493 строки
11 KiB
C
493 строки
11 KiB
C
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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// Copyright (C) 2018 Facebook
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#define _GNU_SOURCE
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#include <errno.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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#include <net/if.h>
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#include <linux/if.h>
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#include <linux/rtnetlink.h>
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#include <linux/tc_act/tc_bpf.h>
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#include <sys/socket.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include "bpf/nlattr.h"
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#include "bpf/libbpf_internal.h"
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#include "main.h"
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#include "netlink_dumper.h"
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struct ip_devname_ifindex {
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char devname[64];
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int ifindex;
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};
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struct bpf_netdev_t {
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struct ip_devname_ifindex *devices;
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int used_len;
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int array_len;
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int filter_idx;
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};
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struct tc_kind_handle {
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char kind[64];
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int handle;
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};
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struct bpf_tcinfo_t {
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struct tc_kind_handle *handle_array;
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int used_len;
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int array_len;
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bool is_qdisc;
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};
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struct bpf_filter_t {
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const char *kind;
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const char *devname;
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int ifindex;
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};
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struct bpf_attach_info {
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__u32 flow_dissector_id;
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};
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enum net_attach_type {
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NET_ATTACH_TYPE_XDP,
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NET_ATTACH_TYPE_XDP_GENERIC,
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NET_ATTACH_TYPE_XDP_DRIVER,
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NET_ATTACH_TYPE_XDP_OFFLOAD,
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};
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static const char * const attach_type_strings[] = {
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[NET_ATTACH_TYPE_XDP] = "xdp",
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[NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric",
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[NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv",
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[NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload",
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};
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const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);
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static enum net_attach_type parse_attach_type(const char *str)
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{
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enum net_attach_type type;
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for (type = 0; type < net_attach_type_size; type++) {
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if (attach_type_strings[type] &&
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is_prefix(str, attach_type_strings[type]))
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return type;
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}
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return net_attach_type_size;
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}
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static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)
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{
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struct bpf_netdev_t *netinfo = cookie;
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struct ifinfomsg *ifinfo = msg;
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if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index)
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return 0;
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if (netinfo->used_len == netinfo->array_len) {
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netinfo->devices = realloc(netinfo->devices,
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(netinfo->array_len + 16) *
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sizeof(struct ip_devname_ifindex));
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if (!netinfo->devices)
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return -ENOMEM;
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netinfo->array_len += 16;
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}
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netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index;
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snprintf(netinfo->devices[netinfo->used_len].devname,
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sizeof(netinfo->devices[netinfo->used_len].devname),
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"%s",
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tb[IFLA_IFNAME]
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? libbpf_nla_getattr_str(tb[IFLA_IFNAME])
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: "");
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netinfo->used_len++;
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return do_xdp_dump(ifinfo, tb);
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}
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static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb)
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{
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struct bpf_tcinfo_t *tcinfo = cookie;
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struct tcmsg *info = msg;
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if (tcinfo->is_qdisc) {
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/* skip clsact qdisc */
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if (tb[TCA_KIND] &&
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strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0)
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return 0;
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if (info->tcm_handle == 0)
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return 0;
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}
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if (tcinfo->used_len == tcinfo->array_len) {
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tcinfo->handle_array = realloc(tcinfo->handle_array,
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(tcinfo->array_len + 16) * sizeof(struct tc_kind_handle));
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if (!tcinfo->handle_array)
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return -ENOMEM;
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tcinfo->array_len += 16;
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}
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tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle;
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snprintf(tcinfo->handle_array[tcinfo->used_len].kind,
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sizeof(tcinfo->handle_array[tcinfo->used_len].kind),
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"%s",
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tb[TCA_KIND]
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? libbpf_nla_getattr_str(tb[TCA_KIND])
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: "unknown");
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tcinfo->used_len++;
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return 0;
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}
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static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb)
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{
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const struct bpf_filter_t *filter_info = cookie;
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return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind,
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filter_info->devname, filter_info->ifindex);
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}
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static int show_dev_tc_bpf(int sock, unsigned int nl_pid,
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struct ip_devname_ifindex *dev)
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{
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struct bpf_filter_t filter_info;
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struct bpf_tcinfo_t tcinfo;
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int i, handle, ret = 0;
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tcinfo.handle_array = NULL;
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tcinfo.used_len = 0;
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tcinfo.array_len = 0;
