Commit 2c5ebd00 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller

mptcp: refactor token container

Replace the radix tree with a hash table allocated
at boot time. The radix tree has some shortcoming:
a single lock is contented by all the mptcp operation,
the lookup currently use such lock, and traversing
all the items would require a lock, too.

With hash table instead we trade a little memory to
address all the above - a per bucket lock is used.

To hash the MPTCP sockets, we re-use the msk' sk_node
entry: the MPTCP sockets are never hashed by the stack.
Replace the existing hash proto callbacks with a dummy
implementation, annotating the above constraint.

Additionally refactor the token creation to code to:

- limit the number of consecutive attempts to a fixed
maximum. Hitting a hash bucket with a long chain is
considered a failed attempt

- accept() no longer can fail to token management.

- if token creation fails at connect() time, we do
fallback to TCP (before the connection was closed)

v1 -> v2:
 - fix "no newline at end of file" - Jakub
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d39dceca
...@@ -1448,20 +1448,6 @@ struct sock *mptcp_sk_clone(const struct sock *sk, ...@@ -1448,20 +1448,6 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
msk->token = subflow_req->token; msk->token = subflow_req->token;
msk->subflow = NULL; 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; msk->write_seq = subflow_req->idsn + 1;
atomic64_set(&msk->snd_una, msk->write_seq); atomic64_set(&msk->snd_una, msk->write_seq);
if (mp_opt->mp_capable) { if (mp_opt->mp_capable) {
...@@ -1547,7 +1533,7 @@ static void mptcp_destroy(struct sock *sk) ...@@ -1547,7 +1533,7 @@ static void mptcp_destroy(struct sock *sk)
{ {
struct mptcp_sock *msk = mptcp_sk(sk); struct mptcp_sock *msk = mptcp_sk(sk);
mptcp_token_destroy(msk->token); mptcp_token_destroy(msk);
if (msk->cached_ext) if (msk->cached_ext)
__skb_ext_put(msk->cached_ext); __skb_ext_put(msk->cached_ext);
...@@ -1636,6 +1622,20 @@ static void mptcp_release_cb(struct sock *sk) ...@@ -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) static int mptcp_get_port(struct sock *sk, unsigned short snum)
{ {
struct mptcp_sock *msk = mptcp_sk(sk); struct mptcp_sock *msk = mptcp_sk(sk);
...@@ -1679,7 +1679,6 @@ void mptcp_finish_connect(struct sock *ssk) ...@@ -1679,7 +1679,6 @@ void mptcp_finish_connect(struct sock *ssk)
*/ */
WRITE_ONCE(msk->remote_key, subflow->remote_key); WRITE_ONCE(msk->remote_key, subflow->remote_key);
WRITE_ONCE(msk->local_key, subflow->local_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->write_seq, subflow->idsn + 1);
WRITE_ONCE(msk->ack_seq, ack_seq); WRITE_ONCE(msk->ack_seq, ack_seq);
WRITE_ONCE(msk->can_ack, 1); WRITE_ONCE(msk->can_ack, 1);
...@@ -1761,8 +1760,8 @@ static struct proto mptcp_prot = { ...@@ -1761,8 +1760,8 @@ static struct proto mptcp_prot = {
.sendmsg = mptcp_sendmsg, .sendmsg = mptcp_sendmsg,
.recvmsg = mptcp_recvmsg, .recvmsg = mptcp_recvmsg,
.release_cb = mptcp_release_cb, .release_cb = mptcp_release_cb,
.hash = inet_hash, .hash = mptcp_hash,
.unhash = inet_unhash, .unhash = mptcp_unhash,
.get_port = mptcp_get_port, .get_port = mptcp_get_port,
.sockets_allocated = &mptcp_sockets_allocated, .sockets_allocated = &mptcp_sockets_allocated,
.memory_allocated = &tcp_memory_allocated, .memory_allocated = &tcp_memory_allocated,
...@@ -1771,6 +1770,7 @@ static struct proto mptcp_prot = { ...@@ -1771,6 +1770,7 @@ static struct proto mptcp_prot = {
.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
.sysctl_mem = sysctl_tcp_mem, .sysctl_mem = sysctl_tcp_mem,
.obj_size = sizeof(struct mptcp_sock), .obj_size = sizeof(struct mptcp_sock),
.slab_flags = SLAB_TYPESAFE_BY_RCU,
.no_autobind = true, .no_autobind = true,
}; };
...@@ -1800,6 +1800,7 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, ...@@ -1800,6 +1800,7 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags) int addr_len, int flags)
{ {
