diff options
author | Vadim Kochan <vadim4j@gmail.com> | 2016-01-26 22:25:06 +0200 |
---|---|---|
committer | Tobias Klauser <tklauser@distanz.ch> | 2016-01-28 16:15:29 +0100 |
commit | fac5a67eb5d4928f7efbf1f0d731a7e93f0f8193 (patch) | |
tree | 5c98747f50297c27f81f605715b0d9762d2ac167 /trafgen_l2.c | |
parent | d053535a66ff864d309dec2303927e410b27e5b6 (diff) |
trafgen: l2: Add ARP header generation logic
Add ARP protocol header fields generation. By default htype ethernet (1)
and ptype IPv4 (0x0800) and the corresponding hlen/plen values will be
initialized and the opcode is set to ARP Request (1).
Source MAC and IP address are set to the device's addresses if not
specified.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
[tk: rephrase and extend commit message]
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Diffstat (limited to 'trafgen_l2.c')
-rw-r--r-- | trafgen_l2.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/trafgen_l2.c b/trafgen_l2.c index 1082049..4bbeea1 100644 --- a/trafgen_l2.c +++ b/trafgen_l2.c @@ -3,6 +3,9 @@ * Subject to the GPL, version 2. */ +#include <net/if_arp.h> +#include <linux/if_ether.h> + #include "built_in.h" #include "trafgen_l2.h" #include "trafgen_proto.h" @@ -26,7 +29,54 @@ static struct proto_hdr eth_hdr = { .header_init = eth_header_init, }; +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; + + proto_lower_default_add(PROTO_ETH); + + lower = proto_current_header(); + + if (lower->id == PROTO_ETH) { + uint8_t bcast[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; + + proto_field_set_default_bytes(lower, ETH_DST_ADDR, bcast); + proto_field_set_default_be16(lower, ETH_PROTO_ID, ETH_P_ARP); + } + + 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, +}; + void protos_l2_init(void) { proto_header_register(ð_hdr); + proto_header_register(&arp_hdr); } |