a simple patch to enable RFC2640 for /usr/libexec/ftpd

[Zhang Weiwu]

I am not actively involved in FreeBSD development. I am an ordinary user
and this is my first post on this list so please just redirect me to
correct place if I posted OT.

I know probably ftpd is not going to accept changes for a lot of
reasons, and I think it's reasonable if ftpd is not accepting anything
but patches that satisfies basic requirements. Here is a patch to enable
ftpd for RFC2640, I think this is a very basic requirement so I hope it
can be accepted and used in next release:

Compare to those who only use English for a life time, probably we Asian
users feel much more painful for character-set issue. To Asian users the
UTF8 compliance as defined in RFC2640 is very important. As FreeBSD is
an international project, UTF8 and related RFC compliance is AFAIK basic
requirement. The attached path added an option -8 to ftpd, when used, it
indicate the file system on server is using UTF-8 and the FTP client
(e.g. smart ftp, filezilla, lftp, gftp ...) should convert the filenames
and path names to local character set (which they do fine). FTP server
tell client to do character conversion if necessary by including "UTF8"
in FEAT.

RFC2640 is the only way to make international ftp server: it is the only
standard way to deliver non-latin filenames to different OSs. a.k.a.
Suppose you set up an FTP server and you want users use the Chinese file
names for both Simplified Chinese version of Windows user and
Traditional Chinese version of Windows.

This is a very simple and (sorry for that) not high quality patch and I
am not a developer so I'd be very thankful if some hacker can check the
correctness of this patch (I myself checked it and is running it on my
FreeBSD server).

P.S. RFC 2640 is based on RFC2389 which also gets implemented here.

-- 
Zhang Weiwu
Real Softservice
http://www.realss.com
+86 592 2091112

diff -u ftpd.FreeBSD-6.1/ftpcmd.y ftpd/ftpcmd.y
--- ftpd.FreeBSD-6.1/ftpcmd.y   Thu Nov 18 21:46:29 2004
+++ ftpd/ftpcmd.y       Mon Apr 16 19:27:31 2007
@@ -95,6 +95,7 @@
 extern int usedefault;
 extern  char tmpline[];
 extern int readonly;
+extern int utf8_mode;
 extern int noepsv;
 extern int noretr;
 extern int noguestretr;
@@ -135,7 +136,7 @@
        ABOR    DELE    CWD     LIST    NLST    SITE
        STAT    HELP    NOOP    MKD     RMD     PWD
        CDUP    STOU    SMNT    SYST    SIZE    MDTM
-       LPRT    LPSV    EPRT    EPSV
+       LPRT    LPSV    EPRT    EPSV    FEAT
 
        UMASK   IDLE    CHMOD   MDFIVE
 
@@ -687,6 +688,16 @@
                        if ($4 != NULL)
                                free($4);
                }
+       | FEAT CRLF
+               {
+                       lreply(211, "Features:");
+                       printf(" EPSV\r\n");
+                       printf(" EPRT\r\n");
+                       printf(" MDTM\r\n");
+                       printf(" SIZE\r\n");
+                       if (utf8_mode) printf(" UTF8\r\n");
+                       reply(211, "End");
+               }
        | SYST check_login CRLF
                {
                        if ($2) {
@@ -1112,6 +1123,7 @@
        { "NLST", NLST, OSTR, 1,        "[ <sp> path-name ]" },
        { "SITE", SITE, SITECMD, 1,     "site-cmd [ <sp> arguments ]" },
        { "SYST", SYST, ARGS, 1,        "(get type of operating system)" },
+       { "FEAT", FEAT, ARGS, 1,        "(get features supported)" },
        { "STAT", STAT, OSTR, 1,        "[ <sp> path-name ]" },
        { "HELP", HELP, OSTR, 1,        "[ <sp> <string> ]" },
        { "NOOP", NOOP, ARGS, 1,        "" },
diff -u ftpd.FreeBSD-6.1/ftpd.8 ftpd/ftpd.8
--- ftpd.FreeBSD-6.1/ftpd.8     Sun Jan 29 21:21:05 2006
+++ ftpd/ftpd.8 Mon Apr 16 20:03:35 2007
@@ -40,7 +40,7 @@
 .Nd Internet File Transfer Protocol server
 .Sh SYNOPSIS
 .Nm
-.Op Fl 46ADdEhMmOoRrSUvW
+.Op Fl 468ADdEhMmOoRrSUvW
 .Op Fl l Op Fl l
 .Op Fl a Ar address
 .Op Fl P Ar port
@@ -78,6 +78,11 @@
 is specified, accept connections via
 .Dv AF_INET6
 socket.
+.It Fl 8
+Server is running in UTF-8 mode, an RFC2640 compliant  client should convert
+all paths and messages from server from UTF-8 to client's local character-set.
+Note enalbing this option does not make server do any filesystem encoding
+conversion, it only tell client to do so.
 .It Fl A
 Allow only anonymous ftp access.
 .It Fl a
@@ -250,6 +255,7 @@
 .It DELE Ta "delete a file [RW]"
 .It EPRT Ta "specify data connection port, multiprotocol"
 .It EPSV Ta "prepare for server-to-server transfer, multiprotocol"
+.It FEAT Ta "give server feature information"
 .It HELP Ta "give help information"
 .It LIST Ta "give list files in a directory" Pq Dq Li "ls -lgA"
 .It LPRT Ta "specify data connection port, multiprotocol"
diff -u ftpd.FreeBSD-6.1/ftpd.c ftpd/ftpd.c
--- ftpd.FreeBSD-6.1/ftpd.c     Thu Mar  9 17:12:44 2006
+++ ftpd/ftpd.c Mon Apr 16 19:25:15 2007
@@ -128,6 +128,7 @@
 int    restricted_data_ports = 1;
 int    paranoid = 1;     /* be extra careful about security */
 int    anon_only = 0;    /* Only anonymous ftp allowed */
+int    utf8_mode = 0;    /* server file system is in UTF-8 */
 int    guest;
 int    dochroot;
 char   *chrootdir;
@@ -308,7 +309,7 @@
        openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
 
        while ((ch = getopt(argc, argv,
-                           "46a:AdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
+                           "468a:AdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
                switch (ch) {
                case '4':
                        family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
@@ -317,6 +318,9 @@
                case '6':
                        family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
                        break;
+
+               case '8':
+                       utf8_mode = 1;
 
                case 'a':
                        bindname = optarg;