Пример #1
0
int     deliver_resolve_addr(LOCAL_STATE state, USER_ATTR usr_attr, char *addr)
{
    TOK822 *tree;
    int     result;

    tree = tok822_scan_addr(addr);
    result = deliver_resolve_tree(state, usr_attr, tree);
    tok822_free_tree(tree);
    return (result);
}
Пример #2
0
int     rewrite_proto(VSTREAM *stream)
{
    RWR_CONTEXT *context;
    TOK822 *tree;

    if (attr_scan(stream, ATTR_FLAG_STRICT,
		  ATTR_TYPE_STR, MAIL_ATTR_RULE, ruleset,
		  ATTR_TYPE_STR, MAIL_ATTR_ADDR, address,
		  ATTR_TYPE_END) != 2)
	return (-1);

    if (strcmp(vstring_str(ruleset), MAIL_ATTR_RWR_LOCAL) == 0)
	context = &local_context;
    else if (strcmp(vstring_str(ruleset), MAIL_ATTR_RWR_REMOTE) == 0)
	context = &remote_context;
    else {
	msg_warn("unknown context: %s", vstring_str(ruleset));
	return (-1);
    }

    /*
     * Sanity check. An address is supposed to be in externalized form.
     */
    if (*vstring_str(address) == 0) {
	msg_warn("rewrite_addr: null address");
	vstring_strcpy(result, vstring_str(address));
    }

    /*
     * Convert the address from externalized (quoted) form to token list,
     * rewrite it, and convert back.
     */
    else {
	tree = tok822_scan_addr(vstring_str(address));
	rewrite_tree(context, tree);
	tok822_externalize(result, tree, TOK822_STR_DEFL);
	tok822_free_tree(tree);
    }
    if (msg_verbose)
	msg_info("`%s' `%s' -> `%s'", vstring_str(ruleset),
		 vstring_str(address), vstring_str(result));

    attr_print(stream, ATTR_FLAG_NONE,
	       ATTR_TYPE_INT, MAIL_ATTR_FLAGS, server_flags,
	       ATTR_TYPE_STR, MAIL_ATTR_ADDR, vstring_str(result),
	       ATTR_TYPE_END);

    if (vstream_fflush(stream) != 0) {
	msg_warn("write rewrite reply: %m");
	return (-1);
    }
    return (0);
}
Пример #3
0
static void resolve_addr(RES_CONTEXT *rp, char *addr,
			         VSTRING *channel, VSTRING *nexthop,
			         VSTRING *nextrcpt, int *flags)
{
    char   *myname = "resolve_addr";
    VSTRING *addr_buf = vstring_alloc(100);
    TOK822 *tree = 0;
    TOK822 *saved_domain = 0;
    TOK822 *domain = 0;
    char   *destination;
    const char *blame = 0;
    const char *rcpt_domain;
    int     addr_len;
    int     loop_count;
    int     loop_max;
    char   *local;
    char   *oper;
    char   *junk;

    *flags = 0;
    vstring_strcpy(channel, "CHANNEL NOT UPDATED");
    vstring_strcpy(nexthop, "NEXTHOP NOT UPDATED");
    vstring_strcpy(nextrcpt, "NEXTRCPT NOT UPDATED");

    /*
     * The address is in internalized (unquoted) form.
     * 
     * In an ideal world we would parse the externalized address form as given
     * to us by the sender.
     * 
     * However, in the real world we have to look for routing characters like
     * %@! in the address local-part, even when that information is quoted
     * due to the presence of special characters or whitespace. Although
     * technically incorrect, this is needed to stop user@domain@domain relay
     * attempts when forwarding mail to a Sendmail MX host.
     * 
     * This suggests that we parse the address in internalized (unquoted) form.
     * Unfortunately, if we do that, the unparser generates incorrect white
     * space between adjacent non-operator tokens. Example: ``first last''
     * needs white space, but ``stuff[stuff]'' does not. This is is not a
     * problem when unparsing the result from parsing externalized forms,
     * because the parser/unparser were designed for valid externalized forms
     * where ``stuff[stuff]'' does not happen.
     * 
     * As a workaround we start with the quoted form and then dequote the
     * local-part only where needed. This will do the right thing in most
     * (but not all) cases.
     */
    addr_len = strlen(addr);
    quote_822_local(addr_buf, addr);
    tree = tok822_scan_addr(vstring_str(addr_buf));

