diff options
Diffstat (limited to 'net/mptcp/subflow.c')
-rw-r--r-- | net/mptcp/subflow.c | 168 |
1 files changed, 123 insertions, 45 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index fabd06f2ff45..bf132575040d 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/netdevice.h> #include <crypto/algapi.h> +#include <crypto/sha.h> #include <net/sock.h> #include <net/inet_common.h> #include <net/inet_hashtables.h> @@ -89,7 +90,7 @@ 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]; + u8 hmac[SHA256_DIGEST_SIZE]; struct mptcp_sock *msk; int local_id; @@ -124,12 +125,11 @@ static void subflow_init_req(struct request_sock *req, { struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); - struct tcp_options_received rx_opt; + struct mptcp_options_received mp_opt; pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); - memset(&rx_opt.mptcp, 0, sizeof(rx_opt.mptcp)); - mptcp_get_options(skb, &rx_opt); + mptcp_get_options(skb, &mp_opt); subflow_req->mp_capable = 0; subflow_req->mp_join = 0; @@ -142,16 +142,16 @@ static void subflow_init_req(struct request_sock *req, return; #endif - if (rx_opt.mptcp.mp_capable) { + if (mp_opt.mp_capable) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); - if (rx_opt.mptcp.mp_join) + if (mp_opt.mp_join) return; - } else if (rx_opt.mptcp.mp_join) { + } else if (mp_opt.mp_join) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); } - if (rx_opt.mptcp.mp_capable && listener->request_mptcp) { + if (mp_opt.mp_capable && listener->request_mptcp) { int err; err = mptcp_token_new_request(req); @@ -159,13 +159,13 @@ 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) { + } else if (mp_opt.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; - subflow_req->token = rx_opt.mptcp.token; - subflow_req->remote_nonce = rx_opt.mptcp.nonce; + subflow_req->backup = mp_opt.backup; + subflow_req->remote_id = mp_opt.join_id; + subflow_req->token = mp_opt.token; + subflow_req->remote_nonce = mp_opt.nonce; pr_debug("token=%u, remote_nonce=%u", subflow_req->token, subflow_req->remote_nonce); if (!subflow_token_join_request(req, skb)) { @@ -202,7 +202,7 @@ static void subflow_v6_init_req(struct request_sock *req, /* 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]; + u8 hmac[SHA256_DIGEST_SIZE]; u64 thmac; subflow_generate_hmac(subflow->remote_key, subflow->local_key, @@ -221,29 +221,55 @@ static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); + struct mptcp_options_received mp_opt; struct sock *parent = subflow->conn; + struct tcp_sock *tp = tcp_sk(sk); subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); - if (inet_sk_state_load(parent) != TCP_ESTABLISHED) { + if (inet_sk_state_load(parent) == TCP_SYN_SENT) { inet_sk_state_store(parent, TCP_ESTABLISHED); parent->sk_state_change(parent); } - if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp) + /* be sure no special action on any packet other than syn-ack */ + if (subflow->conn_finished) + return; + + subflow->conn_finished = 1; + + mptcp_get_options(skb, &mp_opt); + if (subflow->request_mptcp && mp_opt.mp_capable) { + subflow->mp_capable = 1; + subflow->can_ack = 1; + subflow->remote_key = mp_opt.sndr_key; + pr_debug("subflow=%p, remote_key=%llu", subflow, + subflow->remote_key); + } else if (subflow->request_join && mp_opt.mp_join) { + subflow->mp_join = 1; + subflow->thmac = mp_opt.thmac; + 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) { + tp->is_mptcp = 0; + } + + if (!tp->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); - subflow->conn_finished = 1; if (skb) { pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq); subflow->ssn_offset = TCP_SKB_CB(skb)->seq; } } else if (subflow->mp_join) { + u8 hmac[SHA256_DIGEST_SIZE]; + pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, subflow->thmac, subflow->remote_nonce); @@ -256,7 +282,9 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) subflow_generate_hmac(subflow->local_key, subflow->remote_key, subflow->local_nonce, subflow->remote_nonce, - subflow->hmac); + hmac); + + memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN); if (skb) subflow->ssn_offset = TCP_SKB_CB(skb)->seq; @@ -264,7 +292,6 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) if (!mptcp_finish_join(sk)) goto do_reset; - subflow->conn_finished = 1; MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); } else { do_reset: @@ -322,10 +349,10 @@ drop: /* 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_options_received *mp_opt) { const struct mptcp_subflow_request_sock *subflow_req; - u8 hmac[MPTCPOPT_HMAC_LEN]; + u8 hmac[SHA256_DIGEST_SIZE]; struct mptcp_sock *msk; bool ret; @@ -339,7 +366,7 @@ static bool subflow_hmac_valid(const struct request_sock *req, subflow_req->local_nonce, hmac); ret = true; - if (crypto_memneq(hmac, rx_opt->mptcp.hmac, sizeof(hmac))) + if (crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN)) ret = false; sock_put((struct sock *)msk); @@ -366,6 +393,7 @@ static void mptcp_sock_destruct(struct sock *sk) sock_orphan(sk); } + mptcp_token_destroy(mptcp_sk(sk)->token); inet_sock_destruct(sk); } @@ -386,6 +414,20 @@ static void subflow_ulp_fallback(struct sock *sk, tcp_sk(sk)->is_mptcp = 0; } +static void subflow_drop_ctx(struct sock *ssk) +{ + struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); + + if (!ctx) + return; + + subflow_ulp_fallback(ssk, ctx); + if (ctx->conn) + sock_put(ctx->conn); + + kfree_rcu(ctx, rcu); +} + static struct sock *subflow_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, struct request_sock *req, @@ -395,7 +437,7 @@ 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; + struct mptcp_options_received mp_opt; bool fallback_is_fatal = false; struct sock *new_msk = NULL; bool fallback = false; @@ -403,7 +445,10 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); - opt_rx.mptcp.mp_capable = 0; + /* we need later a valid 'mp_capable' value even when options are not + * parsed + */ + mp_opt.mp_capable = 0; if (tcp_rsk(req)->is_mptcp == 0) goto create_child; @@ -418,22 +463,21 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, goto create_msk; } - mptcp_get_options(skb, &opt_rx); - if (!opt_rx.mptcp.mp_capable) { + mptcp_get_options(skb, &mp_opt); + if (!mp_opt.mp_capable) { fallback = true; goto create_child; } create_msk: - new_msk = mptcp_sk_clone(listener->conn, &opt_rx, req); + new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); if (!new_msk) fallback = true; } 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)) { + mptcp_get_options(skb, &mp_opt); + if (!mp_opt.mp_join || + !subflow_hmac_valid(req, &mp_opt)) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); return NULL; } @@ -446,18 +490,17 @@ create_child: if (child && *own_req) { struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); + tcp_rsk(req)->drop_req = false; + /* we need to fallback on ctx allocation failure and on pre-reqs * checking above. In the latter scenario we additionally need * to reset the context to non MPTCP status. */ if (!ctx || fallback) { if (fallback_is_fatal) - goto close_child; + goto dispose_child; - if (ctx) { - subflow_ulp_fallback(child, ctx); - kfree_rcu(ctx, rcu); - } + subflow_drop_ctx(child); goto out; } @@ -473,21 +516,22 @@ create_child: /* with OoO packets we can reach here without ingress * mpc option */ - ctx->remote_key = opt_rx.mptcp.sndr_key; - ctx->fully_established = opt_rx.mptcp.mp_capable; - ctx->can_ack = opt_rx.mptcp.mp_capable; + ctx->remote_key = mp_opt.sndr_key; + ctx->fully_established = mp_opt.mp_capable; + ctx->can_ack = mp_opt.mp_capable; } else if (ctx->mp_join) { struct mptcp_sock *owner; owner = mptcp_token_get_sock(ctx->token); if (!owner) - goto close_child; + goto dispose_child; ctx->conn = (struct sock *)owner; if (!mptcp_finish_join(child)) - goto close_child; + goto dispose_child; SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); + tcp_rsk(req)->drop_req = true; } } @@ -499,16 +543,20 @@ out: /* check for expected invariant - should never trigger, just help * catching eariler subtle bugs */ - WARN_ON_ONCE(*own_req && child && tcp_sk(child)->is_mptcp && + WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp && (!mptcp_subflow_ctx(child) || !mptcp_subflow_ctx(child)->conn)); return child; -close_child: +dispose_child: + subflow_drop_ctx(child); + tcp_rsk(req)->drop_req = true; tcp_send_active_reset(child, GFP_ATOMIC); - inet_csk_prepare_forced_close(child); + inet_csk_prepare_for_destroy_sock(child); tcp_done(child); - return NULL; + + /* The last child reference will be released by the caller */ + return child; } static struct inet_connection_sock_af_ops subflow_specific; @@ -637,9 +685,11 @@ static enum mapping_status get_mapping_status(struct sock *ssk) if (!mpext->dsn64) { map_seq = expand_seq(subflow->map_seq, subflow->map_data_len, mpext->data_seq); + subflow->use_64bit_ack = 0; pr_debug("expanded seq=%llu", subflow->map_seq); } else { map_seq = mpext->data_seq; + subflow->use_64bit_ack = 1; } if (subflow->map_valid) { @@ -821,6 +871,24 @@ bool mptcp_subflow_data_available(struct sock *sk) return subflow->data_avail; } +/* If ssk has an mptcp parent socket, use the mptcp rcvbuf occupancy, + * not the ssk one. + * + * In mptcp, rwin is about the mptcp-level connection data. + * + * Data that is still on the ssk rx queue can thus be ignored, + * as far as mptcp peer is concerened that data is still inflight. + * DSS ACK is updated when skb is moved to the mptcp rx queue. + */ +void mptcp_space(const struct sock *ssk, int *space, int *full_space) +{ + const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + const struct sock *sk = subflow->conn; + + *space = tcp_space(sk); + *full_space = tcp_full_space(sk); +} + static void subflow_data_ready(struct sock *sk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); @@ -988,6 +1056,16 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) if (err) return err; + /* the newly created socket really belongs to the owning MPTCP master + * socket, even if for additional subflows the allocation is performed + * by a kernel workqueue. Adjust inode references, so that the + * procfs/diag interaces really show this one belonging to the correct + * user. + */ + SOCK_INODE(sf)->i_ino = SOCK_INODE(sk->sk_socket)->i_ino; + SOCK_INODE(sf)->i_uid = SOCK_INODE(sk->sk_socket)->i_uid; + SOCK_INODE(sf)->i_gid = SOCK_INODE(sk->sk_socket)->i_gid; + subflow = mptcp_subflow_ctx(sf->sk); pr_debug("subflow=%p", subflow); |