2 * Distributed under the terms of the GNU GPL version 2.
3 * Copyright (c) 2007, 2008, 2009, 2010 Nicira Networks.
5 * Significant portions of this file may be copied from parts of the Linux
6 * kernel, by Linus Torvalds and others.
11 #include <linux/netdevice.h>
12 #include <linux/etherdevice.h>
13 #include <linux/if_ether.h>
14 #include <linux/if_vlan.h>
15 #include <net/llc_pdu.h>
16 #include <linux/kernel.h>
17 #include <linux/jiffies.h>
18 #include <linux/llc.h>
19 #include <linux/module.h>
21 #include <linux/rcupdate.h>
22 #include <linux/if_arp.h>
23 #include <linux/if_ether.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/icmp.h>
32 struct kmem_cache *flow_cache;
36 __be16 ar_hrd; /* format of hardware address */
37 __be16 ar_pro; /* format of protocol address */
38 unsigned char ar_hln; /* length of hardware address */
39 unsigned char ar_pln; /* length of protocol address */
40 __be16 ar_op; /* ARP opcode (command) */
42 /* Ethernet+IPv4 specific members. */
43 unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
44 unsigned char ar_sip[4]; /* sender IP address */
45 unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
46 unsigned char ar_tip[4]; /* target IP address */
47 } __attribute__((packed));
49 static inline int arphdr_ok(struct sk_buff *skb)
51 int nh_ofs = skb_network_offset(skb);
52 return pskb_may_pull(skb, nh_ofs + sizeof(struct arp_eth_header));
55 static inline int iphdr_ok(struct sk_buff *skb)
57 int nh_ofs = skb_network_offset(skb);
58 if (skb->len >= nh_ofs + sizeof(struct iphdr)) {
59 int ip_len = ip_hdrlen(skb);
60 return (ip_len >= sizeof(struct iphdr)
61 && pskb_may_pull(skb, nh_ofs + ip_len));
66 static inline int tcphdr_ok(struct sk_buff *skb)
68 int th_ofs = skb_transport_offset(skb);
69 if (pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))) {
70 int tcp_len = tcp_hdrlen(skb);
71 return (tcp_len >= sizeof(struct tcphdr)
72 && skb->len >= th_ofs + tcp_len);
77 static inline int udphdr_ok(struct sk_buff *skb)
79 int th_ofs = skb_transport_offset(skb);
80 return pskb_may_pull(skb, th_ofs + sizeof(struct udphdr));
83 static inline int icmphdr_ok(struct sk_buff *skb)
85 int th_ofs = skb_transport_offset(skb);
86 return pskb_may_pull(skb, th_ofs + sizeof(struct icmphdr));
89 #define TCP_FLAGS_OFFSET 13
90 #define TCP_FLAG_MASK 0x3f
92 static inline struct ovs_tcphdr *ovs_tcp_hdr(const struct sk_buff *skb)
94 return (struct ovs_tcphdr *)skb_transport_header(skb);
97 void flow_used(struct sw_flow *flow, struct sk_buff *skb)
102 if (flow->key.dl_type == htons(ETH_P_IP) && iphdr_ok(skb)) {
103 struct iphdr *nh = ip_hdr(skb);
104 flow->ip_tos = nh->tos;
105 if (flow->key.nw_proto == IPPROTO_TCP && tcphdr_ok(skb)) {
106 u8 *tcp = (u8 *)tcp_hdr(skb);
107 tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
111 spin_lock_irqsave(&flow->lock, flags);
112 getnstimeofday(&flow->used);
113 flow->packet_count++;
114 flow->byte_count += skb->len;
115 flow->tcp_flags |= tcp_flags;
116 spin_unlock_irqrestore(&flow->lock, flags);
119 struct sw_flow_actions *flow_actions_alloc(size_t n_actions)
121 struct sw_flow_actions *sfa;
123 if (n_actions > (PAGE_SIZE - sizeof *sfa) / sizeof(union odp_action))
124 return ERR_PTR(-EINVAL);
126 sfa = kmalloc(sizeof *sfa + n_actions * sizeof(union odp_action),
129 return ERR_PTR(-ENOMEM);
131 sfa->n_actions = n_actions;
136 /* Frees 'flow' immediately. */
137 void flow_free(struct sw_flow *flow)
141 kfree(flow->sf_acts);
142 kmem_cache_free(flow_cache, flow);
145 /* RCU callback used by flow_deferred_free. */
146 static void rcu_free_flow_callback(struct rcu_head *rcu)
148 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
152 /* Schedules 'flow' to be freed after the next RCU grace period.
153 * The caller must hold rcu_read_lock for this to be sensible. */
154 void flow_deferred_free(struct sw_flow *flow)
156 call_rcu(&flow->rcu, rcu_free_flow_callback);
159 /* RCU callback used by flow_deferred_free_acts. */
160 static void rcu_free_acts_callback(struct rcu_head *rcu)
162 struct sw_flow_actions *sf_acts = container_of(rcu,
163 struct sw_flow_actions, rcu);
167 /* Schedules 'sf_acts' to be freed after the next RCU grace period.
