Re: [dpdk-stable] [PATCH] lib/librte_cmdline: fix CLI parsing issue

["Lu, Wenzhuo" <wenzhuo.lu@intel.com>]

Hi Oilvier,
As we discussed before, I send this patch. Would you like to take a look at it? Better fix it before release 17.05, thanks.


> -----Original Message-----
> From: Lu, Wenzhuo
> Sent: Tuesday, April 25, 2017 11:11 AM
> To: dev@dpdk.org
> Cc: olivier.matz@6wind.com; Lu, Wenzhuo; stable@dpdk.org
> Subject: [PATCH] lib/librte_cmdline: fix CLI parsing issue
> 
> When parsing a CLI, all the CLI instances are checked one by one. Even if an
> instance already matches the CLI, the parsing will not stop for ambiguous
> check.
> The problem is that the following check may change the parsing result of the
> previous one even if the following instance doesn't match.
> 
> Use a temporary validate for the parsing result when trying to match an
> instance and only store the result when it matches, so the previous result
> has no chance to be changed.
> 
> Fixes: af75078fece3 ("first public release")
> CC: stable@dpdk.org
> 
> Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
> ---
>  lib/librte_cmdline/cmdline_parse.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_cmdline/cmdline_parse.c
> b/lib/librte_cmdline/cmdline_parse.c
> index 763c286..b814880 100644
> --- a/lib/librte_cmdline/cmdline_parse.c
> +++ b/lib/librte_cmdline/cmdline_parse.c
> @@ -258,7 +258,7 @@
>  	union {
>  		char buf[CMDLINE_PARSE_RESULT_BUFSIZE];
>  		long double align; /* strong alignment constraint for buf */
> -	} result;
> +	} result, tmp_result;
>  	cmdline_parse_token_hdr_t
> *dyn_tokens[CMDLINE_PARSE_DYNAMIC_TOKENS];
>  	void (*f)(void *, struct cmdline *, void *) = NULL;
>  	void *data = NULL;
> @@ -321,14 +321,16 @@
>  		debug_printf("INST %d\n", inst_num);
> 
>  		/* fully parsed */
> -		tok = match_inst(inst, buf, 0, result.buf, sizeof(result.buf),
> -				 &dyn_tokens);
> +		tok = match_inst(inst, buf, 0, tmp_result.buf,
> +				 sizeof(tmp_result.buf), &dyn_tokens);
> 
>  		if (tok > 0) /* we matched at least one token */
>  			err = CMDLINE_PARSE_BAD_ARGS;
> 
>  		else if (!tok) {
>  			debug_printf("INST fully parsed\n");
> +			memcpy(&result, &tmp_result,
> +			       sizeof(result));
>  			/* skip spaces */
>  			while (isblank2(*curbuf)) {
>  				curbuf++;
> --
> 1.9.3