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freebsd-dev/sys/kern/uipc_sockbuf.c
Mark Johnston f94acf52a4 socket: Rename sb(un)lock() and interlock with listen(2) 
In preparation for moving sockbuf locks into the containing socket,
provide alternative macros for the sockbuf I/O locks:
SOCK_IO_SEND_(UN)LOCK() and SOCK_IO_RECV_(UN)LOCK().  These operate on a
socket rather than a socket buffer.  Note that these locks are used only
to prevent concurrent readers and writters from interleaving I/O.

When locking for I/O, return an error if the socket is a listening
socket.  Currently the check is racy since the sockbuf sx locks are
destroyed during the transition to a listening socket, but that will no
longer be true after some follow-up changes.

Modify a few places to check for errors from
sblock()/SOCK_IO_(SEND|RECV)_LOCK() where they were not before.  In
particular, add checks to sendfile() and sorflush().

Reviewed by:	tuexen, gallatin
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D31657
2021-09-07 15:06:48 -04:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1988, 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.
*
* @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_kern_tls.h"
#include "opt_param.h"
#include <sys/param.h>
#include <sys/aio.h> /* for aio_swake proto */
#include <sys/kernel.h>
#include <sys/ktls.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
/*
* Function pointer set by the AIO routines so that the socket buffer code
* can call back into the AIO module if it is loaded.
*/
void (*aio_swake)(struct socket *, struct sockbuf *);
/*
* Primitive routines for operating on socket buffers
*/
u_long sb_max = SB_MAX;
u_long sb_max_adj =
(quad_t)SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
static u_long sb_efficiency = 8; /* parameter for sbreserve() */
#ifdef KERN_TLS
static void sbcompress_ktls_rx(struct sockbuf *sb, struct mbuf *m,
struct mbuf *n);
#endif
static struct mbuf *sbcut_internal(struct sockbuf *sb, int len);
static void sbflush_internal(struct sockbuf *sb);
/*
* Our own version of m_clrprotoflags(), that can preserve M_NOTREADY.
*/
static void
sbm_clrprotoflags(struct mbuf *m, int flags)
{
int mask;
mask = ~M_PROTOFLAGS;
if (flags & PRUS_NOTREADY)
mask |= M_NOTREADY;
while (m) {
m->m_flags &= mask;
m = m->m_next;
}
}
/*
* Compress M_NOTREADY mbufs after they have been readied by sbready().
*
* sbcompress() skips M_NOTREADY mbufs since the data is not available to
* be copied at the time of sbcompress(). This function combines small
* mbufs similar to sbcompress() once mbufs are ready. 'm0' is the first
* mbuf sbready() marked ready, and 'end' is the first mbuf still not
* ready.
*/
static void
sbready_compress(struct sockbuf *sb, struct mbuf *m0, struct mbuf *end)
{
struct mbuf *m, *n;
int ext_size;
SOCKBUF_LOCK_ASSERT(sb);
if ((sb->sb_flags & SB_NOCOALESCE) != 0)
return;
for (m = m0; m != end; m = m->m_next) {
MPASS((m->m_flags & M_NOTREADY) == 0);
/*
* NB: In sbcompress(), 'n' is the last mbuf in the
* socket buffer and 'm' is the new mbuf being copied
* into the trailing space of 'n'. Here, the roles
* are reversed and 'n' is the next mbuf after 'm'
* that is being copied into the trailing space of
* 'm'.
*/
n = m->m_next;
#ifdef KERN_TLS
/* Try to coalesce adjacent ktls mbuf hdr/trailers. */
if ((n != NULL) && (n != end) && (m->m_flags & M_EOR) == 0 &&
(m->m_flags & M_EXTPG) &&
(n->m_flags & M_EXTPG) &&
!mbuf_has_tls_session(m) &&
!mbuf_has_tls_session(n)) {
int hdr_len, trail_len;
hdr_len = n->m_epg_hdrlen;
trail_len = m->m_epg_trllen;
if (trail_len != 0 && hdr_len != 0 &&
trail_len + hdr_len <= MBUF_PEXT_TRAIL_LEN) {
/* copy n's header to m's trailer */
memcpy(&m->m_epg_trail[trail_len],
n->m_epg_hdr, hdr_len);
m->m_epg_trllen += hdr_len;
m->m_len += hdr_len;
n->m_epg_hdrlen = 0;
n->m_len -= hdr_len;
}
}
#endif
/* Compress small unmapped mbufs into plain mbufs. */
if ((m->m_flags & M_EXTPG) && m->m_len <= MLEN &&
!mbuf_has_tls_session(m)) {
ext_size = m->m_ext.ext_size;
if (mb_unmapped_compress(m) == 0) {
sb->sb_mbcnt -= ext_size;
sb->sb_ccnt -= 1;
}
}
while ((n != NULL) && (n != end) && (m->m_flags & M_EOR) == 0 &&
M_WRITABLE(m) &&
(m->m_flags & M_EXTPG) == 0 &&
!mbuf_has_tls_session(n) &&
!mbuf_has_tls_session(m) &&
n->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
n->m_len <= M_TRAILINGSPACE(m) &&
m->m_type == n->m_type) {
KASSERT(sb->sb_lastrecord != n,
("%s: merging start of record (%p) into previous mbuf (%p)",
__func__, n, m));
m_copydata(n, 0, n->m_len, mtodo(m, m->m_len));
m->m_len += n->m_len;
m->m_next = n->m_next;
m->m_flags |= n->m_flags & M_EOR;
if (sb->sb_mbtail == n)
sb->sb_mbtail = m;
sb->sb_mbcnt -= MSIZE;
sb->sb_mcnt -= 1;
if (n->m_flags & M_EXT) {
sb->sb_mbcnt -= n->m_ext.ext_size;
sb->sb_ccnt -= 1;
}
m_free(n);
n = m->m_next;
}
}
SBLASTRECORDCHK(sb);
SBLASTMBUFCHK(sb);
}
/*
* Mark ready "count" units of I/O starting with "m". Most mbufs
* count as a single unit of I/O except for M_EXTPG mbufs which
* are backed by multiple pages.
