diff options
Diffstat (limited to 'libnetdata/ebpf/ebpf.c')
| -rw-r--r-- | libnetdata/ebpf/ebpf.c | 1427 |
1 files changed, 1427 insertions, 0 deletions
diff --git a/libnetdata/ebpf/ebpf.c b/libnetdata/ebpf/ebpf.c new file mode 100644 index 0000000..382485e --- /dev/null +++ b/libnetdata/ebpf/ebpf.c @@ -0,0 +1,1427 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <dlfcn.h> +#include <sys/utsname.h> + +#include "../libnetdata.h" + +char *ebpf_user_config_dir = CONFIG_DIR; +char *ebpf_stock_config_dir = LIBCONFIG_DIR; + +/* +static int clean_kprobe_event(FILE *out, char *filename, char *father_pid, netdata_ebpf_events_t *ptr) +{ + int fd = open(filename, O_WRONLY | O_APPEND, 0); + if (fd < 0) { + if (out) { + fprintf(out, "Cannot open %s : %s\n", filename, strerror(errno)); + } + return 1; + } + + char cmd[1024]; + int length = snprintf(cmd, 1023, "-:kprobes/%c_netdata_%s_%s", ptr->type, ptr->name, father_pid); + int ret = 0; + if (length > 0) { + ssize_t written = write(fd, cmd, strlen(cmd)); + if (written < 0) { + if (out) { + fprintf( + out, "Cannot remove the event (%d, %d) '%s' from %s : %s\n", getppid(), getpid(), cmd, filename, + strerror((int)errno)); + } + ret = 1; + } + } + + close(fd); + + return ret; +} + +int clean_kprobe_events(FILE *out, int pid, netdata_ebpf_events_t *ptr) +{ + debug(D_EXIT, "Cleaning parent process events."); + char filename[FILENAME_MAX + 1]; + snprintf(filename, FILENAME_MAX, "%s%s", NETDATA_DEBUGFS, "kprobe_events"); + + char removeme[16]; + snprintf(removeme, 15, "%d", pid); + + int i; + for (i = 0; ptr[i].name; i++) { + if (clean_kprobe_event(out, filename, removeme, &ptr[i])) { + break; + } + } + + return 0; +} +*/ + +//---------------------------------------------------------------------------------------------------------------------- + +/** + * Get Kernel version + * + * Get the current kernel from /proc and returns an integer value representing it + * + * @return it returns a value representing the kernel version. + */ +int ebpf_get_kernel_version() +{ + char major[16], minor[16], patch[16]; + char ver[VERSION_STRING_LEN]; + char *version = ver; + + int fd = open("/proc/sys/kernel/osrelease", O_RDONLY); + if (fd < 0) + return -1; + + ssize_t len = read(fd, ver, sizeof(ver)); + if (len < 0) { + close(fd); + return -1; + } + + close(fd); + + char *move = major; + while (*version && *version != '.') + *move++ = *version++; + *move = '\0'; + + version++; + move = minor; + while (*version && *version != '.') + *move++ = *version++; + *move = '\0'; + + if (*version) + version++; + else + return -1; + + move = patch; + while (*version && *version != '\n' && *version != '-') + *move++ = *version++; + *move = '\0'; + + // This new rule is fixing kernel version according the formula: + // KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c))) + // that was extracted from /usr/include/linux/version.h + int ipatch = (int)str2l(patch); + if (ipatch > 255) + ipatch = 255; + + return ((int)(str2l(major) * 65536) + (int)(str2l(minor) * 256) + ipatch); +} + +/** + * Get RH release + * + * Read Red Hat release from /etc/redhat-release + * + * @return It returns RH release on success and -1 otherwise + */ +int get_redhat_release() +{ + char buffer[VERSION_STRING_LEN + 1]; + int major, minor; + FILE *fp = fopen("/etc/redhat-release", "r"); + + if (fp) { + major = 0; + minor = -1; + size_t length = fread(buffer, sizeof(char), VERSION_STRING_LEN, fp); + if (length > 4) { + buffer[length] = '\0'; + char *end = strchr(buffer, '.'); + char *start; + if (end) { + *end = 0x0; + + if (end > buffer) { + start = end - 1; + + major = strtol(start, NULL, 10); + start = ++end; + + end++; + if (end) { + end = 0x00; + minor = strtol(start, NULL, 10); + } else { + minor = -1; + } + } + } + } + + fclose(fp); + return ((major * 256) + minor); + } else { + return -1; + } +} + +/** + * Check if the kernel is in a list of rejected ones + * + * @return Returns 1 if the kernel is rejected, 0 otherwise. + */ +static int kernel_is_rejected() +{ + // Get kernel version from system + char version_string[VERSION_STRING_LEN + 1]; + int version_string_len = 0; + + if (read_file("/proc/version_signature", version_string, VERSION_STRING_LEN)) { + if (read_file("/proc/version", version_string, VERSION_STRING_LEN)) { + struct utsname uname_buf; + if (!uname(&uname_buf)) { + info("Cannot check kernel version"); + return 0; + } + version_string_len = + snprintfz(version_string, VERSION_STRING_LEN, "%s %s", uname_buf.release, uname_buf.version); + } + } + + if (!version_string_len) + version_string_len = strlen(version_string); + + // Open a file with a list of rejected kernels + char *config_dir = getenv("NETDATA_USER_CONFIG_DIR"); + if (config_dir == NULL) { + config_dir = CONFIG_DIR; + } + + char filename[FILENAME_MAX + 