Merge "Move libipchecksum to frameworks/libs/net." am: fcf3fefe0b am:... (8be1b328) · Commits · e / os / android_system_core

libnetutils/Android.bp

+4 −16

Original line number	Diff line number	Diff line
		@@ -23,7 +23,6 @@ cc_library_shared {
		},

		srcs: [
		"checksum.c",
		"dhcpclient.c",
		"dhcpmsg.c",
		"ifc_utils.c",
		@@ -35,6 +34,10 @@ cc_library_shared {
		"liblog",
		],

		static_libs: [
		"libip_checksum",
		],

		cflags: ["-Werror"],

		export_include_dirs: ["include"],
		@@ -45,21 +48,6 @@ cc_library_shared {
		],
		}

		cc_library_static {
		name: "libipchecksum",

		srcs: [
		"checksum.c",
		],

		cflags: [
		"-Wall",
		"-Werror",
		],

		export_include_dirs: ["include"],
		}

		cc_binary {
		name: "dhcpdbg",

libnetutils/checksum.c

deleted100644 → 0

+0 −145

Original line number	Diff line number	Diff line
		/*
		* 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.
		*
		* checksum.c - ipv4/ipv6 checksum calculation
		*/
		#include <netinet/icmp6.h>
		#include <netinet/in.h>
		#include <netinet/ip.h>
		#include <netinet/ip6.h>
		#include <netinet/ip_icmp.h>
		#include <netinet/tcp.h>
		#include <netinet/udp.h>

		#include "netutils/checksum.h"

		/* function: ip_checksum_add
		* adds data to a checksum. only known to work on little-endian hosts
		* current - the current checksum (or 0 to start a new checksum)
		* data - the data to add to the checksum
		* len - length of data
		*/
		uint32_t ip_checksum_add(uint32_t current, const void* data, int len) {
		uint32_t checksum = current;
		int left = len;
		const uint16_t* data_16 = data;

		while (left > 1) {
		checksum += *data_16;
		data_16++;
		left -= 2;
		}
		if (left) {
		checksum += (uint8_t)data_16;
		}

		return checksum;
		}

		/* function: ip_checksum_fold
		* folds a 32-bit partial checksum into 16 bits
		* temp_sum - sum from ip_checksum_add
		* returns: the folded checksum in network byte order
		*/
		uint16_t ip_checksum_fold(uint32_t temp_sum) {
		while (temp_sum > 0xffff) {
		temp_sum = (temp_sum >> 16) + (temp_sum & 0xFFFF);
		}
		return temp_sum;
		}

		/* function: ip_checksum_finish
		* folds and closes the checksum
		* temp_sum - sum from ip_checksum_add
		* returns: a header checksum value in network byte order
		*/
		uint16_t ip_checksum_finish(uint32_t temp_sum) {
		return ~ip_checksum_fold(temp_sum);
		}

		/* function: ip_checksum
		* combined ip_checksum_add and ip_checksum_finish
		* data - data to checksum
		* len - length of data
		*/
		uint16_t ip_checksum(const void* data, int len) {
		// TODO: consider starting from 0xffff so the checksum of a buffer entirely consisting of zeros
		// is correctly calculated as 0.
		uint32_t temp_sum;

		temp_sum = ip_checksum_add(0, data, len);
		return ip_checksum_finish(temp_sum);
		}

		/* function: ipv6_pseudo_header_checksum
		* calculate the pseudo header checksum for use in tcp/udp/icmp headers
		* ip6 - the ipv6 header
		* len - the transport length (transport header + payload)
		* protocol - the transport layer protocol, can be different from ip6->ip6_nxt for fragments
		*/
		uint32_t ipv6_pseudo_header_checksum(const struct ip6_hdr* ip6, uint32_t len, uint8_t protocol) {
		uint32_t checksum_len = htonl(len);
		uint32_t checksum_next = htonl(protocol);

		uint32_t current = 0;

		current = ip_checksum_add(current, &(ip6->ip6_src), sizeof(struct in6_addr));
		current = ip_checksum_add(current, &(ip6->ip6_dst), sizeof(struct in6_addr));
		current = ip_checksum_add(current, &checksum_len, sizeof(checksum_len));
		current = ip_checksum_add(current, &checksum_next, sizeof(checksum_next));

		return current;
		}

		/* function: ipv4_pseudo_header_checksum
		* calculate the pseudo header checksum for use in tcp/udp headers
		* ip - the ipv4 header
		* len - the transport length (transport header + payload)
		*/
		uint32_t ipv4_pseudo_header_checksum(const struct iphdr* ip, uint16_t len) {
		uint16_t temp_protocol, temp_length;

		temp_protocol = htons(ip->protocol);
		temp_length = htons(len);

		uint32_t current = 0;

		current = ip_checksum_add(current, &(ip->saddr), sizeof(uint32_t));
		current = ip_checksum_add(current, &(ip->daddr), sizeof(uint32_t));
		current = ip_checksum_add(current, &temp_protocol, sizeof(uint16_t));
		current = ip_checksum_add(current, &temp_length, sizeof(uint16_t));

		return current;
		}

		/* function: ip_checksum_adjust
		* calculates a new checksum given a previous checksum and the old and new pseudo-header checksums
		* checksum - the header checksum in the original packet in network byte order
		* old_hdr_sum - the pseudo-header checksum of the original packet
		* new_hdr_sum - the pseudo-header checksum of the translated packet
		* returns: the new header checksum in network byte order
		*/
		uint16_t ip_checksum_adjust(uint16_t checksum, uint32_t old_hdr_sum, uint32_t new_hdr_sum) {
		// Algorithm suggested in RFC 1624.
		// http://tools.ietf.org/html/rfc1624#section-3
		checksum = ~checksum;
		uint16_t folded_sum = ip_checksum_fold(checksum + new_hdr_sum);
		uint16_t folded_old = ip_checksum_fold(old_hdr_sum);
		if (folded_sum > folded_old) {
		return ~(folded_sum - folded_old);
		} else {
		return ~(folded_sum - folded_old - 1); // end-around borrow
		}
		}

libnetutils/include/netutils/checksum.h

deleted100644 → 0

+0 −34

Original line number	Diff line number	Diff line
		/*
		* 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.
		*
		* checksum.h - checksum functions
		*/
		#ifndef __CHECKSUM_H__
		#define __CHECKSUM_H__

		#include <netinet/ip.h>
		#include <netinet/ip6.h>
		#include <stdint.h>

		uint32_t ip_checksum_add(uint32_t current, const void* data, int len);
		uint16_t ip_checksum_finish(uint32_t temp_sum);
		uint16_t ip_checksum(const void* data, int len);

		uint32_t ipv6_pseudo_header_checksum(const struct ip6_hdr* ip6, uint32_t len, uint8_t protocol);
		uint32_t ipv4_pseudo_header_checksum(const struct iphdr* ip, uint16_t len);

		uint16_t ip_checksum_adjust(uint16_t checksum, uint32_t old_hdr_sum, uint32_t new_hdr_sum);

		#endif /* __CHECKSUM_H__ */