]> andersk Git - openssh.git/blobdiff - session.c
- markus@cvs.openbsd.org 2001/10/09 21:59:41
[openssh.git] / session.c
index 187f38edd2690b78bc944fb15eea185b7cb419f7..0d6ebdaeafe91f248a6b5f6bcd3cdb8ba1ca1d9c 100644 (file)
--- a/session.c
+++ b/session.c
@@ -9,7 +9,7 @@
  * called by a name other than "ssh" or "Secure Shell".
  *
  * SSH2 support by Markus Friedl.
- * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ * 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
@@ -33,7 +33,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.91 2001/06/19 14:09:45 markus Exp $");
+RCSID("$OpenBSD: session.c,v 1.106 2001/10/09 21:59:41 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -99,7 +99,8 @@ typedef struct Session Session;
 struct Session {
        int     used;
        int     self;
-       struct  passwd *pw;
+       struct passwd *pw;
+       Authctxt *authctxt;
        pid_t   pid;
        /* tty */
        char    *term;
@@ -120,25 +121,26 @@ struct Session {
 /* func */
 
 Session *session_new(void);
-void   session_set_fds(Session *s, int fdin, int fdout, int fderr);
-void   session_pty_cleanup(void *session);
-int    session_pty_req(Session *s);
-void   session_proctitle(Session *s);
-int    session_setup_x11fwd(Session *s);
-void   session_close(Session *s);
-void   do_exec_pty(Session *s, const char *command);
-void   do_exec_no_pty(Session *s, const char *command);
-void   do_exec(Session *s, const char *command);
-void   do_login(Session *s, const char *command);
+void   session_set_fds(Session *, int, int, int);
+static void    session_pty_cleanup(void *);
+void   session_proctitle(Session *);
+int    session_setup_x11fwd(Session *);
+void   do_exec_pty(Session *, const char *);
+void   do_exec_no_pty(Session *, const char *);
+void   do_exec(Session *, const char *);
+void   do_login(Session *, const char *);
 #ifdef LOGIN_NEEDS_UTMPX
-void   do_pre_login(Session *s);
+static void    do_pre_login(Session *s);
 #endif
-void   do_child(Session *s, const char *command);
+void   do_child(Session *, const char *);
 void   do_motd(void);
-int    check_quietlogin(Session *s, const char *command);
+int    check_quietlogin(Session *, const char *);
 
-void   do_authenticated1(Authctxt *authctxt);
-void   do_authenticated2(Authctxt *authctxt);
+static void do_authenticated1(Authctxt *);
+static void do_authenticated2(Authctxt *);
+
+static void session_close(Session *);
+static int session_pty_req(Session *);
 
 /* import */
 extern ServerOptions options;
@@ -150,7 +152,7 @@ extern int startup_pipe;
 extern void destroy_sensitive_data(void);
 
 /* original command from peer. */
-char *original_command = NULL;
+const char *original_command = NULL;
 
 /* data */
 #define MAX_SESSIONS 10
@@ -201,6 +203,14 @@ do_authenticated(Authctxt *authctxt)
        /* remove agent socket */
        if (auth_get_socket_name())
                auth_sock_cleanup_proc(authctxt->pw);
+#ifdef KRB4
+       if (options.kerberos_ticket_cleanup)
+               krb4_cleanup_proc(authctxt);
+#endif
+#ifdef KRB5
+       if (options.kerberos_ticket_cleanup)
+               krb5_cleanup_proc(authctxt);
+#endif
 }
 
 /*
@@ -209,7 +219,7 @@ do_authenticated(Authctxt *authctxt)
  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
  * are requested, etc.
  */
-void
+static void
 do_authenticated1(Authctxt *authctxt)
 {
        Session *s;
@@ -219,6 +229,7 @@ do_authenticated1(Authctxt *authctxt)
        u_int proto_len, data_len, dlen;
 
        s = session_new();
+       s->authctxt = authctxt;
        s->pw = authctxt->pw;
 
