Files
linux/include/uapi/linux
Florian Westphal c11c5906bc mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support
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 {
		__kernel_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.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-18 14:20:01 +01:00
..
2021-01-25 18:44:44 +01:00
2020-05-28 11:22:14 +02:00
2021-08-17 11:47:53 -04:00
2020-12-28 14:21:31 +00:00
2019-12-18 18:07:31 +01:00
2021-02-09 10:58:19 +01:00
2021-06-10 20:59:05 -04:00
2020-08-12 10:58:00 -07:00
2019-03-07 18:32:01 -08:00
2020-10-09 12:47:02 -06:00
2021-08-23 13:19:09 +02:00
2021-08-23 13:19:09 +02:00
2019-10-09 22:31:14 -04:00
2019-09-25 17:51:39 -07:00
2019-08-02 14:44:02 +10:00
2021-08-10 13:32:40 -04:00
2020-07-19 19:20:22 -07:00
2020-06-24 21:34:11 +02:00
2020-05-14 16:44:25 +02:00
2019-03-27 13:30:07 -07:00
2018-06-18 15:11:53 +10:00
2021-02-08 13:01:24 +01:00
2021-06-03 15:31:34 -07:00
2018-09-05 22:27:11 -07:00
2020-07-13 15:32:56 -07:00
2020-04-20 12:43:24 -07:00
2021-02-26 09:41:03 -08:00
2021-05-21 15:03:50 +02:00
2020-05-21 08:20:35 -06:00
2021-03-10 09:34:06 +01:00
2021-07-29 15:06:50 +01:00
2020-08-18 15:44:44 +02:00
2021-07-06 10:37:46 -05:00
2019-10-02 20:32:27 -06:00
2019-01-22 10:21:45 +01:00
2019-07-30 20:34:34 +02:00
2018-03-20 03:17:41 +02:00
2020-03-29 22:30:57 -07:00
2021-01-16 23:19:26 +01:00
2021-03-10 09:34:06 +01:00
2021-06-23 12:56:08 -07:00
2019-12-18 18:07:31 +01:00
2021-01-07 16:17:32 +01:00
2021-09-16 14:36:26 +01:00
2018-09-03 13:29:38 +02:00
2019-12-09 09:59:07 +01:00
2020-03-29 23:29:08 +02:00
2018-02-06 18:32:44 -08:00
2020-10-23 11:55:28 -04:00
2020-10-23 11:55:28 -04:00
2019-08-01 21:49:46 +02:00
2021-06-12 13:16:45 -07:00
2020-07-13 15:32:56 -07:00
2021-07-29 08:04:10 +02:00