libbb: add bb_unsetenv (taken from hush).
[oweals/busybox.git] / miscutils / crond.c
index 6056cb0657e43dd36d03926c08318979b06c9d45..12560fa367a846254f43d0cf792bede510ad3ed2 100644 (file)
  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 
-#include <sys/syslog.h>
 #include "libbb.h"
+#include <syslog.h>
+
+/* 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
+#else
+#define SETENV_LEAKS 1
+#endif
+
 
 #ifndef CRONTABS
 #define CRONTABS        "/var/spool/cron/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                     */
-       int cf_Ready;           /* bool: one or more jobs ready */
-       int cf_Running;         /* bool: one or more jobs running */
-       int cf_Deleted;         /* marked for deletion, ignore  */
+       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  */
 } CronFile;
 
 typedef struct CronLine {
        struct CronLine *cl_Next;
-       char *cl_Shell;         /* shell command                        */
-       pid_t cl_Pid;           /* running pid, 0, or armed (-1)        */
-       int cl_MailFlag;        /* running pid is for mail              */
-       int cl_MailPos;         /* 'empty file' size                    */
-       char cl_Mins[60];       /* 0-59                                 */
-       char cl_Hrs[24];        /* 0-23                                 */
-       char cl_Days[32];       /* 1-31                                 */
-       char cl_Mons[12];       /* 0-11                                 */
-       char cl_Dow[7];         /* 0-6, beginning sunday                */
+       char *cl_Shell;         /* shell command                        */
+       pid_t cl_Pid;           /* running pid, 0, or armed (-1)        */
+#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                 */
+#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                                 */
 } CronLine;
 
-#define RUN_RANOUT      1
-#define RUN_RUNNING     2
-#define RUN_FAILED      3
 
 #define DaemonUid 0
 
-#if ENABLE_DEBUG_CROND_OPTION
-static unsigned DebugOpt;
+
+enum {
+       OPT_l = (1 << 0),
+       OPT_L = (1 << 1),
+       OPT_f = (1 << 2),
+       OPT_b = (1 << 3),
+       OPT_S = (1 << 4),
+       OPT_c = (1 << 5),
+       OPT_d = (1 << 6) * ENABLE_FEATURE_CROND_D,
+};
+#if ENABLE_FEATURE_CROND_D
+#define DebugOpt (option_mask32 & OPT_d)
+#else
+#define DebugOpt 0
 #endif
 
-static unsigned LogLevel = 8;
-static const char *LogFile;
-static const char *CDir = CRONTABS;
 
-static void startlogger(void);
+struct globals {
+       unsigned LogLevel; /* = 8; */
+       const char *LogFile;
+       const char *CDir; /* = CRONTABS; */
+       CronFile *FileBase;
+#if SETENV_LEAKS
+       char *env_var_user;
+       char *env_var_home;
+#endif
+};
+#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; \
+} 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);
-
+static void RunJob(const char *user, CronLine *line);
 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
-static void EndJob(const char *user, CronLine * line);
+static void EndJob(const char *user, CronLine *line);
 #else
-#define EndJob(user, line)  line->cl_Pid = 0
+#define EndJob(user, line)  ((line)->cl_Pid = 0)
 #endif
-
 static void DeleteFile(const char *userName);
 
-static CronFile *FileBase;
 
+#define LVL5  "\x05"
+#define LVL7  "\x07"
+#define LVL8  "\x08"
+#define LVL9  "\x09"
+#define WARN9 "\x49"
+#define DIE9  "\xc9"
+/* level >= 20 is "error" */
+#define ERR20 "\x14"
 
 static void crondlog(const char *ctl, ...)
 {
        va_list va;
-       const char *fmt;
-       int level = (int) (ctl[0] & 0xf);
-       int type = level == 20 ?
-               LOG_ERR : ((ctl[0] & 0100) ? LOG_WARNING : LOG_NOTICE);
-
+       int level = (ctl[0] & 0x1f);
 
