| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20250703-mctp-bind-v1-4-bb7e97c24613@codeconstruct.com.au>
Date: Thu, 03 Jul 2025 17:11:51 +0800
From: Matt Johnston <matt@...econstruct.com.au>
To: Jeremy Kerr <jk@...econstruct.com.au>,
"David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
Simon Horman <horms@...nel.org>
Cc: netdev@...r.kernel.org, Matt Johnston <matt@...econstruct.com.au>
Subject: [PATCH net-next 4/7] net: mctp: Use hashtable for binds
Ensure that a specific EID (remote or local) bind will match in
preference to a MCTP_ADDR_ANY bind.
This adds infrastructure for binding a socket to receive messages from a
specific remote peer address, a future commit will expose an API for
this.
Signed-off-by: Matt Johnston <matt@...econstruct.com.au>
---
include/net/netns/mctp.h | 15 ++++++++--
net/mctp/af_mctp.c | 11 ++++---
net/mctp/route.c | 76 +++++++++++++++++++++++++++++++++++++-----------
3 files changed, 79 insertions(+), 23 deletions(-)
diff --git a/include/net/netns/mctp.h b/include/net/netns/mctp.h
index 1db8f9aaddb4b96f4803df9f30a762f5f88d7f7f..9f4f1c1065a8f00bbd5b1df5fa8f1cedf8d60686 100644
--- a/include/net/netns/mctp.h
+++ b/include/net/netns/mctp.h
@@ -6,19 +6,25 @@
#ifndef __NETNS_MCTP_H__
#define __NETNS_MCTP_H__
+#include <linux/hash.h>
#include <linux/mutex.h>
#include <linux/types.h>
+#define MCTP_BINDS_BITS 7
+#define MCTP_BINDS_SIZE (1 << MCTP_BINDS_BITS)
+#define MCTP_BINDS_MASK (MCTP_BINDS_SIZE - 1)
+
struct netns_mctp {
/* Only updated under RTNL, entries freed via RCU */
struct list_head routes;
- /* Bound sockets: list of sockets bound by type.
+ /* Bound sockets: hash table of sockets, keyed by (type, src_eid, dest_eid).
+ * Specific src_eid/dest_eid entries also have an entry for MCTP_ADDR_ANY.
* This list is updated from non-atomic contexts (under bind_lock),
* and read (under rcu) in packet rx
*/
struct mutex bind_lock;
- struct hlist_head binds;
+ struct hlist_head binds[MCTP_BINDS_SIZE];
/* tag allocations. This list is read and updated from atomic contexts,
* but elements are free()ed after a RCU grace-period
@@ -34,4 +40,9 @@ struct netns_mctp {
struct list_head neighbours;
};
+static inline u32 mctp_bind_hash(u8 type, u8 local_addr, u8 peer_addr)
+{
+ return hash_32(type | (u32)local_addr << 8 | (u32)peer_addr << 16, MCTP_BINDS_BITS);
+}
+
#endif /* __NETNS_MCTP_H__ */
diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index 4751f5fc082dcab27df77a9c5acbc6abb4e861d5..7638e22bf03848868768700fdac07f74891dad0d 100644
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -643,17 +643,17 @@ static int mctp_sk_hash(struct sock *sk)
struct net *net = sock_net(sk);
struct sock *existing;
struct mctp_sock *msk;
+ u32 hash;
int rc;
msk = container_of(sk, struct mctp_sock, sk);
- /* Bind lookup runs under RCU, remain live during that. */
- sock_set_flag(sk, SOCK_RCU_FREE);
+ hash = mctp_bind_hash(msk->bind_type, msk->bind_addr, MCTP_ADDR_ANY);
mutex_lock(&net->mctp.bind_lock);
/* Prevent duplicate binds. */
- sk_for_each(existing, &net->mctp.binds) {
+ sk_for_each(existing, &net->mctp.binds[hash]) {
struct mctp_sock *mex = container_of(existing, struct mctp_sock, sk);
if (mex->bind_type == msk->bind_type &&
