Hi，Ferruh
> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Monday, March 25, 2019 4:46 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 3/25/2019 3:39 AM, Zhao1, Wei wrote:
> > Hi,
> >
> >> -----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 ;) )
> >
> >
> > Why delete these check from parse_hex_string()?
>
> The point is using 'strtoul' instead of your functions, so that you won't need
> 'get_hex_val()' at all, or won't need 'isxdigit()' because 'strtoul' will
> check it,
> won't need size should be multiply of two restriction '(*size & 1)' because of
> implementation change. Probably you will need NULL checks, but again point
> is why not using 'strtoul' instead of writing your version of it?
Yes, we can use 'strtoul' , but my point is that I think we need these check
code even if we use the code 'strtoul' .
isxdigit(*c)) is need because *c may be sring "0xrgh" which is not hex.
If we use strtoul will return 0 for that ,we can not distinguish between error
or input is zero.
'(*size & 1) can be delete, I agree.
/* Check input parameters */
if ((src == NULL) ||
(dst == NULL) ||
(size == NULL) ||
(*size == 0))
return -1;
for (c = src, i = 0; i < *size; c++, i++) {
if (isxdigit(*c))
continue;
else
return -1;
}
> >
> > /* 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;
> > }
> >
> >
> >
> >>
> >> <...>
> >>
> >>> + /* 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"
