trafgen_l2.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Subject to the GPL, version 2.
   4  */
   5
   6 #include <net/if_arp.h>
   7 #include <linux/if_ether.h>
   8
   9 #include "die.h"
  10 #include "built_in.h"
  11 #include "trafgen_l2.h"
  12 #include "trafgen_proto.h"
  13
  14 static struct proto_field eth_fields[] = {
  15         { .id = ETH_DST_ADDR, .len = 6, },
  16         { .id = ETH_SRC_ADDR, .len = 6, .offset = 6 },
  17         { .id = ETH_TYPE,     .len = 2, .offset = 12 },
  18 };
  19
  20 static uint16_t pid_to_eth(enum proto_id pid)
  21 {
  22         switch (pid) {
  23         case PROTO_ARP:
  24                 return ETH_P_ARP;
  25         case PROTO_IP4:
  26                 return ETH_P_IP;
  27         case PROTO_IP6:
  28                 return ETH_P_IPV6;
  29         case PROTO_MPLS:
  30                 return ETH_P_MPLS_UC;
  31         case PROTO_VLAN:
  32                 return ETH_P_8021Q;
  33         case PROTO_PAUSE:
  34         case PROTO_PFC:
  35                 return ETH_P_PAUSE;
  36         default:
  37                 bug();
  38         }
  39 }
  40
  41 static void eth_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
  42 {
  43         proto_hdr_field_set_default_be16(hdr, ETH_TYPE, pid_to_eth(pid));
  44 }
  45
  46 static void eth_header_init(struct proto_hdr *hdr)
  47 {
  48         proto_header_fields_add(hdr, eth_fields, array_size(eth_fields));
  49
  50         proto_hdr_field_set_default_dev_mac(hdr, ETH_SRC_ADDR);
  51 }
  52
  53 static const struct proto_ops eth_proto_ops = {
  54         .id             = PROTO_ETH,
  55         .layer          = PROTO_L2,
  56         .header_init    = eth_header_init,
  57         .set_next_proto = eth_set_next_proto,
  58 };
  59
  60 static struct proto_field pause_fields[] = {
  61         { .id = PAUSE_OPCODE,   .len = 2, .offset = 0 },
  62         { .id = PAUSE_TIME,     .len = 2, .offset = 2 },
  63 };
  64
  65 static void pause_header_init(struct proto_hdr *hdr)
  66 {
  67         uint8_t eth_dst[6] = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x01 };
  68
  69         struct proto_hdr *lower;
  70
  71         lower = proto_lower_default_add(hdr, PROTO_ETH);
  72         proto_hdr_field_set_default_bytes(lower, ETH_DST_ADDR, eth_dst);
  73
  74         proto_header_fields_add(hdr, pause_fields, array_size(pause_fields));
  75         proto_hdr_field_set_default_be16(hdr, PAUSE_OPCODE, 0x1);
  76 }
  77
  78 static struct proto_ops pause_proto_ops = {
  79         .id             = PROTO_PAUSE,
  80         .layer          = PROTO_L2,
  81         .header_init    = pause_header_init,
  82 };
  83
  84 static struct proto_field pfc_fields[] = {
  85         { .id = PFC_OPCODE,  .len = 2, .offset = 0 },
  86         { .id = PFC_PRIO,    .len = 2, .offset = 2 },
  87         { .id = PFC_PRIO_0,  .len = 2, .offset = 2, .mask = 0x0001 },
  88         { .id = PFC_PRIO_1,  .len = 2, .offset = 2, .mask = 0x0002, .shift = 1 },
  89         { .id = PFC_PRIO_2,  .len = 2, .offset = 2, .mask = 0x0004, .shift = 2 },
  90         { .id = PFC_PRIO_3,  .len = 2, .offset = 2, .mask = 0x0008, .shift = 3 },
  91         { .id = PFC_PRIO_4,  .len = 2, .offset = 2, .mask = 0x0010, .shift = 4 },
