Commit 4b15121d authored by Amery Hung's avatar Amery Hung Committed by Martin KaFai Lau
Browse files

libbpf: Support creating and destroying qdisc 



Extend struct bpf_tc_hook with handle, qdisc name and a new attach type,
BPF_TC_QDISC, to allow users to add or remove any qdisc specified in
addition to clsact.

Signed-off-by: default avatarAmery Hung <amery.hung@bytedance.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-8-ameryhung@gmail.com
parent e582778f

tools/lib/bpf/libbpf.h

+4 −1
Original line number Diff line number Diff line
@@ -1283,6 +1283,7 @@ enum bpf_tc_attach_point { 
	BPF_TC_INGRESS = 1 << 0,

	BPF_TC_EGRESS  = 1 << 1,

	BPF_TC_CUSTOM  = 1 << 2,

	BPF_TC_QDISC   = 1 << 3,

};



#define BPF_TC_PARENT(a, b) 	\
@@ -1297,9 +1298,11 @@ struct bpf_tc_hook { 
	int ifindex;

	enum bpf_tc_attach_point attach_point;

	__u32 parent;

	__u32 handle;

	const char *qdisc;

	size_t :0;

};

#define bpf_tc_hook__last_field parent

#define bpf_tc_hook__last_field qdisc



struct bpf_tc_opts {

	size_t sz;

tools/lib/bpf/netlink.c

+17 −3
Original line number Diff line number Diff line
@@ -529,9 +529,9 @@ int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id) 
}





typedef int (*qdisc_config_t)(struct libbpf_nla_req *req);

typedef int (*qdisc_config_t)(struct libbpf_nla_req *req, const struct bpf_tc_hook *hook);



static int clsact_config(struct libbpf_nla_req *req)

static int clsact_config(struct libbpf_nla_req *req, const struct bpf_tc_hook *hook)

{

	req->tc.tcm_parent = TC_H_CLSACT;

	req->tc.tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0);
@@ -539,6 +539,16 @@ static int clsact_config(struct libbpf_nla_req *req) 
	return nlattr_add(req, TCA_KIND, "clsact", sizeof("clsact"));

}



static int qdisc_config(struct libbpf_nla_req *req, const struct bpf_tc_hook *hook)

{

	const char *qdisc = OPTS_GET(hook, qdisc, NULL);



	req->tc.tcm_parent = OPTS_GET(hook, parent, TC_H_ROOT);

	req->tc.tcm_handle = OPTS_GET(hook, handle, 0);



	return nlattr_add(req, TCA_KIND, qdisc, strlen(qdisc) + 1);

}



static int attach_point_to_config(struct bpf_tc_hook *hook,

				  qdisc_config_t *config)

{
@@ -552,6 +562,9 @@ static int attach_point_to_config(struct bpf_tc_hook *hook, 
		return 0;

	case BPF_TC_CUSTOM:

		return -EOPNOTSUPP;

	case BPF_TC_QDISC:

		*config = &qdisc_config;

		return 0;

	default:

		return -EINVAL;

	}
@@ -596,7 +609,7 @@ static int tc_qdisc_modify(struct bpf_tc_hook *hook, int cmd, int flags) 
	req.tc.tcm_family  = AF_UNSPEC;

	req.tc.tcm_ifindex = OPTS_GET(hook, ifindex, 0);



	ret = config(&req);

	ret = config(&req, hook);

	if (ret < 0)

		return ret;
@@ -639,6 +652,7 @@ int bpf_tc_hook_destroy(struct bpf_tc_hook *hook) 
	case BPF_TC_INGRESS:

	case BPF_TC_EGRESS:

		return libbpf_err(__bpf_tc_detach(hook, NULL, true));

	case BPF_TC_QDISC:

	case BPF_TC_INGRESS | BPF_TC_EGRESS:

		return libbpf_err(tc_qdisc_delete(hook));

	case BPF_TC_CUSTOM: