/* $NetBSD: database.c,v 1.9 2017/06/09 17:36:30 christos Exp $ */
/* Copyright 1988,1990,1993,1994 by Paul Vixie
* All rights reserved
*/
/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
#if !defined(lint) && !defined(LINT)
#if 0
static char rcsid[] = "Id: database.c,v 1.7 2004/01/23 18:56:42 vixie Exp";
#else
__RCSID("$NetBSD: database.c,v 1.9 2017/06/09 17:36:30 christos Exp $");
#endif
#endif
/* vix 26jan87 [RCS has the log]
*/
#include "cron.h"
#define TMAX(a,b) ((a)>(b)?(a):(b))
struct spooldir {
const char *path;
const char *uname;
const char *fname;
struct stat st;
};
static struct spooldir spools[] = {
{ .path = SPOOL_DIR, },
{ .path = CROND_DIR, .uname = "root", .fname = "*system*", },
{ .path = NULL, }
};
static void process_crontab(const char *, const char *,
const char *, struct stat *,
cron_db *, cron_db *);
static void
process_dir(struct spooldir *sp, cron_db *new_db, cron_db *old_db)
{
DIR *dir;
DIR_T *dp;
const char *dname = sp->path;
struct stat *st = &sp->st;
if (st->st_mtime == 0)
return;
/* we used to keep this dir open all the time, for the sake of
* efficiency. however, we need to close it in every fork, and
* we fork a lot more often than the mtime of the dir changes.
*/
if (!(dir = opendir(dname))) {
log_it("CRON", getpid(), "OPENDIR FAILED", dname);
(void) exit(ERROR_EXIT);
}
while (NULL != (dp = readdir(dir))) {
char fname[MAXNAMLEN+1], tabname[MAXNAMLEN+1];
size_t i, len;
/*
* Homage to...
*/
static const char *junk[] = {
"rpmsave", "rpmorig", "rpmnew",
};
/* avoid file names beginning with ".". this is good
* because we would otherwise waste two guaranteed calls
* to getpwnam() for . and .., and there shouldn't be
* hidden files in here anyway (in the non system case).
*/
if (dp->d_name[0] == '.')
continue;
/* ignore files starting with # ... */
if (dp->d_name[0] == '#')
continue;
len = strlen(dp->d_name);
/* ... or too big or to small ... */
if (len == 0 || len >= sizeof(fname)) {
log_it(dp->d_name, getpid(), "ORPHAN",
"name too short or long");
continue;
}
/* ... or ending with ~ ... */
if (dp->d_name[len - 1] == '~')
continue;
(void)strlcpy(fname, dp->d_name, sizeof(fname));
/* ... or look for blacklisted extensions */
for (i = 0; i < __arraycount(junk); i++) {
char *p;
if ((p = strrchr(fname, '.')) != NULL &&
strcmp(p + 1, junk[i]) == 0)
break;
}
if (i != __arraycount(junk))
continue;
if (!glue_strings(tabname, sizeof tabname, dname, fname, '/')) {
log_it(fname, getpid(), "ORPHAN",
"could not glue strings");
continue;
}
process_crontab(sp->uname ? sp->uname : fname,
sp->fname ? sp->fname : fname,
tabname, st, new_db, old_db);
}
(void)closedir(dir);
}
void
load_database(cron_db *old_db) {
struct stat syscron_stat;
cron_db new_db;
user *u, *nu;
time_t maxtime;
Debug(DLOAD, ("[%ld] load_database()\n", (long)getpid()));
/* track system crontab file
*/
if (stat(SYSCRONTAB, &syscron_stat) < OK)
syscron_stat.st_mtime = 0;
maxtime = syscron_stat.st_mtime;
for (struct spooldir *p = spools; p->path; p++) {
if (stat(p->path, &p->st) < OK) {
if (errno == ENOENT) {
p->st.st_mtime = 0;
continue;
}
log_it("CRON", getpid(), "STAT FAILED", p->path);
(void) exit(ERROR_EXIT);
}
if (p->st.st_mtime > maxtime)
maxtime = p->st.st_mtime;
}
/* if spooldir's mtime has not changed, we don't need to fiddle with
* the database.
*
* Note that old_db->mtime is initialized to 0 in main(), and
* so is guaranteed to be different than the stat() mtime the first
* time this function is called.
*/
if (old_db->mtime == maxtime) {
Debug(DLOAD, ("[%ld] spool dir mtime unch, no load needed.\n",
(long)getpid()));
return;
}
/* something's different. make a new database, moving unchanged
* elements from the old database, reloading elements that have
* actually changed. Whatever is left in the old database when
* we're done is chaff -- crontabs that disappeared.
