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Commit | Line | Data |
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064af421 BP |
1 | /* |
2 | * Distributed under the terms of the GNU GPL version 2. | |
982b8810 | 3 | * Copyright (c) 2007, 2008, 2009, 2010, 2011 Nicira Networks. |
a14bc59f BP |
4 | * |
5 | * Significant portions of this file may be copied from parts of the Linux | |
6 | * kernel, by Linus Torvalds and others. | |
064af421 BP |
7 | */ |
8 | ||
9 | /* Functions for executing flow actions. */ | |
10 | ||
e9141eec PS |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
12 | ||
064af421 BP |
13 | #include <linux/skbuff.h> |
14 | #include <linux/in.h> | |
15 | #include <linux/ip.h> | |
16 | #include <linux/tcp.h> | |
17 | #include <linux/udp.h> | |
18 | #include <linux/in6.h> | |
401eeb92 | 19 | #include <linux/if_arp.h> |
064af421 | 20 | #include <linux/if_vlan.h> |
f1193301 | 21 | #include <net/inet_ecn.h> |
064af421 BP |
22 | #include <net/ip.h> |
23 | #include <net/checksum.h> | |
f2459fe7 | 24 | |
064af421 | 25 | #include "actions.h" |
dd8d6b8c | 26 | #include "checksum.h" |
f2459fe7 | 27 | #include "datapath.h" |
064af421 | 28 | #include "openvswitch/datapath-protocol.h" |
6ce39213 | 29 | #include "vlan.h" |
f2459fe7 | 30 | #include "vport.h" |
064af421 | 31 | |
6ff686f2 PS |
32 | static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, |
33 | const struct nlattr *attr, int len, bool keep_skb); | |
871dfe07 | 34 | |
10db8b20 | 35 | static int make_writable(struct sk_buff *skb, int write_len) |
064af421 | 36 | { |
10db8b20 JG |
37 | if (!skb_cloned(skb) || skb_clone_writable(skb, write_len)) |
38 | return 0; | |
0cd8a05e | 39 | |
10db8b20 | 40 | return pskb_expand_head(skb, 0, 0, GFP_ATOMIC); |
064af421 BP |
41 | } |
42 | ||
d9065a90 PS |
43 | /* remove VLAN header from packet and update csum accrodingly. */ |
44 | static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci) | |
064af421 | 45 | { |
064af421 | 46 | struct ethhdr *eh; |
d9065a90 | 47 | struct vlan_ethhdr *veth; |
10db8b20 | 48 | int err; |
064af421 | 49 | |
10db8b20 JG |
50 | err = make_writable(skb, VLAN_ETH_HLEN); |
51 | if (unlikely(err)) | |
52 | return err; | |
6ce39213 | 53 | |
dd8d6b8c | 54 | if (get_ip_summed(skb) == OVS_CSUM_COMPLETE) |
635c9298 JG |
55 | skb->csum = csum_sub(skb->csum, csum_partial(skb->data |
56 | + ETH_HLEN, VLAN_HLEN, 0)); | |
57 | ||
d9065a90 PS |
58 | veth = (struct vlan_ethhdr *) skb->data; |
59 | *current_tci = veth->h_vlan_TCI; | |
60 | ||
6ce39213 | 61 | memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN); |
064af421 | 62 | |
d9065a90 | 63 | eh = (struct ethhdr *)__skb_pull(skb, VLAN_HLEN); |
064af421 BP |
64 | |
65 | skb->protocol = eh->h_proto; | |
66 | skb->mac_header += VLAN_HLEN; | |
67 | ||
10db8b20 | 68 | return 0; |
064af421 BP |
69 | } |
70 | ||
d9065a90 | 71 | static int pop_vlan(struct sk_buff *skb) |
064af421 | 72 | { |
d9065a90 PS |
73 | __be16 tci; |
74 | int err; | |
10db8b20 | 75 | |
d9065a90 PS |
76 | if (likely(vlan_tx_tag_present(skb))) { |
77 | vlan_set_tci(skb, 0); | |
78 | } else { | |
79 | if (unlikely(skb->protocol != htons(ETH_P_8021Q) || | |
80 | skb->len < VLAN_ETH_HLEN)) | |