        /*
@@ -303,18 +314,70 @@ do_authenticated1(Authctxt *authctxt)
                        if (packet_set_maxsize(packet_get_int()) > 0)
                                success = 1;
                        break;
+                       
+#if defined(AFS) || defined(KRB5)
+               case SSH_CMSG_HAVE_KERBEROS_TGT:
+                       if (!options.kerberos_tgt_passing) {
+                               verbose("Kerberos TGT passing disabled.");
+                       } else {
+                               char *kdata = packet_get_string(&dlen);
+                               packet_integrity_check(plen, 4 + dlen, type);
+                               
+                               /* XXX - 0x41, see creds_to_radix version */
+                               if (kdata[0] != 0x41) {
+#ifdef KRB5
+                                       krb5_data tgt;
+                                       tgt.data = kdata;
+                                       tgt.length = dlen;
+                                       
+                                       if (auth_krb5_tgt(s->authctxt, &tgt))
+                                               success = 1;
+                                       else
+                                               verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
+#endif /* KRB5 */
+                               } else {
+#ifdef AFS
+                                       if (auth_krb4_tgt(s->authctxt, kdata))
+                                               success = 1;
+                                       else
+                                               verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
+#endif /* AFS */
+                               }
+                               xfree(kdata);
+                       }
+                       break;
+#endif /* AFS || KRB5 */
+                       
+#ifdef AFS
+               case SSH_CMSG_HAVE_AFS_TOKEN:
+                       if (!options.afs_token_passing || !k_hasafs()) {
+                               verbose("AFS token passing disabled.");
+                       } else {
+                               /* Accept AFS token. */
+                               char *token = packet_get_string(&dlen);
+                               packet_integrity_check(plen, 4 + dlen, type);
+                               
+                               if (auth_afs_token(s->authctxt, token))
+                                       success = 1;
+                               else
+                                       verbose("AFS token refused for %.100s",
+                                           s->authctxt->user);
+                               xfree(token);
+                       }
+                       break;
+#endif /* AFS */
 
                case SSH_CMSG_EXEC_SHELL:
                case SSH_CMSG_EXEC_CMD:
                        if (type == SSH_CMSG_EXEC_CMD) {
                                command = packet_get_string(&dlen);
                                debug("Exec command '%.500s'", command);
-                               packet_integrity_check(plen, 4 + dlen, type);
+                               do_exec(s, command);
+                               xfree(command);
                        } else {
-                               command = NULL;
-                               packet_integrity_check(plen, 0, type);
+                               do_exec(s, NULL);
                        }
-                       do_exec(s, command);
+                       packet_done();
                        session_close(s);
                        return;
 
@@ -367,6 +430,7 @@ do_exec_no_pty(Session *s, const char *command)
        session_proctitle(s);
 
 #if defined(USE_PAM)
+       do_pam_session(s->pw->pw_name, NULL);
        do_pam_setcred(1);
 #endif /* USE_PAM */
 
@@ -487,26 +551,22 @@ do_exec_pty(Session *s, const char *command)
 
        /* Fork the child. */
        if ((pid = fork()) == 0) {
+
                /* Child.  Reinitialize the log because the pid has changed. */
                log_init(__progname, options.log_level, options.log_facility, log_stderr);
-
                /* Close the master side of the pseudo tty. */
                close(ptyfd);
 
                /* Make the pseudo tty our controlling tty. */
                pty_make_controlling_tty(&ttyfd, s->tty);
 
-               /* Redirect stdin from the pseudo tty. */
-               if (dup2(ttyfd, fileno(stdin)) < 0)
-                       error("dup2 stdin failed: %.100s", strerror(errno));
-
-               /* Redirect stdout to the pseudo tty. */
-               if (dup2(ttyfd, fileno(stdout)) < 0)
-                       error("dup2 stdin failed: %.100s", strerror(errno));
-
-               /* Redirect stderr to the pseudo tty. */
-               if (dup2(ttyfd, fileno(stderr)) < 0)
-                       error("dup2 stdin failed: %.100s", strerror(errno));
+               /* 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);
@@ -562,7 +622,7 @@ do_exec_pty(Session *s, const char *command)
 }
 
 #ifdef LOGIN_NEEDS_UTMPX
-void
+static void
 do_pre_login(Session *s)
 {
        socklen_t fromlen;
@@ -599,7 +659,6 @@ do_exec(Session *s, const char *command)
        if (forced_command) {
                original_command = command;
                command = forced_command;
-               forced_command = NULL;
                debug("Forced command '%.900s'", command);
        }
 
