332 lines
7.8 KiB
C
332 lines
7.8 KiB
C
// SPDX-License-Identifier: LGPL-2.1
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/* Copyright (c) 2018 Facebook */
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#include <stdlib.h>
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#include <memory.h>
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#include <unistd.h>
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#include <linux/bpf.h>
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#include <linux/rtnetlink.h>
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#include <sys/socket.h>
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#include <errno.h>
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#include <time.h>
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#include "bpf.h"
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#include "libbpf.h"
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#include "nlattr.h"
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#ifndef SOL_NETLINK
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#define SOL_NETLINK 270
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#endif
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int bpf_netlink_open(__u32 *nl_pid)
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{
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struct sockaddr_nl sa;
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socklen_t addrlen;
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int one = 1, ret;
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int sock;
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memset(&sa, 0, sizeof(sa));
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sa.nl_family = AF_NETLINK;
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sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
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if (sock < 0)
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return -errno;
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if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
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&one, sizeof(one)) < 0) {
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fprintf(stderr, "Netlink error reporting not supported\n");
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}
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if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
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ret = -errno;
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goto cleanup;
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}
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addrlen = sizeof(sa);
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if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
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ret = -errno;
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goto cleanup;
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}
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if (addrlen != sizeof(sa)) {
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ret = -LIBBPF_ERRNO__INTERNAL;
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goto cleanup;
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}
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*nl_pid = sa.nl_pid;
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return sock;
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cleanup:
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close(sock);
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return ret;
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}
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static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq,
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__dump_nlmsg_t _fn, dump_nlmsg_t fn,
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void *cookie)
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{
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bool multipart = true;
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struct nlmsgerr *err;
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struct nlmsghdr *nh;
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char buf[4096];
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int len, ret;
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while (multipart) {
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multipart = false;
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len = recv(sock, buf, sizeof(buf), 0);
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if (len < 0) {
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ret = -errno;
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goto done;
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}
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if (len == 0)
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break;
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for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
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nh = NLMSG_NEXT(nh, len)) {
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if (nh->nlmsg_pid != nl_pid) {
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ret = -LIBBPF_ERRNO__WRNGPID;
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goto done;
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}
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if (nh->nlmsg_seq != seq) {
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ret = -LIBBPF_ERRNO__INVSEQ;
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goto done;
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}
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if (nh->nlmsg_flags & NLM_F_MULTI)
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multipart = true;
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switch (nh->nlmsg_type) {
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case NLMSG_ERROR:
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err = (struct nlmsgerr *)NLMSG_DATA(nh);
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if (!err->error)
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continue;
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ret = err->error;
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nla_dump_errormsg(nh);
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goto done;
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case NLMSG_DONE:
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return 0;
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default:
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break;
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}
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if (_fn) {
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ret = _fn(nh, fn, cookie);
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if (ret)
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return ret;
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}
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}
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}
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ret = 0;
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done:
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return ret;
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}
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int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
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{
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int sock, seq = 0, ret;
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struct nlattr *nla, *nla_xdp;
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struct {
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struct nlmsghdr nh;
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struct ifinfomsg ifinfo;
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char attrbuf[64];
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} req;
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__u32 nl_pid;
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sock = bpf_netlink_open(&nl_pid);
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if (sock < 0)
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return sock;
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memset(&req, 0, sizeof(req));
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req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
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req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
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req.nh.nlmsg_type = RTM_SETLINK;
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req.nh.nlmsg_pid = 0;
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req.nh.nlmsg_seq = ++seq;
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req.ifinfo.ifi_family = AF_UNSPEC;
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req.ifinfo.ifi_index = ifindex;
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/* started nested attribute for XDP */
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nla = (struct nlattr *)(((char *)&req)
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+ NLMSG_ALIGN(req.nh.nlmsg_len));
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nla->nla_type = NLA_F_NESTED | IFLA_XDP;
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nla->nla_len = NLA_HDRLEN;
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/* add XDP fd */
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nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
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nla_xdp->nla_type = IFLA_XDP_FD;
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nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
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memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
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nla->nla_len += nla_xdp->nla_len;
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/* if user passed in any flags, add those too */
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if (flags) {
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nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
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nla_xdp->nla_type = IFLA_XDP_FLAGS;
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nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
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memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
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nla->nla_len += nla_xdp->nla_len;
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}
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req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
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if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
