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freebsd-nq/sys/kern/uipc_sockbuf.c
Roy Marples 7045b1603b socket: Implement SO_RERROR 
SO_RERROR indicates that receive buffer overflows should be handled as
errors. Historically receive buffer overflows have been ignored and
programs could not tell if they missed messages or messages had been
truncated because of overflows. Since programs historically do not
expect to get receive overflow errors, this behavior is not the
default.

This is really really important for programs that use route(4) to keep
in sync with the system. If we loose a message then we need to reload
the full system state, otherwise the behaviour from that point is
undefined and can lead to chasing bogus bug reports.

Reviewed by:	philip (network), kbowling (transport), gbe (manpages)
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D26652
2021-07-28 09:35:09 -07:00

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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));
}
int
sblock(struct sockbuf *sb, int flags)
{
KASSERT((flags & SBL_VALID) == flags,
("sblock: flags invalid (0x%x)", flags));
if (flags & SBL_WAIT) {
if ((sb->sb_flags & SB_NOINTR) ||
(flags & SBL_NOINTR)) {
sx_xlock(&sb->sb_sx);
return (0);
}
return (sx_xlock_sig(&sb->sb_sx));
} else {
if (sx_try_xlock(&sb->sb_sx) == 0)
return (EWOULDBLOCK);
return (0);
}
}
void
sbunlock(struct sockbuf *sb)
{
sx_xunlock(&sb->sb_sx);
}
/*
* 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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