Merge branch 'feature/lwip_fstat' into 'master'

lw-ip: Add partial fstat vfs support to set st_mode

Closes IDFGH-5459

See merge request espressif/esp-idf!14854

components/lwip/port/esp32/vfs_lwip.c

@@ -70,13 +70,25 @@ static int lwip_ioctl_r_wrapper(int fd, int cmd, va_list args)
     return lwip_ioctl(fd, cmd, va_arg(args, void *));
 }
 
+static int lwip_fstat(int fd, struct stat * st)
+{
+    if (st == NULL || fd < LWIP_SOCKET_OFFSET || fd > (MAX_FDS - 1)) {
+        errno = EBADF;
+        return -1;
+    }
+    memset(st, 0, sizeof(*st));
+    /* set the stat mode to socket type */
+    st->st_mode = S_IFSOCK;
+    return 0;
+}
+
 void esp_vfs_lwip_sockets_register(void)
 {
     esp_vfs_t vfs = {
         .flags = ESP_VFS_FLAG_DEFAULT,
         .write = &lwip_write,
         .open = NULL,
-        .fstat = NULL,
+        .fstat = &lwip_fstat,
         .close = &lwip_close,
         .read = &lwip_read,
         .fcntl = &lwip_fcntl_r_wrapper,

components/vfs/test/test_vfs_lwip.c

@@ -0,0 +1,37 @@
+// Copyright 2021 Espressif Systems (Shanghai) CO LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <unistd.h>
+#include <sys/fcntl.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include "unity.h"
+#include "test_utils.h"
+
+TEST_CASE("fstat() sets st_mode to socket type", "[vfs][lwip]")
+{
+    test_case_uses_tcpip();
+    int socket_fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+    struct stat stat = { 0 };
+    fstat(socket_fd, &stat);
+
+    TEST_ASSERT_TRUE(S_ISSOCK(stat.st_mode));
+    TEST_ASSERT_FALSE(S_ISBLK(stat.st_mode));
+    TEST_ASSERT_FALSE(S_ISCHR(stat.st_mode));
+    TEST_ASSERT_FALSE(S_ISDIR(stat.st_mode));
+    TEST_ASSERT_FALSE(S_ISREG(stat.st_mode));
+    TEST_ASSERT_FALSE(S_ISLNK(stat.st_mode));
+
+    close(socket_fd);
+}