[bgpd] AS4 bugfix by Chris Caputo <ccaputo@alt.net>
* bgpd/bgp_aspath.c: (aspath_make_str_count) "assert (len < str_size)" was
getting hit under certain 4-byte ASN conditions. New realloc strategy.
* bgpd/bgp_aspath.c: (aspath_key_make) const warning fix.
"%d" -> "%u" 4-byte ASN corrections. Prevent negative number when ASN is
above 2^31.
diff --git a/bgpd/bgp_aspath.c b/bgpd/bgp_aspath.c
index 006fc91..a1e4608 100644
--- a/bgpd/bgp_aspath.c
+++ b/bgpd/bgp_aspath.c
@@ -393,25 +393,6 @@
return ' ';
}
-/* countup asns from this segment and index onward */
-static int
-assegment_count_asns (struct assegment *seg, int from)
-{
- int count = 0;
- while (seg)
- {
- if (!from)
- count += seg->length;
- else
- {
- count += (seg->length - from);
- from = 0;
- }
- seg = seg->next;
- }
- return count;
-}
-
unsigned int
aspath_count_confeds (struct aspath *aspath)
{
@@ -521,6 +502,21 @@
return num;
}
+static void
+aspath_make_str_big_enough (int len,
+ char **str_buf,
+ int *str_size,
+ int count_to_be_added)
+{
+#define TERMINATOR 1
+ while (len + count_to_be_added + TERMINATOR > *str_size)
+ {
+ *str_size *= 2;
+ *str_buf = XREALLOC (MTYPE_AS_STR, *str_buf, *str_size);
+ }
+#undef TERMINATOR
+}
+
/* Convert aspath structure to string expression. */
static char *
aspath_make_str_count (struct aspath *as)
@@ -540,18 +536,7 @@
seg = as->segments;
- /* ASN takes 5 chars at least, plus seperator, see below.
- * If there is one differing segment type, we need an additional
- * 2 chars for segment delimiters, and the final '\0'.
- * Hopefully this is large enough to avoid hitting the realloc
- * code below for most common sequences.
- *
- * With 32bit ASNs, this range will increase, but only worth changing
- * once there are significant numbers of ASN >= 100000
- */
-#define ASN_STR_LEN (5 + 1)
- str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1,
- ASPATH_STR_DEFAULT_LEN);
+ str_size = ASPATH_STR_DEFAULT_LEN;
str_buf = XMALLOC (MTYPE_AS_STR, str_size);
while (seg)
@@ -575,32 +560,24 @@
return NULL;
}
- /* We might need to increase str_buf, particularly if path has
- * differing segments types, our initial guesstimate above will
- * have been wrong. need 5 chars for ASN, a seperator each and
- * potentially two segment delimiters, plus a space between each
- * segment and trailing zero.
- *
- * This may need to revised if/when significant numbers of
- * ASNs >= 100000 are assigned and in-use on the internet...
- */
-#define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1)
- if ( (len + SEGMENT_STR_LEN(seg)) > str_size)
- {
- str_size = len + SEGMENT_STR_LEN(seg);
- str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size);
- }
-#undef ASN_STR_LEN
-#undef SEGMENT_STR_LEN
-
if (seg->type != AS_SEQUENCE)
- len += snprintf (str_buf + len, str_size - len,
- "%c",
- aspath_delimiter_char (seg->type, AS_SEG_START));
+ {
+ aspath_make_str_big_enough (len, &str_buf, &str_size, 1); /* %c */
+ len += snprintf (str_buf + len, str_size - len,
+ "%c",
+ aspath_delimiter_char (seg->type, AS_SEG_START));
+ }
/* write out the ASNs, with their seperators, bar the last one*/
for (i = 0; i < seg->length; i++)
{
+#define APPROX_DIG_CNT(x) (x < 100000U ? 5 : 10)
+ /* %u + %c + %c + " " (last two are below loop) */
+ aspath_make_str_big_enough (len,
+ &str_buf,
+ &str_size,
+ APPROX_DIG_CNT(seg->as[i]) + 1 + 1 + 1);
+
len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]);
if (i < (seg->length - 1))
@@ -1771,8 +1748,8 @@
static int
aspath_cmp (const void *arg1, const void *arg2)
{
- const struct assegment *seg1 = ((struct aspath *)arg1)->segments;
- const struct assegment *seg2 = ((struct aspath *)arg2)->segments;
+ const struct assegment *seg1 = ((const struct aspath *)arg1)->segments;
+ const struct assegment *seg2 = ((const struct aspath *)arg2)->segments;
while (seg1 || seg2)
{