| 1 | /* |
| 2 | * $Id: libnet_build_ethernet.c,v 1.19 2005/11/29 22:50:14 carlosc Exp $ |
| 3 | * |
| 4 | * libnet |
| 5 | * libnet_build_ethernet.c - ethernet 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 | libnet_ptag_t |
| 43 | libnet_build_ethernet(u_int8_t *dst, u_int8_t *src, u_int16_t type, u_int8_t *payload, |
| 44 | u_int32_t payload_s, libnet_t *l, libnet_ptag_t ptag) |
| 45 | { |
| 46 | u_int32_t n, h; |
| 47 | libnet_pblock_t *p; |
| 48 | struct libnet_ethernet_hdr eth_hdr; |
| 49 | |
| 50 | if (l == NULL) |
| 51 | { |
| 52 | return (-1); |
| 53 | } |
| 54 | |
| 55 | /* sanity check injection type if we're not in advanced mode */ |
| 56 | if (l->injection_type != LIBNET_LINK && |
| 57 | !(((l->injection_type) & LIBNET_ADV_MASK))) |
| 58 | { |
| 59 | snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, |
| 60 | "%s(): called with non-link layer wire injection primitive", |
| 61 | __func__); |
| 62 | p = NULL; |
| 63 | goto bad; |
| 64 | } |
| 65 | |
| 66 | n = LIBNET_ETH_H + payload_s; |
| 67 | h = 0; |
| 68 | |
| 69 | /* |
| 70 | * Find the existing protocol block if a ptag is specified, or create |
| 71 | * a new one. |
| 72 | */ |
| 73 | p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ETH_H); |
| 74 | if (p == NULL) |
| 75 | { |
| 76 | return (-1); |
| 77 | } |
| 78 | |
| 79 | memset(ð_hdr, 0, sizeof(eth_hdr)); |
| 80 | memcpy(eth_hdr.ether_dhost, dst, ETHER_ADDR_LEN); /* destination address */ |
| 81 | memcpy(eth_hdr.ether_shost, src, ETHER_ADDR_LEN); /* source address */ |
| 82 | eth_hdr.ether_type = htons(type); /* packet type */ |
| 83 | |
| 84 | n = libnet_pblock_append(l, p, (u_int8_t *)ð_hdr, LIBNET_ETH_H); |
| 85 | if (n == -1) |
| 86 | { |
| 87 | goto bad; |
| 88 | } |
| 89 | |
| 90 | if ((payload && !payload_s) || (!payload && payload_s)) |
| 91 | { |
| 92 | snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, |
| 93 | "%s(): payload inconsistency\n", __func__); |
| 94 | goto bad; |
| 95 | } |
| 96 | |
| 97 | if (payload && payload_s) |
| 98 | { |
| 99 | n = libnet_pblock_append(l, p, payload, payload_s); |
| 100 | if (n == -1) |
| 101 | { |
| 102 | goto bad; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ETH_H)); |
| 107 | bad: |
| 108 | libnet_pblock_delete(l, p); |
| 109 | return (-1); |
| 110 | } |
| 111 | |
| 112 | |
| 113 | libnet_ptag_t |
| 114 | libnet_autobuild_ethernet(u_int8_t *dst, u_int16_t type, libnet_t *l) |
| 115 | { |
| 116 | u_int32_t n, h; |
| 117 | struct libnet_ether_addr *src; |
| 118 | libnet_pblock_t *p; |
| 119 | libnet_ptag_t ptag; |
| 120 | struct libnet_ethernet_hdr eth_hdr; |
| 121 | |
| 122 | if (l == NULL) |
| 123 | { |
| 124 | return (-1); |
| 125 | } |
| 126 | |
| 127 | /* sanity check injection type if we're not in advanced mode */ |
| 128 | if (l->injection_type != LIBNET_LINK && |
| 129 | !(((l->injection_type) & LIBNET_ADV_MASK))) |
| 130 | { |
| 131 | snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, |
| 132 | "libnet_autobuild_ethernet() called with non-link layer wire" |
| 133 | " injection primitive"); |
| 134 | p = NULL; |
| 135 | goto bad; |
| 136 | } |
| 137 | |
| 138 | n = LIBNET_ETH_H; |
| 139 | h = 0; |
| 140 | ptag = LIBNET_PTAG_INITIALIZER; |
| 141 | src = libnet_get_hwaddr(l); |
| 142 | if (src == NULL) |
| 143 | { |
| 144 | /* err msg set in libnet_get_hwaddr() */ |
| 145 | return (-1); |
| 146 | } |
| 147 | |
| 148 | /* |
| 149 | * Create a new pblock. |
| 150 | */ |
| 151 | p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ETH_H); |
| 152 | if (p == NULL) |
| 153 | { |
| 154 | return (-1); |
| 155 | } |
| 156 | |
| 157 | memset(ð_hdr, 0, sizeof(eth_hdr)); |
| 158 | memcpy(eth_hdr.ether_dhost, dst, ETHER_ADDR_LEN); /* destination address */ |
| 159 | memcpy(eth_hdr.ether_shost, src, ETHER_ADDR_LEN); /* source address */ |
| 160 | eth_hdr.ether_type = htons(type); /* packet type */ |
| 161 | |
| 162 | n = libnet_pblock_append(l, p, (u_int8_t *)ð_hdr, LIBNET_ETH_H); |
| 163 | if (n == -1) |
| 164 | { |
| 165 | goto bad; |
| 166 | } |
| 167 | |
| 168 | return (libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ETH_H)); |
| 169 | bad: |
| 170 | libnet_pblock_delete(l, p); |
| 171 | return (-1); |
| 172 | } |
| 173 | /* EOF */ |