![Joe Stringer](/assets/img/avatar_default.png)
This declaration was made in samples/bpf/libbpf.c for convenience, but there's already one in tools/perf/perf-sys.h. Reuse that one. Committer notes: Testing it: $ make -j4 O=../build/v4.9.0-rc8+ samples/bpf/ make[1]: Entering directory '/home/build/v4.9.0-rc8+' CHK include/config/kernel.release GEN ./Makefile CHK include/generated/uapi/linux/version.h Using /home/acme/git/linux as source for kernel CHK include/generated/utsrelease.h CHK include/generated/timeconst.h CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL /home/acme/git/linux/scripts/checksyscalls.sh HOSTCC samples/bpf/test_verifier.o HOSTCC samples/bpf/libbpf.o HOSTCC samples/bpf/../../tools/lib/bpf/bpf.o HOSTCC samples/bpf/test_maps.o HOSTCC samples/bpf/sock_example.o HOSTCC samples/bpf/bpf_load.o <SNIP> HOSTLD samples/bpf/trace_event HOSTLD samples/bpf/sampleip HOSTLD samples/bpf/tc_l2_redirect make[1]: Leaving directory '/home/build/v4.9.0-rc8+' $ Also tested the offwaketime resulting from the rebuild, seems to work as before. Signed-off-by: Joe Stringer <joe@ovn.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20161209024620.31660-7-joe@ovn.org [ Use -I$(srctree)/tools/lib/ to support out of source code tree builds ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
558 lines
13 KiB
C
558 lines
13 KiB
C
#include <stdio.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <libelf.h>
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#include <gelf.h>
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#include <errno.h>
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#include <unistd.h>
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#include <string.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <linux/bpf.h>
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#include <linux/filter.h>
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#include <linux/perf_event.h>
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#include <linux/netlink.h>
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#include <linux/rtnetlink.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/syscall.h>
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#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <poll.h>
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#include <ctype.h>
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#include "libbpf.h"
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#include "bpf_load.h"
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#include "perf-sys.h"
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#define DEBUGFS "/sys/kernel/debug/tracing/"
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static char license[128];
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static int kern_version;
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static bool processed_sec[128];
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char bpf_log_buf[BPF_LOG_BUF_SIZE];
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int map_fd[MAX_MAPS];
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int prog_fd[MAX_PROGS];
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int event_fd[MAX_PROGS];
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int prog_cnt;
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int prog_array_fd = -1;
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struct bpf_map_def {
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unsigned int type;
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unsigned int key_size;
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unsigned int value_size;
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unsigned int max_entries;
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unsigned int map_flags;
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};
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static int populate_prog_array(const char *event, int prog_fd)
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{
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int ind = atoi(event), err;
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err = bpf_map_update_elem(prog_array_fd, &ind, &prog_fd, BPF_ANY);
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if (err < 0) {
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printf("failed to store prog_fd in prog_array\n");
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return -1;
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}
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return 0;
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}
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static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
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{
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bool is_socket = strncmp(event, "socket", 6) == 0;
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bool is_kprobe = strncmp(event, "kprobe/", 7) == 0;
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bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
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bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
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bool is_xdp = strncmp(event, "xdp", 3) == 0;
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bool is_perf_event = strncmp(event, "perf_event", 10) == 0;
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bool is_cgroup_skb = strncmp(event, "cgroup/skb", 10) == 0;
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bool is_cgroup_sk = strncmp(event, "cgroup/sock", 11) == 0;
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size_t insns_cnt = size / sizeof(struct bpf_insn);
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enum bpf_prog_type prog_type;
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char buf[256];
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int fd, efd, err, id;
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struct perf_event_attr attr = {};
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attr.type = PERF_TYPE_TRACEPOINT;
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attr.sample_type = PERF_SAMPLE_RAW;
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attr.sample_period = 1;
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attr.wakeup_events = 1;
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if (is_socket) {
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prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
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} else if (is_kprobe || is_kretprobe) {
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prog_type = BPF_PROG_TYPE_KPROBE;
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} else if (is_tracepoint) {
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prog_type = BPF_PROG_TYPE_TRACEPOINT;
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} else if (is_xdp) {
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prog_type = BPF_PROG_TYPE_XDP;
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} else if (is_perf_event) {
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prog_type = BPF_PROG_TYPE_PERF_EVENT;
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} else if (is_cgroup_skb) {
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prog_type = BPF_PROG_TYPE_CGROUP_SKB;
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} else if (is_cgroup_sk) {
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prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
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} else {
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printf("Unknown event '%s'\n", event);
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return -1;
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}
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fd = bpf_load_program(prog_type, prog, insns_cnt, license, kern_version,
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bpf_log_buf, BPF_LOG_BUF_SIZE);
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if (fd < 0) {
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printf("bpf_load_program() err=%d\n%s", errno, bpf_log_buf);
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return -1;
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}
