* Copyright (c) 1989 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 2000, Marek Michałkiewicz
* Copyright (c) 2000 - 2006, Tomasz Kłoczko
- * Copyright (c) 2007 - 2008, Nicolas François
+ * Copyright (c) 2007 - 2011, Nicolas François
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
#include <signal.h>
#include <stdio.h>
#include <sys/types.h>
+#include <unistd.h>
+#ifndef USE_PAM
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#endif /* !USE_PAM */
#include "prototypes.h"
#include "defines.h"
-#include "exitcodes.h"
#include "pwauth.h"
#include "getdef.h"
#ifdef USE_PAM
#include "pam_defs.h"
-#endif
-/*
- * Assorted #defines to control su's behavior
- */
+#endif /* USE_PAM */
+/*@-exitarg@*/
+#include "exitcodes.h"
+
/*
* Global variables
*/
+const char *Prog;
+static /*@observer@*/const char *caller_tty = NULL; /* Name of tty SU is run from */
+static bool caller_is_root = false;
+static uid_t caller_uid;
+#ifndef USE_PAM
+static bool caller_on_console = false;
+#ifdef SU_ACCESS
+static /*@only@*/char *caller_pass;
+#endif
+#endif /* !USE_PAM */
+static bool doshell = false;
+static bool fakelogin = false;
+static /*@observer@*/const char *shellstr;
+static /*@null@*/char *command = NULL;
+
+
/* not needed by sulog.c anymore */
static char name[BUFSIZ];
-static char oldname[BUFSIZ];
+static char caller_name[BUFSIZ];
/* If nonzero, change some environment vars to indicate the user su'd to. */
-static int change_environment;
+static bool change_environment = true;
#ifdef USE_PAM
static pam_handle_t *pamh = NULL;
static int caught = 0;
+/* PID of the child, in case it needs to be killed */
+static pid_t pid_child = 0;
#endif
-static char *Prog;
-extern struct passwd pwent;
-
/*
* External identifiers
*/
-extern char **newenvp;
-extern char **environ;
-extern size_t newenvc;
+extern char **newenvp; /* libmisc/env.c */
+extern size_t newenvc; /* libmisc/env.c */
/* local function prototypes */
-#ifndef USE_PAM
-
+static void execve_shell (const char *shellname,
+ char *args[],
+ char *const envp[]);
+#ifdef USE_PAM
+static RETSIGTYPE kill_child (int unused(s));
+static void prepare_pam_close_session (void);
+#else /* !USE_PAM */
static RETSIGTYPE die (int);
-static int iswheel (const char *);
+static bool iswheel (const char *);
+#endif /* !USE_PAM */
+static bool restricted_shell (const char *shellname);
+static /*@noreturn@*/void su_failure (const char *tty, bool su_to_root);
+static /*@only@*/struct passwd * check_perms (void);
+#ifdef USE_PAM
+static void check_perms_pam (const struct passwd *pw);
+#else /* !USE_PAM */
+static void check_perms_nopam (const struct passwd *pw);
+#endif /* !USE_PAM */
+static void save_caller_context (char **argv);
+static void process_flags (int argc, char **argv);
+static void set_environment (struct passwd *pw);
+#ifndef USE_PAM
/*
* die - set or reset termio modes.
*
{
static TERMIO sgtty;
- if (killed)
+ if (killed != 0) {
STTY (0, &sgtty);
- else
+ } else {
GTTY (0, &sgtty);
+ }
- if (killed) {
+ if (killed != 0) {
closelog ();
- exit (killed);
+ exit (128+killed);
}
}
-static int iswheel (const char *username)
+static bool iswheel (const char *username)
{
struct group *grp;
grp = getgrnam ("wheel"); /* !USE_PAM, no need for xgetgrnam */
- if (!grp || !grp->gr_mem)
- return 0;
+ if ( (NULL ==grp)
+ || (NULL == grp->gr_mem)) {
+ return false;
+ }
return is_on_list (grp->gr_mem, username);
}
-#endif /* !USE_PAM */
+#else /* USE_PAM */
+static RETSIGTYPE kill_child (int unused(s))
+{
+ if (0 != pid_child) {
+ (void) kill (pid_child, SIGKILL);
+ (void) fputs (_(" ...killed.\n"), stderr);
+ } else {
+ (void) fputs (_(" ...waiting for child to terminate.\n"),
+ stderr);
+ }
+ exit (255);
+}
+#endif /* USE_PAM */
/* borrowed from GNU sh-utils' "su.c" */
-static int restricted_shell (const char *shellstr)
+static bool restricted_shell (const char *shellname)
{
- char *line;
+ /*@observer@*/const char *line;
setusershell ();
while ((line = getusershell ()) != NULL) {
- if (*line != '#' && strcmp (line, shellstr) == 0) {
+ if (('#' != *line) && (strcmp (line, shellname) == 0)) {
endusershell ();
- return 0;
+ return false;
}
}
endusershell ();
- return 1;
+ return true;
}
-static void su_failure (const char *tty)
+static /*@noreturn@*/void su_failure (const char *tty, bool su_to_root)
{
- sulog (tty, 0, oldname, name); /* log failed attempt */
+ sulog (tty, false, caller_name, name); /* log failed attempt */
#ifdef USE_SYSLOG
- if (getdef_bool ("SYSLOG_SU_ENAB"))
- SYSLOG ((pwent.pw_uid ? LOG_INFO : LOG_NOTICE,
- "- %s %s:%s", tty,
- oldname[0] ? oldname : "???", name[0] ? name : "???"));
+ if (getdef_bool ("SYSLOG_SU_ENAB")) {
+ SYSLOG ((su_to_root ? LOG_NOTICE : LOG_INFO,
+ "- %s %s:%s", tty,
+ ('\0' != caller_name[0]) ? caller_name : "???",
+ ('\0' != name[0]) ? name : "???"));
+ }
closelog ();
#endif
exit (1);
}
+/*
+ * execve_shell - Execute a shell with execve, or interpret it with
+ * /bin/sh
+ */
+static void execve_shell (const char *shellname,
+ char *args[],
+ char *const envp[])
+{
+ int err;
+ (void) execve (shellname, (char **) args, envp);
+ err = errno;
+
+ if (access (shellname, R_OK|X_OK) == 0) {
+ /*
+ * Assume this is a shell script (with no shebang).
