81 lines
1.7 KiB
C
81 lines
1.7 KiB
C
/*
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* Copyright (c) 2014 Chris Anderson
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*
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* Use of this source code is governed by a MIT-style
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* license that can be found in the LICENSE file or at
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* https://opensource.org/licenses/MIT
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*/
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#include "minip-internal.h"
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/* XXX alternate implementation, merge */
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uint16_t ones_sum16(uint32_t sum, const void *_buf, int len) {
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const uint16_t *buf = _buf;
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while (len >= 2) {
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sum += *buf++;
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if (sum & 0x80000000)
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sum = (sum & 0xffff) + (sum >> 16);
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len -= 2;
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}
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if (len) {
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uint16_t temp = htons((*(uint8_t *)buf) << 8);
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sum += temp;
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}
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while (sum >> 16)
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sum = (sum & 0xffff) + (sum >> 16);
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return sum;
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}
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uint16_t rfc1701_chksum(const uint8_t *buf, size_t len) {
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uint32_t total = 0;
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uint16_t chksum = 0;
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const uint16_t *p = (const uint16_t *) buf;
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// Length is in bytes
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for (size_t i = 0; i < len / 2; i++ ) {
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total += p[i];
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}
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chksum = (total & 0xFFFF) + (total >> 16);
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chksum = ~chksum;
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return chksum;
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}
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#if MINIP_USE_UDP_CHECKSUM
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uint16_t rfc768_chksum(struct ipv4_hdr *ipv4, struct udp_hdr *udp) {
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uint32_t total = 0;
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uint16_t chksum = 0;
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size_t len = ntohs(udp->len);
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uint16_t *p;
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p = (uint16_t *)ipv4->src_addr;
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total += htons(p[0]);
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total += htons(p[1]);
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p = (uint16_t *)ipv4->dst_addr;
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total += htons(p[0]);
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total += htons(p[1]);
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p = (const uint16_t *)udp->data;
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for (size_t i = 0; i < len / 2; i++ ) {
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total += p[i];
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}
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total += IP_PROTO_UDP;
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total += udp->len;
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total += udp->src_port;
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total += udp->dst_port;
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total += ipv4->len;
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chksum = (total & 0xFFFF) + (total >> 16);
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chksum = ~chksum;
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return chksum;
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}
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#endif
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