Enable socket-api `recvmsg()` and `sendmsg()` (#1042)

Implement socket-api `recvmsg()` and `sendmsg()` for wasm app,
add sample and update document.

.gitignore

@@ -23,4 +23,6 @@ product-mini/platforms/linux-sgx/enclave-sample/iwasm
 build_out
 tests/wamr-test-suites/workspace
 
-!/test-tools/wamr-ide/VSCode-Extension/.vscode
+!/test-tools/wamr-ide/VSCode-Extension/.vscode
+
+samples/socket-api/wasm-src/inc/pthread.h

core/iwasm/libraries/lib-socket/inc/wasi_socket_ext.h

@@ -80,6 +80,12 @@ connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
 int
 listen(int sockfd, int backlog);
 
+ssize_t
+recvmsg(int sockfd, struct msghdr *msg, int flags);
+
+ssize_t
+sendmsg(int sockfd, const struct msghdr *msg, int flags);
+
 int
 socket(int domain, int type, int protocol);
 #endif

core/iwasm/libraries/lib-socket/src/wasi/wasi_socket_ext.c

@@ -7,6 +7,7 @@
 #include <errno.h>
 #include <netinet/in.h>
 #include <string.h>
+#include <stdlib.h>
 #include <sys/socket.h>
 #include <wasi/api.h>
 #include <wasi_socket_ext.h>
@@ -126,6 +127,10 @@ connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
     __wasi_addr_t wasi_addr = { 0 };
     __wasi_errno_t error;
 
+    if (NULL == addr) {
+        HANDLE_ERROR(__WASI_ERRNO_INVAL)
+    }
+
     error = sockaddr_to_wasi_addr(addr, addrlen, &wasi_addr);
     HANDLE_ERROR(error)
 
@@ -143,6 +148,79 @@ listen(int sockfd, int backlog)
     return __WASI_ERRNO_SUCCESS;
 }
 
+ssize_t
+recvmsg(int sockfd, struct msghdr *msg, int flags)
+{
+    // Prepare input parameters.
+    __wasi_iovec_t *ri_data = NULL;
+    size_t i = 0;
+    size_t ro_datalen;
+    __wasi_roflags_t ro_flags;
+
+    if (NULL == msg) {
+        HANDLE_ERROR(__WASI_ERRNO_INVAL)
+    }
+
+    // Validate flags.
+    if (flags != 0) {
+        HANDLE_ERROR(__WASI_ERRNO_NOPROTOOPT)
+    }
+
+    // __wasi_ciovec_t -> struct iovec
+    if (!(ri_data = malloc(sizeof(__wasi_iovec_t) * msg->msg_iovlen))) {
+        HANDLE_ERROR(__WASI_ERRNO_NOMEM)
+    }
+
+    for (i = 0; i < msg->msg_iovlen; i++) {
+        ri_data[i].buf = msg->msg_iov[i].iov_base;
+        ri_data[i].buf_len = msg->msg_iov[i].iov_len;
+    }
+
+    // Perform system call.
+    __wasi_errno_t error = __wasi_sock_recv(sockfd, ri_data, msg->msg_iovlen, 0,
+                                            &ro_datalen, &ro_flags);
+    free(ri_data);
+    HANDLE_ERROR(error)
+
+    return ro_datalen;
+}
+
+ssize_t
+sendmsg(int sockfd, const struct msghdr *msg, int flags)
+{
+    // Prepare input parameters.
+    __wasi_ciovec_t *si_data = NULL;
+    size_t so_datalen = 0;
+    size_t i = 0;
+
+    if (NULL == msg) {
+        HANDLE_ERROR(__WASI_ERRNO_INVAL)
+    }
+
+    // This implementation does not support any flags.
+    if (flags != 0) {
+        HANDLE_ERROR(__WASI_ERRNO_NOPROTOOPT)
+    }
+
+    // struct iovec -> __wasi_ciovec_t
+    if (!(si_data = malloc(sizeof(__wasi_ciovec_t) * msg->msg_iovlen))) {
+        HANDLE_ERROR(__WASI_ERRNO_NOMEM)
+    }
+
+    for (i = 0; i < msg->msg_iovlen; i++) {
+        si_data[i].buf = msg->msg_iov[i].iov_base;
+        si_data[i].buf_len = msg->msg_iov[i].iov_len;
+    }
+
+    // Perform system call.
+    __wasi_errno_t error =
+        __wasi_sock_send(sockfd, si_data, msg->msg_iovlen, 0, &so_datalen);
+    free(si_data);
+    HANDLE_ERROR(error)
+
+    return so_datalen;
+}
+
 int
 socket(int domain, int type, int protocol)
 {