@@ -608,16 +667,9 @@ do_exec(Session *s, const char *command)
        else
                do_exec_no_pty(s, command);
 
-       if (command != NULL)
-               xfree(command);
-
-       if (original_command != NULL) {
-               xfree(original_command);
-               original_command = NULL;
-       }
+       original_command = NULL;
 }
 
-
 /* administrative, login(1)-like work */
 void
 do_login(Session *s, const char *command)
@@ -724,7 +776,7 @@ int
 check_quietlogin(Session *s, const char *command)
 {
        char buf[256];
-       struct passwd * pw = s->pw;
+       struct passwd *pw = s->pw;
        struct stat st;
 
        /* Return 1 if .hushlogin exists or a command given. */
@@ -745,7 +797,7 @@ 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.
  */
-void
+static void
 child_set_env(char ***envp, u_int *envsizep, const char *name,
              const char *value)
 {
@@ -786,7 +838,7 @@ child_set_env(char ***envp, u_int *envsizep, const char *name,
  * Otherwise, it must consist of empty lines, comments (line starts with '#')
  * and assignments of the form name=value.  No other forms are allowed.
  */
-void
+static void
 read_environment_file(char ***env, u_int *envsize,
                      const char *filename)
 {
@@ -825,7 +877,7 @@ read_environment_file(char ***env, u_int *envsize,
 /*
  * Sets any environment variables which have been specified by PAM
  */
-void do_pam_environment(char ***env, int *envsize)
+void do_pam_environment(char ***env, u_int *envsize)
 {
        char *equals, var_name[512], var_val[512];
        char **pam_env;
@@ -854,7 +906,7 @@ void do_pam_environment(char ***env, int *envsize)
 #endif /* USE_PAM */
 
 #ifdef HAVE_CYGWIN
-void copy_environment(char ***env, int *envsize)
+void copy_environment(char ***env, u_int *envsize)
 {
        char *equals, var_name[512], var_val[512];
        int i;
@@ -966,7 +1018,7 @@ void
 do_child(Session *s, const char *command)
 {
        const char *shell, *hostname = NULL, *cp = NULL;
-       struct passwd * pw = s->pw;
+       struct passwd *pw = s->pw;
        char buf[256];
        char cmd[1024];
        FILE *f = NULL;
@@ -997,7 +1049,7 @@ do_child(Session *s, const char *command)
        if (options.use_login && command != NULL)
                options.use_login = 0;
 
-#if !defined(USE_PAM) && !defined(HAVE_OSF_SIA)
+#if !defined(HAVE_OSF_SIA)
        if (!options.use_login) {
 # ifdef HAVE_LOGIN_CAP
                if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
@@ -1015,7 +1067,7 @@ do_child(Session *s, const char *command)
                        exit(254);
                }
        }
-#endif /* USE_PAM || HAVE_OSF_SIA */
+#endif /* HAVE_OSF_SIA */
 
        /* Set login name, uid, gid, and groups. */
        /* Login(1) does this as well, and it needs uid 0 for the "-h"
@@ -1141,18 +1193,6 @@ do_child(Session *s, const char *command)
        shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
 #endif
 
-#ifdef AFS
-       /* Try to get AFS tokens for the local cell. */
-       if (k_hasafs()) {
-               char cell[64];
-
-               if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
-                       krb_afslog(cell, 0);
-
-               krb_afslog(0, 0);
-       }
-#endif /* AFS */
-
        /* Initialize the environment. */
        envsize = 100;
        env = xmalloc(envsize * sizeof(char *));
@@ -1232,16 +1272,16 @@ do_child(Session *s, const char *command)
                child_set_env(&env, &envsize, "KRB5CCNAME", cp);
        read_environment_file(&env, &envsize, "/etc/environment");
 #endif
-
 #ifdef KRB4
-       {
-               extern char *ticket;
-
-               if (ticket)
-                       child_set_env(&env, &envsize, "KRBTKFILE", ticket);
-       }
-#endif /* KRB4 */
-
+       if (s->authctxt->krb4_ticket_file)
+               child_set_env(&env, &envsize, "KRBTKFILE",
+                   s->authctxt->krb4_ticket_file);
+#endif
+#ifdef KRB5
+       if (s->authctxt->krb5_ticket_file)
+               child_set_env(&env, &envsize, "KRB5CCNAME",
+                   s->authctxt->krb5_ticket_file);
+#endif
 #ifdef USE_PAM
        /* Pull in any environment variables that may have been set by PAM. */
        do_pam_environment(&env, &envsize);
@@ -1302,22 +1342,34 @@ do_child(Session *s, const char *command)
        for (i = 3; i < 64; i++)
                close(i);
 
