Hi All
I'm testing this patch to permit synchronization of states that use
route-to or reply-to for policy routing, this patch apply to OpenBSD
v4.6 -stable, this is the problem:
when pfsync send an state that uses route-to or reply-to option to the
other machine, it only sends only current next-hop address in rt_addr
member of pfsync_state struct, the peer gets the pfsync data and it
will try to insert the state and bind it to ruleset, when the
secondary machine gets active and a packet going to pass through pf
will try to process pf_route if the state matches with a rule with
route/reply option, but the interface information hadn't inserted into
the state so the state will has st->rt_kif = NULL then the packet will
be droped in pf_route function.
To complete the route/reply option of one state and keep compatibility
with pfsync_state structure, we can use the data space holding by pad
member into pfsync_state_peer, it seems to not be used by other
function, so we can free rename it, I rename it as ex_info (extra info),
so we can use it to put the info to complete the state. The ex_info
data is 6 bytes length so we can't put the st->rt_kif->pfik_name data
here. We can put the relative position of the rt_kif into the
route/reply pool, this manner we need only 2 bytes to send the integer
that represents the relative position into the pool, this position
will only tell us
where the interface can be found, it no necesary be the exact pool, so
when a peer
receives the pfsync data it can bind it into the pool if the both
ruleset have a checksum match.
I made some tests and it is running fine, this patch can be ported to
the -current version of cvs, but we need to make a little changes
beacuse rpool member of pf_rule struct has a new name: route.
The modified functions was: pfsync_state_export, pfsync_state_import
and pfsync_in_upd, the pfsync_in_upd was inserted a new state with
flags equal to zero, now it insert the new state with the pkt->flags,
so if the ruleset checksum matches this state will be attached to the
ruleset in pfsync_state_import function
===================================================================
RCS file: src/sys/net/RCS/if_pfsync.c,v
retrieving revision 1.127
diff -u -r1.127 src/sys/net/if_pfsync.c
--- src/sys/net/if_pfsync.c 2010/01/13 23:06:38 1.127
+++ src/sys/net/if_pfsync.c 2010/01/14 21:45:18
@@ -398,6 +398,9 @@
void
pfsync_state_export(struct pfsync_state *sp, struct pf_state *st)
{
+ struct pf_pooladdr *acur = NULL;
+ struct pf_rule *r = NULL;
+ int count = 0;
bzero(sp, sizeof(struct pfsync_state));
/* copy from state key */
@@ -449,6 +452,20 @@
else
sp->nat_rule = htonl(st->nat_rule.ptr->nr);
+ /* insert the rpool position reference for route-to states */
+ if(st->rt_kif) {
+ if(sp->rule != htonl(-1) && ntohl(sp->rule) <
pf_main_ruleset.rules[PF_RULESET_FILTER].active.rcount)
+ r =
pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr_array[ntohl(sp->rule)];
+ if(r != NULL) {
+ TAILQ_FOREACH(acur, &r->rpool.list, entries) {
+ count++;
+ if(st->rt_kif == acur->kif)
+ break;
+ }
+ }
+ bcopy(&count, &sp->dst.ex_info, sizeof(count));
+ }
+
pf_state_counter_hton(st->packets[0], sp->packets[0]);
pf_state_counter_hton(st->packets[1], sp->packets[1]);
pf_state_counter_hton(st->bytes[0], sp->bytes[0]);
@@ -465,6 +482,9 @@
struct pfi_kif *kif;
int pool_flags;
int error;
+ struct pf_pooladdr *acur;
+ int count;
+ int i;
if (sp->creatorid == 0 && pf_status.debug >= PF_DEBUG_MISC) {
