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1318 lines
35 KiB
1318 lines
35 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* Multipath TCP |
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* |
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* Copyright (c) 2017 - 2019, Intel Corporation. |
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*/ |
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|
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#define pr_fmt(fmt) "MPTCP: " fmt |
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|
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#include <linux/kernel.h> |
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#include <crypto/sha2.h> |
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#include <net/tcp.h> |
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#include <net/mptcp.h> |
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#include "protocol.h" |
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#include "mib.h" |
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|
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static bool mptcp_cap_flag_sha256(u8 flags) |
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{ |
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return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256; |
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} |
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|
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static void mptcp_parse_option(const struct sk_buff *skb, |
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const unsigned char *ptr, int opsize, |
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struct mptcp_options_received *mp_opt) |
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{ |
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u8 subtype = *ptr >> 4; |
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int expected_opsize; |
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u8 version; |
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u8 flags; |
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|
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switch (subtype) { |
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case MPTCPOPT_MP_CAPABLE: |
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/* strict size checking */ |
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if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { |
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if (skb->len > tcp_hdr(skb)->doff << 2) |
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expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA; |
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else |
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expected_opsize = TCPOLEN_MPTCP_MPC_ACK; |
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} else { |
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if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK) |
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expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK; |
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else |
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expected_opsize = TCPOLEN_MPTCP_MPC_SYN; |
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} |
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if (opsize != expected_opsize) |
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break; |
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|
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/* try to be gentle vs future versions on the initial syn */ |
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version = *ptr++ & MPTCP_VERSION_MASK; |
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if (opsize != TCPOLEN_MPTCP_MPC_SYN) { |
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if (version != MPTCP_SUPPORTED_VERSION) |
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break; |
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} else if (version < MPTCP_SUPPORTED_VERSION) { |
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break; |
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} |
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|
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flags = *ptr++; |
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if (!mptcp_cap_flag_sha256(flags) || |
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(flags & MPTCP_CAP_EXTENSIBILITY)) |
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break; |
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|
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/* RFC 6824, Section 3.1: |
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* "For the Checksum Required bit (labeled "A"), if either |
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* host requires the use of checksums, checksums MUST be used. |
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* In other words, the only way for checksums not to be used |
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* is if both hosts in their SYNs set A=0." |
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* |
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* Section 3.3.0: |
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* "If a checksum is not present when its use has been |
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* negotiated, the receiver MUST close the subflow with a RST as |
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* it is considered broken." |
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* |
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* We don't implement DSS checksum - fall back to TCP. |
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*/ |
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if (flags & MPTCP_CAP_CHECKSUM_REQD) |
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break; |
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mp_opt->mp_capable = 1; |
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if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) { |
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mp_opt->sndr_key = get_unaligned_be64(ptr); |
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ptr += 8; |
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} |
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if (opsize >= TCPOLEN_MPTCP_MPC_ACK) { |
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mp_opt->rcvr_key = get_unaligned_be64(ptr); |
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ptr += 8; |
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} |
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if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA) { |
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/* Section 3.1.: |
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* "the data parameters in a MP_CAPABLE are semantically |
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* equivalent to those in a DSS option and can be used |
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* interchangeably." |
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*/ |
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mp_opt->dss = 1; |
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mp_opt->use_map = 1; |
