[MPTCP] Re: [PATCH] mptcp: allow dumping subflow context to userspace

add ulp-specific diagnostic functions, so that subflow information can be dumped to userspace programs like 'ss'.

Signed-off-by: Davide Caratti <dcaratti(a)redhat.com&gt; --- Notes: changes since RFC: - dump all subflow-related infos except keys include/uapi/linux/inet_diag.h | 1 + include/uapi/linux/mptcp.h | 34 ++++++++++++ net/mptcp/Makefile | 2 +- net/mptcp/diag.c | 95 ++++++++++++++++++++++++++++++++++ net/mptcp/protocol.h | 3 ++ net/mptcp/subflow.c | 2 + 6 files changed, 136 insertions(+), 1 deletion(-) create mode 100644 include/uapi/linux/mptcp.h create mode 100644 net/mptcp/diag.c diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h index a1ff345b3f33..13d16b887512 100644 --- a/include/uapi/linux/inet_diag.h +++ b/include/uapi/linux/inet_diag.h @@ -163,6 +163,7 @@ enum { INET_ULP_INFO_UNSPEC, INET_ULP_INFO_NAME, INET_ULP_INFO_TLS, + INET_ULP_INFO_MPTCP, __INET_ULP_INFO_MAX, }; #define INET_ULP_INFO_MAX (__INET_ULP_INFO_MAX - 1) diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h new file mode 100644 index 000000000000..2856b89cc36e --- /dev/null +++ b/include/uapi/linux/mptcp.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +#ifndef _UAPI_MPTCP_H +#define _UAPI_MPTCP_H + +#include <linux/types.h> + +#define SUBFLOW_FLAGS_MCAP_REM BIT(0) +#define SUBFLOW_FLAGS_MCAP_LOC BIT(1) +#define SUBFLOW_FLAGS_JOIN_REM BIT(2) +#define SUBFLOW_FLAGS_JOIN_LOC BIT(3) +#define SUBFLOW_FLAGS_BKUP_REM BIT(4) +#define SUBFLOW_FLAGS_BKUP_LOC BIT(5) +#define SUBFLOW_FLAGS_4THACK BIT(6) +#define SUBFLOW_FLAGS_CONNECTED BIT(7) +#define SUBFLOW_FLAGS_MAPVALID BIT(8)

