int
rf_lookup_hostlist(router_instance *rblock, address_item *addr,
uschar *ignore_target_hosts, int lookup_type, int hff_code,
address_item **addr_new)
{
BOOL self_send = FALSE;
/* Look up each host address. A lookup may add additional items into the chain
if there are multiple addresses. Hence the use of next_h to start each cycle of
the loop at the next original host. If any host is identified as being the local
host, omit it and any subsequent hosts - i.e. treat the list like an ordered
list of MX hosts. If the first host is the local host, act according to the
"self" option in the configuration. */
for (host_item * prev = NULL, * h = addr->host_list, *next_h; h; h = next_h)
{
const uschar *canonical_name;
int rc, len, port, mx, sort_key;
next_h = h->next;
if (h->address) { prev = h; continue; }
DEBUG(D_route|D_host_lookup)
debug_printf("finding IP address for %s\n", h->name);
/* Handle any port setting that may be on the name; it will be removed
from the end of the name. */
port = host_item_get_port(h);
/* Store the previous mx and sort_key values, which were assigned in
host_build_hostlist and will be overwritten by host_find_bydns. */
mx = h->mx;
sort_key = h->sort_key;
/* If the name ends with "/MX", we interpret it to mean "the list of hosts
pointed to by MX records with this name", and the MX record values override
the ordering from host_build_hostlist. */
len = Ustrlen(h->name);
if (len > 3 && strcmpic(h->name + len - 3, US"/mx") == 0)
{
int whichrrs = lookup_type & LK_IPV4_ONLY
? HOST_FIND_BY_MX | HOST_FIND_IPV4_ONLY
: lookup_type & LK_IPV4_PREFER
? HOST_FIND_BY_MX | HOST_FIND_IPV4_FIRST
: HOST_FIND_BY_MX;
DEBUG(D_route|D_host_lookup)
debug_printf("doing DNS MX lookup for %s\n", h->name);
mx = MX_NONE;
h->name = string_copyn(h->name, len - 3);
rc = host_find_bydns(h,
ignore_target_hosts,
whichrrs, /* look only for MX records */
NULL, /* SRV service not relevant */
NULL, /* failing srv domains not relevant */
NULL, /* no special mx failing domains */
&rblock->dnssec, /* dnssec request/require */
NULL, /* fully_qualified_name */
NULL); /* indicate local host removed */
}
/* If explicitly configured to look up by name, or if the "host name" is
actually an IP address, do a byname lookup. */
else if (lookup_type & LK_BYNAME || string_is_ip_address(h->name, NULL) != 0)
{
DEBUG(D_route|D_host_lookup) debug_printf("calling host_find_byname\n");
rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
&canonical_name, TRUE);
}
/* Otherwise, do a DNS lookup. If that yields "host not found", and the
lookup type is the default (i.e. "bydns" is not explicitly configured),
follow up with a byname lookup, just in case. */
else
{
BOOL removed;
int whichrrs = lookup_type & LK_IPV4_ONLY
? HOST_FIND_BY_A
: lookup_type & LK_IPV4_PREFER
? HOST_FIND_BY_A | HOST_FIND_BY_AAAA | HOST_FIND_IPV4_FIRST
: HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
DEBUG(D_route|D_host_lookup) debug_printf("doing DNS lookup\n");
switch (rc = host_find_bydns(h, ignore_target_hosts, whichrrs, NULL,
NULL, NULL,
&rblock->dnssec, /* domains for request/require */
&canonical_name, &removed))
{
case HOST_FOUND:
if (removed) setflag(addr, af_local_host_removed);
break;
case HOST_FIND_FAILED:
if (lookup_type & LK_DEFAULT)
{
DEBUG(D_route|D_host_lookup)
debug_printf("DNS lookup failed: trying getipnodebyname\n");
rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
&canonical_name, TRUE);
}
break;
}
}
/* Temporary failure defers, unless pass_on_timeout is set */
if (rc == HOST_FIND_SECURITY)
{
addr->message = string_sprintf("host lookup for %s done insecurely" , h->name);
addr->basic_errno = ERRNO_DNSDEFER;
return DEFER;
}
if (rc == HOST_FIND_AGAIN)
{
if (rblock->pass_on_timeout)
{
DEBUG(D_route)
debug_printf("%s router timed out and pass_on_timeout set\n",
rblock->name);
return PASS;
}
addr->message = string_sprintf("host lookup for %s did not complete "
"(DNS timeout?)", h->name);
addr->basic_errno = ERRNO_DNSDEFER;
return DEFER;
}
/* Permanent failure is controlled by host_find_failed */
if (rc == HOST_FIND_FAILED)
