| /* |
| * Copyright (c) 2015 PLUMgrid, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #ifndef _GNU_SOURCE |
| #define _GNU_SOURCE |
| #endif |
| |
| #include <arpa/inet.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <linux/bpf.h> |
| #include <linux/bpf_common.h> |
| #include <linux/if_packet.h> |
| #include <linux/perf_event.h> |
| #include <linux/pkt_cls.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/sched.h> |
| #include <linux/unistd.h> |
| #include <linux/version.h> |
| #include <net/ethernet.h> |
| #include <net/if.h> |
| #include <sched.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/ioctl.h> |
| #include <sys/resource.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| #include <linux/if_alg.h> |
| |
| #include "libbpf.h" |
| #include "perf_reader.h" |
| |
| // TODO: remove these defines when linux-libc-dev exports them properly |
| |
| #ifndef __NR_bpf |
| #if defined(__powerpc64__) |
| #define __NR_bpf 361 |
| #elif defined(__s390x__) |
| #define __NR_bpf 351 |
| #elif defined(__aarch64__) |
| #define __NR_bpf 280 |
| #else |
| #define __NR_bpf 321 |
| #endif |
| #endif |
| |
| #ifndef SO_ATTACH_BPF |
| #define SO_ATTACH_BPF 50 |
| #endif |
| |
| #ifndef PERF_EVENT_IOC_SET_BPF |
| #define PERF_EVENT_IOC_SET_BPF _IOW('$', 8, __u32) |
| #endif |
| |
| #ifndef PERF_FLAG_FD_CLOEXEC |
| #define PERF_FLAG_FD_CLOEXEC (1UL << 3) |
| #endif |
| |
| static int probe_perf_reader_page_cnt = 8; |
| |
| static uint64_t ptr_to_u64(void *ptr) |
| { |
| return (uint64_t) (unsigned long) ptr; |
| } |
| |
| int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries, int map_flags) |
| { |
| union bpf_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_type = map_type; |
| attr.key_size = key_size; |
| attr.value_size = value_size; |
| attr.max_entries = max_entries; |
| attr.map_flags = map_flags; |
| |
| int ret = syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr)); |
| if (ret < 0 && errno == EPERM) { |
| // see note below about the rationale for this retry |
| |
| struct rlimit rl = {}; |
| if (getrlimit(RLIMIT_MEMLOCK, &rl) == 0) { |
| rl.rlim_max = RLIM_INFINITY; |
| rl.rlim_cur = rl.rlim_max; |
| if (setrlimit(RLIMIT_MEMLOCK, &rl) == 0) |
| ret = syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr)); |
| } |
| } |
| return ret; |
| } |
| |
| int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags) |
| { |
| union bpf_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_fd = fd; |
| attr.key = ptr_to_u64(key); |
| attr.value = ptr_to_u64(value); |
| attr.flags = flags; |
| |
| return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); |
| } |
| |
| int bpf_lookup_elem(int fd, void *key, void *value) |
| { |
| union bpf_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_fd = fd; |
| attr.key = ptr_to_u64(key); |
| attr.value = ptr_to_u64(value); |
| |
| return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); |
| } |
| |
| int bpf_delete_elem(int fd, void *key) |
| { |
| union bpf_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_fd = fd; |
| attr.key = ptr_to_u64(key); |
| |
| return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); |
| } |
| |
| int bpf_get_first_key(int fd, void *key, size_t key_size) |
| { |
| union bpf_attr attr; |
| int i, res; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_fd = fd; |
| attr.key = 0; |
| attr.next_key = ptr_to_u64(key); |
| |
| // 4.12 and above kernel supports passing NULL to BPF_MAP_GET_NEXT_KEY |
| // to get first key of the map. For older kernels, the call will fail. |
