/** * lsyncd.c Live (Mirror) Syncing Demon * * License: GPLv2 (see COPYING) or any later version * * Authors: Axel Kittenberger * * This is the core. It contains as minimal as possible glues * to the operating system needed for lsyncd operation. All high-level * logic is coded (when feasable) into lsyncd.lua */ #include "config.h" #define LUA_USE_APICHECK 1 #ifdef HAVE_SYS_INOTIFY_H # include #else # error Missing ; supply kernel-headers and rerun configure. #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define time_after(a,b) ((long)(b) - (long)(a) < 0) #define time_before(a,b) time_after(b,a) #define time_after_eq(a,b) ((long)(a) - (long)(b) >= 0) #define time_before_eq(a,b) time_after_eq(b,a) /** * Event types core sends to runner. */ enum event_type { NONE = 0, ATTRIB = 1, MODIFY = 2, CREATE = 3, DELETE = 4, MOVE = 5, }; /** * The Lua part of lsyncd if compiled into the binary. */ #ifndef LSYNCD_DEFAULT_RUNNER_FILE extern char _binary_luac_out_start; extern char _binary_luac_out_end; #endif /** * The inotify file descriptor. */ static int inotify_fd; /** * TODO allow configure. */ static const uint32_t standard_event_mask = IN_ATTRIB | IN_CLOSE_WRITE | IN_CREATE | IN_DELETE | IN_DELETE_SELF | IN_MOVED_FROM | IN_MOVED_TO | IN_DONT_FOLLOW | IN_ONLYDIR; /** * configuration parameters */ static struct settings { /** * If not null lsyncd logs in this file. */ char * log_file; /** * If true lsyncd sends log messages to syslog */ bool log_syslog; /** * -1 logs everything, 0 normal mode, * LOG_ERROR errors only */ int log_level; } settings = { .log_file = NULL, .log_syslog = false, .log_level = 0, }; /** * True when lsyncd daemonized itself. */ static bool is_daemon = false; /** * True after first configuration phase. This is to write configuration error * messages to stdout/stderr after being first started. Then it uses whatever * it has been configured to. This survives a reset by HUP signal or * inotify OVERFLOW! */ static bool running = false; /** * Set to TERM or HUP in signal handler, when lsyncd should end or reset ASAP. */ static volatile sig_atomic_t reset = 0; /** * The kernels clock ticks per second. */ static long clocks_per_sec; /** * signal handler */ void sig_child(int sig) { /* nothing */ } /** * predeclerations -- see below */ static void * s_calloc(size_t nmemb, size_t size); static void * s_malloc(size_t size); static void * s_realloc(void *ptr, size_t size); static char * s_strdup(const char *src); /***************************************************************************** * Logging ****************************************************************************/ /** * A logging category */ struct logcat { char *name; int priority; }; /** * A table of all enabled logging categories. * Sorted by first letter to have to do less comparisons; */ static struct logcat *logcats[26] = {0,}; /** * Returns the positive priority if category is configured to be logged. * or -1 */ static int check_logcat(const char *name) { struct logcat *lc; if (name[0] < 'A' || name[0] > 'Z') { return false; } lc = logcats[name[0]-'A']; if (!lc) { return -1; } while (lc->name) { if (!strcmp(lc->name, name)) { return lc->priority; } lc++; } return -1; } /** * Adds a logging category * @return true if OK. */ static bool add_logcat(const char *name, int priority) { struct logcat *lc; if (!strcmp("all", name)) { settings.log_level = -1; return true; } if (!strcmp("scarce", name)) { settings.log_level = LOG_ERR; return true; } /* category must start with capital letter */ if (name[0] < 'A' || name[0] > 'Z') { return false; } if (!logcats[name[0]-'A']) { /* en empty capital letter */ lc = logcats[name[0]-'A'] = s_calloc(2, sizeof(struct logcat)); } else { /* length of letter list */ int ll = 0; /* counts list