Implement sock_send_to and sock_recv_from system calls (#1457)

samples/socket-api/wasm-src/udp_client.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2022 Amazon.com Inc. or its affiliates. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#ifdef __wasi__
+#include <wasi_socket_ext.h>
+#endif
+
+static void
+init_sockaddr_inet(struct sockaddr_in *addr)
+{
+    /* 127.0.0.1:1234 */
+    addr->sin_family = AF_INET;
+    addr->sin_port = htons(1234);
+    addr->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+}
+
+static void
+init_sockaddr_inet6(struct sockaddr_in6 *addr)
+{
+    /* [::1]:1234 */
+    addr->sin6_family = AF_INET6;
+    addr->sin6_port = htons(1234);
+    addr->sin6_addr = in6addr_loopback;
+}
+
+int
+main(int argc, char *argv[])
+{
+    int socket_fd, ret, af;
+    char buffer[1024] = { 0 };
+    socklen_t serverlen;
+    struct sockaddr_storage server_address = { 0 };
+    const char *message = "Hello from client";
+
+    if (argc > 1 && strcmp(argv[1], "inet6") == 0) {
+        af = AF_INET6;
+        init_sockaddr_inet6((struct sockaddr_in6 *)&server_address);
+        serverlen = sizeof(struct sockaddr_in6);
+    }
+    else {
+        af = AF_INET;
+        init_sockaddr_inet((struct sockaddr_in *)&server_address);
+        serverlen = sizeof(struct sockaddr_in);
+    }
+
+    printf("[Client] Create socket\n");
+    socket_fd = socket(af, SOCK_DGRAM, 0);
+    if (socket_fd == -1) {
+        perror("Create socket failed");
+        return EXIT_FAILURE;
+    }
+
+    printf("[Client] Client send\n");
+    ret = sendto(socket_fd, message, strlen(message), 0,
+                 (struct sockaddr *)&server_address, serverlen);
+    if (ret < 0) {
+        close(socket_fd);
+        perror("Send failed");
+        return EXIT_FAILURE;
+    }
+
+    printf("[Client] Client receive\n");
+    serverlen = sizeof(server_address);
+    ret = recvfrom(socket_fd, buffer, sizeof(buffer), 0,
+                   (struct sockaddr *)&server_address, &serverlen);
+
+    if (ret > 0) {
+        printf("[Client] Buffer recieved: %s\n", buffer);
+    }
+
+    close(socket_fd);
+    printf("[Client] BYE \n");
+    return EXIT_SUCCESS;
+}