10db8b20 | 81 | return 0; |
064af421 | 82 | |
d9065a90 PS |
83 | err = __pop_vlan_tci(skb, &tci); |
84 | if (err) | |
10db8b20 | 85 | return err; |
064af421 | 86 | } |
d9065a90 PS |
87 | /* move next vlan tag to hw accel tag */ |
88 | if (likely(skb->protocol != htons(ETH_P_8021Q) || | |
89 | skb->len < VLAN_ETH_HLEN)) | |
90 | return 0; | |
91 | ||
92 | err = __pop_vlan_tci(skb, &tci); | |
93 | if (unlikely(err)) | |
94 | return err; | |
064af421 | 95 | |
10db8b20 | 96 | __vlan_hwaccel_put_tag(skb, ntohs(tci)); |
d9065a90 PS |
97 | return 0; |
98 | } | |
99 | ||
100 | static int push_vlan(struct sk_buff *skb, __be16 new_tci) | |
101 | { | |
102 | if (unlikely(vlan_tx_tag_present(skb))) { | |
103 | u16 current_tag; | |
104 | ||
105 | /* push down current VLAN tag */ | |
106 | current_tag = vlan_tx_tag_get(skb); | |
107 | ||
108 | if (!__vlan_put_tag(skb, current_tag)) | |
109 | return -ENOMEM; | |
10db8b20 | 110 | |
d9065a90 PS |
111 | if (get_ip_summed(skb) == OVS_CSUM_COMPLETE) |
112 | skb->csum = csum_add(skb->csum, csum_partial(skb->data | |
113 | + ETH_HLEN, VLAN_HLEN, 0)); | |
114 | ||
115 | } | |
116 | __vlan_hwaccel_put_tag(skb, ntohs(new_tci)); | |
10db8b20 | 117 | return 0; |
064af421 BP |
118 | } |
119 | ||
a4af2475 | 120 | static bool is_ip(struct sk_buff *skb) |
ca78c6b6 | 121 | { |
76abe283 | 122 | return (OVS_CB(skb)->flow->key.eth.type == htons(ETH_P_IP) && |
ca78c6b6 BP |
123 | skb->transport_header > skb->network_header); |
124 | } | |
125 | ||
a4af2475 | 126 | static __sum16 *get_l4_checksum(struct sk_buff *skb) |
ca78c6b6 | 127 | { |
28bad473 | 128 | u8 nw_proto = OVS_CB(skb)->flow->key.ip.proto; |
ca78c6b6 | 129 | int transport_len = skb->len - skb_transport_offset(skb); |
a4af2475 | 130 | if (nw_proto == IPPROTO_TCP) { |
ca78c6b6 BP |
131 | if (likely(transport_len >= sizeof(struct tcphdr))) |
132 | return &tcp_hdr(skb)->check; | |
a4af2475 | 133 | } else if (nw_proto == IPPROTO_UDP) { |
ca78c6b6 BP |
134 | if (likely(transport_len >= sizeof(struct udphdr))) |
135 | return &udp_hdr(skb)->check; | |
136 | } | |
137 | return NULL; | |
138 | } | |
139 | ||
10db8b20 | 140 | static int set_nw_addr(struct sk_buff *skb, const struct nlattr *a) |
064af421 | 141 | { |
cdee00fd | 142 | __be32 new_nwaddr = nla_get_be32(a); |
ca78c6b6 BP |
143 | struct iphdr *nh; |
144 | __sum16 *check; | |
145 | __be32 *nwaddr; | |
10db8b20 | 146 | int err; |
ca78c6b6 | 147 | |
a4af2475 | 148 | if (unlikely(!is_ip(skb))) |
10db8b20 | 149 | return 0; |
064af421 | 150 | |
10db8b20 JG |
151 | err = make_writable(skb, skb_network_offset(skb) + |
152 | sizeof(struct iphdr)); | |
153 | if (unlikely(err)) | |
154 | return err; | |
ca78c6b6 BP |
155 | |
156 | nh = ip_hdr(skb); | |
df2c07f4 | 157 | nwaddr = nla_type(a) == OVS_ACTION_ATTR_SET_NW_SRC ? &nh->saddr : &nh->daddr; |
ca78c6b6 | 158 | |
a4af2475 | 159 | check = get_l4_checksum(skb); |
ca78c6b6 | 160 | if (likely(check)) |
cdee00fd BP |
161 | inet_proto_csum_replace4(check, skb, *nwaddr, new_nwaddr, 1); |
162 | csum_replace4(&nh->check, *nwaddr, new_nwaddr); | |
ca78c6b6 | 163 | |
a4a26436 SH |
164 | skb_clear_rxhash(skb); |
165 | ||
cdee00fd | 166 | *nwaddr = new_nwaddr; |
