Move checksum code from clatd to libnetutils.
This allows us to use it elsewhere, for example, in netd. Bug: 65674744 Test: builds, boots Test: atest clatd_test clatd_microbenchmark Change-Id: Ic2cea1cd658ffd23ba9fbe45cb6b28e3b5312005
This commit is contained in:
Lorenzo Colitti
parent
2356fefaf8
commit
98de5958cf
10 changed files with 14 additions and 185 deletions
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@ -21,7 +21,6 @@ cc_defaults {
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filegroup {
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name: "clatd_common",
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srcs: [
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"checksum.c",
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"config.c",
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"clatd.c",
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"dns64.c",
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@ -90,7 +89,9 @@ cc_test {
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defaults: ["clatd_defaults"],
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srcs: [
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"clatd_microbenchmark.c",
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"checksum.c",
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"tun.c",
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],
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shared_libs: [
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"libnetutils",
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],
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}
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142
checksum.c
142
checksum.c
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@ -1,142 +0,0 @@
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/*
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* Copyright 2011 Daniel Drown
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* checksum.c - ipv4/ipv6 checksum calculation
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*/
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#include <netinet/icmp6.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/ip6.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/tcp.h>
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#include <netinet/udp.h>
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#include "checksum.h"
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/* function: ip_checksum_add
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* adds data to a checksum
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* current - the current checksum (or 0 to start a new checksum)
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* data - the data to add to the checksum
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* len - length of data
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*/
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uint32_t ip_checksum_add(uint32_t current, const void *data, int len) {
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uint32_t checksum = current;
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int left = len;
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const uint16_t *data_16 = data;
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while (left > 1) {
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checksum += *data_16;
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data_16++;
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left -= 2;
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}
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if (left) {
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checksum += *(uint8_t *)data_16;
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}
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return checksum;
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}
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/* function: ip_checksum_fold
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* folds a 32-bit partial checksum into 16 bits
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* temp_sum - sum from ip_checksum_add
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* returns: the folded checksum in network byte order
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*/
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uint16_t ip_checksum_fold(uint32_t temp_sum) {
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while (temp_sum > 0xffff) {
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temp_sum = (temp_sum >> 16) + (temp_sum & 0xFFFF);
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}
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return temp_sum;
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}
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/* function: ip_checksum_finish
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* folds and closes the checksum
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* temp_sum - sum from ip_checksum_add
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* returns: a header checksum value in network byte order
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*/
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uint16_t ip_checksum_finish(uint32_t temp_sum) { return ~ip_checksum_fold(temp_sum); }
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/* function: ip_checksum
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* combined ip_checksum_add and ip_checksum_finish
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* data - data to checksum
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* len - length of data
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*/
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uint16_t ip_checksum(const void *data, int len) {
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uint32_t temp_sum;
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temp_sum = ip_checksum_add(0, data, len);
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return ip_checksum_finish(temp_sum);
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}
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/* function: ipv6_pseudo_header_checksum
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* calculate the pseudo header checksum for use in tcp/udp/icmp headers
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* ip6 - the ipv6 header
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* len - the transport length (transport header + payload)
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* protocol - the transport layer protocol, can be different from ip6->ip6_nxt for fragments
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*/
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uint32_t ipv6_pseudo_header_checksum(const struct ip6_hdr *ip6, uint16_t len, uint8_t protocol) {
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uint32_t checksum_len, checksum_next;
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checksum_len = htonl((uint32_t)len);
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checksum_next = htonl(protocol);
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uint32_t current = 0;
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current = ip_checksum_add(current, &(ip6->ip6_src), sizeof(struct in6_addr));
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current = ip_checksum_add(current, &(ip6->ip6_dst), sizeof(struct in6_addr));
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current = ip_checksum_add(current, &checksum_len, sizeof(checksum_len));
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current = ip_checksum_add(current, &checksum_next, sizeof(checksum_next));
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return current;
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}
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/* function: ipv4_pseudo_header_checksum
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* calculate the pseudo header checksum for use in tcp/udp headers
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* ip - the ipv4 header
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* len - the transport length (transport header + payload)
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*/
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uint32_t ipv4_pseudo_header_checksum(const struct iphdr *ip, uint16_t len) {
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uint16_t temp_protocol, temp_length;
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temp_protocol = htons(ip->protocol);
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temp_length = htons(len);
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uint32_t current = 0;
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current = ip_checksum_add(current, &(ip->saddr), sizeof(uint32_t));
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current = ip_checksum_add(current, &(ip->daddr), sizeof(uint32_t));
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current = ip_checksum_add(current, &temp_protocol, sizeof(uint16_t));
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current = ip_checksum_add(current, &temp_length, sizeof(uint16_t));
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return current;
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}
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/* function: ip_checksum_adjust
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* calculates a new checksum given a previous checksum and the old and new pseudo-header checksums
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* checksum - the header checksum in the original packet in network byte order
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* old_hdr_sum - the pseudo-header checksum of the original packet
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* new_hdr_sum - the pseudo-header checksum of the translated packet
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* returns: the new header checksum in network byte order
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*/
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uint16_t ip_checksum_adjust(uint16_t checksum, uint32_t old_hdr_sum, uint32_t new_hdr_sum) {
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// Algorithm suggested in RFC 1624.
