Commit 73c59d6f authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-sched-load-modules-via-alias' 

Michal Koutný says:

====================
net/sched: Load modules via alias

These modules may be loaded lazily without user's awareness and
control. Add respective aliases to modules and request them under these
aliases so that modprobe's blacklisting mechanism (through aliases)
works for them. (The same pattern exists e.g. for filesystem
modules.)

For example (before the change):
  $ tc filter add dev lo parent 10: protocol ip prio 10 handle 1: cgroup
  # cls_cgroup module is loaded despite a `blacklist cls_cgroup` entry
  # in /etc/modprobe.d/*.conf

After the change:
  $ tc filter add dev lo parent 10: protocol ip prio 10 handle 1: cgroup
  Error: TC classifier not found.
  We have an error talking to the kernel
  # explicit/acknowledged (privileged) action is needed
  $ modprobe cls_cgroup
  # blacklist entry won't apply to this direct modprobe, module is
  # loaded with awareness

A considered alternative was invoking `modprobe -b` always from
request_module(), however, dismissed as too intrusive and slightly
confusing in favor of the precedented aliases (the commit 7f78e035
("fs: Limit sys_mount to only request filesystem modules.").

User experience suffers in both alternatives. Its improvement is
orthogonal to blacklist honoring.

v1: https://lore.kernel.org/r/20231121175640.9981-1-mkoutny@suse.com
v2 https://lore.kernel.org/r/20231206192752.18989-1-mkoutny@suse.com
v3 https://lore.kernel.org/r/20240112180646.13232-1-mkoutny@suse.com
v4 https://lore.kernel.org/r/20240123135242.11430-1-mkoutny@suse.com



Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
====================

Link: https://lore.kernel.org/r/20240201130943.19536-1-mkoutny@suse.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents d81c0792 6cff0158

include/net/act_api.h

+2 −0
Original line number Diff line number Diff line
@@ -201,6 +201,8 @@ int tcf_idr_release(struct tc_action *a, bool bind); 
int tcf_register_action(struct tc_action_ops *a, struct pernet_operations *ops);

int tcf_unregister_action(struct tc_action_ops *a,

			  struct pernet_operations *ops);

#define NET_ACT_ALIAS_PREFIX "net-act-"

#define MODULE_ALIAS_NET_ACT(kind)	MODULE_ALIAS(NET_ACT_ALIAS_PREFIX kind)

int tcf_action_destroy(struct tc_action *actions[], int bind);

int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,

		    int nr_actions, struct tcf_result *res);

include/net/pkt_cls.h

+2 −0
Original line number Diff line number Diff line
@@ -24,6 +24,8 @@ struct tcf_walker { 


int register_tcf_proto_ops(struct tcf_proto_ops *ops);

void unregister_tcf_proto_ops(struct tcf_proto_ops *ops);

#define NET_CLS_ALIAS_PREFIX "net-cls-"

#define MODULE_ALIAS_NET_CLS(kind)	MODULE_ALIAS(NET_CLS_ALIAS_PREFIX kind)



struct tcf_block_ext_info {

	enum flow_block_binder_type binder_type;

include/net/pkt_sched.h

+2 −0
Original line number Diff line number Diff line
@@ -100,6 +100,8 @@ struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops, 


int register_qdisc(struct Qdisc_ops *qops);

void unregister_qdisc(struct Qdisc_ops *qops);

#define NET_SCH_ALIAS_PREFIX "net-sch-"

#define MODULE_ALIAS_NET_SCH(id)	MODULE_ALIAS(NET_SCH_ALIAS_PREFIX id)

void qdisc_get_default(char *id, size_t len);

int qdisc_set_default(const char *id);

net/sched/act_api.c

+1 −1
Original line number Diff line number Diff line
@@ -1363,7 +1363,7 @@ struct tc_action_ops *tc_action_load_ops(struct nlattr *nla, u32 flags, 


		if (rtnl_held)

			rtnl_unlock();

		request_module("act_%s", act_name);

		request_module(NET_ACT_ALIAS_PREFIX "%s", act_name);

		if (rtnl_held)

			rtnl_lock();

net/sched/act_bpf.c

+1 −0
Original line number Diff line number Diff line
@@ -401,6 +401,7 @@ static struct tc_action_ops act_bpf_ops __read_mostly = { 
	.init		=	tcf_bpf_init,

	.size		=	sizeof(struct tcf_bpf),

};

MODULE_ALIAS_NET_ACT("bpf");



static __net_init int bpf_init_net(struct net *net)

{