Merge pull request #15161 from brummer-simon/gnrc_tcp-hide_global_variables

gnrc_tcp: Hide remaining global variables

sys/net/gnrc/transport_layer/tcp/gnrc_tcp.c

@@ -49,16 +49,6 @@
  */
 static evtimer_t _tcp_mbox_timer;
 
-/**
- * @brief Head of liked TCB list.
- */
-gnrc_tcp_tcb_t *_list_tcb_head;
-
-/**
- * @brief Mutex for TCB list synchronization.
- */
-mutex_t _list_tcb_lock;
-
 static void _sched_mbox(evtimer_mbox_event_t *event, uint32_t offset,
                         uint16_t type, mbox_t *mbox)
 {
@@ -352,11 +342,7 @@ int gnrc_tcp_ep_from_str(gnrc_tcp_ep_t *ep, const char *str)
 
 int gnrc_tcp_init(void)
 {
-    /* Initialize mutex for TCB list synchronization */
-    mutex_init(&(_list_tcb_lock));
-
     /* Initialize TCB list */
-    _list_tcb_head = NULL;
     _rcvbuf_init();
 
     /* Initialize timers */

sys/net/gnrc/transport_layer/tcp/gnrc_tcp_common.c

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2020 Simon Brummer
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     net_gnrc
+ * @{
+ *
+ * @file
+ * @brief       GNRC TCP common function implementation
+ *
+ * @author      Simon Brummer <simon.brummer@posteo.de>
+ * @}
+ */
+
+#include "internal/common.h"
+
+static tcb_list_t _list = {NULL, MUTEX_INIT};
+
+tcb_list_t *_gnrc_tcp_common_get_tcb_list(void)
+{
+    return &_list;
+}

sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c

@@ -216,8 +216,9 @@ static int _receive(gnrc_pktsnip_t *pkt)
     }
 
     /* Find TCB to for this packet */
-    mutex_lock(&_list_tcb_lock);
+    tcb_list_t *list = _gnrc_tcp_common_get_tcb_list();
-    tcb = _list_tcb_head;
+    mutex_lock(&list->lock);
+    tcb = list->head;
     while (tcb) {
 #ifdef MODULE_GNRC_IPV6
         /* Check if current TCB is fitting for the incoming packet */
@@ -250,7 +251,7 @@ static int _receive(gnrc_pktsnip_t *pkt)
 #endif
         tcb = tcb->next;
     }
-    mutex_unlock(&_list_tcb_lock);
+    mutex_unlock(&list->lock);
 
     /* Call FSM with event RCVD_PKT if a fitting TCB was found */
     /* cppcheck-suppress knownConditionTrueFalse

sys/net/gnrc/transport_layer/tcp/gnrc_tcp_fsm.c

@@ -56,7 +56,8 @@
 static int _is_local_port_in_use(const uint16_t port_number)
 {
     gnrc_tcp_tcb_t *iter = NULL;
-    LL_SEARCH_SCALAR(_list_tcb_head, iter, local_port, port_number);
+    tcb_list_t *list = _gnrc_tcp_common_get_tcb_list();
+    LL_SEARCH_SCALAR(list->head, iter, local_port, port_number);
     return (iter != NULL);
 }
 
@@ -124,6 +125,7 @@ static int _transition_to(gnrc_tcp_tcb_t *tcb, fsm_state_t state)
     DEBUG("_transition_to: %d\n", state);
 
     gnrc_tcp_tcb_t *iter = NULL;
+    tcb_list_t *list = _gnrc_tcp_common_get_tcb_list();
 
     switch (state) {
         case FSM_STATE_CLOSED:
@@ -131,9 +133,9 @@ static int _transition_to(gnrc_tcp_tcb_t *tcb, fsm_state_t state)
             _clear_retransmit(tcb);
 
