[PATCH v2 lksctp-tools] testlib: improve test_bind function

[Jianwen Ji <jijianwen@gmail.com>]

Try to bind again if the errno is EADDRINUSE.
Some tests failed to run sometimes, here is one snapshot:

   ...

   test_sockopt.c 25 PASS : setsockopt(SCTP_PEER_ADDR_PARAMS) - one-to-many style invalid hb demand
   test_sockopt.c 26 BROK : bind: Address already in use
   DUMP_CORE ../../src/testlib/sctputil.h: 145

   ...

   test_1_to_1_sendmsg.c 10 PASS : sendmsg() on a closed association - EPIPE
   test_1_to_1_sendmsg.c 11 BROK : bind: Address already in use
   DUMP_CORE ../../src/testlib/sctputil.h: 145

The reason is that it closed a socket and then created a new socket
to bind the same socket address as before, which was not released
yet.

Signed-off-by: Jianwen Ji <jijianwen@gmail.com>
---
 src/testlib/sctputil.h | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/testlib/sctputil.h b/src/testlib/sctputil.h
index 9dbabd4..5b807c7 100644
--- a/src/testlib/sctputil.h
+++ b/src/testlib/sctputil.h
@@ -54,6 +54,7 @@
 #endif
 
 #include <string.h>
+#include <unistd.h>
 
 typedef union {
 	struct sockaddr_in v4;	
@@ -72,6 +73,10 @@ typedef union {
 #endif
 #define SCTP_TESTPORT_2 (SCTP_TESTPORT_1+1)
 
+#ifndef MAX_BIND_RETRYS
+#define MAX_BIND_RETRYS 10
+#endif
+
 #define SCTP_IP_BCAST  	htonl(0xffffffff)
 #define SCTP_IP_LOOPBACK  htonl(0x7f000001)
 
@@ -140,9 +145,22 @@ static inline int test_socket(int domain, int type, int protocol)
 
 static inline int test_bind(int sk, struct sockaddr *addr, socklen_t addrlen)
 {
-	int error = bind(sk, addr, addrlen);
-        if (-1 = error)
-                tst_brkm(TBROK, tst_exit, "bind: %s", strerror(errno));
+	int error = 0, i = 0;
+
+	do {
+		if (i > 0) sleep(1); /* sleep a while before new try... */
+
+		error = bind(sk, addr, addrlen);
+		if (-1 = error && errno != EADDRINUSE) {
+			tst_brkm(TBROK, tst_exit, "bind: %s", strerror(errno));
+		}
+
+		i++;
+		if (i >= MAX_BIND_RETRYS) {
+			tst_brkm(TBROK, tst_exit, "bind: %s", strerror(errno));
+		}
+	} while (error < 0 && i < MAX_BIND_RETRYS);
+
 	return error;
 }
 
-- 
2.14.5