udplite: Protection against coverage value wrap-around

This patch clamps the cscov setsockopt values to a maximum of 0xFFFF.

Setsockopt values greater than 0xffff can cause an unwanted
wrap-around.  Further, IPv6 jumbograms are not supported (RFC 3838,
3.5), so that values greater than 0xffff are not even useful.

Further changes: fixed a typo in the documentation.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gerrit Renker 2008-07-21 13:35:08 -07:00 committed by David S. Miller
parent 6579e57b31
commit 47112e25da
2 changed files with 5 additions and 1 deletions

View File

@ -148,7 +148,7 @@
getsockopt(sockfd, SOL_SOCKET, SO_NO_CHECK, &value, ...);
is meaningless (as in TCP). Packets with a zero checksum field are
illegal (cf. RFC 3828, sec. 3.1) will be silently discarded.
illegal (cf. RFC 3828, sec. 3.1) and will be silently discarded.
4) Fragmentation

View File

@ -1325,6 +1325,8 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
return -ENOPROTOOPT;
if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
val = 8;
else if (val > USHORT_MAX)
val = USHORT_MAX;
up->pcslen = val;
up->pcflag |= UDPLITE_SEND_CC;
break;
@ -1337,6 +1339,8 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
return -ENOPROTOOPT;
if (val != 0 && val < 8) /* Avoid silly minimal values. */
val = 8;
else if (val > USHORT_MAX)
val = USHORT_MAX;
up->pcrlen = val;
up->pcflag |= UDPLITE_RECV_CC;
break;