samples/socket-api/CMakeLists.txt

@@ -89,14 +89,17 @@ ExternalProject_Add(wasm-app
   INSTALL_COMMAND   ${CMAKE_COMMAND} -E copy
                       tcp_client.wasm ${CMAKE_CURRENT_SOURCE_DIR}/build
                       tcp_server.wasm ${CMAKE_CURRENT_SOURCE_DIR}/build
-                      tcp_client.wasm.dump ${CMAKE_CURRENT_SOURCE_DIR}/build
-                      tcp_server.wasm.dump ${CMAKE_CURRENT_SOURCE_DIR}/build
+                      send_recv.wasm ${CMAKE_CURRENT_SOURCE_DIR}/build
 )
 
 add_executable(tcp_server ${CMAKE_CURRENT_SOURCE_DIR}/wasm-src/tcp_server.c)
 target_link_libraries(tcp_server pthread)
+
 add_executable(tcp_client ${CMAKE_CURRENT_SOURCE_DIR}/wasm-src/tcp_client.c)
 
+add_executable(send_recv ${CMAKE_CURRENT_SOURCE_DIR}/wasm-src/send_recv.c)
+target_link_libraries(send_recv pthread)
+
 ############################################
 ## Build iwasm with wasi and pthread support
 ############################################

samples/socket-api/README.md

@@ -1,5 +1,4 @@
-"socket-api" sample introduction
-================================
+# "socket-api" sample introduction
 