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mp_opt->mpc_map = 1; |
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mp_opt->data_len = get_unaligned_be16(ptr); |
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ptr += 2; |
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} |
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pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d", |
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version, flags, opsize, mp_opt->sndr_key, |
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mp_opt->rcvr_key, mp_opt->data_len); |
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break; |
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|
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case MPTCPOPT_MP_JOIN: |
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mp_opt->mp_join = 1; |
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if (opsize == TCPOLEN_MPTCP_MPJ_SYN) { |
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mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; |
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mp_opt->join_id = *ptr++; |
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mp_opt->token = get_unaligned_be32(ptr); |
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ptr += 4; |
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mp_opt->nonce = get_unaligned_be32(ptr); |
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ptr += 4; |
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pr_debug("MP_JOIN bkup=%u, id=%u, token=%u, nonce=%u", |
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mp_opt->backup, mp_opt->join_id, |
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mp_opt->token, mp_opt->nonce); |
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} else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) { |
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mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; |
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mp_opt->join_id = *ptr++; |
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mp_opt->thmac = get_unaligned_be64(ptr); |
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ptr += 8; |
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mp_opt->nonce = get_unaligned_be32(ptr); |
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ptr += 4; |
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pr_debug("MP_JOIN bkup=%u, id=%u, thmac=%llu, nonce=%u", |
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mp_opt->backup, mp_opt->join_id, |
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mp_opt->thmac, mp_opt->nonce); |
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} else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) { |
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ptr += 2; |
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memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN); |
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pr_debug("MP_JOIN hmac"); |
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} else { |
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pr_warn("MP_JOIN bad option size"); |
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mp_opt->mp_join = 0; |
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} |
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break; |
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|
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case MPTCPOPT_DSS: |
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pr_debug("DSS"); |
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ptr++; |
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|
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/* we must clear 'mpc_map' be able to detect MP_CAPABLE |
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* map vs DSS map in mptcp_incoming_options(), and reconstruct |
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* map info accordingly |
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*/ |
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mp_opt->mpc_map = 0; |
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flags = (*ptr++) & MPTCP_DSS_FLAG_MASK; |
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mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0; |
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mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0; |
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mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0; |
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mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0; |
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mp_opt->use_ack = (flags & MPTCP_DSS_HAS_ACK); |
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|
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pr_debug("data_fin=%d dsn64=%d use_map=%d ack64=%d use_ack=%d", |
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mp_opt->data_fin, mp_opt->dsn64, |
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mp_opt->use_map, mp_opt->ack64, |
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mp_opt->use_ack); |
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expected_opsize = TCPOLEN_MPTCP_DSS_BASE; |
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|
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if (mp_opt->use_ack) { |
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if (mp_opt->ack64) |
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expected_opsize += TCPOLEN_MPTCP_DSS_ACK64; |
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else |
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expected_opsize += TCPOLEN_MPTCP_DSS_ACK32; |
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} |
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if (mp_opt->use_map) { |
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if (mp_opt->dsn64) |
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expected_opsize += TCPOLEN_MPTCP_DSS_MAP64; |
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else |
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expected_opsize += TCPOLEN_MPTCP_DSS_MAP32; |
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} |
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|
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/* RFC 6824, Section 3.3: |
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* If a checksum is present, but its use had |
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* not been negotiated in the MP_CAPABLE handshake, |
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* the checksum field MUST be ignored. |
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*/ |
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if (opsize != expected_opsize && |
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opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) |
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break; |
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mp_opt->dss = 1; |
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|
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if (mp_opt->use_ack) { |
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if (mp_opt->ack64) { |
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mp_opt->data_ack = get_unaligned_be64(ptr); |
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ptr += 8; |
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} else { |
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mp_opt->data_ack = get_unaligned_be32(ptr); |
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ptr += 4; |
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} |
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pr_debug("data_ack=%llu", mp_opt->data_ack); |
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} |
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if (mp_opt->use_map) { |
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if (mp_opt->dsn64) { |
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mp_opt->data_seq = get_unaligned_be64(ptr); |
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ptr += 8; |
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} else { |
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mp_opt->data_seq = get_unaligned_be32(ptr); |
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ptr += 4; |
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} |
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mp_opt->subflow_seq = get_unaligned_be32(ptr); |
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ptr += 4; |
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mp_opt->data_len = get_unaligned_be16(ptr); |
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ptr += 2; |
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pr_debug("data_seq=%llu subflow_seq=%u data_len=%u", |
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mp_opt->data_seq, mp_opt->subflow_seq, |
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mp_opt->data_len); |
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} |
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break; |
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case MPTCPOPT_ADD_ADDR: |
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mp_opt->echo = (*ptr++) & MPTCP_ADDR_ECHO; |
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if (!mp_opt->echo) { |
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if (opsize == TCPOLEN_MPTCP_ADD_ADDR || |
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opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT) |
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mp_opt->family = MPTCP_ADDR_IPVERSION_4; |
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#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
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else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6 || |
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opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT) |
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mp_opt->family = MPTCP_ADDR_IPVERSION_6; |
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#endif |
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else |
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break; |
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} else { |
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if (opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE || |
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opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) |
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mp_opt->family = MPTCP_ADDR_IPVERSION_4; |
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#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
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else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE || |
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opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) |
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mp_opt->family = MPTCP_ADDR_IPVERSION_6; |
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#endif |
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else |
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break; |
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} |
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mp_opt->add_addr = 1; |
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mp_opt->addr_id = *ptr++; |
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if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) { |
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memcpy((u8 *)&mp_opt->addr.s_addr, (u8 *)ptr, 4); |
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ptr += 4; |
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if (opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT || |
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opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) { |
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mp_opt->port = get_unaligned_be16(ptr); |
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ptr += 2; |
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} |
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} |
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#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
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else { |
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memcpy(mp_opt->addr6.s6_addr, (u8 *)ptr, 16); |
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ptr += 16; |
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if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT || |
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opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) { |
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mp_opt->port = get_unaligned_be16(ptr); |
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ptr += 2; |
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} |
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} |
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#endif |
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if (!mp_opt->echo) { |
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mp_opt->ahmac = get_unaligned_be64(ptr); |
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ptr += 8; |
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} |
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pr_debug("ADD_ADDR%s: id=%d, ahmac=%llu, echo=%d, port=%d", |
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(mp_opt->family == MPTCP_ADDR_IPVERSION_6) ? "6" : "", |
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mp_opt->addr_id, mp_opt->ahmac, mp_opt->echo, mp_opt->port); |
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break; |
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case MPTCPOPT_RM_ADDR: |
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if (opsize != TCPOLEN_MPTCP_RM_ADDR_BASE) |
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break; |
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ptr++; |
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mp_opt->rm_addr = 1; |
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mp_opt->rm_id = *ptr++; |
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pr_debug("RM_ADDR: id=%d", mp_opt->rm_id); |
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break; |
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case MPTCPOPT_MP_PRIO: |
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if (opsize != TCPOLEN_MPTCP_PRIO) |
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break; |
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mp_opt->mp_prio = 1; |
