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Diffstat (limited to 'src/virtual/virtual.c')
| -rw-r--r-- | src/virtual/virtual.c | 565 |
1 files changed, 565 insertions, 0 deletions
diff --git a/src/virtual/virtual.c b/src/virtual/virtual.c new file mode 100644 index 0000000..29b1b71 --- /dev/null +++ b/src/virtual/virtual.c @@ -0,0 +1,565 @@ +/*++ +/* NAME +/* virtual 8 +/* SUMMARY +/* Postfix virtual domain mail delivery agent +/* SYNOPSIS +/* \fBvirtual\fR [generic Postfix daemon options] +/* DESCRIPTION +/* The \fBvirtual\fR(8) delivery agent is designed for virtual mail +/* hosting services. Originally based on the Postfix \fBlocal\fR(8) +/* delivery +/* agent, this agent looks up recipients with map lookups of their +/* full recipient address, instead of using hard-coded unix password +/* file lookups of the address local part only. +/* +/* This delivery agent only delivers mail. Other features such as +/* mail forwarding, out-of-office notifications, etc., must be +/* configured via virtual_alias maps or via similar lookup mechanisms. +/* MAILBOX LOCATION +/* .ad +/* .fi +/* The mailbox location is controlled by the \fBvirtual_mailbox_base\fR +/* and \fBvirtual_mailbox_maps\fR configuration parameters (see below). +/* The \fBvirtual_mailbox_maps\fR table is indexed by the recipient +/* address as described under TABLE SEARCH ORDER below. +/* +/* The mailbox pathname is constructed as follows: +/* +/* .nf +/* \fB$virtual_mailbox_base/$virtual_mailbox_maps(\fIrecipient\fB)\fR +/* .fi +/* +/* where \fIrecipient\fR is the full recipient address. +/* UNIX MAILBOX FORMAT +/* .ad +/* .fi +/* When the mailbox location does not end in \fB/\fR, the message +/* is delivered in UNIX mailbox format. This format stores multiple +/* messages in one textfile. +/* +/* The \fBvirtual\fR(8) delivery agent prepends a "\fBFrom \fIsender +/* time_stamp\fR" envelope header to each message, prepends a +/* \fBDelivered-To:\fR message header with the envelope recipient +/* address, +/* prepends an \fBX-Original-To:\fR header with the recipient address as +/* given to Postfix, +/* prepends a \fBReturn-Path:\fR message header with the +/* envelope sender address, prepends a \fB>\fR character to lines +/* beginning with "\fBFrom \fR", and appends an empty line. +/* +/* The mailbox is locked for exclusive access while delivery is in +/* progress. In case of problems, an attempt is made to truncate the +/* mailbox to its original length. +/* QMAIL MAILDIR FORMAT +/* .ad +/* .fi +/* When the mailbox location ends in \fB/\fR, the message is delivered +/* in qmail \fBmaildir\fR format. This format stores one message per file. +/* +/* The \fBvirtual\fR(8) delivery agent prepends a \fBDelivered-To:\fR +/* message header with the final envelope recipient address, +/* prepends an \fBX-Original-To:\fR header with the recipient address as +/* given to Postfix, and prepends a +/* \fBReturn-Path:\fR message header with the envelope sender address. +/* +/* By definition, \fBmaildir\fR format does not require application-level +/* file locking during mail delivery or retrieval. +/* MAILBOX OWNERSHIP +/* .ad +/* .fi +/* Mailbox ownership is controlled by the \fBvirtual_uid_maps\fR +/* and \fBvirtual_gid_maps\fR lookup tables, which are indexed +/* with the full recipient address. Each table provides +/* a string with the numerical user and group ID, respectively. +/* +/* The \fBvirtual_minimum_uid\fR parameter imposes a lower bound on +/* numerical user ID values that may be specified in any +/* \fBvirtual_uid_maps\fR. +/* CASE FOLDING +/* .ad +/* .fi +/* All delivery decisions are made using the full recipient +/* address, folded to lower case. See also the next section +/* for a few exceptions with optional address extensions. +/* TABLE SEARCH ORDER +/* .ad +/* .fi +/* Normally, a lookup table is specified as a text file that +/* serves as input to the \fBpostmap\fR(1) command. The result, an +/* indexed file in \fBdbm\fR or \fBdb\fR format, is used for fast +/* searching