--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: pkbuf.c,v 1.1 2000/06/17 10:39:19 mdw Exp $
+ *
+ * Simple packet buffering
+ *
+ * (c) 2000 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: pkbuf.c,v $
+ * Revision 1.1 2000/06/17 10:39:19 mdw
+ * Experimental new support for packet buffering.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc.h"
+#include "arena.h"
+#include "pkbuf.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @pkbuf_flush@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @octet *p@ = pointer to where to start searching
+ * @size_t len@ = length of new material added
+ *
+ * Returns: ---
+ *
+ * Use: Flushes any complete packets in a packet buffer. New
+ * material is assumed to have been added starting at @p@. If
+ * @p@ is null, then the scan starts at the beginning of the
+ * buffer, and the size of data already in the buffer is used in
+ * place of @len@.
+ *
+ * It is assumed that the buffer is initially enabled. You
+ * shouldn't be contributing data to a disabled buffer anyway.
+ * However, the buffer handler may at some point disable itself,
+ * and @pkbuf_flush@ can cope with this eventuality. Any
+ * pending data is left at the start of the buffer and can be
+ * flushed out by calling @pkbuf_flush(b, 0, 0)@ if the buffer
+ * is ever re-enabled.
+ */
+
+void pkbuf_flush(pkbuf *pk, octet *p, size_t len)
+{
+ size_t l;
+ size_t keep;
+
+ /* --- Initialize variables as necessary --- */
+
+ if (!p) {
+ p = pk->buf;
+ len = pk->len;
+ }
+ l = p + len - pk->buf;
+ p = pk->buf;
+
+ /* --- Now grind through any packets which have accumulated --- */
+
+ while (l > pk->want) {
+ size_t sz = pk->want;
+
+ /* --- Pass a packet to the user handler --- */
+
+ keep = 0;
+ pk->func(p, sz, pk, &keep, pk->p);
+
+ /* --- Adjust all the pointers for the next packet --- */
+
+ sz -= keep;
+ p += sz;
+ l -= sz;
+
+ /* --- Abort here if disabled --- */
+
+ if (!(pk->f & PKBUF_ENABLE))
+ break;
+ }
+
+ /* --- Shunt data around in the buffer --- */
+
+ if (p > pk->buf && l != 0)
+ memmove(pk->buf, p, l);
+ pk->len = l;
+}
+
+/* --- @pkbuf_close@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Informs the client that no more data is likely to arrive. If
+ * there is a partial packet in the buffer, it is discarded.
+ */
+
+void pkbuf_close(pkbuf *pk)
+{
+ if (pk->buf) {
+ fprintf(stderr, "*** destroying buffer, closing down\n");
+ x_free(pk->a, pk->buf);
+ pk->buf = 0;
+ }
+ if (pk->f & PKBUF_ENABLE)
+ pk->func(0, 0, pk, 0, pk->p);
+}
+
+/* --- @pkbuf_free@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @octet **p@ = output pointer to free space
+ *
+ * Returns: Free buffer size.
+ *
+ * Use: Returns the free portion of a packet buffer. Data can then
+ * be written to this portion, and split out into packets by
+ * calling @pkbuf_flush@. A buffer is allocated if none
+ * currently exists.
+ */
+
+size_t pkbuf_free(pkbuf *pk, octet **p)
+{
+ if (!pk->buf) {
+ fprintf(stderr, "*** allocating new buffer\n");
+ pk->buf = x_alloc(pk->a, pk->sz);
+ }
+ *p = pk->buf + pk->len;
+ return (pk->sz - pk->len);
+}
+
+/* --- @pkbuf_snarf@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @const void *p@ = pointer to input data buffer
+ * @size_t sz@ = size of data in input buffer
+ *
+ * Returns: ---
+ *
+ * Use: Snarfs the data from the input buffer and spits it out as
+ * packets. This interface ignores the complexities of dealing
+ * with disablement: you should be using @pkbuf_free@ to
+ * contribute data if you want to cope with that.