*/
int
sbready(struct sockbuf *sb, struct mbuf *m0, int count)
{
struct mbuf *m;
u_int blocker;
SOCKBUF_LOCK_ASSERT(sb);
KASSERT(sb->sb_fnrdy != NULL, ("%s: sb %p NULL fnrdy", __func__, sb));
KASSERT(count > 0, ("%s: invalid count %d", __func__, count));
m = m0;
blocker = (sb->sb_fnrdy == m) ? M_BLOCKED : 0;
while (count > 0) {
KASSERT(m->m_flags & M_NOTREADY,
("%s: m %p !M_NOTREADY", __func__, m));
if ((m->m_flags & M_EXTPG) != 0 && m->m_epg_npgs != 0) {
if (count < m->m_epg_nrdy) {
m->m_epg_nrdy -= count;
count = 0;
break;
}
count -= m->m_epg_nrdy;
m->m_epg_nrdy = 0;
} else
count--;
m->m_flags &= ~(M_NOTREADY | blocker);
if (blocker)
sb->sb_acc += m->m_len;
m = m->m_next;
}
/*
* If the first mbuf is still not fully ready because only
* some of its backing pages were readied, no further progress
* can be made.
*/
if (m0 == m) {
MPASS(m->m_flags & M_NOTREADY);
return (EINPROGRESS);
}
if (!blocker) {
sbready_compress(sb, m0, m);
return (EINPROGRESS);
}
/* This one was blocking all the queue. */
for (; m && (m->m_flags & M_NOTREADY) == 0; m = m->m_next) {
KASSERT(m->m_flags & M_BLOCKED,
("%s: m %p !M_BLOCKED", __func__, m));
m->m_flags &= ~M_BLOCKED;
sb->sb_acc += m->m_len;
}
sb->sb_fnrdy = m;
sbready_compress(sb, m0, m);
return (0);
}
/*
* Adjust sockbuf state reflecting allocation of m.
*/
void
sballoc(struct sockbuf *sb, struct mbuf *m)
{
SOCKBUF_LOCK_ASSERT(sb);
sb->sb_ccc += m->m_len;
if (sb->sb_fnrdy == NULL) {
if (m->m_flags & M_NOTREADY)
sb->sb_fnrdy = m;
else
sb->sb_acc += m->m_len;
} else
m->m_flags |= M_BLOCKED;
if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
sb->sb_ctl += m->m_len;
sb->sb_mbcnt += MSIZE;
sb->sb_mcnt += 1;
if (m->m_flags & M_EXT) {
sb->sb_mbcnt += m->m_ext.ext_size;
sb->sb_ccnt += 1;
}
}
/*
* Adjust sockbuf state reflecting freeing of m.
*/
void
sbfree(struct sockbuf *sb, struct mbuf *m)
{
#if 0 /* XXX: not yet: soclose() call path comes here w/o lock. */
SOCKBUF_LOCK_ASSERT(sb);
#endif
sb->sb_ccc -= m->m_len;
if (!(m->m_flags & M_NOTAVAIL))
sb->sb_acc -= m->m_len;
if (m == sb->sb_fnrdy) {
struct mbuf *n;
KASSERT(m->m_flags & M_NOTREADY,
("%s: m %p !M_NOTREADY", __func__, m));
n = m->m_next;
while (n != NULL && !(n->m_flags & M_NOTREADY)) {
n->m_flags &= ~M_BLOCKED;
sb->sb_acc += n->m_len;
n = n->m_next;
}
sb->sb_fnrdy = n;
}
if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
sb->sb_ctl -= m->m_len;
sb->sb_mbcnt -= MSIZE;
sb->sb_mcnt -= 1;
if (m->m_flags & M_EXT) {
sb->sb_mbcnt -= m->m_ext.ext_size;
sb->sb_ccnt -= 1;
}
if (sb->sb_sndptr == m) {
sb->sb_sndptr = NULL;
sb->sb_sndptroff = 0;
}
if (sb->sb_sndptroff != 0)
sb->sb_sndptroff -= m->m_len;
}
#ifdef KERN_TLS
/*
* Similar to sballoc/sbfree but does not adjust state associated with
* the sb_mb chain such as sb_fnrdy or sb_sndptr*. Also assumes mbufs
* are not ready.
*/
void
sballoc_ktls_rx(struct sockbuf *sb, struct mbuf *m)
{
SOCKBUF_LOCK_ASSERT(sb);
sb->sb_ccc += m->m_len;
sb->sb_tlscc += m->m_len;
sb->sb_mbcnt += MSIZE;
sb->sb_mcnt += 1;
if (m->m_flags & M_EXT) {
sb->sb_mbcnt += m->m_ext.ext_size;
sb->sb_ccnt += 1;
}
}
void
sbfree_ktls_rx(struct sockbuf *sb, struct mbuf *m)
{
#if 0 /* XXX: not yet: soclose() call path comes here w/o lock. */
SOCKBUF_LOCK_ASSERT(sb);
#endif
sb->sb_ccc -= m->m_len;
sb->sb_tlscc -= m->m_len;
sb->sb_mbcnt -= MSIZE;
sb->sb_mcnt -= 1;
if (m->m_flags & M_EXT) {
sb->sb_mbcnt -= m->m_ext.ext_size;
sb->sb_ccnt -= 1;
}
}
#endif
/*
* Socantsendmore indicates that no more data will be sent on the socket; it
* would normally be applied to a socket when the user informs the system
* that no more data is to be sent, by the protocol code (in case
* PRU_SHUTDOWN). Socantrcvmore indicates that no more data will be
* received, and will normally be applied to the socket by a protocol when it
* detects that the peer will send no more data. Data queued for reading in
* the socket may yet be read.
*/
void
socantsendmore_locked(struct socket *so)
{
SOCKBUF_LOCK_ASSERT(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sowwakeup_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
}
void
socantsendmore(struct socket *so)
{
SOCKBUF_LOCK(&so->so_snd);
socantsendmore_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
}
void
socantrcvmore_locked(struct socket *so)
{
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
#ifdef KERN_TLS
if (so->so_rcv.sb_flags & SB_TLS_RX)
ktls_check_rx(&so->so_rcv);
#endif
sorwakeup_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
void
socantrcvmore(struct socket *so)
{
SOCKBUF_LOCK(&so->so_rcv);
socantrcvmore_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
void
soroverflow_locked(struct socket *so)
{
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_options & SO_RERROR) {
so->so_rerror = ENOBUFS;
sorwakeup_locked(so);
} else
SOCKBUF_UNLOCK(&so->so_rcv);
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
void
soroverflow(struct socket *so)
{
SOCKBUF_LOCK(&so->so_rcv);
soroverflow_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
/*
* Wait for data to arrive at/drain from a socket buffer.
