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--- util/netevent.c.orig 2023-08-30 01:01:13.000000000 -0700
+++ util/netevent.c 2023-10-12 19:00:53.157995000 -0700
@@ -116,6 +116,8 @@
/** timeout in millisec to wait for write to unblock, packets dropped after.*/
#define SEND_BLOCKED_WAIT_TIMEOUT 200
+/** max number of times to wait for write to unblock, packets dropped after.*/
+#define SEND_BLOCKED_MAX_RETRY 5
/** Let's make timestamping code cleaner and redefine SO_TIMESTAMP* */
#ifndef SO_TIMESTAMP
@@ -402,9 +404,10 @@
WSAGetLastError() == WSAENOBUFS ||
WSAGetLastError() == WSAEWOULDBLOCK) {
#endif
+ int retries = 0;
/* if we set the fd blocking, other threads suddenly
* have a blocking fd that they operate on */
- while(sent == -1 && (
+ while(sent == -1 && retries < SEND_BLOCKED_MAX_RETRY && (
#ifndef USE_WINSOCK
errno == EAGAIN || errno == EINTR ||
# ifdef EWOULDBLOCK
@@ -419,6 +422,13 @@
#endif
)) {
#if defined(HAVE_POLL) || defined(USE_WINSOCK)
+ int send_nobufs = (
+#ifndef USE_WINSOCK
+ errno == ENOBUFS
+#else
+ WSAGetLastError() == WSAENOBUFS
+#endif
+ );
struct pollfd p;
int pret;
memset(&p, 0, sizeof(p));
@@ -457,8 +467,48 @@
log_err("poll udp out failed: %s",
sock_strerror(errno));
return 0;
+ } else if((pret < 0 &&
+#ifndef USE_WINSOCK
+ errno == ENOBUFS
+#else
+ WSAGetLastError() == WSAENOBUFS
+#endif
+ ) || (send_nobufs && retries > 0)) {
+ /* ENOBUFS, and poll returned without
+ * a timeout. Or the retried send call
+ * returned ENOBUFS. It is good to
+ * wait a bit for the error to clear. */
+ /* The timeout is 20*(2^(retries+1)),
+ * it increases exponentially, starting
+ * at 40 msec. After 5 tries, 1240 msec
+ * have passed in total, when poll
+ * returned the error, and 1200 msec
+ * when send returned the errors. */
+#ifndef USE_WINSOCK
+ pret = poll(NULL, 0, (SEND_BLOCKED_WAIT_TIMEOUT/10)<<(retries+1));
+#else
+ pret = WSAPoll(NULL, 0, (SEND_BLOCKED_WAIT_TIMEOUT/10)<<(retries+1));
+#endif
+ if(pret < 0 &&
+#ifndef USE_WINSOCK
+ errno != EAGAIN && errno != EINTR &&
+# ifdef EWOULDBLOCK
+ errno != EWOULDBLOCK &&
+# endif
+ errno != ENOBUFS
+#else
+ WSAGetLastError() != WSAEINPROGRESS &&
+ WSAGetLastError() != WSAEINTR &&
+ WSAGetLastError() != WSAENOBUFS &&
+ WSAGetLastError() != WSAEWOULDBLOCK
+#endif
+ ) {
+ log_err("poll udp out timer failed: %s",
+ sock_strerror(errno));
+ }
}
#endif /* defined(HAVE_POLL) || defined(USE_WINSOCK) */
+ retries++;
if (!is_connected) {
sent = sendto(c->fd, (void*)sldns_buffer_begin(packet),
sldns_buffer_remaining(packet), 0,
@@ -665,7 +715,8 @@
WSAGetLastError() == WSAENOBUFS ||
WSAGetLastError() == WSAEWOULDBLOCK) {
#endif
- while(sent == -1 && (
+ int retries = 0;
+ while(sent == -1 && retries < SEND_BLOCKED_MAX_RETRY && (
#ifndef USE_WINSOCK
errno == EAGAIN || errno == EINTR ||
# ifdef EWOULDBLOCK
@@ -680,6 +731,13 @@
#endif
)) {
#if defined(HAVE_POLL) || defined(USE_WINSOCK)
+ int send_nobufs = (
+#ifndef USE_WINSOCK
+ errno == ENOBUFS
+#else
+ WSAGetLastError() == WSAENOBUFS
+#endif
+ );
struct pollfd p;
int pret;
memset(&p, 0, sizeof(p));
@@ -718,8 +776,48 @@
log_err("poll udp out failed: %s",
sock_strerror(errno));
return 0;
+ } else if((pret < 0 &&
+#ifndef USE_WINSOCK
+ errno == ENOBUFS
+#else
+ WSAGetLastError() == WSAENOBUFS
+#endif
+ ) || (send_nobufs && retries > 0)) {
+ /* ENOBUFS, and poll returned without
+ * a timeout. Or the retried send call
+ * returned ENOBUFS. It is good to
+ * wait a bit for the error to clear. */
+ /* The timeout is 20*(2^(retries+1)),
+ * it increases exponentially, starting
+ * at 40 msec. After 5 tries, 1240 msec
+ * have passed in total, when poll
+ * returned the error, and 1200 msec
+ * when send returned the errors. */
+#ifndef USE_WINSOCK
+ pret = poll(NULL, 0, (SEND_BLOCKED_WAIT_TIMEOUT/10)<<(retries+1));
+#else
+ pret = WSAPoll(NULL, 0, (SEND_BLOCKED_WAIT_TIMEOUT/10)<<(retries+1));
+#endif
+ if(pret < 0 &&
+#ifndef USE_WINSOCK
+ errno != EAGAIN && errno != EINTR &&
+# ifdef EWOULDBLOCK
+ errno != EWOULDBLOCK &&
+# endif
+ errno != ENOBUFS
+#else
+ WSAGetLastError() != WSAEINPROGRESS &&
+ WSAGetLastError() != WSAEINTR &&
+ WSAGetLastError() != WSAENOBUFS &&
+ WSAGetLastError() != WSAEWOULDBLOCK
+#endif
+ ) {
+ log_err("poll udp out timer failed: %s",
+ sock_strerror(errno));
+ }
}
#endif /* defined(HAVE_POLL) || defined(USE_WINSOCK) */
+ retries++;
sent = sendmsg(c->fd, &msg, 0);
}
}
|
