/*++ /* NAME /* alias 3 /* SUMMARY /* alias data base lookups /* SYNOPSIS /* #include "local.h" /* /* int deliver_alias(state, usr_attr, name, statusp) /* LOCAL_STATE state; /* USER_ATTR usr_attr; /* char *name; /* int *statusp; /* DESCRIPTION /* deliver_alias() looks up the expansion of the recipient in /* the global alias database and delivers the message to the /* listed destinations. The result is zero when no alias was found /* or when the message should be delivered to the user instead. /* /* deliver_alias() has wired-in knowledge about a few reserved /* recipient names. /* .IP \(bu /* When no alias is found for the local \fIpostmaster\fR or /* \fImailer-daemon\fR a warning is issued and the message /* is discarded. /* .IP \(bu /* When an alias exists for recipient \fIname\fR, and an alias /* exists for \fIowner-name\fR, the sender address is changed /* to \fIowner-name\fR, and the owner delivery attribute is /* set accordingly. This feature is disabled with /* "owner_request_special = no". /* .PP /* Arguments: /* .IP state /* Attributes that specify the message, recipient and more. /* Expansion type (alias, include, .forward). /* A table with the results from expanding aliases or lists. /* A table with delivered-to: addresses taken from the message. /* .IP usr_attr /* User attributes (rights, environment). /* .IP name /* The alias to be looked up. /* .IP statusp /* Delivery status. See below. /* DIAGNOSTICS /* Fatal errors: out of memory. The delivery status is non-zero /* when delivery should be tried again. /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /*--*/ /* System library. */ #include <sys_defs.h> #include <sys/stat.h> #include <unistd.h> #include <string.h> #include <fcntl.h> #include <errno.h> #ifdef STRCASECMP_IN_STRINGS_H #include <strings.h> #endif /* Utility library. */ #include <msg.h> #include <htable.h> #include <dict.h> #include <argv.h> #include <stringops.h> #include <mymalloc.h> #include <vstring.h> #include <vstream.h> /* Global library. */ #include <mail_params.h> #include <defer.h> #include <maps.h> #include <bounce.h> #include <mypwd.h> #include <canon_addr.h> #include <sent.h> #include <trace.h> #include <dsn_mask.h> /* Application-specific. */ #include "local.h" /* Application-specific. */ #define NO 0 #define YES 1 /* deliver_alias - expand alias file entry */ int deliver_alias(LOCAL_STATE state, USER_ATTR usr_attr, char *name, int *statusp) { const char *myname = "deliver_alias"; const char *alias_result; char *saved_alias_result; char *owner; char **cpp; struct mypasswd *alias_pwd; VSTRING *canon_owner; DICT *dict; const char *owner_rhs; /* owner alias, RHS */ int alias_count; int dsn_notify; char *dsn_envid; int dsn_ret; const char *dsn_orcpt; /* * Make verbose logging easier to understand. */ state.level++; if (msg_verbose) MSG_LOG_STATE(myname, state); /* * DUPLICATE/LOOP ELIMINATION * * We cannot do duplicate elimination here. Sendmail compatibility requires * that we allow multiple deliveries to the same alias, even recursively! * For example, we must deliver to mailbox any messags that are addressed * to the alias of a user that lists that same alias in her own .forward * file. Yuck! This is just an example of some really perverse semantics * that people will expect Postfix to implement just like sendmail. * * We can recognize one special case: when an alias includes its own name, * deliver to the user instead, just like sendmail. Otherwise, we just * bail out when nesting reaches some unreasonable depth, and blame it on * a possible alias loop. */ if (state.msg_attr.exp_from != 0 && strcasecmp(state.msg_attr.exp_from, name) == 