build: correct libtool parameter used within Makefiles

This corrects the parameters passed to libtool when linking
the shared libraries. The paramter name is -version-info not
-version.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
build: fix autoconf multicast check on OpenBSD

Fix the "BSD struct ip_mreq hack" autoconf test to work with OpenBSD.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
ripd: clear sockaddr_in before using

ripd_create_socket() failed in bind() on Mac OS X 10.7 since there was garbage
in unused fields of struct sockaddr_in.

* ripd/ripd.c: zero out struct sockaddr_sin from before filling.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
build: fix extract.pl for cross compilation

extract.pl should invoke the C preprocessor for the target system, not the
host.

* vtysh/extract.pl.in: use @CPP@ to get target cpp

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
lib: bring some changes over from bgp_table to table

  * lib/table.c

    - Maintain table node count. Expose it via the route_table_count()
      function (from revision cbdfbaa5).

    - route_unlock_node(): Add assertion (from revision 228da428).

    - route_table_free(): Make static and fix up cleanup code (from
      revision 228da428).

    - route_node_delete(): Change to be static.

    - Add 'const' qualifier in a couple places.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
lib: prepare table code for reuse by bgp_table

  * lib/table.[ch]

    - Add a macro (ROUTE_NODE_FIELDS) that expands to all the fields
      of a route_node structure.

    - Add the route_table_delegate_t structure, a function vector
      which allows clients to customize the behavior of one or more
      tables.

      The delegate currently contains the 'create_node' and
      'destroy_node' functions, and hence enables a table to use an
      alternative node structure. The alternative node is expected to
      embed the fields of a route_node using ROUTE_NODE_FIELDS.

    - Add route_table_init_with_delegate() to create a new table with
      a given delegate.

    - Make route_table_init() a thin wrapper around
      route_table_init_with_delegate(). The delegate it passes in
      simply creates/destroys route_node structures as before.

    - Add a user data pointer (info) to the route_table
      structure. This can be used by a client to keep per-table state.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
bgpd: make bgp_table a wrapper around table library

Make the BGP table code a thin wrapper around the table implementation
in libzebra.

  * bgpd/bgp_table.[ch]

    - Use the ROUTE_NODE_FIELDS macro to embed the fields of a
      route_node in the bgp_node structure.

    - Add a route_table field to the bgp_table structure.

      Initialize the route_table with a delegate, such that the nodes
      in the table are bgp_node structures.

    - Add inline wrappers that call route_table functions underneath,
      and accept/return the correct BGP types.

  * bgpd/bgp_route.c

    Change some code to use inline wrappers instead of accessing
    fields of nodes/tables directly. The latter does not always work
    because the types of some fields need to be translated now.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
lib/table: add route_table_get_next() and iterator

  * lib/table.[ch]

    - Add a function (route_table_get_next()) to get the route_node in
      a tree that succeeds a given prefix in iteration order.

      This allows one to reliably walk nodes in a tree while allowing
      modifications, and is useful for achieving scale and
      performance. Other approaches are also possible -- the main plus
      point of this one is that it does not require any state about
      the walk to be maintained in the table data structures.

    - Add an iterator for walking the nodes in a tree. This introduces
      a new structure (route_table_iter_t) and the following main
      functions.

        route_table_iter_init()
        route_table_iter_pause()
        route_table_iter_next()
        route_table_iter_cleanup()

      The iterator normally uses node pointers and the existing
      route_next() function to walk nodes efficiently. When an
      iteration is 'paused' with route_table_iter_pause(), it stores
      the last prefix processed. The next call to
      route_table_iter_next() transparently invokes
      route_table_get_next() with the prefix to resume iteration.

  * bgpd/bgp_table.[ch]

    Add wrappers for the new table features described above.

  * tests/table_test.c

    Add tests for the new table code.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Revert "ospfd: Do not fall back to intervening router."

This reverts commit 9289c6ff55cd96c943d23e43fc9e5f987aa965ed.

The commit reverted an earlier change which was fixed a bug that caused
black-holes to remote destinations with multiple paths, that could occur
during convergence. Overall, the previous code is more correct.
zebra: make static routes respect table setting

Make static routes respect non-default routing tables.

