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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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56
src/IP.h
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@ -117,7 +117,8 @@ public:
/**
* Initializes the header chain from an IPv6 header structure.
*/
IPv6_Hdr_Chain(const struct ip6_hdr* ip6) { Init(ip6, false); }
IPv6_Hdr_Chain(const struct ip6_hdr* ip6) : route0_hdr_idx(0)
{ Init(ip6, false); }
~IPv6_Hdr_Chain()
{ for ( size_t i = 0; i < chain.size(); ++i ) delete chain[i]; }
@ -171,6 +172,27 @@ public:
{ return IsFragment() ?
(ntohs(GetFragHdr()->ip6f_offlg) & 0x0001) != 0 : 0; }
/**
* Returns the final destination of the packet this chain belongs to.
* If the chain doesn't contain any routing type 0 header with non-zero
* segments left, this is the destination in the main IP header, else
* it's the last address in the routing header. (If there were to be
* more than one routing type 0 header with non-zero segments left, the
* last one would be the one referenced).
*/
IPAddr FinalDst() const
{
if ( route0_hdr_idx )
{
const struct in6_addr* a = (const struct in6_addr*)
(chain[route0_hdr_idx]->Data() +
chain[route0_hdr_idx]->Length() - 16);
return IPAddr(*a);
}
else
return IPAddr(((const struct ip6_hdr*)(chain[0]->Data()))->ip6_dst);
}
/**
* Returns a vector of ip6_ext_hdr RecordVals that includes script-layer
* representation of all extension headers in the chain.
@ -186,13 +208,24 @@ protected:
* Initializes the header chain from an IPv6 header structure, and replaces
* the first next protocol pointer field that points to a fragment header.
*/
IPv6_Hdr_Chain(const struct ip6_hdr* ip6, uint16 next)
IPv6_Hdr_Chain(const struct ip6_hdr* ip6, uint16 next) : route0_hdr_idx(0)
{ Init(ip6, true, next); }
void Init(const struct ip6_hdr* ip6, bool set_next, uint16 next = 0);
vector<IPv6_Hdr*> chain;
uint16 length; // The summation of all header lengths in the chain in bytes.
/**
* The summation of all header lengths in the chain in bytes.
*/
uint16 length;
/**
* Index of routing type 0 header with non-zero segments left in the header
* chain or zero if none exists (it's fine since the main IP header must
* always be at index zero).
*/
uint8 route0_hdr_idx;
};
class IP_Hdr {
@ -248,7 +281,22 @@ public:
IPAddr SrcAddr() const
{ return ip4 ? IPAddr(ip4->ip_src) : IPAddr(ip6->ip6_src); }
IPAddr DstAddr() const
/**
* Returns the final destination address of the header's packet, which
* for IPv6 packets without a routing type 0 extension header and IPv4
* packets is the destination address in the IP header. For IPv6 packets
* with a routing type 0 extension header and a non-zero number of
* segments left, the final destination is the last address in the routing
* header. If the segments left of a routing type 0 header were zero,
* then the final destination is in the IP header itself.
*/
IPAddr FinalDstAddr() const
{ return ip4 ? IPAddr(ip4->ip_dst) : ip6_hdrs->FinalDst(); }
/**
* Returns the destination address held in the IP header.
*/
IPAddr IPHeaderDstAddr() const
{ return ip4 ? IPAddr(ip4->ip_dst) : IPAddr(ip6->ip6_dst); }
/**