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-rw-r--r--contrib/tcpdump/print-bgp.c47
1 files changed, 39 insertions, 8 deletions
diff --git a/contrib/tcpdump/print-bgp.c b/contrib/tcpdump/print-bgp.c
index d6377fb..3610b25 100644
--- a/contrib/tcpdump/print-bgp.c
+++ b/contrib/tcpdump/print-bgp.c
@@ -622,6 +622,26 @@ trunc:
return -2;
}
+/*
+ * As I remember, some versions of systems have an snprintf() that
+ * returns -1 if the buffer would have overflowed. If the return
+ * value is negative, set buflen to 0, to indicate that we've filled
+ * the buffer up.
+ *
+ * If the return value is greater than buflen, that means that
+ * the buffer would have overflowed; again, set buflen to 0 in
+ * that case.
+ */
+#define UPDATE_BUF_BUFLEN(buf, buflen, strlen) \
+ if (strlen<0) \
+ buflen=0; \
+ else if ((u_int)strlen>buflen) \
+ buflen=0; \
+ else { \
+ buflen-=strlen; \
+ buf+=strlen; \
+ }
+
static int
decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen)
{
@@ -632,11 +652,13 @@ decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen)
tlen=plen;
pptr+=2;
TCHECK2(pptr[0],15);
+ buf[0]='\0';
strlen=snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u",
bgp_vpn_rd_print(pptr),
EXTRACT_16BITS(pptr+8),
EXTRACT_16BITS(pptr+10),
EXTRACT_24BITS(pptr+12)>>4); /* the label is offsetted by 4 bits so lets shift it right */
+ UPDATE_BUF_BUFLEN(buf, buflen, strlen);
pptr+=15;
tlen-=15;
@@ -652,23 +674,32 @@ decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen)
switch(tlv_type) {
case 1:
- strlen+=snprintf(buf+strlen,buflen-strlen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
- tlv_type,
- tlv_len);
+ if (buflen!=0) {
+ strlen=snprintf(buf,buflen, "\n\t\tcircuit status vector (%u) length: %u: 0x",
+ tlv_type,
+ tlv_len);
+ UPDATE_BUF_BUFLEN(buf, buflen, strlen);
+ }
ttlv_len=ttlv_len/8+1; /* how many bytes do we need to read ? */
while (ttlv_len>0) {
TCHECK(pptr[0]);
- strlen+=snprintf(buf+strlen,buflen-strlen, "%02x",*pptr++);
+ if (buflen!=0) {
+ strlen=snprintf(buf,buflen, "%02x",*pptr++);
+ UPDATE_BUF_BUFLEN(buf, buflen, strlen);
+ }
ttlv_len--;
}
break;
default:
- snprintf(buf+strlen,buflen-strlen, "\n\t\tunknown TLV #%u, length: %u",
- tlv_type,
- tlv_len);
+ if (buflen!=0) {
+ strlen=snprintf(buf,buflen, "\n\t\tunknown TLV #%u, length: %u",
+ tlv_type,
+ tlv_len);
+ UPDATE_BUF_BUFLEN(buf, buflen, strlen);
+ }
break;
}
- tlen-=(tlv_len<<3); /* the tlv-length is expressed in bits so lets shift it tright */
+ tlen-=(tlv_len<<3); /* the tlv-length is expressed in bits so lets shift it right */
}
return plen+2;
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