From 06bb56f43c30f9759a004f72400f9d3216975afa Mon Sep 17 00:00:00 2001 From: Andre Oppermann Date: Mon, 3 May 2004 13:52:47 +0000 Subject: [PATCH] Optimize IP fastforwarding some more: o New function ip_findroute() to reduce code duplication for the route lookup cases. (luigi) o Store ip_len in host byte order on the stack instead of using it via indirection from the mbuf. This allows to defer the host byte conversion to a later point and makes a quicker fallback to normal ip_input() processing. (luigi) o Check if route is dampned with RTF_REJECT flag and drop packet already here when ARP is unable to resolve destination address. An ICMP unreachable is sent to inform the sender. o Check if interface output queue is full and drop packet already here. No ICMP notification is sent because signalling source quench is depreciated. o Check if media_state is down (used for ethernet type interfaces) and drop the packet already here. An ICMP unreachable is sent to inform the sender. o Do not account sent packets to the interface address counters. They are only for packets with that 'ia' as source address. o Update and clarify some comments. Submitted by: luigi (most of it) --- sys/netinet/ip_fastfwd.c | 209 +++++++++++++++++++++------------------ 1 file changed, 114 insertions(+), 95 deletions(-) diff --git a/sys/netinet/ip_fastfwd.c b/sys/netinet/ip_fastfwd.c index 3463a33df6e1..a73c499e17d9 100644 --- a/sys/netinet/ip_fastfwd.c +++ b/sys/netinet/ip_fastfwd.c @@ -117,6 +117,42 @@ static int ipfastforward_active = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, fastforwarding, CTLFLAG_RW, &ipfastforward_active, 0, "Enable fast IP forwarding"); +static struct sockaddr_in * +ip_findroute(struct route *ro, in_addr_t dest, struct mbuf *m) +{ + struct sockaddr_in *dst; + struct rtentry *rt; + + /* + * Find route to destination. + */ + bzero(ro, sizeof(*ro)); + dst = (struct sockaddr_in *)&ro->ro_dst; + dst->sin_family = AF_INET; + dst->sin_len = sizeof(*dst); + dst->sin_addr.s_addr = dest; + rtalloc_ign(ro, RTF_CLONING); + + /* + * Route there and interface still up? + */ + rt = ro->ro_rt; + if (rt && (rt->rt_flags & RTF_UP) && + (rt->rt_ifp->if_flags & IFF_UP) && + (rt->rt_ifp->if_flags & IFF_RUNNING)) { + if (rt->rt_flags & RTF_GATEWAY) + dst = (struct sockaddr_in *)rt->rt_gateway; + } else { + ipstat.ips_noroute++; + ipstat.ips_cantforward++; + if (rt) + RTFREE(rt); + icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, NULL); + return NULL; + } + return dst; +} + /* * Try to forward a packet based on the destination address. * This is a fast path optimized for the plain forwarding case. @@ -137,10 +173,10 @@ ip_fastforward(struct mbuf *m) struct sockaddr_in *dst = NULL; struct in_ifaddr *ia = NULL; struct ifaddr *ifa = NULL; - struct ifnet *ifp = NULL; + struct ifnet *ifp; struct ip_fw_args args; in_addr_t odest, dest; - u_short sum; + u_short sum, ip_len; int error = 0; int hlen, ipfw, mtu; @@ -153,6 +189,8 @@ ip_fastforward(struct mbuf *m) M_ASSERTVALID(m); M_ASSERTPKTHDR(m); + ro.ro_rt = NULL; + /* * Step 1: check for packet drop conditions (and sanity checks) */ @@ -217,16 +255,12 @@ ip_fastforward(struct mbuf *m) } m->m_pkthdr.csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); - /* - * Convert to host representation - */ - ip->ip_len = ntohs(ip->ip_len); - ip->ip_off = ntohs(ip->ip_off); + ip_len = ntohs(ip->ip_len); /* * Is IP length longer than packet we have got? */ - if (m->m_pkthdr.len < ip->ip_len) { + if (m->m_pkthdr.len < ip_len) { ipstat.ips_tooshort++; goto drop; } @@ -234,12 +268,12 @@ ip_fastforward(struct mbuf *m) /* * Is packet longer than IP header tells us? If yes, truncate packet. */ - if (m->m_pkthdr.len > ip->ip_len) { + if (m->m_pkthdr.len > ip_len) { if (m->m_len == m->m_pkthdr.len) { - m->m_len = ip->ip_len; - m->m_pkthdr.len = ip->ip_len; + m->m_len = ip_len; + m->m_pkthdr.len = ip_len; } else - m_adj(m, ip->ip_len - m->m_pkthdr.len); + m_adj(m, ip_len - m->m_pkthdr.len); } /* @@ -258,8 +292,16 @@ ip_fastforward(struct mbuf *m) /* * Only IP packets without options */ - if (ip->ip_hl != (sizeof(struct ip) >> 2)) - goto fallback; + if (ip->ip_hl != (sizeof(struct ip) >> 2)) { + if (ip_doopts == 1) + return 0; + else if (ip_doopts == 2) { + icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_FILTER_PROHIB, + 0, NULL); + return 1; + } + /* else ignore IP options and continue */ + } /* * Only unicast IP, not from loopback, no L2 or IP broadcast, @@ -277,14 +319,14 @@ ip_fastforward(struct mbuf *m) IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || ip->ip_dst.s_addr == INADDR_ANY ) - goto fallback; + return 0; /* * Is it for a local address on this host? */ LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) { if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr) - goto fallback; + return 0; } /* @@ -296,16 +338,10 @@ ip_fastforward(struct mbuf *m) continue; ia = ifatoia(ifa); if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr) - goto fallback; + return 0; if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == ip->ip_dst.s_addr) - goto fallback; - continue; -fallback: - /* return packet back to netisr for slow processing */ - ip->ip_len = htons(ip->ip_len); - ip->ip_off = htons(ip->ip_off); - return 0; + return 0; } } ipstat.ips_total++; @@ -314,6 +350,12 @@ ip_fastforward(struct mbuf *m) * Step 3: incoming packet firewall processing */ + /* + * Convert to host representation + */ + ip->ip_len = ntohs(ip->ip_len); + ip->ip_off = ntohs(ip->ip_off); + odest = dest = ip->ip_dst.s_addr; #ifdef PFIL_HOOKS /* @@ -462,31 +504,9 @@ ip_fastforward(struct mbuf *m) /* * Find route to destination. */ - bzero(&ro, sizeof(ro)); - dst = (struct sockaddr_in *)&ro.ro_dst; - dst->sin_family = AF_INET; - dst->sin_len = sizeof(*dst); - dst->sin_addr.s_addr = dest; - rtalloc_ign(&ro, RTF_CLONING); - - /* - * Route there and interface still up? - */ - if (ro.ro_rt && - (ro.ro_rt->rt_flags & RTF_UP) && - (ro.ro_rt->rt_ifp->if_flags & IFF_UP)) { - ia = ifatoia(ro.ro_rt->rt_ifa); - ifp = ro.ro_rt->rt_ifp; - if (ro.ro_rt->rt_flags & RTF_GATEWAY) - dst = (struct sockaddr_in *)ro.ro_rt->rt_gateway; - } else { - ipstat.ips_noroute++; - ipstat.ips_cantforward++; - icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, NULL); - if (ro.ro_rt) - RTFREE(ro.ro_rt); - return 1; - } + if ((dst = ip_findroute(&ro, dest, m)) == NULL) + return 1; /* icmp unreach already sent */ + ifp = ro.ro_rt->rt_ifp; /* * Step 5: outgoing firewall packet processing @@ -497,8 +517,7 @@ ip_fastforward(struct mbuf *m) * Run through list of hooks for output packets. */ if (pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT) || m == NULL) { - RTFREE(ro.ro_rt); - return 1; + goto consumed; } M_ASSERTVALID(m); @@ -518,10 +537,9 @@ ip_fastforward(struct mbuf *m) M_ASSERTVALID(m); M_ASSERTPKTHDR(m); - if ((ipfw & IP_FW_PORT_DENY_FLAG) || m == NULL) { - RTFREE(ro.ro_rt); + if ((ipfw & IP_FW_PORT_DENY_FLAG) || m == NULL) goto drop; - } + if (DUMMYNET_LOADED && (ipfw & IP_FW_PORT_DYNT_FLAG) != 0) { /* * XXX note: if the ifp or rt entry