2 * netsniff-ng - the packet sniffing beast
3 * Subject to the GPL, version 2.
6 #include <linux/if_ether.h>
11 #include "trafgen_l2.h"
12 #include "trafgen_l3.h"
13 #include "trafgen_proto.h"
14 #include "trafgen_conf.h"
16 static struct proto_field ipv4_fields
[] = {
17 { .id
= IP4_VER
, .len
= 1, .offset
= 0, .shift
= 4, .mask
= 0xf0 },
18 { .id
= IP4_IHL
, .len
= 1, .offset
= 0, .shift
= 0, .mask
= 0x0f },
19 { .id
= IP4_DSCP
, .len
= 1, .offset
= 1, .shift
= 2, .mask
= 0xfc },
20 { .id
= IP4_ECN
, .len
= 1, .offset
= 1, .shift
= 0, .mask
= 0x03 },
21 { .id
= IP4_TOS
, .len
= 1, .offset
= 1 },
22 { .id
= IP4_LEN
, .len
= 2, .offset
= 2 },
23 { .id
= IP4_ID
, .len
= 2, .offset
= 4 },
24 { .id
= IP4_FLAGS
, .len
= 2, .offset
= 6, .shift
= 13, .mask
= 0xe000 },
25 { .id
= IP4_MF
, .len
= 2, .offset
= 6, .shift
= 13, .mask
= 0x2000 },
26 { .id
= IP4_DF
, .len
= 2, .offset
= 6, .shift
= 14, .mask
= 0x4000 },
27 { .id
= IP4_FRAG_OFFS
, .len
= 2, .offset
= 6, .shift
= 0, .mask
= 0x1fff },
28 { .id
= IP4_TTL
, .len
= 1, .offset
= 8 },
29 { .id
= IP4_PROTO
, .len
= 1, .offset
= 9 },
30 { .id
= IP4_CSUM
, .len
= 2, .offset
= 10 },
31 { .id
= IP4_SADDR
, .len
= 4, .offset
= 12 },
32 { .id
= IP4_DADDR
, .len
= 4, .offset
= 16 },
35 static void ipv4_header_init(struct proto_hdr
*hdr
)
37 proto_lower_default_add(hdr
, PROTO_ETH
);
39 proto_header_fields_add(hdr
, ipv4_fields
, array_size(ipv4_fields
));
41 proto_field_set_default_u8(hdr
, IP4_VER
, 4);
42 proto_field_set_default_u8(hdr
, IP4_IHL
, 5);
43 proto_field_set_default_dev_ipv4(hdr
, IP4_SADDR
);
46 static void ipv4_packet_finish(struct proto_hdr
*hdr
)
48 struct packet
*pkt
= current_packet();
51 total_len
= pkt
->len
- hdr
->pkt_offset
;
52 proto_field_set_default_be16(hdr
, IP4_LEN
, total_len
);
54 if (!proto_field_is_set(hdr
, IP4_CSUM
)) {
58 ihl
= proto_field_get_u8(hdr
, IP4_IHL
);
59 csum
= htons(calc_csum(&pkt
->payload
[hdr
->pkt_offset
], ihl
* 4));
60 proto_field_set_u16(hdr
, IP4_CSUM
, bswap_16(csum
));
64 static void ipv4_set_next_proto(struct proto_hdr
*hdr
, enum proto_id pid
)
70 ip_proto
= IPPROTO_IPIP
;
73 ip_proto
= IPPROTO_UDP
;
76 ip_proto
= IPPROTO_TCP
;
82 proto_field_set_default_u8(hdr
, IP4_PROTO
, ip_proto
);
85 static struct proto_hdr ipv4_hdr
= {
88 .header_init
= ipv4_header_init
,
89 .packet_finish
= ipv4_packet_finish
,
90 .set_next_proto
= ipv4_set_next_proto
,
93 static struct proto_field ipv6_fields
[] = {
94 { .id
= IP6_VER
, .len
= 4, .offset
= 0, .shift
= 28, .mask
= 0xf0000000 },
95 { .id
= IP6_CLASS
, .len
= 4, .offset
= 0, .shift
= 20, .mask
= 0x0ff00000 },
96 { .id
= IP6_FLOW_LBL
, .len
= 4, .offset
= 0, .shift
= 0, .mask
= 0x000fffff },
97 { .id
= IP6_LEN
, .len
= 2, .offset
= 4 },
98 { .id
= IP6_NEXT_HDR
, .len
= 1, .offset
= 6 },
99 { .id
= IP6_HOP_LIMIT
, .len
= 1, .offset
= 7 },
100 { .id
= IP6_SADDR
, .len
= 16, .offset
= 8 },
101 { .id
= IP6_DADDR
, .len
= 16, .offset
= 24 },
104 static void ipv6_header_init(struct proto_hdr
*hdr
)
106 proto_lower_default_add(hdr
, PROTO_ETH
);
108 proto_header_fields_add(hdr
, ipv6_fields
, array_size(ipv6_fields
));
110 proto_field_set_default_be32(hdr
, IP6_VER
, 6);
111 proto_field_set_default_dev_ipv6(hdr
, IP6_SADDR
);
114 #define IPV6_HDR_LEN 40
116 static void ipv6_packet_finish(struct proto_hdr
*hdr
)
118 struct packet
*pkt
= current_packet();
119 uint16_t total_len
= pkt
->len
- hdr
->pkt_offset
- IPV6_HDR_LEN
;
121 proto_field_set_default_be16(hdr
, IP6_LEN
, total_len
);
124 static void ipv6_set_next_proto(struct proto_hdr
*hdr
, enum proto_id pid
)
130 ip_proto
= IPPROTO_ICMPV6
;
133 ip_proto
= IPPROTO_UDP
;
136 ip_proto
= IPPROTO_TCP
;
142 proto_field_set_default_u8(hdr
, IP6_NEXT_HDR
, ip_proto
);
145 static struct proto_hdr ipv6_hdr
= {
148 .header_init
= ipv6_header_init
,
149 .packet_finish
= ipv6_packet_finish
,
150 .set_next_proto
= ipv6_set_next_proto
,
153 void protos_l3_init(void)
155 proto_header_register(&ipv4_hdr
);
156 proto_header_register(&ipv6_hdr
);