diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index 7dc8f9c878..06d35462ba 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -908,8 +908,9 @@ connection_ap_rewrite_and_attach_if_allowed(entry_connection_t *conn,
return connection_ap_handshake_rewrite_and_attach(conn, circ, cpath);
}
-/* Try to perform any map-based rewriting of the target address in conn,
- * filling in the fields of out as we go.
+/* Try to perform any map-based rewriting of the target address in
+ * conn, filling in the fields of out as we go, and modifying
+ * conn->socks_request.address as appropriate.
*/
STATIC void
connection_ap_handshake_rewrite(entry_connection_t *conn,
@@ -919,6 +920,7 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
const or_options_t *options = get_options();
tor_addr_t addr_tmp;
+ /* Initialize all the fields of 'out' to reasonable defaults */
out->automap = 0;
out->exit_source = ADDRMAPSRC_NONE;
out->map_expires = TIME_MAX;
@@ -926,12 +928,17 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
out->should_close = 0;
out->orig_address[0] = 0;
- tor_strlower(socks->address); /* normalize it */
+ /* We convert all incoming addresses to lowercase. */
+ tor_strlower(socks->address);
+ /* Remember the original address. */
strlcpy(out->orig_address, socks->address, sizeof(out->orig_address));
log_debug(LD_APP,"Client asked for %s:%d",
safe_str_client(socks->address),
socks->port);
+ /* Check for whether this is a .exit address. By default, those are
+ * disallowed when they're coming straight from the client, but you're
+ * allowed to have them in MapAddress commands and so forth. */
if (!strcmpend(socks->address, ".exit") && !options->AllowDotExit) {
log_warn(LD_APP, "The \".exit\" notation is disabled in Tor due to "
"security risks. Set AllowDotExit in your torrc to enable "
@@ -943,9 +950,18 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
return;
}
- if (! conn->original_dest_address)
+ /* Remember the original address so we can tell the user about what
+ * they actually said, not just what it turned into. */
+ if (! conn->original_dest_address) {
+ /* Is the 'if' necessary here? XXXX */
conn->original_dest_address = tor_strdup(conn->socks_request->address);
+ }
+ /* First, apply MapAddress and MAPADDRESS mappings. We need to do
+ * these only for non-reverse lookups, since they don't exist for those.
+ * We need to do this before we consider automapping, since we might
+ * e.g. resolve irc.oftc.net into irconionaddress.onion, at which point
+ * we'd need to automap it. */
if (socks->command != SOCKS_COMMAND_RESOLVE_PTR) {
const unsigned rewrite_flags = AMR_FLAG_USE_MAPADDRESS;
if (addressmap_rewrite(socks->address, sizeof(socks->address),
@@ -955,12 +971,20 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
}
}
+ /* Now, handle automapping. Automapping happens when we're asked to
+ * resolve a hostname, and AutomapHostsOnResolve is set, and
+ * the hostname has a suffix listed in AutomapHostsSuffixes.
+ */
if (socks->command == SOCKS_COMMAND_RESOLVE &&
tor_addr_parse(&addr_tmp, socks->address)<0 &&
options->AutomapHostsOnResolve) {
+ /* Check the suffix... */
out->automap = addressmap_address_should_automap(socks->address, options);
if (out->automap) {
+ /* If we get here, then we should apply an automapping for this. */
const char *new_addr;
+ /* We return an IPv4 address by default, or an IPv6 address if we
+ * are allowed to do so. */
int addr_type = RESOLVED_TYPE_IPV4;
if (conn->socks_request->socks_version != 4) {
if (!conn->ipv4_traffic_ok ||
@@ -968,6 +992,10 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
conn->prefer_ipv6_virtaddr)
addr_type = RESOLVED_TYPE_IPV6;
}
+ /* Okay, register the target address as automapped, and find the new
+ * address we're supposed to give as a resolve answer. (Return a cached
+ * value if we've looked up this address before.