1]; + snprintfz(filename, FILENAME_MAX, "%s/ebpf.d/%s", config_dir, EBPF_KERNEL_REJECT_LIST_FILE); + FILE *kernel_reject_list = fopen(filename, "r"); + + if (!kernel_reject_list) { + // Keep this to have compatibility with old versions + snprintfz(filename, FILENAME_MAX, "%s/%s", config_dir, EBPF_KERNEL_REJECT_LIST_FILE); + kernel_reject_list = fopen(filename, "r"); + + if (!kernel_reject_list) { + config_dir = getenv("NETDATA_STOCK_CONFIG_DIR"); + if (config_dir == NULL) { + config_dir = LIBCONFIG_DIR; + } + + snprintfz(filename, FILENAME_MAX, "%s/ebpf.d/%s", config_dir, EBPF_KERNEL_REJECT_LIST_FILE); + kernel_reject_list = fopen(filename, "r"); + + if (!kernel_reject_list) + return 0; + } + } + + // Find if the kernel is in the reject list + char *reject_string = NULL; + size_t buf_len = 0; + ssize_t reject_string_len; + while ((reject_string_len = getline(&reject_string, &buf_len, kernel_reject_list) - 1) > 0) { + if (version_string_len >= reject_string_len) { + if (!strncmp(version_string, reject_string, reject_string_len)) { + info("A buggy kernel is detected"); + fclose(kernel_reject_list); + freez(reject_string); + return 1; + } + } + } + + fclose(kernel_reject_list); + free(reject_string); + + return 0; +} + +static int has_ebpf_kernel_version(int version) +{ + if (kernel_is_rejected()) + return 0; + + // Kernel 4.11.0 or RH > 7.5 + return (version >= NETDATA_MINIMUM_EBPF_KERNEL || get_redhat_release() >= NETDATA_MINIMUM_RH_VERSION); +} + +int has_condition_to_run(int version) +{ + if (!has_ebpf_kernel_version(version)) + return 0; + + return 1; +} + +//---------------------------------------------------------------------------------------------------------------------- + +/** + * Kernel Name + * + * Select kernel name used by eBPF programs + * + * Netdata delivers for users eBPF programs with specific suffixes that represent the kernels they were + * compiled, when we load the eBPF program, the suffix must be the nereast possible of the kernel running. + * + * @param selector select the kernel version. + * + * @return It returns the string to load kernel. + */ +static char *ebpf_select_kernel_name(uint32_t selector) +{ + static char *kernel_names[] = { NETDATA_IDX_STR_V3_10, NETDATA_IDX_STR_V4_14, NETDATA_IDX_STR_V4_16, + NETDATA_IDX_STR_V4_18, NETDATA_IDX_STR_V5_4, NETDATA_IDX_STR_V5_10, + NETDATA_IDX_STR_V5_11, NETDATA_IDX_STR_V5_14, NETDATA_IDX_STR_V5_15, + NETDATA_IDX_STR_V5_16 + }; + + return kernel_names[selector]; +} + +/** + * Select Max Index + * + * Select last index that will be tested on host. + * + * @param is_rhf is Red Hat fammily? + * @param kver the kernel version + * + * @return it returns the index to access kernel string. + */ +static int ebpf_select_max_index(int is_rhf, uint32_t kver) +{ + if (is_rhf > 0) { // Is Red Hat family + if (kver >= NETDATA_EBPF_KERNEL_5_14) + return NETDATA_IDX_V5_14; + else if (kver >= NETDATA_EBPF_KERNEL_5_4 && kver < NETDATA_EBPF_KERNEL_5_5) // For Oracle Linux + return NETDATA_IDX_V5_4; + else if (kver >= NETDATA_EBPF_KERNEL_4_11) + return NETDATA_IDX_V4_18; + } else { // Kernels from kernel.org + if (kver >= NETDATA_EBPF_KERNEL_5_16) + return NETDATA_IDX_V5_16; + else if (kver >= NETDATA_EBPF_KERNEL_5_15) + return NETDATA_IDX_V5_15; + else if (kver >= NETDATA_EBPF_KERNEL_5_11) + return NETDATA_IDX_V5_11; + else if (kver >= NETDATA_EBPF_KERNEL_5_10) + return NETDATA_IDX_V5_10; + else if (kver >= NETDATA_EBPF_KERNEL_4_17) + return NETDATA_IDX_V5_4; + else if (kver >= NETDATA_EBPF_KERNEL_4_15) + return NETDATA_IDX_V4_16; + else if (kver >= NETDATA_EBPF_KERNEL_4_11) + return NETDATA_IDX_V4_14; + } + + return NETDATA_IDX_V3_10; +} + +/** + * Select Index + * + * Select index to load data. + * + * @param kernels is the variable with kernel versions. + * @param is_rhf is Red Hat fammily? + * param kver the kernel version + */ +static uint32_t ebpf_select_index(uint32_t kernels, int is_rhf, uint32_t kver) +{ + uint32_t start = ebpf_select_max_index(is_rhf, kver); + uint32_t idx; + + if (is_rhf == -1) + kernels &= ~NETDATA_V5_14; + + for (idx = start; idx; idx--) { + if (kernels & 1 << idx) + break; + } + + return idx; +} + +/** + * Mount Name + * + * Mount name of eBPF program to be loaded. + * + * Netdata eBPF programs has the following format: + * + * Tnetdata_ebpf_N.V.o + * + * where: + * T - Is the eBPF type. When starts with 'p', this means we are only adding probes, + * and when they start with 'r' we are using retprobes. + * N - The eBPF program name. + * V - The kernel version in string format. + * + * @param out the vector where the name will be stored + * @param path + * @param len the size of the out vector. + * @param kver the kernel version + * @param name the eBPF program name. + * @param is_return is return or entry ? + */ +static void ebpf_mount_name(char *out, size_t len, char *path, uint32_t kver, const char *name, int is_return) +{ + char *version = ebpf_select_kernel_name(kver); + snprintfz(out, len, "%s/ebpf.d/%cnetdata_ebpf_%s.