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1 | /* |
2 | * $Id: libnet_build_arp.c,v 1.20 2005/11/29 22:16:29 carlosc Exp $ | |
3 | * | |
4 | * libnet | |
5 | * libnet_build_arp.c - ARP packet assembler | |
6 | * | |
7 | * Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com> | |
8 | * All rights reserved. | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or without | |
11 | * modification, are permitted provided that the following conditions | |
12 | * are met: | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * | |
19 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
29 | * SUCH DAMAGE. | |
30 | * | |
31 | */ | |
32 | ||
33 | #if (HAVE_CONFIG_H) | |
34 | #include "../include/config.h" | |
35 | #endif | |
36 | #if (!(_WIN32) || (__CYGWIN__)) | |
37 | #include "../include/libnet.h" | |
38 | #else | |
39 | #include "../include/win32/libnet.h" | |
40 | #endif | |
41 | ||
42 | ||
43 | libnet_ptag_t | |
44 | libnet_build_arp(u_int16_t hrd, u_int16_t pro, u_int8_t hln, u_int8_t pln, | |
45 | u_int16_t op, u_int8_t *sha, u_int8_t *spa, u_int8_t *tha, u_int8_t *tpa, | |
46 | u_int8_t *payload, u_int32_t payload_s, libnet_t *l, libnet_ptag_t ptag) | |
47 | { | |
48 | u_int32_t n, h; | |
49 | libnet_pblock_t *p; | |
50 | struct libnet_arp_hdr arp_hdr; | |
51 | ||
52 | if (l == NULL) | |
53 | { | |
54 | return (-1); | |
55 | } | |
56 | ||
57 | n = LIBNET_ARP_H + (2 * hln) + (2 * pln) + payload_s; | |
58 | h = 0; /* ARP headers have no checksum */ | |
59 | ||
60 | /* | |
61 | * Find the existing protocol block if a ptag is specified, or create | |
62 | * a new one. | |
63 | */ | |
64 | p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ARP_H); | |
65 | if (p == NULL) | |
66 | { | |
67 | return (-1); | |
68 | } | |
69 | ||
70 | memset(&arp_hdr, 0, sizeof(arp_hdr)); | |
71 | arp_hdr.ar_hrd = htons(hrd); /* hardware address type */ | |
72 | arp_hdr.ar_pro = htons(pro); /* protocol address type */ | |
73 | arp_hdr.ar_hln = hln; /* hardware address length */ | |
74 | arp_hdr.ar_pln = pln; /* protocol address length */ | |
75 | arp_hdr.ar_op = htons(op); /* opcode command */ | |
76 | ||
77 | n = libnet_pblock_append(l, p, (u_int8_t *)&arp_hdr, LIBNET_ARP_H); | |
78 | if (n == -1) | |
79 | { | |
80 | /* err msg set in libnet_pblock_append() */ | |
81 | goto bad; | |
82 | } | |
83 | n = libnet_pblock_append(l, p, sha, hln); | |
84 | if (n == -1) | |
85 | { | |
86 | /* err msg set in libnet_pblock_append() */ | |
87 | goto bad; | |
88 | } | |
89 | n = libnet_pblock_append(l, p, spa, pln); | |
90 | if (n == -1) | |
91 | { | |
92 | /* err msg set in libnet_pblock_append() */ | |
93 | goto bad; | |
94 | } | |
95 | n = libnet_pblock_append(l, p, tha, hln); | |
96 | if (n == -1) | |
97 | { | |
98 | /* err msg set in libnet_pblock_append() */ | |
99 | goto bad; | |
100 | } | |
101 | n = libnet_pblock_append(l, p, tpa, pln); | |
102 | if (n == -1) | |
103 | { | |
104 | /* err msg set in libnet_pblock_append() */ | |
105 | goto bad; | |
106 | } | |
107 | ||
108 | if ((payload && !payload_s) || (!payload && payload_s)) | |
109 | { | |
110 | snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, | |
111 | "%s(): payload inconsistency\n", __func__); | |
112 | goto bad; | |
113 | } | |
114 | ||
115 | if (payload && payload_s) | |
116 | { | |
117 | n = libnet_pblock_append(l, p, payload, payload_s); | |
118 | if (n == -1) | |
119 | { | |
120 | /* err msg set in libnet_pblock_append() */ | |
121 | goto bad; | |
122 | } | |
123 | } | |
124 | ||
125 | return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ARP_H)); | |
126 | bad: | |
127 | libnet_pblock_delete(l, p); | |
128 | return (-1); | |
129 | } | |
130 | ||
131 | libnet_ptag_t | |
132 | libnet_autobuild_arp(u_int16_t op, u_int8_t *sha, u_int8_t *spa, u_int8_t *tha, | |
133 | u_int8_t *tpa, libnet_t *l) | |
134 | { | |
135 | u_short hrd; | |
136 | ||
137 | switch (l->link_type) | |
138 | { | |
139 | case 1: /* DLT_EN10MB */ | |
140 | hrd = ARPHRD_ETHER; | |
141 | break; | |
142 | case 6: /* DLT_IEEE802 */ | |
143 | hrd = ARPHRD_IEEE802; | |
144 | break; | |
145 | default: | |
146 | hrd = 0; | |
147 | snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, | |
148 | "%s(): unsupported link type\n", __func__); | |
149 | return (-1); | |
150 | /* add other link-layers */ | |
151 | } | |
152 | ||
153 | return (libnet_build_arp( | |
154 | hrd, /* hardware addr */ | |
155 | ETHERTYPE_IP, /* protocol addr */ | |
156 | 6, /* hardware addr size */ | |
157 | 4, /* protocol addr size */ | |
158 | op, /* operation type */ | |
159 | sha, /* sender hardware addr */ | |
160 | spa, /* sender protocol addr */ | |
161 | tha, /* target hardware addr */ | |
162 | tpa, /* target protocol addr */ | |
163 | NULL, /* payload */ | |
164 | 0, /* payload size */ | |
165 | l, /* libnet context */ | |
166 | 0)); /* libnet id */ | |
167 | } | |
168 | ||
169 | /* EOF */ |