Re: [PATCH v2 1/2] cmdline: add function to verify valid commands

[Olivier Matz <olivier.matz@6wind.com>]

Hi Bruce,

Just few minor comments below.

On Fri, May 20, 2022 at 04:12:39PM +0100, Bruce Richardson wrote:
> The cmdline library cmdline_parse() function parses a command and
> executes the action automatically too. The cmdline_valid_buffer function
> also uses this function to validate commands, meaning that there is no
> function to validate a command as ok without executing it.
> 
> To fix this omission, we extract the body of cmdline_parse into a new
> static inline function with an extra parameter to indicate whether the
> action should be performed or not. Then we create two wrappers around
> that - a replacement for the existing cmdline_parse function where the
> extra parameter is "true" to execute the command, and a new function
> "cmdline_parse_check" which passes the parameter as "false" to perform
> cmdline validation only.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>  lib/cmdline/cmdline_parse.c | 20 +++++++++++++++++---
>  lib/cmdline/cmdline_parse.h | 17 +++++++++++++++--
>  lib/cmdline/version.map     |  3 +++
>  3 files changed, 35 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/cmdline/cmdline_parse.c b/lib/cmdline/cmdline_parse.c
> index 349ec87bd7..b7fdc67ae5 100644
> --- a/lib/cmdline/cmdline_parse.c
> +++ b/lib/cmdline/cmdline_parse.c
> @@ -7,6 +7,7 @@
>  #include <stdio.h>
>  #include <errno.h>
>  #include <string.h>
> +#include <stdbool.h>
>  
>  #include <rte_string_fns.h>
>  
> @@ -182,8 +183,8 @@ match_inst(cmdline_parse_inst_t *inst, const char *buf,
>  }
>  
>  
> -int
> -cmdline_parse(struct cmdline *cl, const char * buf)
> +static inline int
> +__cmdline_parse(struct cmdline *cl, const char *buf, bool call_fn)
>  {
>  	unsigned int inst_num=0;
>  	cmdline_parse_inst_t *inst;
> @@ -284,7 +285,8 @@ cmdline_parse(struct cmdline *cl, const char * buf)
>  
>  	/* call func */
>  	if (f) {
> -		f(result.buf, cl, data);
> +		if (call_fn)
> +			f(result.buf, cl, data);

Maybe nicer to test in one line:

if (f && call_fn)


>  	}
>  
>  	/* no match */
> @@ -296,6 +298,18 @@ cmdline_parse(struct cmdline *cl, const char * buf)
>  	return linelen;
>  }
>  
> +int
> +cmdline_parse(struct cmdline *cl, const char *buf)
> +{
> +	return __cmdline_parse(cl, buf, true);
> +}
> +
> +int
> +cmdline_parse_check(struct cmdline *cl, const char *buf)
> +{
> +	return __cmdline_parse(cl, buf, false);
> +}
> +
>  int
>  cmdline_complete(struct cmdline *cl, const char *buf, int *state,
>  		 char *dst, unsigned int size)
> diff --git a/lib/cmdline/cmdline_parse.h b/lib/cmdline/cmdline_parse.h
> index e4d802fff7..6dd210d843 100644
> --- a/lib/cmdline/cmdline_parse.h
> +++ b/lib/cmdline/cmdline_parse.h
> @@ -7,6 +7,8 @@
>  #ifndef _CMDLINE_PARSE_H_
>  #define _CMDLINE_PARSE_H_
>  
> +#include <rte_compat.h>
> +
>  #ifdef __cplusplus
>  extern "C" {
>  #endif
> @@ -149,11 +151,22 @@ typedef cmdline_parse_inst_t *cmdline_parse_ctx_t;
>   * argument buf must ends with "\n\0". The function returns
>   * CMDLINE_PARSE_AMBIGUOUS, CMDLINE_PARSE_NOMATCH or
>   * CMDLINE_PARSE_BAD_ARGS on error. Else it calls the associated
> - * function (defined in the context) and returns 0
> - * (CMDLINE_PARSE_SUCCESS).
> + * function (defined in the context) and returns the parsed line length (>= 0)

Can we add a dot at the end?

>   */
>  int cmdline_parse(struct cmdline *cl, const char *buf);
>  
> +/**
> + * Try to parse a buffer according to the specified context, but do not
> + * perform any function calls if parse is successful.
> + *
> + * The argument buf must ends with "\n\0".
> + * The function returns CMDLINE_PARSE_AMBIGUOUS, CMDLINE_PARSE_NOMATCH or
> + * CMDLINE_PARSE_BAD_ARGS on error and returns the parsed line length (>=0).
> + * on successful parse

Same here.

> + */
> +__rte_experimental
> +int cmdline_parse_check(struct cmdline *cl, const char *buf);
> +
>  /**
>   * complete() must be called with *state==0 (try to complete) or
>   * with *state==-1 (just display choices), then called without
> diff --git a/lib/cmdline/version.map b/lib/cmdline/version.map
> index b9bbb87510..fc7fdd6ea4 100644
> --- a/lib/cmdline/version.map
> +++ b/lib/cmdline/version.map
> @@ -81,5 +81,8 @@ EXPERIMENTAL {
>  	rdline_get_history_buffer_size;
>  	rdline_get_opaque;
>  
> +	# added in 22.07
> +	cmdline_parse_check;
> +
>  	local: *;
>  };
> -- 
> 2.34.1
> 

With these changes:
Acked-by: Olivier Matz <olivier.matz@6wind.com>