BEFORE PATCH
------------

! in zebra.conf
table 1

! add static route
vtysh> ip route 10.0.0.0/30 eth0

cumulus@net-top0:~$ ip route
default via 192.168.0.2 dev eth0
10.0.0.0/30 dev eth0  proto zebra
192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.15

! nothing in table 1
cumulus@net-top0:~$ ip route show table 1

AFTER PATCH
-----------

! in zebra.conf
table 1

! add static route
vtysh> ip route 10.0.0.0/30 eth0

cumulus@net-top0:~$ ip route
default via 192.168.0.2 dev eth0
192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.15

! static route in table 1
cumulus@net-top0:~$ ip route show table 1
10.0.0.0/30 dev eth0  proto zebra

Signed-off-by: Nolan Leake <nolan@cumulusnetworks.com>
Reviewed-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
lib: improve fletcher checksum validation

OVERVIEW

The checksum used in OSPF (rfc2328) is specified in rc905 annex B.  There is an
sample implementation in rfc1008 which forms the basis of the quagga
implementation.  This algorithm works perfectly when generating a checksum;
however, validation is a bit problematic.

The following LSA (generated by a non-quagga implementation) is received by
quagga and marked with an invalid checksum; however, it passes both the rfc905
and rfc1008 validation checks.

static uint8_t lsa_10_121_233_29[] = {
   0x0e, 0x10, 0x02, 0x03,
   0x09, 0x00, 0x35, 0x40,
   0x0a, 0x79, 0xe9, 0x1d,
   0x80, 0x00, 0x00, 0x03,
   0x00, 0x8a, 0x00, 0x1c,
   0xff, 0xff, 0xff, 0xe0,
   0x00, 0x00, 0x36, 0xb0
};

LS Type: Summary-LSA (IP network)
   LS Age: 3600 seconds
   Do Not Age: False
   Options: 0x02 (E)
   Link-State Advertisement Type: Summary-LSA (IP network) (3)
   Link State ID: 9.0.53.64
   Advertising Router: 10.121.233.29 (10.121.233.29)
   LS Sequence Number: 0x80000003
   LS Checksum: 0x008a
   Length: 28
   Netmask: 255.255.255.224
   Metric: 14000

You'll note that one byte of the checksum is 0x00; quagga would calculate the
checksum as 0xff8a.

It can be argued that the sourcing implementation generates an incorrect
checksum; however, rfc905 indicates that, for 1's complement arithmetic, the
value 255 shall be regarded as 0, thus either values are valid.

EXPLANATION

The quagga ospfd and ospf6d implementations operate by copying the PDU's
existing checksum in a holding variable, calculating the checksum, and comparing
the resulting checksum to the original.  As a note, this implementation has the
side effect of modifying the contents of the PDU.

Evaluation of both rfc905 and rfc1008 shows that checksum validation should
involve calculating the sum over the PDU and checking that both resulting C0 and
C1 values are zero.  This behavior is enacted in the rfc1008 implementation by
calling encodecc with k = 0 (checksum offset); however, this functionality had
been omitted from the quagga implementation.

PATCH

This patch adds the ability to call the quagga's fletcher_checksum() with a
checksum offset value of 0xffff (aka FLETCHER_CHECKSUM_VALIDATE) which returns
the sum over the buffer (a value of 0 indicates a valid checksum).  This is
similar to the mechanism in rfc1008 when called with k = 0.  The patch also
introduces ospf_lsa_checksum_valid().

ospf6d had it's own implementation of the fletcher checksum in
ospf6_lsa_checksum(); it's the same algorithm as in fletcher_checksum().  This
patch removes the local implementation in favor of the library's as well as creates
and uses ospf6_lsa_checksum_valid().

quagga's ISIS implementation suffers from the same problem; however, I do not
have the facilities to validate a fix to ISIS, thus this change has been left to
the ISIS maintainers.  The function iso_csum_verify() should be reduced to
running the fletcher checksum over the buffer using an offset of 0.

