diff options
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/options.c | 107 | ||||
| -rw-r--r-- | net/mptcp/protocol.c | 96 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 23 | ||||
| -rw-r--r-- | net/mptcp/subflow.c | 158 | ||||
| -rw-r--r-- | net/mptcp/token.c | 27 |
5 files changed, 366 insertions, 45 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index a3661318a7af..8e2b2dbadf6d 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -96,6 +96,38 @@ void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr, 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++; @@ -572,37 +604,80 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, 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; } @@ -641,7 +716,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 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)) { @@ -700,8 +775,6 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, } mpext->data_fin = mp_opt->data_fin; - - mptcp_pm_fully_established(msk); } void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts) @@ -787,6 +860,16 @@ mp_capable_done: 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; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5f93e8c94ef9..f2dac715a17e 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -104,19 +104,6 @@ set_state: 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) @@ -391,6 +378,43 @@ out: 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; @@ -438,10 +462,17 @@ fallback: 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); @@ -1070,6 +1101,37 @@ static void mptcp_sock_graft(struct sock *sk, struct socket *parent) 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); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 8d4761ae3951..ef94e36b8560 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -17,6 +17,9 @@ #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) @@ -36,6 +39,9 @@ #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 @@ -53,6 +59,9 @@ #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) @@ -162,11 +171,15 @@ struct mptcp_subflow_request_sock { 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 * @@ -190,15 +203,23 @@ struct mptcp_subflow_context { 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 */ @@ -270,11 +291,13 @@ void mptcp_get_options(const struct sk_buff *skb, 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); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index eb82cb33dde2..e7caa4f6e1e5 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -9,6 +9,7 @@ #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> @@ -47,6 +48,52 @@ static void subflow_req_destructor(struct request_sock *req) 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) @@ -61,6 +108,7 @@ static void subflow_init_req(struct request_sock *req, 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 @@ -71,6 +119,9 @@ static void subflow_init_req(struct request_sock *req, 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; @@ -79,6 +130,18 @@ static void subflow_init_req(struct request_sock *req, 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 + } } } @@ -178,6 +241,32 @@ drop: } #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, @@ -188,6 +277,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, 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; @@ -221,6 +311,13 @@ create_msk: 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: @@ -230,11 +327,14 @@ 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 @@ -244,6 +344,16 @@ create_child: 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; } } @@ -252,6 +362,12 @@ out: 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; @@ -566,7 +682,7 @@ static void subflow_data_ready(struct sock *sk) 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); @@ -785,7 +901,8 @@ static void subflow_ulp_clone(const struct request_sock *req, 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; } @@ -796,9 +913,6 @@ static void subflow_ulp_clone(const struct request_sock *req, 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; @@ -807,14 +921,26 @@ static void subflow_ulp_clone(const struct request_sock *req, 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 = { diff --git a/net/mptcp/token.c b/net/mptcp/token.c index b71b53c0ac8d..129a5ad1bc35 100644 --- a/net/mptcp/token.c +++ b/net/mptcp/token.c @@ -141,6 +141,33 @@ int mptcp_token_new_accept(u32 token, struct sock *conn) } /** + * 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 * |