CVS: Indicate any relevant BUGIDs here

Relevant BUGIDs:

Purpose of commit: new feature

Commit summary:
---------------

2006-01-24  Thorsten Kukuk  <kukuk@thkukuk.de>

        * configure.in: Add modules/pam_exec.
        * modules/Makefile.am: Add pam_exec subdirectory.
        * modules/pam_exec/README: New.
        * modules/pam_exec/Makefile.am: New.
        * modules/pam_exec/pam_exec.8: New.
        * modules/pam_exec/pam_exec.c: New.
        * modules/pam_exec/pam_exec.8.xml: New.
        * po/POTFILES.in: Add modules/pam_exec/pam_exec.c.
        * po/*.po: Merge new pam_exec strings.

7 files changed, 622 insertions, 1 deletions

diff --git a/modules/Makefile.am b/modules/Makefile.am
index a120a97e..a259d738 100644
--- a/modules/Makefile.am
+++ b/modules/Makefile.am
@@ -8,7 +8,7 @@ SUBDIRS = pam_access pam_cracklib pam_debug pam_deny pam_echo \
 	pam_motd pam_nologin pam_permit pam_pwdb pam_rhosts pam_rootok \
 	pam_securetty pam_selinux pam_shells pam_stress pam_succeed_if \
 	pam_tally pam_time pam_umask pam_unix pam_userdb pam_warn \
-	pam_wheel pam_xauth
+	pam_wheel pam_xauth pam_exec
 
 
 CLEANFILES = *~
diff --git a/modules/pam_exec/.cvsignore b/modules/pam_exec/.cvsignore
new file mode 100644
index 00000000..9fb98574
--- /dev/null
+++ b/modules/pam_exec/.cvsignore
@@ -0,0 +1,6 @@
+*.la
+*.lo
+.deps
+.libs
+Makefile
+Makefile.in
diff --git a/modules/pam_exec/Makefile.am b/modules/pam_exec/Makefile.am
new file mode 100644
index 00000000..8310f3b6
--- /dev/null
+++ b/modules/pam_exec/Makefile.am
@@ -0,0 +1,21 @@
+#
+# Copyright (c) 2006 Thorsten Kukuk <kukuk@suse.de>
+#
+
+CLEANFILES = *~
+
+EXTRA_DIST = README $(MANS)
+
+man_MANS = pam_exec.8
+
+securelibdir = $(SECUREDIR)
+secureconfdir = $(SCONFIGDIR)
+
+AM_CFLAGS = -I$(top_srcdir)/libpam/include -I$(top_srcdir)/libpamc/include
+AM_LDFLAGS = -no-undefined -avoid-version -module \
+	-L$(top_builddir)/libpam -lpam
+if HAVE_VERSIONING
+  AM_LDFLAGS += -Wl,--version-script=$(srcdir)/../modules.map
+endif
+
+securelib_LTLIBRARIES = pam_exec.la
diff --git a/modules/pam_exec/README b/modules/pam_exec/README
new file mode 100644
index 00000000..8451ef03
--- /dev/null
+++ b/modules/pam_exec/README
@@ -0,0 +1,29 @@
+
+pam_exec module:
+	Call <prog> <arguments>
+
+
+USAGE:
+        For the services you wish to run a program put the following
+	line in the config as the last line for that service:
+
+        <type>    required     pam_exec.so [options] /path/prog ...
+
+	and pam_exec.so will run "/path/prog ...".
+
+
+OPTIONS:
+
+	debug		print debug informations
+
+	seteuid		pam_exec.so will call setuid(seteuid()), so that
+			the program will run with the same rights as the 
+			calling applications (effective user ID). The
+			default is that the program will be run with the
+			permissions of the calling user (real user ID).
+
+	log=<file>	the output is appended to this file.
