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// SPDX-License-Identifier: GPL-2.0
#include <error.h>
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "flow_dissector_load.h"
const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector";
const char *cfg_map_name = "jmp_table";
bool cfg_attach = true;
char *cfg_prog_name;
char *cfg_path_name;
static void load_and_attach_program(void)
{
int prog_fd, ret;
struct bpf_object *obj;
/* Use libbpf 1.0 API mode */
libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
ret = bpf_flow_load(&obj, cfg_path_name, cfg_prog_name,
cfg_map_name, NULL, &prog_fd, NULL);
if (ret)
error(1, 0, "bpf_flow_load %s", cfg_path_name);
ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);
if (ret)
error(1, 0, "bpf_prog_attach %s", cfg_path_name);
ret = bpf_object__pin(obj, cfg_pin_path);
if (ret)
error(1, 0, "bpf_object__pin %s", cfg_pin_path);
}
static void detach_program(void)
{
char command[64];
int ret;
ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);
if (ret)
error(1, 0, "bpf_prog_detach");
/* To unpin, it is necessary and sufficient to just remove this dir */
sprintf(command, "rm -r %s", cfg_pin_path);
ret = system(command);
if (ret)
error(1, errno, "%s", command);
}
static void parse_opts(int argc, char **argv)
{
bool attach = false;
bool detach = false;
int c;
while ((c = getopt(argc, argv, "adp:s:")) != -1) {
switch (c) {
case 'a':
if (detach)
error(1, 0, "attach/detach are exclusive");
attach = true;
break;
case 'd':
if (attach)
error(1, 0, "attach/detach are exclusive");
detach = true;
break;
case 'p':
if (cfg_path_name)
error(1, 0, "only one path can be given");
cfg_path_name = optarg;
break;
case 's':
if (cfg_prog_name)
error(1, 0, "only one prog can be given");
cfg_prog_name = optarg;
break;
}
}
if (detach)
cfg_attach = false;
if (cfg_attach && !cfg_path_name)
error(1, 0, "must provide a path to the BPF program");
if (cfg_attach && !cfg_prog_name)
error(1, 0, "must provide a section name");
}
int main(int argc, char **argv)
{
parse_opts(argc, argv);
if (cfg_attach)
load_and_attach_program();
else
detach_program();
return 0;
}
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