[PATCH mptcp-next 0/5] mptcp: add SOL_MPTCP getsockopt support

[PATCH mptcp-next 0/5] mptcp: add SOL_MPTCP getsockopt support

[Florian Westphal]

This adds the MPTCP_INFO, MPTCP_TCPINFO and MPTCP_SUBFLOW_ADDRS
mptcp getsockopt optnames.

MPTCP_INFO exposes the mptcp_info struct as an alternative to the
existing netlink diag interface.

MPTCP_TCPINFO exposes the tcp_info struct.
Unlike SOL_TCP/TCP_INFO, this returns one struct for each active
subflow.

MPTCP_SUBFLOW_ADDRS allows userspace to discover the ip addresses/ports
used by the local and remote endpoints, one for each active tcp subflow.

MPTCP_TCPINFO and MPTCP_SUBFLOW_ADDRS share the same meta-header that
needs to be pre-filled by userspace with the size of the data structures
it expects.  This is done to allow extension of the involved structs
later on, without breaking backwards compatibility.

The meta-structure can also be used to discover the required space
to obtain all information, as kernel will fill in the number of
active subflows even if there is not enough room for the requested info
itself.

More information is available in the individual patches.
Last patch adds test cases for the three optnames.

Florian Westphal (5):
  mptcp: add new mptcp_fill_diag helper
  mptcp: add MPTCP_INFO getsockopt
  mptcp: add MPTCP_TCPINFO getsockopt support
  mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support
  selftests: mptcp: add mptcp getsockopt test cases

 include/linux/socket.h                        |   1 +
 include/net/mptcp.h                           |   4 +
 include/uapi/linux/mptcp.h                    |  29 +
 net/mptcp/mptcp_diag.c                        |  26 +-
 net/mptcp/sockopt.c                           | 258 +++++++++
 tools/testing/selftests/net/mptcp/Makefile    |   4 +-
 .../selftests/net/mptcp/mptcp_sockopt.c       | 545 ++++++++++++++++++
 .../selftests/net/mptcp/mptcp_sockopt.sh      |  31 +-
 8 files changed, 869 insertions(+), 29 deletions(-)
 create mode 100644 tools/testing/selftests/net/mptcp/mptcp_sockopt.c

-- 
2.31.1

[PATCH mptcp-next 1/5] mptcp: add new mptcp_fill_diag helper

[Florian Westphal]

Will be re-used from getsockopt path.
Since diag can be a module, we can't export the helper from diag, it
needs to be moved to core.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 include/net/mptcp.h    |  4 ++++
 net/mptcp/mptcp_diag.c | 26 +-------------------------
 net/mptcp/sockopt.c    | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 6026bbefbffd..f83fa48408b3 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -12,6 +12,8 @@
 #include <linux/tcp.h>
 #include <linux/types.h>
 
+struct mptcp_info;
+struct mptcp_sock;
 struct seq_file;
 
 /* MPTCP sk_buff extension data */
@@ -121,6 +123,8 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 			 struct mptcp_out_options *opts);
 
+void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);
+
 /* move the skb extension owership, with the assumption that 'to' is
  * newly allocated
  */
diff --git a/net/mptcp/mptcp_diag.c b/net/mptcp/mptcp_diag.c
index f48eb6315bbb..fdf0c1f15a65 100644
--- a/net/mptcp/mptcp_diag.c
+++ b/net/mptcp/mptcp_diag.c
@@ -113,37 +113,13 @@ static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
 	struct mptcp_info *info = _info;
-	u32 flags = 0;
-	bool slow;
-	u8 val;
 
 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
 	if (!info)
 		return;
 
-	slow = lock_sock_fast(sk);
-	info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);
-	info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);
-	info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);
-	info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used);
-	info->mptcpi_subflows_max = mptcp_pm_get_subflows_max(msk);
-	val = mptcp_pm_get_add_addr_signal_max(msk);
-	info->mptcpi_add_addr_signal_max = val;
-	val = mptcp_pm_get_add_addr_accept_max(msk);
-	info->mptcpi_add_addr_accepted_max = val;
-	info->mptcpi_local_addr_max = mptcp_pm_get_local_addr_max(msk);
-	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags))
-		flags |= MPTCP_INFO_FLAG_FALLBACK;
-	if (READ_ONCE(msk->can_ack))
-		flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED;
-	info->mptcpi_flags = flags;
-	info->mptcpi_token = READ_ONCE(msk->token);
-	info->mptcpi_write_seq = READ_ONCE(msk->write_seq);
-	info->mptcpi_snd_una = READ_ONCE(msk->snd_una);
-	info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq);
-	info->mptcpi_csum_enabled = READ_ONCE(msk->csum_enabled);
-	unlock_sock_fast(sk, slow);
+	mptcp_diag_fill_info(msk, info);
 }
 
 static const struct inet_diag_handler mptcp_diag_handler = {
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 8c03afac5ca0..54f0d521a399 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -670,6 +670,38 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int
 	return ret;
 }
 
+void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
+{
+	struct sock *sk = &msk->sk.icsk_inet.sk;
+	bool slow = lock_sock_fast(sk);
+	u32 flags = 0;
+	u8 val;
+
+	info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);
+	info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);
+	info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);
+	info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used);
+	info->mptcpi_subflows_max = mptcp_pm_get_subflows_max(msk);
+	val = mptcp_pm_get_add_addr_signal_max(msk);
+	info->mptcpi_add_addr_signal_max = val;
+	val = mptcp_pm_get_add_addr_accept_max(msk);
+	info->mptcpi_add_addr_accepted_max = val;
+	info->mptcpi_local_addr_max = mptcp_pm_get_local_addr_max(msk);
+	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags))
+		flags |= MPTCP_INFO_FLAG_FALLBACK;
+	if (READ_ONCE(msk->can_ack))
+		flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED;
+	info->mptcpi_flags = flags;
+	info->mptcpi_token = READ_ONCE(msk->token);
+	info->mptcpi_write_seq = READ_ONCE(msk->write_seq);
+	info->mptcpi_snd_una = READ_ONCE(msk->snd_una);
+	info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq);
+	info->mptcpi_csum_enabled = READ_ONCE(msk->csum_enabled);
+
+	unlock_sock_fast(sk, slow);
+}
+EXPORT_SYMBOL_GPL(mptcp_diag_fill_info);
+
 static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
 				    char __user *optval, int __user *optlen)
 {
-- 
2.31.1

[PATCH mptcp-next 2/5] mptcp: add MPTCP_INFO getsockopt

[Florian Westphal]

Its not compatible with mptcp.org kernel one.

1. mptcp.org defines a different 'struct mptcp_info', with embedded
userspace addresses to store additional data such as endpoint addresses.

2. Mat Martineau points out the mptcp.org approach doesn't work with
BPF_CGROUP_RUN_PROG_GETSOCKOPT() which assumes that copying in
optsize bytes from optval provides all data that got copied to
userspace.

This provides mptcp_info data for the given mptcp socket.

Userspace sets optlen to the size of the structure it expects.
The kernel updates it to contain the number of bytes that it copied.

This allows to append more information to the structure later.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 include/linux/socket.h     |  1 +
 include/uapi/linux/mptcp.h |  4 ++++
 net/mptcp/sockopt.c        | 40 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index fd9ce51582d8..a2326a963232 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -364,6 +364,7 @@ struct ucred {
 #define SOL_KCM		281
 #define SOL_TLS		282
 #define SOL_XDP		283
+#define SOL_MPTCP	284
 
 /* IPX options */
 #define IPX_TYPE	1
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index f66038b9551f..c450feba6f9c 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -4,6 +4,7 @@
 
 #include <linux/const.h>
 #include <linux/types.h>
+#include <linux/in.h>
 
 #define MPTCP_SUBFLOW_FLAG_MCAP_REM		_BITUL(0)
 #define MPTCP_SUBFLOW_FLAG_MCAP_LOC		_BITUL(1)
@@ -193,4 +194,7 @@ enum mptcp_event_attr {
 #define MPTCP_RST_EBADPERF	5
 #define MPTCP_RST_EMIDDLEBOX	6
 
+/* MPTCP socket options */
+#define MPTCP_INFO 1
+
 #endif /* _UAPI_MPTCP_H */
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 54f0d521a399..eba294a071c8 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -673,10 +673,14 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int
 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
 {
 	struct sock *sk = &msk->sk.icsk_inet.sk;
-	bool slow = lock_sock_fast(sk);
 	u32 flags = 0;
+	bool slow;
 	u8 val;
 
+	memset(info, 0, sizeof(*info));
+
+	slow = lock_sock_fast(sk);
+
 	info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);
 	info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);
 	info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);
@@ -702,6 +706,27 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
 }
 EXPORT_SYMBOL_GPL(mptcp_diag_fill_info);
 
+static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, int __user *_u_optlen)
+{
+	struct mptcp_info m_info;
+	int len;
+
+	if (get_user(len, _u_optlen))
+		return -EFAULT;
+
+	len = min_t(unsigned int, len, sizeof(struct mptcp_info));
+
+	mptcp_diag_fill_info(msk, &m_info);
+
+	if (put_user(len, _u_optlen))
+		return -EFAULT;
+
+	if (copy_to_user(optval, &m_info, len))
+		return -EFAULT;
+
+	return 0;
+}
+
 static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
 				    char __user *optval, int __user *optlen)
 {
@@ -716,6 +741,17 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
 	return -EOPNOTSUPP;
 }
 
+static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname,
+				      char __user *optval, int __user *optlen)
+{
+	switch (optname) {
+	case MPTCP_INFO:
+		return mptcp_getsockopt_info(msk, optval, optlen);
+	}
+
+	return -EOPNOTSUPP;
+}
+
 int mptcp_getsockopt(struct sock *sk, int level, int optname,
 		     char __user *optval, int __user *option)
 {
@@ -738,6 +774,8 @@ int mptcp_getsockopt(struct sock *sk, int level, int optname,
 
 	if (level == SOL_TCP)
 		return mptcp_getsockopt_sol_tcp(msk, optname, optval, option);
+	if (level == SOL_MPTCP)
+		return mptcp_getsockopt_sol_mptcp(msk, optname, optval, option);
 	return -EOPNOTSUPP;
 }
 
-- 
2.31.1

[PATCH mptcp-next 3/5] mptcp: add MPTCP_TCPINFO getsockopt support

[Florian Westphal]

Allow users to retrieve TCP_INFO data of all subflows.
Users need to pre-initialize a meta header that has to be
prepended to the data buffer that will be filled with the
tcp info data.

