X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=miscutils%2Fcrond.c;h=a0b73c77497018d1abed6c469bac6da8623150ab;hb=774bce8e8ba1e424c953e8f13aee8f0778c8a911;hp=ad217f00714d1b0a7d62ec5462a7378c28041c25;hpb=78fcec4dc700dde189b0149ddfb53d321c4c75be;p=oweals%2Fbusybox.git diff --git a/miscutils/crond.c b/miscutils/crond.c index ad217f007..a0b73c774 100644 --- a/miscutils/crond.c +++ b/miscutils/crond.c @@ -8,65 +8,77 @@ * (version 2.3.2) * Vladimir Oleynik (C) 2002 * - * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ +//usage:#define crond_trivial_usage +//usage: "-fbS -l N " IF_FEATURE_CROND_D("-d N ") "-L LOGFILE -c DIR" +//usage:#define crond_full_usage "\n\n" +//usage: " -f Foreground" +//usage: "\n -b Background (default)" +//usage: "\n -S Log to syslog (default)" +//usage: "\n -l Set log level. 0 is the most verbose, default 8" +//usage: IF_FEATURE_CROND_D( +//usage: "\n -d Set log level, log to stderr" +//usage: ) +//usage: "\n -L Log to file" +//usage: "\n -c Working dir" + #include "libbb.h" #include /* glibc frees previous setenv'ed value when we do next setenv() * of the same variable. uclibc does not do this! */ #if (defined(__GLIBC__) && !defined(__UCLIBC__)) /* || OTHER_SAFE_LIBC... */ -#define SETENV_LEAKS 0 +# define SETENV_LEAKS 0 #else -#define SETENV_LEAKS 1 +# define SETENV_LEAKS 1 #endif #define TMPDIR CONFIG_FEATURE_CROND_DIR #define CRONTABS CONFIG_FEATURE_CROND_DIR "/crontabs" #ifndef SENDMAIL -#define SENDMAIL "sendmail" +# define SENDMAIL "sendmail" #endif #ifndef SENDMAIL_ARGS -#define SENDMAIL_ARGS "-ti", NULL +# define SENDMAIL_ARGS "-ti" #endif #ifndef CRONUPDATE -#define CRONUPDATE "cron.update" +# define CRONUPDATE "cron.update" #endif #ifndef MAXLINES -#define MAXLINES 256 /* max lines in non-root crontabs */ +# define MAXLINES 256 /* max lines in non-root crontabs */ #endif typedef struct CronFile { - struct CronFile *cf_Next; - struct CronLine *cf_LineBase; - char *cf_User; /* username */ - smallint cf_Ready; /* bool: one or more jobs ready */ - smallint cf_Running; /* bool: one or more jobs running */ - smallint cf_Deleted; /* marked for deletion, ignore */ + struct CronFile *cf_next; + struct CronLine *cf_lines; + char *cf_username; + smallint cf_wants_starting; /* bool: one or more jobs ready */ + smallint cf_has_running; /* bool: one or more jobs running */ + smallint cf_deleted; /* marked for deletion (but still has running jobs) */ } CronFile; typedef struct CronLine { - struct CronLine *cl_Next; - char *cl_Shell; /* shell command */ - pid_t cl_Pid; /* running pid, 0, or armed (-1) */ + struct CronLine *cl_next; + char *cl_cmd; /* shell command */ + pid_t cl_pid; /* >0:running, <0:needs to be started in this minute, 0:dormant */ #if ENABLE_FEATURE_CROND_CALL_SENDMAIL - int cl_MailPos; /* 'empty file' size */ - smallint cl_MailFlag; /* running pid is for mail */ - char *cl_MailTo; /* whom to mail results */ + int cl_empty_mail_size; /* size of mail header only, 0 if no mailfile */ + char *cl_mailto; /* whom to mail results, may be NULL */ #endif /* ordered by size, not in natural order. makes code smaller: */ - char cl_Dow[7]; /* 0-6, beginning sunday */ - char cl_Mons[12]; /* 0-11 */ - char cl_Hrs[24]; /* 0-23 */ - char cl_Days[32]; /* 1-31 */ - char cl_Mins[60]; /* 0-59 */ + char cl_Dow[7]; /* 0-6, beginning sunday */ + char cl_Mons[12]; /* 0-11 */ + char cl_Hrs[24]; /* 0-23 */ + char cl_Days[32]; /* 1-31 */ + char cl_Mins[60]; /* 0-59 */ } CronLine; -#define DaemonUid 0 +#define DAEMON_UID 0 enum { @@ -79,49 +91,30 @@ enum { OPT_d = (1 << 6) * ENABLE_FEATURE_CROND_D, }; #if ENABLE_FEATURE_CROND_D -#define DebugOpt (option_mask32 & OPT_d) +# define DebugOpt (option_mask32 & OPT_d) #else -#define DebugOpt 0 +# define DebugOpt 0 #endif struct globals { - unsigned LogLevel; /* = 8; */ - const char *LogFile; - const char *CDir; /* = CRONTABS; */ - CronFile *FileBase; + unsigned log_level; /* = 8; */ + time_t crontab_dir_mtime; + const char *log_filename; + const char *crontab_dir_name; /* = CRONTABS; */ + CronFile *cron_files; #if SETENV_LEAKS char *env_var_user; char *env_var_home; #endif -}; +} FIX_ALIASING; #define G (*(struct globals*)&bb_common_bufsiz1) -#define LogLevel (G.LogLevel ) -#define LogFile (G.LogFile ) -#define CDir (G.CDir ) -#define FileBase (G.FileBase ) -#define env_var_user (G.env_var_user ) -#define env_var_home (G.env_var_home ) #define INIT_G() do { \ - LogLevel = 8; \ - CDir = CRONTABS; \ + G.log_level = 8; \ + G.crontab_dir_name = CRONTABS; \ } while (0) -static void CheckUpdates(void); -static void SynchronizeDir(void); -static int TestJobs(time_t t1, time_t t2); -static void RunJobs(void); -static int CheckJobs(void); -static void RunJob(const char *user, CronLine *line); -#if ENABLE_FEATURE_CROND_CALL_SENDMAIL -static void EndJob(const char *user, CronLine *line); -#else -#define EndJob(user, line) ((line)->cl_Pid = 0) -#endif -static void DeleteFile(const char *userName); - - /* 0 is the most verbose, default 8 */ #define LVL5 "\x05" #define LVL7 "\x07" @@ -138,12 +131,12 @@ static void crondlog(const char *ctl, ...) int level = (ctl[0] & 0x1f); va_start(va, ctl); - if (level >= (int)LogLevel) { + if (level >= (int)G.log_level) { /* Debug mode: all to (non-redirected) stderr, */ /* Syslog mode: all to syslog (logmode = LOGMODE_SYSLOG), */ - if (!DebugOpt && LogFile) { + if (!DebugOpt && G.log_filename) { /* Otherwise (log to file): we reopen log file at every write: */ - int logfd = open3_or_warn(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0666); + int logfd = open_or_warn(G.log_filename, O_WRONLY | O_CREAT | O_APPEND); if (logfd >= 0) xmove_fd(logfd, STDERR_FILENO); } @@ -163,142 +156,6 @@ static void crondlog(const char *ctl, ...) exit(20); } -int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int crond_main(int argc UNUSED_PARAM, char **argv) -{ - unsigned opts; - - INIT_G(); - - /* "-b after -f is ignored", and so on for every pair a-b */ - opt_complementary = "f-b:b-f:S-L:L-S" IF_FEATURE_CROND_D(":d-l") - ":l+:d+"; /* -l and -d have numeric param */ - opts = getopt32(argv, "l:L:fbSc:" IF_FEATURE_CROND_D("d:"), - &LogLevel, &LogFile, &CDir - IF_FEATURE_CROND_D(,&LogLevel)); - /* both -d N and -l N set the same variable: LogLevel */ - - if (!(opts & OPT_f)) { - /* close stdin, stdout, stderr. - * close unused descriptors - don't need them. */ - bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv); - } - - if (!(opts & OPT_d) && LogFile == NULL) { - /* logging to syslog */ - openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON); - logmode = LOGMODE_SYSLOG; - } - - xchdir(CDir); - //signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */ - xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */ - crondlog(LVL8 "crond (busybox "BB_VER") started, log level %d", LogLevel); - SynchronizeDir(); - - /* main loop - synchronize to 1 second after the minute, minimum sleep - * of 1 second. */ - { - time_t t1 = time(NULL); - int rescan = 60; - int sleep_time = 60; - - write_pidfile("/var/run/crond.pid"); - for (;;) { - time_t t2; - long dt; - - sleep((sleep_time + 1) - (time(NULL) % sleep_time)); - - t2 = time(NULL); - dt = (long)t2 - (long)t1; - - /* - * The file 'cron.update' is checked to determine new cron - * jobs. The directory is rescanned once an hour to deal - * with any screwups. - * - * check for disparity. Disparities over an hour either way - * result in resynchronization. A reverse-indexed disparity - * less then an hour causes us to effectively sleep until we - * match the original time (i.e. no re-execution of jobs that - * have just been run). A forward-indexed disparity less then - * an hour causes intermediate jobs to be run, but only once - * in the worst case. - * - * when running jobs, the inequality used is greater but not - * equal to t1, and less then or equal to t2. - */ - if (--rescan == 0) { - rescan = 60; - SynchronizeDir(); - } - CheckUpdates(); - if (DebugOpt) - crondlog(LVL5 "wakeup dt=%ld", dt); - if (dt < -60 * 60 || dt > 60 * 60) { - crondlog(WARN9 "time disparity of %ld minutes detected", dt / 60); - } else if (dt > 0) { - TestJobs(t1, t2); - RunJobs(); - sleep(5); - if (CheckJobs() > 0) { - sleep_time = 10; - } else { - sleep_time = 60; - } - } - t1 = t2; - } /* for (;;) */ - } - - return 0; /* not reached */ -} - -#if SETENV_LEAKS -/* We set environment *before* vfork (because we want to use vfork), - * so we cannot use setenv() - repeated calls to setenv() may leak