Diagnose attempts to connect the wrong protocol to a network port.
[openvswitch] / lib / flow.c
1 /*
2  * Copyright (c) 2008, 2009, 2010 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 #include "unaligned.h"
31 #include "xtoxll.h"
32
33 #include "vlog.h"
34 #define THIS_MODULE VLM_flow
35
36 static struct arp_eth_header *
37 pull_arp(struct ofpbuf *packet)
38 {
39     return ofpbuf_try_pull(packet, ARP_ETH_HEADER_LEN);
40 }
41
42 static struct ip_header *
43 pull_ip(struct ofpbuf *packet)
44 {
45     if (packet->size >= IP_HEADER_LEN) {
46         struct ip_header *ip = packet->data;
47         int ip_len = IP_IHL(ip->ip_ihl_ver) * 4;
48         if (ip_len >= IP_HEADER_LEN && packet->size >= ip_len) {
49             return ofpbuf_pull(packet, ip_len);
50         }
51     }
52     return NULL;
53 }
54
55 static struct tcp_header *
56 pull_tcp(struct ofpbuf *packet) 
57 {
58     if (packet->size >= TCP_HEADER_LEN) {
59         struct tcp_header *tcp = packet->data;
60         int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
61         if (tcp_len >= TCP_HEADER_LEN && packet->size >= tcp_len) {
62             return ofpbuf_pull(packet, tcp_len);
63         }
64     }
65     return NULL;
66 }
67
68 static struct udp_header *
69 pull_udp(struct ofpbuf *packet) 
70 {
71     return ofpbuf_try_pull(packet, UDP_HEADER_LEN);
72 }
73
74 static struct icmp_header *
75 pull_icmp(struct ofpbuf *packet) 
76 {
77     return ofpbuf_try_pull(packet, ICMP_HEADER_LEN);
78 }
79
80 static struct eth_header *
81 pull_eth(struct ofpbuf *packet) 
82 {
83     return ofpbuf_try_pull(packet, ETH_HEADER_LEN);
84 }
85
86 static struct vlan_header *
87 pull_vlan(struct ofpbuf *packet)
88 {
89     return ofpbuf_try_pull(packet, VLAN_HEADER_LEN);
90 }
91
92 /* Returns 1 if 'packet' is an IP fragment, 0 otherwise.
93  * 'tun_id' is in network byte order, while 'in_port' is in host byte order.
94  * These byte orders are the same as they are in struct odp_flow_key. */
95 int
96 flow_extract(struct ofpbuf *packet, uint32_t tun_id, uint16_t in_port,
97              flow_t *flow)
98 {
99     struct ofpbuf b = *packet;
100     struct eth_header *eth;
101     int retval = 0;
102
103     COVERAGE_INC(flow_extract);
104
105     memset(flow, 0, sizeof *flow);
106     flow->tun_id = tun_id;
107     flow->in_port = in_port;
108     flow->dl_vlan = htons(OFP_VLAN_NONE);
109
110     packet->l2 = b.data;
111     packet->l3 = NULL;
112     packet->l4 = NULL;
113     packet->l7 = NULL;
114
115     eth = pull_eth(&b);
116     if (eth) {
117         if (ntohs(eth->eth_type) >= OFP_DL_TYPE_ETH2_CUTOFF) {
118             /* This is an Ethernet II frame */
119             flow->dl_type = eth->eth_type;
120         } else {
121             /* This is an 802.2 frame */
122             struct llc_header *llc = ofpbuf_at(&b, 0, sizeof *llc);
123             struct snap_header *snap = ofpbuf_at(&b, sizeof *llc,
124                                                  sizeof *snap);
125             if (llc == NULL) {
126                 return 0;
127             }
128             if (snap
129                 && llc->llc_dsap == LLC_DSAP_SNAP
130                 && llc->llc_ssap == LLC_SSAP_SNAP
131                 && llc->llc_cntl == LLC_CNTL_SNAP
132                 && !memcmp(snap->snap_org, SNAP_ORG_ETHERNET,
133                            sizeof snap->snap_org)) {
134                 flow->dl_type = snap->snap_type;
135                 ofpbuf_pull(&b, LLC_SNAP_HEADER_LEN);
136             } else {
137                 flow->dl_type = htons(OFP_DL_TYPE_NOT_ETH_TYPE);
138                 ofpbuf_pull(&b, sizeof(struct llc_header));
139             }
140         }
141
142         /* Check for a VLAN tag */
143         if (flow->dl_type == htons(ETH_TYPE_VLAN)) {
144             struct vlan_header *vh = pull_vlan(&b);
145             if (vh) {
146                 flow->dl_type = vh->vlan_next_type;
147                 flow->dl_vlan = vh->vlan_tci & htons(VLAN_VID_MASK);
148                 flow->dl_vlan_pcp = (ntohs(vh->vlan_tci) & 0xe000) >> 13;
149             }
150         }
151         memcpy(flow->dl_src, eth->eth_src, ETH_ADDR_LEN);
152         memcpy(flow->dl_dst, eth->eth_dst, ETH_ADDR_LEN);
153
154         packet->l3 = b.data;
155         if (flow->dl_type == htons(ETH_TYPE_IP)) {
156             const struct ip_header *nh = pull_ip(&b);
157             if (nh) {
158                 flow->nw_src = get_unaligned_u32(&nh->ip_src);
159                 flow->nw_dst = get_unaligned_u32(&nh->ip_dst);
160                 flow->nw_tos = nh->ip_tos & IP_DSCP_MASK;
161                 flow->nw_proto = nh->ip_proto;
162                 packet->l4 = b.data;
163                 if (!IP_IS_FRAGMENT(nh->ip_frag_off)) {
164                     if (flow->nw_proto == IP_TYPE_TCP) {
165                         const struct tcp_header *tcp = pull_tcp(&b);
166                         if (tcp) {
167                             flow->tp_src = tcp->tcp_src;
168                             flow->tp_dst = tcp->tcp_dst;
169                             packet->l7 = b.data;
170                         } else {
171                             /* Avoid tricking other code into thinking that
172                              * this packet has an L4 header. */
173                             flow->nw_proto = 0;
174                         }
175                     } else if (flow->nw_proto == IP_TYPE_UDP) {
176                         const struct udp_header *udp = pull_udp(&b);
177                         if (udp) {
178                             flow->tp_src = udp->udp_src;
179                             flow->tp_dst = udp->udp_dst;
180                             packet->l7 = b.data;
181                         } else {
182                             /* Avoid tricking other code into thinking that
183                              * this packet has an L4 header. */
184                             flow->nw_proto = 0;
185                         }
186                     } else if (flow->nw_proto == IP_TYPE_ICMP) {
187                         const struct icmp_header *icmp = pull_icmp(&b);
188                         if (icmp) {
189                             flow->icmp_type = htons(icmp->icmp_type);
190                             flow->icmp_code = htons(icmp->icmp_code);
191                             packet->l7 = b.data;
192                         } else {
193                             /* Avoid tricking other code into thinking that
194                              * this packet has an L4 header. */
195                             flow->nw_proto = 0;
196                         }
197                     }
198                 } else {
199                     retval = 1;
200                 }
201             }
202         } else if (flow->dl_type == htons(ETH_TYPE_ARP)) {
203             const struct arp_eth_header *arp = pull_arp(&b);
204             if (arp && arp->ar_hrd == htons(1)
205                     && arp->ar_pro == htons(ETH_TYPE_IP) 
206                     && arp->ar_hln == ETH_ADDR_LEN
207                     && arp->ar_pln == 4) {
208                 /* We only match on the lower 8 bits of the opcode. */
209                 if (ntohs(arp->ar_op) <= 0xff) {
210                     flow->nw_proto = ntohs(arp->ar_op);
211                 }
212
213                 if ((flow->nw_proto == ARP_OP_REQUEST) 
214                         || (flow->nw_proto == ARP_OP_REPLY)) {
215                     flow->nw_src = arp->ar_spa;
216                     flow->nw_dst = arp->ar_tpa;
217                 }
218             }
219         }
220     }
221     return retval;
222 }
223
224 /* Extracts the flow stats for a packet.  The 'flow' and 'packet'
225  * arguments must have been initialized through a call to flow_extract().