+ * Interpret it with /bin/sh
+ */
+ size_t n_args = 0;
+ char **targs;
+ while (NULL != args[n_args]) {
+ n_args++;
+ }
+ targs = (char **) xmalloc ((n_args + 3) * sizeof (args[0]));
+ targs[0] = "sh";
+ targs[1] = "-";
+ targs[2] = xstrdup (shellname);
+ targs[n_args+2] = NULL;
+ while (1 != n_args) {
+ targs[n_args+1] = args[n_args - 1];
+ n_args--;
+ }
+
+ (void) execve (SHELL, targs, envp);
+ } else {
+ errno = err;
+ }
+}
#ifdef USE_PAM
/* Signal handler for parent process later */
-static void catch_signals (unused int sig)
+static void catch_signals (int sig)
{
- ++caught;
+ caught = sig;
}
-/* This I ripped out of su.c from sh-utils after the Mandrake pam patch
- * have been applied. Some work was needed to get it integrated into
- * su.c from shadow.
+/*
+ * prepare_pam_close_session - Fork and wait for the child to close the session
+ *
+ * Only the child returns. The parent will wait for the child to
+ * terminate and exit.
*/
-static void run_shell (const char *shellstr, char *args[], int doshell,
- char *const envp[])
+static void prepare_pam_close_session (void)
{
- int child;
sigset_t ourset;
int status;
int ret;
- child = fork ();
- if (child == 0) { /* child shell */
- /*
- * PAM_DATA_SILENT is not supported by some modules, and
- * there is no strong need to clean up the process space's
- * memory since we will either call exec or exit.
- pam_end (pamh, PAM_SUCCESS | PAM_DATA_SILENT);
- */
-
- if (doshell)
- (void) shell (shellstr, (char *) args[0], envp);
- else
- (void) execve (shellstr, (char **) args, envp);
- exit (errno == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
- } else if (child == -1) {
- (void) fprintf (stderr, "%s: Cannot fork user shell\n", Prog);
+ pid_child = fork ();
+ if (pid_child == 0) { /* child shell */
+ return; /* Only the child will return from pam_create_session */
+ } else if ((pid_t)-1 == pid_child) {
+ (void) fprintf (stderr,
+ _("%s: Cannot fork user shell\n"),
+ Prog);
SYSLOG ((LOG_WARN, "Cannot execute %s", shellstr));
closelog ();
exit (1);
+ /* Only the child returns. See above. */
}
+
/* parent only */
sigfillset (&ourset);
- if (sigprocmask (SIG_BLOCK, &ourset, NULL)) {
- (void) fprintf (stderr, "%s: signal malfunction\n", Prog);
- caught = 1;
+ if (sigprocmask (SIG_BLOCK, &ourset, NULL) != 0) {
+ (void) fprintf (stderr,
+ _("%s: signal malfunction\n"),
+ Prog);
+ caught = SIGTERM;
}
- if (!caught) {
+ if (0 == caught) {
struct sigaction action;
action.sa_handler = catch_signals;
action.sa_flags = 0;
sigemptyset (&ourset);
- if (sigaddset (&ourset, SIGTERM)
- || sigaddset (&ourset, SIGALRM)
- || sigaction (SIGTERM, &action, NULL)
- || sigprocmask (SIG_UNBLOCK, &ourset, NULL)
+ if ( (sigaddset (&ourset, SIGTERM) != 0)
+ || (sigaddset (&ourset, SIGALRM) != 0)
+ || (sigaction (SIGTERM, &action, NULL) != 0)
+ || ( !doshell /* handle SIGINT (Ctrl-C), SIGQUIT
+ * (Ctrl-\), and SIGTSTP (Ctrl-Z)
+ * since the child will not control
+ * the tty.
+ */
+ && ( (sigaddset (&ourset, SIGINT) != 0)
+ || (sigaddset (&ourset, SIGQUIT) != 0)
+ || (sigaddset (&ourset, SIGTSTP) != 0)
+ || (sigaction (SIGINT, &action, NULL) != 0)
+ || (sigaction (SIGQUIT, &action, NULL) != 0)
+ || (sigaction (SIGTSTP, &action, NULL) != 0)))
+ || (sigprocmask (SIG_UNBLOCK, &ourset, NULL) != 0)
) {
fprintf (stderr,
- "%s: signal masking malfunction\n", Prog);
- caught = 1;
+ _("%s: signal masking malfunction\n"),
+ Prog);
+ caught = SIGTERM;
}
}
- if (!caught) {
+ if (0 == caught) {
+ bool stop = true;
+
do {
- int pid;
+ pid_t pid;
+ stop = true;
pid = waitpid (-1, &status, WUNTRACED);
- if ((pid != -1) && WIFSTOPPED (status)) {
+ /* When interrupted by signal, the signal will be
+ * forwarded to the child, and termination will be
+ * forced later.
+ */
+ if ( ((pid_t)-1 == pid)
+ && (EINTR == errno)
+ && (SIGTSTP == caught)) {
+ /* Except for SIGTSTP, which request to
+ * stop the child.
+ * We will SIGSTOP ourself on the next
+ * waitpid round.
+ */
+ kill (pid_child, SIGSTOP);
+ stop = false;
+ } else if ( ((pid_t)-1 != pid)
+ && (0 != WIFSTOPPED (status))) {
/* The child (shell) was suspended.
* Suspend su. */
- kill (getpid (), WSTOPSIG(status));
+ kill (getpid (), SIGSTOP);
/* wake child when resumed */
kill (pid, SIGCONT);
+ stop = false;
}
- } while (WIFSTOPPED (status));
+ } while (!stop);
}
- if (caught) {
- fprintf (stderr, "\nSession terminated, killing shell...");
- kill (child, SIGTERM);
+ if (0 != caught) {
+ (void) fputs ("\n", stderr);
+ (void) fputs (_("Session terminated, terminating shell..."),
+ stderr);
+ (void) kill (pid_child, caught);
}
ret = pam_close_session (pamh, 0);
- if (ret != PAM_SUCCESS) {
+ if (PAM_SUCCESS != ret) {
SYSLOG ((LOG_ERR, "pam_close_session: %s",
- pam_strerror (pamh, ret)));
+ pam_strerror (pamh, ret)));
fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
- pam_end (pamh, ret);
- exit (1);
}
- ret = pam_end (pamh, PAM_SUCCESS);
+ (void) pam_setcred (pamh, PAM_DELETE_CRED);
+ (void) pam_end (pamh, PAM_SUCCESS);
+
+ if (0 != caught) {
+ (void) signal (SIGALRM, kill_child);
+ (void) alarm (2);
- if (caught) {
- sleep (2);
- kill (child, SIGKILL);
- fprintf (stderr, " ...killed.\n");
- exit (-1);
+ (void) wait (&status);
+ (void) fputs (_(" ...terminated.\n"), stderr);
}
- exit (WIFEXITED (status)
- ? WEXITSTATUS (status)
- : WTERMSIG (status) + 128);
+ exit ((0 != WIFEXITED (status)) ? WEXITSTATUS (status)
+ : WTERMSIG (status) + 128);
+ /* Only the child returns. See above. */
}
-#endif
+#endif /* USE_PAM */
/*
* usage - print command line syntax and exit
- */
-static void usage (void)
+ */
+static void usage (int status)
{
+ (void)
fputs (_("Usage: su [options] [LOGIN]\n"
"\n"
"Options:\n"
" --preserve-environment do not reset environment variables, and\n"
" keep the same shell\n"
" -s, --shell SHELL use SHELL instead of the default in passwd\n"
- "\n"), stderr);
- exit (E_USAGE);
+ "\n"), (E_SUCCESS != status) ? stderr : stdout);
+ exit (status);
}
-/*
- * su - switch user id
- *
- * su changes the user's ids to the values for the specified user. if
- * no new user name is specified, "root" is used by default.
