diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mcron/base.scm | 247 | ||||
| -rw-r--r-- | src/mcron/config.scm.in | 35 | ||||
| -rw-r--r-- | src/mcron/environment.scm | 97 | ||||
| -rw-r--r-- | src/mcron/job-specifier.scm | 256 | ||||
| -rw-r--r-- | src/mcron/redirect.scm | 190 | ||||
| -rw-r--r-- | src/mcron/scripts/cron.scm | 177 | ||||
| -rw-r--r-- | src/mcron/scripts/crontab.scm | 225 | ||||
| -rw-r--r-- | src/mcron/scripts/mcron.scm | 136 | ||||
| -rw-r--r-- | src/mcron/utils.scm | 116 | ||||
| -rw-r--r-- | src/mcron/vixie-specification.scm | 205 | ||||
| -rw-r--r-- | src/mcron/vixie-time.scm | 383 | ||||
| -rw-r--r-- | src/wrapper.c | 85 |
12 files changed, 2152 insertions, 0 deletions
diff --git a/src/mcron/base.scm b/src/mcron/base.scm new file mode 100644 index 0000000..c100b4f --- /dev/null +++ b/src/mcron/base.scm @@ -0,0 +1,247 @@ +;;;; base.scm -- core procedures +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> +;;; Copyright © 2016 Ludovic Courtès <ludo@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron base) + #:use-module (ice-9 match) + #:use-module (mcron environment) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-2) + #:use-module (srfi srfi-9) + #:export (add-job + remove-user-jobs + get-schedule + run-job-loop + ;; Deprecated and undocumented procedures. + use-system-job-list + use-user-job-list + clear-system-jobs) + #:re-export (clear-environment-mods + append-environment-mods)) + +;; The list of all jobs known to the system. Each element of the list is +;; +;; (make-job user next-time-function action environment displayable next-time) +;; +;; where action must be a procedure, and the environment is an alist of +;; modifications that need making to the UNIX environment before the action is +;; run. The next-time element is the only one that is modified during the +;; running of a cron process (i.e. all the others are set once and for all at +;; configuration time). +;; +;; The reason we maintain two lists is that jobs in /etc/crontab may be placed +;; in one, and all other jobs go in the other. This makes it possible to remove +;; all the jobs in the first list in one go, and separately we can remove all +;; jobs from the second list which belong to a particular user. This behaviour +;; is required for full vixie compatibility. + +(define system-job-list '()) +(define user-job-list '()) + +(define configuration-source 'user) + +(define (use-system-job-list) (set! configuration-source 'system)) +(define (use-user-job-list) (set! configuration-source 'user)) + +;; A cron job. +(define-record-type <job> + (make-job user time-proc action environment displayable next-time) + job? + (user job:user) ;object : passwd entry + (time-proc job:next-time-function) ;proc : with one 'time' parameter + (action job:action) ;thunk : user's code + (environment job:environment) ;alist : environment variables + (displayable job:displayable) ;string : visible in schedule + (next-time job:next-time ;number : time in UNIX format + job:next-time-set!)) + +;; Remove jobs from the user-job-list belonging to this user. + +(define (remove-user-jobs user) + (if (or (string? user) + (integer? user)) + (set! user (getpw user))) + (set! user-job-list + (remove (lambda (job) (eqv? (passwd:uid user) + (passwd:uid (job:user job)))) + user-job-list))) + + + +;; Remove all the jobs on the system job list. + +(define (clear-system-jobs) (set! system-job-list '())) + + + +;; Add a new job with the given specifications to the head of the appropriate +;; jobs list. + +(define (add-job time-proc action displayable configuration-time + configuration-user) + (let ((entry (make-job configuration-user + time-proc + action + (get-current-environment-mods-copy) + displayable + (time-proc configuration-time)))) + (if (eq? configuration-source 'user) + (set! user-job-list (cons entry user-job-list)) + (set! system-job-list (cons entry system-job-list))))) + +(define (find-next-jobs) + "Procedure to locate the jobs in the global job-list with the +lowest (soonest) next-times. These are the jobs for which we must schedule +the mcron program (under any personality) to next wake up. The return value +is a cons cell consisting of the next time (maintained in the next-time +variable) and a list of the job entries that are to run at this +time (maintained in the next-jobs-list variable). + +The procedure works by first obtaining the time of the first job on the list, +and setting this job in the next-jobs-list. Then for each other entry on the +job-list, either the job runs earlier than any other that have been scanned, +in which case the next-time and next-jobs-list are re-initialized to +accomodate, or the job runs at the same time as the next job, in which case +the next-jobs-list is simply augmented with the new job, or else the job runs +later than others noted in which case we ignore it for now and continue to +recurse the list." + (let loop ((jobs (append system-job-list user-job-list)) + (next-time (inf)) + (next-jobs '())) + (match jobs + (() + (cons (and (finite? next-time) next-time) next-jobs)) + ((job . rest) + (let ((this-time (job:next-time job))) + (cond ((< this-time next-time) + (loop rest this-time (list job))) + ((= this-time next-time) + (loop rest next-time (cons job next-jobs))) + (else + (loop rest next-time next-jobs)))))))) + +;; Create a string containing a textual list of the next count jobs to run. +;; +;; Enter a loop of displaying the next set of jobs to run, artificially +;; forwarding the time to the next time point (instead of waiting for it to +;; occur as we would do in a normal run of mcron), and recurse around the loop +;; count times. +;; +;; Note that this has the effect of mutating the job timings. Thus the program +;; must exit after calling this function; the internal data state will be left +;; unusable. + +(define (get-schedule count) + (with-output-to-string + (lambda () + (do ((count count (- count 1))) + ((eqv? count 0)) + (and-let* + ((next-jobs (find-next-jobs)) + (time (car next-jobs)) + (date-string (strftime "%c %z\n" (localtime time)))) + (for-each (lambda (job) + (display date-string) + (display (job:displayable job)) + (newline)(newline) + (job:next-time-set! job ((job:next-time-function job) + (job:next-time job)))) + (cdr next-jobs))))))) + + + +;; For proper housekeeping, it is necessary to keep a record of the number of +;; child processes we fork off to run the jobs. + +(define number-children 0) + + + +;; For every job on the list, fork a process to run it (noting the fact by +;; increasing the number-children counter), and in the new process set up the +;; run-time environment exactly as it should be before running the job proper. +;; +;; In the parent, update the job entry by computing the next time the job needs +;; to run. + +(define (run-jobs jobs-list) + (for-each + (lambda (job) + (if (eqv? (primitive-fork) 0) + (dynamic-wind + (const #t) + (lambda () + (setgid (passwd:gid (job:user job))) + (setuid (passwd:uid (job:user job))) + (chdir (passwd:dir (job:user job))) + (modify-environment (job:environment job) (job:user job)) + ((job:action job))) + (lambda () + (primitive-exit 0))) + (begin + (set! number-children (+ number-children 1)) + (job:next-time-set! job ((job:next-time-function job) + (current-time)))))) + jobs-list)) + + + +;; Give any zombie children a chance to die, and decrease the number known to +;; exist. + +(define (child-cleanup) + (do () ((or (<= number-children 0) + (eqv? (car (waitpid WAIT_ANY WNOHANG)) 0))) + (set! number-children (- number-children 1)))) + +(define* (run-job-loop #:optional fd-list) + ;; Loop over all job specifications, get a list of the next ones to run (may + ;; be more than one). Set an alarm and go to sleep. When we wake, run the + ;; jobs and reap any children (old jobs) that have completed. Repeat ad + ;; infinitum. + ;; + ;; Note that, if we wake ahead of time, it can only mean that a signal has + ;; been sent by a crontab job to tell us to re-read a crontab file. In this + ;; case we break out of the loop here, and let the main procedure deal with + ;; the situation (it will eventually re-call this function, thus maintaining + ;; the loop). + (call-with-current-continuation + (lambda (break) + (let loop () + (match (find-next-jobs) + ((next-time . next-jobs-lst) + (let ((sleep-time (if next-time + (- next-time (current-time)) + 2000000000))) + (when (and + (> sleep-time 0) + (not (null? (catch 'system-error + (λ () + (car (select fd-list '() '() sleep-time))) + (λ (key . args) + (let ((err (car (last args)))) + (cond ((member err (list EINTR EAGAIN)) + (child-cleanup) + '()) + (else + (apply throw key args))))))))) + (break)) + (run-jobs next-jobs-lst) + (child-cleanup) + (loop)))))))) diff --git a/src/mcron/config.scm.in b/src/mcron/config.scm.in new file mode 100644 index 0000000..2b0bc7f --- /dev/null +++ b/src/mcron/config.scm.in @@ -0,0 +1,35 @@ +;;;; config.scm -- variables defined at configure time +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron config)) + +(define-public config-debug @CONFIG_DEBUG@) +(define-public config-package-name "@PACKAGE_NAME@") +(define-public config-package-version "@PACKAGE_VERSION@") +(define-public