diff options
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/protocol.c | 45 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 14 | ||||
| -rw-r--r-- | net/mptcp/subflow.c | 19 | ||||
| -rw-r--r-- | net/mptcp/token.c | 271 |
4 files changed, 236 insertions, 113 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 9163a05b9e46..be09fd525f8f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1448,20 +1448,6 @@ struct sock *mptcp_sk_clone(const struct sock *sk, msk->token = subflow_req->token; msk->subflow = NULL; - if (unlikely(mptcp_token_new_accept(subflow_req->token, nsk))) { - nsk->sk_state = TCP_CLOSE; - bh_unlock_sock(nsk); - - /* we can't call into mptcp_close() here - possible BH context - * free the sock directly. - * sk_clone_lock() sets nsk refcnt to two, hence call sk_free() - * too. - */ - sk_common_release(nsk); - sk_free(nsk); - return NULL; - } - msk->write_seq = subflow_req->idsn + 1; atomic64_set(&msk->snd_una, msk->write_seq); if (mp_opt->mp_capable) { @@ -1547,7 +1533,7 @@ static void mptcp_destroy(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); - mptcp_token_destroy(msk->token); + mptcp_token_destroy(msk); if (msk->cached_ext) __skb_ext_put(msk->cached_ext); @@ -1636,6 +1622,20 @@ static void mptcp_release_cb(struct sock *sk) } } +static int mptcp_hash(struct sock *sk) +{ + /* should never be called, + * we hash the TCP subflows not the master socket + */ + WARN_ON_ONCE(1); + return 0; +} + +static void mptcp_unhash(struct sock *sk) +{ + /* called from sk_common_release(), but nothing to do here */ +} + static int mptcp_get_port(struct sock *sk, unsigned short snum) { struct mptcp_sock *msk = mptcp_sk(sk); @@ -1679,7 +1679,6 @@ void mptcp_finish_connect(struct sock *ssk) */ WRITE_ONCE(msk->remote_key, subflow->remote_key); WRITE_ONCE(msk->local_key, subflow->local_key); - WRITE_ONCE(msk->token, subflow->token); WRITE_ONCE(msk->write_seq, subflow->idsn + 1); WRITE_ONCE(msk->ack_seq, ack_seq); WRITE_ONCE(msk->can_ack, 1); @@ -1761,8 +1760,8 @@ static struct proto mptcp_prot = { .sendmsg = mptcp_sendmsg, .recvmsg = mptcp_recvmsg, .release_cb = mptcp_release_cb, - .hash = inet_hash, - .unhash = inet_unhash, + .hash = mptcp_hash, + .unhash = mptcp_unhash, .get_port = mptcp_get_port, .sockets_allocated = &mptcp_sockets_allocated, .memory_allocated = &tcp_memory_allocated, @@ -1771,6 +1770,7 @@ static struct proto mptcp_prot = { .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), .sysctl_mem = sysctl_tcp_mem, .obj_size = sizeof(struct mptcp_sock), + .slab_flags = SLAB_TYPESAFE_BY_RCU, .no_autobind = true, }; @@ -1800,6 +1800,7 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags) { struct mptcp_sock *msk = mptcp_sk(sock->sk); + struct mptcp_subflow_context *subflow; struct socket *ssock; int err; @@ -1812,19 +1813,23 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, goto do_connect; } + mptcp_token_destroy(msk); ssock = __mptcp_socket_create(msk, TCP_SYN_SENT); if (IS_ERR(ssock)) { err = PTR_ERR(ssock); goto unlock; } + subflow = mptcp_subflow_ctx(ssock->sk); #ifdef CONFIG_TCP_MD5SIG /* no MPTCP if MD5SIG is enabled on this socket or we may run out of * TCP option space. */ if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) - mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0; + subflow->request_mptcp = 0; #endif + if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) + subflow->request_mptcp = 0; do_connect: err = ssock->ops->connect(ssock, uaddr, addr_len, flags); @@ -1888,6 +1893,7 @@ static int mptcp_listen(struct socket *sock, int backlog) pr_debug("msk=%p", msk); lock_sock(sock->sk); + mptcp_token_destroy(msk); ssock = __mptcp_socket_create(msk, TCP_LISTEN); if (IS_ERR(ssock)) { err = PTR_ERR(ssock); @@ -2086,6 +2092,7 @@ void __init mptcp_proto_init(void) mptcp_subflow_init(); mptcp_pm_init(); + mptcp_token_init(); if (proto_register(&mptcp_prot, 1) != 0) panic("Failed to register MPTCP proto.