1 /* Copyright 1988,1990,1993,1994 by Paul Vixie
4 * Distribute freely, except: don't remove my name from the source or
5 * documentation (don't take credit for my work), mark your changes (don't
6 * get me blamed for your possible bugs), don't alter or remove this
7 * notice. May be sold if buildable source is provided to buyer. No
8 * warrantee of any kind, express or implied, is included with this
9 * software; use at your own risk, responsibility for damages (if any) to
10 * anyone resulting from the use of this software rests entirely with the
13 * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
14 * I'll try to keep a version up to date. I can be reached as follows:
15 * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul
17 * $FreeBSD: src/usr.sbin/cron/cron/do_command.c,v 1.15.2.5 2001/05/04 00:59:40 peter Exp $
18 * $DragonFly: src/usr.sbin/cron/cron/do_command.c,v 1.2 2003/06/17 04:29:53 dillon Exp $
22 #include <sys/signal.h>
24 # include <sys/universe.h>
29 #if defined(LOGIN_CAP)
30 # include <login_cap.h>
34 static void child_process __P((entry *, user *)),
35 do_univ __P((user *));
43 Debug(DPROC, ("[%d] do_command(%s, (%s,%d,%d))\n",
44 getpid(), e->cmd, u->name, e->uid, e->gid))
46 /* fork to become asynchronous -- parent process is done immediately,
47 * and continues to run the normal cron code, which means return to
48 * tick(). the child and grandchild don't leave this function, alive.
50 * vfork() is unsuitable, since we have much to do, and the parent
51 * needs to be able to run off and fork other processes.
55 log_it("CRON",getpid(),"error","can't fork");
59 acquire_daemonlock(1);
61 Debug(DPROC, ("[%d] child process done, exiting\n", getpid()))
68 Debug(DPROC, ("[%d] main process returning to work\n", getpid()))
77 int stdin_pipe[2], stdout_pipe[2];
78 register char *input_data;
79 char *usernm, *mailto;
81 # if defined(LOGIN_CAP)
86 Debug(DPROC, ("[%d] child_process('%s')\n", getpid(), e->cmd))
88 /* mark ourselves as different to PS command watchers by upshifting
89 * our program name. This has no effect on some kernels.
91 setproctitle("running job");
93 /* discover some useful and important environment settings
95 usernm = env_get("LOGNAME", e->envp);
96 mailto = env_get("MAILTO", e->envp);
99 /* our parent is watching for our death by catching SIGCHLD. we
100 * do not care to watch for our children's deaths this way -- we
101 * use wait() explictly. so we have to disable the signal (which
102 * was inherited from the parent).
104 (void) signal(SIGCHLD, SIG_DFL);
106 /* on system-V systems, we are ignoring SIGCLD. we have to stop
107 * ignoring it now or the wait() in cron_pclose() won't work.
108 * because of this, we have to wait() for our children here, as well.
110 (void) signal(SIGCLD, SIG_DFL);
113 /* create some pipes to talk to our future child
115 pipe(stdin_pipe); /* child's stdin */
116 pipe(stdout_pipe); /* child's stdout */
118 /* since we are a forked process, we can diddle the command string
119 * we were passed -- nobody else is going to use it again, right?
121 * if a % is present in the command, previous characters are the
122 * command, and subsequent characters are the additional input to
123 * the command. Subsequent %'s will be transformed into newlines,
124 * but that happens later.
126 * If there are escaped %'s, remove the escape character.
129 register int escaped = FALSE;
133 for (input_data = p = e->cmd; (ch = *input_data);
138 if (ch == '%' || ch == '\\')
148 *input_data++ = '\0';
155 /* fork again, this time so we can exec the user's command.
159 log_it("CRON",getpid(),"error","can't vfork");
163 Debug(DPROC, ("[%d] grandchild process Vfork()'ed\n",
166 /* write a log message. we've waited this long to do it
167 * because it was not until now that we knew the PID that
168 * the actual user command shell was going to get and the
169 * PID is part of the log message.
172 char *x = mkprints((u_char *)e->cmd, strlen(e->cmd));
174 log_it(usernm, getpid(), "CMD", x);
178 /* that's the last thing we'll log. close the log files.
