Add workaround for CentOS/RedHat writev bug to inet_drv

1 files changed, 17 insertions, 2 deletions

diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 236b8710fb..09577ffa8a 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -9711,7 +9711,7 @@ static int tcp_inet_output(tcp_descriptor* desc, HANDLE event)
     else if (IS_CONNECTED(INETP(desc))) {
 	for (;;) {
 	    int vsize;
-	    ssize_t n;
+	    ssize_t n,res;
 	    SysIOVec* iov;
 
 	    if ((iov = driver_peekq(ix, &vsize)) == NULL) {
@@ -9722,7 +9722,8 @@ static int tcp_inet_output(tcp_descriptor* desc, HANDLE event)
 	    vsize = vsize > MAX_VSIZE ? MAX_VSIZE : vsize;
 	    DEBUGF(("tcp_inet_output(%ld): s=%d, About to send %d items\r\n", 
 		    (long)desc->inet.port, desc->inet.s, vsize));
-	    if (IS_SOCKET_ERROR(sock_sendv(desc->inet.s, iov, vsize, &n, 0))) {
+	    if (IS_SOCKET_ERROR(res = sock_sendv(desc->inet.s, iov, vsize, &n, 0))) {
+	    write_error:
 		if ((sock_errno() != ERRNO_BLOCK) && (sock_errno() != EINTR)) {
 		    DEBUGF(("tcp_inet_output(%ld): sock_sendv(%d) errno = %d\r\n",
 			    (long)desc->inet.port, vsize, sock_errno()));
@@ -9733,6 +9734,20 @@ static int tcp_inet_output(tcp_descriptor* desc, HANDLE event)
 		desc->inet.send_would_block = 1;
 #endif
 		goto done;
+	    } else if (res == 0) { /* Workaround for redhat/CentOS bug */
+	      size_t howmuch = 0x7FFFFFFF; /* max signed 32bit */
+	      int x;
+	      for(x = 0; x < vsize && iov[x].iov_len == 0; ++x)
+		;
+	      if (x < vsize) {
+		if (howmuch > iov[x].iov_len) {
+		  howmuch = iov[x].iov_len;
+		}
+		n = sock_send(desc->inet.s, iov[x].iov_base,howmuch,0);
+		if (IS_SOCKET_ERROR(n)) {
+		  goto write_error;
+		}
+	      }
 	    }
 	    if (driver_deq(ix, n) <= desc->low) {
 		if (IS_BUSY(INETP(desc))) {