  92         { .id = PFC_PRIO_5,  .len = 2, .offset = 2, .mask = 0x0020, .shift = 5 },
  93         { .id = PFC_PRIO_6,  .len = 2, .offset = 2, .mask = 0x0040, .shift = 6 },
  94         { .id = PFC_PRIO_7,  .len = 2, .offset = 2, .mask = 0x0080, .shift = 7 },
  95         { .id = PFC_TIME_0,  .len = 2, .offset = 4,  },
  96         { .id = PFC_TIME_1,  .len = 2, .offset = 6,  },
  97         { .id = PFC_TIME_2,  .len = 2, .offset = 8,  },
  98         { .id = PFC_TIME_3,  .len = 2, .offset = 10, },
  99         { .id = PFC_TIME_4,  .len = 2, .offset = 12, },
 100         { .id = PFC_TIME_5,  .len = 2, .offset = 14, },
 101         { .id = PFC_TIME_6,  .len = 2, .offset = 16, },
 102         { .id = PFC_TIME_7,  .len = 2, .offset = 18, },
 103 };
 104
 105 static void pfc_header_init(struct proto_hdr *hdr)
 106 {
 107         uint8_t eth_dst[6] = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x01 };
 108
 109         struct proto_hdr *lower;
 110
 111         lower = proto_lower_default_add(hdr, PROTO_ETH);
 112         proto_hdr_field_set_default_bytes(lower, ETH_DST_ADDR, eth_dst);
 113
 114         proto_header_fields_add(hdr, pfc_fields, array_size(pfc_fields));
 115         proto_hdr_field_set_default_be16(hdr, PFC_OPCODE, 0x0101);
 116 }
 117
 118 static struct proto_ops pfc_proto_ops = {
 119         .id             = PROTO_PFC,
 120         .layer          = PROTO_L2,
 121         .header_init    = pfc_header_init,
 122 };
 123
 124 static struct proto_field vlan_fields[] = {
 125         /* TPID overlaps with Ethernet header and points to ether type */
 126         { .id = VLAN_TPID, .len = 2, .offset = -2 },
 127         { .id = VLAN_TCI,  .len = 2, .offset = 0 },
 128         { .id = VLAN_PCP,  .len = 2, .offset = 0, .shift = 13, .mask = 0xe000 },
 129         { .id = VLAN_DEI,  .len = 2, .offset = 0, .shift = 12, .mask = 0x1000 },
 130         { .id = VLAN_VID,  .len = 2, .offset = 0, .shift = 0,  .mask = 0xfff },
 131         /* Original ether type is stored after VLAN header */
 132         { .id = VLAN_ETYPE, .len = 2, .offset = 2 },
 133 };
 134
 135 static void vlan_header_init(struct proto_hdr *hdr)
 136 {
 137         struct proto_hdr *lower = proto_lower_default_add(hdr, PROTO_ETH);
 138         uint16_t lower_etype = 0;
 139
 140         proto_header_fields_add(hdr, vlan_fields, array_size(vlan_fields));
 141
 142         if (lower->ops->id == PROTO_ETH)
 143                 lower_etype = proto_hdr_field_get_u16(lower, ETH_TYPE);
 144         else if (lower->ops->id == PROTO_VLAN)
 145                 lower_etype = proto_hdr_field_get_u16(lower, VLAN_ETYPE);
 146
 147         proto_hdr_field_set_be16(hdr, VLAN_ETYPE, lower_etype);
 148         proto_hdr_field_set_default_be16(hdr, VLAN_TPID, pid_to_eth(hdr->ops->id));
 149 }
 150
 151 static void vlan_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
 152 {
 153         if (pid != PROTO_VLAN)
 154                 proto_hdr_field_set_be16(hdr, VLAN_ETYPE, pid_to_eth(pid));
 155 }
 156
 157 static const struct proto_ops vlan_proto_ops = {
 158         .id             = PROTO_VLAN,
 159         .layer          = PROTO_L2,
 160         .header_init    = vlan_header_init,
 161         .set_next_proto = vlan_set_next_proto,
 162 };
 163