+ */
+
+void pkbuf_snarf(pkbuf *pk, const void *p, size_t sz)
+{
+ const octet *pp = p;
+ while (sz && (pk->f & PKBUF_ENABLE)) {
+ size_t bsz;
+ octet *bp;
+
+ bsz = pkbuf_free(pk, &bp);
+ if (bsz > sz)
+ bsz = sz;
+ memcpy(bp, pp, bsz);
+ pkbuf_flush(pk, bp, bsz);
+ pp += bsz;
+ sz -= bsz;
+ }
+}
+
+/* --- @pkbuf_want@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @size_t want@ = how many octets wanted for next packet
+ *
+ * Returns: ---
+ *
+ * Use: Sets the desired size for the next packet to be read. If
+ * it's larger than the current buffer, the buffer is extended.
+ */
+
+void pkbuf_want(pkbuf *pk, size_t want)
+{
+ pk->want = want;
+ if (want > pk->sz) {
+ do pk->sz <<= 1; while (want < pk->sz);
+ if (pk->buf) {
+ if (pk->len)
+ pk->buf = x_realloc(pk->a, pk->buf, pk->sz);
+ else {
+ x_free(pk->a, pk->buf);
+ pk->buf = 0;
+ }
+ }
+ }
+}
+
+/* --- @pkbuf_init@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @void (*func)(octet *b, size_t sz, pkbuf *pk,@
+ * @size_t *keep, void *p)@ =
+ * handler function
+ * @void *p@ = argument pointer for @func@
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a packet buffer block. Any packets are passed to
+ * the provided function for handling.
+ */
+
+void pkbuf_init(pkbuf *pk,
+ void (*func)(octet */*b*/, size_t /*sz*/,
+ pkbuf */*pk*/, size_t */*keep*/, void */*p*/),
+ void *p)
+{
+ pk->func = func;
+ pk->p = p;
+ pk->len = 0;
+ pk->f = PKBUF_ENABLE;
+ pk->buf = 0;
+ pk->sz = 256;
+ pk->want = 1;
+ pk->a = arena_global;
+}
+
+/* --- @pkbuf_destroy@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Deallocates a line buffer and frees any resources it owned.
+ */
+
+void pkbuf_destroy(pkbuf *pk)
+{
+ if (pk->buf) {
+ x_free(pk->a, pk->buf);
+ pk->buf = 0;
+ }
+}
+
+/*----- That's all, folks -------------------------------------------------*/
--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: pkbuf.h,v 1.1 2000/06/17 10:39:19 mdw Exp $
+ *
+ * Simple packet buffering
+ *
+ * (c) 2000 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: pkbuf.h,v $
+ * Revision 1.1 2000/06/17 10:39:19 mdw
+ * Experimental new support for packet buffering.
+ *
+ */
+
+#ifndef MLIB_PKBUF_H
+#define MLIB_PKBUF_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#ifndef MLIB_ARENA_H
+# include "arena.h"
+#endif
+
+#ifndef MLIB_BITS_H
+# include "bits.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct pkbuf {
+ size_t sz; /* Size of current buffer */
+ size_t len; /* Length of data in the buffer */
+ size_t want; /* Want this many bytes for packet */
+ unsigned f; /* Various state flags */
+ void (*func)(octet */*b*/, size_t /*sz*/,
+ struct pkbuf */*pk*/, size_t */*keep*/,
+ void */*p*/); /* Handler function */
+ void *p; /* Argument for handler */
+ arena *a; /* Memory allocation arena */
+ octet *buf; /* Actual buffer space */
+} pkbuf;
+
+enum {
+ PKBUF_ENABLE = 1 /* Buffer is currently enabled */
+};
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @pkbuf_flush@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @octet *p@ = pointer to where to start searching
+ * @size_t len@ = length of new material added
+ *
+ * Returns: ---
+ *
+ * Use: Flushes any complete packets in a packet buffer. New
+ * material is assumed to have been added starting at @p@. If
+ * @p@ is null, then the scan starts at the beginning of the
+ * buffer, and the size of data already in the buffer is used in
+ * place of @len@.
+ *
+ * It is assumed that the buffer is initially enabled. You
+ * shouldn't be contributing data to a disabled buffer anyway.