\n"); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 571d39a1a17c..c05552e5fa23 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -250,6 +250,7 @@ struct mptcp_subflow_request_sock { u32 local_nonce; u32 remote_nonce; struct mptcp_sock *msk; + struct hlist_nulls_node token_node; }; static inline struct mptcp_subflow_request_sock * @@ -372,12 +373,19 @@ bool mptcp_finish_join(struct sock *sk); void mptcp_data_acked(struct sock *sk); void mptcp_subflow_eof(struct sock *sk); +void __init mptcp_token_init(void); +static inline void mptcp_token_init_request(struct request_sock *req) +{ + mptcp_subflow_rsk(req)->token_node.pprev = NULL; +} + int mptcp_token_new_request(struct request_sock *req); -void mptcp_token_destroy_request(u32 token); +void mptcp_token_destroy_request(struct request_sock *req); int mptcp_token_new_connect(struct sock *sk); -int mptcp_token_new_accept(u32 token, struct sock *conn); +void mptcp_token_accept(struct mptcp_subflow_request_sock *r, + struct mptcp_sock *msk); struct mptcp_sock *mptcp_token_get_sock(u32 token); -void mptcp_token_destroy(u32 token); +void mptcp_token_destroy(struct mptcp_sock *msk); void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn); static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index c2389ba2d4ee..102db8c88e97 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -32,12 +32,9 @@ static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, static int subflow_rebuild_header(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - int local_id, err = 0; + int local_id; - if (subflow->request_mptcp && !subflow->token) { - pr_debug("subflow=%p", sk); - err = mptcp_token_new_connect(sk); - } else if (subflow->request_join && !subflow->local_nonce) { + if (subflow->request_join && !subflow->local_nonce) { struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn; pr_debug("subflow=%p", sk); @@ -57,9 +54,6 @@ static int subflow_rebuild_header(struct sock *sk) } out: - if (err) - return err; - return subflow->icsk_af_ops->rebuild_header(sk); } @@ -72,8 +66,7 @@ static void subflow_req_destructor(struct request_sock *req) if (subflow_req->msk) sock_put((struct sock *)subflow_req->msk); - if (subflow_req->mp_capable) - mptcp_token_destroy_request(subflow_req->token); + mptcp_token_destroy_request(req); tcp_request_sock_ops.destructor(req); } @@ -135,6 +128,7 @@ static void subflow_init_req(struct request_sock *req, subflow_req->mp_capable = 0; subflow_req->mp_join = 0; subflow_req->msk = NULL; + mptcp_token_init_request(req); #ifdef CONFIG_TCP_MD5SIG /* no MPTCP if MD5SIG is enabled on this socket or we may run out of @@ -250,7 +244,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) subflow->remote_nonce = mp_opt.nonce; pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, subflow->thmac, subflow->remote_nonce); - } else if (subflow->request_mptcp) { + } else { tp->is_mptcp = 0; } @@ -386,7 +380,7 @@ static void mptcp_sock_destruct(struct sock *sk) sock_orphan(sk); } - mptcp_token_destroy(mptcp_sk(sk)->token); + mptcp_token_destroy(mptcp_sk(sk)); inet_sock_destruct(sk); } @@ -505,6 +499,7 @@ create_child: */ new_msk->sk_destruct = mptcp_sock_destruct; mptcp_pm_new_connection(mptcp_sk(new_msk), 1); + mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); ctx->conn = new_msk; new_msk = NULL; diff --git a/net/mptcp/token.c b/net/mptcp/token.c index 33352dd99d4d..9c0771774815 100644 --- a/net/mptcp/token.c +++ b/net/mptcp/token.c @@ -24,7 +24,7 @@ #include <linux/kernel.h> #include <linux/module.h> -#include <linux/radix-tree.h> +#include <linux/memblock.h> #include <linux/ip.h> #include <linux/tcp.h> #include <net/sock.h> @@ -33,10 +33,55 @@ #include <net/mptcp.h> #include "protocol.h" -static RADIX_TREE(token_tree, GFP_ATOMIC); -static RADIX_TREE(token_req_tree, GFP_ATOMIC); -static DEFINE_SPINLOCK(token_tree_lock); -static int token_used __read_mostly; +#define TOKEN_MAX_RETRIES 4 +#define TOKEN_MAX_CHAIN_LEN 4 + +struct token_bucket { + spinlock_t lock; + int chain_len; + struct hlist_nulls_head req_chain; + struct hlist_nulls_head