| res = syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); |
| if (res < 0 && errno == EFAULT) { |
| // Fall back to try to find a non-existing key. |
| static unsigned char try_values[3] = {0, 0xff, 0x55}; |
| attr.key = ptr_to_u64(key); |
| for (i = 0; i < 3; i++) { |
| memset(key, try_values[i], key_size); |
| // We want to check the existence of the key but we don't know the size |
| // of map's value. So we pass an invalid pointer for value, expect |
| // the call to fail and check if the error is ENOENT indicating the |
| // key doesn't exist. If we use NULL for the invalid pointer, it might |
| // trigger a page fault in kernel and affect performance. Hence we use |
| // ~0 which will fail and return fast. |
| // This should fail since we pass an invalid pointer for value. |
| if (bpf_lookup_elem(fd, key, (void *)~0) >= 0) |
| return -1; |
| // This means the key doesn't exist. |
| if (errno == ENOENT) |
| return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); |
| } |
| return -1; |
| } else { |
| return res; |
| } |
| } |
| |
| int bpf_get_next_key(int fd, void *key, void *next_key) |
| { |
| union bpf_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_fd = fd; |
| attr.key = ptr_to_u64(key); |
| attr.next_key = ptr_to_u64(next_key); |
| |
| return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); |
| } |
| |
| static void bpf_print_hints(char *log) |
| { |
| if (log == NULL) |
| return; |
| |
| // The following error strings will need maintenance to match LLVM. |
| |
| // stack busting |
| if (strstr(log, "invalid stack off=-") != NULL) { |
| fprintf(stderr, "HINT: Looks like you exceeded the BPF stack limit. " |
| "This can happen if you allocate too much local variable storage. " |
| "For example, if you allocated a 1 Kbyte struct (maybe for " |
| "BPF_PERF_OUTPUT), busting a max stack of 512 bytes.\n\n"); |
| } |
| |
| // didn't check NULL on map lookup |
| if (strstr(log, "invalid mem access 'map_value_or_null'") != NULL) { |
| fprintf(stderr, "HINT: The 'map_value_or_null' error can happen if " |
| "you dereference a pointer value from a map lookup without first " |
| "checking if that pointer is NULL.\n\n"); |
| } |
| |
| // lacking a bpf_probe_read |
| if (strstr(log, "invalid mem access 'inv'") != NULL) { |
| fprintf(stderr, "HINT: The invalid mem access 'inv' error can happen " |
| "if you try to dereference memory without first using " |
| "bpf_probe_read() to copy it to the BPF stack. Sometimes the " |
| "bpf_probe_read is automatic by the bcc rewriter, other times " |
| "you'll need to be explicit.\n\n"); |
| } |
| } |
| #define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u)) |
| |
| int bpf_obj_get_info(int prog_map_fd, void *info, int *info_len) |
| { |
| union bpf_attr attr; |
| int err; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.info.bpf_fd = prog_map_fd; |
| attr.info.info_len = *info_len; |
| attr.info.info = ptr_to_u64(info); |
| |
| err = syscall(__NR_bpf, BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); |
| if (!err) |
| *info_len = attr.info.info_len; |
| |
| return err; |
| } |
| |
| int bpf_prog_compute_tag(const struct bpf_insn *insns, int prog_len, |
| unsigned long long *ptag) |
| { |
| struct sockaddr_alg alg = { |
| .salg_family = AF_ALG, |
| .salg_type = "hash", |
| .salg_name = "sha1", |
| }; |
| int shafd = socket(AF_ALG, SOCK_SEQPACKET, 0); |
| if (shafd < 0) { |
| fprintf(stderr, "sha1 socket not available %s\n", strerror(errno)); |
| return -1; |
| } |
| int ret = bind(shafd, (struct sockaddr *)&alg, sizeof(alg)); |
| if (ret < 0) { |
| fprintf(stderr, "sha1 bind fail %s\n", strerror(errno)); |
| close(shafd); |
| return ret; |
| } |
| int shafd2 = accept(shafd, NULL, 0); |
| if (shafd2 < 0) { |
| fprintf(stderr, "sha1 accept fail %s\n", strerror(errno)); |
| close(shafd); |
| return -1; |
| } |
| struct bpf_insn prog[prog_len / 8]; |
| bool map_ld_seen = false; |
| int i; |
| for (i = 0; i < prog_len / 8; i++) { |
| prog[i] = insns[i]; |
| if (insns[i].code == (BPF_LD | BPF_DW | BPF_IMM) && |
| insns[i].src_reg == BPF_PSEUDO_MAP_FD && |
| !map_ld_seen) { |
| prog[i].imm = 0; |
| map_ld_seen = true; |
| } else if (insns[i].code == 0 && map_ld_seen) { |
| prog[i].imm = 0; |
| map_ld_seen = false; |
| } else { |
| map_ld_seen = false; |
| } |
| } |
| ret = write(shafd2, prog, prog_len); |
| if (ret != prog_len) { |
| fprintf(stderr, "sha1 write fail %s\n", strerror(errno)); |
| close(shafd2); |
| close(shafd); |
| return -1; |
| } |
| |
| union { |
| unsigned char sha[20]; |
| unsigned long long tag; |
| } u = {}; |
| ret = read(shafd2, u.sha, 20); |
| if (ret != 20) { |
| fprintf(stderr, "sha1 read fail %s\n", strerror(errno)); |
| close(shafd2); |
| close(shafd); |
| return -1; |
| } |
| *ptag = __builtin_bswap64(u.tag); |
| return 0; |
| } |
| |
| int bpf_prog_get_tag(int fd, unsigned long long *ptag) |
| { |
| char fmt[64]; |
| snprintf(fmt, sizeof(fmt), "/proc/self/fdinfo/%d", fd); |
| FILE * f = fopen(fmt, "r"); |
| if (!f) { |
| /* fprintf(stderr, "failed to open fdinfo %s\n", strerror(errno));*/ |
| return -1; |
| } |
| fgets(fmt, sizeof(fmt), f); // pos |
| fgets(fmt, sizeof(fmt), f); // flags |
| fgets(fmt, sizeof(fmt), f); // mnt_id |
| fgets(fmt, sizeof(fmt), f); // prog_type |
| fgets(fmt, sizeof(fmt), f); // prog_jited |
| fgets(fmt, sizeof(fmt), f); // prog_tag |
| fclose(f); |
| char *p = strchr(fmt, ':'); |
| if (!p) { |
| /* fprintf(stderr, "broken fdinfo %s\n", fmt);*/ |
| return -2; |
| } |
| unsigned long long tag = 0; |
| sscanf(p + 1, "%llx", &tag); |
| *ptag = tag; |
| return 0; |
| } |
| |
| int bpf_prog_load(enum bpf_prog_type prog_type, |
| const struct bpf_insn *insns, int prog_len, |
| const char *license, unsigned kern_version, |
| char *log_buf, unsigned log_buf_size) |
| { |
| union bpf_attr attr; |
| char *bpf_log_buffer = NULL; |
| unsigned buffer_size = 0; |
| int ret = 0; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.prog_type = prog_type; |
| attr.insns = ptr_to_u64((void *) insns); |
| attr.insn_cnt = prog_len / sizeof(struct bpf_insn); |
| attr.license = ptr_to_u64((void *) license); |
| attr.log_buf = ptr_to_u64(log_buf); |
| attr.log_size = log_buf_size; |
| attr.log_level = log_buf ? 1 : 0; |
| |
| attr.kern_version = kern_version; |
| if (log_buf) |
| log_buf[0] = 0; |
| |
| if (attr.insn_cnt > BPF_MAXINSNS) { |
| ret = -1; |
| errno = EINVAL; |
| fprintf(stderr, |
| "bpf: %s. Program too large (%d insns), at most %d insns\n\n", |
| strerror(errno), attr.insn_cnt, BPF_MAXINSNS); |
| return ret; |
| } |
| |
| ret = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); |
| |
| if (ret < 0 && errno == EPERM) { |
| // When EPERM is returned, two reasons are possible: |
| // 1. user has no permissions for bpf() |
| // 2. user has insufficent rlimit for locked memory |
| // Unfortunately, there is no api to inspect the current usage of locked |
| // mem for the user, so an accurate calculation of how much memory to lock |
| // for this new program is difficult to calculate. As a hack, bump the limit |