- *
- * Any additional arguments are passed to the user's shell. In
- * particular, the argument "-c" will cause the next argument to be
- * interpreted as a command by the common shell programs.
- */
-int main (int argc, char **argv)
-{
- char *cp;
- const char *tty = 0; /* Name of tty SU is run from */
- int doshell = 0;
- int fakelogin = 0;
- int amroot = 0;
- uid_t my_uid;
- struct passwd *pw = 0;
- char **envp = environ;
- char *shellstr = 0, *command = 0;
-
#ifdef USE_PAM
- char **envcp;
+static void check_perms_pam (const struct passwd *pw)
+{
int ret;
-#else /* !USE_PAM */
- int err = 0;
+ ret = pam_authenticate (pamh, 0);
+ if (PAM_SUCCESS != ret) {
+ SYSLOG ((LOG_ERR, "pam_authenticate: %s",
+ pam_strerror (pamh, ret)));
+ fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
+ (void) pam_end (pamh, ret);
+ su_failure (caller_tty, 0 == pw->pw_uid);
+ }
+ ret = pam_acct_mgmt (pamh, 0);
+ if (PAM_SUCCESS != ret) {
+ if (caller_is_root) {
+ fprintf (stderr,
+ _("%s: %s\n(Ignored)\n"),
+ Prog, pam_strerror (pamh, ret));
+ } else if (PAM_NEW_AUTHTOK_REQD == ret) {
+ ret = pam_chauthtok (pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
+ if (PAM_SUCCESS != ret) {
+ SYSLOG ((LOG_ERR, "pam_chauthtok: %s",
+ pam_strerror (pamh, ret)));
+ fprintf (stderr,
+ _("%s: %s\n"),
+ Prog, pam_strerror (pamh, ret));
+ (void) pam_end (pamh, ret);
+ su_failure (caller_tty, 0 == pw->pw_uid);
+ }
+ } else {
+ SYSLOG ((LOG_ERR, "pam_acct_mgmt: %s",
+ pam_strerror (pamh, ret)));
+ fprintf (stderr,
+ _("%s: %s\n"),
+ Prog, pam_strerror (pamh, ret));
+ (void) pam_end (pamh, ret);
+ su_failure (caller_tty, 0 == pw->pw_uid);
+ }
+ }
+}
+#else /* !USE_PAM */
+static void check_perms_nopam (const struct passwd *pw)
+{
+ /*@observer@*/const struct spwd *spwd = NULL;
+ /*@observer@*/const char *password = pw->pw_passwd;
RETSIGTYPE (*oldsig) (int);
- int is_console = 0;
- struct spwd *spwd = 0;
+ if (caller_is_root) {
+ return;
+ }
-#ifdef SU_ACCESS
- char *oldpass;
-#endif
-#endif /* !USE_PAM */
+ /*
+ * BSD systems only allow "wheel" to SU to root. USG systems don't,
+ * so we make this a configurable option.
+ */
- sanitize_env ();
+ /* The original Shadow 3.3.2 did this differently. Do it like BSD:
+ *
+ * - check for UID 0 instead of name "root" - there are systems with
+ * several root accounts under different names,
+ *
+ * - check the contents of /etc/group instead of the current group
+ * set (you must be listed as a member, GID 0 is not sufficient).
+ *
+ * In addition to this traditional feature, we now have complete su
+ * access control (allow, deny, no password, own password). Thanks
+ * to Chris Evans <lady0110@sable.ox.ac.uk>.
+ */
- (void) setlocale (LC_ALL, "");
- (void) bindtextdomain (PACKAGE, LOCALEDIR);
- (void) textdomain (PACKAGE);
+ if ( (0 == pw->pw_uid)
+ && getdef_bool ("SU_WHEEL_ONLY")
+ && !iswheel (caller_name)) {
+ fprintf (stderr,
+ _("You are not authorized to su %s\n"),
+ name);
+ exit (1);
+ }
+ spwd = getspnam (name); /* !USE_PAM, no need for xgetspnam */
+#ifdef SU_ACCESS
+ if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
+ if (NULL != spwd) {
+ password = spwd->sp_pwdp;
+ }
+ }
- change_environment = 1;
+ switch (check_su_auth (caller_name, name, 0 == pw->pw_uid)) {
+ case 0: /* normal su, require target user's password */
+ break;
+ case 1: /* require no password */
+ password = ""; /* XXX warning: const */
+ break;
+ case 2: /* require own password */
+ (void) puts (_("(Enter your own password)"));
+ password = caller_pass;
+ break;
+ default: /* access denied (-1) or unexpected value */
+ fprintf (stderr,
+ _("You are not authorized to su %s\n"),
+ name);
+ exit (1);
+ }
+#endif /* SU_ACCESS */
+ /*
+ * Set up a signal handler in case the user types QUIT.
+ */
+ die (0);
+ oldsig = signal (SIGQUIT, die);
/*
- * Get the program name. The program name is used as a prefix to
- * most error messages.
+ * See if the system defined authentication method is being used.
+ * The first character of an administrator defined method is an '@'
+ * character.
*/
- Prog = Basename (argv[0]);
+ if (pw_auth (password, name, PW_SU, (char *) 0) != 0) {
+ SYSLOG (((pw->pw_uid != 0)? LOG_NOTICE : LOG_WARN,
+ "Authentication failed for %s", name));
+ fprintf(stderr, _("%s: Authentication failure\n"), Prog);
+ su_failure (caller_tty, 0 == pw->pw_uid);
+ }
+ (void) signal (SIGQUIT, oldsig);
- OPENLOG ("su");
+ /*
+ * Check to see if the account is expired. root gets to ignore any
+ * expired accounts, but normal users can't become a user with an
+ * expired password.
