OpenBSD-4.6/lib/libevent/buffer.c
/* $OpenBSD: buffer.c,v 1.15 2008/05/02 06:09:11 brad Exp $ */
/*
* Copyright (c) 2002, 2003 Niels Provos <provos@citi.umich.edu>
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_VASPRINTF
/* If we have vasprintf, we need to define this before we include stdio.h. */
#define _GNU_SOURCE
#endif
#include <sys/types.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_STDARG_H
#include <stdarg.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "event.h"
struct evbuffer *
evbuffer_new(void)
{
struct evbuffer *buffer;
buffer = calloc(1, sizeof(struct evbuffer));
return (buffer);
}
void
evbuffer_free(struct evbuffer *buffer)
{
if (buffer->orig_buffer != NULL)
free(buffer->orig_buffer);
free(buffer);
}
/*
* This is a destructive add. The data from one buffer moves into
* the other buffer.
*/
#define SWAP(x,y) do { \
(x)->buffer = (y)->buffer; \
(x)->orig_buffer = (y)->orig_buffer; \
(x)->misalign = (y)->misalign; \
(x)->totallen = (y)->totallen; \
(x)->off = (y)->off; \
} while (0)
int
evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
{
int res;
/* Short cut for better performance */
if (outbuf->off == 0) {
struct evbuffer tmp;
size_t oldoff = inbuf->off;
/* Swap them directly */
SWAP(&tmp, outbuf);
SWAP(outbuf, inbuf);
SWAP(inbuf, &tmp);
/*
* Optimization comes with a price; we need to notify the
* buffer if necessary of the changes. oldoff is the amount
* of data that we transferred from inbuf to outbuf
*/
if (inbuf->off != oldoff && inbuf->cb != NULL)
(*inbuf->cb)(inbuf, oldoff, inbuf->off, inbuf->cbarg);
if (oldoff && outbuf->cb != NULL)
(*outbuf->cb)(outbuf, 0, oldoff, outbuf->cbarg);
return (0);
}
res = evbuffer_add(outbuf, inbuf->buffer, inbuf->off);
if (res == 0) {
/* We drain the input buffer on success */
evbuffer_drain(inbuf, inbuf->off);
}
return (res);
}
int
evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
{
char *buffer;
size_t space;
size_t oldoff = buf->off;
int sz;
va_list aq;
/* make sure that at least some space is available */
evbuffer_expand(buf, 64);
for (;;) {
size_t used = buf->misalign + buf->off;
buffer = (char *)buf->buffer + buf->off;
assert(buf->totallen >= used);
space = buf->totallen - used;
#ifndef va_copy
#define va_copy(dst, src) memcpy(&(dst), &(src), sizeof(va_list))
#endif
va_copy(aq, ap);
#ifdef WIN32
sz = vsnprintf(buffer, space - 1, fmt, aq);
buffer[space - 1] = '\0';
#else
sz = vsnprintf(buffer, space, fmt, aq);
#endif
va_end(aq);
if (sz < 0)
return (-1);
if (sz < space) {
buf->off += sz;
if (buf->cb != NULL)
(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
return (sz);
}
if (evbuffer_expand(buf, sz + 1) == -1)
return (-1);
}
/* NOTREACHED */
}
int
evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...)
{
int res = -1;
va_list ap;
va_start(ap, fmt);
res = evbuffer_add_vprintf(buf, fmt, ap);
va_end(ap);
return (res);
}
/* Reads data from an event buffer and drains the bytes read */
int
evbuffer_remove(struct evbuffer *buf, void *data, size_t datlen)
{
size_t nread = datlen;
if (nread >= buf->off)
nread = buf->off;
memcpy(data, buf->buffer, nread);
evbuffer_drain(buf, nread);
return (nread);
}
/*
* Reads a line terminated by either '\r\n', '\n\r' or '\r' or '\n'.
* The returned buffer needs to be freed by the called.
*/
char *
evbuffer_readline(struct evbuffer *buffer)
{
u_char *data = EVBUFFER_DATA(buffer);
size_t len = EVBUFFER_LENGTH(buffer);
char *line;
unsigned int i;
for (i = 0; i < len; i++) {
if (data[i] == '\r' || data[i] == '\n')
break;
}
if (i == len)
return (NULL);
if ((line = malloc(i + 1)) == NULL) {
fprintf(stderr, "%s: out of memory\n", __func__);
evbuffer_drain(buffer, i);
return (NULL);
}
memcpy(line, data, i);
line[i] = '\0';
/*
* Some protocols terminate a line with '\r\n', so check for
* that, too.