184 /* get new pgrp, void tty, etc.
188 /* close the pipe ends that we won't use. this doesn't affect
189 * the parent, who has to read and write them; it keeps the
190 * kernel from recording us as a potential client TWICE --
191 * which would keep it from sending SIGPIPE in otherwise
192 * appropriate circumstances.
194 close(stdin_pipe[WRITE_PIPE]);
195 close(stdout_pipe[READ_PIPE]);
197 /* grandchild process. make std{in,out} be the ends of
198 * pipes opened by our daddy; make stderr go to stdout.
200 close(STDIN); dup2(stdin_pipe[READ_PIPE], STDIN);
201 close(STDOUT); dup2(stdout_pipe[WRITE_PIPE], STDOUT);
202 close(STDERR); dup2(STDOUT, STDERR);
204 /* close the pipes we just dup'ed. The resources will remain.
206 close(stdin_pipe[READ_PIPE]);
207 close(stdout_pipe[WRITE_PIPE]);
209 /* set our login universe. Do this in the grandchild
210 * so that the child can invoke /usr/lib/sendmail
215 # if defined(LOGIN_CAP)
216 /* Set user's entire context, but skip the environment
217 * as cron provides a separate interface for this
219 if ((pwd = getpwnam(usernm)) == NULL)
220 pwd = getpwuid(e->uid);
223 pwd->pw_gid = e->gid;
224 if (e->class != NULL)
225 lc = login_getclass(e->class);
228 setusercontext(lc, pwd, e->uid,
229 LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETENV)) == 0)
232 /* fall back to the old method */
235 /* set our directory, uid and gid. Set gid first,
236 * since once we set uid, we've lost root privledges.
240 initgroups(usernm, e->gid);
243 setuid(e->uid); /* we aren't root after this..*/
244 #if defined(LOGIN_CAP)
249 chdir(env_get("HOME", e->envp));
254 char *shell = env_get("SHELL", e->envp);
257 if (DebugFlags & DTEST) {
259 "debug DTEST is on, not exec'ing command.\n");
261 "\tcmd='%s' shell='%s'\n", e->cmd, shell);
264 # endif /*DEBUGGING*/
265 execle(shell, shell, "-c", e->cmd, (char *)0, e->envp);
266 warn("execl: couldn't exec `%s'", shell);
277 /* middle process, child of original cron, parent of process running
278 * the user's command.
281 Debug(DPROC, ("[%d] child continues, closing pipes\n", getpid()))
283 /* close the ends of the pipe that will only be referenced in the
284 * grandchild process...
286 close(stdin_pipe[READ_PIPE]);
287 close(stdout_pipe[WRITE_PIPE]);
290 * write, to the pipe connected to child's stdin, any input specified
291 * after a % in the crontab entry. while we copy, convert any
292 * additional %'s to newlines. when done, if some characters were
293 * written and the last one wasn't a newline, write a newline.
295 * Note that if the input data won't fit into one pipe buffer (2K
296 * or 4K on most BSD systems), and the child doesn't read its stdin,
297 * we would block here. thus we must fork again.
300 if (*input_data && fork() == 0) {
301 register FILE *out = fdopen(stdin_pipe[WRITE_PIPE], "w");
302 register int need_newline = FALSE;
303 register int escaped = FALSE;
307 warn("fdopen failed in child2");
311 Debug(DPROC, ("[%d] child2 sending data to grandchild\n", getpid()))
313 /* close the pipe we don't use, since we inherited it and
314 * are part of its reference count now.
316 close(stdout_pipe[READ_PIPE]);
321 * \x -> \x for all x != %
323 while ((ch = *input_data++)) {
332 if (!(escaped = (ch == '\\'))) {
334 need_newline = (ch != '\n');
342 /* close the pipe, causing an EOF condition. fclose causes
343 * stdin_pipe[WRITE_PIPE] to be closed, too.
347 Debug(DPROC, ("[%d] child2 done sending to grandchild\n", getpid()))
351 /* close the pipe to the grandkiddie's stdin, since its wicked uncle
352 * ernie back there has it open and will close it when he's done.