The meta header looks like this:

struct mptcp_subflow_data {
 __u32 size_subflow_data;/* size of this structure in userspace */
 __u32 num_subflows;	/* must be 0, set by kernel */
 __u32 size_kernel;	/* must be 0, set by kernel */
 __u32 size_user;	/* size of one element in data[] */
} __attribute__((aligned(8)));

size_subflow_data has to be set to 'sizeof(struct mptcp_subflow_data)'.
This allows to extend mptcp_subflow_data structure later on without
breaking backwards compatibility.

If the structure is extended later on, kernel knows where the
userspace-provided meta header ends, even if userspace uses an
older (smaller) version of the structure.

num_subflows must be set to 0. If the getsockopt request
succeeds (return value is 0), it will be updated to contain
the number of active subflows for the given logical connection.

size_kernel must be set to 0. If the getsockopt request
is successful, it will contain the size of the 'struct tcp_info'
as known by the kernel.  This is informational only.

size_user must be set to 'sizeof(struct tcp_info)'.
This allows the kernel to only fill in the space reserved/expected
by userspace.

Example:

struct my_tcp_info {
  struct mptcp_subflow_data d;
  struct tcp_info ti[2];
};
struct my_tcp_info ti;
socklen_t olen;

memset(&ti, 0, sizeof(ti));

ti.d.size_subflow_data = sizeof(struct mptcp_subflow_data);
ti.d.size_user = sizeof(struct tcp_info);
olen = sizeof(ti);

ret = getsockopt(fd, SOL_MPTCP, MPTCP_TCPINFO, &ti, &olen);
if (ret < 0)
	die_perror("getsockopt MPTCP_TCPINFO");

mptcp_subflow_data.num_subflows is populated with the number of
subflows that exist on the kernel side for the logical mptcp connection.

This allows userspace to re-try with a larger tcp_info array if
the number of subflows was larger than the available space in the ti[]
array.

olen has to be set to the number of bytes that userspace has allocated
to receive the kernel data.  It will be updated to contain the real
number bytes that have been copied to by the kernel.

In the above example, if the number if subflows was 1,
olen is equal to 'sizeof(struct mptcp_subflow_data) + sizeof(struct tcp_info).
For 2 or more subflows olen is equal to 'sizeof(struct my_tcp_info)'.

olen is never increased vs. what was reserved.
If there was more data that could not be copied due to lack of space
in the option buffer, userspace can detect this by checking
mptcp_subflow_data->num_subflows.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 include/uapi/linux/mptcp.h | 10 ++++-
 net/mptcp/sockopt.c        | 92 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index c450feba6f9c..7c368fccd83e 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -194,7 +194,15 @@ enum mptcp_event_attr {
 #define MPTCP_RST_EBADPERF	5
 #define MPTCP_RST_EMIDDLEBOX	6
 
+struct mptcp_subflow_data {
+	__u32		size_subflow_data;		/* size of this structure in userspace */
+	__u32		num_subflows;			/* must be 0, set by kernel */
+	__u32		size_kernel;			/* must be 0, set by kernel */
+	__u32		size_user;			/* size of one element in data[] */
+} __attribute__((aligned(8)));
+
 /* MPTCP socket options */
-#define MPTCP_INFO 1
+#define MPTCP_INFO		1
+#define MPTCP_TCPINFO		2
 
 #endif /* _UAPI_MPTCP_H */
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index eba294a071c8..ac8e6823db4f 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -723,6 +723,96 @@ static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, in
 
 	if (copy_to_user(optval, &m_info, len))
 		return -EFAULT;
+	return 0;
+}
+
+static int mptcp_get_subflow_data(struct mptcp_subflow_data *sfd,
+				  char __user *optval, int __user *_u_optlen)
+{
+#define MIN_INFO_OPTLEN_SIZE	16
+	int len, copylen;
+
+	if (get_user(len, _u_optlen))
+		return -EFAULT;
+
+	if (len <= MIN_INFO_OPTLEN_SIZE)
+		return -EINVAL;
+
+	memset(sfd, 0, sizeof(*sfd));
+
+	copylen = min_t(unsigned int, len, sizeof(*sfd));
+	if (copy_from_user(sfd, optval, copylen))
+		return -EFAULT;
+
+	/* size_subflow_data is u32, but len is signed */
+	if (sfd->size_subflow_data > INT_MAX ||
+	    sfd->size_user > INT_MAX)
+		return -EINVAL;
+
+	if (sfd->size_subflow_data < MIN_INFO_OPTLEN_SIZE ||
+	    sfd->size_subflow_data > len)
+		return -EINVAL;
+
+	if (sfd->num_subflows || sfd->size_kernel)
+		return -EINVAL;
+
+	return len - sfd->size_subflow_data;
+}
+
+static int mptcp_getsockopt_tcpinfo(struct mptcp_sock *msk, char __user *optval,
+				    int __user *_u_optlen)
+{
+	struct mptcp_subflow_context *subflow;
+	struct sock *sk = &msk->sk.icsk_inet.sk;
+	unsigned int sfcount = 0, copied = 0;
+	struct mptcp_subflow_data sfd;
+	char __user *infoptr;
+	int len;
+
+	len = mptcp_get_subflow_data(&sfd, optval, _u_optlen);
+	if (len < 0)
+		return len;
+
+	sfd.size_kernel = sizeof(struct tcp_info);
+	sfd.size_user = min_t(unsigned int, sfd.size_user,
+			      sizeof(struct tcp_info));
+
+	infoptr = optval + sfd.size_subflow_data;
+
+	lock_sock(sk);
+
+	mptcp_for_each_subflow(msk, subflow) {
+		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+		++sfcount;
+
+		if (len >= sfd.size_user) {
+			struct tcp_info info;
+
+			tcp_get_info(ssk, &info);
+
+			if (copy_to_user(infoptr, &info, sfd.size_user)) {
+				release_sock(sk);
+				return -EFAULT;
+			}
+
+			infoptr += sfd.size_user;
+			copied += sfd.size_user;
+			len -= sfd.size_user;
+		}
+	}
+
+	release_sock(sk);
+
+	copied += sfd.size_subflow_data;
+
+	if (put_user(copied, _u_optlen))
+		return -EFAULT;
+
+	sfd.num_subflows = sfcount;
+
+	if (copy_to_user(optval, &sfd, sfd.size_subflow_data))
+		return -EFAULT;
 
 	return 0;
 }
@@ -747,6 +837,8 @@ static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname,
 	switch (optname) {
 	case MPTCP_INFO:
 		return mptcp_getsockopt_info(msk, optval, optlen);
+	case MPTCP_TCPINFO:
+		return mptcp_getsockopt_tcpinfo(msk, optval, optlen);
 	}
 
 	return -EOPNOTSUPP;
-- 
2.31.1

[PATCH mptcp-next 4/5] mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support

[Florian Westphal]

This retrieves the address pairs of all subflows currently
active for a given mptcp connection.

It re-uses the same meta-header as for MPTCP_TCPINFO.

A new structure is provided to hold the subflow
address data:

struct mptcp_subflow_addrs {
	union {
		sa_family_t sa_family;
		struct sockaddr sa_local;
		struct sockaddr_in sin_local;
		struct sockaddr_in6 sin6_local;
		struct sockaddr_storage ss_local;
	};
	union {
		struct sockaddr sa_remote;
		struct sockaddr_in sin_remote;
		struct sockaddr_in6 sin6_remote;
		struct sockaddr_storage ss_remote;
	};
};

Usage of the new getsockopt is very similar to
MPTCP_TCPINFO one.

Userspace allocates a
'struct mptcp_subflow_data', followed by one or
more 'struct mptcp_subflow_addrs', then inits the
mptcp_subflow_data structure as follows:

struct mptcp_subflow_addrs *sf_addr;
struct mptcp_subflow_data *addr;
socklen_t olen = sizeof(*addr) + (8 * sizeof(*sf_addr));

addr = malloc(olen);
addr->size_subflow_data = sizeof(*addr);
addr->num_subflows = 0;
addr->size_kernel = 0;
addr->size_user = sizeof(struct mptcp_subflow_addrs);

sf_addr = (struct mptcp_subflow_addrs *)(addr + 1);

and then retrieves the endpoint addresses via:
ret = getsockopt(fd, SOL_MPTCP, MPTCP_SUBFLOW_ADDRS,
		 addr, &olen);

If the call succeeds, kernel will have added up to 8
endpoint addresses after the 'mptcp_subflow_data' header.