    /*
     * Let the optimizer replace multiple expansions of this macro by a GOTO
     * to a single instance.
     */
#define FREE_MEMORY_AND_RETURN { \
	if (saved_domain) \
	    tok822_free_tree(saved_domain); \
	if(tree) \
	    tok822_free_tree(tree); \
	if (addr_buf) \
	    vstring_free(addr_buf); \
	return; \
    }

    /*
     * Preliminary resolver: strip off all instances of the local domain.
     * Terminate when no destination domain is left over, or when the
     * destination domain is remote.
     * 
     * XXX To whom it may concern. If you change the resolver loop below, or
     * quote_822_local.c, or tok822_parse.c, be sure to re-run the tests
     * under "make resolve_clnt_test" in the global directory.
     */
#define RESOLVE_LOCAL(domain) \
    resolve_local(STR(tok822_internalize(addr_buf, domain, TOK822_STR_DEFL)))

    dict_errno = 0;

    for (loop_count = 0, loop_max = addr_len + 100; /* void */ ; loop_count++) {

	/*
	 * Grr. resolve_local() table lookups may fail. It may be OK for
	 * local file lookup code to abort upon failure, but with
	 * network-based tables it is preferable to return an error
	 * indication to the requestor.
	 */
	if (dict_errno) {
	    *flags |= RESOLVE_FLAG_FAIL;
	    FREE_MEMORY_AND_RETURN;
	}

	/*
	 * XXX Should never happen, but if this happens with some
	 * pathological address, then that is not sufficient reason to
	 * disrupt the operation of an MTA.
	 */
	if (loop_count > loop_max) {
	    msg_warn("resolve_addr: <%s>: giving up after %d iterations",
		     addr, loop_count);
	    break;
	}

	/*
	 * Strip trailing dot at end of domain, but not dot-dot or at-dot.
	 * This merely makes diagnostics more accurate by leaving bogus
	 * addresses alone.
	 */
	if (tree->tail
	    && tree->tail->type == '.'
	    && tok822_rfind_type(tree->tail, '@') != 0
	    && tree->tail->prev->type != '.'
	    && tree->tail->prev->type != '@')
	    tok822_free_tree(tok822_sub_keep_before(tree, tree->tail));

	/*
	 * Strip trailing @.
	 */
	if (var_resolve_nulldom
	    && tree->tail
	    && tree->tail->type == '@')
	    tok822_free_tree(tok822_sub_keep_before(tree, tree->tail));

	/*
	 * Strip (and save) @domain if local.
	 */
	if ((domain = tok822_rfind_type(tree->tail, '@')) != 0) {
	    if (domain->next && RESOLVE_LOCAL(domain->next) == 0)
		break;
	    tok822_sub_keep_before(tree, domain);
	    if (saved_domain)
		tok822_free_tree(saved_domain);
	    saved_domain = domain;
	    domain = 0;				/* safety for future change */
	}

	/*
	 * After stripping the local domain, if any, replace foo%bar by
	 * foo@bar, site!user by user@site, rewrite to canonical form, and
	 * retry.
	 */
	if (tok822_rfind_type(tree->tail, '@')
	    || (var_swap_bangpath && tok822_rfind_type(tree->tail, '!'))
	    || (var_percent_hack && tok822_rfind_type(tree->tail, '%'))) {
	    rewrite_tree(REWRITE_CANON, tree);
	    continue;
	}

	/*
	 * If the local-part is a quoted string, crack it open when we're
	 * permitted to do so and look for routing operators. This is
	 * technically incorrect, but is needed to stop relaying problems.
	 * 
	 * XXX Do another feeble attempt to keep local-part info quoted.
	 */
	if (var_resolve_dequoted
	    && tree->head && tree->head == tree->tail
	    && tree->head->type == TOK822_QSTRING
	    && ((oper = strrchr(local = STR(tree->head->vstr), '@')) != 0
		|| (var_percent_hack && (oper = strrchr(local, '%')) != 0)
	     || (var_swap_bangpath && (oper = strrchr(local, '!')) != 0))) {
	    if (*oper == '%')
		*oper = '@';
	    tok822_internalize(addr_buf, tree->head, TOK822_STR_DEFL);
	    if (*oper == '@') {
		junk = mystrdup(STR(addr_buf));
		quote_822_local(addr_buf, junk);
		myfree(junk);
	    }
	    tok822_free(tree->head);
	    tree->head = tok822_scan(STR(addr_buf), &tree->tail);
	    rewrite_tree(REWRITE_CANON, tree);
	    continue;
	}

