freebsd-dev/sys/sys/sockbuf.h
Randall Stewart 89e560f441 This commit brings in a new refactored TCP stack called Rack.
Rack includes the following features:
 - A different SACK processing scheme (the old sack structures are not used).
 - RACK (Recent acknowledgment) where counting dup-acks is no longer done
        instead time is used to knwo when to retransmit. (see the I-D)
 - TLP (Tail Loss Probe) where we will probe for tail-losses to attempt
        to try not to take a retransmit time-out. (see the I-D)
 - Burst mitigation using TCPHTPS
 - PRR (partial rate reduction) see the RFC.

Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.

Note that any connection that does not support SACK will be kicked
back to the "default" base  FreeBSD stack (currently known as "default").

To build this into your kernel you will need to enable in your
kernel:
   makeoptions WITH_EXTRA_TCP_STACKS=1
   options TCPHPTS

Sponsored by:	Netflix Inc.
Differential Revision:		https://reviews.freebsd.org/D15525
2018-06-07 18:18:13 +00:00

255 lines
9.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)socketvar.h 8.3 (Berkeley) 2/19/95
*
* $FreeBSD$
*/
#ifndef _SYS_SOCKBUF_H_
#define _SYS_SOCKBUF_H_
/*
* Constants for sb_flags field of struct sockbuf/xsockbuf.
*/
#define SB_WAIT 0x04 /* someone is waiting for data/space */
#define SB_SEL 0x08 /* someone is selecting */
#define SB_ASYNC 0x10 /* ASYNC I/O, need signals */
#define SB_UPCALL 0x20 /* someone wants an upcall */
#define SB_NOINTR 0x40 /* operations not interruptible */
#define SB_AIO 0x80 /* AIO operations queued */
#define SB_KNOTE 0x100 /* kernel note attached */
#define SB_NOCOALESCE 0x200 /* don't coalesce new data into existing mbufs */
#define SB_IN_TOE 0x400 /* socket buffer is in the middle of an operation */
#define SB_AUTOSIZE 0x800 /* automatically size socket buffer */
#define SB_STOP 0x1000 /* backpressure indicator */
#define SB_AIO_RUNNING 0x2000 /* AIO operation running */
#define SBS_CANTSENDMORE 0x0010 /* can't send more data to peer */
#define SBS_CANTRCVMORE 0x0020 /* can't receive more data from peer */
#define SBS_RCVATMARK 0x0040 /* at mark on input */
#if defined(_KERNEL) || defined(_WANT_SOCKET)
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_sx.h>
#include <sys/_task.h>
#define SB_MAX (2*1024*1024) /* default for max chars in sockbuf */
struct mbuf;
struct sockaddr;
struct socket;
struct thread;
struct selinfo;
/*
* Variables for socket buffering.
*
* Locking key to struct sockbuf:
* (a) locked by SOCKBUF_LOCK().
*/
struct sockbuf {
struct mtx sb_mtx; /* sockbuf lock */
struct sx sb_sx; /* prevent I/O interlacing */
struct selinfo *sb_sel; /* process selecting read/write */
short sb_state; /* (a) socket state on sockbuf */
#define sb_startzero sb_mb
struct mbuf *sb_mb; /* (a) the mbuf chain */
struct mbuf *sb_mbtail; /* (a) the last mbuf in the chain */
struct mbuf *sb_lastrecord; /* (a) first mbuf of last
* record in socket buffer */
struct mbuf *sb_sndptr; /* (a) pointer into mbuf chain */
struct mbuf *sb_fnrdy; /* (a) pointer to first not ready buffer */
u_int sb_sndptroff; /* (a) byte offset of ptr into chain */
u_int sb_acc; /* (a) available chars in buffer */
u_int sb_ccc; /* (a) claimed chars in buffer */
u_int sb_hiwat; /* (a) max actual char count */
u_int sb_mbcnt; /* (a) chars of mbufs used */
u_int sb_mcnt; /* (a) number of mbufs in buffer */
u_int sb_ccnt; /* (a) number of clusters in buffer */
u_int sb_mbmax; /* (a) max chars of mbufs to use */
u_int sb_ctl; /* (a) non-data chars in buffer */
int sb_lowat; /* (a) low water mark */
sbintime_t sb_timeo; /* (a) timeout for read/write */
short sb_flags; /* (a) flags, see below */
int (*sb_upcall)(struct socket *, void *, int); /* (a) */
void *sb_upcallarg; /* (a) */
TAILQ_HEAD(, kaiocb) sb_aiojobq; /* (a) pending AIO ops */
struct task sb_aiotask; /* AIO task */
};
#endif /* defined(_KERNEL) || defined(_WANT_SOCKET) */
#ifdef _KERNEL
/*
* Per-socket buffer mutex used to protect most fields in the socket
* buffer.
*/
#define SOCKBUF_MTX(_sb) (&(_sb)->sb_mtx)
#define SOCKBUF_LOCK_INIT(_sb, _name) \
mtx_init(SOCKBUF_MTX(_sb), _name, NULL, MTX_DEF)
#define SOCKBUF_LOCK_DESTROY(_sb) mtx_destroy(SOCKBUF_MTX(_sb))
#define SOCKBUF_LOCK(_sb) mtx_lock(SOCKBUF_MTX(_sb))