{
if (hff_code == hff_ignore)
{
if (prev == NULL) addr->host_list = next_h; else prev->next = next_h;
continue; /* With the next host, leave prev unchanged */
}
if (hff_code == hff_pass) return PASS;
if (hff_code == hff_decline) return DECLINE;
addr->basic_errno = ERRNO_UNKNOWNHOST;
addr->message =
string_sprintf("lookup of host \"%s\" failed in %s router%s",
h->name, rblock->name,
f.host_find_failed_syntax? ": syntax error in name" : "");
if (hff_code == hff_defer) return DEFER;
if (hff_code == hff_fail) return FAIL;
addr->special_action = SPECIAL_FREEZE;
return DEFER;
}
/* Deal with the settings that were previously cleared:
port, mx and sort_key. */
if (port != PORT_NONE)
for (host_item * hh = h; hh != next_h; hh = hh->next)
hh->port = port;
if (mx != MX_NONE)
for (host_item * hh = h; hh != next_h; hh = hh->next)
{
hh->mx = mx;
hh->sort_key = sort_key;
}
/* A local host gets chopped, with its successors, if there are previous
hosts. Otherwise the self option is used. If it is set to "send", any
subsequent hosts that are also the local host do NOT get chopped. */
if (rc == HOST_FOUND_LOCAL && !self_send)
{
if (prev)
{
DEBUG(D_route)
{
debug_printf("Removed from host list:\n");
for (; h; h = h->next) debug_printf(" %s\n", h->name);
}
prev->next = NULL;
setflag(addr, af_local_host_removed);
break;
}
rc = rf_self_action(addr, h, rblock->self_code, rblock->self_rewrite,
rblock->self, addr_new);
if (rc != OK)
{
addr->host_list = NULL; /* Kill the host list for */
return rc; /* anything other than "send" */
}
self_send = TRUE;
}
/* Ensure that prev is the host before next_h; this will not be h if a lookup
found multiple addresses or multiple MX records. */
prev = h;
while (prev->next != next_h) prev = prev->next;
}
return OK;
}
/* Create a socket and connect to host (name or number, ipv6 ok)
at one of port-range.
Arguments:
type SOCK_DGRAM or SOCK_STREAM
af AF_INET6 or AF_INET for the socket type
address the remote address, in text form
portlo,porthi the remote port range
timeout a timeout
connhost if not NULL, host_item filled in with connection details
errstr pointer for allocated string on error
Return:
socket fd, or -1 on failure (having allocated an error string)
*/
int
ip_connectedsocket(int type, const uschar * hostname, int portlo, int porthi,
int timeout, host_item * connhost, uschar ** errstr)
{
int namelen, port;
host_item shost;
host_item *h;
int af = 0, fd, fd4 = -1, fd6 = -1;
shost.next = NULL;
shost.address = NULL;
shost.port = portlo;
shost.mx = -1;
namelen = Ustrlen(hostname);
/* Anything enclosed in [] must be an IP address. */
if (hostname[0] == '[' &&
hostname[namelen - 1] == ']')
{
uschar * host = string_copy(hostname);
host[namelen - 1] = 0;
host++;
if (string_is_ip_address(host, NULL) == 0)
{
*errstr = string_sprintf("malformed IP address \"%s\"", hostname);
return -1;
}
shost.name = shost.address = host;
}
/* Otherwise check for an unadorned IP address */
else if (string_is_ip_address(hostname, NULL) != 0)
shost.name = shost.address = string_copy(hostname);
/* Otherwise lookup IP address(es) from the name */
else
{
shost.name = string_copy(hostname);
if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL,
FALSE) != HOST_FOUND)
{
*errstr = string_sprintf("no IP address found for host %s", shost.name);
return -1;
}
}
/* Try to connect to the server - test each IP till one works */
for (h = &shost; h != NULL; h = h->next)
{
fd = (Ustrchr(h->address, ':') != 0)
? (fd6 < 0) ? (fd6 = ip_socket(type, af = AF_INET6)) : fd6
: (fd4 < 0) ? (fd4 = ip_socket(type, af = AF_INET )) : fd4;
if (fd < 0)
{
*errstr = string_sprintf("failed to create socket: %s", strerror(errno));
goto bad;
}
for(port = portlo; port <= porthi; port++)
if (ip_connect(fd, af, h->address, port, timeout) == 0)
{
if (fd != fd6) close(fd6);
if (fd != fd4) close(fd4);
if (connhost) {
h->port = port;
*connhost = *h;
connhost->next = NULL;
}
return fd;
}
}
*errstr = string_sprintf("failed to connect to any address for %s: %s",
hostname, strerror(errno));
bad:
close(fd4); close(fd6); return -1;
}