struct mptcp_sock *msk = mptcp_sk(sock->sk); struct mptcp_sock *msk = mptcp_sk(sock->sk);
struct mptcp_subflow_context *subflow;
struct socket *ssock; struct socket *ssock;
int err; int err;
...@@ -1812,19 +1813,23 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, ...@@ -1812,19 +1813,23 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
goto do_connect; goto do_connect;
} }
mptcp_token_destroy(msk);
ssock = __mptcp_socket_create(msk, TCP_SYN_SENT); ssock = __mptcp_socket_create(msk, TCP_SYN_SENT);
if (IS_ERR(ssock)) { if (IS_ERR(ssock)) {
err = PTR_ERR(ssock); err = PTR_ERR(ssock);
goto unlock; goto unlock;
} }
subflow = mptcp_subflow_ctx(ssock->sk);
#ifdef CONFIG_TCP_MD5SIG #ifdef CONFIG_TCP_MD5SIG
/* no MPTCP if MD5SIG is enabled on this socket or we may run out of /* no MPTCP if MD5SIG is enabled on this socket or we may run out of
* TCP option space. * TCP option space.
*/ */
if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0; subflow->request_mptcp = 0;
#endif #endif
if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk))
subflow->request_mptcp = 0;
do_connect: do_connect:
err = ssock->ops->connect(ssock, uaddr, addr_len, flags); err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
...@@ -1888,6 +1893,7 @@ static int mptcp_listen(struct socket *sock, int backlog) ...@@ -1888,6 +1893,7 @@ static int mptcp_listen(struct socket *sock, int backlog)
pr_debug("msk=%p", msk); pr_debug("msk=%p", msk);
lock_sock(sock->sk); lock_sock(sock->sk);
mptcp_token_destroy(msk);
ssock = __mptcp_socket_create(msk, TCP_LISTEN); ssock = __mptcp_socket_create(msk, TCP_LISTEN);
if (IS_ERR(ssock)) { if (IS_ERR(ssock)) {
err = PTR_ERR(ssock); err = PTR_ERR(ssock);
...@@ -2086,6 +2092,7 @@ void __init mptcp_proto_init(void) ...@@ -2086,6 +2092,7 @@ void __init mptcp_proto_init(void)
mptcp_subflow_init(); mptcp_subflow_init();
mptcp_pm_init(); mptcp_pm_init();
mptcp_token_init();
if (proto_register(&mptcp_prot, 1) != 0) if (proto_register(&mptcp_prot, 1) != 0)
panic("Failed to register MPTCP proto.\n"); panic("Failed to register MPTCP proto.\n");
......
...@@ -250,6 +250,7 @@ struct mptcp_subflow_request_sock { ...@@ -250,6 +250,7 @@ struct mptcp_subflow_request_sock {
u32 local_nonce; u32 local_nonce;
u32 remote_nonce; u32 remote_nonce;
struct mptcp_sock *msk; struct mptcp_sock *msk;
struct hlist_nulls_node token_node;
}; };
static inline struct mptcp_subflow_request_sock * static inline struct mptcp_subflow_request_sock *
...@@ -372,12 +373,19 @@ bool mptcp_finish_join(struct sock *sk); ...@@ -372,12 +373,19 @@ bool mptcp_finish_join(struct sock *sk);
void mptcp_data_acked(struct sock *sk); void mptcp_data_acked(struct sock *sk);
void mptcp_subflow_eof(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); 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_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); 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); 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) static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
......
...@@ -32,12 +32,9 @@ static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, ...@@ -32,12 +32,9 @@ static void SUBFLOW_REQ_INC_STATS(struct request_sock *req,
static int subflow_rebuild_header(struct sock *sk) static int subflow_rebuild_header(struct sock *sk)
{ {
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
int local_id, err = 0; int local_id;
if (subflow->request_mptcp && !subflow->token) { if (subflow->request_join && !subflow->local_nonce) {
pr_debug("subflow=%p", sk);
err = mptcp_token_new_connect(sk);
} else if (subflow->request_join && !subflow->local_nonce) {
struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn; struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn;
pr_debug("subflow=%p", sk); pr_debug("subflow=%p", sk);
...@@ -57,9 +54,6 @@ static int subflow_rebuild_header(struct sock *sk) ...@@ -57,9 +54,6 @@ static int subflow_rebuild_header(struct sock *sk)
} }
out: out:
if (err)
return err;
