1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * crond -d[#] -c <crondir> -f -b
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4 | *
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5 | * run as root, but NOT setuid root
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6 | *
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7 | * Copyright 1994 Matthew Dillon (dillon@apollo.west.oic.com)
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8 | * (version 2.3.2)
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9 | * Vladimir Oleynik <dzo@simtreas.ru> (C) 2002
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10 | *
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11 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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12 | */
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13 |
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14 | //usage:#define crond_trivial_usage
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15 | //usage: "-fbS -l N " IF_FEATURE_CROND_D("-d N ") "-L LOGFILE -c DIR"
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16 | //usage:#define crond_full_usage "\n\n"
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17 | //usage: " -f Foreground"
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18 | //usage: "\n -b Background (default)"
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19 | //usage: "\n -S Log to syslog (default)"
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20 | //usage: "\n -l Set log level. 0 is the most verbose, default 8"
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21 | //usage: IF_FEATURE_CROND_D(
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22 | //usage: "\n -d Set log level, log to stderr"
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23 | //usage: )
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24 | //usage: "\n -L Log to file"
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25 | //usage: "\n -c Working dir"
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26 |
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27 | #include "libbb.h"
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28 | #include <syslog.h>
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29 |
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30 | /* glibc frees previous setenv'ed value when we do next setenv()
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31 | * of the same variable. uclibc does not do this! */
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32 | #if (defined(__GLIBC__) && !defined(__UCLIBC__)) /* || OTHER_SAFE_LIBC... */
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33 | # define SETENV_LEAKS 0
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34 | #else
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35 | # define SETENV_LEAKS 1
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36 | #endif
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37 |
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38 |
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39 | #define TMPDIR CONFIG_FEATURE_CROND_DIR
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40 | #define CRONTABS CONFIG_FEATURE_CROND_DIR "/crontabs"
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41 | #ifndef SENDMAIL
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42 | # define SENDMAIL "sendmail"
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43 | #endif
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44 | #ifndef SENDMAIL_ARGS
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45 | # define SENDMAIL_ARGS "-ti"
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46 | #endif
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47 | #ifndef CRONUPDATE
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48 | # define CRONUPDATE "cron.update"
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49 | #endif
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50 | #ifndef MAXLINES
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51 | # define MAXLINES 256 /* max lines in non-root crontabs */
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52 | #endif
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53 |
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54 |
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55 | typedef struct CronFile {
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56 | struct CronFile *cf_next;
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57 | struct CronLine *cf_lines;
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58 | char *cf_username;
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59 | smallint cf_wants_starting; /* bool: one or more jobs ready */
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60 | smallint cf_has_running; /* bool: one or more jobs running */
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61 | smallint cf_deleted; /* marked for deletion (but still has running jobs) */
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62 | } CronFile;
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63 |
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64 | typedef struct CronLine {
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65 | struct CronLine *cl_next;
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66 | char *cl_cmd; /* shell command */
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67 | pid_t cl_pid; /* >0:running, <0:needs to be started in this minute, 0:dormant */
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68 | #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
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69 | int cl_empty_mail_size; /* size of mail header only, 0 if no mailfile */
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70 | char *cl_mailto; /* whom to mail results, may be NULL */
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71 | #endif
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72 | /* ordered by size, not in natural order. makes code smaller: */
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73 | char cl_Dow[7]; /* 0-6, beginning sunday */
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74 | char cl_Mons[12]; /* 0-11 */
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75 | char cl_Hrs[24]; /* 0-23 */
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76 | char cl_Days[32]; /* 1-31 */
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77 | char cl_Mins[60]; /* 0-59 */
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78 | } CronLine;
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79 |
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80 |
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81 | #define DAEMON_UID 0
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82 |
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83 |
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84 | enum {
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85 | OPT_l = (1 << 0),
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86 | OPT_L = (1 << 1),
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87 | OPT_f = (1 << 2),
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88 | OPT_b = (1 << 3),
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89 | OPT_S = (1 << 4),
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90 | OPT_c = (1 << 5),
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91 | OPT_d = (1 << 6) * ENABLE_FEATURE_CROND_D,
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92 | };
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93 | #if ENABLE_FEATURE_CROND_D
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94 | # define DebugOpt (option_mask32 & OPT_d)
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95 | #else
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96 | # define DebugOpt 0
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97 | #endif
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98 |
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99 |
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100 | struct globals {
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101 | unsigned log_level; /* = 8; */
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102 | time_t crontab_dir_mtime;
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103 | const char *log_filename;
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104 | const char *crontab_dir_name; /* = CRONTABS; */
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105 | CronFile *cron_files;
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106 | #if SETENV_LEAKS
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107 | char *env_var_user;
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108 | char *env_var_home;
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109 | #endif
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110 | } FIX_ALIASING;
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111 | #define G (*(struct globals*)&bb_common_bufsiz1)
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112 | #define INIT_G() do { \
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113 | G.log_level = 8; \
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114 | G.crontab_dir_name = CRONTABS; \
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115 | } while (0)
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116 |
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117 |
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118 | /* 0 is the most verbose, default 8 */
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119 | #define LVL5 "\x05"
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120 | #define LVL7 "\x07"
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121 | #define LVL8 "\x08"
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122 | #define WARN9 "\x49"
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123 | #define DIE9 "\xc9"
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124 | /* level >= 20 is "error" */
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125 | #define ERR20 "\x14"
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126 |
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127 | static void crondlog(const char *ctl, ...) __attribute__ ((format (printf, 1, 2)));
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128 | static void crondlog(const char *ctl, ...)