config-package-string "@PACKAGE_STRING@") +(define-public config-package-bugreport "@PACKAGE_BUGREPORT@") +(define-public config-package-url "@PACKAGE_URL@") +(define-public config-sendmail "@SENDMAIL@") + +(define-public config-spool-dir "@CONFIG_SPOOL_DIR@") +(define-public config-socket-file "@CONFIG_SOCKET_FILE@") +(define-public config-allow-file "@CONFIG_ALLOW_FILE@") +(define-public config-deny-file "@CONFIG_DENY_FILE@") +(define-public config-pid-file "@CONFIG_PID_FILE@") +(define-public config-tmp-dir "@CONFIG_TMP_DIR@") diff --git a/src/mcron/environment.scm b/src/mcron/environment.scm new file mode 100644 index 0000000..f6b9637 --- /dev/null +++ b/src/mcron/environment.scm @@ -0,0 +1,97 @@ +;;;; environment.scm -- interact with the job process environment +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +;;;; Commentary: +;;; +;;; Define the variable current-environment-mods, and the procedures +;;; append-environment-mods (which is available to user configuration files), +;;; clear-environment-mods and modify-environment. The idea is that the +;;; current-environment-mods is a list of pairs of environment names and +;;; values, and represents the cumulated environment settings in a +;;; configuration file. When a job definition is seen in a configuration file, +;;; the current-environment-mods are copied into the internal job description, +;;; and when the job actually runs these environment modifications are applied +;;; to the UNIX environment in which the job runs. +;;; +;;;; Code: + +(define-module (mcron environment) + #:export (modify-environment + clear-environment-mods + append-environment-mods + get-current-environment-mods-copy)) + + + +;; As we parse configuration files, we build up an alist of environment +;; variables here. + +(define current-environment-mods '()) + + + +;; Each time a job is added to the system, we take a snapshot of the current +;; set of environment modifiers. + +(define (get-current-environment-mods-copy) + (list-copy current-environment-mods)) + + + +;; When we start to parse a new configuration file, we want to start with a +;; fresh environment (actually an umodified version of the pervading mcron +;; environment). + +(define (clear-environment-mods) + (set! current-environment-mods '())) + + + +;; Procedure to add another environment setting to the alist above. This is +;; used both implicitly by the Vixie parser, and can be used directly by users +;; in scheme configuration files. The return value is purely for the +;; convenience of the parse-vixie-environment in the vixie-specification module +;; (yuk). + +(define (append-environment-mods name value) + (set! current-environment-mods (append current-environment-mods + (list (cons name value)))) + #t) + +(define (modify-environment env passwd-entry) + "Modify the environment (in the UNIX sense) by setting the variables from +ENV and some default ones which are modulated by PASSWD-ENTRY. \"LOGNAME\" +and \"USER\" environment variables can't be overided by ENV. ENV must be an +alist which associate environment variables to their value. PASSWD-ENTRY must +be an object representing user information which corresponds to a valid entry +in /etc/passwd. The return value is not specified." + (for-each (lambda (pair) (setenv (car pair) (cdr pair))) + (let ((home-dir (passwd:dir passwd-entry)) + (user-name (passwd:name passwd-entry))) + (append + ;; Default environment variables which can be overided by ENV. + `(("HOME" . ,home-dir) + ("CWD" . ,home-dir) + ("SHELL" . ,(passwd:shell passwd-entry)) + ("TERM" . #f) + ("TERMCAP" . #f)) + env + ;; Environment variables with imposed values. + `(("LOGNAME" . ,user-name) + ("USER" . ,user-name)))))) diff --git a/src/mcron/job-specifier.scm b/src/mcron/job-specifier.scm new file mode 100644 index 0000000..d4c05bd --- /dev/null +++ b/src/mcron/job-specifier.scm @@ -0,0 +1,256 @@ +;;;; job-specifier.scm -- public interface for defining jobs +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +;;;; Commentary: +;;; +;;; Define all the functions that can be used by scheme Mcron configuration +;;; files, namely the procedures for working out next times, the job procedure +;;; for registering new jobs (actually a wrapper around the base add-job +;;; function), and the procedure for declaring environment modifications. +;;; +;;;; Code: + +(define-module (mcron job-specifier) + #:use-module (ice-9 match) + #:use-module (mcron base) + #:use-module (mcron environment) + #:use-module (mcron vixie-time) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-26) + #:re-export (append-environment-mods) + #:export (range + next-year-from next-year + next-month-from next-month + next-day-from next-day + next-hour-from next-hour + next-minute-from next-minute + next-second-from next-second + set-configuration-user + set-configuration-time + job)) + +(define* (range start end #:optional (step 1)) + "Produces a list of values from START up to (but not including) END. An +optional STEP may be supplied, and (if positive) only every step'th value will +go into the list. For example, (range 1 6 2) returns '(1 3 5)." + (unfold (cut >= <> end) identity (cute + <> (max step 1)) start)) + +(define (%find-best-next current next-list) + ;; Takes a value and a list of possible next values. It returns a pair + ;; consisting of the smallest element of the NEXT-LIST, and the smallest + ;; element larger than the CURRENT value. If an example of the latter + ;; cannot be found, +INF.0 will be returned. + (let loop ((smallest (inf)) (closest+ (inf)) (lst next-list)) + (match lst + (() (cons smallest closest+)) + ((time . rest) + (loop (min time smallest) + (if (> time current) (min time closest+) closest+) + rest))))) + +(define (bump-time time value-list component higher-component + set-component! set-higher-component!) + ;; Return the time corresponding to some near future hour. If hour-list is + ;; not supplied, the time returned corresponds to the start of the next hour + ;; of the day. + ;; + ;; If the hour-list is supplied the time returned corresponds to the first + ;; hour of the day in the future which is contained in the list. If all the + ;; values in the list are less than the current hour, then the time returned + ;; will correspond to the first hour in the list *on the following day*. + ;; + ;; ... except that the function is actually generalized to deal with + ;; seconds, minutes, etc., in an obvious way :-) + ;; + ;; Note that value-list always comes from an optional argument to a + ;; procedure, so is wrapped up as the first element of a list (i.e. it is a + ;; list inside a list). + (match value-list + (() + (set-component! time (1+ (component time)))) + ((val . rest) + (match (%find-best-next (component time) val) + ((smallest . closest+) + (cond ((inf? closest+) + (set-higher-component! time (1+ (higher-component time))) + (set-component! time smallest)) + (else + (set-component! time closest+))))))) + (first (mktime time))) + +;; Set of configuration methods which use the above general function to bump +;; specific components of time to the next legitimate value. In each case, all +;; the components smaller than that of interest are taken to zero, so that for +;; example the time of the next year will be the time at which the next year +;; actually starts. + +(define* (next-year-from current-time #:optional (year-list '())) + (let ((time (localtime current-time))) + (set-tm:mon time 0) + (set-tm:mday time 1) + (set-tm:hour time 0) + (set-tm:min time 0) + (set-tm:sec time 0) + (bump-time time year-list tm:year tm:year set-tm:year set-tm:year))) + +(define* (next-month-from current-time #:optional (month-list '())) + (let ((time (localtime current-time))) + (set-tm:mday time 1) + (set-tm:hour time 0) + (set-tm:min time 0) + (set-tm:sec time 0) + (bump-time time month-list tm:mon tm:year set-tm:mon set-tm:year))) + +(define* (next-day-from current-time #:optional (day-list '())) + (let ((time (localtime current-time))) + (set-tm:hour time 0) + (set-tm:min time 0) + (set-tm:sec time 0) + (bump-time time day-list tm:mday tm:mon set-tm:mday set-tm:mon))) + +(define* (next-hour-from current-time #:optional (hour-list '())) + (let ((time (localtime current-time))) + (set-tm:min time 0) + (set-tm:sec time 0) + (bump-time time hour-list tm:hour tm:mday set-tm:hour set-tm:mday))) + +(define* (next-minute-from current-time #:optional (minute-list '())) + (let ((time (localtime current-time))) + (set-tm:sec time 0) + (bump-time time minute-list tm:min tm:hour set-tm:min set-tm:hour))) + +(define* (next-second-from current-time #:optional (second-list '())) + (let ((time (localtime current-time))) + (bump-time time second-list tm:sec tm:min set-tm:sec set-tm:min))) + +;;; The following procedures are convenient for configuration files. They are +;;; wrappers for the next-X-from functions above, by implicitly using +;;; %CURRENT-ACTION-TIME as the time argument. + +(define %current-action-time + ;; The time a job was last run, the time from which the next time to run a + ;; job must be computed. (When the program is first run, this time is set to + ;; the configuration time so that jobs run from that moment forwards.) Once + ;; we have