MCLALLOC must be called at splimp

[unix-history] / usr / src / sys / kern / uipc_socket2.c

diff --git a/usr/src/sys/kern/uipc_socket2.c b/usr/src/sys/kern/uipc_socket2.c
index 6a5dc40..5cffe30 100644 (file)
--- a/usr/src/sys/kern/uipc_socket2.c
+++ b/usr/src/sys/kern/uipc_socket2.c
@@ -1,19 +1,23 @@
-/*     uipc_socket2.c  4.4     81/11/21        */
-
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/dir.h"
-#include "../h/user.h"
-#include "../h/proc.h"
-#include "../h/file.h"
-#include "../h/inode.h"
-#include "../h/buf.h"
-#include "../h/mbuf.h"
-#include "../h/protosw.h"
-#include "../h/socket.h"
-#include "../h/socketvar.h"
-#include "../net/inet.h"
-#include "../net/inet_systm.h"
+/*
+ * Copyright (c) 1982, 1986 Regents of the University of California.
+ * All rights reserved.  The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ *
+ *     @(#)uipc_socket2.c      7.1 (Berkeley) %G%
+ */
+
+#include "param.h"
+#include "systm.h"
+#include "dir.h"
+#include "user.h"
+#include "proc.h"
+#include "file.h"
+#include "inode.h"
+#include "buf.h"
+#include "mbuf.h"
+#include "protosw.h"
+#include "socket.h"
+#include "socketvar.h"

 
 /*
  * Primitive routines for operating on sockets and socket buffers
 
 /*
  * Primitive routines for operating on sockets and socket buffers


@@ -21,10 +25,36 @@
 
 /*
  * Procedures to manipulate state flags of socket
 
 /*
  * Procedures to manipulate state flags of socket

- * and do appropriate wakeups.
+ * 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)
 soisconnecting(so)

-       struct socket *so;
+       register struct socket *so;

 {
 
        so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
 {
 
        so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);


@@ -33,25 +63,37 @@ soisconnecting(so)
 }
 
 soisconnected(so)
 }
 
 soisconnected(so)

-       struct socket *so;
+       register struct socket *so;

 {
 {

-
+       register struct socket *head = so->so_head;
+
+       if (head) {
+               if (soqremque(so, 0) == 0)
+                       panic("soisconnected");
+               soqinsque(head, so, 1);
+               sorwakeup(head);
+               wakeup((caddr_t)&head->so_timeo);
+       }

        so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING);
        so->so_state |= SS_ISCONNECTED;
        wakeup((caddr_t)&so->so_timeo);
        so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING);
        so->so_state |= SS_ISCONNECTED;
        wakeup((caddr_t)&so->so_timeo);

+       sorwakeup(so);
+       sowwakeup(so);

 }
 
 soisdisconnecting(so)
 }
 
 soisdisconnecting(so)

-       struct socket *so;
+       register struct socket *so;

 {
 
 {
 

-       so->so_state &= ~(SS_ISCONNECTED|SS_ISCONNECTING);
+       so->so_state &= ~SS_ISCONNECTING;

        so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
        wakeup((caddr_t)&so->so_timeo);
        so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
        wakeup((caddr_t)&so->so_timeo);

+       sowwakeup(so);
+       sorwakeup(so);

 }
 
 soisdisconnected(so)
 }
 
 soisdisconnected(so)

-       struct socket *so;
+       register struct socket *so;

 {
 
        so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
 {
 
        so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);


@@ -61,6 +103,100 @@ soisdisconnected(so)
        sorwakeup(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.
+ */
+struct socket *
+sonewconn(head)
+       register struct socket *head;
+{
+       register struct socket *so;
+       register struct mbuf *m;
+
+       if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2)
+               goto bad;
+       m = m_getclr(M_DONTWAIT, MT_SOCKET);
+       if (m == NULL)
+               goto bad;
+       so = mtod(m, struct socket *);
+       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_pgrp = head->so_pgrp;
+       soqinsque(head, so, 0);
+       if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH,
+           (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) {
+               (void) soqremque(so, 0);
+               (void) m_free(m);
+               goto bad;
+       }
+       return (so);
+bad:
+       return ((struct socket *)0);
+}
+
+soqinsque(head, so, q)
+       register struct socket *head, *so;
+       int q;
+{
+
+       so->so_head = head;
+       if (q == 0) {
+               head->so_q0len++;
+               so->so_q0 = head->so_q0;
+               head->so_q0 = so;
+       } else {
+               head->so_qlen++;
+               so->so_q = head->so_q;
+               head->so_q = 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 == head)
+                       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;
 {
 socantsendmore(so)
        struct socket *so;
 {


