change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/samples/bpf/xdp1_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 PLUMgrid
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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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@@ -15,17 +12,30 @@
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 #include <unistd.h>
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 #include <libgen.h>
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 #include <sys/resource.h>
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+#include <net/if.h>
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 #include "bpf_util.h"
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-#include "bpf/bpf.h"
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-#include "bpf/libbpf.h"
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+#include <bpf/bpf.h>
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+#include <bpf/libbpf.h>
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 static int ifindex;
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-static __u32 xdp_flags;
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+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
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+static __u32 prog_id;
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 static void int_exit(int sig)
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 {
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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 (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 interface\n");
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+	else
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+		printf("program on interface changed, not removing\n");
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 	exit(0);
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 }
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@@ -34,26 +44,24 @@
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 static void poll_stats(int map_fd, int interval)
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 {
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 	unsigned int nr_cpus = bpf_num_possible_cpus();
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-	const unsigned int nr_keys = 256;
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-	__u64 values[nr_cpus], prev[nr_keys][nr_cpus];
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-	__u32 key;
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+	__u64 values[nr_cpus], prev[UINT8_MAX] = { 0 };
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 	int i;
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-	memset(prev, 0, sizeof(prev));
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-
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 	while (1) {
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+		__u32 key = UINT32_MAX;
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+
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 		sleep(interval);
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-		for (key = 0; key < nr_keys; key++) {
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+		while (bpf_map_get_next_key(map_fd, &key, &key) != -1) {
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 			__u64 sum = 0;
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 			assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);
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 			for (i = 0; i < nr_cpus; i++)
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-				sum += (values[i] - prev[key][i]);
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-			if (sum)
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+				sum += values[i];
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+			if (sum > prev[key])
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 				printf("proto %u: %10llu pkt/s\n",
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-				       key, sum / interval);
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-			memcpy(prev[key], values, sizeof(values));
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+				       key, (sum - prev[key]) / interval);
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+			prev[key] = sum;
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 		}
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 	}
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 }
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@@ -61,10 +69,11 @@
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 static void usage(const char *prog)
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 {
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 	fprintf(stderr,
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-		"usage: %s [OPTS] IFINDEX\n\n"
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+		"usage: %s [OPTS] IFACE\n\n"
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 		"OPTS:\n"
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 		"    -S    use skb-mode\n"
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-		"    -N    enforce native mode\n",
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+		"    -N    enforce native mode\n"
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+		"    -F    force loading prog\n",
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 		prog);
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 }
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@@ -74,11 +83,14 @@
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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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-	const char *optstr = "SN";
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+	struct bpf_prog_info info = {};
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+	__u32 info_len = sizeof(info);
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+	const char *optstr = "FSN";
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 	int prog_fd, map_fd, opt;
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 	struct bpf_object *obj;
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 	struct bpf_map *map;
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 	char filename[256];
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+	int err;
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 	while ((opt = getopt(argc, argv, optstr)) != -1) {
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 		switch (opt) {
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@@ -86,13 +98,19 @@
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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(basename(argv[0]));
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 			return 1;
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 		}
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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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 	if (optind == argc) {
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 		usage(basename(argv[0]));
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@@ -104,7 +122,11 @@
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 		return 1;
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 	}
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-	ifindex = strtoul(argv[optind], NULL, 0);
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+	ifindex = if_nametoindex(argv[optind]);
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+	if (!ifindex) {
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+		perror("if_nametoindex");
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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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 	prog_load_attr.file = filename;
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@@ -120,7 +142,7 @@
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 	map_fd = bpf_map__fd(map);
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 	if (!prog_fd) {
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-		printf("load_bpf_file: %s\n", strerror(errno));
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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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@@ -132,6 +154,13 @@
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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(map_fd, 2);
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 	return 0;