add REDIRECT

hc

2024-10-09 05e59e5fb0064c97a1c10921ecd549f2d4a58565

 kernel/samples/bpf/xdp1_user.c
..
..
@@ -1,8 +1,5 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
1
2
 /* Copyright (c) 2016 PLUMgrid
2
- *
3
- * This program is free software; you can redistribute it and/or
4
- * modify it under the terms of version 2 of the GNU General Public
5
- * License as published by the Free Software Foundation.
6
3
  */
7
4
 #include <linux/bpf.h>
8
5
 #include <linux/if_link.h>
..
..
@@ -15,17 +12,30 @@
15
12
 #include <unistd.h>
16
13
 #include <libgen.h>
17
14
 #include <sys/resource.h>
15
+#include <net/if.h>
18
16
 
19
17
 #include "bpf_util.h"
20
-#include "bpf/bpf.h"
21
-#include "bpf/libbpf.h"
18
+#include <bpf/bpf.h>
19
+#include <bpf/libbpf.h>
22
20
 
23
21
 static int ifindex;
24
-static __u32 xdp_flags;
22
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
23
+static __u32 prog_id;
25
24
 
26
25
 static void int_exit(int sig)
27
26
 {
28
-	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
27
+	__u32 curr_prog_id = 0;
28
+
29
+	if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
30
+		printf("bpf_get_link_xdp_id failed\n");
31
+		exit(1);
32
+	}
33
+	if (prog_id == curr_prog_id)
34
+		bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
35
+	else if (!curr_prog_id)
36
+		printf("couldn't find a prog id on a given interface\n");
37
+	else
38
+		printf("program on interface changed, not removing\n");
29
39
 	exit(0);
30
40
 }
31
41
 
..
..
@@ -34,26 +44,24 @@
34
44
 static void poll_stats(int map_fd, int interval)
35
45
 {
36
46
 	unsigned int nr_cpus = bpf_num_possible_cpus();
37
-	const unsigned int nr_keys = 256;
38
-	__u64 values[nr_cpus], prev[nr_keys][nr_cpus];
39
-	__u32 key;
47
+	__u64 values[nr_cpus], prev[UINT8_MAX] = { 0 };
40
48
 	int i;
41
49
 
42
-	memset(prev, 0, sizeof(prev));
43
-
44
50
 	while (1) {
51
+		__u32 key = UINT32_MAX;
52
+
45
53
 		sleep(interval);
46
54
 
47
-		for (key = 0; key < nr_keys; key++) {
55
+		while (bpf_map_get_next_key(map_fd, &key, &key) != -1) {
48
56
 			__u64 sum = 0;
49
57
 
50
58
 			assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);
51
59
 			for (i = 0; i < nr_cpus; i++)
52
-				sum += (values[i] - prev[key][i]);
53
-			if (sum)
60
+				sum += values[i];
61
+			if (sum > prev[key])
54
62
 				printf("proto %u: %10llu pkt/s\n",
55
-				       key, sum / interval);
56
-			memcpy(prev[key], values, sizeof(values));
63
+				       key, (sum - prev[key]) / interval);
64
+			prev[key] = sum;
57
65
 		}
58
66
 	}
59
67
 }
..
..
@@ -61,10 +69,11 @@
61
69
 static void usage(const char *prog)
62
70
 {
63
71
 	fprintf(stderr,
64
-		"usage: %s [OPTS] IFINDEX\n\n"
72
+		"usage: %s [OPTS] IFACE\n\n"
65
73
 		"OPTS:\n"
66
74
 		"    -S    use skb-mode\n"
67
-		"    -N    enforce native mode\n",
75
+		"    -N    enforce native mode\n"
76
+		"    -F    force loading prog\n",
68
77
 		prog);
69
78
 }
70
79
 
..
..
@@ -74,11 +83,14 @@
74
83
 	struct bpf_prog_load_attr prog_load_attr = {
75
84
 		.prog_type	= BPF_PROG_TYPE_XDP,
76
85
 	};
77
-	const char *optstr = "SN";
86
+	struct bpf_prog_info info = {};
87
+	__u32 info_len = sizeof(info);
88
+	const char *optstr = "FSN";
78
89
 	int prog_fd, map_fd, opt;
79
90
 	struct bpf_object *obj;
80
91
 	struct bpf_map *map;
81
92
 	char filename[256];
93
+	int err;
82
94
 
83
95
 	while ((opt = getopt(argc, argv, optstr)) != -1) {
84
96
 		switch (opt) {
..
..
@@ -86,13 +98,19 @@
86
98
 			xdp_flags |= XDP_FLAGS_SKB_MODE;
87
99
 			break;
88
100
 		case 'N':
89
-			xdp_flags |= XDP_FLAGS_DRV_MODE;
101
+			/* default, set below */
102
+			break;
103
+		case 'F':
104
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
90
105
 			break;
91
106
 		default:
92
107
 			usage(basename(argv[0]));
93
108
 			return 1;
94
109
 		}
95
110
 	}
111
+
112
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
113
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
96
114
 
97
115
 	if (optind == argc) {
98
116
 		usage(basename(argv[0]));
..
..
@@ -104,7 +122,11 @@
104
122
 		return 1;
105
123
 	}
106
124
 
107
-	ifindex = strtoul(argv[optind], NULL, 0);
125
+	ifindex = if_nametoindex(argv[optind]);
126
+	if (!ifindex) {
127
+		perror("if_nametoindex");
128
+		return 1;
129
+	}
108
130
 
109
131
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
110
132
 	prog_load_attr.file = filename;
..
..
@@ -120,7 +142,7 @@
120
142
 	map_fd = bpf_map__fd(map);
121
143
 
122
144
 	if (!prog_fd) {
123
-		printf("load_bpf_file: %s\n", strerror(errno));
145
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
124
146
 		return 1;
125
147
 	}
126
148
 
..
..
@@ -132,6 +154,13 @@
132
154
 		return 1;
133
155
 	}
134
156
 
157
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
158
+	if (err) {
159
+		printf("can't get prog info - %s\n", strerror(errno));
160
+		return err;
161
+	}
162
+	prog_id = info.id;
163
+
135
164
 	poll_stats(map_fd, 2);
136
165
 
137
166
 	return 0;