by the mail system. +/* +/* The search order is as follows. The search stops +/* upon the first successful lookup. +/* .IP \(bu +/* When the recipient has an optional address extension the +/* \fIuser+extension@domain.tld\fR address is looked up first. +/* .sp +/* With Postfix versions before 2.1, the optional address extension +/* is always ignored. +/* .IP \(bu +/* The \fIuser@domain.tld\fR address, without address extension, +/* is looked up next. +/* .IP \(bu +/* Finally, the recipient \fI@domain\fR is looked up. +/* .PP +/* When the table is provided via other means such as NIS, LDAP +/* or SQL, the same lookups are done as for ordinary indexed files. +/* +/* Alternatively, a table can be provided as a regular-expression +/* map where patterns are given as regular expressions. In that case, +/* only the full recipient address is given to the regular-expression +/* map. +/* SECURITY +/* .ad +/* .fi +/* The \fBvirtual\fR(8) delivery agent is not security sensitive, provided +/* that the lookup tables with recipient user/group ID information are +/* adequately protected. This program is not designed to run chrooted. +/* +/* The \fBvirtual\fR(8) delivery agent disallows regular expression +/* substitution of $1 etc. in regular expression lookup tables, +/* because that would open a security hole. +/* +/* The \fBvirtual\fR(8) delivery agent will silently ignore requests +/* to use the \fBproxymap\fR(8) server. Instead it will open the +/* table directly. Before Postfix version 2.2, the virtual +/* delivery agent will terminate with a fatal error. +/* STANDARDS +/* RFC 822 (ARPA Internet Text Messages) +/* DIAGNOSTICS +/* Mail bounces when the recipient has no mailbox or when the +/* recipient is over disk quota. In all other cases, mail for +/* an existing recipient is deferred and a warning is logged. +/* +/* Problems and transactions are logged to \fBsyslogd\fR(8) +/* or \fBpostlogd\fR(8). +/* Corrupted message files are marked so that the queue +/* manager can move them to the \fBcorrupt\fR queue afterwards. +/* +/* Depending on the setting of the \fBnotify_classes\fR parameter, +/* the postmaster is notified of bounces and of other trouble. +/* BUGS +/* This delivery agent supports address extensions in email +/* addresses and in lookup table keys, but does not propagate +/* address extension information to the result of table lookup. +/* +/* Postfix should have lookup tables that can return multiple result +/* attributes. In order to avoid the inconvenience of maintaining +/* three tables, use an LDAP or MYSQL database. +/* CONFIGURATION PARAMETERS +/* .ad +/* .fi +/* Changes to \fBmain.cf\fR are picked up automatically, as +/* \fBvirtual\fR(8) +/* processes run for only a limited amount of time. Use the command +/* "\fBpostfix reload\fR" to speed up a change. +/* +/* The text below provides only a parameter summary. See +/* \fBpostconf\fR(5) for more details including examples. +/* MAILBOX DELIVERY CONTROLS +/* .ad +/* .fi +/* .IP "\fBvirtual_mailbox_base (empty)\fR" +/* A prefix that the \fBvirtual\fR(8) delivery agent prepends to all pathname +/* results from $virtual_mailbox_maps table lookups. +/* .IP "\fBvirtual_mailbox_maps (empty)\fR" +/* Optional lookup tables with all valid addresses in the domains that +/* match $virtual_mailbox_domains. +/* .IP "\fBvirtual_minimum_uid (100)\fR" +/* The minimum user ID value that the \fBvirtual\fR(8) delivery agent accepts +/* as a result from $virtual_uid_maps table lookup. +/* .IP "\fBvirtual_uid_maps (empty)\fR" +/* Lookup tables with the per-recipient user ID that the \fBvirtual\fR(8) +/* delivery agent uses while writing to the recipient's mailbox. +/* .IP "\fBvirtual_gid_maps (empty)\fR" +/* Lookup tables with the per-recipient group ID for \fBvirtual\fR(8) mailbox +/* delivery. +/* .PP +/* Available in Postfix version 2.0 and later: +/* .IP "\fBvirtual_mailbox_domains ($virtual_mailbox_maps)\fR" +/* Postfix is final destination for the specified list of domains; +/* mail is delivered via