X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/c5bf32e67c40b2b56bf2e237322c7843b5749108..HEAD:/session.c diff --git a/session.c b/session.c index 545e27fb..fd7acbe0 100644 --- a/session.c +++ b/session.c @@ -1,4 +1,4 @@ -/* $OpenBSD: session.c,v 1.227 2008/02/10 10:54:29 djm Exp $ */ +/* $OpenBSD: session.c,v 1.251 2010/01/12 08:33:17 dtucker Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -59,6 +59,7 @@ #include #include +#include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "ssh.h" #include "ssh1.h" @@ -94,19 +95,22 @@ #include #endif -/* Magic name for internal sftp-server */ -#define INTERNAL_SFTP_NAME "internal-sftp" +#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); +void session_set_fds(Session *, int, int, int, int); void session_pty_cleanup(Session *); 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 *); +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); @@ -134,12 +138,14 @@ extern Buffer loginmsg; const char *original_command = NULL; /* data */ -#define MAX_SESSIONS 20 -Session sessions[MAX_SESSIONS]; +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_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; @@ -169,7 +175,7 @@ static int auth_input_request_forwarding(struct passwd * pw) { Channel *nc; - int sock; + int sock = -1; struct sockaddr_un sunaddr; if (auth_sock_name != NULL) { @@ -181,51 +187,69 @@ auth_input_request_forwarding(struct passwd * pw) 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-XXXXXXXXXX", MAXPATHLEN); + 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(); - xfree(auth_sock_name); xfree(auth_sock_dir); - auth_sock_name = NULL; auth_sock_dir = NULL; - return 0; + goto authsock_err; } - snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", - auth_sock_dir, (long) getpid()); + + xasprintf(&auth_sock_name, "%s/agent.%ld", + auth_sock_dir, (long) getpid()); /* Create the socket. */ sock = socket(AF_UNIX, SOCK_STREAM, 0); - if (sock < 0) - packet_disconnect("socket: %.100s", strerror(errno)); + if (sock < 0) { + error("socket: %.100s", strerror(errno)); + restore_uid(); + goto authsock_err; + } /* 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)); + if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) { + error("bind: %.100s", strerror(errno)); + restore_uid(); + goto authsock_err; + } /* Restore the privileged uid. */ restore_uid(); /* Start listening on the socket. */ - if (listen(sock, SSH_LISTEN_BACKLOG) < 0) - packet_disconnect("listen: %.100s", strerror(errno)); + if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { + error("listen: %.100s", strerror(errno)); + 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); - strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); + nc->path = xstrdup(auth_sock_name); return 1; + + authsock_err: + if (auth_sock_name != NULL) + xfree(auth_sock_name); + if (auth_sock_dir != NULL) { + rmdir(auth_sock_dir); + xfree(auth_sock_dir); + } + if (sock != -1) + close(sock); + auth_sock_name = NULL; + auth_sock_dir = NULL; + return 0; } static void @@ -338,7 +362,8 @@ do_authenticated1(Authctxt *authctxt) break; case SSH_CMSG_AGENT_REQUEST_FORWARDING: - if (no_agent_forwarding_flag || compat13) { + if (!options.allow_agent_forwarding || + no_agent_forwarding_flag || compat13) { debug("Authentication agent forwarding not permitted for this authentication."); break; } @@ -374,10 +399,14 @@ do_authenticated1(Authctxt *authctxt) if (type == SSH_CMSG_EXEC_CMD) { command = packet_get_string(&dlen); debug("Exec command '%.500s'", command); - do_exec(s, command); + if (do_exec(s, command) != 0) + packet_disconnect( + "command execution failed"); xfree(command); } else { - do_exec(s, NULL); + if (do_exec(s, NULL) != 0) + packet_disconnect( + "shell execution failed"); } packet_check_eom(); session_close(s); @@ -402,46 +431,84 @@ do_authenticated1(Authctxt *authctxt) } } +#define USE_PIPES /* * 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 +int 