diff --git a/mongoose.c b/mongoose.c
index 485d2a255ea317275b6f6799aa8a952a6fcade84..8b60b340a80d88518868141fde4ecb97e3898927 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -529,7 +529,7 @@ static char *posix_realpath(const char *path, char *resolved_path) {
#ifdef _WIN32
return _fullpath(resolved_path, path, _MAX_PATH);
#elif MG_ARCH == MG_ARCH_ESP32 || MG_ARCH == MG_ARCH_ESP8266 || \
- MG_ARCH == MG_ARCH_FREERTOS_TCP
+ MG_ARCH == MG_ARCH_FREERTOS_TCP || MG_ARCH == MG_ARCH_FREERTOS_LWIP
if (resolved_path == NULL) resolved_path = malloc(strlen(path) + 1);
strcpy(resolved_path, path);
return resolved_path;
@@ -1830,6 +1830,7 @@ bool mg_log_prefix(int level, const char *file, int line, const char *fname) {
time_t t = time(NULL);
struct tm tmp, *tm = gmtime_r(&t, &tmp);
int n, tag;
+ (void)tmp;
strftime(timebuf, sizeof(timebuf), "%Y-%m-%d %H:%M:%S", tm);
tag = level == LL_ERROR ? 'E' : level == LL_INFO ? 'I' : ' ';
n = snprintf(buf, sizeof(buf), "%s %c %s:%d:%s", timebuf, tag, p, line,
@@ -2944,6 +2945,8 @@ static void mg_set_non_blocking_mode(SOCKET fd) {
const BaseType_t off = 0;
setsockopt(fd, 0, FREERTOS_SO_RCVTIMEO, &off, sizeof(off));
setsockopt(fd, 0, FREERTOS_SO_SNDTIMEO, &off, sizeof(off));
+#elif MG_ARCH == MG_ARCH_FREERTOS_LWIP
+ lwip_fcntl(fd, F_SETFL, O_NONBLOCK);
#else
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK, FD_CLOEXEC);
#endif
@@ -2961,16 +2964,21 @@ SOCKET mg_open_listener(const char *url, struct mg_addr *addr) {
int on = 1, af = addr->is_ip6 ? AF_INET6 : AF_INET;
int type = strncmp(url, "udp:", 4) == 0 ? SOCK_DGRAM : SOCK_STREAM;
int proto = type == SOCK_DGRAM ? IPPROTO_UDP : IPPROTO_TCP;
+ (void)on;
if ((fd = socket(af, type, proto)) != INVALID_SOCKET &&
-#if !defined(_WIN32) || !defined(SO_EXCLUSIVEADDRUSE)
- // SO_RESUSEADDR is not enabled on Windows because the semantics of
- // SO_REUSEADDR on UNIX and Windows is different. On Windows,
- // SO_REUSEADDR allows to bind a socket to a port without error even if
- // the port is already open by another program. This is not the behavior
- // SO_REUSEADDR was designed for, and leads to hard-to-track failure
- // scenarios. Therefore, SO_REUSEADDR was disabled on Windows unless
- // SO_EXCLUSIVEADDRUSE is supported and set on a socket.
+#if (!defined(_WIN32) || !defined(SO_EXCLUSIVEADDRUSE)) \
+ && (!defined(LWIP_SOCKET) || (defined(LWIP_SOCKET) && SO_REUSE == 1))
+ // 1. SO_RESUSEADDR is not enabled on Windows because the semantics of
+ // SO_REUSEADDR on UNIX and Windows is different. On Windows,
+ // SO_REUSEADDR allows to bind a socket to a port without error even if
+ // the port is already open by another program. This is not the behavior
+ // SO_REUSEADDR was designed for, and leads to hard-to-track failure
+ // scenarios. Therefore, SO_REUSEADDR was disabled on Windows unless
+ // SO_EXCLUSIVEADDRUSE is supported and set on a socket.
