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| | #include <string.h>
#include "lookup.h"
int __dns_parse(const unsigned char *r, int rlen, int (*callback)(void *, int, const void *, int, const void *, int), void *ctx)
{
int qdcount, ancount;
const unsigned char *p;
int len;
if (rlen<12) return -1;
if ((r[3]&15)) return 0;
p = r+12;
qdcount = r[4]*256 + r[5];
ancount = r[6]*256 + r[7];
if (qdcount+ancount > 64) return -1;
while (qdcount--) {
while (p-r < rlen && *p-1U < 127) p++;
if (p>r+rlen-6 || *p>193 || (*p==193 && p[1]>254))
return -1;
p += 5 + !!*p;
}
while (ancount--) {
while (p-r < rlen && *p-1U < 127) p++;
if (p>r+rlen-12 || *p>193 || (*p==193 && p[1]>254))
return -1;
p += 1 + !!*p;
len = p[8]*256 + p[9];
if (len+10 > r+rlen-p) return -1;
if (callback(ctx, p[1], p+10, len, r, rlen) < 0) return -1;
p += 10 + len;
}
return 0;
}
|