/* Stream for SNMP. See aspath_snmp_pathseg */
static struct stream *snmp_stream;
\f
-static inline as_t *
+static as_t *
assegment_data_new (int num)
{
return (XCALLOC (MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE (num, 1)));
}
-static inline void
+static void
assegment_data_free (as_t *asdata)
{
XFREE (MTYPE_AS_SEG_DATA,asdata);
/* Unintern aspath from AS path bucket. */
void
-aspath_unintern (struct aspath *aspath)
+aspath_unintern (struct aspath **aspath)
{
struct aspath *ret;
+ struct aspath *asp = *aspath;
+
+ if (asp->refcnt)
+ asp->refcnt--;
- if (aspath->refcnt)
- aspath->refcnt--;
-
- if (aspath->refcnt == 0)
+ if (asp->refcnt == 0)
{
/* This aspath must exist in aspath hash table. */
- ret = hash_release (ashash, aspath);
+ ret = hash_release (ashash, asp);
assert (ret != NULL);
- aspath_free (aspath);
+ aspath_free (asp);
+ *aspath = NULL;
}
}
return aspath;
}
-/* parse as-segment byte stream in struct assegment
- *
- * Returns NULL if the AS_PATH or AS4_PATH is not valid.
- */
-static struct assegment *
-assegments_parse (struct stream *s, size_t length, int use32bit, int as4_path)
+/* parse as-segment byte stream in struct assegment */
+static int
+assegments_parse (struct stream *s, size_t length,
+ struct assegment **result, int use32bit)
{
struct assegment_header segh;
struct assegment *seg, *prev = NULL, *head = NULL;
+ size_t bytes = 0;
- assert (length > 0); /* does not expect empty AS_PATH or AS4_PATH */
+ /* empty aspath (ie iBGP or somesuch) */
+ if (length == 0)
+ return 0;
if (BGP_DEBUG (as4, AS4_SEGMENT))
zlog_debug ("[AS4SEG] Parse aspath segment: got total byte length %lu",
(unsigned long) length);
-
- /* double check that length does not exceed stream */
- if (STREAM_READABLE(s) < length)
- return NULL;
+ /* basic checks */
+ if ((STREAM_READABLE(s) < length)
+ || (STREAM_READABLE(s) < AS_HEADER_SIZE)
+ || (length % AS16_VALUE_SIZE ))
+ return -1;
- /* deal with each segment in turn */
- while (length > 0)
+ while (bytes < length)
{
int i;
size_t seg_size;
- /* softly softly, get the header first on its own */
- if (length < AS_HEADER_SIZE)
+ if ((length - bytes) <= AS_HEADER_SIZE)
{
- assegment_free_all (head);
- return NULL;
+ if (head)
+ assegment_free_all (head);
+ return -1;
}
+ /* softly softly, get the header first on its own */
segh.type = stream_getc (s);
segh.length = stream_getc (s);
seg_size = ASSEGMENT_SIZE(segh.length, use32bit);
- /* includes the header bytes */
if (BGP_DEBUG (as4, AS4_SEGMENT))
zlog_debug ("[AS4SEG] Parse aspath segment: got type %d, length %d",
segh.type, segh.length);
+ /* check it.. */
+ if ( ((bytes + seg_size) > length)
+ /* 1771bis 4.3b: seg length contains one or more */
+ || (segh.length == 0)
+ /* Paranoia in case someone changes type of segment length.
+ * Shift both values by 0x10 to make the comparison operate
+ * on more, than 8 bits (otherwise it's a warning, bug #564).