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prog_fd[prog_cnt++] = fd;
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if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk)
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return 0;
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if (is_socket) {
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event += 6;
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if (*event != '/')
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return 0;
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event++;
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if (!isdigit(*event)) {
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printf("invalid prog number\n");
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return -1;
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}
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return populate_prog_array(event, fd);
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}
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if (is_kprobe || is_kretprobe) {
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if (is_kprobe)
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event += 7;
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else
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event += 10;
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if (*event == 0) {
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printf("event name cannot be empty\n");
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return -1;
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}
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if (isdigit(*event))
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return populate_prog_array(event, fd);
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snprintf(buf, sizeof(buf),
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"echo '%c:%s %s' >> /sys/kernel/debug/tracing/kprobe_events",
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is_kprobe ? 'p' : 'r', event, event);
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err = system(buf);
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if (err < 0) {
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printf("failed to create kprobe '%s' error '%s'\n",
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event, strerror(errno));
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return -1;
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}
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strcpy(buf, DEBUGFS);
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strcat(buf, "events/kprobes/");
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strcat(buf, event);
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strcat(buf, "/id");
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} else if (is_tracepoint) {
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event += 11;
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if (*event == 0) {
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printf("event name cannot be empty\n");
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return -1;
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}
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strcpy(buf, DEBUGFS);
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strcat(buf, "events/");
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strcat(buf, event);
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strcat(buf, "/id");
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}
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efd = open(buf, O_RDONLY, 0);
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if (efd < 0) {
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printf("failed to open event %s\n", event);
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return -1;
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}
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err = read(efd, buf, sizeof(buf));
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if (err < 0 || err >= sizeof(buf)) {
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printf("read from '%s' failed '%s'\n", event, strerror(errno));
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return -1;
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}
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close(efd);
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buf[err] = 0;
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id = atoi(buf);
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attr.config = id;
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efd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
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if (efd < 0) {
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printf("event %d fd %d err %s\n", id, efd, strerror(errno));
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return -1;
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}
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event_fd[prog_cnt - 1] = efd;
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ioctl(efd, PERF_EVENT_IOC_ENABLE, 0);
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ioctl(efd, PERF_EVENT_IOC_SET_BPF, fd);
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return 0;
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}
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static int load_maps(struct bpf_map_def *maps, int len)
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{
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int i;
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for (i = 0; i < len / sizeof(struct bpf_map_def); i++) {
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map_fd[i] = bpf_create_map(maps[i].type,
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maps[i].key_size,
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maps[i].value_size,
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maps[i].max_entries,
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maps[i].map_flags);
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if (map_fd[i] < 0) {
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printf("failed to create a map: %d %s\n",
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errno, strerror(errno));
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return 1;
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}
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if (maps[i].type == BPF_MAP_TYPE_PROG_ARRAY)
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prog_array_fd = map_fd[i];
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}
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return 0;
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}
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static int get_sec(Elf *elf, int i, GElf_Ehdr *ehdr, char **shname,
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GElf_Shdr *shdr, Elf_Data **data)
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{
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Elf_Scn *scn;
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scn = elf_getscn(elf, i);
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if (!scn)
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return 1;
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if (gelf_getshdr(scn, shdr) != shdr)
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return 2;
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*shname = elf_strptr(elf, ehdr->e_shstrndx, shdr->sh_name);
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if (!*shname || !shdr->sh_size)
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return 3;
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*data = elf_getdata(scn, 0);
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if (!*data || elf_getdata(scn, *data) != NULL)
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return 4;
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return 0;
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}
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static int parse_relo_and_apply(Elf_Data *data, Elf_Data *symbols,
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GElf_Shdr *shdr, struct bpf_insn *insn)
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{
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int i, nrels;
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nrels = shdr->sh_size / shdr->sh_entsize;
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for (i = 0; i < nrels; i++) {
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GElf_Sym sym;
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GElf_Rel rel;
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unsigned int insn_idx;
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gelf_getrel(data, i, &rel);
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insn_idx = rel.r_offset / sizeof(struct bpf_insn);
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gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym);
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if (insn[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
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printf("invalid relo for insn[%d].code 0x%x\n",
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insn_idx, insn[insn_idx].code);
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return 1;
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}
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insn[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
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insn[insn_idx].imm = map_fd[sym.st_value / sizeof(struct bpf_map_def)];
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}
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return 0;
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}
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int load_bpf_file(char *path)
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{
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int fd, i;
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Elf *elf;
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GElf_Ehdr ehdr;
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GElf_Shdr shdr, shdr_prog;
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Elf_Data *data, *data_prog, *symbols = NULL;
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char *shname, *shname_prog;
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if (elf_version(EV_CURRENT) == EV_NONE)
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return 1;
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fd = open(path, O_RDONLY, 0);
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if (fd < 0)
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return 1;
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elf = elf_begin(fd, ELF_C_READ, NULL);
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if (!elf)
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return 1;
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if (gelf_getehdr(elf, &ehdr) != &ehdr)
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return 1;
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/* clear all kprobes */
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i = system("echo \"\" > /sys/kernel/debug/tracing/kprobe_events");
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/* scan over all elf sections to get license and map info */
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for (i = 1; i < ehdr.e_shnum; i++) {
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if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
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continue;
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if (0) /* helpful for llvm debugging */
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printf("section %d:%s data %p size %zd link %d flags %d\n",
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i, shname, data->d_buf, data->d_size,
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shdr.sh_link, (int) shdr.sh_flags);
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if (strcmp(shname, "license") == 0) {
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processed_sec[i] = true;
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memcpy(license, data->d_buf, data->d_size);
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} else if (strcmp(shname, "version") == 0) {
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processed_sec[i] = true;
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if (data->d_size != sizeof(int)) {
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printf("invalid size of version section %zd\n",
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data->d_size);
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return 1;
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}
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memcpy(&kern_version, data->d_buf, sizeof(int));
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} else if (strcmp(shname, "maps") == 0) {
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processed_sec[i] = true;
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if (load_maps(data->d_buf, data->d_size))
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return 1;
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} else if (shdr.sh_type == SHT_SYMTAB) {
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symbols = data;
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}
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}
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/* load programs that need map fixup (relocations) */
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for (i = 1; i < ehdr.e_shnum; i++) {
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if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
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continue;
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if (shdr.sh_type == SHT_REL) {
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struct bpf_insn *insns;
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if (get_sec(elf, shdr.sh_info, &ehdr, &shname_prog,
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&shdr_prog, &data_prog))
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continue;
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if (shdr_prog.sh_type != SHT_PROGBITS ||
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!(shdr_prog.sh_flags & SHF_EXECINSTR))
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continue;
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insns = (struct bpf_insn *) data_prog->d_buf;
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processed_sec[shdr.sh_info] = true;
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processed_sec[i] = true;
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if (parse_relo_and_apply(data, symbols, &shdr, insns))
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continue;
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if (memcmp(shname_prog, "kprobe/", 7) == 0 ||
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memcmp(shname_prog, "kretprobe/", 10) == 0 ||
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memcmp(shname_prog, "tracepoint/", 11) == 0 ||
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memcmp(shname_prog, "xdp", 3) == 0 ||
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memcmp(shname_prog, "perf_event", 10) == 0 ||
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memcmp(shname_prog, "socket", 6) == 0 ||
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memcmp(shname_prog, "cgroup/", 7) == 0)
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load_and_attach(shname_prog, insns, data_prog->d_size);
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}
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}
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/* load programs that don't use maps */
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for (i = 1; i < ehdr.e_shnum; i++) {
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if (processed_sec[i])
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continue;
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if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
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continue;
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if (memcmp(shname, "kprobe/", 7) == 0 ||
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memcmp(shname, "kretprobe/", 10) == 0 ||
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memcmp(shname, "tracepoint/", 11) == 0 ||