+
+
+AUTHOR:
+	Thorsten Kukuk <kukuk@thkukuk.de>
diff --git a/modules/pam_exec/pam_exec.8 b/modules/pam_exec/pam_exec.8
new file mode 100644
index 00000000..6ecd2dc9
--- /dev/null
+++ b/modules/pam_exec/pam_exec.8
@@ -0,0 +1,79 @@
+.\" ** You probably do not want to edit this file directly **
+.\" It was generated using the DocBook XSL Stylesheets (version 1.69.1).
+.\" Instead of manually editing it, you probably should edit the DocBook XML
+.\" source for it and then use the DocBook XSL Stylesheets to regenerate it.
+.TH "PAM_EXEC" "8" "01/24/2006" "Linux\-PAM Manual" "Linux\-PAM Manual"
+.\" disable hyphenation
+.nh
+.\" disable justification (adjust text to left margin only)
+.ad l
+.SH "NAME"
+pam_exec \- PAM module which calls an external command
+.SH "SYNOPSIS"
+.HP 12
+\fBpam_exec.so\fR [debug] [seteuid] [log=\fIfile\fR] \fIcommand\fR [\fI...\fR]
+.SH "DESCRIPTION"
+.PP
+pam_exec is a PAM module that can be used to run an external command.
+.SH "OPTIONS"
+.PP
+.TP
+\fBdebug\fR
+Print debug information.
+.TP
+\fBlog=\fR\fB\fIfile\fR\fR
+The output of the command is appended to
+\fIfile\fR
+.TP
+\fBseteuid\fR
+Per default pam_exec.so will execute the external command with the real user ID of the calling process. Specifying this option means the command is run with the effective user ID.
+.SH "MODULE SERVICES PROVIDED"
+.PP
+The services
+\fBauth\fR,
+\fBaccount\fR,
+\fBpassword\fR
+and
+\fBsession\fR
+are supported.
+.SH "RETURN VALUES"
+.PP
+.TP
+\fBPAM_SUCCESS\fR
+The external command runs successfull.
+.TP
+\fBPAM_SERVICE_ERR\fR
+No argument or a wrong number of arguments were given.
+.TP
+\fBPAM_SYSTEM_ERR\fR
+A system error occured or the command to execute failed.
+.TP
+\fBPAM_IGNORE\fR
+\fBpam_setcred\fR
+was called, which does not execute the command.
+.SH "EXAMPLES"
+.PP
+Add the following line to
+\fI/etc/pam.d/passwd\fR
+to rebuild the NIS database after each local password change:
+.sp
+.nf
+        passwd optional pam_exec.so seteuid make \-C /var/yp
+      
+.fi
+.sp
+This will execute the command
+.sp
+.nf
+make \-C /var/yp
+.fi
+.sp
+with effective user ID.
+.SH "SEE ALSO"
+.PP
+\fBpam.conf\fR(5),
+\fBpam.d\fR(8),
+\fBpam\fR(8)
+.SH "AUTHOR"
+.PP
+pam_exec was written by Thorsten Kukuk <kukuk@thkukuk.de>.
diff --git a/modules/pam_exec/pam_exec.8.xml b/modules/pam_exec/pam_exec.8.xml
new file mode 100644
index 00000000..112f76cd
--- /dev/null
+++ b/modules/pam_exec/pam_exec.8.xml
@@ -0,0 +1,202 @@
+<?xml version="1.0" encoding='UTF-8'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+	"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
+
+<refentry id="pam_exec">
+
+  <refmeta>
+    <refentrytitle>pam_exec</refentrytitle>
+    <manvolnum>8</manvolnum>
+    <refmiscinfo class="sectdesc">Linux-PAM Manual</refmiscinfo>
+  </refmeta>
+
+  <refnamediv>
+    <refname>pam_exec</refname>
+    <refpurpose>PAM module which calls an external command</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <cmdsynopsis id="pam_exec-cmdsynopsis">
+      <command>pam_exec.so</command>
+      <arg choice="opt">
+	debug
+      </arg>
+      <arg choice="opt">
+        seteuid
+      </arg>
+      <arg choice="opt">
+        log=<replaceable>file</replaceable>
+      </arg>
+      <arg choice="plain">
+       <replaceable>command</replaceable>
+      </arg>
+      <arg choice="opt">
+        <replaceable>...</replaceable>
+      </arg>
+    </cmdsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1 id="pam_exec-description">
+
+    <title>Description</title>
+
+    <para>
+      pam_exec is a PAM module that can be used to run
+      an external command.