+ */
+ if (NULL != spwd) {
+ (void) expire (pw, spwd);
+ }
/*
- * Process the command line arguments.
+ * Check to see if the account permits "su". root gets to ignore any
+ * restricted accounts, but normal users can't become a user if
+ * there is a "SU" entry in the /etc/porttime file denying access to
+ * the account.
*/
+ if (!isttytime (name, "SU", time ((time_t *) 0))) {
+ SYSLOG (((0 != pw->pw_uid) ? LOG_WARN : LOG_CRIT,
+ "SU by %s to restricted account %s",
+ caller_name, name));
+ fprintf (stderr,
+ _("%s: You are not authorized to su at that time\n"),
+ Prog);
+ su_failure (caller_tty, 0 == pw->pw_uid);
+ }
+}
+#endif /* !USE_PAM */
- {
- /*
- * Parse the command line options.
- */
- int option_index = 0;
- int c;
- static struct option long_options[] = {
- {"command", required_argument, NULL, 'c'},
- {"help", no_argument, NULL, 'h'},
- {"login", no_argument, NULL, 'l'},
- {"preserve-environment", no_argument, NULL, 'p'},
- {"shell", required_argument, NULL, 's'},
- {NULL, 0, NULL, '\0'}
- };
-
- while ((c =
- getopt_long (argc, argv, "c:hlmps:", long_options,
- &option_index)) != -1) {
- switch (c) {
- case 'c':
- command = optarg;
- break;
- case 'h':
- usage ();
- break;
- case 'l':
- fakelogin = 1;
- break;
- case 'm':
- case 'p':
- /* This will only have an effect if the target
- * user do not have a restricted shell, or if
- * su is called by root.
- */
- change_environment = 0;
- break;
- case 's':
- shellstr = optarg;
- break;
- default:
- usage (); /* NOT REACHED */
- }
- }
+/*
+ * check_perms - check permissions to switch to the user 'name'
+ *
+ * In case of subsystem login, the user is first authenticated in the
+ * caller's root subsystem, and then in the user's target subsystem.
+ */
+static /*@only@*/struct passwd * check_perms (void)
+{
+#ifdef USE_PAM
+ const char *tmp_name;
+ int ret;
+#endif /* !USE_PAM */
+ /*
+ * The password file entries for the user is gotten and the account
+ * validated.
+ */
+ struct passwd *pw = xgetpwnam (name);
+ if (NULL == pw) {
+ (void) fprintf (stderr,
+ _("No passwd entry for user '%s'\n"), name);
+ SYSLOG ((LOG_ERR, "No passwd entry for user '%s'", name));
+ su_failure (caller_tty, true);
+ }
- if (optind < argc && !strcmp (argv[optind], "-")) {
- fakelogin = 1;
- optind++;
- if (optind < argc && !strcmp (argv[optind], "--"))
- optind++;
+ (void) signal (SIGINT, SIG_IGN);
+ (void) signal (SIGQUIT, SIG_IGN);
+
+#ifdef USE_PAM
+ check_perms_pam (pw);
+ /* PAM authentication can request a change of account */
+ ret = pam_get_item(pamh, PAM_USER, (const void **) &tmp_name);
+ if (ret != PAM_SUCCESS) {
+ SYSLOG((LOG_ERR, "pam_get_item: internal PAM error\n"));
+ (void) fprintf (stderr,
+ "%s: Internal PAM error retrieving username\n",
+ Prog);
+ (void) pam_end (pamh, ret);
+ su_failure (caller_tty, 0 == pw->pw_uid);
+ }
+ if (strcmp (name, tmp_name) != 0) {
+ SYSLOG ((LOG_INFO,
+ "Change user from '%s' to '%s' as requested by PAM",
+ name, tmp_name));
+ strncpy (name, tmp_name, sizeof(name) - 1);
+ name[sizeof(name) - 1] = '\0';
+ pw = xgetpwnam (name);
+ if (NULL == pw) {
+ (void) fprintf (stderr,
+ _("No passwd entry for user '%s'\n"),
+ name);
+ SYSLOG ((LOG_ERR,
+ "No passwd entry for user '%s'", name));
+ su_failure (caller_tty, true);
}
}
+#else /* !USE_PAM */
+ check_perms_nopam (pw);
+#endif /* !USE_PAM */
- initenv ();
+ (void) signal (SIGINT, SIG_DFL);
+ (void) signal (SIGQUIT, SIG_DFL);
- my_uid = getuid ();
- amroot = (my_uid == 0);
+ /*
+ * Even if --shell is specified, the subsystem login test is based on
+ * the shell specified in /etc/passwd (not the one specified with
+ * --shell, which will be the one executed in the chroot later).
+ */
+ if ('*' == pw->pw_shell[0]) { /* subsystem root required */
+ subsystem (pw); /* change to the subsystem root */
+ endpwent (); /* close the old password databases */
+ endspent ();
+ pw_free (pw);
+ return check_perms (); /* authenticate in the subsystem */
+ }
+
+ return pw;
+}
+
+/*
+ * save_caller_context - save information from the call context
+ *
+ * Save the program's name (Prog), caller's UID (caller_uid /
+ * caller_is_root), name (caller_name), and password (caller_pass),
+ * the TTY (ttyp), and whether su was called from a console
+ * (is_console) for further processing and before they might change.
+ */
+static void save_caller_context (char **argv)
+{
+ struct passwd *pw = NULL;
+#ifndef USE_PAM
+#ifdef SU_ACCESS
+ const char *password = NULL;
+#endif /* SU_ACCESS */
+#endif /* !USE_PAM */
+ /*
+ * Get the program name. The program name is used as a prefix to
+ * most error messages.
+ */
+ Prog = Basename (argv[0]);
+
+ caller_uid = getuid ();
+ caller_is_root = (caller_uid == 0);
/*
* Get the tty name. Entries will be logged indicating that the user
* tried to change to the named new user from the current terminal.