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memcmp(shname, "xdp", 3) == 0 ||
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memcmp(shname, "perf_event", 10) == 0 ||
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memcmp(shname, "socket", 6) == 0 ||
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memcmp(shname, "cgroup/", 7) == 0)
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load_and_attach(shname, data->d_buf, data->d_size);
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}
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close(fd);
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return 0;
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}
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void read_trace_pipe(void)
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{
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int trace_fd;
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trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
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if (trace_fd < 0)
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return;
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while (1) {
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static char buf[4096];
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ssize_t sz;
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sz = read(trace_fd, buf, sizeof(buf));
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if (sz > 0) {
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buf[sz] = 0;
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puts(buf);
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}
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}
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}
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#define MAX_SYMS 300000
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static struct ksym syms[MAX_SYMS];
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static int sym_cnt;
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static int ksym_cmp(const void *p1, const void *p2)
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{
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return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
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}
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int load_kallsyms(void)
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{
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FILE *f = fopen("/proc/kallsyms", "r");
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char func[256], buf[256];
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char symbol;
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void *addr;
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int i = 0;
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if (!f)
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return -ENOENT;
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while (!feof(f)) {
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if (!fgets(buf, sizeof(buf), f))
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break;
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if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
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break;
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if (!addr)
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continue;
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syms[i].addr = (long) addr;
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syms[i].name = strdup(func);
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i++;
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}
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sym_cnt = i;
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qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
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return 0;
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}
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struct ksym *ksym_search(long key)
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{
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int start = 0, end = sym_cnt;
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int result;
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while (start < end) {
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size_t mid = start + (end - start) / 2;
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result = key - syms[mid].addr;
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if (result < 0)
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end = mid;
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else if (result > 0)
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start = mid + 1;
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else
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return &syms[mid];
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}
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if (start >= 1 && syms[start - 1].addr < key &&
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key < syms[start].addr)
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/* valid ksym */
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return &syms[start - 1];
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/* out of range. return _stext */
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return &syms[0];
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}
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int set_link_xdp_fd(int ifindex, int fd)
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{
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struct sockaddr_nl sa;
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int sock, seq = 0, len, ret = -1;
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char buf[4096];
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struct nlattr *nla, *nla_xdp;
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struct {
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struct nlmsghdr nh;
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struct ifinfomsg ifinfo;
|
|
char attrbuf[64];
|
|
} req;
|
|
struct nlmsghdr *nh;
|
|
struct nlmsgerr *err;
|
|
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.nl_family = AF_NETLINK;
|
|
|
|
sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
|
|
if (sock < 0) {
|
|
printf("open netlink socket: %s\n", strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
|
|
printf("bind to netlink: %s\n", strerror(errno));
|
|
goto cleanup;
|
|
}
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
|
|
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
|
|
req.nh.nlmsg_type = RTM_SETLINK;
|
|
req.nh.nlmsg_pid = 0;
|
|
req.nh.nlmsg_seq = ++seq;
|
|
req.ifinfo.ifi_family = AF_UNSPEC;
|
|
req.ifinfo.ifi_index = ifindex;
|
|
nla = (struct nlattr *)(((char *)&req)
|
|
+ NLMSG_ALIGN(req.nh.nlmsg_len));
|
|
nla->nla_type = NLA_F_NESTED | 43/*IFLA_XDP*/;
|
|
|
|
nla_xdp = (struct nlattr *)((char *)nla + NLA_HDRLEN);
|
|
nla_xdp->nla_type = 1/*IFLA_XDP_FD*/;
|
|
nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
|
|
memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
|
|
nla->nla_len = NLA_HDRLEN + nla_xdp->nla_len;
|
|
|
|
req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
|
|
|
|
if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
|
|
printf("send to netlink: %s\n", strerror(errno));
|
|
goto cleanup;
|
|
}
|
|
|
|
len = recv(sock, buf, sizeof(buf), 0);
|
|
if (len < 0) {
|
|
printf("recv from netlink: %s\n", strerror(errno));
|
|
goto cleanup;
|
|
}
|
|
|
|
for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
|
|
nh = NLMSG_NEXT(nh, len)) {
|
|
if (nh->nlmsg_pid != getpid()) {
|
|
printf("Wrong pid %d, expected %d\n",
|
|
nh->nlmsg_pid, getpid());
|
|
goto cleanup;
|
|
}
|
|
if (nh->nlmsg_seq != seq) {
|
|
printf("Wrong seq %d, expected %d\n",
|
|
nh->nlmsg_seq, seq);
|
|
goto cleanup;
|
|
}
|
|
switch (nh->nlmsg_type) {
|
|
case NLMSG_ERROR:
|
|
err = (struct nlmsgerr *)NLMSG_DATA(nh);
|
|
if (!err->error)
|
|
continue;
|
|
printf("nlmsg error %s\n", strerror(-err->error));
|
|
goto cleanup;
|
|
case NLMSG_DONE:
|
|
break;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
cleanup:
|
|
close(sock);
|
|
return ret;
|
|
}
|