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dns_packet_*

dns_packet_*

Section: C Library Functions (3)
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NAME

dns_packet_* - The dns_packet library interface  

SYNOPSIS

#include <dns.h>

newpos = dns_packet_copy(buf, len, pos, out, outlen);

  char *buf;
  unsigned int len;
  unsigned int pos;
  unsigned int newpos;
  char *out;
  unsigned int outlen;

newpos = dns_packet_getname(buf, len, pos, &dn);

  char *buf;
  unsigned int len;
  unsigned int pos;
  unsigned int newpos;
  char *dn = 0;

newpos = dns_packet_skipname(buf, len, pos);

  char *buf;
  unsigned int len;
  unsigned int pos;
  unsigned int newpos;  

DESCRIPTION

dns_packet_copy reads outlen bytes from position pos of a DNS packet stored at buf, copies the bytes into out, and returns pos + outlen. However, if reading the bytes would require reading past the first len bytes of the packet, dns_packet_copy returns 0, setting errno appropriately.

dns_packet_getname reads a compressed domain name from position pos of a DNS packet stored at buf, copies the name into dn, and returns the position in the packet immediately after the name.

If the name is misformatted, or if reading the name would require reading past the first len bytes of the packet, or if there is not enough memory for dn, dns_packet_getname returns 0, setting errno appropriately, and leaves dn alone.

dns_packet_skipname is like dns_packet_getname but discards the resulting domain name. It does not allocate memory.

Beware that, even if dns_packet_skipname returns nonzero, a future dns_packet_getname from the same position may fail: it may run out of memory, or encounter a format error not detected by dns_packet_skipname.  

SEE ALSO

dns_domain(3), dns_ip4(3), dns_ip4_qualify(3), dns_mx(3), dns_name4(3), dns_random(3), dns_transmit(3), dns_txt(3)

http://cr.yp.to/djbdns/blurb/library.html


 

Index

NAME
SYNOPSIS
DESCRIPTION
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 21:45:10 GMT, April 16, 2011