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/jhash.h>
18 #include <linux/jiffies.h>
19 #include <linux/llc.h>
20 #include <linux/module.h>
22 #include <linux/rcupdate.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_ether.h>
26 #include <linux/tcp.h>
27 #include <linux/udp.h>
28 #include <linux/icmp.h>
29 #include <net/inet_ecn.h>
34 struct kmem_cache *flow_cache;
35 static unsigned int hash_seed;
39 __be16 ar_hrd; /* format of hardware address */
40 __be16 ar_pro; /* format of protocol address */
41 unsigned char ar_hln; /* length of hardware address */
42 unsigned char ar_pln; /* length of protocol address */
43 __be16 ar_op; /* ARP opcode (command) */
45 /* Ethernet+IPv4 specific members. */
46 unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
47 unsigned char ar_sip[4]; /* sender IP address */
48 unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
49 unsigned char ar_tip[4]; /* target IP address */
50 } __attribute__((packed));
52 static inline int arphdr_ok(struct sk_buff *skb)
54 int nh_ofs = skb_network_offset(skb);
55 return pskb_may_pull(skb, nh_ofs + sizeof(struct arp_eth_header));
58 static inline int iphdr_ok(struct sk_buff *skb)
60 int nh_ofs = skb_network_offset(skb);
61 if (skb->len >= nh_ofs + sizeof(struct iphdr)) {
62 int ip_len = ip_hdrlen(skb);
63 return (ip_len >= sizeof(struct iphdr)
64 && pskb_may_pull(skb, nh_ofs + ip_len));
69 static inline int tcphdr_ok(struct sk_buff *skb)
71 int th_ofs = skb_transport_offset(skb);
72 if (pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))) {
73 int tcp_len = tcp_hdrlen(skb);
74 return (tcp_len >= sizeof(struct tcphdr)
75 && skb->len >= th_ofs + tcp_len);
80 static inline int udphdr_ok(struct sk_buff *skb)
82 int th_ofs = skb_transport_offset(skb);
83 return pskb_may_pull(skb, th_ofs + sizeof(struct udphdr));
86 static inline int icmphdr_ok(struct sk_buff *skb)
88 int th_ofs = skb_transport_offset(skb);
89 return pskb_may_pull(skb, th_ofs + sizeof(struct icmphdr));
92 #define TCP_FLAGS_OFFSET 13
93 #define TCP_FLAG_MASK 0x3f
95 void flow_used(struct sw_flow *flow, struct sk_buff *skb)
99 if (flow->key.dl_type == htons(ETH_P_IP) &&
100 flow->key.nw_proto == IPPROTO_TCP) {
101 u8 *tcp = (u8 *)tcp_hdr(skb);
102 tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
105 spin_lock_bh(&flow->lock);
106 flow->used = jiffies;
107 flow->packet_count++;
108 flow->byte_count += skb->len;
109 flow->tcp_flags |= tcp_flags;
110 spin_unlock_bh(&flow->lock);
113 struct sw_flow_actions *flow_actions_alloc(size_t n_actions)
115 struct sw_flow_actions *sfa;
117 if (n_actions > (PAGE_SIZE - sizeof *sfa) / sizeof(union odp_action))
118 return ERR_PTR(-EINVAL);
120 sfa = kmalloc(sizeof *sfa + n_actions * sizeof(union odp_action),
123 return ERR_PTR(-ENOMEM);
125 sfa->n_actions = n_actions;
130 /* Frees 'flow' immediately. */
131 static void flow_free(struct sw_flow *flow)
135 kfree(flow->sf_acts);
136 kmem_cache_free(flow_cache, flow);
139 void flow_free_tbl(struct tbl_node *node)
141 struct sw_flow *flow = flow_cast(node);
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 static void parse_vlan(struct sk_buff *skb, struct odp_flow_key *key)
177 __be16 eth_type; /* ETH_P_8021Q */
180 struct qtag_prefix *qp;
182 if (skb->len < sizeof(struct qtag_prefix) + sizeof(__be16))
185 qp = (struct qtag_prefix *) skb->data;
186 key->dl_vlan = qp->tci & htons(VLAN_VID_MASK);
187 key->dl_vlan_pcp = (ntohs(qp->tci) & VLAN_PCP_MASK) >> VLAN_PCP_SHIFT;
188 __skb_pull(skb, sizeof(struct qtag_prefix));
191 static __be16 parse_ethertype(struct sk_buff *skb)
193 struct llc_snap_hdr {
194 u8 dsap; /* Always 0xAA */
195 u8 ssap; /* Always 0xAA */
200 struct llc_snap_hdr *llc;
203 proto = *(__be16 *) skb->data;
204 __skb_pull(skb, sizeof(__be16));
206 if (ntohs(proto) >= ODP_DL_TYPE_ETH2_CUTOFF)
209 if (unlikely(skb->len < sizeof(struct llc_snap_hdr)))