memory! - * Using putenv(), and freeing memory after unsetenv() won't leak */ -static void safe_setenv(char **pvar_val, const char *var, const char *val) -{ - char *var_val = *pvar_val; - - if (var_val) { - bb_unsetenv(var_val); - free(var_val); - } - *pvar_val = xasprintf("%s=%s", var, val); - putenv(*pvar_val); -} -#endif - -static void SetEnv(struct passwd *pas) -{ -#if SETENV_LEAKS - safe_setenv(&env_var_user, "USER", pas->pw_name); - safe_setenv(&env_var_home, "HOME", pas->pw_dir); - /* if we want to set user's shell instead: */ - /*safe_setenv(env_var_user, "SHELL", pas->pw_shell);*/ -#else - xsetenv("USER", pas->pw_name); - xsetenv("HOME", pas->pw_dir); -#endif - /* currently, we use constant one: */ - /*setenv("SHELL", DEFAULT_SHELL, 1); - done earlier */ -} - -static void ChangeUser(struct passwd *pas) -{ - /* careful: we're after vfork! */ - change_identity(pas); /* - initgroups, setgid, setuid */ - if (chdir(pas->pw_dir) < 0) { - crondlog(WARN9 "can't chdir(%s)", pas->pw_dir); - if (chdir(TMPDIR) < 0) { - crondlog(DIE9 "can't chdir(%s)", TMPDIR); /* exits */ - } - } -} - static const char DowAry[] ALIGN1 = "sun""mon""tue""wed""thu""fri""sat" /* "Sun""Mon""Tue""Wed""Thu""Fri""Sat" */ @@ -326,7 +183,7 @@ static void ParseField(char *user, char *ary, int modvalue, int off, /* Handle numeric digit or symbol or '*' */ if (*ptr == '*') { - n1 = 0; /* everything will be filled */ + n1 = 0; /* everything will be filled */ n2 = modvalue - 1; skip = 1; ++ptr; @@ -399,7 +256,6 @@ static void ParseField(char *user, char *ary, int modvalue, int off, goto err; } } while (n1 != n2); - } if (*ptr != ',') { break; @@ -415,12 +271,12 @@ static void ParseField(char *user, char *ary, int modvalue, int off, return; } - if (DebugOpt && (LogLevel <= 5)) { /* like LVL5 */ + if (DebugOpt && (G.log_level <= 5)) { /* like LVL5 */ /* can't use crondlog, it inserts '\n' */ int i; for (i = 0; i < modvalue; ++i) fprintf(stderr, "%d", (unsigned char)ary[i]); - fputc('\n', stderr); + bb_putchar_stderr('\n'); } } @@ -450,7 +306,60 @@ static void FixDayDow(CronLine *line) } } -static void SynchronizeFile(const char *fileName) +/* + * delete_cronfile() - delete user database + * + * Note: multiple entries for same user may exist if we were unable to + * completely delete a database due to running processes. + */ +//FIXME: we will start a new job even if the old job is running +//if crontab was reloaded: crond thinks that "new" job is different from "old" +//even if they are in fact completely the same. Example +//Crontab was: +// 0-59 * * * * job1 +// 0-59 * * * * long_running_job2 +//User edits crontab to: +// 0-59 * * * * job1_updated +// 0-59 * * * * long_running_job2 +//Bug: crond can now start another long_running_job2 even if old one +//is still running. +//OTOH most other versions of cron do not wait for job termination anyway, +//they end up with multiple copies of jobs if they don't terminate soon enough. +static void delete_cronfile(const char *userName) +{ + CronFile **pfile = &G.cron_files; + CronFile *file; + + while ((file = *pfile) != NULL) { + if (strcmp(userName, file->cf_username) == 0) { + CronLine **pline = &file->cf_lines; + CronLine *line; + + file->cf_has_running = 0; + file->cf_deleted = 1; + + while ((line = *pline) != NULL) { + if (line->cl_pid > 0) { + file->cf_has_running = 1; + pline = &line->cl_next; + } else { + *pline = line->cl_next; + free(line->cl_cmd); + free(line); + } + } + if (file->cf_has_running == 0) { + *pfile = file->cf_next; + free(file->cf_username); + free(file); + continue; + } + } + pfile = &file->cf_next; + } +} + +static void load_crontab(const char *fileName) { struct parser_t *parser; struct stat sbuf; @@ -460,23 +369,26 @@ static void SynchronizeFile(const char *fileName) char *mailTo = NULL; #endif - if (!fileName) + delete_cronfile(fileName); + + if (!getpwnam(fileName)) { + crondlog(LVL7 "ignoring file '%s' (no such user)", fileName); return; + } - DeleteFile(fileName); parser = config_open(fileName); if (!parser) return; maxLines = (strcmp(fileName, "root") == 0) ? 