From: Christian Kastner Date: Fri, 15 Jan 2016 23:05:10 +0100 Subject: Selective logging This implements a fine-grained control over what the cron daemon logs when it executes jobs. This is driven via the '-L' command line option, which accepts a bitmask of values for logging the start, end, failure and PID of jobs. The following things can be logged: * Start of cron jobs * End of cron jobs * Failed jobs * Include PID of cron job in messages The default is to log the start of jobs. Initially contributed by Steve Fosdick . Bug-Debian: https://bugs.debian.org/271747 Bug-Debian: https://bugs.debian.org/318247 Forwarded: no Last-Update: 2016-01-15 Index: cron/cron.h =================================================================== --- cron.orig/cron.h +++ cron/cron.h @@ -138,6 +138,12 @@ typedef int time_min; +/* Log levels */ +#define CRON_LOG_JOBSTART 0x01 +#define CRON_LOG_JOBEND 0x02 +#define CRON_LOG_JOBFAILED 0x04 +#define CRON_LOG_JOBPID 0x08 + #define SECONDS_PER_MINUTE 60 #define FIRST_MINUTE 0 @@ -210,7 +216,6 @@ typedef struct _cron_db { time_t sysd_mtime; /* last modtime on system crondir */ } cron_db; - void set_cron_uid __P((void)), set_cron_cwd __P((void)), load_database __P((cron_db *)), @@ -294,6 +299,7 @@ static long GMToff; int stay_foreground; int lsbsysinit_mode; +int log_level; char cron_default_mail_charset[MAX_ENVSTR] = ""; @@ -310,6 +316,7 @@ extern char *copyright[], *DowNames[], *ProgramName; extern int lsbsysinit_mode; +extern int log_level; extern int LineNumber; extern time_t StartTime; extern time_min timeRunning; Index: cron/do_command.c =================================================================== --- cron.orig/do_command.c +++ cron/do_command.c @@ -131,6 +131,7 @@ child_process(e, u) register char *input_data; char *usernm, *mailto; int children = 0; + pid_t job_pid; #if defined(USE_PAM) int retcode = 0; #endif @@ -228,7 +229,7 @@ child_process(e, u) /* fork again, this time so we can exec the user's command. */ - switch (fork()) { + switch (job_pid = fork()) { case -1: log_it("CRON",getpid(),"error","can't fork"); exit(ERROR_EXIT); @@ -242,14 +243,12 @@ child_process(e, u) * the actual user command shell was going to get and the * PID is part of the log message. */ - /*local*/{ + if ((log_level & CRON_LOG_JOBSTART) && ! (log_level & CRON_LOG_JOBPID)) { char *x = mkprints((u_char *)e->cmd, strlen(e->cmd)); - log_it(usernm, getpid(), "CMD", x); free(x); } - - /* that's the last thing we'll log. close the log files. + /* nothing to log from now on. close the log files. */ log_close(); @@ -357,6 +356,16 @@ child_process(e, u) break; default: /* parent process */ + /* write a log message if we want the parent and child + * PID values + */ + if ( (log_level & CRON_LOG_JOBSTART) && (log_level & CRON_LOG_JOBPID)) { + char logcmd[MAX_COMMAND + 8]; + snprintf(logcmd, sizeof(logcmd), "[%d] %s", (int) job_pid, e->cmd); + char *x = mkprints((u_char *)logcmd, strlen(logcmd)); + log_it(usernm, getpid(), "CMD", x); + free(x); + } break; } @@ -458,17 +467,19 @@ child_process(e, u) Debug(DPROC, ("[%d] grandchild #%d finished, status=%04x\n", getpid(), pid, WEXITSTATUS(waiter))) - if (WIFEXITED(waiter) && WEXITSTATUS(waiter)) { - status = waiter; - snprintf(msg, 256, "grandchild #%d failed with exit " - "status %d", pid, WEXITSTATUS(waiter)); - log_it("CRON", getpid(), "error", msg); - } else if (WIFSIGNALED(waiter)) { - status = waiter; - snprintf(msg, 256, "grandchild #%d terminated by signal" - " %d%s", pid, WTERMSIG(waiter), - WCOREDUMP(waiter) ? ", dumped core" : ""); - log_it("CRON", getpid(), "error", msg); + if (log_level & CRON_LOG_JOBFAILED) { + if (WIFEXITED(waiter) && WEXITSTATUS(waiter)) { + status = waiter; + snprintf(msg, 256, "grandchild #%d failed with exit " + "status %d", pid, WEXITSTATUS(waiter)); + log_it("CRON", getpid(), "error", msg); + } else if (WIFSIGNALED(waiter)) { + status = waiter; + snprintf(msg, 256, "grandchild #%d terminated by signal" + " %d%s", pid, WTERMSIG(waiter), + WCOREDUMP(waiter) ? ", dumped core" : ""); + log_it("CRON", getpid(), "error", msg); + } } } @@ -616,6 +627,19 @@ child_process(e, u) mail_finished: fclose(tmpout); + if (log_level & CRON_LOG_JOBEND) { + char *x; + if (log_level & CRON_LOG_JOBPID) { + char logcmd[MAX_COMMAND + 8]; + snprintf(logcmd, sizeof(logcmd), "[%d] %s", (int) job_pid, e->cmd); + x = mkprints((u_char *)logcmd, strlen(logcmd)); + } else { + x = mkprints((u_char *)e->cmd, strlen(e->cmd)); + } + log_it(usernm, job_pid, "END", x); + free(x); + } + #if defined(USE_PAM) pam_setcred(pamh, PAM_DELETE_CRED | PAM_SILENT); retcode = pam_close_session(pamh, PAM_SILENT); Index: cron/cron.c =================================================================== --- cron.orig/cron.c +++ cron/cron.c @@ -447,9 +447,9 @@ sighup_handler(int x) { #if DEBUGGING -const char *getoptarg = "flx:"; +const char *getoptarg = "flL:x:"; #else -const char *getoptarg = "fl"; +const char *getoptarg = "flL:"; #endif static void @@ -461,6 +461,7 @@ parse_args(argc, argv) stay_foreground = 0; lsbsysinit_mode = 0; + log_level = 1; while (EOF != (argch = getopt(argc, argv, getoptarg))) { switch (argch) { @@ -472,6 +473,9 @@ parse_args(argc, argv) case 'l': lsbsysinit_mode = 1; break; + case 'L': + log_level = atoi(optarg); + break; #if DEBUGGING case 'x': if (!set_debug_flags(optarg)) Index: cron/cron.8 =================================================================== --- cron.orig/cron.8 +++ cron/cron.8 @@ -25,6 +25,8 @@ cron \- daemon to execute scheduled comm cron .RB [ \-f ] .RB [ \-l ] +.RB [ \-L +.IR loglevel ] .SH DESCRIPTION .I cron is started automatically from /etc/init.d on entering multi-user @@ -38,6 +40,27 @@ Stay in foreground mode, don't daemonize Enable LSB compliant names for /etc/cron.d files. This setting, however, does not affect the parsing of files under /etc/cron.hourly, /etc/cron.daily, /etc/cron.weekly or /etc/cron.monthly. +.TP +.B \-L loglevel +Tell cron what to log about \fBjobs\fR (errors are logged regardless of this +value) as the sum of the following values: +.br +.RS 12 +.IP \fB1\fR +will log the start of all cron jobs +.IP \fB2\fR +will log the end of all cron jobs +.IP \fB4\fR +will log all failed jobs (exit status != 0) +.IP \fB8\fR +will log the process number of all cron jobs +.RE +.IP +The default is to log the start of all jobs (1). +Logging will be disabled if +.I levels +is set to zero (0). +A value of fifteen (15) will select all options. .SH NOTES .PP .I cron @@ -271,7 +294,7 @@ daemon. This file determines whether will read the system's environment variables and makes it possible to add additional options to the .I cron -program before it is executed, for example to define how +program before it is executed, either to configure its logging or to define how it will treat the files under /etc/cron.d. .SH "SEE ALSO"