40 lines
746 B
C
40 lines
746 B
C
#pragma once
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#include <stdint.h>
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struct ip_common {
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uint8_t version;
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uint8_t proto;
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uint8_t hdr_size;
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uint16_t size;
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};
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_pure_
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static inline uint8_t ip_get_version (const uint8_t *data, size_t size)
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{
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if (size<20)
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return 0;
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return data[0]>>4;
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}
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static inline int ip_get_common (struct ip_common *ic, const uint8_t *data, size_t size)
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{
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ic->version = ip_get_version(data, size);
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switch (ic->version) {
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case 4:
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ic->proto = data[9];
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ic->hdr_size = (data[0]&0xF)<<2;
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ic->size = ((data[2]<<8)|data[3]);
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return 0;
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case 6:
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ic->proto = data[6];
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ic->hdr_size = 40;
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ic->size = ((data[4]<<8)|data[5])+40;
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return 0;
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}
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return -1;
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}
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