forked from jengelh/iptables
71 lines
2.2 KiB
Diff
71 lines
2.2 KiB
Diff
|
Index: iptables-1.6.1/iptables/iptables-batch.c
|
||
|
|
===================================================================
|
||
|
|
--- iptables-1.6.1.orig/iptables/iptables-batch.c
|
||
|
|
+++ iptables-1.6.1/iptables/iptables-batch.c
|
||
|
|
@@ -404,6 +404,34 @@ main(int argc, char *argv[])
|
||
|
|
tables[3].handle = NULL;
|
||
|
|
current_table = &tables[0];
|
||
|
|
|
||
|
|
+ /*
|
||
|
|
+ * we need to lock the complete batch processing against parallel
|
||
|
|
+ * modification by other processes. Otherwise we can end up with
|
||
|
|
+ * EAGAIN errors.
|
||
|
|
+ *
|
||
|
|
+ * the do_command{4,6} function already locks itself, but the
|
||
|
|
+ * complete call sequence needs to be locked until the commit is
|
||
|
|
+ * performed.
|
||
|
|
+ *
|
||
|
|
+ * sadly the xtables_lock() implementation is not very cooperative.
|
||
|
|
+ * There's no unlock() equivalent. The lock file descriptor is smiply
|
||
|
|
+ * left open until the process exits. Thus we'd have deadlocks when
|
||
|
|
+ * calling do_command{4,6} the second time.
|
||
|
|
+ *
|
||
|
|
+ * To prevent this, part of this patch adds logic to avoid taking the
|
||
|
|
+ * lock a second time in the same process in xtables_lock()
|
||
|
|
+ */
|
||
|
|
+
|
||
|
|
+ const struct timeval wait_interval = {
|
||
|
|
+ .tv_sec = 1,
|
||
|
|
+ };
|
||
|
|
+
|
||
|
|
+ if( xtables_lock(-1, &wait_interval) != true )
|
||
|
|
+ {
|
||
|
|
+ fprintf(stderr, "failed to acquire the xtables lock\n");
|
||
|
|
+ exit(1);
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
while((r = getline(&iline, &llen, fp)) != -1)
|
||
|
|
{
|
||
|
|
if(llen < 1 || !*iline)
|
||
|
|
Index: iptables-1.6.1/iptables/xshared.c
|
||
|
|
===================================================================
|
||
|
|
--- iptables-1.6.1.orig/iptables/xshared.c
|
||
|
|
+++ iptables-1.6.1/iptables/xshared.c
|
||
|
|
@@ -250,8 +250,14 @@ void xs_init_match(struct xtables_match
|
||
|
|
bool xtables_lock(int wait, struct timeval *wait_interval)
|
||
|
|
{
|
||
|
|
struct timeval time_left, wait_time, waited_time;
|
||
|
|
+ static bool already_locked = false;
|
||
|
|
int fd, i = 0;
|
||
|
|
|
||
|
|
+ if( already_locked ) {
|
||
|
|
+ // avoid dead-locks, see iptables-batch.c
|
||
|
|
+ return true;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
time_left.tv_sec = wait;
|
||
|
|
time_left.tv_usec = 0;
|
||
|
|
waited_time.tv_sec = 0;
|
||
|
|
@@ -262,8 +268,10 @@ bool xtables_lock(int wait, struct timev
|
||
|
|
return true;
|
||
|
|
|
||
|
|
while (1) {
|
||
|
|
- if (flock(fd, LOCK_EX | LOCK_NB) == 0)
|
||
|
|
+ if (flock(fd, LOCK_EX | LOCK_NB) == 0) {
|
||
|
|
+ already_locked = true;
|
||
|
|
return true;
|
||
|
|
+ }
|
||
|
|
if (++i % 10 == 0) {
|
||
|
|
if (wait != -1)
|
||
|
|
fprintf(stderr, "Another app is currently holding the xtables lock; "
|