-/*
+/*
* lockfile.c:
*
- * Copyright (c) 2008 James McKenzie <james@fishsoup.dhs.org>,
+ * Copyright (c) 2008 James McKenzie <sympathy@madingley.org>,
* All rights reserved.
*
*/
-static char rcsid[] = "$Id$";
+static char rcsid[] =
+ "$Id: lockfile.c,v 1.17 2010/07/16 11:04:10 james Exp $";
-/*
- * $Log$
+/*
+ * $Log: lockfile.c,v $
+ * Revision 1.17 2010/07/16 11:04:10 james
+ * ignore tedious return values
+ *
+ * Revision 1.16 2008/05/09 12:56:11 james
+ * *** empty log message ***
+ *
+ * Revision 1.15 2008/03/07 14:13:40 james
+ * *** empty log message ***
+ *
+ * Revision 1.14 2008/03/07 13:16:02 james
+ * *** empty log message ***
+ *
+ * Revision 1.13 2008/03/07 12:37:04 james
+ * *** empty log message ***
+ *
+ * Revision 1.12 2008/03/03 06:04:42 james
+ * *** empty log message ***
+ *
+ * Revision 1.11 2008/03/02 10:38:18 james
+ * *** empty log message ***
+ *
+ * Revision 1.10 2008/03/02 10:37:56 james
+ * *** empty log message ***
+ *
+ * Revision 1.9 2008/02/15 23:52:12 james
+ * *** empty log message ***
+ *
+ * Revision 1.8 2008/02/15 20:52:36 james
+ * *** empty log message ***
+ *
+ * Revision 1.7 2008/02/15 19:51:30 james
+ * *** empty log message ***
+ *
+ * Revision 1.6 2008/02/15 19:09:00 james
+ * *** empty log message ***
+ *
+ * Revision 1.5 2008/02/15 18:26:49 james
+ * *** empty log message ***
+ *
+ * Revision 1.4 2008/02/15 18:16:48 james
+ * *** empty log message ***
+ *
* Revision 1.3 2008/02/15 18:16:35 james
* *** empty log message ***
*
#define LOCK_ASCII
#undef LOCK_BINARY
+#define STALE_CHECK_INTERVAL 10
+
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <fcntl.h>
#include <dirent.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/time.h>
#include "lockfile.h"
+extern void *xmalloc (size_t);
+
Filelist *
filelist_new (void)
{
- Filelist *fl = (Filelist *) malloc (sizeof (Filelist));
+ Filelist *fl = (Filelist *) xmalloc (sizeof (Filelist));
fl->head = NULL;
if (i >= FILE_LIST_MAX_LEN)
return;
- for (fle=fl->head;fle;fle=fle->next)
- if (!strcmp(fle->name,fn)) return;
+ for (fle = fl->head; fle; fle = fle->next)
+ if (!strcmp (fle->name, fn))
+ return;
- fle = malloc (sizeof (Filelist_ent));
+ fle = xmalloc (sizeof (Filelist_ent));
strcpy (fle->name, fn);
free (fl);
}
-void filelist_print(Filelist *fl,FILE *f)
+void
+filelist_print (Filelist * fl, FILE * f)
{
-Filelist_ent *fle;
-if (!fl) {
- fprintf(f,"(empty list)\n");
- return;
-}
- for (fle=fl->head;fle;fle=fle->next)
- fprintf(f,"%s\n",fle->name);
+ Filelist_ent *fle;
+ if (!fl) {
+ fprintf (f, "(empty list)\n");
+ return;
+ }
+ for (fle = fl->head; fle; fle = fle->next)
+ fprintf (f, "%s\n", fle->name);
}
static int uuid = -1, ugid;
struct passwd *pw;
- if (uuid < 0)
- {
- if (pw = getpwnam ("uucp"))
- {
- uuid = pw->pw_uid;
- ugid = pw->pw_gid;
- }
- else
- {
- return -1;
- }
+ if (uuid < 0) {
+ if (pw = getpwnam ("uucp")) {
+ uuid = pw->pw_uid;
+ ugid = pw->pw_gid;
+ } else {
+ return -1;
}
+ }
return fchown (fd, uuid, ugid);
}
unlink (tmpfn);
fd = open (tmpfn, O_WRONLY | O_CREAT | O_TRUNC, 0444);
- if (fd < 0)
- {
- unlink (tmpfn);
- return -1;
- }
+ if (fd < 0) {
+ unlink (tmpfn);
+ return -1;
+ }
- write (fd, buf, i);
+ int result;
+ result = write (fd, buf, i);
fchmod (fd, 044);
- if (chown_uucp (fd))
- {
- close (fd);
- unlink (tmpfn);
- return -1;
- }
+#if 0
+ if (chown_uucp (fd)) {
+ close (fd);
