mctp: Add flow extension to skb

This change adds a new skb extension for MCTP, to represent a
request/response flow.

The intention is to use this in a later change to allow i2c controllers
to correctly configure a multiplexer over a flow.

Since we have a cleanup function in the core path (if an extension is
present), we'll need to make CONFIG_MCTP a bool, rather than a tristate.

Includes a fix for a build warning with clang:
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeremy Kerr 2021-10-29 11:01:44 +08:00 committed by David S. Miller
parent 212c10c3c6
commit 78476d315e
4 changed files with 35 additions and 1 deletions

View File

@ -4243,6 +4243,9 @@ enum skb_ext_id {
#endif
#if IS_ENABLED(CONFIG_MPTCP)
SKB_EXT_MPTCP,
#endif
#if IS_ENABLED(CONFIG_MCTP_FLOWS)
SKB_EXT_MCTP,
#endif
SKB_EXT_NUM, /* must be last */
};

View File

@ -189,6 +189,13 @@ static inline struct mctp_skb_cb *mctp_cb(struct sk_buff *skb)
return (void *)(skb->cb);
}
/* If CONFIG_MCTP_FLOWS, we may add one of these as a SKB extension,
* indicating the flow to the device driver.
*/
struct mctp_flow {
struct mctp_sk_key *key;
};
/* Route definition.
*
* These are held in the pernet->mctp.routes list, with RCU protection for

View File

@ -70,6 +70,7 @@
#include <net/xfrm.h>
#include <net/mpls.h>
#include <net/mptcp.h>
#include <net/mctp.h>
#include <net/page_pool.h>
#include <linux/uaccess.h>
@ -4440,6 +4441,9 @@ static const u8 skb_ext_type_len[] = {
#if IS_ENABLED(CONFIG_MPTCP)
[SKB_EXT_MPTCP] = SKB_EXT_CHUNKSIZEOF(struct mptcp_ext),
#endif
#if IS_ENABLED(CONFIG_MCTP_FLOWS)
[SKB_EXT_MCTP] = SKB_EXT_CHUNKSIZEOF(struct mctp_flow),
#endif
};
static __always_inline unsigned int skb_ext_total_length(void)
@ -4456,6 +4460,9 @@ static __always_inline unsigned int skb_ext_total_length(void)
#endif
#if IS_ENABLED(CONFIG_MPTCP)
skb_ext_type_len[SKB_EXT_MPTCP] +
#endif
#if IS_ENABLED(CONFIG_MCTP_FLOWS)
skb_ext_type_len[SKB_EXT_MCTP] +
#endif
0;
}
@ -6529,6 +6536,14 @@ static void skb_ext_put_sp(struct sec_path *sp)
}
#endif
#ifdef CONFIG_MCTP_FLOWS
static void skb_ext_put_mctp(struct mctp_flow *flow)
{
if (flow->key)
mctp_key_unref(flow->key);
}
#endif
void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
{
struct skb_ext *ext = skb->extensions;
@ -6564,6 +6579,10 @@ free_now:
if (__skb_ext_exist(ext, SKB_EXT_SEC_PATH))
skb_ext_put_sp(skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH));
#endif
#ifdef CONFIG_MCTP_FLOWS
if (__skb_ext_exist(ext, SKB_EXT_MCTP))
skb_ext_put_mctp(skb_ext_get_ptr(ext, SKB_EXT_MCTP));
#endif
kmem_cache_free(skbuff_ext_cache, ext);
}

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@ -1,7 +1,7 @@
menuconfig MCTP
depends on NET
tristate "MCTP core protocol support"
bool "MCTP core protocol support"
help
Management Component Transport Protocol (MCTP) is an in-system
protocol for communicating between management controllers and
@ -16,3 +16,8 @@ config MCTP_TEST
bool "MCTP core tests" if !KUNIT_ALL_TESTS
depends on MCTP=y && KUNIT=y
default KUNIT_ALL_TESTS
config MCTP_FLOWS
bool
depends on MCTP
select SKB_EXTENSIONS