From ec2e506c680deaa8e1a087986db6d73ba63a04be Mon Sep 17 00:00:00 2001 From: Xin Long Date: Wed, 14 Mar 2018 19:05:33 +0800 Subject: sctp: add SCTP_AUTH_FREE_KEY type for AUTHENTICATION_EVENT This patch is to add SCTP_AUTH_FREE_KEY type for AUTHENTICATION_EVENT, as described in section 6.1.8 of RFC6458. SCTP_AUTH_FREE_KEY: This report indicates that the SCTP implementation will no longer use the key identifier specified in auth_keynumber. After deactivating a key, it would never be used again, which means it's refcnt can't be held/increased by new chunks. But there may be some chunks in out queue still using it. So only when refcnt is 1, which means no chunk in outqueue is using/holding this key either, this EVENT would be sent. When users receive this notification, they could do DEL_KEY sockopt to remove this shkey, and also tell the peer that this key won't be used in any chunk thoroughly from now on, then the peer can remove it as well safely. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/auth.c | 14 ++++++++++++++ net/sctp/sm_make_chunk.c | 20 +++++++++++++++++++- net/sctp/sm_statefuns.c | 2 +- net/sctp/socket.c | 19 ++++++++++++++++++- 4 files changed, 52 insertions(+), 3 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/auth.c b/net/sctp/auth.c index a073123fc485..e64630cd3331 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -992,6 +992,20 @@ int sctp_auth_deact_key_id(struct sctp_endpoint *ep, if (!found) return -EINVAL; + /* refcnt == 1 and !list_empty mean it's not being used anywhere + * and deactivated will be set, so it's time to notify userland + * that this shkey can be freed. + */ + if (asoc && !list_empty(&key->key_list) && + refcount_read(&key->refcnt) == 1) { + struct sctp_ulpevent *ev; + + ev = sctp_ulpevent_make_authkey(asoc, key->key_id, + SCTP_AUTH_FREE_KEY, GFP_KERNEL); + if (ev) + asoc->stream.si->enqueue_event(&asoc->ulpq, ev); + } + key->deactivated = 1; return 0; diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 10f071cdf188..cc20bc39ee7c 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -89,8 +89,26 @@ static void sctp_control_release_owner(struct sk_buff *skb) { struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; - if (chunk->shkey) + if (chunk->shkey) { + struct sctp_shared_key *shkey = chunk->shkey; + struct sctp_association *asoc = chunk->asoc; + + /* refcnt == 2 and !list_empty mean after this release, it's + * not being used anywhere, and it's time to notify userland + * that this shkey can be freed if it's been deactivated. + */ + if (shkey->deactivated && !list_empty(&shkey->key_list) && + refcount_read(&shkey->refcnt) == 2) { + struct sctp_ulpevent *ev; + + ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, + SCTP_AUTH_FREE_KEY, + GFP_KERNEL); + if (ev) + asoc->stream.si->enqueue_event(&asoc->ulpq, ev); + } sctp_auth_shkey_release(chunk->shkey); + } } static void sctp_control_set_owner_w(struct sctp_chunk *chunk) diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 792e0e2be320..1e41dee70b51 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -4246,7 +4246,7 @@ enum sctp_disposition sctp_sf_eat_auth(struct net *net, struct sctp_ulpevent *ev; ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id), - SCTP_AUTH_NEWKEY, GFP_ATOMIC); + SCTP_AUTH_NEW_KEY, GFP_ATOMIC); if (!ev) return -ENOMEM; diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 65cc354c520f..aeecdd620c45 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -8166,8 +8166,25 @@ static void sctp_wfree(struct sk_buff *skb) sk->sk_wmem_queued -= skb->truesize; sk_mem_uncharge(sk, skb->truesize); - if (chunk->shkey) + if (chunk->shkey) { + struct sctp_shared_key *shkey = chunk->shkey; + + /* refcnt == 2 and !list_empty mean after this release, it's + * not being used anywhere, and it's time to notify userland + * that this shkey can be freed if it's been deactivated. + */ + if (shkey->deactivated && !list_empty(&shkey->key_list) && + refcount_read(&shkey->refcnt) == 2) { + struct sctp_ulpevent *ev; + + ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, + SCTP_AUTH_FREE_KEY, + GFP_KERNEL); + if (ev) + asoc->stream.si->enqueue_event(&asoc->ulpq, ev); + } sctp_auth_shkey_release(chunk->shkey); + } sock_wfree(skb); sctp_wake_up_waiters(sk, asoc); -- cgit v1.2.3-59-g8ed1b