*/
int
sbwait(struct sockbuf *sb)
{
SOCKBUF_LOCK_ASSERT(sb);
sb->sb_flags |= SB_WAIT;
return (msleep_sbt(&sb->sb_acc, SOCKBUF_MTX(sb),
(sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
sb->sb_timeo, 0, 0));
}
/*
* Wakeup processes waiting on a socket buffer. Do asynchronous notification
* via SIGIO if the socket has the SS_ASYNC flag set.
*
* Called with the socket buffer lock held; will release the lock by the end
* of the function. This allows the caller to acquire the socket buffer lock
* while testing for the need for various sorts of wakeup and hold it through
* to the point where it's no longer required. We currently hold the lock
* through calls out to other subsystems (with the exception of kqueue), and
* then release it to avoid lock order issues. It's not clear that's
* correct.
*/
void
sowakeup(struct socket *so, struct sockbuf *sb)
{
int ret;
SOCKBUF_LOCK_ASSERT(sb);
selwakeuppri(sb->sb_sel, PSOCK);
if (!SEL_WAITING(sb->sb_sel))
sb->sb_flags &= ~SB_SEL;
if (sb->sb_flags & SB_WAIT) {
sb->sb_flags &= ~SB_WAIT;
wakeup(&sb->sb_acc);
}
KNOTE_LOCKED(&sb->sb_sel->si_note, 0);
if (sb->sb_upcall != NULL) {
ret = sb->sb_upcall(so, sb->sb_upcallarg, M_NOWAIT);
if (ret == SU_ISCONNECTED) {
KASSERT(sb == &so->so_rcv,
("SO_SND upcall returned SU_ISCONNECTED"));
soupcall_clear(so, SO_RCV);
}
} else
ret = SU_OK;
if (sb->sb_flags & SB_AIO)
sowakeup_aio(so, sb);
SOCKBUF_UNLOCK(sb);
if (ret == SU_ISCONNECTED)
soisconnected(so);
if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
pgsigio(&so->so_sigio, SIGIO, 0);
mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
}
/*
* Socket buffer (struct sockbuf) utility routines.
*
* Each socket contains two socket buffers: one for sending data and one for
* receiving data. Each buffer contains a queue of mbufs, information about
* the number of mbufs and amount of data in the queue, and other fields
* allowing select() statements and notification on data availability to be
* implemented.
*
* Data stored in a socket buffer is maintained as a list of records. Each
* record is a list of mbufs chained together with the m_next field. Records
* are chained together with the m_nextpkt field. The upper level routine
* soreceive() expects the following conventions to be observed when placing
* information in the receive buffer:
*
* 1. If the protocol requires each message be preceded by the sender's name,
* then a record containing that name must be present before any
* associated data (mbuf's must be of type MT_SONAME).
* 2. If the protocol supports the exchange of ``access rights'' (really just
* additional data associated with the message), and there are ``rights''
* to be received, then a record containing this data should be present
* (mbuf's must be of type MT_RIGHTS).
* 3. If a name or rights record exists, then it must be followed by a data
* record, perhaps of zero length.
*
* Before using a new socket structure it is first necessary to reserve
* buffer space to the socket, by calling sbreserve(). This should commit
* some of the available buffer space in the system buffer pool for the
* socket (currently, it does nothing but enforce limits). The space should
* be released by calling sbrelease() when the socket is destroyed.
*/
int
soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
{
struct thread *td = curthread;
SOCKBUF_LOCK(&so->so_snd);
SOCKBUF_LOCK(&so->so_rcv);
if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
goto bad;
if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
goto bad2;
if (so->so_rcv.sb_lowat == 0)
so->so_rcv.sb_lowat = 1;
if (so->so_snd.sb_lowat == 0)
so->so_snd.sb_lowat = MCLBYTES;
if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_snd);
return (0);
bad2:
sbrelease_locked(&so->so_snd, so);
bad:
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_snd);
return (ENOBUFS);
}
static int
sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
{
int error = 0;
u_long tmp_sb_max = sb_max;
error = sysctl_handle_long(oidp, &tmp_sb_max, arg2, req);
if (error || !req->newptr)
return (error);
if (tmp_sb_max < MSIZE + MCLBYTES)
return (EINVAL);
sb_max = tmp_sb_max;
sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
return (0);
}
/*
* Allot mbufs to a sockbuf. Attempt to scale mbmax so that mbcnt doesn't
* become limiting if buffering efficiency is near the normal case.
*/
int
sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so,
struct thread *td)
{
rlim_t sbsize_limit;
SOCKBUF_LOCK_ASSERT(sb);
/*
* When a thread is passed, we take into account the thread's socket
* buffer size limit. The caller will generally pass curthread, but
* in the TCP input path, NULL will be passed to indicate that no
* appropriate thread resource limits are available. In that case,
* we don't apply a process limit.
