Diff below moves the code that updates an ARP cache into its own
function. The goal of this refactoring is to defer the insertion
of a route entry to a serialized context: a task.
Inserting a route might will possibly require the caller to sleep,
so this function will be called in the hot path if a route entry
already exist or in a task, after inserting a new route.
All ARP regress tests pass.
ok?
Index: netinet/if_ether.c
===================================================================
RCS file: /cvs/src/sys/netinet/if_ether.c,v
retrieving revision 1.205
diff -u -p -r1.205 if_ether.c
--- netinet/if_ether.c 27 Apr 2016 14:47:27 -0000 1.205
+++ netinet/if_ether.c 17 May 2016 12:42:10 -0000
@@ -83,6 +83,7 @@ void arptimer(void *);
struct rtentry *arplookup(u_int32_t, int, int, u_int);
void in_arpinput(struct mbuf *);
void in_revarpinput(struct mbuf *);
+int arpcache(struct ifnet *, struct ether_arp *, struct rtentry *);
LIST_HEAD(, llinfo_arp) arp_list;
struct pool arp_pool; /* pool for llinfo_arp structures */
@@ -451,17 +452,14 @@ in_arpinput(struct mbuf *m)
struct ether_arp *ea;
struct ifnet *ifp;
struct ether_header *eh;
- struct llinfo_arp *la = NULL;
struct rtentry *rt = NULL;
- struct sockaddr_dl *sdl;
struct sockaddr sa;
struct sockaddr_in sin;
struct in_addr isaddr, itaddr;
- struct mbuf *mh;
uint8_t enaddr[ETHER_ADDR_LEN];
char addr[INET_ADDRSTRLEN];
- int op, changed = 0, target = 0;
- unsigned int len, rdomain;
+ int op, target = 0;
+ unsigned int rdomain;
rdomain = rtable_l2(m->m_pkthdr.ph_rtableid);
@@ -481,14 +479,12 @@ in_arpinput(struct mbuf *m)
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
- if (ETHER_IS_MULTICAST(&ea->arp_sha[0])) {
- if (!memcmp(ea->arp_sha, etherbroadcastaddr,
- sizeof (ea->arp_sha))) {
- inet_ntop(AF_INET, &isaddr, addr, sizeof(addr));
- log(LOG_ERR, "arp: ether address is broadcast for "
- "IP address %s!\n", addr);
- goto out;
- }
+ if (ETHER_IS_MULTICAST(&ea->arp_sha[0]) &&
+ !memcmp(ea->arp_sha, etherbroadcastaddr, sizeof(ea->arp_sha))) {
+ inet_ntop(AF_INET, &isaddr, addr, sizeof(addr));
+ log(LOG_ERR, "arp: ether address is broadcast for IP address "
+ "%s!\n", addr);
+ goto out;
}
memcpy(enaddr, LLADDR(ifp->if_sadl), ETHER_ADDR_LEN);
@@ -521,101 +517,13 @@ in_arpinput(struct mbuf *m)
"duplicate IP address %s sent from ethernet address %s\n",
addr, ether_sprintf(ea->arp_sha));
itaddr = isaddr;
- } else if (rt != NULL && (sdl = satosdl(rt->rt_gateway)) != NULL) {
- la = (struct llinfo_arp *)rt->rt_llinfo;
- if (sdl->sdl_alen) {
- if (memcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) {
- if (rt->rt_flags &
- (RTF_PERMANENT_ARP|RTF_LOCAL)) {
- inet_ntop(AF_INET, &isaddr, addr,
- sizeof(addr));
- log(LOG_WARNING, "arp: attempt to"
- " overwrite permanent entry for %s"
- " by %s on %s\n", addr,
- ether_sprintf(ea->arp_sha),
- ifp->if_xname);
- goto out;
- } else if (rt->rt_ifidx != ifp->if_index) {
-#if NCARP > 0
- if (ifp->if_type != IFT_CARP)
-#endif
- {
- struct ifnet *rifp = if_get(
- rt->rt_ifidx);
- if (rifp == NULL)
- goto out;
- inet_ntop(AF_INET, &isaddr,
- addr, sizeof(addr));
- log(LOG_WARNING, "arp: attempt"
- " to overwrite entry for"
- " %s on %s by %s on %s\n",
- addr, rifp->if_xname,
- ether_sprintf(ea->arp_sha),
- ifp->if_xname);
- if_put(rifp);
- }
- goto out;
- } else {
- inet_ntop(AF_INET, &isaddr, addr,
- sizeof(addr));
- log(LOG_INFO, "arp info overwritten for"
- " %s by %s on %s\n", addr,
- ether_sprintf(ea->arp_sha),
- ifp->if_xname);
- rt->rt_expire = 1;/* no longer static */
- }
- changed = 1;
- }
- } else if (!if_isconnected(ifp, rt->rt_ifidx)) {
- struct ifnet *rifp = if_get(rt->rt_ifidx);
- if (rifp == NULL)
- goto out;
- inet_ntop(AF_INET, &isaddr, addr, sizeof(addr));
- log(LOG_WARNING,
- "arp: attempt to add entry for %s "
- "on %s by %s on %s\n", addr,
- rifp->if_xname,
- ether_sprintf(ea->arp_sha),
- ifp->if_xname);
- if_put(rifp);
