Crash_Override/OVMS3-idf
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

lwip: Check for underflow in FD_SET()/FD_GET()

Browse source 
select() only works with LWIP sockets which have a high LWIP_SOCKET_OFFSET,
so chance of accidental underflow is high.
This commit is contained in:
Angus Gratton 2017-10-04 10:41:09 +11:00 committed by Angus Gratton
parent 3f83914f7a
commit 541493d877
1 changed files with 2 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
components/lwip/include/lwip/lwip/sockets.h
View file

@ -431,9 +431,9 @@ typedef struct ip_mreq {
/* Make FD_SETSIZE match NUM_SOCKETS in socket.c */
#define FD_SETSIZE MEMP_NUM_NETCONN
#define FDSETSAFESET(n, code) do { \
if (((n) - LWIP_SOCKET_OFFSET < MEMP_NUM_NETCONN) && (((int)(n) - LWIP_SOCKET_OFFSET) >= 0)) { \
if (n >= LWIP_SOCKET_OFFSET && ((n) - LWIP_SOCKET_OFFSET < MEMP_NUM_NETCONN) && (((int)(n) - LWIP_SOCKET_OFFSET) >= 0)) { \
code; }} while(0)
#define FDSETSAFEGET(n, code) (((n) - LWIP_SOCKET_OFFSET < MEMP_NUM_NETCONN) && (((int)(n) - LWIP_SOCKET_OFFSET) >= 0) ?\
#define FDSETSAFEGET(n, code) (n >= LWIP_SOCKET_OFFSET && ((n) - LWIP_SOCKET_OFFSET < MEMP_NUM_NETCONN) && (((int)(n) - LWIP_SOCKET_OFFSET) >= 0) ?\
(code) : 0)
#define FD_SET(n, p) FDSETSAFESET(n, (p)->fd_bits[((n)-LWIP_SOCKET_OFFSET)/8] |= (1 << (((n)-LWIP_SOCKET_OFFSET) & 7)))
#define FD_CLR(n, p) FDSETSAFESET(n, (p)->fd_bits[((n)-LWIP_SOCKET_OFFSET)/8] &= ~(1 << (((n)-LWIP_SOCKET_OFFSET) & 7)))