+ // 2. In case of LWIP, SO_REUSEADDR should be explicitly enabled, by defining
+ // SO_REUSE (in lwipopts.h), otherwise the code below will compile
+ // but won't work! (setsockopt will return EINVAL)
!setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &on, sizeof(on)) &&
#endif
#if defined(_WIN32) && defined(SO_EXCLUSIVEADDRUSE) && !defined(WINCE)
diff --git a/mongoose.h b/mongoose.h
index ba48ced28621c1b277515735bccd399d8dcdedb0..69883995b91945cd0fefe93f7d3c04591f61ed48 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -192,10 +192,10 @@ extern "C" {
#if MG_ARCH == MG_ARCH_FREERTOS_LWIP
-#include <errno.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
+#include <string.h>
#if defined(__GNUC__)
#include <sys/stat.h>
@@ -213,6 +213,17 @@ struct timeval {
#include <lwip/sockets.h>
+#if LWIP_SOCKET != 1
+// Sockets support disabled in LWIP by default
+#error Set LWIP_SOCKET variable to 1 (in lwipopts.h)
+#endif
+
+#if LWIP_POSIX_SOCKETS_IO_NAMES != 0
+// LWIP_POSIX_SOCKETS_IO_NAMES must be disabled in posix-compatible OS enviroment
+// (freertos mimics to one) otherwise names like `read` and `write` conflict
+#error LWIP_POSIX_SOCKETS_IO_NAMES must be set to 0 (in lwipopts.h) for FreeRTOS
+#endif
+
#define MG_INT64_FMT "%lld"
#define MG_DIRSEP '/'
diff --git a/src/arch_freertos_lwip.h b/src/arch_freertos_lwip.h
index 4e5ebc384fb138801302a45f99d0b155092fc51d..56213b97236d654f55be647d654b6d5a76b63c6c 100644
--- a/src/arch_freertos_lwip.h
+++ b/src/arch_freertos_lwip.h
@@ -2,10 +2,10 @@
#if MG_ARCH == MG_ARCH_FREERTOS_LWIP
-#include <errno.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
+#include <string.h>
#if defined(__GNUC__)
#include <sys/stat.h>
@@ -23,6 +23,17 @@ struct timeval {
#include <lwip/sockets.h>
+#if LWIP_SOCKET != 1
+// Sockets support disabled in LWIP by default
+#error Set LWIP_SOCKET variable to 1 (in lwipopts.h)
+#endif
+
+#if LWIP_POSIX_SOCKETS_IO_NAMES != 0
+// LWIP_POSIX_SOCKETS_IO_NAMES must be disabled in posix-compatible OS enviroment
+// (freertos mimics to one) otherwise names like `read` and `write` conflict
+#error LWIP_POSIX_SOCKETS_IO_NAMES must be set to 0 (in lwipopts.h) for FreeRTOS
+#endif
+
#define MG_INT64_FMT "%lld"
#define MG_DIRSEP '/'
diff --git a/src/fs_posix.c b/src/fs_posix.c
index 15e4d2dd6cb08886da3211a940ea454601d3cf8d..e5c55f09c54651ab9dc905adf114ea8e9e281ff0 100644
--- a/src/fs_posix.c
+++ b/src/fs_posix.c
@@ -5,7 +5,7 @@ static char *posix_realpath(const char *path, char *resolved_path) {
#ifdef _WIN32
return _fullpath(resolved_path, path, _MAX_PATH);
#elif MG_ARCH == MG_ARCH_ESP32 || MG_ARCH == MG_ARCH_ESP8266 || \
- MG_ARCH == MG_ARCH_FREERTOS_TCP
+ MG_ARCH == MG_ARCH_FREERTOS_TCP || MG_ARCH == MG_ARCH_FREERTOS_LWIP
if (resolved_path == NULL) resolved_path = malloc(strlen(path) + 1);
strcpy(resolved_path, path);
return resolved_path;
diff --git a/src/log.c b/src/log.c
