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Improve handling of IPv6 routing type 0 extension headers.

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- flow_weird event with name argument value of "routing0_hdr" is raised
  for packets containing an IPv6 routing type 0 header because this
  type of header is now deprecated according to RFC 5095.

- packets with a routing type 0 header and non-zero segments left
  now use the last address in that header in order to associate
  with a connection/flow and for calculating TCP/UDP checksums.

- added a set of IPv4/IPv6 TCP/UDP checksum unit tests
This commit is contained in:
Jon Siwek 2012-03-27 16:05:45 -05:00
parent d889f14638
commit f4101b5265
39 changed files with 171 additions and 121 deletions
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79
src/net_util.cc
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@ -31,85 +31,6 @@ int ones_complement_checksum(const void* p, int b, uint32 sum)
return sum;
}
int ones_complement_checksum(const IPAddr& a, uint32 sum)
{
const uint32* bytes;
int len = a.GetBytes(&bytes);
return ones_complement_checksum(bytes, len*4, sum);
}
int tcp_checksum(const struct ip* ip, const struct tcphdr* tp, int len)
{
// ### Note, this is only correct for IPv4. This routine is only
// used by the connection compressor (which we turn off for IPv6
// traffic).
int tcp_len = tp->th_off * 4 + len;
uint32 sum;
if ( len % 2 == 1 )
// Add in pad byte.
sum = htons(((const u_char*) tp)[tcp_len - 1] << 8);
else
sum = 0;
sum = ones_complement_checksum((void*) &ip->ip_src.s_addr, 4, sum);
sum = ones_complement_checksum((void*) &ip->ip_dst.s_addr, 4, sum);
uint32 addl_pseudo =
(htons(IPPROTO_TCP) << 16) | htons((unsigned short) tcp_len);
sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum);
sum = ones_complement_checksum((void*) tp, tcp_len, sum);
return sum;
}
int udp_checksum(const struct ip* ip, const struct udphdr* up, int len)
{
uint32 sum;
if ( len % 2 == 1 )
// Add in pad byte.
sum = htons(((const u_char*) up)[len - 1] << 8);
else
sum = 0;
sum = ones_complement_checksum((void*) &ip->ip_src.s_addr, 4, sum);
sum = ones_complement_checksum((void*) &ip->ip_dst.s_addr, 4, sum);
uint32 addl_pseudo =
(htons(IPPROTO_UDP) << 16) | htons((unsigned short) len);
sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum);
sum = ones_complement_checksum((void*) up, len, sum);
return sum;
}
int udp6_checksum(const struct ip6_hdr* ip6, const struct udphdr* up, int len)
{
uint32 sum;
if ( len % 2 == 1 )
// Add in pad byte.
sum = htons(((const u_char*) up)[len - 1] << 8);
else
sum = 0;
sum = ones_complement_checksum((void*) ip6->ip6_src.s6_addr, 16, sum);
sum = ones_complement_checksum((void*) ip6->ip6_dst.s6_addr, 16, sum);
uint32 l = htonl(len);
sum = ones_complement_checksum((void*) &l, 4, sum);
uint32 addl_pseudo = htons(IPPROTO_UDP);
sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum);
sum = ones_complement_checksum((void*) up, len, sum);
return sum;
}
int icmp_checksum(const struct icmp* icmpp, int len)
{
uint32 sum;