Gromox

Gromox is the central groupware server component of grommunio. It is capable of serving as a drop-in replacement for Microsoft Exchange. Connectivity options include RPC/HTTP (Outlook Anywhere), MAPI/HTTP, EWS, IMAP, POP3, an SMTP-speaking LDA, and a PHP module with a MAPI function subset. Components can scale-out over multiple hosts.

Gromox is modular and consists of a set of components and programs to provide its feature set. This repository includes a number of manual pages, for which a rendered version is at docs.grommunio.com.

Instructions for compilation are in doc/install.rst. There is also other, mostly technical, documentation in the doc/ directory.

Gromox relies on other components to provide a sensibly complete mail system,

• Admin API/CLI (Management): grommunio Admin API/CLI
• Admin Web Interface (Management): grommunio Admin Web
• User Web Interface (Web UI): grommunio Web
• Exchange ActiveSync (EAS) (Mobile Devices): grommunio Sync
• CalDAV & CardDAV (Interoperability with Clients): grommunio DAV
• a mail transfer agent like Postfix, Exim, and more
• mail security solutions like rspamd and others (commercial ones included)

The grommunio Appliance ships these essentials and has a ready-to-run installation of Gromox.

Support

Support is available through grommunio GmbH and its partners. See https://grommunio.com/ for details. A community forum is at https://community.grommunio.com/.

The source code repository and technical issue tracker can be found at https://github.com/grommunio/gromox.

For direct contact and supplying information about a security-related responsible disclosure, contact dev@grommunio.com.

Standards and protocols

See doc/protocols.rst for a discussion.

Contributing

• https://docs.github.com/en/get-started/quickstart/contributing-to-projects
• Alternatively, upload commits to a git store of your choosing, or export the series as a patchset using git format-patch, then convey the git link/patches through our direct contact address (above).

Coding and social style

When in Rome, do as the Romans do.

Source layout

• exch/:
  • emsmdb/: Decoder for EMSMDB/OXCROPS calls (good starting point/grepable keyword: rop_ext_pull(EXT_PULL &x, ROP_BUFFER &r) function) and handler entrypoint for these calls (gsp.: rop_dispatch)
  • ews/: Logic for handling EWS requests (gsp.: EWSPlugin::dispatch)
  • exmdb/: The Information Store server. Decoder for EXRPC calls is in lib/exmdb_ext.cpp:exmdb_ext_pull_request; the big case switch() function is autogenerated during make into include/exmdb_dispatch.cpp; mailbox logic functions begin with the grepable substring BOOL exmdb_server::.
  • http/: HTTP server
    • HTTP request parser (gsp.: htparse_rdhead, and htparse_rdhead_st near /* met the end of request header */)
    • MSRPC parser (gsp.: pdu_processor_input)
  • mh/: Handler for OXCMAPIHTTP requests. There is little actual mailbox logic, since the code forwards to emsmdb/nsp functions.
  • midb/: A support server specifically for gromox-imap/gromox-pop3, gsp. mail_engine_commands. Text-based input protocol.
  • mysql_adaptor/: User database support functions
  • nsp/: Decoder for OXNSPI requests (gsp.: exchange_nsp_ndr_pull), and logic to handle those (gsp.: exchange_nsp_dispatch)
  • zcore/: State keeper for requests from PHP-MAPI. Decoder for ZRPC requests gsp. rpc_parser_dispatch, and mailbox logic gsp. ec_error_t zs_)
  • authmgr.cpp: component for directing authentication between MySQL/LDAP
  • oxdisco.cpp: Handler for AutoDiscover requests
• lib/: functions shared on a large scale
  • lib/email/: Parser for e-mail, calendar, contacts (RFC 5322, 5545, 6350)
  • lib/mapi/: Data structures mostly specific to MAPI
    • oxcical.cpp: Logic for conversion between parsed iCalendar and MAPI calendaring items
    • oxcmail.cpp: Logic for conversion between parsed e-mail and MAPI messaging items
    • oxvcard.cpp: Logic for conversion between parsed vCards and MAPI contact items
• mda/: Message Delivery Agent
  • exmdb_local/ gsp. exmdb_local_hook
  • delivery_app/: Delivery Agent
  • smtp/: SMTP protocol handler of the MDA
• mra/: Message Retrieval Agents (IMAP, POP3); these are midb clients (not exrpc clients), gsp. imap_parser_dispatch_cmd2 and pop3_parser_dispatch_cmd2.