On 1/16/2019 12:48 PM, Bruce Richardson wrote:
> Add the strlcat function to DPDK to exist alongside the strlcpy one. While
> strncat is generally safe for use for concatenation, the API for the
> strlcat function is perhaps a little nicer to use, and supports truncation
> detection.
>
> See commit: 5364de644a4b ("eal: support strlcpy function") for more
> details on the function selection logic, since we only should be using the
> DPDK-provided version when no system-provided version is present.
>
> Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
> ---
> .../common/include/rte_string_fns.h | 15 +++++++
> test/test/test_string_fns.c | 45 +++++++++++++++++++
> 2 files changed, 60 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/rte_string_fns.h
> b/lib/librte_eal/common/include/rte_string_fns.h
> index 9a2a1ff90..e7a1656f0 100644
> --- a/lib/librte_eal/common/include/rte_string_fns.h
> +++ b/lib/librte_eal/common/include/rte_string_fns.h
> @@ -59,10 +59,24 @@ rte_strlcpy(char *dst, const char *src, size_t size)
> return (size_t)snprintf(dst, size, "%s", src);
> }
>
> +/**
> + * @internal
> + * DPDK-specific version of strlcat for systems without
> + * libc or libbsd copies of the function
> + */
> +static inline size_t
> +rte_strlcat(char *dst, const char *src, size_t size)
> +{
> + size_t l = strnlen(dst, size);
> + return l + ((l < size) ?
> + rte_strlcpy(&dst[l], src, size - l) : strlen(src));
I think operation is complex for ternary operation, regular if check can be
simpler, other than that looks good to me.
> +}
> +
> /* pull in a strlcpy function */
> #ifdef RTE_EXEC_ENV_BSDAPP
> #ifndef __BSD_VISIBLE /* non-standard functions are hidden */
> #define strlcpy(dst, src, size) rte_strlcpy(dst, src, size)
> +#define strlcat(dst, src, size) rte_strlcat(dst, src, size)
> #endif
>
> #else /* non-BSD platforms */
> @@ -71,6 +85,7 @@ rte_strlcpy(char *dst, const char *src, size_t size)
>
> #else /* no BSD header files, create own */
> #define strlcpy(dst, src, size) rte_strlcpy(dst, src, size)
> +#define strlcat(dst, src, size) rte_strlcat(dst, src, size)
>
> #endif /* RTE_USE_LIBBSD */
> #endif /* BSDAPP */
> diff --git a/test/test/test_string_fns.c b/test/test/test_string_fns.c
> index 3f091ab92..3bd8ed5d8 100644
> --- a/test/test/test_string_fns.c
> +++ b/test/test/test_string_fns.c
> @@ -129,11 +129,56 @@ test_rte_strsplit(void)
> return 0;
> }
>
> +int
> +test_rte_strlcat(void)
> +{
> + /* only run actual unit tests if we have system-provided strlcat */
> +#if defined(__BSD_VISIBLE) || defined(RTE_USE_LIBBSD)
> +#define BUF_LEN 32
> + const char dst[BUF_LEN] = "Test string";
> + const char src[] = " appended";
> + char bsd_dst[BUF_LEN];
> + char rte_dst[BUF_LEN];
> + size_t i, bsd_ret, rte_ret;
> +
> + LOG("dst = '%s', strlen(dst) = %zu\n", dst, strlen(dst));
> + LOG("src = '%s', strlen(src) = %zu\n", src, strlen(src));
> + LOG("---\n");
> +
> + for (i = 0; i < BUF_LEN; i++) {
> + /* initialize destination buffers */
> + memcpy(bsd_dst, dst, BUF_LEN);
> + memcpy(rte_dst, dst, BUF_LEN);
> + /* compare implementations */
> + bsd_ret = strlcat(bsd_dst, src, i);
> + rte_ret = rte_strlcat(rte_dst, src, i);
> + if (bsd_ret != rte_ret) {
> + LOG("Incorrect retval for buf length = %zu\n", i);
> + LOG("BSD: '%zu', rte: '%zu'\n", bsd_ret, rte_ret);
> + return -1;
> + }
> + if (memcmp(bsd_dst, rte_dst, BUF_LEN) != 0) {
> + LOG("Resulting buffers don't match\n");
> + LOG("BSD: '%s', rte: '%s'\n", bsd_dst, rte_dst);
> + return -1;
> + }
> + LOG("buffer size = %zu: dst = '%s', ret = %zu\n",
> + i, rte_dst, rte_ret);
> + }
> + LOG("Checked %zu combinations\n", i);
> +#undef BUF_LEN
> +#endif /* defined(__BSD_VISIBLE) || defined(RTE_USE_LIBBSD) */
> +
> + return 0;
> +}
> +
> static int
> test_string_fns(void)
> {
> if (test_rte_strsplit() < 0)
> return -1;
> + if (test_rte_strlcat() < 0)
> + return -1;
> return 0;
> }
>
>