+ */
+ || ((sizeof segh.length > 1)
+ && (0x10 + segh.length > 0x10 + AS_SEGMENT_MAX)))
+ {
+ if (head)
+ assegment_free_all (head);
+ return -1;
+ }
+
switch (segh.type)
{
case AS_SEQUENCE:
case AS_SET:
- break ;
-
case AS_CONFED_SEQUENCE:
case AS_CONFED_SET:
- if (!as4_path)
- break ;
- /* RFC4893 3: "invalid for the AS4_PATH attribute" */
- /* fall through */
-
- default: /* reject unknown or invalid AS_PATH segment types */
- seg_size = 0 ;
- }
-
- /* Stop now if segment is not valid (discarding anything collected to date)
- *
- * RFC4271 4.3, Path Attributes, b) AS_PATH:
- *
- * "path segment value field contains one or more AS numbers"
- */
- if ((seg_size == 0) || (seg_size > length) || (segh.length == 0))
- {
- assegment_free_all (head);
- return NULL;
+ break;
+ default:
+ if (head)
+ assegment_free_all (head);
+ return -1;
}
- length -= seg_size ;
-
/* now its safe to trust lengths */
seg = assegment_new (segh.type, segh.length);
for (i = 0; i < segh.length; i++)
seg->as[i] = (use32bit) ? stream_getl (s) : stream_getw (s);
+ bytes += seg_size;
+
if (BGP_DEBUG (as4, AS4_SEGMENT))
- zlog_debug ("[AS4SEG] Parse aspath segment: length left: %lu",
- (unsigned long) length);
+ zlog_debug ("[AS4SEG] Parse aspath segment: Bytes now: %lu",
+ (unsigned long) bytes);
prev = seg;
}
- return assegment_normalise (head);
+ *result = assegment_normalise (head);
+ return 0;
}
-/* AS path parse function -- parses AS_PATH and AS4_PATH attributes
- *
- * Requires: s -- stream, currently positioned before first segment
- * of AS_PATH or AS4_PATH (ie after attribute header)
- * length -- length of the value of the AS_PATH or AS4_PATH
- * use32bit -- true <=> 4Byte ASN, otherwise 2Byte ASN
- * as4_path -- true <=> AS4_PATH, otherwise AS_PATH
- *
- * Returns: if valid: address of struct aspath in the hash of known aspaths,
- * with reference count incremented.
- * else: NULL
- *
- * NB: empty AS path (length == 0) is valid. The returned struct aspath will
- * have segments == NULL and str == zero length string (unique).
+/* AS path parse function. pnt is a pointer to byte stream and length
+ is length of byte stream. If there is same AS path in the the AS
+ path hash then return it else make new AS path structure.
+
+ On error NULL is returned.
*/
struct aspath *
-aspath_parse (struct stream *s, size_t length, int use32bit, int as4_path)
+aspath_parse (struct stream *s, size_t length, int use32bit)
{
struct aspath as;
struct aspath *find;
- /* Parse each segment and construct normalised list of struct assegment */
- memset (&as, 0, sizeof (struct aspath));
- if (length != 0)
- {
- as.segments = assegments_parse (s, length, use32bit, as4_path);
+ /* If length is odd it's malformed AS path. */
+ /* Nit-picking: if (use32bit == 0) it is malformed if odd,
+ * otherwise its malformed when length is larger than 2 and (length-2)
+ * is not dividable by 4.
+ * But... this time we're lazy
+ */
+ if (length % AS16_VALUE_SIZE )
+ return NULL;
- if (as.segments == NULL)
- return NULL ; /* Invalid AS_PATH or AS4_PATH */
- } ;
+ memset (&as, 0, sizeof (struct aspath));
+ if (assegments_parse (s, length, &as.segments, use32bit) < 0)
+ return NULL;
/* If already same aspath exist then return it. */
find = hash_get (ashash, &as, aspath_hash_alloc);
- assert(find) ; /* valid aspath, so must find or create */
-
/* aspath_hash_alloc dupes segments too. that probably could be
* optimised out.
*/
if (as.str)
XFREE (MTYPE_AS_STR, as.str);
+ if (! find)
+ return NULL;
find->refcnt++;
return find;
}
-static inline void
+static void
assegment_data_put (struct stream *s, as_t *as, int num, int use32bit)
{
int i;
}
}
-static inline size_t
+static size_t
assegment_header_put (struct stream *s, u_char type, int length)
{
size_t lenp;
struct aspath *
aspath_empty (void)
{
- return aspath_parse (NULL, 0, 1, 0); /* 32Bit ;-) not AS4_PATH */
+ return aspath_parse (NULL, 0, 1); /* 32Bit ;-) */
}
struct aspath *
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