cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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flow_dissector_load.c (2349B)

      1// SPDX-License-Identifier: GPL-2.0
      2#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	else
    109		detach_program();
    110	return 0;
    111}