mirror of
https://github.com/Cisco-Talos/clamav.git
synced 2026-05-02 20:56:48 -04:00
8e04c25fec
We have some special functions to wrap malloc, calloc, and realloc to make sure we don't allocate more than some limit, similar to the max-filesize and max-scansize limits. Our wrappers are really only needed when allocating memory for scans based on untrusted user input, where a scan file could have bytes that claim you need to allocate some ridiculous amount of memory. Right now they're named: - cli_malloc - cli_calloc - cli_realloc - cli_realloc2 ... and these names do not convey their purpose This commit renames them to: - cli_max_malloc - cli_max_calloc - cli_max_realloc - cli_max_realloc2 The realloc ones also have an additional feature in that they will not free your pointer if you try to realloc to 0 bytes. Freeing the memory is undefined by the C spec, and only done with some realloc implementations, so this stabilizes on the behavior of not doing that, which should prevent accidental double-free's. So for the case where you may want to realloc and do not need to have a maximum, this commit adds the following functions: - cli_safer_realloc - cli_safer_realloc2 These are used for the MPOOL_REALLOC and MPOOL_REALLOC2 macros when MPOOL is disabled (e.g. because mmap-support is not found), so as to match the behavior in the mpool_realloc/2 functions that do not make use of the allocation-limit.
104 lines
3.3 KiB
C
104 lines
3.3 KiB
C
/*
|
|
* Copyright (C) 2013-2024 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
|
|
* Copyright (C) 2008-2013 Sourcefire, Inc.
|
|
*
|
|
* Authors: Török Edvin
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
|
* MA 02110-1301, USA.
|
|
*/
|
|
#ifndef TEXTBUF_H
|
|
#define TEXTBUF_H
|
|
|
|
struct text_buffer {
|
|
char *data;
|
|
size_t pos;
|
|
size_t capacity;
|
|
};
|
|
|
|
/**
|
|
* @brief If the provided text_buffer capacity is smaller than the requested len,
|
|
* then resize the text_buffer to be at least `len` bytes in size.
|
|
*
|
|
* Note: If a resize is required, it will allocate an additional 4096 bytes, minimum.
|
|
*
|
|
* Safety: Will NOT free the text_buffer data if the realloc fails!
|
|
*
|
|
* @param txtbuf
|
|
* @param len
|
|
* @return int
|
|
*/
|
|
static inline int textbuffer_ensure_capacity(struct text_buffer *txtbuf, size_t len)
|
|
{
|
|
if (txtbuf->pos + len > txtbuf->capacity) {
|
|
char *d;
|
|
unsigned capacity = MAX(txtbuf->pos + len, txtbuf->capacity + 4096);
|
|
d = cli_max_realloc(txtbuf->data, capacity);
|
|
if (!d)
|
|
return -1;
|
|
txtbuf->capacity = capacity;
|
|
txtbuf->data = d;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* @brief Append bytes from source `s` to the data in text_buffer `txtbuf`. Reallocate to a larger buf as needed.
|
|
*
|
|
* Safety: `s` must be at least `len` bytes in length.
|
|
*
|
|
* @param txtbuf The destination text_buffer.
|
|
* @param s Pointer to the source data.
|
|
* @param len The number of bytes to copy from `s` to append to `txtbuf`
|
|
* @return int 0 on success. -1 on failure
|
|
*/
|
|
static inline int textbuffer_append_len(struct text_buffer *txtbuf, const char *s, size_t len)
|
|
{
|
|
if (textbuffer_ensure_capacity(txtbuf, len) == -1)
|
|
return -1;
|
|
memcpy(&txtbuf->data[txtbuf->pos], s, len);
|
|
txtbuf->pos += len;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* @brief A wrapper around textbuffer_append_len() for source buffers that are NULL-terminated strings.
|
|
*
|
|
* @param txtbuf The destination text_buffer.
|
|
* @param s Pointer to the source data.
|
|
* @return int 0 on success. -1 on failure
|
|
*/
|
|
static inline int textbuffer_append(struct text_buffer *txtbuf, const char *s)
|
|
{
|
|
size_t len = strlen(s);
|
|
return textbuffer_append_len(txtbuf, s, len);
|
|
}
|
|
|
|
/**
|
|
* @brief Append a single character from source `c` to the data in text_buffer `txtbuf`. Reallocate to a larger buf as needed.
|
|
*
|
|
* @param txtbuf The destination text_buffer.
|
|
* @param c Pointer to the source data.
|
|
* @return int 0 on success. -1 on failure
|
|
*/
|
|
static inline int textbuffer_putc(struct text_buffer *txtbuf, const char c)
|
|
{
|
|
if (textbuffer_ensure_capacity(txtbuf, 1) == -1)
|
|
return -1;
|
|
txtbuf->data[txtbuf->pos++] = c;
|
|
return 0;
|
|
}
|
|
|
|
#endif
|