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129 | {
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130 | va_list va;
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131 | int level = (ctl[0] & 0x1f);
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132 |
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133 | va_start(va, ctl);
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134 | if (level >= (int)G.log_level) {
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135 | /* Debug mode: all to (non-redirected) stderr, */
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136 | /* Syslog mode: all to syslog (logmode = LOGMODE_SYSLOG), */
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137 | if (!DebugOpt && G.log_filename) {
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138 | /* Otherwise (log to file): we reopen log file at every write: */
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139 | int logfd = open_or_warn(G.log_filename, O_WRONLY | O_CREAT | O_APPEND);
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140 | if (logfd >= 0)
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141 | xmove_fd(logfd, STDERR_FILENO);
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142 | }
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143 | /* When we log to syslog, level > 8 is logged at LOG_ERR
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144 | * syslog level, level <= 8 is logged at LOG_INFO. */
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145 | if (level > 8) {
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146 | bb_verror_msg(ctl + 1, va, /* strerr: */ NULL);
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147 | } else {
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148 | char *msg = NULL;
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149 | vasprintf(&msg, ctl + 1, va);
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150 | bb_info_msg("%s: %s", applet_name, msg);
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151 | free(msg);
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152 | }
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153 | }
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154 | va_end(va);
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155 | if (ctl[0] & 0x80)
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156 | exit(20);
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157 | }
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158 |
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159 | static const char DowAry[] ALIGN1 =
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160 | "sun""mon""tue""wed""thu""fri""sat"
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161 | /* "Sun""Mon""Tue""Wed""Thu""Fri""Sat" */
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162 | ;
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163 |
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164 | static const char MonAry[] ALIGN1 =
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165 | "jan""feb""mar""apr""may""jun""jul""aug""sep""oct""nov""dec"
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166 | /* "Jan""Feb""Mar""Apr""May""Jun""Jul""Aug""Sep""Oct""Nov""Dec" */
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167 | ;
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168 |
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169 | static void ParseField(char *user, char *ary, int modvalue, int off,
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170 | const char *names, char *ptr)
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171 | /* 'names' is a pointer to a set of 3-char abbreviations */
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172 | {
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173 | char *base = ptr;
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174 | int n1 = -1;
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175 | int n2 = -1;
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176 |
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177 | // this can't happen due to config_read()
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178 | /*if (base == NULL)
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179 | return;*/
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180 |
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181 | while (1) {
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182 | int skip = 0;
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183 |
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184 | /* Handle numeric digit or symbol or '*' */
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185 | if (*ptr == '*') {
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186 | n1 = 0; /* everything will be filled */
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187 | n2 = modvalue - 1;
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188 | skip = 1;
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189 | ++ptr;
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190 | } else if (isdigit(*ptr)) {
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191 | char *endp;
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192 | if (n1 < 0) {
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193 | n1 = strtol(ptr, &endp, 10) + off;
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194 | } else {
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195 | n2 = strtol(ptr, &endp, 10) + off;
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196 | }
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197 | ptr = endp; /* gcc likes temp var for &endp */
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198 | skip = 1;
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199 | } else if (names) {
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200 | int i;
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201 |
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202 | for (i = 0; names[i]; i += 3) {
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203 | /* was using strncmp before... */
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204 | if (strncasecmp(ptr, &names[i], 3) == 0) {
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205 | ptr += 3;
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206 | if (n1 < 0) {
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207 | n1 = i / 3;
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208 | } else {
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209 | n2 = i / 3;
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210 | }
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211 | skip = 1;
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212 | break;
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213 | }
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214 | }
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215 | }
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216 |
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217 | /* handle optional range '-' */
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218 | if (skip == 0) {
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219 | goto err;
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220 | }
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221 | if (*ptr == '-' && n2 < 0) {
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222 | ++ptr;
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223 | continue;
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224 | }
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225 |
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226 | /*
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227 | * collapse single-value ranges, handle skipmark, and fill
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228 | * in the character array appropriately.