+ +enum { + MPTCP_SUBFLOW_UNSPEC, + MPTCP_SUBFLOW_TOKEN_REM, + MPTCP_SUBFLOW_TOKEN_LOC, + MPTCP_SUBFLOW_RELWRITE_SEQ, + MPTCP_SUBFLOW_MAP_SEQ, + MPTCP_SUBFLOW_MAP_SFSEQ, + MPTCP_SUBFLOW_SSN_OFFSET, + MPTCP_SUBFLOW_MAP_DATALEN, + MPTCP_SUBFLOW_FLAGS, + MPTCP_SUBFLOW_ID_REM, + MPTCP_SUBFLOW_ID_LOC, + MPTCP_SUBFLOW_PAD, + __MPTCP_SUBFLOW_MAX +}; + +#define MPTCP_SUBFLOW_MAX (__MPTCP_SUBFLOW_MAX - 1) +#endif /* _UAPI_MPTCP_H */ diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile index 289fdf4339c1..6b556e2995ec 100644 --- a/net/mptcp/Makefile +++ b/net/mptcp/Makefile @@ -1,4 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_MPTCP) += mptcp.o -mptcp-y := protocol.o subflow.o options.o token.o crypto.o pm.o ctrl.o +mptcp-y := protocol.o subflow.o options.o token.o crypto.o pm.o ctrl.o diag.o diff --git a/net/mptcp/diag.c b/net/mptcp/diag.c new file mode 100644 index 000000000000..a42c96619faa --- /dev/null +++ b/net/mptcp/diag.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* MPTCP socket monitoring support + * + * Copyright (c) 2019 Red Hat + * + * Author: Davide Caratti <dcaratti(a)redhat.com&gt; + */ + +#include <linux/kernel.h> +#include <linux/net.h> +#include <linux/inet_diag.h> +#include <net/netlink.h> +#include <uapi/linux/mptcp.h> +#include "protocol.h" + +int subflow_get_info(const struct sock *sk, struct sk_buff *skb) +{ + struct subflow_context *sf; + struct nlattr *start; + u32 flags = 0; + int err; + + start = nla_nest_start_noflag(skb, INET_ULP_INFO_MPTCP); + if (!start) + return -EMSGSIZE; + + rcu_read_lock(); + sf = rcu_dereference(inet_csk(sk)->icsk_ulp_data); + if (!sf) { + err = 0; + goto nla_failure; + } + + if (sf->mp_capable) + flags |= SUBFLOW_FLAGS_MCAP_REM; + if (sf->request_mptcp) + flags |= SUBFLOW_FLAGS_MCAP_LOC; + if (sf->mp_join) + flags |= SUBFLOW_FLAGS_JOIN_REM; + if (sf->request_join) + flags |= SUBFLOW_FLAGS_JOIN_LOC; + if (sf->backup) + flags |= SUBFLOW_FLAGS_BKUP_REM; + if (sf->request_bkup) + flags |= SUBFLOW_FLAGS_BKUP_LOC; + if (sf->fourth_ack) + flags |= SUBFLOW_FLAGS_4THACK; + if (sf->conn_finished) + flags |= SUBFLOW_FLAGS_CONNECTED; + if (sf->map_valid) + flags |= SUBFLOW_FLAGS_MAPVALID; + + if (nla_put_u32(skb, MPTCP_SUBFLOW_TOKEN_REM, sf->remote_token) || + nla_put_u32(skb, MPTCP_SUBFLOW_TOKEN_LOC, sf->token) || + nla_put_u32(skb, MPTCP_SUBFLOW_RELWRITE_SEQ, sf->rel_write_seq) || + nla_put_u64_64bit(skb, MPTCP_SUBFLOW_MAP_SEQ, sf->map_seq, + MPTCP_SUBFLOW_PAD) || + nla_put_u32(skb, MPTCP_SUBFLOW_MAP_SFSEQ, sf->map_subflow_seq) || + nla_put_u32(skb, MPTCP_SUBFLOW_SSN_OFFSET, sf->ssn_offset) || + nla_put_u16(skb, MPTCP_SUBFLOW_MAP_DATALEN, sf->map_data_len) || + nla_put_u32(skb, MPTCP_SUBFLOW_FLAGS, flags) || + nla_put_u8(skb, MPTCP_SUBFLOW_ID_REM, sf->remote_id) || + nla_put_u8(skb, MPTCP_SUBFLOW_ID_LOC, sf->local_id)) { + err = -EMSGSIZE; + goto nla_failure; + } + + rcu_read_unlock(); + nla_nest_end(skb, start); + return 0; + +nla_failure: + rcu_read_unlock(); + nla_nest_cancel(skb, start); + return err; +} + +size_t subflow_get_info_size(const struct sock *sk) +{ + size_t size = 0; + + size += nla_total_size(0) + /* INET_ULP_INFO_MPTCP */ + nla_total_size(4) + /* MPTCP_SUBFLOW_TOKEN_REM */ + nla_total_size(4) + /* MPTCP_SUBFLOW_TOKEN_LOC */ + nla_total_size(4) + /* MPTCP_SUBFLOW_RELWRITE_SEQ */ + nla_total_size_64bit(8) + /* MPTCP_SUBFLOW_MAP_SEQ */ + nla_total_size(4) + /* MPTCP_SUBFLOW_MAP_SFSEQ */ + nla_total_size(2) + /* MPTCP_SUBFLOW_SSN_OFFSET */ + nla_total_size(2) + /* MPTCP_SUBFLOW_MAP_DATALEN */ + nla_total_size(4) + /* MPTCP_SUBFLOW_FLAGS */ + nla_total_size(1) + /* MPTCP_SUBFLOW_ID_REM */ + nla_total_size(1) + /* MPTCP_SUBFLOW_ID_LOC */ + 0; + return size; +} diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index f3f293c82058..f38639cc35b4 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -314,4 +314,7 @@ static inline bool before64(__u64 seq1, __u64 seq2) #define after64(seq2, seq1) before64(seq1, seq2) +size_t subflow_get_info_size(const struct sock *sk); +int subflow_get_info(const struct sock *sk, struct sk_buff *skb);