@@ -78,25 +214,8 @@ socantrcvmore(so)
 }
 
 /*
 }
 
 /*

- * Select a socket.
+ * Socket select/wakeup routines.

  */
  */

-soselect(so, flag)
-       register struct socket *so;
-       int flag;
-{
-
-       if (flag & FREAD) {
-               if (soreadable(so))
-                       return (1);
-               sbselqueue(&so->so_rcv);
-       }
-       if (flag & FWRITE) {
-               if (sowriteable(so))
-                       return (1);
-               sbselqueue(&so->so_snd);
-       }
-       return (0);
-}

 
 /*
  * Queue a process for a select on a socket buffer.
 
 /*
  * Queue a process for a select on a socket buffer.


@@ -127,7 +246,7 @@ sbwait(sb)
  * Wakeup processes waiting on a socket buffer.
  */
 sbwakeup(sb)
  * Wakeup processes waiting on a socket buffer.
  */
 sbwakeup(sb)

-       struct sockbuf *sb;
+       register struct sockbuf *sb;

 {
 
        if (sb->sb_sel) {
 {
 
        if (sb->sb_sel) {


@@ -137,21 +256,91 @@ sbwakeup(sb)
        }
        if (sb->sb_flags & SB_WAIT) {
                sb->sb_flags &= ~SB_WAIT;
        }
        if (sb->sb_flags & SB_WAIT) {
                sb->sb_flags &= ~SB_WAIT;

-               wakeup((caddr_t)sb->sb_cc);
+               wakeup((caddr_t)&sb->sb_cc);

        }
 }
 
        }
 }
 

+/*
+ * Wakeup socket readers and writers.
+ * Do asynchronous notification via SIGIO
+ * if the socket has the SS_ASYNC flag set.
+ */
+sowakeup(so, sb)
+       register struct socket *so;
+       struct sockbuf *sb;
+{
+       register struct proc *p;
+
+       sbwakeup(sb);
+       if (so->so_state & SS_ASYNC) {
+               if (so->so_pgrp < 0)
+                       gsignal(-so->so_pgrp, SIGIO);
+               else if (so->so_pgrp > 0 && (p = pfind(so->so_pgrp)) != 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_act 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 commits
+ * some of the available buffer space in the system buffer pool for the
+ * socket.  The space should be released by calling sbrelease() when the
+ * socket is destroyed.
+ */
+
+soreserve(so, sndcc, rcvcc)
+       register struct socket *so;
+       int sndcc, rcvcc;
+{
+
+       if (sbreserve(&so->so_snd, sndcc) == 0)
+               goto bad;
+       if (sbreserve(&so->so_rcv, rcvcc) == 0)
+               goto bad2;
+       return (0);
+bad2:
+       sbrelease(&so->so_snd);
+bad:
+       return (ENOBUFS);
+}
+

 /*
  * Allot mbufs to a sockbuf.
 /*
  * Allot mbufs to a sockbuf.

+ * Attempt to scale cc so that mbcnt doesn't become limiting
+ * if buffering efficiency is near the normal case.

  */
 sbreserve(sb, cc)
        struct sockbuf *sb;
 {
 
  */
 sbreserve(sb, cc)
        struct sockbuf *sb;
 {
 

-       if (m_reserve(cc) == 0)
+       if ((unsigned) cc > (unsigned)SB_MAX * CLBYTES / (2 * MSIZE + CLBYTES))

                return (0);
        sb->sb_hiwat = cc;
                return (0);
        sb->sb_hiwat = cc;

-       sb->sb_mbmax = (cc*2)/MSIZE;
+       sb->sb_mbmax = MIN(cc * 2, SB_MAX);

        return (1);
 }
 
        return (1);
 }
 


@@ -163,111 +352,270 @@ sbrelease(sb)
 {
 
        sbflush(sb);
 {
 
        sbflush(sb);

-       m_release(sb->sb_hiwat);

        sb->sb_hiwat = sb->sb_mbmax = 0;
 }
 
 /*
        sb->sb_hiwat = sb->sb_mbmax = 0;
 }
 
 /*

- * Routines to add (at the end) and remove (from the beginning)
- * data from a mbuf queue.
+ * 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 queue m to sockbuf 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.

