[mirror_ubuntu-eoan-kernel.git] / tools / lib / bpf / netlink.c

// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2018 Facebook */

#include <stdlib.h>
#include <memory.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#include <errno.h>
#include <time.h>

#include "bpf.h"
#include "libbpf.h"
#include "nlattr.h"

#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif

typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
			      void *cookie);

struct xdp_id_md {
	int ifindex;
	__u32 flags;
	__u32 id;
};

int libbpf_netlink_open(__u32 *nl_pid)
{
	struct sockaddr_nl sa;
	socklen_t addrlen;
	int one = 1, ret;
	int sock;

	memset(&sa, 0, sizeof(sa));
	sa.nl_family = AF_NETLINK;

	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	if (sock < 0)
		return -errno;

	if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
		       &one, sizeof(one)) < 0) {
		fprintf(stderr, "Netlink error reporting not supported\n");
	}

	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
		ret = -errno;
		goto cleanup;
	}

	addrlen = sizeof(sa);
	if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
		ret = -errno;
		goto cleanup;
	}

	if (addrlen != sizeof(sa)) {
		ret = -LIBBPF_ERRNO__INTERNAL;
		goto cleanup;
	}

	*nl_pid = sa.nl_pid;
	return sock;

cleanup:
	close(sock);
	return ret;
}

static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq,
			    __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
			    void *cookie)
{
	bool multipart = true;
	struct nlmsgerr *err;
	struct nlmsghdr *nh;
	char buf[4096];
	int len, ret;

	while (multipart) {
		multipart = false;
		len = recv(sock, buf, sizeof(buf), 0);
		if (len < 0) {
			ret = -errno;
			goto done;
		}

		if (len == 0)
			break;

		for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
		     nh = NLMSG_NEXT(nh, len)) {
			if (nh->nlmsg_pid != nl_pid) {
				ret = -LIBBPF_ERRNO__WRNGPID;
				goto done;
			}
			if (nh->nlmsg_seq != seq) {
				ret = -LIBBPF_ERRNO__INVSEQ;
				goto done;
			}
			if (nh->nlmsg_flags & NLM_F_MULTI)
				multipart = true;
			switch (nh->nlmsg_type) {
			case NLMSG_ERROR:
				err = (struct nlmsgerr *)NLMSG_DATA(nh);
				if (!err->error)
					continue;
				ret = err->error;
				libbpf_nla_dump_errormsg(nh);
				goto done;
			case NLMSG_DONE:
				return 0;
			default:
				break;
			}
			if (_fn) {
				ret = _fn(nh, fn, cookie);
				if (ret)
					return ret;
			}
		}
	}
	ret = 0;
done:
	return ret;
}

int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
{
	int sock, seq = 0, ret;
	struct nlattr *nla, *nla_xdp;
	struct {
		struct nlmsghdr  nh;
		struct ifinfomsg ifinfo;
		char             attrbuf[64];
	} req;
	__u32 nl_pid;

	sock = libbpf_netlink_open(&nl_pid);
	if (sock < 0)
		return sock;

	memset(&req, 0, sizeof(req));
	req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
	req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
	req.nh.nlmsg_type = RTM_SETLINK;
	req.nh.nlmsg_pid = 0;
	req.nh.nlmsg_seq = ++seq;
	req.ifinfo.ifi_family = AF_UNSPEC;
	req.ifinfo.ifi_index = ifindex;

	/* started nested attribute for XDP */
	nla = (struct nlattr *)(((char *)&req)
				+ NLMSG_ALIGN(req.nh.nlmsg_len));
	nla->nla_type = NLA_F_NESTED | IFLA_XDP;
	nla->nla_len = NLA_HDRLEN;

	/* add XDP fd */
	nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
	nla_xdp->nla_type = IFLA_XDP_FD;
	nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
	memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
	nla->nla_len += nla_xdp->nla_len;

	/* if user passed in any flags, add those too */
	if (flags) {
		nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
		nla_xdp->nla_type = IFLA_XDP_FLAGS;
		nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
		memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
		nla->nla_len += nla_xdp->nla_len;
	}

	req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);

	if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
		ret = -errno;
		goto cleanup;
	}
	ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL);

cleanup:
	close(sock);
	return ret;
}

static int __dump_link_nlmsg(struct nlmsghdr *nlh,
			     libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
{
	struct nlattr *tb[IFLA_MAX + 1], *attr;
	struct ifinfomsg *ifi = NLMSG_DATA(nlh);
	int len;