return subflow->icsk_af_ops->rebuild_header(sk); return subflow->icsk_af_ops->rebuild_header(sk);
} }
...@@ -72,8 +66,7 @@ static void subflow_req_destructor(struct request_sock *req) ...@@ -72,8 +66,7 @@ static void subflow_req_destructor(struct request_sock *req)
if (subflow_req->msk) if (subflow_req->msk)
sock_put((struct sock *)subflow_req->msk); sock_put((struct sock *)subflow_req->msk);
if (subflow_req->mp_capable) mptcp_token_destroy_request(req);
mptcp_token_destroy_request(subflow_req->token);
tcp_request_sock_ops.destructor(req); tcp_request_sock_ops.destructor(req);
} }
...@@ -135,6 +128,7 @@ static void subflow_init_req(struct request_sock *req, ...@@ -135,6 +128,7 @@ static void subflow_init_req(struct request_sock *req,
subflow_req->mp_capable = 0; subflow_req->mp_capable = 0;
subflow_req->mp_join = 0; subflow_req->mp_join = 0;
subflow_req->msk = NULL; subflow_req->msk = NULL;
mptcp_token_init_request(req);
#ifdef CONFIG_TCP_MD5SIG #ifdef CONFIG_TCP_MD5SIG
/* no MPTCP if MD5SIG is enabled on this socket or we may run out of /* 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) ...@@ -250,7 +244,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
subflow->remote_nonce = mp_opt.nonce; subflow->remote_nonce = mp_opt.nonce;
pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow,
subflow->thmac, subflow->remote_nonce); subflow->thmac, subflow->remote_nonce);
} else if (subflow->request_mptcp) { } else {
tp->is_mptcp = 0; tp->is_mptcp = 0;
} }
...@@ -386,7 +380,7 @@ static void mptcp_sock_destruct(struct sock *sk) ...@@ -386,7 +380,7 @@ static void mptcp_sock_destruct(struct sock *sk)
sock_orphan(sk); sock_orphan(sk);
} }
mptcp_token_destroy(mptcp_sk(sk)->token); mptcp_token_destroy(mptcp_sk(sk));
inet_sock_destruct(sk); inet_sock_destruct(sk);
} }
...@@ -505,6 +499,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, ...@@ -505,6 +499,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
*/ */
new_msk->sk_destruct = mptcp_sock_destruct; new_msk->sk_destruct = mptcp_sock_destruct;
mptcp_pm_new_connection(mptcp_sk(new_msk), 1); mptcp_pm_new_connection(mptcp_sk(new_msk), 1);
mptcp_token_accept(subflow_req, mptcp_sk(new_msk));
ctx->conn = new_msk; ctx->conn = new_msk;
new_msk = NULL; new_msk = NULL;
......
...@@ -24,7 +24,7 @@ ...@@ -24,7 +24,7 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/radix-tree.h> #include <linux/memblock.h>
#include <linux/ip.h> #include <linux/ip.h>
#include <linux/tcp.h> #include <linux/tcp.h>
#include <net/sock.h> #include <net/sock.h>
...@@ -33,10 +33,55 @@ ...@@ -33,10 +33,55 @@
#include <net/mptcp.h> #include <net/mptcp.h>
#include "protocol.h" #include "protocol.h"
static RADIX_TREE(token_tree, GFP_ATOMIC); #define TOKEN_MAX_RETRIES 4
static RADIX_TREE(token_req_tree, GFP_ATOMIC); #define TOKEN_MAX_CHAIN_LEN 4
static DEFINE_SPINLOCK(token_tree_lock);
static int token_used __read_mostly; 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 * mptcp_token_new_request - create new key/idsn/token for subflow_request
...@@ -52,11 +97,11 @@ static int token_used __read_mostly; ...@@ -52,11 +97,11 @@ static int token_used __read_mostly;
int mptcp_token_new_request(struct request_sock *req) int mptcp_token_new_request(struct request_sock *req)
{ {
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
int err; int retries = TOKEN_MAX_RETRIES;
struct token_bucket *bucket;
while (1) {
u32 token; u32 token;
again:
mptcp_crypto_key_gen_sha(&subflow_req->local_key, mptcp_crypto_key_gen_sha(&subflow_req->local_key,
&subflow_req->token, &subflow_req->token,
&subflow_req->idsn); &subflow_req->idsn);
...@@ -65,17 +110,19 @@ int mptcp_token_new_request(struct request_sock *req) ...@@ -65,17 +110,19 @@ int mptcp_token_new_request(struct request_sock *req)
subflow_req->idsn); subflow_req->idsn);
token = subflow_req->token; token = subflow_req->token;
spin_lock_bh(&token_tree_lock); bucket = token_bucket(token);
if (!radix_tree_lookup(&token_req_tree, token) && spin_lock_bh(&bucket->lock);