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mp_opt->backup = *ptr++ & MPTCP_PRIO_BKUP; |
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pr_debug("MP_PRIO: prio=%d", mp_opt->backup); |
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break; |
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case MPTCPOPT_MP_FASTCLOSE: |
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if (opsize != TCPOLEN_MPTCP_FASTCLOSE) |
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break; |
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|
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ptr += 2; |
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mp_opt->rcvr_key = get_unaligned_be64(ptr); |
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ptr += 8; |
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mp_opt->fastclose = 1; |
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break; |
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|
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default: |
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break; |
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} |
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} |
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void mptcp_get_options(const struct sk_buff *skb, |
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struct mptcp_options_received *mp_opt) |
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{ |
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const struct tcphdr *th = tcp_hdr(skb); |
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const unsigned char *ptr; |
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int length; |
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|
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/* initialize option status */ |
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mp_opt->mp_capable = 0; |
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mp_opt->mp_join = 0; |
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mp_opt->add_addr = 0; |
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mp_opt->ahmac = 0; |
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mp_opt->fastclose = 0; |
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mp_opt->port = 0; |
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mp_opt->rm_addr = 0; |
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mp_opt->dss = 0; |
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mp_opt->mp_prio = 0; |
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length = (th->doff * 4) - sizeof(struct tcphdr); |
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ptr = (const unsigned char *)(th + 1); |
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|
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while (length > 0) { |
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int opcode = *ptr++; |
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int opsize; |
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|
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switch (opcode) { |
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case TCPOPT_EOL: |
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return; |
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case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ |
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length--; |
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continue; |
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default: |
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opsize = *ptr++; |
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if (opsize < 2) /* "silly options" */ |
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return; |
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if (opsize > length) |
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return; /* don't parse partial options */ |
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if (opcode == TCPOPT_MPTCP) |
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mptcp_parse_option(skb, ptr, opsize, mp_opt); |
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ptr += opsize - 2; |
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length -= opsize; |
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} |
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} |
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} |
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|
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bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, |
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unsigned int *size, struct mptcp_out_options *opts) |
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{ |
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struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
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|
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/* we will use snd_isn to detect first pkt [re]transmission |
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* in mptcp_established_options_mp() |
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*/ |
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subflow->snd_isn = TCP_SKB_CB(skb)->end_seq; |
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if (subflow->request_mptcp) { |
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opts->suboptions = OPTION_MPTCP_MPC_SYN; |
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*size = TCPOLEN_MPTCP_MPC_SYN; |
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return true; |
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} else if (subflow->request_join) { |
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pr_debug("remote_token=%u, nonce=%u", subflow->remote_token, |
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subflow->local_nonce); |
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opts->suboptions = OPTION_MPTCP_MPJ_SYN; |
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opts->join_id = subflow->local_id; |
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opts->token = subflow->remote_token; |
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opts->nonce = subflow->local_nonce; |
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opts->backup = subflow->request_bkup; |
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*size = TCPOLEN_MPTCP_MPJ_SYN; |
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return true; |
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} |
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return false; |
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} |
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|
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/* MP_JOIN client subflow must wait for 4th ack before sending any data: |
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* TCP can't schedule delack timer before the subflow is fully established. |
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* MPTCP uses the delack timer to do 3rd ack retransmissions |
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*/ |
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static void schedule_3rdack_retransmission(struct sock *sk) |
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{ |
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struct inet_connection_sock *icsk = inet_csk(sk); |