*/
if (cc > sb_max_adj)
return (0);
if (td != NULL) {
sbsize_limit = lim_cur(td, RLIMIT_SBSIZE);
} else
sbsize_limit = RLIM_INFINITY;
if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
sbsize_limit))
return (0);
sb->sb_mbmax = min(cc * sb_efficiency, sb_max);
if (sb->sb_lowat > sb->sb_hiwat)
sb->sb_lowat = sb->sb_hiwat;
return (1);
}
int
sbsetopt(struct socket *so, int cmd, u_long cc)
{
struct sockbuf *sb;
short *flags;
u_int *hiwat, *lowat;
int error;
sb = NULL;
SOCK_LOCK(so);
if (SOLISTENING(so)) {
switch (cmd) {
case SO_SNDLOWAT:
case SO_SNDBUF:
lowat = &so->sol_sbsnd_lowat;
hiwat = &so->sol_sbsnd_hiwat;
flags = &so->sol_sbsnd_flags;
break;
case SO_RCVLOWAT:
case SO_RCVBUF:
lowat = &so->sol_sbrcv_lowat;
hiwat = &so->sol_sbrcv_hiwat;
flags = &so->sol_sbrcv_flags;
break;
}
} else {
switch (cmd) {
case SO_SNDLOWAT:
case SO_SNDBUF:
sb = &so->so_snd;
break;
case SO_RCVLOWAT:
case SO_RCVBUF:
sb = &so->so_rcv;
break;
}
flags = &sb->sb_flags;
hiwat = &sb->sb_hiwat;
lowat = &sb->sb_lowat;
SOCKBUF_LOCK(sb);
}
error = 0;
switch (cmd) {
case SO_SNDBUF:
case SO_RCVBUF:
if (SOLISTENING(so)) {
if (cc > sb_max_adj) {
error = ENOBUFS;
break;
}
*hiwat = cc;
if (*lowat > *hiwat)
*lowat = *hiwat;
} else {
if (!sbreserve_locked(sb, cc, so, curthread))
error = ENOBUFS;
}
if (error == 0)
*flags &= ~SB_AUTOSIZE;
break;
case SO_SNDLOWAT:
case SO_RCVLOWAT:
/*
* Make sure the low-water is never greater than the
* high-water.
*/
*lowat = (cc > *hiwat) ? *hiwat : cc;
break;
}
if (!SOLISTENING(so))
SOCKBUF_UNLOCK(sb);
SOCK_UNLOCK(so);
return (error);
}
/*
* Free mbufs held by a socket, and reserved mbuf space.
*/
void
sbrelease_internal(struct sockbuf *sb, struct socket *so)
{
sbflush_internal(sb);
(void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
RLIM_INFINITY);
sb->sb_mbmax = 0;
}
void
sbrelease_locked(struct sockbuf *sb, struct socket *so)
{
SOCKBUF_LOCK_ASSERT(sb);
sbrelease_internal(sb, so);
}
void
sbrelease(struct sockbuf *sb, struct socket *so)
{
SOCKBUF_LOCK(sb);
sbrelease_locked(sb, so);
SOCKBUF_UNLOCK(sb);
}
void
sbdestroy(struct sockbuf *sb, struct socket *so)
{
sbrelease_internal(sb, so);
#ifdef KERN_TLS
if (sb->sb_tls_info != NULL)
ktls_free(sb->sb_tls_info);
sb->sb_tls_info = NULL;
#endif
}
/*
* Routines to add and remove data from an mbuf queue.
*
* The routines sbappend() or sbappendrecord() are normally called to append
* new mbufs to a socket buffer, after checking that adequate space is
* available, comparing the function sbspace() with the amount of data to be
* added. sbappendrecord() differs from sbappend() in that data supplied is
* treated as the beginning of a new record. To place a sender's address,
* optional access rights, and data in a socket receive buffer,
* sbappendaddr() should be used. To place access rights and data in a
* socket receive buffer, sbappendrights() should be used. In either case,
* the new data begins a new record. Note that unlike sbappend() and
* sbappendrecord(), these routines check for the caller that there will be
* enough space to store the data. Each fails if there is not enough space,
* or if it cannot find mbufs to store additional information in.
*
* Reliable protocols may use the socket send buffer to hold data awaiting
* acknowledgement. Data is normally copied from a socket send buffer in a
* protocol with m_copy for output to a peer, and then removing the data from
* the socket buffer with sbdrop() or sbdroprecord() when the data is
* acknowledged by the peer.
*/
#ifdef SOCKBUF_DEBUG
void
sblastrecordchk(struct sockbuf *sb, const char *file, int line)
{
struct mbuf *m = sb->sb_mb;
SOCKBUF_LOCK_ASSERT(sb);
while (m && m->m_nextpkt)
m = m->m_nextpkt;
if (m != sb->sb_lastrecord) {
printf("%s: sb_mb %p sb_lastrecord %p last %p\n",
__func__, sb->sb_mb, sb->sb_lastrecord, m);
printf("packet chain:\n");
for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
printf("\t%p\n", m);
panic("%s from %s:%u", __func__, file, line);
}
}
void
sblastmbufchk(struct sockbuf *sb, const char *file, int line)
{
struct mbuf *m = sb->sb_mb;
struct mbuf *n;
SOCKBUF_LOCK_ASSERT(sb);
while (m && m->m_nextpkt)
m = m->m_nextpkt;
while (m && m->m_next)
m = m->m_next;
if (m != sb->sb_mbtail) {
printf("%s: sb_mb %p sb_mbtail %p last %p\n",
__func__, sb->sb_mb, sb->sb_mbtail, m);
printf("packet tree:\n");
for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
printf("\t");
for (n = m; n != NULL; n = n->m_next)
printf("%p ", n);
printf("\n");
}
panic("%s from %s:%u", __func__, file, line);
}
#ifdef KERN_TLS
m = sb->sb_mtls;
while (m && m->m_next)
m = m->m_next;
if (m != sb->sb_mtlstail) {
printf("%s: sb_mtls %p sb_mtlstail %p last %p\n",
__func__, sb->sb_mtls, sb->sb_mtlstail, m);
printf("TLS packet tree:\n");
printf("\t");
for (m = sb->sb_mtls; m != NULL; m = m->m_next) {
printf("%p ", m);
}
printf("\n");
panic("%s from %s:%u", __func__, file, line);
}
#endif
}
#endif /* SOCKBUF_DEBUG */
#define SBLINKRECORD(sb, m0) do { \
SOCKBUF_LOCK_ASSERT(sb); \
if ((sb)->sb_lastrecord != NULL) \
(sb)->sb_lastrecord->m_nextpkt = (m0); \
else \
(sb)->sb_mb = (m0); \
(sb)->sb_lastrecord = (m0); \
} while (/*CONSTCOND*/0)
/*
* Append mbuf chain m to the last record in the socket buffer sb. The
* additional space associated the mbuf chain is recorded in sb. Empty mbufs
* are discarded and mbufs are compacted where possible.
*/
void
sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags)
{
struct mbuf *n;
SOCKBUF_LOCK_ASSERT(sb);
if (m == NULL)
return;
sbm_clrprotoflags(m, flags);
SBLASTRECORDCHK(sb);
n = sb->sb_mb;
if (n) {
while (n->m_nextpkt)
n = n->m_nextpkt;
do {
if (n->m_flags & M_EOR) {
sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
return;
}
} while (n->m_next && (n = n->m_next));
} else {
/*
* XXX Would like to simply use sb_mbtail here, but
* XXX I need to verify that I won't miss an EOR that
* XXX way.
