cron(8): set the environment variables of the user and/or login class

Prior to processing environment variable set in the crontab file as those
should be of higher precedent, pull in the user or login class environment.

This is another supporting feature for allowing one to configure system-wide
settings that may affect both regular cron jobs as well as services.

This is the final part of D21481.

Submitted by:	Andrew Gierth <andrew_tao173.riddles.org.uk>

2 files changed, 31 insertions, 8 deletions

diff --git a/usr.sbin/cron/cron/do_command.c b/usr.sbin/cron/cron/do_command.c
index 4a9a49e6c8ae..375f55caf7c0 100644
--- a/usr.sbin/cron/cron/do_command.c
+++ b/usr.sbin/cron/cron/do_command.c
@@ -43,6 +43,8 @@ static void		child_process(entry *, user *),
 
 static WAIT_T		wait_on_child(PID_T, const char *);
 
+extern char	*environ;
+
 void
 do_command(e, u)
 	entry	*e;
@@ -285,9 +287,11 @@ child_process(e, u)
 		 */
 		do_univ(u);
 
+		environ = NULL;
+
 # if defined(LOGIN_CAP)
-		/* Set user's entire context, but skip the environment
-		 * as cron provides a separate interface for this
+		/* Set user's entire context, but note that PATH will
+		 * be overridden later
 		 */
 		if ((pwd = getpwnam(usernm)) == NULL)
 			pwd = getpwuid(e->uid);
@@ -299,7 +303,7 @@ child_process(e, u)
 		}
 		if (pwd &&
 		    setusercontext(lc, pwd, e->uid,
-			    LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETENV)) == 0)
+			    LOGIN_SETALL) == 0)
 			(void) endpwent();
 		else {
 			/* fall back to the old method */
@@ -342,6 +346,18 @@ child_process(e, u)
 		 */
 		{
 			char	*shell = env_get("SHELL", e->envp);
+			char	**p;
+
+			/* Apply the environment from the entry, overriding existing
+			 * values (this will always set PATH, LOGNAME, etc.) putenv
+			 * should not fail unless malloc does.
+			 */
+			for (p = e->envp; *p; ++p) {
+				if (putenv(*p) != 0) {
+					warn("putenv");
+					_exit(ERROR_EXIT);
+				}
+			}
 
 # if DEBUGGING
 			if (DebugFlags & DTEST) {
@@ -352,9 +368,8 @@ child_process(e, u)
 				_exit(OK_EXIT);
 			}
 # endif /*DEBUGGING*/
-			execle(shell, shell, "-c", e->cmd, (char *)NULL,
-			    e->envp);
-			warn("execle: couldn't exec `%s'", shell);
+			execl(shell, shell, "-c", e->cmd, (char *)NULL);
+			warn("execl: couldn't exec `%s'", shell);
 			_exit(ERROR_EXIT);
 		}
 		break;
diff --git a/usr.sbin/cron/crontab/crontab.5 b/usr.sbin/cron/crontab/crontab.5
index 9943adfaf356..adc2b2b5ae95 100644
--- a/usr.sbin/cron/crontab/crontab.5
+++ b/usr.sbin/cron/crontab/crontab.5
@@ -17,7 +17,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 24, 2019
+.Dd January 19, 2020
 .Dt CRONTAB 5
 .Os
 .Sh NAME
@@ -82,10 +82,18 @@ and
 are set from the
 .Pa /etc/passwd
 line of the crontab's owner.
+In addition, the environment variables of the
+user's login class, with the exception of
+.Ev PATH ,
+will be set from
+.Pa /etc/login.conf.db
+and
+.Pa ~/.login_conf .
 .Ev HOME ,
 .Ev PATH
 and
-.Ev SHELL
+.Ev SHELL ,
+and any variables set from the login class,
 may be overridden by settings in the crontab;
 .Ev LOGNAME
 may not.