ca78c6b6 | 167 | |
10db8b20 | 168 | return 0; |
064af421 BP |
169 | } |
170 | ||
10db8b20 | 171 | static int set_nw_tos(struct sk_buff *skb, u8 nw_tos) |
959a2ecd | 172 | { |
10db8b20 JG |
173 | struct iphdr *nh = ip_hdr(skb); |
174 | u8 old, new; | |
175 | int err; | |
176 | ||
a4af2475 | 177 | if (unlikely(!is_ip(skb))) |
10db8b20 JG |
178 | return 0; |
179 | ||
180 | err = make_writable(skb, skb_network_offset(skb) + | |
181 | sizeof(struct iphdr)); | |
182 | if (unlikely(err)) | |
183 | return err; | |
184 | ||
185 | /* Set the DSCP bits and preserve the ECN bits. */ | |
186 | old = nh->tos; | |
187 | new = nw_tos | (nh->tos & INET_ECN_MASK); | |
188 | csum_replace4(&nh->check, (__force __be32)old, | |
189 | (__force __be32)new); | |
190 | nh->tos = new; | |
191 | ||
192 | return 0; | |
959a2ecd JP |
193 | } |
194 | ||
10db8b20 | 195 | static int set_tp_port(struct sk_buff *skb, const struct nlattr *a) |
064af421 | 196 | { |
ca78c6b6 BP |
197 | struct udphdr *th; |
198 | __sum16 *check; | |
199 | __be16 *port; | |
10db8b20 | 200 | int err; |
064af421 | 201 | |
a4af2475 | 202 | if (unlikely(!is_ip(skb))) |
10db8b20 | 203 | return 0; |
064af421 | 204 | |
10db8b20 JG |
205 | err = make_writable(skb, skb_transport_offset(skb) + |
206 | sizeof(struct tcphdr)); | |
207 | if (unlikely(err)) | |
208 | return err; | |
ca78c6b6 BP |
209 | |
210 | /* Must follow make_writable() since that can move the skb data. */ | |
a4af2475 | 211 | check = get_l4_checksum(skb); |
ca78c6b6 | 212 | if (unlikely(!check)) |
10db8b20 | 213 | return 0; |
064af421 | 214 | |
ca78c6b6 BP |
215 | /* |
216 | * Update port and checksum. | |
217 | * | |
218 | * This is OK because source and destination port numbers are at the | |
219 | * same offsets in both UDP and TCP headers, and get_l4_checksum() only | |
220 | * supports those protocols. | |
221 | */ | |
222 | th = udp_hdr(skb); | |
df2c07f4 | 223 | port = nla_type(a) == OVS_ACTION_ATTR_SET_TP_SRC ? &th->source : &th->dest; |
cdee00fd BP |
224 | inet_proto_csum_replace2(check, skb, *port, nla_get_be16(a), 0); |
225 | *port = nla_get_be16(a); | |
a4a26436 | 226 | skb_clear_rxhash(skb); |
ca78c6b6 | 227 | |
10db8b20 | 228 | return 0; |
064af421 BP |
229 | } |
230 | ||
f15c8639 | 231 | static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port) |
064af421 | 232 | { |
f15c8639 | 233 | struct vport *vport; |
064af421 | 234 | |
f15c8639 JG |
235 | if (unlikely(!skb)) |
236 | return -ENOMEM; | |
064af421 | 237 | |
f15c8639 JG |
238 | vport = rcu_dereference(dp->ports[out_port]); |
239 | if (unlikely(!vport)) { | |
240 | kfree_skb(skb); | |
241 | return -ENODEV; | |
242 | } | |
064af421 | 243 | |
f15c8639 JG |
244 | vport_send(vport, skb); |
245 | return 0; | |
064af421 BP |
246 | } |
247 | ||
b85d8d61 | 248 | static int output_userspace(struct datapath *dp, struct sk_buff *skb, u64 arg) |
064af421 | 249 | { |
856081f6 BP |
250 | struct dp_upcall_info upcall; |
251 | ||
df2c07f4 | 252 | upcall.cmd = OVS_PACKET_CMD_ACTION; |
a4af2475 | 253 | upcall.key = &OVS_CB(skb)->flow->key; |
856081f6 | 254 | upcall.userdata = arg; |
856081f6 | 255 | return dp_upcall(dp, skb, &upcall); |
064af421 BP |
256 | } |
257 | ||
6ff686f2 PS |