        va_start(va, ctl);
-       fmt = ctl + 1;
-       if (level >= LogLevel) {
-
-#if ENABLE_DEBUG_CROND_OPTION
-               if (DebugOpt) {
-                       vfprintf(stderr, fmt, va);
-               } else
-#endif
-               if (LogFile == 0) {
-                       vsyslog(type, fmt, va);
-               } else {
-#if !ENABLE_DEBUG_CROND_OPTION
-                       int logfd = open(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600);
-#else
+       if (level >= (int)LogLevel) {
+               /* Debug mode: all to (non-redirected) stderr, */
+               /* Syslog mode: all to syslog (logmode = LOGMODE_SYSLOG), */
+               if (!DebugOpt && LogFile) {
+                       /* Otherwise (log to file): we reopen log file at every write: */
                        int logfd = open3_or_warn(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600);
-#endif
-                       if (logfd >= 0) {
-                               vdprintf(logfd, fmt, va);
-                               close(logfd);
-                       }
+                       if (logfd >= 0)
+                               xmove_fd(logfd, STDERR_FILENO);
                }
+// TODO: ERR -> error, WARN -> warning, LVL -> info
+               bb_verror_msg(ctl + 1, va, /* strerr: */ NULL);
        }
        va_end(va);
-       if (ctl[0] & 0200) {
+       if (ctl[0] & 0x80)
                exit(20);
-       }
 }
 
 int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int crond_main(int ac, char **av)
+int crond_main(int argc UNUSED_PARAM, char **argv)
 {
        unsigned opt;
-       char *lopt, *Lopt, *copt;
-       USE_DEBUG_CROND_OPTION(char *dopt;)
-
-       opt_complementary = "f-b:b-f:S-L:L-S" USE_DEBUG_CROND_OPTION(":d-l");
-       opterr = 0;                     /* disable getopt 'errors' message. */
-       opt = getopt32(av, "l:L:fbSc:" USE_DEBUG_CROND_OPTION("d:"),
-                       &lopt, &Lopt, &copt USE_DEBUG_CROND_OPTION(, &dopt));
-       if (opt & 1) /* -l */
-               LogLevel = xatou(lopt);
-       if (opt & 2) /* -L */
-               if (*Lopt)
-                       LogFile = Lopt;
-       if (opt & 32) /* -c */
-               if (*copt)
-                       CDir = copt;
-#if ENABLE_DEBUG_CROND_OPTION
-       if (opt & 64) { /* -d */
-               DebugOpt = xatou(dopt);
-               LogLevel = 0;
-       }
-#endif
 
-       /* close stdin and stdout, stderr.
-        * close unused descriptors -  don't need.
-        * optional detach from controlling terminal
-        */
-       if (!(opt & 4))
-               bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, av);
+       INIT_G();
 
-       xchdir(CDir);
-       signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */
+       /* "-b after -f is ignored", and so on for every pair a-b */
+       opt_complementary = "f-b:b-f:S-L:L-S" USE_FEATURE_CROND_D(":d-l")
+                       ":l+:d+"; /* -l and -d have numeric param */
+       opt = getopt32(argv, "l:L:fbSc:" USE_FEATURE_CROND_D("d:"),
+                       &LogLevel, &LogFile, &CDir
+                       USE_FEATURE_CROND_D(,&LogLevel));
+       /* both -d N and -l N set the same variable: LogLevel */
 
-       startlogger();  /* need if syslog mode selected */
+       if (!(opt & OPT_f)) {
+               /* close stdin, stdout, stderr.
+                * close unused descriptors - don't need them. */
+               bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
+       }
 
-       /*
-        * main loop - synchronize to 1 second after the minute, minimum sleep
-        *             of 1 second.
-        */
-       crondlog("\011%s " BB_VER " started, log level %d\n",
-                        applet_name, LogLevel);
+       if (!DebugOpt && 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(LVL9 "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);
                time_t t2;
                long dt;
                int rescan = 60;
-               short sleep_time = 60;
+               int sleep_time = 60;
 
                write_pidfile("/var/run/crond.pid");
                for (;;) {
-                       sleep((sleep_time + 1) - (short) (time(NULL) % sleep_time));
+                       sleep((sleep_time + 1) - (time(NULL) % sleep_time));
 
                        t2 = time(NULL);
-                       dt = t2 - t1;
+                       dt = (long)t2 - (long)t1;
 
                        /*
                         * The file 'cron.update' is checked to determine new cron
@@ -205,19 +223,15 @@ int crond_main(int ac, char **av)
                         * 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 ENABLE_DEBUG_CROND_OPTION
                        if (DebugOpt)
-                               crondlog("\005Wakeup dt=%d\n", dt);
-#endif
+                               crondlog(LVL5 "wakeup dt=%ld", dt);
                        if (dt < -60 * 60 || dt > 60 * 60) {
-                               t1 = t2;
-                               crondlog("\111time disparity of %d minutes detected\n", dt / 60);
+                               crondlog(WARN9 "time disparity of %d minutes detected", dt / 60);
                        } else if (dt > 0) {
                                TestJobs(t1, t2);
                                RunJobs();
@@ -227,66 +241,57 @@ int crond_main(int ac, char **av)
                                } else {
                                        sleep_time = 60;
                                }
-                               t1 = t2;
                        }
+                       t1 = t2;
                }
        }
        return 0; /* not reached */
 }
 
