Re: [PATCH mptcp-next v6 02/14] mptcp: handle local addrs announced by userspace PMs

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

On Mon, 28 Mar 2022, Kishen Maloor wrote:

> This change adds an internal function to store/retrieve local
> addrs announced by userspace PM implementations to/from its kernel
> context. The function addresses the requirements of three scenarios:
> 1) ADD_ADDR announcements (which require that a local id be
> provided), 2) retrieving the local id associated with an address,
> and also where one may need to be assigned, and 3) reissuance of
> ADD_ADDRs when there's a successful match of addr/id.
>
> The list of all stored local addr entries is held under the
> MPTCP sock structure. Memory for these entries is allocated from
> the sock option buffer, so the list of addrs is bounded by optmem_max.
> The list if not released via REMOVE_ADDR signals is ultimately
> freed when the sock is destructed.
>
> Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
> ---
> v6:
> -Move local_addr_list into struct mptcp_pm_data.
> -Replace mptcp_data_lock() with the pm spinlock.
> -Move mptcp_userspace_pm_append_new_local_addr() and
> mptcp_free_local_addr_list() into a new pm_userspace.c.
> -Make addresses_equal() helper non-static and rename to
> mptcp_addresses_equal().
> ---
> net/mptcp/Makefile       |  2 +-
> net/mptcp/pm.c           |  1 +
> net/mptcp/pm_netlink.c   | 34 +++++++++---------
> net/mptcp/pm_userspace.c | 74 ++++++++++++++++++++++++++++++++++++++++
> net/mptcp/protocol.c     |  1 +
> net/mptcp/protocol.h     |  7 ++++
> 6 files changed, 101 insertions(+), 18 deletions(-)
> create mode 100644 net/mptcp/pm_userspace.c
>
> diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile
> index e54daceac58b..cb7f53f6ab22 100644
> --- a/net/mptcp/Makefile
> +++ b/net/mptcp/Makefile
> @@ -2,7 +2,7 @@
> obj-$(CONFIG_MPTCP) += mptcp.o
>
> mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o diag.o \
> -	   mib.o pm_netlink.o sockopt.o
> +	   mib.o pm_netlink.o sockopt.o pm_userspace.o
>
> obj-$(CONFIG_SYN_COOKIES) += syncookies.o
> obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o
> diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
> index 5d6832c4d9f2..cdc2d79071f8 100644
> --- a/net/mptcp/pm.c
> +++ b/net/mptcp/pm.c
> @@ -469,6 +469,7 @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
> {
> 	spin_lock_init(&msk->pm.lock);
> 	INIT_LIST_HEAD(&msk->pm.anno_list);
> +	INIT_LIST_HEAD(&msk->pm.userspace_pm_local_addr_list);
> 	mptcp_pm_data_reset(msk);
> }
>
> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> index 8d04c8d8a8df..836f6df9f744 100644
> --- a/net/mptcp/pm_netlink.c
> +++ b/net/mptcp/pm_netlink.c
> @@ -55,8 +55,8 @@ struct pm_nl_pernet {
> #define MPTCP_PM_ADDR_MAX	8
> #define ADD_ADDR_RETRANS_MAX	3
>
> -static bool addresses_equal(const struct mptcp_addr_info *a,
> -			    const struct mptcp_addr_info *b, bool use_port)
> +bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
> +			   const struct mptcp_addr_info *b, bool use_port)

There's a minor conflict with the export branch here after the get_pernet 
helpers were added. I know you're planning a rebase but figured I'd 
capture it here on the ML.


--
Mat Martineau
Intel