210 return htons(ODP_DL_TYPE_NOT_ETH_TYPE);
212 llc = (struct llc_snap_hdr *) skb->data;
213 if (llc->dsap != LLC_SAP_SNAP ||
214 llc->ssap != LLC_SAP_SNAP ||
215 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
216 return htons(ODP_DL_TYPE_NOT_ETH_TYPE);
218 __skb_pull(skb, sizeof(struct llc_snap_hdr));
219 return llc->ethertype;
222 /* Parses the Ethernet frame in 'skb', which was received on 'in_port',
223 * and initializes 'key' to match. Returns 1 if 'skb' contains an IP
224 * fragment, 0 otherwise. */
225 int flow_extract(struct sk_buff *skb, u16 in_port, struct odp_flow_key *key)
230 memset(key, 0, sizeof *key);
231 key->tun_id = OVS_CB(skb)->tun_id;
232 key->in_port = in_port;
233 key->dl_vlan = htons(ODP_VLAN_NONE);
235 if (skb->len < sizeof *eth)
237 if (!pskb_may_pull(skb, skb->len >= 64 ? 64 : skb->len))
240 skb_reset_mac_header(skb);
244 memcpy(key->dl_src, eth->h_source, ETH_ALEN);
245 memcpy(key->dl_dst, eth->h_dest, ETH_ALEN);
247 /* dl_type, dl_vlan, dl_vlan_pcp. */
248 __skb_pull(skb, 2 * ETH_ALEN);
249 if (eth->h_proto == htons(ETH_P_8021Q))
250 parse_vlan(skb, key);
251 key->dl_type = parse_ethertype(skb);
252 skb_reset_network_header(skb);
253 __skb_push(skb, skb->data - (unsigned char *)eth);
256 if (key->dl_type == htons(ETH_P_IP) && iphdr_ok(skb)) {
257 struct iphdr *nh = ip_hdr(skb);
258 int th_ofs = skb_network_offset(skb) + nh->ihl * 4;
259 key->nw_src = nh->saddr;
260 key->nw_dst = nh->daddr;
261 key->nw_tos = nh->tos & ~INET_ECN_MASK;
262 key->nw_proto = nh->protocol;
263 skb_set_transport_header(skb, th_ofs);
265 /* Transport layer. */
266 if (!(nh->frag_off & htons(IP_MF | IP_OFFSET))) {
267 if (key->nw_proto == IPPROTO_TCP) {
268 if (tcphdr_ok(skb)) {
269 struct tcphdr *tcp = tcp_hdr(skb);
270 key->tp_src = tcp->source;
271 key->tp_dst = tcp->dest;
273 /* Avoid tricking other code into
274 * thinking that this packet has an L4
278 } else if (key->nw_proto == IPPROTO_UDP) {
279 if (udphdr_ok(skb)) {
280 struct udphdr *udp = udp_hdr(skb);
281 key->tp_src = udp->source;
282 key->tp_dst = udp->dest;
284 /* Avoid tricking other code into
285 * thinking that this packet has an L4
289 } else if (key->nw_proto == IPPROTO_ICMP) {
290 if (icmphdr_ok(skb)) {
291 struct icmphdr *icmp = icmp_hdr(skb);
292 /* The ICMP type and code fields use the 16-bit
293 * transport port fields, so we need to store them
294 * in 16-bit network byte order. */
295 key->tp_src = htons(icmp->type);
296 key->tp_dst = htons(icmp->code);
298 /* Avoid tricking other code into
299 * thinking that this packet has an L4
307 } else if (key->dl_type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
308 struct arp_eth_header *arp;
310 arp = (struct arp_eth_header *)skb_network_header(skb);
312 if (arp->ar_hrd == htons(ARPHRD_ETHER)
313 && arp->ar_pro == htons(ETH_P_IP)
314 && arp->ar_hln == ETH_ALEN
315 && arp->ar_pln == 4) {
317 /* We only match on the lower 8 bits of the opcode. */
318 if (ntohs(arp->ar_op) <= 0xff) {
319 key->nw_proto = ntohs(arp->ar_op);
322 if (key->nw_proto == ARPOP_REQUEST
323 || key->nw_proto == ARPOP_REPLY) {
324 memcpy(&key->nw_src, arp->ar_sip, sizeof(key->nw_src));
325 memcpy(&key->nw_dst, arp->ar_tip, sizeof(key->nw_dst));
329 skb_reset_transport_header(skb);
334 u32 flow_hash(const struct odp_flow_key *key)
336 return jhash2((u32*)key, sizeof *key / sizeof(u32), hash_seed);
339 int flow_cmp(const struct tbl_node *node, void *key2_)
341 const struct odp_flow_key *key1 = &flow_cast(node)->key;
342 const struct odp_flow_key *key2 = key2_;
344 return !memcmp(key1, key2, sizeof(struct odp_flow_key));
347 /* Initializes the flow module.
348 * Returns zero if successful or a negative error code. */
351 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
353 if (flow_cache == NULL)
356 get_random_bytes(&hash_seed, sizeof hash_seed);
361 /* Uninitializes the flow module. */
364 kmem_cache_destroy(flow_cache);