Author: melifaro
Date: Thu Aug 13 13:38:09 2015
New Revision: 286722
URL: https://svnweb.freebsd.org/changeset/base/286722
Log:
Move lle update code from from gigantic ip_arpinput() to
separate bunch of functions. The goal is to isolate actual lle
updates to permit more fine-grained locking.
Do all lle link-level update under AFDATA wlock.
Sponsored by: Yandex LLC
Modified:
head/sys/netinet/if_ether.c
Modified: head/sys/netinet/if_ether.c
==============================================================================
--- head/sys/netinet/if_ether.c Thu Aug 13 13:21:00 2015 (r286721)
+++ head/sys/netinet/if_ether.c Thu Aug 13 13:38:09 2015 (r286722)
@@ -130,6 +130,13 @@ static void arptimer(void *);
static void in_arpinput(struct mbuf *);
#endif
+static void arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr,
+ struct ifnet *ifp, int bridged, struct llentry *la);
+static void arp_update_lle(struct arphdr *ah, struct ifnet *ifp,
+ struct llentry *la);
+static void arp_mark_lle_reachable(struct llentry *la);
+
+
static const struct netisr_handler arp_nh = {
.nh_name = "arp",
.nh_handler = arpintr,
@@ -576,10 +583,10 @@ in_arpinput(struct mbuf *m)
struct sockaddr sa;
struct in_addr isaddr, itaddr, myaddr;
u_int8_t *enaddr = NULL;
- int op, flags;
+ int op;
int req_len;
int bridged = 0, is_bridge = 0;
- int carped, create;
+ int carped;
struct sockaddr_in sin;
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_family = AF_INET;
@@ -708,6 +715,16 @@ match:
"%s!\n", inet_ntoa(isaddr));
goto drop;
}
+
+ if (ifp->if_addrlen != ah->ar_hln) {
+ LLE_WUNLOCK(la);
+ ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, "
+ "i/f %d (ignored)\n", ifp->if_addrlen,
+ (u_char *) ar_sha(ah), ":", ah->ar_hln,
+ ifp->if_addrlen);
+ goto drop;
+ }
+
/*
* Warn if another host is using the same IP address, but only if the
* IP address isn't 0.0.0.0, which is used for DHCP only, in which
@@ -730,100 +747,22 @@ match:
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_family = AF_INET;
sin.sin_addr = isaddr;
- create = (itaddr.s_addr == myaddr.s_addr) ? 1 : 0;
- flags = LLE_EXCLUSIVE;
- IF_AFDATA_LOCK(ifp);
- if (create != 0)
- la = lla_create(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
- else
- la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
- IF_AFDATA_UNLOCK(ifp);
- if (la != NULL) {
- /* the following is not an error when doing bridging */
- if (!bridged && la->lle_tbl->llt_ifp != ifp) {
- if (log_arp_wrong_iface)
- ARP_LOG(LOG_WARNING, "%s is on %s "
- "but got reply from %*D on %s\n",
- inet_ntoa(isaddr),
- la->lle_tbl->llt_ifp->if_xname,
- ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
- ifp->if_xname);
- LLE_WUNLOCK(la);
- goto reply;
- }
- if ((la->la_flags & LLE_VALID) &&
- bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
- if (la->la_flags & LLE_STATIC) {
- LLE_WUNLOCK(la);
- if (log_arp_permanent_modify)
- ARP_LOG(LOG_ERR,
- "%*D attempts to modify "
- "permanent entry for %s on %s\n",
- ifp->if_addrlen,
- (u_char *)ar_sha(ah), ":",
- inet_ntoa(isaddr), ifp->if_xname);
- goto reply;
- }
- if (log_arp_movements) {
- ARP_LOG(LOG_INFO, "%s moved from %*D "
- "to %*D on %s\n",
- inet_ntoa(isaddr),
- ifp->if_addrlen,
- (u_char *)&la->ll_addr, ":",
- ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
- ifp->if_xname);
- }
- }
-
- if (ifp->if_addrlen != ah->ar_hln) {
- LLE_WUNLOCK(la);
- ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, "
- "i/f %d (ignored)\n", ifp->if_addrlen,
- (u_char *) ar_sha(ah), ":", ah->ar_hln,
- ifp->if_addrlen);
- goto drop;
- }
- (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
- la->la_flags |= LLE_VALID;
-
- EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED);
-
- if (!(la->la_flags & LLE_STATIC)) {
- int canceled;
-
- LLE_ADDREF(la);
- la->la_expire = time_uptime + V_arpt_keep;
- canceled = callout_reset(&la->lle_timer,
- hz * V_arpt_keep, arptimer, la);
- if (canceled)
- LLE_REMREF(la);
- }
- la->la_asked = 0;
- la->la_preempt = V_arp_maxtries;
+ IF_AFDATA_RLOCK(ifp);
+ la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, (struct sockaddr *)&sin);
+ IF_AFDATA_RUNLOCK(ifp);
+ if (la != NULL)
+ arp_check_update_lle(ah, isaddr, ifp, bridged, la);
+ else if (itaddr.s_addr == myaddr.s_addr) {
/*
- * The packets are all freed within the call to the output
- * routine.
- *
- * NB: The lock MUST be released before the call to the
- * output routine.
+ * Reply to our address, but no lle exists yet.
+ * do we really have to create an entry?