  */
 sbappend(sb, m)
  */
 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_act)
+                       n = n->m_act;
+               while (n->m_next)
+                       n = n->m_next;
+       }
+       sbcompress(sb, m, n);
+}
+
+/*
+ * 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;
        register struct mbuf *m;

+
+       if (m0 == 0)
+               return;
+       if (m = sb->sb_mb)
+               while (m->m_act)
+                       m = m->m_act;
+       /*
+        * Put the first mbuf on the queue.
+        * Note this permits zero length records.
+        */
+       sballoc(sb, m0);
+       if (m)
+               m->m_act = m0;
+       else
+               sb->sb_mb = m0;
+       m = m0->m_next;
+       m0->m_next = 0;
+       sbcompress(sb, m, m0);
+}
+
+/*
+ * Append address and data, and optionally, rights
+ * to the receive queue of a socket.  Return 0 if
+ * no space in sockbuf or insufficient mbufs.
+ */
+sbappendaddr(sb, asa, m0, rights0)

        register struct sockbuf *sb;
        register struct sockbuf *sb;

+       struct sockaddr *asa;
+       struct mbuf *rights0, *m0;

 {
 {

-       register struct mbuf **np, *n;
+       register struct mbuf *m, *n;
+       int space = sizeof (*asa);

 
 

-       np = &sb->sb_mb;
-       while ((n = *np) && n->m_next)
-               np = &n->m_next;
-       while (m) {
-               if (n && n->m_off <= MMAXOFF && m->m_off <= MMAXOFF &&
-                  (int)n->m_act == 0 && (int)m->m_act == 0 &&
-                  (n->m_off + n->m_len + m->m_off) <= MMAXOFF) {
-                       bcopy(mtod(m, caddr_t), mtod(n, caddr_t),
-                           (unsigned)m->m_len);
-                       n->m_len += m->m_len;
-                       sb->sb_cc += m->m_len;
-                       m = m_free(m);
-                       continue;
+       for (m = m0; m; m = m->m_next)
+               space += m->m_len;
+       if (rights0)
+               space += rights0->m_len;
+       if (space > sbspace(sb))
+               return (0);
+       MGET(m, M_DONTWAIT, MT_SONAME);
+       if (m == 0)
+               return (0);
+       *mtod(m, struct sockaddr *) = *asa;
+       m->m_len = sizeof (*asa);
+       if (rights0 && rights0->m_len) {
+               m->m_next = m_copy(rights0, 0, rights0->m_len);
+               if (m->m_next == 0) {
+                       m_freem(m);
+                       return (0);

                }
                }

-               sballoc(sb, m);
-               *np = m;
-               n = m;
-               np = &n->m_next;
-               m = m->m_next;
+               sballoc(sb, m->m_next);

        }
        }

+       sballoc(sb, m);
+       if (n = sb->sb_mb) {
+               while (n->m_act)
+                       n = n->m_act;
+               n->m_act = m;
+       } else
+               sb->sb_mb = m;
+       if (m->m_next)
+               m = m->m_next;
+       if (m0)
+               sbcompress(sb, m0, m);
+       return (1);

 }
 
 }
 

-sbappendaddr(sb, asa, m0)
+sbappendrights(sb, m0, rights)

        struct sockbuf *sb;
        struct sockbuf *sb;

-       struct sockaddr *asa;
-       struct mbuf *m0;
+       struct mbuf *rights, *m0;

 {
 {

-       struct sockaddr *msa;
-       register struct mbuf *m;
-       register int len = sizeof (struct sockaddr);
+       register struct mbuf *m, *n;
+       int space = 0;