	/*
	 * An empty local-part or an empty quoted string local-part becomes
	 * the local MAILER-DAEMON, for consistency with our own From:
	 * message headers.
	 */
	if (tree->head && tree->head == tree->tail
	    && tree->head->type == TOK822_QSTRING
	    && VSTRING_LEN(tree->head->vstr) == 0) {
	    tok822_free(tree->head);
	    tree->head = 0;
	}
	/* XXX must be localpart only, not user@domain form. */
	if (tree->head == 0)
	    tree->head = tok822_scan(var_empty_addr, &tree->tail);

	/*
	 * We're done. There are no domains left to strip off the address,
	 * and all null local-part information is sanitized.
	 */
	domain = 0;
	break;
    }

    vstring_free(addr_buf);
    addr_buf = 0;

    /*
     * Make sure the resolved envelope recipient has the user@domain form. If
     * no domain was specified in the address, assume the local machine. See
     * above for what happens with an empty address.
     */
    if (domain == 0) {
	if (saved_domain) {
	    tok822_sub_append(tree, saved_domain);
	    saved_domain = 0;
	} else {
	    tok822_sub_append(tree, tok822_alloc('@', (char *) 0));
	    tok822_sub_append(tree, tok822_scan(var_myhostname, (TOK822 **) 0));
	}
    }

    /*
     * Transform the recipient address back to internal form.
     * 
     * XXX This may produce incorrect results if we cracked open a quoted
     * local-part with routing operators; see discussion above at the top of
     * the big loop.
     */
    tok822_internalize(nextrcpt, tree, TOK822_STR_DEFL);
    rcpt_domain = strrchr(STR(nextrcpt), '@') + 1;
    if (*rcpt_domain == '[' ? !valid_hostliteral(rcpt_domain, DONT_GRIPE) :
	(!valid_hostname(rcpt_domain, DONT_GRIPE)
	 || valid_hostaddr(rcpt_domain, DONT_GRIPE)))
	*flags |= RESOLVE_FLAG_ERROR;
    tok822_free_tree(tree);
    tree = 0;

    /*
     * XXX Short-cut invalid address forms.
     */
    if (*flags & RESOLVE_FLAG_ERROR) {
	*flags |= RESOLVE_CLASS_DEFAULT;
	FREE_MEMORY_AND_RETURN;
    }

    /*
     * Recognize routing operators in the local-part, even when we do not
     * recognize ! or % as valid routing operators locally. This is needed to
     * prevent backup MX hosts from relaying third-party destinations through
     * primary MX hosts, otherwise the backup host could end up on black
     * lists. Ignore local swap_bangpath and percent_hack settings because we
     * can't know how the next MX host is set up.
     */
    if (strcmp(STR(nextrcpt) + strcspn(STR(nextrcpt), "@!%") + 1, rcpt_domain))
	*flags |= RESOLVE_FLAG_ROUTED;

    /*
     * With local, virtual, relay, or other non-local destinations, give the
     * highest precedence to transport associated nexthop information.
     * 
     * Otherwise, with relay or other non-local destinations, the relayhost
     * setting overrides the destination domain name.
     * 
     * XXX Nag if the recipient domain is listed in multiple domain lists. The
     * result is implementation defined, and may break when internals change.
     * 
     * For now, we distinguish only a fixed number of address classes.
     * Eventually this may become extensible, so that new classes can be
     * configured with their own domain list, delivery transport, and
     * recipient table.
     */
#define STREQ(x,y) (strcmp((x), (y)) == 0)