             /* Remove connection from active connections */
-            mutex_lock(&_list_tcb_lock);
+            mutex_lock(&list->lock);
-            LL_DELETE(_list_tcb_head, tcb);
+            LL_DELETE(list->head, tcb);
-            mutex_unlock(&_list_tcb_lock);
+            mutex_unlock(&list->lock);
 
             /* Free potentially allocated receive buffer */
             _rcvbuf_release_buffer(tcb);
@@ -153,25 +155,25 @@ static int _transition_to(gnrc_tcp_tcb_t *tcb, fsm_state_t state)
             tcb->peer_port = PORT_UNSPEC;
 
             /* Add connection to active connections (if not already active) */
-            mutex_lock(&_list_tcb_lock);
+            mutex_lock(&list->lock);
-            LL_SEARCH(_list_tcb_head, iter, tcb, TCB_EQUAL);
+            LL_SEARCH(list->head, iter, tcb, TCB_EQUAL);
             if (iter == NULL) {
-                LL_PREPEND(_list_tcb_head, tcb);
+                LL_PREPEND(list->head, tcb);
             }
-            mutex_unlock(&_list_tcb_lock);
+            mutex_unlock(&list->lock);
             break;
 
         case FSM_STATE_SYN_SENT:
             /* Add connection to active connections (if not already active) */
-            mutex_lock(&_list_tcb_lock);
+            mutex_lock(&list->lock);
-            LL_SEARCH(_list_tcb_head, iter, tcb, TCB_EQUAL);
+            LL_SEARCH(list->head, iter, tcb, TCB_EQUAL);
             /* If connection is not already active: Check port number, append TCB */
             if (iter == NULL) {
                 /* Check if port number was specified */
                 if (tcb->local_port != PORT_UNSPEC) {
                     /* Check if given port number is in use: return error */
                     if (_is_local_port_in_use(tcb->local_port)) {
-                        mutex_unlock(&_list_tcb_lock);
+                        mutex_unlock(&list->lock);
                         return -EADDRINUSE;
                     }
                 }
@@ -179,9 +181,9 @@ static int _transition_to(gnrc_tcp_tcb_t *tcb, fsm_state_t state)
                 else {
                     tcb->local_port = _get_random_local_port();
                 }
-                LL_PREPEND(_list_tcb_head, tcb);
+                LL_PREPEND(list->head, tcb);
             }
-            mutex_unlock(&_list_tcb_lock);
+            mutex_unlock(&list->lock);
             break;
 
         case FSM_STATE_SYN_RCVD:
@@ -443,7 +445,7 @@ static int _fsm_rcvd_pkt(gnrc_tcp_tcb_t *tcb, gnrc_pktsnip_t *in_pkt)
             uint16_t dst = byteorder_ntohs(tcp_hdr->dst_port);
 
             /* Check if SYN request is handled by another connection */
-            lst = _list_tcb_head;
+            lst = _gnrc_tcp_common_get_tcb_list()->head;
             while (lst) {
                 /* Compare port numbers and network layer addresses */
                 if (lst->local_port == dst && lst->peer_port == src) {

sys/net/gnrc/transport_layer/tcp/internal/common.h

@@ -115,14 +115,19 @@ extern "C" {
 #define GET_OFFSET( x ) (((x) & MSK_OFFSET) >> 12)
 
 /**
- * @brief Head of linked TCB list.
+ * @brief TCB list type.
  */
-extern gnrc_tcp_tcb_t *_list_tcb_head;
+typedef struct {
+    gnrc_tcp_tcb_t *head; /**< Head of TCB list */
+    mutex_t lock;         /**< Lock of TCB list */
+} tcb_list_t;
 
 /**
- * @brief Mutex to protect TCB list.
+ * @brief Function to access to TCB list
+ *
+ * @returns Pointer to global TCB list.
  */
-extern mutex_t _list_tcb_lock;
+tcb_list_t *_gnrc_tcp_common_get_tcb_list(void);
 
 #ifdef __cplusplus
 }