net: mctp: avoid confusion over local/peer dest/source addresses

We have a double-swap of local and peer addresses in
mctp_alloc_local_tag; the arguments in both call sites are swapped, but
there is also a swap in the implementation of alloc_local_tag. This is
opaque because we're using source/dest address references, which don't
match the local/peer semantics.

Avoid this confusion by naming the arguments as 'local' and 'peer', and
remove the double swap. The calling order now matches mctp_key_alloc.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/include/net/mctp.h b/include/net/mctp.h
index da86e106c91d57b2eedfc7bb301867eb8e51c123..f937a325ea6f2c809b4d6bdf514d90ffd1cc08cb 100644 (file)
--- a/include/net/mctp.h
+++ b/include/net/mctp.h
@@ -87,7 +87,7 @@ struct mctp_sock {
 };
 
 /* Key for matching incoming packets to sockets or reassembly contexts.
- * Packets are matched on (src,dest,tag).
+ * Packets are matched on (peer EID, local EID, tag).
  *
  * Lifetime / locking requirements:
  *
@@ -254,7 +254,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
 
 void mctp_key_unref(struct mctp_sk_key *key);
 struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
-                                        mctp_eid_t daddr, mctp_eid_t saddr,
+                                        mctp_eid_t local, mctp_eid_t peer,
                                         bool manual, u8 *tagp);
 
 /* routing <--> device interface */

diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index f6be58b68c6f368ec641580755bd1a4bad6b5e2d..d8197e9e233bd06a4fe18e41a7277a503c3bc308 100644 (file)
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -367,7 +367,7 @@ static int mctp_ioctl_alloctag(struct mctp_sock *msk, unsigned long arg)
        if (ctl.flags)
                return -EINVAL;
 
-       key = mctp_alloc_local_tag(msk, ctl.peer_addr, MCTP_ADDR_ANY,
+       key = mctp_alloc_local_tag(msk, MCTP_ADDR_ANY, ctl.peer_addr,
                                   true, &tag);
        if (IS_ERR(key))
                return PTR_ERR(key);

diff --git a/net/mctp/route.c b/net/mctp/route.c
index 7a47a58aa54b446acf7451ba6bdc1b834adda327..04d29e910af9ae6780c4205c037a3ecc9136ff5f 100644 (file)
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -596,11 +596,11 @@ static void mctp_reserve_tag(struct net *net, struct mctp_sk_key *key,
        refcount_inc(&key->refs);
 }
 
-/* Allocate a locally-owned tag value for (saddr, daddr), and reserve
+/* Allocate a locally-owned tag value for (local, peer), and reserve
  * it for the socket msk
  */
 struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
-                                        mctp_eid_t daddr, mctp_eid_t saddr,
+                                        mctp_eid_t local, mctp_eid_t peer,
                                         bool manual, u8 *tagp)
 {
        struct net *net = sock_net(&msk->sk);
@@ -610,11 +610,11 @@ struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
        u8 tagbits;
 
        /* for NULL destination EIDs, we may get a response from any peer */
-       if (daddr == MCTP_ADDR_NULL)
-               daddr = MCTP_ADDR_ANY;
+       if (peer == MCTP_ADDR_NULL)
+               peer = MCTP_ADDR_ANY;
 
        /* be optimistic, alloc now */
-       key = mctp_key_alloc(msk, saddr, daddr, 0, GFP_KERNEL);
+       key = mctp_key_alloc(msk, local, peer, 0, GFP_KERNEL);
        if (!key)
                return ERR_PTR(-ENOMEM);
 
@@ -635,8 +635,8 @@ struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
                if (tmp->tag & MCTP_HDR_FLAG_TO)
                        continue;
 
-               if (!(mctp_address_matches(tmp->peer_addr, daddr) &&
-                     mctp_address_matches(tmp->local_addr, saddr)))
+               if (!(mctp_address_matches(tmp->peer_addr, peer) &&
+                     mctp_address_matches(tmp->local_addr, local)))
                        continue;
 
                spin_lock(&tmp->lock);
@@ -924,7 +924,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
                        key = mctp_lookup_prealloc_tag(msk, daddr,
                                                       req_tag, &tag);
                else
-                       key = mctp_alloc_local_tag(msk, daddr, saddr,
+                       key = mctp_alloc_local_tag(msk, saddr, daddr,
                                                   false, &tag);
 
                if (IS_ERR(key)) {