From 05e59e5fb0064c97a1c10921ecd549f2d4a58565 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 09 Oct 2024 06:14:40 +0000
Subject: [PATCH] add REDIRECT
---
kernel/samples/bpf/xdp_sample_pkts_user.c | 151 ++++++++++++++++++++++++++++++-------------------
1 files changed, 92 insertions(+), 59 deletions(-)
diff --git a/kernel/samples/bpf/xdp_sample_pkts_user.c b/kernel/samples/bpf/xdp_sample_pkts_user.c
index 8dd87c1..4b2a300 100644
--- a/kernel/samples/bpf/xdp_sample_pkts_user.c
+++ b/kernel/samples/bpf/xdp_sample_pkts_user.c
@@ -10,42 +10,68 @@
#include <sys/sysinfo.h>
#include <sys/ioctl.h>
#include <signal.h>
-#include <libbpf.h>
+#include <bpf/libbpf.h>
#include <bpf/bpf.h>
+#include <sys/resource.h>
+#include <libgen.h>
+#include <linux/if_link.h>
#include "perf-sys.h"
-#include "trace_helpers.h"
-#define MAX_CPUS 128
-static int pmu_fds[MAX_CPUS], if_idx;
-static struct perf_event_mmap_page *headers[MAX_CPUS];
+static int if_idx;
static char *if_name;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static __u32 prog_id;
+static struct perf_buffer *pb = NULL;
static int do_attach(int idx, int fd, const char *name)
{
+ struct bpf_prog_info info = {};
+ __u32 info_len = sizeof(info);
int err;
- err = bpf_set_link_xdp_fd(idx, fd, 0);
- if (err < 0)
+ err = bpf_set_link_xdp_fd(idx, fd, xdp_flags);
+ if (err < 0) {
printf("ERROR: failed to attach program to %s\n", name);
+ return err;
+ }
+
+ err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+ if (err) {
+ printf("can't get prog info - %s\n", strerror(errno));
+ return err;
+ }
+ prog_id = info.id;
return err;
}
static int do_detach(int idx, const char *name)
{
- int err;
+ __u32 curr_prog_id = 0;
+ int err = 0;
- err = bpf_set_link_xdp_fd(idx, -1, 0);
- if (err < 0)
- printf("ERROR: failed to detach program from %s\n", name);
+ err = bpf_get_link_xdp_id(idx, &curr_prog_id, xdp_flags);
+ if (err) {
+ printf("bpf_get_link_xdp_id failed\n");
+ return err;
+ }
+ if (prog_id == curr_prog_id) {
+ err = bpf_set_link_xdp_fd(idx, -1, xdp_flags);
+ if (err < 0)
+ printf("ERROR: failed to detach prog from %s\n", name);
+ } else if (!curr_prog_id) {
+ printf("couldn't find a prog id on a %s\n", name);
+ } else {
+ printf("program on interface changed, not removing\n");
+ }
return err;
}
#define SAMPLE_SIZE 64
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
{
struct {
__u16 cookie;
@@ -55,68 +81,72 @@
int i;
if (e->cookie != 0xdead) {
- printf("BUG cookie %x sized %d\n",
- e->cookie, size);
- return LIBBPF_PERF_EVENT_ERROR;
+ printf("BUG cookie %x sized %d\n", e->cookie, size);
+ return;
}
printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
for (i = 0; i < 14 && i < e->pkt_len; i++)
printf("%02x ", e->pkt_data[i]);
printf("\n");
-
- return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(int map_fd, int num)
-{
- struct perf_event_attr attr = {
- .sample_type = PERF_SAMPLE_RAW,
- .type = PERF_TYPE_SOFTWARE,
- .config = PERF_COUNT_SW_BPF_OUTPUT,
- .wakeup_events = 1, /* get an fd notification for every event */
- };
- int i;
-
- for (i = 0; i < num; i++) {
- int key = i;
-
- pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/,
- -1/*group_fd*/, 0);
-
- assert(pmu_fds[i] >= 0);
- assert(bpf_map_update_elem(map_fd, &key,
- &pmu_fds[i], BPF_ANY) == 0);
- ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0);
- }
}
static void sig_handler(int signo)
{
do_detach(if_idx, if_name);
+ perf_buffer__free(pb);
exit(0);
+}
+
+static void usage(const char *prog)
+{
+ fprintf(stderr,
+ "%s: %s [OPTS] <ifname|ifindex>\n\n"
+ "OPTS:\n"
+ " -F force loading prog\n",
+ __func__, prog);
}
int main(int argc, char **argv)
{
+ struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
struct bpf_prog_load_attr prog_load_attr = {
.prog_type = BPF_PROG_TYPE_XDP,
};
+ struct perf_buffer_opts pb_opts = {};
+ const char *optstr = "FS";
+ int prog_fd, map_fd, opt;
struct bpf_object *obj;
struct bpf_map *map;
- int prog_fd, map_fd;
char filename[256];
- int ret, err, i;
- int numcpus;
+ int ret, err;
- if (argc < 2) {
- printf("Usage: %s <ifname>\n", argv[0]);
+ while ((opt = getopt(argc, argv, optstr)) != -1) {
+ switch (opt) {
+ case 'F':
+ xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+ break;
+ case 'S':
+ xdp_flags |= XDP_FLAGS_SKB_MODE;
+ break;
+ default:
+ usage(basename(argv[0]));
+ return 1;
+ }
+ }
+
+ if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+ xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+ if (optind == argc) {
+ usage(basename(argv[0]));
return 1;
}
- numcpus = get_nprocs();
- if (numcpus > MAX_CPUS)
- numcpus = MAX_CPUS;
+ if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+ perror("setrlimit(RLIMIT_MEMLOCK)");
+ return 1;
+ }
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
prog_load_attr.file = filename;
@@ -125,7 +155,7 @@
return 1;
if (!prog_fd) {
- printf("load_bpf_file: %s\n", strerror(errno));
+ printf("bpf_prog_load_xattr: %s\n", strerror(errno));
return 1;
}
@@ -136,16 +166,16 @@
}
map_fd = bpf_map__fd(map);
- if_idx = if_nametoindex(argv[1]);
+ if_idx = if_nametoindex(argv[optind]);
if (!if_idx)
- if_idx = strtoul(argv[1], NULL, 0);
+ if_idx = strtoul(argv[optind], NULL, 0);
if (!if_idx) {
fprintf(stderr, "Invalid ifname\n");
return 1;
}
- if_name = argv[1];
- err = do_attach(if_idx, prog_fd, argv[1]);
+ if_name = argv[optind];
+ err = do_attach(if_idx, prog_fd, if_name);
if (err)
return err;
@@ -156,14 +186,17 @@
return 1;
}
- test_bpf_perf_event(map_fd, numcpus);
+ pb_opts.sample_cb = print_bpf_output;
+ pb = perf_buffer__new(map_fd, 8, &pb_opts);
+ err = libbpf_get_error(pb);
+ if (err) {
+ perror("perf_buffer setup failed");
+ return 1;
+ }
- for (i = 0; i < numcpus; i++)
- if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0)
- return 1;
+ while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
+ }
- ret = perf_event_poller_multi(pmu_fds, headers, numcpus,
- print_bpf_output);
kill(0, SIGINT);
return ret;
}
--
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