diff options
| -rw-r--r-- | include/net/mptcp.h | 1 | ||||
| -rw-r--r-- | net/mptcp/options.c | 155 | ||||
| -rw-r--r-- | net/mptcp/protocol.c | 116 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 20 |
4 files changed, 286 insertions, 6 deletions
diff --git a/include/net/mptcp.h b/include/net/mptcp.h index eabc57c3fde4..06dcc665135e 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -32,6 +32,7 @@ struct mptcp_out_options { u16 suboptions; u64 sndr_key; u64 rcvr_key; + struct mptcp_ext ext_copy; #endif }; diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 52ff2301b68b..5ea127bc7f01 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -134,13 +134,13 @@ void mptcp_rcv_synsent(struct sock *sk) } } -bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, - unsigned int *size, unsigned int remaining, - struct mptcp_out_options *opts) +static bool mptcp_established_options_mp(struct sock *sk, unsigned int *size, + unsigned int remaining, + struct mptcp_out_options *opts) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - if (subflow->mp_capable && !subflow->fourth_ack) { + if (!subflow->fourth_ack) { opts->suboptions = OPTION_MPTCP_MPC_ACK; opts->sndr_key = subflow->local_key; opts->rcvr_key = subflow->remote_key; @@ -153,6 +153,112 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, return false; } +static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow, + struct mptcp_ext *ext) +{ + ext->data_fin = 1; + + if (!ext->use_map) { + /* RFC6824 requires a DSS mapping with specific values + * if DATA_FIN is set but no data payload is mapped + */ + ext->use_map = 1; + ext->dsn64 = 1; + ext->data_seq = mptcp_sk(subflow->conn)->write_seq; + ext->subflow_seq = 0; + ext->data_len = 1; + } else { + /* If there's an existing DSS mapping, DATA_FIN consumes + * 1 additional byte of mapping space. + */ + ext->data_len++; + } +} + +static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, + unsigned int *size, + unsigned int remaining, + struct mptcp_out_options *opts) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); + unsigned int dss_size = 0; + struct mptcp_ext *mpext; + struct mptcp_sock *msk; + unsigned int ack_size; + u8 tcp_fin; + + if (skb) { + mpext = mptcp_get_ext(skb); + tcp_fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; + } else { + mpext = NULL; + tcp_fin = 0; + } + + if (!skb || (mpext && mpext->use_map) || tcp_fin) { + unsigned int map_size; + + map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64; + + remaining -= map_size; + dss_size = map_size; + if (mpext) + opts->ext_copy = *mpext; + + if (skb && tcp_fin && + subflow->conn->sk_state != TCP_ESTABLISHED) + mptcp_write_data_fin(subflow, &opts->ext_copy); + } + + ack_size = TCPOLEN_MPTCP_DSS_ACK64; + + /* Add kind/length/subtype/flag overhead if mapping is not populated */ + if (dss_size == 0) + ack_size += TCPOLEN_MPTCP_DSS_BASE; + + dss_size += ack_size; + + msk = mptcp_sk(mptcp_subflow_ctx(sk)->conn); + if (msk) { + opts->ext_copy.data_ack = msk->ack_seq; + } else { + mptcp_crypto_key_sha(mptcp_subflow_ctx(sk)->remote_key, + NULL, &opts->ext_copy.data_ack); + opts->ext_copy.data_ack++; + } + + opts->ext_copy.ack64 = 1; + opts->ext_copy.use_ack = 1; + + *size = ALIGN(dss_size, 4); + return true; +} + +bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, + unsigned int *size, unsigned int remaining, + struct mptcp_out_options *opts) +{ + unsigned int opt_size = 0; + bool ret = false; + + if (mptcp_established_options_mp(sk, &opt_size, remaining, opts)) + ret = true; + else if (mptcp_established_options_dss(sk, skb, &opt_size, remaining, + opts)) + ret = true; + + /* we reserved enough space for the above options, and exceeding the + * TCP option space would be fatal + */ + if (WARN_ON_ONCE(opt_size > remaining)) + return false; + + *size += opt_size; + remaining -= opt_size; + + return ret; +} + bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, struct mptcp_out_options *opts) { @@ -194,4 +300,45 @@ void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts) ptr += 2; } } + + if (opts->ext_copy.use_ack || opts->ext_copy.use_map) { + struct mptcp_ext *mpext = &opts->ext_copy; + u8 len = TCPOLEN_MPTCP_DSS_BASE; + u8 flags = 0; + + if (mpext->use_ack) { + len += TCPOLEN_MPTCP_DSS_ACK64; + flags = MPTCP_DSS_HAS_ACK | MPTCP_DSS_ACK64; + } + + if (mpext->use_map) { + len += TCPOLEN_MPTCP_DSS_MAP64; + + /* Use only 64-bit mapping flags for now, add + * support for optional 32-bit mappings later. + */ + flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64; + if (mpext->data_fin) + flags |= MPTCP_DSS_DATA_FIN; + } + + *ptr++ = htonl((TCPOPT_MPTCP << 24) | + (len << 16) | + (MPTCPOPT_DSS << 12) | + (flags)); + + if (mpext->use_ack) { + put_unaligned_be64(mpext->data_ack, ptr); + ptr += 2; + } + + if (mpext->use_map) { + put_unaligned_be64(mpext->data_seq, ptr); + ptr += 2; + put_unaligned_be32(mpext->subflow_seq, ptr); + ptr += 1; + put_unaligned_be32(mpext->data_len << 16 | + TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); + } + } } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 875ca48de4b2..8cf49193b1c0 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -97,12 +97,93 @@ static struct sock *mptcp_subflow_get(const struct mptcp_sock *msk) return NULL; } +static bool mptcp_ext_cache_refill(struct mptcp_sock *msk) +{ + if (!msk->cached_ext) + msk->cached_ext = __skb_ext_alloc(); + + return !!msk->cached_ext; +} + +static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, + struct msghdr *msg, long *timeo) +{ + int mss_now = 0, size_goal = 0, ret = 0; + struct mptcp_sock *msk = mptcp_sk(sk); + struct mptcp_ext *mpext = NULL; + struct page_frag *pfrag; + struct sk_buff *skb; + size_t psize; + + /* use the mptcp page cache so that we can easily move the data + * from one substream to another, but do per subflow memory accounting + */ + pfrag = sk_page_frag(sk); + while (!sk_page_frag_refill(ssk, pfrag) || + !mptcp_ext_cache_refill(msk)) { + ret = sk_stream_wait_memory(ssk, timeo); + if (ret) + return ret; + } + + /* compute copy limit */ + mss_now = tcp_send_mss(ssk, &size_goal, msg->msg_flags); + psize = min_t(int, pfrag->size - pfrag->offset, size_goal); + + pr_debug("left=%zu", msg_data_left(msg)); + psize = copy_page_from_iter(pfrag->page, pfrag->offset, + min_t(size_t, msg_data_left(msg), psize), + &msg->msg_iter); + pr_debug("left=%zu", msg_data_left(msg)); + if (!psize) + return -EINVAL; + + /* Mark the end of the previous write so the beginning of the + * next write (with its own mptcp skb extension data) is not + * collapsed. + */ + skb = tcp_write_queue_tail(ssk); + if (skb) + TCP_SKB_CB(skb)->eor = 1; + + ret = do_tcp_sendpages(ssk, pfrag->page, pfrag->offset, psize, + msg->msg_flags | MSG_SENDPAGE_NOTLAST); + if (ret <= 0) + return ret; + if (unlikely(ret < psize)) + iov_iter_revert(&msg->msg_iter, psize - ret); + + skb = tcp_write_queue_tail(ssk); + mpext = __skb_ext_set(skb, SKB_EXT_MPTCP, msk->cached_ext); + msk->cached_ext = NULL; + + memset(mpext, 0, sizeof(*mpext)); + mpext->data_seq = msk->write_seq; + mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq; + mpext->data_len = ret; + mpext->use_map = 1; + mpext->dsn64 = 1; + + pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d", + mpext->data_seq, mpext->subflow_seq, mpext->data_len, + mpext->dsn64); + + pfrag->offset += ret; + msk->write_seq += ret; + mptcp_subflow_ctx(ssk)->rel_write_seq += ret; + + tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle, size_goal); + return ret; +} + static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { struct mptcp_sock *msk = mptcp_sk(sk); struct socket *ssock; + size_t copied = 0; struct sock *ssk; - int ret; + int ret = 0; + long timeo; if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) return -EOPNOTSUPP; @@ -116,14 +197,29 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) return ret; } + timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); + ssk = mptcp_subflow_get(msk); if (!ssk) { release_sock(sk); return -ENOTCONN; } - ret = sock_sendmsg(ssk->sk_socket, msg); + pr_debug("conn_list->subflow=%p", ssk); + lock_sock(ssk); + while (msg_data_left(msg)) { + ret = mptcp_sendmsg_frag(sk, ssk, msg, &timeo); + if (ret < 0) + break; + + copied += ret; + } + + if (copied > 0) + ret = copied; + + release_sock(ssk); release_sock(sk); return ret; } @@ -235,6 +331,8 @@ static void mptcp_close(struct sock *sk, long timeout) __mptcp_close_ssk(sk, ssk, subflow, timeout); } + if (msk->cached_ext) + __skb_ext_put(msk->cached_ext); release_sock(sk); sk_common_release(sk); } @@ -286,6 +384,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, struct mptcp_subflow_context *subflow; struct sock *new_mptcp_sock; struct sock *ssk = newsk; + u64 ack_seq; subflow = mptcp_subflow_ctx(newsk); lock_sock(sk); @@ -310,6 +409,12 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, msk->subflow = NULL; mptcp_token_update_accept(newsk, new_mptcp_sock); + + mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); + msk->write_seq = subflow->idsn + 1; + ack_seq++; + msk->ack_seq = ack_seq; + subflow->rel_write_seq = 1; newsk = new_mptcp_sock; mptcp_copy_inaddrs(newsk, ssk); list_add(&subflow->node, &msk->conn_list); @@ -404,6 +509,7 @@ void mptcp_finish_connect(struct sock *ssk) struct mptcp_subflow_context *subflow; struct mptcp_sock *msk; struct sock *sk; + u64 ack_seq; subflow = mptcp_subflow_ctx(ssk); @@ -413,12 +519,18 @@ void mptcp_finish_connect(struct sock *ssk) sk = subflow->conn; msk = mptcp_sk(sk); + mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq); + ack_seq++; + subflow->rel_write_seq = 1; + /* the socket is not connected yet, no msk/subflow ops can access/race * accessing the field below */ 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); } static void mptcp_sock_graft(struct sock *sk, struct socket *parent) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 5f43fa0275c0..384ec4804198 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -32,6 +32,10 @@ #define TCPOLEN_MPTCP_MPC_SYN 12 #define TCPOLEN_MPTCP_MPC_SYNACK 12 #define TCPOLEN_MPTCP_MPC_ACK 20 +#define TCPOLEN_MPTCP_DSS_BASE 4 +#define TCPOLEN_MPTCP_DSS_ACK64 8 +#define TCPOLEN_MPTCP_DSS_MAP64 14 +#define TCPOLEN_MPTCP_DSS_CHECKSUM 2 /* MPTCP MP_CAPABLE flags */ #define MPTCP_VERSION_MASK (0x0F) @@ -40,14 +44,24 @@ #define MPTCP_CAP_HMAC_SHA1 BIT(0) #define MPTCP_CAP_FLAG_MASK (0x3F) +/* MPTCP DSS flags */ +#define MPTCP_DSS_DATA_FIN BIT(4) +#define MPTCP_DSS_DSN64 BIT(3) +#define MPTCP_DSS_HAS_MAP BIT(2) +#define MPTCP_DSS_ACK64 BIT(1) +#define MPTCP_DSS_HAS_ACK BIT(0) + /* MPTCP connection sock */ struct mptcp_sock { /* inet_connection_sock must be the first member */ struct inet_connection_sock sk; u64 local_key; u64 remote_key; + u64 write_seq; + u64 ack_seq; u32 token; struct list_head conn_list; + struct skb_ext *cached_ext; /* for the next sendmsg */ struct socket *subflow; /* outgoing connect/listener/!mp_capable */ }; @@ -83,6 +97,7 @@ struct mptcp_subflow_context { u64 remote_key; u64 idsn; u32 token; + u32 rel_write_seq; u32 request_mptcp : 1, /* send MP_CAPABLE */ mp_capable : 1, /* remote is MPTCP capable */ fourth_ack : 1, /* send initial DSS */ @@ -144,4 +159,9 @@ static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn) void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2, u32 *hash_out); +static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb) +{ + return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP); +} + #endif /* __MPTCP_PROTOCOL_H */ |