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authorMatt Johnston <matt@codeconstruct.com.au>2022-02-09 07:05:57 +0300
committerDavid S. Miller <davem@davemloft.net>2022-02-09 15:00:11 +0300
commit63ed1aab3d40aa61aaa66819bdce9377ac7f40fa (patch)
tree6f239012c2653e6f0d89ef1ac483467e2590a339 /net/mctp/route.c
parent0de55a7d1133d0ab1acad5d91eea6ccd8cf6d448 (diff)
downloadlinux-63ed1aab3d40aa61aaa66819bdce9377ac7f40fa.tar.xz
mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag control
This change adds a couple of new ioctls for mctp sockets: SIOCMCTPALLOCTAG and SIOCMCTPDROPTAG. These ioctls provide facilities for explicit allocation / release of tags, overriding the automatic allocate-on-send/release-on-reply and timeout behaviours. This allows userspace more control over messages that may not fit a simple request/response model. In order to indicate a pre-allocated tag to the sendmsg() syscall, we introduce a new flag to the struct sockaddr_mctp.smctp_tag value: MCTP_TAG_PREALLOC. Additional changes from Jeremy Kerr <jk@codeconstruct.com.au>. Contains a fix that was: Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mctp/route.c')
-rw-r--r--net/mctp/route.c114
1 files changed, 86 insertions, 28 deletions
diff --git a/net/mctp/route.c b/net/mctp/route.c
index 35f72e99e188..17e3482aa770 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -203,29 +203,38 @@ static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
return rc;
}
-/* We're done with the key; unset valid and remove from lists. There may still
- * be outstanding refs on the key though...
+/* Helper for mctp_route_input().
+ * We're done with the key; unlock and unref the key.
+ * For the usual case of automatic expiry we remove the key from lists.
+ * In the case that manual allocation is set on a key we release the lock
+ * and local ref, reset reassembly, but don't remove from lists.
*/
-static void __mctp_key_unlock_drop(struct mctp_sk_key *key, struct net *net,
- unsigned long flags)
- __releases(&key->lock)
+static void __mctp_key_done_in(struct mctp_sk_key *key, struct net *net,
+ unsigned long flags, unsigned long reason)
+__releases(&key->lock)
{
struct sk_buff *skb;
+ trace_mctp_key_release(key, reason);
skb = key->reasm_head;
key->reasm_head = NULL;
- key->reasm_dead = true;
- key->valid = false;
- mctp_dev_release_key(key->dev, key);
+
+ if (!key->manual_alloc) {
+ key->reasm_dead = true;
+ key->valid = false;
+ mctp_dev_release_key(key->dev, key);
+ }
spin_unlock_irqrestore(&key->lock, flags);
- spin_lock_irqsave(&net->mctp.keys_lock, flags);
- hlist_del(&key->hlist);
- hlist_del(&key->sklist);
- spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
+ if (!key->manual_alloc) {
+ spin_lock_irqsave(&net->mctp.keys_lock, flags);
+ hlist_del(&key->hlist);
+ hlist_del(&key->sklist);
+ spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
- /* one unref for the lists */
- mctp_key_unref(key);
+ /* unref for the lists */
+ mctp_key_unref(key);
+ }
/* and one for the local reference */
mctp_key_unref(key);
@@ -379,9 +388,8 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
/* we've hit a pending reassembly; not much we
* can do but drop it
*/
- trace_mctp_key_release(key,
- MCTP_TRACE_KEY_REPLIED);
- __mctp_key_unlock_drop(key, net, f);
