Skip to content

Commit

Permalink
Merge branch 'mptcp-subflow-disconnected'
Browse files Browse the repository at this point in the history 
Mat Martineau says:

====================
MPTCP: Allow initial subflow to be disconnected

An MPTCP connection is aggregated from multiple TCP subflows, and can
involve multiple IP addresses on either peer. The addresses used in the
initial subflow connection are assigned address id 0 on each side of the
link. More addresses can be added and shared with the peer using address
IDs of 1 or larger. MPTCP in Linux shares non-zero address IDs across
all MPTCP connections in a net namespace, which allows userspace to
manage subflow connections across a number of sockets. However, this
makes the address with id 0 a special case, since the IP address
associated with id 0 is potentially different for each socket.

This patch set allows the initial subflow to be disconnected when
userspace specifies an address to remove using both id 0 and an IP
address, or when the peer sends an RM_ADDR for id 0.

Patches 1 and 3 implement the change for requests from the peer and
userspace, respectively.

Patch 2 consolidates some code for disconnecting subflows.

Patches 4-6 update the self tests to cover removal of subflows using
address id 0.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
David S. Miller committed Mar 31, 2021
2 parents b812865 + 5e287fe commit 65550f0
Show file tree
Hide file tree
Showing 4 changed files with 143 additions and 61 deletions.
129 changes: 76 additions & 53 deletions net/mptcp/pm_netlink.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -586,47 +586,68 @@ int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
return -EINVAL;
}

static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
const struct mptcp_rm_list *rm_list,
enum linux_mptcp_mib_field rm_type)
{
struct mptcp_subflow_context *subflow, *tmp;
struct sock *sk = (struct sock *)msk;
u8 i;

pr_debug("address rm_list_nr %d", msk->pm.rm_list_rx.nr);
pr_debug("%s rm_list_nr %d",
rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);

msk_owned_by_me(msk);

if (!msk->pm.rm_list_rx.nr)
if (!rm_list->nr)
return;

if (list_empty(&msk->conn_list))
return;

for (i = 0; i < msk->pm.rm_list_rx.nr; i++) {
for (i = 0; i < rm_list->nr; i++) {
list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
u8 id = subflow->local_id;

if (msk->pm.rm_list_rx.ids[i] != subflow->remote_id)
if (rm_type == MPTCP_MIB_RMADDR)
id = subflow->remote_id;

if (rm_list->ids[i] != id)
continue;

pr_debug(" -> address rm_list_ids[%d]=%u", i, msk->pm.rm_list_rx.ids[i]);
pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u",
rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
i, rm_list->ids[i], subflow->local_id, subflow->remote_id);
spin_unlock_bh(&msk->pm.lock);
mptcp_subflow_shutdown(sk, ssk, how);
mptcp_close_ssk(sk, ssk, subflow);
spin_lock_bh(&msk->pm.lock);

msk->pm.add_addr_accepted--;
if (rm_type == MPTCP_MIB_RMADDR) {
msk->pm.add_addr_accepted--;
WRITE_ONCE(msk->pm.accept_addr, true);
} else if (rm_type == MPTCP_MIB_RMSUBFLOW) {
msk->pm.local_addr_used--;
}
msk->pm.subflows--;
WRITE_ONCE(msk->pm.accept_addr, true);

__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMADDR);

break;
__MPTCP_INC_STATS(sock_net(sk), rm_type);
}
}
}

static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
{
mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
}

void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
const struct mptcp_rm_list *rm_list)
{
mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
}

void mptcp_pm_nl_work(struct mptcp_sock *msk)
{
struct mptcp_pm_data *pm = &msk->pm;
Expand Down Expand Up @@ -660,47 +681,6 @@ void mptcp_pm_nl_work(struct mptcp_sock *msk)
spin_unlock_bh(&msk->pm.lock);
}

void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
const struct mptcp_rm_list *rm_list)
{
struct mptcp_subflow_context *subflow, *tmp;
struct sock *sk = (struct sock *)msk;
u8 i;

pr_debug("subflow rm_list_nr %d", rm_list->nr);

msk_owned_by_me(msk);

if (!rm_list->nr)
return;

if (list_empty(&msk->conn_list))
return;

for (i = 0; i < rm_list->nr; i++) {
list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
int how = RCV_SHUTDOWN | SEND_SHUTDOWN;

if (rm_list->ids[i] != subflow->local_id)
continue;

pr_debug(" -> subflow rm_list_ids[%d]=%u", i, rm_list->ids[i]);
spin_unlock_bh(&msk->pm.lock);
mptcp_subflow_shutdown(sk, ssk, how);
mptcp_close_ssk(sk, ssk, subflow);
spin_lock_bh(&msk->pm.lock);

msk->pm.local_addr_used--;
msk->pm.subflows--;