*/
- if (isatty (0) && (cp = ttyname (0))) {
- if (strncmp (cp, "/dev/", 5) == 0)
- tty = cp + 5;
- else
- tty = cp;
+ caller_tty = ttyname (0);
+ if ((isatty (0) != 0) && (NULL != caller_tty)) {
#ifndef USE_PAM
- is_console = console (tty);
-#endif
+ caller_on_console = console (caller_tty);
+#endif /* !USE_PAM */
} else {
/*
* Be more paranoid, like su from SimplePAMApps. --marekm
*/
- if (!amroot) {
+ if (!caller_is_root) {
fprintf (stderr,
- _("%s: must be run from a terminal\n"), Prog);
+ _("%s: must be run from a terminal\n"),
+ Prog);
exit (1);
}
- tty = "???";
- }
-
- /*
- * The next argument must be either a user ID, or some flag to a
- * subshell. Pretty sticky since you can't have an argument which
- * doesn't start with a "-" unless you specify the new user name.
- * Any remaining arguments will be passed to the user's login shell.
- */
- if (optind < argc && argv[optind][0] != '-') {
- STRFCPY (name, argv[optind++]); /* use this login id */
- if (optind < argc && !strcmp (argv[optind], "--"))
- optind++;
+ caller_tty = "???";
}
- if (!name[0]) /* use default user ID */
- (void) strcpy (name, "root");
-
- doshell = argc == optind; /* any arguments remaining? */
- if (command)
- doshell = 0;
/*
* Get the user's real name. The current UID is used to determine
* who has executed su. That user ID must exist.
*/
pw = get_my_pwent ();
- if (!pw) {
- SYSLOG ((LOG_CRIT, "Unknown UID: %u", my_uid));
- su_failure (tty);
+ if (NULL == pw) {
+ fprintf (stderr,
+ _("%s: Cannot determine your user name.\n"),
+ Prog);
+ SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
+ (unsigned long) caller_uid));
+ su_failure (caller_tty, true); /* unknown target UID*/
}
- STRFCPY (oldname, pw->pw_name);
+ STRFCPY (caller_name, pw->pw_name);
#ifndef USE_PAM
#ifdef SU_ACCESS
* Sort out the password of user calling su, in case needed later
* -- chris
*/
- if ((spwd = getspnam (oldname))) /* !USE_PAM, no need for xgetspnam */
- pw->pw_passwd = spwd->sp_pwdp;
- oldpass = xstrdup (pw->pw_passwd);
+ password = pw->pw_passwd;
+ if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
+ const struct spwd *spwd = getspnam (caller_name);
+ if (NULL != spwd) {
+ password = spwd->sp_pwdp;
+ }
+ }
+ free (caller_pass);
+ caller_pass = xstrdup (password);
#endif /* SU_ACCESS */
+#endif /* !USE_PAM */
+ pw_free (pw);
+}
-#else /* USE_PAM */
- ret = pam_start ("su", name, &conv, &pamh);
- if (ret != PAM_SUCCESS) {
- SYSLOG ((LOG_ERR, "pam_start: error %d", ret);
- fprintf (stderr, _("%s: pam_start: error %d\n"),
- Prog, ret));
- exit (1);
+/*
+ * process_flags - Process the command line arguments
+ *
+ * process_flags() interprets the command line arguments and sets
+ * the values that the user will be created with accordingly. The
+ * values are checked for sanity.
+ */
+static void process_flags (int argc, char **argv)
+{
+ int c;
+ static struct option long_options[] = {
+ {"command", required_argument, NULL, 'c'},
+ {"help", no_argument, NULL, 'h'},
+ {"login", no_argument, NULL, 'l'},
+ {"preserve-environment", no_argument, NULL, 'p'},
+ {"shell", required_argument, NULL, 's'},
+ {NULL, 0, NULL, '\0'}
+ };
+
+ while ((c = getopt_long (argc, argv, "c:hlmps:",
+ long_options, NULL)) != -1) {
+ switch (c) {
+ case 'c':
+ command = optarg;
+ break;
+ case 'h':
+ usage (E_SUCCESS);
+ break;
+ case 'l':
+ fakelogin = true;
+ break;
+ case 'm':
+ case 'p':
+ /* This will only have an effect if the target
+ * user do not have a restricted shell, or if
+ * su is called by root.
+ */
+ change_environment = false;
+ break;
+ case 's':
+ shellstr = optarg;
+ break;
+ default:
+ usage (E_USAGE); /* NOT REACHED */
+ }
}
- ret = pam_set_item (pamh, PAM_TTY, (const void *) tty);
- if (ret == PAM_SUCCESS)
- ret = pam_set_item (pamh, PAM_RUSER, (const void *) oldname);
- if (ret != PAM_SUCCESS) {
- SYSLOG ((LOG_ERR, "pam_set_item: %s",
- pam_strerror (pamh, ret)));
- fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
- pam_end (pamh, ret);
- exit (1);
+ if ((optind < argc) && (strcmp (argv[optind], "-") == 0)) {
+ fakelogin = true;
+ optind++;
+ if ( (optind < argc)
+ && (strcmp (argv[optind], "--") == 0)) {
+ optind++;
+ }
}
-#endif /* USE_PAM */
- top:
/*
- * This is the common point for validating a user whose name is
- * known. It will be reached either by normal processing, or if the
- * user is to be logged into a subsystem root.
- *
- * The password file entries for the user is gotten and the account
- * validated.
+ * The next argument must be either a user ID, or some flag to a
+ * subshell. Pretty sticky since you can't have an argument which
+ * doesn't start with a "-" unless you specify the new user name.
+ * Any remaining arguments will be passed to the user's login shell.
*/
- if (!(pw = xgetpwnam (name))) {
- (void) fprintf (stderr, _("Unknown id: %s\n"), name);
- closelog ();
- exit (1);
+ if ((optind < argc) && ('-' != argv[optind][0])) {
+ STRFCPY (name, argv[optind++]); /* use this login id */
+ if ((optind < argc) && (strcmp (argv[optind], "--") == 0)) {
+ optind++;
+ }
+ }
+ if ('\0' == name[0]) { /* use default user */
+ struct passwd *root_pw = getpwnam ("root");
+ if ((NULL != root_pw) && (0 == root_pw->pw_uid)) {
+ (void) strcpy (name, "root");
+ } else {
+ root_pw = getpwuid (0);
+ if (NULL == root_pw) {
+ SYSLOG ((LOG_CRIT, "There is no UID 0 user."));
+ su_failure (caller_tty, true);
+ }
+ (void) strcpy (name, root_pw->pw_name);
+ }
}
-#ifndef USE_PAM
- spwd = NULL;
- if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0
- && (spwd = getspnam (name))) /* !USE_PAM, no need for xgetspnam */
- pw->pw_passwd = spwd->sp_pwdp;
-#endif /* !USE_PAM */
- pwent = *pw;
- /* If su is not called by root, and the target user has a restricted
- * shell, the environment must be changed.
