On Fri, 2008-01-25 at 14:48 +0100, Martin Preen wrote:

Hello, I have a question about the way Dovecot limits file system access. Currently we're using Dovecot 1.0.5 (Solaris 10).

In some cases users have a symbolic link like "z: -> /" in their mail directory. As a result there are log entries like

Jan 25 13:30:31 imap1 dovecot: [ID 107833 mail.error] IMAP(xyz): stat(/home/xyz/.wine/dosdevices/c:/windows/profiles/xyz/.../z:/proc/28381/root/proc/28381/.../root/proc/28381/Player/#SharedObje Jan 25 13:30:31 imap1 dovecot: [ID 107833 mail.error] IMAP(xyz): x) failed: File name too long

So you're exposing the entire home directory to Dovecot? Everything would go a lot more nicely (and faster) if Dovecot would have access only to actual mailboxes. Can't you just force everyone to use e.g. ~/mail/ directory (mail_location = mbox:~/mail)?

Is there something I can do (these links should be ignored) ? Or is it a bug ?

I don't think Dovecot should ignore those kind of errors, because if it happens on a normal mail directory, it's most likely a problem sysadmin should know about and fix. But in this kind of a mixed system.. well, modifying sources would be the only solution.

In some cases users have a symbolic link like "z: -> /" in their mail directory. As a result there are log entries like

stat(/home/xyz/.wine/dosdevices/c:/windows/profiles/xyz/.../z:/proc/28381/root/proc/28381/.../root/proc/28381/Player/#SharedObje Jan 25 13:30:31 imap1 dovecot: [ID 107833 mail.error] IMAP(xyz): x) failed: File name too long

Like you, our users store mail in their home directories* and sometimes they make symlinks to strange places like -> /usr.

I patched dovecot to simply ignore symlinks; maybe you can, too.

diff -c -r dovecot-1.0.0-pristine/src/lib-storage/index/mbox/mbox-list.c dovecot-1.0.0/src/lib-storage/index/mbox/mbox-list.c *** dovecot-1.0.0-pristine/src/lib-storage/index/mbox/mbox-list.c Mon Feb 5 05:57:32 2007 --- dovecot-1.0.0/src/lib-storage/index/mbox/mbox-list.c Thu Apr 26 09:56:22 2007

*** 69,74 **** --- 69,85 ---- static int list_opendir(struct mail_storage *storage, const char *path, bool root, DIR **dirp) {

• /* ACS local modification */

•   struct stat st;

•   if (lstat(*path == '\0' ? "/" : path, &st) < 0) {

•           mail_storage_set_error(storage, "lstat failed!");

•           return -1;

•   }

•   if (st.st_mode & S_IFLNK) {

•           return 0; /*ignore*/

•   }

• /* end ACS local modification */

•   *dirp = opendir(*path == '\0' ? "/" : path);
    if (*dirp != NULL)
            return 1;

-- Adam

• although we're finally starting to convert our 30k users over to dedicated maildirs+NFS. I'll share my experiences with the list once we're done (early March I hope).

-- Adam Tilghman | Systems Support / Academic Computing | +1 858 822 0711 agt@ucsd.edu | University of California, San Diego | fax +1 858 534 7018