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