+    </para>
+
+  </refsect1>
+
+  <refsect1 id="pam_exec-options">
+
+    <title>Options</title>
+    <para>
+      <variablelist>
+
+        <varlistentry>
+          <term>
+            <option>debug</option>
+          </term>
+          <listitem>
+            <para>
+	      Print debug information.
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term>
+            <option>log=<replaceable>file</replaceable></option>
+          </term>
+          <listitem>
+            <para>
+	      The output of the command is appended to
+              <filename>file</filename>
+            </para>
+          </listitem>
+	</varlistentry>
+
+        <varlistentry>
+          <term>
+            <option>seteuid</option>
+          </term>
+          <listitem>
+            <para>
+  	      Per default pam_exec.so will execute the external command
+     	      with the real user ID of the calling process.
+              Specifying this option means the command is run
+              with the effective user ID.
+            </para>
+          </listitem>
+        </varlistentry>
+
+      </variablelist>
+
+    </para>
+  </refsect1>
+
+  <refsect1 id="pam_exec-services">
+    <title>Module Services Provided</title>
+    <para>
+      The services <option>auth</option>, <option>account</option>,
+      <option>password</option> and <option>session</option> are supported.
+    </para>
+  </refsect1>
+
+  <refsect1 id='pam_exec-return_values'>
+    <title>Return Values</title>
+    <para>
+      <variablelist>
+
+        <varlistentry>
+          <term>
+            <option>PAM_SUCCESS</option>
+          </term>
+          <listitem>
+            <para>
+              The external command runs successfull.
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term>
+            <option>PAM_SERVICE_ERR</option>
+          </term>
+          <listitem>
+            <para>
+	      No argument or a wrong number of arguments were given.
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term>
+            <option>PAM_SYSTEM_ERR</option>
+          </term>
+          <listitem>
+            <para>
+	      A system error occured or the command to execute failed.
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term>
+            <option>PAM_IGNORE</option>
+          </term>
+          <listitem>
+            <para>
+	      <function>pam_setcred</function> was called, which
+	      does not execute the command.
+            </para>
+          </listitem>
+        </varlistentry>
+
+      </variablelist>
+    </para>
+  </refsect1>
+
+  <refsect1 id='pam_exec-examples'>
+    <title>Examples</title>
+    <para>
+      Add the following line to <filename>/etc/pam.d/passwd</filename> to
+      rebuild the NIS database after each local password change:
+      <programlisting>
+        passwd optional pam_exec.so seteuid make -C /var/yp
+      </programlisting>
+
+      This will execute the command
+      <programlisting>make -C /var/yp</programlisting>
+       with effective user ID.
+    </para>
+  </refsect1>
+
+  <refsect1 id='pam_exec-see_also'>
+    <title>See Also</title>
+    <para>
+      <citerefentry>
+	<refentrytitle>pam.conf</refentrytitle>
+	<manvolnum>5</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+	<refentrytitle>pam.d</refentrytitle>
+	<manvolnum>8</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+	<refentrytitle>pam</refentrytitle>
+	<manvolnum>8</manvolnum>
+      </citerefentry>
+    </para>
+  </refsect1>
+
+  <refsect1 id='pam_exec-author'>
+    <title>Author</title>
+      <para>
+        pam_exec was written by Thorsten Kukuk &lt;kukuk@thkukuk.de&gt;.