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struct tcp_sock *tp = tcp_sk(sk); |
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unsigned long timeout; |
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|
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/* reschedule with a timeout above RTT, as we must look only for drop */ |
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if (tp->srtt_us) |
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timeout = tp->srtt_us << 1; |
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else |
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timeout = TCP_TIMEOUT_INIT; |
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|
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WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER); |
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icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; |
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icsk->icsk_ack.timeout = timeout; |
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sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); |
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} |
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|
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static void clear_3rdack_retransmission(struct sock *sk) |
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{ |
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struct inet_connection_sock *icsk = inet_csk(sk); |
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|
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sk_stop_timer(sk, &icsk->icsk_delack_timer); |
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icsk->icsk_ack.timeout = 0; |
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icsk->icsk_ack.ato = 0; |
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icsk->icsk_ack.pending &= ~(ICSK_ACK_SCHED | ICSK_ACK_TIMER); |
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} |
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|
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static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, |
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bool snd_data_fin_enable, |
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unsigned int *size, |
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unsigned int remaining, |
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struct mptcp_out_options *opts) |
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{ |
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struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
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struct mptcp_ext *mpext; |
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unsigned int data_len; |
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|
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/* When skb is not available, we better over-estimate the emitted |
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* options len. A full DSS option (28 bytes) is longer than |
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* TCPOLEN_MPTCP_MPC_ACK_DATA(22) or TCPOLEN_MPTCP_MPJ_ACK(24), so |
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* tell the caller to defer the estimate to |
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* mptcp_established_options_dss(), which will reserve enough space. |
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*/ |
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if (!skb) |
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return false; |
|
|
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/* MPC/MPJ needed only on 3rd ack packet, DATA_FIN and TCP shutdown take precedence */ |
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if (subflow->fully_established || snd_data_fin_enable || |
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subflow->snd_isn != TCP_SKB_CB(skb)->seq || |
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sk->sk_state != TCP_ESTABLISHED) |
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return false; |
|
|
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if (subflow->mp_capable) { |
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mpext = mptcp_get_ext(skb); |
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data_len = mpext ? mpext->data_len : 0; |
|
|
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/* we will check ext_copy.data_len in mptcp_write_options() to |
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* discriminate between TCPOLEN_MPTCP_MPC_ACK_DATA and |
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* TCPOLEN_MPTCP_MPC_ACK |
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*/ |
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opts->ext_copy.data_len = data_len; |
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opts->suboptions = OPTION_MPTCP_MPC_ACK; |
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opts->sndr_key = subflow->local_key; |
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opts->rcvr_key = subflow->remote_key; |
|
|
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/* Section 3.1. |
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* The MP_CAPABLE option is carried on the SYN, SYN/ACK, and ACK |
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* packets that start the first subflow of an MPTCP connection, |
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* as well as the first packet that carries data |
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*/ |
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if (data_len > 0) |
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*size = ALIGN(TCPOLEN_MPTCP_MPC_ACK_DATA, 4); |
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else |
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*size = TCPOLEN_MPTCP_MPC_ACK; |
|
|
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pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d", |
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subflow, subflow->local_key, subflow->remote_key, |
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data_len); |
|
|
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return true; |
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} else if (subflow->mp_join) { |
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opts->suboptions = OPTION_MPTCP_MPJ_ACK; |
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memcpy(opts->hmac, subflow->hmac, MPTCPOPT_HMAC_LEN); |
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*size = TCPOLEN_MPTCP_MPJ_ACK; |
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pr_debug("subflow=%p", subflow); |
|
|
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schedule_3rdack_retransmission(sk); |
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return true; |
|
} |
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return false; |
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} |
|
|
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static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow, |
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struct sk_buff *skb, struct mptcp_ext *ext) |
|
{ |
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/* The write_seq value has already been incremented, so the actual |