+       /*
+        * Must take new environment into use so that .ssh/rc, /etc/sshrc and
+        * xauth are run in the proper environment.
+        */
+       environ = env;
+
+#ifdef AFS
+       /* Try to get AFS tokens for the local cell. */
+       if (k_hasafs()) {
+               char cell[64];
+               
+               if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
+                       krb_afslog(cell, 0);
+               
+               krb_afslog(0, 0);
+       }
+#endif /* AFS */
+
        /* Change current directory to the user\'s home directory. */
        if (chdir(pw->pw_dir) < 0) {
                fprintf(stderr, "Could not chdir to home directory %s: %s\n",
-                       pw->pw_dir, strerror(errno));
+                   pw->pw_dir, strerror(errno));
 #ifdef HAVE_LOGIN_CAP
                if (login_getcapbool(lc, "requirehome", 0))
                        exit(1);
 #endif
        }
 
-       /*
-        * Must take new environment into use so that .ssh/rc, /etc/sshrc and
-        * xauth are run in the proper environment.
-        */
-       environ = env;
-
        /*
         * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
         * in this order).
@@ -1406,25 +1458,6 @@ do_child(Session *s, const char *command)
                if (!options.use_login) {
                        char buf[256];
 
-                       /*
-                        * Check for mail if we have a tty and it was enabled
-                        * in server options.
-                        */
-                       if (s->ttyfd != -1 && options.check_mail) {
-                               char *mailbox;
-                               struct stat mailstat;
-
-                               mailbox = getenv("MAIL");
-                               if (mailbox != NULL) {
-                                       if (stat(mailbox, &mailstat) != 0 ||
-                                           mailstat.st_size == 0)
-                                               printf("No mail.\n");
-                                       else if (mailstat.st_mtime < mailstat.st_atime)
-                                               printf("You have mail.\n");
-                                       else
-                                               printf("You have new mail.\n");
-                               }
-                       }
                        /* Start the shell.  Set initial character to '-'. */
                        buf[0] = '-';
                        strncpy(buf + 1, cp, sizeof(buf) - 1);
@@ -1446,7 +1479,7 @@ do_child(Session *s, const char *command)
 #ifdef LOGIN_NEEDS_TERM
                             s->term? s->term : "unknown",
 #endif
-                            "-p", "-f", "--", pw->pw_name, NULL);
+                            "-p", "-f", "--", pw->pw_name, (char *)NULL);
 
                        /* Login couldn't be executed, die. */
 
@@ -1495,7 +1528,7 @@ session_new(void)
        return NULL;
 }
 
-void
+static void
 session_dump(void)
 {
        int i;
@@ -1511,7 +1544,7 @@ session_dump(void)
 }
 
 int
-session_open(int chanid)
+session_open(Authctxt *authctxt, int chanid)
 {
        Session *s = session_new();
        debug("session_open: channel %d", chanid);
@@ -1519,7 +1552,8 @@ session_open(int chanid)
                error("no more sessions");
                return 0;
        }
-       s->pw = auth_get_user();
+       s->authctxt = authctxt;
+       s->pw = authctxt->pw;
        if (s->pw == NULL)
                fatal("no user for session %d", s->self);
        debug("session_open: session %d: link with channel %d", s->self, chanid);
@@ -1527,7 +1561,7 @@ session_open(int chanid)
        return 1;
 }
 
-Session *
+static Session *
 session_by_channel(int id)
 {
        int i;
@@ -1543,7 +1577,7 @@ session_by_channel(int id)
        return NULL;
 }
 
-Session *
+static Session *
 session_by_pid(pid_t pid)
 {
        int i;
@@ -1558,7 +1592,7 @@ session_by_pid(pid_t pid)
        return NULL;
 }
 
-int
+static int
 session_window_change_req(Session *s)
 {
        s->col = packet_get_int();
@@ -1570,7 +1604,7 @@ session_window_change_req(Session *s)
        return 1;
 }
 