-static int ChangeUser(const char *user)
+#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)
 {
-       struct passwd *pas;
-       const char *err_msg;
-
-       /*
-        * Obtain password entry and change privileges
-        */
-       pas = getpwnam(user);
-       if (pas == 0) {
-               crondlog("\011failed to get uid for %s", user);
-               return -1;
-       }
-       setenv("USER", pas->pw_name, 1);
-       setenv("HOME", pas->pw_dir, 1);
-       setenv("SHELL", DEFAULT_SHELL, 1);
+       char *var_val = *pvar_val;
 
-       /*
-        * Change running state to the user in question
-        */
-       err_msg = change_identity_e2str(pas);
-       if (err_msg) {
-               crondlog("\011%s for user %s", err_msg, user);
-               return -1;
+       if (var_val) {
+               bb_unsetenv(var_val);
+               free(var_val);
        }
-       if (chdir(pas->pw_dir) < 0) {
-               crondlog("\011chdir failed: %s: %m", pas->pw_dir);
-               if (chdir(TMPDIR) < 0) {
-                       crondlog("\011chdir failed: %s: %m", TMPDIR);
-                       return -1;
-               }
-       }
-       return pas->pw_uid;
+       *pvar_val = xasprintf("%s=%s", var, val);
+       putenv(*pvar_val);
 }
+#endif
 
-static void startlogger(void)
+static void SetEnv(struct passwd *pas)
 {
-       if (LogFile == 0) {
-               openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON);
-       }
-#if ENABLE_DEBUG_CROND_OPTION
-       else {                          /* test logfile */
-               int logfd;
+#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 */
+}
 
-               logfd = open3_or_warn(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600);
-               if (logfd >= 0) {
-                       close(logfd);
+static void ChangeUser(struct passwd *pas)
+{
+       /* careful: we're after vfork! */
+       change_identity(pas); /* - initgroups, setgid, setuid */
+       if (chdir(pas->pw_dir) < 0) {
+               crondlog(LVL9 "can't chdir(%s)", pas->pw_dir);
+               if (chdir(TMPDIR) < 0) {
+                       crondlog(DIE9 "can't chdir(%s)", TMPDIR); /* exits */
                }
        }
-#endif
 }
 
-
 static const char DowAry[] ALIGN1 =
        "sun""mon""tue""wed""thu""fri""sat"
        /* "Sun""Mon""Tue""Wed""Thu""Fri""Sat" */
@@ -297,7 +302,7 @@ static const char MonAry[] ALIGN1 =
        /* "Jan""Feb""Mar""Apr""May""Jun""Jul""Aug""Sep""Oct""Nov""Dec" */
 ;
 
-static char *ParseField(char *user, char *ary, int modvalue, int off,
+static void ParseField(char *user, char *ary, int modvalue, int off,
                                const char *names, char *ptr)
 /* 'names' is a pointer to a set of 3-char abbreviations */
 {
@@ -305,21 +310,20 @@ static char *ParseField(char *user, char *ary, int modvalue, int off,
        int n1 = -1;
        int n2 = -1;
 
-       if (base == NULL) {
-               return NULL;
-       }
+       // this can't happen due to config_read()
+       /*if (base == NULL)
+               return;*/
 
-       while (*ptr != ' ' && *ptr != '\t' && *ptr != '\n') {
+       while (1) {
                int skip = 0;
 
                /* Handle numeric digit or symbol or '*' */
-
                if (*ptr == '*') {
                        n1 = 0;         /* everything will be filled */
                        n2 = modvalue - 1;
                        skip = 1;
                        ++ptr;
-               } else if (*ptr >= '0' && *ptr <= '9') {
+               } else if (isdigit(*ptr)) {
                        if (n1 < 0) {
                                n1 = strtol(ptr, &ptr, 10) + off;
                        } else {
@@ -345,10 +349,8 @@ static char *ParseField(char *user, char *ary, int modvalue, int off,
                }
 