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* sequence number for the DATA_FIN is one less. |
|
*/ |
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u64 data_fin_tx_seq = READ_ONCE(mptcp_sk(subflow->conn)->write_seq) - 1; |
|
|
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if (!ext->use_map || !skb->len) { |
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/* RFC6824 requires a DSS mapping with specific values |
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* if DATA_FIN is set but no data payload is mapped |
|
*/ |
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ext->data_fin = 1; |
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ext->use_map = 1; |
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ext->dsn64 = 1; |
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ext->data_seq = data_fin_tx_seq; |
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ext->subflow_seq = 0; |
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ext->data_len = 1; |
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} else if (ext->data_seq + ext->data_len == data_fin_tx_seq) { |
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/* If there's an existing DSS mapping and it is the |
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* final mapping, DATA_FIN consumes 1 additional byte of |
|
* mapping space. |
|
*/ |
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ext->data_fin = 1; |
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ext->data_len++; |
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} |
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} |
|
|
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static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, |
|
bool snd_data_fin_enable, |
|
unsigned int *size, |
|
unsigned int remaining, |
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struct mptcp_out_options *opts) |
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{ |
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
|
struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
|
unsigned int dss_size = 0; |
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struct mptcp_ext *mpext; |
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unsigned int ack_size; |
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bool ret = false; |
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u64 ack_seq; |
|
|
|
mpext = skb ? mptcp_get_ext(skb) : NULL; |
|
|
|
if (!skb || (mpext && mpext->use_map) || snd_data_fin_enable) { |
|
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 && snd_data_fin_enable) |
|
mptcp_write_data_fin(subflow, skb, &opts->ext_copy); |
|
ret = true; |
|
} |
|
|
|
/* passive sockets msk will set the 'can_ack' after accept(), even |
|
* if the first subflow may have the already the remote key handy |
|
*/ |
|
opts->ext_copy.use_ack = 0; |
|
if (!READ_ONCE(msk->can_ack)) { |
|
*size = ALIGN(dss_size, 4); |
|
return ret; |
|
} |
|
|
|
ack_seq = READ_ONCE(msk->ack_seq); |
|
if (READ_ONCE(msk->use_64bit_ack)) { |
|
ack_size = TCPOLEN_MPTCP_DSS_ACK64; |
|
opts->ext_copy.data_ack = ack_seq; |
|
opts->ext_copy.ack64 = 1; |
|
} else { |
|
ack_size = TCPOLEN_MPTCP_DSS_ACK32; |
|
opts->ext_copy.data_ack32 = (uint32_t)ack_seq; |
|
opts->ext_copy.ack64 = 0; |
|
} |
|
opts->ext_copy.use_ack = 1; |
|
WRITE_ONCE(msk->old_wspace, __mptcp_space((struct sock *)msk)); |
|
|
|
/* 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; |
|
|
|
*size = ALIGN(dss_size, 4); |
|
return true; |
|
} |
|
|
|
static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, |
|
struct in_addr *addr, u16 port) |
|
{ |
|
u8 hmac[SHA256_DIGEST_SIZE]; |
|
u8 msg[7]; |
|
|
|
msg[0] = addr_id; |
|
memcpy(&msg[1], &addr->s_addr, 4); |
|
msg[5] = port >> 8; |
|
msg[6] = port & 0xFF; |
|
|
|
mptcp_crypto_hmac_sha(key1, key2, msg, 7, hmac); |
|
|
|
return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); |
|
} |
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
static u64 add_addr6_generate_hmac(u64 key1, u64 key2, u8 addr_id, |
|
struct in6_addr *addr, u16 port) |
|
{ |
|
u8 hmac[SHA256_DIGEST_SIZE]; |
|
u8 msg[19]; |
|
|
|
msg[0] = addr_id; |
|
memcpy(&msg[1], &addr->s6_addr, 16); |
|
msg[17] = port >> 8; |
|
msg[18] = port & 0xFF; |
|
|
|
mptcp_crypto_hmac_sha(key1, key2, msg, 19, hmac); |
|
|
|
return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); |
|
} |
|
#endif |
|
|
|
static bool mptcp_established_options_add_addr(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); |
|
struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
|
bool drop_other_suboptions = false; |
|
unsigned int opt_size = *size; |
|
struct mptcp_addr_info saddr; |
|
bool echo; |
|
bool port; |
|
int len; |
|
|
|
if ((mptcp_pm_should_add_signal_ipv6(msk) || |
|
mptcp_pm_should_add_signal_port(msk)) && |
|
skb && skb_is_tcp_pure_ack(skb)) { |
|
pr_debug("drop other suboptions"); |
|
opts->suboptions = 0; |
|
opts->ext_copy.use_ack = 0; |
|
opts->ext_copy.use_map = 0; |
|
remaining += opt_size; |
|
drop_other_suboptions = true; |
|
} |
|
|
|
if (!mptcp_pm_should_add_signal(msk) || |
|
!(mptcp_pm_add_addr_signal(msk, remaining, &saddr, &echo, &port))) |
|
return false; |
|
|
|
len = mptcp_add_addr_len(saddr.family, echo, port); |
|
if (remaining < len) |
|
return false; |
|
|
|
*size = len; |
|
if (drop_other_suboptions) |
|
*size -= opt_size; |
|
opts->addr_id = saddr.id; |
|
if (port) |
|
opts->port = ntohs(saddr.port); |
|
if (saddr.family == AF_INET) { |
|
opts->suboptions |= OPTION_MPTCP_ADD_ADDR; |
|
opts->addr = saddr.addr; |
|
if (!echo) { |
|
opts->ahmac = add_addr_generate_hmac(msk->local_key, |
|
msk->remote_key, |
|
opts->addr_id, |
|
&opts->addr, |
|
opts->port); |
|
} |
|
} |
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
else if (saddr.family == AF_INET6) { |
|
opts->suboptions |= OPTION_MPTCP_ADD_ADDR6; |
|
opts->addr6 = saddr.addr6; |
|
if (!echo) { |
|
opts->ahmac = add_addr6_generate_hmac(msk->local_key, |
|
msk->remote_key, |
|
opts->addr_id, |
|
&opts->addr6, |
|
opts->port); |
|
} |
|
} |
|
#endif |
|
pr_debug("addr_id=%d, ahmac=%llu, echo=%d, port=%d", |
|
opts->addr_id, opts->ahmac, echo, opts->port); |
|
|
|
return true; |
|
} |
|
|
|
static bool mptcp_established_options_rm_addr(struct sock *sk, |
|
unsigned int *size, |
|
unsigned int remaining, |
|
struct mptcp_out_options *opts) |
|
{ |
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
|
struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
|
u8 rm_id; |
|
|
|
if (!mptcp_pm_should_rm_signal(msk) || |
|
!(mptcp_pm_rm_addr_signal(msk, remaining, &rm_id))) |
|
return false; |
|
|
|
if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE) |
|
return false; |
|
|
|
*size = TCPOLEN_MPTCP_RM_ADDR_BASE; |
|
opts->suboptions |= OPTION_MPTCP_RM_ADDR; |
|
opts->rm_id = rm_id; |
|
|
|
pr_debug("rm_id=%d", opts->rm_id); |
|
|
|
return true; |
|
} |
|
|
|
static bool mptcp_established_options_mp_prio(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->send_mp_prio) |
|
return false; |
|
|
|
/* account for the trailing 'nop' option */ |
|
if (remaining < TCPOLEN_MPTCP_PRIO_ALIGN) |
|
return false; |
|
|
|
*size = TCPOLEN_MPTCP_PRIO_ALIGN; |
|
opts->suboptions |= OPTION_MPTCP_PRIO; |
|
opts->backup = subflow->request_bkup; |
|
|
|
pr_debug("prio=%d", opts->backup); |
|
|
|
return true; |
|
} |
|
|
|
bool mptcp_established_options(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); |
|
struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
