dpif-netdev: Fix validation of VLAN PCP value in userspace datapath.
[openvswitch] / lib / flow.c
1 /*
2  * Copyright (c) 2008, 2009 Nicira Networks.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at:
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #include <config.h>
17 #include <sys/types.h>
18 #include "flow.h"
19 #include <inttypes.h>
20 #include <netinet/in.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include "coverage.h"
24 #include "dynamic-string.h"
25 #include "hash.h"
26 #include "ofpbuf.h"
27 #include "openflow/openflow.h"
28 #include "openvswitch/datapath-protocol.h"
29 #include "packets.h"
30
31 #include "vlog.h"
32 #define THIS_MODULE VLM_flow
33
34 static struct arp_eth_header *
35 pull_arp(struct ofpbuf *packet)
36 {
37     return ofpbuf_try_pull(packet, ARP_ETH_HEADER_LEN);
38 }
39
40 static struct ip_header *
41 pull_ip(struct ofpbuf *packet)
42 {
43     if (packet->size >= IP_HEADER_LEN) {
44         struct ip_header *ip = packet->data;
45         int ip_len = IP_IHL(ip->ip_ihl_ver) * 4;
46         if (ip_len >= IP_HEADER_LEN && packet->size >= ip_len) {
47             return ofpbuf_pull(packet, ip_len);
48         }
49     }
50     return NULL;
51 }
52
53 static struct tcp_header *
54 pull_tcp(struct ofpbuf *packet) 
55 {
56     if (packet->size >= TCP_HEADER_LEN) {
57         struct tcp_header *tcp = packet->data;
58         int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
59         if (tcp_len >= TCP_HEADER_LEN && packet->size >= tcp_len) {
60             return ofpbuf_pull(packet, tcp_len);
61         }
62     }
63     return NULL;
64 }
65
66 static struct udp_header *
67 pull_udp(struct ofpbuf *packet) 
68 {
69     return ofpbuf_try_pull(packet, UDP_HEADER_LEN);
70 }
71
72 static struct icmp_header *
73 pull_icmp(struct ofpbuf *packet) 
74 {
75     return ofpbuf_try_pull(packet, ICMP_HEADER_LEN);
76 }
77
78 static struct eth_header *
79 pull_eth(struct ofpbuf *packet) 
80 {
81     return ofpbuf_try_pull(packet, ETH_HEADER_LEN);
82 }
83
84 static struct vlan_header *
85 pull_vlan(struct ofpbuf *packet)
86 {
87     return ofpbuf_try_pull(packet, VLAN_HEADER_LEN);
88 }
89
90 /* Returns 1 if 'packet' is an IP fragment, 0 otherwise. */
91 int
92 flow_extract(struct ofpbuf *packet, uint16_t in_port, flow_t *flow)
93 {
94     struct ofpbuf b = *packet;
95     struct eth_header *eth;
96     int retval = 0;
97
98     COVERAGE_INC(flow_extract);
99
100     memset(flow, 0, sizeof *flow);
101     flow->dl_vlan = htons(OFP_VLAN_NONE);
102     flow->in_port = in_port;
103
104     packet->l2 = b.data;
105     packet->l3 = NULL;
106     packet->l4 = NULL;
107     packet->l7 = NULL;
108
109     eth = pull_eth(&b);
110     if (eth) {
111         if (ntohs(eth->eth_type) >= OFP_DL_TYPE_ETH2_CUTOFF) {
112             /* This is an Ethernet II frame */
113             flow->dl_type = eth->eth_type;
114         } else {
115             /* This is an 802.2 frame */
116             struct llc_header *llc = ofpbuf_at(&b, 0, sizeof *llc);
117             struct snap_header *snap = ofpbuf_at(&b, sizeof *llc,
118                                                  sizeof *snap);
119             if (llc == NULL) {
120                 return 0;
121             }
122             if (snap
123                 && llc->llc_dsap == LLC_DSAP_SNAP
124                 && llc->llc_ssap == LLC_SSAP_SNAP
125                 && llc->llc_cntl == LLC_CNTL_SNAP
126                 && !memcmp(snap->snap_org, SNAP_ORG_ETHERNET,
127                            sizeof snap->snap_org)) {
128                 flow->dl_type = snap->snap_type;
129                 ofpbuf_pull(&b, LLC_SNAP_HEADER_LEN);
130             } else {
131                 flow->dl_type = htons(OFP_DL_TYPE_NOT_ETH_TYPE);
132                 ofpbuf_pull(&b, sizeof(struct llc_header));
133             }
134         }
135
136         /* Check for a VLAN tag */
137         if (flow->dl_type == htons(ETH_TYPE_VLAN)) {
138             struct vlan_header *vh = pull_vlan(&b);
139             if (vh) {
140                 flow->dl_type = vh->vlan_next_type;
141                 flow->dl_vlan = vh->vlan_tci & htons(VLAN_VID_MASK);
142             }
143         }
144         memcpy(flow->dl_src, eth->eth_src, ETH_ADDR_LEN);
145         memcpy(flow->dl_dst, eth->eth_dst, ETH_ADDR_LEN);
146
147         packet->l3 = b.data;
148         if (flow->dl_type == htons(ETH_TYPE_IP)) {
149             const struct ip_header *nh = pull_ip(&b);
150             if (nh) {
151                 flow->nw_src = nh->ip_src;
152                 flow->nw_dst = nh->ip_dst;
153                 flow->nw_proto = nh->ip_proto;
154                 packet->l4 = b.data;
155                 if (!IP_IS_FRAGMENT(nh->ip_frag_off)) {
156                     if (flow->nw_proto == IP_TYPE_TCP) {
157                         const struct tcp_header *tcp = pull_tcp(&b);
158                         if (tcp) {
159                             flow->tp_src = tcp->tcp_src;
160                             flow->tp_dst = tcp->tcp_dst;
161                             packet->l7 = b.data;
162                         } else {
163                             /* Avoid tricking other code into thinking that
164                              * this packet has an L4 header. */
165                             flow->nw_proto = 0;
166                         }
167                     } else if (flow->nw_proto == IP_TYPE_UDP) {
168                         const struct udp_header *udp = pull_udp(&b);
169                         if (udp) {
170                             flow->tp_src = udp->udp_src;
171                             flow->tp_dst = udp->udp_dst;
172                             packet->l7 = b.data;
173                         } else {
174                             /* Avoid tricking other code into thinking that
175                              * this packet has an L4 header. */
176                             flow->nw_proto = 0;
177                         }
178                     } else if (flow->nw_proto == IP_TYPE_ICMP) {
179                         const struct icmp_header *icmp = pull_icmp(&b);
180                         if (icmp) {
181                             flow->icmp_type = htons(icmp->icmp_type);
182                             flow->icmp_code = htons(icmp->icmp_code);
183                             packet->l7 = b.data;
184                         } else {
185                             /* Avoid tricking other code into thinking that
186                              * this packet has an L4 header. */
187                             flow->nw_proto = 0;
188                         }
189                     }
190                 } else {
191                     retval = 1;
192                 }
193             }
194         } else if (flow->dl_type == htons(ETH_TYPE_ARP)) {
195             const struct arp_eth_header *arp = pull_arp(&b);
196             if (arp && arp->ar_hrd == htons(1)
197                     && arp->ar_pro == htons(ETH_TYPE_IP) 
198                     && arp->ar_hln == ETH_ADDR_LEN
199                     && arp->ar_pln == 4) {
200                 /* We only match on the lower 8 bits of the opcode. */
201                 if (ntohs(arp->ar_op) <= 0xff) {
202                     flow->nw_proto = ntohs(arp->ar_op);
203                 }
204
205                 if ((flow->nw_proto == ARP_OP_REQUEST) 
206                         || (flow->nw_proto == ARP_OP_REPLY)) {
207                     flow->nw_src = arp->ar_spa;
208                     flow->nw_dst = arp->ar_tpa;
209                 }
210             }
211         }
212     }
213     return retval;
214 }
215
216 /* Extracts the flow stats for a packet.  The 'flow' and 'packet'
217  * arguments must have been initialized through a call to flow_extract().
