diff options
author | Matt Johnston <matt@codeconstruct.com.au> | 2022-02-09 07:05:57 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2022-02-09 15:00:11 +0300 |
commit | 63ed1aab3d40aa61aaa66819bdce9377ac7f40fa (patch) | |
tree | 6f239012c2653e6f0d89ef1ac483467e2590a339 /net/mctp/route.c | |
parent | 0de55a7d1133d0ab1acad5d91eea6ccd8cf6d448 (diff) | |
download | linux-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.c | 114 |
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); |