Ano-sys
56 lines
1.3 KiB
C
56 lines
1.3 KiB
C
#include "util.h"
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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char *memstr(char *haystack, size_t n, string needle) {
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char *end = haystack + n;
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// Iterate through the memory (haystack)
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while ((haystack = memchr(haystack, needle[0], end - haystack)) != NULL) {
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if (strncmp(haystack, needle, strlen(needle)) == 0) {
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return haystack;
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}
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}
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return NULL;
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}
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uint16_t safe_strtoul(const char *restrict nptr, char **restrict endptr,
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int base, const string message) {
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errno = 0;
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uint16_t result =
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strtoul(nptr, endptr, base); // Convert string to unsigned int
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if (errno != 0) {
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fprintf(stderr, "%s\n", message);
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exit(EXIT_FAILURE);
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}
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return result;
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}
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uint16_t pseudo_hash(const unsigned char *buffer, size_t buf_len) {
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// we use tcp crc16 check here
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uint32_t hash = 0;
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// add zero padding to the end if buf_len not even
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size_t pad_length = buf_len % 2 ? buf_len + 1 : buf_len;
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uint8_t *int_buffer = calloc(pad_length, sizeof *buffer);
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memcpy(int_buffer, buffer, buf_len);
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for (size_t i = 0; i < pad_length; i+=2) {
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hash += int_buffer[i] << 8 | int_buffer[i+1];
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}
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hash = (hash & 0xFFFF) + (hash >> 16);
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free(int_buffer);
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return (uint16_t) ~hash;
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}
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