1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com> 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 */ 13 14 #include <linux/bpf.h> 15 #include <linux/if_link.h> 16 #include <linux/limits.h> 17 #include <net/if.h> 18 #include <errno.h> 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <stdbool.h> 22 #include <string.h> 23 #include <unistd.h> 24 #include <fcntl.h> 25 #include <libgen.h> 26 27 #include "bpf/libbpf.h" 28 #include <bpf/bpf.h> 29 30 31 static int do_attach(int idx, int fd, const char *name) 32 { 33 int err; 34 35 err = bpf_set_link_xdp_fd(idx, fd, 0); 36 if (err < 0) 37 printf("ERROR: failed to attach program to %s\n", name); 38 39 return err; 40 } 41 42 static int do_detach(int idx, const char *name) 43 { 44 int err; 45 46 err = bpf_set_link_xdp_fd(idx, -1, 0); 47 if (err < 0) 48 printf("ERROR: failed to detach program from %s\n", name); 49 50 return err; 51 } 52 53 static void usage(const char *prog) 54 { 55 fprintf(stderr, 56 "usage: %s [OPTS] interface-list\n" 57 "\nOPTS:\n" 58 " -d detach program\n" 59 " -D direct table lookups (skip fib rules)\n", 60 prog); 61 } 62 63 int main(int argc, char **argv) 64 { 65 struct bpf_prog_load_attr prog_load_attr = { 66 .prog_type = BPF_PROG_TYPE_XDP, 67 }; 68 const char *prog_name = "xdp_fwd"; 69 struct bpf_program *prog; 70 char filename[PATH_MAX]; 71 struct bpf_object *obj; 72 int opt, i, idx, err; 73 int prog_fd, map_fd; 74 int attach = 1; 75 int ret = 0; 76 77 while ((opt = getopt(argc, argv, ":dD")) != -1) { 78 switch (opt) { 79 case 'd': 80 attach = 0; 81 break; 82 case 'D': 83 prog_name = "xdp_fwd_direct"; 84 break; 85 default: 86 usage(basename(argv[0])); 87 return 1; 88 } 89 } 90 91 if (optind == argc) { 92 usage(basename(argv[0])); 93 return 1; 94 } 95 96 if (attach) { 97 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 98 prog_load_attr.file = filename; 99 100 if (access(filename, O_RDONLY) < 0) { 101 printf("error accessing file %s: %s\n", 102 filename, strerror(errno)); 103 return 1; 104 } 105 106 if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) 107 return 1; 108 109 prog = bpf_object__find_program_by_title(obj, prog_name); 110 prog_fd = bpf_program__fd(prog); 111 if (prog_fd < 0) { 112 printf("program not found: %s\n", strerror(prog_fd)); 113 return 1; 114 } 115 map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj, 116 "tx_port")); 117 if (map_fd < 0) { 118 printf("map not found: %s\n", strerror(map_fd)); 119 return 1; 120 } 121 } 122 if (attach) { 123 for (i = 1; i < 64; ++i) 124 bpf_map_update_elem(map_fd, &i, &i, 0); 125 } 126 127 for (i = optind; i < argc; ++i) { 128 idx = if_nametoindex(argv[i]); 129 if (!idx) 130 idx = strtoul(argv[i], NULL, 0); 131 132 if (!idx) { 133 fprintf(stderr, "Invalid arg\n"); 134 return 1; 135 } 136 if (!attach) { 137 err = do_detach(idx, argv[i]); 138 if (err) 139 ret = err; 140 } else { 141 err = do_attach(idx, prog_fd, argv[i]); 142 if (err) 143 ret = err; 144 } 145 } 146 147 return ret; 148 } 149