| // to unlimited. If program load fails again, return the error. |
| |
| struct rlimit rl = {}; |
| if (getrlimit(RLIMIT_MEMLOCK, &rl) == 0) { |
| rl.rlim_max = RLIM_INFINITY; |
| rl.rlim_cur = rl.rlim_max; |
| if (setrlimit(RLIMIT_MEMLOCK, &rl) == 0) |
| ret = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); |
| } |
| } |
| |
| if (ret < 0 && !log_buf) { |
| |
| buffer_size = LOG_BUF_SIZE; |
| // caller did not specify log_buf but failure should be printed, |
| // so repeat the syscall and print the result to stderr |
| for (;;) { |
| bpf_log_buffer = malloc(buffer_size); |
| if (!bpf_log_buffer) { |
| fprintf(stderr, |
| "bpf: buffer log memory allocation failed for error %s\n\n", |
| strerror(errno)); |
| return ret; |
| } |
| bpf_log_buffer[0] = 0; |
| |
| attr.log_buf = ptr_to_u64(bpf_log_buffer); |
| attr.log_size = buffer_size; |
| attr.log_level = bpf_log_buffer ? 1 : 0; |
| |
| ret = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); |
| if (ret < 0 && errno == ENOSPC) { |
| free(bpf_log_buffer); |
| bpf_log_buffer = NULL; |
| buffer_size <<= 1; |
| } else { |
| break; |
| } |
| } |
| |
| fprintf(stderr, "bpf: %s\n%s\n", strerror(errno), bpf_log_buffer); |
| bpf_print_hints(bpf_log_buffer); |
| |
| free(bpf_log_buffer); |
| } |
| return ret; |
| } |
| |
| int bpf_open_raw_sock(const char *name) |
| { |
| struct sockaddr_ll sll; |
| int sock; |
| |
| sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL)); |
| if (sock < 0) { |
| fprintf(stderr, "cannot create raw socket\n"); |
| return -1; |
| } |
| |
| memset(&sll, 0, sizeof(sll)); |
| sll.sll_family = AF_PACKET; |
| sll.sll_ifindex = if_nametoindex(name); |
| if (sll.sll_ifindex == 0) { |
| fprintf(stderr, "bpf: Resolving device name to index: %s\n", strerror(errno)); |
| close(sock); |
| return -1; |
| } |
| sll.sll_protocol = htons(ETH_P_ALL); |
| if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) { |
| fprintf(stderr, "bind to %s: %s\n", name, strerror(errno)); |
| close(sock); |
| return -1; |
| } |
| |
| return sock; |
| } |
| |
| int bpf_attach_socket(int sock, int prog) { |
| return setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog, sizeof(prog)); |
| } |
| |
| static int bpf_attach_tracing_event(int progfd, const char *event_path, |
| struct perf_reader *reader, int pid, int cpu, int group_fd) { |
| int efd, pfd; |
| ssize_t bytes; |
| char buf[256]; |
| struct perf_event_attr attr = {}; |
| |
| snprintf(buf, sizeof(buf), "%s/id", event_path); |
| efd = open(buf, O_RDONLY, 0); |
| if (efd < 0) { |
| fprintf(stderr, "open(%s): %s\n", buf, strerror(errno)); |
| return -1; |
| } |
| |
| bytes = read(efd, buf, sizeof(buf)); |
| if (bytes <= 0 || bytes >= sizeof(buf)) { |
| fprintf(stderr, "read(%s): %s\n", buf, strerror(errno)); |
| close(efd); |
| return -1; |
| } |
| close(efd); |
| buf[bytes] = '\0'; |
| attr.config = strtol(buf, NULL, 0); |
| attr.type = PERF_TYPE_TRACEPOINT; |
| attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN; |
| attr.sample_period = 1; |
| attr.wakeup_events = 1; |
| pfd = syscall(__NR_perf_event_open, &attr, pid, cpu, group_fd, PERF_FLAG_FD_CLOEXEC); |
| if (pfd < 0) { |
| fprintf(stderr, "perf_event_open(%s/id): %s\n", event_path, strerror(errno)); |
| return -1; |
| } |
| perf_reader_set_fd(reader, pfd); |
| |
| if (perf_reader_mmap(reader, attr.type, attr.sample_type) < 0) |
| return -1; |
| |
| if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, progfd) < 0) { |
| perror("ioctl(PERF_EVENT_IOC_SET_BPF)"); |
| return -1; |
| } |
