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Merge branch 'mptcp-refactor-token-container'

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Paolo Abeni says:

====================
mptcp: refactor token container

Currently the msk sockets are stored in a single radix tree, protected by a
global spin_lock. This series moves to an hash table, allocated at boot time,
with per bucker spin_lock - alike inet_hashtables, but using a different key:
the token itself.

The above improves scalability, as write operations will have a far later chance
to compete for lock acquisition, allows lockless lookup, and will allow
easier msk traversing - e.g. for diag interface implementation's sake.

This also introduces trivial, related, kunit tests and move the existing in
kernel's one to kunit.

v1 -> v2:
 - fixed a few extra and sparse warns
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2020-06-26 16:21:39 -07:00
commit e562d0868e
11 changed files with 486 additions and 189 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
net/mptcp/Kconfig
View File

@ -18,12 +18,20 @@ config MPTCP_IPV6
select IPV6
default y
config MPTCP_HMAC_TEST
bool "Tests for MPTCP HMAC implementation"
help
This option enable boot time self-test for the HMAC implementation
used by the MPTCP code
Say N if you are unsure.
endif
config MPTCP_KUNIT_TESTS
tristate "This builds the MPTCP KUnit tests" if !KUNIT_ALL_TESTS
select MPTCP
depends on KUNIT
default KUNIT_ALL_TESTS
help
Currently covers the MPTCP crypto and token helpers.
Only useful for kernel devs running KUnit test harness and are not
for inclusion into a production build.
For more information on KUnit and unit tests in general please refer
to the KUnit documentation in Documentation/dev-tools/kunit/.
If unsure, say N.

4
net/mptcp/Makefile
View File

@ -3,3 +3,7 @@ obj-$(CONFIG_MPTCP) += mptcp.o
mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o diag.o \
mib.o pm_netlink.o
mptcp_crypto_test-objs := crypto_test.o
mptcp_token_test-objs := token_test.o
obj-$(CONFIG_MPTCP_KUNIT_TESTS) += mptcp_crypto_test.o mptcp_token_test.o

63
net/mptcp/crypto.c
View File

@ -87,65 +87,6 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac)
sha256_final(&state, (u8 *)hmac);
}
#ifdef CONFIG_MPTCP_HMAC_TEST
struct test_cast {
char *key;
char *msg;
char *result;
};
/* we can't reuse RFC 4231 test vectors, as we have constraint on the
* input and key size.
*/
static struct test_cast tests[] = {
{
.key = "0b0b0b0b0b0b0b0b",
.msg = "48692054",
.result = "8385e24fb4235ac37556b6b886db106284a1da671699f46db1f235ec622dcafa",
},
{
.key = "aaaaaaaaaaaaaaaa",
.msg = "dddddddd",
.result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492984e1eb71aff9022f71046e9",
},
{
.key = "0102030405060708",
.msg = "cdcdcdcd",
.result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6f23b4d8c4da736a5dbbc6e7d",
},
};
static int __init test_mptcp_crypto(void)
{
char hmac[32], hmac_hex[65];
u32 nonce1, nonce2;
u64 key1, key2;
u8 msg[8];
int i, j;
for (i = 0; i < ARRAY_SIZE(tests); ++i) {
/* mptcp hmap will convert to be before computing the hmac */
key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0]));
key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8]));
nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0]));
nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4]));
put_unaligned_be32(nonce1, &msg[0]);
put_unaligned_be32(nonce2, &msg[4]);
mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac);
for (j = 0; j < 32; ++j)
sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff);
hmac_hex[64] = 0;
if (memcmp(hmac_hex, tests[i].result, 64))
pr_err("test %d failed, got %s expected %s", i,
hmac_hex, tests[i].result);
else
pr_info("test %d [ ok ]", i);
}
return 0;
}
late_initcall(test_mptcp_crypto);
#if IS_MODULE(CONFIG_MPTCP_KUNIT_TESTS)
EXPORT_SYMBOL_GPL(mptcp_crypto_hmac_sha);
#endif

72
net/mptcp/crypto_test.c Normal file
View File

@ -0,0 +1,72 @@
// SPDX-License-Identifier: GPL-2.0
#include <kunit/test.h>
#include "protocol.h"
struct test_case {
char *key;
char *msg;
char *result;
};
/* we can't reuse RFC 4231 test vectors, as we have constraint on the
* input and key size.
*/
static struct test_case tests[] = {
{
.key = "0b0b0b0b0b0b0b0b",
.msg = "48692054",
.result = "8385e24fb4235ac37556b6b886db106284a1da671699f46db1f235ec622dcafa",
},
{
.key = "aaaaaaaaaaaaaaaa",
.msg = "dddddddd",
.result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492984e1eb71aff9022f71046e9",
},
{
.key = "0102030405060708",
.msg = "cdcdcdcd",
.result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6f23b4d8c4da736a5dbbc6e7d",
},
};
static void mptcp_crypto_test_basic(struct kunit *test)
{
char hmac[32], hmac_hex[65];
u32 nonce1, nonce2;
u64 key1, key2;
u8 msg[8];
int i, j;
for (i = 0; i < ARRAY_SIZE(tests); ++i) {
/* mptcp hmap will convert to be before computing the hmac */
key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0]));
key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8]));
nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0]));
nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4]));
put_unaligned_be32(nonce1, &msg[0]);
put_unaligned_be32(nonce2, &msg[4]);
mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac);
for (j = 0; j < 32; ++j)
sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff);
hmac_hex[64] = 0;
KUNIT_EXPECT_STREQ(test, &hmac_hex[0], tests[i].result);
}
}
static struct kunit_case mptcp_crypto_test_cases[] = {
KUNIT_CASE(mptcp_crypto_test_basic),
{}
};
static struct kunit_suite mptcp_crypto_suite = {
.name = "mptcp-crypto",
.test_cases = mptcp_crypto_test_cases,
};
kunit_test_suite(mptcp_crypto_suite);
MODULE_LICENSE("GPL");

2
net/mptcp/pm.c
View File

@ -234,7 +234,7 @@ void mptcp_pm_close(struct mptcp_sock *msk)
sock_put((struct sock *)msk);
}
void mptcp_pm_init(void)
void __init mptcp_pm_init(void)
{
pm_wq = alloc_workqueue("pm_wq", WQ_UNBOUND | WQ_MEM_RECLAIM, 8);
if (!pm_wq)

2
net/mptcp/pm_netlink.c
View File

@ -851,7 +851,7 @@ static struct pernet_operations mptcp_pm_pernet_ops = {
.size = sizeof(struct pm_nl_pernet),
};
void mptcp_pm_nl_init(void)
void __init mptcp_pm_nl_init(void)
{
if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
panic("Failed to register MPTCP PM pernet subsystem.\n");

49
net/mptcp/protocol.c
View File

@ -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);
@ -2077,7 +2083,7 @@ static struct inet_protosw mptcp_protosw = {
.flags = INET_PROTOSW_ICSK,
};
void mptcp_proto_init(void)
void __init mptcp_proto_init(void)
{
mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;
@ -2086,6 +2092,7 @@ void 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");
@ -2139,7 +2146,7 @@ static struct inet_protosw mptcp_v6_protosw = {
.flags = INET_PROTOSW_ICSK,
};
int mptcp_proto_v6_init(void)
int __init mptcp_proto_v6_init(void)
{
int err;

24
net/mptcp/protocol.h
View File

@ -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 *
@ -337,7 +338,7 @@ mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
int mptcp_is_enabled(struct net *net);
bool mptcp_subflow_data_available(struct sock *sk);
void mptcp_subflow_init(void);
void __init mptcp_subflow_init(void);
/* called with sk socket lock held */
int __mptcp_subflow_connect(struct sock *sk, int ifindex,
@ -355,9 +356,9 @@ static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
}
void mptcp_proto_init(void);
void __init mptcp_proto_init(void);
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcp_proto_v6_init(void);
int __init mptcp_proto_v6_init(void);
#endif
struct sock *mptcp_sk_clone(const struct sock *sk,
@ -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)
@ -394,7 +402,7 @@ static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
void mptcp_pm_init(void);
void __init mptcp_pm_init(void);
void mptcp_pm_data_init(struct mptcp_sock *msk);
void mptcp_pm_close(struct mptcp_sock *msk);
void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
@ -428,7 +436,7 @@ bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
struct mptcp_addr_info *saddr);
int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
void mptcp_pm_nl_init(void);
void __init mptcp_pm_nl_init(void);
void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);

21
net/mptcp/subflow.c
View File

@ -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;
@ -1255,7 +1250,7 @@ static int subflow_ops_init(struct request_sock_ops *subflow_ops)
return 0;
}
void mptcp_subflow_init(void)
void __init mptcp_subflow_init(void)
{
subflow_request_sock_ops = tcp_request_sock_ops;
if (subflow_ops_init(&subflow_request_sock_ops) != 0)

274
net/mptcp/token.c
View File

@ -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;
int retries = TOKEN_MAX_RETRIES;
struct token_bucket *bucket;
u32 token;
while (1) {
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);
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);
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;
struct mptcp_sock *msk = mptcp_sk(subflow->conn);
int retries = TOKEN_MAX_RETRIES;
struct token_bucket *bucket;
while (1) {
u32 token;
pr_debug("ssk=%p, local_key=%llu, token=%u, idsn=%llu\n",
sk, subflow->local_key, subflow->token, subflow->idsn);
mptcp_crypto_key_gen_sha(&subflow->local_key, &subflow->token,
&subflow->idsn);
again:
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);
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 +207,112 @@ int mptcp_token_new_accept(u32 token, struct sock *conn)
*/
struct mptcp_sock *mptcp_token_get_sock(u32 token)
{
struct sock *conn;
struct hlist_nulls_node *pos;
struct token_bucket *bucket;
struct mptcp_sock *msk;
struct sock *sk;
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);
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;
return mptcp_sk(conn);
not_found:
msk = NULL;
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);
}
}
#if IS_MODULE(CONFIG_MPTCP_KUNIT_TESTS)
EXPORT_SYMBOL_GPL(mptcp_token_new_request);
EXPORT_SYMBOL_GPL(mptcp_token_new_connect);
EXPORT_SYMBOL_GPL(mptcp_token_accept);
EXPORT_SYMBOL_GPL(mptcp_token_get_sock);
EXPORT_SYMBOL_GPL(mptcp_token_destroy_request);
EXPORT_SYMBOL_GPL(mptcp_token_destroy);
#endif

