File: [local] / src / usr.bin / cvs / buf.c (download)
Revision 1.85, Fri Jun 28 13:35:00 2019 UTC (4 years, 11 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_7_0_BASE, OPENBSD_7_0, OPENBSD_6_9_BASE, OPENBSD_6_9, OPENBSD_6_8_BASE, OPENBSD_6_8, OPENBSD_6_7_BASE, OPENBSD_6_7, OPENBSD_6_6_BASE, OPENBSD_6_6 Changes since 1.84: +3 -3 lines
When system calls indicate an error they return -1, not some arbitrary
value < 0. errno is only updated in this case. Change all (most?)
callers of syscalls to follow this better, and let's see if this strictness
helps us in the future.
|
/* $OpenBSD: buf.c,v 1.85 2019/06/28 13:35:00 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/stat.h>
#include <sys/time.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "atomicio.h"
#include "cvs.h"
#include "buf.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.
*/
BUF *
buf_load(const char *path)
{
int fd;
BUF *bp;
if ((fd = open(path, O_RDONLY, 0600)) == -1)
fatal("buf_load: failed to load '%s' : %s", path,
strerror(errno));
bp = buf_load_fd(fd);
(void)close(fd);
return (bp);
}
BUF *
buf_load_fd(int fd)
{
struct stat st;
BUF *buf;
if (fstat(fd, &st) == -1)
fatal("buf_load_fd: fstat: %s", strerror(errno));
if (lseek(fd, 0, SEEK_SET) == -1)
fatal("buf_load_fd: lseek: %s", strerror(errno));
if ((uintmax_t)st.st_size > SIZE_MAX)
fatal("buf_load_fd: file size too big");
buf = buf_alloc(st.st_size);
if (atomicio(read, fd, buf->cb_buf, buf->cb_size) != buf->cb_size)
fatal("buf_load_fd: read: %s", strerror(errno));
buf->cb_len = buf->cb_size;
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.
*/
void *
buf_release(BUF *b)
{
void *tmp;
tmp = b->cb_buf;
free(b);
return (tmp);
}
/*
* 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 C-string <str> to the end of the buffer <b>.
*/
void
buf_puts(BUF *b, const char *str)
{
buf_append(b, str, strlen(str));
}
/*
* 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.
*/
void
buf_append(BUF *b, const void *data, size_t len)
{
size_t left;
u_char *bp;
left = SIZE_LEFT(b);
if (left < len)
buf_grow(b, len - left);
bp = b->cb_buf + b->cb_len;
memcpy(bp, data, len);
b->cb_len += len;
}
/*
* 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)
{
if (atomicio(vwrite, fd, b->cb_buf, b->cb_len) != b->cb_len)
return (-1);
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
fatal("open: `%s': %s", path, strerror(errno));
}
if (buf_write_fd(b, fd) == -1) {
(void)unlink(path);
fatal("buf_write: buf_write_fd: `%s'", path);
}
if (fchmod(fd, mode) == -1)
cvs_log(LP_ERR, "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). If <tv> is specified file
* access and modification time is set to <tv>.
* NB. This function will modify <template>, as per mkstemp
*/
int
buf_write_stmp(BUF *b, char *template, struct timeval *tv)
{
int fd;
if ((fd = mkstemp(template)) == -1)
fatal("mkstemp: `%s': %s", template, strerror(errno));
if (buf_write_fd(b, fd) == -1) {
(void)unlink(template);
fatal("buf_write_stmp: buf_write_fd: `%s'", template);
}
if (tv != NULL) {
if (futimes(fd, tv) == -1)
fatal("buf_write_stmp: futimes failed");
}
worklist_add(template, &temp_files);
if (lseek(fd, 0, SEEK_SET) == -1)
fatal("buf_write_stmp: lseek: %s", strerror(errno));
return (fd);
}
u_char *
buf_get(BUF *bp)
{
return (bp->cb_buf);
}
int
buf_differ(const BUF *b1, const BUF *b2)
{
if (b1->cb_len != b2->cb_len)
return (1);
return (memcmp(b1->cb_buf, b2->cb_buf, b1->cb_len));
}
/*
* 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;
}