diff options
Diffstat (limited to 'net/mptcp/subflow.c')
| -rw-r--r-- | net/mptcp/subflow.c | 150 |
1 files changed, 148 insertions, 2 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index e7caa4f6e1e5..ba636cd84a3c 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -24,13 +24,31 @@ static int subflow_rebuild_header(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - int err = 0; + int local_id, err = 0; 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) { + struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn; + + pr_debug("subflow=%p", sk); + + do { + get_random_bytes(&subflow->local_nonce, sizeof(u32)); + } while (!subflow->local_nonce); + + if (subflow->local_id) + goto out; + + local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); + if (local_id < 0) + return -EINVAL; + + subflow->local_id = local_id; } +out: if (err) return err; @@ -131,6 +149,7 @@ static void subflow_init_req(struct request_sock *req, subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; } else if (rx_opt.mptcp.mp_join && listener->request_mptcp) { + subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; subflow_req->mp_join = 1; subflow_req->backup = rx_opt.mptcp.backup; subflow_req->remote_id = rx_opt.mptcp.join_id; @@ -169,6 +188,25 @@ static void subflow_v6_init_req(struct request_sock *req, } #endif +/* validate received truncated hmac and create hmac for third ACK */ +static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) +{ + u8 hmac[MPTCPOPT_HMAC_LEN]; + u64 thmac; + + subflow_generate_hmac(subflow->remote_key, subflow->local_key, + subflow->remote_nonce, subflow->local_nonce, + hmac); + + thmac = get_unaligned_be64(hmac); + pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", + subflow, subflow->token, + (unsigned long long)thmac, + (unsigned long long)subflow->thmac); + + return thmac == subflow->thmac; +} + static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); @@ -181,7 +219,10 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) parent->sk_state_change(parent); } - if (!subflow->conn_finished) { + if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp) + return; + + if (subflow->mp_capable) { pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk), subflow->remote_key); mptcp_finish_connect(sk); @@ -191,6 +232,31 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq); subflow->ssn_offset = TCP_SKB_CB(skb)->seq; } + } else if (subflow->mp_join) { + pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", + subflow, subflow->thmac, + subflow->remote_nonce); + if (!subflow_thmac_valid(subflow)) { + subflow->mp_join = 0; + goto do_reset; + } + + subflow_generate_hmac(subflow->local_key, subflow->remote_key, + subflow->local_nonce, + subflow->remote_nonce, + subflow->hmac); + + if (skb) + subflow->ssn_offset = TCP_SKB_CB(skb)->seq; + + if (!mptcp_finish_join(sk)) + goto do_reset; + + subflow->conn_finished = 1; + } else { +do_reset: + tcp_send_active_reset(sk, GFP_ATOMIC); + tcp_done(sk); } } @@ -737,6 +803,85 @@ void mptcpv6_handle_mapped(struct sock *sk, bool mapped) } #endif +static void mptcp_info2sockaddr(const struct mptcp_addr_info *info, + struct sockaddr_storage *addr) +{ + memset(addr, 0, sizeof(*addr)); + addr->ss_family = info->family; + if (addr->ss_family == AF_INET) { + struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; + + in_addr->sin_addr = info->addr; + in_addr->sin_port = info->port; + } +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + else if (addr->ss_family == AF_INET6) { + struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; + + in6_addr->sin6_addr = info->addr6; + in6_addr->sin6_port = info->port; + } +#endif +} + +int __mptcp_subflow_connect(struct sock *sk, int ifindex, + const struct mptcp_addr_info *loc, + const struct mptcp_addr_info *remote) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct mptcp_subflow_context *subflow; + struct sockaddr_storage addr; + struct socket *sf; + u32 remote_token; + int addrlen; + int err; + + if (sk->sk_state != TCP_ESTABLISHED) + return -ENOTCONN; + + err = mptcp_subflow_create_socket(sk, &sf); + if (err) + return err; + + subflow = mptcp_subflow_ctx(sf->sk); + subflow->remote_key = msk->remote_key; + subflow->local_key = msk->local_key; + subflow->token = msk->token; + mptcp_info2sockaddr(loc, &addr); + + addrlen = sizeof(struct sockaddr_in); +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (loc->family == AF_INET6) + addrlen = sizeof(struct sockaddr_in6); +#endif + sf->sk->sk_bound_dev_if = ifindex; + err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); + if (err) + goto failed; + + mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); + pr_debug("msk=%p remote_token=%u", msk, remote_token); + subflow->remote_token = remote_token; + subflow->local_id = loc->id; + subflow->request_join = 1; + subflow->request_bkup = 1; + mptcp_info2sockaddr(remote, &addr); + + err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); + if (err && err != -EINPROGRESS) + goto failed; + + spin_lock_bh(&msk->join_list_lock); + list_add_tail(&subflow->node, &msk->join_list); + spin_unlock_bh(&msk->join_list_lock); + + return err; + +failed: + sock_release(sf); + return err; +} + int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) { struct mptcp_subflow_context *subflow; @@ -934,6 +1079,7 @@ static void subflow_ulp_clone(const struct request_sock *req, new_ctx->ssn_offset = subflow_req->ssn_offset; new_ctx->idsn = subflow_req->idsn; } else if (subflow_req->mp_join) { + new_ctx->ssn_offset = subflow_req->ssn_offset; new_ctx->mp_join = 1; new_ctx->fully_established = 1; new_ctx->backup = subflow_req->backup; |