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|
/* pam_motd module */
/*
* Modified for pam_motd by Ben Collins <bcollins@debian.org>
*
* Based off of:
* $Id$
*
* Written by Michael K. Johnson <johnsonm@redhat.com> 1996/10/24
*
*/
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <syslog.h>
#include <security/_pam_macros.h>
#include <security/pam_ext.h>
/*
* here, we make a definition for the externally accessible function
* in this file (this definition is required for static a module
* but strongly encouraged generally) it is used to instruct the
* modules include file to define the function prototypes.
*/
#define PAM_SM_SESSION
#define DEFAULT_MOTD "/etc/motd"
#define DEFAULT_MOTD_D "/etc/motd.d"
#include <security/pam_modules.h>
#include <security/pam_modutil.h>
/* --- session management functions (only) --- */
int
pam_sm_close_session (pam_handle_t *pamh UNUSED, int flags UNUSED,
int argc UNUSED, const char **argv UNUSED)
{
return PAM_IGNORE;
}
static char default_motd[] = DEFAULT_MOTD;
static char default_motd_dir[] = DEFAULT_MOTD_D;
static void try_to_display_fd(pam_handle_t *pamh, int fd)
{
struct stat st;
char *mtmp = NULL;
/* fill in message buffer with contents of motd */
if ((fstat(fd, &st) < 0) || !st.st_size || st.st_size > 0x10000)
return;
if (!(mtmp = malloc(st.st_size+1)))
return;
if (pam_modutil_read(fd, mtmp, st.st_size) == st.st_size) {
if (mtmp[st.st_size-1] == '\n')
mtmp[st.st_size-1] = '\0';
else
mtmp[st.st_size] = '\0';
pam_info (pamh, "%s", mtmp);
}
_pam_drop(mtmp);
}
static void try_to_display_directory(pam_handle_t *pamh, const char *dirname)
{
DIR *dirp;
dirp = opendir(dirname);
if (dirp != NULL) {
struct dirent *entry;
while ((entry = readdir(dirp))) {
int fd = openat(dirfd(dirp), entry->d_name, O_RDONLY);
if (fd >= 0) {
try_to_display_fd(pamh, fd);
close(fd);
}
}
closedir(dirp);
}
}
int pam_sm_open_session(pam_handle_t *pamh, int flags,
int argc, const char **argv)
{
int retval = PAM_IGNORE;
const char *motd_path = NULL;
const char *motd_dir_path = NULL;
if (flags & PAM_SILENT) {
return retval;
}
for (; argc-- > 0; ++argv) {
if (!strncmp(*argv,"motd=",5)) {
motd_path = 5 + *argv;
if (*motd_path != '\0') {
D(("set motd path: %s", motd_path));
} else {
motd_path = NULL;
pam_syslog(pamh, LOG_ERR,
"motd= specification missing argument - ignored");
}
}
else if (!strncmp(*argv,"motd_dir=",9)) {
motd_dir_path = 9 + *argv;
if (*motd_dir_path != '\0') {
D(("set motd.d path: %s", motd_dir_path));
} else {
motd_dir_path = NULL;
pam_syslog(pamh, LOG_ERR,
"motd_dir= specification missing argument - ignored");
}
}
else
pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv);
}
if (motd_path == NULL && motd_dir_path == NULL) {
motd_path = default_motd;
motd_dir_path = default_motd_dir;
}
if (motd_path != NULL) {
int fd = open(motd_path, O_RDONLY, 0);
if (fd >= 0) {
try_to_display_fd(pamh, fd);
close(fd);
}
}
if (motd_dir_path != NULL)
try_to_display_directory(pamh, motd_dir_path);
return retval;
}
/* end of module definition */
|