354 close(stdin_pipe[WRITE_PIPE]);
359 * read output from the grandchild. it's stderr has been redirected to
360 * it's stdout, which has been redirected to our pipe. if there is any
361 * output, we'll be mailing it to the user whose crontab this is...
362 * when the grandchild exits, we'll get EOF.
365 Debug(DPROC, ("[%d] child reading output from grandchild\n", getpid()))
368 register FILE *in = fdopen(stdout_pipe[READ_PIPE], "r");
369 register int ch = getc(in);
372 warn("fdopen failed in child");
378 register int bytes = 1;
382 ("[%d] got data (%x:%c) from grandchild\n",
385 /* get name of recipient. this is MAILTO if set to a
386 * valid local username; USER otherwise.
389 /* MAILTO was present in the environment
392 /* ... but it's empty. set to NULL
397 /* MAILTO not present, set to USER.
402 /* if we are supposed to be mailing, MAILTO will
403 * be non-NULL. only in this case should we set
404 * up the mail command and subjects and stuff...
409 auto char mailcmd[MAX_COMMAND];
410 auto char hostname[MAXHOSTNAMELEN];
412 (void) gethostname(hostname, MAXHOSTNAMELEN);
413 (void) snprintf(mailcmd, sizeof(mailcmd),
415 if (!(mail = cron_popen(mailcmd, "w", e))) {
417 (void) _exit(ERROR_EXIT);
419 fprintf(mail, "From: %s (Cron Daemon)\n", usernm);
420 fprintf(mail, "To: %s\n", mailto);
421 fprintf(mail, "Subject: Cron <%s@%s> %s\n",
422 usernm, first_word(hostname, "."),
424 # if defined(MAIL_DATE)
425 fprintf(mail, "Date: %s\n",
426 arpadate(&TargetTime));
427 # endif /* MAIL_DATE */
428 for (env = e->envp; *env; env++)
429 fprintf(mail, "X-Cron-Env: <%s>\n",
433 /* this was the first char from the pipe
438 /* we have to read the input pipe no matter whether
439 * we mail or not, but obviously we only write to
440 * mail pipe if we ARE mailing.
443 while (EOF != (ch = getc(in))) {
449 /* only close pipe if we opened it -- i.e., we're
454 Debug(DPROC, ("[%d] closing pipe to mail\n",
456 /* Note: the pclose will probably see
457 * the termination of the grandchild
458 * in addition to the mail process, since
459 * it (the grandchild) is likely to exit
460 * after closing its stdout.
462 status = cron_pclose(mail);
465 /* if there was output and we could not mail it,
466 * log the facts so the poor user can figure out
469 if (mailto && status) {
470 char buf[MAX_TEMPSTR];
472 snprintf(buf, sizeof(buf),
473 "mailed %d byte%s of output but got status 0x%04x\n",
474 bytes, (bytes==1)?"":"s",
476 log_it(usernm, getpid(), "MAIL", buf);
479 } /*if data from grandchild*/
481 Debug(DPROC, ("[%d] got EOF from grandchild\n", getpid()))
483 fclose(in); /* also closes stdout_pipe[READ_PIPE] */
486 /* wait for children to die.
488 for (; children > 0; children--)
493 Debug(DPROC, ("[%d] waiting for grandchild #%d to finish\n",
497 Debug(DPROC, ("[%d] no more grandchildren--mail written?\n",
501 Debug(DPROC, ("[%d] grandchild #%d finished, status=%04x",
502 getpid(), pid, WEXITSTATUS(waiter)))
503 if (WIFSIGNALED(waiter) && WCOREDUMP(waiter))
504 Debug(DPROC, (", dumped core"))
515 /* Dynix (Sequent) hack to put the user associated with
516 * the passed user structure into the ATT universe if
517 * necessary. We have to dig the gecos info out of
518 * the user's password entry to see if the magic
519 * "universe(att)" string is present.
526 p = getpwuid(u->uid);
534 for (i = 0; i < 4; i++)
536 if ((s = strchr(s, ',')) == NULL)
540 if (strcmp(s, "universe(att)"))
543 (void) universe(U_ATT);