*/
if ((n = sb->sb_lastrecord) != NULL) {
do {
if (n->m_flags & M_EOR) {
sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
return;
}
} while (n->m_next && (n = n->m_next));
} else {
/*
* If this is the first record in the socket buffer,
* it's also the last record.
*/
sb->sb_lastrecord = m;
}
}
sbcompress(sb, m, n);
SBLASTRECORDCHK(sb);
}
/*
* Append mbuf chain m to the last record in the socket buffer sb. The
* additional space associated the mbuf chain is recorded in sb. Empty mbufs
* are discarded and mbufs are compacted where possible.
*/
void
sbappend(struct sockbuf *sb, struct mbuf *m, int flags)
{
SOCKBUF_LOCK(sb);
sbappend_locked(sb, m, flags);
SOCKBUF_UNLOCK(sb);
}
#ifdef KERN_TLS
/*
* Append an mbuf containing encrypted TLS data. The data
* is marked M_NOTREADY until it has been decrypted and
* stored as a TLS record.
*/
static void
sbappend_ktls_rx(struct sockbuf *sb, struct mbuf *m)
{
struct mbuf *n;
SBLASTMBUFCHK(sb);
/* Remove all packet headers and mbuf tags to get a pure data chain. */
m_demote(m, 1, 0);
for (n = m; n != NULL; n = n->m_next)
n->m_flags |= M_NOTREADY;
sbcompress_ktls_rx(sb, m, sb->sb_mtlstail);
ktls_check_rx(sb);
}
#endif
/*
* This version of sbappend() should only be used when the caller absolutely
* knows that there will never be more than one record in the socket buffer,
* that is, a stream protocol (such as TCP).
*/
void
sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags)
{
SOCKBUF_LOCK_ASSERT(sb);
KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
#ifdef KERN_TLS
/*
* Decrypted TLS records are appended as records via
* sbappendrecord(). TCP passes encrypted TLS records to this
* function which must be scheduled for decryption.
*/
if (sb->sb_flags & SB_TLS_RX) {
sbappend_ktls_rx(sb, m);
return;
}
#endif
KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
SBLASTMBUFCHK(sb);
#ifdef KERN_TLS
if (sb->sb_tls_info != NULL)
ktls_seq(sb, m);
#endif
/* Remove all packet headers and mbuf tags to get a pure data chain. */
m_demote(m, 1, flags & PRUS_NOTREADY ? M_NOTREADY : 0);
sbcompress(sb, m, sb->sb_mbtail);
sb->sb_lastrecord = sb->sb_mb;
SBLASTRECORDCHK(sb);
}
/*
* This version of sbappend() should only be used when the caller absolutely
* knows that there will never be more than one record in the socket buffer,
* that is, a stream protocol (such as TCP).
*/
void
sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags)
{
SOCKBUF_LOCK(sb);
sbappendstream_locked(sb, m, flags);
SOCKBUF_UNLOCK(sb);
}
#ifdef SOCKBUF_DEBUG
void
sbcheck(struct sockbuf *sb, const char *file, int line)
{
struct mbuf *m, *n, *fnrdy;
u_long acc, ccc, mbcnt;
#ifdef KERN_TLS
u_long tlscc;
#endif
SOCKBUF_LOCK_ASSERT(sb);
acc = ccc = mbcnt = 0;
fnrdy = NULL;
for (m = sb->sb_mb; m; m = n) {
n = m->m_nextpkt;
for (; m; m = m->m_next) {
if (m->m_len == 0) {
printf("sb %p empty mbuf %p\n", sb, m);
goto fail;
}
if ((m->m_flags & M_NOTREADY) && fnrdy == NULL) {
if (m != sb->sb_fnrdy) {
printf("sb %p: fnrdy %p != m %p\n",
sb, sb->sb_fnrdy, m);
goto fail;
}
fnrdy = m;
}
if (fnrdy) {
if (!(m->m_flags & M_NOTAVAIL)) {
printf("sb %p: fnrdy %p, m %p is avail\n",
sb, sb->sb_fnrdy, m);
goto fail;
}
} else
acc += m->m_len;
ccc += m->m_len;
mbcnt += MSIZE;
if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
mbcnt += m->m_ext.ext_size;
}
}
#ifdef KERN_TLS
/*
* Account for mbufs "detached" by ktls_detach_record() while
* they are decrypted by ktls_decrypt(). tlsdcc gives a count
* of the detached bytes that are included in ccc. The mbufs
* and clusters are not included in the socket buffer
* accounting.
*/
ccc += sb->sb_tlsdcc;
tlscc = 0;
for (m = sb->sb_mtls; m; m = m->m_next) {
if (m->m_nextpkt != NULL) {
printf("sb %p TLS mbuf %p with nextpkt\n", sb, m);
goto fail;
}
if ((m->m_flags & M_NOTREADY) == 0) {
printf("sb %p TLS mbuf %p ready\n", sb, m);
goto fail;
}
tlscc += m->m_len;
ccc += m->m_len;
mbcnt += MSIZE;
if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
mbcnt += m->m_ext.ext_size;
}
if (sb->sb_tlscc != tlscc) {
printf("tlscc %ld/%u dcc %u\n", tlscc, sb->sb_tlscc,
sb->sb_tlsdcc);
goto fail;
}
#endif
if (acc != sb->sb_acc || ccc != sb->sb_ccc || mbcnt != sb->sb_mbcnt) {
printf("acc %ld/%u ccc %ld/%u mbcnt %ld/%u\n",
acc, sb->sb_acc, ccc, sb->sb_ccc, mbcnt, sb->sb_mbcnt);
#ifdef KERN_TLS
printf("tlscc %ld/%u dcc %u\n", tlscc, sb->sb_tlscc,
sb->sb_tlsdcc);
#endif
goto fail;
}
return;
fail:
panic("%s from %s:%u", __func__, file, line);
}
#endif
/*
* As above, except the mbuf chain begins a new record.
*/
void
sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0)
{
struct mbuf *m;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 == NULL)
return;
m_clrprotoflags(m0);
/*
* Put the first mbuf on the queue. Note this permits zero length
* records.