168 * The caller must hold rcu_read_lock for this to be sensible. */
169 void flow_deferred_free_acts(struct sw_flow_actions *sf_acts)
171 call_rcu(&sf_acts->rcu, rcu_free_acts_callback);
174 #define SNAP_OUI_LEN 3
179 u8 dsap; /* Always 0xAA */
180 u8 ssap; /* Always 0xAA */
182 u8 oui[SNAP_OUI_LEN];
184 } __attribute__ ((packed));
186 static int is_snap(const struct eth_snap_hdr *esh)
188 return (esh->dsap == LLC_SAP_SNAP
189 && esh->ssap == LLC_SAP_SNAP
190 && !memcmp(esh->oui, "\0\0\0", 3));
193 /* Parses the Ethernet frame in 'skb', which was received on 'in_port',
194 * and initializes 'key' to match. Returns 1 if 'skb' contains an IP
195 * fragment, 0 otherwise. */
196 int flow_extract(struct sk_buff *skb, u16 in_port, struct odp_flow_key *key)
199 struct eth_snap_hdr *esh;
203 memset(key, 0, sizeof *key);
204 key->dl_vlan = htons(ODP_VLAN_NONE);
205 key->in_port = in_port;
207 if (skb->len < sizeof *eth)
209 if (!pskb_may_pull(skb, skb->len >= 64 ? 64 : skb->len)) {
213 skb_reset_mac_header(skb);
215 esh = (struct eth_snap_hdr *) eth;
216 nh_ofs = sizeof *eth;
217 if (likely(ntohs(eth->h_proto) >= ODP_DL_TYPE_ETH2_CUTOFF))
218 key->dl_type = eth->h_proto;
219 else if (skb->len >= sizeof *esh && is_snap(esh)) {
220 key->dl_type = esh->ethertype;
221 nh_ofs = sizeof *esh;
223 key->dl_type = htons(ODP_DL_TYPE_NOT_ETH_TYPE);
224 if (skb->len >= nh_ofs + sizeof(struct llc_pdu_un)) {
225 nh_ofs += sizeof(struct llc_pdu_un);
229 /* Check for a VLAN tag */
230 if (key->dl_type == htons(ETH_P_8021Q) &&
231 skb->len >= nh_ofs + sizeof(struct vlan_hdr)) {
232 struct vlan_hdr *vh = (struct vlan_hdr*)(skb->data + nh_ofs);
233 key->dl_type = vh->h_vlan_encapsulated_proto;
234 key->dl_vlan = vh->h_vlan_TCI & htons(VLAN_VID_MASK);
235 key->dl_vlan_pcp = (ntohs(vh->h_vlan_TCI) & VLAN_PCP_MASK) >> VLAN_PCP_SHIFT;
236 nh_ofs += sizeof(struct vlan_hdr);
238 memcpy(key->dl_src, eth->h_source, ETH_ALEN);
239 memcpy(key->dl_dst, eth->h_dest, ETH_ALEN);
240 skb_set_network_header(skb, nh_ofs);
243 if (key->dl_type == htons(ETH_P_IP) && iphdr_ok(skb)) {
244 struct iphdr *nh = ip_hdr(skb);
245 int th_ofs = nh_ofs + nh->ihl * 4;
246 key->nw_src = nh->saddr;
247 key->nw_dst = nh->daddr;
248 key->nw_tos = nh->tos & ~INET_ECN_MASK;
249 key->nw_proto = nh->protocol;
250 skb_set_transport_header(skb, th_ofs);
252 /* Transport layer. */
253 if (!(nh->frag_off & htons(IP_MF | IP_OFFSET))) {
254 if (key->nw_proto == IPPROTO_TCP) {
255 if (tcphdr_ok(skb)) {
256 struct tcphdr *tcp = tcp_hdr(skb);
257 key->tp_src = tcp->source;
258 key->tp_dst = tcp->dest;
260 /* Avoid tricking other code into
261 * thinking that this packet has an L4
265 } else if (key->nw_proto == IPPROTO_UDP) {
266 if (udphdr_ok(skb)) {
267 struct udphdr *udp = udp_hdr(skb);
268 key->tp_src = udp->source;
269 key->tp_dst = udp->dest;
271 /* Avoid tricking other code into
272 * thinking that this packet has an L4
276 } else if (key->nw_proto == IPPROTO_ICMP) {
277 if (icmphdr_ok(skb)) {
278 struct icmphdr *icmp = icmp_hdr(skb);
279 /* The ICMP type and code fields use the 16-bit
280 * transport port fields, so we need to store them
281 * in 16-bit network byte order. */
282 key->tp_src = htons(icmp->type);
283 key->tp_dst = htons(icmp->code);
285 /* Avoid tricking other code into
286 * thinking that this packet has an L4
294 } else if (key->dl_type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
295 struct arp_eth_header *arp;
297 arp = (struct arp_eth_header *)skb_network_header(skb);
299 if (arp->ar_hrd == htons(ARPHRD_ETHER)
300 && arp->ar_pro == htons(ETH_P_IP)
301 && arp->ar_hln == ETH_ALEN
302 && arp->ar_pln == 4) {
304 /* We only match on the lower 8 bits of the opcode. */
305 if (ntohs(arp->ar_op) <= 0xff) {
306 key->nw_proto = ntohs(arp->ar_op);
309 if (key->nw_proto == ARPOP_REQUEST
310 || key->nw_proto == ARPOP_REPLY) {
311 memcpy(&key->nw_src, arp->ar_sip, sizeof(key->nw_src));
312 memcpy(&key->nw_dst, arp->ar_tip, sizeof(key->nw_dst));
316 skb_reset_transport_header(skb);
321 /* Initializes the flow module.
322 * Returns zero if successful or a negative error code. */
325 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
327 if (flow_cache == NULL)
333 /* Uninitializes the flow module. */
336 kmem_cache_destroy(flow_cache);