!radix_tree_lookup(&token_tree, token)) if (__token_bucket_busy(bucket, token)) {
break; spin_unlock_bh(&bucket->lock);
spin_unlock_bh(&token_tree_lock); if (!--retries)
return -EBUSY;
goto again;
} }
err = radix_tree_insert(&token_req_tree, hlist_nulls_add_head_rcu(&subflow_req->token_node, &bucket->req_chain);
subflow_req->token, &token_used); bucket->chain_len++;
spin_unlock_bh(&token_tree_lock); spin_unlock_bh(&bucket->lock);
return err; return 0;
} }
/** /**
...@@ -97,48 +144,56 @@ int mptcp_token_new_request(struct request_sock *req) ...@@ -97,48 +144,56 @@ int mptcp_token_new_request(struct request_sock *req)
int mptcp_token_new_connect(struct sock *sk) int mptcp_token_new_connect(struct sock *sk)
{ {
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
struct sock *mptcp_sock = subflow->conn; struct mptcp_sock *msk = mptcp_sk(subflow->conn);
int err; int retries = TOKEN_MAX_RETRIES;
struct token_bucket *bucket;
while (1) { pr_debug("ssk=%p, local_key=%llu, token=%u, idsn=%llu\n",
u32 token; sk, subflow->local_key, subflow->token, subflow->idsn);
again:
mptcp_crypto_key_gen_sha(&subflow->local_key, &subflow->token, mptcp_crypto_key_gen_sha(&subflow->local_key, &subflow->token,
&subflow->idsn); &subflow->idsn);
pr_debug("ssk=%p, local_key=%llu, token=%u, idsn=%llu\n", bucket = token_bucket(subflow->token);
sk, subflow->local_key, subflow->token, subflow->idsn); spin_lock_bh(&bucket->lock);
if (__token_bucket_busy(bucket, subflow->token)) {
token = subflow->token; spin_unlock_bh(&bucket->lock);
spin_lock_bh(&token_tree_lock); if (!--retries)
if (!radix_tree_lookup(&token_req_tree, token) && return -EBUSY;
!radix_tree_lookup(&token_tree, token)) goto again;
break;
spin_unlock_bh(&token_tree_lock);
} }
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 * mptcp_token_accept - replace a req sk with full sock in token hash
* @token: the token to insert to the tree * @req: the request socket to be removed
* @conn: the just cloned socket linked to the new connection * @msk: the just cloned socket linked to the new connection
* *
* Called when a SYN packet creates a new logical connection, i.e. * Called when a SYN packet creates a new logical connection, i.e.
* is not a join request. * 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); bucket = token_bucket(req->token);
err = radix_tree_insert(&token_tree, token, conn); spin_lock_bh(&bucket->lock);
spin_unlock_bh(&token_tree_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) ...@@ -152,45 +207,103 @@ int mptcp_token_new_accept(u32 token, struct sock *conn)
*/ */
struct mptcp_sock *mptcp_token_get_sock(u32 token) struct mptcp_sock *mptcp_token_get_sock(u32 token)
{ {
struct sock *conn; struct hlist_nulls_node *pos;
struct token_bucket *bucket;
spin_lock_bh(&token_tree_lock); struct mptcp_sock *msk;
conn = radix_tree_lookup(&token_tree, token); struct sock *sk;
if (conn) {
/* token still reserved? */ rcu_read_lock();
if (conn == (struct sock *)&token_used) bucket = token_bucket(token);
conn = NULL;
else again:
sock_hold(conn); 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;
} }
spin_unlock_bh(&token_tree_lock); goto found;
}
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 * 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 * Remove the token associated to @req.
* by @token.
*/ */
void mptcp_token_destroy_request(u32 token) void mptcp_token_destroy_request(struct request_sock *req)
{ {
spin_lock_bh(&token_tree_lock); struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
radix_tree_delete(&token_req_tree, token); struct mptcp_subflow_request_sock *pos;
spin_unlock_bh(&token_tree_lock); 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 * 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); struct token_bucket *bucket;
radix_tree_delete(&token_tree, token); struct mptcp_sock *pos;
spin_unlock_bh(&token_tree_lock);
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);
}
} }
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