*/
sballoc(sb, m0);
SBLASTRECORDCHK(sb);
SBLINKRECORD(sb, m0);
sb->sb_mbtail = m0;
m = m0->m_next;
m0->m_next = 0;
if (m && (m0->m_flags & M_EOR)) {
m0->m_flags &= ~M_EOR;
m->m_flags |= M_EOR;
}
/* always call sbcompress() so it can do SBLASTMBUFCHK() */
sbcompress(sb, m, m0);
}
/*
* As above, except the mbuf chain begins a new record.
*/
void
sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
{
SOCKBUF_LOCK(sb);
sbappendrecord_locked(sb, m0);
SOCKBUF_UNLOCK(sb);
}
/* Helper routine that appends data, control, and address to a sockbuf. */
static int
sbappendaddr_locked_internal(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control, struct mbuf *ctrl_last)
{
struct mbuf *m, *n, *nlast;
#if MSIZE <= 256
if (asa->sa_len > MLEN)
return (0);
#endif
m = m_get(M_NOWAIT, MT_SONAME);
if (m == NULL)
return (0);
m->m_len = asa->sa_len;
bcopy(asa, mtod(m, caddr_t), asa->sa_len);
if (m0) {
m_clrprotoflags(m0);
m_tag_delete_chain(m0, NULL);
/*
* Clear some persistent info from pkthdr.
* We don't use m_demote(), because some netgraph consumers
* expect M_PKTHDR presence.
*/
m0->m_pkthdr.rcvif = NULL;
m0->m_pkthdr.flowid = 0;
m0->m_pkthdr.csum_flags = 0;
m0->m_pkthdr.fibnum = 0;
m0->m_pkthdr.rsstype = 0;
}
if (ctrl_last)
ctrl_last->m_next = m0; /* concatenate data to control */
else
control = m0;
m->m_next = control;
for (n = m; n->m_next != NULL; n = n->m_next)
sballoc(sb, n);
sballoc(sb, n);
nlast = n;
SBLINKRECORD(sb, m);
sb->sb_mbtail = nlast;
SBLASTMBUFCHK(sb);
SBLASTRECORDCHK(sb);
return (1);
}
/*
* Append address and data, and optionally, control (ancillary) data to the
* receive queue of a socket. If present, m0 must include a packet header
* with total length. Returns 0 if no space in sockbuf or insufficient
* mbufs.
*/
int
sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control)
{
struct mbuf *ctrl_last;
int space = asa->sa_len;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr_locked");
if (m0)
space += m0->m_pkthdr.len;
space += m_length(control, &ctrl_last);
if (space > sbspace(sb))
return (0);
return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
}
/*
* Append address and data, and optionally, control (ancillary) data to the
* receive queue of a socket. If present, m0 must include a packet header
* with total length. Returns 0 if insufficient mbufs. Does not validate space
* on the receiving sockbuf.
*/
int
sbappendaddr_nospacecheck_locked(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control)
{
struct mbuf *ctrl_last;
SOCKBUF_LOCK_ASSERT(sb);
ctrl_last = (control == NULL) ? NULL : m_last(control);
return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
}
/*
* Append address and data, and optionally, control (ancillary) data to the
* receive queue of a socket. If present, m0 must include a packet header
* with total length. Returns 0 if no space in sockbuf or insufficient
* mbufs.
*/
int
sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control)
{
int retval;
SOCKBUF_LOCK(sb);
retval = sbappendaddr_locked(sb, asa, m0, control);
SOCKBUF_UNLOCK(sb);
return (retval);
}
void
sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
struct mbuf *control, int flags)
{
struct mbuf *m, *mlast;
sbm_clrprotoflags(m0, flags);
m_last(control)->m_next = m0;
SBLASTRECORDCHK(sb);
for (m = control; m->m_next; m = m->m_next)
sballoc(sb, m);
sballoc(sb, m);
mlast = m;
SBLINKRECORD(sb, control);
sb->sb_mbtail = mlast;
SBLASTMBUFCHK(sb);
SBLASTRECORDCHK(sb);
}
void
sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control,
int flags)
{
SOCKBUF_LOCK(sb);
sbappendcontrol_locked(sb, m0, control, flags);
SOCKBUF_UNLOCK(sb);
}
/*
* Append the data in mbuf chain (m) into the socket buffer sb following mbuf
* (n). If (n) is NULL, the buffer is presumed empty.
*
* When the data is compressed, mbufs in the chain may be handled in one of
* three ways:
*
* (1) The mbuf may simply be dropped, if it contributes nothing (no data, no
* record boundary, and no change in data type).
*
* (2) The mbuf may be coalesced -- i.e., data in the mbuf may be copied into
* an mbuf already in the socket buffer. This can occur if an
* appropriate mbuf exists, there is room, both mbufs are not marked as
* not ready, and no merging of data types will occur.
*
* (3) The mbuf may be appended to the end of the existing mbuf chain.
*
* If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as
* end-of-record.
*/
void
sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
{
int eor = 0;
struct mbuf *o;
SOCKBUF_LOCK_ASSERT(sb);
while (m) {
eor |= m->m_flags & M_EOR;
if (m->m_len == 0 &&
(eor == 0 ||
(((o = m->m_next) || (o = n)) &&
o->m_type == m->m_type))) {
if (sb->sb_lastrecord == m)
sb->sb_lastrecord = m->m_next;
m = m_free(m);
continue;
}
if (n && (n->m_flags & M_EOR) == 0 &&
M_WRITABLE(n) &&
((sb->sb_flags & SB_NOCOALESCE) == 0) &&
!(m->m_flags & M_NOTREADY) &&
!(n->m_flags & (M_NOTREADY | M_EXTPG)) &&
!mbuf_has_tls_session(m) &&
!mbuf_has_tls_session(n) &&
m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
m->m_len <= M_TRAILINGSPACE(n) &&
n->m_type == m->m_type) {
m_copydata(m, 0, m->m_len, mtodo(n, n->m_len));
n->m_len += m->m_len;
sb->sb_ccc += m->m_len;
if (sb->sb_fnrdy == NULL)
sb->sb_acc += m->m_len;
if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
/* XXX: Probably don't need.*/
sb->sb_ctl += m->m_len;
m = m_free(m);
continue;
}
if (m->m_len <= MLEN && (m->m_flags & M_EXTPG) &&
(m->m_flags & M_NOTREADY) == 0 &&
!mbuf_has_tls_session(m))
(void)mb_unmapped_compress(m);
if (n)
n->m_next = m;
else
sb->sb_mb = m;
sb->sb_mbtail = m;
sballoc(sb, m);
n = m;
m->m_flags &= ~M_EOR;
m = m->m_next;
n->m_next = 0;
}
if (eor) {
KASSERT(n != NULL, ("sbcompress: eor && n == NULL"));
n->m_flags |= eor;
}
SBLASTMBUFCHK(sb);
}
#ifdef KERN_TLS
/*
* A version of sbcompress() for encrypted TLS RX mbufs. These mbufs
* are appended to the 'sb_mtls' chain instead of 'sb_mb' and are also
* a bit simpler (no EOR markers, always MT_DATA, etc.).