Userspace needs to re-check 'olen' value to detect how
many bytes have been filled in by the kernel.

Userspace can check addr->num_subflows to discover when
there were more subflows that available data space.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 include/uapi/linux/mptcp.h | 17 +++++++
 net/mptcp/sockopt.c        | 96 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 7c368fccd83e..f6cfd2c4ca5b 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -201,8 +201,25 @@ struct mptcp_subflow_data {
 	__u32		size_user;			/* size of one element in data[] */
 } __attribute__((aligned(8)));
 
+struct mptcp_subflow_addrs {
+	union {
+		sa_family_t sa_family;
+		struct sockaddr sa_local;
+		struct sockaddr_in sin_local;
+		struct sockaddr_in6 sin6_local;
+		struct sockaddr_storage ss_local;
+	};
+	union {
+		struct sockaddr sa_remote;
+		struct sockaddr_in sin_remote;
+		struct sockaddr_in6 sin6_remote;
+		struct sockaddr_storage ss_remote;
+	};
+};
+
 /* MPTCP socket options */
 #define MPTCP_INFO		1
 #define MPTCP_TCPINFO		2
+#define MPTCP_SUBFLOW_ADDRS	3
 
 #endif /* _UAPI_MPTCP_H */
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index ac8e6823db4f..a30bc848ffcb 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -817,6 +817,100 @@ static int mptcp_getsockopt_tcpinfo(struct mptcp_sock *msk, char __user *optval,
 	return 0;
 }
 
+static void mptcp_get_sub_addrs(const struct sock *sk, struct mptcp_subflow_addrs *a)
+{
+	struct inet_sock *inet = inet_sk(sk);
+
+	memset(a, 0, sizeof(*a));
+
+	if (sk->sk_family == AF_INET) {
+		a->sin_local.sin_family = AF_INET;
+		a->sin_local.sin_port = inet->inet_sport;
+		a->sin_local.sin_addr.s_addr = inet->inet_rcv_saddr;
+
+		if (!a->sin_local.sin_addr.s_addr)
+			a->sin_local.sin_addr.s_addr = inet->inet_saddr;
+
+		a->sin_remote.sin_family = AF_INET;
+		a->sin_remote.sin_port = inet->inet_dport;
+		a->sin_remote.sin_addr.s_addr = inet->inet_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (sk->sk_family == AF_INET6) {
+		const struct ipv6_pinfo *np = inet6_sk(sk);
+
+		a->sin6_local.sin6_family = AF_INET6;
+		a->sin6_local.sin6_port = inet->inet_sport;
+
+		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+			a->sin6_local.sin6_addr = np->saddr;
+		else
+			a->sin6_local.sin6_addr = sk->sk_v6_rcv_saddr;
+
+		a->sin6_remote.sin6_family = AF_INET6;
+		a->sin6_remote.sin6_port = inet->inet_dport;
+		a->sin6_remote.sin6_addr = sk->sk_v6_daddr;
+#endif
+	}
+}
+
+static int mptcp_getsockopt_subflow_addrs(struct mptcp_sock *msk, char __user *optval,
+					  int __user *_u_optlen)
+{
+	struct mptcp_subflow_context *subflow;
+	struct sock *sk = &msk->sk.icsk_inet.sk;
+	unsigned int sfcount = 0, copied = 0;
+	struct mptcp_subflow_data sfd;
+	char __user *addrptr;
+	int len;
+
+	len = mptcp_get_subflow_data(&sfd, optval, _u_optlen);
+	if (len < 0)
+		return len;
+
+	sfd.size_kernel = sizeof(struct mptcp_subflow_addrs);
+	sfd.size_user = min_t(unsigned int, sfd.size_user,
+			      sizeof(struct mptcp_subflow_addrs));
+
+	addrptr = optval + sfd.size_subflow_data;
+
+	lock_sock(sk);
+
+	mptcp_for_each_subflow(msk, subflow) {
+		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+		++sfcount;
+
+		if (len >= sfd.size_user) {
+			struct mptcp_subflow_addrs a;
+
+			mptcp_get_sub_addrs(ssk, &a);
+
+			if (copy_to_user(addrptr, &a, sfd.size_user)) {
+				release_sock(sk);
+				return -EFAULT;
+			}
+
+			addrptr += sfd.size_user;
+			copied += sfd.size_user;
+			len -= sfd.size_user;
+		}
+	}
+
+	release_sock(sk);
+
+	copied += sfd.size_subflow_data;
+
+	if (put_user(copied, _u_optlen))
+		return -EFAULT;
+
+	sfd.num_subflows = sfcount;
+
+	if (copy_to_user(optval, &sfd, sfd.size_subflow_data))
+		return -EFAULT;
+
+	return 0;
+}
+
 static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
 				    char __user *optval, int __user *optlen)
 {
@@ -839,6 +933,8 @@ static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname,
 		return mptcp_getsockopt_info(msk, optval, optlen);
 	case MPTCP_TCPINFO:
 		return mptcp_getsockopt_tcpinfo(msk, optval, optlen);
+	case MPTCP_SUBFLOW_ADDRS:
+		return mptcp_getsockopt_subflow_addrs(msk, optval, optlen);
 	}
 
 	return -EOPNOTSUPP;
-- 
2.31.1

[PATCH mptcp-next 5/5] selftests: mptcp: add mptcp getsockopt test cases

[Florian Westphal]

Add a test program that retrieves the three info types:
1. mptcp meta information
2. tcp info for subflow
3. subflow endpoint addresses

For all three rudimentary checks are added.

1. Meta information checks that the logical mptcp
   sequence numbers advance as expected, based on the bytes read
   (init seq + bytes_received/sent) and the connection state
   (after close, we should exect 1 extra byte due to FIN).

2. TCP info checks the number of bytes sent/received vs.
   sums of read/write syscall return values.

3. Subflow endpoint addresses are checked vs. getsockname/getpeername
   result.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 tools/testing/selftests/net/mptcp/Makefile    |   4 +-
 .../selftests/net/mptcp/mptcp_sockopt.c       | 545 ++++++++++++++++++
 .../selftests/net/mptcp/mptcp_sockopt.sh      |  31 +-
 3 files changed, 576 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/net/mptcp/mptcp_sockopt.c

diff --git a/tools/testing/selftests/net/mptcp/Makefile b/tools/testing/selftests/net/mptcp/Makefile
index f1464f09b080..7437929a2109 100644
--- a/tools/testing/selftests/net/mptcp/Makefile
+++ b/tools/testing/selftests/net/mptcp/Makefile
@@ -6,9 +6,9 @@ KSFT_KHDR_INSTALL := 1
 CFLAGS =  -Wall -Wl,--no-as-needed -O2 -g  -I$(top_srcdir)/usr/include
 
 TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh \
-	      simult_flows.sh mptcp_sockopt.sh
+	      simult_flows.sh mptcp_sockopt.sh mptcp_sockopt.sh
 
-TEST_GEN_FILES = mptcp_connect pm_nl_ctl
+TEST_GEN_FILES = mptcp_connect pm_nl_ctl mptcp_sockopt
 
