This prevented one from writing a packet-wise analyzer that needs access
to IP headers and can be attached to a connection via signature match.
None of the analyzers currently shipping are affected. And maybe it's
unlikely there will be many that ever would be, but it's awkward for the
API to omit IP headers in this special case (i.e. packets buffer for use
with DPD signature matching).
Addresses BIT-1298
Replaced some with InternalWarning or InternalAnalyzerError, the later
being a new method which signals the analyzer to not process further
input. Some usages I just removed if they didn't make sense or clearly
couldn't happen. Also did some minor refactors of related code while
reviewing/exploring ways to get rid of InternalError usages.
Also, for TCP content file write failures there's a new event:
"contents_file_write_failure".
Without this change, flow labeling of connections over IPv6 are
only available in the per-packet types of events (e.g. new_packet)
in which header fields can be inspected, but now minimal tracking
of the most recent flow label is done internally and that's available
per-connection for all events that use connection record arguments.
Specifically, this adds a "flow_label" field to the "endpoint" record
type, which is used for both the "orig" and "resp" fields of
"connection" records. The new "connection_flow_label_changed" event
also allows tracking of changes in flow labels: it's raised each time
one direction of the connection starts using a different label.
* origin/topic/icmp6:
Fixes for IPv6 truncation and ICMP/ICMP6 analysis.
Change ICMPv6 checksum calculation to use IP_Hdr wrapper.
Update IPv6 atomic fragment unit test to filter output of ICMPv6.
Add more data to icmp events
More code cleanup
Add more icmpv6 events, and general code cleanup
Fix compile failure after merge from master
Significant edit pass over ICMPv6 code.
Porting Matti's branch to git.
Closes#808.
- Add more guards against trying to analyze captured packets with a
truncated IPv6 static header or extension header chain.
- Add back in the ICMP payload tracking for ICMP "connections".
- Fix 'icmp_context' record construction. Some field assignments
were mismatched for ICMP and ICMP6. Source and destination
addresses were set incorrectly for context packets that don't
contain a full IP header. Some fields for ICMP6 weren't filled out.
- Changed ICMP Time Exceeded packets to raise the 'icmp_time_exceeded'
event instead of 'icmp_error_message'.
- Add unit tests for truncation and the main types of ICMP/ICMP6
that have specific events.
- Documentation clarifications.
* origin/topic/jsiwek/mobile-ipv6:
Add support for mobile IPv6 Mobility Header (RFC 6275).
Refactor IP_Hdr routing header handling, add MobileIPv6 Home Address handling.
Revert TCP checksumming to cache common data, like it did before.
Revert "Improve handling of IPv6 Routing Type 0 headers."
Improve handling of IPv6 routing type 0 extension headers.
- Accessible at script-layer through 'mobile_ipv6_message' event.
- All Mobile IPv6 analysis now enabled through --enable-mobile-ipv6
configure-time option, otherwise the mobility header, routing type 2,
and Home Address Destination option are ignored.
- For RH0 headers with non-zero segments left, a "routing0_segleft"
flow_weird event is raised (with a destination indicating the last
address in the routing header), and an "rh0_segleft" event can also
be handled if the other contents of the packet header are of interest.
No further analysis is done as the complexity required to correctly
identify destination endpoints of connections doesn't seem worth it
as RH0 has been deprecated by RFC 5095.
- For RH0 headers without any segments left, a "routing0_header"
flow_weird event is raised, but further analysis still occurs
as normal.
- 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
In response to feedback from Robin:
- rename "ip_hdr" to "ip4_hdr"
- pkt_hdr$ip6 is now of type "ip6_hdr" instead of "ip6_hdr_chain"
- "ip6_hdr_chain" no longer contains an "ip6_hdr" field, instead
it's the other way around, "ip6_hdr" contains an "ip6_hdr_chain"
- other internal refactoring
* origin/topic/jsiwek/ipv6-ext-headers:
Update PacketFilter/Discarder code for IP version independence.
Add a few comments to IP.h
Fix some IPv6 header related bugs.
Add IPv6 fragment reassembly.
Add handling for IPv6 extension header chains (addresses #531)
The signatures of script-layer functions 'discarder_check_ip',
'discarder_check_tcp', 'discarder_check_udp', and 'discarder_check_icmp'
were changed to use the more general 'pkt_hdr' type as a parameter
instead of individual header types.
- IPv6 payload length calculation didn't count main 40 byte IPv6 header.
- Fix how IPv6 headers that use TLV options are built.
- Fix ip6_hdr_chain$ext_order starting index at 1 instead of 0.
- The script-layer 'pkt_hdr' type is extended with a new 'ip6' field
representing the full IPv6 header chain.
- The 'new_packet' event is now raised for IPv6 packets (addresses #523)
- A new event called 'ipv6_ext_header' is raised for any IPv6 packet
containing extension headers.
- A new event called 'esp_packet' is raised for any packets using ESP
('new_packet' and 'ipv6_ext_header' events provide connection info,
but that info can't be provided here since the upper-layer payload
is encrypted).
- The 'unknown_protocol' weird is now raised more reliably when Bro
sees a transport protocol or IPv6 extension header it can't handle.
(addresses #522)
Still need to do IPv6 fragment reassembly and needs more testing.
- non-binpac DNS analyzer now also generates dns_a6_reply event
- ExpectedConn class refactored to use IPAddr's
- BinaryExpr::AddrFold simplified
- IP_Hdr src/dst address accessor methods changed to construct IPAddr
objects on the fly from ip4/ip6 members.
Addresses #770.
Internally, all BROv6 preprocessor switches were removed and
addr/subnet representations wrapped in the new IPAddr/IPPrefix classes.
Some script-layer changes of note:
- dns_AAAA_reply event signature changed: the string representation
of an IPv6 addr is easily derived from the addr value, it doesn't
need to be another parameter. This event also now generated directly
by the DNS analyzer instead of being "faked" into a dns_A_reply event.
- removed addr_to_count BIF. It used to return the host-order
count representation of IPv4 addresses only. To make it more
generic, we might later add a BIF to return a vector of counts
in order to support IPv6.
- changed the result of enclosing addr variables in vertical pipes
(e.g. |my_addr|) to return the bit-width of the address type which
is 128 for IPv6 and 32 for IPv4. It used to function the same
way as addr_to_count mentioned above.
- remove bro_has_ipv6 BIF
