On 4/9/2019 8:38 AM, Zhao1, Wei wrote:
> Hi, Ferruh
>
>> -----Original Message-----
>> From: Yigit, Ferruh
>> Sent: Friday, March 22, 2019 10:56 PM
>> To: Zhao1, Wei <wei.zh...@intel.com>; dev@dpdk.org
>> Cc: sta...@dpdk.org; step...@networkplumber.org; Ananyev, Konstantin
>> <konstantin.anan...@intel.com>
>> Subject: Re: [dpdk-stable] [PATCH v3] app/testpmd: fix support of hex string
>> parser for flow API
>>
>> On 3/22/2019 3:15 AM, Wei Zhao wrote:
>>> There is need for users to set configuration of HEX number for RSS
>>> key. The key byte should be pass down as hex number not as char
>>> string. This patch enable cmdline flow parse HEX number, in order to
>>> not using string which pass ASIC number.
>>>
>>> Fixes: f4d623f96119 ("app/testpmd: fix missing RSS fields in flow
>>> action")
>>> Cc: sta...@dpdk.org
>>>
>>> Signed-off-by: Wei Zhao <wei.zh...@intel.com>
>>> Tested-by: Peng Yuan <yuan.p...@intel.com>
>>
>> <...>
>>
>>> @@ -4475,6 +4486,138 @@ parse_string(struct context *ctx, const struct
>> token *token,
>>> return -1;
>>> }
>>>
>>> +static uint32_t
>>> +get_hex_val(char c)
>>> +{
>>> + switch (c) {
>>> + case '0': case '1': case '2': case '3': case '4': case '5':
>>> + case '6': case '7': case '8': case '9':
>>> + return c - '0';
>>> + case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
>>> + return c - 'A' + 10;
>>> + case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
>>> + return c - 'a' + 10;
>>> + default:
>>> + return 0;
>>> + }
>>> +}
>>> +
>>> +static int
>>> +parse_hex_string(const char *src, uint8_t *dst, uint32_t *size) {
>>> + const char *c;
>>> + uint32_t i;
>>> +
>>> + /* Check input parameters */
>>> + if ((src == NULL) ||
>>> + (dst == NULL) ||
>>> + (size == NULL) ||
>>> + (*size == 0))
>>> + return -1;
>>> + if ((*size & 1) != 0)
>>> + return -1;
>>> +
>>> + for (c = src, i = 0; i < *size; c++, i++) {
>>> + if (isxdigit(*c))
>>> + continue;
>>> + else
>>> + return -1;
>>> + }
>>> +
>>> + *size = *size / 2;
>>> +
>>> + /* Convert chars to bytes */
>>> + for (i = 0; i < *size; i++)
>>> + dst[i] = get_hex_val(src[2 * i]) * 16 +
>>> + get_hex_val(src[2 * i + 1]);
>>> +
>>> + return 0;
>>> +}
>>
>> I can see this has been discussed already but what would you think updating
>> the 'parse_hex_string' something like following, it is less code to maintain:
>>
>> static int
>> parse_hex_string(const char *src, uint8_t *dst, uint32_t *size) {
>> int len;
>> int i
>> for (i = 0, len = 0; i < *size; i += 2) {
>> char tmp[3];
>> snprintf(tmp, 3, src + i);
>> dst[len++] = strtoul(tmp, NULL, 16);
>> }
>> dst[len] = 0;
>> *size = len;
>> return 0;
>> }
>>
>> (indeed with better error checking on strtoul ;) )
>>
>> <...>
>
>
>
> I have change code style as your guide as bellow,
> but strtoul() seems do not work, it return c with a none-null every time.
> you can have a try yourself.
Hi Wei,
Yes it return 'c' none-null, which is OK/expected.
According man page:
"
If endptr is not NULL, strtol() stores the address of the first invalid
character in *endptr. If there were no digits at all, strtol() stores the
original value of nptr in *endptr (and returns 0). In particular, if *nptr is
not '\0' but **endptr is '\0' on return, the entire string is valid.
"
First invalid char in below is 'tmp[2]', which is '0', so 'strtol' returns
'&tmp[2]', this is aligned with what described above.
It says, "if *nptr is not '\0' but **endptr is '\0' on return, the entire string
is valid.", beware it says "**endptr is '\0'", so following check should work:
if (*c != 0) {
len--;
dst[len] = 0;
*size = len;
return -1;
}
>
>
> static int
> parse_hex_string(const char *src, uint8_t *dst, uint32_t *size)
> {
> char *c = NULL;
> uint32_t i, len;
> char tmp[3];
>
> /* Check input parameters */
> if ((src == NULL) ||
> (dst == NULL) ||
> (size == NULL) ||
> (*size == 0))
> return -1;
>
> /* Convert chars to bytes */
> for (i = 0, len = 0; i < *size; i += 2) {
> snprintf(tmp, 3, "%s" ,src + i);
> dst[len++] = strtoul(tmp, &c, 16);
> if(c)
> return -1;
> }
> dst[len] = 0;
> *size = len;
>
> return 0;
> }
>
>>
>>> + /* Output buffer is not necessarily NUL-terminated. */
>>> + memcpy(buf, hex_tmp, hexlen);
>>> + memset((uint8_t *)buf + len, 0x00, size - hexlen);
>>
>> Can't this overflow the 'buf'? since "len = 2 * hexlen"
>> I guess intention is "buf + hexlen"
