#include <machine/rtems-bsd-kernel-space.h>
/*-
* 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.
* 4. 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 <rtems/bsd/local/opt_param.h>
#include <rtems/bsd/sys/param.h>
#include <sys/aio.h> /* for aio_swake proto */
#include <sys/kernel.h>
#include <rtems/bsd/sys/lock.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() */
static void sbdrop_internal(struct sockbuf *sb, int len);
static void sbflush_internal(struct sockbuf *sb);
/*
* 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;
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);
}
/*
* 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(&sb->sb_cc, &sb->sb_mtx,
(sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
sb->sb_timeo));
}
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_cc);
}
KNOTE_LOCKED(&sb->sb_sel.si_note, 0);
if (sb->sb_upcall != NULL) {
ret = sb->sb_upcall(so, sb->sb_upcallarg, M_DONTWAIT);
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)
aio_swake(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) {
#ifndef __rtems__
PROC_LOCK(td->td_proc);
sbsize_limit = lim_cur(td->td_proc, RLIMIT_SBSIZE);
PROC_UNLOCK(td->td_proc);
#else /* __rtems__ */
sbsize_limit = RLIM_INFINITY;
#endif /* __rtems__ */
} 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
sbreserve(struct sockbuf *sb, u_long cc, struct socket *so,
struct thread *td)
{
int error;
SOCKBUF_LOCK(sb);
error = sbreserve_locked(sb, cc, so, td);
SOCKBUF_UNLOCK(sb);
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);
}
/*
* 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);
}
}
#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)
{
struct mbuf *n;
SOCKBUF_LOCK_ASSERT(sb);
if (m == 0)
return;
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)
{
SOCKBUF_LOCK(sb);
sbappend_locked(sb, m);
SOCKBUF_UNLOCK(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_locked(struct sockbuf *sb, struct mbuf *m)
{
SOCKBUF_LOCK_ASSERT(sb);
KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
SBLASTMBUFCHK(sb);
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)
{
SOCKBUF_LOCK(sb);
sbappendstream_locked(sb, m);
SOCKBUF_UNLOCK(sb);
}
#ifdef SOCKBUF_DEBUG
void
sbcheck(struct sockbuf *sb)
{
struct mbuf *m;
struct mbuf *n = 0;
u_long len = 0, mbcnt = 0;
SOCKBUF_LOCK_ASSERT(sb);
for (m = sb->sb_mb; m; m = n) {
n = m->m_nextpkt;
for (; m; m = m->m_next) {
len += m->m_len;
mbcnt += MSIZE;
if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
mbcnt += m->m_ext.ext_size;
}
}
if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
printf("cc %ld != %u || mbcnt %ld != %u\n", len, sb->sb_cc,
mbcnt, sb->sb_mbcnt);
panic("sbcheck");
}
}
#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 == 0)
return;
/*
* 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
MGET(m, M_DONTWAIT, MT_SONAME);
if (m == 0)
return (0);
m->m_len = asa->sa_len;
bcopy(asa, mtod(m, caddr_t), asa->sa_len);
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);
}
int
sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
struct mbuf *control)
{
struct mbuf *m, *n, *mlast;
int space;
SOCKBUF_LOCK_ASSERT(sb);
if (control == 0)
panic("sbappendcontrol_locked");
space = m_length(control, &n) + m_length(m0, NULL);
if (space > sbspace(sb))
return (0);
n->m_next = m0; /* concatenate data to control */
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);
return (1);
}
int
sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control)
{
int retval;
SOCKBUF_LOCK(sb);
retval = sbappendcontrol_locked(sb, m0, control);
SOCKBUF_UNLOCK(sb);
return (retval);
}
/*
* 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, 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_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
m->m_len <= M_TRAILINGSPACE(n) &&
n->m_type == m->m_type) {
bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
(unsigned)m->m_len);
n->m_len += m->m_len;
sb->sb_cc += 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 (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);
}
/*
* Free all mbufs in a sockbuf. Check that all resources are reclaimed.
*/
static void
sbflush_internal(struct sockbuf *sb)
{
while (sb->sb_mbcnt) {
/*
* Don't call sbdrop(sb, 0) if the leading mbuf is non-empty:
* we would loop forever. Panic instead.
*/
if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len))
break;
sbdrop_internal(sb, (int)sb->sb_cc);
}
if (sb->sb_cc || sb->sb_mb || sb->sb_mbcnt)
panic("sbflush_internal: cc %u || mb %p || mbcnt %u",
sb->sb_cc, (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);
}
/*
* Drop data from (the front of) a sockbuf.
*/
static void
sbdrop_internal(struct sockbuf *sb, int len)
{
struct mbuf *m;
struct mbuf *next;
next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
while (len > 0) {
if (m == 0) {
if (next == 0)
panic("sbdrop");
m = next;
next = m->m_nextpkt;
continue;
}
if (m->m_len > len) {
m->m_len -= len;
m->m_data += len;
sb->sb_cc -= 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;
sbfree(sb, m);
m = m_free(m);
}
while (m && m->m_len == 0) {
sbfree(sb, m);
m = m_free(m);
}
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;
}
}
/*
* Drop data from (the front of) a sockbuf.
*/
void
sbdrop_locked(struct sockbuf *sb, int len)
{
SOCKBUF_LOCK_ASSERT(sb);
sbdrop_internal(sb, len);
}
void
sbdrop(struct sockbuf *sb, int len)
{
SOCKBUF_LOCK(sb);
sbdrop_locked(sb, len);
SOCKBUF_UNLOCK(sb);
}
/*
* Maintain a pointer and offset pair into the socket buffer mbuf chain to
* avoid traversal of the entire socket buffer for larger offsets.
*/
struct mbuf *
sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff)
{
struct mbuf *m, *ret;
KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
KASSERT(off + len <= sb->sb_cc, ("%s: beyond sb", __func__));
KASSERT(sb->sb_sndptroff <= sb->sb_cc, ("%s: sndptroff broken", __func__));
/*
* Is off below stored offset? Happens on retransmits.
* Just return, we can't help here.
*/
if (sb->sb_sndptroff > off) {
*moff = off;
return (sb->sb_mb);
}
/* Return closest mbuf in chain for current offset. */
*moff = off - sb->sb_sndptroff;
m = ret = sb->sb_sndptr ? sb->sb_sndptr : sb->sb_mb;
if (*moff == m->m_len) {
*moff = 0;
sb->sb_sndptroff += m->m_len;
m = ret = m->m_next;
KASSERT(ret->m_len > 0,
("mbuf %p in sockbuf %p chain has no valid data", ret, sb));
}
/* Advance by len to be as close as possible for the next transmit. */
for (off = off - sb->sb_sndptroff + len - 1;
off > 0 && m != NULL && off >= m->m_len;
m = m->m_next) {
sb->sb_sndptroff += m->m_len;
off -= m->m_len;
}
if (off > 0 && m == NULL)
panic("%s: sockbuf %p and mbuf %p clashing", __func__, sb, ret);
sb->sb_sndptr = m;
return (ret);
}
/*
* 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(caddr_t p, int size, int type, int level)
{
struct cmsghdr *cp;
struct mbuf *m;
if (CMSG_SPACE((u_int)size) > MCLBYTES)
return ((struct mbuf *) NULL);
if (CMSG_SPACE((u_int)size) > MLEN)
m = m_getcl(M_DONTWAIT, MT_CONTROL, 0);
else
m = m_get(M_DONTWAIT, 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);
}
/*
* 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_cc;
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, &dummy, 0, "");
SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW,
&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, "");
