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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/kern/uipc_sockbuf.c.orig |
/*- * 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: release/9.1.0/sys/kern/uipc_sockbuf.c 225169 2011-08-25 09:20:13Z bz $"); #include "opt_param.h" #include <sys/param.h> #include <sys/aio.h> /* for aio_swake proto */ #include <sys/kernel.h> #include <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) { PROC_LOCK(td->td_proc); sbsize_limit = lim_cur(td->td_proc, RLIMIT_SBSIZE); PROC_UNLOCK(td->td_proc); } 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); } /* * 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 *m, *n, *nlast; 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, &n); if (space > sbspace(sb)) return (0); #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 (n) n->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(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; /* 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); } /* * 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")); 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, "");