%s.o", + path, + (is_return) ? 'r' : 'p', + name, + version); +} + +//---------------------------------------------------------------------------------------------------------------------- + +/** + * Statistics from targets + * + * Count the information from targets. + * + * @param report the output structure + * @param targets vector with information about the eBPF plugin. + */ +static void ebpf_stats_targets(ebpf_plugin_stats_t *report, netdata_ebpf_targets_t *targets) +{ + if (!targets) { + report->probes = report->tracepoints = report->trampolines = 0; + return; + } + + int i = 0; + while (targets[i].name) { + switch (targets[i].mode) { + case EBPF_LOAD_PROBE: { + report->probes++; + break; + } + case EBPF_LOAD_RETPROBE: { + report->retprobes++; + break; + } + case EBPF_LOAD_TRACEPOINT: { + report->tracepoints++; + break; + } + case EBPF_LOAD_TRAMPOLINE: { + report->trampolines++; + break; + } + } + + i++; + } +} + +/** + * Update General stats + * + * Update eBPF plugin statistics that has relationship with the thread. + * + * This function must be called with mutex associated to charts is locked. + * + * @param report the output structure + * @param em the structure with information about how the module/thread is working. + */ +void ebpf_update_stats(ebpf_plugin_stats_t *report, ebpf_module_t *em) +{ + report->threads++; + + // It is not necessary to report more information. + if (!em->enabled) + return; + + report->running++; + + // In theory the `else if` is useless, because when this function is called, the module should not stay in + // EBPF_LOAD_PLAY_DICE. We have this additional condition to detect errors from developers. + if (em->load & EBPF_LOAD_LEGACY) + report->legacy++; + else if (em->load & EBPF_LOAD_CORE) + report->core++; + + ebpf_stats_targets(report, em->targets); +} + +//---------------------------------------------------------------------------------------------------------------------- + +void ebpf_update_pid_table(ebpf_local_maps_t *pid, ebpf_module_t *em) +{ + pid->user_input = em->pid_map_size; +} + +/** + * Update map size + * + * Update map size with information read from configuration files. + * + * @param map the structure with file descriptor to update. + * @param lmap the structure with information from configuration files. + * @param em the structure with information about how the module/thread is working. + * @param map_name the name of the file used to log. + */ +void ebpf_update_map_size(struct bpf_map *map, ebpf_local_maps_t *lmap, ebpf_module_t *em, const char *map_name __maybe_unused) +{ + uint32_t define_size = 0; + uint32_t apps_type = NETDATA_EBPF_MAP_PID | NETDATA_EBPF_MAP_RESIZABLE; + if (lmap->user_input && lmap->user_input != lmap->internal_input) { + define_size = lmap->internal_input; +#ifdef NETDATA_INTERNAL_CHECKS + info("Changing map %s from size %u to %u ", map_name, lmap->internal_input, lmap->user_input); +#endif + } else if (((lmap->type & apps_type) == apps_type) && (!em->apps_charts) && (!em->cgroup_charts)) { + lmap->user_input = ND_EBPF_DEFAULT_MIN_PID; + } else if (((em->apps_charts) || (em->cgroup_charts)) && (em->apps_level != NETDATA_APPS_NOT_SET)) { + switch (em->apps_level) { + case NETDATA_APPS_LEVEL_ALL: { + define_size = lmap->user_input; + break; + } + case NETDATA_APPS_LEVEL_PARENT: { + define_size = ND_EBPF_DEFAULT_PID_SIZE / 2; + break; + } + case NETDATA_APPS_LEVEL_REAL_PARENT: + default: { + define_size = ND_EBPF_DEFAULT_PID_SIZE / 3; + } + } + } + + if (!define_size) + return; + +#ifdef LIBBPF_MAJOR_VERSION + bpf_map__set_max_entries(map, define_size); +#else + bpf_map__resize(map, define_size); +#endif +} + +/** + * Update Legacy map sizes + * + * Update map size for eBPF legacy code. + * + * @param program the structure with values read from binary. + * @param em the structure with information about how the module/thread is working. + */ +static void ebpf_update_legacy_map_sizes(struct bpf_object *program, ebpf_module_t *em) +{ + struct bpf_map *map; + ebpf_local_maps_t *maps = em->maps; + if (!maps) + return; + + bpf_map__for_each(map, program) + { + const char *map_name = bpf_map__name(map); + int i = 0; ; + while (maps[i].name) { + ebpf_local_maps_t *w = &maps[i]; + if (w->type & NETDATA_EBPF_MAP_RESIZABLE) { + if (!strcmp(w->name, map_name)) { + ebpf_update_map_size(map, w, em, map_name); + } + } + + i++; + } + } +} + +size_t ebpf_count_programs(struct bpf_object *obj) +{ + size_t tot = 0; + struct bpf_program *prog; + bpf_object__for_each_program(prog, obj) + { + tot++; + } + + return tot; +} + +static ebpf_specify_name_t *ebpf_find_names(ebpf_specify_name_t *names, const char *prog_name) +{ + size_t i = 0; + while (names[i].program_name) { + if (!strcmp(prog_name, names[i].program_name)) + return &names[i]; + + i++; + } + + return NULL; +} + +static struct bpf_link **ebpf_attach_programs(struct bpf_object *obj, size_t length, ebpf_specify_name_t *names) +{ + struct bpf_link **links = callocz(length , sizeof(struct bpf_link *)); + size_t i = 0; + struct bpf_program *prog; + ebpf_specify_name_t *w; + bpf_object__for_each_program(prog, obj) + { + if (names) { + const char *name = bpf_program__name(prog); + w = ebpf_find_names(names, name); + } else + w = NULL; + + if (w) { + enum bpf_prog_type type = bpf_program__get_type(prog); + if (type == BPF_PROG_TYPE_KPROBE) + links[i] = bpf_program__attach_kprobe(prog, w->retprobe, w->optional); + } else + links[i] = bpf_program__attach(prog); + + if (libbpf_get_error(links[i])) { + links[i] = NULL; + } + + i++; + } + + return links; +} + +static void ebpf_update_maps(ebpf_module_t *em, struct bpf_object *obj) +{ + if (!em->maps) + return; + + ebpf_local_maps_t *maps = em->maps; + struct bpf_map *map; + bpf_map__for_each(map, obj) + { + int fd = bpf_map__fd(map); + if (maps) { + const char *map_name = bpf_map__name(map); + int j = 0; ; + while (maps[j].name) { + ebpf_local_maps_t *w = &maps[j]; + if (w->map_fd == ND_EBPF_MAP_FD_NOT_INITIALIZED && !strcmp(map_name, w->name)) + w->map_fd = fd; + + j++; + } + } + } +} + +/** + * Update Controller + * + * Update controller value with user input. + * + * @param fd the table file descriptor + * @param em structure with information about eBPF program we will load. + */ +void ebpf_update_controller(int fd, ebpf_module_t *em) +{ + uint32_t values[NETDATA_CONTROLLER_END] = { + (em->apps_charts & NETDATA_EBPF_APPS_FLAG_YES) | em->cgroup_charts, + em->apps_level + }; + uint32_t key; + uint32_t end = (em->apps_level != NETDATA_APPS_NOT_SET) ? NETDATA_CONTROLLER_END : NETDATA_CONTROLLER_APPS_LEVEL; + + for (key = NETDATA_CONTROLLER_APPS_ENABLED; key < end; key++) { + int ret = bpf_map_update_elem(fd, &key, &values[key], 0); + if (ret) + error("Add key(%u) for controller table failed.", key); + } +} + +/** + * Update Legacy controller + * + * Update legacy controller table when eBPF program has it. + * + * @param em structure with information about eBPF program we will load. + * @param obj bpf object with tables. + */ +static void ebpf_update_legacy_controller(ebpf_module_t *em, struct bpf_object *obj) +{ + ebpf_local_maps_t *maps = em->maps; + if (!maps) + return; + + struct bpf_map *map; + bpf_map__for_each(map, obj) + { + size_t i = 0; + while (maps[i].name) { + ebpf_local_maps_t *w = &maps[i]; + if (w->map_fd != ND_EBPF_MAP_FD_NOT_INITIALIZED && (w->type & NETDATA_EBPF_MAP_CONTROLLER)) { + w->type &= ~NETDATA_EBPF_MAP_CONTROLLER; + w->type |= NETDATA_EBPF_MAP_CONTROLLER_UPDATED; + + ebpf_update_controller(w->map_fd, em); + } + i++; + } + } +} + +/** + * Load Program + * + * Load eBPF program into kernel + * + * @param plugins_dir directory where binary are stored + * @param em structure with information about eBPF program we will load. + * @param kver the kernel version according /usr/include/linux/version.h + * @param is_rhf is a kernel from Red Hat Family? + * @param obj structure where we will store object loaded. + * + * @return it returns a link for each target we associated an eBPF program. + */ +struct bpf_link **ebpf_load_program(char *plugins_dir, ebpf_module_t *em, int kver, int is_rhf, + struct bpf_object **obj) +{ + char lpath[4096]; + + uint32_t idx = ebpf_select_index(em->kernels, is_rhf, kver); + + ebpf_mount_name(lpath, 4095, plugins_dir, idx, em->thread_name, em->mode); + + // When this function is called ebpf.plugin is using legacy code, so we should reset the variable + em->load &= ~ NETDATA_EBPF_LOAD_METHODS; + em->load |= EBPF_LOAD_LEGACY; + + *obj = bpf_object__open_file(lpath, NULL); + if (libbpf_get_error(obj)) { + error("Cannot open BPF object %s", lpath); + bpf_object__close(*obj); + return NULL; + } + + ebpf_update_legacy_map_sizes(*obj, em); + + if (bpf_object__load(*obj)) { + error("ERROR: loading BPF object file failed %s\n", lpath); + bpf_object__close(*obj); + return NULL; + } + + ebpf_update_maps(em, *obj); + ebpf_update_legacy_controller(em, *obj); + + size_t count_programs = ebpf_count_programs(*obj); + +#ifdef NETDATA_INTERNAL_CHECKS + info("eBPF program %s loaded with success!", lpath); +#endif + + return ebpf_attach_programs(*obj, count_programs, em->names); +} + +char *ebpf_find_symbol(char *search) +{ + char filename[FILENAME_MAX + 1]; + char *ret = NULL; + snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, NETDATA_KALLSYMS); + procfile *ff = procfile_open(filename, " \t", PROCFILE_FLAG_DEFAULT); + if(unlikely(!ff)) { + error("Cannot open %s%s", netdata_configured_host_prefix, NETDATA_KALLSYMS); + return