                /* handle optional range '-' */
-
                if (skip == 0) {
-                       crondlog("\111failed user %s parsing %s\n", user, base);
-                       return NULL;
+                       goto err;
                }
                if (*ptr == '-' && n2 < 0) {
                        ++ptr;
@@ -359,18 +361,17 @@ static char *ParseField(char *user, char *ary, int modvalue, int off,
                 * collapse single-value ranges, handle skipmark, and fill
                 * in the character array appropriately.
                 */
-
                if (n2 < 0) {
                        n2 = n1;
                }
                if (*ptr == '/') {
                        skip = strtol(ptr + 1, &ptr, 10);
                }
+
                /*
                 * fill array, using a failsafe is the easiest way to prevent
                 * an endless loop
                 */
-
                {
                        int s0 = 1;
                        int failsafe = 1024;
@@ -383,13 +384,11 @@ static char *ParseField(char *user, char *ary, int modvalue, int off,
                                        ary[n1 % modvalue] = 1;
                                        s0 = skip;
                                }
-                       }
-                       while (n1 != n2 && --failsafe);
+                               if (--failsafe == 0) {
+                                       goto err;
+                               }
+                       } while (n1 != n2);
 
-                       if (failsafe == 0) {
-                               crondlog("\111failed user %s parsing %s\n", user, base);
-                               return NULL;
-                       }
                }
                if (*ptr != ',') {
                        break;
@@ -399,147 +398,132 @@ static char *ParseField(char *user, char *ary, int modvalue, int off,
                n2 = -1;
        }
 
-       if (*ptr != ' ' && *ptr != '\t' && *ptr != '\n') {
-               crondlog("\111failed user %s parsing %s\n", user, base);
-               return NULL;
+       if (*ptr) {
+ err:
+               crondlog(WARN9 "user %s: parse error at %s", user, base);
+               return;
        }
 
-       while (*ptr == ' ' || *ptr == '\t' || *ptr == '\n') {
-               ++ptr;
-       }
-#if ENABLE_DEBUG_CROND_OPTION
-       if (DebugOpt) {
+       if (DebugOpt && (LogLevel <= 5)) { /* like LVL5 */
+               /* can't use crondlog, it inserts '\n' */
                int i;
-
-               for (i = 0; i < modvalue; ++i) {
-                       crondlog("\005%d", ary[i]);
-               }
-               crondlog("\005\n");
+               for (i = 0; i < modvalue; ++i)
+                       fprintf(stderr, "%d", (unsigned char)ary[i]);
+               fputc('\n', stderr);
        }
-#endif
-
-       return ptr;
 }
 
-static void FixDayDow(CronLine * line)
+static void FixDayDow(CronLine *line)
 {
-       int i;
+       unsigned i;
        int weekUsed = 0;
        int daysUsed = 0;
 
-       for (i = 0; i < (int)(ARRAY_SIZE(line->cl_Dow)); ++i) {
+       for (i = 0; i < ARRAY_SIZE(line->cl_Dow); ++i) {
                if (line->cl_Dow[i] == 0) {
                        weekUsed = 1;
                        break;
                }
        }
-       for (i = 0; i < (int)(ARRAY_SIZE(line->cl_Days)); ++i) {
+       for (i = 0; i < ARRAY_SIZE(line->cl_Days); ++i) {
                if (line->cl_Days[i] == 0) {
                        daysUsed = 1;
                        break;
                }
        }
-       if (weekUsed && !daysUsed) {
-               memset(line->cl_Days, 0, sizeof(line->cl_Days));
-       }
-       if (daysUsed && !weekUsed) {
-               memset(line->cl_Dow, 0, sizeof(line->cl_Dow));
+       if (weekUsed != daysUsed) {
+               if (weekUsed)
+                       memset(line->cl_Days, 0, sizeof(line->cl_Days));
+               else /* daysUsed */
+                       memset(line->cl_Dow, 0, sizeof(line->cl_Dow));
        }
 }
 
-
-
 static void SynchronizeFile(const char *fileName)
 {
-       int maxEntries = MAXLINES;
+       struct parser_t *parser;
+       struct stat sbuf;
        int maxLines;
-       char buf[1024];
-
-       if (strcmp(fileName, "root") == 0) {
-               maxEntries = 65535;
-       }
-       maxLines = maxEntries * 10;
-
-       if (fileName) {
-               FILE *fi;
-
-               DeleteFile(fileName);
-
-               fi = fopen(fileName, "r");
-               if (fi != NULL) {
-                       struct stat sbuf;
-
-                       if (fstat(fileno(fi), &sbuf) == 0 && sbuf.st_uid == DaemonUid) {
-                               CronFile *file = xzalloc(sizeof(CronFile));
-                               CronLine **pline;
-
-                               file->cf_User = strdup(fileName);
-                               pline = &file->cf_LineBase;
-
-                               while (fgets(buf, sizeof(buf), fi) != NULL && --maxLines) {
-                                       CronLine line;
-                                       char *ptr;
+       char *tokens[6];
+#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+       char *mailTo = NULL;
+#endif
 
