[bgpd] Merge AS4 support

2007-10-14 Paul Jakma <paul.jakma@sun.com>

	* NEWS: Note that MRT dumps are now version 2
	* (general) Merge in Juergen Kammer's AS4 patch.

2007-09-27 Paul Jakma <paul.jakma@sun.com>

	* bgp_aspath.c: (assegment_normalise) remove duplicates from
	  from sets.
	  (aspath_reconcile_as4) disregard a broken part of the RFC around
	  error handling in path reconciliation.
	* aspath_test.c: Test dupe-weeding from sets.
	  Test that reconciliation merges AS_PATH and AS4_PATH where
	  former is shorter than latter.

2007-09-26 Paul Jakma <paul.jakma@sun.com>

	* aspath_test.c: Test AS4_PATH reconcilation where length
	  of AS_PATH and AS4_PATH is same.

2007-09-25 Paul Jakma <paul.jakma@sun.com>

	* bgp_open.c: (peek_for_as4_capability) Fix to work.
	* bgp_packet.c: (bgp_open_receive) Fix sanity check of as4.
	* tests/bgp_capability_test.c: (general) Extend tests to validate
	  peek_for_as4_capability.
	  Add test of full OPEN Option block, with multiple capabilities,
	  both as a series of Option, and a single option.
	  Add some crap to beginning of stream, to prevent code depending
	  on getp == 0.

2007-09-18 Paul Jakma <paul.jakma@sun.com>

	* bgp_open.c: (bgp_capability_as4) debug printf inline with others.
	  (peek_for_as4_capability) There's no need to signal failure, as
	  failure is better dealt with through full capability parser -
	  just return the AS4, simpler.
	* bgp_packet.c: (bgp_open_receive) Update to match
	  peek_for_as4_capability change.
	  Allow use of BGP_AS_TRANS by 2b speakers.
	  Use NOTIFY_OPEN_ERR rather than CEASE for OPEN parsing errors.
	  (bgp_capability_msg_parse) missing argument to debug print
	  (bgp_capability_receive) missing return values.
	* tests/bgp_capability_test.c: (parse_test) update for changes to
	  peek_for_as4_capability

2007-07-25 Paul Jakma <paul.jakma@sun.com>

	* Remove 2-byte size macros, just make existing macros take
	  argument to indicate which size to use.
	  Adjust all users - typically they want '1'.
	* bgp_aspath.c: (aspath_has_as4) New, return 1 if there are any
	  as4's in a path.
	  (aspath_put) Return the number of bytes actually written, to
	  fix the bug Juergen noted: Splitting of segments will change
	  the number of bytes written from that already written to the
	  AS_PATH header.
	  (aspath_snmp_pathseg) Pass 2-byte flag to aspath_put. SNMP
	  is still defined as 2b.
	  (aspath_aggregate) fix latent bug.
	  (aspath_reconcile_as4) AS_PATH+NEW_AS_PATH reconciliation
	  function.
	  (aspath_key_make) Hash the AS_PATH string, rather than
	  just taking the addition of assegment ASes as the hash value,
	  hopefully sligthly more collision resistant.
	  (bgp_attr_munge_as4_attrs) Collide the NEW_ attributes
	  together with the OLD 2-byte forms, code Juergen
	  had in bgp_attr_parse but re-organised a bit.
	  (bgp_attr_parse) Bunch of code from Juergen moves
	  to previous function.
	  (bgp_packet_attribute) Compact significantly by
	  just /always/ using extended-length attr header.
	  Fix bug Juergen noted, by using aspath_put's
	  (new) returned size value for the attr header rather
	  than the (guesstimate) of aspath_size() - the two could
	  differ when aspath_put had to split large segments, unlikely
	  this bug was ever hit in the 'wild'.
	  (bgp_dump_routes_attr) Always use extended-len and
	  use aspath_put return for header length. Output 4b ASN
	  for AS_PATH and AGGREGATOR.
	* bgp_ecommunity.c: (ecommunity_{hash_make,cmp}) fix
	  hash callback declarations to match prototypes.
	  (ecommunity_gettoken) Updated for ECOMMUNITY_ENCODE_AS4,
	  complete rewrite of Juergen's changes (no asdot support)
	* bgp_open.c: (bgp_capability_as4) New, does what it says
	  on the tin.
	  (peek_for_as4_capability) Rewritten to use streams and
	  bgp_capability_as4.
	* bgp_packet.c: (bgp_open_send) minor edit
	  checked (in the abstract at least) with Juergen.
	  Changes are to be more accepting, e.g, allow AS_TRANS on
	  a 2-byte session.
	* (general) Update all commands to use CMD_AS_RANGE.
	* bgp_vty.c: (bgp_clear) Fix return vals to use CMD_..
	  Remove stuff replicated by VTY_GET_LONG
	  (bgp_clear_vty) Return bgp_clear directly to vty.
	* tests/aspath_test.c: Exercise 32bit parsing. Test reconcile
	  function.
	* tests/ecommunity_test.c: New, test AS4 ecommunity changes,
	  positive test only at this time, error cases not tested yet.

