Improve network error reporting on Windows

Windows doesn't report network errors though errno, it has its own facilities.

6 files changed, 119 insertions, 24 deletions

diff --git a/auto_tests/network_test.c b/auto_tests/network_test.c
index 15757d4d..6f535ee1 100644
--- a/auto_tests/network_test.c
+++ b/auto_tests/network_test.c
@@ -38,7 +38,10 @@ START_TEST(test_addr_resolv_localhost)
 
     int res = addr_resolve(localhost, &ip, nullptr);
 
-    ck_assert_msg(res > 0, "Resolver failed: %u, %s", errno, strerror(errno));
+    int error = net_error();
+    const char *strerror = net_new_strerror(error);
+    ck_assert_msg(res > 0, "Resolver failed: %d, %s", error, strerror);
+    net_kill_strerror(strerror);
 
     char ip_str[IP_NTOA_LEN];
     ck_assert_msg(ip.family == TOX_AF_INET, "Expected family TOX_AF_INET, got %u.", ip.family);
@@ -54,7 +57,10 @@ START_TEST(test_addr_resolv_localhost)
         localhost_split = 1;
     }
 
-    ck_assert_msg(res > 0, "Resolver failed: %u, %s", errno, strerror(errno));
+    error = net_error();
+    strerror = net_new_strerror(error);
+    ck_assert_msg(res > 0, "Resolver failed: %d, %s", error, strerror);
+    net_kill_strerror(strerror);
 
     ck_assert_msg(ip.family == TOX_AF_INET6, "Expected family TOX_AF_INET6 (%u), got %u.", TOX_AF_INET6, ip.family);
     IP6 ip6_loopback = get_ip6_loopback();
@@ -71,7 +77,10 @@ START_TEST(test_addr_resolv_localhost)
     IP extra;
     ip_reset(&extra);
     res = addr_resolve(localhost, &ip, &extra);
-    ck_assert_msg(res > 0, "Resolver failed: %u, %s", errno, strerror(errno));
+    error = net_error();
+    strerror = net_new_strerror(error);
+    ck_assert_msg(res > 0, "Resolver failed: %d, %s", error, strerror);
+    net_kill_strerror(strerror);
 
 #if USE_IPV6
     ck_assert_msg(ip.family == TOX_AF_INET6, "Expected family TOX_AF_INET6 (%u), got %u.", TOX_AF_INET6, ip.family);
@@ -157,6 +166,8 @@ static Suite *network_suite(void)
 {
     Suite *s = suite_create("Network");
 
+    networking_at_startup();
+
     DEFTESTCASE(addr_resolv_localhost);
     DEFTESTCASE(ip_equal);
 
diff --git a/testing/av_test.c b/testing/av_test.c
index 0d61edec..5cc3b5dd 100644
--- a/testing/av_test.c
+++ b/testing/av_test.c
@@ -64,7 +64,6 @@ extern "C" {
 #include <opencv/highgui.h>
 
 #include <assert.h>
-#include <errno.h>
 #include <sched.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/toxav/bwcontroller.c b/toxav/bwcontroller.c
index 5c6782ba..d786080e 100644
--- a/toxav/bwcontroller.c
+++ b/toxav/bwcontroller.c
@@ -145,8 +145,10 @@ void send_update(BWController *bwc)
             msg->recv = net_htonl(bwc->cycle.recv);
 
             if (-1 == m_send_custom_lossy_packet(bwc->m, bwc->friend_number, bwc_packet, sizeof(bwc_packet))) {
-                LOGGER_WARNING(bwc->m->log, "BWC send failed (len: %u)! std error: %s",
-                               (unsigned)sizeof(bwc_packet), strerror(errno));
+                const char *netstrerror = net_new_strerror(net_error());
+                LOGGER_WARNING(bwc->m->log, "BWC send failed (len: %u)! std error: %s, net error %s",
+                               (unsigned)sizeof(bwc_packet), strerror(errno), netstrerror);
+                net_kill_strerror(netstrerror);
             }
         }
 
diff --git a/toxav/rtp.c b/toxav/rtp.c
index c760d333..a65dbafe 100644
--- a/toxav/rtp.c
+++ b/toxav/rtp.c
@@ -802,8 +802,10 @@ int rtp_send_data(RTPSession *session, const uint8_t *data, uint32_t length,
         memcpy(rdata + 1 + RTP_HEADER_SIZE, data, length);
 
         if (-1 == m_send_custom_lossy_packet(session->m, session->friend_number, rdata, SIZEOF_VLA(rdata))) {
-            LOGGER_WARNING(session->m->log, "RTP send failed (len: %u)! std error: %s",
-                           (unsigned)SIZEOF_VLA(rdata), strerror(errno));
+            const char *netstrerror = net_new_strerror(net_error());
+            LOGGER_WARNING(session->m->log, "RTP send failed (len: %u)! std error: %s, net error: %s",
+                           (unsigned)SIZEOF_VLA(rdata), strerror(errno), netstrerror);
+            net_kill_strerror(netstrerror);
         }
     } else {
         /**
@@ -819,8 +821,10 @@ int rtp_send_data(RTPSession *session, const uint8_t *data, uint32_t length,
 