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229 | */
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230 | if (n2 < 0) {
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231 | n2 = n1;
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232 | }
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233 | if (*ptr == '/') {
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234 | char *endp;
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235 | skip = strtol(ptr + 1, &endp, 10);
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236 | ptr = endp; /* gcc likes temp var for &endp */
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237 | }
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238 |
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239 | /*
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240 | * fill array, using a failsafe is the easiest way to prevent
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241 | * an endless loop
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242 | */
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243 | {
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244 | int s0 = 1;
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245 | int failsafe = 1024;
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246 |
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247 | --n1;
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248 | do {
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249 | n1 = (n1 + 1) % modvalue;
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250 |
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251 | if (--s0 == 0) {
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252 | ary[n1 % modvalue] = 1;
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253 | s0 = skip;
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254 | }
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255 | if (--failsafe == 0) {
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256 | goto err;
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257 | }
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258 | } while (n1 != n2);
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259 | }
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260 | if (*ptr != ',') {
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261 | break;
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262 | }
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263 | ++ptr;
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264 | n1 = -1;
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265 | n2 = -1;
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266 | }
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267 |
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268 | if (*ptr) {
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269 | err:
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270 | crondlog(WARN9 "user %s: parse error at %s", user, base);
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271 | return;
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272 | }
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273 |
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274 | if (DebugOpt && (G.log_level <= 5)) { /* like LVL5 */
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275 | /* can't use crondlog, it inserts '\n' */
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276 | int i;
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277 | for (i = 0; i < modvalue; ++i)
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278 | fprintf(stderr, "%d", (unsigned char)ary[i]);
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279 | bb_putchar_stderr('\n');
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280 | }
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281 | }
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282 |
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283 | static void FixDayDow(CronLine *line)
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284 | {
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285 | unsigned i;
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286 | int weekUsed = 0;
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287 | int daysUsed = 0;
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288 |
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289 | for (i = 0; i < ARRAY_SIZE(line->cl_Dow); ++i) {
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290 | if (line->cl_Dow[i] == 0) {
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291 | weekUsed = 1;
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292 | break;
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293 | }
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294 | }
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295 | for (i = 0; i < ARRAY_SIZE(line->cl_Days); ++i) {
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296 | if (line->cl_Days[i] == 0) {
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297 | daysUsed = 1;
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298 | break;
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299 | }
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300 | }
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301 | if (weekUsed != daysUsed) {
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302 | if (weekUsed)
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303 | memset(line->cl_Days, 0, sizeof(line->cl_Days));
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304 | else /* daysUsed */
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305 | memset(line->cl_Dow, 0, sizeof(line->cl_Dow));
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306 | }
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307 | }
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308 |
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309 | /*
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310 | * delete_cronfile() - delete user database
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311 | *
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312 | * Note: multiple entries for same user may exist if we were unable to
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313 | * completely delete a database due to running processes.
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314 | */
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315 | //FIXME: we will start a new job even if the old job is running
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316 | //if crontab was reloaded: crond thinks that "new" job is different from "old"
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317 | //even if they are in fact completely the same. Example
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318 | //Crontab was:
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319 | // 0-59 * * * * job1
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320 | // 0-59 * * * * long_running_job2
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321 | //User edits crontab to:
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322 | // 0-59 * * * * job1_updated
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323 | // 0-59 * * * * long_running_job2
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324 | //Bug: crond can now start another long_running_job2 even if old one
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325 | //is still running.
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326 | //OTOH most other versions of cron do not wait for job termination anyway,
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327 | //they end up with multiple copies of jobs if they don't terminate soon enough.
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328 | static void delete_cronfile(const char *userName)
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329 | {
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330 | CronFile **pfile = &G.cron_files;
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331 | CronFile *file;
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332 |
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333 | while ((file = *pfile) != NULL) {
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334 | if (strcmp(userName, file->cf_username) == 0) {
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335 | CronLine **pline = &file->cf_lines;
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336 | CronLine *line;
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337 |
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338 | file->cf_has_running = 0;
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339 | file->cf_deleted = 1;
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340 |
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341 | while ((line = *pline) != NULL) {
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342 | if (line->cl_pid > 0) {
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343 | file->cf_has_running = 1;
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344 | pline = &line->cl_next;
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345 | } else {
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346 | *pline = line->cl_next;
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347 | free(line->cl_cmd);
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348 | free(line);
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349 | }
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350 | }
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351 | if (file->cf_has_running == 0) {
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352 | *pfile = file->cf_next;
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353 | free(file->cf_username);
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354 | free(file);
