2 * Distributed under the terms of the GNU GPL version 2.
3 * Copyright (c) 2007, 2008 The Board of Trustees of The Leland
4 * Stanford Junior University
8 #include <linux/netdevice.h>
9 #include <linux/etherdevice.h>
10 #include <linux/if_ether.h>
11 #include <linux/if_vlan.h>
12 #include <net/llc_pdu.h>
14 #include <linux/kernel.h>
15 #include <linux/tcp.h>
16 #include <linux/udp.h>
18 #include <linux/rcupdate.h>
24 struct kmem_cache *flow_cache;
26 /* Internal function used to compare fields in flow. */
28 int flow_fields_match(const struct sw_flow_key *a, const struct sw_flow_key *b,
31 return ((w & OFPFW_IN_PORT || a->in_port == b->in_port)
32 && (w & OFPFW_DL_VLAN || a->dl_vlan == b->dl_vlan)
33 && (w & OFPFW_DL_SRC || !memcmp(a->dl_src, b->dl_src, ETH_ALEN))
34 && (w & OFPFW_DL_DST || !memcmp(a->dl_dst, b->dl_dst, ETH_ALEN))
35 && (w & OFPFW_DL_TYPE || a->dl_type == b->dl_type)
36 && (w & OFPFW_NW_SRC || a->nw_src == b->nw_src)
37 && (w & OFPFW_NW_DST || a->nw_dst == b->nw_dst)
38 && (w & OFPFW_NW_PROTO || a->nw_proto == b->nw_proto)
39 && (w & OFPFW_TP_SRC || a->tp_src == b->tp_src)
40 && (w & OFPFW_TP_DST || a->tp_dst == b->tp_dst));
43 /* Returns nonzero if 'a' and 'b' match, that is, if their fields are equal
44 * modulo wildcards, zero otherwise. */
46 int flow_matches(const struct sw_flow_key *a, const struct sw_flow_key *b)
48 return flow_fields_match(a, b, (a->wildcards | b->wildcards));
51 /* Returns nonzero if 't' (the table entry's key) and 'd' (the key
52 * describing the deletion) match, that is, if their fields are
53 * equal modulo wildcards, zero otherwise. If 'strict' is nonzero, the
54 * wildcards must match in both 't_key' and 'd_key'. Note that the
55 * table's wildcards are ignored unless 'strict' is set. */
57 int flow_del_matches(const struct sw_flow_key *t, const struct sw_flow_key *d, int strict)
59 if (strict && (t->wildcards != d->wildcards))
62 return flow_fields_match(t, d, d->wildcards);
65 void flow_extract_match(struct sw_flow_key* to, const struct ofp_match* from)
67 to->wildcards = ntohs(from->wildcards) & OFPFW_ALL;
68 memset(to->pad, '\0', sizeof(to->pad));
69 to->in_port = from->in_port;
70 to->dl_vlan = from->dl_vlan;
71 memcpy(to->dl_src, from->dl_src, ETH_ALEN);
72 memcpy(to->dl_dst, from->dl_dst, ETH_ALEN);
73 to->dl_type = from->dl_type;
75 if (likely(from->dl_type == htons(ETH_P_IP))) {
76 to->nw_src = from->nw_src;
77 to->nw_dst = from->nw_dst;
78 to->nw_proto = from->nw_proto;
80 if ((from->nw_proto != IPPROTO_TCP && from->nw_proto != IPPROTO_UDP)) {
83 to->tp_src = from->tp_src;
84 to->tp_dst = from->tp_dst;
97 void flow_fill_match(struct ofp_match* to, const struct sw_flow_key* from)
99 to->wildcards = htons(from->wildcards);
100 to->in_port = from->in_port;
101 to->dl_vlan = from->dl_vlan;
102 memcpy(to->dl_src, from->dl_src, ETH_ALEN);
103 memcpy(to->dl_dst, from->dl_dst, ETH_ALEN);
104 to->dl_type = from->dl_type;
105 to->nw_src = from->nw_src;
106 to->nw_dst = from->nw_dst;
107 to->nw_proto = from->nw_proto;
108 to->tp_src = from->tp_src;
109 to->tp_dst = from->tp_dst;
110 memset(to->pad, '\0', sizeof(to->pad));
113 /* Returns true if 'flow' can be deleted and set up for a deferred free, false
114 * if deletion has already been scheduled (by another thread).
116 * Caller must hold rcu_read_lock. */
117 int flow_del(struct sw_flow *flow)
119 return !atomic_cmpxchg(&flow->deleted, 0, 1);
122 /* Allocates and returns a new flow with 'n_actions' action, using allocation
123 * flags 'flags'. Returns the new flow or a null pointer on failure. */
124 struct sw_flow *flow_alloc(int n_actions, gfp_t flags)
126 struct sw_flow *flow = kmem_cache_alloc(flow_cache, flags);
130 flow->n_actions = n_actions;
131 flow->actions = kmalloc(n_actions * sizeof *flow->actions,
133 if (unlikely(!flow->actions) && n_actions > 0) {
134 kmem_cache_free(flow_cache, flow);
140 /* Frees 'flow' immediately. */
141 void flow_free(struct sw_flow *flow)
145 kfree(flow->actions);
146 kmem_cache_free(flow_cache, flow);
149 /* RCU callback used by flow_deferred_free. */
150 static void rcu_callback(struct rcu_head *rcu)
152 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
156 /* Schedules 'flow' to be freed after the next RCU grace period.