 TEST_FILES := settings
 
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
new file mode 100644
index 000000000000..522b394fe011
--- /dev/null
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
@@ -0,0 +1,545 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <netdb.h>
+#include <netinet/in.h>
+
+#include <linux/tcp.h>
+
+static int pf = AF_INET;
+
+#ifndef IPPROTO_MPTCP
+#define IPPROTO_MPTCP 262
+#endif
+#ifndef SOL_MPTCP
+#define SOL_MPTCP 284
+#endif
+
+#ifndef TCP_TCPINFO
+struct mptcp_subflow_data {
+	__u32		size_subflow_data;		/* size of this structure in userspace */
+	__u32		num_subflows;			/* must be 0, set by kernel */
+	__u32		size_kernel;			/* must be 0, set by kernel */
+	__u32		size_user;			/* size of one element in data[] */
+} __attribute__((aligned(8)));
+
+struct mptcp_subflow_addrs {
+	union {
+		sa_family_t sa_family;
+		struct sockaddr sa_local;
+		struct sockaddr_in sin_local;
+		struct sockaddr_in6 sin6_local;
+		struct sockaddr_storage ss_local;
+	};
+	union {
+		struct sockaddr sa_remote;
+		struct sockaddr_in sin_remote;
+		struct sockaddr_in6 sin6_remote;
+		struct sockaddr_storage ss_remote;
+	};
+};
+
+#define MPTCP_INFO		1
+#define MPTCP_TCPINFO		2
+#define MPTCP_SUBFLOW_ADDRS	3
+#endif
+
+struct mptcp_info {
+	__u8	mptcpi_subflows;
+	__u8	mptcpi_add_addr_signal;
+	__u8	mptcpi_add_addr_accepted;
+	__u8	mptcpi_subflows_max;
+	__u8	mptcpi_add_addr_signal_max;
+	__u8	mptcpi_add_addr_accepted_max;
+	__u32	mptcpi_flags;
+	__u32	mptcpi_token;
+	__u64	mptcpi_write_seq;
+	__u64	mptcpi_snd_una;
+	__u64	mptcpi_rcv_nxt;
+	__u8	mptcpi_local_addr_used;
+	__u8	mptcpi_local_addr_max;
+	__u8	mptcpi_csum_enabled;
+};
+
+enum sockopt_check_flags {
+	EOF_RECEIVED = 1 << 0,
+};
+
+struct so_state {
+	struct mptcp_info mi;
+};
+
+static void die_perror(const char *msg)
+{
+	perror(msg);
+	exit(1);
+}
+
+static void die_usage(int r)
+{
+	fprintf(stderr, "Usage: mptcp_sockopt [-6]\n");
+	exit(r);
+}
+
+static void xerror(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fputc('\n', stderr);
+	exit(1);
+}
+
+static const char *getxinfo_strerr(int err)
+{
+	if (err == EAI_SYSTEM)
+		return strerror(errno);
+
+	return gai_strerror(err);
+}
+
+static void xgetaddrinfo(const char *node, const char *service,
+			 const struct addrinfo *hints,
+			 struct addrinfo **res)
+{
+	int err = getaddrinfo(node, service, hints, res);
+
+	if (err) {
+		const char *errstr = getxinfo_strerr(err);
+
+		fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n",
+			node ? node : "", service ? service : "", errstr);
+		exit(1);
+	}
+}
+
+static int sock_listen_mptcp(const char * const listenaddr,
+			     const char * const port)
+{
+	int sock;
+	struct addrinfo hints = {
+		.ai_protocol = IPPROTO_TCP,
+		.ai_socktype = SOCK_STREAM,
+		.ai_flags = AI_PASSIVE | AI_NUMERICHOST
+	};
+
+	hints.ai_family = pf;
+
+	struct addrinfo *a, *addr;
+	int one = 1;
+
+	xgetaddrinfo(listenaddr, port, &hints, &addr);
+	hints.ai_family = pf;
+
+	for (a = addr; a; a = a->ai_next) {
+		sock = socket(a->ai_family, a->ai_socktype, IPPROTO_MPTCP);
+		if (sock < 0)
+			continue;
+
+		if (-1 == setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one,
+				     sizeof(one)))
+			perror("setsockopt");
+
+		if (bind(sock, a->ai_addr, a->ai_addrlen) == 0)
+			break; /* success */
+
+		perror("bind");
+		close(sock);
+		sock = -1;
+	}
+
+	freeaddrinfo(addr);
+
+	if (sock < 0)
+		xerror("could not create listen socket");
+
+	if (listen(sock, 20))
+		die_perror("listen");
+
+	return sock;
+}
+
+static int sock_connect_mptcp(const char * const remoteaddr,
+			      const char * const port, int proto)
+{
+	struct addrinfo hints = {
+		.ai_protocol = IPPROTO_TCP,
+		.ai_socktype = SOCK_STREAM,
+	};
+	struct addrinfo *a, *addr;
+	int sock = -1;
+
+	hints.ai_family = pf;
+
+	xgetaddrinfo(remoteaddr, port, &hints, &addr);
+	for (a = addr; a; a = a->ai_next) {
+		sock = socket(a->ai_family, a->ai_socktype, proto);
+		if (sock < 0)
+			continue;
+
+		if (connect(sock, a->ai_addr, a->ai_addrlen) == 0)
+			break; /* success */
+
+		die_perror("connect");
+	}
+
+	if (sock < 0)
+		xerror("could not create connect socket");
+
+	freeaddrinfo(addr);
+	return sock;
+}
+
+static void parse_opts(int argc, char **argv)
+{
+	int c;
+
+	while ((c = getopt(argc, argv, "h6")) != -1) {
+		switch (c) {
+		case 'h':
+			die_usage(0);
+			break;
+		case '6':
+			pf = AF_INET6;
+			break;
+		default:
+			die_usage(1);
+			break;
+		}
+	}
+}
+
+static void do_getsockopt_mptcp_info(struct so_state *s, int fd, size_t r, size_t w, uint32_t flags)
+{
+	struct mptcp_info i;
+	socklen_t olen;
+	int ret;
+
+	olen = sizeof(i);
+	ret = getsockopt(fd, SOL_MPTCP, MPTCP_INFO, &i, &olen);
+
+	if (ret < 0)
+		die_perror("getsockopt MPTCP_INFO");
+
+	assert(olen == sizeof(i));
+
+	if (s->mi.mptcpi_write_seq == 0)
+		s->mi = i;
+
+	assert(s->mi.mptcpi_write_seq + w == i.mptcpi_write_seq);
+
+	if (flags & EOF_RECEIVED)
+		r += 1;
+
+	assert(s->mi.mptcpi_rcv_nxt + r == i.mptcpi_rcv_nxt);
+}
+
+static void do_getsockopt_tcp_info(int fd, size_t r, size_t w)
+{
+	struct my_tcp_info {
+		struct mptcp_subflow_data d;
+		struct tcp_info ti[2];
+	} ti;
+	socklen_t olen;
+	int ret;
+
+	memset(&ti, 0, sizeof(ti));
+
+	ti.d.size_subflow_data = sizeof(struct mptcp_subflow_data);
+	ti.d.size_user = sizeof(struct tcp_info);
+	olen = sizeof(ti);
+
+	ret = getsockopt(fd, SOL_MPTCP, MPTCP_TCPINFO, &ti, &olen);
+	if (ret < 0)
+		die_perror("getsockopt MPTCP_TCPINFO");
+
+	assert(olen <= sizeof(ti));
+	assert(ti.d.size_user == ti.d.size_kernel);
+	assert(ti.d.size_user == sizeof(struct tcp_info));
+	assert(ti.d.num_subflows == 1);
+
+	assert(olen > (socklen_t)sizeof(struct mptcp_subflow_data));
+	olen -= sizeof(struct mptcp_subflow_data);
+	assert(olen == sizeof(struct tcp_info));
+
+	assert(ti.ti[0].tcpi_bytes_sent == w);
+	assert(ti.ti[0].tcpi_bytes_received == r);
+}
+
+static void do_getsockopt_subflow_addrs(int fd)
+{
+	struct sockaddr_storage remote, local;
+	socklen_t olen, rlen, llen;
+	int ret;
+	struct my_addrs {
+		struct mptcp_subflow_data d;
+		struct mptcp_subflow_addrs addr[2];
+	} addrs;
+
+	memset(&addrs, 0, sizeof(addrs));
+	memset(&local, 0, sizeof(local));
+	memset(&remote, 0, sizeof(remote));
+
+	addrs.d.size_subflow_data = sizeof(struct mptcp_subflow_data);
+	addrs.d.size_user = sizeof(struct mptcp_subflow_addrs);
+	olen = sizeof(addrs);
+
+	ret = getsockopt(fd, SOL_MPTCP, MPTCP_SUBFLOW_ADDRS, &addrs, &olen);
+	if (ret < 0)
+		die_perror("getsockopt MPTCP_SUBFLOW_ADDRS");
+
+	assert(olen <= sizeof(addrs));
+	assert(addrs.d.size_user == addrs.d.size_kernel);
+	assert(addrs.d.size_user == sizeof(struct mptcp_subflow_addrs));
+	assert(addrs.d.num_subflows == 1);
+
+	assert(olen > (socklen_t)sizeof(struct mptcp_subflow_data));
+	olen -= sizeof(struct mptcp_subflow_data);
+	assert(olen == sizeof(struct mptcp_subflow_addrs));
+
+	llen = sizeof(local);
+	ret = getsockname(fd, (struct sockaddr *)&local, &llen);
+	if (ret < 0)
+		die_perror("getsockname");
+	rlen = sizeof(remote);
+	ret = getpeername(fd, (struct sockaddr *)&remote, &rlen);
+	if (ret < 0)
+		die_perror("getpeername");
+
+	assert(rlen > 0);
+	assert(rlen == llen);
+
+	assert(remote.ss_family == local.ss_family);
+
+	assert(memcmp(&local, &addrs.addr[0].ss_local, sizeof(local)) == 0);
+	assert(memcmp(&remote, &addrs.addr[0].ss_remote, sizeof(remote)) == 0);
+}
+
+static void do_getsockopts(struct so_state *s, int fd, size_t r, size_t w, uint32_t flags)
+{
+	do_getsockopt_mptcp_info(s, fd, r, w, flags);
+
+	do_getsockopt_tcp_info(fd, r, w);
+
+	do_getsockopt_subflow_addrs(fd);
+}
+
+static void connect_one_server(int fd)
+{
+	char buf[4096], buf2[4096];
+	struct so_state s;
+	size_t len, i;
+	ssize_t ret;
+
+	memset(&s, 0, sizeof(s));
+
+	len = rand() % (sizeof(buf) - 1);
+
+	if (len < 128)
+		len = 128;
+
+	for (i = 0; i < len ; i++) {
+		buf[i] = rand() % 26;
+		buf[i] += 'A';
+	}
+
+	buf[i] = '\n';
+
+	do_getsockopts(&s, fd, 0, 0, 0);
+
+	ret = write(fd, buf, len);
+	if (ret < 0)
+		die_perror("write");
+
+	if (ret != (ssize_t)len)
+		xerror("short write");
+
+	do_getsockopts(&s, fd, 0, ret, 0);
+
+	ret = read(fd, buf2, sizeof(buf2));
+	if (ret < 0)
+		die_perror("read");
+
+	if ((size_t)ret != len)
+		xerror("incomplete read");
+
+	if (memcmp(buf, buf2, len))
+		xerror("data corruption");
+
+	do_getsockopts(&s, fd, ret, ret, 0);
+	close(fd);
+}
+
+static void process_one_client(int fd)
+{
+	ssize_t ret, ret2, ret3;
+	struct so_state s;
+	char buf[4096];
+
+	memset(&s, 0, sizeof(s));
+
+	do_getsockopts(&s, fd, 0, 0, 0);
+
+	ret = read(fd, buf, sizeof(buf));
+	if (ret < 0)
+		die_perror("read");
+
+	sleep(1);
+	do_getsockopts(&s, fd, ret, 0, 0);
+
+	ret2 = write(fd, buf, ret);
+	if (ret2 < 0)
+		die_perror("write");
+
+	/* wait for hangup */
+	ret3 = read(fd, buf, 1);
+	if (ret3 != 0)
+		xerror("expected EOF, got %lu", ret3);
+
+	do_getsockopts(&s, fd, ret, ret2, EOF_RECEIVED);
+	close(ret2);
+}
+
+static int xaccept(int s)
+{
+	int fd = accept(s, NULL, 0);
+
+	if (fd < 0)
+		die_perror("accept");
+
+	return fd;
+}
+
+static int server(int readyfd)
+{
+	int fd, r;
+
+	switch (pf) {
+	case AF_INET:
+		fd = sock_listen_mptcp("127.0.0.1", "15432");
+		break;
+	case AF_INET6:
+		fd = sock_listen_mptcp("::1", "15432");
+		break;
+	default:
+		xerror("Unknown pf %d\n", pf);
+	}
+
+	r = close(readyfd);
+	if (r < 0)
+		die_perror("close pipe");
+
+	alarm(15);
+	r = xaccept(fd);
+
+	process_one_client(r);
+
+	return 0;
+}
+
+static int client(void)
+{
+	int fd;
+
+	alarm(15);
+
+	switch (pf) {
+	case AF_INET:
+		fd = sock_connect_mptcp("127.0.0.1", "15432", IPPROTO_MPTCP);
+		break;
+	case AF_INET6:
+		fd = sock_connect_mptcp("::1", "15432", IPPROTO_MPTCP);
+		break;
+	default:
+		xerror("Unknown pf %d\n", pf);
+	}
+
+	connect_one_server(fd);
+
+	return 0;
+}
+
+static pid_t xfork(void)
+{
+	pid_t p = fork();
+
+	if (p < 0)
+		die_perror("fork");
+
+	return p;
+}
+
+static int rcheck(int wstatus, const char *what)
+{
+	if (WIFEXITED(wstatus)) {
+		if (WEXITSTATUS(wstatus) == 0)
+			return 0;
+		fprintf(stderr, "%s exited, status=%d\n", what, WEXITSTATUS(wstatus));
+		return WEXITSTATUS(wstatus);
+	} else if (WIFSIGNALED(wstatus)) {
+		xerror("%s killed by signal %d\n", what, WTERMSIG(wstatus));
+	} else if (WIFSTOPPED(wstatus)) {
+		xerror("%s stopped by signal %d\n", what, WSTOPSIG(wstatus));
+	}
+
+	return 111;
+}
+
+int main(int argc, char *argv[])
+{
+	int e1, e2, wstatus;
+	pid_t s, c, ret;
+	int pipefds[2];
+
+	parse_opts(argc, argv);
+
+	e1 = pipe(pipefds);
+	if (e1 < 0)
+		die_perror("pipe");
+
+	s = xfork();
+	if (s == 0)
+		return server(pipefds[1]);
+
+	close(pipefds[1]);
+
+	/* wait until server bound a socket */
+	e1 = read(pipefds[0], &e1, 4);
+	if (e1 < 0)
+		die_perror("read from pipe");
+
+	close(pipefds[0]);
+	c = xfork();
+	if (c == 0)
+		return client();
+
+	ret = waitpid(s, &wstatus, 0);
+	if (ret == -1)
+		die_perror("waitpid");
+	e1 = rcheck(wstatus, "server");
+	ret = waitpid(c, &wstatus, 0);
+	if (ret == -1)
+		die_perror("waitpid");
+	e2 = rcheck(wstatus, "client");
+
+	return e1 ? e1 : e2;
+}
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
index 1579e471a5e7..41de643788b8 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
@@ -239,12 +239,35 @@ make_file()
 	echo "Created $name (size $size KB) containing data sent by $who"
 }
 