+ */
new_addr = addressmap_register_virtual_address(
addr_type, tor_strdup(socks->address));
if (! new_addr) {
@@ -984,6 +1012,8 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
}
}
+ /* Now handle reverse lookups, if they're in the cache. This doesn't
+ * happen too often, since client-side DNS caching is off by default. */
if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
unsigned rewrite_flags = 0;
if (conn->use_cached_ipv4_answers)
@@ -1007,6 +1037,10 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
out->should_close = 1;
return;
}
+
+ /* Hang on, did we find an answer saying that this is a reverse lookup for
+ * an internal address? If so, we should reject it if we're condigured to
+ * do so. */
if (options->ClientDNSRejectInternalAddresses) {
/* Don't let people try to do a reverse lookup on 10.0.0.1. */
tor_addr_t addr;
@@ -1022,8 +1056,16 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
return;
}
}
- } else if (!out->automap) {
- /* For address map controls, remap the address. */
+ }
+
+ /* If we didn't automap it before, then this is still the address
+ * that came straight from the user, mapped according to any
+ * MapAddress/MAPADDRESS commands. Now other mappings, including
+ * previously registered Automap entries, TrackHostExits entries,
+ * and client-side DNS cache entries (not recommended).
+ */
+ if (!socks->command != SOCKS_COMMAND_RESOLVE_PTR &&
+ !out->automap) {
unsigned rewrite_flags = AMR_FLAG_USE_AUTOMAP | AMR_FLAG_USE_TRACKEXIT;
addressmap_entry_source_t exit_source2;
if (conn->use_cached_ipv4_answers)
@@ -1036,15 +1078,20 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
REMAP_STREAM_SOURCE_CACHE);
}
if (out->exit_source == ADDRMAPSRC_NONE) {
+ /* If it wasn't a .exit before, maybe it turned into a .exit. Remember
+ * the original source of a .exit. */
out->exit_source = exit_source2;
}
}
+ /* Check to see whether we're about to use an address in the virtual
+ * range without actually having gotten it from an Automap. */
if (!out->automap && address_is_in_virtual_range(socks->address)) {
- /* This address was probably handed out by client_dns_get_unmapped_address,
- * but the mapping was discarded for some reason. We *don't* want to send
- * the address through Tor; that's likely to fail, and may leak
- * information.
+ /* This address was probably handed out by
+ * client_dns_get_unmapped_address, but the mapping was discarded for some
+ * reason. Or the user typed in a virtual address range manually. We
+ * *don't* want to send the address through Tor; that's likely to fail,
+ * and may leak information.
*/
log_warn(LD_APP,"Missing mapping for virtual address '%s'. Refusing.",
safe_str_client(socks->address));
@@ -1075,7 +1122,6 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
crypt_path_t *cpath)
{
socks_request_t *socks = conn->socks_request;
- hostname_type_t addresstype;
const or_options_t *options = get_options();
connection_t *base_conn = ENTRY_TO_CONN(conn);
time_t now = time(NULL);
@@ -1085,22 +1131,27 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
connection_ap_handshake_rewrite(conn,&rr);
if (rr.should_close) {
+ /* connection_ap_handshake_rewrite told us to close the connection,
+ * either because it sent back an answer, or because it sent back an
+ * error */
connection_mark_unattached_ap(conn, rr.end_reason);
- if (0 != (rr.end_reason & END_STREAM_REASON_DONE))
+ if (END_STREAM_REASON_DONE == (rr.end_reason & END_STREAM_REASON_MASK))
return 0;
else
return -1;
}
- time_t map_expires = rr.map_expires;
- int automap = rr.automap;
- addressmap_entry_source_t exit_source = rr.exit_source;
+ const time_t map_expires = rr.map_expires;
+ const int automap = rr.automap;
+ const addressmap_entry_source_t exit_source = rr.exit_source;
/* Parse the address provided by SOCKS. Modify it in-place if it
* specifies a hidden-service (.onion) or particular exit node (.exit).
*/
- addresstype = parse_extended_hostname(socks->address);
+ const hostname_type_t addresstype = parse_extended_hostname(socks->address);
+ /* Now see whether the hostname is bogus. This could happen because of an
+ * onion hostname whose format we don't recognize. */
if (addresstype == BAD_HOSTNAME) {
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
@@ -1108,16 +1159,21 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
+ /* If this is a .exit hostname, strip off the .name.exit part, and
+ * see whether we're going to connect there, and otherwise handle it.
+ * (The ".exit" part got stripped off by "parse_extended_hostname").
+ *
+ * We'll set chosen_exit_name and/or close the connection as appropriate.