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tcinfo.is_qdisc = false;
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ret = libbpf_nl_get_class(sock, nl_pid, dev->ifindex,
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dump_class_qdisc_nlmsg, &tcinfo);
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if (ret)
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goto out;
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tcinfo.is_qdisc = true;
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ret = libbpf_nl_get_qdisc(sock, nl_pid, dev->ifindex,
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dump_class_qdisc_nlmsg, &tcinfo);
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if (ret)
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goto out;
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filter_info.devname = dev->devname;
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filter_info.ifindex = dev->ifindex;
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for (i = 0; i < tcinfo.used_len; i++) {
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filter_info.kind = tcinfo.handle_array[i].kind;
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ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex,
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tcinfo.handle_array[i].handle,
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dump_filter_nlmsg, &filter_info);
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if (ret)
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goto out;
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}
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/* root, ingress and egress handle */
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handle = TC_H_ROOT;
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filter_info.kind = "root";
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ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,
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dump_filter_nlmsg, &filter_info);
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if (ret)
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goto out;
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handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
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filter_info.kind = "clsact/ingress";
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ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,
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dump_filter_nlmsg, &filter_info);
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if (ret)
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goto out;
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handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
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filter_info.kind = "clsact/egress";
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ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,
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dump_filter_nlmsg, &filter_info);
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if (ret)
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goto out;
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out:
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free(tcinfo.handle_array);
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return 0;
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}
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static int query_flow_dissector(struct bpf_attach_info *attach_info)
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{
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__u32 attach_flags;
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__u32 prog_ids[1];
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__u32 prog_cnt;
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int err;
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int fd;
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fd = open("/proc/self/ns/net", O_RDONLY);
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if (fd < 0) {
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p_err("can't open /proc/self/ns/net: %s",
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strerror(errno));
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return -1;
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}
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prog_cnt = ARRAY_SIZE(prog_ids);
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err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0,
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&attach_flags, prog_ids, &prog_cnt);
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close(fd);
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if (err) {
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if (errno == EINVAL) {
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/* Older kernel's don't support querying
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* flow dissector programs.
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*/
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errno = 0;
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return 0;
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}
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p_err("can't query prog: %s", strerror(errno));
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return -1;
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}
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if (prog_cnt == 1)
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attach_info->flow_dissector_id = prog_ids[0];
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return 0;
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}
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static int net_parse_dev(int *argc, char ***argv)
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{
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int ifindex;
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if (is_prefix(**argv, "dev")) {
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NEXT_ARGP();
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ifindex = if_nametoindex(**argv);
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if (!ifindex)
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p_err("invalid devname %s", **argv);
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NEXT_ARGP();
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} else {
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p_err("expected 'dev', got: '%s'?", **argv);
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return -1;
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}
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return ifindex;
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}
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static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type,
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int ifindex, bool overwrite)
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{
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__u32 flags = 0;
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if (!overwrite)
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flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
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if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC)
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flags |= XDP_FLAGS_SKB_MODE;
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if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER)
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flags |= XDP_FLAGS_DRV_MODE;
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if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD)
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flags |= XDP_FLAGS_HW_MODE;
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return bpf_set_link_xdp_fd(ifindex, progfd, flags);
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}
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static int do_attach(int argc, char **argv)
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{
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enum net_attach_type attach_type;
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int progfd, ifindex, err = 0;
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bool overwrite = false;
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/* parse attach args */
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if (!REQ_ARGS(5))
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return -EINVAL;
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attach_type = parse_attach_type(*argv);
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if (attach_type == net_attach_type_size) {
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p_err("invalid net attach/detach type: %s", *argv);
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return -EINVAL;
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}
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NEXT_ARG();
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progfd = prog_parse_fd(&argc, &argv);
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if (progfd < 0)
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return -EINVAL;
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ifindex = net_parse_dev(&argc, &argv);
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if (ifindex < 1) {
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close(progfd);
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return -EINVAL;
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}
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if (argc) {
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if (is_prefix(*argv, "overwrite")) {
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overwrite = true;
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} else {
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p_err("expected 'overwrite', got: '%s'?", *argv);
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close(progfd);
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return -EINVAL;
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}
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}
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/* attach xdp prog */
