Commit 6963c508 authored by Gregory Detal's avatar Gregory Detal Committed by Jakub Kicinski
Browse files

mptcp: only allow set existing scheduler for net.mptcp.scheduler 



The current behavior is to accept any strings as inputs, this results in
an inconsistent result where an unexisting scheduler can be set:

  # sysctl -w net.mptcp.scheduler=notdefault
  net.mptcp.scheduler = notdefault

This patch changes this behavior by checking for existing scheduler
before accepting the input.

Fixes: e3b2870b ("mptcp: add a new sysctl scheduler")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGregory Detal <gregory.detal@gmail.com>
Reviewed-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Tested-by: default avatarGeliang Tang <geliang@kernel.org>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240506-upstream-net-20240506-mptcp-sched-exist-v1-1-2ed1529e521e@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 19e35f24

net/mptcp/ctrl.c

+38 −1
Original line number Diff line number Diff line
@@ -96,6 +96,43 @@ static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet) 
}



#ifdef CONFIG_SYSCTL

static int mptcp_set_scheduler(const struct net *net, const char *name)

{

	struct mptcp_pernet *pernet = mptcp_get_pernet(net);

	struct mptcp_sched_ops *sched;

	int ret = 0;



	rcu_read_lock();

	sched = mptcp_sched_find(name);

	if (sched)

		strscpy(pernet->scheduler, name, MPTCP_SCHED_NAME_MAX);

	else

		ret = -ENOENT;

	rcu_read_unlock();



	return ret;

}



static int proc_scheduler(struct ctl_table *ctl, int write,

			  void *buffer, size_t *lenp, loff_t *ppos)

{

	const struct net *net = current->nsproxy->net_ns;

	char val[MPTCP_SCHED_NAME_MAX];

	struct ctl_table tbl = {

		.data = val,

		.maxlen = MPTCP_SCHED_NAME_MAX,

	};

	int ret;



	strscpy(val, mptcp_get_scheduler(net), MPTCP_SCHED_NAME_MAX);



	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);

	if (write && ret == 0)

		ret = mptcp_set_scheduler(net, val);



	return ret;

}



static struct ctl_table mptcp_sysctl_table[] = {

	{

		.procname = "enabled",
@@ -148,7 +185,7 @@ static struct ctl_table mptcp_sysctl_table[] = { 
		.procname = "scheduler",

		.maxlen	= MPTCP_SCHED_NAME_MAX,

		.mode = 0644,

		.proc_handler = proc_dostring,

		.proc_handler = proc_scheduler,

	},

	{

		.procname = "close_timeout",