the $virtual_transport mail delivery transport. +/* .IP "\fBvirtual_transport (virtual)\fR" +/* The default mail delivery transport and next-hop destination for +/* final delivery to domains listed with $virtual_mailbox_domains. +/* .PP +/* Available in Postfix version 2.5.3 and later: +/* .IP "\fBstrict_mailbox_ownership (yes)\fR" +/* Defer delivery when a mailbox file is not owned by its recipient. +/* LOCKING CONTROLS +/* .ad +/* .fi +/* .IP "\fBvirtual_mailbox_lock (see 'postconf -d' output)\fR" +/* How to lock a UNIX-style \fBvirtual\fR(8) mailbox before attempting +/* delivery. +/* .IP "\fBdeliver_lock_attempts (20)\fR" +/* The maximal number of attempts to acquire an exclusive lock on a +/* mailbox file or \fBbounce\fR(8) logfile. +/* .IP "\fBdeliver_lock_delay (1s)\fR" +/* The time between attempts to acquire an exclusive lock on a mailbox +/* file or \fBbounce\fR(8) logfile. +/* .IP "\fBstale_lock_time (500s)\fR" +/* The time after which a stale exclusive mailbox lockfile is removed. +/* RESOURCE AND RATE CONTROLS +/* .ad +/* .fi +/* .IP "\fBvirtual_mailbox_limit (51200000)\fR" +/* The maximal size in bytes of an individual \fBvirtual\fR(8) mailbox or +/* maildir file, or zero (no limit). +/* .PP +/* Implemented in the qmgr(8) daemon: +/* .IP "\fBvirtual_destination_concurrency_limit ($default_destination_concurrency_limit)\fR" +/* The maximal number of parallel deliveries to the same destination +/* via the virtual message delivery transport. +/* .IP "\fBvirtual_destination_recipient_limit ($default_destination_recipient_limit)\fR" +/* The maximal number of recipients per message for the virtual +/* message delivery transport. +/* MISCELLANEOUS CONTROLS +/* .ad +/* .fi +/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" +/* The default location of the Postfix main.cf and master.cf +/* configuration files. +/* .IP "\fBdaemon_timeout (18000s)\fR" +/* How much time a Postfix daemon process may take to handle a +/* request before it is terminated by a built-in watchdog timer. +/* .IP "\fBdelay_logging_resolution_limit (2)\fR" +/* The maximal number of digits after the decimal point when logging +/* sub-second delay values. +/* .IP "\fBipc_timeout (3600s)\fR" +/* The time limit for sending or receiving information over an internal +/* communication channel. +/* .IP "\fBmax_idle (100s)\fR" +/* The maximum amount of time that an idle Postfix daemon process waits +/* for an incoming connection before terminating voluntarily. +/* .IP "\fBmax_use (100)\fR" +/* The maximal number of incoming connections that a Postfix daemon +/* process will service before terminating voluntarily. +/* .IP "\fBprocess_id (read-only)\fR" +/* The process ID of a Postfix command or daemon process. +/* .IP "\fBprocess_name (read-only)\fR" +/* The process name of a Postfix command or daemon process. +/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" +/* The location of the Postfix top-level queue directory. +/* .IP "\fBsyslog_facility (mail)\fR" +/* The syslog facility of Postfix logging. +/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" +/* A prefix that is prepended to the process name in syslog +/* records, so that, for example, "smtpd" becomes "prefix/smtpd". +/* .PP +/* Available in Postfix version 3.0 and later: +/* .IP "\fBvirtual_delivery_status_filter ($default_delivery_status_filter)\fR" +/* Optional filter for the \fBvirtual\fR(8) delivery agent to change the +/* delivery status code or explanatory text of successful or unsuccessful +/* deliveries. +/* .PP +/* Available in Postfix version 3.3 and later: +/* .IP "\fBenable_original_recipient (yes)\fR" +/* Enable support for the original recipient address after an +/* address is rewritten to a different address (for example with +/* aliasing or with canonical mapping). +/* .IP "\fBservice_name (read-only)\fR" +/* The master.cf service name of a Postfix daemon process. +/* SEE ALSO +/* qmgr(8), queue manager +/* bounce(8), delivery status reports +/* postconf(5), configuration parameters +/* postlogd(8), Postfix logging +/* syslogd(8), system logging +/* README_FILES +/* Use "\fBpostconf readme_directory\fR" or +/* "\fBpostconf html_directory\fR" to locate this information. +/* VIRTUAL_README, domain hosting howto +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* HISTORY +/* .ad +/* .fi +/* This delivery agent was originally based on the Postfix local delivery +/* agent. Modifications mainly consisted of removing code that either +/* was not applicable or that was not safe in this context: aliases, +/* ~user/.forward files, delivery to "|command" or to /file/name. +/* +/* The \fBDelivered-To:\fR message header appears in the \fBqmail\fR +/* system by Daniel Bernstein. +/* +/* The \fBmaildir\fR structure appears in the \fBqmail\fR system +/* by Daniel Bernstein. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/* +/* Andrew McNamara +/* andrewm@connect.com.au +/* connect.com.au Pty. Ltd. +/* Level 3, 213 Miller St +/* North Sydney 2060, NSW, Australia +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <stdlib.h> +#ifdef USE_PATHS_H +#include <paths.h> /* XXX mail_spool_dir dependency */ +#endif + +/* Utility library. */ + +#include <msg.h> +#include <vstring.h> +#include <vstream.h> +#include <iostuff.h> +#include <set_eugid.h> +#include <dict.h> + +/* Global library. */ + +#include <mail_queue.h> +#include <recipient_list.h> +#include <deliver_request.h> +#include <deliver_completed.h> +#include <mail_params.h> +#include <mail_version.h> +#include <mail_conf.h> +#include <mail_params.h> +#include <mail_addr_find.h> +#include <flush_clnt.h> + +/* Single server skeleton. */ + +#include <mail_server.h> + +/* Application-specific. */ + +#include "virtual.h" + + /* + * Tunable parameters. + */ +char *var_virt_mailbox_maps; +char *var_virt_uid_maps; +char *var_virt_gid_maps; +int var_virt_minimum_uid; +char *var_virt_mailbox_base; +char *var_virt_mailbox_lock; +long var_virt_mailbox_limit; +char *var_mail_spool_dir; /* XXX dependency fix */ +bool var_strict_mbox_owner; +char *var_virt_dsn_filter; + + /* + * Mappings. + */ +MAPS *virtual_mailbox_maps; +MAPS *virtual_uid_maps; +MAPS *virtual_gid_maps; + + /* + * Bit masks. + */ +int virtual_mbox_lock_mask; + +/* local_deliver - deliver message with extreme prejudice */ + +static int local_deliver(DELIVER_REQUEST *rqst, char *service) +{ + const char *myname = "local_deliver"; + RECIPIENT *rcpt_end = rqst->rcpt_list.info + rqst->rcpt_list.len; + RECIPIENT *rcpt; + int rcpt_stat; + int msg_stat; + LOCAL_STATE state; + USER_ATTR usr_attr; + + if (msg_verbose) + msg_info("local_deliver: %s from %s", rqst->queue_id, rqst->sender); + + /* + * Initialize the delivery attributes that are not recipient specific. + */ + state.level = 0; + deliver_attr_init(&state.msg_attr); + state.msg_attr.queue_name = rqst->queue_name; + state.msg_attr.queue_id = rqst->queue_id; + state.msg_attr.fp = rqst->fp; + state.msg_attr.offset = rqst->data_offset; + state.msg_attr.sender = rqst->sender; + state.msg_attr.dsn_envid = rqst->dsn_envid; + state.msg_attr.dsn_ret = rqst->dsn_ret; + state.msg_attr.relay = service; + state.msg_attr.msg_stats = rqst->msg_stats; + RESET_USER_ATTR(usr_attr, state.level); + state.request = rqst; + + /* + * Iterate over each recipient named in the delivery request. When the + * mail delivery status for a given recipient is definite (i.e. bounced + * or delivered), update the message queue file and cross off the + * recipient. Update the per-message delivery status. + */ + for (msg_stat = 0, rcpt = rqst->rcpt_list.info; rcpt < rcpt_end; rcpt++) { + state.msg_attr.rcpt = *rcpt; + rcpt_stat = deliver_recipient(state, usr_attr); + if (rcpt_stat == 0 && (rqst->flags & DEL_REQ_FLAG_SUCCESS)) + deliver_completed(state.msg_attr.fp, rcpt->offset); + msg_stat |= rcpt_stat; + } + + deliver_attr_free(&state.msg_attr); + return (msg_stat); +} + +/* local_service - perform service for client */ + +static void local_service(VSTREAM *stream, char *service, char **argv) +{ + DELIVER_REQUEST *request; + int status; + + /* + * Sanity check. This service takes no command-line arguments. + */ + if (argv[0]) + msg_fatal("unexpected command-line argument: %s", argv[0]); + + /* + * This routine runs whenever a client connects to the UNIX-domain socket + * that is dedicated to local mail delivery service. What we see below is + * a little protocol to (1) tell the client that we are ready, (2) read a + * delivery request from the client, and (3) report the completion status + * of that request. + */ + if ((request = deliver_request_read(stream)) != 0) { + status = local_deliver(request, service); + deliver_request_done(stream, request, status); + } +} + +/* pre_accept - see if tables have changed */ + +static void pre_accept(char *unused_name, char **unused_argv) +{ + const char *table; + + if ((table = dict_changed_name()) != 0) { + msg_info("table %s has changed -- restarting", table); + exit(0); + } +} + +/* post_init - post-jail initialization */ + +static void post_init(char *unused_name, char **unused_argv) +{ + + /* + * Drop privileges most of the time. + */ + set_eugid(var_owner_uid, var_owner_gid); + + /* + * No case folding needed: the recipient address is case folded. + */ + virtual_mailbox_maps = + maps_create(VAR_VIRT_MAILBOX_MAPS, var_virt_mailbox_maps, + DICT_FLAG_LOCK | DICT_FLAG_PARANOID + | DICT_FLAG_UTF8_REQUEST); + + virtual_uid_maps = + maps_create(VAR_VIRT_UID_MAPS, var_virt_uid_maps, + DICT_FLAG_LOCK | DICT_FLAG_PARANOID + | DICT_FLAG_UTF8_REQUEST); + + virtual_gid_maps = + maps_create(VAR_VIRT_GID_MAPS, var_virt_gid_maps, + DICT_FLAG_LOCK | DICT_FLAG_PARANOID + | DICT_FLAG_UTF8_REQUEST); + + virtual_mbox_lock_mask = mbox_lock_mask(var_virt_mailbox_lock); +} + +/* pre_init - pre-jail initialization */ + +static void pre_init(char *unused_name, char **unused_argv) +{ + + /* + * Reset the file size limit from the message size limit to the mailbox + * size limit. + * + * We can't have mailbox size limit smaller than the message size limit, + * because that prohibits the delivery agent from updating the queue + * file. + */ + if (var_virt_mailbox_limit) { + if (var_virt_mailbox_limit < var_message_limit || var_message_limit == 0) + msg_fatal("main.cf configuration error: %s is smaller than %s", + VAR_VIRT_MAILBOX_LIMIT, VAR_MESSAGE_LIMIT); + set_file_limit(var_virt_mailbox_limit); + } + + /* + * flush client. + */ + flush_init(); +} + +MAIL_VERSION_STAMP_DECLARE; + +/* main - pass control to the single-threaded skeleton */ + +int main(int argc, char **argv) +{ + static const CONFIG_INT_TABLE int_table[] = { + VAR_VIRT_MINUID, DEF_VIRT_MINUID, &var_virt_minimum_uid, 1, 0, + 0, + }; + static const CONFIG_LONG_TABLE long_table[] = { + VAR_VIRT_MAILBOX_LIMIT, DEF_VIRT_MAILBOX_LIMIT, &var_virt_mailbox_limit, 0, 0, + 0, + }; + static const CONFIG_STR_TABLE str_table[] = { + VAR_MAIL_SPOOL_DIR, DEF_MAIL_SPOOL_DIR, &var_mail_spool_dir, 0, 0, + VAR_VIRT_MAILBOX_MAPS, DEF_VIRT_MAILBOX_MAPS, &var_virt_mailbox_maps, 0, 0, + VAR_VIRT_UID_MAPS, DEF_VIRT_UID_MAPS, &var_virt_uid_maps, 0, 0, + VAR_VIRT_GID_MAPS, DEF_VIRT_GID_MAPS, &var_virt_gid_maps, 0, 0, + VAR_VIRT_MAILBOX_BASE, DEF_VIRT_MAILBOX_BASE, &var_virt_mailbox_base, 1, 0, + VAR_VIRT_MAILBOX_LOCK, DEF_VIRT_MAILBOX_LOCK, &var_virt_mailbox_lock, 1, 0, + VAR_VIRT_DSN_FILTER, DEF_VIRT_DSN_FILTER, &var_virt_dsn_filter, 0, 0, + 0, + }; + static const CONFIG_BOOL_TABLE bool_table[] = { + VAR_STRICT_MBOX_OWNER, DEF_STRICT_MBOX_OWNER, &var_strict_mbox_owner, + 0, + }; + + /* + * Fingerprint executables and core dumps. + */ + MAIL_VERSION_STAMP_ALLOCATE; + + single_server_main(argc, argv, local_service, + CA_MAIL_SERVER_INT_TABLE(int_table), + CA_MAIL_SERVER_LONG_TABLE(long_table), + CA_MAIL_SERVER_STR_TABLE(str_table), + CA_MAIL_SERVER_BOOL_TABLE(bool_table), + CA_MAIL_SERVER_PRE_INIT(pre_init), + CA_MAIL_SERVER_POST_INIT(post_init), + CA_MAIL_SERVER_PRE_ACCEPT(pre_accept), + CA_MAIL_SERVER_PRIVILEGED, + CA_MAIL_SERVER_BOUNCE_INIT(VAR_VIRT_DSN_FILTER, + &var_virt_dsn_filter), + 0); +} |