+do_mptcp_sockopt_tests()
+{
+	local lret=0
+
+	./mptcp_sockopt
+	lret=$?
+
+	if [ $lret -ne 0 ]; then
+		echo "FAIL: SOL_MPTCP getsockopt" 1>&2
+		ret=$lret
+		return
+	fi
+
+	./mptcp_sockopt -6
+	lret=$?
+
+	if [ $lret -ne 0 ]; then
+		echo "FAIL: SOL_MPTCP getsockopt (ipv6)" 1>&2
+		ret=$lret
+		return
+	fi
+}
+
 run_tests()
 {
 	listener_ns="$1"
 	connector_ns="$2"
 	connect_addr="$3"
-	lret=0
+	local lret=0
 
 	do_transfer ${listener_ns} ${connector_ns} MPTCP MPTCP ${connect_addr}
 
@@ -268,9 +291,13 @@ trap cleanup EXIT
 run_tests $ns1 $ns2 10.0.1.1
 run_tests $ns1 $ns2 dead:beef:1::1
 
-
 if [ $ret -eq 0 ];then
 	echo "PASS: all packets had packet mark set"
 fi
 
+do_mptcp_sockopt_tests
+if [ $ret -eq 0 ];then
+	echo "PASS: SOL_MPTCP getsockopt has expected information"
+fi
+
 exit $ret
-- 
2.31.1

Re: [PATCH mptcp-next 4/5] mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2651 bytes --]

Hi Florian,

I love your patch! Yet something to improve:

[auto build test ERROR on kselftest/next]
[also build test ERROR on mptcp/export linus/master v5.14-rc5 next-20210811]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: i386-randconfig-a004-20210811 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
        git checkout bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        # save the attached .config to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from <command-line>:32:
>> ./usr/include/linux/mptcp.h:205:3: error: unknown type name 'sa_family_t'
     205 |   sa_family_t sa_family;
         |   ^~~~~~~~~~~
>> ./usr/include/linux/mptcp.h:206:19: error: field 'sa_local' has incomplete type
     206 |   struct sockaddr sa_local;
         |                   ^~~~~~~~
>> ./usr/include/linux/mptcp.h:208:23: error: field 'sin6_local' has incomplete type
     208 |   struct sockaddr_in6 sin6_local;
         |                       ^~~~~~~~~~
>> ./usr/include/linux/mptcp.h:209:27: error: field 'ss_local' has incomplete type
     209 |   struct sockaddr_storage ss_local;
         |                           ^~~~~~~~
>> ./usr/include/linux/mptcp.h:212:19: error: field 'sa_remote' has incomplete type
     212 |   struct sockaddr sa_remote;
         |                   ^~~~~~~~~
>> ./usr/include/linux/mptcp.h:214:23: error: field 'sin6_remote' has incomplete type
     214 |   struct sockaddr_in6 sin6_remote;
         |                       ^~~~~~~~~~~
>> ./usr/include/linux/mptcp.h:215:27: error: field 'ss_remote' has incomplete type
     215 |   struct sockaddr_storage ss_remote;
         |                           ^~~~~~~~~

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 31997 bytes --]

Re: [PATCH mptcp-next 4/5] mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2707 bytes --]

Hi Florian,

I love your patch! Yet something to improve:

[auto build test ERROR on kselftest/next]
[also build test ERROR on mptcp/export linus/master v5.14-rc5 next-20210811]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: i386-randconfig-a004-20210811 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
        git checkout bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        # save the attached .config to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from <command-line>:32:
>> ./usr/include/linux/mptcp.h:205:3: error: unknown type name 'sa_family_t'
     205 |   sa_family_t sa_family;
         |   ^~~~~~~~~~~
>> ./usr/include/linux/mptcp.h:206:19: error: field 'sa_local' has incomplete type
     206 |   struct sockaddr sa_local;
         |                   ^~~~~~~~
>> ./usr/include/linux/mptcp.h:208:23: error: field 'sin6_local' has incomplete type
     208 |   struct sockaddr_in6 sin6_local;
         |                       ^~~~~~~~~~
>> ./usr/include/linux/mptcp.h:209:27: error: field 'ss_local' has incomplete type
     209 |   struct sockaddr_storage ss_local;
         |                           ^~~~~~~~
>> ./usr/include/linux/mptcp.h:212:19: error: field 'sa_remote' has incomplete type
     212 |   struct sockaddr sa_remote;
         |                   ^~~~~~~~~
>> ./usr/include/linux/mptcp.h:214:23: error: field 'sin6_remote' has incomplete type
     214 |   struct sockaddr_in6 sin6_remote;
         |                       ^~~~~~~~~~~
>> ./usr/include/linux/mptcp.h:215:27: error: field 'ss_remote' has incomplete type
     215 |   struct sockaddr_storage ss_remote;
         |                           ^~~~~~~~~

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 31997 bytes --]

Re: [PATCH mptcp-next 4/5] mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 4024 bytes --]

Hi Florian,

I love your patch! Yet something to improve:

