1 /*
2 * $Id: libnet_build_arp.c,v 1.13 2004/04/13 17:32:28 mike 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
libnet_build_arp(uint16_t hrd,uint16_t pro,uint8_t hln,uint8_t pln,uint16_t op,const uint8_t * sha,const uint8_t * spa,const uint8_t * tha,const uint8_t * tpa,const uint8_t * payload,uint32_t payload_s,libnet_t * l,libnet_ptag_t ptag)44 libnet_build_arp(uint16_t hrd, uint16_t pro, uint8_t hln, uint8_t pln,
45 uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha, const uint8_t *tpa,
46 const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
47 {
48 uint32_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, (uint8_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 /* boilerplate payload sanity check / append macro */
109 LIBNET_DO_PAYLOAD(l, p);
110
111 return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ARP_H));
112 bad:
113 libnet_pblock_delete(l, p);
114 return (-1);
115 }
116
117 libnet_ptag_t
libnet_autobuild_arp(uint16_t op,const uint8_t * sha,const uint8_t * spa,const uint8_t * tha,uint8_t * tpa,libnet_t * l)118 libnet_autobuild_arp(uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha,
119 uint8_t *tpa, libnet_t *l)
120 {
121 u_short hrd;
122
123 switch (l->link_type)
124 {
125 case 1: /* DLT_EN10MB */
126 hrd = ARPHRD_ETHER;
127 break;
128 case 6: /* DLT_IEEE802 */
129 hrd = ARPHRD_IEEE802;
130 break;
131 default:
132 hrd = 0;
133 snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
134 "%s(): unsupported link type\n", __func__);
135 return (-1);
136 /* add other link-layers */
137 }
138
139 return (libnet_build_arp(
140 hrd, /* hardware addr */
141 ETHERTYPE_IP, /* protocol addr */
142 6, /* hardware addr size */
143 4, /* protocol addr size */
144 op, /* operation type */
145 sha, /* sender hardware addr */
146 spa, /* sender protocol addr */
147 tha, /* target hardware addr */
148 tpa, /* target protocol addr */
149 NULL, /* payload */
150 0, /* payload size */
151 l, /* libnet context */
152 0)); /* libnet id */
153 }
154
155 /* EOF */
156