	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
	attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
	if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
		return -LIBBPF_ERRNO__NLPARSE;

	return dump_link_nlmsg(cookie, ifi, tb);
}

static unsigned char get_xdp_id_attr(unsigned char mode, __u32 flags)
{
	if (mode != XDP_ATTACHED_MULTI)
		return IFLA_XDP_PROG_ID;
	if (flags & XDP_FLAGS_DRV_MODE)
		return IFLA_XDP_DRV_PROG_ID;
	if (flags & XDP_FLAGS_HW_MODE)
		return IFLA_XDP_HW_PROG_ID;
	if (flags & XDP_FLAGS_SKB_MODE)
		return IFLA_XDP_SKB_PROG_ID;

	return IFLA_XDP_UNSPEC;
}

static int get_xdp_id(void *cookie, void *msg, struct nlattr **tb)
{
	struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
	struct xdp_id_md *xdp_id = cookie;
	struct ifinfomsg *ifinfo = msg;
	unsigned char mode, xdp_attr;
	int ret;

	if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
		return 0;

	if (!tb[IFLA_XDP])
		return 0;

	ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
	if (ret)
		return ret;

	if (!xdp_tb[IFLA_XDP_ATTACHED])
		return 0;

	mode = libbpf_nla_getattr_u8(xdp_tb[IFLA_XDP_ATTACHED]);
	if (mode == XDP_ATTACHED_NONE)
		return 0;

	xdp_attr = get_xdp_id_attr(mode, xdp_id->flags);
	if (!xdp_attr || !xdp_tb[xdp_attr])
		return 0;

	xdp_id->id = libbpf_nla_getattr_u32(xdp_tb[xdp_attr]);

	return 0;
}

int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags)
{
	struct xdp_id_md xdp_id = {};
	int sock, ret;
	__u32 nl_pid;
	__u32 mask;

	if (flags & ~XDP_FLAGS_MASK)
		return -EINVAL;

	/* Check whether the single {HW,DRV,SKB} mode is set */
	flags &= (XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE);
	mask = flags - 1;
	if (flags && flags & mask)
		return -EINVAL;

	sock = libbpf_netlink_open(&nl_pid);
	if (sock < 0)
		return sock;

	xdp_id.ifindex = ifindex;
	xdp_id.flags = flags;

	ret = libbpf_nl_get_link(sock, nl_pid, get_xdp_id, &xdp_id);
	if (!ret)
		*prog_id = xdp_id.id;

	close(sock);
	return ret;
}

int libbpf_nl_get_link(int sock, unsigned int nl_pid,
		       libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
{
	struct {
		struct nlmsghdr nlh;
		struct ifinfomsg ifm;
	} req = {
		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
		.nlh.nlmsg_type = RTM_GETLINK,
		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
		.ifm.ifi_family = AF_PACKET,
	};
	int seq = time(NULL);

	req.nlh.nlmsg_seq = seq;
	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
		return -errno;

	return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
				dump_link_nlmsg, cookie);
}

static int __dump_class_nlmsg(struct nlmsghdr *nlh,
			      libbpf_dump_nlmsg_t dump_class_nlmsg,
			      void *cookie)
{
	struct nlattr *tb[TCA_MAX + 1], *attr;
	struct tcmsg *t = NLMSG_DATA(nlh);
	int len;

	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
	attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
		return -LIBBPF_ERRNO__NLPARSE;

	return dump_class_nlmsg(cookie, t, tb);
}

int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
			libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie)
{
	struct {
		struct nlmsghdr nlh;
		struct tcmsg t;
	} req = {
		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
		.nlh.nlmsg_type = RTM_GETTCLASS,
		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
		.t.tcm_family = AF_UNSPEC,
		.t.tcm_ifindex = ifindex,
	};
	int seq = time(NULL);

	req.nlh.nlmsg_seq = seq;
	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
		return -errno;

	return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
				dump_class_nlmsg, cookie);
}

static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
			      libbpf_dump_nlmsg_t dump_qdisc_nlmsg,
			      void *cookie)
{
	struct nlattr *tb[TCA_MAX + 1], *attr;
	struct tcmsg *t = NLMSG_DATA(nlh);
	int len;

