Joshua Brindle | 13cd4c8 | 2008-08-19 15:30:36 -0400 | [diff] [blame^] | 1 | /* |
| 2 | * utmpwatcher.c |
| 3 | * |
| 4 | * Copyright (C) 2006 Red Hat |
| 5 | * see file 'COPYING' for use and warranty information |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License as |
| 9 | * published by the Free Software Foundation; either version 2 of |
| 10 | * the License, or (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | .* |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 20 | * 02111-1307 USA |
| 21 | * |
| 22 | * Authors: |
| 23 | * Dan Walsh <dwalsh@redhat.com> |
| 24 | * |
| 25 | * |
| 26 | */ |
| 27 | |
| 28 | #define _GNU_SOURCE |
| 29 | #include <sys/inotify.h> |
| 30 | #include <stdio.h> |
| 31 | #include <stdlib.h> |
| 32 | #include <string.h> |
| 33 | #include <sys/types.h> |
| 34 | #include <sys/stat.h> |
| 35 | #include <syslog.h> |
| 36 | |
| 37 | #include <limits.h> |
| 38 | #include <utmp.h> |
| 39 | #include <sys/types.h> |
| 40 | #include <pwd.h> |
| 41 | #include "restorecond.h" |
| 42 | #include "utmpwatcher.h" |
| 43 | #include "stringslist.h" |
| 44 | |
| 45 | static struct stringsList *utmp_ptr = NULL; |
| 46 | static int utmp_wd = -1; |
| 47 | |
| 48 | unsigned int utmpwatcher_handle(int inotify_fd, int wd) |
| 49 | { |
| 50 | int changed = 0; |
| 51 | struct utmp u; |
| 52 | char *utmp_path = "/var/run/utmp"; |
| 53 | struct stringsList *prev_utmp_ptr = utmp_ptr; |
| 54 | if (wd != utmp_wd) |
| 55 | return -1; |
| 56 | |
| 57 | utmp_ptr = NULL; |
| 58 | FILE *cfg = fopen(utmp_path, "r"); |
| 59 | if (!cfg) |
| 60 | exitApp("Error reading config file."); |
| 61 | |
| 62 | while (fread(&u, sizeof(struct utmp), 1, cfg) > 0) { |
| 63 | if (u.ut_type == USER_PROCESS) |
| 64 | strings_list_add(&utmp_ptr, u.ut_user); |
| 65 | } |
| 66 | fclose(cfg); |
| 67 | if (utmp_wd >= 0) |
| 68 | inotify_rm_watch(inotify_fd, utmp_wd); |
| 69 | |
| 70 | utmp_wd = |
| 71 | inotify_add_watch(inotify_fd, utmp_path, IN_MOVED_FROM | IN_MODIFY); |
| 72 | if (prev_utmp_ptr) { |
| 73 | changed = strings_list_diff(prev_utmp_ptr, utmp_ptr); |
| 74 | strings_list_free(prev_utmp_ptr); |
| 75 | } |
| 76 | return changed; |
| 77 | } |
| 78 | |
| 79 | static void watch_file(int inotify_fd, const char *file) |
| 80 | { |
| 81 | struct stringsList *ptr = utmp_ptr; |
| 82 | |
| 83 | while (ptr) { |
| 84 | struct passwd *pwd = getpwnam(ptr->string); |
| 85 | if (pwd) { |
| 86 | char *path = NULL; |
| 87 | if (asprintf(&path, "%s%s", pwd->pw_dir, file) < 0) |
| 88 | exitApp("Error allocating memory."); |
| 89 | watch_list_add(inotify_fd, path); |
| 90 | free(path); |
| 91 | } |
| 92 | ptr = ptr->next; |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | void utmpwatcher_add(int inotify_fd, const char *path) |
| 97 | { |
| 98 | if (utmp_ptr == NULL) { |
| 99 | utmpwatcher_handle(inotify_fd, utmp_wd); |
| 100 | } |
| 101 | watch_file(inotify_fd, path); |
| 102 | } |
| 103 | |
| 104 | void utmpwatcher_free(void) |
| 105 | { |
| 106 | if (utmp_ptr) |
| 107 | strings_list_free(utmp_ptr); |
| 108 | } |
| 109 | |
| 110 | #ifdef TEST |
| 111 | int main(int argc, char **argv) |
| 112 | { |
| 113 | read_utmp(); |
| 114 | return 0; |
| 115 | } |
| 116 | #endif |