334 lines
6.5 KiB
C
334 lines
6.5 KiB
C
/* $OpenBSD: buf.c,v 1.29 2021/10/24 21:24:17 deraadt Exp $ */
|
|
/*
|
|
* Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
|
|
* 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. 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 ``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.
|
|
*/
|
|
|
|
#include <sys/queue.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "buf.h"
|
|
#include "xmalloc.h"
|
|
#include "worklist.h"
|
|
|
|
#define BUF_INCR 128
|
|
|
|
struct buf {
|
|
/* buffer handle, buffer size, and data length */
|
|
u_char *cb_buf;
|
|
size_t cb_size;
|
|
size_t cb_len;
|
|
};
|
|
|
|
#define SIZE_LEFT(b) (b->cb_size - b->cb_len)
|
|
|
|
static void buf_grow(BUF *, size_t);
|
|
|
|
/*
|
|
* Create a new buffer structure and return a pointer to it. This structure
|
|
* uses dynamically-allocated memory and must be freed with buf_free(), once
|
|
* the buffer is no longer needed.
|
|
*/
|
|
BUF *
|
|
buf_alloc(size_t len)
|
|
{
|
|
BUF *b;
|
|
|
|
b = xmalloc(sizeof(*b));
|
|
/* Postpone creation of zero-sized buffers */
|
|
if (len > 0)
|
|
b->cb_buf = xcalloc(1, len);
|
|
else
|
|
b->cb_buf = NULL;
|
|
|
|
b->cb_size = len;
|
|
b->cb_len = 0;
|
|
|
|
return (b);
|
|
}
|
|
|
|
/*
|
|
* Open the file specified by <path> and load all of its contents into a
|
|
* buffer.
|
|
* Returns the loaded buffer on success or NULL on failure.
|
|
* Sets errno on error.
|
|
*/
|
|
BUF *
|
|
buf_load(const char *path)
|
|
{
|
|
int fd;
|
|
ssize_t ret;
|
|
size_t len;
|
|
u_char *bp;
|
|
struct stat st;
|
|
BUF *buf;
|
|
|
|
buf = NULL;
|
|
|
|
if ((fd = open(path, O_RDONLY)) == -1)
|
|
goto out;
|
|
|
|
if (fstat(fd, &st) == -1)
|
|
goto out;
|
|
|
|
if ((uintmax_t)st.st_size > SIZE_MAX) {
|
|
errno = EFBIG;
|
|
goto out;
|
|
}
|
|
buf = buf_alloc(st.st_size);
|
|
for (bp = buf->cb_buf; ; bp += (size_t)ret) {
|
|
len = SIZE_LEFT(buf);
|
|
ret = read(fd, bp, len);
|
|
if (ret == -1) {
|
|
int saved_errno;
|
|
|
|
saved_errno = errno;
|
|
buf_free(buf);
|
|
buf = NULL;
|
|
errno = saved_errno;
|
|
goto out;
|
|
} else if (ret == 0)
|
|
break;
|
|
|
|
buf->cb_len += (size_t)ret;
|
|
}
|
|
|
|
out:
|
|
if (fd != -1) {
|
|
int saved_errno;
|
|
|
|
/* We may want to preserve errno here. */
|
|
saved_errno = errno;
|
|
(void)close(fd);
|
|
errno = saved_errno;
|
|
}
|
|
|
|
return (buf);
|
|
}
|
|
|
|
void
|
|
buf_free(BUF *b)
|
|
{
|
|
if (b == NULL)
|
|
return;
|
|
free(b->cb_buf);
|
|
free(b);
|
|
}
|
|
|
|
/*
|
|
* Free the buffer <b>'s structural information but do not free the contents
|
|
* of the buffer. Instead, they are returned and should be freed later using
|
|
* free().
|
|
*/
|
|
void *
|
|
buf_release(BUF *b)
|
|
{
|
|
void *tmp;
|
|
|
|
tmp = b->cb_buf;
|
|
free(b);
|
|
return (tmp);
|
|
}
|
|
|
|
u_char *
|
|
buf_get(BUF *b)
|
|
{
|
|
return (b->cb_buf);
|
|
}
|
|
|
|
/*
|
|
* Empty the contents of the buffer <b> and reset pointers.
|
|
*/
|
|
void
|
|
buf_empty(BUF *b)
|
|
{
|
|
memset(b->cb_buf, 0, b->cb_size);
|
|
b->cb_len = 0;
|
|
}
|
|
|
|
/*
|
|
* Append a single character <c> to the end of the buffer <b>.
