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.

core/newlib_syscalls.c

@@ -14,6 +14,21 @@
 #include <stdlib.h>
 #include <stdout_redirect.h>
 #include <sys/time.h>
+#include <lwip/sockets.h>
+
+/*
+ * The file descriptor index space is allocated in blocks. The first block of 3
+ * is for newlib I/O the stdin stdout and stderr. The next block of
+ * MEMP_NUM_NETCONN is allocated for lwip sockets, and the remainer to file
+ * system descriptors. The newlib default FD_SETSIZE is 64.
+ */
+#if LWIP_SOCKET_OFFSET < 3
+#error Expecting a LWIP_SOCKET_OFFSET >= 3, to allow room for the standard I/O descriptors.
+#endif
+#define FILE_DESCRIPTOR_OFFSET (LWIP_SOCKET_OFFSET + MEMP_NUM_NETCONN)
+#if FILE_DESCRIPTOR_OFFSET > FD_SETSIZE
+#error Too many lwip sockets for the FD_SETSIZE.
+#endif
 
 extern void *xPortSupervisorStackPointer;
 
@@ -81,10 +96,17 @@ __attribute__((weak)) long _write_filesystem_r(struct _reent *r, int fd, const c
 
 __attribute__((weak)) long _write_r(struct _reent *r, int fd, const char *ptr, int len )
 {
-    if(fd != r->_stdout->_file) {
+    if (fd >= FILE_DESCRIPTOR_OFFSET) {
         return _write_filesystem_r(r, fd, ptr, len);
     }
-    return current_stdout_write_r(r, fd, ptr, len);
+    if (fd >= LWIP_SOCKET_OFFSET) {
+        return lwip_write(fd, ptr, len);
+    }
+    if (fd == r->_stdout->_file) {
+        current_stdout_write_r(r, fd, ptr, len);
+    }
+    r->_errno = EBADF;
+    return -1;
 }
 
 /* syscall implementation for stdio read from UART */
@@ -109,10 +131,36 @@ __attribute__((weak)) long _read_filesystem_r( struct _reent *r, int fd, char *p
 
 __attribute__((weak)) long _read_r( struct _reent *r, int fd, char *ptr, int len )
 {
-    if(fd != r->_stdin->_file) {
+    if (fd >= FILE_DESCRIPTOR_OFFSET) {
         return _read_filesystem_r(r, fd, ptr, len);
     }
-    return _read_stdin_r(r, fd, ptr, len);
+    if (fd >= LWIP_SOCKET_OFFSET) {
+        return lwip_read(fd, ptr, len);
+    }
+    if (fd == r->_stdin->_file) {
+        _read_stdin_r(r, fd, ptr, len);
+    }
+    r->_errno = EBADF;
+    return -1;
+}
+
+/* default implementation, replace in a filesystem */
+__attribute__((weak)) int _close_filesystem_r(struct _reent *r, int fd)
+{
+    r->_errno = EBADF;
+    return -1;
+}
+
+__attribute__((weak)) int _close_r(struct _reent *r, int fd)
+{
+    if (fd >= FILE_DESCRIPTOR_OFFSET) {
+        return _close_filesystem_r(r, fd);
+    }
+    if (fd >= LWIP_SOCKET_OFFSET) {
+        return lwip_close(fd);
+    }
+    r->_errno = EBADF;
+    return -1;
 }
 
 /* Stub syscall implementations follow, to allow compiling newlib functions that
@@ -121,9 +169,6 @@ __attribute__((weak)) long _read_r( struct _reent *r, int fd, char *ptr, int len
 __attribute__((weak, alias("syscall_returns_enosys"))) 
 int _open_r(struct _reent *r, const char *pathname, int flags, int mode);
 
-__attribute__((weak, alias("syscall_returns_enosys"))) 
-int _close_r(struct _reent *r, int fd);
-
 __attribute__((weak, alias("syscall_returns_enosys"))) 
 int _unlink_r(struct _reent *r, const char *path);
 

examples/http_get/http_get.c

@@ -7,6 +7,7 @@
 #include "espressif/esp_common.h"
 #include "esp/uart.h"
 
+#include <unistd.h>
 #include <string.h>
 
 #include "FreeRTOS.h"

examples/http_get_bearssl/http_get_bearssl.c

@@ -13,6 +13,7 @@
 #include "esp/uart.h"
 #include "esp/hwrand.h"
 
+#include <unistd.h>
 #include <string.h>
 
 #include "FreeRTOS.h"

examples/tls_server_bearssl/tls_server_bearssl.c

@@ -19,6 +19,7 @@
 #include "esp/uart.h"
 #include "esp/hwrand.h"
 
+#include <unistd.h>
 #include <string.h>
 
 #include "FreeRTOS.h"

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>
@@ -1722,7 +1723,7 @@ static void dns_task(void *pvParameters)
 
     const struct ifreq ifreq0 = { "en0" };
     const struct ifreq ifreq1 = { "en1" };
-    lwip_setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
+    setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
                sdk_wifi_get_opmode() == STATIONAP_MODE ? &ifreq1 : &ifreq0,
                sizeof(ifreq0));
 

lwip/include/arch/cc.h

@@ -39,6 +39,7 @@
 #include <sys/time.h>
 #include <sys/errno.h>
 #include <esp/hwrand.h>
+#include <fcntl.h>
 
 struct ip4_addr;
 struct esf_buf;

lwip/include/lwipopts.h

@@ -144,6 +144,15 @@
    ------------------------------------------------
 */
 
+/**
+ * MEMP_NUM_NETCONN: the number of struct netconns.
+ * (only needed if you use the sequential API, like api_lib.c)
+ * This also sets the number of lwip socket descriptors.
+ */
+#ifndef MEMP_NUM_NETCONN
+#define MEMP_NUM_NETCONN                12
+#endif
+
 /*
    --------------------------------
    ---------- ARP options -------
@@ -549,6 +558,25 @@
    ---------- Socket options ----------
    ------------------------------------
 */
+
+/**
+ * LWIP_POSIX_SOCKETS_IO_NAMES==1: Enable POSIX-style sockets functions names.
+ * Disable this option if you use a POSIX operating system that uses the same
+ * names (read, write & close). (only used if you use sockets.c)
+ */
+#define LWIP_POSIX_SOCKETS_IO_NAMES     0
+
+/**
+ * LWIP_SOCKET_OFFSET==n: Increases the file descriptor number created by LwIP with n.
+ * This can be useful when there are multiple APIs which create file descriptors.
+ * When they all start with a different offset and you won't make them overlap you can
+ * re implement read/write/close/ioctl/fnctl to send the requested action to the right
+ * library (sharing select will need more work though).
+ */
+#ifndef LWIP_SOCKET_OFFSET
+#define LWIP_SOCKET_OFFSET              3
+#endif
+
 /**
  * LWIP_SO_SNDTIMEO==1: Enable send timeout for sockets/netconns and
  * SO_SNDTIMEO processing.

lwip/lwip

@@ -1 +1 @@
-Subproject commit 74676d46f0bc5ed82515f8e247008b7c45ec6cf6
+Subproject commit f372198834caf642c4b2d29d98fc1e120e3ce2b2