*/
- if (la->la_hold != NULL) {
- struct mbuf *m_hold, *m_hold_next;
-
- m_hold = la->la_hold;
- la->la_hold = NULL;
- la->la_numheld = 0;
- lltable_fill_sa_entry(la, (struct sockaddr *)&sa);
- LLE_WUNLOCK(la);
- for (; m_hold != NULL; m_hold = m_hold_next) {
- m_hold_next = m_hold->m_nextpkt;
- m_hold->m_nextpkt = NULL;
- /* Avoid confusing lower layers. */
- m_clrprotoflags(m_hold);
- (*ifp->if_output)(ifp, m_hold, &sa, NULL);
- }
- } else
- LLE_WUNLOCK(la);
+ IF_AFDATA_WLOCK(ifp);
+ la = lla_create(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
+ arp_update_lle(ah, ifp, la);
+ IF_AFDATA_WUNLOCK(ifp);
+ arp_mark_lle_reachable(la);
+ LLE_WUNLOCK(la);
}
reply:
if (op != ARPOP_REQUEST)
@@ -934,6 +873,140 @@ drop:
}
#endif
+/*
+ * Checks received arp data against existing @la.
+ * Updates lle state/performs notification if necessary.
+ */
+static void
+arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr, struct ifnet
*ifp,
+ int bridged, struct llentry *la)
+{
+ struct sockaddr sa;
+ struct mbuf *m_hold, *m_hold_next;
+
+ LLE_WLOCK_ASSERT(la);
+
+ /* the following is not an error when doing bridging */
+ if (!bridged && la->lle_tbl->llt_ifp != ifp) {
+ if (log_arp_wrong_iface)
+ ARP_LOG(LOG_WARNING, "%s is on %s "
+ "but got reply from %*D on %s\n",
+ inet_ntoa(isaddr),
+ la->lle_tbl->llt_ifp->if_xname,
+ ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
+ ifp->if_xname);
+ LLE_WUNLOCK(la);
+ return;
+ }
+ if ((la->la_flags & LLE_VALID) &&
+ bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
+ if (la->la_flags & LLE_STATIC) {
+ LLE_WUNLOCK(la);
+ if (log_arp_permanent_modify)
+ ARP_LOG(LOG_ERR,
+ "%*D attempts to modify "
+ "permanent entry for %s on %s\n",
+ ifp->if_addrlen,
+ (u_char *)ar_sha(ah), ":",
+ inet_ntoa(isaddr), ifp->if_xname);
+ return;
+ }
+ if (log_arp_movements) {
+ ARP_LOG(LOG_INFO, "%s moved from %*D "
+ "to %*D on %s\n",
+ inet_ntoa(isaddr),
+ ifp->if_addrlen,
+ (u_char *)&la->ll_addr, ":",
+ ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
+ ifp->if_xname);
+ }
+ }
+
+ /* Check if something has changed */
+ if (memcmp(&la->ll_addr, ar_sha(ah), ifp->if_addrlen) != 0 ||
+ (la->la_flags & LLE_VALID) == 0) {
+ /* Perform real LLE update */
+ /* use afdata WLOCK to update fields */
+ LLE_ADDREF(la);
+ LLE_WUNLOCK(la);
+ IF_AFDATA_WLOCK(ifp);
+ LLE_WLOCK(la);
+
+ /*
+ * Since we droppped LLE lock, other thread might have deleted
+ * this lle. Check and return
+ */
+ if ((la->la_flags & LLE_DELETED) != 0) {
+ IF_AFDATA_WUNLOCK(ifp);
+ LLE_FREE_LOCKED(la);
+ return;
+ }
+
+ /* Update data */
+ arp_update_lle(ah, ifp, la);
+
+ IF_AFDATA_WUNLOCK(ifp);
+ LLE_REMREF(la);
+ }
+
+ arp_mark_lle_reachable(la);
+
+ /*
+ * The packets are all freed within the call to the output
+ * routine.
+ *
+ * NB: The lock MUST be released before the call to the
+ * output routine.
+ */
+ if (la->la_hold != NULL) {
+ m_hold = la->la_hold;
+ la->la_hold = NULL;
+ la->la_numheld = 0;
+ lltable_fill_sa_entry(la, &sa);
+ LLE_WUNLOCK(la);
+ for (; m_hold != NULL; m_hold = m_hold_next) {
+ m_hold_next = m_hold->m_nextpkt;
+ m_hold->m_nextpkt = NULL;
+ /* Avoid confusing lower layers. */
+ m_clrprotoflags(m_hold);
+ (*ifp->if_output)(ifp, m_hold, &sa, NULL);
+ }
+ } else
+ LLE_WUNLOCK(la);
+}
+
+/*
+ * Updates @la fields used by fast path code.
+ */
+static void
+arp_update_lle(struct arphdr *ah, struct ifnet *ifp, struct llentry *la)
+{
+
+ memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
+ la->la_flags |= LLE_VALID;
+}
+
+static void
+arp_mark_lle_reachable(struct llentry *la)
+{
+ int canceled;
+
+ LLE_WLOCK_ASSERT(la);
+
+ EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED);
+
+ if (!(la->la_flags & LLE_STATIC)) {
+ LLE_ADDREF(la);
+ la->la_expire = time_uptime + V_arpt_keep;
+ canceled = callout_reset(&la->lle_timer,
+ hz * V_arpt_keep, arptimer, la);
+ if (canceled)
+ LLE_REMREF(la);
+ }
+ la->la_asked = 0;
+ la->la_preempt = V_arp_maxtries;
+}
+
void
arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
{
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