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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xdp_sample_pkts_user.c (4028B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <stdio.h>
      3#include <stdlib.h>
      4#include <string.h>
      5#include <linux/perf_event.h>
      6#include <linux/bpf.h>
      7#include <net/if.h>
      8#include <errno.h>
      9#include <assert.h>
     10#include <sys/sysinfo.h>
     11#include <sys/ioctl.h>
     12#include <signal.h>
     13#include <bpf/libbpf.h>
     14#include <bpf/bpf.h>
     15#include <libgen.h>
     16#include <linux/if_link.h>
     17
     18#include "perf-sys.h"
     19
     20static int if_idx;
     21static char *if_name;
     22static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
     23static __u32 prog_id;
     24static struct perf_buffer *pb = NULL;
     25
     26static int do_attach(int idx, int fd, const char *name)
     27{
     28	struct bpf_prog_info info = {};
     29	__u32 info_len = sizeof(info);
     30	int err;
     31
     32	err = bpf_xdp_attach(idx, fd, xdp_flags, NULL);
     33	if (err < 0) {
     34		printf("ERROR: failed to attach program to %s\n", name);
     35		return err;
     36	}
     37
     38	err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
     39	if (err) {
     40		printf("can't get prog info - %s\n", strerror(errno));
     41		return err;
     42	}
     43	prog_id = info.id;
     44
     45	return err;
     46}
     47
     48static int do_detach(int idx, const char *name)
     49{
     50	__u32 curr_prog_id = 0;
     51	int err = 0;
     52
     53	err = bpf_xdp_query_id(idx, xdp_flags, &curr_prog_id);
     54	if (err) {
     55		printf("bpf_xdp_query_id failed\n");
     56		return err;
     57	}
     58	if (prog_id == curr_prog_id) {
     59		err = bpf_xdp_detach(idx, xdp_flags, NULL);
     60		if (err < 0)
     61			printf("ERROR: failed to detach prog from %s\n", name);
     62	} else if (!curr_prog_id) {
     63		printf("couldn't find a prog id on a %s\n", name);
     64	} else {
     65		printf("program on interface changed, not removing\n");
     66	}
     67
     68	return err;
     69}
     70
     71#define SAMPLE_SIZE 64
     72
     73static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
     74{
     75	struct {
     76		__u16 cookie;
     77		__u16 pkt_len;
     78		__u8  pkt_data[SAMPLE_SIZE];
     79	} __packed *e = data;
     80	int i;
     81
     82	if (e->cookie != 0xdead) {
     83		printf("BUG cookie %x sized %d\n", e->cookie, size);
     84		return;
     85	}
     86
     87	printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
     88	for (i = 0; i < 14 && i < e->pkt_len; i++)
     89		printf("%02x ", e->pkt_data[i]);
     90	printf("\n");
     91}
     92
     93static void sig_handler(int signo)
     94{
     95	do_detach(if_idx, if_name);
     96	perf_buffer__free(pb);
     97	exit(0);
     98}
     99
    100static void usage(const char *prog)
    101{
    102	fprintf(stderr,
    103		"%s: %s [OPTS] <ifname|ifindex>\n\n"
    104		"OPTS:\n"
    105		"    -F    force loading prog\n"
    106		"    -S    use skb-mode\n",
    107		__func__, prog);
    108}
    109
    110int main(int argc, char **argv)
    111{
    112	const char *optstr = "FS";
    113	int prog_fd, map_fd, opt;
    114	struct bpf_program *prog;
    115	struct bpf_object *obj;
    116	struct bpf_map *map;
    117	char filename[256];
    118	int ret, err;
    119
    120	while ((opt = getopt(argc, argv, optstr)) != -1) {
    121		switch (opt) {
    122		case 'F':
    123			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
    124			break;
    125		case 'S':
    126			xdp_flags |= XDP_FLAGS_SKB_MODE;
    127			break;
    128		default:
    129			usage(basename(argv[0]));
    130			return 1;
    131		}
    132	}
    133
    134	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
    135		xdp_flags |= XDP_FLAGS_DRV_MODE;
    136
    137	if (optind == argc) {
    138		usage(basename(argv[0]));
    139		return 1;
    140	}
    141
    142	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
    143
    144	obj = bpf_object__open_file(filename, NULL);
    145	if (libbpf_get_error(obj))
    146		return 1;
    147
    148	prog = bpf_object__next_program(obj, NULL);
    149	bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
    150
    151	err = bpf_object__load(obj);
    152	if (err)
    153		return 1;
    154
    155	prog_fd = bpf_program__fd(prog);
    156
    157	map = bpf_object__next_map(obj, NULL);
    158	if (!map) {
    159		printf("finding a map in obj file failed\n");
    160		return 1;
    161	}
    162	map_fd = bpf_map__fd(map);
    163
    164	if_idx = if_nametoindex(argv[optind]);
    165	if (!if_idx)
    166		if_idx = strtoul(argv[optind], NULL, 0);
    167
    168	if (!if_idx) {
    169		fprintf(stderr, "Invalid ifname\n");
    170		return 1;
    171	}
    172	if_name = argv[optind];
    173	err = do_attach(if_idx, prog_fd, if_name);
    174	if (err)
    175		return err;
    176
    177	if (signal(SIGINT, sig_handler) ||
    178	    signal(SIGHUP, sig_handler) ||
    179	    signal(SIGTERM, sig_handler)) {
    180		perror("signal");
    181		return 1;
    182	}
    183
    184	pb = perf_buffer__new(map_fd, 8, print_bpf_output, NULL, NULL, NULL);
    185	err = libbpf_get_error(pb);
    186	if (err) {
    187		perror("perf_buffer setup failed");
    188		return 1;
    189	}
    190
    191	while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
    192	}
    193
    194	kill(0, SIGINT);
    195	return ret;
    196}