+ unlink (tmpfn);
+ return -1;
+ }
+#else
+ chown_uucp (fd);
+#endif
close (fd);
- if (link (tmpfn, name) < 0)
- {
- unlink (tmpfn);
- return -1;
- }
+ if (link (tmpfn, name) < 0) {
+ unlink (tmpfn);
+ return -1;
+ }
unlink (tmpfn);
return 0;
char *lock_dirs[] =
{ "/var/lock/uucp", "/var/spool/lock", "/var/spool/uucp", "/etc/locks",
"/usr/spool/uucp", "/var/spool/locks", "/usr/spool/lock",
- "/usr/spool/locks",
- "/usr/spool/uucp/LCK"
+ "/usr/spool/locks", "/usr/spool/uucp/LCK", "/var/lock"
};
int i;
- for (i = 0; i < (sizeof (lock_dirs) / sizeof (char *)); ++i)
- {
- if (stat (lock_dirs[i], &stbuf))
- continue;
- strcpy (buf, lock_dirs[i]);
- strcat (buf, "/");
- strcat (buf, leaf);
- filelist_add (fl, buf);
- }
+ for (i = 0; i < (sizeof (lock_dirs) / sizeof (char *)); ++i) {
+ if (stat (lock_dirs[i], &stbuf))
+ continue;
+ strcpy (buf, lock_dirs[i]);
+ strcat (buf, "/");
+ strcat (buf, leaf);
+ filelist_add (fl, buf);
+ }
}
static void
do_tedious_mangling (Filelist * fl, char *buf, char *ptr, char inv, int lower)
{
- while (*ptr)
- {
- if (lower && (*ptr >= 'A') && (*ptr <= 'Z'))
- *ptr |= 32;
- if (*ptr == '/')
- *ptr = inv;
- ptr++;
- }
+ while (*ptr) {
+ if (lower && (*ptr >= 'A') && (*ptr <= 'Z'))
+ *ptr |= 32;
+ if (*ptr == '/')
+ *ptr = inv;
+ ptr++;
+ }
lockfile_add_places (fl, buf);
}
ptr++;
lockfile_regularize_and_add (fl, ptr);
- if (!strncmp (ptr, "dev/", 4))
- {
- ptr += 4;
- lockfile_regularize_and_add (fl, ptr);
- }
+ if (!strncmp (ptr, "dev/", 4)) {
+ ptr += 4;
+ lockfile_regularize_and_add (fl, ptr);
+ }
}
d = opendir (dir);
- if (!d) return;
+ if (!d)
+ return;
- while ((de = readdir (d)))
- {
- strcpy (buf, dir);
- strcat (buf, de->d_name);
+ while ((de = readdir (d))) {
+ strcpy (buf, dir);
+ strcat (buf, de->d_name);
- if (stat (buf, &ent_stat))
- continue;
- if (!S_ISCHR (ent_stat.st_mode))
- continue;
- if (ent_stat.st_rdev != dev)
- continue;
+ if (stat (buf, &ent_stat))
+ continue;
+ if (!S_ISCHR (ent_stat.st_mode))
+ continue;
+ if (ent_stat.st_rdev != dev)
+ continue;
- lockfile_add_name_from_path (fl, buf);
+ lockfile_add_name_from_path (fl, buf);
- }
+ }
closedir (d);
}
Filelist *
-lockfile_make_list(char *device)
+lockfile_make_list (char *device)
{
struct stat dev_stat;
Filelist *ret = NULL;
ret = filelist_new ();
- lockfile_add_name_from_dev (ret, dev_stat.st_rdev);
+ if (ret) {
+ lockfile_add_name_from_dev (ret, dev_stat.st_rdev);
- lockfile_add_name_from_path (ret, device);
+ lockfile_add_name_from_path (ret, device);
- lockfile_check_dir_for_dev (ret, "/dev/", dev_stat.st_rdev);
- lockfile_check_dir_for_dev (ret, "/dev/usb/", dev_stat.st_rdev);
- lockfile_check_dir_for_dev (ret, "/dev/tts/", dev_stat.st_rdev);
+ lockfile_check_dir_for_dev (ret, "/dev/", dev_stat.st_rdev);
+ lockfile_check_dir_for_dev (ret, "/dev/usb/", dev_stat.st_rdev);
+ lockfile_check_dir_for_dev (ret, "/dev/tts/", dev_stat.st_rdev);
+ }
return ret;
}
-void lockfile_remove_stale(Filelist *fl)
+static void
+remove_stale_lock (char *path)
+{
+ int fd;
+ int pid;
+ char apid[20];
+ int length;
+
+ fd = open (path, O_RDONLY);
+ if (fd < 0)
+ return;
+
+ length = read (fd, apid, sizeof (apid) - 1);
+ if (length < 0)
+ length = 0;
+ apid[length] = 0;
+
+ pid = 0;
+ if (length == sizeof (pid) || sscanf (apid, "%d", &pid) != 1 || pid == 0) {
+ pid = *((int *) apid);
+#ifdef LOCK_ASCII
+ fprintf (stderr,
