From 0714812134d7dcadeb7ecfbfeb18788aa7e1eaac Mon Sep 17 00:00:00 2001 From: Jesse Gross Date: Fri, 3 Oct 2014 15:35:29 -0700 Subject: [PATCH] openvswitch: Eliminate memset() from flow_extract. As new protocols are added, the size of the flow key tends to increase although few protocols care about all of the fields. In order to optimize this for hashing and matching, OVS uses a variable length portion of the key. However, when fields are extracted from the packet we must still zero out the entire key. This is no longer necessary now that OVS implements masking. Any fields (or holes in the structure) which are not part of a given protocol will be by definition not part of the mask and zeroed out during lookup. Furthermore, since masking already uses variable length keys this zeroing operation automatically benefits as well. In principle, the only thing that needs to be done at this point is remove the memset() at the beginning of flow. However, some fields assume that they are initialized to zero, which now must be done explicitly. In addition, in the event of an error we must also zero out corresponding fields to signal that there is no valid data present. These increase the total amount of code but very little of it is executed in non-error situations. Removing the memset() reduces the profile of ovs_flow_extract() from 0.64% to 0.56% when tested with large packets on a 10G link. Suggested-by: Pravin Shelar Signed-off-by: Jesse Gross Signed-off-by: Andy Zhou Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/openvswitch/flow.c | 54 +++++++++++++++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 9 deletions(-) diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 4010423f2831..913bdc1a83c0 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -462,6 +462,7 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) * update skb->csum here. */ + key->eth.tci = 0; if (vlan_tx_tag_present(skb)) key->eth.tci = htons(skb->vlan_tci); else if (eth->h_proto == htons(ETH_P_8021Q)) @@ -482,6 +483,8 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) error = check_iphdr(skb); if (unlikely(error)) { + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv4, 0, sizeof(key->ipv4)); if (error == -EINVAL) { skb->transport_header = skb->network_header; error = 0; @@ -503,8 +506,10 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) return 0; } if (nh->frag_off & htons(IP_MF) || - skb_shinfo(skb)->gso_type & SKB_GSO_UDP) + skb_shinfo(skb)->gso_type & SKB_GSO_UDP) key->ip.frag = OVS_FRAG_TYPE_FIRST; + else + key->ip.frag = OVS_FRAG_TYPE_NONE; /* Transport layer. */ if (key->ip.proto == IPPROTO_TCP) { @@ -513,18 +518,25 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) key->tp.src = tcp->source; key->tp.dst = tcp->dest; key->tp.flags = TCP_FLAGS_BE16(tcp); + } else { + memset(&key->tp, 0, sizeof(key->tp)); } + } else if (key->ip.proto == IPPROTO_UDP) { if (udphdr_ok(skb)) { struct udphdr *udp = udp_hdr(skb); key->tp.src = udp->source; key->tp.dst = udp->dest; + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } else if (key->ip.proto == IPPROTO_SCTP) { if (sctphdr_ok(skb)) { struct sctphdr *sctp = sctp_hdr(skb); key->tp.src = sctp->source; key->tp.dst = sctp->dest; + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } else if (key->ip.proto == IPPROTO_ICMP) { if (icmphdr_ok(skb)) { @@ -534,33 +546,44 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) * them in 16-bit network byte order. */ key->tp.src = htons(icmp->type); key->tp.dst = htons(icmp->code); + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } - } else if ((key->eth.type == htons(ETH_P_ARP) || - key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) { + } else if (key->eth.type == htons(ETH_P_ARP) || + key->eth.type == htons(ETH_P_RARP)) { struct arp_eth_header *arp; arp = (struct arp_eth_header *)skb_network_header(skb); - if (arp->ar_hrd == htons(ARPHRD_ETHER) - && arp->ar_pro == htons(ETH_P_IP) - && arp->ar_hln == ETH_ALEN - && arp->ar_pln == 4) { + if (arphdr_ok(skb) && + arp->ar_hrd == htons(ARPHRD_ETHER) && + arp->ar_pro == htons(ETH_P_IP) && + arp->ar_hln == ETH_ALEN && + arp->ar_pln == 4) { /* We only match on the lower 8 bits of the opcode. */ if (ntohs(arp->ar_op) <= 0xff) key->ip.proto = ntohs(arp->ar_op); + else + key->ip.proto = 0; + memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src)); memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst)); ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha); ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha); + } else { + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv4, 0, sizeof(key->ipv4)); } } else if (key->eth.type == htons(ETH_P_IPV6)) { int nh_len; /* IPv6 Header + Extensions */ nh_len = parse_ipv6hdr(skb, key); if (unlikely(nh_len < 0)) { + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr)); if (nh_len == -EINVAL) { skb->transport_header = skb->network_header; error = 0; @@ -582,24 +605,32 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) key->tp.src = tcp->source; key->tp.dst = tcp->dest; key->tp.flags = TCP_FLAGS_BE16(tcp); + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } else if (key->ip.proto == NEXTHDR_UDP) { if (udphdr_ok(skb)) { struct udphdr *udp = udp_hdr(skb); key->tp.src = udp->source; key->tp.dst = udp->dest; + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } else if (key->ip.proto == NEXTHDR_SCTP) { if (sctphdr_ok(skb)) { struct sctphdr *sctp = sctp_hdr(skb); key->tp.src = sctp->source; key->tp.dst = sctp->dest; + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } else if (key->ip.proto == NEXTHDR_ICMP) { if (icmp6hdr_ok(skb)) { error = parse_icmpv6(skb, key, nh_len); if (error) return error; + } else { + memset(&key->tp, 0, sizeof(key->tp)); } } } @@ -615,13 +646,19 @@ int ovs_flow_key_extract(struct ovs_key_ipv4_tunnel *tun_key, struct sk_buff *skb, struct sw_flow_key *key) { /* Extract metadata from packet. */ - memset(key, 0, sizeof(*key)); if (tun_key) memcpy(&key->tun_key, tun_key, sizeof(key->tun_key)); + else + memset(&key->tun_key, 0, sizeof(key->tun_key)); key->phy.priority = skb->priority; key->phy.in_port = OVS_CB(skb)->input_vport->port_no; key->phy.skb_mark = skb->mark; + key->ovs_flow_hash = 0; + key->recirc_id = 0; + + /* Flags are always used as part of stats */ + key->tp.flags = 0; return key_extract(skb, key); } @@ -632,7 +669,6 @@ int ovs_flow_key_extract_userspace(const struct nlattr *attr, { int err; - memset(key, 0, sizeof(*key)); /* Extract metadata from netlink attributes. */ err = ovs_nla_get_flow_metadata(attr, key); if (err) -- 2.20.1