| /* |
| * 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 <inttypes.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 this when CentOS 6 support is not needed anymore |
| #include "setns.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 |
| |
| // TODO: Remove this when CentOS 6 support is not needed anymore |
| #ifndef AF_ALG |
| #define AF_ALG 38 |
| #endif |
| |
| #define min(x, y) ((x) < (y) ? (x) : (y)) |
| |
| struct bpf_helper { |
| char *name; |
| char *required_version; |
| }; |
| |
| static struct bpf_helper helpers[] = { |
| {"map_lookup_elem", "3.19"}, |
| {"map_update_elem", "3.19"}, |
| {"map_delete_elem", "3.19"}, |
| {"probe_read", "4.1"}, |
| {"ktime_get_ns", "4.1"}, |
| {"trace_printk", "4.1"}, |
| {"get_prandom_u32", "4.1"}, |
| {"get_smp_processor_id", "4.1"}, |
| {"skb_store_bytes", "4.1"}, |
| {"l3_csum_replace", "4.1"}, |
| {"l4_csum_replace", "4.1"}, |
| {"tail_call", "4.2"}, |
| {"clone_redirect", "4.2"}, |
| {"get_current_pid_tgid", "4.2"}, |
| {"get_current_uid_gid", "4.2"}, |
| {"get_current_comm", "4.2"}, |
| {"get_cgroup_classid", "4.3"}, |
| {"skb_vlan_push", "4.3"}, |
| {"skb_vlan_pop", "4.3"}, |
| {"skb_get_tunnel_key", "4.3"}, |
| {"skb_set_tunnel_key", "4.3"}, |
| {"perf_event_read", "4.3"}, |
| {"redirect", "4.4"}, |
| {"get_route_realm", "4.4"}, |
| {"perf_event_output", "4.4"}, |
| {"skb_load_bytes", "4.5"}, |
| {"get_stackid", "4.6"}, |
| {"csum_diff", "4.6"}, |
| {"skb_get_tunnel_opt", "4.6"}, |
| {"skb_set_tunnel_opt", "4.6"}, |
| {"skb_change_proto", "4.8"}, |
| {"skb_change_type", "4.8"}, |
| {"skb_under_cgroup", "4.8"}, |
| {"get_hash_recalc", "4.8"}, |
| {"get_current_task", "4.8"}, |
| {"probe_write_user", "4.8"}, |
| {"current_task_under_cgroup", "4.9"}, |
| {"skb_change_tail", "4.9"}, |
| {"skb_pull_data", "4.9"}, |
| {"csum_update", "4.9"}, |
| {"set_hash_invalid", "4.9"}, |
| {"get_numa_node_id", "4.10"}, |
| {"skb_change_head", "4.10"}, |
| {"xdp_adjust_head", "4.10"}, |
| {"probe_read_str", "4.11"}, |
| {"get_socket_cookie", "4.12"}, |
| {"get_socket_uid", "4.12"}, |
| {"set_hash", "4.13"}, |
| {"setsockopt", "4.13"}, |
| {"skb_adjust_room", "4.13"}, |
| {"redirect_map", "4.14"}, |
| {"sk_redirect_map", "4.14"}, |
| {"sock_map_update", "4.14"}, |
| {"xdp_adjust_meta", "4.15"}, |
| {"perf_event_read_value", "4.15"}, |
| {"perf_prog_read_value", "4.15"}, |
| {"getsockopt", "4.15"}, |
| {"override_return", "4.16"}, |
| {"sock_ops_cb_flags_set", "4.16"}, |
| {"msg_redirect_map", "4.17"}, |
| {"msg_apply_bytes", "4.17"}, |
| {"msg_cork_bytes", "4.17"}, |
| {"msg_pull_data", "4.17"}, |
| {"bind", "4.17"}, |
| {"xdp_adjust_tail", "4.18"}, |
| {"skb_get_xfrm_state", "4.18"}, |
| {"get_stack", "4.18"}, |
| {"skb_load_bytes_relative", "4.18"}, |
| {"fib_lookup", "4.18"}, |
| {"sock_hash_update", "4.18"}, |
| {"msg_redirect_hash", "4.18"}, |
| {"sk_redirect_hash", "4.18"}, |
| {"lwt_push_encap", "4.18"}, |
| {"lwt_seg6_store_bytes", "4.18"}, |
| {"lwt_seg6_adjust_srh", "4.18"}, |
| {"lwt_seg6_action", "4.18"}, |
| {"rc_repeat", "4.18"}, |
| {"rc_keydown", "4.18"}, |
| }; |
| |
| static uint64_t ptr_to_u64(void *ptr) |
| { |
| return (uint64_t) (unsigned long) ptr; |
| } |
| |
| int bpf_create_map(enum bpf_map_type map_type, const char *name, |
| int key_size, int value_size, |
| int max_entries, int map_flags) |
| { |
| size_t name_len = name ? strlen(name) : 0; |
| 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; |
| memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1)); |
| |
| int ret = syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr)); |
| |
| if (ret < 0 && name_len && (errno == E2BIG || errno == EINVAL)) { |