*/
new_db.mtime = maxtime;
new_db.head = new_db.tail = NULL;
if (syscron_stat.st_mtime)
process_crontab("root", "*system*", SYSCRONTAB,
&syscron_stat, &new_db, old_db);
for (struct spooldir *p = spools; p->path; p++)
process_dir(p, &new_db, old_db);
/* if we don't do this, then when our children eventually call
* getpwnam() in do_command.c's child_process to verify MAILTO=,
* they will screw us up (and v-v).
*/
endpwent();
/* whatever's left in the old database is now junk.
*/
Debug(DLOAD, ("unlinking old database:\n"));
for (u = old_db->head; u != NULL; u = nu) {
Debug(DLOAD, ("\t%s\n", u->name));
nu = u->next;
unlink_user(old_db, u);
free_user(u);
}
/* overwrite the database control block with the new one.
*/
*old_db = new_db;
Debug(DLOAD, ("load_database is done\n"));
}
void
link_user(cron_db *db, user *u) {
if (db->head == NULL)
db->head = u;
if (db->tail)
db->tail->next = u;
u->prev = db->tail;
u->next = NULL;
db->tail = u;
}
void
unlink_user(cron_db *db, user *u) {
if (u->prev == NULL)
db->head = u->next;
else
u->prev->next = u->next;
if (u->next == NULL)
db->tail = u->prev;
else
u->next->prev = u->prev;
}
user *
find_user(cron_db *db, const char *name) {
user *u;
for (u = db->head; u != NULL; u = u->next)
if (strcmp(u->name, name) == 0)
break;
return (u);
}
static void
process_crontab(const char *uname, const char *fname, const char *tabname,
struct stat *statbuf, cron_db *new_db, cron_db *old_db)
{
struct passwd *pw = NULL;
int crontab_fd = OK - 1;
mode_t eqmode = 0400, badmode = 0;
user *u;
if (strcmp(fname, "*system*") == 0) {
/*
* SYSCRONTAB:
* Allow it to become readable by group and others, but
* not writable.
*/
eqmode = 0;
badmode = 022;
} else if ((pw = getpwnam(uname)) == NULL) {
/* file doesn't have a user in passwd file.
*/
log_it(fname, getpid(), "ORPHAN", "no passwd entry");
goto next_crontab;
}
if ((crontab_fd = open(tabname, O_RDONLY|O_NONBLOCK|O_NOFOLLOW, 0)) < OK) {
/* crontab not accessible?
*/
log_it(fname, getpid(), "CAN'T OPEN", tabname);
goto next_crontab;
}
if (fstat(crontab_fd, statbuf) < OK) {
log_it(fname, getpid(), "FSTAT FAILED", tabname);
goto next_crontab;
}
if (!S_ISREG(statbuf->st_mode)) {
log_it(fname, getpid(), "NOT REGULAR", tabname);
goto next_crontab;
}
if ((eqmode && (statbuf->st_mode & 07577) != eqmode) ||
(badmode && (statbuf->st_mode & badmode) != 0)) {
log_it(fname, getpid(), "BAD FILE MODE", tabname);
goto next_crontab;
}
if (statbuf->st_uid != ROOT_UID && (pw == NULL ||
statbuf->st_uid != pw->pw_uid || strcmp(uname, pw->pw_name) != 0)) {
log_it(fname, getpid(), "WRONG FILE OWNER", tabname);
goto next_crontab;
}
if (statbuf->st_nlink != 1) {
log_it(fname, getpid(), "BAD LINK COUNT", tabname);
goto next_crontab;
}
Debug(DLOAD, ("\t%s:", fname));
u = find_user(old_db, fname);
if (u != NULL) {
/* if crontab has not changed since we last read it
* in, then we can just use our existing entry.
*/
if (u->mtime == statbuf->st_mtime) {
Debug(DLOAD, (" [no change, using old data]"));
unlink_user(old_db, u);
link_user(new_db, u);
goto next_crontab;
}
/* before we fall through to the code that will reload
* the user, let's deallocate and unlink the user in
* the old database. This is more a point of memory
* efficiency than anything else, since all leftover
* users will be deleted from the old database when
* we finish with the crontab...
*/
Debug(DLOAD, (" [delete old data]"));
unlink_user(old_db, u);
free_user(u);
log_it(fname, getpid(), "RELOAD", tabname);
}
u = load_user(crontab_fd, pw, fname);
if (u != NULL) {
u->mtime = statbuf->st_mtime;
link_user(new_db, u);
}
next_crontab:
if (crontab_fd >= OK) {
Debug(DLOAD, (" [done]\n"));
(void)close(crontab_fd);
}
}