task #14314: include cleanups

Couple of more cleanups for task #14314 involving includes:
  1) if.h name should match if_api.c due to LwIP convention and history.
     Standard if.h include can be used with compatibility header in
     posix/net/if.h
  2) API header (if.h) should not be included in core code. This include
     has been eliminated by moving the definition of IF_NAMESIZE to
     netif.h as NETIF_NAMESIZE.  This is now the canonical definition
     and IF_NAMESIZE just maps to it to provide the standard type

src/api/if_api.c

@@ -40,7 +40,7 @@
 
 #if LWIP_SOCKET
 
-#include "lwip/if.h"
+#include "lwip/if_api.h"
 #include "lwip/netifapi.h"
 
 char *

src/api/netifapi.c

@@ -269,8 +269,8 @@ netifapi_netif_name_to_index(const char *name, u8_t *idx)
   *idx = 0;
 
 #if LWIP_MPU_COMPATIBLE
-  strncpy(NETIFAPI_VAR_REF(msg).msg.ifs.name, name, IF_NAMESIZE - 1);
-  NETIFAPI_VAR_REF(msg).msg.ifs.name[IF_NAMESIZE - 1] = '\0';
+  strncpy(NETIFAPI_VAR_REF(msg).msg.ifs.name, name, NETIF_NAMESIZE - 1);
+  NETIFAPI_VAR_REF(msg).msg.ifs.name[NETIF_NAMESIZE - 1] = '\0';
 #else
   NETIFAPI_VAR_REF(msg).msg.ifs.name = LWIP_CONST_CAST(char*, name);
 #endif /* LWIP_MPU_COMPATIBLE */
@@ -289,7 +289,7 @@ netifapi_netif_name_to_index(const char *name, u8_t *idx)
 *
 * @param idx the interface index of the netif
 * @param name output name of the found netif, empty '\0' string if netif not found.
-*             name should be of at least IF_NAMESIZE bytes
+*             name should be of at least NETIF_NAMESIZE bytes
 */
 err_t
 netifapi_netif_index_to_name(u8_t idx, char *name)
@@ -305,8 +305,8 @@ netifapi_netif_index_to_name(u8_t idx, char *name)
   err = tcpip_api_call(netifapi_do_index_to_name, &API_VAR_REF(msg).call);
 #if LWIP_MPU_COMPATIBLE
   if (!err) {
-    strncpy(name, NETIFAPI_VAR_REF(msg).msg.ifs.name, IF_NAMESIZE - 1);
-    name[IF_NAMESIZE - 1] = '\0';
+    strncpy(name, NETIFAPI_VAR_REF(msg).msg.ifs.name, NETIF_NAMESIZE - 1);
+    name[NETIF_NAMESIZE - 1] = '\0';
   }
 #endif /* LWIP_MPU_COMPATIBLE */
   NETIFAPI_VAR_FREE(msg);

src/core/netif.c

@@ -65,7 +65,6 @@
 #include "lwip/stats.h"
 #include "lwip/sys.h"
 #include "lwip/ip.h"
-#include "lwip/if.h"
 #if ENABLE_LOOPBACK
 #if LWIP_NETIF_LOOPBACK_MULTITHREADING
 #include "lwip/tcpip.h"
@@ -1322,7 +1321,7 @@ netif_name_to_index(const char *name)
 * or NULL if not found/on error
 *
 * @param idx the interface index of the netif
-* @param name char buffer of at least IF_NAMESIZE bytes
+* @param name char buffer of at least NETIF_NAMESIZE bytes
 */
 char *
 netif_index_to_name(u8_t idx, char *name)
@@ -1339,7 +1338,7 @@ netif_index_to_name(u8_t idx, char *name)
     if (curif->num == num) {
       name[0] = curif->name[0];
       name[1] = curif->name[1];
-      lwip_itoa(&name[2], IF_NAMESIZE - 2, num);
+      lwip_itoa(&name[2], NETIF_NAMESIZE - 2, num);
       return name;
     }
     curif = curif->next;

src/include/lwip/if_api.h

@@ -40,8 +40,9 @@
 #define LWIP_HDR_IF_H
 
 #include "lwip/opt.h"
+#include "lwip/netif.h"
 
-#define IF_NAMESIZE 6 /* 2 chars, 3 nums, 1 \0 */
+#define IF_NAMESIZE NETIF_NAMESIZE
 
 char * lwip_if_indextoname(unsigned int ifindex, char *ifname);
 unsigned int lwip_if_nametoindex(const char *ifname);

src/include/lwip/netif.h

@@ -63,6 +63,12 @@ extern "C" {
 #define NETIF_MAX_HWADDR_LEN 6U
 #endif
 
+/** The size of a fully constructed netif name which the
+ * netif can be identified by in APIs. Composed of
+ * 2 chars, 3 (max) digits, and 1 \0
+ */
+#define NETIF_NAMESIZE 6
+
 /**
  * @defgroup netif_flags Flags
  * @ingroup netif

src/include/lwip/netifapi.h

@@ -40,7 +40,6 @@
 #include "lwip/netif.h"
 #include "lwip/dhcp.h"
 #include "lwip/autoip.h"
-#include "lwip/if.h"
 #include "lwip/priv/tcpip_priv.h"
 
 #ifdef __cplusplus
@@ -76,7 +75,7 @@ struct netifapi_msg {
     } common;
     struct {
 #if LWIP_MPU_COMPATIBLE
-      char name[IF_NAMESIZE];
+      char name[NETIF_NAMESIZE];
 #else /* LWIP_MPU_COMPATIBLE */
       char *name;
 #endif /* LWIP_MPU_COMPATIBLE */

src/include/posix/net/if.h

@@ -1,6 +1,6 @@
 /**
  * @file
- * This file is a posix wrapper for lwip/if.h.
+ * This file is a posix wrapper for lwip/if_api.h.
  */
 
 /*
@@ -30,4 +30,4 @@
  *
  */
 
-#include "lwip/if.h"
+#include "lwip/if_api.h"