|
unsigned int opt_size = 0; |
|
bool snd_data_fin; |
|
bool ret = false; |
|
|
|
opts->suboptions = 0; |
|
|
|
if (unlikely(__mptcp_check_fallback(msk))) |
|
return false; |
|
|
|
/* prevent adding of any MPTCP related options on reset packet |
|
* until we support MP_TCPRST/MP_FASTCLOSE |
|
*/ |
|
if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) |
|
return false; |
|
|
|
snd_data_fin = mptcp_data_fin_enabled(msk); |
|
if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts)) |
|
ret = true; |
|
else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &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; |
|
if (mptcp_established_options_add_addr(sk, skb, &opt_size, remaining, opts)) { |
|
*size += opt_size; |
|
remaining -= opt_size; |
|
ret = true; |
|
} else if (mptcp_established_options_rm_addr(sk, &opt_size, remaining, opts)) { |
|
*size += opt_size; |
|
remaining -= opt_size; |
|
ret = true; |
|
} |
|
|
|
if (mptcp_established_options_mp_prio(sk, &opt_size, remaining, opts)) { |
|
*size += opt_size; |
|
remaining -= opt_size; |
|
ret = true; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, |
|
struct mptcp_out_options *opts) |
|
{ |
|
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); |
|
|
|
if (subflow_req->mp_capable) { |
|
opts->suboptions = OPTION_MPTCP_MPC_SYNACK; |
|
opts->sndr_key = subflow_req->local_key; |
|
*size = TCPOLEN_MPTCP_MPC_SYNACK; |
|
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_sock *msk, struct sock *ssk, |
|
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 |
|
* will make the subflow fully established |
|
*/ |
|
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(ssk); |
|
goto fully_established; |
|
} |
|
|
|
/* we must process OoO packets before the first subflow is fully |
|
* established. OoO packets are instead a protocol violation |
|
* for MP_JOIN subflows as the peer must not send any data |
|
* before receiving the forth ack - cfr. RFC 8684 section 3.2. |
|
*/ |
|
if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1) { |
|
if (subflow->mp_join) |
|
goto reset; |
|
return subflow->mp_capable; |
|
} |
|
|
|
if (mp_opt->dss && mp_opt->use_ack) { |
|
/* subflows are fully established as soon as we get any |
|
* additional ack. |
|
*/ |
|
subflow->fully_established = 1; |
|
WRITE_ONCE(msk->fully_established, true); |
|
goto fully_established; |
|
} |
|
|
|
if (mp_opt->add_addr) { |
|
WRITE_ONCE(msk->fully_established, true); |
|
return true; |
|
} |
|
|
|
/* If the first established packet does not contain MP_CAPABLE + data |
|
* then fallback to TCP. Fallback scenarios requires a reset for |
|
* MP_JOIN subflows. |
|
*/ |
|
if (!mp_opt->mp_capable) { |
|
if (subflow->mp_join) |
|
goto reset; |
|
subflow->mp_capable = 0; |
|
pr_fallback(msk); |
|
__mptcp_do_fallback(msk); |
|
return false; |
|
} |
|
|
|
if (unlikely(!READ_ONCE(msk->pm.server_side))) |
|
pr_warn_once("bogus mpc option on established client sk"); |
|
mptcp_subflow_fully_established(subflow, mp_opt); |
|
|
|
fully_established: |
|
/* if the subflow is not already linked into the conn_list, we can't |
|
* notify the PM: this subflow is still on the listener queue |
|
* and the PM possibly acquiring the subflow lock could race with |
|
* the listener close |
|
*/ |
|
if (likely(subflow->pm_notified) || list_empty(&subflow->node)) |
|
return true; |
|
|
|
subflow->pm_notified = 1; |
|
if (subflow->mp_join) { |
|
clear_3rdack_retransmission(ssk); |
|
mptcp_pm_subflow_established(msk, subflow); |
|
} else { |
|
mptcp_pm_fully_established(msk, ssk, GFP_ATOMIC); |
|
} |
|
return true; |
|
|
|
reset: |
|
mptcp_subflow_reset(ssk); |
|
return false; |
|
} |
|
|
|
static u64 expand_ack(u64 old_ack, u64 cur_ack, bool use_64bit) |
|
{ |
|
u32 old_ack32, cur_ack32; |
|
|
|
if (use_64bit) |
|
return cur_ack; |
|
|
|
old_ack32 = (u32)old_ack; |
|
cur_ack32 = (u32)cur_ack; |
|
cur_ack = (old_ack & GENMASK_ULL(63, 32)) + cur_ack32; |
|
if (unlikely(before(cur_ack32, old_ack32))) |
|
return cur_ack + (1LL << 32); |
|
return cur_ack; |
|
} |
|
|
|
static void ack_update_msk(struct mptcp_sock *msk, |
|
struct sock *ssk, |
|
struct mptcp_options_received *mp_opt) |
|
{ |
|
u64 new_wnd_end, new_snd_una, snd_nxt = READ_ONCE(msk->snd_nxt); |
|
struct sock *sk = (struct sock *)msk; |
|
u64 old_snd_una; |
|
|
|
mptcp_data_lock(sk); |
|
|
|
/* avoid ack expansion on update conflict, to reduce the risk of |
|
* wrongly expanding to a future ack sequence number, which is way |
|
* more dangerous than missing an ack |
|
*/ |
|
old_snd_una = msk->snd_una; |
|
new_snd_una = expand_ack(old_snd_una, mp_opt->data_ack, mp_opt->ack64); |
|
|
|
/* ACK for data not even sent yet? Ignore. */ |
|
if (after64(new_snd_una, snd_nxt)) |
|
new_snd_una = old_snd_una; |
|
|
|
new_wnd_end = new_snd_una + tcp_sk(ssk)->snd_wnd; |
|
|
|
if (after64(new_wnd_end, msk->wnd_end)) |
|
msk->wnd_end = new_wnd_end; |
|
|
|
/* this assumes mptcp_incoming_options() is invoked after tcp_ack() */ |
|
if (after64(msk->wnd_end, READ_ONCE(msk->snd_nxt))) |
|
__mptcp_check_push(sk, ssk); |
|
|
|
if (after64(new_snd_una, old_snd_una)) { |
|
msk->snd_una = new_snd_una; |
|
__mptcp_data_acked(sk); |
|
} |
|
mptcp_data_unlock(sk); |
|
} |
|
|
|
bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit) |
|
{ |
|
/* Skip if DATA_FIN was already received. |
|
* If updating simultaneously with the recvmsg loop, values |
|
* should match. If they mismatch, the peer is misbehaving and |
|
* we will prefer the most recent information. |
|
*/ |
|
if (READ_ONCE(msk->rcv_data_fin) || !READ_ONCE(msk->first)) |
|
return false; |
|
|
|
WRITE_ONCE(msk->rcv_data_fin_seq, |
|
expand_ack(READ_ONCE(msk->ack_seq), data_fin_seq, use_64bit)); |
|
WRITE_ONCE(msk->rcv_data_fin, 1); |
|
|
|
return true; |
|
} |
|
|
|
static bool add_addr_hmac_valid(struct mptcp_sock *msk, |
|
struct mptcp_options_received *mp_opt) |
|
{ |
|
u64 hmac = 0; |
|
|
|
if (mp_opt->echo) |
|
return true; |
|
|
|
if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) |
|
hmac = add_addr_generate_hmac(msk->remote_key, |
|
msk->local_key, |
|
mp_opt->addr_id, &mp_opt->addr, |
|
mp_opt->port); |
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
else |
|
hmac = add_addr6_generate_hmac(msk->remote_key, |
|
msk->local_key, |
|
mp_opt->addr_id, &mp_opt->addr6, |
|
mp_opt->port); |
|
#endif |
|
|
|
pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n", |
|
msk, (unsigned long long)hmac, |
|
(unsigned long long)mp_opt->ahmac); |
|
|
|
return hmac == mp_opt->ahmac; |
|
} |
|
|
|
void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
|
struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
|
struct mptcp_options_received mp_opt; |
|
struct mptcp_ext *mpext; |
|
|
|
if (__mptcp_check_fallback(msk)) { |
|
/* Keep it simple and unconditionally trigger send data cleanup and |
|
* pending queue spooling. We will need to acquire the data lock |
|
* for more accurate checks, and once the lock is acquired, such |
|
* helpers are cheap. |
|
*/ |
|
mptcp_data_lock(subflow->conn); |
|
if (sk_stream_memory_free(sk)) |
|
__mptcp_check_push(subflow->conn, sk); |
|
__mptcp_data_acked(subflow->conn); |
|
mptcp_data_unlock(subflow->conn); |
|
return; |
|
} |
|
|
|
mptcp_get_options(skb, &mp_opt); |
|
if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) |
|
return; |
|
|
|
if (mp_opt.fastclose && |
|
msk->local_key == mp_opt.rcvr_key) { |
|
WRITE_ONCE(msk->rcv_fastclose, true); |
|
mptcp_schedule_work((struct sock *)msk); |
|
} |
|
|
