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Diffstat (limited to 'common/packet.c')
| -rw-r--r-- | common/packet.c | 309 |
1 files changed, 0 insertions, 309 deletions
diff --git a/common/packet.c b/common/packet.c deleted file mode 100644 index e5b57528..00000000 --- a/common/packet.c +++ /dev/null @@ -1,309 +0,0 @@ -/* packet.c - - Packet assembly code, originally contributed by Archie Cobbs. */ - -/* - * Copyright (c) 1995, 1996 The Internet Software Consortium. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of The Internet Software Consortium nor the names - * of its contributors may be used to endorse or promote products derived - * from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND - * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, - * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE - * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR - * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF - * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND - * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * This software has been written for the Internet Software Consortium - * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie - * Enterprises. To learn more about the Internet Software Consortium, - * see ``http://www.vix.com/isc''. To learn more about Vixie - * Enterprises, see ``http://www.vix.com''. - */ - -#ifndef lint -static char copyright[] = -"@(#) Copyright (c) 1996 The Internet Software Consortium. All rights reserved.\n"; -#endif /* not lint */ - -#include "dhcpd.h" -#if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING) -#include <netinet/in_systm.h> -#include "includes/netinet/ip.h" -#include "includes/netinet/udp.h" -#include "includes/netinet/if_ether.h" - -static u_int32_t checksum PROTO ((unsigned char *, int, u_int32_t)); -static u_int32_t wrapsum PROTO ((u_int32_t)); - -/* Compute the easy part of the checksum on a range of bytes. */ - -static u_int32_t checksum (buf, nbytes, sum) - unsigned char *buf; - int nbytes; - u_int32_t sum; -{ - int i; - -#ifdef DEBUG_CHECKSUM - debug ("checksum (%x %d %x)", buf, nbytes, sum); -#endif - - /* Checksum all the pairs of bytes first... */ - for (i = 0; i < (nbytes & ~1); i += 2) { -#ifdef DEBUG_CHECKSUM_VERBOSE - debug ("sum = %x", sum); -#endif - sum += (u_int16_t) ntohs(*((u_int16_t *)buf)++); - } - - /* If there's a single byte left over, checksum it, too. Network - byte order is big-endian, so the remaining byte is the high byte. */ - if (i < nbytes) { -#ifdef DEBUG_CHECKSUM_VERBOSE - debug ("sum = %x", sum); -#endif - sum += (*buf) << 8; - } - - return sum; -} - -/* Fold the upper sixteen bits of the checksum down into the lower bits, - complement the sum, and then put it into network byte order. */ - -static u_int32_t wrapsum (sum) - u_int32_t sum; -{ -#ifdef DEBUG_CHECKSUM - debug ("wrapsum (%x)", sum); -#endif - - while (sum > 0x10000) { - sum = (sum >> 16) + (sum & 0xFFFF); -#ifdef DEBUG_CHECKSUM_VERBOSE - debug ("sum = %x", sum); -#endif - sum += (sum >> 16); -#ifdef DEBUG_CHECKSUM_VERBOSE - debug ("sum = %x", sum); -#endif - } - sum = sum ^ 0xFFFF; -#ifdef DEBUG_CHECKSUM_VERBOSE - debug ("sum = %x", sum); -#endif - -#ifdef DEBUG_CHECKSUM - debug ("wrapsum returns %x", htons (sum)); -#endif - return htons(sum); -} -#endif /* PACKET_ASSEMBLY || PACKET_DECODING */ - -#ifdef PACKET_ASSEMBLY -/* Assemble an hardware header... */ -/* XXX currently only supports ethernet; doesn't check for other types. */ - -void assemble_hw_header (interface, buf, bufix, to) - struct interface_info *interface; - unsigned char *buf; - int *bufix; - struct hardware *to; -{ - struct ether_header eh; - - if (to) - memcpy (eh.ether_dhost, to -> haddr, sizeof eh.ether_dhost); - else - memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost)); - if (interface -> hw_address.hlen == sizeof (eh.ether_shost)) - memcpy (eh.ether_shost, interface -> hw_address.haddr, - sizeof (eh.ether_shost)); - else - memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost)); - eh.ether_type = htons (ETHERTYPE_IP); - - memcpy (&buf [*bufix], &eh, sizeof eh); - *bufix += sizeof eh; -} - -/* UDP header and IP header assembled together for convenience. */ - -void assemble_udp_ip_header (interface, buf, bufix, - from, to, port, data, len) - struct interface_info *interface; - unsigned char *buf; - int *bufix; - u_int32_t from; - u_int32_t to; - u_int16_t port; - unsigned char *data; - int len; -{ - struct ip ip; - struct udphdr udp; - - /* Fill out the IP header */ - ip.ip_v = 4; - ip.ip_hl = 5; - ip.ip_tos = IPTOS_LOWDELAY; - ip.ip_len = htons(sizeof(ip) + sizeof(udp) + len); - ip.ip_id = 0; - ip.ip_off = 0; - ip.ip_ttl = 16; - ip.ip_p = IPPROTO_UDP; - ip.ip_sum = 0; - ip.ip_src.s_addr = from; - ip.ip_dst.s_addr = to; - - /* Checksum the IP header... */ - ip.ip_sum = wrapsum (checksum ((unsigned char *)&ip, sizeof ip, 0)); - - /* Copy the ip header into the buffer... */ - memcpy (&buf [*bufix], &ip, sizeof ip); - *bufix += sizeof ip; - - /* Fill out the UDP header */ - udp.uh_sport = server_port; /* XXX */ - udp.uh_dport = port; /* XXX */ - udp.uh_ulen = htons(sizeof(udp) + len); - memset (&udp.uh_sum, 0, sizeof udp.uh_sum); - - /* Compute UDP checksums, including the ``pseudo-header'', the UDP - header and the data. */ - -#if 0 - udp.uh_sum = - wrapsum (checksum ((unsigned char *)&udp, sizeof udp, - checksum (data, len, - checksum ((unsigned char *) - &ip.ip_src, - sizeof ip.ip_src, - IPPROTO_UDP + - (u_int32_t) - ntohs (udp.uh_ulen))))); -#endif - - /* Copy the udp header into the buffer... */ - memcpy (&buf [*bufix], &udp, sizeof udp); - *bufix += sizeof udp; -} -#endif /* PACKET_ASSEMBLY */ - -#ifdef PACKET_DECODING -/* Decode a hardware header... */ -/* XXX currently only supports ethernet; doesn't check for other types. */ - -size_t decode_hw_header (interface, buf, bufix, from) - struct interface_info *interface; - unsigned char *buf; - int bufix; - struct hardware *from; -{ - struct ether_header eh; - - memcpy (&eh, buf + bufix, sizeof eh); - -#ifdef USERLAND_FILTER - if (ntohs (eh.ether_type) != ETHERTYPE_IP) - return -1; -#endif - memcpy (from -> haddr, eh.ether_shost, sizeof (eh.ether_shost)); - from -> htype = ARPHRD_ETHER; - from -> hlen = sizeof eh.ether_shost; - - return sizeof eh; -} - -/* UDP header and IP header decoded together for convenience. */ - -size_t decode_udp_ip_header (interface, buf, bufix, from, data, len) - struct interface_info *interface; - unsigned char *buf; - int bufix; - struct sockaddr_in *from; - unsigned char *data; - int len; -{ - struct ip *ip; - struct udphdr *udp; - u_int32_t ip_len = (buf [bufix] & 0xf) << 2; - u_int32_t sum, usum; - - ip = (struct ip *)(buf + bufix); - udp = (struct udphdr *)(buf + bufix + ip_len); - -#ifdef USERLAND_FILTER - /* Is it a UDP packet? */ - if (ip -> ip_p != IPPROTO_UDP) - return -1; - - /* Is it to the port we're serving? */ - if (udp -> uh_dport != server_port) - return -1; -#endif /* USERLAND_FILTER */ - - /* Check the IP header checksum - it should be zero. */ - if (wrapsum (checksum (buf + bufix, ip_len, 0))) { - note ("Bad IP checksum: %x", - wrapsum (checksum (buf + bufix, sizeof *ip, 0))); - return -1; - } - - /* Copy out the IP source address... */ - memcpy (&from -> sin_addr, &ip -> ip_src, 4); - - /* Compute UDP checksums, including the ``pseudo-header'', the UDP - header and the data. If the UDP checksum field is zero, we're - not supposed to do a checksum. */ - - if (!data) { - data = buf + bufix + ip_len + sizeof *udp; - len -= ip_len + sizeof *udp; - } - -#if 0 - usum = udp -> uh_sum; - udp -> uh_sum = 0; - - sum = wrapsum (checksum ((unsigned char *)udp, sizeof *udp, - checksum (data, len, - checksum ((unsigned char *) - &ip -> ip_src, - sizeof ip -> ip_src, - IPPROTO_UDP + - (u_int32_t) - ntohs (udp -> uh_ulen))))); - - if (usum && usum != sum) { - note ("Bad udp checksum: %x %x", usum, sum); - return -1; - } -#endif - - /* Copy out the port... */ - memcpy (&from -> sin_port, &udp -> uh_sport, sizeof udp -> uh_sport); - - return ip_len + sizeof *udp; -} -#endif /* PACKET_DECODING */ |