	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
	attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
		return -LIBBPF_ERRNO__NLPARSE;

	return dump_qdisc_nlmsg(cookie, t, tb);
}

int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
			libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
{
	struct {
		struct nlmsghdr nlh;
		struct tcmsg t;
	} req = {
		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
		.nlh.nlmsg_type = RTM_GETQDISC,
		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
		.t.tcm_family = AF_UNSPEC,
		.t.tcm_ifindex = ifindex,
	};
	int seq = time(NULL);

	req.nlh.nlmsg_seq = seq;
	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
		return -errno;

	return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
				dump_qdisc_nlmsg, cookie);
}

static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
			       libbpf_dump_nlmsg_t dump_filter_nlmsg,
			       void *cookie)
{
	struct nlattr *tb[TCA_MAX + 1], *attr;
	struct tcmsg *t = NLMSG_DATA(nlh);
	int len;

	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
	attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
		return -LIBBPF_ERRNO__NLPARSE;

	return dump_filter_nlmsg(cookie, t, tb);
}

int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
			 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie)
{
	struct {
		struct nlmsghdr nlh;
		struct tcmsg t;
	} req = {
		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
		.nlh.nlmsg_type = RTM_GETTFILTER,
		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
		.t.tcm_family = AF_UNSPEC,
		.t.tcm_ifindex = ifindex,
		.t.tcm_parent = handle,
	};
	int seq = time(NULL);

	req.nlh.nlmsg_seq = seq;
	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
		return -errno;