length */ for(lc = logcats[name[0]-'A']; lc->name; lc++) { ll++; } /* enlarge list */ logcats[name[0]-'A'] = s_realloc(logcats[name[0]-'A'], (ll + 2) * sizeof(struct logcat)); /* go to list end */ for(lc = logcats[name[0]-'A']; lc->name; lc++) { if (!strcmp(name, lc->name)) { /* already there */ return true; } } } lc->name = s_strdup(name); lc->priority = priority; /* terminates the list */ lc[1].name = NULL; return true; } /** * Logs a string. * * @param priorty the priority of the log message * @param cat the category * @param message the log message */ #define logstring(cat, message) \ {int p; if ((p = check_logcat(cat)) >= settings.log_level) \ {logstring0(p, cat, message);}} static void logstring0(int priority, const char *cat, const char *message) { /* in case of logall and not found category priority will be -1 */ if (priority < 0) { priority = LOG_DEBUG; } if (!running) { /* lsyncd is in intial configuration. * thus just print to normal stdout/stderr. */ if (priority >= LOG_ERR) { fprintf(stderr, "%s: %s\n", cat, message); } else { printf("%s: %s\n", cat, message); } return; } /* writes on console if not daemon */ if (!is_daemon) { char ct[255]; /* gets current timestamp hour:minute:second */ time_t mtime; time(&mtime); strftime(ct, sizeof(ct), "%T", localtime(&mtime)); FILE * flog = priority <= LOG_ERR ? stderr : stdout; fprintf(flog, "%s %s: %s\n", ct, cat, message); } /* writes to file if configured so */ if (settings.log_file) { FILE * flog = fopen(settings.log_file, "a"); /* gets current timestamp day-time-year */ char * ct; time_t mtime; time(&mtime); ct = ctime(&mtime); /* cuts trailing linefeed */ ct[strlen(ct) - 1] = 0; if (flog == NULL) { fprintf(stderr, "Cannot open logfile [%s]!\n", settings.log_file); exit(-1); // ERRNO } fprintf(flog, "%s %s: %s", ct, cat, message); fclose(flog); } /* sends to syslog if configured so */ if (settings.log_syslog) { syslog(priority, "%s, %s", cat, message); } return; } /** * Let the core print logmessage comfortably. * This uses the lua_State for it easy string buffers only. */ #define printlogf(L, cat, ...) \ {int p; if ((p = check_logcat(cat)) >= settings.log_level) \ {printlogf0(L, p, cat, __VA_ARGS__);}} static void printlogf0(lua_State *L, int priority, const char *cat, const char *fmt, ...) __attribute__((format(printf, 4, 5))); static void printlogf0(lua_State *L, int priority, const char *cat, const char *fmt, ...) { va_list ap; va_start(ap, fmt); lua_pushvfstring(L, fmt, ap); va_end(ap); logstring0(priority, cat, luaL_checkstring(L, -1)); lua_pop(L, 1); return; } /***************************************************************************** * Simple memory management ****************************************************************************/ /** * "secured" calloc. */ void * s_calloc(size_t nmemb, size_t size) { void *r = calloc(nmemb, size); if (r == NULL) { logstring0(LOG_ERR, "Error", "Out of memory!"); exit(-1); // ERRNO } return r; } /** * "secured" malloc. the deamon shall kill itself * in case of out of memory. */ static void * s_malloc(size_t size) { void *r = malloc(size); if (r == NULL) { logstring0(LOG_ERR, "Error", "Out of memory!"); exit(-1); // ERRNO } return r; } /** * "secured" realloc. */ static void * s_realloc(void *ptr, size_t size) { void *r = realloc(ptr, size); if (r == NULL) { logstring0(LOG_ERR, "Error", "Out of memory!"); exit(-1); } return r; } /** * "secured" strdup. */ static char * s_strdup(const char *src) { char *s = strdup(src); if (s == NULL) { logstring0(LOG_ERR, "Error", "Out of memory!"); exit(-1); // ERRNO } return s; } /***************************************************************************** * Library calls for lsyncd.lua * * These are as minimal as possible glues to the operating system needed