diff options
Diffstat (limited to 'sys/kern/uipc_sockbuf.c')
| -rw-r--r-- | sys/kern/uipc_sockbuf.c | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c new file mode 100644 index 000000000000..d4af592d79b5 --- /dev/null +++ b/sys/kern/uipc_sockbuf.c @@ -0,0 +1,755 @@ +/* + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 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/param.h> +#include <sys/systm.h> +#include <sys/proc.h> +#include <sys/file.h> +#include <sys/buf.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/protosw.h> +#include <sys/socket.h> +#include <sys/socketvar.h> + +/* + * Primitive routines for operating on sockets and socket buffers + */ + +/* strings for sleep message: */ +char netio[] = "netio"; +char netcon[] = "netcon"; +char netcls[] = "netcls"; + +u_long sb_max = SB_MAX; /* patchable */ + +/* + * Procedures to manipulate state flags of socket + * and do appropriate wakeups. Normal sequence from the + * active (originating) side is that soisconnecting() is + * called during processing of connect() call, + * resulting in an eventual call to soisconnected() if/when the + * connection is established. When the connection is torn down + * soisdisconnecting() is called during processing of disconnect() call, + * and soisdisconnected() is called when the connection to the peer + * is totally severed. The semantics of these routines are such that + * connectionless protocols can call soisconnected() and soisdisconnected() + * only, bypassing the in-progress calls when setting up a ``connection'' + * takes no time. + * + * From the passive side, a socket is created with + * two queues of sockets: so_q0 for connections in progress + * and so_q for connections already made and awaiting user acceptance. + * As a protocol is preparing incoming connections, it creates a socket + * structure queued on so_q0 by calling sonewconn(). When the connection + * is established, soisconnected() is called, and transfers the + * socket structure to so_q, making it available to accept(). + * + * If a socket is closed with sockets on either + * so_q0 or so_q, these sockets are dropped. + * + * If higher level protocols are implemented in + * the kernel, the wakeups done here will sometimes + * cause software-interrupt process scheduling. + */ + +soisconnecting(so) + register struct socket *so; +{ + + so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); + so->so_state |= SS_ISCONNECTING; +} + +soisconnected(so) + register struct socket *so; +{ + register struct socket *head = so->so_head; + + so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); + so->so_state |= SS_ISCONNECTED; + if (head && soqremque(so, 0)) { + soqinsque(head, so, 1); + sorwakeup(head); + wakeup((caddr_t)&head->so_timeo); + } else { + wakeup((caddr_t)&so->so_timeo); + sorwakeup(so); + sowwakeup(so); + } +} + +soisdisconnecting(so) + register struct socket *so; +{ + + so->so_state &= ~SS_ISCONNECTING; + so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); + wakeup((caddr_t)&so->so_timeo); + sowwakeup(so); + sorwakeup(so); +} + +soisdisconnected(so) + register struct socket *so; +{ + + so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); + so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); + wakeup((caddr_t)&so->so_timeo); + sowwakeup(so); + sorwakeup(so); +} + +/* + * When an attempt at a new connection is noted on a socket + * which accepts connections, sonewconn is called. If the + * connection is possible (subject to space constraints, etc.) + * then we allocate a new structure, propoerly linked into the + * data structure of the original socket, and return this. + * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. + * + * Currently, sonewconn() is defined as sonewconn1() in socketvar.h + * to catch calls that are missing the (new) second parameter. + */ +struct socket * +sonewconn1(head, connstatus) + register struct socket *head; + int connstatus; +{ + register struct socket *so; + int soqueue = connstatus ? 