+ * However, the buffer handler may at some point disable itself,
+ * and @pkbuf_flush@ can cope with this eventuality. Any
+ * pending data is left at the start of the buffer and can be
+ * flushed out by calling @pkbuf_flush(b, 0, 0)@ if the buffer
+ * is ever re-enabled.
+ */
+
+extern void pkbuf_flush(pkbuf */*pk*/, octet */*p*/, size_t /*len*/);
+
+/* --- @pkbuf_close@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Informs the client that no more data is likely to arrive. If
+ * there is a partial packet in the buffer, it is discarded.
+ */
+
+extern void pkbuf_close(pkbuf */*pk*/);
+
+/* --- @pkbuf_free@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @octet **p@ = output pointer to free space
+ *
+ * Returns: Free buffer size.
+ *
+ * Use: Returns the free portion of a packet buffer. Data can then
+ * be written to this portion, and split out into packets by
+ * calling @pkbuf_flush@.
+ */
+
+extern size_t pkbuf_free(pkbuf */*pk*/, octet **/*p*/);
+
+/* --- @pkbuf_snarf@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @const void *p@ = pointer to input data buffer
+ * @size_t sz@ = size of data in input buffer
+ *
+ * Returns: ---
+ *
+ * Use: Snarfs the data from the input buffer and spits it out as
+ * packets. This interface ignores the complexities of dealing
+ * with disablement: you should be using @pkbuf_free@ to
+ * contribute data if you want to cope with that.
+ */
+
+extern void pkbuf_snarf(pkbuf */*pk*/, const void */*p*/, size_t /*sz*/);
+
+/* --- @pkbuf_want@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @size_t want@ = how many octets wanted for next packet
+ *
+ * Returns: ---
+ *
+ * Use: Sets the desired size for the next packet to be read. If
+ * it's larger than the current buffer, the buffer is extended.
+ */
+
+extern void pkbuf_want(pkbuf */*pk*/, size_t /*want*/);
+
+/* --- @pkbuf_init@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @void (*func)(octet *b, size_t sz, pkbuf *pk,@
+ * @size_t *keep, void *p)@ =
+ * handler function
+ * @void *p@ = argument pointer for @func@
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a packet buffer block. Any packets are passed to
+ * the provided function for handling.
+ */
+
+extern void pkbuf_init(pkbuf */*pk*/,
+ void (*/*func*/)(octet */*b*/, size_t /*sz*/,
+ pkbuf */*pk*/, size_t */*keep*/,
+ void */*p*/),
+ void */*p*/);
+
+/* --- @pkbuf_destroy@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Deallocates a packet buffer and frees any resources it owned.
+ */
+
+extern void pkbuf_destroy(pkbuf */*pk*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: selpk.c,v 1.1 2000/06/17 10:39:19 mdw Exp $
+ *
+ * Packet-buffering select handler
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: selpk.c,v $
+ * Revision 1.1 2000/06/17 10:39:19 mdw
+ * Experimental new support for packet buffering.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include "pkbuf.h"
+#include "sel.h"
+#include "selpk.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @selpk_enable@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Enables a buffer for reading, and emits any queued packets
+ * to the buffer's owner.
+ */
+
+void selpk_enable(selpk *pk)
+{
+ if (!(pk->pk.f & PKBUF_ENABLE)) {
+ pk->pk.f |= PKBUF_ENABLE;
+ sel_addfile(&pk->reader);
+ pkbuf_flush(&pk->pk, 0, 0);
+ }
+}
+
+/* --- @selpk_disable@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to a buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Disables a buffer. It won't be read from until it's
+ * enabled again.
+ */
+
+void selpk_disable(selpk *pk)
+{
+ if (pk->pk.f & PKBUF_ENABLE) {
+ pk->pk.f &= ~PKBUF_ENABLE;
+ sel_rmfile(&pk->reader);
+ }
+}
+
+/* --- @selpk_read@ --- *
+ *
+ * Arguments: @int fd@ = file descriptor to read from
+ * @int mode@ = what we can do to the file
+ * @void *vp@ = pointer to buffer context
+ *
+ * Returns: ---
+ *
+ * Use: Acts on the result of a @select@ call.