    dict_errno = 0;
    if (domain != 0) {

	/*
	 * Virtual alias domain.
	 */
	if (virt_alias_doms
	    && string_list_match(virt_alias_doms, rcpt_domain)) {
	    if (var_helpful_warnings) {
		if (virt_mailbox_doms
		    && string_list_match(virt_mailbox_doms, rcpt_domain))
		    msg_warn("do not list domain %s in BOTH %s and %s",
			     rcpt_domain, VAR_VIRT_ALIAS_DOMS,
			     VAR_VIRT_MAILBOX_DOMS);
		if (relay_domains
		    && domain_list_match(relay_domains, rcpt_domain))
		    msg_warn("do not list domain %s in BOTH %s and %s",
			     rcpt_domain, VAR_VIRT_ALIAS_DOMS,
			     VAR_RELAY_DOMAINS);
#if 0
		if (strcasecmp(rcpt_domain, var_myorigin) == 0)
		    msg_warn("do not list $%s (%s) in %s",
			   VAR_MYORIGIN, var_myorigin, VAR_VIRT_ALIAS_DOMS);
#endif
	    }
	    vstring_strcpy(channel, MAIL_SERVICE_ERROR);
	    vstring_sprintf(nexthop, "User unknown%s",
			    var_show_unk_rcpt_table ?
			    " in virtual alias table" : "");
	    *flags |= RESOLVE_CLASS_ALIAS;
	} else if (dict_errno != 0) {
	    msg_warn("%s lookup failure", VAR_VIRT_ALIAS_DOMS);
	    *flags |= RESOLVE_FLAG_FAIL;
	    FREE_MEMORY_AND_RETURN;
	}

	/*
	 * Virtual mailbox domain.
	 */
	else if (virt_mailbox_doms
		 && string_list_match(virt_mailbox_doms, rcpt_domain)) {
	    if (var_helpful_warnings) {
		if (relay_domains
		    && domain_list_match(relay_domains, rcpt_domain))
		    msg_warn("do not list domain %s in BOTH %s and %s",
			     rcpt_domain, VAR_VIRT_MAILBOX_DOMS,
			     VAR_RELAY_DOMAINS);
	    }
	    vstring_strcpy(channel, RES_PARAM_VALUE(rp->virt_transport));
	    vstring_strcpy(nexthop, rcpt_domain);
	    blame = rp->virt_transport_name;
	    *flags |= RESOLVE_CLASS_VIRTUAL;
	} else if (dict_errno != 0) {
	    msg_warn("%s lookup failure", VAR_VIRT_MAILBOX_DOMS);
	    *flags |= RESOLVE_FLAG_FAIL;
	    FREE_MEMORY_AND_RETURN;
	} else {

	    /*
	     * Off-host relay destination.
	     */
	    if (relay_domains
		&& domain_list_match(relay_domains, rcpt_domain)) {
		vstring_strcpy(channel, RES_PARAM_VALUE(rp->relay_transport));
		blame = rp->relay_transport_name;
		*flags |= RESOLVE_CLASS_RELAY;
	    } else if (dict_errno != 0) {
		msg_warn("%s lookup failure", VAR_RELAY_DOMAINS);
		*flags |= RESOLVE_FLAG_FAIL;
		FREE_MEMORY_AND_RETURN;
	    }

	    /*
	     * Other off-host destination.
	     */
	    else {
		vstring_strcpy(channel, RES_PARAM_VALUE(rp->def_transport));
		blame = rp->def_transport_name;
		*flags |= RESOLVE_CLASS_DEFAULT;
	    }

	    /*
	     * With off-host delivery, relayhost overrides recipient domain.
	     */
	    if (*RES_PARAM_VALUE(rp->relayhost))
		vstring_strcpy(nexthop, RES_PARAM_VALUE(rp->relayhost));
	    else
		vstring_strcpy(nexthop, rcpt_domain);
	}
    }