this, we supply versions of the time computation commands above + ;; which implicitly assume this value. + (make-parameter 0)) + +(define* (next-year #:optional (args '())) + "Compute the next year from %CURRENT-ACTION-TIME parameter object." + (next-year-from (%current-action-time) args)) + +(define* (next-month #:optional (args '())) + "Compute the next month from %CURRENT-ACTION-TIME parameter object." + (next-month-from (%current-action-time) args)) + +(define* (next-day #:optional (args '())) + "Compute the next day from %CURRENT-ACTION-TIME parameter object." + (next-day-from (%current-action-time) args)) + +(define* (next-hour #:optional (args '())) + "Compute the next hour from %CURRENT-ACTION-TIME parameter object." + (next-hour-from (%current-action-time) args)) + +(define* (next-minute #:optional (args '())) + "Compute the next minute from %CURRENT-ACTION-TIME parameter object." + (next-minute-from (%current-action-time) args)) + +(define* (next-second #:optional (args '())) + "Compute the next second from %CURRENT-ACTION-TIME parameter object." + (next-second-from (%current-action-time) args)) + +;; The default user for running jobs is the current one (who invoked this +;; program). There are exceptions: when cron parses /etc/crontab the user is +;; specified on each individual line; when cron parses /var/cron/tabs/* the user +;; is derived from the filename of the crontab. These cases are dealt with by +;; mutating this variable. Note that the variable is only used at configuration +;; time; a UID is stored with each job and it is that which takes effect when +;; the job actually runs. + +(define configuration-user (getpw (getuid))) +(define configuration-time (current-time)) + +(define (set-configuration-user user) + (set! configuration-user (if (or (string? user) + (integer? user)) + (getpw user) + user))) +(define (set-configuration-time time) (set! configuration-time time)) + + + +;; The job function, available to configuration files for adding a job rule to +;; the system. +;; +;; Here we must 'normalize' the next-time-function so that it is always a lambda +;; function which takes one argument (the last time the job ran) and returns a +;; single value (the next time the job should run). If the input value is a +;; string this is parsed as a Vixie-style time specification, and if it is a +;; list then we arrange to eval it (but note that such lists are expected to +;; ignore the function parameter - the last run time is always read from the +;; %CURRENT-ACTION-TIME parameter object). A similar normalization is applied to +;; the action. +;; +;; Here we also compute the first time that the job is supposed to run, by +;; finding the next legitimate time from the current configuration time (set +;; right at the top of this program). + +(define* (job time-proc action #:optional displayable + #:key (user configuration-user)) + (let ((action (cond ((procedure? action) action) + ((list? action) (lambda () (primitive-eval action))) + ((string? action) (lambda () (system action))) + (else + (throw 'mcron-error 2 + "job: invalid second argument (action; should be lambda " + "function, string or list)")))) + + (time-proc + (cond ((procedure? time-proc) time-proc) + ((string? time-proc) (parse-vixie-time time-proc)) + ((list? time-proc) (lambda (current-time) + (primitive-eval time-proc))) + (else + (throw 'mcron-error 3 + "job: invalid first argument (next-time-function; " + "should be function, string or list)")))) + (displayable + (cond (displayable displayable) + ((procedure? action) "Lambda function") + ((string? action) action) + ((list? action) (with-output-to-string + (lambda () (display action)))))) + (user* (if (or (string? user) (integer? user)) + (getpw user) + user))) + (add-job (lambda (current-time) + (parameterize ((%current-action-time current-time)) + ;; Allow for daylight savings time changes. + (let* ((next (time-proc current-time)) + (gmtoff (tm:gmtoff (localtime next))) + (d (+ next + (- gmtoff + (tm:gmtoff (localtime current-time)))))) + (if (eqv? (tm:gmtoff (localtime d)) gmtoff) + d + next)))) + action + displayable + configuration-time + user*))) diff --git a/src/mcron/redirect.scm b/src/mcron/redirect.scm new file mode 100644 index 0000000..6711407 --- /dev/null +++ b/src/mcron/redirect.scm @@ -0,0 +1,190 @@ +;;;; redirect.scm -- modify job outputs +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +;;;; Commentary: +;;; +;;; Provide the (with-mail-out action . user) procedure. This procedure runs +;;; the action in a child process, allowing the user control over the input +;;; and output (including standard error). The input is governed (only in the +;;; case of a string action) by the placing of percentage signs in the string; +;;; the first delimits the true action from the standard input, and subsequent +;;; ones denote newlines to be placed into the input. The output (if there +;;; actually is any) is controlled by the MAILTO environment variable. If +;;; this is not defined, output is e-mailed to the user passed as argument, if +;;; any, or else the owner of the action; if defined but empty then any output +;;; is sunk to /dev/null; otherwise output is e-mailed to the address held in +;;; the MAILTO variable. +;;; +;;;; Code: + +(define-module (mcron redirect) + #:use-module (ice-9 popen) + #:use-module (ice-9 regex) + #:use-module (mcron config) + #:use-module (mcron vixie-time) + #:export (with-mail-out)) + +;; An action string consists of a sequence of characters forming a command +;; executable by the shell, possibly followed by an non-escaped percentage +;; sign. The text after the percentage sign is to be fed to the command's +;; standard input, with further unescaped percents being substituted with +;; newlines. The escape character can itself be escaped. +;; +;; This regexp separates the two halves of the string, and indeed determines if +;; the second part is present. + +(define action-string-regexp (make-regexp "((\\\\%|[^%])*)%(.*)$")) + + + +;; This regexp identifies an escaped percentage sign. + +(define e-percent (make-regexp "\\\\%")) + + +;; Function to execute some action (this may be a shell command, lamdba function +;; or list of scheme procedures) in a forked process, with the input coming from +;; the string, and output (including the error output) being sent to a pipe +;; opened on a mail transport. + +(define (with-mail-out action . user) + + ;; Determine the name of the user who is to recieve the mail, looking for a + ;; name in the optional user argument, then in the MAILTO environment + ;; variable, and finally in the LOGNAME environment variable. (The case + ;; MAILTO="" is dealt with specially below.) + + (let* ((mailto (getenv "MAILTO")) + (user (cond (mailto mailto) + ((not (null? user)) (car user)) + (else (getenv "LOGNAME")))) + (parent->child (pipe)) + (child->parent (pipe)) + (child-pid (primitive-fork))) + + + ;; The child process. Close redundant ends of pipes, remap the standard + ;; streams, and run the action, taking care to chop off the input part of an + ;; action string. + + (if (eqv? child-pid 0) + (begin + (close (cdr parent->child)) + (close (car child->parent)) + + (dup2 (port->fdes (car parent->child)) 0) + (close (car parent->child)) + (dup2 (port->fdes (cdr child->parent)) 1) + (close (cdr child->parent)) + (dup2 1 2) + + (cond ((string? action) + (let ((match (regexp-exec action-string-regexp action))) + (system (if match + (let ((action (match:substring match 1))) + (do ((match (regexp-exec e-percent action) + (regexp-exec e-percent action))) + ((not match)) + (set! action (string-append + (match:prefix match) + "%" + (match:suffix match)))) + action) + action)))) + + ((procedure? action) (action)) + ((list? action) (primitive-eval action))) + + (primitive-exit 0))) + + + ;; The parent process. Get rid of redundant pipe ends. + + (close (car parent->child)) + (close (cdr child->parent)) + + + ;; Put stuff to child from after '%' in command line, replacing + ;; other %'s with newlines. Ugly or what? + + (if (string? action) + (let ((port (cdr parent->child)) + (match (regexp-exec action-string-regexp action))) + (if (and match + (match:substring match 3)) + (with-input-from-string (match:substring match 3) + (lambda () + (let loop () + (let ((next-char (read-char))) + (if (not (eof-object? next-char)) + (cond + ((char=? next-char #\%) + (newline port) + (loop)) + ((char=? next-char #\\) + (let ((escape (read-char))) + (if (eof-object? escape) + (display #\\ port) + (if (char=? escape #\%) + (begin + (display #\% port) + (loop)) + (begin + (display #\\ port) + (display escape port) + (loop)))))) + (else + (display next-char port) + (loop))))))))))) + + + ;; So the child process doesn't hang on to its input expecting more stuff. + + (close (cdr parent->child)) + + + ;; That's got streaming into the child's input out of the way, now we stream + ;; the child's output to a mail sink, but only if there is something there + ;; in the first place. + + (if (eof-object? (peek-char (car child->parent))) + + (read-char (car child->parent)) + + (begin + (set-current-output-port (if (and (string? mailto) + (string=? mailto "")) + (open-output-file "/dev/null") + (open-output-pipe + (string-append config-sendmail + " " + user)))) + (set-current-input-port (car child->parent)) + (display "To: ") (display user) (newline) + (display "From: mcron") (newline) + (display (string-append "Subject: " user "@" (gethostname))) + (newline) + (newline) + + (do ((next-char (read-char) (read-char))) + ((eof-object? next-char)) + (display next-char)))) + + (close (car child->parent)) + + (waitpid child-pid))) diff --git a/src/mcron/scripts/cron.scm b/src/mcron/scripts/cron.scm new file mode 100644 index 0000000..d043d79 --- /dev/null +++ b/src/mcron/scripts/cron.scm @@ -0,0 +1,177 @@ +;;;; cron -- daemon for running jobs at scheduled times +;;; Copyright © 2003, 2012 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron scripts cron) + #:use-module (mcron base) + #:use-module (mcron config) + #:use-module (mcron job-specifier) + #:use-module (mcron utils) + #:use-module (mcron vixie-specification) + #:use-module (srfi srfi-2) + #:export (main)) + +(define (show-help) + (display "Usage: cron [OPTIONS] +Unless an option is specified, run a cron daemon as a detached process, +reading all the information in the users' crontabs and in /etc/crontab. + + -v, --version Display version + -h, --help Display this help message + -sN, --schedule[=]N Display the next N jobs that will be run by cron + -n, --noetc Do not check /etc/crontab for updates (HIGHLY + RECOMMENDED).") + (newline) + (show-package-information)) + +(define %options + `((schedule (single-char #\s) (value #t) + (predicate ,(λ (str) (string->number str)))) + (noetc (single-char #\n) (value #f)) + (version (single-char #\v) (value #f)) + (help (single-char #\h) (value #f)))) + +(define (delete-run-file) + "Remove the /var/run/cron.pid file so that crontab and other invocations of +cron don't get the wrong idea that a daemon is currently running. This +procedure is called from the C front-end whenever a terminal signal is +received." + (catch #t + (λ () + (delete-file config-pid-file) + (delete-file config-socket-file)) + noop) + (quit)) + +(define (cron-file-descriptors) + "Establish a socket to listen for updates from a crontab program, and return +a list containing the file descriptors correponding to the files read by +crontab. This requires that command-type is 'cron." + (catch #t + (λ () + (let ((sock (socket AF_UNIX SOCK_STREAM 0))) + (bind sock AF_UNIX config-socket-file) + (listen sock 5) + (list sock))) + (λ (key . args) + (delete-file config-pid-file) + (mcron-error 1 "Cannot bind to UNIX socket " config-socket-file)))) + +(define (process-files-in-system-directory) + "Process all the files in the crontab directory. When the job procedure is +run on behalf of the configuration files, the jobs are registered on the +system with the appropriate user. Only root should be able to perform this +operation. The permissions on the /var/cron/tabs directory enforce this." + + (define (user-entry name) + ;; Return the user database entry if NAME is valid, otherwise #f. + (false-if-exception (getpwnam name))) + + (catch #t + (λ () + (for-each-file + (λ (user) + (and-let* ((entry (user-entry user))) ;crontab without user? + (set-configuration-user entry) + (catch-mcron-error + (read-vixie-file (string-append config-spool-dir "/" user))))) + config-spool-dir)) + (λ (key . args) + (mcron-error 4 + "You do not have permission to access the system crontabs.")))) + +(define (%process-files schedule? noetc?) + ;; XXX: What is this supposed to do? + (when schedule? + (with-output-to-file config-pid-file noop)) + ;; Clear MAILTO so that outputs are sent to the various users. + (setenv "MAILTO" #f) + ;; XXX: At compile time, this yields a "possibly unbound variable" warning, + ;; but this is OK since it is bound in the C wrapper. + (c-set-cron-signals) + ;; Having defined all the necessary procedures for scanning various sets of + ;; files, we perform the actual configuration of the program depending on + ;; the personality we are running as. If it is mcron, we either scan the + ;; files passed on the command line, or else all the ones in the user's + ;; .config/cron (or .cron) directory. If we are running under the cron + ;; personality, we read the /var/cron/tabs directory and also the + ;; /etc/crontab file. + (process-files-in-system-directory) + (use-system-job-list) + (catch-mcron-error + (read-vixie-file "/etc/crontab" parse-system-vixie-line)) + (use-user-job-list) + (unless noetc? + (display "\ +WARNING: cron will check for updates to /etc/crontab EVERY MINUTE. If you do +not use this file, or you are prepared to manually restart cron whenever you +make a change, then it is HIGHLY RECOMMENDED that you use the --noetc +option.\n") + (set-configuration-user "root") + (job '(- (next-minute-from (next-minute)) 6) + check-system-crontab + "/etc/crontab update checker."))) + + +;;; +;;; Entry point. +;;; + +(define* (main #:optional (args (command-line))) + (let ((opts (parse-args args %options))) + (when config-debug + (debug-enable 'backtrace)) + (cond + ((option-ref opts 'help #f) + (show-help) + (exit 0)) + ((option-ref opts 'version #f) + (show-version "cron") + (exit 0)) + ((not (zero? (getuid))) + (mcron-error 16 + "This program must be run by the root user (and should" + " have been installed as such).")) + ((access? config-pid-file F_OK) + (mcron-error 1 + "A cron daemon is already running.\n (If you are sure" + " this is not true, remove the file\n " + config-pid-file ".)")) + (else + (%process-files (option-ref opts 'schedule #f) + (option-ref opts 'noetc #f)) + (cond ((option-ref opts 'schedule #f) ;display jobs schedule + => (λ (count) + (display (get-schedule (max 1 (string->number count)))) + (exit 0))) + (else (case (primitive-fork) ;run the daemon + ((0) + (setsid) + ;; we can now write the PID file. + (with-output-to-file config-pid-file + (λ () (display (getpid)) (newline)))) + (else (exit 0))))) + ;; Forever execute the 'run-job-loop', and when it drops out (can + ;; only be because a message has come in on the socket) we + ;; process the socket request before restarting the loop again. + (catch-mcron-error + (let ((fdes-list (cron-file-descriptors))) + (while #t + (run-job-loop fdes-list) + (unless (null? fdes-list) + (process-update-request fdes-list))))))))) diff --git a/src/mcron/scripts/crontab.scm b/src/mcron/scripts/crontab.scm new file mode 100644 index 0000000..502fec6 --- /dev/null +++ b/src/mcron/scripts/crontab.scm @@ -0,0 +1,225 @@ +;;;; crontab -- edit user's cron tabs +;;; Copyright © 2003, 2004 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron scripts crontab) + #:use-module (ice-9 rdelim) + #:use-module (mcron config) + #:use-module (mcron utils) + #:use-module (mcron vixie-specification) + #:export (main)) + +(define* (show-help) + (display "Usage: crontab [-u user] file + crontab [-u user] { -e | -l | -r } + (default operation is replace, per 1003.2) + -e (edit user's crontab) + -l (list user's crontab) + -r (delete user's crontab") + (newline) + (show-package-information)) + +(define %options + '((user (single-char #\u) (value #t)) + (edit (single-char #\e) (value #f)) + (list (single-char #\l) (value #f)) + (remove (single-char #\r) (value #f)) + (version (single-char #\v) (value #f)) + (help (single-char #\h) (value #f)))) + + +;;; +;;; Entry point. +;;; + +(define* (main #:optional (args (command-line))) + (let ((opts (parse-args args %options))) + (when config-debug + (debug-enable 'backtrace)) + (cond ((option-ref opts 'help #f) + (show-help) + (exit 0)) + ((option-ref opts 'version #f) + (show-version "crontab") + (exit 0))) + (let ((hit-server + (λ (user-name) + ;; Procedure to communicate with running cron daemon that a user + ;; has modified his crontab. The user name is written to the + ;; /var/cron/socket UNIX socket. + (catch #t + (λ () + (let ((socket (socket AF_UNIX SOCK_STREAM 0))) + (connect socket AF_UNIX config-socket-file) + (display user-name socket) + (close socket))) + (λ (key . args) + (display "Warning: a cron daemon is not running.\n"))))) + + ;; Procedure to scan a file containing one user name per line (such + ;; as /var/cron/allow and /var/cron/deny), and determine if the + ;; given name is in there. The procedure returns #t, #f, or '() if + ;; the file does not exist. + (in-access-file? + (λ (file name) + (catch #t + (λ () + (with-input-from-file file + (λ () + (let loop ((input (read-line))) + (if (eof-object? input) + #f + (if (string=? input name) + #t + (loop (read-line)))))))) + (λ (key . args) '())))) + + ;; This program should have been installed SUID root. Here we get + ;; the passwd entry for the real user who is running this program. + (crontab-real-user (passwd:name (getpw (getuid))))) + + ;; If the real user is not allowed to use crontab due to the + ;; /var/cron/allow and/or /var/cron/deny files, bomb out now. + (if (or (eq? (in-access-file? config-allow-file crontab-real-user) #f) + (eq? (in-access-file? config-deny-file crontab-real-user) #t)) + (mcron-error 6 "Access denied by system operator.")) + + ;; Check that no more than one of the mutually exclusive options are + ;; being used. + (when (> (+ (if (option-ref opts 'edit #f) 1 0) + (if (option-ref opts 'list #f) 1 0) + (if (option-ref opts 'remove #f) 1 0)) + 1) + (mcron-error 7 "Only one of options -e, -l or -r can be used.")) + + ;; Check that a non-root user is trying to read someone else's files. + (when (and (not (zero? (getuid))) + (option-ref opts 'user #f)) + (mcron-error 8 "Only root can use the -u option.")) + + (letrec* (;; Iff the --user option is given, the crontab-user may be + ;; different from the real user. + (crontab-user (option-ref opts 'user crontab-real-user)) + ;; So now we know which crontab file we will be manipulating. + (crontab-file (string-append config-spool-dir "/" crontab-user)) + ;; Display the prompt and wait for user to type his + ;; choice. Return #t if the answer begins with 'y' or 'Y', + ;; return #f if it begins with 'n' or 'N', otherwise ask + ;; again. + (get-yes-no (λ (prompt . re-prompt) + (if (not (null? re-prompt)) + (display "Please answer y or n.