| if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { |
| perror("ioctl(PERF_EVENT_IOC_ENABLE)"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| void * bpf_attach_kprobe(int progfd, enum bpf_probe_attach_type attach_type, const char *ev_name, |
| const char *fn_name, |
| pid_t pid, int cpu, int group_fd, |
| perf_reader_cb cb, void *cb_cookie) |
| { |
| int kfd; |
| char buf[256]; |
| char event_alias[128]; |
| struct perf_reader *reader = NULL; |
| static char *event_type = "kprobe"; |
| |
| reader = perf_reader_new(cb, NULL, NULL, cb_cookie, probe_perf_reader_page_cnt); |
| if (!reader) |
| goto error; |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", event_type); |
| kfd = open(buf, O_WRONLY | O_APPEND, 0); |
| if (kfd < 0) { |
| fprintf(stderr, "open(%s): %s\n", buf, strerror(errno)); |
| goto error; |
| } |
| |
| snprintf(event_alias, sizeof(event_alias), "%s_bcc_%d", ev_name, getpid()); |
| snprintf(buf, sizeof(buf), "%c:%ss/%s %s", attach_type==BPF_PROBE_ENTRY ? 'p' : 'r', |
| event_type, event_alias, fn_name); |
| if (write(kfd, buf, strlen(buf)) < 0) { |
| if (errno == EINVAL) |
| fprintf(stderr, "check dmesg output for possible cause\n"); |
| close(kfd); |
| goto error; |
| } |
| close(kfd); |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s", event_type, event_alias); |
| if (bpf_attach_tracing_event(progfd, buf, reader, pid, cpu, group_fd) < 0) |
| goto error; |
| |
| return reader; |
| |
| error: |
| perf_reader_free(reader); |
| return NULL; |
| |
| } |
| |
| static int enter_mount_ns(int pid) { |
| struct stat self_stat, target_stat; |
| int self_fd = -1, target_fd = -1; |
| char buf[64]; |
| |
| if (pid < 0) |
| return -1; |
| |
| if ((size_t)snprintf(buf, sizeof(buf), "/proc/%d/ns/mnt", pid) >= sizeof(buf)) |
| return -1; |
| |
| self_fd = open("/proc/self/ns/mnt", O_RDONLY); |
| if (self_fd < 0) { |
| perror("open(/proc/self/ns/mnt)"); |
| return -1; |
| } |
| |
| target_fd = open(buf, O_RDONLY); |
| if (target_fd < 0) { |
| perror("open(/proc/<pid>/ns/mnt)"); |
| goto error; |
| } |
| |
| if (fstat(self_fd, &self_stat)) { |
| perror("fstat(self_fd)"); |
| goto error; |
| } |
| |
| if (fstat(target_fd, &target_stat)) { |
| perror("fstat(target_fd)"); |
| goto error; |
| } |
| |
| // both target and current ns are same, avoid setns and close all fds |
| if (self_stat.st_ino == target_stat.st_ino) |
| goto error; |
| |
| if (setns(target_fd, CLONE_NEWNS)) { |
| perror("setns(target)"); |
| goto error; |
| } |
| |
| close(target_fd); |
| return self_fd; |
| |
| error: |
| if (self_fd >= 0) |
| close(self_fd); |
| if (target_fd >= 0) |
| close(target_fd); |
| return -1; |
| } |
| |
| static void exit_mount_ns(int fd) { |
| if (fd < 0) |
| return; |
| |
| if (setns(fd, CLONE_NEWNS)) |
| perror("setns"); |
| } |
| |
| void * bpf_attach_uprobe(int progfd, enum bpf_probe_attach_type attach_type, const char *ev_name, |
| const char *binary_path, uint64_t offset, |
| pid_t pid, int cpu, int group_fd, |
| perf_reader_cb cb, void *cb_cookie) |
| { |
| char buf[PATH_MAX]; |
| char event_alias[PATH_MAX]; |
| struct perf_reader *reader = NULL; |
| static char *event_type = "uprobe"; |
| int res, kfd = -1, ns_fd = -1; |
| |
| reader = perf_reader_new(cb, NULL, NULL, cb_cookie, probe_perf_reader_page_cnt); |
| if (!reader) |
| goto error; |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", event_type); |
| kfd = open(buf, O_WRONLY | O_APPEND, 0); |
| if (kfd < 0) { |
| fprintf(stderr, "open(%s): %s\n", buf, strerror(errno)); |
| goto error; |
| } |
| |
