Bruce Richardson 5364de644a eal: support strlcpy function
The strncpy function is error prone for doing "safe" string copies, so
we generally try to use "snprintf" instead in the code. The function
"strlcpy" is a better alternative, since it better conveys the
intention of the programmer, and doesn't suffer from the non-null
terminating behaviour of it's n'ed brethern.

The downside of this function is that it is not available by default
on linux, though standard in the BSD's. It is available on most
distros by installing "libbsd" package.

This patch therefore provides the following in rte_string_fns.h to ensure
that strlcpy is available there:
* for BSD, include string.h as normal
* if RTE_USE_LIBBSD is set, include <bsd/string.h>
* if not set, fallback to snprintf for strlcpy

Using make build system, the RTE_USE_LIBBSD is a hard-coded value to "n",
but when using meson, it's automatically set based on what is available
on the platform.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
2018-04-04 17:33:08 +02:00

84 lines
1.9 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2010-2014 Intel Corporation
*/
/**
* @file
*
* String-related functions as replacement for libc equivalents
*/
#ifndef _RTE_STRING_FNS_H_
#define _RTE_STRING_FNS_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdio.h>
/**
* Takes string "string" parameter and splits it at character "delim"
* up to maxtokens-1 times - to give "maxtokens" resulting tokens. Like
* strtok or strsep functions, this modifies its input string, by replacing
* instances of "delim" with '\\0'. All resultant tokens are returned in the
* "tokens" array which must have enough entries to hold "maxtokens".
*
* @param string
* The input string to be split into tokens
*
* @param stringlen
* The max length of the input buffer
*
* @param tokens
* The array to hold the pointers to the tokens in the string
*
* @param maxtokens
* The number of elements in the tokens array. At most, maxtokens-1 splits
* of the string will be done.
*
* @param delim
* The character on which the split of the data will be done
*
* @return
* The number of tokens in the tokens array.
*/
int
rte_strsplit(char *string, int stringlen,
char **tokens, int maxtokens, char delim);
/**
* @internal
* DPDK-specific version of strlcpy for systems without
* libc or libbsd copies of the function
*/
static inline size_t
rte_strlcpy(char *dst, const char *src, size_t size)
{
return snprintf(dst, size, "%s", src);
}
/* pull in a strlcpy function */
#ifdef RTE_EXEC_ENV_BSDAPP
#include <string.h>
#ifndef __BSD_VISIBLE /* non-standard functions are hidden */
#define strlcpy(dst, src, size) rte_strlcpy(dst, src, size)
#endif
#else /* non-BSD platforms */
#ifdef RTE_USE_LIBBSD
#include <bsd/string.h>
#else /* no BSD header files, create own */
#define strlcpy(dst, src, size) rte_strlcpy(dst, src, size)
#endif /* RTE_USE_LIBBSD */
#endif /* BSDAPP */
#ifdef __cplusplus
}
#endif
#endif /* RTE_STRING_FNS_H */