-int
+static int
 session_pty_req(Session *s)
 {
        u_int len;
@@ -1635,34 +1669,42 @@ session_pty_req(Session *s)
        return 1;
 }
 
-int
+static int
 session_subsystem_req(Session *s)
 {
+       struct stat st;
        u_int len;
        int success = 0;
-       char *subsys = packet_get_string(&len);
+       char *cmd, *subsys = packet_get_string(&len);
        int i;
 
        packet_done();
        log("subsystem request for %s", subsys);
 
        for (i = 0; i < options.num_subsystems; i++) {
-               if(strcmp(subsys, options.subsystem_name[i]) == 0) {
-                       debug("subsystem: exec() %s", options.subsystem_command[i]);
+               if (strcmp(subsys, options.subsystem_name[i]) == 0) {
+                       cmd = options.subsystem_command[i];
+                       if (stat(cmd, &st) < 0) {
+                               error("subsystem: cannot stat %s: %s", cmd,
+                                   strerror(errno));
+                               break;
+                       }
+                       debug("subsystem: exec() %s", cmd);
                        s->is_subsystem = 1;
-                       do_exec_no_pty(s, options.subsystem_command[i]);
+                       do_exec(s, cmd);
                        success = 1;
                }
        }
 
        if (!success)
-               log("subsystem request for %s failed, subsystem not found", subsys);
+               log("subsystem request for %s failed, subsystem not found",
+                   subsys);
 
        xfree(subsys);
        return success;
 }
 
-int
+static int
 session_x11_req(Session *s)
 {
        int success;
@@ -1683,7 +1725,7 @@ session_x11_req(Session *s)
        return success;
 }
 
-int
+static int
 session_shell_req(Session *s)
 {
        packet_done();
@@ -1691,17 +1733,18 @@ session_shell_req(Session *s)
        return 1;
 }
 
-int
+static int
 session_exec_req(Session *s)
 {
        u_int len;
        char *command = packet_get_string(&len);
        packet_done();
        do_exec(s, command);
+       xfree(command);
        return 1;
 }
 
-int
+static int
 session_auth_agent_req(Session *s)
 {
        static int called = 0;
@@ -1794,7 +1837,7 @@ session_set_fds(Session *s, int fdin, int fdout, int fderr)
  * Function to perform pty cleanup. Also called if we get aborted abnormally
  * (e.g., due to a dropped connection).
  */
-void
+static void
 session_pty_cleanup(void *session)
 {
        Session *s = session;
@@ -1824,7 +1867,7 @@ session_pty_cleanup(void *session)
                error("close(s->ptymaster): %s", strerror(errno));
 }
 
-void
+static void
 session_exit_message(Session *s, int status)
 {
        Channel *c;
@@ -1873,7 +1916,7 @@ session_exit_message(Session *s, int status)
        s->chanid = -1;
 }
 
-void
+static void
 session_close(Session *s)
 {
        debug("session_close: session %d pid %d", s->self, s->pid);
@@ -1923,18 +1966,32 @@ session_close_by_channel(int id, void *arg)
        s->chanid = -1;
 
        debug("session_close_by_channel: channel %d kill %d", id, s->pid);
-       if (s->pid == 0) {
-               /* close session immediately */
-               session_close(s);
-       } else {
-               /* notify child, delay session cleanup */
-               if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
+       if (s->pid != 0) {
+               /* notify child */
+               if (kill(s->pid, SIGHUP) < 0)
                        error("session_close_by_channel: kill %d: %s",
                            s->pid, strerror(errno));
        }
+       session_close(s);
+}
+
+void
+session_close_all(void)
+{
+       int i;
+       for(i = 0; i < MAX_SESSIONS; i++) {
+               Session *s = &sessions[i];
+               if (s->used) {
+                       if (s->chanid != -1) {
+                               channel_cancel_cleanup(s->chanid);
+                               s->chanid = -1;
+                       }
+                       session_close(s);
+               }
+       }
 }
 
-char *
+static char *
 session_tty_list(void)
 {
        static char buf[1024];
@@ -1997,8 +2054,8 @@ session_setup_x11fwd(Session *s)
        return 1;
 }
 
-void
+static void
 do_authenticated2(Authctxt *authctxt)
 {
-       server_loop2();
+       server_loop2(authctxt);
 }
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