|
if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) { |
|
struct mptcp_addr_info addr; |
|
|
|
addr.port = htons(mp_opt.port); |
|
addr.id = mp_opt.addr_id; |
|
if (mp_opt.family == MPTCP_ADDR_IPVERSION_4) { |
|
addr.family = AF_INET; |
|
addr.addr = mp_opt.addr; |
|
} |
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
else if (mp_opt.family == MPTCP_ADDR_IPVERSION_6) { |
|
addr.family = AF_INET6; |
|
addr.addr6 = mp_opt.addr6; |
|
} |
|
#endif |
|
if (!mp_opt.echo) { |
|
mptcp_pm_add_addr_received(msk, &addr); |
|
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR); |
|
} else { |
|
mptcp_pm_del_add_timer(msk, &addr); |
|
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD); |
|
} |
|
|
|
if (mp_opt.port) |
|
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_PORTADD); |
|
|
|
mp_opt.add_addr = 0; |
|
} |
|
|
|
if (mp_opt.rm_addr) { |
|
mptcp_pm_rm_addr_received(msk, mp_opt.rm_id); |
|
mp_opt.rm_addr = 0; |
|
} |
|
|
|
if (mp_opt.mp_prio) { |
|
mptcp_pm_mp_prio_received(sk, mp_opt.backup); |
|
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIORX); |
|
mp_opt.mp_prio = 0; |
|
} |
|
|
|
if (!mp_opt.dss) |
|
return; |
|
|
|
/* we can't wait for recvmsg() to update the ack_seq, otherwise |
|
* monodirectional flows will stuck |
|
*/ |
|
if (mp_opt.use_ack) |
|
ack_update_msk(msk, sk, &mp_opt); |
|
|
|
/* Zero-data-length packets are dropped by the caller and not |
|
* propagated to the MPTCP layer, so the skb extension does not |
|
* need to be allocated or populated. DATA_FIN information, if |
|
* present, needs to be updated here before the skb is freed. |
|
*/ |
|
if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { |
|
if (mp_opt.data_fin && mp_opt.data_len == 1 && |
|
mptcp_update_rcv_data_fin(msk, mp_opt.data_seq, mp_opt.dsn64) && |
|
schedule_work(&msk->work)) |
|
sock_hold(subflow->conn); |
|
|
|
return; |
|
} |
|
|
|
mpext = skb_ext_add(skb, SKB_EXT_MPTCP); |
|
if (!mpext) |
|
return; |
|
|
|
memset(mpext, 0, sizeof(*mpext)); |
|
|
|
if (mp_opt.use_map) { |
|
if (mp_opt.mpc_map) { |
|
/* this is an MP_CAPABLE carrying MPTCP data |
|
* we know this map the first chunk of data |
|
*/ |
|
mptcp_crypto_key_sha(subflow->remote_key, NULL, |
|
&mpext->data_seq); |
|
mpext->data_seq++; |
|
mpext->subflow_seq = 1; |
|
mpext->dsn64 = 1; |
|
mpext->mpc_map = 1; |
|
mpext->data_fin = 0; |
|
} else { |
|
mpext->data_seq = mp_opt.data_seq; |
|
mpext->subflow_seq = mp_opt.subflow_seq; |
|
mpext->dsn64 = mp_opt.dsn64; |
|
mpext->data_fin = mp_opt.data_fin; |
|
} |
|
mpext->data_len = mp_opt.data_len; |
|
mpext->use_map = 1; |
|
} |
|
} |
|
|
|
static void mptcp_set_rwin(const struct tcp_sock *tp) |
|
{ |
|
const struct sock *ssk = (const struct sock *)tp; |
|
const struct mptcp_subflow_context *subflow; |
|
struct mptcp_sock *msk; |
|
u64 ack_seq; |
|
|
|
subflow = mptcp_subflow_ctx(ssk); |
|
msk = mptcp_sk(subflow->conn); |
|
|
|
ack_seq = READ_ONCE(msk->ack_seq) + tp->rcv_wnd; |
|
|
|
if (after64(ack_seq, READ_ONCE(msk->rcv_wnd_sent))) |
|
WRITE_ONCE(msk->rcv_wnd_sent, ack_seq); |
|
} |
|
|
|
void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, |
|
struct mptcp_out_options *opts) |
|
{ |
|
if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | |
|
OPTION_MPTCP_MPC_ACK) & opts->suboptions) { |
|
u8 len; |
|
|
|
if (OPTION_MPTCP_MPC_SYN & opts->suboptions) |
|
len = TCPOLEN_MPTCP_MPC_SYN; |
|
else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) |
|
len = TCPOLEN_MPTCP_MPC_SYNACK; |
|
else if (opts->ext_copy.data_len) |
|
len = TCPOLEN_MPTCP_MPC_ACK_DATA; |
|
else |
|
len = TCPOLEN_MPTCP_MPC_ACK; |
|
|
|
*ptr++ = mptcp_option(MPTCPOPT_MP_CAPABLE, len, |
|
MPTCP_SUPPORTED_VERSION, |
|
MPTCP_CAP_HMAC_SHA256); |
|
|
|
if (!((OPTION_MPTCP_MPC_SYNACK | OPTION_MPTCP_MPC_ACK) & |
|
opts->suboptions)) |
|
goto mp_capable_done; |
|
|
|
put_unaligned_be64(opts->sndr_key, ptr); |
|
ptr += 2; |
|
if (!((OPTION_MPTCP_MPC_ACK) & opts->suboptions)) |
|
goto mp_capable_done; |
|
|
|
put_unaligned_be64(opts->rcvr_key, ptr); |
|
ptr += 2; |
|
if (!opts->ext_copy.data_len) |
|
goto mp_capable_done; |
|
|
|
put_unaligned_be32(opts->ext_copy.data_len << 16 | |
|
TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); |
|
ptr += 1; |
|
} |
|
|
|
mp_capable_done: |
|
if ((OPTION_MPTCP_ADD_ADDR |
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
| OPTION_MPTCP_ADD_ADDR6 |
|
#endif |
|
) & opts->suboptions) { |
|
u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE; |
|
u8 echo = MPTCP_ADDR_ECHO; |
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
if (OPTION_MPTCP_ADD_ADDR6 & opts->suboptions) |
|
len = TCPOLEN_MPTCP_ADD_ADDR6_BASE; |
|
#endif |
|
|
|
if (opts->port) |
|
len += TCPOLEN_MPTCP_PORT_LEN; |
|
|
|
if (opts->ahmac) { |
|
len += sizeof(opts->ahmac); |
|
echo = 0; |
|
} |
|
|
|
*ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, |
|
len, echo, opts->addr_id); |
|
if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) { |
|
memcpy((u8 *)ptr, (u8 *)&opts->addr.s_addr, 4); |
|
ptr += 1; |
|
} |
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
else if (OPTION_MPTCP_ADD_ADDR6 & opts->suboptions) { |
|
memcpy((u8 *)ptr, opts->addr6.s6_addr, 16); |
|
ptr += 4; |
|
} |
|
#endif |
|
|
|
if (!opts->port) { |
|
if (opts->ahmac) { |
|
put_unaligned_be64(opts->ahmac, ptr); |
|
ptr += 2; |
|
} |
|
} else { |
|
if (opts->ahmac) { |
|
u8 *bptr = (u8 *)ptr; |
|
|
|
put_unaligned_be16(opts->port, bptr); |
|
bptr += 2; |
|
put_unaligned_be64(opts->ahmac, bptr); |
|
bptr += 8; |
|
put_unaligned_be16(TCPOPT_NOP << 8 | |
|
TCPOPT_NOP, bptr); |
|
|
|
ptr += 3; |
|
} else { |
|
put_unaligned_be32(opts->port << 16 | |
|
TCPOPT_NOP << 8 | |
|
TCPOPT_NOP, ptr); |
|
ptr += 1; |
|
} |
|
} |
|
} |
|
|
|
if (OPTION_MPTCP_RM_ADDR & opts->suboptions) { |
|
*ptr++ = mptcp_option(MPTCPOPT_RM_ADDR, |
|
TCPOLEN_MPTCP_RM_ADDR_BASE, |
|
0, opts->rm_id); |
|
} |
|
|
|
if (OPTION_MPTCP_PRIO & opts->suboptions) { |
|
const struct sock *ssk = (const struct sock *)tp; |
|
struct mptcp_subflow_context *subflow; |
|
|
|
subflow = mptcp_subflow_ctx(ssk); |
|
subflow->send_mp_prio = 0; |
|
|
|
*ptr++ = mptcp_option(MPTCPOPT_MP_PRIO, |
|
TCPOLEN_MPTCP_PRIO, |
|
opts->backup, TCPOPT_NOP); |
|
} |
|
|
|
if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) { |
|
*ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, |
|
TCPOLEN_MPTCP_MPJ_SYN, |
|
opts->backup, opts->join_id); |
|
put_unaligned_be32(opts->token, ptr); |
|
ptr += 1; |
|
put_unaligned_be32(opts->nonce, ptr); |
|
ptr += 1; |
|
} |
|
|
|
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 (OPTION_MPTCP_MPJ_ACK & opts->suboptions) { |
|
*ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, |
|
TCPOLEN_MPTCP_MPJ_ACK, 0, 0); |
|
memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN); |
|
ptr += 5; |
|
} |
|
|
|
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) { |
|
flags = MPTCP_DSS_HAS_ACK; |
|
if (mpext->ack64) { |
|
len += TCPOLEN_MPTCP_DSS_ACK64; |
|
flags |= MPTCP_DSS_ACK64; |
|
} else { |
|
len += TCPOLEN_MPTCP_DSS_ACK32; |
|
} |
|
} |
|
|
|
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++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags); |
|
|
|
if (mpext->use_ack) { |
|
if (mpext->ack64) { |
|
put_unaligned_be64(mpext->data_ack, ptr); |
|
ptr += 2; |
|
} else { |
|
put_unaligned_be32(mpext->data_ack32, ptr); |
|
ptr += 1; |
|
} |
|
} |
|
|
|
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); |
|
} |
|
} |
|
|
|
if (tp) |
|
mptcp_set_rwin(tp); |
|
}
|
|
|