[PATCH mptcp-next v11 01/11] selftests: mptcp: sockopt: reseed RNG after fork

From: Geliang Tang <[email protected]>

xfork() does not reseed the RNG in the child, so server and client
processes use the same rand() sequence. Restore the per-fork reseed
from mptcp_inq.c by calling init_rng() in the child, ensuring
independent random values for buffer contents and transfer sizes.

These codes are from mptcp_inq.c.

Signed-off-by: Geliang Tang <[email protected]>
---
 tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
index b6e58d936ebe..05afe8dd1381 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
@@ -128,6 +128,8 @@ struct so_state {
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 #endif
 
+static void init_rng(void);
+
 static void __noreturn die_perror(const char *msg)
 {
 	perror(msg);
@@ -799,6 +801,8 @@ static pid_t xfork(void)
 
 	if (p < 0)
 		die_perror("fork");
+	else if (p == 0)
+		init_rng();
 
 	return p;
 }
-- 
2.53.0