 This sample demonstrates how to use WAMR socket-api to develop wasm network applications.
 Two wasm applications are provided: tcp-server and tcp-client, and this sample demonstrates
@@ -19,26 +18,30 @@ cmake ..
 make
 ```
 
-The file `tcp_server.wasm`, `tcp_client.wasm` and `iwasm` will be created.
-And also file `tcp_server` and `tcp_client` of native version are created.
+`iwasm` and three Wasm modules, `tcp_server.wasm`, `tcp_client.wasm`, `send_recv.wasm`
+will be generated. And their corresponding native version, `tcp_server`,
+`tcp_client`, `send_recv` are generated too.
 
-Note that iwasm is built with libc-wasi and lib-pthread enabled.
+> Note that iwasm is built with libc-wasi and lib-pthread enabled.
 
 ## Run workload
 
 Start the tcp server, which opens port 1234 and waits for clients to connect.
+
 ```bash
 cd build
 ./iwasm --addr-pool=0.0.0.0/15 tcp_server.wasm
 ```
 
 Start the tcp client, which connects the server and receives message.
+
 ```bash
 cd build
 ./iwasm --addr-pool=127.0.0.1/15 tcp_client.wasm
 ```
 
 The output of client is like:
+
 ```bash
 [Client] Create socket
 [Client] Connect socket
@@ -54,4 +57,29 @@ Say Hi from the Server
 [Client] BYE
 ```
 
+`send_recv.wasm` contains a thread as a server and a thread as a client. They
+send and receive data via 127.0.0.1:1234.
+
+```bash
+$ ./iwasm --addr-pool=127.0.0.1/0  ./send_recv.wasm
+```
+
+The output is:
+
+```bash
+Server is online ...
+Client is running...
+Start receiving.
+Start sending.
+Send 106 bytes successfully!
+Receive 106 bytes successlly!
+Data:
+  The stars shine down
+  It brings us light
+  Light comes down
+  To make us paths
+  It watches us
+  And mourns for us
+```
+
 Refer to [socket api document](../../doc/socket_api.md) for more details.

samples/socket-api/wasm-src/CMakeLists.txt

@@ -78,3 +78,4 @@ endfunction()
 
 compile_with_clang(tcp_server.c)
 compile_with_clang(tcp_client.c)
+compile_with_clang(send_recv.c)

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

@@ -0,0 +1,209 @@
+/*
+ * Copyright (C) 2019 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#ifdef __wasi__
+#include <wasi_socket_ext.h>
+#endif
+
+static pthread_mutex_t lock = { 0 };
+static pthread_cond_t cond = { 0 };
+static bool server_is_ready = false;
+
+void *
+run_as_server(void *arg)
+{
+    int sock = -1, on = 1;
+    struct sockaddr_in addr = { 0 };
+    int addrlen = 0;
+    int new_sock = -1;
+    char *buf[] = {
+        "The stars shine down", "It brings us light", "Light comes down",
+        "To make us paths",     "It watches us",      "And mourns for us",
+    };
+    struct iovec iov[] = {
+        { .iov_base = buf[0], .iov_len = strlen(buf[0]) + 1 },
+        { .iov_base = buf[1], .iov_len = strlen(buf[1]) + 1 },
+        { .iov_base = buf[2], .iov_len = strlen(buf[2]) + 1 },
+        { .iov_base = buf[3], .iov_len = strlen(buf[3]) + 1 },
+        { .iov_base = buf[4], .iov_len = strlen(buf[4]) + 1 },
+        { .iov_base = buf[5], .iov_len = strlen(buf[5]) + 1 },
+    };
+    struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 6 };
+    ssize_t send_len = 0;
+
+    pthread_mutex_lock(&lock);
+    sock = socket(AF_INET, SOCK_STREAM, 0);
+    if (sock < 0) {
+        perror("Create a socket failed");
+        goto RETURN;
+    }
+
+#ifndef __wasi__
+    if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on))) {
+        perror("Setsockopt failed");
+        goto RETURN;
+    }
+#endif
+
+    /* 0.0.0.0:1234 */
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(1234);
+    addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+    addrlen = sizeof(addr);
+    if (bind(sock, (struct sockaddr *)&addr, addrlen) < 0) {
+        perror("Bind failed");
+        goto UNLOCK_SHUTDOWN;
+    }
+
+    if (listen(sock, 0) < 0) {
+        perror("Listen failed");
+        goto UNLOCK_SHUTDOWN;
+    }
+
+    server_is_ready = true;
+    pthread_cond_signal(&cond);
+    pthread_mutex_unlock(&lock);
+
+    printf("Server is online ... \n");
+
+    new_sock = accept(sock, (struct sockaddr *)&addr, (socklen_t *)&addrlen);
+    if (new_sock < 0) {
+        perror("Accept failed");
+        goto SHUTDOWN;
+    }
+
+    printf("Start sending. \n");
+    send_len = sendmsg(new_sock, &msg, 0);
+    if (send_len < 0) {
+        perror("Sendmsg failed");
+        goto SHUTDOWN;
+    }
+    printf("Send %ld bytes successfully!\n", send_len);
+
+SHUTDOWN:
+    shutdown(sock, SHUT_RD);
+    return NULL;
+
+UNLOCK_SHUTDOWN:
+    shutdown(sock, SHUT_RD);
+RETURN:
+    pthread_mutex_unlock(&lock);
+    return NULL;
+}
+
+void *
+run_as_client(void *arg)
+{
+    int sock = -1;
+    struct sockaddr_in addr = { 0 };
+    char buf[256] = { 0 };
+    struct iovec iov = { .iov_base = buf, .iov_len = sizeof(buf) };
+    struct msghdr msg = { .msg_iov = &iov, .msg_iovlen = 1 };
+    ssize_t recv_len = 0;
+
+    pthread_mutex_lock(&lock);
+    while (false == server_is_ready) {
+        pthread_cond_wait(&cond, &lock);
+    }
+    pthread_mutex_unlock(&lock);
+
+    printf("Client is running...\n");
+    sock = socket(AF_INET, SOCK_STREAM, 0);
+    if (sock < 0) {
+        perror("Create a socket failed");
+        goto RETURN;
+    }
+
+    /* 127.0.0.1:1234 */
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(1234);
+    addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+    if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+        perror("Connect failed");
+        goto UNLOCK_SHUTDOWN;
+    }
+
+    printf("Start receiving. \n");
+    recv_len = recvmsg(sock, &msg, 0);
+    if (recv_len < 0) {
+        perror("Recvmsg failed");
+        goto SHUTDOWN;
+    }
+
+    printf("Receive %ld bytes successlly!\n", recv_len);
+    printf("Data:\n");
+
+    uint8_t i = 0;
+    char *s = msg.msg_iov->iov_base;
+    for (i = 0; i < 6; i++) {
+        printf("  %s\n", s);
+        s += strlen(s) + 1;
+    }
+
+SHUTDOWN:
+    shutdown(sock, SHUT_RD);
+    return NULL;
+
+UNLOCK_SHUTDOWN:
+    shutdown(sock, SHUT_RD);
+RETURN:
+    pthread_mutex_unlock(&lock);
+    return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+    pthread_t cs[2] = { 0 };
+    uint8_t i = 0;
+    int ret = EXIT_SUCCESS;
+
+    if (pthread_mutex_init(&lock, NULL)) {
+        perror("Initialize mutex failed");
+        ret = EXIT_FAILURE;
+        goto RETURN;
+    }
+
+    if (pthread_cond_init(&cond, NULL)) {
+        perror("Initialize condition failed");
+        ret = EXIT_FAILURE;
+        goto DESTROY_MUTEX;
+    }
+
+    if (pthread_create(&cs[0], NULL, run_as_server, NULL)) {
+        perror("Create a server thread failed");
+        ret = EXIT_FAILURE;
+        goto DESTROY_COND;
+    }
+
+    if (pthread_create(&cs[1], NULL, run_as_client, NULL)) {
+        perror("Create a client thread failed");
+        ret = EXIT_FAILURE;
+        goto DESTROY_COND;
+    }
+
+    for (i = 0; i < 2; i++) {
+        pthread_join(cs[i], NULL);
+    }
+
+DESTROY_COND:
+    pthread_cond_destroy(&cond);
+DESTROY_MUTEX:
+    pthread_mutex_destroy(&lock);
+RETURN:
+    return ret;
+}