 164 static struct proto_field arp_fields[] = {
 165         { .id = ARP_HTYPE, .len = 2 },
 166         { .id = ARP_PTYPE, .len = 2, .offset = 2 },
 167         { .id = ARP_HLEN,  .len = 1, .offset = 4 },
 168         { .id = ARP_PLEN,  .len = 1, .offset = 5 },
 169         { .id = ARP_OPER,  .len = 2, .offset = 6 },
 170         { .id = ARP_SHA,   .len = 6, .offset = 8 },
 171         { .id = ARP_SPA,   .len = 4, .offset = 14 },
 172         { .id = ARP_THA,   .len = 6, .offset = 18 },
 173         { .id = ARP_TPA,   .len = 4, .offset = 24 },
 174 };
 175
 176 static void arp_header_init(struct proto_hdr *hdr)
 177 {
 178         struct proto_hdr *lower = proto_lower_default_add(hdr, PROTO_ETH);
 179
 180         if (lower->ops->id == PROTO_ETH) {
 181                 const uint8_t bcast[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 182
 183                 proto_hdr_field_set_default_bytes(lower, ETH_DST_ADDR, bcast);
 184         }
 185
 186         proto_header_fields_add(hdr, arp_fields, array_size(arp_fields));
 187
 188         /* Generate Announce request by default */
 189         proto_hdr_field_set_default_be16(hdr, ARP_HTYPE, ARPHRD_ETHER);
 190         proto_hdr_field_set_default_be16(hdr, ARP_PTYPE, ETH_P_IP);
 191         proto_hdr_field_set_default_u8(hdr, ARP_HLEN, 6);
 192         proto_hdr_field_set_default_u8(hdr, ARP_PLEN, 4);
 193         proto_hdr_field_set_default_be16(hdr, ARP_OPER, ARPOP_REQUEST);
 194         proto_hdr_field_set_default_dev_mac(hdr, ARP_SHA);
 195         proto_hdr_field_set_default_dev_ipv4(hdr, ARP_SPA);
 196         proto_hdr_field_set_default_dev_ipv4(hdr, ARP_TPA);
 197 }
 198
 199 static const struct proto_ops arp_proto_ops = {
 200         .id             = PROTO_ARP,
 201         .layer          = PROTO_L2,
 202         .header_init    = arp_header_init,
 203 };
 204
 205 static struct proto_field mpls_fields[] = {
 206         { .id = MPLS_LABEL, .len = 4, .shift = 12, .mask = 0xfffff000 },
 207         { .id = MPLS_TC,    .len = 4, .shift = 9,  .mask = 0xe00 },
 208         { .id = MPLS_LAST,  .len = 4, .shift = 8,  .mask = 0x100 },
 209         { .id = MPLS_TTL,   .len = 4, .shift = 0,  .mask = 0xff },
 210 };
 211
 212 static void mpls_header_init(struct proto_hdr *hdr)
 213 {
 214         proto_lower_default_add(hdr, PROTO_ETH);
 215
 216         proto_header_fields_add(hdr, mpls_fields, array_size(mpls_fields));
 217
 218         proto_hdr_field_set_default_be32(hdr, MPLS_LAST, 1);
 219 }
 220
 221 static void mpls_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
 222 {
 223         if (pid == PROTO_MPLS)
 224                 proto_hdr_field_set_default_be32(hdr, MPLS_LAST, 0);
 225 }
 226
 227 static const struct proto_ops mpls_proto_ops = {
 228         .id             = PROTO_MPLS,
 229         .layer          = PROTO_L2,
 230         .header_init    = mpls_header_init,
 231         .set_next_proto = mpls_set_next_proto,
 232 };
 233
 234 void protos_l2_init(void)
 235 {
 236         proto_ops_register(&eth_proto_ops);
 237         proto_ops_register(&pause_proto_ops);
 238         proto_ops_register(&pfc_proto_ops);
 239         proto_ops_register(&vlan_proto_ops);
 240         proto_ops_register(&arp_proto_ops);
 241         proto_ops_register(&mpls_proto_ops);
 242 }