*/
if ( i < len - 1 ) {
char fch = data[i], sch = data[i+1];
/* Drain one more character if needed */
if ( (sch == '\r' || sch == '\n') && sch != fch )
i += 1;
}
evbuffer_drain(buffer, i + 1);
return (line);
}
/* Adds data to an event buffer */
static void
evbuffer_align(struct evbuffer *buf)
{
memmove(buf->orig_buffer, buf->buffer, buf->off);
buf->buffer = buf->orig_buffer;
buf->misalign = 0;
}
/* Expands the available space in the event buffer to at least datlen */
int
evbuffer_expand(struct evbuffer *buf, size_t datlen)
{
size_t need = buf->misalign + buf->off + datlen;
/* If we can fit all the data, then we don't have to do anything */
if (buf->totallen >= need)
return (0);
/*
* If the misalignment fulfills our data needs, we just force an
* alignment to happen. Afterwards, we have enough space.
*/
if (buf->misalign >= datlen) {
evbuffer_align(buf);
} else {
void *newbuf;
size_t length = buf->totallen;
if (length < 256)
length = 256;
while (length < need)
length <<= 1;
if (buf->orig_buffer != buf->buffer)
evbuffer_align(buf);
if ((newbuf = realloc(buf->buffer, length)) == NULL)
return (-1);
buf->orig_buffer = buf->buffer = newbuf;
buf->totallen = length;
}
return (0);
}
int
evbuffer_add(struct evbuffer *buf, const void *data, size_t datlen)
{
size_t need = buf->misalign + buf->off + datlen;
size_t oldoff = buf->off;
if (buf->totallen < need) {
if (evbuffer_expand(buf, datlen) == -1)
return (-1);
}
memcpy(buf->buffer + buf->off, data, datlen);
buf->off += datlen;
if (datlen && buf->cb != NULL)
(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
return (0);
}
void
evbuffer_drain(struct evbuffer *buf, size_t len)
{
size_t oldoff = buf->off;
if (len >= buf->off) {
buf->off = 0;
buf->buffer = buf->orig_buffer;
buf->misalign = 0;
goto done;
}
buf->buffer += len;
buf->misalign += len;
buf->off -= len;
done:
/* Tell someone about changes in this buffer */
if (buf->off != oldoff && buf->cb != NULL)
(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
}
/*
* Reads data from a file descriptor into a buffer.
*/
#define EVBUFFER_MAX_READ 4096
int
evbuffer_read(struct evbuffer *buf, int fd, int howmuch)
{
u_char *p;
size_t oldoff = buf->off;
int n = EVBUFFER_MAX_READ;
#ifdef WIN32
DWORD dwBytesRead;
#endif
#ifdef FIONREAD
if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
n = EVBUFFER_MAX_READ;
} else if (n > EVBUFFER_MAX_READ && n > howmuch) {
/*
* It's possible that a lot of data is available for
* reading. We do not want to exhaust resources
* before the reader has a chance to do something
* about it. If the reader does not tell us how much
* data we should read, we artifically limit it.
*/
if (n > buf->totallen << 2)
n = buf->totallen << 2;
if (n < EVBUFFER_MAX_READ)
n = EVBUFFER_MAX_READ;
}
#endif
if (howmuch < 0 || howmuch > n)
howmuch = n;
/* If we don't have FIONREAD, we might waste some space here */
if (evbuffer_expand(buf, howmuch) == -1)
return (-1);
/* We can append new data at this point */
p = buf->buffer + buf->off;
#ifndef WIN32
n = read(fd, p, howmuch);
if (n == -1)
return (-1);
if (n == 0)
return (0);
#else
n = ReadFile((HANDLE)fd, p, howmuch, &dwBytesRead, NULL);
if (n == 0)
return (-1);
if (dwBytesRead == 0)
return (0);
n = dwBytesRead;
#endif
buf->off += n;
/* Tell someone about changes in this buffer */
if (buf->off != oldoff && buf->cb != NULL)
(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
return (n);
}
int
evbuffer_write(struct evbuffer *buffer, int fd)
{
int n;
#ifdef WIN32
DWORD dwBytesWritten;
#endif
#ifndef WIN32
n = write(fd, buffer->buffer, buffer->off);
if (n == -1)
return (-1);
if (n == 0)
return (0);
#else
n = WriteFile((HANDLE)fd, buffer->buffer, buffer->off, &dwBytesWritten, NULL);
if (n == 0)
return (-1);
if (dwBytesWritten == 0)
return (0);
n = dwBytesWritten;
#endif
evbuffer_drain(buffer, n);
return (n);
}
u_char *
evbuffer_find(struct evbuffer *buffer, const u_char *what, size_t len)
{
u_char *search = buffer->buffer, *end = search + buffer->off;
u_char *p;
while (search < end &&
(p = memchr(search, *what, end - search)) != NULL) {
if (p + len > end)
break;
if (memcmp(p, what, len) == 0)
return (p);
search = p + 1;
}
return (NULL);
}
void evbuffer_setcb(struct evbuffer *buffer,
void (*cb)(struct evbuffer *, size_t, size_t, void *),
void *cbarg)
{
buffer->cb = cb;
buffer->cbarg = cbarg;
}