Subject: Re: [PATCH iproute2-next v2 5/8] dcb: rewr: add new dcb-rewr subcommand

From: Petr Machata <[email-masked]>
Date: Tue, 30 May 2023 21:58:33 +0200

Daniel Machon <[email-masked]> writes:

> Add a new subcommand 'rewr' for configuring the in-kernel DCB rewrite
> table. The rewr-table of the kernel is similar to the APP-table, and so
> is this new subcommand. Therefore, much of the existing bookkeeping code
> from dcb-app, can be reused in the dcb-rewr implementation.
>
> Initially, only support for configuring PCP and DSCP-based rewrite has
> been added.
>
> Signed-off-by: Daniel Machon <[email-masked]>

Looks good overall, barring the comment about dcb_app_parse_mapping_cb()
that I made in the other patch, and a handful of nits below.

> ---
>  dcb/Makefile   |   3 +-
>  dcb/dcb.c      |   4 +-
>  dcb/dcb.h      |  32 ++++++
>  dcb/dcb_app.c  |  49 ++++----
>  dcb/dcb_rewr.c | 355 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 416 insertions(+), 27 deletions(-)

> diff --git a/dcb/dcb.h b/dcb/dcb.h
> index b3bc30cd02c5..092dc90e8358 100644
> --- a/dcb/dcb.h
> +++ b/dcb/dcb.h
> @@ -54,6 +54,10 @@ void dcb_print_array_on_off(const __u8 *array, size_t size);
>  void dcb_print_array_kw(const __u8 *array, size_t array_size,
>  			const char *const kw[], size_t kw_size);
>  
> +/* dcp_rewr.c */
> +
> +int dcb_cmd_rewr(struct dcb *dcb, int argc, char **argv);
> +
>  /* dcb_app.c */
>  
>  struct dcb_app_table {
> @@ -70,8 +74,29 @@ struct dcb_app_parse_mapping {
>  	int err;
>  };
>  
> +#define DCB_APP_PCP_MAX 15

This should be removed from dcb_app.c as well.

> +#define DCB_APP_DSCP_MAX 63

DCB_APP_DSCP_MAX should be introduced in a separate patch together with
the s/63/DCB_APP_DSCP_MAX/ of the existing code, instead of including it
all here. It's a concern separate from the main topic of the patch.

> +
>  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
>  
> +int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab);
> +int dcb_app_add_del(struct dcb *dcb, const char *dev, int command,
> +		    const struct dcb_app_table *tab,
> +		    bool (*filter)(const struct dcb_app *));
> +
> +bool dcb_app_is_dscp(const struct dcb_app *app);
> +bool dcb_app_is_pcp(const struct dcb_app *app);
> +
> +int dcb_app_print_pid_dscp(__u16 protocol);
> +int dcb_app_print_pid_pcp(__u16 protocol);
> +int dcb_app_print_pid_dec(__u16 protocol);
> +void dcb_app_print_filtered(const struct dcb_app_table *tab,
> +			    bool (*filter)(const struct dcb_app *),
> +			    void (*print_pid_prio)(int (*print_pid)(__u16),
> +						   const struct dcb_app *),
> +			    int (*print_pid)(__u16 protocol),
> +			    const char *json_name, const char *fp_name);
> +
>  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
>  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
>  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> @@ -80,11 +105,18 @@ bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>  bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>  
>  int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
> +int dcb_app_table_copy(struct dcb_app_table *a, const struct dcb_app_table *b);
> +void dcb_app_table_sort(struct dcb_app_table *tab);
> +void dcb_app_table_fini(struct dcb_app_table *tab);
> +void dcb_app_table_remove_existing(struct dcb_app_table *a,
> +				   const struct dcb_app_table *b);
>  void dcb_app_table_remove_replaced(struct dcb_app_table *a,
>  				   const struct dcb_app_table *b,
>  				   bool (*key_eq)(const struct dcb_app *aa,
>  						  const struct dcb_app *ab));
>  
> +int dcb_app_parse_pcp(__u32 *key, const char *arg);
> +int dcb_app_parse_dscp(__u32 *key, const char *arg);
>  void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
>  
>  /* dcb_apptrust.c */
> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> index 97cba658aa6b..3cb1bb302ed6 100644
> --- a/dcb/dcb_app.c
> +++ b/dcb/dcb_app.c

> @@ -643,9 +642,9 @@ static int dcb_app_add_del_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)

> +static int dcb_cmd_rewr_replace(struct dcb *dcb, const char *dev, int argc,
> +				char **argv)
> +{

[...]

> +}
> +
> +

Two blank lines.

> +static int dcb_cmd_rewr_show(struct dcb *dcb, const char *dev, int argc,
> +			     char **argv)
> +{