- */
- change_environment |= (restricted_shell (pwent.pw_shell) && !amroot);
+ doshell = (argc == optind); /* any arguments remaining? */
+ if (NULL != command) {
+ doshell = false;
+ }
+}
+static void set_environment (struct passwd *pw)
+{
+ const char *cp;
/*
* If a new login is being set up, the old environment will be
* ignored and a new one created later on.
- * (note: in the case of a subsystem, the shell will be restricted,
- * and this won't be executed on the first pass)
*/
- if (fakelogin && change_environment) {
+ if (change_environment && fakelogin) {
/*
* The terminal type will be left alone if it is present in
* the environment already.
*/
- if ((cp = getenv ("TERM")))
+ cp = getenv ("TERM");
+ if (NULL != cp) {
addenv ("TERM", cp);
+ }
+
+ /*
+ * For some terminals COLORTERM seems to be the only way
+ * for checking for that specific terminal. For instance,
+ * gnome-terminal sets its TERM as "xterm" but its
+ * COLORTERM as "gnome-terminal". The COLORTERM variable
+ * is also of use when running GNU screen since it sets
+ * TERM to "screen" but doesn't touch COLORTERM.
+ */
+ cp = getenv ("COLORTERM");
+ if (NULL != cp) {
+ addenv ("COLORTERM", cp);
+ }
+
#ifndef USE_PAM
- if ((cp = getdef_str ("ENV_TZ")))
- addenv (*cp == '/' ? tz (cp) : cp, NULL);
+ cp = getdef_str ("ENV_TZ");
+ if (NULL != cp) {
+ addenv (('/' == *cp) ? tz (cp) : cp, NULL);
+ }
/*
* The clock frequency will be reset to the login value if required
*/
- if ((cp = getdef_str ("ENV_HZ")))
+ cp = getdef_str ("ENV_HZ");
+ if (NULL != cp) {
addenv (cp, NULL); /* set the default $HZ, if one */
+ }
+#endif /* !USE_PAM */
/*
* Also leave DISPLAY and XAUTHORITY if present, else
* pam_xauth will not work.
*/
- if ((cp = getenv ("DISPLAY")))
+ cp = getenv ("DISPLAY");
+ if (NULL != cp) {
addenv ("DISPLAY", cp);
- if ((cp = getenv ("XAUTHORITY")))
+ }
+ cp = getenv ("XAUTHORITY");
+ if (NULL != cp) {
addenv ("XAUTHORITY", cp);
-#endif /* !USE_PAM */
+ }
} else {
- while (*envp)
- addenv (*envp++, NULL);
+ char **envp = environ;
+ while (NULL != *envp) {
+ addenv (*envp, NULL);
+ envp++;
+ }
}
-#ifndef USE_PAM
- /*
- * BSD systems only allow "wheel" to SU to root. USG systems don't,
- * so we make this a configurable option.
- */
+ cp = getdef_str ((pw->pw_uid == 0) ? "ENV_SUPATH" : "ENV_PATH");
+ if (NULL == cp) {
+ addenv ((pw->pw_uid == 0) ? "PATH=/sbin:/bin:/usr/sbin:/usr/bin" : "PATH=/bin:/usr/bin", NULL);
+ } else if (strchr (cp, '=') != NULL) {
+ addenv (cp, NULL);
+ } else {
+ addenv ("PATH", cp);
+ }
- /* The original Shadow 3.3.2 did this differently. Do it like BSD:
- *
- * - check for UID 0 instead of name "root" - there are systems with
- * several root accounts under different names,
- *
- * - check the contents of /etc/group instead of the current group
- * set (you must be listed as a member, GID 0 is not sufficient).
- *
- * In addition to this traditional feature, we now have complete su
- * access control (allow, deny, no password, own password). Thanks
- * to Chris Evans <lady0110@sable.ox.ac.uk>.
+ if (getenv ("IFS") != NULL) { /* don't export user IFS ... */
+ addenv ("IFS= \t\n", NULL); /* ... instead, set a safe IFS */
+ }
+
+#ifdef USE_PAM
+ /* we need to setup the environment *after* pam_open_session(),
+ * else the UID is changed before stuff like pam_xauth could
+ * run, and we cannot access /etc/shadow and co
*/
+ environ = newenvp; /* make new environment active */
- if (!amroot) {
- if (pwent.pw_uid == 0 && getdef_bool ("SU_WHEEL_ONLY")
- && !iswheel (oldname)) {
- fprintf (stderr,
- _("You are not authorized to su %s\n"), name);
- exit (1);
- }
-#ifdef SU_ACCESS
- switch (check_su_auth (oldname, name)) {
- case 0: /* normal su, require target user's password */
- break;
- case 1: /* require no password */
- pwent.pw_passwd = ""; /* XXX warning: const */
- break;
- case 2: /* require own password */
- puts (_("(Enter your own password)"));
- pwent.pw_passwd = oldpass;
- break;
- default: /* access denied (-1) or unexpected value */
- fprintf (stderr,
- _("You are not authorized to su %s\n"), name);
- exit (1);
+ if (change_environment) {
+ /* update environment with all pam set variables */
+ char **envcp = pam_getenvlist (pamh);
+ if (NULL != envcp) {
+ while (NULL != *envcp) {
+ addenv (*envcp, NULL);
+ envcp++;
+ }
}
-#endif /* SU_ACCESS */
}
+
+#else /* !USE_PAM */
+ environ = newenvp; /* make new environment active */
#endif /* !USE_PAM */
- /* If the user do not want to change the environment,
- * use the current SHELL.
- * (unless another shell is required by the command line)
- */
- if (shellstr == NULL && change_environment == 0)
- shellstr = getenv ("SHELL");
- /* For users with non null UID, if this user has a restricted
- * shell, the shell must be the one specified in /etc/passwd
- */
- if (shellstr != NULL && !amroot && restricted_shell (pwent.pw_shell))
- shellstr = NULL;
- /* If the shell is not set at this time, use the shell specified
- * in /etc/passwd.
- */
- if (shellstr == NULL)
- shellstr = (char *) strdup (pwent.pw_shell);
+ if (change_environment) {
+ if (fakelogin) {
+ if (shellstr != pw->pw_shell) {
+ free (pw->pw_shell);
+ pw->pw_shell = xstrdup (shellstr);
+ }
+ setup_env (pw);
+ } else {
+ addenv ("HOME", pw->pw_dir);
+ addenv ("USER", pw->pw_name);
+ addenv ("LOGNAME", pw->pw_name);
+ addenv ("SHELL", shellstr);
+ }
+ }
- /*
- * Set the default shell.