-                                       trim(buf);
-                                       if (buf[0] == 0 || buf[0] == '#') {
-                                               continue;
-                                       }
-                                       if (--maxEntries == 0) {
-                                               break;
-                                       }
-                                       memset(&line, 0, sizeof(line));
+       if (!fileName)
+               return;
 
-#if ENABLE_DEBUG_CROND_OPTION
-                                       if (DebugOpt) {
-                                               crondlog("\111User %s Entry %s\n", fileName, buf);
-                                       }
-#endif
+       DeleteFile(fileName);
+       parser = config_open(fileName);
+       if (!parser)
+               return;
 
-                                       /* parse date ranges */
-                                       ptr = ParseField(file->cf_User, line.cl_Mins, 60, 0, NULL, buf);
-                                       ptr = ParseField(file->cf_User, line.cl_Hrs, 24, 0, NULL, ptr);
-                                       ptr = ParseField(file->cf_User, line.cl_Days, 32, 0, NULL, ptr);
-                                       ptr = ParseField(file->cf_User, line.cl_Mons, 12, -1, MonAry, ptr);
-                                       ptr = ParseField(file->cf_User, line.cl_Dow, 7, 0, DowAry, ptr);
+       maxLines = (strcmp(fileName, "root") == 0) ? 65535 : MAXLINES;
 
-                                       /* check failure */
-                                       if (ptr == NULL) {
-                                               continue;
-                                       }
+       if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DaemonUid) {
+               CronFile *file = xzalloc(sizeof(CronFile));
+               CronLine **pline;
+               int n;
 
-                                       /*
-                                        * fix days and dow - if one is not * and the other
-                                        * is *, the other is set to 0, and vise-versa
-                                        */
+               file->cf_User = xstrdup(fileName);
+               pline = &file->cf_LineBase;
 
-                                       FixDayDow(&line);
+               while (1) {
+                       CronLine *line;
 
-                                       *pline = xzalloc(sizeof(CronLine));
-                                       **pline = line;
+                       if (!--maxLines)
+                               break;
+                       n = config_read(parser, tokens, 6, 1, "# \t", PARSE_NORMAL | PARSE_KEEP_COPY);
+                       if (!n)
+                               break;
 
-                                       /* copy command */
-                                       (*pline)->cl_Shell = strdup(ptr);
+                       if (DebugOpt)
+                               crondlog(LVL5 "user:%s entry:%s", fileName, parser->data);
 
-#if ENABLE_DEBUG_CROND_OPTION
-                                       if (DebugOpt) {
-                                               crondlog("\111    Command %s\n", ptr);
-                                       }
+                       /* check if line is setting MAILTO= */
+                       if (0 == strncmp(tokens[0], "MAILTO=", 7)) {
+#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+                               free(mailTo);
+                               mailTo = (tokens[0][7]) ? xstrdup(&tokens[0][7]) : NULL;
+#endif /* otherwise just ignore such lines */
+                               continue;
+                       }
+                       /* check if a minimum of tokens is specified */
+                       if (n < 6)
+                               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]);
+                       /*
+                        * fix days and dow - if one is not "*" and the other
+                        * is "*", the other is set to 0, and vise-versa
+                        */
+                       FixDayDow(line);
+#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+                       /* copy mailto (can be NULL) */
+                       line->cl_MailTo = xstrdup(mailTo);
 #endif
+                       /* copy command */
+                       line->cl_Shell = xstrdup(tokens[5]);
+                       if (DebugOpt) {
+                               crondlog(LVL5 " command:%s", tokens[5]);
+                       }
+                       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;
 
-                                       pline = &((*pline)->cl_Next);
-                               }
-                               *pline = NULL;
-
-                               file->cf_Next = FileBase;
-                               FileBase = file;
+               file->cf_Next = FileBase;
+               FileBase = file;
 