msk_chain; +}; + +static struct token_bucket *token_hash __read_mostly; +static unsigned int token_mask __read_mostly; + +static struct token_bucket *token_bucket(u32 token) +{ + return &token_hash[token & token_mask]; +} + +/* called with bucket lock held */ +static struct mptcp_subflow_request_sock * +__token_lookup_req(struct token_bucket *t, u32 token) +{ + struct mptcp_subflow_request_sock *req; + struct hlist_nulls_node *pos; + + hlist_nulls_for_each_entry_rcu(req, pos, &t->req_chain, token_node) + if (req->token == token) + return req; + return NULL; +} + +/* called with bucket lock held */ +static struct mptcp_sock * +__token_lookup_msk(struct token_bucket *t, u32 token) +{ + struct hlist_nulls_node *pos; + struct sock *sk; + + sk_nulls_for_each_rcu(sk, pos, &t->msk_chain) + if (mptcp_sk(sk)->token == token) + return mptcp_sk(sk); + return NULL; +} + +static bool __token_bucket_busy(struct token_bucket *t, u32 token) +{ + return !token || t->chain_len >= TOKEN_MAX_CHAIN_LEN || + __token_lookup_req(t, token) || __token_lookup_msk(t, token); +} /** * mptcp_token_new_request - create new key/idsn/token for subflow_request @@ -52,30 +97,32 @@ static int token_used __read_mostly; int mptcp_token_new_request(struct request_sock *req) { struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); - int err; - - while (1) { - u32 token; - - mptcp_crypto_key_gen_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); - - token = subflow_req->token; - spin_lock_bh(&token_tree_lock); - if (!radix_tree_lookup(&token_req_tree, token) && - !radix_tree_lookup(&token_tree, token)) - break; - spin_unlock_bh(&token_tree_lock); + 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); + pr_debug("req=%p local_key=%llu, token=%u, idsn=%llu\n", + req, subflow_req->local_key, subflow_req->token, + subflow_req->idsn); + + token = subflow_req->token; + bucket = token_bucket(token); + spin_lock_bh(&bucket->lock); + if (__token_bucket_busy(bucket, token)) { + spin_unlock_bh(&bucket->lock); + if (!--retries) + return -EBUSY; + goto again; } - err = radix_tree_insert(&token_req_tree, - subflow_req->token, &token_used); - spin_unlock_bh(&token_tree_lock); - return err; + hlist_nulls_add_head_rcu(&subflow_req->token_node, &bucket->req_chain); + bucket->chain_len++; + spin_unlock_bh(&bucket->lock); + return 0; } /** @@ -97,48 +144,56 @@ int mptcp_token_new_request(struct request_sock *req) int mptcp_token_new_connect(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - struct sock *mptcp_sock = subflow->conn; - int err; - - while (1) { - u32 token; + struct mptcp_sock *msk = mptcp_sk(subflow->conn); + int retries = TOKEN_MAX_RETRIES; + struct token_bucket *bucket; - mptcp_crypto_key_gen_sha(&subflow->local_key, &subflow->token, - &subflow->idsn); + pr_debug("ssk=%p, local_key=%llu, token=%u, idsn=%llu\n", + sk, subflow->local_key, subflow->token, subflow->idsn); - pr_debug("ssk=%p, local_key=%llu, token=%u, idsn=%llu\n", - sk, subflow->local_key, subflow->token, subflow->idsn); +again: + mptcp_crypto_key_gen_sha(&subflow->local_key, &subflow->token, + &subflow->idsn); - token = subflow->token; - spin_lock_bh(&token_tree_lock); - if (!radix_tree_lookup(&token_req_tree, token) && - !radix_tree_lookup(&token_tree, token)) - break; - spin_unlock_bh(&token_tree_lock); + bucket = token_bucket(subflow->token); + spin_lock_bh(&bucket->lock); + if (__token_bucket_busy(bucket, subflow->token)) { + spin_unlock_bh(&bucket->lock); + if (!