\n")) + (display (string-append prompt " ")) + (let ((r (read-line))) + (if (not (string-null? r)) + (case (string-ref r 0) + ((#\y #\Y) #t) + ((#\n #\N) #f) + (else (get-yes-no prompt #t))) + (get-yes-no prompt #t)))))) + ;; There are four possible sub-personalities to the crontab + ;; personality: list, remove, edit and replace (when the user uses no + ;; options but supplies file names on the command line). + (cond + ;; In the list personality, we simply open the crontab and copy it + ;; character-by-character to the standard output. If anything goes + ;; wrong, it can only mean that this user does not have a crontab + ;; file. + ((option-ref opts 'list #f) + (catch #t + (λ () + (with-input-from-file crontab-file + (λ () + (do ((input (read-char) (read-char))) + ((eof-object? input)) + (display input))))) + (λ (key . args) + (display (string-append "No crontab for " + crontab-user + " exists.\n"))))) + + ;; In the edit personality, we determine the name of a temporary file + ;; and an editor command, copy an existing crontab file (if it is + ;; there) to the temporary file, making sure the ownership is set so + ;; the real user can edit it; once the editor returns we try to read + ;; the file to check that it is parseable (but do nothing more with + ;; the configuration), and if it is okay (this program is still + ;; running!) we move the temporary file to the real crontab, wake the + ;; cron daemon up, and remove the temporary file. If the parse fails, + ;; we give user a choice of editing the file again or quitting the + ;; program and losing all changes made. + ((option-ref opts 'edit #f) + (let ((temp-file (string-append config-tmp-dir + "/crontab." + (number->string (getpid))))) + (catch #t + (λ () (copy-file crontab-file temp-file)) + (λ (key . args) (with-output-to-file temp-file noop))) + (chown temp-file (getuid) (getgid)) + (let retry () + (system (string-append + (or (getenv "VISUAL") (getenv "EDITOR") "vi") + " " + temp-file)) + (catch 'mcron-error + (λ () (read-vixie-file temp-file)) + (λ (key exit-code . msg) + (apply mcron-error 0 msg) + (if (get-yes-no "Edit again?") + (retry) + (begin + (mcron-error 0 "Crontab not changed") + (primitive-exit 0)))))) + (copy-file temp-file crontab-file) + (delete-file temp-file) + (hit-server crontab-user))) + + ;; In the remove personality we simply make an effort to delete the + ;; crontab and wake the daemon. No worries if this fails. + ((option-ref opts 'remove #f) + (catch #t + (λ () + (delete-file crontab-file) + (hit-server crontab-user)) + noop)) + + ;; XXX: This comment is wrong. + ;; In the case of the replace personality we loop over all the + ;; arguments on the command line, and for each one parse the file to + ;; make sure it is parseable (but subsequently ignore the + ;; configuration), and all being well we copy it to the crontab + ;; location; we deal with the standard input in the same way but + ;; different. :-) In either case the server is woken so that it will + ;; read the newly installed crontab. + ((not (null? (option-ref opts '() '()))) + (let ((input-file (car (option-ref opts '() '())))) + (catch-mcron-error + (if (string=? input-file "-") + (let ((input-string (read-string))) + (read-vixie-port (open-input-string input-string)) + (with-output-to-file crontab-file + (λ () (display input-string)))) + (begin + (read-vixie-file input-file) + (copy-file input-file crontab-file)))) + (hit-server crontab-user))) + + ;; The user is being silly. The message here is identical to the one + ;; Vixie cron used to put out, for total compatibility. + (else (mcron-error 15 + "usage error: file name must be specified for replace."))))))) diff --git a/src/mcron/scripts/mcron.scm b/src/mcron/scripts/mcron.scm new file mode 100644 index 0000000..b6c7729 --- /dev/null +++ b/src/mcron/scripts/mcron.scm @@ -0,0 +1,136 @@ +;;;; mcron -- run jobs at scheduled times +;;; Copyright © 2003, 2012 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron scripts mcron) + #:use-module (mcron base) + #:use-module (mcron config) + #:use-module (mcron job-specifier) ;for user/system files + #:use-module (mcron utils) + #:use-module (mcron vixie-specification) + #:export (main)) + +(define (show-help) + (display "Usage: mcron [OPTIONS] [FILES] +Run an mcron process according to the specifications in the FILES (`-' for +standard input), or use all the files in ~/.config/cron (or the +deprecated ~/.cron) with .guile or .vixie extensions. + + -v, --version Display version + -h, --help Display this help message + -sN, --schedule[=]N Display the next N jobs that will be run by mcron + -d, --daemon Immediately detach the program from the terminal + and run as a daemon process + -i, --stdin=(guile|vixie) Format of data passed as standard input or + file arguments (default guile)") + (newline) + (show-package-information)) + +(define %options + `((schedule (single-char #\s) (value #t) + (predicate ,(λ (str) (string->number str)))) + (daemon (single-char #\d) (value #f)) + (noetc (single-char #\n) (value #f)) + (stdin (single-char #\i) (value #t) + (predicate ,(λ (val) + (or (string=? val "guile") + (string=? val "vixie"))))) + (version (single-char #\v) (value #f)) + (help (single-char #\h) (value #f)))) + +(define process-user-file + (let ((guile-regexp (make-regexp "\\.gui(le)?$")) + (vixie-regexp (make-regexp "\\.vix(ie)?$"))) + (lambda* (file-name #:optional guile-syntax? #:key (input "guile")) + "Process FILE-NAME according its extension. When GUILE-SYNTAX? is TRUE, +force guile syntax usage. If FILE-NAME format is not recognized, it is +silently ignored." + (cond ((string=? "-" file-name) + (if (string=? input "vixie") + (read-vixie-port (current-input-port)) + (eval-string (read-string)))) + ((or guile-syntax? (regexp-exec guile-regexp file-name)) + (load file-name)) + ((regexp-exec vixie-regexp file-name) + (read-vixie-file file-name)))))) + +(define (process-files-in-user-directory input-type) + "Process files in $XDG_CONFIG_HOME/cron and/or ~/.cron directories (if +$XDG_CONFIG_HOME is not defined uses ~/.config/cron instead)." + (let ((errors 0) + (home-directory (passwd:dir (getpw (getuid))))) + (map (λ (dir) + (catch #t + (λ () + (for-each-file + (λ (file) + (process-user-file (string-append dir "/" file) + #:input input-type)) + dir)) + (λ (key . args) + (set! errors (1+ errors))))) + (list (string-append home-directory "/.cron") + (string-append (or (getenv "XDG_CONFIG_HOME") + (string-append home-directory "/.config")) + "/cron"))) + (when (eq? 2 errors) + (mcron-error 13 + "Cannot read files in your ~/.config/cron (or ~/.cron) directory.")))) + +(define (%process-files files input-type) + (if (null? files) + (process-files-in-user-directory input-type) + (for-each (λ (file) (process-user-file file #t)) files))) + + +;;; +;;; Entry point. +;;; + +(define* (main #:optional (args (command-line))) + (let ((opts (parse-args args %options))) + (when config-debug + (debug-enable 'backtrace)) + (cond ((option-ref opts 'help #f) + (show-help) + (exit 0)) + ((option-ref opts 'version #f) + (show-version "mcron") + (exit 0)) + (else + (%process-files (option-ref opts '() '()) + (option-ref opts 'stdin "guile")) + (cond ((option-ref opts 'schedule #f) ;display jobs schedule + => (λ (count) + (display (get-schedule (max 1 (string->number count)))) + (exit 0))) + ((option-ref opts 'daemon #f) ;run mcron as a daemon + (case (primitive-fork) + ((0) (setsid)) + (else (exit 0))))) + ;; Forever execute the 'run-job-loop', and when it drops out (can + ;; only be because a message has come in on the socket) we process + ;; the socket request before restarting the loop again. + (catch-mcron-error + (let ((fdes-list '())) + (while #t + (run-job-loop fdes-list) + ;; we can also drop out of run-job-loop because of a SIGCHLD, + ;; so must test FDES-LIST. + (unless (null? fdes-list) + (process-update-request fdes-list))))))))) diff --git a/src/mcron/utils.scm b/src/mcron/utils.scm new file mode 100644 index 0000000..062e756 --- /dev/null +++ b/src/mcron/utils.scm @@ -0,0 +1,116 @@ +;;;; utils.scm -- helper procedures +;;; Copyright © 2003, 2012 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron utils) + #:use-module (ice-9 getopt-long) + #:use-module (ice-9 rdelim) + #:use-module (mcron config) + #:use-module (mcron base) + #:use-module (mcron job-specifier) + #:use-module (mcron vixie-specification) + #:export (catch-mcron-error + mcron-error + parse-args + show-version + show-package-information + for-each-file + process-update-request) + #:re-export (option-ref + read-string)) + +(define (mcron-error exit-code . rest) + "Print an error message (made up from the parts of REST), and if the +EXIT-CODE error is fatal (present and non-zero) then exit to the system with +EXIT-CODE." + (with-output-to-port (current-error-port) + (lambda () + (for-each display (cons "mcron: " rest)) + (newline))) + (when (and exit-code (not (eq? exit-code 0))) + (primitive-exit exit-code))) + +(define-syntax-rule (catch-mcron-error exp ...) + "Evaluate EXP .... if an 'mcron-error exception occurs, print its diagnostics +and exit with its error code." + (catch 'mcron-error + (lambda () exp ...) + (lambda (key exit-code . msg) + (apply mcron-error exit-code msg)))) + +(define (parse-args args option-desc-list) + "Parse ARGS with OPTION-DESC-LIST specification." + (catch 'misc-error + (lambda () (getopt-long args option-desc-list)) + (lambda (key func fmt args . rest) + (mcron-error 1 (apply format (append (list #f fmt) args)))))) + +(define (show-version command) + "Display version information for COMMAND and quit." + (let* ((name config-package-name) + (short-name (cadr (string-split name #\space))) + (version config-package-version)) + (simple-format #t "~a (~a) ~a +Copyright (C) 2015 the ~a authors. +License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> +This is free software: you are free to change and redistribute it. +There is NO WARRANTY, to the extent permitted by law.\n" + command name version short-name))) + +(define (show-package-information) + "Display where to get help and send bug reports." + (simple-format #t "\nReport bugs to: ~a. +~a home page: <~a> +General help using GNU software: <http://www.gnu.org/gethelp/>\n" + config-package-bugreport + config-package-name + config-package-url)) + +(define (for-each-file proc directory) + "Apply PROC to each file in DIRECTORY. DIRECTORY must be a valid directory name. +PROC must be a procedure that take one file name argument. The return value +is not specified" + (let ((dir (opendir directory))) + (let loop ((file-name (readdir dir))) + (if (eof-object? file-name) + (closedir dir) + (begin + (proc file-name) + (loop (readdir dir))))))) + +(define (process-update-request fdes-list) + "Read a user name from the socket, dealing with the /etc/crontab special +case, remove all the user's jobs from the job list, and then re-read the +user's updated file. In the special case drop all the system jobs and re-read +the /etc/crontab file. This function should be called whenever a message +comes in on the above socket." + (let* ((sock (car (accept (car fdes-list)))) + (user-name (read-line sock))) + (close sock) + (set-configuration-time (current-time)) + (catch-mcron-error + (if (string=? user-name "/etc/crontab") + (begin + (clear-system-jobs) + (use-system-job-list) + (read-vixie-file "/etc/crontab" parse-system-vixie-line) + (use-user-job-list)) + (let ((user (getpw user-name))) + (remove-user-jobs user) + (set-configuration-user user) + (read-vixie-file (string-append config-spool-dir "/" user-name))))))) diff --git a/src/mcron/vixie-specification.scm b/src/mcron/vixie-specification.scm new file mode 100644 index 0000000..cf2679a --- /dev/null +++ b/src/mcron/vixie-specification.scm @@ -0,0 +1,205 @@ +;;;; vixie-specification.scm -- read Vixie-sytle configuration file +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +;;;; Commentary: +;;; +;;; Methods for reading a complete Vixie-style configuration file, either from +;;; a real file or an already opened port. It also exposes the method for +;;; parsing the time-specification part of a Vixie string, so that these can +;;; be used to form the next-time-function of a job in a Guile configuration +;;; file. +;;; +;;;; Code: + +(define-module (mcron vixie-specification) + #:use-module (ice-9 regex) + #:use-module (ice-9 rdelim) + #:use-module (mcron base) + #:use-module (mcron config) + #:use-module (mcron job-specifier) + #:use-module (mcron redirect) + #:use-module (mcron vixie-time) + #:use-module (srfi srfi-1) + #:export (parse-user-vixie-line + parse-system-vixie-line + read-vixie-port + read-vixie-file + check-system-crontab)) + +;; A line in a Vixie-style crontab file which gives a command specification +;; carries two pieces of information: a time specification consisting of five +;; space-separated items, and a command which is also separated from the time +;; specification by a space. The line is broken into the two components, and the +;; job procedure run to add the two pieces of information to the job list (this +;; will in turn use the above function to turn the time specification into a +;; function for computing future run times of the command). + +(define parse-user-vixie-line-regexp + (make-regexp "^[[:space:]]*(([^[:space:]]+[[:space:]]+){5})(.*)$")) + +(define (parse-user-vixie-line line) + (let ((match (regexp-exec parse-user-vixie-line-regexp line))) + (if (not match) + (throw 'mcron-error 10 "Bad job line in Vixie file.")) + (job (match:substring match 1) + (lambda () (with-mail-out (match:substring match 3))) + (match:substring match 3)))) + + + +;; The case of reading a line from /etc/crontab is similar to above but the user +;; ID appears in the sixth field, before the action. + +(define parse-system-vixie-line-regexp + (make-regexp (string-append "^[[:space:]]*(([^[:space:]]+[[:space:]]+){5})" + "([[:alpha:]][[:alnum:]_]*)[[:space:]]+(.*)$"))) + +(define (parse-system-vixie-line line) + (let ((match (regexp-exec parse-system-vixie-line-regexp line))) + (if (not match) + (throw 'mcron-error 11 "Bad job line in /etc/crontab.")) + (let ((user (match:substring match 3))) + (set-configuration-user user) + (job (match:substring match 1) + (lambda () (with-mail-out (match:substring match 4) + user)) + (match:substring match 4))))) + + + +;; Procedure to act on an environment variable specification in a Vixie-style +;; configuration file, by adding an entry to the alist above. Returns #t if the +;; operation was successful, #f if the line could not be interpreted as an +;; environment specification. + +(define parse-vixie-environment-regexp1 + (make-regexp + "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*\"(.*)\"[ \t]*$")) +(define parse-vixie-environment-regexp2 + (make-regexp + "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*'(.*)'[ \t]*$")) +(define parse-vixie-environment-regexp3 + (make-regexp + "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*(.*[^ \t])[ \t]*$")) +(define parse-vixie-environment-regexp4 + (make-regexp + "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*$")) + + +(define (parse-vixie-environment string) + (let ((match (or (regexp-exec parse-vixie-environment-regexp1 string) + (regexp-exec parse-vixie-environment-regexp2 string) + (regexp-exec parse-vixie-environment-regexp3 string)))) + (if match + (append-environment-mods (match:substring match 1) + (match:substring match 2)) + (and=> (regexp-exec parse-vixie-environment-regexp4 string) + (λ (match) + (append-environment-mods (match:substring match 1) #f)))))) + +;; The next procedure reads an entire Vixie-style file. For each line in the +;; file there are three possibilities (after continuation lines have been +;; appended): the line is blank or contains only a comment, the line contains an +;; environment modifier which will be handled in the mcron environment module, +;; or the line contains a command specification in which case we use the +;; procedure above to add an entry to the internal job list. +;; +;; Note that the environment modifications are cleared, so that there is no +;; interference between crontab files (this might lead to unpredictable +;; behaviour because the order in which crontab files are processed, if there is +;; more than one, is generally undefined). + +(define read-vixie-file-comment-regexp + (make-regexp "^[[:space:]]*(#.*)?