On Fri, Nov 12, 2021 at 12:56 PM Alejandro Colomar (man-pages) <alx.manpages@xxxxxxxxx> wrote: > > Hi Wei, > > On 11/5/21 18:19, Wei Wang wrote: > > On Fri, Oct 15, 2021 at 3:12 PM Alejandro Colomar (man-pages) > > <alx.manpages@xxxxxxxxx> wrote: > >> > >> Hi Wei, > >> > >> On 10/15/21 6:08 PM, Wei Wang wrote: > >>> On Fri, Sep 24, 2021 at 4:54 PM Wei Wang <weiwan@xxxxxxxxxx> wrote: > >>>> > >>>> TCP_FASTOPEN socket option was added by: > >>>> commit 8336886f786fdacbc19b719c1f7ea91eb70706d4 > >>>> TCP_FASTOPEN_CONNECT socket option was added by the following patch > >>>> series: > >>>> commit 065263f40f0972d5f1cd294bb0242bd5aa5f06b2 > >>>> commit 25776aa943401662617437841b3d3ea4693ee98a > >>>> commit 19f6d3f3c8422d65b5e3d2162e30ef07c6e21ea2 > >>>> commit 3979ad7e82dfe3fb94a51c3915e64ec64afa45c3 > >>>> Add detailed description for these 2 options. > >>>> Also add descriptions for /proc entry tcp_fastopen and tcp_fastopen_key. > >>>> > >>>> Signed-off-by: Wei Wang <weiwan@xxxxxxxxxx> > > Sorry for the delay. > I have applied it now. > I also applied some minor changes on top of your patch > (see below). > Thank you so much for the fixes and thanks for applying, Alex! > Thanks! > Alex > > > --- > > tcp.7: Minor tweaks to Wei's patch > > - wsfix > - Boldface literals (see groff_man(7)). > - Replace '\ ' by \~, per Branden's advise. > - Use phrasal semantic newlines. > - Put '...' in a C comment, to avoid interfering with groff. > It has the side effect that the code example is pure C now. > - Remove incorrect trailing '.IP'. > > Cc: Wei Wang <weiwan@xxxxxxxxxx> > Signed-off-by: Alejandro Colomar <alx.manpages@xxxxxxxxx> > > diff --git a/man7/tcp.7 b/man7/tcp.7 > index 264e3ccc4..69d85c05a 100644 > --- a/man7/tcp.7 > +++ b/man7/tcp.7 > @@ -423,26 +423,31 @@ option. > .\" Since 2.4.0-test7 > Enable RFC\ 2883 TCP Duplicate SACK support. > .TP > -.IR tcp_fastopen " (Bitmask; default: 0x1; since Linux 3.7)" > -Enables RFC\ 7413 Fast Open support. > +.IR tcp_fastopen " (Bitmask; default: 0x1; since Linux 3.7)" > +Enables RFC\~7413 Fast Open support. > The flag is used as a bitmap with the following values: > .RS > -.IP 0x1 > +.TP > +.B 0x1 > Enables client side Fast Open support > -.IP 0x2 > +.TP > +.B 0x2 > Enables server side Fast Open support > -.IP 0x4 > +.TP > +.B 0x4 > Allows client side to transmit data in SYN without Fast Open option > -.IP 0x200 > +.TP > +.B 0x200 > Allows server side to accept SYN data without Fast Open option > -.IP 0x400 > +.TP > +.B 0x400 > Enables Fast Open on all listeners without > .B TCP_FASTOPEN > socket option > .RE > .TP > .IR tcp_fastopen_key " (since Linux 3.7)" > -Set server side RFC\ 7413 Fast Open key to generate Fast Open cookie > +Set server side RFC\~7413 Fast Open key to generate Fast Open cookie > when server side Fast Open support is enabled. > .TP > .IR tcp_ecn " (Integer; default: see below; since Linux 2.4)" > @@ -1226,19 +1231,19 @@ This option should not be used in code intended > to be > portable. > .TP > .BR TCP_FASTOPEN " (since Linux 3.6)" > -This option enables Fast Open (RFC\ 7413) on the listener socket. > +This option enables Fast Open (RFC\~7413) on the listener socket. > The value specifies the maximum length of pending SYNs > (similar to the backlog argument in > .BR listen (2)). > Once enabled, > -the listener socket grants the TCP Fast Open cookie on incoming > -SYN with TCP Fast Open option. > +the listener socket grants the TCP Fast Open cookie > +on incoming SYN with TCP Fast Open option. > .IP > More importantly it accepts the data in SYN with a valid Fast Open cookie > and responds SYN-ACK acknowledging both the data and the SYN sequence. > .BR accept (2) > -returns a socket that is available for read and write when the handshake > -has not completed yet. > +returns a socket that is available for read and write > +when the handshake has not completed yet. > Thus the data exchange can commence before the handshake completes. > This option requires enabling the server-side support on sysctl > .IR net.ipv4.tcp_fastopen > @@ -1252,18 +1257,18 @@ or > below. > .TP > .BR TCP_FASTOPEN_CONNECT " (since Linux 4.11)" > -This option enables an alternative way to perform Fast Open on the active > -side (client). > +This option enables an alternative way to perform Fast Open > +on the active side (client). > When this option is enabled, > .BR connect (2) > -would behave differently depending on if a Fast Open cookie is available > -for the destination. > +would behave differently depending on > +if a Fast Open cookie is available for the destination. > .IP > If a cookie is not available (i.e. first contact to the destination), > .BR connect (2) > behaves as usual by sending a SYN immediately, > -except the SYN would include an empty Fast Open cookie option to solicit a > -cookie. > +except the SYN would include an empty Fast Open cookie option > +to solicit a cookie. > .IP > If a cookie is available, > .BR connect (2) > @@ -1297,13 +1302,12 @@ without > .BR write (2) > will cause the blocking socket to be blocked forever. > .IP > -The application should either set > +The application should either set > .B TCP_FASTOPEN_CONNECT > socket option before > .BR write (2) > or > -.BR sendmsg (2) > -, > +.BR sendmsg (2), > or call > .BR write (2) > or > @@ -1322,11 +1326,10 @@ setsockopt(s, IPPROTO_TCP, TCP_FASTOPEN_CONNECT, > 1, ...); > connect(s); > write(s); // write() should always follow connect() in order to > trigger SYN to go out > read(s)/write(s); > -... > +/* ... */ > close(s); > .EE > .in > -.IP > .SS Sockets API > TCP provides limited support for out-of-band data, > in the form of (a single byte of) urgent data.