Signed-off-by: JR Rivers <jrrivers@cumulusnetworks.com>
Reviewed-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Reviewed-by: Nolan Leake <nolan@cumulusnetworks.com>
Reviewed-by: Ayan Banerjee <ayan@cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
ospfd: blackhole route removal for area range

ISSUE

When an area range is created in which there the sub-area has routes that are
smaller than the range, an ABR creates a blackhole route to cover the range.
When the range is removed, the blackhole route is not removed.

--A----B----C---

B is an ABR with A in area 1 and C in area 0.  If A advertises `10.2.0.0/30` and
`10.2.0.4/30` and B is configured with `area 0.0.0.1 range 10.2.0.0/29` a
blackhole is created on B (`blackhole 10.2.0.0/29 proto zebra`).  When the
area/range is removed via the command line, the blackhole remains in existence
even though the "range" route is removed from area 0 and the individual routes
are propagated.

PATCH

The reason for this behavior is that, prior to this patch, the range is deleted
from the area's list, so when ospf_abr_manage_discard_routes() gets called,
there is nothing to clean up.  The patch removes the discard route as part of
the processing of the command line (ospf_area_range_unset()).

Signed-off-by: JR Rivers <jrrivers@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
ospfd: ABR algorithm not propagating MAXAGE LSAs into area

When a range (or sub-range) is deleted, the area is notified by propagating a
MAXAGE LSA.  This LSA stays in the database for a while to both insure
propagation as well as in the off chance that it's useful in the near future.

Unfortunately, the ABR algorithm was treating these MAXAGE LSAs as unchanged and
not propagating them within the areas.

Signed-off-by: JR Rivers <jrrivers@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Reviewed-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
ospfd: respect max-metric over configured cost for summary LSAs

ISSUE

When max-metric router-lsa administrative is invoked on an ABR created with...
area <area> range <addr/mask>
the summary LSAs are sent out with 65535 (max-metric) added to the normal cost.

When max-metric router-lsa administrative is invoked on an ABR created with...
area <area> range <addr/mask> cost <cost>
the summary LSAs are sent out with <cost> (the max-metric is ignored).  This
second behavior effectively incapacitates the max-metric function.

PATCH

This patch evaluates the state of the router and if it's isolated as a stub
router (rfc3137) via `max-metric router-lsa`, we unconditionally uses the
value of 0xff0000 when advertising summary LSAs.

Signed-off-by: JR Rivers <jrrivers@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Reviewed-by: Ayan Banerjee <ayan@cumulusnetworks.com>
Reviewed-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
lib: improve sanity checks in stream_set_endp()

  * lib/stream.c: (stream_set_endp) Add checks to make sure that the
    supplied 'endp' is within the 'size' of the stream, and that the
    current read pointer 'getp' is not beyond the specified 'endp'.
isisd: tighten checks on ISIS pdu length

  * isisd/isis_pdu.c: Fix problem where isisd would crash if it
    received a LAN IIH with the 'pdu length' field set to zero.
    Similar problems can occur in parsing other ISIS PDUs as well --
    check that the PDU length in an ISIS hello, LSP or SNP packet is
    at least as big as the size of the respective fixed header.
isisd: fix null pointer dereference in send_lsp()

  * isisd/isis_pdu.c: (send_lsp) Handle case where there are no LSPs
    on the LSP transmission queue. This can happen if, for instance,
    the queue is cleared because of protocol events before the
    send_lsp thread gets a chance to run.
isisd: pull up invalid prefix assert()

processing invalid prefixes causes isisd to assert() or otherwise
misbehave in ip_masklen/apply_mask.  pull up the assert() to indicate
better there's broken data in isisd's LSDB.

  * isisd/isis_spf.c: assert() prefix lengths

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
isisd: don't process invalid prefixes from TLVs

it's possible to feed invalid prefixes (1.2.3.4/40 or dead::beef/200) on
IS-IS.  if this is not checked, it will later cause an assert in
processing.  let's simply abort processing the TLV if the prefix is
invalid.

  * isisd/isis_tlv.c: check prefix lengths for validity

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
lib: add array_size() helper

implement array_size as sizeof(array) / sizeof(array element)

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>