__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);

break;
}
}
}

static bool address_use_port(struct mptcp_pm_addr_entry *entry)
{
return (entry->addr.flags &
Expand Down Expand Up @@ -1176,6 +1156,41 @@ static void mptcp_pm_free_addr_entry(struct mptcp_pm_addr_entry *entry)
}
}

static int mptcp_nl_remove_id_zero_address(struct net *net,
struct mptcp_addr_info *addr)
{
struct mptcp_rm_list list = { .nr = 0 };
long s_slot = 0, s_num = 0;
struct mptcp_sock *msk;

list.ids[list.nr++] = 0;

while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
struct sock *sk = (struct sock *)msk;
struct mptcp_addr_info msk_local;

if (list_empty(&msk->conn_list))
goto next;

local_address((struct sock_common *)msk, &msk_local);
if (!addresses_equal(&msk_local, addr, addr->port))
goto next;

lock_sock(sk);
spin_lock_bh(&msk->pm.lock);
mptcp_pm_remove_addr(msk, &list);
mptcp_pm_nl_rm_subflow_received(msk, &list);
spin_unlock_bh(&msk->pm.lock);
release_sock(sk);

next:
sock_put(sk);
cond_resched();
}

return 0;
}

static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
Expand All @@ -1188,6 +1203,14 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
if (ret < 0)
return ret;

/* the zero id address is special: the first address used by the msk
* always gets such an id, so different subflows can have different zero
* id addresses. Additionally zero id is not accounted for in id_bitmap.
* Let's use an 'mptcp_rm_list' instead of the common remove code.
*/
if (addr.addr.id == 0)
return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);

spin_lock_bh(&pernet->lock);
entry = __lookup_addr_by_id(pernet, addr.addr.id);
if (!entry) {
Expand Down
35 changes: 33 additions & 2 deletions tools/testing/selftests/net/mptcp/mptcp_join.sh
View file
Original file line number Diff line number Diff line change
Expand Up @@ -294,9 +294,12 @@ do_transfer()
let id+=1
done
fi
else
elif [ $rm_nr_ns1 -eq 8 ]; then
sleep 1
ip netns exec ${listener_ns} ./pm_nl_ctl flush
elif [ $rm_nr_ns1 -eq 9 ]; then
sleep 1
ip netns exec ${listener_ns} ./pm_nl_ctl del 0 ${connect_addr}
fi
fi

Expand Down Expand Up @@ -333,9 +336,18 @@ do_transfer()
let id+=1
done
fi
else
elif [ $rm_nr_ns2 -eq 8 ]; then
sleep 1
ip netns exec ${connector_ns} ./pm_nl_ctl flush
elif [ $rm_nr_ns2 -eq 9 ]; then
local addr
if is_v6 "${connect_addr}"; then
addr="dead:beef:1::2"
else
addr="10.0.1.2"
fi
sleep 1
ip netns exec ${connector_ns} ./pm_nl_ctl del 0 $addr
fi
fi

Expand Down Expand Up @@ -988,6 +1000,25 @@ remove_tests()
chk_join_nr "flush invalid addresses" 1 1 1
chk_add_nr 3 3
chk_rm_nr 3 1 invert

# remove id 0 subflow
reset
ip netns exec $ns1 ./pm_nl_ctl limits 0 1
ip netns exec $ns2 ./pm_nl_ctl limits 0 1
ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
run_tests $ns1 $ns2 10.0.1.1 0 0 -9 slow
chk_join_nr "remove id 0 subflow" 1 1 1
chk_rm_nr 1 1

