
| } |
| |
| debug3("%s: checking '%s'", __func__, component); |
| |
| if (stat(component, &st) != 0) |
| fatal("%s: stat(\"%s\"): %s", __func__, |
| component, strerror(errno)); |
| if (st.st_uid != 0 || (st.st_mode & 022) != 0) |
| fatal("bad ownership or modes for chroot " |
| "directory %s\"%s\"", |
| cp == NULL ? "" : "component ", component); |
| if (!S_ISDIR(st.st_mode)) |
| fatal("chroot path %s\"%s\" is not a directory", |
| cp == NULL ? "" : "component ", component); |
| |
| } |
| |
| if (chdir(path) == -1) |
| fatal("Unable to chdir to chroot path \"%s\": " |
| "%s", path, strerror(errno)); |
| if (chroot(path) == -1) |
| fatal("chroot(\"%s\"): %s", path, strerror(errno)); |
| if (chdir("/") == -1) |
| fatal("%s: chdir(/) after chroot: %s", |
| __func__, strerror(errno)); |
| verbose("Changed root directory to \"%s\"", path); |
| } |
| |
| /* Set login name, uid, gid, and groups. */ |
| void |
| do_setusercontext(struct passwd *pw) |
| { |
| char *chroot_path, *tmp; |
| |
| platform_setusercontext(pw); |
| |
| if (platform_privileged_uidswap()) { |
| #ifdef HAVE_LOGIN_CAP |
| if (setusercontext(lc, pw, pw->pw_uid, |
| (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) { |
| perror("unable to set user context"); |
| exit(1); |
| } |
| #else |
| 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(); |
| #endif |
| |
| platform_setusercontext_post_groups(pw); |
| |
| if (!in_chroot && options.chroot_directory != NULL && |
| strcasecmp(options.chroot_directory, "none") != 0) { |
| tmp = tilde_expand_filename(options.chroot_directory, |
| pw->pw_uid); |
| chroot_path = percent_expand(tmp, "h", pw->pw_dir, |
| "u", pw->pw_name, (char *)NULL); |
| safely_chroot(chroot_path, pw->pw_uid); |
| free(tmp); |
| free(chroot_path); |
| /* Make sure we don't attempt to chroot again */ |
| free(options.chroot_directory); |
| options.chroot_directory = NULL; |
| in_chroot = 1; |
| } |
| |
| #ifdef HAVE_LOGIN_CAP |
| if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) { |
| perror("unable to set user context (setuser)"); |
| exit(1); |
| } |
| /* |
| * FreeBSD's setusercontext() will not apply the user's |
| * own umask setting unless running with the user's UID. |
| */ |
| (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUMASK); |
| #else |
| # ifdef USE_LIBIAF |
| /* |
| * In a chroot environment, the set_id() will always fail; |
| * typically because of the lack of necessary authentication |
| * services and runtime such as ./usr/lib/libiaf.so, |
| * ./usr/lib/libpam.so.1, and ./etc/passwd We skip it in the |
| * internal sftp chroot case. We'll lose auditing and ACLs but |
| * permanently_set_uid will take care of the rest. |
| */ |
| if (!in_chroot && set_id(pw->pw_name) != 0) |
| fatal("set_id(%s) Failed", pw->pw_name); |
| # endif /* USE_LIBIAF */ |
| /* Permanently switch to the desired uid. */ |
| permanently_set_uid(pw); |
| #endif |
| } else if (options.chroot_directory != NULL && |
| strcasecmp(options.chroot_directory, "none") != 0) { |
| fatal("server lacks privileges to chroot to ChrootDirectory"); |
| } |
| |
| if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) |
| fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); |
| } |
| |
| static void |
| do_pwchange(Session *s) |
| { |
| fflush(NULL); |
| fprintf(stderr, "WARNING: Your password has expired.\n"); |
| if (s->ttyfd != -1) { |
| fprintf(stderr, |
| "You must change your password now and login again!\n"); |
| #ifdef WITH_SELINUX |
| setexeccon(NULL); |
| #endif |
| #ifdef PASSWD_NEEDS_USERNAME |
| execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name, |
| (char *)NULL); |
| #else |
| execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); |
| #endif |
| perror("passwd"); |
| } else { |
| fprintf(stderr, |
| "Password change required but no TTY available.\n"); |
| } |
| exit(1); |
| } |
| |
| static void |
| child_close_fds(void) |
| { |
| extern int auth_sock; |
| |
| if (auth_sock != -1) { |
| close(auth_sock); |
| auth_sock = -1; |
| } |
| |
| 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. |
| */ |
| closefrom(STDERR_FILENO + 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. |
| */ |
| #define ARGV_MAX 10 |
| void |
| do_child(Session *s, const char *command) |
| { |
| extern char **environ; |
| char **env; |
| char *argv[ARGV_MAX]; |
| const char *shell, *shell0; |
| struct passwd *pw = s->pw; |
| int r = 0; |
| |
| /* remove hostkey from the child's memory */ |
| destroy_sensitive_data(); |
| packet_clear_keys(); |
| |
| /* Force a password change */ |
| if (s->authctxt->force_pwchange) { |
| do_setusercontext(pw); |
| child_close_fds(); |
| do_pwchange(s); |
| exit(1); |
| } |
| |
| #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. |
| */ |
| #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 */ |
| /* When PAM is enabled we rely on it to do the nologin check */ |
| if (!options.use_pam) |
| do_nologin(pw); |
| do_setusercontext(pw); |
| /* |
| * PAM session modules in do_setusercontext may have |
| * generated messages, so if this in an interactive |
| * login then display them too. |
| */ |
| if (!check_quietlogin(s, command)) |
| display_loginmsg(); |
| #endif /* HAVE_OSF_SIA */ |
| |
| #ifdef USE_PAM |
| if (options.use_pam && !is_pam_session_open()) { |
| debug3("PAM session not opened, exiting"); |
| display_loginmsg(); |
| exit(254); |
| } |
| #endif |
| |
| /* |
| * 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 |
| |
| /* |
| * 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 |
| * ssh_remote_ipaddr there. |
| */ |
| child_close_fds(); |
| |
| /* |
| * Must take new environment into use so that .ssh/rc, |
| * /etc/ssh/sshrc and xauth are run in the proper environment. |
| */ |
| environ = env; |
| |
| #if defined(KRB5) && defined(USE_AFS) |
| /* |
| * At this point, we check to see if AFS is active and if we have |
| * a valid Kerberos 5 TGT. If so, it seems like a good idea to see |
| * if we can (and need to) extend the ticket into an AFS token. If |
| * we don't do this, we run into potential problems if the user's |
| * home directory is in AFS and it's not world-readable. |
| */ |
| |
| if (options.kerberos_get_afs_token && k_hasafs() && |
| (s->authctxt->krb5_ctx != NULL)) { |
| char cell[64]; |
| |
| debug("Getting AFS token"); |
| |
| k_setpag(); |
| |
| if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) |
| krb5_afslog(s->authctxt->krb5_ctx, |
| s->authctxt->krb5_fwd_ccache, cell, NULL); |
| |
| krb5_afslog_home(s->authctxt->krb5_ctx, |
| s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); |
| } |
| #endif |
| |
| /* Change current directory to the user's home directory. */ |
| if (chdir(pw->pw_dir) < 0) { |
| /* Suppress missing homedir warning for chroot case */ |
| #ifdef HAVE_LOGIN_CAP |
| r = login_getcapbool(lc, "requirehome", 0); |
| #endif |
| if (r || !in_chroot) { |
| fprintf(stderr, "Could not chdir to home " |
| "directory %s: %s\n", pw->pw_dir, |
| strerror(errno)); |
| } |
| if (r) |
| exit(1); |
| } |
| |
| closefrom(STDERR_FILENO + 1); |
| |
