HTTP3: fix Windows build

The ngtcp2 QUIC backend was using the MSG_DONTWAIT flag for send/recv
in order to perform nonblocking operations. On Windows this flag does
not exist. Instead, the socket must be set to nonblocking mode via
ioctlsocket.

This change sets the nonblocking flag on UDP sockets used for QUIC on
all platforms so the use of MSG_DONTWAIT is not needed.

Fixes #4531
Closes #4532

1 files changed, 7 insertions, 7 deletions

diff --git a/lib/vquic/ngtcp2.c b/lib/vquic/ngtcp2.c
index 29a84d1c3..864751101 100644
--- a/lib/vquic/ngtcp2.c
+++ b/lib/vquic/ngtcp2.c
@@ -550,7 +550,7 @@ CURLcode Curl_quic_connect(struct connectdata *conn,
   if(!Curl_addr2string((struct sockaddr*)addr, addrlen, ipbuf, &port)) {
     char buffer[STRERROR_LEN];
     failf(data, "ssrem inet_ntop() failed with errno %d: %s",
-          errno, Curl_strerror(errno, buffer, sizeof(buffer)));
+          SOCKERRNO, Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
     return CURLE_BAD_FUNCTION_ARGUMENT;
   }
 
@@ -1404,13 +1404,13 @@ static CURLcode ng_process_ingress(struct connectdata *conn, int sockfd,
 
   for(;;) {
     remote_addrlen = sizeof(remote_addr);
-    while((recvd = recvfrom(sockfd, buf, bufsize, MSG_DONTWAIT,
+    while((recvd = recvfrom(sockfd, buf, bufsize, 0,
                             (struct sockaddr *)&remote_addr,
                             &remote_addrlen)) == -1 &&
-          errno == EINTR)
+          SOCKERRNO == EINTR)
       ;
     if(recvd == -1) {
-      if(errno == EAGAIN || errno == EWOULDBLOCK)
+      if(SOCKERRNO == EAGAIN || SOCKERRNO == EWOULDBLOCK)
         break;
 
       failf(conn->data, "ngtcp2: recvfrom() unexpectedly returned %d", recvd);
@@ -1544,14 +1544,14 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
     }
 
     memcpy(&remote_addr, ps.path.remote.addr, ps.path.remote.addrlen);
-    while((sent = sendto(sockfd, out, outlen, MSG_DONTWAIT,
+    while((sent = sendto(sockfd, out, outlen, 0,
                          (struct sockaddr *)&remote_addr,
                          (socklen_t)ps.path.remote.addrlen)) == -1 &&
-          errno == EINTR)
+          SOCKERRNO == EINTR)
       ;
 
     if(sent == -1) {
-      if(errno == EAGAIN || errno == EWOULDBLOCK) {
+      if(SOCKERRNO == EAGAIN || SOCKERRNO == EWOULDBLOCK) {
         /* TODO Cache packet */
         break;
       }