+ */
if (addresstype == EXIT_HOSTNAME) {
- /* foo.exit -- modify conn->chosen_exit_node to specify the exit
- * node, and conn->address to hold only the address portion. */
- char *s = strrchr(socks->address,'.');
-
- /* If StrictNodes is not set, then .exit overrides ExcludeNodes. */
+ /* If StrictNodes is not set, then .exit overrides ExcludeNodes but
+ * not ExcludeExitNodes. */
routerset_t *excludeset = options->StrictNodes ?
options->ExcludeExitNodesUnion_ : options->ExcludeExitNodes;
- const node_t *node;
+ const node_t *node = NULL;
+ /* If this .exit was added by an AUTOMAP, then it came straight from
+ * a user. Make sure that options->AllowDotExit permits that. */
if (exit_source == ADDRMAPSRC_AUTOMAP && !options->AllowDotExit) {
/* Whoops; this one is stale. It must have gotten added earlier,
* when AllowDotExit was on. */
@@ -1130,6 +1186,8 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
+ /* Double-check to make sure there are no .exits coming from
+ * impossible/weird sources. */
if (exit_source == ADDRMAPSRC_DNS ||
(exit_source == ADDRMAPSRC_NONE && !options->AllowDotExit)) {
/* It shouldn't be possible to get a .exit address from any of these
@@ -1144,9 +1202,12 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
}
tor_assert(!automap);
+ /* Now, find the character before the .(name) part. */
+ char *s = strrchr(socks->address,'.');
if (s) {
/* The address was of the form "(stuff).(name).exit */
if (s[1] != '\0') {
+ /* Looks like a real .exit one. */
conn->chosen_exit_name = tor_strdup(s+1);
node = node_get_by_nickname(conn->chosen_exit_name, 1);
@@ -1165,7 +1226,8 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
} else {
- /* It looks like they just asked for "foo.exit". */
+ /* It looks like they just asked for "foo.exit". That's a special
+ * form that means (foo's address).foo.exit. */
conn->chosen_exit_name = tor_strdup(socks->address);
node = node_get_by_nickname(conn->chosen_exit_name, 1);
@@ -1174,6 +1236,7 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
node_get_address_string(node, socks->address, sizeof(socks->address));
}
}
+
/* Now make sure that the chosen exit exists... */
if (!node) {
log_warn(LD_APP,
@@ -1195,8 +1258,12 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
implies no. */
}
+ /* Now, handle everything that isn't a .onion address. */
if (addresstype != ONION_HOSTNAME) {
- /* not a hidden-service request (i.e. normal or .exit) */
+ /* Not a hidden-service request. It's either a hostname or an IP,
+ * possibly with a .exit that we stripped off. */
+
+ /* Check for funny characters in the address. */
if (address_is_invalid_destination(socks->address, 1)) {
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
@@ -1207,6 +1274,8 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
+ /* If we're running in Tor2webMode, we don't allow anything BUT .onion
+ * addresses. */
if (options->Tor2webMode) {
log_warn(LD_APP, "Refusing to connect to non-hidden-service hostname %s "
"because tor2web mode is enabled.",
@@ -1215,6 +1284,9 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
+ /* See if this is a hostname lookup that we can answer immediately.
+ * (For example, an attempt to look up the IP address for an IP address.)
+ */
if (socks->command == SOCKS_COMMAND_RESOLVE) {
tor_addr_t answer;
/* Reply to resolves immediately if we can. */
@@ -1231,14 +1303,22 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
tor_assert(!automap);
rep_hist_note_used_resolve(now); /* help predict this next time */
} else if (socks->command == SOCKS_COMMAND_CONNECT) {
+ /* Special handling for attempts to connect */
tor_assert(!automap);
+ /* Don't allow connections to port 0. */
if (socks->port == 0) {
log_notice(LD_APP,"Application asked to connect to port 0. Refusing.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
+ /* You can't make connections to internal addresses, by default.
