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 <linux/icmp.h> 22 #include <linux/if_tun.h> 23 #include <netinet/icmp6.h> 24 #include <netinet/in.h> 25 #include <netinet/ip.h> 26 #include <netinet/ip6.h> 27 #include <netinet/ip_icmp.h> 28 #include <netinet/tcp.h> 29 #include <netinet/udp.h> 30 31 #include "clatd.h" 32 #include "common.h" 33 34 #define MAX_TCP_HDR (15 * 4) // Data offset field is 4 bits and counts in 32-bit words. 35 36 // Calculates the checksum over all the packet components starting from pos. 37 uint16_t packet_checksum(uint32_t checksum, clat_packet packet, clat_packet_index pos); 38 39 // Returns the total length of the packet components after pos. 40 uint16_t packet_length(clat_packet packet, clat_packet_index pos); 41 42 // Returns true iff the given IPv6 address is in the plat subnet. 43 int is_in_plat_subnet(const struct in6_addr *addr6); 44 45 // Functions to create tun, IPv4, and IPv6 headers. 46 void fill_tun_header(struct tun_pi *tun_header, uint16_t proto); 47 void fill_ip_header(struct iphdr *ip_targ, uint16_t payload_len, uint8_t protocol, 48 const struct ip6_hdr *old_header); 49 void fill_ip6_header(struct ip6_hdr *ip6, uint16_t payload_len, uint8_t protocol, 50 const struct iphdr *old_header); 51 52 // Translate and send packets. 53 void translate_packet(int fd, int to_ipv6, const uint8_t *packet, size_t packetsize); 54 55 // Translate IPv4 and IPv6 packets. 56 int ipv4_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len); 57 int ipv6_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len); 58 59 // Deal with fragmented packets. 60 size_t maybe_fill_frag_header(struct ip6_frag *frag_hdr, struct ip6_hdr *ip6_targ, 61 const struct iphdr *old_header); 62 uint8_t parse_frag_header(const struct ip6_frag *frag_hdr, struct iphdr *ip_targ); 63 64 // Deal with fragmented packets. 65 size_t maybe_fill_frag_header(struct ip6_frag *frag_hdr, struct ip6_hdr *ip6_targ, 66 const struct iphdr *old_header); 67 uint8_t parse_frag_header(const struct ip6_frag *frag_hdr, struct iphdr *ip_targ); 68 69 // Translate ICMP packets. 70 int icmp_to_icmp6(clat_packet out, clat_packet_index pos, const struct icmphdr *icmp, 71 uint32_t checksum, const uint8_t *payload, size_t payload_size); 72 int icmp6_to_icmp(clat_packet out, clat_packet_index pos, const struct icmp6_hdr *icmp6, 73 const uint8_t *payload, size_t payload_size); 74 75 // Translate generic IP packets. 76 int generic_packet(clat_packet out, clat_packet_index pos, const uint8_t *payload, size_t len); 77 78 // Translate TCP and UDP packets. 79 int tcp_packet(clat_packet out, clat_packet_index pos, const struct tcphdr *tcp, uint32_t old_sum, 80 uint32_t new_sum, size_t len); 81 int udp_packet(clat_packet out, clat_packet_index pos, const struct udphdr *udp, uint32_t old_sum, 82 uint32_t new_sum, size_t len); 83 84 int tcp_translate(clat_packet out, clat_packet_index pos, const struct tcphdr *tcp, 85 size_t header_size, uint32_t old_sum, uint32_t new_sum, const uint8_t *payload, 86 size_t payload_size); 87 int udp_translate(clat_packet out, clat_packet_index pos, const struct udphdr *udp, 88 uint32_t old_sum, uint32_t new_sum, const uint8_t *payload, size_t payload_size); 89 90 #endif /* __TRANSLATE_H__ */ 91