+ */
+
+static void selpk_read(int fd, unsigned mode, void *vp)
+{
+ selpk *pk = vp;
+ octet *p;
+ size_t sz;
+ int n;
+
+ sz = pkbuf_free(&pk->pk, &p);
+ n = read(fd, p, sz);
+ if (n == 0)
+ pkbuf_close(&pk->pk);
+ else if (n > 0)
+ pkbuf_flush(&pk->pk, p, n);
+ else switch (errno) {
+ case EINTR:
+ case EAGAIN:
+#if EAGAIN != EWOULDBLOCK
+ case EWOULDBLOCK:
+#endif
+ return;
+ default:
+ pkbuf_close(&pk->pk);
+ }
+}
+
+/* --- @selpk_want@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ * @size_t sz@ = size of buffer
+ *
+ * Returns: ---
+ *
+ * Use: Sets the size of the packet to be read next.
+ */
+
+void selpk_want(selpk *pk, size_t sz)
+{
+ pkbuf_want(&pk->pk, sz);
+}
+
+/* --- @selpk_init@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ * @sel_state *s@ = pointer to select state to attach to
+ * @int fd@ = file descriptor to listen to
+ * @void (*func)(char *s, void *p)@ = function to call
+ * @void *p@ = argument for function
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a buffer block.
+ */
+
+void selpk_init(selpk *pk,
+ sel_state *s,
+ int fd,
+ void (*func)(octet */*b*/, size_t /*sz*/, pkbuf */*pk*/,
+ size_t */*keep*/, void */*p*/),
+ void *p)
+{
+ pkbuf_init(&pk->pk, func, p);
+ pk->pk.f &= ~PKBUF_ENABLE;
+ sel_initfile(s, &pk->reader, fd, SEL_READ, selpk_read, pk);
+ selpk_enable(pk);
+}
+
+/* --- @selpk_destroy@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Deallocates a packet buffer and frees any resources it owned.
+ */
+
+void selpk_destroy(selpk *pk)
+{
+ selpk_disable(pk);
+ pkbuf_destroy(&pk->pk);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: selpk.h,v 1.1 2000/06/17 10:39:19 mdw Exp $
+ *
+ * Packet-buffering select handler
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: selpk.h,v $
+ * Revision 1.1 2000/06/17 10:39:19 mdw
+ * Experimental new support for packet buffering.
+ *
+ */
+
+#ifndef MLIB_SELPK_H
+#define MLIB_SELPK_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#ifndef MLIB_PKBUF_H
+# include "pkbuf.h"
+#endif
+
+#ifndef MLIB_SEL_H
+# include "sel.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct selpk {
+ sel_file reader; /* File selection object */
+ pkbuf pk; /* Packet buffering object */
+} selpk;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @selpk_enable@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Enables a buffer for reading, and emits any queued packets
+ * to the buffer's owner.
+ */
+
+extern void selpk_enable(selpk */*pk*/);
+
+/* --- @selpk_disable@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to a buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Disables a buffer. It won't be read from until it's
+ * enabled again.
+ */
+
+extern void selpk_disable(selpk */*pk*/);
+
+/* --- @selpk_want@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ * @size_t want@ = size of packet to read
+ *
+ * Returns: ---
+ *
+ * Use: Sets the size of the packet to be read next.
+ */
+
+extern void selpk_setsize(selpk */*pk*/, size_t /*sz*/);
+
+/* --- @selpk_init@ --- *
+ *
+ * Arguments: @selpk *pk@ = pointer to buffer block
+ * @sel_state *s@ = pointer to select state to attach to
+ * @int fd@ = file descriptor to listen to
+ * @void (*func)(...)@ = function to call
+ * @void *p@ = argument for function
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a buffer block.
+ */
+
+extern void selpk_init(selpk */*pk*/,
+ sel_state */*s*/,
+ int /*fd*/,
+ void (*/*func*/)(octet */*b*/, size_t /*sz*/,
+ pkbuf */*pk*/, size_t */*keep*/,
+ void */*p*/),
+ void */*p*/);
+
+/* --- @selpk_destroy@ --- *
+ *
+ * Arguments: @lbuf *b@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Deallocates a packet buffer and frees any resources it owned.
+ */
+
+extern void selpk_destroy(selpk */*pk*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
~mdw / mLib / commitdiff