UPASFS(4) UPASFS(4) NAME upasfs - mail file server SYNOPSIS upas/fs [ -DSbdfilnps ][ -c cachtarg ][ -f mailbox ][ -m mntpoint ] DESCRIPTION Fs is a user level file system that caches mailboxes and presents them as a file system. A user normally starts fs in his/her profile after starting plumber(4) and before starting a window system, such as rio(1) or acme(1). The file system is used by nedmail(1), acme(1)'s mail reader, and imap4d and pop3 (both pop3(8)) to parse messages. Fs also generates plumbing messages used by biff and faces(1) to provide mail announcements. The mailbox itself becomes a directory under /mail/fs. Each message in the mailbox becomes a numbered directory in the mailbox directory, and each attachment becomes a numbered directory in the message directory. Since an attachment may itself be a mail message, this structure can recurse ad nau- seam. Each message and attachment directory contains the files: body the message minus the RFC2822 style headers cc the address(es) from the CC: header date the date in the message, or if none, the time of delivery digest an SHA1 digest of the message contents disposition inline or file filename a name to use to file an attachment flags persistant message flags as per IMAP ffrom the parsed name of the sender from the from address in the From: header, or if none, the address on the envelope. header the RFC822 headers info described below, essentially a summary of the header info inreplyto contents of the in-reply-to: header lines the number of lines in the message body messageid the parsed RFC2822 MessageID mimeheader the mime headers raw the undecoded MIME message rawbody the undecoded message body rawheader the undecoded message header references the parsed MessageIDs of each referenced mes- sage, one per line replyto the address to send any replies to. UPASFS(4) UPASFS(4) subject the contents of the subject line to the address(es) from the To: line. type the MIME content type unixheader the envelope header from the mailbox unixdate the date portion of the Unix From line. unixdatesec the mdir filename for mdir messages. The por- tion before the dot is always the date from the Unix From line in seconds since epoch. The info file contains the following information, one item per line. Lists of addresses are single space separated. sender address recipient addresses cc addresses reply address envelope date subject MIME content type MIME disposition filename SHA1 digest bcc addresses in-reply-to: contents RFC822 date message senders message id number of lines in body size of message message flags unixdatesec name from From: header Deleting message directories causes the message to be removed from the mailbox. The mailbox is scanned and the structure updated whenever the mailbox changes. Message directories are not renum- bered. The results of the scan are recorded in mailbox.idx. The file /mail/fs/ctl is used to direct fs to open, close, rename, create or remove new mailboxes, and also to delete or flag groups of messages atomically. The messages that can be written to this file are: open path mboxname opens a new mailbox. path is the file to open, and mboxname is the name that appears under /mail/fs. close mboxname close mboxname. The close takes affect only after all files open under /mail/fs/mboxname have been closed. UPASFS(4) UPASFS(4) create mboxname create a new maibox, mboxname. The mailbox type must support creation. rename [-t] old new rename the mailbox old to new. The t flag truncates rather than removes the old mailbox. The renaming takes effect immedately. While mailboxes of any type may be renamed, it is not possible to use rename to convert folder types. remove [-rt] mboxname remove mboxname. The r flag removes any subfolders while the t flag truncates, rather than removes. delete mboxname number ... Delete the messages with the given num- bers from mboxname. flag mboxname flags number ... flag the given messages. The flags file records persistant message flags. These flags are a superset of the standard IMAP message flags. Flags are stored in order. Unset flags are represented by a `-' while set flags are represented by the following ordered characters a answered D deleted d draft f flagged r recent s seen S stored Messages of the form [+-]flags may be written to the flags file. Fs maintains the r flag. Mail readers are expected to maintain other flags. The options are: -D Trace 9P protocol messages. -S Log to console in addition to the standard places. -b stands for biffing. Each time new mail is received, a message is printed to standard output containing the sender address, subject, and number of bytes. It is intended for peo- ple telnetting in who want mail announcements. -c cachetarg attempt to keep the cache below cachetarg bytes. -d loud debugging. -f file use file as the mailbox instead of the default, /mail/box/username/mbox. -i chatty index debugging. UPASFS(4) UPASFS(4) -l logging. Turn on logging via syslog (and to the console with -S) to the file /sys/log/fs. -m mntpt mount on mntpt rather than the default /mail/fs. -n Don't open a mailbox initially. Overridden by -f. -p turn off plumbing. Unless this is specified, fs sends a message to the plumb port, seemail, from source mailfs for each message received or deleted. The message contains the attributes sender=<contents of from file>, filetype=mail, mailtype=deleted or new, and length=<message length in bytes>. The con- tents of the message is the full path name of the directory representing the message. -s causes fs to put itself in /srv with a name of the form /srv/upasfs.user. -m specifies a mount point other than /mail/fs. Fs will exit once all references to its directory have dis- appeared. Fs interprets mailbox file names of the form /proto/host/user to mean access an account on host using the given protocol. Authentication is delegated to factotum(4). The final /user may be omitted, in which case the user name is gleaned from the key held by factotum. The following pro- tocols are supported: pop cleartext POP with password authentication apop cleartext POP with challenge-response (APOP) authentication poptls TLS-encrypted POP with password authentication apoptls TLS-encrypted POP with challenge-response (APOP) authentication imap cleartext IMAP with CRAM-MD5 or password authenti- cation imaps TLS-encrypted IMAP CRAM-MD5 or password authentica- tion The two IMAP protocols allow an optional fourth field speci- fying a mailbox name, for example /imap/server/user/stored. Poptls and apoptls connect to port 110 in plaintext and start TLS using the POP STLS command. Imaps connects to port 993 and starts TLS before initiating the IMAP conversa- tion. There should probably be pops, apops, and imaptls protocols as well. (Pops and apops would connect to port 995 and start TLS before initiating the POP conversation, and imaptls would connect to port 143 in plaintext and start TLS using the IMAP STARTTLS command. (That's the nice thing about standards-there's so many to choose from.)) UPASFS(4) UPASFS(4) FILES /mail/box/* mail directories /mail/box/*/mbox mailbox files /mail/box/*/mbox.idx mailbox indicies /mail/box/*/L.mbox mutual exclusion lock for altering mbox (mbox format only) SOURCE /sys/src/cmd/upas/fs SEE ALSO aliasmail(8), faces(1), filter(1), mail(1), marshal(1), mdir(6), mlmgr(1), nedmail(1), pop3(8), qer(8), rewrite(6), send(8), upasfs(4), Erik Quanstrom ``Scaling Upas'', Procedings of IWP9, Octo- ber, 2008.