mptcp: allow dumping subflow context to userspace

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

v2 -> v3:
- uapi: use bit macros appropriate for userspace

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Davide Caratti 2020-03-27 14:48:49 -07:00 committed by David S. Miller
parent 3b1d6210a9
commit 5147dfb508
7 changed files with 146 additions and 1 deletions

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@ -11727,6 +11727,7 @@ W: https://github.com/multipath-tcp/mptcp_net-next/wiki
B: https://github.com/multipath-tcp/mptcp_net-next/issues
S: Maintained
F: include/net/mptcp.h
F: include/uapi/linux/mptcp.h
F: net/mptcp/
F: tools/testing/selftests/net/mptcp/

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@ -166,6 +166,7 @@ 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)

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@ -0,0 +1,35 @@
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
#ifndef _UAPI_MPTCP_H
#define _UAPI_MPTCP_H
#include <linux/const.h>
#include <linux/types.h>
#define MPTCP_SUBFLOW_FLAG_MCAP_REM _BITUL(0)
#define MPTCP_SUBFLOW_FLAG_MCAP_LOC _BITUL(1)
#define MPTCP_SUBFLOW_FLAG_JOIN_REM _BITUL(2)
#define MPTCP_SUBFLOW_FLAG_JOIN_LOC _BITUL(3)
#define MPTCP_SUBFLOW_FLAG_BKUP_REM _BITUL(4)
#define MPTCP_SUBFLOW_FLAG_BKUP_LOC _BITUL(5)
#define MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED _BITUL(6)
#define MPTCP_SUBFLOW_FLAG_CONNECTED _BITUL(7)
#define MPTCP_SUBFLOW_FLAG_MAPVALID _BITUL(8)
enum {
MPTCP_SUBFLOW_ATTR_UNSPEC,
MPTCP_SUBFLOW_ATTR_TOKEN_REM,
MPTCP_SUBFLOW_ATTR_TOKEN_LOC,
MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
MPTCP_SUBFLOW_ATTR_MAP_SEQ,
MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
MPTCP_SUBFLOW_ATTR_SSN_OFFSET,
MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
MPTCP_SUBFLOW_ATTR_FLAGS,
MPTCP_SUBFLOW_ATTR_ID_REM,
MPTCP_SUBFLOW_ATTR_ID_LOC,
MPTCP_SUBFLOW_ATTR_PAD,
__MPTCP_SUBFLOW_ATTR_MAX
};
#define MPTCP_SUBFLOW_ATTR_MAX (__MPTCP_SUBFLOW_ATTR_MAX - 1)
#endif /* _UAPI_MPTCP_H */

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@ -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 ctrl.o pm.o
mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o diag.o

104
net/mptcp/diag.c Normal file
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@ -0,0 +1,104 @@
// SPDX-License-Identifier: GPL-2.0
/* MPTCP socket monitoring support
*
* Copyright (c) 2019 Red Hat
*
* Author: Davide Caratti <dcaratti@redhat.com>
*/
#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"
static int subflow_get_info(const struct sock *sk, struct sk_buff *skb)
{
struct mptcp_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 |= MPTCP_SUBFLOW_FLAG_MCAP_REM;
if (sf->request_mptcp)
flags |= MPTCP_SUBFLOW_FLAG_MCAP_LOC;
if (sf->mp_join)
flags |= MPTCP_SUBFLOW_FLAG_JOIN_REM;
if (sf->request_join)
flags |= MPTCP_SUBFLOW_FLAG_JOIN_LOC;
if (sf->backup)
flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM;
if (sf->request_bkup)
flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC;
if (sf->fully_established)
flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED;
if (sf->conn_finished)
flags |= MPTCP_SUBFLOW_FLAG_CONNECTED;
if (sf->map_valid)
flags |= MPTCP_SUBFLOW_FLAG_MAPVALID;
if (nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_REM, sf->remote_token) ||
nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_LOC, sf->token) ||
nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
sf->rel_write_seq) ||
nla_put_u64_64bit(skb, MPTCP_SUBFLOW_ATTR_MAP_SEQ, sf->map_seq,
MPTCP_SUBFLOW_ATTR_PAD) ||
nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
sf->map_subflow_seq) ||
nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_SSN_OFFSET, sf->ssn_offset) ||
nla_put_u16(skb, MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
sf->map_data_len) ||
nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_FLAGS, flags) ||
nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_REM, sf->remote_id) ||
nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_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;
}
static 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_ATTR_TOKEN_REM */
nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_TOKEN_LOC */
nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ */
nla_total_size_64bit(8) + /* MPTCP_SUBFLOW_ATTR_MAP_SEQ */
nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_MAP_SFSEQ */
nla_total_size(2) + /* MPTCP_SUBFLOW_ATTR_SSN_OFFSET */
nla_total_size(2) + /* MPTCP_SUBFLOW_ATTR_MAP_DATALEN */
nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_FLAGS */
nla_total_size(1) + /* MPTCP_SUBFLOW_ATTR_ID_REM */
nla_total_size(1) + /* MPTCP_SUBFLOW_ATTR_ID_LOC */
0;
return size;
}
void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops)
{
ops->get_info = subflow_get_info;
ops->get_info_size = subflow_get_info_size;
}

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@ -408,4 +408,6 @@ static inline bool before64(__u64 seq1, __u64 seq2)
#define after64(seq2, seq1) before64(seq1, seq2)
void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
#endif /* __MPTCP_PROTOCOL_H */

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@ -1148,6 +1148,8 @@ void mptcp_subflow_init(void)
subflow_v6m_specific.net_frag_header_len = 0;
#endif
mptcp_diag_subflow_init(&subflow_ulp_ops);
if (tcp_register_ulp(&subflow_ulp_ops) != 0)
panic("MPTCP: failed to register subflows to ULP\n");
}