| memset(attr.map_name, 0, BPF_OBJ_NAME_LEN); |
| 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(int ret, char *log) |
| { |
| if (ret < 0) |
| fprintf(stderr, "bpf: Failed to load program: %s\n", strerror(errno)); |
| if (log == NULL) |
| return; |
| else |
| fprintf(stderr, "%s\n", log); |
| |
| if (ret >= 0) |
| 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"); |
| } |
| |
| // helper function not found in kernel |
| char *helper_str = strstr(log, "invalid func "); |
| if (helper_str != NULL) { |
| helper_str += strlen("invalid func "); |
| char *str = strchr(helper_str, '#'); |
| if (str != NULL) { |
| helper_str = str + 1; |
| } |
| int helper_id = atoi(helper_str); |
| if (helper_id && helper_id < sizeof(helpers) / sizeof(struct bpf_helper)) { |
| struct bpf_helper helper = helpers[helper_id - 1]; |
| fprintf(stderr, "HINT: bpf_%s missing (added in Linux %s).\n\n", |
| helper.name, helper.required_version); |
| } |
| } |
| } |
| #define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u)) |
| |
| int bpf_obj_get_info(int prog_map_fd, void *info, uint32_t *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); |
| close(shafd2); |
| close(shafd); |
| 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 char *name, |
| const struct bpf_insn *insns, int prog_len, |
| const char *license, unsigned kern_version, |
| int log_level, char *log_buf, unsigned log_buf_size) |
| { |
| size_t name_len = name ? strlen(name) : 0; |
| union bpf_attr attr; |
| char *tmp_log_buf = NULL; |
| unsigned tmp_log_buf_size = 0; |
| int ret = 0, name_offset = 0; |
| |
| memset(&attr, 0, sizeof(attr)); |
| |
| attr.prog_type = prog_type; |
| attr.kern_version = kern_version; |
| attr.license = ptr_to_u64((void *)license); |
| |
| attr.insns = ptr_to_u64((void *)insns); |
| attr.insn_cnt = prog_len / sizeof(struct bpf_insn); |
| if (attr.insn_cnt > BPF_MAXINSNS) { |
| errno = EINVAL; |
| fprintf(stderr, |
| "bpf: %s. Program too large (%u insns), at most %d insns\n\n", |
| strerror(errno), attr.insn_cnt, BPF_MAXINSNS); |
| return -1; |
| } |
| |
| attr.log_level = log_level; |
| if (attr.log_level > 0) { |
| if (log_buf_size > 0) { |
| // Use user-provided log buffer if availiable. |
| log_buf[0] = 0; |
| attr.log_buf = ptr_to_u64(log_buf); |
| attr.log_size = log_buf_size; |
| } else { |
| // Create and use temporary log buffer if user didn't provide one. |
| tmp_log_buf_size = LOG_BUF_SIZE; |
| tmp_log_buf = malloc(tmp_log_buf_size); |
| if (!tmp_log_buf) { |
| fprintf(stderr, "bpf: Failed to allocate temporary log buffer: %s\n\n", |
| strerror(errno)); |
| attr.log_level = 0; |
| } else { |
| tmp_log_buf[0] = 0; |
| attr.log_buf = ptr_to_u64(tmp_log_buf); |
| attr.log_size = tmp_log_buf_size; |
| } |
| } |
| } |
| |
| if (strncmp(name, "kprobe__", 8) == 0) |
| name_offset = 8; |
| else if (strncmp(name, "tracepoint__", 12) == 0) |
| name_offset = 12; |
| else if (strncmp(name, "raw_tracepoint__", 16) == 0) |
| name_offset = 16; |
| memcpy(attr.prog_name, name + name_offset, |
| min(name_len - name_offset, BPF_OBJ_NAME_LEN - 1)); |
| |
| ret = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); |
| // BPF object name is not supported on older Kernels. |
| // If we failed due to this, clear the name and try again. |
| if (ret < 0 && name_len && (errno == E2BIG || errno == EINVAL)) { |
| memset(attr.prog_name, 0, BPF_OBJ_NAME_LEN); |
| 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)); |
| } |
| } |
| |
| // The load has failed. Handle log message. |
| if (ret < 0) { |
| // User has provided a log buffer. |
| if (log_buf_size) { |
