Enhance sock_addr_local syscall (#1320)

Slightly change the __wasi_sock_addr_local interface - since we already have
a `__wasi_addr_t` structure which is an union, there's no need for passing the
length around - the address buffer will always have the right length (i.e. max
of all address families).

core/shared/platform/common/posix/posix_socket.c

@@ -270,5 +270,54 @@ os_socket_addr_resolve(const char *host, const char *service,
     *max_info_size = pos;
     freeaddrinfo(result);
 
+    return BHT_OK;
+}
+
+int
+os_socket_addr_local(bh_socket_t socket, uint8_t *buf, size_t buflen,
+                     uint16_t *port, uint8_t *is_ipv4)
+{
+    struct sockaddr_storage addr_storage = { 0 };
+    socklen_t addr_len = sizeof(addr_storage);
+    int ret;
+
+    assert(buf);
+    assert(is_ipv4);
+    assert(port);
+
+    ret = getsockname(socket, (struct sockaddr *)&addr_storage, &addr_len);
+
+    if (ret != BHT_OK) {
+        return BHT_ERROR;
+    }
+
+    switch (addr_storage.ss_family) {
+        case AF_INET:
+        {
+            struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr_storage;
+
+            assert(buflen >= sizeof(addr_in->sin_addr));
+            *port = ntohs(addr_in->sin_port);
+            memcpy(buf, &addr_in->sin_addr, sizeof(addr_in->sin_addr));
+            *is_ipv4 = true;
+            break;
+        }
+        case AF_INET6:
+        {
+            struct sockaddr_in6 *addr_in = (struct sockaddr_in6 *)&addr_storage;
+            assert(buflen >= sizeof(addr_in->sin6_addr));
+            *port = ntohs(addr_in->sin6_port);
+
+            for (int i = 0; i < 8; i++) {
+                ((uint16_t *)buf)[i] =
+                    ntohs(((uint16_t *)&addr_in->sin6_addr)[i]);
+            }
+            *is_ipv4 = false;
+            break;
+        }
+        default:
+            return BHT_ERROR;
+    }
+
     return BHT_OK;
 }

core/shared/platform/include/platform_api_extension.h

@@ -374,6 +374,25 @@ os_socket_addr_resolve(const char *host, const char *service,
                        bh_addr_info_t *addr_info, size_t addr_info_size,
                        size_t *max_info_size);
 
+/**
+ * Returns an binary address and a port of the local socket
+ *
+ * @param socket the local socket
+ *
+ * @param buf buffer to store the address
+ *
+ * @param buflen length of the buf buffer
+ *
+ * @param port a buffer for storing socket's port
+ *
+ * @param is_ipv4 a buffer for storing information about the address family
+ *
+ * @return On success, returns 0; otherwise, it returns -1.
+ */
+int
+os_socket_addr_local(bh_socket_t socket, uint8_t *buf, size_t buflen,
+                     uint16_t *port, uint8_t *is_ipv4);
+
 #ifdef __cplusplus
 }
 #endif

core/shared/platform/linux-sgx/sgx_socket.c

@@ -105,7 +105,7 @@ htonl(uint32 value)
     return value;
 }
 
-static uint32
+uint32
 ntohl(uint32 value)
 {
     return htonl(value);
@@ -632,4 +632,13 @@ os_socket_addr_resolve(const char *host, const char *service,
     return BHT_ERROR;
 }
 
+int
+os_socket_addr_local(bh_socket_t socket, uint8_t *buf, size_t buflen,
+                     uint16_t *port, uint8_t *is_ipv4)
+{
+    errno = ENOSYS;
+
+    return BHT_ERROR;
+}
+
 #endif

core/shared/platform/linux-sgx/sgx_socket.h

@@ -95,6 +95,9 @@ struct sockaddr {
     char sa_data[14];             /* Address data.  */
 };
 
+uint32_t
+ntohl(uint32_t value);
+
 int
 socket(int domain, int type, int protocol);
 

core/shared/platform/windows/win_socket.c

@@ -171,5 +171,14 @@ os_socket_addr_resolve(const char *host, const char *service,
 {
     errno = ENOSYS;
 
+    return BHT_ERROR;
+}
+
+int
+os_socket_addr_local(bh_socket_t socket, uint8_t *buf, size_t buflen,
+                     uint16_t *port, uint8_t *is_ipv4)
+{
+    errno = ENOSYS;
+
     return BHT_ERROR;
 }