+      </para>
+  </refsect1>
+
+</refentry>
+<!-- vim: sw=2
+-->
diff --git a/modules/pam_exec/pam_exec.c b/modules/pam_exec/pam_exec.c
new file mode 100644
index 00000000..7bbaed21
--- /dev/null
+++ b/modules/pam_exec/pam_exec.c
@@ -0,0 +1,284 @@
+/*
+ * Copyright (c) 2006 Thorsten Kukuk <kukuk@thkukuk.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+
+#define PAM_SM_AUTH
+#define PAM_SM_ACCOUNT
+#define PAM_SM_SESSION
+#define PAM_SM_PASSWORD
+
+#include <security/pam_modules.h>
+#include <security/pam_modutil.h>
+#include <security/pam_ext.h>
+
+static int
+call_exec (pam_handle_t *pamh, int argc, const char **argv)
+{
+  int debug = 0;
+  int call_setuid = 0;
+  int optargc;
+  const char *logfile = NULL;
+  pid_t pid;
+
+  if (argc < 1) {
+    pam_syslog (pamh, LOG_ERR,
+		"This module needs at least one argument");
+    return PAM_SERVICE_ERR;
+  }
+
+  for (optargc = 0; optargc < argc; optargc++)
+    {
+      if (argv[optargc][0] == '/') /* paths starts with / */
+	break;
+
+      if (strcasecmp (argv[optargc], "debug") == 0)
+	debug = 1;
+      else if (strncasecmp (argv[optargc], "log=", 4) == 0)
+	logfile = &argv[optargc][4];
+      else if (strcasecmp (argv[optargc], "seteuid") == 0)
+	call_setuid = 1;
+      else
+	break; /* Unknown option, assume program to execute. */
+    }
+
+
+  if (optargc >= argc) {
+    pam_syslog (pamh, LOG_ERR, "No path given as argument");
+    return PAM_SERVICE_ERR;
+  }
+
+  pid = fork();
+  if (pid == -1)
+    return PAM_SYSTEM_ERR;
+  if (pid > 0) /* parent */
+    {
+      int status = 0;
+      pid_t retval;
+      while ((retval = waitpid (pid, &status, 0)) == -1 &&
+	     errno == EINTR);
+      if (retval == (pid_t)-1)
+	{
+	  pam_syslog (pamh, LOG_ERR, "waitpid returns with -1: %m");
+	  return PAM_SYSTEM_ERR;
+	}
+      else if (status != 0)
+	{
+	  if (WIFEXITED(status))
+	    {
+	      pam_syslog (pamh, LOG_ERR, "%s failed: exit code %d",
+			  argv[optargc], WEXITSTATUS(status));
+	      pam_error (pamh, _("%s failed: exit code %d"),
+			 argv[optargc], WEXITSTATUS(status));
+	    }
+	  else if (WIFSIGNALED(status))
+	    {
+	      pam_syslog (pamh, LOG_ERR, "%s failed: caught signal %d%s",
+			  argv[optargc], WTERMSIG(status),
+			  WCOREDUMP(status) ? " (core dumped)" : "");
+	      pam_error (pamh, _("%s failed: caught signal %d%s"),
+			 argv[optargc], WTERMSIG(status),
+			 WCOREDUMP(status) ? " (core dumped)" : "");
+	    }
+	  else
+	    {
+	      pam_syslog (pamh, LOG_ERR, "%s failed: unknown status 0x%x",
+			  argv[optargc], status);
+	      pam_error (pamh, _("%s failed: unknown status 0x%x"),
+			 argv[optargc], status);
+	    }
+	  return PAM_SYSTEM_ERR;
+	}
+      return PAM_SUCCESS;
+    }
+  else /* child */
+    {
+      char **arggv;
+      int i;
+
+      for (i = 0; i < sysconf (_SC_OPEN_MAX); i++)
+	close (i);
+
+      /* New stdin.  */
+      if ((i = open ("/dev/null", O_RDWR)) < 0)
+	{
+	  int err = errno;
