Re: [PATCH mptcp-next v2 20/36] mptcp: add loc and rem for set_flags

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 22/10/2024 11:14, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> This patch updates the interfaces set_flags to reduce repetitive code,
> adds two more parameters "loc" and "rem" for them. These addresses are
> parsed in public helper mptcp_pm_nl_set_flags_doit(), then pass them
> to mptcp_pm_nl_set_flags() and mptcp_userspace_pm_set_flags().
> 
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
>  net/mptcp/pm_netlink.c   | 57 ++++++++++++++++++++++++----------------
>  net/mptcp/pm_userspace.c | 28 ++++++--------------
>  net/mptcp/protocol.h     |  4 ++-
>  3 files changed, 46 insertions(+), 43 deletions(-)
> 
> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> index 5fb1d5d8bf57..5cd5241da3c6 100644
> --- a/net/mptcp/pm_netlink.c
> +++ b/net/mptcp/pm_netlink.c
> @@ -2045,10 +2045,10 @@ static int mptcp_nl_set_flags(struct net *net,
>  	return ret;
>  }
>  
> -static int mptcp_pm_nl_set_flags(struct genl_info *info)
> +static int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *loc,
> +				 struct mptcp_addr_info *rem,
> +				 struct genl_info *info)
>  {
> -	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
> -	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
>  	u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
>  			   MPTCP_PM_ADDR_FLAG_FULLMESH;
>  	struct net *net = genl_info_net(info);
> @@ -2056,59 +2056,72 @@ static int mptcp_pm_nl_set_flags(struct genl_info *info)
>  	struct pm_nl_pernet *pernet;
>  	u8 lookup_by_id = 0;
>  	u8 bkup = 0;
> -	int ret;
>  
>  	pernet = pm_nl_get_pernet(net);
>  
> -	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
> -	if (ret < 0)
> -		return ret;
> -
> -	if (addr.addr.family == AF_UNSPEC) {
> +	if (loc->addr.family == AF_UNSPEC) {
>  		lookup_by_id = 1;
> -		if (!addr.addr.id) {
> +		if (!loc->addr.id) {
>  			GENL_SET_ERR_MSG(info, "missing required inputs");
>  			return -EOPNOTSUPP;
>  		}
>  	}
>  
> -	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
> +	if (loc->flags & MPTCP_PM_ADDR_FLAG_BACKUP)
>  		bkup = 1;
>  
>  	spin_lock_bh(&pernet->lock);
> -	entry = lookup_by_id ? __lookup_addr_by_id(pernet, addr.addr.id) :
> -			       __lookup_addr(pernet, &addr.addr);
> +	entry = lookup_by_id ? __lookup_addr_by_id(pernet, loc->addr.id) :
> +			       __lookup_addr(pernet, &loc->addr);
>  	if (!entry) {
>  		spin_unlock_bh(&pernet->lock);
>  		GENL_SET_ERR_MSG(info, "address not found");
>  		return -EINVAL;
>  	}
> -	if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
> +	if ((loc->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
>  	    (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
>  		spin_unlock_bh(&pernet->lock);
>  		GENL_SET_ERR_MSG(info, "invalid addr flags");
>  		return -EINVAL;
>  	}
>  
> -	changed = (addr.flags ^ entry->flags) & mask;
> -	entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
> -	addr = *entry;
> +	changed = (loc->flags ^ entry->flags) & mask;
> +	entry->flags = (entry->flags & ~mask) | (loc->flags & mask);
> +	*loc = *entry;
>  	spin_unlock_bh(&pernet->lock);
>  
> -	mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
> +	mptcp_nl_set_flags(net, &loc->addr, bkup, changed);
>  	return 0;
>  }
>  
> -static int mptcp_pm_set_flags(struct genl_info *info)
> +static int mptcp_pm_set_flags(struct mptcp_pm_addr_entry *loc,
> +			      struct mptcp_addr_info *rem,
> +			      struct genl_info *info)
>  {
>  	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
> -		return mptcp_userspace_pm_set_flags(info);
> -	return mptcp_pm_nl_set_flags(info);
> +		return mptcp_userspace_pm_set_flags(loc, rem, info);
> +	return mptcp_pm_nl_set_flags(loc, rem, info);
>  }
>  
>  int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
>  {
> -	return mptcp_pm_set_flags(info);
> +	struct mptcp_pm_addr_entry loc = { .addr = { .family = AF_UNSPEC }, };
> +	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
> +	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];

(detail: maybe clearer to call it "attr_loc", similar to "attr_rem")

> +	struct mptcp_addr_info rem = { .family = AF_UNSPEC, };
> +	int ret;
> +
> +	ret = mptcp_pm_parse_entry(attr, info, false, &loc);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (attr_rem) {
> +		ret = mptcp_pm_parse_addr(attr_rem, info, &rem);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return mptcp_pm_set_flags(&loc, &rem, info);

Nothing to change here, but linked to a previous comment for another
patch of this series: I think it would be clearer to move
mptcp_pm_nl_set_flags_doit() and similar (mptcp_pm_nl_get_addr_dumpit()
+ mptcp_pm_nl_get_addr_doit()) to pm.c: these helpers are generic,
implemented for each PM.

Similarly, we can move the content of their linked function
(mptcp_pm_set_flags(), mptcp_pm_dump_addr() and mptcp_pm_get_addr()) in
there. If this last step makes sense for the future changes of course,
but for the moment, these helpers are only used in one place, just next
to, and only 3 basic lines: 'if (X) return A; return B'.

>  }
>  
>  static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
(...)

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.