*/
static void
sbcompress_ktls_rx(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
{
SOCKBUF_LOCK_ASSERT(sb);
while (m) {
KASSERT((m->m_flags & M_EOR) == 0,
("TLS RX mbuf %p with EOR", m));
KASSERT(m->m_type == MT_DATA,
("TLS RX mbuf %p is not MT_DATA", m));
KASSERT((m->m_flags & M_NOTREADY) != 0,
("TLS RX mbuf %p ready", m));
KASSERT((m->m_flags & M_EXTPG) == 0,
("TLS RX mbuf %p unmapped", m));
if (m->m_len == 0) {
m = m_free(m);
continue;
}
/*
* Even though both 'n' and 'm' are NOTREADY, it's ok
* to coalesce the data.
*/
if (n &&
M_WRITABLE(n) &&
((sb->sb_flags & SB_NOCOALESCE) == 0) &&
!(n->m_flags & (M_EXTPG)) &&
m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
m->m_len <= M_TRAILINGSPACE(n)) {
m_copydata(m, 0, m->m_len, mtodo(n, n->m_len));
n->m_len += m->m_len;
sb->sb_ccc += m->m_len;
sb->sb_tlscc += m->m_len;
m = m_free(m);
continue;
}
if (n)
n->m_next = m;
else
sb->sb_mtls = m;
sb->sb_mtlstail = m;
sballoc_ktls_rx(sb, m);
n = m;
m = m->m_next;
n->m_next = NULL;
}
SBLASTMBUFCHK(sb);
}
#endif
/*
* Free all mbufs in a sockbuf. Check that all resources are reclaimed.
*/
static void
sbflush_internal(struct sockbuf *sb)
{
while (sb->sb_mbcnt || sb->sb_tlsdcc) {
/*
* Don't call sbcut(sb, 0) if the leading mbuf is non-empty:
* we would loop forever. Panic instead.
*/
if (sb->sb_ccc == 0 && (sb->sb_mb == NULL || sb->sb_mb->m_len))
break;
m_freem(sbcut_internal(sb, (int)sb->sb_ccc));
}
KASSERT(sb->sb_ccc == 0 && sb->sb_mb == 0 && sb->sb_mbcnt == 0,
("%s: ccc %u mb %p mbcnt %u", __func__,
sb->sb_ccc, (void *)sb->sb_mb, sb->sb_mbcnt));
}
void
sbflush_locked(struct sockbuf *sb)
{
SOCKBUF_LOCK_ASSERT(sb);
sbflush_internal(sb);
}
void
sbflush(struct sockbuf *sb)
{
SOCKBUF_LOCK(sb);
sbflush_locked(sb);
SOCKBUF_UNLOCK(sb);
}
/*
* Cut data from (the front of) a sockbuf.
*/
static struct mbuf *
sbcut_internal(struct sockbuf *sb, int len)
{
struct mbuf *m, *next, *mfree;
bool is_tls;
KASSERT(len >= 0, ("%s: len is %d but it is supposed to be >= 0",
__func__, len));
KASSERT(len <= sb->sb_ccc, ("%s: len: %d is > ccc: %u",
__func__, len, sb->sb_ccc));
next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
is_tls = false;
mfree = NULL;
while (len > 0) {
if (m == NULL) {
#ifdef KERN_TLS
if (next == NULL && !is_tls) {
if (sb->sb_tlsdcc != 0) {
MPASS(len >= sb->sb_tlsdcc);
len -= sb->sb_tlsdcc;
sb->sb_ccc -= sb->sb_tlsdcc;
sb->sb_tlsdcc = 0;
if (len == 0)
break;
}
next = sb->sb_mtls;
is_tls = true;
}
#endif
KASSERT(next, ("%s: no next, len %d", __func__, len));
m = next;
next = m->m_nextpkt;
}
if (m->m_len > len) {
KASSERT(!(m->m_flags & M_NOTAVAIL),
("%s: m %p M_NOTAVAIL", __func__, m));
m->m_len -= len;
m->m_data += len;
sb->sb_ccc -= len;
sb->sb_acc -= len;
if (sb->sb_sndptroff != 0)
sb->sb_sndptroff -= len;
if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA)
sb->sb_ctl -= len;
break;
}
len -= m->m_len;
#ifdef KERN_TLS
if (is_tls)
sbfree_ktls_rx(sb, m);
else
#endif
sbfree(sb, m);
/*
* Do not put M_NOTREADY buffers to the free list, they
* are referenced from outside.
*/
if (m->m_flags & M_NOTREADY && !is_tls)
m = m->m_next;
else {
struct mbuf *n;
n = m->m_next;
m->m_next = mfree;
mfree = m;
m = n;
}
}
/*
* Free any zero-length mbufs from the buffer.
* For SOCK_DGRAM sockets such mbufs represent empty records.
* XXX: For SOCK_STREAM sockets such mbufs can appear in the buffer,
* when sosend_generic() needs to send only control data.
*/
while (m && m->m_len == 0) {
struct mbuf *n;
sbfree(sb, m);
n = m->m_next;
m->m_next = mfree;
mfree = m;
m = n;
}
#ifdef KERN_TLS
if (is_tls) {
sb->sb_mb = NULL;
sb->sb_mtls = m;
if (m == NULL)
sb->sb_mtlstail = NULL;
} else
#endif
if (m) {
sb->sb_mb = m;
m->m_nextpkt = next;
} else
sb->sb_mb = next;
/*
* First part is an inline SB_EMPTY_FIXUP(). Second part makes sure
* sb_lastrecord is up-to-date if we dropped part of the last record.
