pintos-os.org Git - openvswitch/blob - lib/flow.c

   1 #include <sys/types.h>
   2 #include "flow.h"
   3 #include <inttypes.h>
   4 #include <netinet/in.h>
   5 #include <string.h>
   6 #include "buffer.h"
   7 #include "hash.h"
   8 #include "ip.h"
   9 #include "mac.h"
  10 #include "openflow.h"
  11 #include "packets.h"
  12
  13 #include "vlog.h"
  14 #define THIS_MODULE VLM_flow
  15
  16 void
  17 flow_extract(const struct buffer *packet, uint16_t in_port, struct flow *flow)
  18 {
  19     struct buffer b = *packet;
  20     struct eth_header *eth;
  21
  22     if (b.size < ETH_TOTAL_MIN) {
  23         VLOG_WARN("packet length %d less than minimum size %d",
  24                   b.size, ETH_TOTAL_MIN);
  25     }
  26
  27     memset(flow, 0, sizeof *flow);
  28     flow->in_port = htons(in_port);
  29
  30     eth = buffer_at(&b, 0, sizeof *eth);
  31     if (eth) {
  32         buffer_pull(&b, ETH_HEADER_LEN);
  33         if (ntohs(eth->eth_type) >= OFP_DL_TYPE_ETH2_CUTOFF) {
  34             /* This is an Ethernet II frame */
  35             flow->dl_type = eth->eth_type;
  36         } else {
  37             /* This is an 802.2 frame */
  38             struct llc_snap_header *h = buffer_at(&b, 0, sizeof *h);
  39             if (h == NULL) {
  40                 return;
  41             }
  42             if (h->llc.llc_dsap == LLC_DSAP_SNAP
  43                 && h->llc.llc_ssap == LLC_SSAP_SNAP
  44                 && h->llc.llc_cntl == LLC_CNTL_SNAP
  45                 && !memcmp(h->snap.snap_org, SNAP_ORG_ETHERNET,
  46                            sizeof h->snap.snap_org)) {
  47                 flow->dl_type = h->snap.snap_type;
  48                 buffer_pull(&b, sizeof *h);
  49             } else {
  50                 flow->dl_type = OFP_DL_TYPE_NOT_ETH_TYPE;
  51                 buffer_pull(&b, sizeof(struct llc_header));
  52             }
  53         }
  54
  55         /* Check for a VLAN tag */
  56         if (flow->dl_type != htons(ETH_TYPE_VLAN)) {
  57             flow->dl_vlan = htons(OFP_VLAN_NONE);
  58         } else {
  59             struct vlan_header *vh = buffer_at(&b, 0, sizeof *vh);
  60             flow->dl_type = vh->vlan_next_type;
  61             flow->dl_vlan = vh->vlan_tci & htons(VLAN_VID);
  62             buffer_pull(&b, sizeof *vh);
  63         }
  64         memcpy(flow->dl_src, eth->eth_src, ETH_ADDR_LEN);
  65         memcpy(flow->dl_dst, eth->eth_dst, ETH_ADDR_LEN);
  66
  67         if (flow->dl_type == htons(ETH_TYPE_IP)) {
  68             const struct ip_header *nh = buffer_at(&b, 0, sizeof *nh);
  69             if (nh) {
  70                 flow->nw_src = nh->ip_src;
  71                 flow->nw_dst = nh->ip_dst;
  72                 flow->nw_proto = nh->ip_proto;
  73                 if (flow->nw_proto == IP_TYPE_TCP
  74                     || flow->nw_proto == IP_TYPE_UDP) {
  75                     int udp_ofs = IP_IHL(nh->ip_ihl_ver) * 4;
  76                     const struct udp_header *th
  77                         = buffer_at(&b, udp_ofs, sizeof *th);
  78                     if (th) {
  79                         flow->tp_src = th->udp_src;
  80                         flow->tp_dst = th->udp_dst;
  81                     }
  82                 }
  83             }
  84         } else if (flow->dl_type == htons(ETH_TYPE_ARP)) {
  85             const struct arp_eth_header *ah = buffer_at(&b, 0, sizeof *ah);
  86             if (ah && ah->ar_hrd == htons(ARP_HRD_ETHERNET)
  87                 && ah->ar_pro == htons(ARP_PRO_IP)
  88                 && ah->ar_hln == ETH_ADDR_LEN
  89                 && ah->ar_pln == sizeof flow->nw_src)
  90             {
  91                 /* check if sha/tha match dl_src/dl_dst? */
  92                 flow->nw_src = ah->ar_spa;
  93                 flow->nw_dst = ah->ar_tpa;
  94             }
  95         }
  96     }
  97 }
  98
  99 void
 100 flow_print(FILE *stream, const struct flow *flow)
 101 {
 102     fprintf(stream,
 103             "port%04x:vlan%04x mac"MAC_FMT"->"MAC_FMT" "
 104             "proto%04x ip"IP_FMT"->"IP_FMT" port%d->%d",
 105             ntohs(flow->in_port), ntohs(flow->dl_vlan),
 106             MAC_ARGS(flow->dl_src), MAC_ARGS(flow->dl_dst),
 107             ntohs(flow->dl_type),
 108             IP_ARGS(&flow->nw_src), IP_ARGS(&flow->nw_dst),
 109             ntohs(flow->tp_src), ntohs(flow->tp_dst));
 110 }
 111
 112 int
 113 flow_compare(const struct flow *a, const struct flow *b)
 114 {
 115     return memcmp(a, b, sizeof *a);
 116 }
 117
 118 unsigned long int
 119 flow_hash(const struct flow *flow, uint32_t basis)
 120 {
 121     return hash_fnv(flow, sizeof *flow, basis);
 122 }