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if (is_prefix("xdp", attach_type_strings[attach_type]))
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err = do_attach_detach_xdp(progfd, attach_type, ifindex,
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overwrite);
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if (err < 0) {
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p_err("interface %s attach failed: %s",
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attach_type_strings[attach_type], strerror(-err));
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return err;
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}
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if (json_output)
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jsonw_null(json_wtr);
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return 0;
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}
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static int do_detach(int argc, char **argv)
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{
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enum net_attach_type attach_type;
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int progfd, ifindex, err = 0;
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/* parse detach args */
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if (!REQ_ARGS(3))
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return -EINVAL;
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attach_type = parse_attach_type(*argv);
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if (attach_type == net_attach_type_size) {
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p_err("invalid net attach/detach type: %s", *argv);
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return -EINVAL;
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}
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NEXT_ARG();
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ifindex = net_parse_dev(&argc, &argv);
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if (ifindex < 1)
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return -EINVAL;
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/* detach xdp prog */
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progfd = -1;
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if (is_prefix("xdp", attach_type_strings[attach_type]))
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err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
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if (err < 0) {
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p_err("interface %s detach failed: %s",
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attach_type_strings[attach_type], strerror(-err));
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return err;
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}
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if (json_output)
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jsonw_null(json_wtr);
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return 0;
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}
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static int do_show(int argc, char **argv)
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{
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struct bpf_attach_info attach_info = {};
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int i, sock, ret, filter_idx = -1;
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struct bpf_netdev_t dev_array;
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unsigned int nl_pid;
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char err_buf[256];
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if (argc == 2) {
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filter_idx = net_parse_dev(&argc, &argv);
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if (filter_idx < 1)
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return -1;
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} else if (argc != 0) {
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usage();
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}
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ret = query_flow_dissector(&attach_info);
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if (ret)
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return -1;
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sock = libbpf_netlink_open(&nl_pid);
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if (sock < 0) {
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fprintf(stderr, "failed to open netlink sock\n");
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return -1;
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}
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dev_array.devices = NULL;
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dev_array.used_len = 0;
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dev_array.array_len = 0;
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dev_array.filter_idx = filter_idx;
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if (json_output)
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jsonw_start_array(json_wtr);
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NET_START_OBJECT;
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NET_START_ARRAY("xdp", "%s:\n");
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ret = libbpf_nl_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
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NET_END_ARRAY("\n");
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if (!ret) {
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NET_START_ARRAY("tc", "%s:\n");
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for (i = 0; i < dev_array.used_len; i++) {
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ret = show_dev_tc_bpf(sock, nl_pid,
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&dev_array.devices[i]);
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if (ret)
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break;
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}
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NET_END_ARRAY("\n");
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}
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NET_START_ARRAY("flow_dissector", "%s:\n");
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if (attach_info.flow_dissector_id > 0)
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NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id);
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NET_END_ARRAY("\n");
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NET_END_OBJECT;
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if (json_output)
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jsonw_end_array(json_wtr);
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if (ret) {
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if (json_output)
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jsonw_null(json_wtr);
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libbpf_strerror(ret, err_buf, sizeof(err_buf));
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fprintf(stderr, "Error: %s\n", err_buf);
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}
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free(dev_array.devices);
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close(sock);
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return ret;
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}
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static int do_help(int argc, char **argv)
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{
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if (json_output) {
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jsonw_null(json_wtr);
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return 0;
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}
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fprintf(stderr,
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"Usage: %s %s { show | list } [dev <devname>]\n"
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" %s %s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
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" %s %s detach ATTACH_TYPE dev <devname>\n"
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" %s %s help\n"
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"\n"
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" " HELP_SPEC_PROGRAM "\n"
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" ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
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"\n"
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"Note: Only xdp and tc attachments are supported now.\n"
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" For progs attached to cgroups, use \"bpftool cgroup\"\n"
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" to dump program attachments. For program types\n"
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" sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
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" consult iproute2.\n",
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bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
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bin_name, argv[-2]);
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return 0;
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}
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static const struct cmd cmds[] = {
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{ "show", do_show },
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{ "list", do_show },
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{ "attach", do_attach },
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{ "detach", do_detach },
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{ "help", do_help },
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{ 0 }
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};
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int do_net(int argc, char **argv)
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{
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return cmd_select(cmds, argc, argv, do_help);
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}
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