-                               if (maxLines == 0 || maxEntries == 0) {
-                                       crondlog("\111Maximum number of lines reached for user %s\n", fileName);
-                               }
-                       }
-                       fclose(fi);
+               if (maxLines == 0) {
+                       crondlog(WARN9 "user %s: too many lines", fileName);
                }
        }
+       config_close(parser);
 }
 
 static void CheckUpdates(void)
@@ -547,10 +531,11 @@ static void CheckUpdates(void)
        FILE *fi;
        char buf[256];
 
-       fi = fopen(CRONUPDATE, "r");
+       fi = fopen_for_read(CRONUPDATE);
        if (fi != NULL) {
-               remove(CRONUPDATE);
+               unlink(CRONUPDATE);
                while (fgets(buf, sizeof(buf), fi) != NULL) {
+                       /* use first word only */
                        SynchronizeFile(strtok(buf, " \t\r\n"));
                }
                fclose(fi);
@@ -559,16 +544,14 @@ static void CheckUpdates(void)
 
 static void SynchronizeDir(void)
 {
+       CronFile *file;
        /* Attempt to delete the database. */
-
-       for (;;) {
-               CronFile *file;
-
-               for (file = FileBase; file && file->cf_Deleted; file = file->cf_Next);
-               if (file == NULL) {
-                       break;
+ again:
+       for (file = FileBase; file; file = file->cf_Next) {
+               if (!file->cf_Deleted) {
+                       DeleteFile(file->cf_User);
+                       goto again;
                }
-               DeleteFile(file->cf_User);
        }
 
        /*
@@ -579,41 +562,36 @@ static void SynchronizeDir(void)
         *
         * scan directory and add associated users
         */
-
-       remove(CRONUPDATE);
+       unlink(CRONUPDATE);
        if (chdir(CDir) < 0) {
-               crondlog("\311cannot find %s\n", CDir);
+               crondlog(DIE9 "can't chdir(%s)", CDir);
        }
        {
                DIR *dir = opendir(".");
                struct dirent *den;
 
-               if (dir) {
-                       while ((den = readdir(dir))) {
-                               if (strchr(den->d_name, '.') != NULL) {
-                                       continue;
-                               }
-                               if (getpwnam(den->d_name)) {
-                                       SynchronizeFile(den->d_name);
-                               } else {
-                                       crondlog("\007ignoring %s\n", den->d_name);
-                               }
+               if (!dir)
+                       crondlog(DIE9 "can't 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);
                        }
-                       closedir(dir);
-               } else {
-                       crondlog("\311cannot open current dir!\n");
                }
+               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;
@@ -657,7 +635,6 @@ static void DeleteFile(const char *userName)
  * 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)
 {
        int nJobs = 0;
@@ -666,40 +643,37 @@ static int TestJobs(time_t t1, time_t t2)
        /* Find jobs > t1 and <= t2 */
 
        for (t = t1 - t1 % 60; t <= t2; t += 60) {
-               if (t > t1) {
-                       struct tm *tp = localtime(&t);
-                       CronFile *file;
-                       CronLine *line;
+               struct tm *tp;
+               CronFile *file;
+               CronLine *line;
+
+               if (t <= t1)
+                       continue;
 
-                       for (file = FileBase; file; file = file->cf_Next) {
-#if ENABLE_DEBUG_CROND_OPTION
+               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("\005FILE %s:\n", file->cf_User);
-#endif
-                               if (file->cf_Deleted)
-                                       continue;
-                               for (line = file->cf_LineBase; line; line = line->cl_Next) {
-#if ENABLE_DEBUG_CROND_OPTION
-                                       if (DebugOpt)
-                                               crondlog("\005    LINE %s\n", line->cl_Shell);
-#endif
-                                       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 ENABLE_DEBUG_CROND_OPTION
-                                               if (DebugOpt) {
-                                                       crondlog("\005    JobToDo: %d %s\n",
-                                                               line->cl_Pid, line->cl_Shell);
-                                               }
-#endif
-                                               if (line->cl_Pid > 0) {
-                                                       crondlog("\010    process already running: %s %s\n",
-                                                               file->cf_User, line->cl_Shell);
-                                               } else if (line->cl_Pid == 0) {
-                                                       line->cl_Pid = -1;
-                                                       file->cf_Ready = 1;
-                                                       ++nJobs;
-                                               }
+                                       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;
                                        }
                                }
                        }
@@ -714,23 +688,21 @@ static void RunJobs(void)
        CronLine *line;
 
        for (file = FileBase; file; file = file->cf_Next) {
-               if (file->cf_Ready) {
-                       file->cf_Ready = 0;
-
-                       for (line = file->cf_LineBase; line; line = line->cl_Next) {
-                               if (line->cl_Pid < 0) {
-
-                                       RunJob(file->cf_User, line);
+               if (!file->cf_Ready)
+                       continue;
 