157 * The caller must hold rcu_read_lock for this to be sensible. */
158 void flow_deferred_free(struct sw_flow *flow)
160 call_rcu(&flow->rcu, rcu_callback);
163 /* Prints a representation of 'key' to the kernel log. */
164 void print_flow(const struct sw_flow_key *key)
166 printk("wild%04x port%04x:vlan%04x mac%02x:%02x:%02x:%02x:%02x:%02x"
167 "->%02x:%02x:%02x:%02x:%02x:%02x "
168 "proto%04x ip%u.%u.%u.%u->%u.%u.%u.%u port%d->%d\n",
169 key->wildcards, ntohs(key->in_port), ntohs(key->dl_vlan),
170 key->dl_src[0], key->dl_src[1], key->dl_src[2],
171 key->dl_src[3], key->dl_src[4], key->dl_src[5],
172 key->dl_dst[0], key->dl_dst[1], key->dl_dst[2],
173 key->dl_dst[3], key->dl_dst[4], key->dl_dst[5],
175 ((unsigned char *)&key->nw_src)[0],
176 ((unsigned char *)&key->nw_src)[1],
177 ((unsigned char *)&key->nw_src)[2],
178 ((unsigned char *)&key->nw_src)[3],
179 ((unsigned char *)&key->nw_dst)[0],
180 ((unsigned char *)&key->nw_dst)[1],
181 ((unsigned char *)&key->nw_dst)[2],
182 ((unsigned char *)&key->nw_dst)[3],
183 ntohs(key->tp_src), ntohs(key->tp_dst));
186 /* Parses the Ethernet frame in 'skb', which was received on 'in_port',
187 * and initializes 'key' to match. */
188 void flow_extract(struct sk_buff *skb, uint16_t in_port,
189 struct sw_flow_key *key)
195 key->in_port = htons(in_port);
197 memset(key->pad, '\0', sizeof(key->pad));
199 /* This code doesn't check that skb->len is long enough to contain the
200 * MAC or network header. With a 46-byte minimum length frame this
201 * assumption is always correct. */
203 /* Doesn't verify checksums. Should it? */
205 /* Data link layer. We only support Ethernet. */
207 nh_ofs = sizeof(struct ethhdr);
208 if (likely(ntohs(mac->h_proto) >= OFP_DL_TYPE_ETH2_CUTOFF)) {
209 /* This is an Ethernet II frame */
210 key->dl_type = mac->h_proto;
212 /* This is an 802.2 frame */
213 if (snap_get_ethertype(skb, &key->dl_type) != -EINVAL) {
214 nh_ofs += sizeof(struct snap_hdr);
216 key->dl_type = OFP_DL_TYPE_NOT_ETH_TYPE;
217 nh_ofs += sizeof(struct llc_pdu_un);
221 /* Check for a VLAN tag */
222 if (likely(key->dl_type != htons(ETH_P_8021Q))) {
223 key->dl_vlan = htons(OFP_VLAN_NONE);
225 struct vlan_hdr *vh = (struct vlan_hdr *)(skb_mac_header(skb) + nh_ofs);
226 key->dl_type = vh->h_vlan_encapsulated_proto;
227 key->dl_vlan = vh->h_vlan_TCI & htons(VLAN_VID_MASK);
228 nh_ofs += sizeof(*vh);
230 memcpy(key->dl_src, mac->h_source, ETH_ALEN);
231 memcpy(key->dl_dst, mac->h_dest, ETH_ALEN);
232 skb_set_network_header(skb, nh_ofs);
235 if (likely(key->dl_type == htons(ETH_P_IP))) {
236 struct iphdr *nh = ip_hdr(skb);
237 key->nw_src = nh->saddr;
238 key->nw_dst = nh->daddr;
239 key->nw_proto = nh->protocol;
240 th_ofs = nh_ofs + nh->ihl * 4;
241 skb_set_transport_header(skb, th_ofs);
243 /* Transport layer. */
244 if ((key->nw_proto != IPPROTO_TCP && key->nw_proto != IPPROTO_UDP)
245 || skb->len < th_ofs + sizeof(struct udphdr)) {
249 key->tp_src = th->source;
250 key->tp_dst = th->dest;
264 /* Initializes the flow module.
265 * Returns zero if successful or a negative error code. */
268 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
270 if (flow_cache == NULL)
276 /* Uninitializes the flow module. */
279 kmem_cache_destroy(flow_cache);