1 #include <linux/skbuff.h>
2 #include <linux/export.h>
4 #include <linux/ipv6.h>
5 #include <linux/if_vlan.h>
8 #include <linux/igmp.h>
9 #include <linux/icmp.h>
10 #include <linux/sctp.h>
11 #include <linux/dccp.h>
12 #include <linux/if_tunnel.h>
13 #include <linux/if_pppox.h>
14 #include <linux/ppp_defs.h>
15 #include <net/flow_keys.h>
17 /* copy saddr & daddr, possibly using 64bit load/store
18 * Equivalent to : flow->src = iph->saddr;
19 * flow->dst = iph->daddr;
21 static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph)
23 BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
24 offsetof(typeof(*flow), src) + sizeof(flow->src));
25 memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
29 * skb_flow_get_ports - extract the upper layer ports and return them
30 * @skb: buffer to extract the ports from
31 * @thoff: transport header offset
32 * @ip_proto: protocol for which to get port offset
34 * The function will try to retrieve the ports at offset thoff + poff where poff
35 * is the protocol port offset returned from proto_ports_offset
37 __be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto)
39 int poff = proto_ports_offset(ip_proto);
42 __be32 *ports, _ports;
44 ports = skb_header_pointer(skb, thoff + poff,
45 sizeof(_ports), &_ports);
52 EXPORT_SYMBOL(skb_flow_get_ports);
54 bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
56 int nhoff = skb_network_offset(skb);
58 __be16 proto = skb->protocol;
60 memset(flow, 0, sizeof(*flow));
64 case htons(ETH_P_IP): {
65 const struct iphdr *iph;
68 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
69 if (!iph || iph->ihl < 5)
71 nhoff += iph->ihl * 4;
73 ip_proto = iph->protocol;
74 if (ip_is_fragment(iph))
77 iph_to_flow_copy_addrs(flow, iph);
80 case htons(ETH_P_IPV6): {
81 const struct ipv6hdr *iph;
84 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
88 ip_proto = iph->nexthdr;
89 flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
90 flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
91 nhoff += sizeof(struct ipv6hdr);
94 case htons(ETH_P_8021AD):
95 case htons(ETH_P_8021Q): {
96 const struct vlan_hdr *vlan;
97 struct vlan_hdr _vlan;
99 vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
103 proto = vlan->h_vlan_encapsulated_proto;
104 nhoff += sizeof(*vlan);
107 case htons(ETH_P_PPP_SES): {
109 struct pppoe_hdr hdr;
112 hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
116 nhoff += PPPOE_SES_HLEN;
120 case htons(PPP_IPV6):
137 hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
141 * Only look inside GRE if version zero and no
144 if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
147 if (hdr->flags & GRE_CSUM)
149 if (hdr->flags & GRE_KEY)
151 if (hdr->flags & GRE_SEQ)
153 if (proto == htons(ETH_P_TEB)) {
154 const struct ethhdr *eth;
157 eth = skb_header_pointer(skb, nhoff,
158 sizeof(_eth), &_eth);
161 proto = eth->h_proto;
162 nhoff += sizeof(*eth);
169 proto = htons(ETH_P_IP);
172 proto = htons(ETH_P_IPV6);
178 flow->n_proto = proto;
179 flow->ip_proto = ip_proto;
180 flow->ports = skb_flow_get_ports(skb, nhoff, ip_proto);
181 flow->thoff = (u16) nhoff;
185 EXPORT_SYMBOL(skb_flow_dissect);
187 static u32 hashrnd __read_mostly;
188 static __always_inline void __flow_hash_secret_init(void)
190 net_get_random_once(&hashrnd, sizeof(hashrnd));
193 static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c)
195 __flow_hash_secret_init();
196 return jhash_3words(a, b, c, hashrnd);
199 static __always_inline u32 __flow_hash_1word(u32 a)
201 __flow_hash_secret_init();
202 return jhash_1word(a, hashrnd);
205 static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
209 /* get a consistent hash (same value on both flow directions) */
210 if (((__force u32)keys->dst < (__force u32)keys->src) ||
211 (((__force u32)keys->dst == (__force u32)keys->src) &&
212 ((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) {
213 swap(keys->dst, keys->src);
214 swap(keys->port16[0], keys->port16[1]);
217 hash = __flow_hash_3words((__force u32)keys->dst,
218 (__force u32)keys->src,
219 (__force u32)keys->ports);
226 u32 flow_hash_from_keys(struct flow_keys *keys)
228 return __flow_hash_from_keys(keys);
230 EXPORT_SYMBOL(flow_hash_from_keys);
233 * __skb_get_hash: calculate a flow hash based on src/dst addresses
234 * and src/dst port numbers. Sets hash in skb to non-zero hash value
235 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
236 * if hash is a canonical 4-tuple hash over transport ports.