| // If logging is not already enabled, enable it and do the syscall again. |
| if (attr.log_level == 0) { |
| attr.log_level = 1; |
| attr.log_buf = ptr_to_u64(log_buf); |
| attr.log_size = log_buf_size; |
| ret = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); |
| } |
| // Print the log message and return. |
| bpf_print_hints(ret, log_buf); |
| if (errno == ENOSPC) |
| fprintf(stderr, "bpf: log_buf size may be insufficient\n"); |
| goto return_result; |
| } |
| |
| // User did not provide log buffer. We will try to increase size of |
| // our temporary log buffer to get full error message. |
| if (tmp_log_buf) |
| free(tmp_log_buf); |
| tmp_log_buf_size = LOG_BUF_SIZE; |
| if (attr.log_level == 0) |
| attr.log_level = 1; |
| for (;;) { |
| tmp_log_buf = malloc(tmp_log_buf_size); |
| if (!tmp_log_buf) { |
| fprintf(stderr, "bpf: Failed to allocate temporary log buffer: %s\n\n", |
| strerror(errno)); |
| goto return_result; |
| } |
| tmp_log_buf[0] = 0; |
| attr.log_buf = ptr_to_u64(tmp_log_buf); |
| attr.log_size = tmp_log_buf_size; |
| |
| ret = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)); |
| if (ret < 0 && errno == ENOSPC) { |
| // Temporary buffer size is not enough. Double it and try again. |
| free(tmp_log_buf); |
| tmp_log_buf = NULL; |
| tmp_log_buf_size <<= 1; |
| } else { |
| break; |
| } |
| } |
| } |
| |
| // Check if we should print the log message if log_level is not 0, |
| // either specified by user or set due to error. |
| if (attr.log_level > 0) { |
| // Don't print if user enabled logging and provided log buffer, |
| // but there is no error. |
| if (log_buf && ret < 0) |
| bpf_print_hints(ret, log_buf); |
| else if (tmp_log_buf) |
| bpf_print_hints(ret, tmp_log_buf); |
| } |
| |
| return_result: |
| if (tmp_log_buf) |
| free(tmp_log_buf); |
| 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; |
| } |
| |
| /* Do not bind on empty interface names */ |
| if (!name || *name == '\0') |
| return sock; |
| |
| 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)); |
| } |
| |
| #define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type" |
| static int bpf_find_probe_type(const char *event_type) |
| { |
| int fd; |
| int ret; |
| char buf[PATH_MAX]; |
| |
| ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type); |
| if (ret < 0 || ret >= sizeof(buf)) |
| return -1; |
| |
| fd = open(buf, O_RDONLY); |
| if (fd < 0) |
| return -1; |
| ret = read(fd, buf, sizeof(buf)); |
| close(fd); |
| if (ret < 0 || ret >= sizeof(buf)) |
| return -1; |
| errno = 0; |
| ret = (int)strtol(buf, NULL, 10); |
| return errno ? -1 : ret; |
| } |
| |
| #define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe" |
| static int bpf_get_retprobe_bit(const char *event_type) |
| { |
| int fd; |
| int ret; |
| char buf[PATH_MAX]; |
| |
| ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type); |
| if (ret < 0 || ret >= sizeof(buf)) |
| return -1; |
| |
| fd = open(buf, O_RDONLY); |
| if (fd < 0) |
| return -1; |
| ret = read(fd, buf, sizeof(buf)); |
| close(fd); |
| if (ret < 0 || ret >= sizeof(buf)) |
| return -1; |
| if (strlen(buf) < strlen("config:")) |
| return -1; |
| errno = 0; |
| ret = (int)strtol(buf + strlen("config:"), NULL, 10); |
| return errno ? -1 : ret; |
| } |
| |
| /* |
| * new kernel API allows creating [k,u]probe with perf_event_open, which |
| * makes it easier to clean up the [k,u]probe. This function tries to |
| * create pfd with the new API. |
| */ |
| static int bpf_try_perf_event_open_with_probe(const char *name, uint64_t offs, |
| int pid, char *event_type, int is_return) |
| { |
| struct perf_event_attr attr = {}; |
| int type = bpf_find_probe_type(event_type); |