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355 | continue;
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356 | }
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357 | }
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358 | pfile = &file->cf_next;
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359 | }
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360 | }
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361 |
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362 | static void load_crontab(const char *fileName)
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363 | {
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364 | struct parser_t *parser;
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365 | struct stat sbuf;
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366 | int maxLines;
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367 | char *tokens[6];
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368 | #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
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369 | char *mailTo = NULL;
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370 | #endif
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371 |
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372 | delete_cronfile(fileName);
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373 |
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374 | if (!getpwnam(fileName)) {
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375 | crondlog(LVL7 "ignoring file '%s' (no such user)", fileName);
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376 | return;
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377 | }
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378 |
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379 | parser = config_open(fileName);
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380 | if (!parser)
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381 | return;
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382 |
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383 | maxLines = (strcmp(fileName, "root") == 0) ? 65535 : MAXLINES;
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384 |
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385 | if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DAEMON_UID) {
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386 | CronFile *file = xzalloc(sizeof(CronFile));
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387 | CronLine **pline;
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388 | int n;
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389 |
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390 | file->cf_username = xstrdup(fileName);
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391 | pline = &file->cf_lines;
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392 |
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393 | while (1) {
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394 | CronLine *line;
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395 |
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396 | if (!--maxLines)
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397 | break;
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398 | n = config_read(parser, tokens, 6, 1, "# \t", PARSE_NORMAL | PARSE_KEEP_COPY);
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399 | if (!n)
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400 | break;
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401 |
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402 | if (DebugOpt)
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403 | crondlog(LVL5 "user:%s entry:%s", fileName, parser->data);
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404 |
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405 | /* check if line is setting MAILTO= */
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406 | if (0 == strncmp(tokens[0], "MAILTO=", 7)) {
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407 | #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
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408 | free(mailTo);
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409 | mailTo = (tokens[0][7]) ? xstrdup(&tokens[0][7]) : NULL;
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410 | #endif /* otherwise just ignore such lines */
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411 | continue;
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412 | }
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413 | /* check if a minimum of tokens is specified */
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414 | if (n < 6)
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415 | continue;
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416 | *pline = line = xzalloc(sizeof(*line));
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417 | /* parse date ranges */
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418 | ParseField(file->cf_username, line->cl_Mins, 60, 0, NULL, tokens[0]);
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419 | ParseField(file->cf_username, line->cl_Hrs, 24, 0, NULL, tokens[1]);
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420 | ParseField(file->cf_username, line->cl_Days, 32, 0, NULL, tokens[2]);
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421 | ParseField(file->cf_username, line->cl_Mons, 12, -1, MonAry, tokens[3]);
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422 | ParseField(file->cf_username, line->cl_Dow, 7, 0, DowAry, tokens[4]);
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423 | /*
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424 | * fix days and dow - if one is not "*" and the other
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425 | * is "*", the other is set to 0, and vise-versa
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426 | */
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427 | FixDayDow(line);
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428 | #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
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429 | /* copy mailto (can be NULL) */
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430 | line->cl_mailto = xstrdup(mailTo);
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431 | #endif
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432 | /* copy command */
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433 | line->cl_cmd = xstrdup(tokens[5]);
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434 | if (DebugOpt) {
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435 | crondlog(LVL5 " command:%s", tokens[5]);
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436 | }
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437 | pline = &line->cl_next;
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438 | //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]);
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439 | }
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440 | *pline = NULL;
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441 |
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442 | file->cf_next = G.cron_files;
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443 | G.cron_files = file;
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444 |
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445 | if (maxLines == 0) {
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446 | crondlog(WARN9 "user %s: too many lines", fileName);
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447 | }
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448 | }
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449 | config_close(parser);
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450 | }
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---|
451 |
|
---|
452 | static void process_cron_update_file(void)
|
---|
453 | {
|
---|
454 | FILE *fi;
|
---|
455 | char buf[256];
|
---|
456 |
|
---|
457 | fi = fopen_for_read(CRONUPDATE);
|
---|
458 | if (fi != NULL) {
|
---|
459 | unlink(CRONUPDATE);
|
---|
460 | while (fgets(buf, sizeof(buf), fi) != NULL) {
|
---|
461 | /* use first word only */
|
---|
462 | skip_non_whitespace(buf)[0] = '\0';
|
---|
463 | load_crontab(buf);
|
---|
464 | }
|
---|
465 | fclose(fi);
|
---|
466 | }
|
---|
467 | }
|
---|
468 |
|
---|
469 | static void rescan_crontab_dir(void)
|
---|
470 | {
|
---|
471 | CronFile *file;
|
---|
472 |
|
---|
473 | /* Delete all files until we only have ones with running jobs (or none) */
|
---|
474 | again:
|
---|
475 | for (file = G.cron_files; file; file = file->cf_next) {
|
---|
476 | if (!file->cf_deleted) {
|
---|
477 | delete_cronfile(file->cf_username);
|
---|
478 | goto again;
|
---|
479 | }
|
---|
480 | }
|
---|
481 |
|
---|
482 | /* Remove cron update file */
|
---|
483 | unlink(CRONUPDATE);
|
---|
484 | /* Re-chdir, in case directory was renamed & deleted */
|
---|
485 | if (chdir(G.crontab_dir_name) < 0) {
|
---|
486 | crondlog(DIE9 "chdir(%s)", G.crontab_dir_name);
|
---|
487 | }
|
---|
488 |
|
---|
489 | /* Scan directory and add associated users */
|
---|
490 | {
|
---|
491 | DIR *dir = opendir(".");
|
---|
492 | struct dirent *den;
|
---|
493 |
|
---|
494 | if (!dir)
|
---|
495 | crondlog(DIE9 "chdir(%s)", "."); /* exits */
|
---|
496 | while ((den = readdir(dir)) != NULL) {
|
---|
497 | if (strchr(den->d_name, '.') != NULL) {
|
---|
498 | continue;
|
---|
499 | }
|
---|
500 | load_crontab(den->d_name);
|
---|
501 | }
|
---|
502 | closedir(dir);
|
---|
503 | }
|
---|
504 | }
|
---|
505 |
|
---|
506 | #if SETENV_LEAKS
|
---|
507 | /* We set environment *before* vfork (because we want to use vfork),
|
---|
508 | * so we cannot use setenv() - repeated calls to setenv() may leak memory!
