bin/181157: [ftpd] [patch] New login.conf(5) capability "ftp-chdir" for ftpd(8)

[Eugene Grosbein]

>Number:         181157
>Category:       bin
>Synopsis:       [ftpd] [patch] New login.conf(5) capability "ftp-chdir" for ftpd(8)
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Fri Aug 09 07:20:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Eugene Grosbein
>Release:        FreeBSD 9.2-BETA2 amd64
>Organization:
RDTC JSC
>Environment:
System: FreeBSD k-45-monitor 9.2-BETA2 FreeBSD 9.2-BETA2 #10 r253755M: Mon Jul 29 12:39:55 NOVT 2013 root at k-45-monitor:/usr/obj/usr/local/src/sys/K-45-MONITOR amd64

>Description:
	ftpd(8) allows us to have chrooted users having initial working directory
	distinct from its home directory with "/home/user/./subdir" syntax in the passwd(5) file.
	This way changes notion of user's home directory for all other system utilities
	and may be undesirable. Let's make it possible for ftpd(8) to change user's
	initial working directory without messing with its home directory.

	The following patch introduces new string "ftp-chdir" capability in login.conf(5).
	For users having this capability ftpd(8) will change current directory to it
	instead of user's home directory upon successful authorization (and chroot(8), if needed).
	Thus, user's home directory may be kept intact in passwd(5), without "/./" hack.

>How-To-Repeat:

	See above.

>Fix:

--- libexec/ftpd/ftpd.8.orig	2013-06-18 14:52:20.000000000 +0700
+++ libexec/ftpd/ftpd.8	2013-08-09 13:35:24.000000000 +0700
@@ -472,6 +472,13 @@
 can fill the drive with unwanted files.
 .El
 .Pp
+Initial working directory may be automatically changed from user's
+home directory to another one with the string "ftp-chdir" capability
+in login.conf(5), unless user's home directory pathname contains the
+.Pa /./
+separator, as described above (that setting has higher priority).
+For chrooted users, "ftp-chdir" points to the directory below new root.
+.Pp
 If the system has multiple IP addresses,
 .Nm
 supports the idea of virtual hosts, which provides the ability to
--- libexec/ftpd/ftpd.c.orig	2013-06-18 14:52:20.000000000 +0700
+++ libexec/ftpd/ftpd.c	2013-08-08 14:25:12.000000000 +0700
@@ -1553,7 +1553,11 @@ skip:
 			 * the old current directory will be accessible as "."
 			 * outside the new root!
 			 */
+#ifdef	LOGIN_CAP
+			homedir = (char *) login_getcapstr(lc, "ftp-chdir", "/", "/");
+#else
 			homedir = "/";
+#endif
 		}
 		/*
 		 * Finally, do chroot()
--- lib/libutil/login.conf.5.orig	2013-08-09 13:36:01.000000000 +0700
+++ lib/libutil/login.conf.5	2013-08-09 13:37:33.000000000 +0700
@@ -225,6 +225,9 @@
 See
 .Xr ftpd 8
 for details.
+.It "ftp-chdir	string		Initial working directory for FTP user. See
+.Xr ftpd 8
+for details.
 .It "label	string			Default MAC policy; see
 .Xr maclabel 7 .
 .It "lang	string		Set $LANG environment variable to the specified value.


>Release-Note:
>Audit-Trail:
>Unformatted: