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If we cannot immediately get the pf_consistency_lock in the purge thread,

Browse Source 
restart the scan after acquiring the lock the hard way.  Otherwise we might
end up with a dead reference.

Reported by:		pfsense
Reviewed by:		eri
Initial patch by:	eri
Tested by:		pfsense
Approved by:		re (kib)
This commit is contained in:
Max Laier 2009-08-19 00:10:10 +00:00
parent 7f21e273a8
commit b5a6cecbcd
2 changed files with 70 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

89
sys/contrib/pf/net/pf.c
View File

@ -971,6 +971,9 @@ void
pf_purge_thread(void *v)
{
int nloops = 0, s;
#ifdef __FreeBSD__
int locked;
#endif
for (;;) {
tsleep(pf_purge_thread, PWAIT, "pftm", 1 * hz);
@ -978,14 +981,19 @@ pf_purge_thread(void *v)
#ifdef __FreeBSD__
sx_slock(&pf_consistency_lock);
PF_LOCK();
locked = 0;
if (pf_end_threads) {
pf_purge_expired_states(pf_status.states);
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
sx_xlock(&pf_consistency_lock);
PF_LOCK();
pf_purge_expired_states(pf_status.states, 1);
pf_purge_expired_fragments();
pf_purge_expired_src_nodes(0);
pf_purge_expired_src_nodes(1);
pf_end_threads++;
sx_sunlock(&pf_consistency_lock);
sx_xunlock(&pf_consistency_lock);
PF_UNLOCK();
wakeup(pf_purge_thread);
kproc_exit(0);
@ -994,20 +1002,44 @@ pf_purge_thread(void *v)
s = splsoftnet();
/* process a fraction of the state table every second */
#ifdef __FreeBSD__
if(!pf_purge_expired_states(1 + (pf_status.states
/ pf_default_rule.timeout[PFTM_INTERVAL]), 0)) {
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
sx_xlock(&pf_consistency_lock);
PF_LOCK();
locked = 1;
pf_purge_expired_states(1 + (pf_status.states
/ pf_default_rule.timeout[PFTM_INTERVAL]), 1);
}
#else
pf_purge_expired_states(1 + (pf_status.states
/ pf_default_rule.timeout[PFTM_INTERVAL]));
#endif
/* purge other expired types every PFTM_INTERVAL seconds */
if (++nloops >= pf_default_rule.timeout[PFTM_INTERVAL]) {
pf_purge_expired_fragments();
pf_purge_expired_src_nodes(0);
if (!pf_purge_expired_src_nodes(locked)) {
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
sx_xlock(&pf_consistency_lock);
PF_LOCK();
locked = 1;
pf_purge_expired_src_nodes(1);
}
nloops = 0;
}
splx(s);
#ifdef __FreeBSD__
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
if (locked)
sx_xunlock(&pf_consistency_lock);
else
sx_sunlock(&pf_consistency_lock);
#endif
}
}
@ -1056,8 +1088,13 @@ pf_state_expires(const struct pf_state *state)
return (state->expire + timeout);
}
#ifdef __FreeBSD__
int
pf_purge_expired_src_nodes(int waslocked)
#else
void
pf_purge_expired_src_nodes(int waslocked)
#endif
{
struct pf_src_node *cur, *next;
int locked = waslocked;
@ -1068,12 +1105,8 @@ pf_purge_expired_src_nodes(int waslocked)
if (cur->states <= 0 && cur->expire <= time_second) {
if (! locked) {
#ifdef __FreeBSD__
if (!sx_try_upgrade(&pf_consistency_lock)) {
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
sx_xlock(&pf_consistency_lock);
PF_LOCK();
}
if (!sx_try_upgrade(&pf_consistency_lock))
return (0);
#else
rw_enter_write(&pf_consistency_lock);
#endif
@ -1100,6 +1133,10 @@ pf_purge_expired_src_nodes(int waslocked)
#else
rw_exit_write(&pf_consistency_lock);
#endif
#ifdef __FreeBSD__
return (1);
#endif
}
void
@ -1202,12 +1239,21 @@ pf_free_state(struct pf_state *cur)
pf_status.states--;
}
#ifdef __FreeBSD__
int
pf_purge_expired_states(u_int32_t maxcheck, int waslocked)
#else
void
pf_purge_expired_states(u_int32_t maxcheck)
#endif
{
static struct pf_state *cur = NULL;
struct pf_state *next;
#ifdef __FreeBSD__
int locked = waslocked;
#else
int locked = 0;
#endif
while (maxcheck--) {
/* wrap to start of list when we hit the end */
@ -1224,12 +1270,8 @@ pf_purge_expired_states(u_int32_t maxcheck)
/* free unlinked state */
if (! locked) {
#ifdef __FreeBSD__
if (!sx_try_upgrade(&pf_consistency_lock)) {
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
sx_xlock(&pf_consistency_lock);
PF_LOCK();
}
if (!sx_try_upgrade(&pf_consistency_lock))
return (0);
#else
rw_enter_write(&pf_consistency_lock);
#endif
@ -1241,12 +1283,8 @@ pf_purge_expired_states(u_int32_t maxcheck)
pf_unlink_state(cur);
if (! locked) {
#ifdef __FreeBSD__
if (!sx_try_upgrade(&pf_consistency_lock)) {
PF_UNLOCK();
sx_sunlock(&pf_consistency_lock);
sx_xlock(&pf_consistency_lock);
PF_LOCK();
}
if (!sx_try_upgrade(&pf_consistency_lock))
return (0);
#else
rw_enter_write(&pf_consistency_lock);
#endif
@ -1257,10 +1295,13 @@ pf_purge_expired_states(u_int32_t maxcheck)
cur = next;
}
if (locked)
#ifdef __FreeBSD__
if (!waslocked && locked)
sx_downgrade(&pf_consistency_lock);
return (1);
#else
if (locked)
rw_exit_write(&pf_consistency_lock);
#endif
}

5
sys/contrib/pf/net/pfvar.h
View File

@ -1593,8 +1593,13 @@ extern struct pool pf_state_pl, pf_altq_pl, pf_pooladdr_pl;
extern struct pool pf_state_scrub_pl;
#endif
extern void pf_purge_thread(void *);
#ifdef __FreeBSD__
extern int pf_purge_expired_src_nodes(int);
extern int pf_purge_expired_states(u_int32_t, int);
#else
extern void pf_purge_expired_src_nodes(int);
extern void pf_purge_expired_states(u_int32_t);
#endif
extern void pf_unlink_state(struct pf_state *);
extern void pf_free_state(struct pf_state *);
extern int pf_insert_state(struct pfi_kif *,