+ * Exceptions are begindir requests (where the address is meaningless,
+ * or cases where you've hand-configured a particular exit, thereby
+ * making the local address meaningful. */
if (options->ClientRejectInternalAddresses &&
!conn->use_begindir && !conn->chosen_exit_name && !circ) {
+ /* If we reach this point then we don't want to allow internal
+ * addresses. Check if we got one. */
tor_addr_t addr;
if (tor_addr_hostname_is_local(socks->address) ||
(tor_addr_parse(&addr, socks->address) >= 0 &&
@@ -1273,31 +1353,46 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
connection_mark_unattached_ap(conn, END_STREAM_REASON_PRIVATE_ADDR);
return -1;
}
- }
+ } /* end "if we should check for internal addresses" */
+ /* Okay. We're still doing a CONNECT, and it wasn't a private
+ * address. Do special handling for literal IP addresses */
{
tor_addr_t addr;
/* XXX Duplicate call to tor_addr_parse. */
if (tor_addr_parse(&addr, socks->address) >= 0) {
+ /* If we reach this point, it's an IPv4 or an IPv6 address. */
sa_family_t family = tor_addr_family(&addr);
+
if ((family == AF_INET && ! conn->ipv4_traffic_ok) ||
(family == AF_INET6 && ! conn->ipv4_traffic_ok)) {
+ /* You can't do an IPv4 address on a v6-only socks listener,
+ * or vice versa. */
log_warn(LD_NET, "Rejecting SOCKS request for an IP address "
"family that this listener does not support.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
} else if (family == AF_INET6 && socks->socks_version == 4) {
+ /* You can't make a socks4 request to an IPv6 address. Socks4
+ * doesn't support that. */
log_warn(LD_NET, "Rejecting SOCKS4 request for an IPv6 address.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
} else if (socks->socks_version == 4 && !conn->ipv4_traffic_ok) {
+ /* You can't do any kind of Socks4 request when IPv4 is forbidden.
+ *
+ * XXX raise this check outside the enclosing block? */
log_warn(LD_NET, "Rejecting SOCKS4 request on a listener with "
"no IPv4 traffic supported.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
} else if (family == AF_INET6) {
+ /* Tell the exit: we won't accept any ipv4 connection to an IPv6
+ * address. */
conn->ipv4_traffic_ok = 0;
} else if (family == AF_INET) {
+ /* Tell the exit: we won't accept any ipv6 connection to an IPv4
+ * address. */
conn->ipv6_traffic_ok = 0;
}
}
@@ -1306,6 +1401,9 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
if (socks->socks_version == 4)
conn->ipv6_traffic_ok = 0;
+ /* Still handling CONNECT. Now, check for exit enclaves. (Which we
+ * don't do on BEGINDIR, or there is a chosen exit.)
+ */
if (!conn->use_begindir && !conn->chosen_exit_name && !circ) {
/* see if we can find a suitable enclave exit */
const node_t *r =
@@ -1322,11 +1420,13 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
}
}
- /* warn or reject if it's using a dangerous port */
+ /* Still handling CONNECT: warn or reject if it's using a dangerous
+ * port. */
if (!conn->use_begindir && !conn->chosen_exit_name && !circ)
if (consider_plaintext_ports(conn, socks->port) < 0)
return -1;
+ /* Remember the port so that we do predicted requests there. */
if (!conn->use_begindir) {
/* help predict this next time */
rep_hist_note_used_port(now, socks->port);
@@ -1335,25 +1435,41 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
rep_hist_note_used_resolve(now); /* help predict this next time */
/* no extra processing needed */
} else {
+ /* We should only be doing CONNECT or RESOLVE! */
tor_fragile_assert();
}
+
+ /* Okay. At this point we've set chosen_exit_name if needed, rewritten the
+ * address, and decided not to reject it for any number of reasons. Now
+ * mark the connection as waiting for a circuit, and try to attach it!
+ */
base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- if ((circ && connection_ap_handshake_attach_chosen_circuit(
- conn, circ, cpath) < 0) ||
- (!circ &&
- connection_ap_handshake_attach_circuit(conn) < 0)) {
+
+ /* If we were given a circuit to attach to, try to attach. Otherwise,
+ * try to find a good one and attach to that. */
+ int rv;
+ if (circ)
+ rv = connection_ap_handshake_attach_chosen_circuit(conn, circ, cpath);
+ else
+ rv = connection_ap_handshake_attach_circuit(conn);
+
+ /* If the above function returned 0 then we're waiting for a circuit.