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 */ + 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]; + /* 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 (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 + if (s == NULL) fatal("do_exec_no_pty: no session"); session_proctitle(s); -#if defined(USE_PAM) - if (options.use_pam && !use_privsep) - do_pam_setcred(1); -#endif /* USE_PAM */ - /* Fork the child. */ - if ((pid = fork()) == 0) { + 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; /* Child. Reinitialize the log since the pid has changed. */ - log_init(__progname, options.log_level, options.log_facility, log_stderr); + log_init(__progname, options.log_level, + options.log_facility, log_stderr); /* * Create a new session and process group since the 4.4BSD @@ -471,7 +538,7 @@ do_exec_no_pty(Session *s, const char *command) if (dup2(perr[1], 2) < 0) perror("dup2 stderr"); close(perr[1]); -#else /* USE_PIPES */ +#else /* * Redirect stdin, stdout, and stderr. Stdin and stdout will * use the same socket, as some programs (particularly rdist) @@ -481,11 +548,14 @@ do_exec_no_pty(Session *s, const char *command) 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. */ + 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"); -#endif /* USE_PIPES */ + close(err[0]); +#endif + #ifdef _UNICOS cray_init_job(s->pw); /* set up cray jid and tmpdir */ @@ -494,19 +564,28 @@ do_exec_no_pty(Session *s, const char *command) /* 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 - if (is_winnt) - cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); + 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); + + /* + * 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]); @@ -518,35 +597,32 @@ do_exec_no_pty(Session *s, const char *command) close(perr[0]); perr[0] = -1; } - session_set_fds(s, pin[1], pout[0], perr[0]); + session_set_fds(s, pin[1], pout[0], perr[0], 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 */ +#else /* We are the parent. Close the child sides of the socket pairs. */ close(inout[0]); close(err[0]); - /* - * 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); - /* * 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]); + session_set_fds(s, inout[1], inout[1], + s->is_subsystem ? -1 : err[1], 0); + if (s->is_subsystem) + close(err[1]); } else { server_loop(pid, inout[1], inout[1], err[1]); /* server_loop has closed inout[1] and err[1]. */ } -#endif /* USE_PIPES */ +#endif + return 0; } /* @@ -555,7 +631,7 @@ do_exec_no_pty(Session *s, const char *command) * setting up file descriptors, controlling tty, updating wtmp, utmp, * lastlog, and other such operations. */ -void +int do_exec_pty(Session *s, const char *command) { int fdout, ptyfd, ttyfd, ptymaster; @@ -566,20 +642,46 @@ do_exec_pty(Session *s, const char *command) ptyfd = s->ptyfd; ttyfd = s->ttyfd; -#if defined(USE_PAM) - if (options.use_pam) { - do_pam_set_tty(s->tty); - if (!use_privsep) - do_pam_setcred(1); + /* + * 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; } -#endif /* Fork the child. */ - if ((pid = fork()) == 0) { + 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); + /* Child. Reinitialize the log because the pid has changed. */ - log_init(__progname, options.log_level, options.log_facility, log_stderr); + log_init(__progname, options.log_level, + options.log_facility, log_stderr); /* Close the master side of the pseudo tty. */ close(ptyfd); @@ -610,48 +712,38 @@ do_exec_pty(Session *s, const char *command) do_pre_login(s); # endif #endif - - /* Do common processing for the child, such as execing the command. */ + /* + * 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 - if (is_winnt) - cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); + 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. */ + s->ptymaster = ptymaster; packet_set_interactive(1); if (compat20) { - session_set_fds(s, ptyfd, fdout, -1); + session_set_fds(s, ptyfd, fdout, -1, 1); } else { server_loop(pid, ptyfd, fdout, -1); /* server_loop _has_ closed ptyfd and fdout. */ } + return 0; } #ifdef LOGIN_NEEDS_UTMPX @@ -686,23 +778,27 @@ do_pre_login(Session *s) * This is called to fork and execute a command. If another command is * to be forced, execute that instead. */ -void +int do_exec(Session *s, const char *command) { + int ret; + if (options.adm_forced_command) { original_command = command; command = options.adm_forced_command; - if (strcmp(INTERNAL_SFTP_NAME, command) == 0) - s->is_subsystem = SUBSYSTEM_INT_SFTP; - else if (s->is_subsystem) + 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; debug("Forced command (config) '%.900s'", command); } else if (forced_command) { original_command = command; command = forced_command; - if (strcmp(INTERNAL_SFTP_NAME, command) == 0) - s->is_subsystem = SUBSYSTEM_INT_SFTP; - else if (s->is_subsystem) + 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; debug("Forced command (key option) '%.900s'", command); } @@ -719,9 +815,9 @@ do_exec(Session *s, const char *command) } #endif if (s->ttyfd != -1) - do_exec_pty(s, command); + ret = do_exec_pty(s, command); else - do_exec_no_pty(s, command); + ret = do_exec_no_pty(s, command); original_command = NULL; @@ -731,6 +827,8 @@ do_exec(Session *s, const char *command) * multiple copies of the login messages. */ buffer_clear(&loginmsg); + + return ret; } /* administrative, login(1)-like work */ @@ -750,7 +848,7 @@ do_login(Session *s, const char *command) fromlen = sizeof(from); if (packet_connection_is_on_socket()) { if (getpeername(packet_get_connection_in(), - (struct sockaddr *) & from, &fromlen) < 0) { + (struct sockaddr *)&from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); cleanup_exit(255); } @@ -835,7 +933,7 @@ check_quietlogin(Session *s, const char *command) /* * Sets the value of the given variable in the environment. If the variable - * already exists, its value is overriden. + * already exists, its value is overridden. */ void child_set_env(char ***envp, u_int *envsizep, const char *name, @@ -1019,7 +1117,7 @@ do_setup_env(Session *s, const char *shell) u_int i, envsize; char **env, *laddr; struct passwd *pw = s->pw; -#ifndef HAVE_LOGIN_CAP +#if !defined (HAVE_LOGIN_CAP) && !defined (HAVE_CYGWIN) char *path = NULL; #endif @@ -1218,8 +1316,9 @@ do_rc_files(Session *s, const char *shell) 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)) { + /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */ + if (!s->is_subsystem && options.adm_forced_command == NULL && + !no_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) @@ -1278,26 +1377,32 @@ static void do_nologin(struct passwd *pw) { FILE *f = NULL; - char buf[1024]; + char buf[1024], *nl, *def_nl = _PATH_NOLOGIN; + struct stat sb; #ifdef HAVE_LOGIN_CAP - if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) - f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, - _PATH_NOLOGIN), "r"); + if (login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) + return; + nl = login_getcapstr(lc, "nologin", def_nl, def_nl); #else - if (pw->pw_uid) - f = fopen(_PATH_NOLOGIN, "r"); + if (pw->pw_uid == 0) + return; + nl = def_nl; #endif - if (f) { - /* /etc/nologin exists. Print its contents and exit. */ - logit("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); + if (stat(nl, &sb) == -1) { + if (nl != def_nl) + xfree(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); } /* @@ -1361,29 +1466,21 @@ do_setusercontext(struct passwd *pw) { char *chroot_path, *tmp; +#ifdef WITH_SELINUX + /* Cache selinux status for later use */ + (void)ssh_selinux_enabled(); +#endif + #ifndef HAVE_CYGWIN if (getuid() == 0 || geteuid() == 0) #endif /* HAVE_CYGWIN */ { - -#ifdef HAVE_SETPCRED - if (setpcred(pw->pw_name, (char **)NULL) == -1) - fatal("Failed to set process credentials"); -#endif /* HAVE_SETPCRED */ #ifdef HAVE_LOGIN_CAP # ifdef __bsdi__ setpgid(0, 0); # endif -#ifdef GSSAPI - if (options.gss_authentication) { - temporarily_use_uid(pw); - ssh_gssapi_storecreds(); - restore_uid(); - } -#endif # ifdef USE_PAM if (options.use_pam) { - do_pam_session(); do_pam_setcred(use_privsep); } # endif /* USE_PAM */ @@ -1411,13 +1508,6 @@ do_setusercontext(struct passwd *pw) exit(1); } endgrent(); -# ifdef GSSAPI - if (options.gss_authentication) { - temporarily_use_uid(pw); - ssh_gssapi_storecreds(); - restore_uid(); - } -# endif # ifdef USE_PAM /* * PAM credentials may take the form of supplementary groups. @@ -1425,7 +1515,6 @@ do_setusercontext(struct passwd *pw) * Reestablish them here. */ if (options.use_pam) { - do_pam_session(); do_pam_setcred(use_privsep); } # endif /* USE_PAM */ @@ -1453,6 +1542,10 @@ do_setusercontext(struct passwd *pw) free(chroot_path); } +#ifdef HAVE_SETPCRED + if (setpcred(pw->pw_name, (char **)NULL) == -1) + fatal("Failed to set process credentials"); +#endif /* HAVE_SETPCRED */ #ifdef HAVE_LOGIN_CAP if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) { perror("unable to set user context (setuser)"); @@ -1464,9 +1557,6 @@ do_setusercontext(struct passwd *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); @@ -1566,6 +1656,7 @@ do_child(Session *s, const char *command) char *argv[ARGV_MAX]; const char *shell, *shell0, *hostname = NULL; struct passwd *pw = s->pw; + int r = 0; /* remove hostkey from the child's memory */ destroy_sensitive_data(); @@ -1681,36 +1772,51 @@ do_child(Session *s, const char *command) /* 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)); + /* Suppress missing homedir warning for chroot case */ #ifdef HAVE_LOGIN_CAP - if (login_getcapbool(lc, "requirehome", 0)) - exit(1); + r = login_getcapbool(lc, "requirehome", 0); #endif + if (r || options.chroot_directory == NULL) + fprintf(stderr, "Could not chdir to home " + "directory %s: %s\n", pw->pw_dir, + strerror(errno)); + if (r) + exit(1); } + closefrom(STDERR_FILENO + 1); + if (!options.use_login) do_rc_files(s, shell); /* restore SIGPIPE for child */ signal(SIGPIPE, SIG_DFL); - if (s->is_subsystem == SUBSYSTEM_INT_SFTP) { + 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@internal-sftp-server", s->pw->pw_name); - args = strdup(command ? command : "sftp-server"); + 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); + if (options.use_login) { launch_login(pw, hostname); /* NEVERREACHED */ @@ -1762,43 +1868,79 @@ do_child(Session *s, const char *command) 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); + } + bzero(&sessions[id], 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) { - 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; + 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 = xrealloc(sessions, sessions_nalloc + 1, + sizeof(*sessions)); + if (tmp == NULL) { + error("%s: cannot allocate %d sessions", + __func__, sessions_nalloc + 1); + return NULL; } - did_init = 1; + sessions = tmp; + session_unused(sessions_nalloc++); } - 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; - s->x11_chanids = NULL; - debug("session_new: session %d", i); - return s; - } + + 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); } - return NULL; + + 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 < MAX_SESSIONS; i++) { + for (i = 0; i < sessions_nalloc; i++) { Session *s = &sessions[i]; - debug("dump: used %d session %d %p channel %d pid %ld", + + debug("dump: used %d next_unused %d session %d %p " + "channel %d pid %ld", s->used, + s->next_unused, s->self, s, s->chanid, @@ -1828,7 +1970,7 @@ Session * session_by_tty(char *tty) { int i; - for (i = 0; i < MAX_SESSIONS; 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); @@ -1844,10 +1986,11 @@ static Session * session_by_channel(int id) { int i; - for (i = 0; i < MAX_SESSIONS; 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); + debug("session_by_channel: session %d channel %d", + i, id); return s; } } @@ -1861,7 +2004,7 @@ session_by_x11_channel(int id) { int i, j; - for (i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < sessions_nalloc; i++) { Session *s = &sessions[i]; if (s->x11_chanids == NULL || !s->used) @@ -1884,7 +2027,7 @@ session_by_pid(pid_t pid) { int i; debug("session_by_pid: pid %ld", (long)pid); - for (i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < sessions_nalloc; i++) { Session *s = &sessions[i]; if (s->used && s->pid == pid) return s; @@ -1940,7 +2083,8 @@ session_pty_req(Session *s) /* Allocate a pty and open it. */ debug("Allocating pty."); - if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { + if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, + sizeof(s->tty)))) { if (s->term) xfree(s->term); s->term = NULL; @@ -1983,18 +2127,17 @@ session_subsystem_req(Session *s) if (strcmp(subsys, options.subsystem_name[i]) == 0) { prog = options.subsystem_command[i]; cmd = options.subsystem_args[i]; - if (!strcmp(INTERNAL_SFTP_NAME, prog)) { + if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) { s->is_subsystem = SUBSYSTEM_INT_SFTP; - } else if (stat(prog, &st) < 0) { - error("subsystem: cannot stat %s: %s", prog, - strerror(errno)); - break; + 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); } - debug("subsystem: exec() %s", cmd); - do_exec(s, cmd); - success = 1; + success = do_exec(s, cmd) == 0; break; } } @@ -2037,19 +2180,19 @@ static int session_shell_req(Session *s) { packet_check_eom(); - do_exec(s, NULL); - return 1; + return do_exec(s, NULL) == 0; } static int session_exec_req(Session *s) { - u_int len; + u_int len, success; + char *command = packet_get_string(&len); packet_check_eom(); - do_exec(s, command); + success = do_exec(s, command) == 0; xfree(command); - return 1; + return success; } static int @@ -2059,8 +2202,7 @@ session_break_req(Session *s) packet_get_int(); /* ignored */ packet_check_eom(); - if (s->ttyfd == -1 || - tcsendbreak(s->ttyfd, 0) < 0) + if (s->ttyfd == -1 || tcsendbreak(s->ttyfd, 0) < 0) return 0; return 1; } @@ -2105,7 +2247,7 @@ session_auth_agent_req(Session *s) { static int called = 0; packet_check_eom(); - if (no_agent_forwarding_flag) { + if (no_agent_forwarding_flag || !options.allow_agent_forwarding) { debug("session_auth_agent_req: no_agent_forwarding_flag"); return 0; } @@ -2161,7 +2303,7 @@ session_input_channel_req(Channel *c, const char *rtype) } void -session_set_fds(Session *s, int fdin, int fdout, int fderr) +session_set_fds(Session *s, int fdin, int fdout, int fderr, int is_tty) { if (!compat20) fatal("session_set_fds: called for proto != 2.0"); @@ -2174,8 +2316,7 @@ session_set_fds(Session *s, int fdin, int fdout, int fderr) channel_set_fds(s->chanid, fdout, fdin, fderr, fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, - 1, - CHAN_SES_WINDOW_DEFAULT); + 1, is_tty, CHAN_SES_WINDOW_DEFAULT); } /* @@ -2207,8 +2348,9 @@ session_pty_cleanup2(Session *s) * 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)); + 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; @@ -2316,7 +2458,7 @@ session_exit_message(Session *s, int status) channel_request_start(s->chanid, "exit-signal", 0); packet_put_cstring(sig2name(WTERMSIG(status))); #ifdef WCOREDUMP - packet_put_char(WCOREDUMP(status)); + packet_put_char(WCOREDUMP(status)? 1 : 0); #else /* WCOREDUMP */ packet_put_char(0); #endif /* WCOREDUMP */ @@ -2368,7 +2510,6 @@ session_close(Session *s) xfree(s->auth_data); if (s->auth_proto) xfree(s->auth_proto); - s->used = 0; if (s->env != NULL) { for (i = 0; i < s->num_env; i++) { xfree(s->env[i].name); @@ -2377,6 +2518,7 @@ session_close(Session *s) xfree(s->env); } session_proctitle(s); + session_unused(s->self); } void @@ -2440,7 +2582,7 @@ void session_destroy_all(void (*closefunc)(Session *)) { int i; - for (i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < sessions_nalloc; i++) { Session *s = &sessions[i]; if (s->used) { if (closefunc != NULL) @@ -2459,7 +2601,7 @@ session_tty_list(void) char *cp; buf[0] = '\0'; - for (i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < sessions_nalloc; i++) { Session *s = &sessions[i]; if (s->used && s->ttyfd != -1) {