[auto build test ERROR on kselftest/next]
[also build test ERROR on mptcp/export linus/master v5.14-rc5 next-20210811]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: x86_64-randconfig-a004-20210811 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d39ebdae674c8efc84ebe8dc32716ec353220530)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
        git checkout bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from <built-in>:1:
>> ./usr/include/linux/mptcp.h:205:3: error: unknown type name 'sa_family_t'
                   sa_family_t sa_family;
                   ^
>> ./usr/include/linux/mptcp.h:206:19: error: field has incomplete type 'struct sockaddr'
                   struct sockaddr sa_local;
                                   ^
   ./usr/include/linux/mptcp.h:206:10: note: forward declaration of 'struct sockaddr'
                   struct sockaddr sa_local;
                          ^
>> ./usr/include/linux/mptcp.h:208:23: error: field has incomplete type 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_local;
                                       ^
   ./usr/include/linux/mptcp.h:208:10: note: forward declaration of 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_local;
                          ^
>> ./usr/include/linux/mptcp.h:209:27: error: field has incomplete type 'struct sockaddr_storage'
                   struct sockaddr_storage ss_local;
                                           ^
   ./usr/include/linux/mptcp.h:209:10: note: forward declaration of 'struct sockaddr_storage'
                   struct sockaddr_storage ss_local;
                          ^
   ./usr/include/linux/mptcp.h:212:19: error: field has incomplete type 'struct sockaddr'
                   struct sockaddr sa_remote;
                                   ^
   ./usr/include/linux/mptcp.h:206:10: note: forward declaration of 'struct sockaddr'
                   struct sockaddr sa_local;
                          ^
   ./usr/include/linux/mptcp.h:214:23: error: field has incomplete type 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_remote;
                                       ^
   ./usr/include/linux/mptcp.h:208:10: note: forward declaration of 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_local;
                          ^
   ./usr/include/linux/mptcp.h:215:27: error: field has incomplete type 'struct sockaddr_storage'
                   struct sockaddr_storage ss_remote;
                                           ^
   ./usr/include/linux/mptcp.h:209:10: note: forward declaration of 'struct sockaddr_storage'
                   struct sockaddr_storage ss_local;
                          ^
   7 errors generated.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 33043 bytes --]

Re: [PATCH mptcp-next 4/5] mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 4101 bytes --]

Hi Florian,

I love your patch! Yet something to improve:

[auto build test ERROR on kselftest/next]
[also build test ERROR on mptcp/export linus/master v5.14-rc5 next-20210811]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: x86_64-randconfig-a004-20210811 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d39ebdae674c8efc84ebe8dc32716ec353220530)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Florian-Westphal/mptcp-add-SOL_MPTCP-getsockopt-support/20210811-212510
        git checkout bd7031682bfb2cfd717fde49bd7f943c09f7a9a5
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from <built-in>:1:
>> ./usr/include/linux/mptcp.h:205:3: error: unknown type name 'sa_family_t'
                   sa_family_t sa_family;
                   ^
>> ./usr/include/linux/mptcp.h:206:19: error: field has incomplete type 'struct sockaddr'
                   struct sockaddr sa_local;
                                   ^
   ./usr/include/linux/mptcp.h:206:10: note: forward declaration of 'struct sockaddr'
                   struct sockaddr sa_local;
                          ^
>> ./usr/include/linux/mptcp.h:208:23: error: field has incomplete type 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_local;
                                       ^
   ./usr/include/linux/mptcp.h:208:10: note: forward declaration of 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_local;
                          ^
>> ./usr/include/linux/mptcp.h:209:27: error: field has incomplete type 'struct sockaddr_storage'
                   struct sockaddr_storage ss_local;
                                           ^
   ./usr/include/linux/mptcp.h:209:10: note: forward declaration of 'struct sockaddr_storage'
                   struct sockaddr_storage ss_local;
                          ^
   ./usr/include/linux/mptcp.h:212:19: error: field has incomplete type 'struct sockaddr'
                   struct sockaddr sa_remote;
                                   ^
   ./usr/include/linux/mptcp.h:206:10: note: forward declaration of 'struct sockaddr'
                   struct sockaddr sa_local;
                          ^
   ./usr/include/linux/mptcp.h:214:23: error: field has incomplete type 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_remote;
                                       ^
   ./usr/include/linux/mptcp.h:208:10: note: forward declaration of 'struct sockaddr_in6'
                   struct sockaddr_in6 sin6_local;
                          ^
   ./usr/include/linux/mptcp.h:215:27: error: field has incomplete type 'struct sockaddr_storage'
                   struct sockaddr_storage ss_remote;
                                           ^
   ./usr/include/linux/mptcp.h:209:10: note: forward declaration of 'struct sockaddr_storage'
                   struct sockaddr_storage ss_local;
                          ^
   7 errors generated.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 33043 bytes --]

Re: [PATCH mptcp-next 0/5] mptcp: add SOL_MPTCP getsockopt support

[Paolo Abeni]

Hello Florian,
On Wed, 2021-08-11 at 15:15 +0200, Florian Westphal wrote:
> This adds the MPTCP_INFO, MPTCP_TCPINFO and MPTCP_SUBFLOW_ADDRS
> mptcp getsockopt optnames.
> 
> MPTCP_INFO exposes the mptcp_info struct as an alternative to the
> existing netlink diag interface.
> 
> MPTCP_TCPINFO exposes the tcp_info struct.
> Unlike SOL_TCP/TCP_INFO, this returns one struct for each active
> subflow.
> 
> MPTCP_SUBFLOW_ADDRS allows userspace to discover the ip addresses/ports
> used by the local and remote endpoints, one for each active tcp subflow.
> 
> MPTCP_TCPINFO and MPTCP_SUBFLOW_ADDRS share the same meta-header that
> needs to be pre-filled by userspace with the size of the data structures
> it expects.  This is done to allow extension of the involved structs
> later on, without breaking backwards compatibility.
> 
> The meta-structure can also be used to discover the required space
> to obtain all information, as kernel will fill in the number of
> active subflows even if there is not enough room for the requested info
> itself.
> 
> More information is available in the individual patches.
> Last patch adds test cases for the three optnames.
> 
> Florian Westphal (5):
>   mptcp: add new mptcp_fill_diag helper
>   mptcp: add MPTCP_INFO getsockopt
>   mptcp: add MPTCP_TCPINFO getsockopt support
>   mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support
>   selftests: mptcp: add mptcp getsockopt test cases
> 
>  include/linux/socket.h                        |   1 +
>  include/net/mptcp.h                           |   4 +
>  include/uapi/linux/mptcp.h                    |  29 +
>  net/mptcp/mptcp_diag.c                        |  26 +-
>  net/mptcp/sockopt.c                           | 258 +++++++++
>  tools/testing/selftests/net/mptcp/Makefile    |   4 +-
>  .../selftests/net/mptcp/mptcp_sockopt.c       | 545 ++++++++++++++++++
>  .../selftests/net/mptcp/mptcp_sockopt.sh      |  31 +-
>  8 files changed, 869 insertions(+), 29 deletions(-)
>  create mode 100644 tools/testing/selftests/net/mptcp/mptcp_sockopt.c

The patches LGTM! I have just a couple of minor curiosity. 

In some helper the argument that carries the option length from user
space is named '_u_optlen', any special reason for that? Encoding the
argument attribute into the user name looks really win32 style from the
early 2000, afaik ;))) [no offense intended!!!]

I don't see how the mptcp_subflow_addrs is going to change/increase the
size with time... do you have some possible ideas/guess?

Anyhow,

Acked-by: Paolo Abeni <pabeni@redhat.com>

Re: [PATCH mptcp-next 0/5] mptcp: add SOL_MPTCP getsockopt support

[Florian Westphal]

Paolo Abeni <pabeni@redhat.com> wrote:
> >  8 files changed, 869 insertions(+), 29 deletions(-)
> >  create mode 100644 tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> 
> The patches LGTM! I have just a couple of minor curiosity. 
> 
> In some helper the argument that carries the option length from user
> space is named '_u_optlen', any special reason for that? Encoding the
> argument attribute into the user name looks really win32 style from the
> early 2000, afaik ;))) [no offense intended!!!]

Ok, I'll rename it to 'int __user *optlen' in v2.

> I don't see how the mptcp_subflow_addrs is going to change/increase the
> size with time... do you have some possible ideas/guess?

No idea. IPv8?  I added struct sockaddr_storage into the union so it will
hopefully be enough but who knows, this API might well live on for decades
and I'd rather have a small back door that allows to increase this if
needed.

Re: [PATCH mptcp-next 5/5] selftests: mptcp: add mptcp getsockopt test cases

[Paolo Abeni]

I'm sorry, I skipped over this patch before sending my previous reply.

On Wed, 2021-08-11 at 15:15 +0200, Florian Westphal wrote:
> Add a test program that retrieves the three info types:
> 1. mptcp meta information
> 2. tcp info for subflow
> 3. subflow endpoint addresses
> 
> For all three rudimentary checks are added.
> 
> 1. Meta information checks that the logical mptcp
>    sequence numbers advance as expected, based on the bytes read
>    (init seq + bytes_received/sent) and the connection state
>    (after close, we should exect 1 extra byte due to FIN).
> 
> 2. TCP info checks the number of bytes sent/received vs.
>    sums of read/write syscall return values.
> 
> 3. Subflow endpoint addresses are checked vs. getsockname/getpeername
>    result.
> 
> Signed-off-by: Florian Westphal <fw@strlen.de>
> ---
>  tools/testing/selftests/net/mptcp/Makefile    |   4 +-
>  .../selftests/net/mptcp/mptcp_sockopt.c       | 545 ++++++++++++++++++
>  .../selftests/net/mptcp/mptcp_sockopt.sh      |  31 +-
>  3 files changed, 576 insertions(+), 4 deletions(-)
>  create mode 100644 tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> 
> diff --git a/tools/testing/selftests/net/mptcp/Makefile b/tools/testing/selftests/net/mptcp/Makefile
> index f1464f09b080..7437929a2109 100644
> --- a/tools/testing/selftests/net/mptcp/Makefile
> +++ b/tools/testing/selftests/net/mptcp/Makefile
> @@ -6,9 +6,9 @@ KSFT_KHDR_INSTALL := 1
>  CFLAGS =  -Wall -Wl,--no-as-needed -O2 -g  -I$(top_srcdir)/usr/include
>  
>  TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh \
> -	      simult_flows.sh mptcp_sockopt.sh
> +	      simult_flows.sh mptcp_sockopt.sh mptcp_sockopt.sh

I guess this change is not needed.

