diff options
Diffstat (limited to 'collectors/systemd-journal.plugin/systemd-journal-watcher.c')
| -rw-r--r-- | collectors/systemd-journal.plugin/systemd-journal-watcher.c | 379 |
1 files changed, 0 insertions, 379 deletions
diff --git a/collectors/systemd-journal.plugin/systemd-journal-watcher.c b/collectors/systemd-journal.plugin/systemd-journal-watcher.c deleted file mode 100644 index ed41f6247..000000000 --- a/collectors/systemd-journal.plugin/systemd-journal-watcher.c +++ /dev/null @@ -1,379 +0,0 @@ -// SPDX-License-Identifier: GPL-3.0-or-later - -#include "systemd-internals.h" -#include <sys/inotify.h> - -#define EVENT_SIZE (sizeof(struct inotify_event)) -#define INITIAL_WATCHES 256 - -#define WATCH_FOR (IN_CREATE | IN_MODIFY | IN_DELETE | IN_DELETE_SELF | IN_MOVED_FROM | IN_MOVED_TO | IN_UNMOUNT) - -typedef struct watch_entry { - int slot; - - int wd; // Watch descriptor - char *path; // Dynamically allocated path - - struct watch_entry *next; // for the free list -} WatchEntry; - -typedef struct { - WatchEntry *watchList; - WatchEntry *freeList; - int watchCount; - int watchListSize; - - size_t errors; - - DICTIONARY *pending; -} Watcher; - -static WatchEntry *get_slot(Watcher *watcher) { - WatchEntry *t; - - if (watcher->freeList != NULL) { - t = watcher->freeList; - watcher->freeList = t->next; - t->next = NULL; - return t; - } - - if (watcher->watchCount == watcher->watchListSize) { - watcher->watchListSize *= 2; - watcher->watchList = reallocz(watcher->watchList, watcher->watchListSize * sizeof(WatchEntry)); - } - - watcher->watchList[watcher->watchCount] = (WatchEntry){ - .slot = watcher->watchCount, - .wd = -1, - .path = NULL, - .next = NULL, - }; - t = &watcher->watchList[watcher->watchCount]; - watcher->watchCount++; - - return t; -} - -static void free_slot(Watcher *watcher, WatchEntry *t) { - t->wd = -1; - freez(t->path); - t->path = NULL; - - // link it to the free list - t->next = watcher->freeList; - watcher->freeList = t; -} - -static int add_watch(Watcher *watcher, int inotifyFd, const char *path) { - WatchEntry *t = get_slot(watcher); - - t->wd = inotify_add_watch(inotifyFd, path, WATCH_FOR); - if (t->wd == -1) { - nd_log(NDLS_COLLECTORS, NDLP_ERR, - "JOURNAL WATCHER: cannot watch directory: '%s'", - path); - - free_slot(watcher, t); - - struct stat info; - if(stat(path, &info) == 0 && S_ISDIR(info.st_mode)) { - // the directory exists, but we failed to add the watch - // increase errors - watcher->errors++; - } - } - else { - t->path = strdupz(path); - - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: watching directory: '%s'", - path); - - } - return t->wd; -} - -static void remove_watch(Watcher *watcher, int inotifyFd, int wd) { - int i; - for (i = 0; i < watcher->watchCount; ++i) { - if (watcher->watchList[i].wd == wd) { - - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: removing watch from directory: '%s'", - watcher->watchList[i].path); - - inotify_rm_watch(inotifyFd, watcher->watchList[i].wd); - free_slot(watcher, &watcher->watchList[i]); - return; - } - } - - nd_log(NDLS_COLLECTORS, NDLP_WARNING, - "JOURNAL WATCHER: cannot find directory watch %d to remove.", - wd); -} - -static void free_watches(Watcher *watcher, int inotifyFd) { - for (int i = 0; i < watcher->watchCount; ++i) { - if (watcher->watchList[i].wd != -1) { - inotify_rm_watch(inotifyFd, watcher->watchList[i].wd); - free_slot(watcher, &watcher->watchList[i]); - } - } - freez(watcher->watchList); - watcher->watchList = NULL; - - dictionary_destroy(watcher->pending); - watcher->pending = NULL; -} - -static char* get_path_from_wd(Watcher *watcher, int wd) { - for (int i = 0; i < watcher->watchCount; ++i) { - if (watcher->watchList[i].wd == wd) - return watcher->watchList[i].path; - } - return NULL; -} - -static bool is_directory_watched(Watcher *watcher, const char *path) { - for (int i = 0; i < watcher->watchCount; ++i) { - if (watcher->watchList[i].wd != -1 && strcmp(watcher->watchList[i].path, path) == 0) { - return true; - } - } - return false; -} - -static void watch_directory_and_subdirectories(Watcher *watcher, int inotifyFd, const char *basePath) { - DICTIONARY *dirs = dictionary_create(DICT_OPTION_SINGLE_THREADED | DICT_OPTION_DONT_OVERWRITE_VALUE); - - journal_directory_scan_recursively(NULL, dirs, basePath, 0); - - void *x; - dfe_start_read(dirs, x) { - const char *dirname = x_dfe.name; - // Check if this directory is already being watched - if (!is_directory_watched(watcher, dirname)) { - add_watch(watcher, inotifyFd, dirname); - } - } - dfe_done(x); - - dictionary_destroy(dirs); -} - -static bool is_subpath(const char *path, const char *subpath) { - // Use strncmp to compare the paths - if (strncmp(path, subpath, strlen(path)) == 0) { - // Ensure that the next character is a '/' or '\0' - char next_char = subpath[strlen(path)]; - return next_char == '/' || next_char == '\0'; - } - - return false; -} - -void remove_directory_watch(Watcher *watcher, int inotifyFd, const char *dirPath) { - for (int i = 0; i < watcher->watchCount; ++i) { - WatchEntry *t = &watcher->watchList[i]; - if (t->wd != -1 && is_subpath(t->path, dirPath)) { - inotify_rm_watch(inotifyFd, t->wd); - free_slot(watcher, t); - } - } - - struct journal_file *jf; - dfe_start_write(journal_files_registry, jf) { - if(is_subpath(jf->filename, dirPath)) - dictionary_del(journal_files_registry, jf->filename); - } - dfe_done(jf); - - dictionary_garbage_collect(journal_files_registry); -} - -void process_event(Watcher *watcher, int inotifyFd, struct inotify_event *event) { - if(!event->len) { - nd_log(NDLS_COLLECTORS, NDLP_NOTICE - , "JOURNAL WATCHER: received event with mask %u and len %u (this is zero) for path: '%s' - ignoring it." - , event->mask, event->len, event->name); - return; - } - - char *dirPath = get_path_from_wd(watcher, event->wd); - if(!dirPath) { - nd_log(NDLS_COLLECTORS, NDLP_NOTICE, - "JOURNAL WATCHER: received event with mask %u and len %u for path: '%s' - " - "but we can't find its watch descriptor - ignoring it." - , event->mask, event->len, event->name); - return; - } - - if(event->mask & IN_DELETE_SELF) { - remove_watch(watcher, inotifyFd, event->wd); - return; - } - - static __thread char fullPath[PATH_MAX]; - snprintfz(fullPath, sizeof(fullPath), "%s/%s", dirPath, event->name); - // fullPath contains the full path to the file - - size_t len = strlen(event->name); - - if(event->mask & IN_ISDIR) { - if (event->mask & (IN_DELETE | IN_MOVED_FROM)) { - // A directory is deleted or moved out - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: Directory deleted or moved out: '%s'", - fullPath); - - // Remove the watch - implement this function based on how you manage your watches - remove_directory_watch(watcher, inotifyFd, fullPath); - } - else if (event->mask & (IN_CREATE | IN_MOVED_TO)) { - // A new directory is created or moved in - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: New directory created or moved in: '%s'", - fullPath); - - // Start watching the new directory - recursive watch - watch_directory_and_subdirectories(watcher, inotifyFd, fullPath); - } - else - nd_log(NDLS_COLLECTORS, NDLP_WARNING, - "JOURNAL WATCHER: Received unhandled event with mask %u for directory '%s'", - event->mask, fullPath); - } - else if(len > sizeof(".journal") - 1 && strcmp(&event->name[len - (sizeof(".journal") - 1)], ".journal") == 0) { - // It is a file that ends in .journal - // add it to our pending list - dictionary_set(watcher->pending, fullPath, NULL, 0); - } - else - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: ignoring event with mask %u for file '%s'", - event->mask, fullPath); -} - -static void process_pending(Watcher *watcher) { - void *x; - dfe_start_write(watcher->pending, x) { - struct stat info; - const char *fullPath = x_dfe.name; - - if(stat(fullPath, &info) != 0) { - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: file '%s' no longer exists, removing it from the registry", - fullPath); - - dictionary_del(journal_files_registry, fullPath); - } - else if(S_ISREG(info.st_mode)) { - nd_log(NDLS_COLLECTORS, NDLP_DEBUG, - "JOURNAL WATCHER: file '%s' has been added/updated, updating the registry", - fullPath); - - struct journal_file t = { - .file_last_modified_ut = info.st_mtim.tv_sec * USEC_PER_SEC + - info.st_mtim.tv_nsec / NSEC_PER_USEC, - .last_scan_monotonic_ut = now_monotonic_usec(), - .size = info.st_size, - .max_journal_vs_realtime_delta_ut = JOURNAL_VS_REALTIME_DELTA_DEFAULT_UT, - }; - struct journal_file *jf = dictionary_set(journal_files_registry, fullPath, &t, sizeof(t)); - journal_file_update_header(jf->filename, jf); - } - - dictionary_del(watcher->pending, fullPath); - } - dfe_done(x); - - dictionary_garbage_collect(watcher->pending); -} - -void *journal_watcher_main(void *arg __maybe_unused) { - while(1) { - Watcher watcher = { - .watchList = mallocz(INITIAL_WATCHES * sizeof(WatchEntry)), - .freeList = NULL, - .watchCount = 0, - .watchListSize = INITIAL_WATCHES, - .pending = dictionary_create(DICT_OPTION_DONT_OVERWRITE_VALUE|DICT_OPTION_SINGLE_THREADED), - .errors = 0, - }; - - int inotifyFd = inotify_init(); - if (inotifyFd < 0) { - nd_log(NDLS_COLLECTORS, NDLP_ERR, "inotify_init() failed."); - free_watches(&watcher, inotifyFd); - return NULL; - } - - for (unsigned i = 0; i < MAX_JOURNAL_DIRECTORIES; i++) { - if (!journal_directories[i].path) break; - watch_directory_and_subdirectories(&watcher, inotifyFd, journal_directories[i].path); - } - - usec_t last_headers_update_ut = now_monotonic_usec(); - struct buffered_reader reader; - while (1) { - buffered_reader_ret_t rc = buffered_reader_read_timeout( - &reader, inotifyFd, SYSTEMD_JOURNAL_EXECUTE_WATCHER_PENDING_EVERY_MS, false); - - if (rc != BUFFERED_READER_READ_OK && rc != BUFFERED_READER_READ_POLL_TIMEOUT) { - nd_log(NDLS_COLLECTORS, NDLP_CRIT, - "JOURNAL WATCHER: cannot read inotify events, buffered_reader_read_timeout() returned %d - " - "restarting the watcher.", - rc); - break; - } - - if(rc == BUFFERED_READER_READ_OK) { - bool unmount_event = false; - - ssize_t i = 0; - while (i < reader.read_len) { - struct inotify_event *event = (struct inotify_event *) &reader.read_buffer[i]; - - if(event->mask & IN_UNMOUNT) { - unmount_event = true; - break; - } - - process_event(&watcher, inotifyFd, event); - i += (ssize_t)EVENT_SIZE + event->len; - } - - reader.read_buffer[0] = '\0'; - reader.read_len = 0; - reader.pos = 0; - - if(unmount_event) - break; - } - - usec_t ut = now_monotonic_usec(); - if (dictionary_entries(watcher.pending) && (rc == BUFFERED_READER_READ_POLL_TIMEOUT || - last_headers_update_ut + (SYSTEMD_JOURNAL_EXECUTE_WATCHER_PENDING_EVERY_MS * USEC_PER_MS) <= ut)) { - process_pending(&watcher); - last_headers_update_ut = ut; - } - - if(watcher.errors) { - nd_log(NDLS_COLLECTORS, NDLP_NOTICE, - "JOURNAL WATCHER: there were errors in setting up inotify watches - restarting the watcher."); - } - } - - close(inotifyFd); - free_watches(&watcher, inotifyFd); - - // this will scan the directories and cleanup the registry - journal_files_registry_update(); - - sleep_usec(5 * USEC_PER_SEC); - } - - return NULL; -} |