0) return (NO); if (state.level > 100) { msg_warn("alias database loop for %s", name); dsb_simple(state.msg_attr.why, "5.4.6", "alias database loop for %s", name); *statusp = bounce_append(BOUNCE_FLAGS(state.request), BOUNCE_ATTR(state.msg_attr)); return (YES); } state.msg_attr.exp_from = name; /* * There are a bunch of roles that we're trying to keep track of. * * First, there's the issue of whose rights should be used when delivering * to "|command" or to /file/name. With alias databases, the rights are * those of who owns the alias, i.e. the database owner. With aliases * owned by root, a default user is used instead. When an alias with * default rights references an include file owned by an ordinary user, * we must use the rights of the include file owner, otherwise the * include file owner could take control of the default account. * * Secondly, there's the question of who to notify of delivery problems. * With aliases that have an owner- alias, the latter is used to set the * sender and owner attributes. Otherwise, the owner attribute is reset * (the alias is globally visible and could be sent to by anyone). */ for (cpp = alias_maps->argv->argv; *cpp; cpp++) { if ((dict = dict_handle(*cpp)) == 0) msg_panic("%s: dictionary not found: %s", myname, *cpp); if ((alias_result = dict_get(dict, name)) != 0) { if (msg_verbose) msg_info("%s: %s: %s = %s", myname, *cpp, name, alias_result); /* * Don't expand a verify-only request. */ if (state.request->flags & DEL_REQ_FLAG_MTA_VRFY) { dsb_simple(state.msg_attr.why, "2.0.0", "aliased to %s", alias_result); *statusp = sent(BOUNCE_FLAGS(state.request), SENT_ATTR(state.msg_attr)); return (YES); } /* * DELIVERY POLICY * * Update the expansion type attribute, so we can decide if * deliveries to |command and /file/name are allowed at all. */ state.msg_attr.exp_type = EXPAND_TYPE_ALIAS; /* * DELIVERY RIGHTS * * What rights to use for |command and /file/name deliveries? The * command and file code will use default rights when the alias * database is owned by root, otherwise it will use the rights of * the alias database owner. */ if (dict->owner.status == DICT_OWNER_TRUSTED) { alias_pwd = 0; RESET_USER_ATTR(usr_attr, state.level); } else { if (dict->owner.status == DICT_OWNER_UNKNOWN) { msg_warn("%s: no owner UID for alias database %s", myname, *cpp); dsb_simple(state.msg_attr.why, "4.3.0", "mail system configuration error"); *statusp = defer_append(BOUNCE_FLAGS(state.request), BOUNCE_ATTR(state.msg_attr)); return (YES); } if ((errno = mypwuid_err(dict->owner.uid, &alias_pwd)) != 0 || alias_pwd == 0) { msg_warn(errno ? "cannot find alias database owner for %s: %m" : "cannot find alias database owner for %s", *cpp); dsb_simple(state.msg_attr.why, "4.3.0", "cannot find alias database owner"); *statusp = defer_append(BOUNCE_FLAGS(state.request), BOUNCE_ATTR(state.msg_attr)); return (YES); } SET_USER_ATTR(usr_attr, alias_pwd, state.level); } /* * WHERE TO REPORT DELIVERY PROBLEMS. * * Use the owner- alias if one is specified, otherwise reset the * owner attribute and use the include file ownership if we can. * Save the dict_lookup() result before something clobbers it. * * Don't match aliases that are based on regexps. */ #define OWNER_ASSIGN(own) \ (own = (var_ownreq_special == 0 ? 