+ __mctp_key_done_in(key, net, f,
+ MCTP_TRACE_KEY_REPLIED);
key = NULL;
}
rc = 0;
@@ -423,9 +431,8 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
} else {
if (key->reasm_head || key->reasm_dead) {
/* duplicate start? drop everything */
- trace_mctp_key_release(key,
- MCTP_TRACE_KEY_INVALIDATED);
- __mctp_key_unlock_drop(key, net, f);
+ __mctp_key_done_in(key, net, f,
+ MCTP_TRACE_KEY_INVALIDATED);
rc = -EEXIST;
key = NULL;
} else {
@@ -448,10 +455,10 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
* the reassembly/response key
*/
if (!rc && flags & MCTP_HDR_FLAG_EOM) {
+ msk = container_of(key->sk, struct mctp_sock, sk);
sock_queue_rcv_skb(key->sk, key->reasm_head);
key->reasm_head = NULL;
- trace_mctp_key_release(key, MCTP_TRACE_KEY_REPLIED);
- __mctp_key_unlock_drop(key, net, f);
+ __mctp_key_done_in(key, net, f, MCTP_TRACE_KEY_REPLIED);
key = NULL;
}
@@ -579,9 +586,9 @@ static void mctp_reserve_tag(struct net *net, struct mctp_sk_key *key,
/* Allocate a locally-owned tag value for (saddr, daddr), and reserve
* it for the socket msk
*/
-static struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
- mctp_eid_t saddr,
- mctp_eid_t daddr, u8 *tagp)
+struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
+ mctp_eid_t daddr, mctp_eid_t saddr,
+ bool manual, u8 *tagp)
{
struct net *net = sock_net(&msk->sk);
struct netns_mctp *mns = &net->mctp;
@@ -636,6 +643,7 @@ static struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
mctp_reserve_tag(net, key, msk);
trace_mctp_key_acquire(key);
+ key->manual_alloc = manual;
*tagp = key->tag;
}
@@ -649,6 +657,50 @@ static struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
return key;
}
+static struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk,
+ mctp_eid_t daddr,
+ u8 req_tag, u8 *tagp)
+{
+ struct net *net = sock_net(&msk->sk);
+ struct netns_mctp *mns = &net->mctp;
+ struct mctp_sk_key *key, *tmp;
+ unsigned long flags;
+
+ req_tag &= ~(MCTP_TAG_PREALLOC | MCTP_TAG_OWNER);
+ key = NULL;
+
+ spin_lock_irqsave(&mns->keys_lock, flags);
+
+ hlist_for_each_entry(tmp, &mns->keys, hlist) {
+ if (tmp->tag != req_tag)
+ continue;
+
+ if (!mctp_address_matches(tmp->peer_addr, daddr))
+ continue;
+
+ if (!tmp->manual_alloc)
+ continue;
+
+ spin_lock(&tmp->lock);
+ if (tmp->valid) {
+ key = tmp;
+ refcount_inc(&key->refs);
+ spin_unlock(&tmp->lock);
+ break;
+ }
+ spin_unlock(&tmp->lock);
+ }
+ spin_unlock_irqrestore(&mns->keys_lock, flags);
+
+ if (!key)
+ return ERR_PTR(-ENOENT);
+
+ if (tagp)
+ *tagp = key->tag;
+
+ return key;
+}
+
/* routing lookups */
static bool mctp_rt_match_eid(struct mctp_route *rt,
unsigned int net, mctp_eid_t eid)
@@ -843,8 +895,14 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
if (rc)
goto out_release;
- if (req_tag & MCTP_HDR_FLAG_TO) {
- key = mctp_alloc_local_tag(msk, saddr, daddr, &tag);
+ if (req_tag & MCTP_TAG_OWNER) {
+ if (req_tag & MCTP_TAG_PREALLOC)
+ key = mctp_lookup_prealloc_tag(msk, daddr,
+ req_tag, &tag);
+ else
+ key = mctp_alloc_local_tag(msk, daddr, saddr,
+ false, &tag);
+
if (IS_ERR(key)) {
rc = PTR_ERR(key);
goto out_release;
@@ -855,7 +913,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
tag |= MCTP_HDR_FLAG_TO;
} else {
key = NULL;
- tag = req_tag;
+ tag = req_tag & MCTP_TAG_MASK;
}
skb->protocol = htons(ETH_P_MCTP);