    /*
     * Local delivery.
     * 
     * XXX Nag if the domain is listed in multiple domain lists. The effect is
     * implementation defined, and may break when internals change.
     */
    else {
	if (var_helpful_warnings) {
	    if (virt_alias_doms
		&& string_list_match(virt_alias_doms, rcpt_domain))
		msg_warn("do not list domain %s in BOTH %s and %s",
			 rcpt_domain, VAR_MYDEST, VAR_VIRT_ALIAS_DOMS);
	    if (virt_mailbox_doms
		&& string_list_match(virt_mailbox_doms, rcpt_domain))
		msg_warn("do not list domain %s in BOTH %s and %s",
			 rcpt_domain, VAR_MYDEST, VAR_VIRT_MAILBOX_DOMS);
	}
	vstring_strcpy(channel, RES_PARAM_VALUE(rp->local_transport));
	vstring_strcpy(nexthop, rcpt_domain);
	blame = rp->local_transport_name;
	*flags |= RESOLVE_CLASS_LOCAL;
    }

    /*
     * An explicit main.cf transport:nexthop setting overrides the nexthop.
     * 
     * XXX We depend on this mechanism to enforce per-recipient concurrencies
     * for local recipients. With "local_transport = local:$myhostname" we
     * force mail for any domain in $mydestination/${proxy,inet}_interfaces
     * to share the same queue.
     */
    if ((destination = split_at(STR(channel), ':')) != 0 && *destination)
	vstring_strcpy(nexthop, destination);

    /*
     * Sanity checks.
     */
    if (*STR(channel) == 0) {
	if (blame == 0)
	    msg_panic("%s: null blame", myname);
	msg_warn("file %s/%s: parameter %s: null transport is not allowed",
		 var_config_dir, MAIN_CONF_FILE, blame);
	*flags |= RESOLVE_FLAG_FAIL;
	FREE_MEMORY_AND_RETURN;
    }
    if (*STR(nexthop) == 0)
	msg_panic("%s: null nexthop", myname);

    /*
     * The transport map can selectively override any transport and/or
     * nexthop host info that is set up above. Unfortunately, the syntax for
     * nexthop information is transport specific. We therefore need sane and
     * intuitive semantics for transport map entries that specify a channel
     * but no nexthop.
     * 
     * With non-error transports, the initial nexthop information is the
     * recipient domain. However, specific main.cf transport definitions may
     * specify a transport-specific destination, such as a host + TCP socket,
     * or the pathname of a UNIX-domain socket. With less precedence than
     * main.cf transport definitions, a main.cf relayhost definition may also
     * override nexthop information for off-host deliveries.
     * 
     * With the error transport, the nexthop information is free text that
     * specifies the reason for non-delivery.
     * 
     * Because nexthop syntax is transport specific we reset the nexthop
     * information to the recipient domain when the transport table specifies
     * a transport without also specifying the nexthop information.
     * 
     * Subtle note: reset nexthop even when the transport table does not change
     * the transport. Otherwise it is hard to get rid of main.cf specified
     * nexthop information.
     * 
     * XXX Don't override the virtual alias class (error:User unknown) result.
     */
    if (rp->transport_info && !(*flags & RESOLVE_CLASS_ALIAS)) {
	if (transport_lookup(rp->transport_info, STR(nextrcpt),
			     rcpt_domain, channel, nexthop) == 0
	    && dict_errno != 0) {
	    msg_warn("%s lookup failure", rp->transport_maps_name);
	    *flags |= RESOLVE_FLAG_FAIL;
	    FREE_MEMORY_AND_RETURN;
	}
    }

    /*
     * Bounce recipients that have moved, regardless of domain address class.
     * We do this last, in anticipation of transport maps that can override
     * the recipient address.
     * 
     * The downside of not doing this in delivery agents is that this table has
     * no effect on local alias expansion results. Such mail will have to
     * make almost an entire iteration through the mail system.
     */
#define IGNORE_ADDR_EXTENSION   ((char **) 0)

    if (relocated_maps != 0) {
	const char *newloc;

	if ((newloc = mail_addr_find(relocated_maps, STR(nextrcpt),
				     IGNORE_ADDR_EXTENSION)) != 0) {
	    vstring_strcpy(channel, MAIL_SERVICE_ERROR);
	    vstring_sprintf(nexthop, "User has moved to %s", newloc);
	} else if (dict_errno != 0) {
	    msg_warn("%s lookup failure", VAR_RELOCATED_MAPS);
	    *flags |= RESOLVE_FLAG_FAIL;
	    FREE_MEMORY_AND_RETURN;
	}
    }

    /*
     * Clean up.
     */
    FREE_MEMORY_AND_RETURN;
}