+ * if it returned 1, we're attached. Both are okay. But if it returned
+ * -1, there was an error, so make sure the connection is marked, and
+ * return -1. */
+ if (rv < 0) {
if (!base_conn->marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
return -1;
}
+
return 0;
} else {
- /* it's a hidden-service request */
- rend_cache_entry_t *entry;
- int r;
- rend_service_authorization_t *client_auth;
- rend_data_t *rend_data;
+ /* If we get here, it's a request for a .onion address! */
tor_assert(!automap);
+
+ /* Check whether it's RESOLVE or RESOLVE_PTR. We don't handle those
+ * for hidden service addresses. */
if (SOCKS_COMMAND_IS_RESOLVE(socks->command)) {
/* if it's a resolve request, fail it right now, rather than
* building all the circuits and then realizing it won't work. */
@@ -1367,6 +1483,8 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
+ /* If we were passed a circuit, then we need to fail. .onion addresses
+ * only work when we launch our own circuits for now. */
if (circ) {
log_warn(LD_CONTROL, "Attachstream to a circuit is not "
"supported for .onion addresses currently. Failing.");
@@ -1374,15 +1492,22 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
return -1;
}
- ENTRY_TO_EDGE_CONN(conn)->rend_data = rend_data =
+ /* Fill in the rend_data field so we can start doing a connection to
+ * a hidden service. */
+ rend_data_t *rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data =
tor_malloc_zero(sizeof(rend_data_t));
strlcpy(rend_data->onion_address, socks->address,
sizeof(rend_data->onion_address));
log_info(LD_REND,"Got a hidden service request for ID '%s'",
safe_str_client(rend_data->onion_address));
- /* see if we already have it cached */
- r = rend_cache_lookup_entry(rend_data->onion_address, -1, &entry);
- if (r<0) {
+
+ /* see if we already have a hidden service descriptor cached for this
+ * address. */
+ rend_cache_entry_t *entry = NULL;
+ const int rend_cache_lookup_result =
+ rend_cache_lookup_entry(rend_data->onion_address, -1, &entry);
+ if (rend_cache_lookup_result < 0) {
+ /* We should already have rejected this address! */
log_warn(LD_BUG,"Invalid service name '%s'",
safe_str_client(rend_data->onion_address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
@@ -1393,8 +1518,10 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
* a stable circuit yet, but we know we'll need *something*. */
rep_hist_note_used_internal(now, 0, 1);
- /* Look up if we have client authorization for it. */
- client_auth = rend_client_lookup_service_authorization(
+ /* Look up if we have client authorization configured for this hidden
+ * service. If we do, associate it with the rend_data. */
+ rend_service_authorization_t *client_auth =
+ rend_client_lookup_service_authorization(
rend_data->onion_address);
if (client_auth) {
log_info(LD_REND, "Using previously configured client authorization "
@@ -1403,12 +1530,16 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
client_auth->descriptor_cookie, REND_DESC_COOKIE_LEN);
rend_data->auth_type = client_auth->auth_type;
}
- if (r==0) {
+
+ /* Now, we either launch an attempt to connect to the hidden service,
+ * or we launch an attempt to look up its descriptor, depending on
+ * whether we had the descriptor. */
+ if (rend_cache_lookup_result == 0) {
base_conn->state = AP_CONN_STATE_RENDDESC_WAIT;
log_info(LD_REND, "Unknown descriptor %s. Fetching.",
safe_str_client(rend_data->onion_address));
rend_client_refetch_v2_renddesc(rend_data);
- } else { /* r > 0 */
+ } else { /* rend_cache_lookup_result > 0 */
base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
log_info(LD_REND, "Descriptor is here. Great.");
if (connection_ap_handshake_attach_circuit(conn) < 0) {
@@ -1419,6 +1550,7 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
}
return 0;
}
+
return 0; /* unreached but keeps the compiler happy */
}
diff --git a/src/or/connection_edge.h b/src/or/connection_edge.h
index d4a20e7f96..0cc391ed82 100644
--- a/src/or/connection_edge.h
+++ b/src/or/connection_edge.h
@@ -151,8 +151,8 @@ typedef struct {
*/
char orig_address[MAX_SOCKS_ADDR_LEN];
/** True iff the address has been automatically remapped to a local
- * address in VirtualAddrNetwork. (Only set true the first time we
- * do the mapping.) */
+ * address in VirtualAddrNetwork. (Only set true when we do a resolve
+ * and get a virtual address; not when we connect to the address.) */
int automap;
/** If this connection has a .exit address, who put it there? */
addressmap_entry_source_t exit_source;