eal: support strlcat function

Message ID 20190116124836.40132-1-bruce.richardson@intel.com
State Superseded, archived
Delegated to: Thomas Monjalon
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Series
  • eal: support strlcat function
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ci/intel-Performance-Testing success Performance Testing PASS
ci/mellanox-Performance-Testing success Performance Testing PASS
ci/checkpatch warning coding style issues

Commit Message

Bruce Richardson Jan. 16, 2019, 12:48 p.m.
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.richardson@intel.com>
---
 .../common/include/rte_string_fns.h           | 15 +++++++
 test/test/test_string_fns.c                   | 45 +++++++++++++++++++
 2 files changed, 60 insertions(+)

Comments

Burakov, Anatoly Jan. 17, 2019, 10:39 a.m. | #1
On 16-Jan-19 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.richardson@intel.com>
> ---

<...>

>   static int
>   test_string_fns(void)
>   {
>   	if (test_rte_strsplit() < 0)
>   		return -1;
> +	if (test_rte_strlcat() < 0)
> +		return -1;
>   	return 0;
>   }
>   
> 

Unrelated, but do we also need to test strlcpy, strscpy and other 
functions that were introduced?
Bruce Richardson Jan. 17, 2019, 11 a.m. | #2
On Thu, Jan 17, 2019 at 10:39:02AM +0000, Burakov, Anatoly wrote:
> On 16-Jan-19 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.richardson@intel.com> ---
> 
> <...>
> 
> >   static int test_string_fns(void) { if (test_rte_strsplit() < 0)
> >   return -1; +	if (test_rte_strlcat() < 0) +		return -1;
> >   return 0; }
> > 
> 
> Unrelated, but do we also need to test strlcpy, strscpy and other
> functions that were introduced?
> 

Yes, I think that would be advisable. I imagine the easiest way to test
them is to do as I have here in running comparisons with a range of inputs,
especially boundary conditions, against a known-good version for platforms
that have the functions built-in.
As always, volunteers and patches welcome... :-)

/Bruce
Burakov, Anatoly Jan. 17, 2019, 11:55 a.m. | #3
On 17-Jan-19 11:00 AM, Bruce Richardson wrote:
> On Thu, Jan 17, 2019 at 10:39:02AM +0000, Burakov, Anatoly wrote:
>> On 16-Jan-19 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.richardson@intel.com> ---
>>
>> <...>
>>
>>>    static int test_string_fns(void) { if (test_rte_strsplit() < 0)
>>>    return -1; +	if (test_rte_strlcat() < 0) +		return -1;
>>>    return 0; }
>>>
>>
>> Unrelated, but do we also need to test strlcpy, strscpy and other
>> functions that were introduced?
>>
> 
> Yes, I think that would be advisable. I imagine the easiest way to test
> them is to do as I have here in running comparisons with a range of inputs,
> especially boundary conditions, against a known-good version for platforms
> that have the functions built-in.
> As always, volunteers and patches welcome... :-)

/action hides

> 
> /Bruce
>
Ferruh Yigit Jan. 17, 2019, 1:10 p.m. | #4
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.richardson@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;
>  }
>  
>

Patch

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));
+}
+
 /* 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;
 }