258 | static int sample(struct datapath *dp, struct sk_buff *skb, |
259 | const struct nlattr *attr) | |
260 | { | |
261 | const struct nlattr *acts_list = NULL; | |
262 | const struct nlattr *a; | |
263 | int rem; | |
264 | ||
265 | for (a = nla_data(attr), rem = nla_len(attr); rem > 0; | |
266 | a = nla_next(a, &rem)) { | |
267 | switch (nla_type(a)) { | |
268 | case OVS_SAMPLE_ATTR_PROBABILITY: | |
269 | if (net_random() >= nla_get_u32(a)) | |
270 | return 0; | |
271 | break; | |
272 | ||
273 | case OVS_SAMPLE_ATTR_ACTIONS: | |
274 | acts_list = a; | |
275 | break; | |
276 | } | |
277 | } | |
278 | ||
279 | return do_execute_actions(dp, skb, nla_data(acts_list), | |
280 | nla_len(acts_list), true); | |
281 | } | |
282 | ||
064af421 | 283 | /* Execute a list of actions against 'skb'. */ |
871dfe07 | 284 | static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, |
6ff686f2 | 285 | const struct nlattr *attr, int len, bool keep_skb) |
064af421 BP |
286 | { |
287 | /* Every output action needs a separate clone of 'skb', but the common | |
288 | * case is just a single output action, so that doing a clone and | |
289 | * then freeing the original skbuff is wasteful. So the following code | |
290 | * is slightly obscure just to avoid that. */ | |
291 | int prev_port = -1; | |
c1c9c9c4 | 292 | u32 priority = skb->priority; |
cdee00fd | 293 | const struct nlattr *a; |
10db8b20 | 294 | int rem; |
72b06300 | 295 | |
6ff686f2 | 296 | for (a = attr, rem = len; rem > 0; |
a4af2475 | 297 | a = nla_next(a, &rem)) { |
10db8b20 JG |
298 | int err = 0; |
299 | ||
064af421 | 300 | if (prev_port != -1) { |
7956695a | 301 | do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port); |
064af421 BP |
302 | prev_port = -1; |
303 | } | |
304 | ||
cdee00fd | 305 | switch (nla_type(a)) { |
df2c07f4 | 306 | case OVS_ACTION_ATTR_OUTPUT: |
cdee00fd | 307 | prev_port = nla_get_u32(a); |
064af421 BP |
308 | break; |
309 | ||
df2c07f4 | 310 | case OVS_ACTION_ATTR_USERSPACE: |
646b8753 | 311 | output_userspace(dp, skb, nla_get_u64(a)); |
064af421 BP |
312 | break; |
313 | ||
df2c07f4 | 314 | case OVS_ACTION_ATTR_SET_TUNNEL: |
b9298d3f | 315 | OVS_CB(skb)->tun_id = nla_get_be64(a); |
659586ef JG |
316 | break; |
317 | ||
d9065a90 PS |
318 | case OVS_ACTION_ATTR_PUSH_VLAN: |
319 | err = push_vlan(skb, nla_get_be16(a)); | |
320 | if (unlikely(err)) /* skb already freed */ | |
321 | return err; | |
064af421 BP |
322 | break; |
323 | ||
d9065a90 PS |
324 | case OVS_ACTION_ATTR_POP_VLAN: |
325 | err = pop_vlan(skb); | |
064af421 BP |
326 | break; |
327 | ||
df2c07f4 | 328 | case OVS_ACTION_ATTR_SET_DL_SRC: |
10db8b20 JG |
329 | err = make_writable(skb, ETH_HLEN); |
330 | if (likely(!err)) | |
331 | memcpy(eth_hdr(skb)->h_source, nla_data(a), ETH_ALEN); | |
cdee00fd BP |
332 | break; |
333 | ||
df2c07f4 | 334 | case OVS_ACTION_ATTR_SET_DL_DST: |
10db8b20 JG |
335 | err = make_writable(skb, ETH_HLEN); |
336 | if (likely(!err)) | |
337 | memcpy(eth_hdr(skb)->h_dest, nla_data(a), ETH_ALEN); | |
064af421 BP |
338 | break; |
339 | ||
df2c07f4 JP |
340 | case OVS_ACTION_ATTR_SET_NW_SRC: |
341 | case OVS_ACTION_ATTR_SET_NW_DST: | |
10db8b20 | 342 | err = set_nw_addr(skb, a); |
