SO_REUSEPORT on linux

Question

Hi

I want to know if SO_REUSEPORT option is enabled in LINUX 2.6 or not ??

If I try to use it and compile my code I get following error

01.c:72: error: `SO_REUSEPORT' undeclared (first use in this function)
01.c:72: error: (Each undeclared identifier is reported only once
01.c:72: error: for each function it appears in.)

Using the above option I guess I can bind two different sockets to same IPADRESS and PORT NUMBER

Answer 1

From /usr/include/asm-generic/socket.h:

/* For setsockopt(2) */
#define SOL_SOCKET      1

#define SO_DEBUG        1
#define SO_REUSEADDR    2
#define SO_TYPE         3
#define SO_ERROR        4
#define SO_DONTROUTE    5
#define SO_BROADCAST    6
#define SO_SNDBUF       7
#define SO_RCVBUF       8
#define SO_SNDBUFFORCE  32
#define SO_RCVBUFFORCE  33
#define SO_KEEPALIVE    9
#define SO_OOBINLINE    10
#define SO_NO_CHECK     11
#define SO_PRIORITY     12
#define SO_LINGER       13
#define SO_BSDCOMPAT    14
/* To add :#define SO_REUSEPORT 15 */

Hmmm. Looks like it's undefined or on the last stages of being depreciated.

Here's what a post on KernelTrap says:

On Linux, SO_REUSEADDR provide most of what SO_REUSEPORT provides on BSD.

In any case, there is absolutely no point in creating multiple TCP listeners.
Multiple threads can accept() on the same listener - at the same time.
--
Rémi Denis-Courmont
http://www.remlab.net/