             if (-1 == m_send_custom_lossy_packet(session->m, session->friend_number,
                                                  rdata, piece + RTP_HEADER_SIZE + 1)) {
-                LOGGER_WARNING(session->m->log, "RTP send failed (len: %d)! std error: %s",
-                               piece + RTP_HEADER_SIZE + 1, strerror(errno));
+                const char *netstrerror = net_new_strerror(net_error());
+                LOGGER_WARNING(session->m->log, "RTP send failed (len: %d)! std error: %s, net error: %s",
+                               piece + RTP_HEADER_SIZE + 1, strerror(errno), netstrerror);
+                net_kill_strerror(netstrerror);
             }
 
             sent += piece;
@@ -837,8 +841,10 @@ int rtp_send_data(RTPSession *session, const uint8_t *data, uint32_t length,
 
             if (-1 == m_send_custom_lossy_packet(session->m, session->friend_number, rdata,
                                                  piece + RTP_HEADER_SIZE + 1)) {
-                LOGGER_WARNING(session->m->log, "RTP send failed (len: %d)! std error: %s",
-                               piece + RTP_HEADER_SIZE + 1, strerror(errno));
+                const char *netstrerror = net_new_strerror(net_error());
+                LOGGER_WARNING(session->m->log, "RTP send failed (len: %d)! std error: %s, net error: %s",
+                               piece + RTP_HEADER_SIZE + 1, strerror(errno), netstrerror);
+                net_kill_strerror(netstrerror);
             }
         }
     }
diff --git a/toxcore/network.c b/toxcore/network.c
index d88ba816..984071d4 100644
--- a/toxcore/network.c
+++ b/toxcore/network.c
@@ -63,15 +63,15 @@
 #include <sys/time.h>
 #include <sys/types.h>
 
+#define TOX_EWOULDBLOCK EWOULDBLOCK
+
 #else
 
 #ifndef IPV6_V6ONLY
 #define IPV6_V6ONLY 27
 #endif
 
-#ifndef EWOULDBLOCK
-#define EWOULDBLOCK WSAEWOULDBLOCK
-#endif
+#define TOX_EWOULDBLOCK WSAEWOULDBLOCK
 
 static const char *inet_ntop(Family family, const void *addr, char *buf, size_t bufsize)
 {
@@ -376,10 +376,13 @@ static void loglogdata(Logger *log, const char *message, const uint8_t *buffer,
     char ip_str[IP_NTOA_LEN];
 
     if (res < 0) { /* Windows doesn't necessarily know %zu */
+        int error = net_error();
+        const char *strerror = net_new_strerror(error);
         LOGGER_TRACE(log, "[%2u] %s %3u%c %s:%u (%u: %s) | %04x%04x",
                      buffer[0], message, (buflen < 999 ? buflen : 999), 'E',
-                     ip_ntoa(&ip_port.ip, ip_str, sizeof(ip_str)), net_ntohs(ip_port.port), errno,
-                     strerror(errno), data_0(buflen, buffer), data_1(buflen, buffer));
+                     ip_ntoa(&ip_port.ip, ip_str, sizeof(ip_str)), net_ntohs(ip_port.port), error,
+                     strerror, data_0(buflen, buffer), data_1(buflen, buffer));
+        net_kill_strerror(strerror);
     } else if ((res > 0) && ((size_t)res <= buflen)) {
         LOGGER_TRACE(log, "[%2u] %s %3u%c %s:%u (%u: %s) | %04x%04x",
                      buffer[0], message, (res < 999 ? res : 999), ((size_t)res < buflen ? '<' : '='),
@@ -498,9 +501,12 @@ static int receivepacket(Logger *log, Socket sock, IP_Port *ip_port, uint8_t *da
     int fail_or_len = recvfrom(sock, (char *) data, MAX_UDP_PACKET_SIZE, 0, (struct sockaddr *)&addr, &addrlen);
 
     if (fail_or_len < 0) {
+        int error = net_error();
 
-        if (fail_or_len < 0 && errno != EWOULDBLOCK) {
-            LOGGER_ERROR(log, "Unexpected error reading from socket: %u, %s", errno, strerror(errno));
+        if (fail_or_len < 0 && error != TOX_EWOULDBLOCK) {
+            const char *strerror = net_new_strerror(error);
+            LOGGER_ERROR(log, "Unexpected error reading from socket: %u, %s", error, strerror);
+            net_kill_strerror(strerror);
         }
 
         return -1; /* Nothing received. */
@@ -681,7 +687,10 @@ Networking_Core *new_networking_ex(Logger *log, IP ip, uint16_t port_from, uint1
 