1 : 0; + + if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) + return ((struct socket *)0); + MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT); + if (so == NULL) + return ((struct socket *)0); + bzero((caddr_t)so, sizeof(*so)); + so->so_type = head->so_type; + so->so_options = head->so_options &~ SO_ACCEPTCONN; + so->so_linger = head->so_linger; + so->so_state = head->so_state | SS_NOFDREF; + so->so_proto = head->so_proto; + so->so_timeo = head->so_timeo; + so->so_pgid = head->so_pgid; + (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat); + soqinsque(head, so, soqueue); + if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, + (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { + (void) soqremque(so, soqueue); + (void) free((caddr_t)so, M_SOCKET); + return ((struct socket *)0); + } + if (connstatus) { + sorwakeup(head); + wakeup((caddr_t)&head->so_timeo); + so->so_state |= connstatus; + } + return (so); +} + +soqinsque(head, so, q) + register struct socket *head, *so; + int q; +{ + + register struct socket **prev; + so->so_head = head; + if (q == 0) { + head->so_q0len++; + so->so_q0 = 0; + for (prev = &(head->so_q0); *prev; ) + prev = &((*prev)->so_q0); + } else { + head->so_qlen++; + so->so_q = 0; + for (prev = &(head->so_q); *prev; ) + prev = &((*prev)->so_q); + } + *prev = so; +} + +soqremque(so, q) + register struct socket *so; + int q; +{ + register struct socket *head, *prev, *next; + + head = so->so_head; + prev = head; + for (;;) { + next = q ? prev->so_q : prev->so_q0; + if (next == so) + break; + if (next == 0) + return (0); + prev = next; + } + if (q == 0) { + prev->so_q0 = next->so_q0; + head->so_q0len--; + } else { + prev->so_q = next->so_q; + head->so_qlen--; + } + next->so_q0 = next->so_q = 0; + next->so_head = 0; + return (1); +} + +/* + * 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. + */ + +socantsendmore(so) + struct socket *so; +{ + + so->so_state |= SS_CANTSENDMORE; + sowwakeup(so); +} + +socantrcvmore(so) + struct socket *so; +{ + + so->so_state |= SS_CANTRCVMORE; + sorwakeup(so); +} + +/* + * Wait for data to arrive at/drain from a socket buffer. + */ +sbwait(sb) + struct sockbuf *sb; +{ + + sb->sb_flags |= SB_WAIT; + return (tsleep((caddr_t)&sb->sb_cc, + (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, + sb->sb_timeo)); +} + +/* + * Lock a sockbuf already known to be locked; + * return any error returned from sleep (EINTR). + */ +sb_lock(sb) + register struct sockbuf *sb; +{ + int error; + + while (sb->sb_flags & SB_LOCK) { + sb->sb_flags |= SB_WANT; + if (error = tsleep((caddr_t)&sb->sb_flags, + (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, + netio, 0)) + return (error); + } + sb->sb_flags |= SB_LOCK; + return (0); +} + +/* + * Wakeup processes waiting on a socket buffer. + * Do asynchronous notification via SIGIO + * if the socket has the SS_ASYNC flag set. + */ +sowakeup(so, sb) + register struct socket *so; + register struct sockbuf *sb; +{ + struct proc *p; + + selwakeup(&sb->sb_sel); + sb->sb_flags &= ~SB_SEL; + if (sb->sb_flags & SB_WAIT) { + sb->sb_flags &= ~SB_WAIT; + wakeup((caddr_t)&sb->sb_cc); + } + if (so->so_state & SS_ASYNC) { + if (so->so_pgid < 0) + gsignal(-so->so_pgid, SIGIO); + else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) + psignal(p, SIGIO); + } +} + +/* + * 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. + */ + +soreserve(so, sndcc, rcvcc) + register struct socket *so; + u_long sndcc, rcvcc; +{ + + if (sbreserve(&so->so_snd, sndcc) == 0) + goto bad; + if (sbreserve(&so->so_rcv, rcvcc) == 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; + return (0); +bad2: + sbrelease(&so->so_snd); +bad: + return (ENOBUFS); +} + +/* + * Allot mbufs to a sockbuf. + * Attempt to scale mbmax so that mbcnt doesn't become limiting + * if buffering efficiency is near the normal case. + */ +sbreserve(sb, cc) + struct sockbuf *sb; + u_long cc; +{ + + if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) + return (0); + sb->sb_hiwat = cc; + sb->sb_mbmax = min(cc * 2, sb_max); + if (sb->sb_lowat > sb->sb_hiwat) + sb->sb_lowat = sb->sb_hiwat; + return (1); +} + +/* + * Free mbufs held by a socket, and reserved mbuf space. + */ +sbrelease(sb) + struct sockbuf *sb; +{ + + sbflush(sb); + sb->sb_hiwat = sb->sb_mbmax = 0; +} + +/* + * 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. + */ + +/* + * 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. + */ +sbappend(sb, m) + struct sockbuf *sb; + struct mbuf *m; +{ + register struct mbuf *n; + + if (m == 0) + return; + if (n = sb->sb_mb) { + while (n->m_nextpkt) + n = n->m_nextpkt; + do { + if (n->m_flags & M_EOR) { + sbappendrecord(sb, m); /* XXXXXX!!!! */ + return; + } + } while (n->m_next && (n = n->m_next)); + } + sbcompress(sb, m, n); +} + +#ifdef SOCKBUF_DEBUG +sbcheck(sb) + register struct sockbuf *sb; +{ + register struct mbuf *m; + register int len = 0, mbcnt = 0; + + for (m = sb->sb_mb; m; m = m->m_next) { + len += m->m_len; + mbcnt += MSIZE; + if (m->m_flags & M_EXT) + mbcnt += m->m_ext.ext_size; + if (m->m_nextpkt) + panic("sbcheck nextpkt"); + } + if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { + printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, + mbcnt, sb->sb_mbcnt); + panic("sbcheck"); + } +} +#endif + +/* + * As above, except the mbuf chain + * begins a new record. + */ +sbappendrecord(sb, m0) + register struct sockbuf *sb; + register struct mbuf *m0; +{ + register struct mbuf *m; + + if (m0 == 0) + return; + if (m = sb->sb_mb) + while (m->m_nextpkt) + m = m->m_nextpkt; + /* + * Put the first mbuf on the queue. + * Note this permits zero length records. + */ + sballoc(sb, m0); + if (m) + m->m_nextpkt = m0; + else + sb->sb_mb = 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; + } + sbcompress(sb, m, m0); +} + +/* + * As above except that OOB data + * is inserted at the beginning of the sockbuf, + * but after any other OOB data. + */ +sbinsertoob(sb, m0) + register struct sockbuf *sb; + register struct mbuf *m0; +{ + register struct mbuf *m; + register struct mbuf **mp; + + if (m0 == 0) + return; + for (mp = &sb->sb_mb; m = *mp; mp = &((*mp)->m_nextpkt)) { + again: + switch (m->m_type) { + + case MT_OOBDATA: + continue; /* WANT next train */ + + case MT_CONTROL: + if (m = m->m_next) + goto again; /* inspect THIS train further */ + } + break; + } + /* + * Put the first mbuf on the queue. + * Note this permits zero length records. + */ + sballoc(sb, m0); + m0->m_nextpkt = *mp; + *mp = 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; + } + sbcompress(sb, m, m0); +} + +/* + * 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. + */ +sbappendaddr(sb, asa, m0, control) + register struct sockbuf *sb; + struct sockaddr *asa; + struct mbuf *m0, *control; +{ + register struct mbuf *m, *n; + int space = asa->sa_len; + +if (m0 && (m0->m_flags & M_PKTHDR) == 0) +panic("sbappendaddr"); + if (m0) + space += m0->m_pkthdr.len; + for (n = control; n; n = n->m_next) { + space += n->m_len; + if (n->m_next == 0) /* keep pointer to last control buf */ + break; + } + if (space > sbspace(sb)) + return (0); + if (asa->sa_len > MLEN) + return (0); + MGET(m, M_DONTWAIT, MT_SONAME); + if (m == 0) + return (0); + m->m_len = asa->sa_len; + bcopy((caddr_t)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; n = n->m_next) + sballoc(sb, n); + if (n = sb->sb_mb) { + while (n->m_nextpkt) + n = n->m_nextpkt; + n->m_nextpkt = m; + } else + sb->sb_mb = m; + return (1); +} + +sbappendcontrol(sb, m0, control) + struct sockbuf *sb; + struct mbuf *control, *m0; +{ + register struct mbuf *m, *n; + int space = 0; + + if (control == 0) + panic("sbappendcontrol"); + for (m = control; ; m = m->m_next) { + space += m->m_len; + if (m->m_next == 0) + break; + } + n = m; /* save pointer to last control buffer */ + for (m = m0; m; m = m->m_next) + space += m->m_len; + if (space > sbspace(sb)) + return (0); + n->m_next = m0; /* concatenate data to control */ + for (m = control; m; m = m->m_next) + sballoc(sb, m); + if (n = sb->sb_mb) { + while (n->m_nextpkt) + n = n->m_nextpkt; + n->m_nextpkt = control; + } else + sb->sb_mb = control; + return (1); +} + +/* + * Compress mbuf chain m into the socket + * buffer sb following mbuf n. If n + * is null, the buffer is presumed empty. + */ +sbcompress(sb, m, n) + register struct sockbuf *sb; + register struct mbuf *m, *n; +{ + register int eor = 0; + register struct mbuf *o; + + 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))) { + m = m_free(m); + continue; + } + if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && + (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && + 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; + m = m_free(m); + continue; + } + if (n) + n->m_next = m; + else + sb->sb_mb = m; + sballoc(sb, m); + n = m; + m->m_flags &= ~M_EOR; + m = m->m_next; + n->m_next = 0; + } + if (eor) { + if (n) + n->m_flags |= eor; + else + printf("semi-panic: sbcompress\n"); + } +} + +/* + * Free all mbufs in a sockbuf. + * Check that all resources are reclaimed. + */ +sbflush(sb) + register struct sockbuf *sb; +{ + + if (sb->sb_flags & SB_LOCK) + panic("sbflush"); + while (sb->sb_mbcnt) + sbdrop(sb, (int)sb->sb_cc); + if (sb->sb_cc || sb->sb_mb) + panic("sbflush 2"); +} + +/* + * Drop data from (the front of) a sockbuf. + */ +sbdrop(sb, len) + register struct sockbuf *sb; + register int len; +{ + register struct mbuf *m, *mn; + 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; + break; + } + len -= m->m_len; + sbfree(sb, m); + MFREE(m, mn); + m = mn; + } + while (m && m->m_len == 0) { + sbfree(sb, m); + MFREE(m, mn); + m = mn; + } + if (m) { + sb->sb_mb = m; + m->m_nextpkt = next; + } else + sb->sb_mb = next; +} + +/* + * Drop a record off the front of a sockbuf + * and move the next record to the front. + */ +sbdroprecord(sb) + register struct sockbuf *sb; +{ + register struct mbuf *m, *mn; + + m = sb->sb_mb; + if (m) { + sb->sb_mb = m->m_nextpkt; + do { + sbfree(sb, m); + MFREE(m, mn); + } while (m = mn); + } +} |