| do_rc_files(s, shell); |
| |
| /* restore SIGPIPE for child */ |
| signal(SIGPIPE, SIG_DFL); |
| |
| if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) { |
| printf("This service allows sftp connections only.\n"); |
| fflush(NULL); |
| exit(1); |
| } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) { |
| extern int optind, optreset; |
| int i; |
| char *p, *args; |
| |
| setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME); |
| args = xstrdup(command ? command : "sftp-server"); |
| for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " "))) |
| if (i < ARGV_MAX - 1) |
| argv[i++] = p; |
| argv[i] = NULL; |
| optind = optreset = 1; |
| __progname = argv[0]; |
| #ifdef WITH_SELINUX |
| ssh_selinux_change_context("sftpd_t"); |
| #endif |
| exit(sftp_server_main(i, argv, s->pw)); |
| } |
| |
| fflush(NULL); |
| |
| /* 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); |
| } |
| |
| void |
| session_unused(int id) |
| { |
| debug3("%s: session id %d unused", __func__, id); |
| if (id >= options.max_sessions || |
| id >= sessions_nalloc) { |
| fatal("%s: insane session id %d (max %d nalloc %d)", |
| __func__, id, options.max_sessions, sessions_nalloc); |
| } |
| memset(&sessions[id], 0, sizeof(*sessions)); |
| sessions[id].self = id; |
| sessions[id].used = 0; |
| sessions[id].chanid = -1; |
| sessions[id].ptyfd = -1; |
| sessions[id].ttyfd = -1; |
| sessions[id].ptymaster = -1; |
| sessions[id].x11_chanids = NULL; |
| sessions[id].next_unused = sessions_first_unused; |
| sessions_first_unused = id; |
| } |
| |
| Session * |
| session_new(void) |
| { |
| Session *s, *tmp; |
| |
| if (sessions_first_unused == -1) { |
| if (sessions_nalloc >= options.max_sessions) |
| return NULL; |
| debug2("%s: allocate (allocated %d max %d)", |
| __func__, sessions_nalloc, options.max_sessions); |
| tmp = xrecallocarray(sessions, sessions_nalloc, |
| sessions_nalloc + 1, sizeof(*sessions)); |
| if (tmp == NULL) { |
| error("%s: cannot allocate %d sessions", |
| __func__, sessions_nalloc + 1); |
| return NULL; |
| } |
| sessions = tmp; |
| session_unused(sessions_nalloc++); |
| } |
| |
| if (sessions_first_unused >= sessions_nalloc || |
| sessions_first_unused < 0) { |
| fatal("%s: insane first_unused %d max %d nalloc %d", |
| __func__, sessions_first_unused, options.max_sessions, |
| sessions_nalloc); |
| } |
| |
| s = &sessions[sessions_first_unused]; |
| if (s->used) { |
| fatal("%s: session %d already used", |
| __func__, sessions_first_unused); |
| } |
| sessions_first_unused = s->next_unused; |
| s->used = 1; |
| s->next_unused = -1; |
| debug("session_new: session %d", s->self); |
| |
| return s; |
| } |
| |
| static void |
| session_dump(void) |
| { |
| int i; |
| for (i = 0; i < sessions_nalloc; i++) { |
| Session *s = &sessions[i]; |
| |
| debug("dump: used %d next_unused %d session %d %p " |
| "channel %d pid %ld", |
| s->used, |
| s->next_unused, |
| 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 || !authctxt->valid) |
| 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 < sessions_nalloc; 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 < sessions_nalloc; 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_x11_channel(int id) |
| { |
| int i, j; |
| |
| for (i = 0; i < sessions_nalloc; i++) { |
| Session *s = &sessions[i]; |
| |
| if (s->x11_chanids == NULL || !s->used) |
| continue; |
| for (j = 0; s->x11_chanids[j] != -1; j++) { |
| if (s->x11_chanids[j] == id) { |
| debug("session_by_x11_channel: session %d " |
| "channel %d", s->self, id); |