|
---|
509 | * Using putenv(), and freeing memory after unsetenv() won't leak */
|
---|
510 | static void safe_setenv(char **pvar_val, const char *var, const char *val)
|
---|
511 | {
|
---|
512 | char *var_val = *pvar_val;
|
---|
513 |
|
---|
514 | if (var_val) {
|
---|
515 | bb_unsetenv_and_free(var_val);
|
---|
516 | }
|
---|
517 | *pvar_val = xasprintf("%s=%s", var, val);
|
---|
518 | putenv(*pvar_val);
|
---|
519 | }
|
---|
520 | #endif
|
---|
521 |
|
---|
522 | static void set_env_vars(struct passwd *pas)
|
---|
523 | {
|
---|
524 | #if SETENV_LEAKS
|
---|
525 | safe_setenv(&G.env_var_user, "USER", pas->pw_name);
|
---|
526 | safe_setenv(&G.env_var_home, "HOME", pas->pw_dir);
|
---|
527 | /* if we want to set user's shell instead: */
|
---|
528 | /*safe_setenv(G.env_var_shell, "SHELL", pas->pw_shell);*/
|
---|
529 | #else
|
---|
530 | xsetenv("USER", pas->pw_name);
|
---|
531 | xsetenv("HOME", pas->pw_dir);
|
---|
532 | #endif
|
---|
533 | /* currently, we use constant one: */
|
---|
534 | /*setenv("SHELL", DEFAULT_SHELL, 1); - done earlier */
|
---|
535 | }
|
---|
536 |
|
---|
537 | static void change_user(struct passwd *pas)
|
---|
538 | {
|
---|
539 | /* careful: we're after vfork! */
|
---|
540 | change_identity(pas); /* - initgroups, setgid, setuid */
|
---|
541 | if (chdir(pas->pw_dir) < 0) {
|
---|
542 | crondlog(WARN9 "chdir(%s)", pas->pw_dir);
|
---|
543 | if (chdir(TMPDIR) < 0) {
|
---|
544 | crondlog(DIE9 "chdir(%s)", TMPDIR); /* exits */
|
---|
545 | }
|
---|
546 | }
|
---|
547 | }
|
---|
548 |
|
---|
549 | // TODO: sendmail should be _run-time_ option, not compile-time!
|
---|
550 | #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
|
---|
551 |
|
---|
552 | static pid_t
|
---|
553 | fork_job(const char *user, int mailFd,
|
---|
554 | const char *prog,
|
---|
555 | const char *shell_cmd /* if NULL, we run sendmail */
|
---|
556 | ) {
|
---|
557 | struct passwd *pas;
|
---|
558 | pid_t pid;
|
---|
559 |
|
---|
560 | /* prepare things before vfork */
|
---|
561 | pas = getpwnam(user);
|
---|
562 | if (!pas) {
|
---|
563 | crondlog(WARN9 "can't get uid for %s", user);
|
---|
564 | goto err;
|
---|
565 | }
|
---|
566 | set_env_vars(pas);
|
---|
567 |
|
---|
568 | pid = vfork();
|
---|
569 | if (pid == 0) {
|
---|
570 | /* CHILD */
|
---|
571 | /* initgroups, setgid, setuid, and chdir to home or TMPDIR */
|
---|
572 | change_user(pas);
|
---|
573 | if (DebugOpt) {
|
---|
574 | crondlog(LVL5 "child running %s", prog);
|
---|
575 | }
|
---|
576 | if (mailFd >= 0) {
|
---|
577 | xmove_fd(mailFd, shell_cmd ? 1 : 0);
|
---|
578 | dup2(1, 2);
|
---|
579 | }
|
---|
580 | /* crond 3.0pl1-100 puts tasks in separate process groups */
|
---|
581 | bb_setpgrp();
|
---|
582 | execlp(prog, prog, (shell_cmd ? "-c" : SENDMAIL_ARGS), shell_cmd, (char *) NULL);
|
---|
583 | crondlog(ERR20 "can't execute '%s' for user %s", prog, user);
|
---|
584 | if (shell_cmd) {
|
---|
585 | fdprintf(1, "Exec failed: %s -c %s\n", prog, shell_cmd);
|
---|
586 | }
|
---|
587 | _exit(EXIT_SUCCESS);
|
---|
588 | }
|
---|
589 |
|
---|
590 | if (pid < 0) {
|
---|
591 | /* FORK FAILED */
|
---|
592 | crondlog(ERR20 "can't vfork");
|
---|
593 | err:
|
---|
594 | pid = 0;
|
---|
595 | } /* else: PARENT, FORK SUCCESS */
|
---|
596 |
|
---|
597 | /*
|
---|
598 | * Close the mail file descriptor.. we can't just leave it open in
|
---|
599 | * a structure, closing it later, because we might run out of descriptors
|
---|
600 | */
|
---|
601 | if (mailFd >= 0) {
|
---|
602 | close(mailFd);
|
---|
603 | }
|
---|
604 | return pid;
|
---|
605 | }
|
---|
606 |
|
---|
607 | static void start_one_job(const char *user, CronLine *line)
|
---|
608 | {
|
---|
609 | char mailFile[128];
|
---|
610 | int mailFd = -1;
|
---|
611 |
|
---|
612 | line->cl_pid = 0;
|
---|
613 | line->cl_empty_mail_size = 0;
|
---|
614 |
|
---|
615 | if (line->cl_mailto) {
|
---|
616 | /* Open mail file (owner is root so nobody can screw with it) */
|
---|
617 | snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, getpid());
|
---|
618 | mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
|
---|
619 |
|
---|
620 | if (mailFd >= 0) {
|
---|
621 | fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_mailto,
|
---|
622 | line->cl_cmd);
|
---|
623 | line->cl_empty_mail_size = lseek(mailFd, 0, SEEK_CUR);
|
---|
624 | } else {
|
---|
625 | crondlog(ERR20 "can't create mail file %s for user %s, "
|
---|
626 | "discarding output", mailFile, user);
|
---|
627 | }
|
---|
628 | }
|
---|
629 |
|
---|
630 | line->cl_pid = fork_job(user, mailFd, DEFAULT_SHELL, line->cl_cmd);
|
---|
631 | if (mailFd >= 0) {
|
---|
632 | if (line->cl_pid <= 0) {
|
---|
633 | unlink(mailFile);
|
---|
634 | } else {
|
---|
635 | /* rename mail-file based on pid of process */
|
---|
636 | char *mailFile2 = xasprintf("%s/cron.%s.%d", TMPDIR, user, (int)line->cl_pid);
|
---|
637 | rename(mailFile, mailFile2); // TODO: xrename?
