lwip: define LWIP_POSIX_SOCKETS_IO_NAMES as zero (#457)

This patch gets the newlib standard stream descriptors playing well with the
lwip socket descriptors and the spiffs file descriptors. The LWIP_SOCKET_OFFSET
is now defined to be 3, rather than zero, to avoid clashing with the standard
stream descriptors, and the SPIFFS_FILEHDL_OFFSET is bumped up to start after
the lwip descriptors.

extras/mbedtls/net_lwip.c

@@ -21,6 +21,7 @@
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 
+#include <fcntl.h>
 #if !defined(MBEDTLS_CONFIG_FILE)
 #include "mbedtls/config.h"
 #else

extras/paho_mqtt_c/MQTTESP8266.c

@@ -20,6 +20,7 @@
   */
 
 #include <espressif/esp_common.h>
+#include <unistd.h>
 #include <lwip/sockets.h>
 #include <lwip/inet.h>
 #include <lwip/netdb.h>

extras/spiffs/esp_spiffs.c

@@ -149,7 +149,8 @@ int _open_r(struct _reent *r, const char *pathname, int flags, int mode)
     return SPIFFS_open(&fs, pathname, spiffs_flags, mode);
 }
 
-int _close_r(struct _reent *r, int fd)
+// This implementation replaces implementation in core/newlib_syscals.c
+int _close_filesystem_r(struct _reent *r, int fd)
 {
     return SPIFFS_close(&fs, (spiffs_file)fd);
 }

extras/spiffs/spiffs_config.h

@@ -198,7 +198,15 @@ typedef unsigned char u8_t;
 // NB: This adds config field fh_ix_offset in the configuration struct when
 // mounting, which must be defined.
 #ifndef SPIFFS_FILEHDL_OFFSET
-#define SPIFFS_FILEHDL_OFFSET                 1
+#define SPIFFS_FILEHDL_OFFSET                 17
+// Not ideal having to use a literal above, which is necessary because this file
+// is also included by tools that run on the host, but at least do some checks
+// when building the target code.
+#ifdef LWIP_SOCKET_OFFSET
+#if SPIFFS_FILEHDL_OFFSET < (LWIP_SOCKET_OFFSET + MEMP_NUM_NETCONN)
+#error SPIFFS_FILEHDL_OFFSET clashes with lwip sockets range.
+#endif
+#endif
 #endif
 
 // Enable this to compile a read only version of spiffs.

extras/wificfg/wificfg.c

@@ -21,6 +21,7 @@
 
 #include <string.h>
 #include <ctype.h>
+#include <unistd.h>
 
 #include <espressif/esp_common.h>
 #include <espressif/user_interface.h>
@@ -1722,9 +1723,9 @@ static void dns_task(void *pvParameters)
 
     const struct ifreq ifreq0 = { "en0" };
     const struct ifreq ifreq1 = { "en1" };
-    lwip_setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
-                    sdk_wifi_get_opmode() == STATIONAP_MODE ? &ifreq1 : &ifreq0,
-                    sizeof(ifreq0));
+    setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
+               sdk_wifi_get_opmode() == STATIONAP_MODE ? &ifreq1 : &ifreq0,
+               sizeof(ifreq0));
 
     for (;;) {
         char buffer[96];