1 /* 2 * Copyright 2011 Daniel Drown 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 * 16 * translate.h - translate from one version of ip to another 17 */ 18 #ifndef __TRANSLATE_H__ 19 #define __TRANSLATE_H__ 20 21 #include <netinet/in.h> 22 #include <netinet/ip.h> 23 #include <netinet/ip_icmp.h> 24 #include <netinet/udp.h> 25 #include <netinet/tcp.h> 26 #include <netinet/ip6.h> 27 #include <netinet/icmp6.h> 28 #include <linux/icmp.h> 29 #include <linux/if_tun.h> 30 31 #include "clatd.h" 32 33 #define MAX_TCP_HDR (15 * 4) // Data offset field is 4 bits and counts in 32-bit words. 34 35 // Calculates the checksum over all the packet components starting from pos. 36 uint16_t packet_checksum(uint32_t checksum, clat_packet packet, clat_packet_index pos); 37 38 // Returns the total length of the packet components after pos. 39 uint16_t packet_length(clat_packet packet, clat_packet_index pos); 40 41 // Returns true iff the given IPv6 address is in the plat subnet. 42 int is_in_plat_subnet(const struct in6_addr *addr6); 43 44 // Functions to create tun, IPv4, and IPv6 headers. 45 void fill_tun_header(struct tun_pi *tun_header, uint16_t proto); 46 void fill_ip_header(struct iphdr *ip_targ, uint16_t payload_len, uint8_t protocol, 47 const struct ip6_hdr *old_header); 48 void fill_ip6_header(struct ip6_hdr *ip6, uint16_t payload_len, uint8_t protocol, 49 const struct iphdr *old_header); 50 51 // Translate and send packets. 52 void translate_packet(int fd, int to_ipv6, const uint8_t *packet, size_t packetsize); 53 54 // Translate IPv4 and IPv6 packets. 55 int ipv4_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len); 56 int ipv6_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len); 57 58 // Deal with fragmented packets. 59 size_t maybe_fill_frag_header(struct ip6_frag *frag_hdr, struct ip6_hdr *ip6_targ, 60 const struct iphdr *old_header); 61 uint8_t parse_frag_header(const struct ip6_frag *frag_hdr, struct iphdr *ip_targ); 62 63 // Deal with fragmented packets. 64 size_t maybe_fill_frag_header(struct ip6_frag *frag_hdr, struct ip6_hdr *ip6_targ, 65 const struct iphdr *old_header); 66 uint8_t parse_frag_header(const struct ip6_frag *frag_hdr, struct iphdr *ip_targ); 67 68 // Translate ICMP packets. 69 int icmp_to_icmp6(clat_packet out, clat_packet_index pos, const struct icmphdr *icmp, 70 uint32_t checksum, const uint8_t *payload, size_t payload_size); 71 int icmp6_to_icmp(clat_packet out, clat_packet_index pos, const struct icmp6_hdr *icmp6, 72 const uint8_t *payload, size_t payload_size); 73 74 // Translate generic IP packets. 75 int generic_packet(clat_packet out, clat_packet_index pos, const uint8_t *payload, size_t len); 76 77 // Translate TCP and UDP packets. 78 int tcp_packet(clat_packet out, clat_packet_index pos, const struct tcphdr *tcp, 79 uint32_t old_sum, uint32_t new_sum, size_t len); 80 int udp_packet(clat_packet out, clat_packet_index pos, const struct udphdr *udp, 81 uint32_t old_sum, uint32_t new_sum, size_t len); 82 83 int tcp_translate(clat_packet out, clat_packet_index pos, const struct tcphdr *tcp, 84 size_t header_size, uint32_t old_sum, uint32_t new_sum, 85 const uint8_t *payload, size_t payload_size); 86 int udp_translate(clat_packet out, clat_packet_index pos, const struct udphdr *udp, 87 uint32_t old_sum, uint32_t new_sum, 88 const uint8_t *payload, size_t payload_size); 89 90 #endif /* __TRANSLATE_H__ */ 91