> -TEST_GEN_FILES = mptcp_connect pm_nl_ctl
> +TEST_GEN_FILES = mptcp_connect pm_nl_ctl mptcp_sockopt
>  
>  TEST_FILES := settings
>  
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> new file mode 100644
> index 000000000000..522b394fe011
> --- /dev/null
> +++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> @@ -0,0 +1,545 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#define _GNU_SOURCE
> +
> +#include <assert.h>
> +#include <errno.h>
> +#include <limits.h>
> +#include <string.h>
> +#include <stdarg.h>
> +#include <stdbool.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <strings.h>
> +#include <unistd.h>
> +
> +#include <sys/socket.h>
> +#include <sys/types.h>
> +#include <sys/wait.h>
> +
> +#include <netdb.h>
> +#include <netinet/in.h>
> +
> +#include <linux/tcp.h>
> +
> +static int pf = AF_INET;
> +
> +#ifndef IPPROTO_MPTCP
> +#define IPPROTO_MPTCP 262
> +#endif
> +#ifndef SOL_MPTCP
> +#define SOL_MPTCP 284
> +#endif
> +
> +#ifndef TCP_TCPINFO
> +struct mptcp_subflow_data {
> +	__u32		size_subflow_data;		/* size of this structure in userspace */
> +	__u32		num_subflows;			/* must be 0, set by kernel */
> +	__u32		size_kernel;			/* must be 0, set by kernel */
> +	__u32		size_user;			/* size of one element in data[] */
> +} __attribute__((aligned(8)));
> +
> +struct mptcp_subflow_addrs {
> +	union {
> +		sa_family_t sa_family;
> +		struct sockaddr sa_local;
> +		struct sockaddr_in sin_local;
> +		struct sockaddr_in6 sin6_local;
> +		struct sockaddr_storage ss_local;
> +	};
> +	union {
> +		struct sockaddr sa_remote;
> +		struct sockaddr_in sin_remote;
> +		struct sockaddr_in6 sin6_remote;
> +		struct sockaddr_storage ss_remote;
> +	};
> +};
> +
> +#define MPTCP_INFO		1
> +#define MPTCP_TCPINFO		2
> +#define MPTCP_SUBFLOW_ADDRS	3
> +#endif
> +
> +struct mptcp_info {
> +	__u8	mptcpi_subflows;
> +	__u8	mptcpi_add_addr_signal;
> +	__u8	mptcpi_add_addr_accepted;
> +	__u8	mptcpi_subflows_max;
> +	__u8	mptcpi_add_addr_signal_max;
> +	__u8	mptcpi_add_addr_accepted_max;
> +	__u32	mptcpi_flags;
> +	__u32	mptcpi_token;
> +	__u64	mptcpi_write_seq;
> +	__u64	mptcpi_snd_una;
> +	__u64	mptcpi_rcv_nxt;
> +	__u8	mptcpi_local_addr_used;
> +	__u8	mptcpi_local_addr_max;
> +	__u8	mptcpi_csum_enabled;
> +};
> +
> +enum sockopt_check_flags {
> +	EOF_RECEIVED = 1 << 0,
> +};
> +
> +struct so_state {
> +	struct mptcp_info mi;
> +};
> +
> +static void die_perror(const char *msg)
> +{
> +	perror(msg);
> +	exit(1);
> +}
> +
> +static void die_usage(int r)
> +{
> +	fprintf(stderr, "Usage: mptcp_sockopt [-6]\n");
> +	exit(r);
> +}
> +
> +static void xerror(const char *fmt, ...)
> +{
> +	va_list ap;
> +
> +	va_start(ap, fmt);
> +	vfprintf(stderr, fmt, ap);
> +	va_end(ap);
> +	fputc('\n', stderr);
> +	exit(1);
> +}
> +
> +static const char *getxinfo_strerr(int err)
> +{
> +	if (err == EAI_SYSTEM)
> +		return strerror(errno);
> +
> +	return gai_strerror(err);
> +}
> +
> +static void xgetaddrinfo(const char *node, const char *service,
> +			 const struct addrinfo *hints,
> +			 struct addrinfo **res)
> +{
> +	int err = getaddrinfo(node, service, hints, res);
> +
> +	if (err) {
> +		const char *errstr = getxinfo_strerr(err);
> +
> +		fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n",
> +			node ? node : "", service ? service : "", errstr);
> +		exit(1);
> +	}
> +}
> +
> +static int sock_listen_mptcp(const char * const listenaddr,
> +			     const char * const port)
> +{
> +	int sock;
> +	struct addrinfo hints = {
> +		.ai_protocol = IPPROTO_TCP,
> +		.ai_socktype = SOCK_STREAM,
> +		.ai_flags = AI_PASSIVE | AI_NUMERICHOST
> +	};
> +
> +	hints.ai_family = pf;
> +
> +	struct addrinfo *a, *addr;
> +	int one = 1;
> +
> +	xgetaddrinfo(listenaddr, port, &hints, &addr);
> +	hints.ai_family = pf;
> +
> +	for (a = addr; a; a = a->ai_next) {
> +		sock = socket(a->ai_family, a->ai_socktype, IPPROTO_MPTCP);
> +		if (sock < 0)
> +			continue;
> +
> +		if (-1 == setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one,
> +				     sizeof(one)))
> +			perror("setsockopt");
> +
> +		if (bind(sock, a->ai_addr, a->ai_addrlen) == 0)
> +			break; /* success */
> +
> +		perror("bind");
> +		close(sock);
> +		sock = -1;
> +	}
> +
> +	freeaddrinfo(addr);
> +
> +	if (sock < 0)
> +		xerror("could not create listen socket");
> +
> +	if (listen(sock, 20))
> +		die_perror("listen");
> +
> +	return sock;
> +}
> +
> +static int sock_connect_mptcp(const char * const remoteaddr,
> +			      const char * const port, int proto)
> +{
> +	struct addrinfo hints = {
> +		.ai_protocol = IPPROTO_TCP,
> +		.ai_socktype = SOCK_STREAM,
> +	};
> +	struct addrinfo *a, *addr;
> +	int sock = -1;
> +
> +	hints.ai_family = pf;
> +
> +	xgetaddrinfo(remoteaddr, port, &hints, &addr);
> +	for (a = addr; a; a = a->ai_next) {
> +		sock = socket(a->ai_family, a->ai_socktype, proto);
> +		if (sock < 0)
> +			continue;
> +
> +		if (connect(sock, a->ai_addr, a->ai_addrlen) == 0)
> +			break; /* success */
> +
> +		die_perror("connect");
> +	}
> +
> +	if (sock < 0)
> +		xerror("could not create connect socket");
> +
> +	freeaddrinfo(addr);
> +	return sock;
> +}
> +
> +static void parse_opts(int argc, char **argv)
> +{
> +	int c;
> +
> +	while ((c = getopt(argc, argv, "h6")) != -1) {
> +		switch (c) {
> +		case 'h':
> +			die_usage(0);
> +			break;
> +		case '6':
> +			pf = AF_INET6;
> +			break;
> +		default:
> +			die_usage(1);
> +			break;
> +		}
> +	}
> +}
> +
> +static void do_getsockopt_mptcp_info(struct so_state *s, int fd, size_t r, size_t w, uint32_t flags)
> +{
> +	struct mptcp_info i;
> +	socklen_t olen;
> +	int ret;
> +
> +	olen = sizeof(i);
> +	ret = getsockopt(fd, SOL_MPTCP, MPTCP_INFO, &i, &olen);
> +
> +	if (ret < 0)
> +		die_perror("getsockopt MPTCP_INFO");
> +
> +	assert(olen == sizeof(i));
> +
> +	if (s->mi.mptcpi_write_seq == 0)
> +		s->mi = i;
> +
> +	assert(s->mi.mptcpi_write_seq + w == i.mptcpi_write_seq);
> +
> +	if (flags & EOF_RECEIVED)
> +		r += 1;
> +
> +	assert(s->mi.mptcpi_rcv_nxt + r == i.mptcpi_rcv_nxt);
> +}
> +
> +static void do_getsockopt_tcp_info(int fd, size_t r, size_t w)
> +{
> +	struct my_tcp_info {
> +		struct mptcp_subflow_data d;
> +		struct tcp_info ti[2];
> +	} ti;
> +	socklen_t olen;
> +	int ret;
> +
> +	memset(&ti, 0, sizeof(ti));
> +
> +	ti.d.size_subflow_data = sizeof(struct mptcp_subflow_data);
> +	ti.d.size_user = sizeof(struct tcp_info);
> +	olen = sizeof(ti);
> +
> +	ret = getsockopt(fd, SOL_MPTCP, MPTCP_TCPINFO, &ti, &olen);
> +	if (ret < 0)
> +		die_perror("getsockopt MPTCP_TCPINFO");

Perhaps we could add some test case for weird lens: too short olen,
size_user gretaer then olen, size_user smaller then size_kernel, WDYT?

