On Wed, Jan 6, 2016 at 4:14 PM, Gleb Smirnoff <gleb...@freebsd.org> wrote: > Author: glebius > Date: Thu Jan 7 00:14:42 2016 > New Revision: 293284 > URL: https://svnweb.freebsd.org/changeset/base/293284 > > Log: > Historically we have two fields in tcpcb to describe sender MSS: t_maxopd, > and t_maxseg. This dualism emerged with T/TCP, but was not properly cleaned > up after T/TCP removal. After all permutations over the years the result is > that t_maxopd stores a minimum of peer offered MSS and MTU reduced by > minimum > protocol header. And t_maxseg stores (t_maxopd - TCPOLEN_TSTAMP_APPA) if > timestamps are in action, or is equal to t_maxopd otherwise. That's a very > rough estimate of MSS reduced by options length. Throughout the code it > was used in places, where preciseness was not important, like cwnd or > ssthresh calculations. > > With this change: > > - t_maxopd goes away. > - t_maxseg now stores MSS not adjusted by options. > - new function tcp_maxseg() is provided, that calculates MSS reduced by > options length. The functions gives a better estimate, since it takes > into account SACK state as well. > > Reviewed by: jtl > Differential Revision: https://reviews.freebsd.org/D3593
This broke the build. >From https://jenkins.freebsd.org/job/FreeBSD_HEAD_i386/2053/ : /usr/src/sys/modules/tcp/fastpath/../../../netinet/tcp_stacks/fastpath.c:481:6: error: no member named 't_maxopd' in 'struct tcpcb' --- all_subdir_sound --- --- all_subdir_sb8 --- ===> sound/driver/sb8 (all) --- all_subdir_tcp/fastpath --- if (DELAY_ACK(tp, tlen)) { ^ ~~ /usr/src/sys/modules/tcp/fastpath/../../../netinet/tcp_stacks/fastpath.c:167:19: note: expanded from macro 'DELAY_ACK' (tlen <= tp->t_maxopd) && \ ^ /usr/src/sys/modules/tcp/fastpath/../../../netinet/tcp_stacks/fastpath.c:606:8: error: no member named 't_maxopd' in 'struct tcpcb' if (DELAY_ACK(tp, tlen) && tlen != 0) ^ ~~ /usr/src/sys/modules/tcp/fastpath/../../../netinet/tcp_stacks/fastpath.c:167:19: note: expanded from macro 'DELAY_ACK' (tlen <= tp->t_maxopd) && \ ^ --- all_subdir_sound --- --- all_subdir_sb16 --- ctfconvert -L VERSION -g sb16.o --- all_subdir_tcp/fastpath --- /usr/src/sys/modules/tcp/fastpath/../../../netinet/tcp_stacks/fastpath.c:1545:8: error: no member named 't_maxopd' in 'struct tcpcb' if (DELAY_ACK(tp, tlen)) ^ ~~ /usr/src/sys/modules/tcp/fastpath/../../../netinet/tcp_stacks/fastpath.c:167:19: note: expanded from macro 'DELAY_ACK' (tlen <= tp->t_maxopd) && \ ^ 3 errors generated. *** [fastpath.o] Error code 1 _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
