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/* $OpenBSD: buffer.c,v 1.5 2003/12/21 18:04:08 claudio Exp $ */
/*
* Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <err.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include "bgpd.h"
TAILQ_HEAD(bufs, buf) bufs = TAILQ_HEAD_INITIALIZER(bufs);
void buf_enqueue(struct buf *);
void buf_dequeue(struct buf *);
struct buf *
buf_open(struct peer *peer, int sock, ssize_t len)
{
struct buf *buf;
if ((buf = calloc(1, sizeof(struct buf))) == NULL)
return (NULL);
if ((buf->buf = malloc(len)) == NULL) {
free(buf);
return (NULL);
}
buf->size = len;
buf->peer = peer;
buf->sock = sock;
return (buf);
}
int
buf_add(struct buf *buf, void *data, ssize_t len)
{
if (buf->wpos + len > buf->size)
return (-1);
memcpy(buf->buf + buf->wpos, data, len);
buf->wpos += len;
return (0);
}
void *
buf_reserve(struct buf *buf, ssize_t len)
{
void *b;
if (buf->wpos + len > buf->size)
return (NULL);
b = buf->buf + buf->wpos;
buf->wpos += len;
return (b);
}
int
buf_close(struct buf *buf)
{
/*
* we first try to write out directly
* if that fails we add the buffer to the queue
*/
int n;
if (buf->peer != NULL && buf->peer->queued_writes == 0) {
if ((n = buf_write(buf)) == -1)
return (-1);
if (n == 1) { /* all data written out */
buf_free(buf);
return (0);
}
}
/* we have to queue */
buf_enqueue(buf);
return (1);
}
int
buf_write(struct buf *buf)
{
ssize_t n;
if ((n = write(buf->sock, buf->buf + buf->rpos,
buf->size-buf->rpos)) == -1) {
if (errno == EAGAIN) /* cannot write immediately */
return (0);
else {
if (buf->peer != NULL)
log_err(buf->peer, "write error");
else
logit(LOG_CRIT, "pipe write error: %s",
strerror(errno));
return (-1);
}
}
if (n < buf->size - buf->rpos) { /* not all data written yet */
buf->rpos += n;
return (0);
} else
return (1);
}
void
buf_free(struct buf *buf)
{
free(buf->buf);
free(buf);
}
void
buf_peer_remove(struct peer *peer)
{
struct buf *buf, *next;
for (buf = TAILQ_FIRST(&bufs); buf != NULL; buf = next) {
next = TAILQ_NEXT(buf, entries);
if (buf->peer == peer)
buf_dequeue(buf);
}
}
int
buf_peer_write(struct peer *peer)
{
/*
* possible race here
* when we cannot write out data completely from a buffer,
* we MUST return and NOT try to write out stuff from later buffers -
* the socket might have become writeable again
*/
struct buf *buf, *next;
int n;
for (buf = TAILQ_FIRST(&bufs); buf != NULL; buf = next) {
next = TAILQ_NEXT(buf, entries);
if (buf->peer == peer) {
if ((n = buf_write(buf)) == -1)
return (-1);
if (n == 1) /* everything written out */
buf_dequeue(buf);
else
return (0);
}
}
return (0);
}
int
buf_sock_write(int sock)
{
/*
* possible race here
* when we cannot write out data completely from a buffer,
* we MUST return and NOT try to write out stuff from later buffers -
* the socket might have become writeable again
*/
struct buf *buf, *next;
int n, cleared = 0;
for (buf = TAILQ_FIRST(&bufs); buf != NULL; buf = next) {
next = TAILQ_NEXT(buf, entries);
if (buf->sock == sock) {
if ((n = buf_write(buf)) == -1)
return (-1);
if (n == 1) { /* everything written out */
buf_dequeue(buf);
cleared++;
} else
return (cleared);
}
}
return (cleared);
}
void
buf_enqueue(struct buf *buf)
{
/* might want a tailq per peer w/ pointers to the bufs */
TAILQ_INSERT_TAIL(&bufs, buf, entries);
if (buf->peer != NULL)
buf->peer->queued_writes++;
}
void
buf_dequeue(struct buf *buf)
{
TAILQ_REMOVE(&bufs, buf, entries);
if (buf->peer != NULL)
buf->peer->queued_writes--;
buf_free(buf);
}
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