	return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
				dump_filter_nlmsg, cookie);
}
Commit	Line	Data
1bc38b8f	1	// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
f7010770 YS	2	/* Copyright (c) 2018 Facebook */
	3
	4	#include <stdlib.h>
	5	#include <memory.h>
	6	#include <unistd.h>
	7	#include <linux/bpf.h>
	8	#include <linux/rtnetlink.h>
	9	#include <sys/socket.h>
	10	#include <errno.h>
	11	#include <time.h>
	12
	13	#include "bpf.h"
	14	#include "libbpf.h"
	15	#include "nlattr.h"
	16
	17	#ifndef SOL_NETLINK
	18	#define SOL_NETLINK 270
	19	#endif
	20
aae57780	21	typedef int (__dump_nlmsg_t)(struct nlmsghdr nlmsg, libbpf_dump_nlmsg_t,
434fe9d4 AI	22	void *cookie);
434fe9d4 AI	23
50db9f07 MF	24	struct xdp_id_md {
	25	int ifindex;
	26	__u32 flags;
	27	__u32 id;
	28	};
	29
aae57780	30	int libbpf_netlink_open(__u32 *nl_pid)
f7010770 YS	31	{
	32	struct sockaddr_nl sa;
	33	socklen_t addrlen;
	34	int one = 1, ret;
	35	int sock;
	36
	37	memset(&sa, 0, sizeof(sa));
	38	sa.nl_family = AF_NETLINK;
	39
	40	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	41	if (sock < 0)
	42	return -errno;
	43
	44	if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
	45	&one, sizeof(one)) < 0) {
	46	fprintf(stderr, "Netlink error reporting not supported\n");
	47	}
	48
	49	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
	50	ret = -errno;
	51	goto cleanup;
	52	}
	53
	54	addrlen = sizeof(sa);
	55	if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
	56	ret = -errno;
	57	goto cleanup;
	58	}
	59
	60	if (addrlen != sizeof(sa)) {
	61	ret = -LIBBPF_ERRNO__INTERNAL;
	62	goto cleanup;
	63	}
	64
	65	*nl_pid = sa.nl_pid;
	66	return sock;
	67
	68	cleanup:
	69	close(sock);
	70	return ret;
	71	}
	72
36f1678d	73	static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq,
aae57780	74	__dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
36f1678d	75	void *cookie)
f7010770	76	{
9d0b3c1f	77	bool multipart = true;
f7010770 YS	78	struct nlmsgerr *err;
	79	struct nlmsghdr *nh;
	80	char buf[4096];
	81	int len, ret;
	82
9d0b3c1f YS	83	while (multipart) {
9d0b3c1f YS	84	multipart = false;
f7010770 YS	85	len = recv(sock, buf, sizeof(buf), 0);
	86	if (len < 0) {
	87	ret = -errno;
	88	goto done;
	89	}
	90
9d0b3c1f YS	91	if (len == 0)
	92	break;
	93
f7010770 YS	94	for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
	95	nh = NLMSG_NEXT(nh, len)) {
	96	if (nh->nlmsg_pid != nl_pid) {
	97	ret = -LIBBPF_ERRNO__WRNGPID;
	98	goto done;
	99	}
	100	if (nh->nlmsg_seq != seq) {
	101	ret = -LIBBPF_ERRNO__INVSEQ;
	102	goto done;
	103	}
9d0b3c1f YS	104	if (nh->nlmsg_flags & NLM_F_MULTI)
9d0b3c1f YS	105	multipart = true;
f7010770 YS	106	switch (nh->nlmsg_type) {
	107	case NLMSG_ERROR:
	108	err = (struct nlmsgerr *)NLMSG_DATA(nh);
	109	if (!err->error)
	110	continue;
	111	ret = err->error;
f04bc8a4	112	libbpf_nla_dump_errormsg(nh);
f7010770 YS	113	goto done;
	114	case NLMSG_DONE:
	115	return 0;
	116	default:
	117	break;
	118	}
36f1678d YS	119	if (_fn) {
	120	ret = _fn(nh, fn, cookie);
	121	if (ret)
	122	return ret;
	123	}
f7010770 YS	124	}
	125	}
	126	ret = 0;
	127	done:
	128	return ret;
	129	}
	130
	131	int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
	132	{
	133	int sock, seq = 0, ret;
	134	struct nlattr nla, nla_xdp;
	135	struct {
	136	struct nlmsghdr nh;
	137	struct ifinfomsg ifinfo;
	138	char attrbuf[64];
	139	} req;
	140	__u32 nl_pid;
	141
aae57780	142	sock = libbpf_netlink_open(&nl_pid);
f7010770 YS	143	if (sock < 0)
	144	return sock;
	145
	146	memset(&req, 0, sizeof(req));
	147	req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
	148	req.nh.nlmsg_flags = NLM_F_REQUEST \| NLM_F_ACK;
	149	req.nh.nlmsg_type = RTM_SETLINK;
	150	req.nh.nlmsg_pid = 0;
	151	req.nh.nlmsg_seq = ++seq;
	152	req.ifinfo.ifi_family = AF_UNSPEC;
	153	req.ifinfo.ifi_index = ifindex;
	154
	155	/* started nested attribute for XDP */
	156	nla = (struct nlattr )(((char )&req)
	157	+ NLMSG_ALIGN(req.nh.nlmsg_len));
	158	nla->nla_type = NLA_F_NESTED \| IFLA_XDP;
	159	nla->nla_len = NLA_HDRLEN;
	160
	161	/* add XDP fd */
