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) {
{
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);
}
}
+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);
*/
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);
.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,
.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,
};
int addr_len, int flags)
{
struct mptcp_sock *msk = mptcp_sk(sock->sk);
+ struct mptcp_subflow_context *subflow;
struct socket *ssock;
int err;
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);
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);
mptcp_subflow_init();
mptcp_pm_init();
+ mptcp_token_init();
if (proto_register(&mptcp_prot, 1) != 0)
panic("Failed to register MPTCP proto.\n");
#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>
#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
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;
}
/**
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);
}
/**
*/
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);
+ }
}
projects / linux.git / commitdiff