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mctp: Implement extended addressing

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This change allows an extended address struct - struct sockaddr_mctp_ext
- to be passed to sendmsg/recvmsg. This allows userspace to specify
output ifindex and physical address information (for sendmsg) or receive
the input ifindex/physaddr for incoming messages (for recvmsg). This is
typically used by userspace for MCTP address discovery and assignment
operations.

The extended addressing facility is conditional on a new sockopt:
MCTP_OPT_ADDR_EXT; userspace must explicitly enable addressing before
the kernel will consume/populate the extended address data.

Includes a fix for an uninitialised var:
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
2021-10-26 09:57:28 +08:00
committed by David S. Miller
parent 971f5c4079
commit 99ce45d5e7
5 changed files with 170 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
include/net/mctp.h
View File

@@ -11,6 +11,7 @@
#include <linux/bits.h>
#include <linux/mctp.h>
#include <linux/netdevice.h>
#include <net/net_namespace.h>
#include <net/sock.h>
@@ -58,6 +59,9 @@ struct mctp_sock {
mctp_eid_t bind_addr;
__u8 bind_type;
/* sendmsg()/recvmsg() uses struct sockaddr_mctp_ext */
bool addr_ext;
/* list of mctp_sk_key, for incoming tag lookup. updates protected
* by sk->net->keys_lock
*/
@@ -153,7 +157,10 @@ struct mctp_sk_key {
struct mctp_skb_cb {
unsigned int magic;
unsigned int net;
int ifindex; /* extended/direct addressing if set */
mctp_eid_t src;
unsigned char halen;
unsigned char haddr[MAX_ADDR_LEN];
};
/* skb control-block accessors with a little extra debugging for initial
@@ -177,6 +184,7 @@ static inline struct mctp_skb_cb *mctp_cb(struct sk_buff *skb)
{
struct mctp_skb_cb *cb = (void *)skb->cb;
BUILD_BUG_ON(sizeof(struct mctp_skb_cb) > sizeof(skb->cb));
WARN_ON(cb->magic != 0x4d435450);
return (void *)(skb->cb);
}
@@ -189,8 +197,7 @@ static inline struct mctp_skb_cb *mctp_cb(struct sk_buff *skb)
*
* Updates to the route table are performed under rtnl; all reads under RCU,
* so routes cannot be referenced over a RCU grace period. Specifically: A
* caller cannot block between mctp_route_lookup and passing the route to
* mctp_do_route.
* caller cannot block between mctp_route_lookup and mctp_route_release()
*/
struct mctp_route {
mctp_eid_t min, max;
@@ -210,8 +217,6 @@ struct mctp_route {
struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
mctp_eid_t daddr);
int mctp_do_route(struct mctp_route *rt, struct sk_buff *skb);
int mctp_local_output(struct sock *sk, struct mctp_route *rt,
struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag);