add_addr : 1,
rm_addr : 1,
family : 4,
- echo : 1;
+ echo : 1,
+ backup : 1;
+ u32 token;
+ u32 nonce;
+ u64 thmac;
+ u8 hmac[20];
+ u8 join_id;
u8 use_map:1,
dsn64:1,
data_fin:1,
u8 addr_id;
u64 ahmac;
u8 rm_id;
+ u8 join_id;
+ u8 backup;
+ u32 nonce;
+ u64 thmac;
struct mptcp_ext ext_copy;
#endif
};
skb_ext_find(from, SKB_EXT_MPTCP));
}
+bool mptcp_sk_is_subflow(const struct sock *sk);
+
#else
static inline void mptcp_init(void)
return true;
}
+static inline bool mptcp_sk_is_subflow(const struct sock *sk)
+{
+ return false;
+}
+
#endif /* CONFIG_MPTCP */
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
if (!child)
goto listen_overflow;
+ if (own_req && sk_is_mptcp(child) && mptcp_sk_is_subflow(child)) {
+ reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
+ inet_csk_reqsk_queue_drop_and_put(sk, req);
+ return child;
+ }
+
sock_rps_save_rxhash(child, skb);
tcp_synack_rtt_meas(child, req);
*req_stolen = !own_req;
mp_opt->rcvr_key, mp_opt->data_len);
break;
+ case MPTCPOPT_MP_JOIN:
+ mp_opt->mp_join = 1;
+ if (opsize == TCPOLEN_MPTCP_MPJ_SYN) {
+ mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;
+ mp_opt->join_id = *ptr++;
+ mp_opt->token = get_unaligned_be32(ptr);
+ ptr += 4;
+ mp_opt->nonce = get_unaligned_be32(ptr);
+ ptr += 4;
+ pr_debug("MP_JOIN bkup=%u, id=%u, token=%u, nonce=%u",
+ mp_opt->backup, mp_opt->join_id,
+ mp_opt->token, mp_opt->nonce);
+ } else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) {
+ mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;
+ mp_opt->join_id = *ptr++;
+ mp_opt->thmac = get_unaligned_be64(ptr);
+ ptr += 8;
+ mp_opt->nonce = get_unaligned_be32(ptr);
+ ptr += 4;
+ pr_debug("MP_JOIN bkup=%u, id=%u, thmac=%llu, nonce=%u",
+ mp_opt->backup, mp_opt->join_id,
+ mp_opt->thmac, mp_opt->nonce);
+ } else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) {
+ ptr += 2;
+ memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN);
+ pr_debug("MP_JOIN hmac");
+ } else {
+ pr_warn("MP_JOIN bad option size");
+ mp_opt->mp_join = 0;
+ }
+ break;
+
case MPTCPOPT_DSS:
pr_debug("DSS");
ptr++;
pr_debug("subflow_req=%p, local_key=%llu",
subflow_req, subflow_req->local_key);
return true;
+ } else if (subflow_req->mp_join) {
+ opts->suboptions = OPTION_MPTCP_MPJ_SYNACK;
+ opts->backup = subflow_req->backup;
+ opts->join_id = subflow_req->local_id;
+ opts->thmac = subflow_req->thmac;
+ opts->nonce = subflow_req->local_nonce;
+ pr_debug("req=%p, bkup=%u, id=%u, thmac=%llu, nonce=%u",
+ subflow_req, opts->backup, opts->join_id,
+ opts->thmac, opts->nonce);
+ *size = TCPOLEN_MPTCP_MPJ_SYNACK;
+ return true;
}
return false;
}
-static bool check_fully_established(struct mptcp_subflow_context *subflow,
+static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk,
+ struct mptcp_subflow_context *subflow,
struct sk_buff *skb,
struct mptcp_options_received *mp_opt)
{
/* here we can process OoO, in-window pkts, only in-sequence 4th ack
- * are relevant
+ * will make the subflow fully established
*/
- if (likely(subflow->fully_established ||
- TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1))
- return true;
+ if (likely(subflow->fully_established)) {
+ /* on passive sockets, check for 3rd ack retransmission
+ * note that msk is always set by subflow_syn_recv_sock()
+ * for mp_join subflows
+ */
+ if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 &&
+ TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq &&
+ subflow->mp_join && mp_opt->mp_join &&
+ READ_ONCE(msk->pm.server_side))
+ tcp_send_ack(sk);
+ goto fully_established;
+ }
+
+ /* we should process OoO packets before the first subflow is fully
+ * established, but not expected for MP_JOIN subflows
+ */
+ if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1)
+ return subflow->mp_capable;
- if (mp_opt->use_ack)
+ if (mp_opt->use_ack) {
+ /* subflows are fully established as soon as we get any
+ * additional ack.
+ */
subflow->fully_established = 1;
+ goto fully_established;
+ }
- if (subflow->can_ack)
- return true;
+ WARN_ON_ONCE(subflow->can_ack);
/* If the first established packet does not contain MP_CAPABLE + data
* then fallback to TCP
*/
if (!mp_opt->mp_capable) {
subflow->mp_capable = 0;
- tcp_sk(mptcp_subflow_tcp_sock(subflow))->is_mptcp = 0;
+ tcp_sk(sk)->is_mptcp = 0;
return false;
}
+
+ subflow->fully_established = 1;
subflow->remote_key = mp_opt->sndr_key;
subflow->can_ack = 1;
+
+fully_established:
+ if (likely(subflow->pm_notified))
+ return true;
+
+ subflow->pm_notified = 1;
+ if (subflow->mp_join)
+ mptcp_pm_subflow_established(msk, subflow);
+ else
+ mptcp_pm_fully_established(msk);
return true;
}
struct mptcp_ext *mpext;
mp_opt = &opt_rx->mptcp;
- if (!check_fully_established(subflow, skb, mp_opt))
+ if (!check_fully_established(msk, sk, subflow, skb, mp_opt))
return;
if (mp_opt->add_addr && add_addr_hmac_valid(msk, mp_opt)) {
}
mpext->data_fin = mp_opt->data_fin;
-
- mptcp_pm_fully_established(msk);
}
void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts)
0, opts->rm_id);
}
+ if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) {
+ *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
+ TCPOLEN_MPTCP_MPJ_SYNACK,
+ opts->backup, opts->join_id);
+ put_unaligned_be64(opts->thmac, ptr);
+ ptr += 2;
+ put_unaligned_be32(opts->nonce, ptr);
+ ptr += 1;
+ }
+
if (opts->ext_copy.use_ack || opts->ext_copy.use_map) {
struct mptcp_ext *mpext = &opts->ext_copy;
u8 len = TCPOLEN_MPTCP_DSS_BASE;
return ssock;
}
-static struct sock *mptcp_subflow_get(const struct mptcp_sock *msk)
-{
- struct mptcp_subflow_context *subflow;
-
- sock_owned_by_me((const struct sock *)msk);
-
- mptcp_for_each_subflow(msk, subflow) {
- return mptcp_subflow_tcp_sock(subflow);
- }
-
- return NULL;
-}
-
static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
struct sk_buff *skb,
unsigned int offset, size_t copy_len)
return ret;
}
+static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
+{
+ struct mptcp_subflow_context *subflow;
+ struct sock *backup = NULL;
+
+ sock_owned_by_me((const struct sock *)msk);
+
+ mptcp_for_each_subflow(msk, subflow) {
+ struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+ if (!sk_stream_memory_free(ssk)) {
+ struct socket *sock = ssk->sk_socket;
+
+ if (sock) {
+ clear_bit(MPTCP_SEND_SPACE, &msk->flags);
+ smp_mb__after_atomic();
+
+ /* enables sk->write_space() callbacks */
+ set_bit(SOCK_NOSPACE, &sock->flags);
+ }
+
+ return NULL;
+ }
+
+ if (subflow->backup) {
+ if (!backup)
+ backup = ssk;
+
+ continue;
+ }
+
+ return ssk;
+ }
+
+ return backup;
+}
+
static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk)
{
struct socket *sock;
return ret >= 0 ? ret + copied : (copied ? copied : ret);
}
- ssk = mptcp_subflow_get(msk);
- if (!ssk) {
- release_sock(sk);
- return -ENOTCONN;
+ ssk = mptcp_subflow_get_send(msk);
+ while (!sk_stream_memory_free(sk) || !ssk) {
+ ret = sk_stream_wait_memory(sk, &timeo);
+ if (ret)
+ goto out;
+
+ ssk = mptcp_subflow_get_send(msk);
+ if (list_empty(&msk->conn_list)) {
+ ret = -ENOTCONN;
+ goto out;
+ }
}
pr_debug("conn_list->subflow=%p", ssk);
write_unlock_bh(&sk->sk_callback_lock);
}
+bool mptcp_finish_join(struct sock *sk)
+{
+ struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+ struct mptcp_sock *msk = mptcp_sk(subflow->conn);
+ struct sock *parent = (void *)msk;
+ struct socket *parent_sock;
+
+ pr_debug("msk=%p, subflow=%p", msk, subflow);
+
+ /* mptcp socket already closing? */
+ if (inet_sk_state_load(parent) != TCP_ESTABLISHED)
+ return false;
+
+ if (!msk->pm.server_side)
+ return true;
+
+ /* passive connection, attach to msk socket */
+ parent_sock = READ_ONCE(parent->sk_socket);
+ if (parent_sock && !sk->sk_socket)
+ mptcp_sock_graft(sk, parent_sock);
+
+ return mptcp_pm_allow_new_subflow(msk);
+}
+
+bool mptcp_sk_is_subflow(const struct sock *sk)
+{
+ struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+
+ return subflow->mp_join == 1;
+}
+
static bool mptcp_memory_free(const struct sock *sk, int wake)
{
struct mptcp_sock *msk = mptcp_sk(sk);
#define OPTION_MPTCP_MPC_SYN BIT(0)
#define OPTION_MPTCP_MPC_SYNACK BIT(1)
#define OPTION_MPTCP_MPC_ACK BIT(2)
+#define OPTION_MPTCP_MPJ_SYN BIT(3)
+#define OPTION_MPTCP_MPJ_SYNACK BIT(4)
+#define OPTION_MPTCP_MPJ_ACK BIT(5)
#define OPTION_MPTCP_ADD_ADDR BIT(6)
#define OPTION_MPTCP_ADD_ADDR6 BIT(7)
#define OPTION_MPTCP_RM_ADDR BIT(8)
#define TCPOLEN_MPTCP_MPC_SYNACK 12
#define TCPOLEN_MPTCP_MPC_ACK 20
#define TCPOLEN_MPTCP_MPC_ACK_DATA 22
+#define TCPOLEN_MPTCP_MPJ_SYN 12
+#define TCPOLEN_MPTCP_MPJ_SYNACK 16
+#define TCPOLEN_MPTCP_MPJ_ACK 24
#define TCPOLEN_MPTCP_DSS_BASE 4
#define TCPOLEN_MPTCP_DSS_ACK32 4
#define TCPOLEN_MPTCP_DSS_ACK64 8
#define TCPOLEN_MPTCP_PORT_LEN 2
#define TCPOLEN_MPTCP_RM_ADDR_BASE 4
+#define MPTCPOPT_BACKUP BIT(0)
+#define MPTCPOPT_HMAC_LEN 20
+
/* MPTCP MP_CAPABLE flags */
#define MPTCP_VERSION_MASK (0x0F)
#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
backup : 1,
remote_key_valid : 1;
u8 local_id;
+ u8 remote_id;
u64 local_key;
u64 remote_key;
u64 idsn;
u32 token;
u32 ssn_offset;
+ u64 thmac;
+ u32 local_nonce;
+ u32 remote_nonce;
};
static inline struct mptcp_subflow_request_sock *
u32 map_data_len;
u32 request_mptcp : 1, /* send MP_CAPABLE */
mp_capable : 1, /* remote is MPTCP capable */
+ mp_join : 1, /* remote is JOINing */
fully_established : 1, /* path validated */
+ pm_notified : 1, /* PM hook called for established status */
conn_finished : 1,
map_valid : 1,
mpc_map : 1,
+ backup : 1,
data_avail : 1,
rx_eof : 1,
data_fin_tx_enable : 1,
can_ack : 1; /* only after processing the remote a key */
u64 data_fin_tx_seq;
+ u32 remote_nonce;
+ u64 thmac;
+ u32 local_nonce;
+ u8 local_id;
+ u8 remote_id;
struct sock *tcp_sock; /* tcp sk backpointer */
struct sock *conn; /* parent mptcp_sock */
void mptcp_finish_connect(struct sock *sk);
void mptcp_data_ready(struct sock *sk, struct sock *ssk);
+bool mptcp_finish_join(struct sock *sk);
int mptcp_token_new_request(struct request_sock *req);
void mptcp_token_destroy_request(u32 token);
int mptcp_token_new_connect(struct sock *sk);
int mptcp_token_new_accept(u32 token, struct sock *conn);
+struct mptcp_sock *mptcp_token_get_sock(u32 token);
void mptcp_token_destroy(u32 token);
void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
+#include <crypto/algapi.h>
#include <net/sock.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
tcp_request_sock_ops.destructor(req);
}
+static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
+ void *hmac)
+{
+ u8 msg[8];
+
+ put_unaligned_be32(nonce1, &msg[0]);
+ put_unaligned_be32(nonce2, &msg[4]);
+
+ mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac);
+}
+
+/* validate received token and create truncated hmac and nonce for SYN-ACK */
+static bool subflow_token_join_request(struct request_sock *req,
+ const struct sk_buff *skb)
+{
+ struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
+ u8 hmac[MPTCPOPT_HMAC_LEN];
+ struct mptcp_sock *msk;
+ int local_id;
+
+ msk = mptcp_token_get_sock(subflow_req->token);
+ if (!msk) {
+ pr_debug("subflow_req=%p, token=%u - not found\n",
+ subflow_req, subflow_req->token);
+ return false;
+ }
+
+ local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req);
+ if (local_id < 0) {
+ sock_put((struct sock *)msk);
+ return false;
+ }
+ subflow_req->local_id = local_id;
+
+ get_random_bytes(&subflow_req->local_nonce, sizeof(u32));
+
+ subflow_generate_hmac(msk->local_key, msk->remote_key,
+ subflow_req->local_nonce,
+ subflow_req->remote_nonce, hmac);
+
+ subflow_req->thmac = get_unaligned_be64(hmac);
+
+ sock_put((struct sock *)msk);
+ return true;
+}
+
static void subflow_init_req(struct request_sock *req,
const struct sock *sk_listener,
struct sk_buff *skb)
mptcp_get_options(skb, &rx_opt);
subflow_req->mp_capable = 0;
+ subflow_req->mp_join = 0;
subflow_req->remote_key_valid = 0;
#ifdef CONFIG_TCP_MD5SIG
return;
#endif
+ if (rx_opt.mptcp.mp_capable && rx_opt.mptcp.mp_join)
+ return;
+
if (rx_opt.mptcp.mp_capable && listener->request_mptcp) {
int err;
subflow_req->mp_capable = 1;
subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
+ } else if (rx_opt.mptcp.mp_join && listener->request_mptcp) {
+ subflow_req->mp_join = 1;
+ subflow_req->backup = rx_opt.mptcp.backup;
+ subflow_req->remote_id = rx_opt.mptcp.join_id;
+ subflow_req->token = rx_opt.mptcp.token;
+ subflow_req->remote_nonce = rx_opt.mptcp.nonce;
+ pr_debug("token=%u, remote_nonce=%u", subflow_req->token,
+ subflow_req->remote_nonce);
+ if (!subflow_token_join_request(req, skb)) {
+ subflow_req->mp_join = 0;
+ // @@ need to trigger RST
+ }
}
}
}
#endif
+/* validate hmac received in third ACK */
+static bool subflow_hmac_valid(const struct request_sock *req,
+ const struct tcp_options_received *rx_opt)
+{
+ const struct mptcp_subflow_request_sock *subflow_req;
+ u8 hmac[MPTCPOPT_HMAC_LEN];
+ struct mptcp_sock *msk;
+ bool ret;
+
+ subflow_req = mptcp_subflow_rsk(req);
+ msk = mptcp_token_get_sock(subflow_req->token);
+ if (!msk)
+ return false;
+
+ subflow_generate_hmac(msk->remote_key, msk->local_key,
+ subflow_req->remote_nonce,
+ subflow_req->local_nonce, hmac);
+
+ ret = true;
+ if (crypto_memneq(hmac, rx_opt->mptcp.hmac, sizeof(hmac)))
+ ret = false;
+
+ sock_put((struct sock *)msk);
+ return ret;
+}
+
static struct sock *subflow_syn_recv_sock(const struct sock *sk,
struct sk_buff *skb,
struct request_sock *req,
struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk);
struct mptcp_subflow_request_sock *subflow_req;
struct tcp_options_received opt_rx;
+ bool fallback_is_fatal = false;
struct sock *new_msk = NULL;
struct sock *child;
new_msk = mptcp_sk_clone(listener->conn, req);
if (!new_msk)
subflow_req->mp_capable = 0;
+ } else if (subflow_req->mp_join) {
+ fallback_is_fatal = true;
+ opt_rx.mptcp.mp_join = 0;
+ mptcp_get_options(skb, &opt_rx);
+ if (!opt_rx.mptcp.mp_join ||
+ !subflow_hmac_valid(req, &opt_rx))
+ return NULL;
}
create_child:
if (child && *own_req) {
struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child);
- /* we have null ctx on TCP fallback, not fatal on MPC
- * handshake
+ /* we have null ctx on TCP fallback, which is fatal on
+ * MPJ handshake
*/
- if (!ctx)
+ if (!ctx) {
+ if (fallback_is_fatal)
+ goto close_child;
goto out;
+ }
if (ctx->mp_capable) {
/* new mpc subflow takes ownership of the newly
mptcp_pm_new_connection(mptcp_sk(new_msk), 1);
ctx->conn = new_msk;
new_msk = NULL;
+ } else if (ctx->mp_join) {
+ struct mptcp_sock *owner;
+
+ owner = mptcp_token_get_sock(ctx->token);
+ if (!owner)
+ goto close_child;
+
+ ctx->conn = (struct sock *)owner;
+ if (!mptcp_finish_join(child))
+ goto close_child;
}
}
if (unlikely(new_msk))
sock_put(new_msk);
return child;
+
+close_child:
+ tcp_send_active_reset(child, GFP_ATOMIC);
+ inet_csk_prepare_forced_close(child);
+ tcp_done(child);
+ return NULL;
}
static struct inet_connection_sock_af_ops subflow_specific;
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
struct sock *parent = subflow->conn;
- if (!subflow->mp_capable) {
+ if (!subflow->mp_capable && !subflow->mp_join) {
subflow->tcp_data_ready(sk);
parent->sk_data_ready(parent);
struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk);
struct mptcp_subflow_context *new_ctx;
- if (!tcp_rsk(req)->is_mptcp || !subflow_req->mp_capable) {
+ if (!tcp_rsk(req)->is_mptcp ||
+ (!subflow_req->mp_capable && !subflow_req->mp_join)) {
subflow_ulp_fallback(newsk, old_ctx);
return;
}
return;
}
- /* see comments in subflow_syn_recv_sock(), MPTCP connection is fully
- * established only after we receive the remote key
- */
new_ctx->conn_finished = 1;
new_ctx->icsk_af_ops = old_ctx->icsk_af_ops;
new_ctx->tcp_data_ready = old_ctx->tcp_data_ready;
new_ctx->rel_write_seq = 1;
new_ctx->tcp_sock = newsk;
- new_ctx->mp_capable = 1;
- new_ctx->fully_established = subflow_req->remote_key_valid;
- new_ctx->can_ack = subflow_req->remote_key_valid;
- new_ctx->remote_key = subflow_req->remote_key;
- new_ctx->local_key = subflow_req->local_key;
- new_ctx->token = subflow_req->token;
- new_ctx->ssn_offset = subflow_req->ssn_offset;
- new_ctx->idsn = subflow_req->idsn;
+ if (subflow_req->mp_capable) {
+ /* see comments in subflow_syn_recv_sock(), MPTCP connection
+ * is fully established only after we receive the remote key
+ */
+ new_ctx->mp_capable = 1;
+ new_ctx->fully_established = subflow_req->remote_key_valid;
+ new_ctx->can_ack = subflow_req->remote_key_valid;
+ new_ctx->remote_key = subflow_req->remote_key;
+ new_ctx->local_key = subflow_req->local_key;
+ new_ctx->token = subflow_req->token;
+ new_ctx->ssn_offset = subflow_req->ssn_offset;
+ new_ctx->idsn = subflow_req->idsn;
+ } else if (subflow_req->mp_join) {
+ new_ctx->mp_join = 1;
+ new_ctx->fully_established = 1;
+ new_ctx->backup = subflow_req->backup;
+ new_ctx->local_id = subflow_req->local_id;
+ new_ctx->token = subflow_req->token;
+ new_ctx->thmac = subflow_req->thmac;
+ }
}
static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = {
return err;
}
+/**
+ * mptcp_token_get_sock - retrieve mptcp connection sock using its token
+ * @token: token of the mptcp connection to retrieve
+ *
+ * This function returns the mptcp connection structure with the given token.
+ * A reference count on the mptcp socket returned is taken.
+ *
+ * returns NULL if no connection with the given token value exists.
+ */
+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);
+ }
+ spin_unlock_bh(&token_tree_lock);
+
+ return mptcp_sk(conn);
+}
+
/**
* mptcp_token_destroy_request - remove mptcp connection/token
* @token - token of mptcp connection to remove
projects / users / hch / configfs.git / commitdiff