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
This commit is contained in:
Alexander V. Chernikov
parent
ccd285e76c
commit
f3bfa7d1cf
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=286722
@ -130,6 +130,13 @@ static void arptimer(void *);
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static void in_arpinput(struct mbuf *);
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#endif
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static void arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr,
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struct ifnet *ifp, int bridged, struct llentry *la);
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static void arp_update_lle(struct arphdr *ah, struct ifnet *ifp,
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struct llentry *la);
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static void arp_mark_lle_reachable(struct llentry *la);
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static const struct netisr_handler arp_nh = {
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.nh_name = "arp",
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.nh_handler = arpintr,
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@ -576,10 +583,10 @@ in_arpinput(struct mbuf *m)
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struct sockaddr sa;
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struct in_addr isaddr, itaddr, myaddr;
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u_int8_t *enaddr = NULL;
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int op, flags;
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int op;
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int req_len;
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int bridged = 0, is_bridge = 0;
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int carped, create;
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int carped;
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struct sockaddr_in sin;
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sin.sin_len = sizeof(struct sockaddr_in);
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sin.sin_family = AF_INET;
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@ -708,6 +715,16 @@ in_arpinput(struct mbuf *m)
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"%s!\n", inet_ntoa(isaddr));
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goto drop;
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}
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if (ifp->if_addrlen != ah->ar_hln) {
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LLE_WUNLOCK(la);
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ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, "
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"i/f %d (ignored)\n", ifp->if_addrlen,
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(u_char *) ar_sha(ah), ":", ah->ar_hln,
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ifp->if_addrlen);
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goto drop;
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}
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/*
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* Warn if another host is using the same IP address, but only if the
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* IP address isn't 0.0.0.0, which is used for DHCP only, in which
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@ -730,100 +747,22 @@ in_arpinput(struct mbuf *m)
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sin.sin_len = sizeof(struct sockaddr_in);
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sin.sin_family = AF_INET;
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sin.sin_addr = isaddr;
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create = (itaddr.s_addr == myaddr.s_addr) ? 1 : 0;
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flags = LLE_EXCLUSIVE;
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IF_AFDATA_LOCK(ifp);
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if (create != 0)
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la = lla_create(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
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else
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la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
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IF_AFDATA_UNLOCK(ifp);
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if (la != NULL) {
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/* the following is not an error when doing bridging */
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if (!bridged && la->lle_tbl->llt_ifp != ifp) {
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if (log_arp_wrong_iface)
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ARP_LOG(LOG_WARNING, "%s is on %s "
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"but got reply from %*D on %s\n",
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inet_ntoa(isaddr),
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la->lle_tbl->llt_ifp->if_xname,
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ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
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ifp->if_xname);
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LLE_WUNLOCK(la);
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goto reply;
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}
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if ((la->la_flags & LLE_VALID) &&
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bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
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if (la->la_flags & LLE_STATIC) {
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LLE_WUNLOCK(la);
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if (log_arp_permanent_modify)
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ARP_LOG(LOG_ERR,
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"%*D attempts to modify "
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"permanent entry for %s on %s\n",
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ifp->if_addrlen,
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(u_char *)ar_sha(ah), ":",
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inet_ntoa(isaddr), ifp->if_xname);
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goto reply;
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}
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if (log_arp_movements) {
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ARP_LOG(LOG_INFO, "%s moved from %*D "
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"to %*D on %s\n",
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inet_ntoa(isaddr),
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ifp->if_addrlen,
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(u_char *)&la->ll_addr, ":",
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ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
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ifp->if_xname);
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}
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}
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if (ifp->if_addrlen != ah->ar_hln) {
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LLE_WUNLOCK(la);
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ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, "
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"i/f %d (ignored)\n", ifp->if_addrlen,
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(u_char *) ar_sha(ah), ":", ah->ar_hln,
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ifp->if_addrlen);
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goto drop;
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}
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(void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
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la->la_flags |= LLE_VALID;
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EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED);
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if (!(la->la_flags & LLE_STATIC)) {
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int canceled;
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LLE_ADDREF(la);
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la->la_expire = time_uptime + V_arpt_keep;
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canceled = callout_reset(&la->lle_timer,
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hz * V_arpt_keep, arptimer, la);
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if (canceled)
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LLE_REMREF(la);
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}
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la->la_asked = 0;
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la->la_preempt = V_arp_maxtries;
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IF_AFDATA_RLOCK(ifp);
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la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, (struct sockaddr *)&sin);
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IF_AFDATA_RUNLOCK(ifp);
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if (la != NULL)
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arp_check_update_lle(ah, isaddr, ifp, bridged, la);
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else if (itaddr.s_addr == myaddr.s_addr) {
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/*
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* The packets are all freed within the call to the output
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* routine.
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*
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* NB: The lock MUST be released before the call to the
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* output routine.
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* Reply to our address, but no lle exists yet.
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* do we really have to create an entry?
