1 /* vi: set sw=4 ts=4: */
5 * usually setuid root, -c option only works if getuid() == geteuid()
7 * Copyright 1994 Matthew Dillon (dillon@apollo.west.oic.com)
8 * Vladimir Oleynik <dzo@simtreas.ru> (C) 2002
10 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
13 //usage:#define crontab_trivial_usage
14 //usage: "[-c DIR] [-u USER] [-ler]|[FILE]"
15 //usage:#define crontab_full_usage "\n\n"
16 //usage: " -c Crontab directory"
18 //usage: "\n -l List crontab"
19 //usage: "\n -e Edit crontab"
20 //usage: "\n -r Delete crontab"
21 //usage: "\n FILE Replace crontab by FILE ('-': stdin)"
25 #define CRONTABS CONFIG_FEATURE_CROND_DIR "/crontabs"
27 #define CRONUPDATE "cron.update"
30 static void edit_file(const struct passwd *pas, const char *file)
36 if (pid) { /* parent */
41 /* CHILD - change user and run editor */
42 /* initgroups, setgid, setuid */
44 setup_environment(pas->pw_shell,
45 SETUP_ENV_CHANGEENV | SETUP_ENV_TO_TMP,
47 ptr = getenv("VISUAL");
49 ptr = getenv("EDITOR");
54 BB_EXECLP(ptr, ptr, file, NULL);
55 bb_perror_msg_and_die("can't execute '%s'", ptr);
58 int crontab_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
59 int crontab_main(int argc UNUSED_PARAM, char **argv)
61 const struct passwd *pas;
62 const char *crontab_dir = CRONTABS;
65 char *user_name; /* -u USER */
70 /* file [opts] Replace crontab from file
71 * - [opts] Replace crontab from stdin
73 * -c dir Crontab directory
74 * -l List crontab for user
75 * -e Edit crontab for user
76 * -r Delete crontab for user
77 * bbox also supports -d == -r, but most other crontab
78 * implementations do not. Deprecated.
86 OPT_ler = OPT_l + OPT_e + OPT_r,
89 opt_complementary = "?1:dr"; /* max one argument; -d implies -r */
90 opt_ler = getopt32(argv, "u:c:lerd", &user_name, &crontab_dir);
93 if (sanitize_env_if_suid()) { /* Clears dangerous stuff, sets PATH */
95 if (opt_ler & (OPT_u|OPT_c))
96 bb_error_msg_and_die(bb_msg_you_must_be_root);
99 if (opt_ler & OPT_u) {
100 pas = xgetpwnam(user_name);
102 pas = xgetpwuid(getuid());
105 #define user_name DONT_USE_ME_BEYOND_THIS_POINT
107 /* From now on, keep only -l, -e, -r bits */
109 if ((opt_ler - 1) & opt_ler) /* more than one bit set? */
112 /* Read replacement file under user's UID/GID/group vector */
113 src_fd = STDIN_FILENO;
114 if (!opt_ler) { /* Replace? */
117 if (NOT_LONE_DASH(argv[0])) {
118 src_fd = xopen_as_uid_gid(argv[0], O_RDONLY, pas->pw_uid, pas->pw_gid);
122 /* cd to our crontab directory */
127 /* Handle requested operation */
130 default: /* case OPT_r: Delete */
131 unlink(pas->pw_name);
134 case OPT_l: /* List */
136 char *args[2] = { pas->pw_name, NULL };
139 * the rest go play with cron update file */
142 case OPT_e: /* Edit */
143 tmp_fname = xasprintf("%s.%u", crontab_dir, (unsigned)getpid());
144 /* No O_EXCL: we don't want to be stuck if earlier crontabs
145 * were killed, leaving stale temp file behind */
146 src_fd = xopen3(tmp_fname, O_RDWR|O_CREAT|O_TRUNC, 0600);
147 fchown(src_fd, pas->pw_uid, pas->pw_gid);
148 fd = open(pas->pw_name, O_RDONLY);
150 bb_copyfd_eof(fd, src_fd);
152 xlseek(src_fd, 0, SEEK_SET);
154 close_on_exec_on(src_fd); /* don't want editor to see this fd */
155 edit_file(pas, tmp_fname);
158 case 0: /* Replace (no -l, -e, or -r were given) */
159 new_fname = xasprintf("%s.new", pas->pw_name);
160 fd = open(new_fname, O_WRONLY|O_CREAT|O_TRUNC|O_APPEND, 0600);
162 bb_copyfd_eof(src_fd, fd);
164 xrename(new_fname, pas->pw_name);
166 bb_error_msg("can't create %s/%s",
167 crontab_dir, new_fname);
175 /* Bump notification file. Handle window where crond picks file up
176 * before we can write our entry out.
178 while ((fd = open(CRONUPDATE, O_WRONLY|O_CREAT|O_APPEND, 0600)) >= 0) {
181 fdprintf(fd, "%s\n", pas->pw_name);
182 if (fstat(fd, &st) != 0 || st.st_nlink != 0) {
187 * file was deleted, maybe crond missed our notification */
192 bb_error_msg("can't append to %s/%s",
193 crontab_dir, CRONUPDATE);