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pam_exec.c revision 1.2 
      1 /*	$NetBSD: pam_exec.c,v 1.2 2004/12/12 08:18:44 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2001,2003 Networks Associates Technology, Inc.
      5  * All rights reserved.
      6  *
      7  * This software was developed for the FreeBSD Project by ThinkSec AS and
      8  * NAI Labs, the Security Research Division of Network Associates, Inc.
      9  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
     10  * DARPA CHATS research program.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. The name of the author may not be used to endorse or promote
     21  *    products derived from this software without specific prior written
     22  *    permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 #ifdef __FreeBSD__
     39 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_exec/pam_exec.c,v 1.3 2003/02/06 12:56:51 des Exp $");
     40 #else
     41 __RCSID("$NetBSD: pam_exec.c,v 1.2 2004/12/12 08:18:44 christos Exp $");
     42 #endif
     43 
     44 #include <sys/types.h>
     45 #include <sys/wait.h>
     46 
     47 #include <errno.h>
     48 #include <stdlib.h>
     49 #include <string.h>
     50 #include <unistd.h>
     51 
     52 #include <security/pam_appl.h>
     53 #include <security/pam_modules.h>
     54 #include <security/openpam.h>
     55 
     56 static int
     57 _pam_exec(pam_handle_t *pamh __unused, int flags __unused,
     58     int argc, const char *argv[])
     59 {
     60 	int childerr, status;
     61 	char **env, **envlist;
     62 	pid_t pid;
     63 
     64 	if (argc < 1)
     65 		return (PAM_SERVICE_ERR);
     66 
     67 	/*
     68 	 * XXX For additional credit, divert child's stdin/stdout/stderr
     69 	 * to the conversation function.
     70 	 */
     71 	envlist = pam_getenvlist(pamh);
     72 	childerr = 0;
     73 	if ((pid = vfork()) == 0) {
     74 		/*LINTED const cast*/
     75 		execve(argv[0], (char **)__UNCONST(argv), envlist);
     76 		childerr = errno;
     77 		_exit(1);
     78 	}
     79 	for (env = envlist; *env != NULL; ++env)
     80 		free(*env);
     81 	free(envlist);
     82 	if (pid == -1) {
     83 		openpam_log(PAM_LOG_ERROR, "vfork(): %m");
     84 		return (PAM_SYSTEM_ERR);
     85 	}
     86 	if (waitpid(pid, &status, 0) == -1) {
     87 		openpam_log(PAM_LOG_ERROR, "waitpid(): %m");
     88 		return (PAM_SYSTEM_ERR);
     89 	}
     90 	if (childerr != 0) {
     91 		openpam_log(PAM_LOG_ERROR, "execv(): %m");
     92 		return (PAM_SYSTEM_ERR);
     93 	}
     94 	if (WIFSIGNALED(status)) {
     95 		openpam_log(PAM_LOG_ERROR, "%s caught signal %d%s",
     96 		    argv[0], WTERMSIG(status),
     97 		    WCOREDUMP(status) ? " (core dumped)" : "");
     98 		return (PAM_SYSTEM_ERR);
     99 	}
    100 	if (!WIFEXITED(status)) {
    101 		openpam_log(PAM_LOG_ERROR, "unknown status 0x%x", status);
    102 		return (PAM_SYSTEM_ERR);
    103 	}
    104 	if (WEXITSTATUS(status) != 0) {
    105 		openpam_log(PAM_LOG_ERROR, "%s returned code %d",
    106 		    argv[0], WEXITSTATUS(status));
    107 		return (PAM_SYSTEM_ERR);
    108 	}
    109 	return (PAM_SUCCESS);
    110 }
    111 
    112 PAM_EXTERN int
    113 pam_sm_authenticate(pam_handle_t *pamh, int flags,
    114     int argc, const char *argv[])
    115 {
    116 
    117 	return (_pam_exec(pamh, flags, argc, argv));
    118 }
    119 
    120 PAM_EXTERN int
    121 pam_sm_setcred(pam_handle_t *pamh, int flags,
    122     int argc, const char *argv[])
    123 {
    124 
    125 	return (_pam_exec(pamh, flags, argc, argv));
    126 }
    127 
    128 PAM_EXTERN int
    129 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
    130     int argc, const char *argv[])
    131 {
    132 
    133 	return (_pam_exec(pamh, flags, argc, argv));
    134 }
    135 
    136 PAM_EXTERN int
    137 pam_sm_open_session(pam_handle_t *pamh, int flags,
    138     int argc, const char *argv[])
    139 {
    140 
    141 	return (_pam_exec(pamh, flags, argc, argv));
    142 }
    143 
    144 PAM_EXTERN int
    145 pam_sm_close_session(pam_handle_t *pamh, int flags,
    146     int argc, const char *argv[])
    147 {
    148 
    149 	return (_pam_exec(pamh, flags, argc, argv));
    150 }
    151 
    152 PAM_EXTERN int
    153 pam_sm_chauthtok(pam_handle_t *pamh, int flags,
    154     int argc, const char *argv[])
    155 {
    156 
    157 	return (_pam_exec(pamh, flags, argc, argv));
    158 }
    159 
    160 PAM_MODULE_ENTRY("pam_exec");
    161