#define SOCKBUF_OWNED(_sb) mtx_owned(SOCKBUF_MTX(_sb))
#define SOCKBUF_UNLOCK(_sb) mtx_unlock(SOCKBUF_MTX(_sb))
#define SOCKBUF_LOCK_ASSERT(_sb) mtx_assert(SOCKBUF_MTX(_sb), MA_OWNED)
#define SOCKBUF_UNLOCK_ASSERT(_sb) mtx_assert(SOCKBUF_MTX(_sb), MA_NOTOWNED)
/*
* Socket buffer private mbuf(9) flags.
*/
#define M_NOTREADY M_PROTO1 /* m_data not populated yet */
#define M_BLOCKED M_PROTO2 /* M_NOTREADY in front of m */
#define M_NOTAVAIL (M_NOTREADY | M_BLOCKED)
void sbappend(struct sockbuf *sb, struct mbuf *m, int flags);
void sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags);
void sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags);
void sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags);
int sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control);
int sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control);
int sbappendaddr_nospacecheck_locked(struct sockbuf *sb,
const struct sockaddr *asa, struct mbuf *m0, struct mbuf *control);
int sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
struct mbuf *control);
int sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
struct mbuf *control);
void sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
void sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0);
void sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
struct mbuf *
sbcreatecontrol(caddr_t p, int size, int type, int level);
void sbdestroy(struct sockbuf *sb, struct socket *so);
void sbdrop(struct sockbuf *sb, int len);
void sbdrop_locked(struct sockbuf *sb, int len);
struct mbuf *
sbcut_locked(struct sockbuf *sb, int len);
void sbdroprecord(struct sockbuf *sb);
void sbdroprecord_locked(struct sockbuf *sb);
void sbflush(struct sockbuf *sb);
void sbflush_locked(struct sockbuf *sb);
void sbrelease(struct sockbuf *sb, struct socket *so);
void sbrelease_internal(struct sockbuf *sb, struct socket *so);
void sbrelease_locked(struct sockbuf *sb, struct socket *so);
int sbsetopt(struct socket *so, int cmd, u_long cc);
int sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so,
struct thread *td);
struct mbuf *
sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff);
struct mbuf *
sbsndptr_noadv(struct sockbuf *sb, u_int off, u_int *moff);
void
sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, u_int len);
struct mbuf *
sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff);
int sbwait(struct sockbuf *sb);
int sblock(struct sockbuf *sb, int flags);
void sbunlock(struct sockbuf *sb);
void sballoc(struct sockbuf *, struct mbuf *);
void sbfree(struct sockbuf *, struct mbuf *);
int sbready(struct sockbuf *, struct mbuf *, int);
/*
* Return how much data is available to be taken out of socket
* buffer right now.
*/
static inline u_int
sbavail(struct sockbuf *sb)
{
#if 0
SOCKBUF_LOCK_ASSERT(sb);
#endif
return (sb->sb_acc);
}
/*
* Return how much data sits there in the socket buffer
* It might be that some data is not yet ready to be read.
*/
static inline u_int
sbused(struct sockbuf *sb)
{
#if 0
SOCKBUF_LOCK_ASSERT(sb);
#endif
return (sb->sb_ccc);
}
/*
* How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
* This is problematical if the fields are unsigned, as the space might
* still be negative (ccc > hiwat or mbcnt > mbmax).
*/
static inline long
sbspace(struct sockbuf *sb)
{
int bleft, mleft; /* size should match sockbuf fields */
#if 0
SOCKBUF_LOCK_ASSERT(sb);
#endif
if (sb->sb_flags & SB_STOP)
return(0);
bleft = sb->sb_hiwat - sb->sb_ccc;
mleft = sb->sb_mbmax - sb->sb_mbcnt;
return ((bleft < mleft) ? bleft : mleft);
}
#define SB_EMPTY_FIXUP(sb) do { \
if ((sb)->sb_mb == NULL) { \
(sb)->sb_mbtail = NULL; \
(sb)->sb_lastrecord = NULL; \
} \
} while (/*CONSTCOND*/0)
#ifdef SOCKBUF_DEBUG
void sblastrecordchk(struct sockbuf *, const char *, int);
void sblastmbufchk(struct sockbuf *, const char *, int);
void sbcheck(struct sockbuf *, const char *, int);
#define SBLASTRECORDCHK(sb) sblastrecordchk((sb), __FILE__, __LINE__)
#define SBLASTMBUFCHK(sb) sblastmbufchk((sb), __FILE__, __LINE__)
#define SBCHECK(sb) sbcheck((sb), __FILE__, __LINE__)
#else
#define SBLASTRECORDCHK(sb) do {} while (0)
#define SBLASTMBUFCHK(sb) do {} while (0)
#define SBCHECK(sb) do {} while (0)
#endif /* SOCKBUF_DEBUG */
#endif /* _KERNEL */
#endif /* _SYS_SOCKBUF_H_ */