-                                       crondlog("\010USER %s pid %3d cmd %s\n",
-                                               file->cf_User, 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;
-                                       }
-                               }
+               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;
                        }
                }
        }
@@ -742,7 +714,6 @@ static void RunJobs(void)
  * Check for job completion, return number of jobs still running after
  * all done.
  */
-
 static int CheckJobs(void)
 {
        CronFile *file;
@@ -754,18 +725,18 @@ static int CheckJobs(void)
                        file->cf_Running = 0;
 
                        for (line = file->cf_LineBase; line; line = line->cl_Next) {
-                               if (line->cl_Pid > 0) {
-                                       int status;
-                                       int 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) {
+                               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;
                                }
                        }
                }
@@ -774,87 +745,98 @@ static int CheckJobs(void)
        return nStillRunning;
 }
 
-
 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+
+// TODO: sendmail should be _run-time_ option, not compile-time!
+
 static void
-ForkJob(const char *user, CronLine * line, int mailFd,
-               const char *prog, const char *cmd, const char *arg, const char *mailf)
+ForkJob(const char *user, CronLine *line, int mailFd,
+               const char *prog, const char *cmd, const char *arg,
+               const char *mail_filename)
 {
-       /* Fork as the user in question and run program */
-       pid_t pid = fork();
+       struct passwd *pas;
+       pid_t pid;
 
-       line->cl_Pid = pid;
+       /* prepare things before vfork */
+       pas = getpwnam(user);
+       if (!pas) {
+               crondlog(LVL9 "can't get uid for %s", user);
+               goto err;
+       }
+       SetEnv(pas);
+
+       pid = vfork();
        if (pid == 0) {
                /* CHILD */
-
-               /* Change running state to the user in question */
-
-               if (ChangeUser(user) < 0) {
-                       exit(0);
-               }
-#if ENABLE_DEBUG_CROND_OPTION
+               /* change running state to the user in question */
+               ChangeUser(pas);
                if (DebugOpt) {
-                       crondlog("\005Child Running %s\n", prog);
+                       crondlog(LVL5 "child running %s", prog);
                }
-#endif
-
                if (mailFd >= 0) {
-                       dup2(mailFd, mailf != NULL);
-                       dup2((mailf ? mailFd : 1), 2);
-                       close(mailFd);
+                       xmove_fd(mailFd, mail_filename ? 1 : 0);
+                       dup2(1, 2);
                }
-               execl(prog, prog, cmd, arg, NULL);
-               crondlog("\024cannot exec, user %s cmd %s %s %s\n", user, prog, cmd, arg);
-               if (mailf) {
+               /* crond 3.0pl1-100 puts tasks in separate process groups */
+               bb_setpgrp();
+               execlp(prog, prog, cmd, arg, 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);
                }
-               exit(0);
-       } else if (pid < 0) {
+               _exit(EXIT_SUCCESS);
+       }
+
+       line->cl_Pid = pid;
+       if (pid < 0) {
                /* FORK FAILED */
-               crondlog("\024cannot fork, user %s\n", user);
+               crondlog(ERR20 "can't vfork");
+ err:
                line->cl_Pid = 0;
-               if (mailf) {
-                       remove(mailf);
+               if (mail_filename) {
+                       unlink(mail_filename);
                }
-       } else if (mailf) {
+       } else if (mail_filename) {
                /* PARENT, FORK SUCCESS
                 * rename mail-file based on pid of process
                 */
                char mailFile2[128];
 
-               snprintf(mailFile2, sizeof(mailFile2), TMPDIR "/cron.%s.%d", user, pid);
-               rename(mailf, mailFile2);
+               snprintf(mailFile2, sizeof(mailFile2), "%s/cron.%s.%d", TMPDIR, user, pid);
+               rename(mail_filename, mailFile2); // TODO: xrename?
        }
+
        /*
         * Close the mail file descriptor.. we can't just leave it open in
         * a structure, closing it later, because we might run out of descriptors
         */
-
        if (mailFd >= 0) {
                close(mailFd);
        }
 }
 
-static void RunJob(const char *user, CronLine * line)
+static void RunJob(const char *user, CronLine *line)
 {
        char mailFile[128];
-       int mailFd;
+       int mailFd = -1;
 
        line->cl_Pid = 0;
        line->cl_MailFlag = 0;
 