*/
m = sb->sb_mb;
if (m == NULL) {
sb->sb_mbtail = NULL;
sb->sb_lastrecord = NULL;
} else if (m->m_nextpkt == NULL) {
sb->sb_lastrecord = m;
}
return (mfree);
}
/*
* Drop data from (the front of) a sockbuf.
*/
void
sbdrop_locked(struct sockbuf *sb, int len)
{
SOCKBUF_LOCK_ASSERT(sb);
m_freem(sbcut_internal(sb, len));
}
/*
* Drop data from (the front of) a sockbuf,
* and return it to caller.
*/
struct mbuf *
sbcut_locked(struct sockbuf *sb, int len)
{
SOCKBUF_LOCK_ASSERT(sb);
return (sbcut_internal(sb, len));
}
void
sbdrop(struct sockbuf *sb, int len)
{
struct mbuf *mfree;
SOCKBUF_LOCK(sb);
mfree = sbcut_internal(sb, len);
SOCKBUF_UNLOCK(sb);
m_freem(mfree);
}
struct mbuf *
sbsndptr_noadv(struct sockbuf *sb, uint32_t off, uint32_t *moff)
{
struct mbuf *m;
KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) {
*moff = off;
if (sb->sb_sndptr == NULL) {
sb->sb_sndptr = sb->sb_mb;
sb->sb_sndptroff = 0;
}
return (sb->sb_mb);
} else {
m = sb->sb_sndptr;
off -= sb->sb_sndptroff;
}
*moff = off;
return (m);
}
void
sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, uint32_t len)
{
/*
* A small copy was done, advance forward the sb_sbsndptr to cover
* it.
*/
struct mbuf *m;
if (mb != sb->sb_sndptr) {
/* Did not copyout at the same mbuf */
return;
}
m = mb;
while (m && (len > 0)) {
if (len >= m->m_len) {
len -= m->m_len;
if (m->m_next) {
sb->sb_sndptroff += m->m_len;
sb->sb_sndptr = m->m_next;
}
m = m->m_next;
} else {
len = 0;
}
}
}
/*
* Return the first mbuf and the mbuf data offset for the provided
* send offset without changing the "sb_sndptroff" field.
*/
struct mbuf *
sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff)
{
struct mbuf *m;
KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
/*
* If the "off" is below the stored offset, which happens on
* retransmits, just use "sb_mb":
*/
if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) {
m = sb->sb_mb;
} else {
m = sb->sb_sndptr;
off -= sb->sb_sndptroff;
}
while (off > 0 && m != NULL) {
if (off < m->m_len)
break;
off -= m->m_len;
m = m->m_next;
}
*moff = off;
return (m);
}
/*
* Drop a record off the front of a sockbuf and move the next record to the
* front.
*/
void
sbdroprecord_locked(struct sockbuf *sb)
{
struct mbuf *m;
SOCKBUF_LOCK_ASSERT(sb);
m = sb->sb_mb;
if (m) {
sb->sb_mb = m->m_nextpkt;
do {
sbfree(sb, m);
m = m_free(m);
} while (m);
}
SB_EMPTY_FIXUP(sb);
}
/*
* Drop a record off the front of a sockbuf and move the next record to the
* front.
*/
void
sbdroprecord(struct sockbuf *sb)
{
SOCKBUF_LOCK(sb);
sbdroprecord_locked(sb);
SOCKBUF_UNLOCK(sb);
}
/*
* Create a "control" mbuf containing the specified data with the specified
* type for presentation on a socket buffer.
*/
struct mbuf *
sbcreatecontrol_how(void *p, int size, int type, int level, int wait)
{
struct cmsghdr *cp;
struct mbuf *m;
MBUF_CHECKSLEEP(wait);
if (CMSG_SPACE((u_int)size) > MCLBYTES)
return ((struct mbuf *) NULL);
if (CMSG_SPACE((u_int)size) > MLEN)
m = m_getcl(wait, MT_CONTROL, 0);
else
m = m_get(wait, MT_CONTROL);
if (m == NULL)
return ((struct mbuf *) NULL);
cp = mtod(m, struct cmsghdr *);
m->m_len = 0;
KASSERT(CMSG_SPACE((u_int)size) <= M_TRAILINGSPACE(m),
("sbcreatecontrol: short mbuf"));
/*
* Don't leave the padding between the msg header and the
* cmsg data and the padding after the cmsg data un-initialized.
*/
bzero(cp, CMSG_SPACE((u_int)size));
if (p != NULL)
(void)memcpy(CMSG_DATA(cp), p, size);
m->m_len = CMSG_SPACE(size);
cp->cmsg_len = CMSG_LEN(size);
cp->cmsg_level = level;
cp->cmsg_type = type;
return (m);
}
struct mbuf *
sbcreatecontrol(caddr_t p, int size, int type, int level)
{
return (sbcreatecontrol_how(p, size, type, level, M_NOWAIT));
}
/*
* This does the same for socket buffers that sotoxsocket does for sockets:
* generate an user-format data structure describing the socket buffer. Note
* that the xsockbuf structure, since it is always embedded in a socket, does
* not include a self pointer nor a length. We make this entry point public
* in case some other mechanism needs it.
*/
void
sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
{
xsb->sb_cc = sb->sb_ccc;
xsb->sb_hiwat = sb->sb_hiwat;
xsb->sb_mbcnt = sb->sb_mbcnt;
xsb->sb_mcnt = sb->sb_mcnt;
xsb->sb_ccnt = sb->sb_ccnt;
xsb->sb_mbmax = sb->sb_mbmax;
xsb->sb_lowat = sb->sb_lowat;
xsb->sb_flags = sb->sb_flags;
xsb->sb_timeo = sb->sb_timeo;
}
/* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
static int dummy;
SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW | CTLFLAG_SKIP, &dummy, 0, "");
SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf,
CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &sb_max, 0,
sysctl_handle_sb_max, "LU",
"Maximum socket buffer size");
SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
&sb_efficiency, 0, "Socket buffer size waste factor");
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