The incoming packet address is checked for a match against the local interface addresses to avoid processing its own packets. The IPv4 implementation used the same code but only initialized 4 of the 16 bytes of the address in the recv function. The interface initialization code in netsock_set_interfaces set all unused bytes to zero but recv_alfred_packet was modified to use 12 random bytes from the stack.
Both functions must work the same way and first set the address bytes to zero and overwrite the actual used bytes with the address bytes. Otherwise, the result of netsock_set_interfaces for own packets is random in the IPv4 implementation.
Fixes: c7da798113a2 ("alfred: IPv4 multicast distribution support.") Signed-off-by: Sven Eckelmann sven@narfation.org --- Cc: Jonathan Haws jhaws@sdl.usu.edu --- recv.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/recv.c b/recv.c index 59d759c..5ff4bb5 100644 --- a/recv.c +++ b/recv.c @@ -416,6 +416,7 @@ int recv_alfred_packet(struct globals *globals, struct interface *interface,
packet = (struct alfred_tlv *)buf;
+ memset(&alfred_source, 0, sizeof(alfred_source)); if (globals->ipv4mode) { memcpy(&alfred_source, &source4.sin_addr, sizeof(source4.sin_addr)); } else {
Tested By: Jonathan Haws jhaws@sdl.usu.edu
On Mon, 2018-10-29 at 18:05 +0100, Sven Eckelmann wrote:
The incoming packet address is checked for a match against the local interface addresses to avoid processing its own packets. The IPv4 implementation used the same code but only initialized 4 of the 16 bytes of the address in the recv function. The interface initialization code in netsock_set_interfaces set all unused bytes to zero but recv_alfred_packet was modified to use 12 random bytes from the stack.
Both functions must work the same way and first set the address bytes to zero and overwrite the actual used bytes with the address bytes. Otherwise, the result of netsock_set_interfaces for own packets is random in the IPv4 implementation.
Fixes: c7da798113a2 ("alfred: IPv4 multicast distribution support.") Signed-off-by: Sven Eckelmann sven@narfation.org
Cc: Jonathan Haws jhaws@sdl.usu.edu
recv.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/recv.c b/recv.c index 59d759c..5ff4bb5 100644 --- a/recv.c +++ b/recv.c @@ -416,6 +416,7 @@ int recv_alfred_packet(struct globals *globals, struct interface *interface,
packet = (struct alfred_tlv *)buf;
- memset(&alfred_source, 0, sizeof(alfred_source)); if (globals->ipv4mode) { memcpy(&alfred_source, &source4.sin_addr,
sizeof(source4.sin_addr)); } else {
b.a.t.m.a.n@lists.open-mesh.org
-
Jonathan Haws -
Sven Eckelmann