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// http://tools.ietf.org/html/rfc1624#section-3
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checksum = ~checksum;
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uint16_t folded_sum = ip_checksum_fold(checksum + new_hdr_sum);
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uint16_t folded_old = ip_checksum_fold(old_hdr_sum);
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if (folded_sum > folded_old) {
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return ~(folded_sum - folded_old);
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} else {
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return ~(folded_sum - folded_old - 1); // end-around borrow
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}
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}
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34
checksum.h
34
checksum.h
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@ -1,34 +0,0 @@
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/*
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* Copyright 2011 Daniel Drown
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* checksum.h - checksum functions
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*/
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#ifndef __CHECKSUM_H__
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#define __CHECKSUM_H__
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#include <netinet/ip.h>
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#include <netinet/ip6.h>
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#include <stdint.h>
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uint32_t ip_checksum_add(uint32_t current, const void *data, int len);
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uint16_t ip_checksum_finish(uint32_t temp_sum);
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uint16_t ip_checksum(const void *data, int len);
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uint32_t ipv6_pseudo_header_checksum(const struct ip6_hdr *ip6, uint16_t len, uint8_t protocol);
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uint32_t ipv4_pseudo_header_checksum(const struct iphdr *ip, uint16_t len);
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uint16_t ip_checksum_adjust(uint16_t checksum, uint32_t old_hdr_sum, uint32_t new_hdr_sum);
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#endif /* __CHECKSUM_H__ */
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@ -41,7 +41,7 @@
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#include <time.h>
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#include <unistd.h>
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#include "checksum.h"
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#include "netutils/checksum.h"
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#include "tun.h"
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#define DEVICENAME "clat4"
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@ -29,10 +29,10 @@
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#include "tun_interface.h"
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extern "C" {
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#include "checksum.h"
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#include "clatd.h"
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#include "config.h"
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#include "getaddr.h"
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#include "netutils/checksum.h"
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#include "translate.h"
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#include "tun.h"
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}
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2
config.c
2
config.c
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@ -25,9 +25,9 @@
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#include <unistd.h>
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#include <cutils/config_utils.h>
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#include <netutils/checksum.h>
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#include <netutils/ifc.h>
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#include "checksum.h"
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#include "clatd.h"
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#include "config.h"
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#include "dns64.h"
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3
dump.c
3
dump.c
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@ -29,7 +29,8 @@
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#include <netinet/tcp.h>
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#include <netinet/udp.h>
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#include "checksum.h"
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#include "netutils/checksum.h"
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#include "clatd.h"
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#include "debug.h"
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#include "logging.h"
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3
ipv4.c
3
ipv4.c
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@ -17,7 +17,8 @@
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*/
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#include <string.h>
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#include "checksum.h"
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#include "netutils/checksum.h"
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#include "debug.h"
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#include "dump.h"
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#include "logging.h"
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3
ipv6.c
3
ipv6.c
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@ -19,7 +19,8 @@
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#include <arpa/inet.h>
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#include "checksum.h"
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#include "netutils/checksum.h"
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#include "config.h"
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#include "debug.h"
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#include "dump.h"
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@ -17,7 +17,8 @@
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*/
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#include <string.h>
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#include "checksum.h"
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#include "netutils/checksum.h"
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#include "clatd.h"
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#include "common.h"
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#include "config.h"
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