| return s; |
| } |
| } |
| } |
| debug("session_by_x11_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 < sessions_nalloc; 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 || !options.permit_tty) { |
| 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; |
| } |
| |
| s->term = packet_get_string(&len); |
| s->col = packet_get_int(); |
| s->row = packet_get_int(); |
| s->xpixel = packet_get_int(); |
| s->ypixel = packet_get_int(); |
| |
| if (strcmp(s->term, "") == 0) { |
| free(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)))) { |
| free(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); |
| |
| n_bytes = packet_remaining(); |
| tty_parse_modes(s->ttyfd, &n_bytes); |
| |
| 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 *prog, *cmd; |
| u_int i; |
| |
| s->subsys = packet_get_string(&len); |
| packet_check_eom(); |
| debug2("subsystem request for %.100s by user %s", s->subsys, |
| s->pw->pw_name); |
| |
| for (i = 0; i < options.num_subsystems; i++) { |
| if (strcmp(s->subsys, options.subsystem_name[i]) == 0) { |
| prog = options.subsystem_command[i]; |
| cmd = options.subsystem_args[i]; |
| if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) { |
| s->is_subsystem = SUBSYSTEM_INT_SFTP; |
| debug("subsystem: %s", prog); |
| } else { |
| if (stat(prog, &st) < 0) |
| debug("subsystem: cannot stat %s: %s", |
| prog, strerror(errno)); |
| s->is_subsystem = SUBSYSTEM_EXT; |
| debug("subsystem: exec() %s", cmd); |
| } |
| success = do_exec(s, cmd) == 0; |
| break; |
| } |
| } |
| |
| if (!success) |
| logit("subsystem request for %.100s by user %s failed, " |
| "subsystem not found", s->subsys, s->pw->pw_name); |
| |
| return success; |
| } |
| |
| static int |
| session_x11_req(Session *s) |
| { |
| int success; |
| |
| if (s->auth_proto != NULL || s->auth_data != NULL) { |
| error("session_x11_req: session %d: " |
| "x11 forwarding already active", s->self); |
| return 0; |
| } |
| 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(); |
| |
| if (xauth_valid_string(s->auth_proto) && |
| xauth_valid_string(s->auth_data)) |
| success = session_setup_x11fwd(s); |
| else { |
| success = 0; |
| error("Invalid X11 forwarding data"); |
| } |
| if (!success) { |
| free(s->auth_proto); |
| free(s->auth_data); |
| s->auth_proto = NULL; |
| s->auth_data = NULL; |
| } |
| return success; |
| } |
| |
| static int |
| session_shell_req(Session *s) |
| { |
| packet_check_eom(); |
| return do_exec(s, NULL) == 0; |
| } |
| |
| static int |
| session_exec_req(Session *s) |
| { |
| u_int len, success; |
| |
| char *command = packet_get_string(&len); |
| packet_check_eom(); |
| success = do_exec(s, command) == 0; |
| free(command); |
| return success; |
| } |
| |
| static int |
| session_break_req(Session *s) |
| { |
| |
| packet_get_int(); /* ignored */ |
| packet_check_eom(); |
| |
| if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0) |
| return 0; |
| return 1; |
| } |
| |
| static int |
| session_env_req(Session *s) |
| { |
| char *name, *val; |
| u_int name_len, val_len, i; |
| |
| name = packet_get_cstring(&name_len); |
| val = packet_get_cstring(&val_len); |
| packet_check_eom(); |
| |
| /* Don't set too many environment variables */ |
| if (s->num_env > 128) { |
| debug2("Ignoring env request %s: too many env vars", name); |
| goto fail; |
| } |
| |
| for (i = 0; i < options.num_accept_env; i++) { |
| if (match_pattern(name, options.accept_env[i])) { |
| debug2("Setting env %d: %s=%s", s->num_env, name, val); |
| s->env = xrecallocarray(s->env, s->num_env, |