| res = snprintf(event_alias, sizeof(event_alias), "%s_bcc_%d", ev_name, getpid()); |
| if (res < 0 || res >= sizeof(event_alias)) { |
| fprintf(stderr, "Event name (%s) is too long for buffer\n", ev_name); |
| goto error; |
| } |
| res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx", attach_type==BPF_PROBE_ENTRY ? 'p' : 'r', |
| event_type, event_alias, binary_path, offset); |
| if (res < 0 || res >= sizeof(buf)) { |
| fprintf(stderr, "Event alias (%s) too long for buffer\n", event_alias); |
| goto error; |
| } |
| |
| ns_fd = enter_mount_ns(pid); |
| if (write(kfd, buf, strlen(buf)) < 0) { |
| if (errno == EINVAL) |
| fprintf(stderr, "check dmesg output for possible cause\n"); |
| goto error; |
| } |
| close(kfd); |
| exit_mount_ns(ns_fd); |
| ns_fd = -1; |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s", event_type, event_alias); |
| if (bpf_attach_tracing_event(progfd, buf, reader, pid, cpu, group_fd) < 0) |
| goto error; |
| |
| return reader; |
| |
| error: |
| if (kfd >= 0) |
| close(kfd); |
| exit_mount_ns(ns_fd); |
| perf_reader_free(reader); |
| return NULL; |
| } |
| |
| static int bpf_detach_probe(const char *ev_name, const char *event_type) |
| { |
| int kfd, res; |
| char buf[PATH_MAX]; |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", event_type); |
| kfd = open(buf, O_WRONLY | O_APPEND, 0); |
| if (kfd < 0) { |
| fprintf(stderr, "open(%s): %s\n", buf, strerror(errno)); |
| goto error; |
| } |
| |
| res = snprintf(buf, sizeof(buf), "-:%ss/%s_bcc_%d", event_type, ev_name, getpid()); |
| if (res < 0 || res >= sizeof(buf)) { |
| fprintf(stderr, "snprintf(%s): %d\n", ev_name, res); |
| goto error; |
| } |
| if (write(kfd, buf, strlen(buf)) < 0) { |
| fprintf(stderr, "write(%s): %s\n", buf, strerror(errno)); |
| goto error; |
| } |
| |
| close(kfd); |
| return 0; |
| |
| error: |
| if (kfd >= 0) |
| close(kfd); |
| return -1; |
| } |
| |
| int bpf_detach_kprobe(const char *ev_name) |
| { |
| return bpf_detach_probe(ev_name, "kprobe"); |
| } |
| |
| int bpf_detach_uprobe(const char *ev_name) |
| { |
| return bpf_detach_probe(ev_name, "uprobe"); |
| } |
| |
| |
| void * bpf_attach_tracepoint(int progfd, const char *tp_category, |
| const char *tp_name, int pid, int cpu, |
| int group_fd, perf_reader_cb cb, void *cb_cookie) { |
| char buf[256]; |
| struct perf_reader *reader = NULL; |
| |
| reader = perf_reader_new(cb, NULL, NULL, cb_cookie, probe_perf_reader_page_cnt); |
| if (!reader) |
| goto error; |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%s/%s", |
| tp_category, tp_name); |
| if (bpf_attach_tracing_event(progfd, buf, reader, pid, cpu, group_fd) < 0) |
| goto error; |
| |
| return reader; |
| |
| error: |
| perf_reader_free(reader); |
| return NULL; |
| } |
| |
| int bpf_detach_tracepoint(const char *tp_category, const char *tp_name) { |
| // Right now, there is nothing to do, but it's a good idea to encourage |
| // callers to detach anything they attach. |
| return 0; |
| } |
| |
| void * bpf_open_perf_buffer(perf_reader_raw_cb raw_cb, |
| perf_reader_lost_cb lost_cb, void *cb_cookie, |
| int pid, int cpu, int page_cnt) { |
| int pfd; |
| struct perf_event_attr attr = {}; |
| struct perf_reader *reader = NULL; |
| |
| reader = perf_reader_new(NULL, raw_cb, lost_cb, cb_cookie, page_cnt); |
| if (!reader) |
| goto error; |
| |
| attr.config = 10;//PERF_COUNT_SW_BPF_OUTPUT; |
| attr.type = PERF_TYPE_SOFTWARE; |
| attr.sample_type = PERF_SAMPLE_RAW; |
| attr.sample_period = 1; |
| attr.wakeup_events = 1; |
| pfd = syscall(__NR_perf_event_open, &attr, pid, cpu, -1, PERF_FLAG_FD_CLOEXEC); |