| int is_return_bit = bpf_get_retprobe_bit(event_type); |
| int cpu = 0; |
| |
| if (type < 0 || is_return_bit < 0) |
| return -1; |
| attr.sample_period = 1; |
| attr.wakeup_events = 1; |
| if (is_return) |
| attr.config |= 1 << is_return_bit; |
| |
| /* |
| * struct perf_event_attr in latest perf_event.h has the following |
| * extension to config1 and config2. To keep bcc compatibe with |
| * older perf_event.h, we use config1 and config2 here instead of |
| * kprobe_func, uprobe_path, kprobe_addr, and probe_offset. |
| * |
| * union { |
| * __u64 bp_addr; |
| * __u64 kprobe_func; |
| * __u64 uprobe_path; |
| * __u64 config1; |
| * }; |
| * union { |
| * __u64 bp_len; |
| * __u64 kprobe_addr; |
| * __u64 probe_offset; |
| * __u64 config2; |
| * }; |
| */ |
| attr.config2 = offs; /* config2 here is kprobe_addr or probe_offset */ |
| attr.size = sizeof(attr); |
| attr.type = type; |
| /* config1 here is kprobe_func or uprobe_path */ |
| attr.config1 = ptr_to_u64((void *)name); |
| // PID filter is only possible for uprobe events. |
| if (pid < 0) |
| pid = -1; |
| // perf_event_open API doesn't allow both pid and cpu to be -1. |
| // So only set it to -1 when PID is not -1. |
| // Tracing events do not do CPU filtering in any cases. |
| if (pid != -1) |
| cpu = -1; |
| return syscall(__NR_perf_event_open, &attr, pid, cpu, -1 /* group_fd */, |
| PERF_FLAG_FD_CLOEXEC); |
| } |
| |
| // When a valid Perf Event FD provided through pfd, it will be used to enable |
| // and attach BPF program to the event, and event_path will be ignored. |
| // Otherwise, event_path is expected to contain the path to the event in debugfs |
| // and it will be used to open the Perf Event FD. |
| // In either case, if the attach partially failed (such as issue with the |
| // ioctl operations), the **caller** need to clean up the Perf Event FD, either |
| // provided by the caller or opened here. |
| static int bpf_attach_tracing_event(int progfd, const char *event_path, int pid, |
| int *pfd) |
| { |
| int efd, cpu = 0; |
| ssize_t bytes; |
| char buf[PATH_MAX]; |
| struct perf_event_attr attr = {}; |
| // Caller did not provided a valid Perf Event FD. Create one with the debugfs |
| // event path provided. |
| if (*pfd < 0) { |
| 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_period = 1; |
| attr.wakeup_events = 1; |
| // PID filter is only possible for uprobe events. |
| if (pid < 0) |
| pid = -1; |
| // perf_event_open API doesn't allow both pid and cpu to be -1. |
| // So only set it to -1 when PID is not -1. |
| // Tracing events do not do CPU filtering in any cases. |
| if (pid != -1) |
| cpu = -1; |
| *pfd = syscall(__NR_perf_event_open, &attr, pid, cpu, -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); |
| if (*pfd < 0) { |
| fprintf(stderr, "perf_event_open(%s/id): %s\n", event_path, strerror(errno)); |
| 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; |
| } |
| |
| int bpf_attach_kprobe(int progfd, enum bpf_probe_attach_type attach_type, |
| const char *ev_name, const char *fn_name, uint64_t fn_offset) |
| { |
| int kfd, pfd = -1; |
| char buf[256]; |
| char event_alias[128]; |
| static char *event_type = "kprobe"; |
| |
| // Try create the kprobe Perf Event with perf_event_open API. |
| pfd = bpf_try_perf_event_open_with_probe(fn_name, fn_offset, -1, event_type, |
| attach_type != BPF_PROBE_ENTRY); |
| // If failed, most likely Kernel doesn't support the new perf_event_open API |
| // yet. Try create the event using debugfs. |
| if (pfd < 0) { |
| 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()); |
| |
| if (fn_offset > 0 && attach_type == BPF_PROBE_ENTRY) |
