Commit f7010770 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

tools/bpf: move bpf/lib netlink related functions into a new file 



There are no functionality change for this patch.

In the subsequent patches, more netlink related library functions
will be added and a separate file is better than cluttering bpf.c.

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 52b7b784

tools/lib/bpf/Build

+1 −1
Original line number Diff line number Diff line 
libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o
 
libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o netlink.o

tools/lib/bpf/bpf.c

+0 −129
Original line number Diff line number Diff line
@@ -28,16 +28,8 @@ 
#include <linux/bpf.h>

#include "bpf.h"

#include "libbpf.h"

#include "nlattr.h"

#include <linux/rtnetlink.h>

#include <linux/if_link.h>

#include <sys/socket.h>

#include <errno.h>



#ifndef SOL_NETLINK

#define SOL_NETLINK 270

#endif



/*

 * When building perf, unistd.h is overridden. __NR_bpf is

 * required to be defined explicitly.
@@ -499,127 +491,6 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd) 
	return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));

}



int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)

{

	struct sockaddr_nl sa;

	int sock, seq = 0, len, ret = -1;

	char buf[4096];

	struct nlattr *nla, *nla_xdp;

	struct {

		struct nlmsghdr  nh;

		struct ifinfomsg ifinfo;

		char             attrbuf[64];

	} req;

	struct nlmsghdr *nh;

	struct nlmsgerr *err;

	socklen_t addrlen;

	int one = 1;



	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;

	}



	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;

	}



	len = recv(sock, buf, sizeof(buf), 0);

	if (len < 0) {

		ret = -errno;

		goto cleanup;

	}



	for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);

	     nh = NLMSG_NEXT(nh, len)) {

		if (nh->nlmsg_pid != sa.nl_pid) {

			ret = -LIBBPF_ERRNO__WRNGPID;

			goto cleanup;

		}

		if (nh->nlmsg_seq != seq) {

			ret = -LIBBPF_ERRNO__INVSEQ;

			goto cleanup;

		}

		switch (nh->nlmsg_type) {

		case NLMSG_ERROR:

			err = (struct nlmsgerr *)NLMSG_DATA(nh);

			if (!err->error)

				continue;

			ret = err->error;

			nla_dump_errormsg(nh);

			goto cleanup;

		case NLMSG_DONE:

			break;

		default:

			break;

		}

	}



	ret = 0;



cleanup:

	close(sock);

	return ret;

}



int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,

		 bool do_log)

{

tools/lib/bpf/netlink.c

0 → 100644
+165 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: LGPL-2.1

/* 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



static int bpf_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)

{

	struct nlmsgerr *err;

	struct nlmsghdr *nh;

	char buf[4096];

	int len, ret;



	while (1) {

		len = recv(sock, buf, sizeof(buf), 0);

		if (len < 0) {

			ret = -errno;

			goto done;

		}



		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;

			}

			switch (nh->nlmsg_type) {

			case NLMSG_ERROR:

				err = (struct nlmsgerr *)NLMSG_DATA(nh);

				if (!err->error)

					continue;

				ret = err->error;

				nla_dump_errormsg(nh);

				goto done;

			case NLMSG_DONE:

				return 0;

			default:

				break;

			}

		}

	}

	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 = bpf_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);



cleanup:

	close(sock);

	return ret;

}