mirror of
https://github.com/opnsense/src.git
synced 2026-06-09 08:43:19 -04:00
add locking
NB: There is a known LOR on the forwarding path; this needs to be resolved
together with a similar issue in the bridge. For the moment it is
believed to be benign.
Sponsored by: FreeBSD Fondation
This commit is contained in:
Sam Leffler
parent
b9651df42c
commit
638ed548b7
2 changed files with 123 additions and 74 deletions
|
|
@ -38,8 +38,10 @@
|
|||
|
||||
#include <sys/param.h>
|
||||
#include <sys/systm.h>
|
||||
#include <sys/lock.h>
|
||||
#include <sys/malloc.h>
|
||||
#include <sys/mbuf.h>
|
||||
#include <sys/mutex.h>
|
||||
#include <sys/protosw.h>
|
||||
#include <sys/socket.h>
|
||||
#include <sys/kernel.h>
|
||||
|
|
@ -59,10 +61,31 @@
|
|||
#define IPFLOW_TIMER (5 * PR_SLOWHZ)
|
||||
#define IPFLOW_HASHBITS 6 /* should not be a multiple of 8 */
|
||||
#define IPFLOW_HASHSIZE (1 << IPFLOW_HASHBITS)
|
||||
static LIST_HEAD(ipflowhead, ipflow) ipflows[IPFLOW_HASHSIZE];
|
||||
#if IPFLOW_HASHSIZE > 255
|
||||
#error "make ipf_hash larger"
|
||||
#endif
|
||||
static struct ipflow_head ipflows[IPFLOW_HASHSIZE];
|
||||
static int ipflow_inuse;
|
||||
#define IPFLOW_MAX 256
|
||||
|
||||
/*
|
||||
* Each flow list has a lock that guards updates to the list and to
|
||||
* all entries on the list. Flow entries hold the hash index for
|
||||
* finding the head of the list so the lock can be found quickly.
|
||||
*
|
||||
* ipflow_inuse holds a count of the number of flow entries present.
|
||||
* This is used to bound the size of the table. When IPFLOW_MAX entries
|
||||
* are present and an additional entry is needed one is chosen for
|
||||
* replacement. We could use atomic ops for this counter but having it
|
||||
* inconsistent doesn't appear to be a problem.
|
||||
*/
|
||||
#define IPFLOW_HEAD_LOCK(_ipfh) mtx_lock(&(_ipfh)->ipfh_mtx)
|
||||
#define IPFLOW_HEAD_UNLOCK(_ipfh) mtx_unlock(&(_ipfh)->ipfh_mtx)
|
||||
#define IPFLOW_LOCK(_ipf) \
|
||||
IPFLOW_HEAD_LOCK(&ipflows[(_ipf)->ipf_hash])
|
||||
#define IPFLOW_UNLOCK(_ipf) \
|
||||
IPFLOW_HEAD_UNLOCK(&ipflows[(_ipf)->ipf_hash])
|
||||
|
||||
static int ipflow_active = 0;
|
||||
SYSCTL_INT(_net_inet_ip, IPCTL_FASTFORWARDING, fastforwarding, CTLFLAG_RW,
|
||||
&ipflow_active, 0, "Enable flow-based IP forwarding");
|
||||
|
|
@ -70,10 +93,7 @@ SYSCTL_INT(_net_inet_ip, IPCTL_FASTFORWARDING, fastforwarding, CTLFLAG_RW,
|
|||
static MALLOC_DEFINE(M_IPFLOW, "ip_flow", "IP flow");
|
||||
|
||||
static unsigned
|
||||
ipflow_hash(
|
||||
struct in_addr dst,
|
||||
struct in_addr src,
|
||||
unsigned tos)
|
||||
ipflow_hash(struct in_addr dst, struct in_addr src, unsigned tos)
|
||||
{
|
||||
unsigned hash = tos;
|
||||
int idx;
|
||||
|
|
@ -83,28 +103,30 @@ ipflow_hash(
|
|||
}
|
||||
|
||||
static struct ipflow *
|
||||
ipflow_lookup(
|
||||
const struct ip *ip)
|
||||
ipflow_lookup(const struct ip *ip)
|
||||
{
|
||||
unsigned hash;
|
||||
struct ipflow_head *head;
|
||||
struct ipflow *ipf;
|
||||
|
||||
hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
|
||||
head = &ipflows[hash];
|
||||
|
||||
ipf = LIST_FIRST(&ipflows[hash]);
|
||||
while (ipf != NULL) {
|
||||
IPFLOW_HEAD_LOCK(head);
|
||||
LIST_FOREACH(ipf, &head->ipfh_head, ipf_next) {
|
||||
if (ip->ip_dst.s_addr == ipf->ipf_dst.s_addr
|
||||
&& ip->ip_src.s_addr == ipf->ipf_src.s_addr
|
||||
&& ip->ip_tos == ipf->ipf_tos)
|
||||
break;
|
||||
ipf = LIST_NEXT(ipf, ipf_next);
|
||||
&& ip->ip_tos == ipf->ipf_tos) {
|
||||
/* NB: return head locked */
|
||||
return ipf;
|
||||
}
|
||||
}
|
||||
return ipf;
|
||||
IPFLOW_HEAD_UNLOCK(head);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
int
|
||||
ipflow_fastforward(
|
||||
struct mbuf *m)
|
||||
ipflow_fastforward(struct mbuf *m)
|
||||
{
|
||||
struct ip *ip;
|
||||
struct ipflow *ipf;
|
||||
|
|
@ -134,14 +156,18 @@ ipflow_fastforward(
|
|||
* Route and interface still up?
|
||||
*/
|
||||
rt = ipf->ipf_ro.ro_rt;
|
||||
if ((rt->rt_flags & RTF_UP) == 0 || (rt->rt_ifp->if_flags & IFF_UP) == 0)
|
||||
if ((rt->rt_flags & RTF_UP) == 0 || (rt->rt_ifp->if_flags & IFF_UP) == 0) {
|
||||
IPFLOW_UNLOCK(ipf);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Packet size OK? TTL?
|
||||
*/
|
||||
if (m->m_pkthdr.len > rt->rt_ifp->if_mtu || ip->ip_ttl <= IPTTLDEC)
|
||||
if (m->m_pkthdr.len > rt->rt_ifp->if_mtu || ip->ip_ttl <= IPTTLDEC) {
|
||||
IPFLOW_UNLOCK(ipf);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Everything checks out and so we can forward this packet.
|
||||
|
|
@ -170,12 +196,12 @@ ipflow_fastforward(
|
|||
else
|
||||
ipf->ipf_errors++;
|
||||
}
|
||||
IPFLOW_UNLOCK(ipf);
|
||||
return 1;
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
ipflow_addstats(
|
||||
struct ipflow *ipf)
|
||||
ipflow_addstats(struct ipflow *ipf)
|
||||
{
|
||||
ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses;
|
||||
ipstat.ips_cantforward += ipf->ipf_errors + ipf->ipf_dropped;
|
||||
|
|
@ -183,36 +209,21 @@ ipflow_addstats(
|
|||
ipstat.ips_fastforward += ipf->ipf_uses;
|
||||
}
|
||||
|
||||
static void
|
||||
ipflow_free(
|
||||
struct ipflow *ipf)
|
||||
{
|
||||
int s;
|
||||
/*
|
||||
* Remove the flow from the hash table (at elevated IPL).
|
||||
* Once it's off the list, we can deal with it at normal
|
||||
* network IPL.
|
||||
*/
|
||||
s = splimp();
|
||||
LIST_REMOVE(ipf, ipf_next);
|
||||
splx(s);
|
||||
ipflow_addstats(ipf);
|
||||
RTFREE(ipf->ipf_ro.ro_rt);
|
||||
ipflow_inuse--;
|
||||
free(ipf, M_IPFLOW);
|
||||
}
|
||||
|
||||
/*
|
||||
* XXX the locking here makes reaping an entry very expensive...