| s->num_env + 1, sizeof(*s->env)); |
| s->env[s->num_env].name = name; |
| s->env[s->num_env].val = val; |
| s->num_env++; |
| return (1); |
| } |
| } |
| debug2("Ignoring env request %s: disallowed name", name); |
| |
| fail: |
| free(name); |
| free(val); |
| return (0); |
| } |
| |
| static int |
| session_auth_agent_req(Session *s) |
| { |
| static int called = 0; |
| packet_check_eom(); |
| if (no_agent_forwarding_flag || !options.allow_agent_forwarding) { |
| 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) { |
| logit("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); |
| } else if (strcmp(rtype, "env") == 0) { |
| success = session_env_req(s); |
| } |
| } |
| if (strcmp(rtype, "window-change") == 0) { |
| success = session_window_change_req(s); |
| } else if (strcmp(rtype, "break") == 0) { |
| success = session_break_req(s); |
| } |
| |
| return success; |
| } |
| |
| void |
| session_set_fds(Session *s, int fdin, int fdout, int fderr, int ignore_fderr, |
| int is_tty) |
| { |
| /* |
| * 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, |
| ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, |
| 1, is_tty, 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(Session *s) |
| { |
| 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 (s->ptymaster != -1 && 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(Session *s) |
| { |
| PRIVSEP(session_pty_cleanup2(s)); |
| } |
| |
| 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_close_x11(int id) |
| { |
| Channel *c; |
| |
| if ((c = channel_by_id(id)) == NULL) { |
| debug("session_close_x11: x11 channel %d missing", id); |
| } else { |
| /* Detach X11 listener */ |
| debug("session_close_x11: detach x11 channel %d", id); |
| channel_cancel_cleanup(id); |
| if (c->ostate != CHAN_OUTPUT_CLOSED) |
| chan_mark_dead(c); |
| } |
| } |
| |
| static void |
| session_close_single_x11(int id, void *arg) |
| { |
| Session *s; |
| u_int i; |
| |
| debug3("session_close_single_x11: channel %d", id); |
| channel_cancel_cleanup(id); |
| if ((s = session_by_x11_channel(id)) == NULL) |
| fatal("session_close_single_x11: no x11 channel %d", id); |
| for (i = 0; s->x11_chanids[i] != -1; i++) { |
| debug("session_close_single_x11: session %d: " |
| "closing channel %d", s->self, s->x11_chanids[i]); |
| /* |
| * The channel "id" is already closing, but make sure we |
| * close all of its siblings. |
| */ |
| if (s->x11_chanids[i] != id) |
| session_close_x11(s->x11_chanids[i]); |
| } |
| free(s->x11_chanids); |
| s->x11_chanids = NULL; |
| free(s->display); |
| s->display = NULL; |
| free(s->auth_proto); |
| s->auth_proto = NULL; |
| free(s->auth_data); |
| s->auth_data = NULL; |
| free(s->auth_display); |
| s->auth_display = NULL; |
| } |
| |
| 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)? 1 : 0); |
| #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); |
| |
| /* |
| * Adjust cleanup callback attachment to send close messages when |
| * the channel gets EOF. The session will be then be closed |
| * by session_close_by_channel when the childs close their fds. |
| */ |
| channel_register_cleanup(c->self, session_close_by_channel, 1); |
| |
| /* |
| * 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); |
| } |
| |
| void |
| session_close(Session *s) |
| { |
| struct ssh *ssh = active_state; /* XXX */ |
| u_int i; |
| |
| verbose("Close session: user %s from %.200s port %d id %d", |
| s->pw->pw_name, |
| ssh_remote_ipaddr(ssh), |
| ssh_remote_port(ssh), |
| s->self); |
| |