for * lsyncd operation. * ****************************************************************************/ static int l_stackdump(lua_State* L); /** * Adds an inotify watch * * @param dir (Lua stack) path to directory * @return (Lua stack) numeric watch descriptor */ static int l_inotifyadd(lua_State *L) { const char *path = luaL_checkstring(L, 1); lua_Integer wd = inotify_add_watch(inotify_fd, path, standard_event_mask); lua_pushinteger(L, wd); return 1; } /** * Removes an inotify watch * * @param dir (Lua stack) numeric watch descriptor * @return nil */ static int l_inotifyrm(lua_State *L) { lua_Integer wd = luaL_checkinteger(L, 1); inotify_rm_watch(inotify_fd, wd); return 0; } /** * Logs a message. * * @param loglevel (Lua stack) loglevel of massage * @param string (Lua stack) the string to log */ static int l_log(lua_State *L) { /* log category */ const char * cat; /* log message */ const char * message; /* log priority */ int priority; cat = luaL_checkstring(L, 1); priority = check_logcat(cat); /* skips filtered messages */ if (priority < settings.log_level) { return 0; } { // replace non string values int i; int top = lua_gettop(L); for (i = 1; i <= top; i++) { int t = lua_type(L, i); switch (t) { case LUA_TTABLE: lua_pushfstring(L, "(Table: %p)", lua_topointer(L, i)); lua_replace(L, i); break; case LUA_TBOOLEAN: if (lua_toboolean(L, i)) { lua_pushstring(L, "(true)"); } else { lua_pushstring(L, "(false)"); } lua_replace(L, i); break; } } } /* concates if there is more than one string parameter */ lua_concat(L, lua_gettop(L) - 1); message = luaL_checkstring(L, 2); logstring0(priority, cat, message); return 0; } /** * Returns (on Lua stack) true if time1 is earler than time2 * @param (on Lua Stack) time1 * @param (on Lua Stack) time2 * @return the true if time1 < time2 */ static int l_clockbefore(lua_State *L) { clock_t t1 = (clock_t) luaL_checkinteger(L, 1); clock_t t2 = (clock_t) luaL_checkinteger(L, 2); lua_pushboolean(L, time_before(t1, t2)); return 1; } /** * Returns (on Lua stack) true if time1 is earler or eq to time2 * @param (on Lua Stack) time1 * @param (on Lua Stack) time2 * @return the true if time1 <= time2 */ static int l_clockbeforeq(lua_State *L) { clock_t t1 = (clock_t) luaL_checkinteger(L, 1); clock_t t2 = (clock_t) luaL_checkinteger(L, 2); lua_pushboolean(L, time_before_eq(t1, t2)); return 1; } /** * Returns (on Lua stack) the earlier or two clock times. * * @param (on Lua Stack) time1 * @param (on Lua Stack) time2 * @return the earlier time */ static int l_earlier(lua_State *L) { clock_t t1 = (clock_t) luaL_checkinteger(L, 1); clock_t t2 = (clock_t) luaL_checkinteger(L, 2); lua_pushinteger(L, time_before(t1, t2) ? t1 : t2); return 1; } /** * Returns (on Lua stack) the current kernels * clock state (jiffies) */ static int l_now(lua_State *L) { lua_pushinteger(L, times(NULL)); return 1; } /** * Returns (on Lua stack) the addition of a clock timer by seconds. * * @param1 (Lua stack) the clock timer * @param2 (Lua stack) seconds to change clock. * * @return (Lua stack) clock timer + seconds. */ static int l_addtoclock(lua_State *L) { clock_t c1 = luaL_checkinteger(L, 1); clock_t c2 = luaL_checkinteger(L, 2); lua_pop(L, 2); lua_pushinteger(L, c1 + c2 * clocks_per_sec); return 1; } /** * Executes a subprocess. Does not wait for it to return. * * @param (Lua stack) Path to binary to call * @params (Lua stack) list of string as arguments * * @return (Lua stack) the pid on success, 0 on failure. */ static int l_exec(lua_State *L) { const char *binary = luaL_checkstring(L, 1); int argc = lua_gettop(L) - 1; pid_t pid; int i; char const **argv = s_calloc(argc + 2, sizeof(char *)); if (check_logcat("Exec") >= settings.log_level) { lua_pushvalue(L, 1); for(i = 1; i <= argc; i++) { lua_pushstring(L, " ["); lua_pushvalue(L, i + 1); lua_pushstring(L, "]"); } lua_concat(L, 3 * argc + 1); logstring0(LOG_DEBUG, "Exec", luaL_checkstring(L, -1)); lua_pop(L, 1); } argv[0] = binary; for(i = 1; i <= argc; i++) { argv[i] = luaL_checkstring(L, i + 1); } argv[i] = NULL; pid = fork(); if (pid == 0) { /* if lsyncd runs as a daemon and has a logfile it will redirect stdout/stderr of child processes to the logfile. */ if (is_daemon && settings.log_file) { if (!freopen(settings.log_file, "a", stdout)) { printlogf(L, "Error", "cannot redirect stdout to '%s'.", settings.log_file); } if (!freopen(settings.log_file, "a", stderr)) { printlogf(L, "Error", "cannot redirect stderr to '%s'.", settings.log_file); } } execv(binary, (char **)argv); /* in a sane world execv does not return! */ printlogf(L, "Error", "Failed executing [%s]!", binary); exit(-1); // ERRNO } free(argv); lua_pushnumber(L, pid); return 1; } /** * Converts a relative directory path to an absolute. * * @param dir a relative path to directory * @return absolute path of directory */ static int l_realdir(lua_State *L) { luaL_Buffer b; char *cbuf; const char *rdir = luaL_checkstring(L, 1); /* use c-library to get absolute path */ cbuf = realpath(rdir, NULL); if (cbuf == NULL) { printlogf(L, "Error", "failure getting absolute path of [%s]", rdir); return 0; } { /* makes sure its a directory */ struct stat st; if (stat(cbuf, &st)) { printlogf(L, "Error", "cannot get absolute path of dir '%s': %s", rdir, strerror(errno)); return 0; } if (!S_ISDIR(st.st_mode)) { printlogf(L, "Error", "cannot get absolute path of dir '%s': is not a directory", rdir); free(cbuf); return 0; } } /* returns absolute path with a concated '/' */ luaL_buffinit(L, &b); luaL_addstring(&b, cbuf); luaL_addchar(&b, '/'); luaL_pushresult(&b); free(cbuf); return 1; } /** * Dumps the LUA stack. For debugging purposes. */ static int l_stackdump(lua_State* L) { int i; int top = lua_gettop(L); printlogf(L, "Debug", "total in stack %d",top); for (i = 1; i <= top; i++) { int t = lua_type(L, i); switch (t) { case LUA_TSTRING: printlogf(L, "Debug", "%d string: '%s'", i, lua_tostring(L, i)); break; case LUA_TBOOLEAN: printlogf(L, "Debug", "%d boolean %s", i, lua_toboolean(L, i) ? "true" : "false"); break; case LUA_TNUMBER: printlogf(L, "Debug", "%d number: %g", i, lua_tonumber(L, i)); break; default: printlogf(L, "Debug", "%d %s", i, lua_typename(L, t)); break; } } return 0; } /** * Reads the directories sub directories. * * @param (Lua stack) absolute path to directory. * @return (Lua stack) a table of directory names. */ static int l_subdirs (lua_State *L) { const char * dirname = luaL_checkstring(L, 1); DIR *d; int idx = 1; d = opendir(dirname); if (d == NULL) { printlogf(L, "Error", "cannot open dir [%s].", dirname); return 0; } lua_newtable(L); while (!reset) { struct dirent *de = readdir(d); bool isdir; if (de == NULL) { /* finished */ break; } if (de->d_type == DT_UNKNOWN) { /* must call stat on some systems :-/ */ char *subdir = s_malloc(strlen(dirname) + strlen(de->d_name) + 2); struct stat st; strcpy(subdir, dirname); strcat(subdir, "/"); strcat(subdir, de->d_name); stat(subdir, &st); isdir = S_ISDIR(st.st_mode); free(subdir); } else { /* readdir can trusted */ isdir = de->d_type == DT_DIR; } if (!isdir || !strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) { /* ignore non directories and . and .. */ continue; } /* add this to the Lua table */ lua_pushnumber(L, idx++); lua_pushstring(L, de->d_name); lua_settable(L, -3); } return 1; } /** * Writes a string to a file descriptor * * @param (Lua Stack) file descriptor * @param (Lua Stack) string. */ int l_writefd(lua_State *L) { int fd = luaL_checkinteger(L, 1); /* concates if there is more than one string parameter */ lua_concat(L, lua_gettop(L) - 1); { const char *s = luaL_checkstring(L, 2); write(fd, s, strlen(s)); } return 0; } /** * Terminates lsyncd daemon. * * @param (Lua stack) exitcode for lsyncd. * * Does not return. */ int l_terminate(lua_State *L) { int exitcode = luaL_checkinteger(L, 1); exit(exitcode); return 0; } /** * Configures core parameters. * * @param (Lua stack) a string for a core configuratoin * @param (Lua stack) --differes depending on string. */ static int l_configure(lua_State *L) { const char * command = luaL_checkstring(L, 1); if (!strcmp(command, "running")) { /* set by runner after first initialize * from this on log to configurated log end instead of * stdout/stderr */ running = true; } else { printlogf(L, "Error", "Internal error, unknown parameter in l_configure(%s)", command); exit(-1); //ERRNO } return 0; } static const luaL_reg lsyncdlib[] = { {"addtoclock", l_addtoclock }, {"clockbefore", l_clockbefore }, {"clockbeforeq", l_clockbeforeq }, {"configure", l_configure }, {"earlier", l_earlier }, {"exec", l_exec }, {"inotifyadd", l_inotifyadd }, {"inotifyrm", l_inotifyrm }, {"log", l_log }, {"now", l_now }, {"realdir", l_realdir }, {"stackdump", l_stackdump }, {"subdirs", l_subdirs }, {"terminate", l_terminate }, {"writefd", l_writefd }, {NULL, NULL} }; /***************************************************************************** * Lsyncd Core ****************************************************************************/ /** * Dummy variable whos address is used as the cores index in the lua registry * to the lua runners function table in the lua registry. */ static int runner; /** * Dummy variable whos address is used as the cores index n the lua registry * to the lua runners error handler. */ static int callError; /** * Pushes a function from the runner on the stack. * Prior it pushed the callError handler. */ static void load_runner_func(lua_State *L, const char *name) { printlogf(L, "Call", "%s()", name); /* pushes the error handler */ lua_pushlightuserdata(L, (void *) &callError); lua_gettable(L, LUA_REGISTRYINDEX); /* pushes the function */ lua_pushlightuserdata(L, (void *) &runner); lua_gettable(L, LUA_REGISTRYINDEX); lua_pushstring(L, name); lua_gettable(L, -2); lua_remove(L, -2); } /** * Buffer for MOVE_FROM events. * Lsyncd buffers MOVE_FROM events to check if */ struct inotify_event * move_event_buf = NULL; /** * Memory allocated for move_event_buf */ size_t move_event_buf_size = 0; /** * true if the buffer is used. */ bool move_event = false; /** * Handles an inotify event. */ static void handle_event(lua_State *L, struct inotify_event *event) { int event_type; /* used to execute two events in case of unmatched MOVE_FROM buffer */ struct inotify_event *after_buf = NULL; logstring("Inotify", "got an event"); if (reset) { return; } if (event && (IN_Q_OVERFLOW & event->mask)) { /* and overflow happened, lets runner/user decide what to do. */ load_runner_func(L, "overflow"); if (lua_pcall(L, 0, 0, -2)) { exit(-1); // ERRNO } lua_pop(L, 1); return; } /* cancel on ignored or resetting */ if (event && (IN_IGNORED & event->mask)) { return; } if (event == NULL) { /* a buffered MOVE_FROM is not followed by anything, thus it is unary */ event = move_event_buf; event_type = DELETE; move_event = false; } else if (move_event && ( !