65535 : MAXLINES; - if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DaemonUid) { + if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DAEMON_UID) { CronFile *file = xzalloc(sizeof(CronFile)); CronLine **pline; int n; - file->cf_User = xstrdup(fileName); - pline = &file->cf_LineBase; + file->cf_username = xstrdup(fileName); + pline = &file->cf_lines; while (1) { CronLine *line; @@ -503,11 +415,11 @@ static void SynchronizeFile(const char *fileName) continue; *pline = line = xzalloc(sizeof(*line)); /* parse date ranges */ - ParseField(file->cf_User, line->cl_Mins, 60, 0, NULL, tokens[0]); - ParseField(file->cf_User, line->cl_Hrs, 24, 0, NULL, tokens[1]); - ParseField(file->cf_User, line->cl_Days, 32, 0, NULL, tokens[2]); - ParseField(file->cf_User, line->cl_Mons, 12, -1, MonAry, tokens[3]); - ParseField(file->cf_User, line->cl_Dow, 7, 0, DowAry, tokens[4]); + ParseField(file->cf_username, line->cl_Mins, 60, 0, NULL, tokens[0]); + ParseField(file->cf_username, line->cl_Hrs, 24, 0, NULL, tokens[1]); + ParseField(file->cf_username, line->cl_Days, 32, 0, NULL, tokens[2]); + ParseField(file->cf_username, line->cl_Mons, 12, -1, MonAry, tokens[3]); + ParseField(file->cf_username, line->cl_Dow, 7, 0, DowAry, tokens[4]); /* * fix days and dow - if one is not "*" and the other * is "*", the other is set to 0, and vise-versa @@ -515,20 +427,20 @@ static void SynchronizeFile(const char *fileName) FixDayDow(line); #if ENABLE_FEATURE_CROND_CALL_SENDMAIL /* copy mailto (can be NULL) */ - line->cl_MailTo = xstrdup(mailTo); + line->cl_mailto = xstrdup(mailTo); #endif /* copy command */ - line->cl_Shell = xstrdup(tokens[5]); + line->cl_cmd = xstrdup(tokens[5]); if (DebugOpt) { crondlog(LVL5 " command:%s", tokens[5]); } - pline = &line->cl_Next; + pline = &line->cl_next; //bb_error_msg("M[%s]F[%s][%s][%s][%s][%s][%s]", mailTo, tokens[0], tokens[1], tokens[2], tokens[3], tokens[4], tokens[5]); } *pline = NULL; - file->cf_Next = FileBase; - FileBase = file; + file->cf_next = G.cron_files; + G.cron_files = file; if (maxLines == 0) { crondlog(WARN9 "user %s: too many lines", fileName); @@ -537,7 +449,7 @@ static void SynchronizeFile(const char *fileName) config_close(parser); } -static void CheckUpdates(void) +static void process_cron_update_file(void) { FILE *fi; char buf[256]; @@ -547,224 +459,101 @@ static void CheckUpdates(void) unlink(CRONUPDATE); while (fgets(buf, sizeof(buf), fi) != NULL) { /* use first word only */ - SynchronizeFile(strtok(buf, " \t\r\n")); + skip_non_whitespace(buf)[0] = '\0'; + load_crontab(buf); } fclose(fi); } } -static void SynchronizeDir(void) +static void rescan_crontab_dir(void) { CronFile *file; - /* Attempt to delete the database. */ + + /* Delete all files until we only have ones with running jobs (or none) */ again: - for (file = FileBase; file; file = file->cf_Next) { - if (!file->cf_Deleted) { - DeleteFile(file->cf_User); + for (file = G.cron_files; file; file = file->cf_next) { + if (!file->cf_deleted) { + delete_cronfile(file->cf_username); goto again; } } - /* - * Remove cron update file - * - * Re-chdir, in case directory was renamed & deleted, or otherwise - * screwed up. - * - * scan directory and add associated users - */ + /* Remove cron update file */ unlink(CRONUPDATE); - if (chdir(CDir) < 0) { - crondlog(DIE9 "can't chdir(%s)", CDir); + /* Re-chdir, in case directory was renamed & deleted */ + if (chdir(G.crontab_dir_name) < 0) { + crondlog(DIE9 "chdir(%s)", G.crontab_dir_name); } + + /* Scan directory and add associated users */ { DIR *dir = opendir("."); struct dirent *den; if (!dir) - crondlog(DIE9 "can't chdir(%s)", "."); /* exits */ + crondlog(DIE9 "chdir(%s)", "."); /* exits */ while ((den = readdir(dir)) != NULL) { if (strchr(den->d_name, '.') != NULL) { continue; } - if (getpwnam(den->d_name)) { - SynchronizeFile(den->d_name); - } else { - crondlog(LVL7 "ignoring %s", den->d_name); - } + load_crontab(den->d_name); } closedir(dir); } } -/* - * DeleteFile() - delete user database - * - * Note: multiple entries for same user may exist if we were unable to - * completely delete a database due to running processes. - */ -static void DeleteFile(const char *userName) -{ - CronFile **pfile = &FileBase; - CronFile *file; - - while ((file = *pfile) != NULL) { - if (strcmp(userName, file->cf_User) == 0) { - CronLine **pline = &file->cf_LineBase; - CronLine *line; - - file->cf_Running = 0; - file->cf_Deleted = 1; - - while ((line = *pline) != NULL) { - if (line->cl_Pid > 0) { - file->cf_Running = 1; - pline = &line->cl_Next; - } else { - *pline = line->cl_Next; - free(line->cl_Shell); - free(line); - } - } - if (file->cf_Running == 0) { - *pfile = file->cf_Next; - free(file->cf_User); - free(file); - } else { - pfile = &file->cf_Next; - } - } else { - pfile = &file->cf_Next; - } - } -} - -/* - * TestJobs() - * - * determine which jobs need to be run. Under normal conditions, the - * period is about a minute (one scan). Worst case it will be one - * hour (60 scans). - */ -static int TestJobs(time_t t1, time_t t2) +#if SETENV_LEAKS +/* We set environment *before* vfork (because we want to use vfork), + * so we cannot use setenv() - repeated calls to setenv() may leak memory! + * Using putenv(), and freeing memory after unsetenv() won't leak */ +static void safe_setenv(char **pvar_val, const char *var, const char *val) { - int nJobs = 0; - time_t t; - - /* Find jobs > t1 and <= t2 */ - - for (t = t1 - t1 % 60; t <= t2; t += 60) { - struct tm *tp; - CronFile *file; - CronLine *line; - - if (t <= t1) - continue; + char *var_val = *pvar_val; - tp = localtime(&t); - for (file = FileBase; file; file = file->cf_Next) { - if (DebugOpt) - crondlog(LVL5 "file %s:", file->cf_User); - if (file->cf_Deleted) - continue; - for (line = file->cf_LineBase; line; line = line->cl_Next) { - if (DebugOpt) - crondlog(LVL5 " line %s", line->cl_Shell); - if (line->cl_Mins[tp->tm_min] && line->cl_Hrs[tp->tm_hour] - && (line->cl_Days[tp->tm_mday] || line->cl_Dow[tp->tm_wday]) - && line->cl_Mons[tp->tm_mon] - ) { - if (DebugOpt) { - crondlog(LVL5 " job: %d %s", - (int)line->cl_Pid, line->cl_Shell); - } - if (line->cl_Pid > 0) { - crondlog(LVL8 "user %s: process already running: %s", - file->cf_User, line->cl_Shell); - } else if (line->cl_Pid == 0) { - line->cl_Pid = -1; - file->cf_Ready = 1; - ++nJobs; - } - } - } - } + if (var_val) { + bb_unsetenv_and_free(var_val); } - return nJobs; + *pvar_val = xasprintf("%s=%s", var, val); + putenv(*pvar_val); } +#endif -static void RunJobs(void) +static void set_env_vars(struct passwd *pas) { - CronFile *file; - CronLine *line; - - for (file = FileBase; file; file = file->cf_Next) { - if (!file->cf_Ready) - continue; - - file->cf_Ready = 0; - for (line = file->cf_LineBase; line; line = line->cl_Next) { - if (line->cl_Pid >= 0) - continue; - - RunJob(file->cf_User, line); - crondlog(LVL8 "USER %s pid %3d cmd %s", - file->cf_User, (int)line->cl_Pid, line->cl_Shell); - if (line->cl_Pid < 0) { - file->cf_Ready = 1; - } else if (line->cl_Pid > 0) { - file->cf_Running = 1; - } - } - } +#if SETENV_LEAKS + safe_setenv(&G.env_var_user, "USER", pas->pw_name); + safe_setenv(&G.env_var_home, "HOME", pas->pw_dir); + /* if we want to set user's shell instead: */ + /*safe_setenv(G.env_var_shell, "SHELL", pas->pw_shell);*/ +#else + xsetenv("USER", pas->pw_name); + xsetenv("HOME", pas->pw_dir); +#endif + /* currently, we use constant one: */ + /*setenv("SHELL", DEFAULT_SHELL, 1); - done earlier */ } -/* - * CheckJobs() - check for job completion - * - * Check for job completion, return number of jobs still running after - * all done. - */ -static int CheckJobs(void) +static void change_user(struct passwd *pas) { - CronFile *file; - CronLine *line; - int nStillRunning = 0; - - for (file = FileBase; file; file = file->cf_Next) { - if (file->cf_Running) { - file->cf_Running = 0; - - for (line = file->cf_LineBase; line; line = line->cl_Next) { - int status, r; - if (line->cl_Pid <= 0) - continue; - - r = waitpid(line->cl_Pid, &status, WNOHANG); - if (r < 0 || r == line->cl_Pid) { - EndJob(file->cf_User, line); - if (line->cl_Pid) { - file->cf_Running = 1; - } - } else if (r == 0) { - file->cf_Running = 1; - } - } + /* careful: we're after vfork! */ + change_identity(pas); /* - initgroups, setgid, setuid */ + if (chdir(pas->pw_dir) < 0) { + crondlog(WARN9 "chdir(%s)", pas->pw_dir); + if (chdir(TMPDIR) < 0) { + crondlog(DIE9 "chdir(%s)", TMPDIR); /* exits */ } - nStillRunning += file->cf_Running; } - return nStillRunning; } -#if ENABLE_FEATURE_CROND_CALL_SENDMAIL - // TODO: sendmail should be _run-time_ option, not compile-time! +#if