diff options
Diffstat (limited to 'net/mptcp/token.c')
| -rw-r--r-- | net/mptcp/token.c | 52 |
1 files changed, 43 insertions, 9 deletions
diff --git a/net/mptcp/token.c b/net/mptcp/token.c index 7d8106026081..8b47c4bb1c6b 100644 --- a/net/mptcp/token.c +++ b/net/mptcp/token.c @@ -83,6 +83,18 @@ static bool __token_bucket_busy(struct token_bucket *t, u32 token) __token_lookup_req(t, token) || __token_lookup_msk(t, token); } +static void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn) +{ + /* we might consider a faster version that computes the key as a + * hash of some information available in the MPTCP socket. Use + * random data at the moment, as it's probably the safest option + * in case multiple sockets are opened in different namespaces at + * the same time. + */ + get_random_bytes(key, sizeof(u64)); + mptcp_crypto_key_sha(*key, token, idsn); +} + /** * mptcp_token_new_request - create new key/idsn/token for subflow_request * @req: the request socket @@ -97,14 +109,12 @@ static bool __token_bucket_busy(struct token_bucket *t, u32 token) int mptcp_token_new_request(struct request_sock *req) { struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); - int retries = TOKEN_MAX_RETRIES; struct token_bucket *bucket; u32 token; -again: - mptcp_crypto_key_gen_sha(&subflow_req->local_key, - &subflow_req->token, - &subflow_req->idsn); + mptcp_crypto_key_sha(subflow_req->local_key, + &subflow_req->token, + &subflow_req->idsn); pr_debug("req=%p local_key=%llu, token=%u, idsn=%llu\n", req, subflow_req->local_key, subflow_req->token, subflow_req->idsn); @@ -114,9 +124,7 @@ again: spin_lock_bh(&bucket->lock); if (__token_bucket_busy(bucket, token)) { spin_unlock_bh(&bucket->lock); - if (!--retries) - return -EBUSY; - goto again; + return -EBUSY; } hlist_nulls_add_head_rcu(&subflow_req->token_node, &bucket->req_chain); @@ -196,6 +204,32 @@ void mptcp_token_accept(struct mptcp_subflow_request_sock *req, spin_unlock_bh(&bucket->lock); } +bool mptcp_token_exists(u32 token) +{ + struct hlist_nulls_node *pos; + struct token_bucket *bucket; + struct mptcp_sock *msk; + struct sock *sk; + + rcu_read_lock(); + bucket = token_bucket(token); + +again: + sk_nulls_for_each_rcu(sk, pos, &bucket->msk_chain) { + msk = mptcp_sk(sk); + if (READ_ONCE(msk->token) == token) + goto found; + } + if (get_nulls_value(pos) != (token & token_mask)) + goto again; + + rcu_read_unlock(); + return false; +found: + rcu_read_unlock(); + return true; +} + /** * mptcp_token_get_sock - retrieve mptcp connection sock using its token * @token: token of the mptcp connection to retrieve @@ -356,7 +390,7 @@ void __init mptcp_token_init(void) sizeof(struct token_bucket), 0, 20,/* one slot per 1MB of memory */ - 0, + HASH_ZERO, NULL, &token_mask, 0, |