diff options
Diffstat (limited to 'collectors/ebpf.plugin/ebpf_cgroup.c')
| -rw-r--r-- | collectors/ebpf.plugin/ebpf_cgroup.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/collectors/ebpf.plugin/ebpf_cgroup.c b/collectors/ebpf.plugin/ebpf_cgroup.c new file mode 100644 index 000000000..ecdc46c0b --- /dev/null +++ b/collectors/ebpf.plugin/ebpf_cgroup.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#include <sys/resource.h> + +#include "ebpf.h" +#include "ebpf_cgroup.h" + +ebpf_cgroup_target_t *ebpf_cgroup_pids = NULL; + +// -------------------------------------------------------------------------------------------------------------------- +// Map shared memory + +/** + * Map Shared Memory locally + * + * Map the shared memory for current process + * + * @param fd file descriptor returned after shm_open was called. + * @param length length of the shared memory + * + * @return It returns a pointer to the region mapped. + */ +static inline void *ebpf_cgroup_map_shm_locally(int fd, size_t length) +{ + void *value; + + value = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (!value) { + error("Cannot map shared memory used between eBPF and cgroup, integration between processes won't happen"); + close(shm_fd_ebpf_cgroup); + shm_fd_ebpf_cgroup = -1; + shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME); + } + + return value; +} + +/** + * Map cgroup shared memory + * + * Map cgroup shared memory from cgroup to plugin + */ +void ebpf_map_cgroup_shared_memory() +{ + static int limit_try = 0; + static time_t next_try = 0; + + if (shm_ebpf_cgroup.header || limit_try > NETDATA_EBPF_CGROUP_MAX_TRIES) + return; + + time_t curr_time = time(NULL); + if (curr_time < next_try) + return; + + limit_try++; + next_try = curr_time + NETDATA_EBPF_CGROUP_NEXT_TRY_SEC; + + shm_fd_ebpf_cgroup = shm_open(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME, O_RDWR, 0660); + if (shm_fd_ebpf_cgroup < 0) { + if (limit_try == NETDATA_EBPF_CGROUP_MAX_TRIES) + error("Shared memory was not initialized, integration between processes won't happen."); + + return; + } + + // Map only header + shm_ebpf_cgroup.header = (netdata_ebpf_cgroup_shm_header_t *) ebpf_cgroup_map_shm_locally(shm_fd_ebpf_cgroup, + sizeof(netdata_ebpf_cgroup_shm_header_t)); + if (!shm_ebpf_cgroup.header) { + limit_try = NETDATA_EBPF_CGROUP_MAX_TRIES + 1; + return; + } + + size_t length = shm_ebpf_cgroup.header->body_length; + + munmap(shm_ebpf_cgroup.header, sizeof(netdata_ebpf_cgroup_shm_header_t)); + + shm_ebpf_cgroup.header = (netdata_ebpf_cgroup_shm_header_t *)ebpf_cgroup_map_shm_locally(shm_fd_ebpf_cgroup, length); + if (!shm_ebpf_cgroup.header) { + limit_try = NETDATA_EBPF_CGROUP_MAX_TRIES + 1; + return; + } + shm_ebpf_cgroup.body = (netdata_ebpf_cgroup_shm_body_t *) ((char *)shm_ebpf_cgroup.header + + sizeof(netdata_ebpf_cgroup_shm_header_t)); + + shm_sem_ebpf_cgroup = sem_open(NETDATA_NAMED_SEMAPHORE_EBPF_CGROUP_NAME, O_CREAT, 0660, 1); + + if (shm_sem_ebpf_cgroup == SEM_FAILED) { + error("Cannot create semaphore, integration between eBPF and cgroup won't happen"); + munmap(shm_ebpf_cgroup.header, length); + shm_ebpf_cgroup.header = NULL; + close(shm_fd_ebpf_cgroup); + shm_fd_ebpf_cgroup = -1; + shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME); + } +} + +// -------------------------------------------------------------------------------------------------------------------- +// Close and Cleanup + +/** + * Close shared memory + */ +void ebpf_close_cgroup_shm() +{ + if (shm_sem_ebpf_cgroup != SEM_FAILED) { + sem_close(shm_sem_ebpf_cgroup); + sem_unlink(NETDATA_NAMED_SEMAPHORE_EBPF_CGROUP_NAME); + shm_sem_ebpf_cgroup = SEM_FAILED; + } + + if (shm_fd_ebpf_cgroup > 0) { + close(shm_fd_ebpf_cgroup); + shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME); + shm_fd_ebpf_cgroup = -1; + } +} + +/** + * Clean Specific cgroup pid + * + * Clean all PIDs associated with cgroup. + * + * @param pt structure pid on target that will have your PRs removed + */ +static inline void ebpf_clean_specific_cgroup_pids(struct pid_on_target2 *pt) +{ + while (pt) { + struct pid_on_target2 *next_pid = pt->next; + + freez(pt); + pt = next_pid; + } +} + +/** + * Cleanup link list + */ +void ebpf_clean_cgroup_pids() +{ + if (!ebpf_cgroup_pids) + return; + + ebpf_cgroup_target_t *ect = ebpf_cgroup_pids; + while (ect) { + ebpf_cgroup_target_t *next_cgroup = ect->next; + + ebpf_clean_specific_cgroup_pids(ect->pids); + freez(ect); + + ect = next_cgroup; + } + ebpf_cgroup_pids = NULL; +} + +/** + * Remove Cgroup Update Target Update List + * + * Remove from cgroup target and update the link list + */ +static void ebpf_remove_cgroup_target_update_list() +{ + ebpf_cgroup_target_t *next, *ect = ebpf_cgroup_pids; + ebpf_cgroup_target_t *prev = ebpf_cgroup_pids; + while (ect) { + next = ect->next; + if (!ect->updated) { + if (ect == ebpf_cgroup_pids) { + ebpf_cgroup_pids = next; + prev = next; + } else { + prev->next = next; + } + + ebpf_clean_specific_cgroup_pids(ect->pids); + freez(ect); + } else { + prev = ect; + } + + ect = next; + } +} + +// -------------------------------------------------------------------------------------------------------------------- +// Fill variables + +/** + * Set Target Data + * + * Set local variable values according shared memory information. + * + * @param out local output variable. + * @param ptr input from shared memory. + */ +static inline void ebpf_cgroup_set_target_data(ebpf_cgroup_target_t *out, netdata_ebpf_cgroup_shm_body_t *ptr) +{ + out->hash = ptr->hash; + snprintfz(out->name, 255, "%s", ptr->name); + out->systemd = ptr->options & CGROUP_OPTIONS_SYSTEM_SLICE_SERVICE; + out->updated = 1; +} + +/** + * Find or create + * + * Find the structure inside the link list or allocate and link when it is not present. + * + * @param ptr Input from shared memory. + * + * @return It returns a pointer for the structure associated with the input. + */ +static ebpf_cgroup_target_t * ebpf_cgroup_find_or_create(netdata_ebpf_cgroup_shm_body_t *ptr) +{ + ebpf_cgroup_target_t *ect, *prev; + for (ect = ebpf_cgroup_pids, prev = ebpf_cgroup_pids; ect; prev = ect, ect = ect->next) { + if (ect->hash == ptr->hash && !strcmp(ect->name, ptr->name)) { + ect->updated = 1; + return ect; + } + } + + ebpf_cgroup_target_t *new_ect = callocz(1, sizeof(ebpf_cgroup_target_t)); + + ebpf_cgroup_set_target_data(new_ect, ptr); + if (!ebpf_cgroup_pids) { + ebpf_cgroup_pids = new_ect; + } else { + prev->next = new_ect; + } + + return new_ect; +} + +/** + * Update pid link list + * + * Update PIDs list associated with specific cgroup. + * + * @param ect cgroup structure where pids will be stored + * @param path file with PIDs associated to cgroup. + */ +static void ebpf_update_pid_link_list(ebpf_cgroup_target_t *ect, char *path) +{ + procfile *ff = procfile_open(path, " \t:", PROCFILE_FLAG_DEFAULT); + if (!ff) + return; + + ff = procfile_readall(ff); + if (!ff) + return; + + size_t lines = procfile_lines(ff), l; + for (l = 0; l < lines ;l++) { + int pid = (int)str2l(procfile_lineword(ff, l, 0)); + if (pid) { + struct pid_on_target2 *pt, *prev; + for (pt = ect->pids, prev = ect->pids; pt; prev = pt, pt = pt->next) { + if (pt->pid == pid) + break; + } + + if (!pt) { + struct pid_on_target2 *w = callocz(1, sizeof(struct pid_on_target2)); + w->pid = pid; + if (!ect->pids) + ect->pids = w; + else + prev->next = w; + } + } + } + + procfile_close(ff); +} + +/** + * Set remove var + * + * Set variable remove. If this variable is not reset, the structure will be removed from link list. + */ + void ebpf_reset_updated_var() + { + ebpf_cgroup_target_t *ect; + for (ect = ebpf_cgroup_pids; ect; ect = ect->next) { + ect->updated = 0; + } + } + +/** + * Parse cgroup shared memory + * + * This function is responsible to copy necessary data from shared memory to local memory. + */ +void ebpf_parse_cgroup_shm_data() +{ + if (shm_ebpf_cgroup.header) { + sem_wait(shm_sem_ebpf_cgroup); + int i, end = shm_ebpf_cgroup.header->cgroup_root_count; + + pthread_mutex_lock(&mutex_cgroup_shm); + + ebpf_remove_cgroup_target_update_list(); + + ebpf_reset_updated_var(); + + for (i = 0; i < end; i++) { + netdata_ebpf_cgroup_shm_body_t *ptr = &shm_ebpf_cgroup.body[i]; + if (ptr->enabled) { + ebpf_cgroup_target_t *ect = ebpf_cgroup_find_or_create(ptr); + ebpf_update_pid_link_list(ect, ptr->path); + } + } + pthread_mutex_unlock(&mutex_cgroup_shm); + + sem_post(shm_sem_ebpf_cgroup); + } +} + +// -------------------------------------------------------------------------------------------------------------------- +// Create charts + +/** + * Create charts on systemd submenu + * + * @param id the chart id + * @param title the value displayed on vertical axis. + * @param units the value displayed on vertical axis. + * @param family Submenu that the chart will be attached on dashboard. + * @param charttype chart type + * @param order the chart order + * @param algorithm the algorithm used by dimension + * @param context add context for chart + * @param module chart module name, this is the eBPF thread. + * @param update_every value to overwrite the update frequency set by the server. + */ +void ebpf_create_charts_on_systemd(char *id, char *title, char *units, char *family, char *charttype, int order, + char *algorithm, char *context, char *module, int update_every) +{ + ebpf_cgroup_target_t *w; + ebpf_write_chart_cmd(NETDATA_SERVICE_FAMILY, id, title, units, family, charttype, context, + order, update_every, module); + + for (w = ebpf_cgroup_pids; w; w = w->next) { + if (unlikely(w->systemd) && unlikely(w->updated)) + fprintf(stdout, "DIMENSION %s '' %s 1 1\n", w->name, algorithm); + } +} |