| 1 | /* |
| 2 | * $Id: libnet_build_dhcp.c,v 1.20 2005/11/29 22:19:59 carlosc Exp $ |
| 3 | * |
| 4 | * libnet |
| 5 | * libnet_build_dhcp.c - DHCP/BOOTP 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_dhcpv4(u_int8_t opcode, u_int8_t htype, u_int8_t hlen, |
| 44 | u_int8_t hopcount, u_int32_t xid, u_int16_t secs, u_int16_t flags, |
| 45 | u_int32_t cip, u_int32_t yip, u_int32_t sip, u_int32_t gip, u_int8_t *chaddr, |
| 46 | u_int8_t *sname, u_int8_t *file, u_int8_t *payload, u_int32_t payload_s, |
| 47 | libnet_t *l, libnet_ptag_t ptag) |
| 48 | { |
| 49 | u_int32_t n, h; |
| 50 | libnet_pblock_t *p; |
| 51 | struct libnet_dhcpv4_hdr dhcp_hdr; |
| 52 | |
| 53 | if (l == NULL) |
| 54 | { |
| 55 | return (-1); |
| 56 | } |
| 57 | |
| 58 | n = LIBNET_DHCPV4_H + payload_s; |
| 59 | h = 0; /* no checksum */ |
| 60 | |
| 61 | /* |
| 62 | * Find the existing protocol block if a ptag is specified, or create |
| 63 | * a new one. |
| 64 | */ |
| 65 | p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_DHCPV4_H); |
| 66 | if (p == NULL) |
| 67 | { |
| 68 | return (-1); |
| 69 | } |
| 70 | |
| 71 | memset(&dhcp_hdr, 0, sizeof(dhcp_hdr)); |
| 72 | dhcp_hdr.dhcp_opcode = opcode; |
| 73 | dhcp_hdr.dhcp_htype = htype; |
| 74 | dhcp_hdr.dhcp_hlen = hlen; |
| 75 | dhcp_hdr.dhcp_hopcount = hopcount; |
| 76 | dhcp_hdr.dhcp_xid = htonl(xid); |
| 77 | dhcp_hdr.dhcp_secs = htons(secs); |
| 78 | dhcp_hdr.dhcp_flags = htons(flags); |
| 79 | dhcp_hdr.dhcp_cip = htonl(cip); |
| 80 | dhcp_hdr.dhcp_yip = htonl(yip); |
| 81 | dhcp_hdr.dhcp_sip = htonl(sip); |
| 82 | dhcp_hdr.dhcp_gip = htonl(gip); |
| 83 | |
| 84 | if (chaddr) |
| 85 | { |
| 86 | memcpy(dhcp_hdr.dhcp_chaddr, chaddr, sizeof (dhcp_hdr.dhcp_chaddr)); |
| 87 | dhcp_hdr.dhcp_chaddr[sizeof(dhcp_hdr.dhcp_chaddr) - 1] = 0; |
| 88 | } |
| 89 | else |
| 90 | { |
| 91 | memset(dhcp_hdr.dhcp_chaddr, 0, sizeof (dhcp_hdr.dhcp_chaddr)); |
| 92 | } |
| 93 | |
| 94 | if (sname) |
| 95 | { |
| 96 | memcpy(dhcp_hdr.dhcp_sname, sname, sizeof (dhcp_hdr.dhcp_sname)); |
| 97 | dhcp_hdr.dhcp_sname[sizeof(dhcp_hdr.dhcp_sname) - 1] = 0; |
| 98 | } |
| 99 | else |
| 100 | { |
| 101 | memset(dhcp_hdr.dhcp_sname, 0, sizeof (dhcp_hdr.dhcp_sname)); |
| 102 | } |
| 103 | |
| 104 | if (file) |
| 105 | { |
| 106 | memcpy(dhcp_hdr.dhcp_file, file, sizeof (dhcp_hdr.dhcp_file)); |
| 107 | dhcp_hdr.dhcp_file[sizeof(dhcp_hdr.dhcp_file) - 1] = 0; |
| 108 | } |
| 109 | else |
| 110 | { |
| 111 | memset(dhcp_hdr.dhcp_file, 0, sizeof(dhcp_hdr.dhcp_file)); |
| 112 | } |
| 113 | dhcp_hdr.dhcp_magic = htonl(DHCP_MAGIC); /* should this be tunable? */ |
| 114 | |
| 115 | n = libnet_pblock_append(l, p, (u_int8_t *)&dhcp_hdr, LIBNET_DHCPV4_H); |
| 116 | if (n == -1) |
| 117 | { |
| 118 | goto bad; |
| 119 | } |
| 120 | |
| 121 | if ((payload && !payload_s) || (!payload && payload_s)) |
| 122 | { |
| 123 | snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, |
| 124 | "%s(): payload inconsistency\n", __func__); |
| 125 | goto bad; |
| 126 | } |
| 127 | |
| 128 | if (payload && payload_s) |
| 129 | { |
| 130 | n = libnet_pblock_append(l, p, payload, payload_s); |
| 131 | if (n == -1) |
| 132 | { |
| 133 | goto bad; |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | return (ptag ? ptag : libnet_pblock_update(l, p, h, |
| 138 | LIBNET_PBLOCK_DHCPV4_H)); |
| 139 | bad: |
| 140 | libnet_pblock_delete(l, p); |
| 141 | return (-1); |
| 142 | } |
| 143 | |
| 144 | libnet_ptag_t |
| 145 | libnet_build_bootpv4(u_int8_t opcode, u_int8_t htype, u_int8_t hlen, |
| 146 | u_int8_t hopcount, u_int32_t xid, u_int16_t secs, u_int16_t flags, |
| 147 | u_int32_t cip, u_int32_t yip, u_int32_t sip, u_int32_t gip, u_int8_t *chaddr, |
| 148 | u_int8_t *sname, u_int8_t *file, u_int8_t *payload, u_int32_t payload_s, |
| 149 | libnet_t *l, libnet_ptag_t ptag) |
| 150 | { |
| 151 | return (libnet_build_dhcpv4(opcode, htype, hlen, hopcount, xid, secs, |
| 152 | flags, cip, yip, sip, gip, chaddr, sname, file, payload, payload_s, |
| 153 | l, ptag)); |
| 154 | } |
| 155 | |
| 156 | /* EOF */ |