Fix socket_ipv4_udp_unbound_loopback_test_linux

Handle "Resource temporarily unavailable" EAGAIN errors with a select
call before calling recvmsg.

Also rename similar helper call from "RecvMsgTimeout" to "RecvTimeout",
because it calls "recv".

PiperOrigin-RevId: 338761695

1 files changed, 14 insertions, 2 deletions

diff --git a/test/syscalls/linux/socket_test_util.cc b/test/syscalls/linux/socket_test_util.cc
index e11792309..a760581b5 100644
--- a/test/syscalls/linux/socket_test_util.cc
+++ b/test/syscalls/linux/socket_test_util.cc
@@ -753,8 +753,7 @@ PosixErrorOr<int> SendMsg(int sock, msghdr* msg, char buf[], int buf_size) {
   return ret;
 }
 
-PosixErrorOr<int> RecvMsgTimeout(int sock, char buf[], int buf_size,
-                                 int timeout) {
+PosixErrorOr<int> RecvTimeout(int sock, char buf[], int buf_size, int timeout) {
   fd_set rfd;
   struct timeval to = {.tv_sec = timeout, .tv_usec = 0};
   FD_ZERO(&rfd);
@@ -767,6 +766,19 @@ PosixErrorOr<int> RecvMsgTimeout(int sock, char buf[], int buf_size,
   return ret;
 }
 
+PosixErrorOr<int> RecvMsgTimeout(int sock, struct msghdr* msg, int timeout) {
+  fd_set rfd;
+  struct timeval to = {.tv_sec = timeout, .tv_usec = 0};
+  FD_ZERO(&rfd);
+  FD_SET(sock, &rfd);
+
+  int ret;
+  RETURN_ERROR_IF_SYSCALL_FAIL(ret = select(1, &rfd, NULL, NULL, &to));
+  RETURN_ERROR_IF_SYSCALL_FAIL(
+      ret = RetryEINTR(recvmsg)(sock, msg, MSG_DONTWAIT));
+  return ret;
+}
+
 void RecvNoData(int sock) {
   char data = 0;
   struct iovec iov;