     /* Check for socket error. */
     if (!sock_valid(temp->sock)) {
-        LOGGER_ERROR(log, "Failed to get a socket?! %u, %s", errno, strerror(errno));
+        int neterror = net_error();
+        const char *strerror = net_new_strerror(neterror);
+        LOGGER_ERROR(log, "Failed to get a socket?! %d, %s", neterror, strerror);
+        net_kill_strerror(strerror);
         free(temp);
 
         if (error) {
@@ -769,8 +778,11 @@ Networking_Core *new_networking_ex(Logger *log, IP ip, uint16_t port_from, uint1
         mreq.ipv6mr_interface = 0;
         int res = setsockopt(temp->sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, (const char *)&mreq, sizeof(mreq));
 
-        LOGGER_DEBUG(log, res < 0 ? "Failed to activate local multicast membership. (%u, %s)" :
-                     "Local multicast group FF02::1 joined successfully", errno, strerror(errno));
+        int neterror = net_error();
+        const char *strerror = net_new_strerror(neterror);
+        LOGGER_DEBUG(log, res < 0 ? "Failed to activate local multicast membership. (%d, %s)" :
+                     "Local multicast group FF02::1 joined successfully", neterror, strerror);
+        net_kill_strerror(strerror);
     }
 
     /* a hanging program or a different user might block the standard port;
@@ -827,9 +839,11 @@ Networking_Core *new_networking_ex(Logger *log, IP ip, uint16_t port_from, uint1
     }
 
     char ip_str[IP_NTOA_LEN];
-    LOGGER_ERROR(log, "Failed to bind socket: %u, %s IP: %s port_from: %u port_to: %u", errno, strerror(errno),
+    int neterror = net_error();
+    const char *strerror = net_new_strerror(neterror);
+    LOGGER_ERROR(log, "Failed to bind socket: %d, %s IP: %s port_from: %u port_to: %u", neterror, strerror,
                  ip_ntoa(&ip, ip_str, sizeof(ip_str)), port_from, port_to);
-
+    net_kill_strerror(strerror);
     kill_networking(temp);
 
     if (error) {
@@ -1520,3 +1534,38 @@ size_t net_unpack_u64(const uint8_t *bytes, uint64_t *v)
     *v = ((uint64_t)hi << 32) | lo;
     return p - bytes;
 }
+
+int net_error(void)
+{
+#if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+    return WSAGetLastError();
+#else
+    return errno;
+#endif
+}
+
+const char *net_new_strerror(int error)
+{
+#if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+    char *str = nullptr;
+    // Windows API is weird. The 5th function arg is of char* type, but we
+    // have to pass char** so that it could assign new memory block to our
+    // pointer, so we have to cast our char** to char* for the compilation
+    // not to fail (otherwise it would fail to find a variant of this function
+    // accepting char** as the 5th arg) and Windows inside casts it back
+    // to char** to do the assignment. So no, this cast you see here, although
+    // it looks weird, is not a mistake.
+    FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, nullptr,
+                   error, 0, (char *)&str, 0, nullptr);
+    return str;
+#else
+    return strerror(error);
+#endif
+}
+
+void net_kill_strerror(const char *strerror)
+{
+#if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+    LocalFree((char *)strerror);
+#endif
+}
diff --git a/toxcore/network.h b/toxcore/network.h
index 405721b2..10ddef02 100644
--- a/toxcore/network.h
+++ b/toxcore/network.h
@@ -404,6 +404,34 @@ void net_freeipport(IP_Port *ip_ports);
  */
 int bind_to_port(Socket sock, int family, uint16_t port);
 
+/* Get the last networking error code.
+ *
+ * Similar to Unix's errno, but cross-platform, as not all platforms use errno
+ * to indicate networking errors.
+ *
+ * Note that different platforms may return different codes for the same error,
+ * so you likely shouldn't be checking the value returned by this function
+ * unless you know what you are doing, you likely just want to use it in
+ * combination with net_new_strerror() to print the error.
+ *
+ * return platform-dependent network error code, if any.
+ */
+int net_error(void);
+
+/* Get a text explanation for the error code from net_error().
+ *
+ * return NULL on failure.
+ * return pointer to a NULL-terminated string describing the error code on
+ * success. The returned string must be freed using net_kill_strerror().
+ */
+const char *net_new_strerror(int error);
+
+/* Frees the string returned by net_new_strerror().
+ * It's valid to pass NULL as the argument, the function does nothing in this
+ * case.
+ */
+void net_kill_strerror(const char *strerror);
+
 /* Initialize networking.
  * bind to ip and port.
  * ip must be in network order EX: 127.0.0.1 = (7F000001).