--retries) + return -EBUSY; + goto again; } - err = radix_tree_insert(&token_tree, subflow->token, mptcp_sock); - spin_unlock_bh(&token_tree_lock); - return err; + WRITE_ONCE(msk->token, subflow->token); + __sk_nulls_add_node_rcu((struct sock *)msk, &bucket->msk_chain); + bucket->chain_len++; + spin_unlock_bh(&bucket->lock); + return 0; } /** - * mptcp_token_new_accept - insert token for later processing - * @token: the token to insert to the tree - * @conn: the just cloned socket linked to the new connection + * mptcp_token_accept - replace a req sk with full sock in token hash + * @req: the request socket to be removed + * @msk: the just cloned socket linked to the new connection * * Called when a SYN packet creates a new logical connection, i.e. * is not a join request. */ -int mptcp_token_new_accept(u32 token, struct sock *conn) +void mptcp_token_accept(struct mptcp_subflow_request_sock *req, + struct mptcp_sock *msk) { - int err; + struct mptcp_subflow_request_sock *pos; + struct token_bucket *bucket; - spin_lock_bh(&token_tree_lock); - err = radix_tree_insert(&token_tree, token, conn); - spin_unlock_bh(&token_tree_lock); + bucket = token_bucket(req->token); + spin_lock_bh(&bucket->lock); - return err; + /* pedantic lookup check for the moved token */ + pos = __token_lookup_req(bucket, req->token); + if (!WARN_ON_ONCE(pos != req)) + hlist_nulls_del_init_rcu(&req->token_node); + __sk_nulls_add_node_rcu((struct sock *)msk, &bucket->msk_chain); + spin_unlock_bh(&bucket->lock); } /** @@ -152,45 +207,103 @@ int mptcp_token_new_accept(u32 token, struct sock *conn) */ struct mptcp_sock *mptcp_token_get_sock(u32 token) { - struct sock *conn; - - spin_lock_bh(&token_tree_lock); - conn = radix_tree_lookup(&token_tree, token); - if (conn) { - /* token still reserved? */ - if (conn == (struct sock *)&token_used) - conn = NULL; - else - sock_hold(conn); + 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) + continue; + if (!refcount_inc_not_zero(&sk->sk_refcnt)) + goto not_found; + if (READ_ONCE(msk->token) != token) { + sock_put(sk); + goto again; + } + goto found; } - spin_unlock_bh(&token_tree_lock); + if (get_nulls_value(pos) != (token & token_mask)) + goto again; + +not_found: + msk = NULL; - return mptcp_sk(conn); +found: + rcu_read_unlock(); + return msk; } /** * mptcp_token_destroy_request - remove mptcp connection/token - * @token: token of mptcp connection to remove + * @req: mptcp request socket dropping the token * - * Remove not-yet-fully-established incoming connection identified - * by @token. + * Remove the token associated to @req. */ -void mptcp_token_destroy_request(u32 token) +void mptcp_token_destroy_request(struct request_sock *req) { - spin_lock_bh(&token_tree_lock); - radix_tree_delete(&token_req_tree, token); - spin_unlock_bh(&token_tree_lock); + struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); + struct mptcp_subflow_request_sock *pos; + struct token_bucket *bucket; + + if (hlist_nulls_unhashed(&subflow_req->token_node)) + return; + + bucket = token_bucket(subflow_req->token); + spin_lock_bh(&bucket->lock); + pos = __token_lookup_req(bucket, subflow_req->token); + if (!WARN_ON_ONCE(pos != subflow_req)) { + hlist_nulls_del_init_rcu(&pos->token_node); + bucket->chain_len--; + } + spin_unlock_bh(&bucket->lock); } /** * mptcp_token_destroy - remove mptcp connection/token - * @token: token of mptcp connection to remove + * @msk: mptcp connection dropping the token * - * Remove the connection identified by @token. + * Remove the token associated to @msk */ -void mptcp_token_destroy(u32 token) +void mptcp_token_destroy(struct mptcp_sock *msk) { - spin_lock_bh(&token_tree_lock); - radix_tree_delete(&token_tree, token); - spin_unlock_bh(&token_tree_lock); + struct token_bucket *bucket; + struct mptcp_sock *pos; + + if (sk_unhashed((struct sock *)msk)) + return; + + bucket = token_bucket(msk->token); + spin_lock_bh(&bucket->lock); + pos = __token_lookup_msk(bucket, msk->token); + if (!WARN_ON_ONCE(pos != msk)) { + __sk_nulls_del_node_init_rcu((struct sock *)pos); + bucket->chain_len--; + } + spin_unlock_bh(&bucket->lock); +} + +void __init mptcp_token_init(void) +{ + int i; + + token_hash = alloc_large_system_hash("MPTCP token", + sizeof(struct token_bucket), + 0, + 20,/* one slot per 1MB of memory */ + 0, + NULL, + &token_mask, + 0, + 64 * 1024); + for (i = 0; i < token_mask + 1; ++i) { + INIT_HLIST_NULLS_HEAD(&token_hash[i].req_chain, i); + INIT_HLIST_NULLS_HEAD(&token_hash[i].msk_chain, i); + spin_lock_init(&token_hash[i].lock); + } } |