Thanks!

/P

Re: [PATCH mptcp-next 5/5] selftests: mptcp: add mptcp getsockopt test cases

[Florian Westphal]

Paolo Abeni <pabeni@redhat.com> wrote:
> >  TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh \
> > -	      simult_flows.sh mptcp_sockopt.sh
> > +	      simult_flows.sh mptcp_sockopt.sh mptcp_sockopt.sh
> 
> I guess this change is not needed.

D'oh.  Will remove this hunk.

> > +	ret = getsockopt(fd, SOL_MPTCP, MPTCP_TCPINFO, &ti, &olen);
> > +	if (ret < 0)
> > +		die_perror("getsockopt MPTCP_TCPINFO");
> 
> Perhaps we could add some test case for weird lens: too short olen,
> size_user gretaer then olen, size_user smaller then size_kernel, WDYT?

Sure, will add those.

Re: [PATCH mptcp-next 2/5] mptcp: add MPTCP_INFO getsockopt

[Mat Martineau]

On Wed, 11 Aug 2021, Florian Westphal wrote:

> Its not compatible with mptcp.org kernel one.
>

One really minor comment (since I know you're working on a v2): probably 
best to refer to "multipath-tcp.org", we've been using mptcp.org as a 
shorthand but we don't want to send people there.


Mat

> 1. mptcp.org defines a different 'struct mptcp_info', with embedded
> userspace addresses to store additional data such as endpoint addresses.
>
> 2. Mat Martineau points out the mptcp.org approach doesn't work with
> BPF_CGROUP_RUN_PROG_GETSOCKOPT() which assumes that copying in
> optsize bytes from optval provides all data that got copied to
> userspace.
>
> This provides mptcp_info data for the given mptcp socket.
>
> Userspace sets optlen to the size of the structure it expects.
> The kernel updates it to contain the number of bytes that it copied.
>
> This allows to append more information to the structure later.
>
> Signed-off-by: Florian Westphal <fw@strlen.de>
> ---
> include/linux/socket.h     |  1 +
> include/uapi/linux/mptcp.h |  4 ++++
> net/mptcp/sockopt.c        | 40 +++++++++++++++++++++++++++++++++++++-
> 3 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index fd9ce51582d8..a2326a963232 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -364,6 +364,7 @@ struct ucred {
> #define SOL_KCM		281
> #define SOL_TLS		282
> #define SOL_XDP		283
> +#define SOL_MPTCP	284
>
> /* IPX options */
> #define IPX_TYPE	1
> diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
> index f66038b9551f..c450feba6f9c 100644
> --- a/include/uapi/linux/mptcp.h
> +++ b/include/uapi/linux/mptcp.h
> @@ -4,6 +4,7 @@
>
> #include <linux/const.h>
> #include <linux/types.h>
> +#include <linux/in.h>
>
> #define MPTCP_SUBFLOW_FLAG_MCAP_REM		_BITUL(0)
> #define MPTCP_SUBFLOW_FLAG_MCAP_LOC		_BITUL(1)
> @@ -193,4 +194,7 @@ enum mptcp_event_attr {
> #define MPTCP_RST_EBADPERF	5
> #define MPTCP_RST_EMIDDLEBOX	6
>
> +/* MPTCP socket options */
> +#define MPTCP_INFO 1
> +
> #endif /* _UAPI_MPTCP_H */
> diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> index 54f0d521a399..eba294a071c8 100644
> --- a/net/mptcp/sockopt.c
> +++ b/net/mptcp/sockopt.c
> @@ -673,10 +673,14 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int
> void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
> {
> 	struct sock *sk = &msk->sk.icsk_inet.sk;
> -	bool slow = lock_sock_fast(sk);
> 	u32 flags = 0;
> +	bool slow;
> 	u8 val;
>
> +	memset(info, 0, sizeof(*info));
> +
> +	slow = lock_sock_fast(sk);
> +
> 	info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);
> 	info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);
> 	info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);
> @@ -702,6 +706,27 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
> }
> EXPORT_SYMBOL_GPL(mptcp_diag_fill_info);
>
> +static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, int __user *_u_optlen)
> +{
> +	struct mptcp_info m_info;
> +	int len;
> +
> +	if (get_user(len, _u_optlen))
> +		return -EFAULT;
> +
> +	len = min_t(unsigned int, len, sizeof(struct mptcp_info));
> +
> +	mptcp_diag_fill_info(msk, &m_info);
> +
> +	if (put_user(len, _u_optlen))
> +		return -EFAULT;
> +
> +	if (copy_to_user(optval, &m_info, len))
> +		return -EFAULT;
> +
> +	return 0;
> +}
> +
> static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
> 				    char __user *optval, int __user *optlen)
> {
> @@ -716,6 +741,17 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
> 	return -EOPNOTSUPP;
> }
>
> +static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname,
> +				      char __user *optval, int __user *optlen)
> +{
> +	switch (optname) {
> +	case MPTCP_INFO:
> +		return mptcp_getsockopt_info(msk, optval, optlen);
> +	}
> +
> +	return -EOPNOTSUPP;
> +}
> +
> int mptcp_getsockopt(struct sock *sk, int level, int optname,
> 		     char __user *optval, int __user *option)
> {
> @@ -738,6 +774,8 @@ int mptcp_getsockopt(struct sock *sk, int level, int optname,
>
> 	if (level == SOL_TCP)
> 		return mptcp_getsockopt_sol_tcp(msk, optname, optval, option);
> +	if (level == SOL_MPTCP)
> +		return mptcp_getsockopt_sol_mptcp(msk, optname, optval, option);
> 	return -EOPNOTSUPP;
> }
>
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel

Re: [PATCH mptcp-next 3/5] mptcp: add MPTCP_TCPINFO getsockopt support

[Mat Martineau]

On Wed, 11 Aug 2021, Florian Westphal wrote:

> diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> index eba294a071c8..ac8e6823db4f 100644
> --- a/net/mptcp/sockopt.c
> +++ b/net/mptcp/sockopt.c
> @@ -723,6 +723,96 @@ static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, in
>
> 	if (copy_to_user(optval, &m_info, len))
> 		return -EFAULT;
> +	return 0;
> +}
> +
> +static int mptcp_get_subflow_data(struct mptcp_subflow_data *sfd,
> +				  char __user *optval, int __user *_u_optlen)
> +{
> +#define MIN_INFO_OPTLEN_SIZE	16

This caught my eye on my first quick review pass, I'm not accustomed to 
seeing inline defines like this in the kernel unless it's part of some 
macro magic. The style guide / checkpatch don't say anything, so I'll just 
suggest it would fit better outside the function scope (but no big deal).


For the rest of the patch set, Paolo already covered the expanded test 
cases, so I'll continue with a more in-depth review when you post v2. 
This iteration of the API is looking like the right direction to me.


Thanks,

Mat


> +	int len, copylen;
> +
> +	if (get_user(len, _u_optlen))
> +		return -EFAULT;
> +
> +	if (len <= MIN_INFO_OPTLEN_SIZE)
> +		return -EINVAL;
> +
> +	memset(sfd, 0, sizeof(*sfd));
> +
> +	copylen = min_t(unsigned int, len, sizeof(*sfd));
> +	if (copy_from_user(sfd, optval, copylen))
> +		return -EFAULT;
> +
> +	/* size_subflow_data is u32, but len is signed */
> +	if (sfd->size_subflow_data > INT_MAX ||
> +	    sfd->size_user > INT_MAX)
> +		return -EINVAL;
> +
> +	if (sfd->size_subflow_data < MIN_INFO_OPTLEN_SIZE ||
> +	    sfd->size_subflow_data > len)
> +		return -EINVAL;
> +
> +	if (sfd->num_subflows || sfd->size_kernel)
> +		return -EINVAL;
> +
> +	return len - sfd->size_subflow_data;
> +}

--
Mat Martineau
Intel

Re: [PATCH mptcp-next 3/5] mptcp: add MPTCP_TCPINFO getsockopt support

[Florian Westphal]

Mat Martineau <mathew.j.martineau@linux.intel.com> wrote:
> 
> 
> On Wed, 11 Aug 2021, Florian Westphal wrote:
> 
> > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> > index eba294a071c8..ac8e6823db4f 100644
> > --- a/net/mptcp/sockopt.c
> > +++ b/net/mptcp/sockopt.c
> > @@ -723,6 +723,96 @@ static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, in
> > 
> > 	if (copy_to_user(optval, &m_info, len))
> > 		return -EFAULT;
> > +	return 0;
> > +}
> > +
> > +static int mptcp_get_subflow_data(struct mptcp_subflow_data *sfd,
> > +				  char __user *optval, int __user *_u_optlen)
> > +{
> > +#define MIN_INFO_OPTLEN_SIZE	16
> 
> This caught my eye on my first quick review pass, I'm not accustomed to
> seeing inline defines like this in the kernel unless it's part of some macro
> magic. The style guide / checkpatch don't say anything, so I'll just suggest
> it would fit better outside the function scope (but no big deal).

An alternative would be to use 'sizeof struct mptcp_subflow_data' here
and change that structure a bit.

Instead of storing the size, add a 'version/flags' field.

That would also allow to extend the structure later: kernel would
expose a 'struct mptcp_subflow_data_v2' or similar if the need would
arise and userspace would tell kernel the size in indirect fashion by
setting a special 'v2 enabled' field.