path: root/tools/bpf/bpftool/net.c

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (C) 2018 Facebook

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include <net/if.h>
#include <linux/rtnetlink.h>
#include <linux/socket.h>
#include <linux/tc_act/tc_bpf.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "bpf/nlattr.h"
#include "main.h"
#include "netlink_dumper.h"

#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif

struct ip_devname_ifindex {
	char	devname[64];
	int	ifindex;
};

struct bpf_netdev_t {
	struct ip_devname_ifindex *devices;
	int	used_len;
	int	array_len;
	int	filter_idx;
};

struct tc_kind_handle {
	char	kind[64];
	int	handle;
};

struct bpf_tcinfo_t {
	struct tc_kind_handle	*handle_array;
	int			used_len;
	int			array_len;
	bool			is_qdisc;
};

struct bpf_filter_t {
	const char	*kind;
	const char	*devname;
	int		ifindex;
};

struct bpf_attach_info {
	__u32 flow_dissector_id;
};

enum net_attach_type {
	NET_ATTACH_TYPE_XDP,
	NET_ATTACH_TYPE_XDP_GENERIC,
	NET_ATTACH_TYPE_XDP_DRIVER,
	NET_ATTACH_TYPE_XDP_OFFLOAD,
	NET_ATTACH_TYPE_TCX_INGRESS,
	NET_ATTACH_TYPE_TCX_EGRESS,
};

static const char * const attach_type_strings[] = {
	[NET_ATTACH_TYPE_XDP]		= "xdp",
	[NET_ATTACH_TYPE_XDP_GENERIC]	= "xdpgeneric",
	[NET_ATTACH_TYPE_XDP_DRIVER]	= "xdpdrv",
	[NET_ATTACH_TYPE_XDP_OFFLOAD]	= "xdpoffload",
	[NET_ATTACH_TYPE_TCX_INGRESS]	= "tcx_ingress",
	[NET_ATTACH_TYPE_TCX_EGRESS]	= "tcx_egress",
};

static const char * const attach_loc_strings[] = {
	[BPF_TCX_INGRESS]		= "tcx/ingress",
	[BPF_TCX_EGRESS]		= "tcx/egress",
	[BPF_NETKIT_PRIMARY]		= "netkit/primary",
	[BPF_NETKIT_PEER]		= "netkit/peer",
};

const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);

static enum net_attach_type parse_attach_type(const char *str)
{
	enum net_attach_type type;

	for (type = 0; type < net_attach_type_size; type++) {
		if (attach_type_strings[type] &&
		    is_prefix(str, attach_type_strings[type]))
			return type;
	}

	return net_attach_type_size;
}

typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);

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

static int 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) {
		p_err("Netlink error reporting not supported");
	}

	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 netlink_recv(int sock, __u32 nl_pid, __u32 seq,
			    __dump_nlmsg_t _fn, 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, (unsigned int)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 =