|
---|
638 | free(mailFile2);
|
---|
639 | }
|
---|
640 | }
|
---|
641 | }
|
---|
642 |
|
---|
643 | /*
|
---|
644 | * process_finished_job - called when job terminates and when mail terminates
|
---|
645 | */
|
---|
646 | static void process_finished_job(const char *user, CronLine *line)
|
---|
647 | {
|
---|
648 | pid_t pid;
|
---|
649 | int mailFd;
|
---|
650 | char mailFile[128];
|
---|
651 | struct stat sbuf;
|
---|
652 |
|
---|
653 | pid = line->cl_pid;
|
---|
654 | line->cl_pid = 0;
|
---|
655 | if (pid <= 0) {
|
---|
656 | /* No job */
|
---|
657 | return;
|
---|
658 | }
|
---|
659 | if (line->cl_empty_mail_size <= 0) {
|
---|
660 | /* End of job and no mail file, or end of sendmail job */
|
---|
661 | return;
|
---|
662 | }
|
---|
663 |
|
---|
664 | /*
|
---|
665 | * End of primary job - check for mail file.
|
---|
666 | * If size has changed and the file is still valid, we send it.
|
---|
667 | */
|
---|
668 | snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, (int)pid);
|
---|
669 | mailFd = open(mailFile, O_RDONLY);
|
---|
670 | unlink(mailFile);
|
---|
671 | if (mailFd < 0) {
|
---|
672 | return;
|
---|
673 | }
|
---|
674 |
|
---|
675 | if (fstat(mailFd, &sbuf) < 0
|
---|
676 | || sbuf.st_uid != DAEMON_UID
|
---|
677 | || sbuf.st_nlink != 0
|
---|
678 | || sbuf.st_size == line->cl_empty_mail_size
|
---|
679 | || !S_ISREG(sbuf.st_mode)
|
---|
680 | ) {
|
---|
681 | close(mailFd);
|
---|
682 | return;
|
---|
683 | }
|
---|
684 | line->cl_empty_mail_size = 0;
|
---|
685 | /* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */
|
---|
686 | line->cl_pid = fork_job(user, mailFd, SENDMAIL, NULL);
|
---|
687 | }
|
---|
688 |
|
---|
689 | #else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
|
---|
690 |
|
---|
691 | static void start_one_job(const char *user, CronLine *line)
|
---|
692 | {
|
---|
693 | struct passwd *pas;
|
---|
694 | pid_t pid;
|
---|
695 |
|
---|
696 | pas = getpwnam(user);
|
---|
697 | if (!pas) {
|
---|
698 | crondlog(WARN9 "can't get uid for %s", user);
|
---|
699 | goto err;
|
---|
700 | }
|
---|
701 |
|
---|
702 | /* Prepare things before vfork */
|
---|
703 | set_env_vars(pas);
|
---|
704 |
|
---|
705 | /* Fork as the user in question and run program */
|
---|
706 | pid = vfork();
|
---|
707 | if (pid == 0) {
|
---|
708 | /* CHILD */
|
---|
709 | /* initgroups, setgid, setuid, and chdir to home or TMPDIR */
|
---|
710 | change_user(pas);
|
---|
711 | if (DebugOpt) {
|
---|
712 | crondlog(LVL5 "child running %s", DEFAULT_SHELL);
|
---|
713 | }
|
---|
714 | /* crond 3.0pl1-100 puts tasks in separate process groups */
|
---|
715 | bb_setpgrp();
|
---|
716 | execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_cmd, (char *) NULL);
|
---|
717 | crondlog(ERR20 "can't execute '%s' for user %s", DEFAULT_SHELL, user);
|
---|
718 | _exit(EXIT_SUCCESS);
|
---|
719 | }
|
---|
720 | if (pid < 0) {
|
---|
721 | /* FORK FAILED */
|
---|
722 | crondlog(ERR20 "can't vfork");
|
---|
723 | err:
|
---|
724 | pid = 0;
|
---|
725 | }
|
---|
726 | line->cl_pid = pid;
|
---|
727 | }
|
---|
728 |
|
---|
729 | #define process_finished_job(user, line) ((line)->cl_pid = 0)
|
---|
730 |
|
---|
731 | #endif /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
|
---|
732 |
|
---|
733 | /*
|
---|
734 | * Determine which jobs need to be run. Under normal conditions, the
|
---|
735 | * period is about a minute (one scan). Worst case it will be one
|
---|
736 | * hour (60 scans).