0 : \ concatenate("owner-", name, (char *) 0))) saved_alias_result = mystrdup(alias_result); if (OWNER_ASSIGN(owner) != 0 && (owner_rhs = maps_find(alias_maps, owner, DICT_FLAG_NONE)) != 0) { canon_owner = canon_addr_internal(vstring_alloc(10), var_exp_own_alias ? owner_rhs : owner); /* Set envelope sender and owner attribute. */ SET_OWNER_ATTR(state.msg_attr, STR(canon_owner), state.level); } else { canon_owner = 0; /* Note: this does not reset the envelope sender. */ if (var_reset_owner_attr) RESET_OWNER_ATTR(state.msg_attr, state.level); } /* * EXTERNAL LOOP CONTROL * * Set the delivered message attribute to the recipient, so that * this message will list the correct forwarding address. */ if (var_frozen_delivered == 0) state.msg_attr.delivered = state.msg_attr.rcpt.address; /* * Deliver. */ alias_count = 0; if (owner != 0 && alias_maps->error != 0) { dsb_simple(state.msg_attr.why, "4.3.0", "alias database unavailable"); *statusp = defer_append(BOUNCE_FLAGS(state.request), BOUNCE_ATTR(state.msg_attr)); } else { /* * XXX DSN * * When delivering to a mailing list (i.e. the envelope sender * is replaced) the ENVID, NOTIFY, RET, and ORCPT parameters * which accompany the redistributed message MUST NOT be * derived from those of the original message. * * When delivering to an alias (i.e. the envelope sender is not * replaced) any ENVID, RET, or ORCPT parameters are * propagated to all forwarding addresses associated with * that alias. The NOTIFY parameter is propagated to the * forwarding addresses, except that any SUCCESS keyword is * removed. */ #define DSN_SAVE_UPDATE(saved, old, new) do { \ saved = old; \ old = new; \ } while (0) DSN_SAVE_UPDATE(dsn_notify, state.msg_attr.rcpt.dsn_notify, dsn_notify == DSN_NOTIFY_SUCCESS ? DSN_NOTIFY_NEVER : dsn_notify & ~DSN_NOTIFY_SUCCESS); if (canon_owner != 0) { DSN_SAVE_UPDATE(dsn_envid, state.msg_attr.dsn_envid, ""); DSN_SAVE_UPDATE(dsn_ret, state.msg_attr.dsn_ret, 0); DSN_SAVE_UPDATE(dsn_orcpt, state.msg_attr.rcpt.dsn_orcpt, ""); state.msg_attr.rcpt.orig_addr = ""; } *statusp = deliver_token_string(state, usr_attr, saved_alias_result, &alias_count); #if 0 if (var_ownreq_special && strncmp("owner-", state.msg_attr.sender, 6) != 0 && alias_count > 10) msg_warn("mailing list \"%s\" needs an \"owner-%s\" alias", name, name); #endif if (alias_count < 1) { msg_warn("no recipient in alias lookup result for %s", name); dsb_simple(state.msg_attr.why, "4.3.0", "alias database unavailable"); *statusp = defer_append(BOUNCE_FLAGS(state.request), BOUNCE_ATTR(state.msg_attr)); } else { /* * XXX DSN * * When delivering to a mailing list (i.e. the envelope * sender address is replaced) and NOTIFY=SUCCESS was * specified, report a DSN of "delivered". * * When delivering to an alias (i.e. the envelope sender * address is not replaced) and NOTIFY=SUCCESS was * specified, report a DSN of "expanded". */ if (dsn_notify & DSN_NOTIFY_SUCCESS) { state.msg_attr.rcpt.dsn_notify = dsn_notify; if (canon_owner != 0) { state.msg_attr.dsn_envid = dsn_envid; state.msg_attr.dsn_ret = dsn_ret; state.msg_attr.rcpt.dsn_orcpt = dsn_orcpt; } dsb_update(state.msg_attr.why, "2.0.0", canon_owner ? "delivered" : "expanded", DSB_SKIP_RMTA, DSB_SKIP_REPLY, "alias expanded"); (void) trace_append(BOUNCE_FLAG_NONE, SENT_ATTR(state.msg_attr)); } } } myfree(saved_alias_result); if (owner) myfree(owner); if (canon_owner) vstring_free(canon_owner); if (alias_pwd) mypwfree(alias_pwd); return (YES); } /* * If the alias database was inaccessible for some reason, defer * further delivery for the current top-level recipient. */ if (alias_result == 0 && dict->error != 0) { msg_warn("%s:%s: lookup of '%s' failed", dict->type, dict->name, name); dsb_simple(state.msg_attr.why, "4.3.0", "alias database unavailable"); *statusp = defer_append(BOUNCE_FLAGS(state.request), BOUNCE_ATTR(state.msg_attr)); return (YES); } else { if (msg_verbose) msg_info("%s: %s: %s not found", myname, *cpp, name); } } /* * Try delivery to a local user instead. */ return (NO); }