# remove id 0 address
reset
ip netns exec $ns1 ./pm_nl_ctl limits 0 1
ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
ip netns exec $ns2 ./pm_nl_ctl limits 1 1
run_tests $ns1 $ns2 10.0.1.1 0 -9 0 slow
chk_join_nr "remove id 0 address" 1 1 1
chk_add_nr 1 1
chk_rm_nr 1 1 invert
}

add_tests()
Expand Down
6 changes: 3 additions & 3 deletions tools/testing/selftests/net/mptcp/pm_netlink.sh
View file
Original file line number Diff line number Diff line change
Expand Up @@ -100,12 +100,12 @@ done
check "ip netns exec $ns1 ./pm_nl_ctl get 9" "id 9 flags signal 10.0.1.9" "hard addr limit"
check "ip netns exec $ns1 ./pm_nl_ctl get 10" "" "above hard addr limit"

for i in `seq 9 256`; do
ip netns exec $ns1 ./pm_nl_ctl del 9
for i in `seq 10 255`; do
ip netns exec $ns1 ./pm_nl_ctl add 10.0.0.9 id $i
ip netns exec $ns1 ./pm_nl_ctl del $i
ip netns exec $ns1 ./pm_nl_ctl add 10.0.0.9 id $((i+1))
done
check "ip netns exec $ns1 ./pm_nl_ctl dump" "id 1 flags 10.0.1.1
id 2 flags 10.0.0.9
id 3 flags signal,backup 10.0.1.3
id 4 flags signal 10.0.1.4
id 5 flags signal 10.0.1.5
Expand Down
34 changes: 31 additions & 3 deletions tools/testing/selftests/net/mptcp/pm_nl_ctl.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,7 @@ static void syntax(char *argv[])
{
fprintf(stderr, "%s add|get|set|del|flush|dump|accept [<args>]\n", argv[0]);
fprintf(stderr, "\tadd [flags signal|subflow|backup] [id <nr>] [dev <name>] <ip>\n");
fprintf(stderr, "\tdel <id>\n");
fprintf(stderr, "\tdel <id> [<ip>]\n");
fprintf(stderr, "\tget <id>\n");
fprintf(stderr, "\tset <ip> [flags backup|nobackup]\n");
fprintf(stderr, "\tflush\n");
Expand Down Expand Up @@ -301,6 +301,7 @@ int del_addr(int fd, int pm_family, int argc, char *argv[])
1024];
struct rtattr *rta, *nest;
struct nlmsghdr *nh;
u_int16_t family;
int nest_start;
u_int8_t id;
int off = 0;
Expand All @@ -310,11 +311,14 @@ int del_addr(int fd, int pm_family, int argc, char *argv[])
off = init_genl_req(data, pm_family, MPTCP_PM_CMD_DEL_ADDR,
MPTCP_PM_VER);

/* the only argument is the address id */
if (argc != 3)
/* the only argument is the address id (nonzero) */
if (argc != 3 && argc != 4)
syntax(argv);

id = atoi(argv[2]);
/* zero id with the IP address */
if (!id && argc != 4)
syntax(argv);

nest_start = off;
nest = (void *)(data + off);
Expand All @@ -328,6 +332,30 @@ int del_addr(int fd, int pm_family, int argc, char *argv[])
rta->rta_len = RTA_LENGTH(1);
memcpy(RTA_DATA(rta), &id, 1);
off += NLMSG_ALIGN(rta->rta_len);

if (!id) {
/* addr data */
rta = (void *)(data + off);
if (inet_pton(AF_INET, argv[3], RTA_DATA(rta))) {
family = AF_INET;
rta->rta_type = MPTCP_PM_ADDR_ATTR_ADDR4;
rta->rta_len = RTA_LENGTH(4);
} else if (inet_pton(AF_INET6, argv[3], RTA_DATA(rta))) {
family = AF_INET6;
rta->rta_type = MPTCP_PM_ADDR_ATTR_ADDR6;
rta->rta_len = RTA_LENGTH(16);
} else {
error(1, errno, "can't parse ip %s", argv[3]);
}
off += NLMSG_ALIGN(rta->rta_len);

/* family */
rta = (void *)(data + off);
rta->rta_type = MPTCP_PM_ADDR_ATTR_FAMILY;
rta->rta_len = RTA_LENGTH(2);
memcpy(RTA_DATA(rta), &family, 2);
off += NLMSG_ALIGN(rta->rta_len);
}
nest->rta_len = off - nest_start;

do_nl_req(fd, nh, off, 0);
Expand Down

0 comments on commit 65550f0

Please sign in to comment.