|
---|
737 | */
|
---|
738 | static void flag_starting_jobs(time_t t1, time_t t2)
|
---|
739 | {
|
---|
740 | time_t t;
|
---|
741 |
|
---|
742 | /* Find jobs > t1 and <= t2 */
|
---|
743 |
|
---|
744 | for (t = t1 - t1 % 60; t <= t2; t += 60) {
|
---|
745 | struct tm *ptm;
|
---|
746 | CronFile *file;
|
---|
747 | CronLine *line;
|
---|
748 |
|
---|
749 | if (t <= t1)
|
---|
750 | continue;
|
---|
751 |
|
---|
752 | ptm = localtime(&t);
|
---|
753 | for (file = G.cron_files; file; file = file->cf_next) {
|
---|
754 | if (DebugOpt)
|
---|
755 | crondlog(LVL5 "file %s:", file->cf_username);
|
---|
756 | if (file->cf_deleted)
|
---|
757 | continue;
|
---|
758 | for (line = file->cf_lines; line; line = line->cl_next) {
|
---|
759 | if (DebugOpt)
|
---|
760 | crondlog(LVL5 " line %s", line->cl_cmd);
|
---|
761 | if (line->cl_Mins[ptm->tm_min]
|
---|
762 | && line->cl_Hrs[ptm->tm_hour]
|
---|
763 | && (line->cl_Days[ptm->tm_mday] || line->cl_Dow[ptm->tm_wday])
|
---|
764 | && line->cl_Mons[ptm->tm_mon]
|
---|
765 | ) {
|
---|
766 | if (DebugOpt) {
|
---|
767 | crondlog(LVL5 " job: %d %s",
|
---|
768 | (int)line->cl_pid, line->cl_cmd);
|
---|
769 | }
|
---|
770 | if (line->cl_pid > 0) {
|
---|
771 | crondlog(LVL8 "user %s: process already running: %s",
|
---|
772 | file->cf_username, line->cl_cmd);
|
---|
773 | } else if (line->cl_pid == 0) {
|
---|
774 | line->cl_pid = -1;
|
---|
775 | file->cf_wants_starting = 1;
|
---|
776 | }
|
---|
777 | }
|
---|
778 | }
|
---|
779 | }
|
---|
780 | }
|
---|
781 | }
|
---|
782 |
|
---|
783 | static void start_jobs(void)
|
---|
784 | {
|
---|
785 | CronFile *file;
|
---|
786 | CronLine *line;
|
---|
787 |
|
---|
788 | for (file = G.cron_files; file; file = file->cf_next) {
|
---|
789 | if (!file->cf_wants_starting)
|
---|
790 | continue;
|
---|
791 |
|
---|
792 | file->cf_wants_starting = 0;
|
---|
793 | for (line = file->cf_lines; line; line = line->cl_next) {
|
---|
794 | pid_t pid;
|
---|
795 | if (line->cl_pid >= 0)
|
---|
796 | continue;
|
---|
797 |
|
---|
798 | start_one_job(file->cf_username, line);
|
---|
799 | pid = line->cl_pid;
|
---|
800 | crondlog(LVL8 "USER %s pid %3d cmd %s",
|
---|
801 | file->cf_username, (int)pid, line->cl_cmd);
|
---|
802 | if (pid < 0) {
|
---|
803 | file->cf_wants_starting = 1;
|
---|
804 | }
|
---|
805 | if (pid > 0) {
|
---|
806 | file->cf_has_running = 1;
|
---|
807 | }
|
---|
808 | }
|
---|
809 | }
|
---|
810 | }
|
---|
811 |
|
---|
812 | /*
|
---|
813 | * Check for job completion, return number of jobs still running after
|
---|
814 | * all done.
|
---|
815 | */
|
---|
816 | static int check_completions(void)
|
---|
817 | {
|
---|
818 | CronFile *file;
|
---|
819 | CronLine *line;
|
---|
820 | int num_still_running = 0;
|
---|
821 |
|
---|
822 | for (file = G.cron_files; file; file = file->cf_next) {
|
---|
823 | if (!file->cf_has_running)
|
---|
824 | continue;
|
---|
825 |
|
---|
826 | file->cf_has_running = 0;
|
---|
827 | for (line = file->cf_lines; line; line = line->cl_next) {
|
---|
828 | int r;
|
---|
829 |
|
---|
830 | if (line->cl_pid <= 0)
|
---|
831 | continue;
|
---|
832 |
|
---|
833 | r = waitpid(line->cl_pid, NULL, WNOHANG);
|
---|
834 | if (r < 0 || r == line->cl_pid) {
|
---|
835 | process_finished_job(file->cf_username, line);
|
---|
836 | if (line->cl_pid == 0) {
|
---|
837 | /* sendmail was not started for it */
|
---|
838 | continue;
|
---|
839 | }
|
---|
840 | /* else: sendmail was started, job is still running, fall thru */
|
---|
841 | }
|
---|
842 | /* else: r == 0: "process is still running" */
|
---|
843 | file->cf_has_running = 1;
|
---|
844 | }
|
---|
845 | //FIXME: if !file->cf_has_running && file->deleted: delete it!
|
---|
846 | //otherwise deleted entries will stay forever, right?