@@ -664,7 +664,10 @@ static int mctp_sk_hash(struct sock *sk)
}
}
- sk_add_node_rcu(sk, &net->mctp.binds);
+ /* Bind lookup runs under RCU, remain live during that. */
+ sock_set_flag(sk, SOCK_RCU_FREE);
+
+ sk_add_node_rcu(sk, &net->mctp.binds[hash]);
rc = 0;
out:
diff --git a/net/mctp/route.c b/net/mctp/route.c
index d9c8e5a5f9ce9aefbf16730c65a1f54caa5592b9..8a8c7841d2382717b3c9a6698036d56f64da77f0 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -38,14 +38,45 @@ static int mctp_route_discard(struct mctp_route *route, struct sk_buff *skb)
return 0;
}
-static struct mctp_sock *mctp_lookup_bind(struct net *net, struct sk_buff *skb)
+static struct mctp_sock *mctp_lookup_bind_details(struct net *net,
+ struct sk_buff *skb,
+ u8 type, u8 dest,
+ u8 src, bool allow_net_any)
{
struct mctp_skb_cb *cb = mctp_cb(skb);
- struct mctp_hdr *mh;
struct sock *sk;
- u8 type;
+ u8 hash;
- WARN_ON(!rcu_read_lock_held());
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ hash = mctp_bind_hash(type, dest, src);
+
+ sk_for_each_rcu(sk, &net->mctp.binds[hash]) {
+ struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
+
+ if (!allow_net_any && msk->bind_net == MCTP_NET_ANY)
+ continue;
+
+ if (msk->bind_net != MCTP_NET_ANY && msk->bind_net != cb->net)
+ continue;
+
+ if (msk->bind_type != type)
+ continue;
+
+ if (!mctp_address_matches(msk->bind_addr, dest))
+ continue;
+
+ return msk;
+ }
+
+ return NULL;
+}
+
+static struct mctp_sock *mctp_lookup_bind(struct net *net, struct sk_buff *skb)
+{
+ struct mctp_sock *msk;
+ struct mctp_hdr *mh;
+ u8 type;
/* TODO: look up in skb->cb? */
mh = mctp_hdr(skb);
@@ -55,20 +86,31 @@ static struct mctp_sock *mctp_lookup_bind(struct net *net, struct sk_buff *skb)
type = (*(u8 *)skb->data) & 0x7f;
- sk_for_each_rcu(sk, &net->mctp.binds) {
- struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
-
- if (msk->bind_net != MCTP_NET_ANY && msk->bind_net != cb->net)
- continue;
-
- if (msk->bind_type != type)
- continue;
-
- if (!mctp_address_matches(msk->bind_addr, mh->dest))
- continue;
+ /* Look for binds in order of widening scope. A given destination or
+ * source address also implies matching on a particular network.
+ *
+ * - Matching destination and source
+ * - Matching destination
+ * - Matching source
+ * - Matching network, any address
+ * - Any network or address
+ */
+ msk = mctp_lookup_bind_details(net, skb, type, mh->dest, mh->src, false);
+ if (msk)
+ return msk;
+ msk = mctp_lookup_bind_details(net, skb, type, MCTP_ADDR_ANY, mh->src, false);
+ if (msk)
+ return msk;
+ msk = mctp_lookup_bind_details(net, skb, type, mh->dest, MCTP_ADDR_ANY, false);
+ if (msk)
+ return msk;
+ msk = mctp_lookup_bind_details(net, skb, type, MCTP_ADDR_ANY, MCTP_ADDR_ANY, false);
+ if (msk)
+ return msk;
+ msk = mctp_lookup_bind_details(net, skb, type, MCTP_ADDR_ANY, MCTP_ADDR_ANY, true);
+ if (msk)
return msk;
- }
return NULL;
}
@@ -1475,7 +1517,7 @@ static int __net_init mctp_routes_net_init(struct net *net)
struct netns_mctp *ns = &net->mctp;
INIT_LIST_HEAD(&ns->routes);
- INIT_HLIST_HEAD(&ns->binds);
+ hash_init(ns->binds);
mutex_init(&ns->bind_lock);
INIT_HLIST_HEAD(&ns->keys);
spin_lock_init(&ns->keys_lock);
--
2.43.0
Powered by blists - more mailing lists