are deleted @@ -531,8 +549,7 @@ ip_fastforward(struct mbuf *m) args.dst = dst; ip_dn_io_ptr(m, ipfw & 0xffff, DN_TO_IP_OUT, &args); - RTFREE(ro.ro_rt); - return 1; + goto consumed; } #ifdef IPDIVERT if (ipfw != 0 && (ipfw & IP_FW_PORT_DYNT_FLAG) == 0) { @@ -573,8 +590,7 @@ ip_fastforward(struct mbuf *m) */ m = clone; if ((ipfw & IP_FW_PORT_TEE_FLAG) == 0) { - RTFREE(ro.ro_rt); - return 1; + goto consumed; } /* Continue if it was tee */ goto passout; @@ -609,8 +625,6 @@ ip_fastforward(struct mbuf *m) sizeof(struct sockaddr_in *), M_NOWAIT); if (mtag == NULL) { - if (ro.ro_rt) - RTFREE(ro.ro_rt); goto drop; } *(struct sockaddr_in **)(mtag+1) = @@ -639,37 +653,42 @@ ip_fastforward(struct mbuf *m) * Redo route lookup with new destination address */ RTFREE(ro.ro_rt); - bzero(&ro, sizeof(ro)); - dst = (struct sockaddr_in *)&ro.ro_dst; - dst->sin_family = AF_INET; - dst->sin_len = sizeof(*dst); - dst->sin_addr.s_addr = dest; - rtalloc_ign(&ro, RTF_CLONING); - - /* - * Route there and interface still up? - */ - if (ro.ro_rt && - (ro.ro_rt->rt_flags & RTF_UP) && - (ro.ro_rt->rt_ifp->if_flags & IFF_UP)) { - ia = ifatoia(ro.ro_rt->rt_ifa); - ifp = ro.ro_rt->rt_ifp; - if (ro.ro_rt->rt_flags & RTF_GATEWAY) - dst = (struct sockaddr_in *)ro.ro_rt->rt_gateway; - } else { - ipstat.ips_noroute++; - ipstat.ips_cantforward++; - icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, NULL); - if (ro.ro_rt) - RTFREE(ro.ro_rt); - return 1; - } + if ((dst = ip_findroute(&ro, dest, m)) == NULL) + return 1; /* icmp unreach already sent */ + ifp = ro.ro_rt->rt_ifp; } /* * Step 6: send off the packet */ + /* + * Check if route is dampned (when ARP is unable to resolve) + */ + if ((ro.ro_rt->rt_flags & RTF_REJECT) && + ro.ro_rt->rt_rmx.rmx_expire >= time_second) { + icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, NULL); + goto consumed; + } + + /* + * Check if there is enough space in the interface queue + */ + if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= + ifp->if_snd.ifq_maxlen) { + ipstat.ips_odropped++; + /* would send source quench here but that is depreciated */ + goto drop; + } + + /* + * Check if media link state of interface is not down + */ + if (ifp->if_link_state == LINK_STATE_DOWN) { + icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, NULL); + goto consumed; + } + /* * Check if packet fits MTU or if hardware will fragement for us */ @@ -690,29 +709,26 @@ ip_fastforward(struct mbuf *m) */ error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, ro.ro_rt); - if (ia) { - ia->ia_ifa.if_opackets++; - ia->ia_ifa.if_obytes += m->m_pkthdr.len; - } } else { /* - * Handle EMSGSIZE with icmp reply - * needfrag for TCP MTU discovery + * Handle EMSGSIZE with icmp reply needfrag for TCP MTU discovery */ if (ip->ip_off & IP_DF) { + ipstat.ips_cantfrag++; icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0, ifp); - ipstat.ips_cantfrag++; - RTFREE(ro.ro_rt); - return 1; + goto consumed; } else { /* * We have to fragement the packet */ m->m_pkthdr.csum_flags |= CSUM_IP; + /* + * ip_fragment expects ip_len and ip_off in host byte + * order but returns all packets in network byte order + */ if (ip_fragment(ip, &m, mtu, ifp->if_hwassist, (~ifp->if_hwassist & CSUM_DELAY_IP))) { - RTFREE(ro.ro_rt); goto drop; } KASSERT(m != NULL, ("null mbuf and no error")); @@ -748,10 +764,13 @@ ip_fastforward(struct mbuf *m) ipstat.ips_forward++; ipstat.ips_fastforward++; } +consumed: RTFREE(ro.ro_rt); return 1; drop: if (m) m_freem(m); + if (ro.ro_rt) + RTFREE(ro.ro_rt); return 1; }