112 lines
2.3 KiB
C
112 lines
2.3 KiB
C
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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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#include "flow_dissector_load.h"
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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_prog_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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int prog_fd, ret;
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struct bpf_object *obj;
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/* Use libbpf 1.0 API mode */
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libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
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ret = bpf_flow_load(&obj, cfg_path_name, cfg_prog_name,
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cfg_map_name, NULL, &prog_fd, NULL);
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if (ret)
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error(1, 0, "bpf_flow_load %s", cfg_path_name);
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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, "%s", 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 path 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_prog_name)
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error(1, 0, "only one prog can be given");
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cfg_prog_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_prog_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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