linux_old1/tools/lib/bpf/netlink.c

332 lines
7.8 KiB
C

// 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
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,
__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, 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;
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 = 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, NULL, NULL, NULL);
cleanup:
close(sock);
return ret;
}
static int __dump_link_nlmsg(struct nlmsghdr *nlh, 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 (nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_link_nlmsg(cookie, ifi, tb);
}
int nl_get_link(int sock, unsigned int nl_pid, 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,
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 (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_class_nlmsg(cookie, t, tb);
}
int nl_get_class(int sock, unsigned int nl_pid, int ifindex,
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,
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 (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_qdisc_nlmsg(cookie, t, tb);
}
int nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
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,
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 (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_filter_nlmsg(cookie, t, tb);
}
int nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
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);
}