| snprintf(buf, sizeof(buf), "p:%ss/%s %s+%"PRIu64, |
| event_type, event_alias, fn_name, fn_offset); |
| else |
| 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 == ENOENT) |
| fprintf(stderr, "cannot attach kprobe, probe entry may not exist\n"); |
| else |
| fprintf(stderr, "cannot attach kprobe, %s\n", strerror(errno)); |
| close(kfd); |
| goto error; |
| } |
| close(kfd); |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s", event_type, event_alias); |
| } |
| // If perf_event_open succeeded, bpf_attach_tracing_event will use the created |
| // Perf Event FD directly and buf would be empty and unused. |
| // Otherwise it will read the event ID from the path in buf, create the |
| // Perf Event event using that ID, and updated value of pfd. |
| if (bpf_attach_tracing_event(progfd, buf, -1 /* PID */, &pfd) == 0) |
| return pfd; |
| |
| error: |
| bpf_close_perf_event_fd(pfd); |
| return -1; |
| } |
| |
| 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"); |
| } |
| |
| int 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) |
| { |
| char buf[PATH_MAX]; |
| char event_alias[PATH_MAX]; |
| static char *event_type = "uprobe"; |
| int res, kfd = -1, pfd = -1, ns_fd = -1; |
| // Try create the uprobe Perf Event with perf_event_open API. |
| pfd = bpf_try_perf_event_open_with_probe(binary_path, offset, pid, event_type, |
| attach_type != BPF_PROBE_ENTRY); |
| // If failed, most likely Kernel doesn't support the new perf_event_open API |
| // yet. Try create the event using debugfs. |
| if (pfd < 0) { |
| 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); |
| kfd = -1; |
| exit_mount_ns(ns_fd); |
| ns_fd = -1; |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s", event_type, event_alias); |
| } |
| // If perf_event_open succeeded, bpf_attach_tracing_event will use the created |
| // Perf Event FD directly and buf would be empty and unused. |
| // Otherwise it will read the event ID from the path in buf, create the |
| // Perf Event event using that ID, and updated value of pfd. |
| if (bpf_attach_tracing_event(progfd, buf, pid, &pfd) == 0) |
| return pfd; |
| |
| error: |
| if (kfd >= 0) |
| close(kfd); |
| exit_mount_ns(ns_fd); |
| bpf_close_perf_event_fd(pfd); |
| return -1; |
| } |
| |
| static int bpf_detach_probe(const char *ev_name, const char *event_type) |
| { |
| int kfd = -1, res; |
| char buf[PATH_MAX]; |
| int found_event = 0; |
| size_t bufsize = 0; |
| char *cptr = NULL; |
| FILE *fp; |
| |
| /* |
| * For [k,u]probe created with perf_event_open (on newer kernel), it is |
| * not necessary to clean it up in [k,u]probe_events. We first look up |
| * the %s_bcc_%d line in [k,u]probe_events. If the event is not found, |
| * it is safe to skip the cleaning up process (write -:... to the file). |
| */ |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", event_type); |
| fp = fopen(buf, "r"); |
| if (!fp) { |
| 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; |
| } |
| |
| while (getline(&cptr, &bufsize, fp) != -1) |
| if (strstr(cptr, buf) != NULL) { |
| found_event = 1; |
| break; |
| } |
| free(cptr); |
| fclose(fp); |
| fp = NULL; |
| |
| if (!found_event) |
| return 0; |
| |
| 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); |
| if (fp) |
| fclose(fp); |
| 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"); |
| } |
| |
| |
| int bpf_attach_tracepoint(int progfd, const char *tp_category, |
| const char *tp_name) |
| { |
| char buf[256]; |
| int pfd = -1; |
| |
| snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%s/%s", |
| tp_category, tp_name); |
| if (bpf_attach_tracing_event(progfd, buf, -1 /* PID */, &pfd) == 0) |