(IN_MOVED_TO & event->mask) || event->cookie != move_event_buf->cookie) ) { /* there is a MOVE_FROM event in the buffer and this is not the match * continue in this function iteration to handler the buffer instead */ after_buf = event; event = move_event_buf; event_type = DELETE; move_event = false; } else if ( move_event && (IN_MOVED_TO & event->mask) && event->cookie == move_event_buf->cookie ) { /* this is indeed a matched move */ event_type = MOVE; move_event = false; } else if (IN_MOVED_FROM & event->mask) { /* just the MOVE_FROM, buffers this event, and wait if next event is * a matching MOVED_TO of this was an unary move out of the watched * tree. */ size_t el = sizeof(struct inotify_event) + event->len; if (move_event_buf_size < el) { move_event_buf_size = el; move_event_buf = s_realloc(move_event_buf, el); } memcpy(move_event_buf, event, el); move_event = true; return; } else if (IN_MOVED_TO & event->mask) { /* must be an unary move-to */ event_type = CREATE; } else if (IN_MOVED_FROM & event->mask) { /* must be an unary move-from */ event_type = DELETE; } else if (IN_ATTRIB & event->mask) { /* just attrib change */ event_type = ATTRIB; } else if (IN_CLOSE_WRITE & event->mask) { /* closed after written something */ event_type = MODIFY; } else if (IN_CREATE & event->mask) { /* a new file */ event_type = CREATE; } else if (IN_DELETE & event->mask) { /* rm'ed */ event_type = DELETE; } else { logstring("Inotify", "skipped some inotify event."); return; } /* and hands over to runner */ load_runner_func(L, "inotifyEvent"); switch(event_type) { case ATTRIB : lua_pushstring(L, "Attrib"); break; case MODIFY : lua_pushstring(L, "Modify"); break; case CREATE : lua_pushstring(L, "Create"); break; case DELETE : lua_pushstring(L, "Delete"); break; case MOVE : lua_pushstring(L, "Move"); break; default : logstring("Error", "Internal: unknown event in handle_event()"); exit(-1); // ERRNO } lua_pushnumber(L, event->wd); lua_pushboolean(L, (event->mask & IN_ISDIR) != 0); lua_pushinteger(L, times(NULL)); if (event_type == MOVE) { lua_pushstring(L, move_event_buf->name); lua_pushstring(L, event->name); } else { lua_pushstring(L, event->name); lua_pushnil(L); } if (lua_pcall(L, 6, 0, -8)) { exit(-1); // ERRNO } lua_pop(L, 1); /* if there is a buffered event executes it */ if (after_buf) { handle_event(L, after_buf); } } /** * Normal operation happens in here. */ static void masterloop(lua_State *L) { size_t readbuf_size = 2048; char *readbuf = s_malloc(readbuf_size); while(!reset) { bool have_alarm; clock_t now = times(NULL); clock_t alarm_time; int do_read; ssize_t len; /* queries runner about soonest alarm */ load_runner_func(L, "getAlarm"); if (lua_pcall(L, 0, 1, -2)) { exit(-1); // ERRNO } if (lua_type(L, -1) == LUA_TBOOLEAN) { have_alarm = lua_toboolean(L, -1); } else { have_alarm = true; alarm_time = (clock_t) luaL_checkinteger(L, -1); } lua_pop(L, 2); if (have_alarm && time_before_eq(alarm_time, now)) { /* there is a delay that wants to be handled already thus do not * read from inotify_fd and jump directly to its handling */ logstring("Masterloop", "immediately handling delays."); do_read = 0; } else { /* use select() to determine what happens next * + a new event on inotify * + an alarm on timeout * + the return of a child process */ sigset_t sigset; fd_set readfds; struct timespec tv; sigemptyset(&sigset); if (have_alarm) { double d = ((double)(alarm_time - now)) / clocks_per_sec; tv.tv_sec = d; tv.tv_nsec = ((d - (long) d)) * 1000000000.0; printlogf(L, "Masterloop", "going into select (timeout %f seconds)", d); } else { logstring("Masterloop", "going into select (no timeout)."); } /* if select returns a positive number there is data on inotify * on zero the timemout occured. */ FD_ZERO(&readfds); FD_SET(inotify_fd, &readfds); do_read = pselect(inotify_fd + 1, &readfds, NULL, NULL, have_alarm ? &tv : NULL, &sigset); logstring("Masterloop", do_read > 0 ? "theres data on inotify." : "core: select() timeout or signal."); } /* reads possible events from inotify stream */ while(do_read > 0) { int i = 0; do { len = read (inotify_fd, readbuf, readbuf_size); if (len < 0 && errno == EINVAL) { /* kernel > 2.6.21 indicates that way that way that * the buffer was too small to fit