2007-07-25 Juergen Kammer <j.kammer@eurodata.de>

	* (general) AS4 support.
	* bgpd.h: as_t changes to 4-bytes.
	* bgp_aspath.h: Add BGP_AS4_MAX and BGP_AS_TRANS defines.
	* bgp_aspath.c: AS_VALUE_SIZE becomes 4-byte, AS16_VALUE_SIZE
	  added for 2-byte.
	  Add AS16 versions of length calc macros.
	  (aspath_count_numas) New, count number of ASes.
	  (aspath_has_as4) New, return 1 if there are any as4's in a
	  path.
	  (assegments_parse) Interpret assegment as 4 or 2 byte,
	  according to how the caller instructs us, with a new
	  argument.
	  (aspath_parse) Add use32bit argument to pass to
	  assegments_parse. Adjust all its callers to pass 1, unless
	  otherwise noted.
	  (assegment_data_put) Adjust to be able to write 2 or 4 byte
	  AS, according to new use32bit argument.
	  (aspath_put) Adjust to write 2 or 4.
	  (aspath_gettoken) Use a long for passed in asno.
	* bgp_attr.c: (attr_str) Add BGP_ATTR_AS4_PATH and
	  BGP_ATTR_AS4_AGGREGATOR.
	  (bgp_attr_aspath) Call aspath_parse with right 2/4 arg, as
	  determined by received-capability flag.
	  (bgp_attr_aspath_check) New, code previously in attr_aspath
	  but moved to new func so it can be run after NEW_AS_PATH
	  reconciliation.
	  (bgp_attr_as4_path) New, handle NEW_AS_PATH.
	  (bgp_attr_aggregator) Adjust to cope with 2/4 byte ASes.
	  (bgp_attr_as4_aggregator) New, read NEW_AGGREGATOR.
	  (bgp_attr_parse) Add handoffs to previous parsers for the two
	  new AS4 NEW_ attributes.
	  Various checks added for NEW/OLD reconciliation.
	  (bgp_packet_attribute) Support 2/4 for AS_PATH and
	  AGGREGATOR, detect when NEW_ attrs need to be sent.
	* bgp_debug.{c,h}: Add 'debug bgp as4'.
	* bgp_dump.c: MRTv2 support, unconditionally enabled, which
	  supports AS4. Based on patches from Erik (RIPE?).
	* bgp_ecommunity.c: (ecommunity_ecom2str) ECOMMUNITY_ENCODE_AS4
	  support.
	* bgp_open.c: (peek_for_as4_capability) New, peek for AS4
	  capability prior to full capability parsing, so we know which
	  ASN to use for struct peer lookup.
	  (bgp_open_capability) Always send AS4 capability.
	* bgp_packet.c: (bgp_open_send) AS4 handling for AS field
	  (bgp_open_receive) Peek for AS4 capability first, and figure
	  out which AS to believe.
	* bgp_vty.c: (bgp_show_peer) Print AS4 cap
	* tests/aspath_test.c: Support asn32 changes, call aspath_parse
	  with 16 bit.
	* vtysh/extract.pl: AS4 compatibility for router bgp ASNUMBER
	* vtysh/extract.pl.in: AS4 compatibility for router bgp ASNUMBER
	* vtysh/vtysh.c: AS4 compatibility for router bgp ASNUMBER

1 files changed, 116 insertions, 0 deletions

diff --git a/bgpd/bgp_open.c b/bgpd/bgp_open.c
index cd235770a..38431d4c6 100644
--- a/bgpd/bgp_open.c
+++ b/bgpd/bgp_open.c
@@ -34,6 +34,7 @@ Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 #include "bgpd/bgp_fsm.h"
 #include "bgpd/bgp_packet.h"
 #include "bgpd/bgp_open.h"
+#include "bgpd/bgp_aspath.h"
 #include "bgpd/bgp_vty.h"
 
 /* BGP-4 Multiprotocol Extentions lead us to the complex world. We can
@@ -427,6 +428,19 @@ bgp_capability_restart (struct peer *peer, struct capability_header *caphdr)
   return 0;
 }
 