140
net/mptcp/token_test.c Normal file
View File

@ -0,0 +1,140 @@
// SPDX-License-Identifier: GPL-2.0
#include <kunit/test.h>
#include "protocol.h"
static struct mptcp_subflow_request_sock *build_req_sock(struct kunit *test)
{
struct mptcp_subflow_request_sock *req;
req = kunit_kzalloc(test, sizeof(struct mptcp_subflow_request_sock),
GFP_USER);
KUNIT_EXPECT_NOT_ERR_OR_NULL(test, req);
mptcp_token_init_request((struct request_sock *)req);
return req;
}
static void mptcp_token_test_req_basic(struct kunit *test)
{
struct mptcp_subflow_request_sock *req = build_req_sock(test);
struct mptcp_sock *null_msk = NULL;
KUNIT_ASSERT_EQ(test, 0,
mptcp_token_new_request((struct request_sock *)req));
KUNIT_EXPECT_NE(test, 0, (int)req->token);
KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(req->token));
/* cleanup */
mptcp_token_destroy_request((struct request_sock *)req);
}
static struct inet_connection_sock *build_icsk(struct kunit *test)
{
struct inet_connection_sock *icsk;
icsk = kunit_kzalloc(test, sizeof(struct inet_connection_sock),
GFP_USER);
KUNIT_EXPECT_NOT_ERR_OR_NULL(test, icsk);
return icsk;
}
static struct mptcp_subflow_context *build_ctx(struct kunit *test)
{
struct mptcp_subflow_context *ctx;
ctx = kunit_kzalloc(test, sizeof(struct mptcp_subflow_context),
GFP_USER);
KUNIT_EXPECT_NOT_ERR_OR_NULL(test, ctx);
return ctx;
}
static struct mptcp_sock *build_msk(struct kunit *test)
{
struct mptcp_sock *msk;
msk = kunit_kzalloc(test, sizeof(struct mptcp_sock), GFP_USER);
KUNIT_EXPECT_NOT_ERR_OR_NULL(test, msk);
refcount_set(&((struct sock *)msk)->sk_refcnt, 1);
return msk;
}
static void mptcp_token_test_msk_basic(struct kunit *test)
{
struct inet_connection_sock *icsk = build_icsk(test);
struct mptcp_subflow_context *ctx = build_ctx(test);
struct mptcp_sock *msk = build_msk(test);
struct mptcp_sock *null_msk = NULL;
struct sock *sk;
rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
ctx->conn = (struct sock *)msk;
sk = (struct sock *)msk;
KUNIT_ASSERT_EQ(test, 0,
mptcp_token_new_connect((struct sock *)icsk));
KUNIT_EXPECT_NE(test, 0, (int)ctx->token);
KUNIT_EXPECT_EQ(test, ctx->token, msk->token);
KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(ctx->token));
KUNIT_EXPECT_EQ(test, 2, (int)refcount_read(&sk->sk_refcnt));
mptcp_token_destroy(msk);
KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(ctx->token));
}
static void mptcp_token_test_accept(struct kunit *test)
{
struct mptcp_subflow_request_sock *req = build_req_sock(test);
struct mptcp_sock *msk = build_msk(test);
KUNIT_ASSERT_EQ(test, 0,
mptcp_token_new_request((struct request_sock *)req));
msk->token = req->token;
mptcp_token_accept(req, msk);
KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(msk->token));
/* this is now a no-op */
mptcp_token_destroy_request((struct request_sock *)req);
KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(msk->token));
/* cleanup */
mptcp_token_destroy(msk);
}
static void mptcp_token_test_destroyed(struct kunit *test)
{
struct mptcp_subflow_request_sock *req = build_req_sock(test);
struct mptcp_sock *msk = build_msk(test);
struct mptcp_sock *null_msk = NULL;
struct sock *sk;
sk = (struct sock *)msk;
KUNIT_ASSERT_EQ(test, 0,
mptcp_token_new_request((struct request_sock *)req));
msk->token = req->token;
mptcp_token_accept(req, msk);
/* simulate race on removal */
refcount_set(&sk->sk_refcnt, 0);
KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(msk->token));
/* cleanup */
mptcp_token_destroy(msk);
}
static struct kunit_case mptcp_token_test_cases[] = {
KUNIT_CASE(mptcp_token_test_req_basic),
KUNIT_CASE(mptcp_token_test_msk_basic),
KUNIT_CASE(mptcp_token_test_accept),
KUNIT_CASE(mptcp_token_test_destroyed),
{}
};
static struct kunit_suite mptcp_token_suite = {
.name = "mptcp-token",
.test_cases = mptcp_token_test_cases,
};
kunit_test_suite(mptcp_token_suite);
MODULE_LICENSE("GPL");