238 void __skb_get_hash(struct sk_buff *skb)
240 struct flow_keys keys;
242 if (!skb_flow_dissect(skb, &keys))
248 skb->hash = __flow_hash_from_keys(&keys);
250 EXPORT_SYMBOL(__skb_get_hash);
253 * Returns a Tx hash based on the given packet descriptor a Tx queues' number
254 * to be used as a distribution range.
256 u16 __skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb,
257 unsigned int num_tx_queues)
261 u16 qcount = num_tx_queues;
263 if (skb_rx_queue_recorded(skb)) {
264 hash = skb_get_rx_queue(skb);
265 while (unlikely(hash >= num_tx_queues))
266 hash -= num_tx_queues;
271 u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
272 qoffset = dev->tc_to_txq[tc].offset;
273 qcount = dev->tc_to_txq[tc].count;
276 if (skb->sk && skb->sk->sk_hash)
277 hash = skb->sk->sk_hash;
279 hash = (__force u16) skb->protocol;
280 hash = __flow_hash_1word(hash);
282 return (u16) (((u64) hash * qcount) >> 32) + qoffset;
284 EXPORT_SYMBOL(__skb_tx_hash);
286 /* __skb_get_poff() returns the offset to the payload as far as it could
287 * be dissected. The main user is currently BPF, so that we can dynamically
288 * truncate packets without needing to push actual payload to the user
289 * space and can analyze headers only, instead.
291 u32 __skb_get_poff(const struct sk_buff *skb)
293 struct flow_keys keys;
296 if (!skb_flow_dissect(skb, &keys))
300 switch (keys.ip_proto) {
302 const struct tcphdr *tcph;
305 tcph = skb_header_pointer(skb, poff, sizeof(_tcph), &_tcph);
309 poff += max_t(u32, sizeof(struct tcphdr), tcph->doff * 4);
313 case IPPROTO_UDPLITE:
314 poff += sizeof(struct udphdr);
316 /* For the rest, we do not really care about header
317 * extensions at this point for now.
320 poff += sizeof(struct icmphdr);
323 poff += sizeof(struct icmp6hdr);
326 poff += sizeof(struct igmphdr);
329 poff += sizeof(struct dccp_hdr);
332 poff += sizeof(struct sctphdr);
339 static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
342 struct xps_dev_maps *dev_maps;
344 int queue_index = -1;
347 dev_maps = rcu_dereference(dev->xps_maps);
349 map = rcu_dereference(
350 dev_maps->cpu_map[raw_smp_processor_id()]);
353 queue_index = map->queues[0];
356 if (skb->sk && skb->sk->sk_hash)
357 hash = skb->sk->sk_hash;
359 hash = (__force u16) skb->protocol ^
361 hash = __flow_hash_1word(hash);
362 queue_index = map->queues[
363 ((u64)hash * map->len) >> 32];
365 if (unlikely(queue_index >= dev->real_num_tx_queues))
377 static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
379 struct sock *sk = skb->sk;
380 int queue_index = sk_tx_queue_get(sk);
382 if (queue_index < 0 || skb->ooo_okay ||
383 queue_index >= dev->real_num_tx_queues) {
384 int new_index = get_xps_queue(dev, skb);
386 new_index = skb_tx_hash(dev, skb);
388 if (queue_index != new_index && sk &&
389 rcu_access_pointer(sk->sk_dst_cache))
390 sk_tx_queue_set(sk, new_index);
392 queue_index = new_index;
398 struct netdev_queue *netdev_pick_tx(struct net_device *dev,
404 if (dev->real_num_tx_queues != 1) {
405 const struct net_device_ops *ops = dev->netdev_ops;
406 if (ops->ndo_select_queue)
407 queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
410 queue_index = __netdev_pick_tx(dev, skb);
413 queue_index = netdev_cap_txqueue(dev, queue_index);
416 skb_set_queue_mapping(skb, queue_index);
417 return netdev_get_tx_queue(dev, queue_index);