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ret = -errno;
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goto cleanup;
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}
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ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL);
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cleanup:
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close(sock);
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return ret;
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}
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static int __dump_link_nlmsg(struct nlmsghdr *nlh, dump_nlmsg_t dump_link_nlmsg,
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void *cookie)
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{
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struct nlattr *tb[IFLA_MAX + 1], *attr;
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struct ifinfomsg *ifi = NLMSG_DATA(nlh);
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int len;
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len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
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attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
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if (nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
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return -LIBBPF_ERRNO__NLPARSE;
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return dump_link_nlmsg(cookie, ifi, tb);
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}
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int nl_get_link(int sock, unsigned int nl_pid, dump_nlmsg_t dump_link_nlmsg,
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void *cookie)
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{
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struct {
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struct nlmsghdr nlh;
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struct ifinfomsg ifm;
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} req = {
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
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.nlh.nlmsg_type = RTM_GETLINK,
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.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
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.ifm.ifi_family = AF_PACKET,
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};
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int seq = time(NULL);
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req.nlh.nlmsg_seq = seq;
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if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
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return -errno;
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return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
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dump_link_nlmsg, cookie);
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}
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static int __dump_class_nlmsg(struct nlmsghdr *nlh,
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dump_nlmsg_t dump_class_nlmsg, void *cookie)
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{
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struct nlattr *tb[TCA_MAX + 1], *attr;
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struct tcmsg *t = NLMSG_DATA(nlh);
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int len;
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len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
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attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
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if (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
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return -LIBBPF_ERRNO__NLPARSE;
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return dump_class_nlmsg(cookie, t, tb);
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}
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int nl_get_class(int sock, unsigned int nl_pid, int ifindex,
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dump_nlmsg_t dump_class_nlmsg, void *cookie)
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{
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struct {
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struct nlmsghdr nlh;
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struct tcmsg t;
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} req = {
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
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.nlh.nlmsg_type = RTM_GETTCLASS,
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.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
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.t.tcm_family = AF_UNSPEC,
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.t.tcm_ifindex = ifindex,
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};
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int seq = time(NULL);
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req.nlh.nlmsg_seq = seq;
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if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
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return -errno;
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return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
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dump_class_nlmsg, cookie);
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}
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static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
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dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
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{
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struct nlattr *tb[TCA_MAX + 1], *attr;
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struct tcmsg *t = NLMSG_DATA(nlh);
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int len;
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len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
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attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
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if (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
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return -LIBBPF_ERRNO__NLPARSE;
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return dump_qdisc_nlmsg(cookie, t, tb);
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}
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int nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
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dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
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{
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struct {
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struct nlmsghdr nlh;
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struct tcmsg t;
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} req = {
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
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.nlh.nlmsg_type = RTM_GETQDISC,
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.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
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.t.tcm_family = AF_UNSPEC,
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.t.tcm_ifindex = ifindex,
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};
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int seq = time(NULL);
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req.nlh.nlmsg_seq = seq;
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if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
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return -errno;
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return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
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dump_qdisc_nlmsg, cookie);
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}
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static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
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dump_nlmsg_t dump_filter_nlmsg, void *cookie)
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{
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struct nlattr *tb[TCA_MAX + 1], *attr;
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struct tcmsg *t = NLMSG_DATA(nlh);
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int len;
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len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
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attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
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if (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
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return -LIBBPF_ERRNO__NLPARSE;
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return dump_filter_nlmsg(cookie, t, tb);
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}
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int nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
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dump_nlmsg_t dump_filter_nlmsg, void *cookie)
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{
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struct {
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struct nlmsghdr nlh;
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struct tcmsg t;
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} req = {
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
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.nlh.nlmsg_type = RTM_GETTFILTER,
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.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
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.t.tcm_family = AF_UNSPEC,
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.t.tcm_ifindex = ifindex,
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.t.tcm_parent = handle,
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};
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int seq = time(NULL);
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req.nlh.nlmsg_seq = seq;
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if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
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return -errno;
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return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
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dump_filter_nlmsg, cookie);
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}
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