Add test case

In support of Internet-5_65.

test/c/timeo

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#ifdef __riscos
+#include "socklib.h"
+#else
+#include "unistd.h"
+#define socketclose(k) close(k)
+#endif
+#include "sys/errno.h"
+#include "sys/socket.h"
+#include "netinet/in.h"
+#include "arpa/inet.h"
+
+/* Purpose: open a socket, give it a receive timeout, trigger
+ *          a receive for which no response is expected, see
+ *          if the timeout fires
+ *
+ * RISC OS: cc -o test timeo.c -Wp -ITCPIPLibs: -lTCPIPLibs:socklib5.o -lTCPIPLibs:inetlib.o -lCLib:stubs.o
+ *          run test
+ * FreeBSD: cc -o test timeo.c -Wno-pointer-sign
+ *          ./test
+ */
+static void showtimeout(int s)
+{
+	struct timeval t;
+	int result, len = sizeof(t);
+
+	result = getsockopt(s, SOL_SOCKET, SO_RCVTIMEO, (void *)&t, &len);
+	if (result < 0)
+	{
+		printf("timeout is unreadable\n");
+		return;
+	}
+	if (t.tv_sec || t.tv_usec)
+	{
+		printf("timeout is %lds+%ldus\n", t.tv_sec, t.tv_usec);
+	}
+	else
+	{
+		printf("timeout is unset\n");
+	}
+}
+
+int main(void)
+{
+	int s = -1, result;
+	struct timeval timeout;
+	struct sockaddr_in sa;
+	char data[64];
+	clock_t start, end;
+
+	errno = 0;
+
+	s = socket(PF_INET, SOCK_STREAM, 0);
+	printf("socket() returned %d (errno = %d)\n", s, errno);
+	if (s < 0) goto bad;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sin_family = AF_INET;
+	sa.sin_port = htons(80);
+	inet_aton("91.203.57.172" /* riscosopen.org */, &sa.sin_addr); 
+	result = connect(s, (const struct sockaddr *)&sa, sizeof(sa));
+	printf("connect() returned %d (errno = %d)\n", result, errno);
+	if (result != 0) goto bad;
+
+	/* Before, try set, after */
+	showtimeout(s);
+
+	timeout.tv_sec = 10;
+	timeout.tv_usec = 0;
+	result = setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, (const void *)&timeout, sizeof(struct timeval));
+	printf("setsockopt(SO_RCVTIMEO) returned %d (errno = %d)\n", result, errno);
+	if (result != 0) goto bad;
+
+	showtimeout(s);
+
+	/* Don't request anything, just wait for data to never come */
+	start = clock();
+	result = recv(s, data, sizeof(data), 0);
+	end = clock();
+	printf("recv() returned %d (errno = %d) "
+	       "after waiting for %lfs\n", result, errno, (double)(end - start) / (double)CLOCKS_PER_SEC);
+
+	socketclose(s);
+
+	return 0;
+bad:
+	if (s != -1) socketclose(s);
+	exit(EXIT_FAILURE);
+}