+static as_t
+bgp_capability_as4 (struct peer *peer, struct capability_header *hdr)
+{
+  as_t as4 = stream_getl (BGP_INPUT(peer));
+  
+  if (BGP_DEBUG (as4, AS4))
+    zlog_debug ("%s [AS4] about to set cap PEER_CAP_AS4_RCV, got as4 %u",
+                peer->host, as4);
+  SET_FLAG (peer->cap, PEER_CAP_AS4_RCV);
+  
+  return as4;
+}
+
 static struct message capcode_str[] =
 {
   { 0,	""},
@@ -507,6 +521,7 @@ bgp_capability_parse (struct peer *peer, size_t length, u_char **error)
           case CAPABILITY_CODE_ORF:
           case CAPABILITY_CODE_ORF_OLD:
           case CAPABILITY_CODE_RESTART:
+          case CAPABILITY_CODE_AS4:
           case CAPABILITY_CODE_DYNAMIC:
               /* Check length. */
               if (caphdr.length < cap_minsizes[caphdr.code])
@@ -566,6 +581,14 @@ bgp_capability_parse (struct peer *peer, size_t length, u_char **error)
           case CAPABILITY_CODE_DYNAMIC:
             SET_FLAG (peer->cap, PEER_CAP_DYNAMIC_RCV);
             break;
+          case CAPABILITY_CODE_AS4:
+              /* Already handled as a special-case parsing of the capabilities
+               * at the beginning of OPEN processing. So we care not a jot
+               * for the value really, only error case.
+               */
+              if (!bgp_capability_as4 (peer, &caphdr))
+                return -1;
+              break;            
           default:
             if (caphdr.code > 128)
               {
@@ -615,6 +638,86 @@ strict_capability_same (struct peer *peer)
   return 1;
 }
 
+/* peek into option, stores ASN to *as4 if the AS4 capability was found.
+ * Returns  0 if no as4 found, as4cap value otherwise.
+ */
+as_t
+peek_for_as4_capability (struct peer *peer, u_char length)
+{
+  struct stream *s = BGP_INPUT (peer);
+  size_t orig_getp = stream_get_getp (s);
+  size_t end = orig_getp + length;
+  as_t as4 = 0;
+  
+  /* The full capability parser will better flag the error.. */
+  if (STREAM_READABLE(s) < length)
+    return 0;
+
+  if (BGP_DEBUG (as4, AS4))
+    zlog_info ("%s [AS4] rcv OPEN w/ OPTION parameter len: %u,"
+                " peeking for as4",
+	        peer->host, length);
+  /* the error cases we DONT handle, we ONLY try to read as4 out of
+   * correctly formatted options.
+   */
+  while (stream_get_getp(s) < end) 
+    {
+      u_char opt_type;
+      u_char opt_length;
+      
+      /* Check the length. */
+      if (stream_get_getp (s) + 2 > end)
+        goto end;
+      
+      /* Fetch option type and length. */
+      opt_type = stream_getc (s);
+      opt_length = stream_getc (s);
+      
+      /* Option length check. */
+      if (stream_get_getp (s) + opt_length > end)
+        goto end;
+      
+      if (opt_type == BGP_OPEN_OPT_CAP)
+        {
+          unsigned long capd_start = stream_get_getp (s);
+          unsigned long capd_end = capd_start + opt_length;
+          
+          assert (capd_end <= end);
+          
+	  while (stream_get_getp (s) < capd_end)
+	    {
+	      struct capability_header hdr;
+	      
+	      if (stream_get_getp (s) + 2 > capd_end)
+                goto end;
+              
+              hdr.code = stream_getc (s);
+              hdr.length = stream_getc (s);
+              
+	      if ((stream_get_getp(s) +  hdr.length) > capd_end)
+		goto end;
+
+	      if (hdr.code == CAPABILITY_CODE_AS4)
+	        {
+	          if (hdr.length != CAPABILITY_CODE_AS4_LEN)
+	            goto end;
+                  
+	          if (BGP_DEBUG (as4, AS4))
+	            zlog_info ("[AS4] found AS4 capability, about to parse");
+	          as4 = bgp_capability_as4 (peer, &hdr);
+	          
+	          goto end;
+                }
+              stream_forward_getp (s, hdr.length);
+	    }
+	}
+    }
+
+end:
+  stream_set_getp (s, orig_getp);
+  return as4;
+}
+
 /* Parse open option */
 int
 bgp_open_option_parse (struct peer *peer, u_char length, int *capability)
@@ -815,6 +918,7 @@ bgp_open_capability (struct stream *s, struct peer *peer)
   unsigned long cp;
   afi_t afi;
   safi_t safi;
+  as_t local_as;
 
   /* Remember current pointer for Opt Parm Len. */
   cp = stream_get_endp (s);
@@ -901,6 +1005,18 @@ bgp_open_capability (struct stream *s, struct peer *peer)
   stream_putc (s, CAPABILITY_CODE_REFRESH);
   stream_putc (s, CAPABILITY_CODE_REFRESH_LEN);
 
+  /* AS4 */
+  SET_FLAG (peer->cap, PEER_CAP_AS4_ADV);
+  stream_putc (s, BGP_OPEN_OPT_CAP);
+  stream_putc (s, CAPABILITY_CODE_AS4_LEN + 2);
+  stream_putc (s, CAPABILITY_CODE_AS4);
+  stream_putc (s, CAPABILITY_CODE_AS4_LEN);
+  if ( peer->change_local_as )
+    local_as = peer->change_local_as;
+  else
+    local_as = peer->local_as;
+  stream_putl (s, local_as );
+
   /* ORF capability. */
   for (afi = AFI_IP ; afi < AFI_MAX ; afi++)
     for (safi = SAFI_UNICAST ; safi < SAFI_MAX ; safi++)