$")) + + +(define (read-vixie-port port . parse-vixie-line) + (clear-environment-mods) + (if port + (let ((parse-vixie-line + (if (null? parse-vixie-line) parse-user-vixie-line + (car parse-vixie-line)))) + (do ((line (read-line port) (read-line port)) + (line-number 1 (1+ line-number))) + ((eof-object? line)) + + (let ((report-line line-number)) + ;; If the line ends with \, append the next line. + (while (and (>= (string-length line) 1) + (char=? (string-ref line + (- (string-length line) 1)) + #\\)) + (let ((next-line (read-line port))) + (if (eof-object? next-line) + (set! next-line "")) + (set! line-number (1+ line-number)) + (set! line + (string-append + (substring line 0 (- (string-length line) 1)) + next-line)))) + + (catch 'mcron-error + (lambda () + ;; Consider the three cases mentioned in the description. + (or (regexp-exec read-vixie-file-comment-regexp line) + (parse-vixie-environment line) + (parse-vixie-line line))) + (lambda (key exit-code . msg) + (throw 'mcron-error exit-code + (apply string-append + (number->string report-line) + ": " + msg))))))))) + + + +;; If a file cannot be opened, we must silently ignore it because it may have +;; been removed by crontab. However, if the file is there it must be parseable, +;; otherwise the error must be propagated to the caller. + +(define (read-vixie-file file-path . parse-vixie-line) + (let ((port #f)) + (catch #t (lambda () (set! port (open-input-file file-path))) + (lambda (key . args) (set! port #f))) + (if port + (catch 'mcron-error + (lambda () + (if (null? parse-vixie-line) + (read-vixie-port port) + (read-vixie-port port (car parse-vixie-line))) + (close port)) + (lambda (key exit-code . msg) + (close port) + (throw 'mcron-error exit-code + (apply string-append file-path ":" msg))))))) + + +;; A procedure which determines if the /etc/crontab file has been recently +;; modified, and, if so, signals the main routine to re-read the file. We run +;; under the with-mail-to command so that the process runs as a child, +;; preventing lockup. If cron is supposed to check for updates to /etc/crontab, +;; then this procedure will be called about 5 seconds before every minute. + +(define (check-system-crontab) + (with-mail-out (lambda () + (let ((mtime (stat:mtime (stat "/etc/crontab")))) + (if (> mtime (- (current-time) 60)) + (let ((socket (socket AF_UNIX SOCK_STREAM 0))) + (connect socket AF_UNIX config-socket-file) + (display "/etc/crontab" socket) + (close socket))))))) diff --git a/src/mcron/vixie-time.scm b/src/mcron/vixie-time.scm new file mode 100644 index 0000000..c4d6bd9 --- /dev/null +++ b/src/mcron/vixie-time.scm @@ -0,0 +1,383 @@ +;;;; vixie-time.scm -- parse Vixie-style times +;;; Copyright © 2003 Dale Mellor <dale_mellor@users.sourceforge.net> +;;; +;;; This file is part of GNU Mcron. +;;; +;;; GNU Mcron is free software: you can redistribute it and/or modify +;;; it under the terms of the GNU General Public License as published by +;;; the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; GNU Mcron is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. + +(define-module (mcron vixie-time) + #:use-module (ice-9 regex) + #:use-module (mcron job-specifier) + #:use-module (srfi srfi-1) + #:export (parse-vixie-time)) + +;; In Vixie-style time specifications three-letter symbols are allowed to stand +;; for the numbers corresponding to months and days of the week. We deal with +;; this by making a textual substitution early on in the processing of the +;; strings. +;; +;; We start by defining, once and for all, a list of cons cells consisting of +;; regexps which will match the symbols - which allow an arbitrary number of +;; other letters to appear after them (so that the user can optionally complete +;; the month and day names; this is an extension of Vixie) - and the value which +;; is to replace the symbol. +;; +;; The procedure then takes a string, and then for each symbol in the +;; parse-symbols list attempts to locate an instance and replace it with an +;; ASCII representation of the value it stands for. The procedure returns the +;; modified string. (Note that each symbol can appear only once, which meets the +;; Vixie specifications technically but still allows silly users to mess things +;; up). + +(define parse-symbols + (map (lambda (symbol-cell) + (cons (make-regexp (string-append (car symbol-cell) "[[:alpha:]]*") + regexp/icase) + (cdr symbol-cell))) + '(("jan" . "0") ("feb" . "1") ("mar" . "2") ("apr" . "3") + ("may" . "4") ("jun" . "5") ("jul" . "6") ("aug" . "7") + ("sep" . "8") ("oct" . "9") ("nov" . "10") ("dec" . "11") + + ("sun" . "0") ("mon" . "1") ("tue" . "2") ("wed" . "3") + ("thu" . "4") ("fri" . "5") ("sat" . "6") ))) + +(define (vixie-substitute-parse-symbols string) + (for-each (lambda (symbol-cell) + (let ((match (regexp-exec (car symbol-cell) string))) + (if match + (set! string (string-append (match:prefix match) + (cdr symbol-cell) + (match:suffix match)))))) + parse-symbols) + string) + + + +;; A Vixie time specification is made up of a space-separated list of elements, +;; and the elements consist of a comma-separated list of subelements. The +;; procedure below takes a string holding a subelement, which should have no +;; spaces or symbols (see above) in it, and returns a list of all values which +;; that subelement indicates. There are five distinct cases which must be dealt +;; with: [1] a single '*' which returns a list of all values; [2] a '*' followed +;; by a step specifier; [3] a range and step specifier; [4] a range; and [5] a +;; single number. +;; +;; To perform the computation required for the '*' cases, we need to pass the +;; limit of the allowable range for this subelement as the third argument. As +;; days of the month start at 1 while all the other time components start at 0, +;; we must pass the base of the range to deal with this case also. + +(define parse-vixie-subelement-regexp + (make-regexp "^([[:digit:]]+)(-([[:digit:]]+)(/([[:digit:]]+))?)?$")) + +(define (parse-vixie-subelement string base limit) + (if (char=? (string-ref string 0) #\*) + (range base limit (if (> (string-length string) 1) + (string->number (substring string 2)) ;; [2] + 1)) ;; [1] + (let ((match (regexp-exec parse-vixie-subelement-regexp string))) + (cond ((not match) + (throw 'mcron-error 9 + "Bad Vixie-style time specification.")) + ((match:substring match 5) + (range (string->number (match:substring match 1)) + (+ 1 (string->number (match:substring match 3))) + (string->number (match:substring match 5)))) ;; [3] + ((match:substring match 3) + (range (string->number (match:substring match 1)) + (+ 1 (string->number (match:substring match 3))))) ;; [4] + (else + (list (string->number (match:substring match 1)))))))) ;; [5] + + + +;; A Vixie element contains the entire specification, without spaces or symbols, +;; of the acceptable values for one of the time components (minutes, hours, +;; days, months, week days). Here we break the comma-separated list into +;; subelements, and process each with the procedure above. The return value is a +;; list of all the valid values of all the subcomponents. +;; +;; The second and third arguments are the base and upper limit on the values +;; that can be accepted for this time element. +;; +;; The effect of the 'apply append' is to merge a list of lists into a single +;; list. + +(define (parse-vixie-element string base limit) + (apply append + (map (lambda (sub-element) + (parse-vixie-subelement sub-element base limit)) + (string-tokenize string (char-set-complement (char-set #\,)))))) + + + +;; Consider there are two lists, one of days in the month, the other of days in +;; the week. This procedure returns an augmented list of days in the month with +;; weekdays accounted for. + +(define (interpolate-weekdays mday-list wday-list month year) + (let ((t (localtime 0))) + (set-tm:mday t 1) + (set-tm:mon t month) + (set-tm:year t year) + (let ((first-day (tm:wday (cdr (mktime t))))) + (apply append + mday-list + (map (lambda (wday) + (let ((first (- wday first-day))) + (if (< first 0) (set! first (+ first 7))) + (range (+ 1 first) 32 7))) + wday-list))))) + + + +;; Return the number of days in a month. Fix up a tm object for the zero'th day +;; of the next month, rationalize the object and extract the day. + +(define (days-in-month month year) + (let ((t (localtime 0))) (set-tm:mday t 0) + (set-tm:mon t (+ month 1)) + (set-tm:year t year) + (tm:mday (cdr (mktime t))))) + + + +;; We will be working with a list of time-spec's, one for each element of a time +;; specification (minute, hour, ...). Each time-spec holds three pieces of +;; information: a list of acceptable values for this time component, a procedure +;; to get the component from a tm object, and a procedure to set the component +;; in a tm object. + +(define (time-spec:list time-spec) (vector-ref time-spec 0)) +(define (time-spec:getter time-spec) (vector-ref time-spec 1)) +(define (time-spec:setter time-spec) (vector-ref time-spec 2)) + + + +;; This procedure modifies the time tm object by setting the component referred +;; to by the time-spec object to its next acceptable value. If this value is not +;; greater than the original (because we have wrapped around the top of the +;; acceptable values list), then the function returns #t, otherwise it returns +;; #f. Thus, if the return value is true then it will be necessary for the +;; caller to increment the next coarser time component as well. +;; +;; The first part of the let block is a concession to humanity; the procedure is +;; simply unreadable without all of these aliases. + +(define (increment-time-component time time-spec) + (let* ((time-list (time-spec:list time-spec)) + (getter (time-spec:getter time-spec)) + (setter (time-spec:setter time-spec)) + (find-best-next (@@ (mcron job-specifier) %find-best-next)) + (next-best (find-best-next (getter time) time-list)) + (wrap-around (eqv? (cdr next-best) 9999))) + (setter time ((if wrap-around car cdr) next-best)) + wrap-around)) + + + +;; There now follows a set of procedures for adjusting an element of time, +;; i.e. taking it to the next acceptable value. In each case, the head of the +;; time-spec-list is expected to correspond to the component of time in +;; question. If the adjusted value wraps around its allowed range, then the next +;; biggest element of time must be adjusted, and