printf("pfsync_state_import: invalid creator id:"
@@ -563,6 +583,19 @@
st->nat_rule.ptr = NULL;
st->anchor.ptr = NULL;
st->rt_kif = NULL;
+ /* try to insert the route-to kif for this state */
+ if(r != &pf_default_rule && r->rpool.cur) {
+ bcopy(&sp->dst.ex_info, &count, sizeof(count));
+ i = 0;
+ TAILQ_FOREACH(acur, &r->rpool.list, entries) {
+ i++;
+ if(i == count) {
+ st->rt_kif = acur->kif;
+ break;
+ }
+ }
+ }
+
st->pfsync_time = time_uptime;
st->sync_state = PFSYNC_S_NONE;
@@ -916,7 +949,7 @@
st = pf_find_state_byid(&id_key);
if (st == NULL) {
/* insert the update */
- if (pfsync_state_import(sp, 0))
+ if (pfsync_state_import(sp, pkt->flags))
pfsyncstats.pfsyncs_badstate++;
continue;
}
===================================================================
RCS file: src/sys/net/RCS/pfvar.h,v
retrieving revision 1.290
diff -u -r1.290 src/sys/net/pfvar.h
--- src/sys/net/pfvar.h 2010/01/13 23:33:23 1.290
+++ src/sys/net/pfvar.h 2010/01/14 19:38:00
@@ -826,7 +826,7 @@
u_int16_t mss; /* Maximum segment size option */
u_int8_t state; /* active state level */
u_int8_t wscale; /* window scaling factor */
- u_int8_t pad[6];
+ u_int8_t ex_info[6];
} __packed;
struct pfsync_state_key {
I sent the other patch before, this patch add a new member to
pfsync_state to hold the ifname of the interface in route/reply-to
state, but to use this patch you will need to recompile some dependent
pfvar.h applications (like pfctl) to use the new data structure, this
patch is used in OpenBSD v4.6 -stable too:
===================================================================
RCS file: src/sys/net/RCS/if_pfsync.c,v
retrieving revision 1.127
diff -u -r1.127 src/sys/net/if_pfsync.c
--- src/sys/net/if_pfsync.c 2010/01/13 23:06:38 1.127
+++ src/sys/net/if_pfsync.c 2010/01/14 01:14:22
@@ -415,6 +415,9 @@
/* copy from state */
strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname));
bcopy(&st->rt_addr, &sp->rt_addr, sizeof(sp->rt_addr));
+ /* if state has route-to option, export rt interface name too*/
+ if(st->rt_kif)
+ strlcpy(sp->rt_ifname, st->rt_kif->pfik_name,
sizeof(sp->rt_ifname));
sp->creation = htonl(time_second - st->creation);
sp->expire = pf_state_expires(st);
if (sp->expire <= time_second)
@@ -562,7 +565,12 @@
st->rule.ptr = r;
st->nat_rule.ptr = NULL;
st->anchor.ptr = NULL;
- st->rt_kif = NULL;
+ /* if the state had mached with ruleset we can bind the
+ interface for route-to, reply-to rules */
+ if(r != &pf_default_rule && r->rpool.cur)
+ st->rt_kif = pfi_kif_get(sp->rt_ifname);
+ else
+ st->rt_kif = NULL;
st->pfsync_time = time_uptime;
st->sync_state = PFSYNC_S_NONE;
@@ -916,7 +924,7 @@
st = pf_find_state_byid(&id_key);
if (st == NULL) {
/* insert the update */
- if (pfsync_state_import(sp, 0))
+ if (pfsync_state_import(sp, pkt->flags))
pfsyncstats.pfsyncs_badstate++;
continue;
}
===================================================================
RCS file: src/sys/net/RCS/pfvar.h,v
retrieving revision 1.290
diff -u -r1.290 src/sys/net/pfvar.h
--- src/sys/net/pfvar.h 2010/01/14 01:04:54 1.290
+++ src/sys/net/pfvar.h 2010/01/14 01:08:05
@@ -841,6 +841,7 @@
struct pfsync_state_peer src;
struct pfsync_state_peer dst;
struct pf_addr rt_addr;
+ char rt_ifname[IFNAMSIZ];
u_int32_t rule;
u_int32_t anchor;
u_int32_t nat_rule;
I hope this can help for some one, please let me know if anybody have
another idea to sync route-to, reply-to states. please send me your suggestions
- Romey