+	  pam_syslog (pamh, LOG_ERR, "open of /dev/null failed: %m");
+	  exit (err);
+	}
+      /* New stdout and stderr.  */
+      if (logfile)
+	{
+	  time_t tm = time (NULL);
+	  char *buffer = NULL;
+
+	  if ((i = open (logfile, O_CREAT|O_APPEND|O_WRONLY))  == -1)
+	    {
+	      int err = errno;
+	      pam_syslog (pamh, LOG_ERR, "open of %s failed: %m",
+			  logfile);
+	      exit (err);
+	    }
+	  if (asprintf (&buffer, "*** %s", ctime (&tm)) > 0)
+	    {
+	      pam_modutil_write (i, buffer, strlen (buffer));
+	      free (buffer);
+	    }
+	}
+      else
+	if (dup (i) == -1)
+	  {
+	    int err = errno;
+	    pam_syslog (pamh, LOG_ERR, "dup failed: %m");
+	    exit (err);
+	  }
+      if (dup (i) == -1)
+        {
+	  int err = errno;
+	  pam_syslog (pamh, LOG_ERR, "dup failed: %m");
+          exit (err);
+        }
+
+      if (call_setuid)
+	if (setuid (geteuid ()) == -1)
+	  {
+	    int err = errno;
+	    pam_syslog (pamh, LOG_ERR, "setuid(%d) failed: %m",
+			geteuid ());
+	    exit (err);
+	  }
+
+      if (setsid () == -1)
+	{
+	  int err = errno;
+	  pam_syslog (pamh, LOG_ERR, "setsid failed: %m");
+	  exit (err);
+	}
+
+      arggv = calloc (argc + 4, sizeof (char *));
+      if (arggv == NULL)
+	exit (ENOMEM);
+
+      for (i = 0; i < (argc - optargc); i++)
+	arggv[i] = argv[i+optargc];
+      arggv[i] = NULL;
+
+      if (debug)
+	pam_syslog (pamh, LOG_DEBUG, "Calling %s ...", arggv[0]);
+
+      if (execv (arggv[0], arggv) == -1)
+	{
+	  int err = errno;
+	  pam_syslog (pamh, LOG_ERR, "execv(%s,...) failed: %m",
+		      arggv[0]);
+	  exit (err);
+	}
+      exit (1); /* should never be reached. */
+    }
+  return PAM_SYSTEM_ERR;
+}
+
+PAM_EXTERN int
+pam_sm_authenticate (pam_handle_t *pamh, int flags UNUSED,
+		     int argc, const char **argv)
+{
+  return call_exec (pamh, argc, argv);
+}
+
+PAM_EXTERN int
+pam_sm_setcred (pam_handle_t *pamh UNUSED, int flags UNUSED,
+		int argc UNUSED, const char **argv UNUSED)
+{
+  return PAM_IGNORE;
+}
+
+/* password updating functions */
+
+PAM_EXTERN int
+pam_sm_chauthtok(pam_handle_t *pamh, int flags,
+		 int argc, const char **argv)
+{
+  if (flags & PAM_PRELIM_CHECK)
+    return PAM_SUCCESS;
+  return call_exec (pamh, argc, argv);
+}
+
+PAM_EXTERN int
+pam_sm_acct_mgmt(pam_handle_t *pamh, int flags UNUSED,
+		 int argc, const char **argv)
+{
+  return call_exec (pamh, argc, argv);
+}
+
+PAM_EXTERN int
+pam_sm_open_session(pam_handle_t *pamh, int flags UNUSED,
+		    int argc, const char **argv)
+{
+  return call_exec (pamh, argc, argv);
+}
+
+PAM_EXTERN int
+pam_sm_close_session(pam_handle_t *pamh, int flags UNUSED,
+		     int argc, const char **argv)
+{
+  return call_exec (pamh, argc, argv);
+}
+
+#ifdef PAM_STATIC
+struct pam_module _pam_exec_modstruct = {
+  "pam_exec",
+  pam_sm_authenticate,
+  pam_sm_setcred,
+  pam_sm_acct_mgmt,
+  pam_sm_open_session,
+  pam_sm_close_session,
+  pam_sm_chauthtok,
+};
+#endif