	162	nla_xdp = (struct nlattr )((char )nla + nla->nla_len);
	163	nla_xdp->nla_type = IFLA_XDP_FD;
	164	nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
	165	memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
	166	nla->nla_len += nla_xdp->nla_len;
	167
	168	/* if user passed in any flags, add those too */
	169	if (flags) {
	170	nla_xdp = (struct nlattr )((char )nla + nla->nla_len);
	171	nla_xdp->nla_type = IFLA_XDP_FLAGS;
	172	nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
	173	memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
	174	nla->nla_len += nla_xdp->nla_len;
	175	}
	176
	177	req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
	178
	179	if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
	180	ret = -errno;
	181	goto cleanup;
	182	}
36f1678d	183	ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL);
f7010770 YS	184
	185	cleanup:
	186	close(sock);
	187	return ret;
	188	}
36f1678d	189
aae57780 AI	190	static int __dump_link_nlmsg(struct nlmsghdr *nlh,
aae57780 AI	191	libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
36f1678d YS	192	{
	193	struct nlattr tb[IFLA_MAX + 1], attr;
	194	struct ifinfomsg *ifi = NLMSG_DATA(nlh);
	195	int len;
	196
	197	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
	198	attr = (struct nlattr ) ((void ) ifi + NLMSG_ALIGN(sizeof(*ifi)));
f04bc8a4	199	if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
36f1678d YS	200	return -LIBBPF_ERRNO__NLPARSE;
	201
	202	return dump_link_nlmsg(cookie, ifi, tb);
	203	}
	204
50db9f07 MF	205	static unsigned char get_xdp_id_attr(unsigned char mode, __u32 flags)
	206	{
	207	if (mode != XDP_ATTACHED_MULTI)
	208	return IFLA_XDP_PROG_ID;
	209	if (flags & XDP_FLAGS_DRV_MODE)
	210	return IFLA_XDP_DRV_PROG_ID;
	211	if (flags & XDP_FLAGS_HW_MODE)
	212	return IFLA_XDP_HW_PROG_ID;
	213	if (flags & XDP_FLAGS_SKB_MODE)
	214	return IFLA_XDP_SKB_PROG_ID;
	215
	216	return IFLA_XDP_UNSPEC;
	217	}
	218
	219	static int get_xdp_id(void cookie, void msg, struct nlattr **tb)
	220	{
	221	struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
	222	struct xdp_id_md *xdp_id = cookie;
	223	struct ifinfomsg *ifinfo = msg;
	224	unsigned char mode, xdp_attr;
	225	int ret;
	226
	227	if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
	228	return 0;
	229
	230	if (!tb[IFLA_XDP])
	231	return 0;
	232
	233	ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
	234	if (ret)
	235	return ret;
	236
	237	if (!xdp_tb[IFLA_XDP_ATTACHED])
	238	return 0;
	239
	240	mode = libbpf_nla_getattr_u8(xdp_tb[IFLA_XDP_ATTACHED]);
	241	if (mode == XDP_ATTACHED_NONE)
	242	return 0;
	243
	244	xdp_attr = get_xdp_id_attr(mode, xdp_id->flags);
	245	if (!xdp_attr \|\| !xdp_tb[xdp_attr])
	246	return 0;
	247
	248	xdp_id->id = libbpf_nla_getattr_u32(xdp_tb[xdp_attr]);
	249
	250	return 0;
	251	}
	252
	253	int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags)
	254	{
	255	struct xdp_id_md xdp_id = {};
	256	int sock, ret;
	257	__u32 nl_pid;
	258	__u32 mask;
	259
	260	if (flags & ~XDP_FLAGS_MASK)
	261	return -EINVAL;
	262
	263	/* Check whether the single {HW,DRV,SKB} mode is set */
	264	flags &= (XDP_FLAGS_SKB_MODE \| XDP_FLAGS_DRV_MODE \| XDP_FLAGS_HW_MODE);
	265	mask = flags - 1;
	266	if (flags && flags & mask)
	267	return -EINVAL;
	268
269	sock = libbpf_netlink_open(&nl_pid);
270	if (sock < 0)
271	return sock;
272
273	xdp_id.ifindex = ifindex;
274	xdp_id.flags = flags;
275
276	ret = libbpf_nl_get_link(sock, nl_pid, get_xdp_id, &xdp_id);
277	if (!ret)
278	*prog_id = xdp_id.id;
279
280	close(sock);
281	return ret;
282	}
283
aae57780 AI	284	int libbpf_nl_get_link(int sock, unsigned int nl_pid,
aae57780 AI	285	libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
36f1678d YS	286	{
	287	struct {
	288	struct nlmsghdr nlh;
	289	struct ifinfomsg ifm;
	290	} req = {
	291	.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
	292	.nlh.nlmsg_type = RTM_GETLINK,
	293	.nlh.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST,
	294	.ifm.ifi_family = AF_PACKET,
	295	};
	296	int seq = time(NULL);
	297
	298	req.nlh.nlmsg_seq = seq;
	299	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
