1 files changed, 262 insertions, 0 deletions
diff --git a/usr.sbin/cron/database.c b/usr.sbin/cron/database.c
new file mode 100644
index 000000000000..33421829b06a
--- /dev/null
+++ b/usr.sbin/cron/database.c
@@ -0,0 +1,262 @@
+/* Copyright 1988,1990,1993,1994 by Paul Vixie
+ * All rights reserved
+ *
+ * Distribute freely, except: don't remove my name from the source or
+ * documentation (don't take credit for my work), mark your changes (don't
+ * get me blamed for your possible bugs), don't alter or remove this
+ * notice.  May be sold if buildable source is provided to buyer.  No
+ * warrantee of any kind, express or implied, is included with this
+ * software; use at your own risk, responsibility for damages (if any) to
+ * anyone resulting from the use of this software rests entirely with the
+ * user.
+ *
+ * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
+ * I'll try to keep a version up to date.  I can be reached as follows:
+ * Paul Vixie          <paul@vix.com>          uunet!decwrl!vixie!paul
+ * From Id: database.c,v 2.8 1994/01/15 20:43:43 vixie Exp
+ */
+
+#if !defined(lint) && !defined(LINT)
+static char rcsid[] = "$Header: /home/cvs/386BSD/src/usr.sbin/cron/database.c,v 1.1 1994/01/22 20:39:01 guido Exp $";
+#endif
+
+/* vix 26jan87 [RCS has the log]
+ */
+
+
+#include "cron.h"
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+
+
+#define TMAX(a,b) ((a)>(b)?(a):(b))
+
+
+static	void		process_crontab __P((char *, char *, char *,
+					     struct stat *,
+					     cron_db *, cron_db *));
+
+
+void
+load_database(old_db)
+	cron_db		*old_db;
+{
+	DIR		*dir;
+	struct stat	statbuf;
+	struct stat	syscron_stat;
+	DIR_T   	*dp;
+	cron_db		new_db;
+	user		*u, *nu;
+
+	Debug(DLOAD, ("[%d] load_database()\n", getpid()))
+
+	/* before we start loading any data, do a stat on SPOOL_DIR
+	 * so that if anything changes as of this moment (i.e., before we've
+	 * cached any of the database), we'll see the changes next time.
+	 */
+	if (stat(SPOOL_DIR, &statbuf) < OK) {
+		log_it("CRON", getpid(), "STAT FAILED", SPOOL_DIR);
+		(void) exit(ERROR_EXIT);
+	}
+
+	/* track system crontab file
+	 */
+	if (stat(SYSCRONTAB, &syscron_stat) < OK)
+		syscron_stat.st_mtime = 0;
+
+	/* 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 == TMAX(statbuf.st_mtime, syscron_stat.st_mtime)) {
+		Debug(DLOAD, ("[%d] spool dir mtime unch, no load needed.\n",
+			      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 = TMAX(statbuf.st_mtime, syscron_stat.st_mtime);
+	new_db.head = new_db.tail = NULL;
+
+	if (syscron_stat.st_mtime) {
+		process_crontab("root", "*system*",
+				SYSCRONTAB, &syscron_stat,
+				&new_db, old_db);
+	}
+
+	/* 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(SPOOL_DIR))) {
+		log_it("CRON", getpid(), "OPENDIR FAILED", SPOOL_DIR);
+		(void) exit(ERROR_EXIT);
+	}
+
+	while (NULL != (dp = readdir(dir))) {
+		char	fname[MAXNAMLEN+1],
+			tabname[MAXNAMLEN+1];
+
+		/* avoid file names beginning with ".".  this is good
+		 * because we would otherwise waste two guaranteed calls
+		 * to getpwnam() for . and .., and also because user names
+		 * starting with a period are just too nasty to consider.
+		 */
+		if (dp->d_name[0] == '.')
+			continue;
+
+		(void) strcpy(fname, dp->d_name);
+		sprintf(tabname, CRON_TAB(fname));
+
+		process_crontab(fname, fname, tabname,
+				&statbuf, &new_db, old_db);
+	}
+	closedir(dir);
+
+	/* 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(db, u)
+	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(db, u)
+	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(db, name)
+	cron_db	*db;
+	char	*name;
+{
+	char	*env_get();
+	user	*u;
+
+	for (u = db->head;  u != NULL;  u = u->next)
+		if (!strcmp(u->name, name))
+			break;
+	return u;
+}
+
+
+static void
+process_crontab(uname, fname, tabname, statbuf, new_db, old_db)
+	char		*uname;
+	char		*fname;
+	char		*tabname;
+	struct stat	*statbuf;
+	cron_db		*new_db;
+	cron_db		*old_db;
+{
+	struct passwd	*pw = NULL;
+	int		crontab_fd = OK - 1;
+	user		*u;
+
+	if (strcmp(fname, "*system*") && !(pw = getpwnam(uname))) {
+		/* 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, 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;
+	}
+
+	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"))
+		close(crontab_fd);
+	}
+}