add REDIRECT

hc

2024-10-09 05e59e5fb0064c97a1c10921ecd549f2d4a58565

 kernel/samples/bpf/xdp_tx_iptunnel_user.c
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@@ -1,8 +1,5 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /* Copyright (c) 2016 Facebook
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- *
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- * This program is free software; you can redistribute it and/or
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- * modify it under the terms of version 2 of the GNU General Public
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- * License as published by the Free Software Foundation.
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  */
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 #include <linux/bpf.h>
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 #include <linux/if_link.h>
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@@ -12,12 +9,13 @@
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 #include <stdio.h>
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 #include <stdlib.h>
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 #include <string.h>
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+#include <net/if.h>
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 #include <sys/resource.h>
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 #include <arpa/inet.h>
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 #include <netinet/ether.h>
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 #include <unistd.h>
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 #include <time.h>
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-#include "bpf_load.h"
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+#include <bpf/libbpf.h>
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 #include <bpf/bpf.h>
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 #include "bpf_util.h"
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 #include "xdp_tx_iptunnel_common.h"
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@@ -25,12 +23,26 @@
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 #define STATS_INTERVAL_S 2U
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 static int ifindex = -1;
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-static __u32 xdp_flags = 0;
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+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
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+static int rxcnt_map_fd;
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+static __u32 prog_id;
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29
 
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 static void int_exit(int sig)
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 {
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-	if (ifindex > -1)
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-		bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
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+	__u32 curr_prog_id = 0;
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+
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+	if (ifindex > -1) {
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+		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
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+			printf("bpf_get_link_xdp_id failed\n");
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+			exit(1);
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+		}
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+		if (prog_id == curr_prog_id)
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+			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
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+		else if (!curr_prog_id)
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+			printf("couldn't find a prog id on a given iface\n");
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+		else
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+			printf("program on interface changed, not removing\n");
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+	}
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 	exit(0);
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 }
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@@ -53,7 +65,8 @@
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 		for (proto = 0; proto < nr_protos; proto++) {
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 			__u64 sum = 0;
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-			assert(bpf_map_lookup_elem(map_fd[0], &proto, values) == 0);
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+			assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
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+						   values) == 0);
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 			for (i = 0; i < nr_cpus; i++)
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 				sum += (values[i] - prev[proto][i]);
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@@ -71,7 +84,7 @@
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 	       "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
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 	       "is used to select packets to encapsulate\n\n");
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 	printf("Usage: %s [...]\n", cmd);
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-	printf("    -i <ifindex> Interface Index\n");
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+	printf("    -i <ifname|ifindex> Interface\n");
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 	printf("    -a <vip-service-address> IPv4 or IPv6\n");
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 	printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
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 	printf("    -s <source-ip> Used in the IPTunnel header\n");
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@@ -81,6 +94,7 @@
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 	printf("    -P <IP-Protocol> Default is TCP\n");
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 	printf("    -S use skb-mode\n");
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 	printf("    -N enforce native mode\n");
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+	printf("    -F Force loading the XDP prog\n");
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 	printf("    -h Display this help\n");
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 }
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@@ -138,16 +152,22 @@
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152
 
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 int main(int argc, char **argv)
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 {
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-	unsigned char opt_flags[256] = {};
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-	unsigned int kill_after_s = 0;
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-	const char *optstr = "i:a:p:s:d:m:T:P:SNh";
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-	int min_port = 0, max_port = 0;
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-	struct iptnl_info tnl = {};
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+	struct bpf_prog_load_attr prog_load_attr = {
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+		.prog_type	= BPF_PROG_TYPE_XDP,
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+	};
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 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
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+	int min_port = 0, max_port = 0, vip2tnl_map_fd;
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+	const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
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+	unsigned char opt_flags[256] = {};
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+	struct bpf_prog_info info = {};
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+	__u32 info_len = sizeof(info);
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+	unsigned int kill_after_s = 0;
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+	struct iptnl_info tnl = {};
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+	struct bpf_object *obj;
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 	struct vip vip = {};
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 	char filename[256];
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-	int opt;
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-	int i;
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+	int opt, prog_fd;
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+	int i, err;
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 	tnl.family = AF_UNSPEC;
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 	vip.protocol = IPPROTO_TCP;
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@@ -162,7 +182,9 @@
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182
 
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 		switch (opt) {
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 		case 'i':
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-			ifindex = atoi(optarg);
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+			ifindex = if_nametoindex(optarg);
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+			if (!ifindex)
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+				ifindex = atoi(optarg);
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 			break;
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 		case 'a':
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 			vip.family = parse_ipstr(optarg, vip.daddr.v6);
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@@ -209,7 +231,10 @@
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 			xdp_flags |= XDP_FLAGS_SKB_MODE;
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 			break;
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 		case 'N':
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-			xdp_flags |= XDP_FLAGS_DRV_MODE;
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+			/* default, set below */
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+			break;
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+		case 'F':
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+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
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 			break;
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 		default:
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 			usage(argv[0]);
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@@ -217,6 +242,9 @@
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 		}
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 		opt_flags[opt] = 0;
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 	}
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+
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+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
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+		xdp_flags |= XDP_FLAGS_DRV_MODE;
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 	for (i = 0; i < strlen(optstr); i++) {
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 		if (opt_flags[(unsigned int)optstr[i]]) {
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@@ -231,15 +259,26 @@
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 		return 1;
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 	}
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-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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-
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-	if (load_bpf_file(filename)) {
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-		printf("%s", bpf_log_buf);
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+	if (!ifindex) {
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+		fprintf(stderr, "Invalid ifname\n");
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 		return 1;
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 	}
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-	if (!prog_fd[0]) {
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-		printf("load_bpf_file: %s\n", strerror(errno));
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+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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+	prog_load_attr.file = filename;
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+
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+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
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+		return 1;
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+
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+	if (!prog_fd) {
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+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
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+		return 1;
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+	}
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+
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+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
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+	vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
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+	if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
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+		printf("bpf_object__find_map_fd_by_name failed\n");
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 		return 1;
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 	}
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@@ -248,17 +287,25 @@
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 	while (min_port <= max_port) {
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 		vip.dport = htons(min_port++);
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-		if (bpf_map_update_elem(map_fd[1], &vip, &tnl, BPF_NOEXIST)) {
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+		if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
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+					BPF_NOEXIST)) {
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 			perror("bpf_map_update_elem(&vip2tnl)");
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 			return 1;
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 		}
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 	}
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-	if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
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+	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
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 		printf("link set xdp fd failed\n");
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 		return 1;
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 	}
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+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
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+	if (err) {
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+		printf("can't get prog info - %s\n", strerror(errno));
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+		return err;
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+	}
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+	prog_id = info.id;
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+
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 	poll_stats(kill_after_s);
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 	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);