stun

commit 9f22bc0a15fc6bb6f61dde681e06500edc266696
parent 419684dcd9ed6ece9200c30438bffb9e9de855cd
Author: sin <sin@2f30.org>
Date:   Sun, 10 Apr 2016 12:38:03 +0100

some comments around readnet()

Diffstat:
M
stun.c
 | 
7
+++++++

1 file changed, 7 insertions(+), 0 deletions(-)
diff --git a/stun.c b/stun.c
@@ -392,6 +392,12 @@ writenet(int fd, unsigned char *pt, int ptlen)
 	return n;
 }
 
+/*
+ * Read one complete packet off the network.  If the payload
+ * length has been tampered with the tag will either not match
+ * or the read will timeout after RCVTIMEO ms.  Timing out is
+ * necessary to make sure the two ends synchronize again.
+ */
 int
 readnet(int fd, unsigned char *pt, int ptlen)
 {
@@ -409,6 +415,7 @@ readnet(int fd, unsigned char *pt, int ptlen)
 		goto err;
 	if ((n = readall(fd, &pkt[noncelen], HDRLEN)) <= 0)
 		goto err;
+	/* if payload len is bogus cap it */
 	if ((ctlen = unpack16(&pkt[noncelen])) > ptlen)
 		ctlen = ptlen;
 	if ((n = readall(fd, &pkt[noncelen + HDRLEN], ctlen + taglen)) <= 0)