|
||||
*/
|
||||
static struct ipflow *
|
||||
ipflow_reap(
|
||||
void)
|
||||
ipflow_reap(void)
|
||||
{
|
||||
struct ipflow *ipf, *maybe_ipf = NULL;
|
||||
struct ipflow *victim = NULL;
|
||||
struct ipflow *ipf;
|
||||
int idx;
|
||||
int s;
|
||||
|
||||
for (idx = 0; idx < IPFLOW_HASHSIZE; idx++) {
|
||||
ipf = LIST_FIRST(&ipflows[idx]);
|
||||
while (ipf != NULL) {
|
||||
struct ipflow_head *head = &ipflows[idx];
|
||||
|
||||
IPFLOW_HEAD_LOCK(head);
|
||||
LIST_FOREACH(ipf, &head->ipfh_head, ipf_next) {
|
||||
/*
|
||||
* If this no longer points to a valid route
|
||||
* reclaim it.
|
||||
|
|
@ -224,38 +235,58 @@ ipflow_reap(
|
|||
* or has had the least uses in the last 1.5
|
||||
* intervals.
|
||||
*/
|
||||
if (maybe_ipf == NULL
|
||||
|| ipf->ipf_timer < maybe_ipf->ipf_timer
|
||||
|| (ipf->ipf_timer == maybe_ipf->ipf_timer
|
||||
if (victim == NULL)
|
||||
victim = ipf;
|
||||
else if (ipf->ipf_timer < victim->ipf_timer
|
||||
|| (ipf->ipf_timer == victim->ipf_timer
|
||||
&& ipf->ipf_last_uses + ipf->ipf_uses <
|
||||
maybe_ipf->ipf_last_uses +
|
||||
maybe_ipf->ipf_uses))
|
||||
maybe_ipf = ipf;
|
||||
ipf = LIST_NEXT(ipf, ipf_next);
|
||||
victim->ipf_last_uses + victim->ipf_uses)) {
|
||||
if (victim->ipf_hash != ipf->ipf_hash)
|
||||
IPFLOW_UNLOCK(victim);
|
||||
victim = ipf;
|
||||
}
|
||||
}
|
||||
if (victim && victim->ipf_hash != idx)
|
||||
IPFLOW_HEAD_UNLOCK(head);
|
||||
}
|
||||
ipf = maybe_ipf;
|
||||
ipf = victim;
|
||||
done:
|
||||
/*
|
||||
* Remove the entry from the flow table.
|
||||
*/
|
||||
s = splimp();
|
||||
LIST_REMOVE(ipf, ipf_next);
|
||||
splx(s);
|
||||
IPFLOW_UNLOCK(ipf);
|
||||
|
||||
ipflow_addstats(ipf);
|
||||
RTFREE(ipf->ipf_ro.ro_rt);
|
||||
return ipf;
|
||||
}
|
||||
|
||||
static void
|
||||
ipflow_free(struct ipflow *ipf)
|
||||
{
|
||||
/*
|
||||
* Remove the flow from the hash table.
|
||||
*/
|
||||
LIST_REMOVE(ipf, ipf_next);
|
||||
|
||||
ipflow_addstats(ipf);
|
||||
RTFREE(ipf->ipf_ro.ro_rt);
|
||||
ipflow_inuse--;
|
||||
free(ipf, M_IPFLOW);
|
||||
}
|
||||
|
||||
void
|
||||
ipflow_slowtimo(
|
||||
void)
|
||||
ipflow_slowtimo(void)
|
||||
{
|
||||
struct ipflow *ipf;
|
||||
int idx;
|
||||
|
||||
for (idx = 0; idx < IPFLOW_HASHSIZE; idx++) {
|
||||
ipf = LIST_FIRST(&ipflows[idx]);
|
||||
struct ipflow_head *head = &ipflows[idx];
|
||||
|
||||
IPFLOW_HEAD_LOCK(head);
|
||||
ipf = LIST_FIRST(&head->ipfh_head);
|
||||
while (ipf != NULL) {
|
||||
struct ipflow *next_ipf = LIST_NEXT(ipf, ipf_next);
|
||||
if (--ipf->ipf_timer == 0) {
|
||||
|
|
@ -269,18 +300,15 @@ ipflow_slowtimo(
|
|||
}
|
||||
ipf = next_ipf;
|
||||
}
|
||||
IPFLOW_HEAD_UNLOCK(head);
|
||||
}
|
||||
}
|
||||
|
||||
void
|
||||
ipflow_create(
|
||||
const struct route *ro,
|
||||
struct mbuf *m)
|
||||
ipflow_create(const struct route *ro, struct mbuf *m)
|
||||
{
|
||||
const struct ip *const ip = mtod(m, struct ip *);
|
||||
struct ipflow *ipf;
|
||||
unsigned hash;
|
||||
int s;
|
||||
|
||||
/*
|
||||
* Don't create cache entries for ICMP messages.