| if (pfd < 0) { |
| fprintf(stderr, "perf_event_open: %s\n", strerror(errno)); |
| fprintf(stderr, " (check your kernel for PERF_COUNT_SW_BPF_OUTPUT support, 4.4 or newer)\n"); |
| goto error; |
| } |
| perf_reader_set_fd(reader, pfd); |
| |
| if (perf_reader_mmap(reader, attr.type, attr.sample_type) < 0) |
| goto error; |
| |
| if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { |
| perror("ioctl(PERF_EVENT_IOC_ENABLE)"); |
| goto error; |
| } |
| |
| return reader; |
| |
| error: |
| if (reader) |
| perf_reader_free(reader); |
| |
| return NULL; |
| } |
| |
| static int invalid_perf_config(uint32_t type, uint64_t config) { |
| switch (type) { |
| case PERF_TYPE_HARDWARE: |
| return config >= PERF_COUNT_HW_MAX; |
| case PERF_TYPE_SOFTWARE: |
| return config >= PERF_COUNT_SW_MAX; |
| case PERF_TYPE_RAW: |
| return 0; |
| default: |
| return 1; |
| } |
| } |
| |
| int bpf_open_perf_event(uint32_t type, uint64_t config, int pid, int cpu) { |
| int fd; |
| struct perf_event_attr attr = {}; |
| |
| if (type != PERF_TYPE_HARDWARE && type != PERF_TYPE_RAW) { |
| fprintf(stderr, "Unsupported perf event type\n"); |
| return -1; |
| } |
| if (invalid_perf_config(type, config)) { |
| fprintf(stderr, "Invalid perf event config\n"); |
| return -1; |
| } |
| |
| attr.sample_period = LONG_MAX; |
| attr.type = type; |
| attr.config = config; |
| |
| fd = syscall(__NR_perf_event_open, &attr, pid, cpu, -1, PERF_FLAG_FD_CLOEXEC); |
| if (fd < 0) { |
| fprintf(stderr, "perf_event_open: %s\n", strerror(errno)); |
| return -1; |
| } |
| |
| if (ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) < 0) { |
| perror("ioctl(PERF_EVENT_IOC_ENABLE)"); |
| close(fd); |
| return -1; |
| } |
| |
| return fd; |
| } |
| |
| int bpf_attach_xdp(const char *dev_name, int progfd, uint32_t flags) { |
| struct sockaddr_nl sa; |
| int sock, seq = 0, len, ret = -1; |
| char buf[4096]; |
| struct nlattr *nla, *nla_xdp; |
| struct { |
| struct nlmsghdr nh; |
| struct ifinfomsg ifinfo; |
| char attrbuf[64]; |
| } req; |
| struct nlmsghdr *nh; |
| struct nlmsgerr *err; |
| socklen_t addrlen; |
| |
| memset(&sa, 0, sizeof(sa)); |
| sa.nl_family = AF_NETLINK; |
| |
| sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); |
| if (sock < 0) { |
| fprintf(stderr, "bpf: opening a netlink socket: %s\n", strerror(errno)); |
| return -1; |
| } |
| |
| if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { |
| fprintf(stderr, "bpf: bind to netlink: %s\n", strerror(errno)); |
| goto cleanup; |
| } |
| |
| addrlen = sizeof(sa); |
| if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { |
| fprintf(stderr, "bpf: get sock name of netlink: %s\n", strerror(errno)); |
| goto cleanup; |
| } |
| |
| if (addrlen != sizeof(sa)) { |
| fprintf(stderr, "bpf: wrong netlink address length: %d\n", addrlen); |
| 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 = if_nametoindex(dev_name); |
| if (req.ifinfo.ifi_index == 0) { |
| fprintf(stderr, "bpf: Resolving device name to index: %s\n", strerror(errno)); |
| goto cleanup; |
| } |
| |
| 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->nla_len = NLA_HDRLEN; |
| |
| // we specify the FD passed over by the user |
| nla_xdp->nla_type = 1/*IFLA_XDP_FD*/; |
| nla_xdp->nla_len = NLA_HDRLEN + sizeof(progfd); |
| memcpy((char *)nla_xdp + NLA_HDRLEN, &progfd, sizeof(progfd)); |
| nla->nla_len += nla_xdp->nla_len; |
| |
| // parse flags as passed by the user |
| if (flags) { |
| nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len); |