- */
- if (shellstr == NULL || shellstr[0] == '\0')
- shellstr = "/bin/sh";
+}
+
+/*
+ * su - switch user id
+ *
+ * su changes the user's ids to the values for the specified user. if
+ * no new user name is specified, "root" or UID 0 is used by default.
+ *
+ * Any additional arguments are passed to the user's shell. In
+ * particular, the argument "-c" will cause the next argument to be
+ * interpreted as a command by the common shell programs.
+ */
+int main (int argc, char **argv)
+{
+ const char *cp;
+ struct passwd *pw = NULL;
- signal (SIGINT, SIG_IGN);
- signal (SIGQUIT, SIG_IGN);
#ifdef USE_PAM
- ret = pam_authenticate (pamh, 0);
- if (ret != PAM_SUCCESS) {
- SYSLOG ((LOG_ERR, "pam_authenticate: %s",
- pam_strerror (pamh, ret)));
+ int ret;
+#endif /* USE_PAM */
+
+ (void) setlocale (LC_ALL, "");
+ (void) bindtextdomain (PACKAGE, LOCALEDIR);
+ (void) textdomain (PACKAGE);
+
+ save_caller_context (argv);
+
+ OPENLOG ("su");
+
+ process_flags (argc, argv);
+
+ initenv ();
+
+#ifdef USE_PAM
+ ret = pam_start ("su", name, &conv, &pamh);
+ if (PAM_SUCCESS != ret) {
+ SYSLOG ((LOG_ERR, "pam_start: error %d", ret);
+ fprintf (stderr,
+ _("%s: pam_start: error %d\n"),
+ Prog, ret));
+ exit (1);
+ }
+
+ ret = pam_set_item (pamh, PAM_TTY, (const void *) caller_tty);
+ if (PAM_SUCCESS == ret) {
+ ret = pam_set_item (pamh, PAM_RUSER, (const void *) caller_name);
+ }
+ if (PAM_SUCCESS != ret) {
+ SYSLOG ((LOG_ERR, "pam_set_item: %s",
+ pam_strerror (pamh, ret)));
fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
pam_end (pamh, ret);
- su_failure (tty);
+ exit (1);
}
+#endif /* USE_PAM */
- ret = pam_acct_mgmt (pamh, 0);
- if (ret != PAM_SUCCESS) {
- if (amroot) {
- fprintf (stderr, _("%s: %s\n(Ignored)\n"), Prog,
- pam_strerror (pamh, ret));
- } else if (ret == PAM_NEW_AUTHTOK_REQD) {
- ret = pam_chauthtok (pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
- if (ret != PAM_SUCCESS) {
- SYSLOG ((LOG_ERR, "pam_chauthtok: %s",
- pam_strerror (pamh, ret)));
- fprintf (stderr, _("%s: %s\n"), Prog,
- pam_strerror (pamh, ret));
- pam_end (pamh, ret);
- su_failure (tty);
- }
- } else {
- SYSLOG ((LOG_ERR, "pam_acct_mgmt: %s",
- pam_strerror (pamh, ret)));
- fprintf (stderr, _("%s: %s\n"), Prog,
- pam_strerror (pamh, ret));
- pam_end (pamh, ret);
- su_failure (tty);
- }
- }
-#else /* !USE_PAM */
- /*
- * Set up a signal handler in case the user types QUIT.
- */
- die (0);
- oldsig = signal (SIGQUIT, die);
+ pw = check_perms ();
- /*
- * See if the system defined authentication method is being used.
- * The first character of an administrator defined method is an '@'
- * character.
+ /* If the user do not want to change the environment,
+ * use the current SHELL.
+ * (unless another shell is required by the command line)
*/
- if (!amroot && pw_auth (pwent.pw_passwd, name, PW_SU, (char *) 0)) {
- SYSLOG ((pwent.pw_uid ? LOG_NOTICE : LOG_WARN,
- "Authentication failed for %s", name));
- su_failure (tty);
+ if ((NULL == shellstr) && !change_environment) {
+ shellstr = getenv ("SHELL");
}
- signal (SIGQUIT, oldsig);
- /*
- * Check to see if the account is expired. root gets to ignore any
- * expired accounts, but normal users can't become a user with an
- * expired password.
+ /* If su is not called by root, and the target user has a
+ * restricted shell, the environment must be changed and the shell
+ * must be the one specified in /etc/passwd.
*/
- if (!amroot) {
- if (!spwd)
- spwd = pwd_to_spwd (&pwent);
-
- if (expire (&pwent, spwd)) {
- /* !USE_PAM, no need for xgetpwnam */
- struct passwd *pwd = getpwnam (name);
-
- /* !USE_PAM, no need for xgetspnam */
- spwd = getspnam (name);
- if (pwd)
- pwent = *pwd;
- }
+ if ( !caller_is_root
+ && restricted_shell (pw->pw_shell)) {
+ shellstr = NULL;
+ change_environment = true;
}
- /*
- * Check to see if the account permits "su". root gets to ignore any
- * restricted accounts, but normal users can't become a user if
- * there is a "SU" entry in the /etc/porttime file denying access to
- * the account.
+ /* If the shell is not set at this time, use the shell specified
+ * in /etc/passwd.
*/
- if (!amroot) {
- if (!isttytime (pwent.pw_name, "SU", time ((time_t *) 0))) {
- SYSLOG ((pwent.pw_uid ? LOG_WARN : LOG_CRIT,
- "SU by %s to restricted account %s",
- oldname, name));
- su_failure (tty);
- }
+ if (NULL == shellstr) {
+ shellstr = pw->pw_shell;
}
-#endif /* !USE_PAM */
-
- signal (SIGINT, SIG_DFL);
- signal (SIGQUIT, SIG_DFL);
-
- cp = getdef_str ((pwent.pw_uid == 0) ? "ENV_SUPATH" : "ENV_PATH");
- if (!cp) {
- addenv ("PATH=/bin:/usr/bin", NULL);
- } else if (strchr (cp, '=')) {
- addenv (cp, NULL);
- } else {
- addenv ("PATH", cp);
- }
-
- if (getenv ("IFS")) /* don't export user IFS ... */
- addenv ("IFS= \t\n", NULL); /* ... instead, set a safe IFS */
/*
- * Even if --shell is specified, the subsystem login test is based on
- * the shell specified in /etc/passwd (not the one specified with
- * --shell, which will be the one executed in the chroot later).
+ * Set the default shell.