| if (s->ttyfd != -1) |
| session_pty_cleanup(s); |
| free(s->term); |
| free(s->display); |
| free(s->x11_chanids); |
| free(s->auth_display); |
| free(s->auth_data); |
| free(s->auth_proto); |
| free(s->subsys); |
| if (s->env != NULL) { |
| for (i = 0; i < s->num_env; i++) { |
| free(s->env[i].name); |
| free(s->env[i].val); |
| } |
| free(s->env); |
| } |
| session_proctitle(s); |
| session_unused(s->self); |
| } |
| |
| 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); |
| if (s->ttyfd != -1) |
| session_pty_cleanup(s); |
| s->pid = 0; |
| } |
| |
| /* |
| * 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); |
| u_int i; |
| |
| 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) |
| session_pty_cleanup(s); |
| return; |
| } |
| /* detach by removing callback */ |
| channel_cancel_cleanup(s->chanid); |
| |
| /* Close any X11 listeners associated with this session */ |
| if (s->x11_chanids != NULL) { |
| for (i = 0; s->x11_chanids[i] != -1; i++) { |
| session_close_x11(s->x11_chanids[i]); |
| s->x11_chanids[i] = -1; |
| } |
| } |
| |
| s->chanid = -1; |
| session_close(s); |
| } |
| |
| void |
| session_destroy_all(void (*closefunc)(Session *)) |
| { |
| int i; |
| for (i = 0; i < sessions_nalloc; 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 < sessions_nalloc; 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[NI_MAXHOST]; |
| u_int i; |
| |
| 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 == NULL || |
| (stat(options.xauth_location, &st) == -1)) { |
| packet_send_debug("No xauth program; cannot forward with spoofing."); |
| 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, &s->x11_chanids) == -1) { |
| debug("x11_create_display_inet failed."); |
| return 0; |
| } |
| for (i = 0; s->x11_chanids[i] != -1; i++) { |
| channel_register_cleanup(s->x11_chanids[i], |
| session_close_single_x11, 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); |
| } |
| |
| void |
| do_cleanup(Authctxt *authctxt) |
| { |
| static int called = 0; |
| |
| debug("do_cleanup"); |
| |
| /* no cleanup if we're in the child for login shell */ |
| if (is_child) |
| return; |
| |
| /* avoid double cleanup */ |
| if (called) |
| return; |
| called = 1; |
| |
| if (authctxt == NULL) |
| return; |
| |
| #ifdef USE_PAM |
| if (options.use_pam) { |
| sshpam_cleanup(); |
| sshpam_thread_cleanup(); |
| } |
| #endif |
| |
| if (!authctxt->authenticated) |
| return; |
| |
| #ifdef KRB5 |
| if (options.kerberos_ticket_cleanup && |
| authctxt->krb5_ctx) |
| krb5_cleanup_proc(authctxt); |
| #endif |
| |
| #ifdef GSSAPI |
| if (options.gss_cleanup_creds) |
| ssh_gssapi_cleanup_creds(); |
| #endif |
| |
| /* remove agent socket */ |
| auth_sock_cleanup_proc(authctxt->pw); |
| |
| /* remove userauth info */ |
| if (auth_info_file != NULL) { |
| temporarily_use_uid(authctxt->pw); |
| unlink(auth_info_file); |
| restore_uid(); |
| free(auth_info_file); |
| auth_info_file = NULL; |
| } |
| |
| /* |
| * Cleanup ptys/utmp only if privsep is disabled, |
| * or if running in monitor. |
| */ |
| if (!use_privsep || mm_is_monitor()) |
| session_destroy_all(session_pty_cleanup2); |
| } |
| |
| /* Return a name for the remote host that fits inside utmp_size */ |
| |
| const char * |
| session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns) |
| { |
| const char *remote = ""; |
| |
| if (utmp_size > 0) |
| remote = auth_get_canonical_hostname(ssh, use_dns); |
| if (utmp_size == 0 || strlen(remote) > utmp_size) |
| remote = ssh_remote_ipaddr(ssh); |
| return remote; |
| } |
| |