|
---|
847 | num_still_running += file->cf_has_running;
|
---|
848 | }
|
---|
849 | return num_still_running;
|
---|
850 | }
|
---|
851 |
|
---|
852 | int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
853 | int crond_main(int argc UNUSED_PARAM, char **argv)
|
---|
854 | {
|
---|
855 | time_t t2;
|
---|
856 | int rescan;
|
---|
857 | int sleep_time;
|
---|
858 | unsigned opts;
|
---|
859 |
|
---|
860 | INIT_G();
|
---|
861 |
|
---|
862 | /* "-b after -f is ignored", and so on for every pair a-b */
|
---|
863 | opt_complementary = "f-b:b-f:S-L:L-S" IF_FEATURE_CROND_D(":d-l")
|
---|
864 | /* -l and -d have numeric param */
|
---|
865 | ":l+" IF_FEATURE_CROND_D(":d+");
|
---|
866 | opts = getopt32(argv, "l:L:fbSc:" IF_FEATURE_CROND_D("d:"),
|
---|
867 | &G.log_level, &G.log_filename, &G.crontab_dir_name
|
---|
868 | IF_FEATURE_CROND_D(,&G.log_level));
|
---|
869 | /* both -d N and -l N set the same variable: G.log_level */
|
---|
870 |
|
---|
871 | if (!(opts & OPT_f)) {
|
---|
872 | /* close stdin, stdout, stderr.
|
---|
873 | * close unused descriptors - don't need them. */
|
---|
874 | bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
|
---|
875 | }
|
---|
876 |
|
---|
877 | if (!(opts & OPT_d) && G.log_filename == NULL) {
|
---|
878 | /* logging to syslog */
|
---|
879 | openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON);
|
---|
880 | logmode = LOGMODE_SYSLOG;
|
---|
881 | }
|
---|
882 |
|
---|
883 | xchdir(G.crontab_dir_name);
|
---|
884 | //signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */
|
---|
885 | xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */
|
---|
886 | crondlog(LVL8 "crond (busybox "BB_VER") started, log level %d", G.log_level);
|
---|
887 | rescan_crontab_dir();
|
---|
888 | write_pidfile(CONFIG_PID_FILE_PATH "/crond.pid");
|
---|
889 |
|
---|
890 | /* Main loop */
|
---|
891 | t2 = time(NULL);
|
---|
892 | rescan = 60;
|
---|
893 | sleep_time = 60;
|
---|
894 | for (;;) {
|
---|
895 | struct stat sbuf;
|
---|
896 | time_t t1;
|
---|
897 | long dt;
|
---|
898 |
|
---|
899 | t1 = t2;
|
---|
900 |
|
---|
901 | /* Synchronize to 1 minute, minimum 1 second */
|
---|
902 | sleep(sleep_time - (time(NULL) % sleep_time) + 1);
|
---|
903 |
|
---|
904 | t2 = time(NULL);
|
---|
905 | dt = (long)t2 - (long)t1;
|
---|
906 |
|
---|
907 | /*
|
---|
908 | * The file 'cron.update' is checked to determine new cron
|
---|
909 | * jobs. The directory is rescanned once an hour to deal
|
---|
910 | * with any screwups.
|
---|
911 | *
|
---|
912 | * Check for time jump. Disparities over an hour either way
|
---|
913 | * result in resynchronization. A negative disparity
|
---|
914 | * less than an hour causes us to effectively sleep until we
|
---|
915 | * match the original time (i.e. no re-execution of jobs that
|
---|
916 | * have just been run). A positive disparity less than
|
---|
917 | * an hour causes intermediate jobs to be run, but only once
|
---|
918 | * in the worst case.
|
---|
919 | *
|
---|
920 | * When running jobs, the inequality used is greater but not
|
---|
921 | * equal to t1, and less then or equal to t2.
|
---|
922 | */
|
---|
923 | if (stat(G.crontab_dir_name, &sbuf) != 0)
|
---|
924 | sbuf.st_mtime = 0; /* force update (once) if dir was deleted */
|
---|
925 | if (G.crontab_dir_mtime != sbuf.st_mtime) {
|
---|
926 | G.crontab_dir_mtime = sbuf.st_mtime;
|
---|
927 | rescan = 1;
|
---|
928 | }
|
---|
929 | if (--rescan == 0) {
|
---|
930 | rescan = 60;
|
---|
931 | rescan_crontab_dir();
|
---|
932 | }
|
---|
933 | process_cron_update_file();
|
---|
934 | if (DebugOpt)
|
---|
935 | crondlog(LVL5 "wakeup dt=%ld", dt);
|
---|
936 | if (dt < -60 * 60 || dt > 60 * 60) {
|
---|
937 | crondlog(WARN9 "time disparity of %ld minutes detected", dt / 60);
|
---|
938 | /* and we do not run any jobs in this case */
|
---|
939 | } else if (dt > 0) {
|
---|
940 | /* Usual case: time advances forward, as expected */
|
---|
941 | flag_starting_jobs(t1, t2);
|
---|
942 | start_jobs();
|
---|
943 | if (check_completions() > 0) {
|
---|
944 | /* some jobs are still running */
|
---|
945 | sleep_time = 10;
|
---|
946 | } else {
|
---|
947 | sleep_time = 60;
|
---|
948 | }
|
---|
949 | }
|
---|
950 | /* else: time jumped back, do not run any jobs */
|
---|
951 | } /* for (;;) */
|
---|
952 |
|
---|
953 | return 0; /* not reached */
|
---|
954 | }
|
---|