ret; + } + + ff = procfile_readall(ff); + if(unlikely(!ff)) + return ret; + + unsigned long i, lines = procfile_lines(ff); + size_t length = strlen(search); + for(i = 0; i < lines ; i++) { + char *cmp = procfile_lineword(ff, i,2);; + if (!strncmp(search, cmp, length)) { + ret = strdupz(cmp); + break; + } + } + + procfile_close(ff); + + return ret; +} + +void ebpf_update_names(ebpf_specify_name_t *opt, ebpf_module_t *em) +{ + int mode = em->mode; + em->names = opt; + + size_t i = 0; + while (opt[i].program_name) { + opt[i].retprobe = (mode == MODE_RETURN); + opt[i].optional = ebpf_find_symbol(opt[i].function_to_attach); + + i++; + } +} + +//---------------------------------------------------------------------------------------------------------------------- + +void ebpf_mount_config_name(char *filename, size_t length, char *path, const char *config) +{ + snprintf(filename, length, "%s/ebpf.d/%s", path, config); +} + +int ebpf_load_config(struct config *config, char *filename) +{ + return appconfig_load(config, filename, 0, NULL); +} + + +static netdata_run_mode_t ebpf_select_mode(char *mode) +{ + if (!strcasecmp(mode,EBPF_CFG_LOAD_MODE_RETURN )) + return MODE_RETURN; + else if (!strcasecmp(mode, "dev")) + return MODE_DEVMODE; + + return MODE_ENTRY; +} + +static void ebpf_select_mode_string(char *output, size_t len, netdata_run_mode_t sel) +{ + if (sel == MODE_RETURN) + strncpyz(output, EBPF_CFG_LOAD_MODE_RETURN, len); + else + strncpyz(output, EBPF_CFG_LOAD_MODE_DEFAULT, len); +} + +/** + * Convert string to load mode + * + * Convert the string given as argument to value present in enum. + * + * @param str value read from configuraion file. + * + * @return It returns the value to be used. + */ +netdata_ebpf_load_mode_t epbf_convert_string_to_load_mode(char *str) +{ + if (!strcasecmp(str, EBPF_CFG_CORE_PROGRAM)) + return EBPF_LOAD_CORE; + else if (!strcasecmp(str, EBPF_CFG_LEGACY_PROGRAM)) + return EBPF_LOAD_LEGACY; + + return EBPF_LOAD_PLAY_DICE; +} + +/** + * Convert load mode to string + * + * @param mode value that will select the string + * + * @return It returns the string associated to mode. + */ +static char *ebpf_convert_load_mode_to_string(netdata_ebpf_load_mode_t mode) +{ + if (mode & EBPF_LOAD_CORE) + return EBPF_CFG_CORE_PROGRAM; + else if (mode & EBPF_LOAD_LEGACY) + return EBPF_CFG_LEGACY_PROGRAM; + + return EBPF_CFG_DEFAULT_PROGRAM; +} + +/** + * Convert collect pid to string + * + * @param level value that will select the string + * + * @return It returns the string associated to level. + */ +static char *ebpf_convert_collect_pid_to_string(netdata_apps_level_t level) +{ + if (level == NETDATA_APPS_LEVEL_REAL_PARENT) + return EBPF_CFG_PID_REAL_PARENT; + else if (level == NETDATA_APPS_LEVEL_PARENT) + return EBPF_CFG_PID_PARENT; + else if (level == NETDATA_APPS_LEVEL_ALL) + return EBPF_CFG_PID_ALL; + + return EBPF_CFG_PID_INTERNAL_USAGE; +} + +/** + * Convert string to apps level + * + * @param str the argument read from config files + * + * @return it returns the level associated to the string or default when it is a wrong value + */ +netdata_apps_level_t ebpf_convert_string_to_apps_level(char *str) +{ + if (!strcasecmp(str, EBPF_CFG_PID_REAL_PARENT)) + return NETDATA_APPS_LEVEL_REAL_PARENT; + else if (!strcasecmp(str, EBPF_CFG_PID_PARENT)) + return NETDATA_APPS_LEVEL_PARENT; + else if (!strcasecmp(str, EBPF_CFG_PID_ALL)) + return NETDATA_APPS_LEVEL_ALL; + + return NETDATA_APPS_NOT_SET; +} + +/** + * CO-RE type + * + * Select the preferential type of CO-RE + * + * @param str value read from configuration file. + * @param lmode load mode used by collector. + */ +netdata_ebpf_program_loaded_t ebpf_convert_core_type(char *str, netdata_run_mode_t lmode) +{ + if (!strcasecmp(str, EBPF_CFG_ATTACH_TRACEPOINT)) + return EBPF_LOAD_TRACEPOINT; + else if (!strcasecmp(str, EBPF_CFG_ATTACH_PROBE)) { + return (lmode == MODE_ENTRY) ? EBPF_LOAD_PROBE : EBPF_LOAD_RETPROBE; + } + + return EBPF_LOAD_TRAMPOLINE; +} + +#ifdef LIBBPF_MAJOR_VERSION +/** + * Adjust Thread Load + * + * Adjust thread configuraton according specified load. + * + * @param mod the main structure that will be adjusted. + * @param file the btf file used with thread. + */ +void ebpf_adjust_thread_load(ebpf_module_t *mod, struct btf *file) +{ + if (!file) { + mod->load &= ~EBPF_LOAD_CORE; + mod->load |= EBPF_LOAD_LEGACY; + } else if (mod->load == EBPF_LOAD_PLAY_DICE && file) { + mod->load &= ~EBPF_LOAD_LEGACY; + mod->load |= EBPF_LOAD_CORE; + } +} + +/** + * Parse BTF file + * + * Parse a specific BTF file present on filesystem + * + * @param filename the file that will be parsed. + * + * @return It returns a pointer for the file on success and NULL otherwise. + */ +struct btf *ebpf_parse_btf_file(const char *filename) +{ + struct btf *bf = btf__parse(filename, NULL); + if (libbpf_get_error(bf)) { + fprintf(stderr, "Cannot parse btf file"); + btf__free(bf); + return NULL; + } + + return bf; +} + +/** + * Load default btf file + * + * Load the default BTF file on environment. + * + * @param path is the fullpath + * @param filename is the file inside BTF path. + */ +struct btf *ebpf_load_btf_file(char *path, char *filename) +{ + char fullpath[PATH_MAX + 1]; + snprintfz(fullpath, PATH_MAX, "%s/%s", path, filename); + struct btf *ret = ebpf_parse_btf_file(fullpath); + if (!ret) + info("Your environment does not have BTF file %s/%s. The plugin will work with 'legacy' code.", + path, filename); + + return ret; +} + +/** + * Find BTF attach type + * + * Search type fr current btf file. + * + * @param file is the structure for the btf file already parsed. + */ +static inline const struct btf_type *ebpf_find_btf_attach_type(struct btf *file) +{ + int id = btf__find_by_name_kind(file, "bpf_attach_type", BTF_KIND_ENUM); + if (id < 0) { + fprintf(stderr, "Cannot find 'bpf_attach_type'"); + + return NULL; + } + + return btf__type_by_id(file, id); +} + +/** + * Is function inside BTF + * + * Look for a specific function inside the given BTF file. + * + * @param file is the structure for the btf file already parsed. + * @param function is the function that we want to find. + */ +int ebpf_is_function_inside_btf(struct btf *file, char *function) +{ + const struct btf_type *type = ebpf_find_btf_attach_type(file); + if (!type) + return -1; + + const struct btf_enum *e = btf_enum(type); + int i, id; + for (id = -1, i = 0; i < btf_vlen(type); i++, e++) { + if (!strcmp(btf__name_by_offset(file, e->name_off), "BPF_TRACE_FENTRY")) { + id = btf__find_by_name_kind(file, function, BTF_KIND_FUNC); + break; + } + } + + return (id > 0) ? 1 : 0; +} +#endif + +/** + * Update target with configuration + * + * Update target load mode with value. + * + * @param em the module structure + * @param value value used to update. + */ +static void ebpf_update_target_with_conf(ebpf_module_t *em, netdata_ebpf_program_loaded_t value) +{ + netdata_ebpf_targets_t *targets = em->targets; + if (!targets) { + return; + } + + int i = 0; + while (targets[i].name) { + targets[i].mode = value; + i++; + } +} + +/** + * Select Load Mode + * + * Select the load mode according the given inputs. + * + * @param btf_file a pointer to the loaded btf file. + * @parma load current value. + * @param btf_file a pointer to the loaded btf file. + * @param is_rhf is Red Hat family? + * + * @return it returns the new load mode. + */ +static netdata_ebpf_load_mode_t ebpf_select_load_mode(struct btf *btf_file, netdata_ebpf_load_mode_t load, + int kver, int is_rh) +{ +#ifdef LIBBPF_MAJOR_VERSION + if ((load & EBPF_LOAD_CORE) || (load & EBPF_LOAD_PLAY_DICE)) { + // Quick fix for Oracle linux 8.x + load = (!btf_file || (is_rh && (kver >= NETDATA_EBPF_KERNEL_5_4 && kver < NETDATA_EBPF_KERNEL_5_5))) ? + EBPF_LOAD_LEGACY : EBPF_LOAD_CORE; + } +#else + load = EBPF_LOAD_LEGACY; +#endif + + return load; +} + +/** + * Update Module using config + * + * Update configuration for a specific thread. + * + * @param modules structure that will be updated + * @oaram origin specify the configuration file loaded + * @param btf_file a pointer to the loaded btf file. + * @param is_rhf is Red Hat family? + */ +void ebpf_update_module_using_config(ebpf_module_t *modules, netdata_ebpf_load_mode_t origin, struct btf *btf_file, + int kver, int is_rh) +{ + char default_value[EBPF_MAX_MODE_LENGTH + 1]; + ebpf_select_mode_string(default_value, EBPF_MAX_MODE_LENGTH, modules->mode); + char *value = appconfig_get(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_LOAD_MODE, default_value); + modules->mode = ebpf_select_mode(value); + + modules->update_every = (int)appconfig_get_number(modules->cfg, EBPF_GLOBAL_SECTION, + EBPF_CFG_UPDATE_EVERY, modules->update_every); + + modules->apps_charts = appconfig_get_boolean(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_APPLICATION, + (int) (modules->apps_charts & NETDATA_EBPF_APPS_FLAG_YES)); + + modules->cgroup_charts = appconfig_get_boolean(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_CGROUP, + modules->cgroup_charts); + + modules->pid_map_size = (uint32_t)appconfig_get_number(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_PID_SIZE, + modules->pid_map_size); + + value = ebpf_convert_load_mode_to_string(modules->load & NETDATA_EBPF_LOAD_METHODS); + value = appconfig_get(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_TYPE_FORMAT, value); + netdata_ebpf_load_mode_t load = epbf_convert_string_to_load_mode(value); + load = ebpf_select_load_mode(btf_file, load, kver, is_rh); + modules->load = origin | load; + + value = appconfig_get(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_CORE_ATTACH, EBPF_CFG_ATTACH_TRAMPOLINE); + netdata_ebpf_program_loaded_t