|
|
*/
|
|
void
|
|
buf_putc(BUF *b, int c)
|
|
{
|
|
u_char *bp;
|
|
|
|
if (SIZE_LEFT(b) == 0)
|
|
buf_grow(b, BUF_INCR);
|
|
bp = b->cb_buf + b->cb_len;
|
|
*bp = (u_char)c;
|
|
b->cb_len++;
|
|
}
|
|
|
|
/*
|
|
* Append a string <s> to the end of buffer <b>.
|
|
*/
|
|
void
|
|
buf_puts(BUF *b, const char *str)
|
|
{
|
|
buf_append(b, str, strlen(str));
|
|
}
|
|
|
|
/*
|
|
* Return u_char at buffer position <pos>.
|
|
*/
|
|
u_char
|
|
buf_getc(BUF *b, size_t pos)
|
|
{
|
|
return (b->cb_buf[pos]);
|
|
}
|
|
|
|
/*
|
|
* Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
|
|
* buffer is too small to accept all data, it will get resized to an
|
|
* appropriate size to accept all data.
|
|
* Returns the number of bytes successfully appended to the buffer.
|
|
*/
|
|
size_t
|
|
buf_append(BUF *b, const void *data, size_t len)
|
|
{
|
|
size_t left, rlen;
|
|
u_char *bp;
|
|
|
|
left = SIZE_LEFT(b);
|
|
rlen = len;
|
|
|
|
if (left < len)
|
|
buf_grow(b, len - left);
|
|
bp = b->cb_buf + b->cb_len;
|
|
memcpy(bp, data, rlen);
|
|
b->cb_len += rlen;
|
|
|
|
return (rlen);
|
|
}
|
|
|
|
/*
|
|
* Returns the size of the buffer that is being used.
|
|
*/
|
|
size_t
|
|
buf_len(BUF *b)
|
|
{
|
|
return (b->cb_len);
|
|
}
|
|
|
|
/*
|
|
* Write the contents of the buffer <b> to the specified <fd>
|
|
*/
|
|
int
|
|
buf_write_fd(BUF *b, int fd)
|
|
{
|
|
u_char *bp;
|
|
size_t len;
|
|
ssize_t ret;
|
|
|
|
len = b->cb_len;
|
|
bp = b->cb_buf;
|
|
|
|
do {
|
|
ret = write(fd, bp, len);
|
|
if (ret == -1) {
|
|
if (errno == EINTR || errno == EAGAIN)
|
|
continue;
|
|
return (-1);
|
|
}
|
|
|
|
len -= (size_t)ret;
|
|
bp += (size_t)ret;
|
|
} while (len > 0);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Write the contents of the buffer <b> to the file whose path is given in
|
|
* <path>. If the file does not exist, it is created with mode <mode>.
|
|
*/
|
|
int
|
|
buf_write(BUF *b, const char *path, mode_t mode)
|
|
{
|
|
int fd;
|
|
open:
|
|
if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
|
|
if (errno == EACCES && unlink(path) != -1)
|
|
goto open;
|
|
else
|
|
err(1, "%s", path);
|
|
}
|
|
|
|
if (buf_write_fd(b, fd) == -1) {
|
|
(void)unlink(path);
|
|
errx(1, "buf_write: buf_write_fd: `%s'", path);
|
|
}
|
|
|
|
if (fchmod(fd, mode) == -1)
|
|
warn("permissions not set on file %s", path);
|
|
|
|
(void)close(fd);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Write the contents of the buffer <b> to a temporary file whose path is
|
|
* specified using <template> (see mkstemp.3).
|
|
* NB. This function will modify <template>, as per mkstemp
|
|
*/
|
|
void
|
|
buf_write_stmp(BUF *b, char *template)
|
|
{
|
|
int fd;
|
|
|
|
if ((fd = mkstemp(template)) == -1)
|
|
err(1, "%s", template);
|
|
|
|
worklist_add(template, &temp_files);
|
|
|
|
if (buf_write_fd(b, fd) == -1) {
|
|
(void)unlink(template);
|
|
errx(1, "buf_write_stmp: buf_write_fd: `%s'", template);
|
|
}
|
|
|
|
(void)close(fd);
|
|
}
|
|
|
|
/*
|
|
* Grow the buffer <b> by <len> bytes. The contents are unchanged by this
|
|
* operation regardless of the result.
|
|
*/
|
|
static void
|
|
buf_grow(BUF *b, size_t len)
|
|
{
|
|
b->cb_buf = xreallocarray(b->cb_buf, 1, b->cb_size + len);
|
|
b->cb_size += len;
|
|
}
|