*/
- if (pwent.pw_shell[0] == '*') { /* subsystem root required */
- pwent.pw_shell++; /* skip the '*' */
- subsystem (&pwent); /* figure out what to execute */
- endpwent ();
- endspent ();
- goto top;
+ if ((NULL == shellstr) || ('\0' == shellstr[0])) {
+ shellstr = SHELL;
}
- sulog (tty, 1, oldname, name); /* save SU information */
- endpwent ();
- endspent ();
+ sulog (caller_tty, true, caller_name, name); /* save SU information */
#ifdef USE_SYSLOG
- if (getdef_bool ("SYSLOG_SU_ENAB"))
- SYSLOG ((LOG_INFO, "+ %s %s:%s", tty,
- oldname[0] ? oldname : "???", name[0] ? name : "???"));
+ if (getdef_bool ("SYSLOG_SU_ENAB")) {
+ SYSLOG ((LOG_INFO, "+ %s %s:%s", caller_tty,
+ ('\0' != caller_name[0]) ? caller_name : "???",
+ ('\0' != name[0]) ? name : "???"));
+ }
#endif
#ifdef USE_PAM
/* set primary group id and supplementary groups */
- if (setup_groups (&pwent)) {
+ if (setup_groups (pw) != 0) {
pam_end (pamh, PAM_ABORT);
exit (1);
}
* and much more, depending on the configured modules
*/
ret = pam_setcred (pamh, PAM_ESTABLISH_CRED);
- if (ret != PAM_SUCCESS) {
+ if (PAM_SUCCESS != ret) {
SYSLOG ((LOG_ERR, "pam_setcred: %s", pam_strerror (pamh, ret)));
fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
- pam_end (pamh, ret);
+ (void) pam_end (pamh, ret);
exit (1);
}
ret = pam_open_session (pamh, 0);
- if (ret != PAM_SUCCESS) {
+ if (PAM_SUCCESS != ret) {
SYSLOG ((LOG_ERR, "pam_open_session: %s",
- pam_strerror (pamh, ret)));
+ pam_strerror (pamh, ret)));
fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
pam_setcred (pamh, PAM_DELETE_CRED);
- pam_end (pamh, ret);
+ (void) pam_end (pamh, ret);
exit (1);
}
- if (change_environment) {
- /* we need to setup the environment *after* pam_open_session(),
- * else the UID is changed before stuff like pam_xauth could
- * run, and we cannot access /etc/shadow and co
- */
- environ = newenvp; /* make new environment active */
-
- /* update environment with all pam set variables */
- envcp = pam_getenvlist (pamh);
- if (envcp) {
- while (*envcp) {
- addenv (*envcp, NULL);
- envcp++;
- }
- }
- }
+ prepare_pam_close_session ();
/* become the new user */
- if (change_uid (&pwent)) {
- pam_close_session (pamh, 0);
- pam_setcred (pamh, PAM_DELETE_CRED);
- pam_end (pamh, PAM_ABORT);
+ if (change_uid (pw) != 0) {
exit (1);
}
#else /* !USE_PAM */
- environ = newenvp; /* make new environment active */
-
/* no limits if su from root (unless su must fake login's behavior) */
- if (!amroot || fakelogin)
- setup_limits (&pwent);
+ if (!caller_is_root || fakelogin) {
+ setup_limits (pw);
+ }
- if (setup_uid_gid (&pwent, is_console))
+ if (setup_uid_gid (pw, caller_on_console) != 0) {
exit (1);
+ }
#endif /* !USE_PAM */
- if (change_environment) {
- if (fakelogin) {
- pwent.pw_shell = shellstr;
- setup_env (&pwent);
- } else {
- addenv ("HOME", pwent.pw_dir);
- addenv ("USER", pwent.pw_name);
- addenv ("LOGNAME", pwent.pw_name);
- addenv ("SHELL", shellstr);
+ set_environment (pw);
+
+ if (!doshell) {
+ /* There is no need for a controlling terminal.
+ * This avoids the callee to inject commands on
+ * the caller's tty. */
+ int err = -1;
+
+#ifdef USE_PAM
+ /* When PAM is used, we are on the child */
+ err = setsid ();
+#else
+ /* Otherwise, we cannot use setsid */
+ int fd = open ("/dev/tty", O_RDWR);
+
+ if (fd >= 0) {
+ err = ioctl (fd, TIOCNOTTY, (char *) 0);
+ (void) close (fd);
+ }
+#endif /* USE_PAM */
+
+ if (-1 == err) {
+ (void) fprintf (stderr,
+ _("%s: Cannot drop the controlling terminal\n"),
+ Prog);
+ exit (1);
}
}
+ /*
+ * PAM_DATA_SILENT is not supported by some modules, and
+ * there is no strong need to clean up the process space's
+ * memory since we will either call exec or exit.
+ pam_end (pamh, PAM_SUCCESS | PAM_DATA_SILENT);
+ */
+
+ endpwent ();
+ endspent ();
/*
* This is a workaround for Linux libc bug/feature (?) - the
* /dev/log file descriptor is open without the close-on-exec flag
char *arg0;
cp = getdef_str ("SU_NAME");
- if (!cp)
+ if (NULL == cp) {
cp = Basename (shellstr);
+ }
arg0 = xmalloc (strlen (cp) + 2);
arg0[0] = '-';
strcpy (arg0 + 1, cp);
cp = arg0;
- } else
+ } else {
cp = Basename (shellstr);
+ }
if (!doshell) {
+ int err;
/* Position argv to the remaining arguments */
argv += optind;
- if (command) {
+ if (NULL != command) {
argv -= 2;
argv[0] = "-c";
argv[1] = command;
* Use the shell and create an argv
* with the rest of the command line included.
*/
- argv[-1] = shellstr;
-#ifndef USE_PAM
- (void) execve (shellstr, &argv[-1], environ);
+ argv[-1] = cp;
+ execve_shell (shellstr, &argv[-1], environ);
err = errno;
- (void) fputs (_("No shell\n"), stderr);
- SYSLOG ((LOG_WARN, "Cannot execute %s", shellstr));
- closelog ();
- exit (err == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
-#else
- run_shell (shellstr, &argv[-1], 0, environ); /* no return */
-#endif
+ (void) fprintf (stderr,
+ _("Cannot execute %s\n"), shellstr);
+ errno = err;
+ } else {
+ (void) shell (shellstr, cp, environ);
}
-#ifndef USE_PAM
- err = shell (shellstr, cp, environ);
- exit (err == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
-#else
- run_shell (shellstr, &cp, 1, environ);
-#endif
- /* NOT REACHED */
- exit (1);
+
+ pw_free (pw);
+
+ return (errno == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
}
+
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