| nla_xdp->nla_type = 3/*IFLA_XDP_FLAGS*/; |
| nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags); |
| memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags)); |
| nla->nla_len += nla_xdp->nla_len; |
| } |
| |
| req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len); |
| |
| if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) { |
| fprintf(stderr, "bpf: send to netlink: %s\n", strerror(errno)); |
| goto cleanup; |
| } |
| |
| len = recv(sock, buf, sizeof(buf), 0); |
| if (len < 0) { |
| fprintf(stderr, "bpf: 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 != sa.nl_pid) { |
| fprintf(stderr, "bpf: Wrong pid %u, expected %u\n", |
| nh->nlmsg_pid, sa.nl_pid); |
| errno = EBADMSG; |
| goto cleanup; |
| } |
| if (nh->nlmsg_seq != seq) { |
| fprintf(stderr, "bpf: Wrong seq %d, expected %d\n", |
| nh->nlmsg_seq, seq); |
| errno = EBADMSG; |
| goto cleanup; |
| } |
| switch (nh->nlmsg_type) { |
| case NLMSG_ERROR: |
| err = (struct nlmsgerr *)NLMSG_DATA(nh); |
| if (!err->error) |
| continue; |
| fprintf(stderr, "bpf: nlmsg error %s\n", strerror(-err->error)); |
| errno = -err->error; |
| goto cleanup; |
| case NLMSG_DONE: |
| break; |
| } |
| } |
| |
| ret = 0; |
| |
| cleanup: |
| close(sock); |
| return ret; |
| } |
| |
| int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config, |
| uint64_t sample_period, uint64_t sample_freq, |
| pid_t pid, int cpu, int group_fd) { |
| if (ev_type != PERF_TYPE_HARDWARE && ev_type != PERF_TYPE_SOFTWARE) { |
| fprintf(stderr, "Unsupported perf event type\n"); |
| return -1; |
| } |
| if (invalid_perf_config(ev_type, ev_config)) { |
| fprintf(stderr, "Invalid perf event config\n"); |
| return -1; |
| } |
| if (!((sample_period > 0) ^ (sample_freq > 0))) { |
| fprintf( |
| stderr, "Exactly one of sample_period / sample_freq should be set\n" |
| ); |
| return -1; |
| } |
| |
| struct perf_event_attr attr = {}; |
| attr.type = ev_type; |
| attr.config = ev_config; |
| attr.inherit = 1; |
| if (sample_freq > 0) { |
| attr.freq = 1; |
| attr.sample_freq = sample_freq; |
| } else { |
| attr.sample_period = sample_period; |
| } |
| |
| int fd = syscall( |
| __NR_perf_event_open, &attr, pid, cpu, group_fd, PERF_FLAG_FD_CLOEXEC |
| ); |
| if (fd < 0) { |
| perror("perf_event_open failed"); |
| return -1; |
| } |
| if (ioctl(fd, PERF_EVENT_IOC_SET_BPF, progfd) != 0) { |
| perror("ioctl(PERF_EVENT_IOC_SET_BPF) failed"); |
| close(fd); |
| return -1; |
| } |
| if (ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) != 0) { |
| perror("ioctl(PERF_EVENT_IOC_ENABLE) failed"); |
| close(fd); |
| return -1; |
| } |
| |
| return fd; |
| } |
| |
| int bpf_close_perf_event_fd(int fd) { |
| int res, error = 0; |
| if (fd >= 0) { |
| res = ioctl(fd, PERF_EVENT_IOC_DISABLE, 0); |
| if (res != 0) { |
| perror("ioctl(PERF_EVENT_IOC_DISABLE) failed"); |
| error = res; |
| } |
| res = close(fd); |
| if (res != 0) { |
| perror("close perf event FD failed"); |
| error = (res && !error) ? res : error; |
| } |
| } |
| return error; |
| } |
| |
| int bpf_obj_pin(int fd, const char *pathname) |
| { |
| union bpf_attr attr; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.pathname = ptr_to_u64((void *)pathname); |
| attr.bpf_fd = fd; |
| |
| return syscall(__NR_bpf, BPF_OBJ_PIN, &attr, sizeof(attr)); |
| } |
| |
| int bpf_obj_get(const char *pathname) |
| { |
| union bpf_attr attr; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.pathname = ptr_to_u64((void *)pathname); |
| |
| return syscall(__NR_bpf, BPF_OBJ_GET, &attr, sizeof(attr)); |
| } |