--- /dev/null
+/*
+ * Copyright (c) 2007-2013 Nicira, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ * This code is derived from kernel flow_dissector.c
+ */
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/if_vlan.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <linux/igmp.h>
+#include <linux/icmp.h>
+#include <linux/sctp.h>
+#include <linux/dccp.h>
+#include <linux/if_tunnel.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_defs.h>
+#include <net/flow_keys.h>
+
+
+/* copy saddr & daddr, possibly using 64bit load/store
+ * Equivalent to : flow->src = iph->saddr;
+ * flow->dst = iph->daddr;
+ */
+static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph)
+{
+ BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
+ offsetof(typeof(*flow), src) + sizeof(flow->src));
+ memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
+}
+
+static bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
+{
+ int poff, nhoff = skb_network_offset(skb);
+ u8 ip_proto;
+ __be16 proto = skb->protocol;
+
+ memset(flow, 0, sizeof(*flow));
+
+again:
+ switch (proto) {
+ case __constant_htons(ETH_P_IP): {
+ const struct iphdr *iph;
+ struct iphdr _iph;
+ip:
+ iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+ if (!iph)
+ return false;
+
+ if (ip_is_fragment(iph))
+ ip_proto = 0;
+ else
+ ip_proto = iph->protocol;
+ iph_to_flow_copy_addrs(flow, iph);
+ nhoff += iph->ihl * 4;
+ break;
+ }
+ case __constant_htons(ETH_P_IPV6): {
+ const struct ipv6hdr *iph;
+ struct ipv6hdr _iph;
+ipv6:
+ iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+ if (!iph)
+ return false;
+
+ ip_proto = iph->nexthdr;
+ flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
+ flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
+ nhoff += sizeof(struct ipv6hdr);
+ break;
+ }
+ case __constant_htons(ETH_P_8021Q): {
+ const struct vlan_hdr *vlan;
+ struct vlan_hdr _vlan;
+
+ vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
+ if (!vlan)
+ return false;
+
+ proto = vlan->h_vlan_encapsulated_proto;
+ nhoff += sizeof(*vlan);
+ goto again;
+ }
+ case __constant_htons(ETH_P_PPP_SES): {
+ struct {
+ struct pppoe_hdr hdr;
+ __be16 proto;
+ } *hdr, _hdr;
+ hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
+ if (!hdr)
+ return false;
+ proto = hdr->proto;
+ nhoff += PPPOE_SES_HLEN;
+ switch (proto) {
+ case __constant_htons(PPP_IP):
+ goto ip;
+ case __constant_htons(PPP_IPV6):
+ goto ipv6;
+ default:
+ return false;
+ }
+ }
+ default:
+ return false;
+ }
+
+ switch (ip_proto) {
+ case IPPROTO_GRE: {
+ struct gre_hdr {
+ __be16 flags;
+ __be16 proto;
+ } *hdr, _hdr;
+
+ hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
+ if (!hdr)
+ return false;
+ /*
+ * Only look inside GRE if version zero and no
+ * routing
+ */
+ if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
+ proto = hdr->proto;
+ nhoff += 4;
+ if (hdr->flags & GRE_CSUM)
+ nhoff += 4;
+ if (hdr->flags & GRE_KEY)
+ nhoff += 4;
+ if (hdr->flags & GRE_SEQ)
+ nhoff += 4;
+ if (proto == htons(ETH_P_TEB)) {
+ const struct ethhdr *eth;
+ struct ethhdr _eth;
+
+ eth = skb_header_pointer(skb, nhoff,
+ sizeof(_eth), &_eth);
+ if (!eth)
+ return false;
+ proto = eth->h_proto;
+ nhoff += sizeof(*eth);
+ }
+ goto again;
+ }
+ break;
+ }
+ case IPPROTO_IPIP:
+ goto again;
+ default:
+ break;
+ }
+
+ flow->ip_proto = ip_proto;
+ poff = proto_ports_offset(ip_proto);
+ if (poff >= 0) {
+ __be32 *ports, _ports;
+
+ nhoff += poff;
+ ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
+ if (ports)
+ flow->ports = *ports;
+ }
+
+ flow->thoff = (u16) nhoff;
+
+ return true;
+}
+
+static u32 hashrnd __read_mostly;
+
+static void init_hashrnd(void)
+{
+ if (likely(hashrnd))
+ return;
+ get_random_bytes(&hashrnd, sizeof(hashrnd));
+}
+
+u32 __skb_get_rxhash(struct sk_buff *skb)
+{
+ struct flow_keys keys;
+ u32 hash;
+
+ if (!skb_flow_dissect(skb, &keys))
+ return 0;
+
+ /* get a consistent hash (same value on both flow directions) */
+ if (((__force u32)keys.dst < (__force u32)keys.src) ||
+ (((__force u32)keys.dst == (__force u32)keys.src) &&
+ ((__force u16)keys.port16[1] < (__force u16)keys.port16[0]))) {
+ swap(keys.dst, keys.src);
+ swap(keys.port16[0], keys.port16[1]);
+ }
+
+ init_hashrnd();
+
+ hash = jhash_3words((__force u32)keys.dst,
+ (__force u32)keys.src,
+ (__force u32)keys.ports, hashrnd);
+ if (!hash)
+ hash = 1;
+
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,34)
+ skb->rxhash = hash;
+#endif
+ return hash;
+}
+#endif
git://git.onelab.eu / sliver-openvswitch.git / blobdiff