|
||||
|
|
@ -304,12 +332,18 @@ ipflow_create(
|
|||
ipflow_inuse++;
|
||||
}
|
||||
bzero((caddr_t) ipf, sizeof(*ipf));
|
||||
|
||||
ipf->ipf_hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
|
||||
ipf->ipf_dst = ip->ip_dst;
|
||||
ipf->ipf_src = ip->ip_src;
|
||||
ipf->ipf_tos = ip->ip_tos;
|
||||
|
||||
IPFLOW_LOCK(ipf);
|
||||
} else {
|
||||
s = splimp();
|
||||
LIST_REMOVE(ipf, ipf_next);
|
||||
splx(s);
|
||||
ipflow_addstats(ipf);
|
||||
RTFREE(ipf->ipf_ro.ro_rt);
|
||||
|
||||
ipflow_addstats(ipf); /* add stats to old route */
|
||||
RTFREE(ipf->ipf_ro.ro_rt); /* clear reference */
|
||||
ipf->ipf_uses = ipf->ipf_last_uses = 0;
|
||||
ipf->ipf_errors = ipf->ipf_dropped = 0;
|
||||
}
|
||||
|
|
@ -319,15 +353,23 @@ ipflow_create(
|
|||
*/
|
||||
ipf->ipf_ro = *ro;
|
||||
ro->ro_rt->rt_refcnt++;
|
||||
ipf->ipf_dst = ip->ip_dst;
|
||||
ipf->ipf_src = ip->ip_src;
|
||||
ipf->ipf_tos = ip->ip_tos;
|
||||
ipf->ipf_timer = IPFLOW_TIMER;
|
||||
/*
|
||||
* Insert into the approriate bucket of the flow table.
|
||||
*/
|
||||
hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
|
||||
s = splimp();
|
||||
LIST_INSERT_HEAD(&ipflows[hash], ipf, ipf_next);
|
||||
splx(s);
|
||||
LIST_INSERT_HEAD(&ipflows[ipf->ipf_hash].ipfh_head, ipf, ipf_next);
|
||||
IPFLOW_UNLOCK(ipf);
|
||||
}
|
||||
|
||||
static void
|
||||
ipflow_init(void)
|
||||
{
|
||||
int idx;
|
||||
|
||||
for (idx = 0; idx < IPFLOW_HASHSIZE; idx++) {
|
||||
struct ipflow_head *head = &ipflows[idx];
|
||||
LIST_INIT(&head->ipfh_head);
|
||||
mtx_init(&head->ipfh_mtx, "ipflow list head", NULL, MTX_DEF);
|
||||
}
|
||||
}
|
||||
SYSINIT(ipflow, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipflow_init, 0);
|
||||
|
|
|
|||
|
|
@ -44,6 +44,8 @@ struct ipflow {
|
|||
struct in_addr ipf_dst; /* destination address */
|
||||
struct in_addr ipf_src; /* source address */
|
||||
|
||||
/* NB: this assumes the size of the list head hash table is <=256 */
|
||||
u_int8_t ipf_hash; /* index in list head table */
|
||||
u_int8_t ipf_tos; /* type-of-service */
|
||||
struct route ipf_ro; /* associated route entry */
|
||||
u_long ipf_uses; /* number of uses in this period */
|
||||
|
|
@ -54,4 +56,9 @@ struct ipflow {
|
|||
u_long ipf_last_uses; /* number of uses in last period */
|
||||
};
|
||||
|
||||
struct ipflow_head {
|
||||
LIST_HEAD(ipflowhead, ipflow) ipfh_head;
|
||||
struct mtx ipfh_mtx;
|
||||
};
|
||||
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in a new issue