2018-09-14 14:46:22 +00:00
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// SPDX-License-Identifier: GPL-2.0
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#include <error.h>
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#include <errno.h>
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#include <getopt.h>
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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 <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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2018-10-29 21:56:48 +00:00
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#include "bpf_rlimit.h"
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2018-09-14 14:46:22 +00:00
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const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector";
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const char *cfg_map_name = "jmp_table";
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bool cfg_attach = true;
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char *cfg_section_name;
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char *cfg_path_name;
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static void load_and_attach_program(void)
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{
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struct bpf_program *prog, *main_prog;
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struct bpf_map *prog_array;
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int i, fd, prog_fd, ret;
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struct bpf_object *obj;
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int prog_array_fd;
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ret = bpf_prog_load(cfg_path_name, BPF_PROG_TYPE_FLOW_DISSECTOR, &obj,
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&prog_fd);
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if (ret)
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error(1, 0, "bpf_prog_load %s", cfg_path_name);
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main_prog = bpf_object__find_program_by_title(obj, cfg_section_name);
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if (!main_prog)
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error(1, 0, "bpf_object__find_program_by_title %s",
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cfg_section_name);
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prog_fd = bpf_program__fd(main_prog);
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if (prog_fd < 0)
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error(1, 0, "bpf_program__fd");
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prog_array = bpf_object__find_map_by_name(obj, cfg_map_name);
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if (!prog_array)
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error(1, 0, "bpf_object__find_map_by_name %s", cfg_map_name);
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prog_array_fd = bpf_map__fd(prog_array);
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if (prog_array_fd < 0)
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error(1, 0, "bpf_map__fd %s", cfg_map_name);
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i = 0;
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bpf_object__for_each_program(prog, obj) {
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fd = bpf_program__fd(prog);
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if (fd < 0)
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error(1, 0, "bpf_program__fd");
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if (fd != prog_fd) {
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printf("%d: %s\n", i, bpf_program__title(prog, false));
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bpf_map_update_elem(prog_array_fd, &i, &fd, BPF_ANY);
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++i;
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}
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}
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ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);
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if (ret)
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error(1, 0, "bpf_prog_attach %s", cfg_path_name);
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ret = bpf_object__pin(obj, cfg_pin_path);
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if (ret)
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error(1, 0, "bpf_object__pin %s", cfg_pin_path);
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}
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static void detach_program(void)
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{
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char command[64];
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int ret;
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ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);
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if (ret)
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error(1, 0, "bpf_prog_detach");
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/* To unpin, it is necessary and sufficient to just remove this dir */
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sprintf(command, "rm -r %s", cfg_pin_path);
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ret = system(command);
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if (ret)
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error(1, errno, command);
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}
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static void parse_opts(int argc, char **argv)
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{
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bool attach = false;
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bool detach = false;
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int c;
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while ((c = getopt(argc, argv, "adp:s:")) != -1) {
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switch (c) {
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case 'a':
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if (detach)
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error(1, 0, "attach/detach are exclusive");
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attach = true;
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break;
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case 'd':
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if (attach)
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error(1, 0, "attach/detach are exclusive");
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detach = true;
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break;
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case 'p':
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if (cfg_path_name)
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error(1, 0, "only one prog name can be given");
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cfg_path_name = optarg;
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break;
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case 's':
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if (cfg_section_name)
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error(1, 0, "only one section can be given");
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cfg_section_name = optarg;
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break;
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}
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}
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if (detach)
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cfg_attach = false;
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if (cfg_attach && !cfg_path_name)
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error(1, 0, "must provide a path to the BPF program");
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if (cfg_attach && !cfg_section_name)
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error(1, 0, "must provide a section name");
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}
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int main(int argc, char **argv)
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{
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parse_opts(argc, argv);
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if (cfg_attach)
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load_and_attach_program();
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else
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detach_program();
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return 0;
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}
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