Author: jhb Date: Wed Jun 3 18:59:31 2020 New Revision: 361767 URL: https://svnweb.freebsd.org/changeset/base/361767
Log: Document SO_NO_OFFLOADS and SO_NO_DDP. Reviewed by: bcr, np MFC after: 1 week Sponsored by: Chelsio Communications Differential Revision: https://reviews.freebsd.org/D25043 Modified: head/lib/libc/sys/getsockopt.2 Modified: head/lib/libc/sys/getsockopt.2 ============================================================================== --- head/lib/libc/sys/getsockopt.2 Wed Jun 3 18:53:56 2020 (r361766) +++ head/lib/libc/sys/getsockopt.2 Wed Jun 3 18:59:31 2020 (r361767) @@ -28,7 +28,7 @@ .\" @(#)getsockopt.2 8.4 (Berkeley) 5/2/95 .\" $FreeBSD$ .\" -.Dd September 11, 2019 +.Dd June 03, 2020 .Dt GETSOCKOPT 2 .Os .Sh NAME @@ -191,6 +191,8 @@ The following options are recognized in .It Dv SO_USER_COOKIE Ta "set the 'so_user_cookie' value for the socket (uint32_t, set only)" .It Dv SO_TS_CLOCK Ta "set specific format of timestamp returned by SO_TIMESTAMP" .It Dv SO_MAX_PACING_RATE Ta "set the maximum transmit rate in bytes per second for the socket" +.It Dv SO_NO_OFFLOAD Ta "disables protocol offloads" +.It Dv SO_NO_DDP Ta "disables direct data placement offload" .El .Pp .Dv SO_DEBUG @@ -512,7 +514,6 @@ the error status. It may be used to check for asynchronous errors on connected datagram sockets or for other asynchronous errors. .Pp -Finally, .Dv SO_LABEL returns the MAC label of the socket. .Dv SO_PEERLABEL @@ -521,6 +522,7 @@ Note that your kernel must be compiled with MAC suppor See .Xr mac 3 for more information. +.Pp .Dv SO_LISTENQLIMIT returns the maximal number of queued connections, as set by .Xr listen 2 . @@ -532,6 +534,17 @@ returns the number of unaccepted incomplete connection .Dv SO_MAX_PACING_RATE instruct the socket and underlying network adapter layers to limit the transfer rate to the given unsigned 32-bit value in bytes per second. +.Pp +.Dv SO_NO_OFFLOAD +disables support for protocol offloads. +At present, this prevents TCP sockets from using TCP offload engines. +.Dv SO_NO_DDP +disables support for a specific TCP offload known as direct data +placement (DDP). +DDP is an offload supported by Chelsio network adapters that permits +reassembled TCP data streams to be received via zero-copy in +user-supplied buffers using +.Xr aio_read 2 . .Sh RETURN VALUES .Rv -std .Sh ERRORS _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