-       /* open mail file - owner root so nobody can screw with it. */
-
-       snprintf(mailFile, sizeof(mailFile), TMPDIR "/cron.%s.%d", user, getpid());
-       mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
+       if (line->cl_MailTo) {
+               /* open mail file - owner 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", user,
-                       line->cl_Shell);
-               line->cl_MailPos = lseek(mailFd, 0, SEEK_CUR);
-       } else {
-               crondlog("\024cannot create mail file user %s file %s, output to /dev/null\n", user, mailFile);
+               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);
+               } else {
+                       crondlog(ERR20 "cannot create mail file %s for user %s, "
+                                       "discarding output", mailFile, user);
+               }
        }
 
        ForkJob(user, line, mailFd, DEFAULT_SHELL, "-c", line->cl_Shell, mailFile);
@@ -863,15 +845,13 @@ static void RunJob(const char *user, CronLine * line)
 /*
  * EndJob - called when job terminates and when mail terminates
  */
-
-static void EndJob(const char *user, CronLine * line)
+static void EndJob(const char *user, CronLine *line)
 {
        int mailFd;
        char mailFile[128];
        struct stat sbuf;
 
        /* No job */
-
        if (line->cl_Pid <= 0) {
                line->cl_Pid = 0;
                return;
@@ -881,11 +861,10 @@ static void EndJob(const char *user, CronLine * line)
         * End of job and no mail file
         * End of sendmail job
         */
-
-       snprintf(mailFile, sizeof(mailFile), TMPDIR "/cron.%s.%d", user, line->cl_Pid);
+       snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, line->cl_Pid);
        line->cl_Pid = 0;
 
-       if (line->cl_MailFlag != 1) {
+       if (line->cl_MailFlag == 0) {
                return;
        }
        line->cl_MailFlag = 0;
@@ -894,9 +873,8 @@ static void EndJob(const char *user, CronLine * line)
         * End of primary job - check for mail file.  If size has increased and
         * the file is still valid, we sendmail it.
         */
-
        mailFd = open(mailFile, O_RDONLY);
-       remove(mailFile);
+       unlink(mailFile);
        if (mailFd < 0) {
                return;
        }
@@ -908,39 +886,48 @@ static void EndJob(const char *user, CronLine * line)
                close(mailFd);
                return;
        }
-       ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL);
+       if (line->cl_MailTo)
+               ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL);
 }
-#else
-/* crond without sendmail */
 
-static void RunJob(const char *user, CronLine * line)
+#else /* crond without sendmail */
+
+static void RunJob(const char *user, CronLine *line)
 {
-       /* Fork as the user in question and run program */
-       pid_t pid = fork();
+       struct passwd *pas;
+       pid_t pid;
+
+       /* prepare things before vfork */
+       pas = getpwnam(user);
+       if (!pas) {
+               crondlog(LVL9 "can't get uid for %s", user);
+               goto err;
+       }
+       SetEnv(pas);
 
+       /* fork as the user in question and run program */
+       pid = vfork();
        if (pid == 0) {
                /* CHILD */
-
-               /* Change running state to the user in question */
-
-               if (ChangeUser(user) < 0) {
-                       exit(0);
-               }
-#if ENABLE_DEBUG_CROND_OPTION
+               /* change running state to the user in question */
+               ChangeUser(pas);
                if (DebugOpt) {
-                       crondlog("\005Child Running %s\n", DEFAULT_SHELL);
+                       crondlog(LVL5 "child running %s", DEFAULT_SHELL);
                }
-#endif
-
+               /* crond 3.0pl1-100 puts tasks in separate process groups */
+               bb_setpgrp();
                execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_Shell, NULL);
-               crondlog("\024cannot exec, user %s cmd %s -c %s\n", user,
-                                DEFAULT_SHELL, line->cl_Shell);
-               exit(0);
-       } else if (pid < 0) {
+               crondlog(ERR20 "can't exec, user %s cmd %s %s %s", user,
+                                DEFAULT_SHELL, "-c", line->cl_Shell);
+               _exit(EXIT_SUCCESS);
+       }
+       if (pid < 0) {
                /* FORK FAILED */
-               crondlog("\024cannot, user %s\n", user);
+               crondlog(ERR20 "can't vfork");
+ err:
                pid = 0;
        }
        line->cl_Pid = pid;
 }
+
 #endif /* ENABLE_FEATURE_CROND_CALL_SENDMAIL */