ENABLE_FEATURE_CROND_CALL_SENDMAIL -static void -ForkJob(const char *user, CronLine *line, int mailFd, - const char *prog, const char *cmd, const char *arg, - const char *mail_filename) -{ +static pid_t +fork_job(const char *user, int mailFd, + const char *prog, + const char *shell_cmd /* if NULL, we run sendmail */ +) { struct passwd *pas; pid_t pid; @@ -774,48 +563,36 @@ ForkJob(const char *user, CronLine *line, int mailFd, crondlog(WARN9 "can't get uid for %s", user); goto err; } - SetEnv(pas); + set_env_vars(pas); pid = vfork(); if (pid == 0) { /* CHILD */ - /* change running state to the user in question */ - ChangeUser(pas); + /* initgroups, setgid, setuid, and chdir to home or TMPDIR */ + change_user(pas); if (DebugOpt) { crondlog(LVL5 "child running %s", prog); } if (mailFd >= 0) { - xmove_fd(mailFd, mail_filename ? 1 : 0); + xmove_fd(mailFd, shell_cmd ? 1 : 0); dup2(1, 2); } /* crond 3.0pl1-100 puts tasks in separate process groups */ bb_setpgrp(); - execlp(prog, prog, cmd, arg, (char *) NULL); - crondlog(ERR20 "can't exec, user %s cmd %s %s %s", user, prog, cmd, arg); - if (mail_filename) { - fdprintf(1, "Exec failed: %s -c %s\n", prog, arg); + execlp(prog, prog, (shell_cmd ? "-c" : SENDMAIL_ARGS), shell_cmd, (char *) NULL); + crondlog(ERR20 "can't execute '%s' for user %s", prog, user); + if (shell_cmd) { + fdprintf(1, "Exec failed: %s -c %s\n", prog, shell_cmd); } _exit(EXIT_SUCCESS); } - line->cl_Pid = pid; if (pid < 0) { /* FORK FAILED */ crondlog(ERR20 "can't vfork"); err: - line->cl_Pid = 0; - if (mail_filename) { - unlink(mail_filename); - } - } else if (mail_filename) { - /* PARENT, FORK SUCCESS - * rename mail-file based on pid of process - */ - char mailFile2[128]; - - snprintf(mailFile2, sizeof(mailFile2), "%s/cron.%s.%d", TMPDIR, user, pid); - rename(mail_filename, mailFile2); // TODO: xrename? - } + pid = 0; + } /* else: PARENT, FORK SUCCESS */ /* * Close the mail file descriptor.. we can't just leave it open in @@ -824,112 +601,120 @@ ForkJob(const char *user, CronLine *line, int mailFd, if (mailFd >= 0) { close(mailFd); } + return pid; } -static void RunJob(const char *user, CronLine *line) +static void start_one_job(const char *user, CronLine *line) { char mailFile[128]; int mailFd = -1; - line->cl_Pid = 0; - line->cl_MailFlag = 0; + line->cl_pid = 0; + line->cl_empty_mail_size = 0; - if (line->cl_MailTo) { - /* open mail file - owner root so nobody can screw with it. */ + if (line->cl_mailto) { + /* Open mail file (owner is root so nobody can screw with it) */ snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, getpid()); mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600); if (mailFd >= 0) { - line->cl_MailFlag = 1; - fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_MailTo, - line->cl_Shell); - line->cl_MailPos = lseek(mailFd, 0, SEEK_CUR); + fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_mailto, + line->cl_cmd); + line->cl_empty_mail_size = lseek(mailFd, 0, SEEK_CUR); } else { crondlog(ERR20 "can't create mail file %s for user %s, " "discarding output", mailFile, user); } } - ForkJob(user, line, mailFd, DEFAULT_SHELL, "-c", line->cl_Shell, mailFile); + line->cl_pid = fork_job(user, mailFd, DEFAULT_SHELL, line->cl_cmd); + if (mailFd >= 0) { + if (line->cl_pid <= 0) { + unlink(mailFile); + } else { + /* rename mail-file based on pid of process */ + char *mailFile2 = xasprintf("%s/cron.%s.%d", TMPDIR, user, (int)line->cl_pid); + rename(mailFile, mailFile2); // TODO: xrename? + free(mailFile2); + } + } } /* - * EndJob - called when job terminates and when mail terminates + * process_finished_job - called when job terminates and when mail terminates */ -static void EndJob(const char *user, CronLine *line) +static void process_finished_job(const char *user, CronLine *line) { + pid_t pid; int mailFd; char mailFile[128]; struct stat sbuf; - /* No job */ - if (line->cl_Pid <= 0) { - line->cl_Pid = 0; + pid = line->cl_pid; + line->cl_pid = 0; + if (pid <= 0) { + /* No job */ return; } - - /* - * End of job and no mail file - * End of sendmail job - */ - snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, line->cl_Pid); - line->cl_Pid = 0; - - if (line->cl_MailFlag == 0) { + if (line->cl_empty_mail_size <= 