	300	return -errno;
	301
	302	return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
	303	dump_link_nlmsg, cookie);
	304	}
	305
	306	static int __dump_class_nlmsg(struct nlmsghdr *nlh,
aae57780 AI	307	libbpf_dump_nlmsg_t dump_class_nlmsg,
aae57780 AI	308	void *cookie)
36f1678d YS	309	{
	310	struct nlattr tb[TCA_MAX + 1], attr;
	311	struct tcmsg *t = NLMSG_DATA(nlh);
	312	int len;
	313
	314	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
	315	attr = (struct nlattr ) ((void ) t + NLMSG_ALIGN(sizeof(*t)));
f04bc8a4	316	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
36f1678d YS	317	return -LIBBPF_ERRNO__NLPARSE;
	318
	319	return dump_class_nlmsg(cookie, t, tb);
	320	}
	321
aae57780 AI	322	int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
aae57780 AI	323	libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie)
36f1678d YS	324	{
	325	struct {
	326	struct nlmsghdr nlh;
	327	struct tcmsg t;
	328	} req = {
	329	.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
	330	.nlh.nlmsg_type = RTM_GETTCLASS,
	331	.nlh.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST,
	332	.t.tcm_family = AF_UNSPEC,
	333	.t.tcm_ifindex = ifindex,
	334	};
	335	int seq = time(NULL);
	336
	337	req.nlh.nlmsg_seq = seq;
	338	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
	339	return -errno;
	340
	341	return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
	342	dump_class_nlmsg, cookie);
	343	}
	344
	345	static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
aae57780 AI	346	libbpf_dump_nlmsg_t dump_qdisc_nlmsg,
aae57780 AI	347	void *cookie)
36f1678d YS	348	{
	349	struct nlattr tb[TCA_MAX + 1], attr;
	350	struct tcmsg *t = NLMSG_DATA(nlh);
	351	int len;
	352
	353	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
	354	attr = (struct nlattr ) ((void ) t + NLMSG_ALIGN(sizeof(*t)));
f04bc8a4	355	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
36f1678d YS	356	return -LIBBPF_ERRNO__NLPARSE;
	357
	358	return dump_qdisc_nlmsg(cookie, t, tb);
	359	}
	360
aae57780 AI	361	int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
aae57780 AI	362	libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
36f1678d YS	363	{
	364	struct {
	365	struct nlmsghdr nlh;
	366	struct tcmsg t;
	367	} req = {
	368	.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
	369	.nlh.nlmsg_type = RTM_GETQDISC,
	370	.nlh.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST,
	371	.t.tcm_family = AF_UNSPEC,
	372	.t.tcm_ifindex = ifindex,
	373	};
	374	int seq = time(NULL);
	375
	376	req.nlh.nlmsg_seq = seq;
	377	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
	378	return -errno;
	379
	380	return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
	381	dump_qdisc_nlmsg, cookie);
	382	}
	383
	384	static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
aae57780 AI	385	libbpf_dump_nlmsg_t dump_filter_nlmsg,
aae57780 AI	386	void *cookie)
36f1678d YS	387	{
	388	struct nlattr tb[TCA_MAX + 1], attr;
	389	struct tcmsg *t = NLMSG_DATA(nlh);
	390	int len;
	391
	392	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
	393	attr = (struct nlattr ) ((void ) t + NLMSG_ALIGN(sizeof(*t)));
f04bc8a4	394	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
36f1678d YS	395	return -LIBBPF_ERRNO__NLPARSE;
	396
	397	return dump_filter_nlmsg(cookie, t, tb);
	398	}
	399
aae57780 AI	400	int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
aae57780 AI	401	libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie)
36f1678d YS	402	{
	403	struct {
	404	struct nlmsghdr nlh;
	405	struct tcmsg t;
	406	} req = {
	407	.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
	408	.nlh.nlmsg_type = RTM_GETTFILTER,
	409	.nlh.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST,
	410	.t.tcm_family = AF_UNSPEC,
	411	.t.tcm_ifindex = ifindex,
	412	.t.tcm_parent = handle,
	413	};
	414	int seq = time(NULL);
	415
	416	req.nlh.nlmsg_seq = seq;
	417	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
	418	return -errno;
	419
	420	return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
	421	dump_filter_nlmsg, cookie);
	422	}