+ } else if (rt != NULL) {
+ if (arpcache(ifp, ea, rt))
goto out;
- }
- sdl->sdl_alen = sizeof(ea->arp_sha);
- memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha));
- if (rt->rt_expire)
- rt->rt_expire = time_second + arpt_keep;
- rt->rt_flags &= ~RTF_REJECT;
- /* Notify userland that an ARP resolution has been done. */
- if (la->la_asked || changed) {
- KERNEL_LOCK();
- rt_sendmsg(rt, RTM_RESOLVE, ifp->if_rdomain);
- KERNEL_UNLOCK();
- }
- la->la_asked = 0;
- while ((len = ml_len(&la->la_ml)) != 0) {
- mh = ml_dequeue(&la->la_ml);
- la_hold_total--;
-
- ifp->if_output(ifp, mh, rt_key(rt), rt);
-
- if (ml_len(&la->la_ml) == len) {
- /* mbuf is back in queue. Discard. */
- while ((mh = ml_dequeue(&la->la_ml)) != NULL) {
- la_hold_total--;
- m_freem(mh);
- }
- break;
- }
- }
}
- if (op != ARPOP_REQUEST) {
-out:
- rtfree(rt);
- if_put(ifp);
- m_freem(m);
- return;
- }
+ if (op != ARPOP_REQUEST)
+ goto out;
rtfree(rt);
if (target) {
@@ -623,6 +531,8 @@ out:
memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
memcpy(ea->arp_sha, LLADDR(ifp->if_sadl), sizeof(ea->arp_sha));
} else {
+ struct sockaddr_dl *sdl;
+
rt = arplookup(itaddr.s_addr, 0, SIN_PROXY, rdomain);
if (rt == NULL)
goto out;
@@ -648,8 +558,107 @@ out:
sa.sa_len = sizeof(sa);
ifp->if_output(ifp, m, &sa, NULL);
if_put(ifp);
+ return;
+
+out:
+ rtfree(rt);
+ if_put(ifp);
+ m_freem(m);
}
+int
+arpcache(struct ifnet *ifp, struct ether_arp *ea, struct rtentry *rt)
+{
+ struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
+ struct sockaddr_dl *sdl = satosdl(rt->rt_gateway);
+ struct in_addr *spa = (struct in_addr *)ea->arp_spa;
+ char addr[INET_ADDRSTRLEN];
+ struct ifnet *rifp;
+ unsigned int len;
+ int changed = 0;
+
+ KASSERT(sdl != NULL);
+
+ if (sdl->sdl_alen > 0) {
+ if (memcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) {
+ if (ISSET(rt->rt_flags, RTF_PERMANENT_ARP|RTF_LOCAL)) {
+ inet_ntop(AF_INET, spa, addr, sizeof(addr));
+ log(LOG_WARNING, "arp: attempt to overwrite "
+ "permanent entry for %s by %s on %s\n", addr,
+ ether_sprintf(ea->arp_sha), ifp->if_xname);
+ return (-1);
+ } else if (rt->rt_ifidx != ifp->if_index) {
+#if NCARP > 0
+ if (ifp->if_type != IFT_CARP)
+#endif
+ {
+ rifp = if_get(rt->rt_ifidx);
+ if (rifp == NULL)
+ return (-1);
+ inet_ntop(AF_INET, spa, addr,
+ sizeof(addr));
+ log(LOG_WARNING, "arp: attempt to "
+ "overwrite entry for %s on %s by "
+ "%s on %s\n", addr, rifp->if_xname,
+ ether_sprintf(ea->arp_sha),
+ ifp->if_xname);
+ if_put(rifp);
+ }
+ return (-1);
+ } else {
+ inet_ntop(AF_INET, spa, addr, sizeof(addr));
+ log(LOG_INFO, "arp info overwritten for %s by "
+ "%s on %s\n", addr,
+ ether_sprintf(ea->arp_sha), ifp->if_xname);
+ rt->rt_expire = 1;/* no longer static */
+ }
+ changed = 1;
+ }
+ } else if (!if_isconnected(ifp, rt->rt_ifidx)) {
+ rifp = if_get(rt->rt_ifidx);
+ if (rifp == NULL)
+ return (-1);
+ inet_ntop(AF_INET, spa, addr, sizeof(addr));
+ log(LOG_WARNING, "arp: attempt to add entry for %s on %s by %s"
+ " on %s\n", addr, rifp->if_xname,
+ ether_sprintf(ea->arp_sha), ifp->if_xname);
+ if_put(rifp);
+ return (-1);
+ }
+ sdl->sdl_alen = sizeof(ea->arp_sha);
+ memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha));
+ if (rt->rt_expire)
+ rt->rt_expire = time_second + arpt_keep;
+ rt->rt_flags &= ~RTF_REJECT;
+
+ /* Notify userland that an ARP resolution has been done. */
+ if (la->la_asked || changed) {
+ KERNEL_LOCK();
+ rt_sendmsg(rt, RTM_RESOLVE, ifp->if_rdomain);
+ KERNEL_UNLOCK();
+ }
+
+ la->la_asked = 0;
+ while ((len = ml_len(&la->la_ml)) != 0) {
+ struct mbuf *mh;
+
+ mh = ml_dequeue(&la->la_ml);
+ la_hold_total--;
+
+ ifp->if_output(ifp, mh, rt_key(rt), rt);
+
+ if (ml_len(&la->la_ml) == len) {
+ /* mbuf is back in queue. Discard. */
+ while ((mh = ml_dequeue(&la->la_ml)) != NULL) {
+ la_hold_total--;
+ m_freem(mh);
+ }
+ break;
+ }
+ }
+
+ return (0);
+}
/*
* Free an arp entry.
*/
