| /* |
| * Copyright 2011 Daniel Drown |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| * translate.h - translate from one version of ip to another |
| */ |
| #ifndef __TRANSLATE_H__ |
| #define __TRANSLATE_H__ |
| |
| #include <linux/if_tun.h> |
| |
| #define MAX_TCP_HDR (15 * 4) // Data offset field is 4 bits and counts in 32-bit words. |
| |
| // A clat_packet is an array of iovec structures representing a packet that we are translating. |
| // The CLAT_POS_XXX constants represent the array indices within the clat_packet that contain |
| // specific parts of the packet. The packet_* functions operate on all the packet segments past a |
| // given position. |
| enum clat_packet_index { CLAT_POS_TUNHDR, CLAT_POS_IPHDR, CLAT_POS_TRANSPORTHDR, |
| CLAT_POS_ICMPERR_IPHDR, CLAT_POS_ICMPERR_TRANSPORTHDR, |
| CLAT_POS_PAYLOAD, CLAT_POS_MAX }; |
| typedef struct iovec clat_packet[CLAT_POS_MAX]; |
| |
| // Calculates the checksum over all the packet components starting from pos. |
| uint16_t packet_checksum(uint32_t checksum, clat_packet packet, int pos); |
| |
| // Returns the total length of the packet components after pos. |
| uint16_t packet_length(clat_packet packet, int pos); |
| |
| // Returns true iff the given IPv6 address is in the plat subnet. |
| int is_in_plat_subnet(const struct in6_addr *addr6); |
| |
| // Functions to create tun, IPv4, and IPv6 headers. |
| void fill_tun_header(struct tun_pi *tun_header, uint16_t proto); |
| void fill_ip_header(struct iphdr *ip_targ, uint16_t payload_len, uint8_t protocol, |
| const struct ip6_hdr *old_header); |
| void fill_ip6_header(struct ip6_hdr *ip6, uint16_t payload_len, uint8_t protocol, |
| const struct iphdr *old_header); |
| |
| // Translate IPv4 and IPv6 packets. |
| int ipv4_packet(clat_packet out, int pos, const char *packet, size_t len); |
| int ipv6_packet(clat_packet out, int pos, const char *packet, size_t len); |
| |
| // Translate ICMP packets. |
| int icmp_to_icmp6(clat_packet out, int pos, const struct icmphdr *icmp, uint32_t checksum, |
| const char *payload, size_t payload_size); |
| int icmp6_to_icmp(clat_packet out, int pos, const struct icmp6_hdr *icmp6, |
| const char *payload, size_t payload_size); |
| |
| // Translate generic IP packets. |
| int generic_packet(clat_packet out, int pos, const char *payload, size_t len); |
| |
| // Translate TCP and UDP packets. |
| int tcp_packet(clat_packet out, int pos, const struct tcphdr *tcp, uint32_t checksum, size_t len); |
| int udp_packet(clat_packet out, int pos, const struct udphdr *udp, uint32_t checksum, size_t len); |
| |
| int tcp_translate(clat_packet out, int pos, const struct tcphdr *tcp, size_t header_size, |
| uint32_t checksum, const char *payload, size_t payload_size); |
| int udp_translate(clat_packet out, int pos, const struct udphdr *udp, uint32_t checksum, |
| const char *payload, size_t payload_size); |
| |
| #endif /* __TRANSLATE_H__ */ |