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);
}
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);
}
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;
}