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*/
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if (la->la_hold != NULL) {
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struct mbuf *m_hold, *m_hold_next;
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m_hold = la->la_hold;
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la->la_hold = NULL;
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la->la_numheld = 0;
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lltable_fill_sa_entry(la, (struct sockaddr *)&sa);
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LLE_WUNLOCK(la);
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for (; m_hold != NULL; m_hold = m_hold_next) {
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m_hold_next = m_hold->m_nextpkt;
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m_hold->m_nextpkt = NULL;
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/* Avoid confusing lower layers. */
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m_clrprotoflags(m_hold);
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(*ifp->if_output)(ifp, m_hold, &sa, NULL);
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}
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} else
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LLE_WUNLOCK(la);
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IF_AFDATA_WLOCK(ifp);
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la = lla_create(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
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arp_update_lle(ah, ifp, la);
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IF_AFDATA_WUNLOCK(ifp);
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arp_mark_lle_reachable(la);
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LLE_WUNLOCK(la);
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}
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reply:
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if (op != ARPOP_REQUEST)
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@ -934,6 +873,140 @@ in_arpinput(struct mbuf *m)
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}
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#endif
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/*
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* Checks received arp data against existing @la.
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* Updates lle state/performs notification if necessary.
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*/
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static void
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arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr, struct ifnet *ifp,
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int bridged, struct llentry *la)
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{
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struct sockaddr sa;
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struct mbuf *m_hold, *m_hold_next;
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LLE_WLOCK_ASSERT(la);
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/* the following is not an error when doing bridging */
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if (!bridged && la->lle_tbl->llt_ifp != ifp) {
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if (log_arp_wrong_iface)
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ARP_LOG(LOG_WARNING, "%s is on %s "
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"but got reply from %*D on %s\n",
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inet_ntoa(isaddr),
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la->lle_tbl->llt_ifp->if_xname,
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ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
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ifp->if_xname);
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LLE_WUNLOCK(la);
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return;
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}
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if ((la->la_flags & LLE_VALID) &&
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bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
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if (la->la_flags & LLE_STATIC) {
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LLE_WUNLOCK(la);
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if (log_arp_permanent_modify)
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ARP_LOG(LOG_ERR,
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"%*D attempts to modify "
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"permanent entry for %s on %s\n",
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ifp->if_addrlen,
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(u_char *)ar_sha(ah), ":",
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inet_ntoa(isaddr), ifp->if_xname);
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return;
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}
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if (log_arp_movements) {
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ARP_LOG(LOG_INFO, "%s moved from %*D "
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"to %*D on %s\n",
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inet_ntoa(isaddr),
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ifp->if_addrlen,
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(u_char *)&la->ll_addr, ":",
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ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
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ifp->if_xname);
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}
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}
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/* Check if something has changed */
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if (memcmp(&la->ll_addr, ar_sha(ah), ifp->if_addrlen) != 0 ||
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(la->la_flags & LLE_VALID) == 0) {
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/* Perform real LLE update */
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/* use afdata WLOCK to update fields */
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LLE_ADDREF(la);
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LLE_WUNLOCK(la);
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IF_AFDATA_WLOCK(ifp);
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LLE_WLOCK(la);
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/*
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* Since we droppped LLE lock, other thread might have deleted
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* this lle. Check and return
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*/
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if ((la->la_flags & LLE_DELETED) != 0) {
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IF_AFDATA_WUNLOCK(ifp);
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LLE_FREE_LOCKED(la);
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return;
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}
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/* Update data */
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arp_update_lle(ah, ifp, la);
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IF_AFDATA_WUNLOCK(ifp);
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LLE_REMREF(la);
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}
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arp_mark_lle_reachable(la);
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/*
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* The packets are all freed within the call to the output
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* routine.
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*
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* NB: The lock MUST be released before the call to the
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* output routine.
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*/
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if (la->la_hold != NULL) {
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m_hold = la->la_hold;
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la->la_hold = NULL;
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la->la_numheld = 0;
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lltable_fill_sa_entry(la, &sa);
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LLE_WUNLOCK(la);
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for (; m_hold != NULL; m_hold = m_hold_next) {
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m_hold_next = m_hold->m_nextpkt;
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m_hold->m_nextpkt = NULL;
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/* Avoid confusing lower layers. */
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m_clrprotoflags(m_hold);
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(*ifp->if_output)(ifp, m_hold, &sa, NULL);
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}
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} else
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LLE_WUNLOCK(la);
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}
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/*
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* Updates @la fields used by fast path code.
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*/
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static void
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arp_update_lle(struct arphdr *ah, struct ifnet *ifp, struct llentry *la)
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{
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memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
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la->la_flags |= LLE_VALID;
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}
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static void
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arp_mark_lle_reachable(struct llentry *la)
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{
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int canceled;
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LLE_WLOCK_ASSERT(la);
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EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED);
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if (!(la->la_flags & LLE_STATIC)) {
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LLE_ADDREF(la);
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la->la_expire = time_uptime + V_arpt_keep;
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canceled = callout_reset(&la->lle_timer,
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hz * V_arpt_keep, arptimer, la);
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if (canceled)
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LLE_REMREF(la);
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}
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la->la_asked = 0;
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la->la_preempt = V_arp_maxtries;
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}
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void
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arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
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{
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