218  */
219 void
220 flow_extract_stats(const flow_t *flow, struct ofpbuf *packet, 
221         struct odp_flow_stats *stats)
222 {
223     memset(stats, '\0', sizeof(*stats));
224
225     if ((flow->dl_type == htons(ETH_TYPE_IP)) && packet->l4) {
226         struct ip_header *ip = packet->l3;
227         stats->ip_tos = ip->ip_tos;
228         if ((flow->nw_proto == IP_TYPE_TCP) && packet->l7) {
229             struct tcp_header *tcp = packet->l4;
230             stats->tcp_flags = TCP_FLAGS(tcp->tcp_ctl);
231         }
232     }
233
234     stats->n_bytes = packet->size;
235     stats->n_packets = 1;
236 }
237
238 /* The Open vSwitch datapath supports matching on ARP payloads, which 
239  * OpenFlow does not.  This function is identical to 'flow_to_match',
240  * but does not hide the datapath's ability to match on ARP. */
241 void
242 flow_to_ovs_match(const flow_t *flow, uint32_t wildcards, 
243                   struct ofp_match *match)
244 {
245     match->wildcards = htonl(wildcards);
246     match->in_port = htons(flow->in_port == ODPP_LOCAL ? OFPP_LOCAL
247                            : flow->in_port);
248     match->dl_vlan = flow->dl_vlan;
249     memcpy(match->dl_src, flow->dl_src, ETH_ADDR_LEN);
250     memcpy(match->dl_dst, flow->dl_dst, ETH_ADDR_LEN);
251     match->dl_type = flow->dl_type;
252     match->nw_src = flow->nw_src;
253     match->nw_dst = flow->nw_dst;
254     match->nw_proto = flow->nw_proto;
255     match->tp_src = flow->tp_src;
256     match->tp_dst = flow->tp_dst;
257     match->pad = 0;
258 }
259
260 /* Extract 'flow' with 'wildcards' into the OpenFlow match structure
261  * 'match'. */
262 void
263 flow_to_match(const flow_t *flow, uint32_t wildcards, struct ofp_match *match)
264 {
265     flow_to_ovs_match(flow, wildcards, match);
266
267     /* The datapath supports matching on an ARP's opcode and IP addresses, 
268      * but OpenFlow does not.  We wildcard and zero out the appropriate
269      * fields so that OpenFlow is unaware of our trickery. */
270     if (flow->dl_type == htons(ETH_TYPE_ARP)) {
271         wildcards |= (OFPFW_NW_PROTO | OFPFW_NW_SRC_ALL | OFPFW_NW_DST_ALL);
272         match->nw_src = 0;
273         match->nw_dst = 0;
274         match->nw_proto = 0;
275     }
276     match->wildcards = htonl(wildcards);
277 }
278
279
280 void
281 flow_from_match(flow_t *flow, uint32_t *wildcards,
282                 const struct ofp_match *match)
283 {
284     if (wildcards) {
285         *wildcards = ntohl(match->wildcards);
286     }
287     /* The datapath supports matching on an ARP's opcode and IP addresses, 
288      * but OpenFlow does not.  In case the controller hasn't, we need to 
289      * set the appropriate wildcard bits so that we're externally 
290      * OpenFlow-compliant. */
291     if (match->dl_type == htons(ETH_TYPE_ARP)) {
292         *wildcards |= (OFPFW_NW_PROTO | OFPFW_NW_SRC_ALL | OFPFW_NW_DST_ALL);
293     }
294
295     flow->nw_src = match->nw_src;
296     flow->nw_dst = match->nw_dst;
297     flow->in_port = (match->in_port == htons(OFPP_LOCAL) ? ODPP_LOCAL
298                      : ntohs(match->in_port));
299     flow->dl_vlan = match->dl_vlan;
300     flow->dl_type = match->dl_type;
301     flow->tp_src = match->tp_src;
302     flow->tp_dst = match->tp_dst;
303     memcpy(flow->dl_src, match->dl_src, ETH_ADDR_LEN);
304     memcpy(flow->dl_dst, match->dl_dst, ETH_ADDR_LEN);
305     flow->nw_proto = match->nw_proto;
306     flow->reserved = 0;
307 }
308
309 char *
310 flow_to_string(const flow_t *flow)
311 {
312     struct ds ds = DS_EMPTY_INITIALIZER;
313     flow_format(&ds, flow);
314     return ds_cstr(&ds);
315 }
316
317 void
318 flow_format(struct ds *ds, const flow_t *flow)
319 {
320     ds_put_format(ds, "in_port%04x:vlan%d mac"ETH_ADDR_FMT"->"ETH_ADDR_FMT" "
321                   "type%04x proto%"PRId8" ip"IP_FMT"->"IP_FMT" port%d->%d",
322                   flow->in_port, ntohs(flow->dl_vlan),
323                   ETH_ADDR_ARGS(flow->dl_src), ETH_ADDR_ARGS(flow->dl_dst),
324                   ntohs(flow->dl_type), flow->nw_proto,
325                   IP_ARGS(&flow->nw_src), IP_ARGS(&flow->nw_dst),
326                   ntohs(flow->tp_src), ntohs(flow->tp_dst));
327 }
328
329 void
330 flow_print(FILE *stream, const flow_t *flow) 
331 {
332     char *s = flow_to_string(flow);
333     fputs(s, stream);
334     free(s);
335 }