index a4c0d721c2ef50d42d48736cc0f71613d14d1ed6..b2e9e984329ed18af28ef61a86b9267960eb7136 100644
--- a/src/log.c
+++ b/src/log.c
@@ -37,6 +37,7 @@ bool mg_log_prefix(int level, const char *file, int line, const char *fname) {
time_t t = time(NULL);
struct tm tmp, *tm = gmtime_r(&t, &tmp);
int n, tag;
+ (void)tmp;
strftime(timebuf, sizeof(timebuf), "%Y-%m-%d %H:%M:%S", tm);
tag = level == LL_ERROR ? 'E' : level == LL_INFO ? 'I' : ' ';
n = snprintf(buf, sizeof(buf), "%s %c %s:%d:%s", timebuf, tag, p, line,
diff --git a/src/sock.c b/src/sock.c
index 05d87594eeaa3591fda984db293094afd8507df5..2b8772f609ad532269ce22d6e22ca2f6ae12973d 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -118,6 +118,8 @@ static void mg_set_non_blocking_mode(SOCKET fd) {
const BaseType_t off = 0;
setsockopt(fd, 0, FREERTOS_SO_RCVTIMEO, &off, sizeof(off));
setsockopt(fd, 0, FREERTOS_SO_SNDTIMEO, &off, sizeof(off));
+#elif MG_ARCH == MG_ARCH_FREERTOS_LWIP
+ lwip_fcntl(fd, F_SETFL, O_NONBLOCK);
#else
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK, FD_CLOEXEC);
#endif
@@ -135,16 +137,21 @@ SOCKET mg_open_listener(const char *url, struct mg_addr *addr) {
int on = 1, af = addr->is_ip6 ? AF_INET6 : AF_INET;
int type = strncmp(url, "udp:", 4) == 0 ? SOCK_DGRAM : SOCK_STREAM;
int proto = type == SOCK_DGRAM ? IPPROTO_UDP : IPPROTO_TCP;
+ (void)on;
if ((fd = socket(af, type, proto)) != INVALID_SOCKET &&
-#if !defined(_WIN32) || !defined(SO_EXCLUSIVEADDRUSE)
- // SO_RESUSEADDR is not enabled on Windows because the semantics of
- // SO_REUSEADDR on UNIX and Windows is different. On Windows,
- // SO_REUSEADDR allows to bind a socket to a port without error even if
- // the port is already open by another program. This is not the behavior
- // SO_REUSEADDR was designed for, and leads to hard-to-track failure
- // scenarios. Therefore, SO_REUSEADDR was disabled on Windows unless
- // SO_EXCLUSIVEADDRUSE is supported and set on a socket.
+#if (!defined(_WIN32) || !defined(SO_EXCLUSIVEADDRUSE)) \
+ && (!defined(LWIP_SOCKET) || (defined(LWIP_SOCKET) && SO_REUSE == 1))
+ // 1. SO_RESUSEADDR is not enabled on Windows because the semantics of
+ // SO_REUSEADDR on UNIX and Windows is different. On Windows,
+ // SO_REUSEADDR allows to bind a socket to a port without error even if
+ // the port is already open by another program. This is not the behavior
+ // SO_REUSEADDR was designed for, and leads to hard-to-track failure
+ // scenarios. Therefore, SO_REUSEADDR was disabled on Windows unless
+ // SO_EXCLUSIVEADDRUSE is supported and set on a socket.
+ // 2. In case of LWIP, SO_REUSEADDR should be explicitly enabled, by defining
+ // SO_REUSE (in lwipopts.h), otherwise the code below will compile
+ // but won't work! (setsockopt will return EINVAL)
!setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &on, sizeof(on)) &&
#endif
#if defined(_WIN32) && defined(SO_EXCLUSIVEADDRUSE) && !defined(WINCE)