226  */
227 void
228 flow_extract_stats(const flow_t *flow, struct ofpbuf *packet, 
229         struct odp_flow_stats *stats)
230 {
231     memset(stats, '\0', sizeof(*stats));
232
233     if ((flow->dl_type == htons(ETH_TYPE_IP)) && packet->l4) {
234         struct ip_header *ip = packet->l3;
235         stats->ip_tos = ip->ip_tos;
236         if ((flow->nw_proto == IP_TYPE_TCP) && packet->l7) {
237             struct tcp_header *tcp = packet->l4;
238             stats->tcp_flags = TCP_FLAGS(tcp->tcp_ctl);
239         }
240     }
241
242     stats->n_bytes = packet->size;
243     stats->n_packets = 1;
244 }
245
246 /* Extract 'flow' with 'wildcards' into the OpenFlow match structure
247  * 'match'. */
248 void
249 flow_to_match(const flow_t *flow, uint32_t wildcards, bool tun_id_from_cookie,
250               struct ofp_match *match)
251 {
252     if (!tun_id_from_cookie) {
253         wildcards &= OFPFW_ALL;
254     }
255     match->wildcards = htonl(wildcards);
256
257     match->in_port = htons(flow->in_port == ODPP_LOCAL ? OFPP_LOCAL
258                            : flow->in_port);
259     match->dl_vlan = flow->dl_vlan;
260     match->dl_vlan_pcp = flow->dl_vlan_pcp;
261     memcpy(match->dl_src, flow->dl_src, ETH_ADDR_LEN);
262     memcpy(match->dl_dst, flow->dl_dst, ETH_ADDR_LEN);
263     match->dl_type = flow->dl_type;
264     match->nw_src = flow->nw_src;
265     match->nw_dst = flow->nw_dst;
266     match->nw_tos = flow->nw_tos;
267     match->nw_proto = flow->nw_proto;
268     match->tp_src = flow->tp_src;
269     match->tp_dst = flow->tp_dst;
270     memset(match->pad1, '\0', sizeof match->pad1);
271     memset(match->pad2, '\0', sizeof match->pad2);
272 }
273
274 void
275 flow_from_match(const struct ofp_match *match, bool tun_id_from_cookie,
276                 uint64_t cookie, flow_t *flow, uint32_t *flow_wildcards)
277 {
278         uint32_t wildcards = ntohl(match->wildcards);
279
280     flow->nw_src = match->nw_src;
281     flow->nw_dst = match->nw_dst;
282     if (tun_id_from_cookie && !(wildcards & NXFW_TUN_ID)) {
283         flow->tun_id = htonl(ntohll(cookie) >> 32);
284     } else {
285         wildcards |= NXFW_TUN_ID;
286         flow->tun_id = 0;
287     }
288     flow->in_port = (match->in_port == htons(OFPP_LOCAL) ? ODPP_LOCAL
289                      : ntohs(match->in_port));
290     flow->dl_vlan = match->dl_vlan;
291     flow->dl_vlan_pcp = match->dl_vlan_pcp;
292     flow->dl_type = match->dl_type;
293     flow->tp_src = match->tp_src;
294     flow->tp_dst = match->tp_dst;
295     memcpy(flow->dl_src, match->dl_src, ETH_ADDR_LEN);
296     memcpy(flow->dl_dst, match->dl_dst, ETH_ADDR_LEN);
297     flow->nw_tos = match->nw_tos;
298     flow->nw_proto = match->nw_proto;
299     memset(flow->reserved, 0, sizeof flow->reserved);
300
301     if (flow_wildcards) {
302         *flow_wildcards = wildcards;
303     }
304 }
305
306 char *
307 flow_to_string(const flow_t *flow)
308 {
309     struct ds ds = DS_EMPTY_INITIALIZER;
310     flow_format(&ds, flow);
311     return ds_cstr(&ds);
312 }
313
314 void
315 flow_format(struct ds *ds, const flow_t *flow)
316 {
317     ds_put_format(ds, "tunnel%08"PRIx32":in_port%04"PRIx16
318                       ":vlan%"PRIu16":pcp%"PRIu8
319                       " mac"ETH_ADDR_FMT"->"ETH_ADDR_FMT
320                       " type%04"PRIx16
321                       " proto%"PRIu8
322                       " tos%"PRIu8
323                       " ip"IP_FMT"->"IP_FMT
324                       " port%"PRIu16"->%"PRIu16,
325                   ntohl(flow->tun_id),
326                   flow->in_port,
327                   ntohs(flow->dl_vlan),
328                   flow->dl_vlan_pcp,
329                   ETH_ADDR_ARGS(flow->dl_src),
330                   ETH_ADDR_ARGS(flow->dl_dst),
331                   ntohs(flow->dl_type),
332                   flow->nw_proto,
333                   flow->nw_tos,
334                   IP_ARGS(&flow->nw_src),
335                   IP_ARGS(&flow->nw_dst),
336                   ntohs(flow->tp_src),
337                   ntohs(flow->tp_dst));
338 }
339
340 void
341 flow_print(FILE *stream, const flow_t *flow) 
342 {
343     char *s = flow_to_string(flow);
344     fputs(s, stream);
345     free(s);
346 }