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/*
* netsniff-ng - the packet sniffing beast
* Subject to the GPL, version 2.
*/
#include <net/if_arp.h>
#include <linux/if_ether.h>
#include "die.h"
#include "built_in.h"
#include "trafgen_l2.h"
#include "trafgen_proto.h"
static struct proto_field eth_fields[] = {
{ .id = ETH_DST_ADDR, .len = 6, },
{ .id = ETH_SRC_ADDR, .len = 6, .offset = 6 },
{ .id = ETH_TYPE, .len = 2, .offset = 12 },
};
static uint16_t pid_to_eth(enum proto_id pid)
{
switch (pid) {
case PROTO_ARP:
return ETH_P_ARP;
case PROTO_IP4:
return ETH_P_IP;
case PROTO_IP6:
return ETH_P_IPV6;
case PROTO_MPLS:
return ETH_P_MPLS_UC;
case PROTO_VLAN:
return ETH_P_8021Q;
default:
bug();
}
}
static void eth_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
{
proto_field_set_default_be16(hdr, ETH_TYPE, pid_to_eth(pid));
}
static void eth_header_init(struct proto_hdr *hdr)
{
proto_header_fields_add(hdr, eth_fields, array_size(eth_fields));
proto_field_set_default_dev_mac(hdr, ETH_SRC_ADDR);
}
static struct proto_hdr eth_hdr = {
.id = PROTO_ETH,
.layer = PROTO_L2,
.header_init = eth_header_init,
.set_next_proto = eth_set_next_proto,
};
static struct proto_field vlan_fields[] = {
/* TPID overlaps with Ethernet header and points to ether type */
{ .id = VLAN_TPID, .len = 2, .offset = -2 },
{ .id = VLAN_TCI, .len = 2, .offset = 0 },
{ .id = VLAN_PCP, .len = 2, .offset = 0, .shift = 13, .mask = 0xe000 },
{ .id = VLAN_DEI, .len = 2, .offset = 0, .shift = 12, .mask = 0x1000 },
{ .id = VLAN_VID, .len = 2, .offset = 0, .shift = 0, .mask = 0xfff },
/* Original ether type is stored after VLAN header */
{ .id = VLAN_ETYPE, .len = 2, .offset = 2 },
};
static void vlan_header_init(struct proto_hdr *hdr)
{
struct proto_hdr *lower;
uint16_t lower_etype = 0;
lower = proto_lower_default_add(hdr, PROTO_ETH);
proto_header_fields_add(hdr, vlan_fields, array_size(vlan_fields));
if (lower->id == PROTO_ETH)
lower_etype = proto_field_get_u16(lower, ETH_TYPE);
else if (lower->id == PROTO_VLAN)
lower_etype = proto_field_get_u16(lower, VLAN_ETYPE);
proto_field_set_be16(hdr, VLAN_ETYPE, lower_etype);
proto_field_set_default_be16(hdr, VLAN_TPID, pid_to_eth(hdr->id));
}
static void vlan_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
{
if (pid != PROTO_VLAN)
proto_field_set_be16(hdr, VLAN_ETYPE, pid_to_eth(pid));
}
static struct proto_hdr vlan_hdr = {
.id = PROTO_VLAN,
.layer = PROTO_L2,
.header_init = vlan_header_init,
.set_next_proto = vlan_set_next_proto,
};
static struct proto_field arp_fields[] = {
{ .id = ARP_HTYPE, .len = 2 },
{ .id = ARP_PTYPE, .len = 2, .offset = 2 },
{ .id = ARP_HLEN, .len = 1, .offset = 4 },
{ .id = ARP_PLEN, .len = 1, .offset = 5 },
{ .id = ARP_OPER, .len = 2, .offset = 6 },
{ .id = ARP_SHA, .len = 6, .offset = 8 },
{ .id = ARP_SPA, .len = 4, .offset = 14 },
{ .id = ARP_THA, .len = 6, .offset = 18 },
{ .id = ARP_TPA, .len = 4, .offset = 24 },
};
static void arp_header_init(struct proto_hdr *hdr)
{
struct proto_hdr *lower;
lower = proto_lower_default_add(hdr, PROTO_ETH);
if (lower->id == PROTO_ETH) {
const uint8_t bcast[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
proto_field_set_default_bytes(lower, ETH_DST_ADDR, bcast);
}
proto_header_fields_add(hdr, arp_fields, array_size(arp_fields));
/* Generate Announce request by default */
proto_field_set_default_be16(hdr, ARP_HTYPE, ARPHRD_ETHER);
proto_field_set_default_be16(hdr, ARP_PTYPE, ETH_P_IP);
proto_field_set_default_u8(hdr, ARP_HLEN, 6);
proto_field_set_default_u8(hdr, ARP_PLEN, 4);
proto_field_set_default_be16(hdr, ARP_OPER, ARPOP_REQUEST);
proto_field_set_default_dev_mac(hdr, ARP_SHA);
proto_field_set_default_dev_ipv4(hdr, ARP_SPA);
proto_field_set_default_dev_ipv4(hdr, ARP_TPA);
}
static struct proto_hdr arp_hdr = {
.id = PROTO_ARP,
.layer = PROTO_L2,
.header_init = arp_header_init,
};
static struct proto_field mpls_fields[] = {
{ .id = MPLS_LABEL, .len = 4, .shift = 12, .mask = 0xfffff000 },
{ .id = MPLS_TC, .len = 4, .shift = 9, .mask = 0xe00 },
{ .id = MPLS_LAST, .len = 4, .shift = 8, .mask = 0x100 },
{ .id = MPLS_TTL, .len = 4, .shift = 0, .mask = 0xff },
};
static void mpls_header_init(struct proto_hdr *hdr)
{
proto_lower_default_add(hdr, PROTO_ETH);
proto_header_fields_add(hdr, mpls_fields, array_size(mpls_fields));
proto_field_set_default_be32(hdr, MPLS_LAST, 1);
}
static void mpls_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
{
if (pid == PROTO_MPLS)
proto_field_set_default_be32(hdr, MPLS_LAST, 0);
}
static struct proto_hdr mpls_hdr = {
.id = PROTO_MPLS,
.layer = PROTO_L2,
.header_init = mpls_header_init,
.set_next_proto = mpls_set_next_proto,
};
void protos_l2_init(void)
{
proto_header_register(ð_hdr);
proto_header_register(&vlan_hdr);
proto_header_register(&arp_hdr);
proto_header_register(&mpls_hdr);
}
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