+ "compiled with ascii locks, found binary lock file (length=%d, pid=%d)!",
+ length, pid);
+#endif
+ }
+#ifdef LOCK_BINARY
+ else {
+ fprintf (stderr,
+ "compiled with binary locks, found ascii lock file (length=%d, pid=%d)!",
+ length, pid);
+ }
+#endif
+
+ close (fd);
+
+ if ((kill (pid, 0) < 0) && (errno == ESRCH)) {
+ fprintf (stderr, "removing stale lock file %s\n", path);
+ unlink (path);
+ }
+
+}
+
+void
+lockfile_remove_stale (Filelist * fl)
{
+ Filelist_ent *fle;
+ struct stat buf;
+
+ for (fle = fl->head; fle; fle = fle->next) {
+ if (stat (fle->name, &buf))
+ continue;
+ remove_stale_lock (fle->name);
+ }
}
-Filelist *lockfile_lock(Filelist *fl)
+Filelist *
+lockfile_lock (Filelist * fl)
{
-Filelist *ret;
-Filelist_ent *fle;
+ Filelist *ret;
+ Filelist_ent *fle;
-ret=filelist_new();
+ ret = filelist_new ();
+
+ if (ret) {
+ lockfile_remove_stale (fl);
-lockfile_remove_stale(fl);
+ for (fle = fl->head; fle; fle = fle->next) {
+ if (lockfile_make (fle->name)) {
+ fprintf (stderr, "Failed to get lockfile %s\n", fle->name);
+ filelist_free (ret);
+ return NULL;
+ }
+ filelist_add (ret, fle->name);
+ }
+ }
-for (fle=fl->head;fle;fle=fle->next) {
- if (lockfile_make(fle->name)) {
- fprintf(stderr,"Failed to get lockfile %s\n",fle->name);
- filelist_free(ret);
- return NULL;
- }
- filelist_add(ret,fle->name);
+ return ret;
}
-return ret;
+void
+lockfile_unlock (Filelist * fl)
+{
+
+ while (fl->head) {
+ unlink (fl->head->name);
+ filelist_remove (fl, fl->head);
+ }
}
-#if 1
-int main(int argc,char *argv[])
+
+/* If we have a passive lock, check noone has an */
+/* active one, returns 1 if he does, 0 if he doesnt */
+int
+serial_lock_check (Serial_lock * l)
{
-Filelist *fl=lockfile_make_list("/dev/ttyS0");
-Filelist *fll;
-Filelist_ent *fle;
+ Filelist_ent *fle;
+ int locks_found = 0;
+ struct stat buf;
+ struct timeval now, dif;
+
+ if (l->mode == SERIAL_LOCK_ACTIVE)
+ return 0;
+
+ for (fle = l->locks_to_check->head; fle; fle = fle->next) {
+ if (!stat (fle->name, &buf))
+ locks_found++;
+ }
+
+ if (!locks_found)
+ return 0;
-filelist_print(fl,stdout);
+ gettimeofday (&now, NULL);
+ timersub (&now, &l->last_stale_purge, &dif);
-fll=lockfile_lock(fl);
+ if (dif.tv_sec > STALE_CHECK_INTERVAL) {
+ lockfile_remove_stale (l->locks_to_check);
+ l->last_stale_purge = now;
+ }
-filelist_print(fll,stdout);
+ return 1;
}
-#endif
+void
+serial_lock_free (Serial_lock * l)
+{
+ if (!l)
+ return;
+
+ if (l->locks_held) {
+ lockfile_unlock (l->locks_held);
+ filelist_free (l->locks_held);
+ }
+
+ if (l->locks_to_check) {
+ filelist_free (l->locks_to_check);
+ }
+
+ free (l);
+}
+
+
+Serial_lock *
+serial_lock_new (char *dev, int mode)
+{
+ Filelist *fl = lockfile_make_list (dev);
+ Serial_lock *l;
+
+ if (!fl)
+ return NULL;
+
+ l = (Serial_lock *) xmalloc (sizeof (Serial_lock));
+
+ l->mode = mode;
+ l->locks_to_check = fl;
+ l->locks_held = NULL;
+ memset (&l->last_stale_purge, 0, sizeof (l->last_stale_purge));
+
+ if (mode == SERIAL_LOCK_PASSIVE)
+ return l;
+
+ l->locks_held = lockfile_lock (l->locks_to_check);
+ if (!l->locks_held) {
+ serial_lock_free (l);
+ return NULL;
+ }
+
+ return l;
+}
+
+
+#if 0
+int
+main (int argc, char *argv[])
+{
+ Filelist *fl = lockfile_make_list ("/dev/ttyS0");
+ Filelist *fll;
+ Filelist_ent *fle;
+
+ filelist_print (fl, stdout);
+
+ fll = lockfile_lock (fl);
+
+ filelist_print (fll, stdout);
+}
+#endif