so on. + +;; There is no specification allowed for the year component of +;; time. Therefore, if we have to make an adjustment (presumably because a +;; monthly adjustment has wrapped around the top of its range) we can simply +;; go to the next year. + +(define (nudge-year! time) + (set-tm:year time (+ (tm:year time) 1))) + + +;; We nudge the month by finding the next allowable value, and if it wraps +;; around we also nudge the year. The time-spec-list will have time-spec +;; objects for month and weekday. + +(define (nudge-month! time time-spec-list) + (and (increment-time-component time (car time-spec-list)) + (nudge-year! time))) + + +;; Try to increment the day component of the time according to the combination +;; of the mday-list and the wday-list. If this wraps around the range, or if +;; this falls outside the current month (31st February, for example), then +;; bump the month, set the day to zero, and recurse on this procedure to find +;; the next day in the new month. +;; +;; The time-spec-list will have time-spec entries for mday, month, and +;; weekday. + +(define (nudge-day! time time-spec-list) + (if (or (increment-time-component + time + (vector + (interpolate-weekdays (time-spec:list (car time-spec-list)) + (time-spec:list (caddr time-spec-list)) + (tm:mon time) + (tm:year time)) + tm:mday + set-tm:mday)) + (> (tm:mday time) (days-in-month (tm:mon time) (tm:year time)))) + (begin + (nudge-month! time (cdr time-spec-list)) + (set-tm:mday time 0) + (nudge-day! time time-spec-list)))) + + + +;; The hour is bumped to the next accceptable value, and the day is bumped if +;; the hour wraps around. +;; +;; The time-spec-list holds specifications for hour, mday, month and weekday. + +(define (nudge-hour! time time-spec-list) + (and (increment-time-component time (car time-spec-list)) + (nudge-day! time (cdr time-spec-list)))) + + + +;; The minute is bumped to the next accceptable value, and the hour is bumped +;; if the minute wraps around. +;; +;; The time-spec-list holds specifications for minute, hour, day-date, month +;; and weekday. + +(define (nudge-min! time time-spec-list) + (and (increment-time-component time (car time-spec-list)) + (nudge-hour! time (cdr time-spec-list)))) + + + + +;; This is a procedure which returns a procedure which computes the next time a +;; command should run after the current time, based on the information in the +;; Vixie-style time specification. +;; +;; We start by computing a list of time-spec objects (described above) for the +;; minute, hour, date, month, year and weekday components of the overall time +;; specification [1]. Special care is taken to produce proper values for +;; fields 2 and 4: according to Vixie specification "If both fields are +;; restricted (ie, aren't *), the command will be run when _either_ field +;; matches the current time." This implies that if one of these fields is *, +;; while the other is not, its value should be '() [0], otherwise +;; interpolate-weekdays below will produce incorrect results. + +;; When we create the return procedure, it is this list to +;; which references to a time-spec-list will be bound. It will be used by the +;; returned procedure [3] to compute the next time a function should run. Any +;; 7's in the weekday component of the list (the last one) are folded into 0's +;; (both values represent sunday) [2]. Any 0's in the month-day component of the +;; list are removed (this allows a solitary zero to be used to indicate that +;; jobs should only run on certain days of the _week_) [2.1]. +;; +;; The returned procedure itself:- +;; +;; Starts by obtaining the current broken-down time [4], and fixing it to +;; ensure that it is an acceptable value, as follows. Each component from the +;; biggest down is checked for acceptability, and if it is not acceptable it +;; is bumped to the next acceptable value (this may cause higher components to +;; also be bumped if there is range wrap-around) and all the lower components +;; are set to -1 so that it can successfully be bumped up to zero if this is +;; an allowed value. The -1 value will be bumped up subsequently to an allowed +;; value [5]. +;; +;; Once it has been asserted that the current time is acceptable, or has been +;; adjusted to one minute before the next acceptable time, the minute +;; component is then bumped to the next acceptable time, which may ripple +;; through the higher components if necessary [6]. We now have the next time +;; the command needs to run. +;; +;; The new time is then converted back into a UNIX time and returned [7]. + +(define (parse-vixie-time string) + (let ((tokens (string-tokenize (vixie-substitute-parse-symbols string)))) + (cond + ((> (length tokens) 5) + (throw 'mcron-error 9 + "Too many fields in Vixie-style time specification")) + ((< (length tokens) 5) + (throw 'mcron-error 9 + "Not enough fields in Vixie-style time specification"))) + (let ((time-spec-list + (map-in-order (lambda (x) (vector + (let* ((n (vector-ref x 0)) + (tok (list-ref tokens n))) + (cond + ((and (= n 4) + (string=? tok "*") + (not (string=? + (list-ref tokens 2) "*"))) + '()) + ((and (= n 2) + (string=? tok "*") + (not (string=? + (list-ref tokens 4) "*"))) + '()) + (else + (parse-vixie-element + tok + (vector-ref x 1) + (vector-ref x 2))))) ; [0] + (vector-ref x 3) + (vector-ref x 4))) + ;; token range-top+1 getter setter + `( #( 0 0 60 ,tm:min ,set-tm:min ) + #( 1 0 24 ,tm:hour ,set-tm:hour ) + #( 2 1 32 ,tm:mday ,set-tm:mday ) + #( 3 0 12 ,tm:mon ,set-tm:mon ) + #( 4 0 7 ,tm:wday ,set-tm:wday ))))) ;; [1] + + (vector-set! (car (last-pair time-spec-list)) + 0 + (map (lambda (time-spec) + (if (eqv? time-spec 7) 0 time-spec)) + (vector-ref (car (last-pair time-spec-list)) 0))) ;; [2] + + (vector-set! (caddr time-spec-list) + 0 + (remove (lambda (day) (eqv? day 0)) + (vector-ref (caddr time-spec-list) 0))) ;; [2.1] + + + (lambda (current-time) ;; [3] + (let ((time (localtime current-time))) ;; [4] + + (if (not (member (tm:mon time) + (time-spec:list (cadddr time-spec-list)))) + (begin + (nudge-month! time (cdddr time-spec-list)) + (set-tm:mday time 0))) + (if (or (eqv? (tm:mday time) 0) + (not (member (tm:mday time) + (interpolate-weekdays + (time-spec:list (caddr time-spec-list)) + (time-spec:list (caddr (cddr time-spec-list))) + (tm:mon time) + (tm:year time))))) + (begin + (nudge-day! time (cddr time-spec-list)) + (set-tm:hour time -1))) + (if (not (member (tm:hour time) + (time-spec:list (cadr time-spec-list)))) + (begin + (nudge-hour! time (cdr time-spec-list)) + (set-tm:min time -1))) ;; [5] + + (set-tm:sec time 0) + (nudge-min! time time-spec-list) ;; [6] + (car (mktime time))))))) ;; [7] + + diff --git a/src/wrapper.c b/src/wrapper.c new file mode 100644 index 0000000..bb7932e --- /dev/null +++ b/src/wrapper.c @@ -0,0 +1,85 @@ +/* wrapper.c -- C code booting Guile + Copyright © 2003, 2014 Dale Mellor <dale_mellor@users.sourceforge.net> + Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org> + + This file is part of GNU Mcron. + + GNU Mcron is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + GNU Mcron is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNU Mcron. If not, see <http://www.gnu.org/licenses/>. */ + +/* This C code represents a thin wrapper around the Guile code of Mcron. It + is needed because the crontab personality requires SUID which is not + permitted for executable scripts. */ + +#include <libguile.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> + +/* Forward declarations. */ +static void inner_main (void *closure, int argc, char **argv); +static void react_to_terminal_signal (int sig); +static SCM set_cron_signals (void); + +int +main (int argc, char **argv) +{ + scm_boot_guile (argc, argv, inner_main, 0); + + return EXIT_SUCCESS; +} + +/* Launch the Mcron Guile main program. */ +static void +inner_main (void *closure, int argc, char **argv) +{ + /* Set Guile load paths to ensure that Mcron modules will be found. */ + if (getenv ("MCRON_UNINSTALLED") == NULL) + { + scm_c_eval_string ("(set! %load-path (cons \"" + PACKAGE_LOAD_PATH "\" %load-path))"); + scm_c_eval_string ("(set! %load-compiled-path (cons \"" + PACKAGE_LOAD_PATH "\" %load-compiled-path))"); + } + scm_set_current_module (scm_c_resolve_module ("mcron scripts " PROGRAM)); + /* Register set_cron_signals to be called from Guile. */ + scm_c_define_gsubr ("c-set-cron-signals", 0, 0, 0, set_cron_signals); + scm_c_eval_string ("(main)"); +} + +/* Set up all the signal handlers as required by the cron personality. This + is necessary to perform the signal processing in C because the sigaction + function won't work when called from Guile. */ +static SCM +set_cron_signals () +{ + static struct sigaction sa; + + memset (&sa, 0, sizeof (sa)); + sa.sa_handler = react_to_terminal_signal; + sigaction (SIGTERM, &sa, 0); + sigaction (SIGINT, &sa, 0); + sigaction (SIGQUIT, &sa, 0); + sigaction (SIGHUP, &sa, 0); + + return SCM_BOOL_T; +} + +/* Handle signal SIG and exit. All signals that mcron handles will produce + the same behavior so we don't need to use SIG in the implementation. */ +static void +react_to_terminal_signal (int sig) +{ + scm_c_eval_string ("(delete-run-file)"); + exit (EXIT_FAILURE); +} |