064af421 BP |
343 | break; |
344 | ||
df2c07f4 | 345 | case OVS_ACTION_ATTR_SET_NW_TOS: |
10db8b20 | 346 | err = set_nw_tos(skb, nla_get_u8(a)); |
959a2ecd JP |
347 | break; |
348 | ||
df2c07f4 JP |
349 | case OVS_ACTION_ATTR_SET_TP_SRC: |
350 | case OVS_ACTION_ATTR_SET_TP_DST: | |
10db8b20 | 351 | err = set_tp_port(skb, a); |
064af421 | 352 | break; |
c1c9c9c4 | 353 | |
df2c07f4 | 354 | case OVS_ACTION_ATTR_SET_PRIORITY: |
cdee00fd | 355 | skb->priority = nla_get_u32(a); |
c1c9c9c4 BP |
356 | break; |
357 | ||
df2c07f4 | 358 | case OVS_ACTION_ATTR_POP_PRIORITY: |
c1c9c9c4 BP |
359 | skb->priority = priority; |
360 | break; | |
10db8b20 | 361 | |
6ff686f2 PS |
362 | case OVS_ACTION_ATTR_SAMPLE: |
363 | err = sample(dp, skb, a); | |
364 | break; | |
365 | ||
366 | } | |
10db8b20 JG |
367 | if (unlikely(err)) { |
368 | kfree_skb(skb); | |
369 | return err; | |
370 | } | |
064af421 | 371 | } |
6c222e55 | 372 | |
6ff686f2 PS |
373 | if (prev_port != -1) { |
374 | if (keep_skb) | |
375 | skb = skb_clone(skb, GFP_ATOMIC); | |
376 | ||
064af421 | 377 | do_output(dp, skb, prev_port); |
6ff686f2 | 378 | } else if (!keep_skb) |
5b95ab0e | 379 | consume_skb(skb); |
10db8b20 | 380 | |
a5225dd6 | 381 | return 0; |
064af421 | 382 | } |
871dfe07 | 383 | |
e9141eec PS |
384 | /* We limit the number of times that we pass into execute_actions() |
385 | * to avoid blowing out the stack in the event that we have a loop. */ | |
386 | #define MAX_LOOPS 5 | |
387 | ||
388 | struct loop_counter { | |
389 | u8 count; /* Count. */ | |
390 | bool looping; /* Loop detected? */ | |
391 | }; | |
392 | ||
393 | static DEFINE_PER_CPU(struct loop_counter, loop_counters); | |
394 | ||
395 | static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions) | |
396 | { | |
397 | if (net_ratelimit()) | |
398 | pr_warn("%s: flow looped %d times, dropping\n", | |
399 | dp_name(dp), MAX_LOOPS); | |
400 | actions->actions_len = 0; | |
401 | return -ELOOP; | |
402 | } | |
403 | ||
871dfe07 | 404 | /* Execute a list of actions against 'skb'. */ |
a4af2475 | 405 | int execute_actions(struct datapath *dp, struct sk_buff *skb) |
871dfe07 | 406 | { |
a4af2475 BP |
407 | struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts); |
408 | struct loop_counter *loop; | |
409 | int error; | |
410 | ||
411 | /* Check whether we've looped too much. */ | |
e9141eec | 412 | loop = &__get_cpu_var(loop_counters); |
a4af2475 BP |
413 | if (unlikely(++loop->count > MAX_LOOPS)) |
414 | loop->looping = true; | |
415 | if (unlikely(loop->looping)) { | |
416 | error = loop_suppress(dp, acts); | |
417 | kfree_skb(skb); | |
418 | goto out_loop; | |
419 | } | |
871dfe07 BP |
420 | |
421 | OVS_CB(skb)->tun_id = 0; | |
6ff686f2 PS |
422 | error = do_execute_actions(dp, skb, acts->actions, |
423 | acts->actions_len, false); | |
a4af2475 BP |
424 | |
425 | /* Check whether sub-actions looped too much. */ | |
426 | if (unlikely(loop->looping)) | |
427 | error = loop_suppress(dp, acts); | |
428 | ||
429 | out_loop: | |
430 | /* Decrement loop counter. */ | |
431 | if (!--loop->count) | |
432 | loop->looping = false; | |
871dfe07 | 433 | |
a4af2475 | 434 | return error; |
871dfe07 | 435 | } |