0) { + /* End of job and no mail file, or end of sendmail job */ return; } - line->cl_MailFlag = 0; /* - * End of primary job - check for mail file. If size has increased and - * the file is still valid, we sendmail it. + * End of primary job - check for mail file. + * If size has changed and the file is still valid, we send it. */ + snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, (int)pid); mailFd = open(mailFile, O_RDONLY); unlink(mailFile); if (mailFd < 0) { return; } - if (fstat(mailFd, &sbuf) < 0 || sbuf.st_uid != DaemonUid - || sbuf.st_nlink != 0 || sbuf.st_size == line->cl_MailPos + if (fstat(mailFd, &sbuf) < 0 + || sbuf.st_uid != DAEMON_UID + || sbuf.st_nlink != 0 + || sbuf.st_size == line->cl_empty_mail_size || !S_ISREG(sbuf.st_mode) ) { close(mailFd); return; } - if (line->cl_MailTo) - ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL); + line->cl_empty_mail_size = 0; + /* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */ + line->cl_pid = fork_job(user, mailFd, SENDMAIL, NULL); } -#else /* crond without sendmail */ +#else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */ -static void RunJob(const char *user, CronLine *line) +static void start_one_job(const char *user, CronLine *line) { struct passwd *pas; pid_t pid; - /* prepare things before vfork */ pas = getpwnam(user); if (!pas) { crondlog(WARN9 "can't get uid for %s", user); goto err; } - SetEnv(pas); - /* fork as the user in question and run program */ + /* Prepare things before vfork */ + set_env_vars(pas); + + /* Fork as the user in question and run program */ pid = vfork(); if (pid == 0) { /* CHILD */ - /* change running state to the user in question */ - ChangeUser(pas); + /* initgroups, setgid, setuid, and chdir to home or TMPDIR */ + change_user(pas); if (DebugOpt) { crondlog(LVL5 "child running %s", DEFAULT_SHELL); } /* crond 3.0pl1-100 puts tasks in separate process groups */ bb_setpgrp(); - execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_Shell, (char *) NULL); - crondlog(ERR20 "can't exec, user %s cmd %s %s %s", user, - DEFAULT_SHELL, "-c", line->cl_Shell); + execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_cmd, (char *) NULL); + crondlog(ERR20 "can't execute '%s' for user %s", DEFAULT_SHELL, user); _exit(EXIT_SUCCESS); } if (pid < 0) { @@ -938,7 +723,232 @@ static void RunJob(const char *user, CronLine *line) err: pid = 0; } - line->cl_Pid = pid; + line->cl_pid = pid; } -#endif /* ENABLE_FEATURE_CROND_CALL_SENDMAIL */ +#define process_finished_job(user, line) ((line)->cl_pid = 0) + +#endif /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */ + +/* + * Determine which jobs need to be run. Under normal conditions, the + * period is about a minute (one scan). Worst case it will be one + * hour (60 scans). + */ +static void flag_starting_jobs(time_t t1, time_t t2) +{ + time_t t; + + /* Find jobs > t1 and <= t2 */ + + for (t = t1 - t1 % 60; t <= t2; t += 60) { + struct tm *ptm; + CronFile *file; + CronLine *line; + + if (t <= t1) + continue; + + ptm = localtime(&t); + for (file = G.cron_files; file; file = file->cf_next) { + if (DebugOpt) + crondlog(LVL5 "file %s:", file->cf_username); + if (file->cf_deleted) + continue; + for (line = file->cf_lines; line; line = line->cl_next) { + if (DebugOpt) + crondlog(LVL5 " line %s", line->cl_cmd); + if (line->cl_Mins[ptm->tm_min] + && line->cl_Hrs[ptm->tm_hour] + && (line->cl_Days[ptm->tm_mday] || line->cl_Dow[ptm->tm_wday]) + && line->cl_Mons[ptm->tm_mon] + ) { + if (DebugOpt) { + crondlog(LVL5 " job: %d %s", + (int)line->cl_pid, line->cl_cmd); + } + if (line->cl_pid > 0) { + crondlog(LVL8 "user %s: process already running: %s", + file->cf_username, line->cl_cmd); + } else if (line->cl_pid == 0) { + line->cl_pid = -1; + file->cf_wants_starting = 1; + } + } + } + } + } +} + +static void start_jobs(void) +{ + CronFile *file; + CronLine *line; + + for (file = G.cron_files; file; file = file->cf_next) { + if (!file->cf_wants_starting) + continue; + + file->cf_wants_starting = 0; + for (line = file->cf_lines; line; line = line->cl_next) { + pid_t pid; + if (line->cl_pid >= 0) + continue; + + start_one_job(file->cf_username, line); + pid = line->cl_pid; + crondlog(LVL8 "USER %s pid %3d cmd %s", + file->cf_username, (int)pid, line->cl_cmd); + if (pid < 0) { + file->cf_wants_starting = 1; + } + if (pid > 0) { + file->cf_has_running = 1; + } + } + } +} + +/* + * Check for job completion, return number of jobs still running after + * all done. + */ +static int check_completions(void) +{ + CronFile *file; + CronLine *line; + int num_still_running = 0; + + for (file = G.cron_files; file; file = file->cf_next) { + if (!file->cf_has_running) + continue; + + file->cf_has_running = 0; + for (line = file->cf_lines; line; line = line->cl_next) { + int r; + + if (line->cl_pid <= 0) + continue; + + r = waitpid(line->cl_pid, NULL, WNOHANG); + if (r < 0 || r == line->cl_pid) { + process_finished_job(file->cf_username, line); + if (line->cl_pid == 0) { + /* sendmail was not started for it */ + continue; + } + /* else: sendmail was started, job is still running, fall thru */ + } + /* else: r == 0: "process is still running" */ + file->cf_has_running = 1; + } +//FIXME: if !file->cf_has_running && file->deleted: delete it! +//otherwise deleted entries will stay forever, right? + num_still_running += file->cf_has_running; + } + return num_still_running; +} + +int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int crond_main(int argc UNUSED_PARAM, char **argv) +{ + time_t t2; + int rescan; + int sleep_time; + unsigned opts; + + INIT_G(); + + /* "-b after -f is ignored", and so on for every pair a-b */ + opt_complementary = "f-b:b-f:S-L:L-S" IF_FEATURE_CROND_D(":d-l") + /* -l and -d have numeric param */ + ":l+" IF_FEATURE_CROND_D(":d+"); + opts = getopt32(argv, "l:L:fbSc:" IF_FEATURE_CROND_D("d:"), + &G.log_level, &G.log_filename, &G.crontab_dir_name + IF_FEATURE_CROND_D(,&G.log_level)); + /* both -d N and -l N set the same variable: G.log_level */ + + if (!(opts & OPT_f)) { + /* close stdin, stdout, stderr. + * close unused descriptors - don't need them. */ + bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv); + } + + if (!(opts & OPT_d) && G.log_filename == NULL) { + /* logging to syslog */ + openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON); + logmode = LOGMODE_SYSLOG; + } + + xchdir(G.crontab_dir_name); + //signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */ + xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */ + crondlog(LVL8 "crond (busybox "BB_VER") started, log level %d", G.log_level); + rescan_crontab_dir(); + write_pidfile("/var/run/crond.pid"); + + /* Main loop */ + t2 = time(NULL); + rescan = 60; + sleep_time = 60; + for (;;) { + struct stat sbuf; + time_t t1; + long dt; + + t1 = t2; + + /* Synchronize to 1 minute, minimum 1 second */ + sleep(sleep_time - (time(NULL) % sleep_time) + 1); + + t2 = time(NULL); + dt = (long)t2 - (long)t1; + + /* + * The file 'cron.update' is checked to determine new cron + * jobs. The directory is rescanned once an hour to deal + * with any screwups. + * + * Check for time jump. Disparities over an hour either way + * result in resynchronization. A negative disparity + * less than an hour causes us to effectively sleep until we + * match the original time (i.e. no re-execution of jobs that + * have just been run). A positive disparity less than + * an hour causes intermediate jobs to be run, but only once + * in the worst case. + * + * When running jobs, the inequality used is greater but not + * equal to t1, and less then or equal to t2. + */ + if (stat(G.crontab_dir_name, &sbuf) != 0) + sbuf.st_mtime = 0; /* force update (once) if dir was deleted */ + if (G.crontab_dir_mtime != sbuf.st_mtime) { + G.crontab_dir_mtime = sbuf.st_mtime; + rescan = 1; + } + if (--rescan == 0) { + rescan = 60; + rescan_crontab_dir(); + } + process_cron_update_file(); + if (DebugOpt) + crondlog(LVL5 "wakeup dt=%ld", dt); + if (dt < -60 * 60 || dt > 60 * 60) { + crondlog(WARN9 "time disparity of %ld minutes detected", dt / 60); + /* and we do not run any jobs in this case */ + } else if (dt > 0) { + /* Usual case: time advances forward, as expected */ + flag_starting_jobs(t1, t2); + start_jobs(); + if (check_completions() > 0) { + /* some jobs are still running */ + sleep_time = 10; + } else { + sleep_time = 60; + } + } + /* else: time jumped back, do not run any jobs */ + } /* for (;;) */ + + return 0; /* not reached */ +}