 
 

+       if (rights == 0)
+               panic("sbappendrights");

        for (m = m0; m; m = m->m_next)
        for (m = m0; m; m = m->m_next)

-               len += m->m_len;
-       if (len > sbspace(sb))
+               space += m->m_len;
+       space += rights->m_len;
+       if (space > sbspace(sb))

                return (0);
                return (0);

-       m = m_get(0);
+       m = m_copy(rights, 0, rights->m_len);

        if (m == 0)
                return (0);
        if (m == 0)
                return (0);

-       m->m_off = MMINOFF;
-       m->m_len = sizeof (struct sockaddr);
-       msa = mtod(m, struct sockaddr *);
-       *msa = *asa;
-       m->m_act = (struct mbuf *)1;
-       sbappend(sb, m);
-       m0->m_act = (struct mbuf *)1;
-       sbappend(sb, m0);
+       sballoc(sb, m);
+       if (n = sb->sb_mb) {
+               while (n->m_act)
+                       n = n->m_act;
+               n->m_act = m;
+       } else
+               sb->sb_mb = m;
+       if (m0)
+               sbcompress(sb, m0, m);

        return (1);
 }
 
 /*
        return (1);
 }
 
 /*

- * Free all mbufs on a sockbuf mbuf chain.
- * Check that resource allocations return to 0.
+ * 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;
+{
+
+       while (m) {
+               if (m->m_len == 0) {
+                       m = m_free(m);
+                       continue;
+               }
+               if (n && n->m_off <= MMAXOFF && m->m_off <= MMAXOFF &&
+                   (n->m_off + n->m_len + m->m_len) <= MMAXOFF &&
+                   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;
+               }
+               sballoc(sb, m);
+               if (n)
+                       n->m_next = m;
+               else
+                       sb->sb_mb = m;
+               n = m;
+               m = m->m_next;
+               n->m_next = 0;
+       }
+}
+
+/*
+ * Free all mbufs in a sockbuf.
+ * Check that all resources are reclaimed.

  */
 sbflush(sb)
  */
 sbflush(sb)

-       struct sockbuf *sb;
+       register struct sockbuf *sb;

 {
 
        if (sb->sb_flags & SB_LOCK)
                panic("sbflush");
 {
 
        if (sb->sb_flags & SB_LOCK)
                panic("sbflush");

-       sbdrop(sb, sb->sb_cc);
+       while (sb->sb_mbcnt)
+               sbdrop(sb, (int)sb->sb_cc);

        if (sb->sb_cc || sb->sb_mbcnt || sb->sb_mb)
                panic("sbflush 2");
 }
 
 /*
        if (sb->sb_cc || sb->sb_mbcnt || sb->sb_mb)
                panic("sbflush 2");
 }
 
 /*

- * Drop data from (the front of) a sockbuf chain.
+ * Drop data from (the front of) a sockbuf.

  */
 sbdrop(sb, len)
        register struct sockbuf *sb;
        register int len;
 {
  */
 sbdrop(sb, len)
        register struct sockbuf *sb;
        register int len;
 {

-       register struct mbuf *m = sb->sb_mb, *mn;
+       register struct mbuf *m, *mn;
+       struct mbuf *next;

 
 

+       next = (m = sb->sb_mb) ? m->m_act : 0;

        while (len > 0) {
        while (len > 0) {

-               if (m == 0)
-                       panic("sbdrop");
-               if (m->m_len <= len) {
-                       len -= m->m_len;
-                       sbfree(sb, m);
-                       MFREE(m, mn);
-                       m = mn;
-               } else {
+               if (m == 0) {
+                       if (next == 0)
+                               panic("sbdrop");
+                       m = next;
+                       next = m->m_act;
+                       continue;
+               }
+               if (m->m_len > len) {

                        m->m_len -= len;
                        m->m_off += len;
                        sb->sb_cc -= len;
                        break;
                }
                        m->m_len -= len;
                        m->m_off += 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_act = 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_act;
+               do {
+                       sbfree(sb, m);
+                       MFREE(m, mn);
+               } while (m = mn);

        }
        }

-       sb->sb_mb = m;

 }
 }