fill_lm = ebpf_convert_core_type(value, modules->mode); + ebpf_update_target_with_conf(modules, fill_lm); + + value = ebpf_convert_collect_pid_to_string(modules->apps_level); + value = appconfig_get(modules->cfg, EBPF_GLOBAL_SECTION, EBPF_CFG_COLLECT_PID, value); + modules->apps_level = ebpf_convert_string_to_apps_level(value); +} + +/** + * Update module + * + * When this function is called, it will load the configuration file and after this + * it updates the global information of ebpf_module. + * If the module has specific configuration, this function will load it, but it will not + * update the variables. + * + * @param em the module structure + * @param btf_file a pointer to the loaded btf file. + * @param is_rhf is Red Hat family? + * @param kver the kernel version + */ +void ebpf_update_module(ebpf_module_t *em, struct btf *btf_file, int kver, int is_rh) +{ + char filename[FILENAME_MAX+1]; + netdata_ebpf_load_mode_t origin; + + ebpf_mount_config_name(filename, FILENAME_MAX, ebpf_user_config_dir, em->config_file); + if (!ebpf_load_config(em->cfg, filename)) { + ebpf_mount_config_name(filename, FILENAME_MAX, ebpf_stock_config_dir, em->config_file); + if (!ebpf_load_config(em->cfg, filename)) { + error("Cannot load the ebpf configuration file %s", em->config_file); + return; + } + // If user defined data globaly, we will have here EBPF_LOADED_FROM_USER, we need to consider this, to avoid + // forcing users to configure thread by thread. + origin = (!(em->load & NETDATA_EBPF_LOAD_SOURCE)) ? EBPF_LOADED_FROM_STOCK : em->load & NETDATA_EBPF_LOAD_SOURCE; + } else + origin = EBPF_LOADED_FROM_USER; + + ebpf_update_module_using_config(em, origin, btf_file, kver, is_rh); +} + +/** + * Adjust Apps Cgroup + * + * Apps and cgroup has internal cleanup that needs attaching tracers to release_task, to avoid overload the function + * we will enable this integration by default, if and only if, we are running with trampolines. + * + * @param em a poiter to the main thread structure. + * @param mode is the mode used with different + */ +void ebpf_adjust_apps_cgroup(ebpf_module_t *em, netdata_ebpf_program_loaded_t mode) +{ + if ((em->load & EBPF_LOADED_FROM_STOCK) && + (em->apps_charts || em->cgroup_charts) && + mode != EBPF_LOAD_TRAMPOLINE) { + em->apps_charts = NETDATA_EBPF_APPS_FLAG_NO; + em->cgroup_charts = 0; + } +} + +//---------------------------------------------------------------------------------------------------------------------- + +/** + * Load Address + * + * Helper used to get address from /proc/kallsym + * + * @param fa address structure + * @param fd file descriptor loaded inside kernel. + */ +void ebpf_load_addresses(ebpf_addresses_t *fa, int fd) +{ + if (fa->addr) + return ; + + procfile *ff = procfile_open("/proc/kallsyms", " \t:", PROCFILE_FLAG_DEFAULT); + if (!ff) + return; + + ff = procfile_readall(ff); + if (!ff) + return; + + fa->hash = simple_hash(fa->function); + + size_t lines = procfile_lines(ff), l; + for(l = 0; l < lines ;l++) { + char *fcnt = procfile_lineword(ff, l, 2); + uint32_t hash = simple_hash(fcnt); + if (fa->hash == hash && !strcmp(fcnt, fa->function)) { + char addr[128]; + snprintf(addr, 127, "0x%s", procfile_lineword(ff, l, 0)); + fa->addr = (unsigned long) strtoul(addr, NULL, 16); + uint32_t key = 0; + bpf_map_update_elem(fd, &key, &fa->addr, BPF_ANY); + } + } + + procfile_close(ff); +} + +//---------------------------------------------------------------------------------------------------------------------- + +/** + * Fill Algorithms + * + * Set one unique dimension for all vector position. + * + * @param algorithms the output vector + * @param length number of elements of algorithms vector + * @param algorithm algorithm used on charts. +*/ +void ebpf_fill_algorithms(int *algorithms, size_t length, int algorithm) +{ + size_t i; + for (i = 0; i < length; i++) { + algorithms[i] = algorithm; + } +} + +/** + * Fill Histogram dimension + * + * Fill the histogram dimension with the specified ranges + */ +char **ebpf_fill_histogram_dimension(size_t maximum) +{ + char *dimensions[] = { "us", "ms", "s"}; + int previous_dim = 0, current_dim = 0; + uint32_t previous_level = 1000, current_level = 1000; + uint32_t previous_divisor = 1, current_divisor = 1; + uint32_t current = 1, previous = 0; + uint32_t selector; + char **out = callocz(maximum, sizeof(char *)); + char range[128]; + size_t end = maximum - 1; + for (selector = 0; selector < end; selector++) { + snprintf(range, 127, "%u%s->%u%s", previous/previous_divisor, dimensions[previous_dim], + current/current_divisor, dimensions[current_dim]); + out[selector] = strdupz(range); + previous = current; + current <<= 1; + + if (previous_dim != 2 && previous > previous_level) { + previous_dim++; + + previous_divisor *= 1000; + previous_level *= 1000; + } + + if (current_dim != 2 && current > current_level) { + current_dim++; + + current_divisor *= 1000; + current_level *= 1000; + } + } + snprintf(range, 127, "%u%s->+Inf", previous/previous_divisor, dimensions[previous_dim]); + out[selector] = strdupz(range); + + return out; +} + +/** + * Histogram dimension cleanup + * + * Cleanup dimensions allocated with function ebpf_fill_histogram_dimension + * + * @param ptr + * @param length + */ +void ebpf_histogram_dimension_cleanup(char **ptr, size_t length) +{ + size_t i; + for (i = 0; i < length; i++) { + freez(ptr[i]); + } + freez(ptr); +} + +//---------------------------------------------------------------------------------------------------------------------- + +/** + * Open tracepoint path + * + * @param filename pointer to store the path + * @param length file length + * @param subsys is the name of your subsystem. + * @param eventname is the name of the event to trace. + * @param flags flags used with syscall open + * + * @return it returns a positive value on success and a negative otherwise. + */ +static inline int ebpf_open_tracepoint_path(char *filename, size_t length, char *subsys, char *eventname, int flags) +{ + snprintfz(filename, length, "%s/events/%s/%s/enable", NETDATA_DEBUGFS, subsys, eventname); + return open(filename, flags, 0); +} + +/** + * Is tracepoint enabled + * + * Check whether the tracepoint is enabled. + * + * @param subsys is the name of your subsystem. + * @param eventname is the name of the event to trace. + * + * @return it returns 1 when it is enabled, 0 when it is disabled and -1 on error. + */ +int ebpf_is_tracepoint_enabled(char *subsys, char *eventname) +{ + char text[FILENAME_MAX + 1]; + int fd = ebpf_open_tracepoint_path(text, FILENAME_MAX, subsys, eventname, O_RDONLY); + if (fd < 0) { + return -1; + } + + ssize_t length = read(fd, text, 1); + if (length != 1) { + close(fd); + return -1; + } + close(fd); + + return (text[0] == '1') ? CONFIG_BOOLEAN_YES : CONFIG_BOOLEAN_NO; +} + +/** + * Change Tracing values + * + * Change value for specific tracepoint enabling or disabling it according value given. + * + * @param subsys is the name of your subsystem. + * @param eventname is the name of the event to trace. + * @param value a value to enable (1) or disable (0) a tracepoint. + * + * @return It returns 0 on success and -1 otherwise + */ +static int ebpf_change_tracing_values(char *subsys, char *eventname, char *value) +{ + if (strcmp("0", value) && strcmp("1", value)) { + error("Invalid value given to either enable or disable a tracepoint."); + return -1; + } + + char filename[1024]; + int fd = ebpf_open_tracepoint_path(filename, 1023, subsys, eventname, O_WRONLY); + if (fd < 0) { + return -1; + } + + ssize_t written = write(fd, value, strlen(value)); + if (written < 0) { + close(fd); + return -1; + } + + close(fd); + return 0; +} + +/** + * Enable tracing values + * + * Enable a tracepoint on a system + * + * @param subsys is the name of your subsystem. + * @param eventname is the name of the event to trace. + * + * @return It returns 0 on success and -1 otherwise + */ +int ebpf_enable_tracing_values(char *subsys, char *eventname) +{ + return ebpf_change_tracing_values(subsys, eventname, "1"); +} + +/** + * Disable tracing values + * + * Disable tracing points enabled by collector + * + * @param subsys is the name of your subsystem. + * @param eventname is the name of the event to trace. + * + * @return It returns 0 on success and -1 otherwise + */ +int ebpf_disable_tracing_values(char *subsys, char *eventname) +{ + return ebpf_change_tracing_values(subsys, eventname, "0"); +} + +/** + * Select PC prefix + * + * Identify the prefix to run on PC architecture. + * + * @return It returns 32 or 64 according to host arch. + */ +static uint32_t ebpf_select_pc_prefix() +{ + long counter = 1; + uint32_t i; + for (i = 0; i < 128; i++) { + counter <<= 1; + if (counter < 0) + break; + } + + return counter; +} + +/** + * Select Host Prefix + * + * Select prefix to syscall when host is running a kernel newer than 4.17.0 + * + * @param output the vector to store data. + * @param length length of output vector. + * @param syscall the syscall that prefix will be attached; + * @param kver the current kernel version in format MAJOR*65536 + MINOR*256 + PATCH + */ +void ebpf_select_host_prefix(char *output, size_t length, char *syscall, int kver) +{ + if (kver < NETDATA_EBPF_KERNEL_4_17) + snprintfz(output, length, "sys_%s", syscall); + else { + uint32_t arch = ebpf_select_pc_prefix(); + // Prefix selected according https://www.kernel.org/doc/html/latest/process/adding-syscalls.html + char *prefix = (arch == 32) ? "__ia32" : "__x64"; + snprintfz(output, length, "%s_sys_%s", prefix, syscall); + } +} + |