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1// SPDX-License-Identifier: GPL-2.02#include <error.h>3#include <errno.h>4#include <getopt.h>5#include <stdio.h>6#include <stdlib.h>7#include <string.h>8#include <sys/stat.h>9#include <fcntl.h>10#include <unistd.h>11#include <bpf/bpf.h>12#include <bpf/libbpf.h>13 14#include "flow_dissector_load.h"15 16const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector";17const char *cfg_map_name = "jmp_table";18bool cfg_attach = true;19char *cfg_prog_name;20char *cfg_path_name;21 22static void load_and_attach_program(void)23{24 int prog_fd, ret;25 struct bpf_object *obj;26 27 /* Use libbpf 1.0 API mode */28 libbpf_set_strict_mode(LIBBPF_STRICT_ALL);29 30 ret = bpf_flow_load(&obj, cfg_path_name, cfg_prog_name,31 cfg_map_name, NULL, &prog_fd, NULL);32 if (ret)33 error(1, 0, "bpf_flow_load %s", cfg_path_name);34 35 ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);36 if (ret)37 error(1, 0, "bpf_prog_attach %s", cfg_path_name);38 39 ret = bpf_object__pin(obj, cfg_pin_path);40 if (ret)41 error(1, 0, "bpf_object__pin %s", cfg_pin_path);42}43 44static void detach_program(void)45{46 char command[64];47 int ret;48 49 ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);50 if (ret)51 error(1, 0, "bpf_prog_detach");52 53 /* To unpin, it is necessary and sufficient to just remove this dir */54 sprintf(command, "rm -r %s", cfg_pin_path);55 ret = system(command);56 if (ret)57 error(1, errno, "%s", command);58}59 60static void parse_opts(int argc, char **argv)61{62 bool attach = false;63 bool detach = false;64 int c;65 66 while ((c = getopt(argc, argv, "adp:s:")) != -1) {67 switch (c) {68 case 'a':69 if (detach)70 error(1, 0, "attach/detach are exclusive");71 attach = true;72 break;73 case 'd':74 if (attach)75 error(1, 0, "attach/detach are exclusive");76 detach = true;77 break;78 case 'p':79 if (cfg_path_name)80 error(1, 0, "only one path can be given");81 82 cfg_path_name = optarg;83 break;84 case 's':85 if (cfg_prog_name)86 error(1, 0, "only one prog can be given");87 88 cfg_prog_name = optarg;89 break;90 }91 }92 93 if (detach)94 cfg_attach = false;95 96 if (cfg_attach && !cfg_path_name)97 error(1, 0, "must provide a path to the BPF program");98 99 if (cfg_attach && !cfg_prog_name)100 error(1, 0, "must provide a section name");101}102 103int main(int argc, char **argv)104{105 parse_opts(argc, argv);106 if (cfg_attach)107 load_and_attach_program();108 else109 detach_program();110 return 0;111}112