| return pfd; |
| |
| bpf_close_perf_event_fd(pfd); |
| return -1; |
| } |
| |
| 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; |
| } |
| |
| int bpf_attach_raw_tracepoint(int progfd, char *tp_name) |
| { |
| union bpf_attr attr; |
| int ret; |
| |
| bzero(&attr, sizeof(attr)); |
| attr.raw_tracepoint.name = ptr_to_u64(tp_name); |
| attr.raw_tracepoint.prog_fd = progfd; |
| |
| ret = syscall(__NR_bpf, BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr)); |
| if (ret < 0) |
| fprintf(stderr, "bpf_attach_raw_tracepoint (%s): %s\n", tp_name, strerror(errno)); |
| return ret; |
| } |
| |
| 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(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) < 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: |
| if (config >= PERF_COUNT_HW_MAX) { |
| fprintf(stderr, "HARDWARE perf event config out of range\n"); |
| goto is_invalid; |
| } |
| return 0; |
| case PERF_TYPE_SOFTWARE: |
| if (config >= PERF_COUNT_SW_MAX) { |
| fprintf(stderr, "SOFTWARE perf event config out of range\n"); |
| goto is_invalid; |
| } else if (config == 10 /* PERF_COUNT_SW_BPF_OUTPUT */) { |
| fprintf(stderr, "Unable to open or attach perf event for BPF_OUTPUT\n"); |
| goto is_invalid; |
| } |
| return 0; |
| case PERF_TYPE_HW_CACHE: |
| if (((config >> 16) >= PERF_COUNT_HW_CACHE_RESULT_MAX) || |
| (((config >> 8) & 0xff) >= PERF_COUNT_HW_CACHE_OP_MAX) || |
| ((config & 0xff) >= PERF_COUNT_HW_CACHE_MAX)) { |
| fprintf(stderr, "HW_CACHE perf event config out of range\n"); |
| goto is_invalid; |
| } |
| return 0; |
| case PERF_TYPE_TRACEPOINT: |
| case PERF_TYPE_BREAKPOINT: |
| fprintf(stderr, |
| "Unable to open or attach TRACEPOINT or BREAKPOINT events\n"); |
| goto is_invalid; |
| default: |
| return 0; |
| } |
| is_invalid: |
| fprintf(stderr, "Invalid perf event type %" PRIu32 " config %" PRIu64 "\n", |
| type, config); |
| 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 (invalid_perf_config(type, config)) { |
| 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_raw(int progfd, void *perf_event_attr, pid_t pid, |
| int cpu, int group_fd, unsigned long extra_flags) { |
| int fd = syscall(__NR_perf_event_open, perf_event_attr, pid, cpu, group_fd, |
| PERF_FLAG_FD_CLOEXEC | extra_flags); |
| 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_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 (invalid_perf_config(ev_type, ev_config)) { |
| 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; |
| if (pid > 0) |
| attr.inherit = 1; |
| if (sample_freq > 0) { |
| attr.freq = 1; |
| attr.sample_freq = sample_freq; |
| } else { |
| attr.sample_period = sample_period; |
| } |
| |
| return bpf_attach_perf_event_raw(progfd, &attr, pid, cpu, group_fd, 0); |
| } |
| |
| 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)); |
| } |
| |
| int bpf_prog_get_next_id(uint32_t start_id, uint32_t *next_id) |
| { |
| union bpf_attr attr; |
| int err; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.start_id = start_id; |
| |
| err = syscall(__NR_bpf, BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr)); |
| if (!err) |
| *next_id = attr.next_id; |
| |
| return err; |
| } |
| |
| int bpf_prog_get_fd_by_id(uint32_t id) |
| { |
| union bpf_attr attr; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.prog_id = id; |
| |
| return syscall(__NR_bpf, BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); |
| } |
| |
| int bpf_map_get_fd_by_id(uint32_t id) |
| { |
| union bpf_attr attr; |
| |
| memset(&attr, 0, sizeof(attr)); |
| attr.map_id = id; |
| |
| return syscall(__NR_bpf, BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); |
| } |