[HUST CSE][components][net][sal] harden socket lifetime and close handling

components/net/sal/impl/af_inet_at.c

@@ -38,6 +38,7 @@ static int at_poll(struct dfs_file *file, struct rt_pollreq *req)
     }
 
     sock = at_get_socket((int)sal_sock->user_data);
+    sal_socket_put(sal_sock);
     if (sock != NULL)
     {
         rt_base_t level;

components/net/sal/impl/af_inet_lwip.c

@@ -258,6 +258,7 @@ static int inet_poll(struct dfs_file *file, struct rt_pollreq *req)
     }
 
     sock = lwip_tryget_socket((int)(size_t)sal_sock->user_data);
+    sal_socket_put(sal_sock);
     if (sock != NULL)
     {
         rt_base_t level;

components/net/sal/impl/proto_mbedtls.c

@@ -96,6 +96,7 @@ int mbedtls_net_send_cb(void *ctx, const unsigned char *buf, size_t len)
 
     /* Register scoket sendto option to TLS send data callback */
     ret = pf->skt_ops->sendto((int) sock->user_data, (void *)buf, len, 0, RT_NULL, RT_NULL);
+    sal_socket_put(sock);
     if (ret < 0)
     {
 #ifdef RT_USING_DFS
@@ -133,6 +134,7 @@ int mbedtls_net_recv_cb( void *ctx, unsigned char *buf, size_t len)
 
     /* Register scoket recvfrom option to TLS recv data callback */
     ret = pf->skt_ops->recvfrom((int) sock->user_data, (void *)buf, len, 0, RT_NULL, RT_NULL);
+    sal_socket_put(sock);
     if (ret < 0)
     {
 #ifdef RT_USING_DFS
@@ -199,24 +201,13 @@ static int mbedtls_connect(void *sock)
 
 static int mbedtls_closesocket(void *sock)
 {
-    struct sal_socket *ssock;
-    int socket;
-
     if (sock == RT_NULL)
     {
         return 0;
     }
 
-    socket = ((MbedTLSSession *) sock)->server_fd.fd;
-    ssock = sal_get_socket(socket);
-    if (ssock == RT_NULL)
-    {
-        return -1;
-    }
-
     /* Close TLS client session, and clean user-data in SAL socket */
     mbedtls_client_close((MbedTLSSession *) sock);
-    ssock->user_data_tls = RT_NULL;
 
     return 0;
 }

components/net/sal/include/sal_low_lvl.h

@@ -14,6 +14,7 @@
 #define SAL_LOW_LEVEL_H__
 
 #include <rtdevice.h>
+#include <ipc/completion.h>
 
 #ifdef SAL_USING_POSIX
 #include <dfs_file.h>
@@ -30,6 +31,14 @@ typedef uint32_t socklen_t;
 /* SAL socket magic word */
 #define SAL_SOCKET_MAGIC               0x5A10
 
+enum sal_socket_state
+{
+    SAL_SOCKET_STATE_INIT = 0,
+    SAL_SOCKET_STATE_OPEN,             /* visible in socket table */
+    SAL_SOCKET_STATE_CLOSING,          /* detached, waiting refcnt drop */
+    SAL_SOCKET_STATE_CLOSED,           /* ready for cache reuse */
+};
+
 /* The maximum number of sockets structure */
 #ifndef SAL_SOCKETS_NUM
 #define SAL_SOCKETS_NUM                DFS_FD_MAX
@@ -63,6 +72,10 @@ struct sal_socket
 #ifdef SAL_USING_TLS
     void *user_data_tls;               /* user-specific TLS data */
 #endif
+    rt_atomic_t refcnt;                /* in-flight SAL references */
+    rt_uint8_t state;                  /* socket lifecycle state */
+    struct rt_completion close_completion; /* wake close waiter */
+    struct sal_socket *next_free;      /* internal cache link */
 };
 
 /* network interface socket opreations */
@@ -109,8 +122,8 @@ struct sal_proto_family
 
 /* SAL(Socket Abstraction Layer) initialize */
 int sal_init(void);
-/* Get SAL socket object by socket descriptor */
 struct sal_socket *sal_get_socket(int sock);
+void sal_socket_put(struct sal_socket *sock);
 
 /* check SAL socket netweork interface device internet status */
 int sal_check_netdev_internet_up(struct netdev *netdev);