a filename. * double its size and try again. When using a lower * kernel and a filename > 2KB appears lsyncd * will fail. (but does a 2KB filename really happen?) */ readbuf_size *= 2; readbuf = s_realloc(readbuf, readbuf_size); continue; } } while(0); while (i < len && !reset) { struct inotify_event *event = (struct inotify_event *) &readbuf[i]; handle_event(L, event); i += sizeof(struct inotify_event) + event->len; } /* check if there is more data */ { struct timespec tv = {.tv_sec = 0, .tv_nsec = 0}; fd_set readfds; FD_ZERO(&readfds); FD_SET(inotify_fd, &readfds); do_read = pselect(inotify_fd + 1, &readfds, NULL, NULL, &tv, NULL); if (do_read > 0) { logstring("Masterloop", "there is more data on inotify."); } } } /* checks if there is an unary MOVE_FROM left in the buffer */ if (move_event) { handle_event(L, NULL); } /* collects zombified child processes */ while(1) { int status; pid_t pid = waitpid(0, &status, WNOHANG); if (pid <= 0) { break; } load_runner_func(L, "collectProcess"); lua_pushinteger(L, pid); lua_pushinteger(L, WEXITSTATUS(status)); if (lua_pcall(L, 2, 0, -4)) { exit(-1); // ERRNO } lua_pop(L, 1); } /* lets the runner do stuff every cycle, * like starting new processes, writing the statusfile etc. */ load_runner_func(L, "cycle"); lua_pushinteger(L, times(NULL)); if (lua_pcall(L, 1, 0, -3)) { exit(-1); // ERRNO } lua_pop(L, 1); } } /** * Main */ int main(int argc, char *argv[]) { /* the Lua interpreter */ lua_State* L; /* scripts */ char * lsyncd_runner_file = NULL; char * lsyncd_config_file = NULL; int argp = 1; /* kernel parameters */ clocks_per_sec = sysconf(_SC_CLK_TCK); /* load Lua */ L = lua_open(); luaL_openlibs(L); { /* checks the lua version */ const char *version; int major, minor; lua_getglobal(L, "_VERSION"); version = luaL_checkstring(L, -1); if (sscanf(version, "Lua %d.%d", &major, &minor) != 2) { fprintf(stderr, "cannot parse lua library version!\n"); return -1; // ERRNO } if ((major < 5) || (major == 5 && minor < 1)) { fprintf(stderr, "lua library is too old. Need 5.1 at least"); return -1; // ERRNO } lua_pop(L, 1); } { /* prepares logging early */ int i = 1; add_logcat("Normal", LOG_NOTICE); add_logcat("Error", LOG_ERR); while (i < argc) { if (strcmp(argv[i], "-log") && strcmp(argv[i], "--log")) { i++; continue; } if (++i >= argc) { break; } if (!add_logcat(argv[i], LOG_NOTICE)) { printlogf(L, "Error", "'%s' is not a valid logging category", argv[i]); return -1; // ERRNO } } } /* registers lsycnd core */ luaL_register(L, "lsyncd", lsyncdlib); lua_setglobal(L, "lysncd"); if (check_logcat("Debug") >= settings.log_level) { /* printlogf doesnt support %ld :-( */ printf("kernels clocks_per_sec=%ld\n", clocks_per_sec); } /* checks if the user overrode default runner file */ if (argp < argc && !strcmp(argv[argp], "--runner")) { if (argp + 1 >= argc) { logstring("Error", "Lsyncd Lua-runner file missing after --runner."); #ifdef LSYNCD_DEFAULT_RUNNER_FILE printlogf(L, "Error", "Using '%s' as default location for runner.", LSYNCD_DEFAULT_RUNNER_FILE); #else logstring("Error", "Using a staticly included runner as default."); #endif return -1; //ERRNO } lsyncd_runner_file = argv[argp + 1]; argp += 2; } else { #ifdef LSYNCD_DEFAULT_RUNNER_FILE lsyncd_runner_file = LSYNCD_DEFAULT_RUNNER_FILE; #endif } if (lsyncd_runner_file) { /* checks if the runner file exists */ struct stat st; if (stat(lsyncd_runner_file, &st)) { printlogf(L, "Error", "Cannot find Lsyncd Lua-runner at '%s'.", lsyncd_runner_file); printlogf(L, "Error", "Maybe specify another place?"); printlogf(L, "Error", "%s --runner RUNNER_FILE CONFIG_FILE", argv[0]); return -1; // ERRNO } /* loads the runner file */ if (luaL_loadfile(L, lsyncd_runner_file)) { printlogf(L, "Error", "error loading '%s': %s", lsyncd_runner_file, lua_tostring(L, -1)); return -1; // ERRNO } } else { #ifndef LSYNCD_DEFAULT_RUNNER_FILE /* loads the runner from binary */ if (luaL_loadbuffer(L, &_binary_luac_out_start, &_binary_luac_out_end - &_binary_luac_out_start, "lsyncd.lua")) { printlogf(L, "Error", "error loading precompiled lsyncd.lua runner: %s", lua_tostring(L, -1)); return -1; // ERRNO } #else /* this should never be possible, security code nevertheless */ logstring("Error", "Internal fail: lsyncd_runner is NULL with non-static runner"); return -1; // ERRNO #endif } { /* place to store the lua runners functions */ /* executes the runner defining all its functions */ if (lua_pcall(L, 0, LUA_MULTRET, 0)) { printlogf(L, "Error", "error preparing '%s': %s", lsyncd_runner_file ? lsyncd_runner_file : "internal runner", lua_tostring(L, -1)); return -1; // ERRNO } lua_pushlightuserdata(L, (void *)&runner); /* switches the value (result of preparing) and the key &runner */ lua_insert(L, 1); /* saves the table of the runners functions in the lua registry */ lua_settable(L, LUA_REGISTRYINDEX); /* saves the error function extra */ /* &callError is the key */ lua_pushlightuserdata(L, (void *) &callError); /* &runner[callError] the value */ lua_pushlightuserdata(L, (void *) &runner); lua_gettable(L, LUA_REGISTRYINDEX); lua_pushstring(L, "callError"); lua_gettable(L, -2); lua_remove(L, -2); lua_settable(L, LUA_REGISTRYINDEX); } { /* asserts version match between runner and core */ const char *lversion; lua_getglobal(L, "lsyncd_version"); lversion = luaL_checkstring(L, -1); if (strcmp(lversion, PACKAGE_VERSION)) { printlogf(L, "Error", "Version mismatch '%s' is '%s', but core is '%s'", lsyncd_runner_file ? lsyncd_runner_file : "internal runner", lversion, PACKAGE_VERSION); return -1; // ERRNO } lua_pop(L, 1); } { /* checks if there is a "-help" or "--help" */ int i; for(i = argp; i < argc; i++) { if (!strcmp(argv[i],"-help") || !strcmp(argv[i],"--help")) { load_runner_func(L, "help"); if (lua_pcall(L, 0, 0, -2)) { exit(-1); // ERRNO } lua_pop(L, 1); return -1; // ERRNO } } } { /* starts the option parser in lua script */ int idx = 1; const char *s; /* creates a table with all remaining argv option arguments */ load_runner_func(L, "configure"); lua_newtable(L); while(argp < argc) { lua_pushnumber(L, idx++); lua_pushstring(L, argv[argp++]); lua_settable(L, -3); } if (lua_pcall(L, 1, 1, -3)) { exit(-1); // ERRNO } s = lua_tostring(L, -1); if (s) { lsyncd_config_file = s_strdup(s); } lua_pop(L, 2); } if (lsyncd_config_file) { /* checks for the configuration and existence of the config file */ struct stat st; if (stat(lsyncd_config_file, &st)) { printlogf(L, "Error", "Cannot find config file at '%s'.", lsyncd_config_file); return -1; // ERRNO } /* loads and executes the config file */ if (luaL_loadfile(L, lsyncd_config_file)) { printlogf(L, "Error", "error loading %s: %s", lsyncd_config_file, lua_tostring(L, -1)); return -1; // ERRNO } if (lua_pcall(L, 0, LUA_MULTRET, 0)) { printlogf(L, "Error", "error preparing %s: %s", lsyncd_config_file, lua_tostring(L, -1)); return -1; // ERRNO } } /* opens inotify */ inotify_fd = inotify_init1(IN_CLOEXEC); if (inotify_fd == -1) { printlogf(L, "Error", "Cannot create inotify instance! (%d:%s)", errno, strerror(errno)); return -1; // ERRNO } { /* adds signal handlers * * listens to SIGCHLD, but blocks it until pselect() * opens up*/ sigset_t set; sigemptyset(&set); sigaddset(&set, SIGCHLD); signal(SIGCHLD, sig_child); sigprocmask(SIG_BLOCK, &set, NULL); } { /* runs initialitions from runner * lua code will set configuration and add watches */ load_runner_func(L, "initialize"); if (lua_pcall(L, 0, 0, -2)) { exit(-1); // ERRNO } lua_pop(L, 1); } masterloop(L); /* cleanup */ close(inotify_fd); lua_close(L); return 0; }