diff options
Diffstat (limited to 'src/libsystemd-network/dhcp-packet.c')
| -rw-r--r-- | src/libsystemd-network/dhcp-packet.c | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/src/libsystemd-network/dhcp-packet.c b/src/libsystemd-network/dhcp-packet.c deleted file mode 100644 index 8be774061d..0000000000 --- a/src/libsystemd-network/dhcp-packet.c +++ /dev/null @@ -1,191 +0,0 @@ -/*** - This file is part of systemd. - - Copyright (C) 2013 Intel Corporation. All rights reserved. - Copyright (C) 2014 Tom Gundersen - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include <errno.h> -#include <net/ethernet.h> -#include <net/if_arp.h> -#include <string.h> - -#include "dhcp-internal.h" -#include "dhcp-protocol.h" - -#define DHCP_CLIENT_MIN_OPTIONS_SIZE 312 - -int dhcp_message_init(DHCPMessage *message, uint8_t op, uint32_t xid, - uint8_t type, uint16_t arp_type, size_t optlen, - size_t *optoffset) { - size_t offset = 0; - int r; - - assert(op == BOOTREQUEST || op == BOOTREPLY); - assert(arp_type == ARPHRD_ETHER || arp_type == ARPHRD_INFINIBAND); - - message->op = op; - message->htype = arp_type; - message->hlen = (arp_type == ARPHRD_ETHER) ? ETHER_ADDR_LEN : 0; - message->xid = htobe32(xid); - message->magic = htobe32(DHCP_MAGIC_COOKIE); - - r = dhcp_option_append(message, optlen, &offset, 0, - SD_DHCP_OPTION_MESSAGE_TYPE, 1, &type); - if (r < 0) - return r; - - *optoffset = offset; - - return 0; -} - -uint16_t dhcp_packet_checksum(uint8_t *buf, size_t len) { - uint64_t *buf_64 = (uint64_t*)buf; - uint64_t *end_64 = buf_64 + (len / sizeof(uint64_t)); - uint64_t sum = 0; - - /* See RFC1071 */ - - while (buf_64 < end_64) { - sum += *buf_64; - if (sum < *buf_64) - /* wrap around in one's complement */ - sum++; - - buf_64++; - } - - if (len % sizeof(uint64_t)) { - /* If the buffer is not aligned to 64-bit, we need - to zero-pad the last few bytes and add them in */ - uint64_t buf_tail = 0; - - memcpy(&buf_tail, buf_64, len % sizeof(uint64_t)); - - sum += buf_tail; - if (sum < buf_tail) - /* wrap around */ - sum++; - } - - while (sum >> 16) - sum = (sum & 0xffff) + (sum >> 16); - - return ~sum; -} - -void dhcp_packet_append_ip_headers(DHCPPacket *packet, be32_t source_addr, - uint16_t source_port, be32_t destination_addr, - uint16_t destination_port, uint16_t len) { - packet->ip.version = IPVERSION; - packet->ip.ihl = DHCP_IP_SIZE / 4; - packet->ip.tot_len = htobe16(len); - - packet->ip.tos = IPTOS_CLASS_CS6; - - packet->ip.protocol = IPPROTO_UDP; - packet->ip.saddr = source_addr; - packet->ip.daddr = destination_addr; - - packet->udp.source = htobe16(source_port); - packet->udp.dest = htobe16(destination_port); - - packet->udp.len = htobe16(len - DHCP_IP_SIZE); - - packet->ip.check = packet->udp.len; - packet->udp.check = dhcp_packet_checksum((uint8_t*)&packet->ip.ttl, len - 8); - - packet->ip.ttl = IPDEFTTL; - packet->ip.check = 0; - packet->ip.check = dhcp_packet_checksum((uint8_t*)&packet->ip, DHCP_IP_SIZE); -} - -int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum) { - size_t hdrlen; - - assert(packet); - - /* IP */ - - if (packet->ip.version != IPVERSION) { - log_debug("ignoring packet: not IPv4"); - return -EINVAL; - } - - if (packet->ip.ihl < 5) { - log_debug("ignoring packet: IPv4 IHL (%u words) invalid", - packet->ip.ihl); - return -EINVAL; - } - - hdrlen = packet->ip.ihl * 4; - if (hdrlen < 20) { - log_debug("ignoring packet: IPv4 IHL (%zu bytes) " - "smaller than minimum (20 bytes)", hdrlen); - return -EINVAL; - } - - if (len < hdrlen) { - log_debug("ignoring packet: packet (%zu bytes) " - "smaller than expected (%zu) by IP header", len, - hdrlen); - return -EINVAL; - } - - /* UDP */ - - if (packet->ip.protocol != IPPROTO_UDP) { - log_debug("ignoring packet: not UDP"); - return -EINVAL; - } - - if (len < hdrlen + be16toh(packet->udp.len)) { - log_debug("ignoring packet: packet (%zu bytes) " - "smaller than expected (%zu) by UDP header", len, - hdrlen + be16toh(packet->udp.len)); - return -EINVAL; - } - - if (be16toh(packet->udp.dest) != DHCP_PORT_CLIENT) { - log_debug("ignoring packet: to port %u, which " - "is not the DHCP client port (%u)", - be16toh(packet->udp.dest), DHCP_PORT_CLIENT); - return -EINVAL; - } - - /* checksums - computing these is relatively expensive, so only do it - if all the other checks have passed - */ - - if (dhcp_packet_checksum((uint8_t*)&packet->ip, hdrlen)) { - log_debug("ignoring packet: invalid IP checksum"); - return -EINVAL; - } - - if (checksum && packet->udp.check) { - packet->ip.check = packet->udp.len; - packet->ip.ttl = 0; - - if (dhcp_packet_checksum((uint8_t*)&packet->ip.ttl, - be16toh(packet->udp.len) + 12)) { - log_debug("ignoring packet: invalid UDP checksum"); - return -EINVAL; - } - } - - return 0; -} |