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tor/src/or/connection_edge.c

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/* Copyright 2001 Matej Pfajfar.
* Copyright 2001-2004 Roger Dingledine.
* Copyright 2004-2005 Roger Dingledine, Nick Mathewson. */
/* See LICENSE for licensing information */
/* $Id$ */
const char connection_edge_c_id[] = "$Id$";
/**
* \file connection_edge.c
* \brief Handle edge streams.
**/
#include "or.h"
#include "tree.h"
static addr_policy_t *socks_policy = NULL;
/* List of exit_redirect_t */
static smartlist_t *redirect_exit_list = NULL;
static int connection_ap_handshake_process_socks(connection_t *conn);
static int address_is_in_virtual_range(const char *addr);
/** An AP stream has failed/finished. If it hasn't already sent back
* a socks reply, send one now (based on endreason). Also set
* has_sent_end to 1, and mark the conn.
*/
void
_connection_mark_unattached_ap(connection_t *conn, int endreason,
int line, const char *file)
{
tor_assert(conn->type == CONN_TYPE_AP);
conn->has_sent_end = 1; /* no circ yet */
if (conn->marked_for_close) {
/* This call will warn as appropriate. */
_connection_mark_for_close(conn, line, file);
return;
}
if (!conn->socks_request->has_finished) {
socks5_reply_status_t socksreason =
connection_edge_end_reason_socks5_response(endreason);
if (endreason == END_STREAM_REASON_ALREADY_SOCKS_REPLIED)
log_fn(LOG_WARN,"Bug: stream (marked at %s:%d) sending two socks replies?",
file, line);
if (conn->socks_request->command == SOCKS_COMMAND_CONNECT)
connection_ap_handshake_socks_reply(conn, NULL, 0, socksreason);
else
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL,-1);
}
_connection_mark_for_close(conn, line, file);
conn->hold_open_until_flushed = 1;
}
/** There was an EOF. Send an end and mark the connection for close.
*/
int
connection_edge_reached_eof(connection_t *conn)
{
#ifdef HALF_OPEN
/* eof reached; we're done reading, but we might want to write more. */
conn->done_receiving = 1;
shutdown(conn->s, 0); /* XXX check return, refactor NM */
if (conn->done_sending) {
connection_edge_end(conn, END_STREAM_REASON_DONE, conn->cpath_layer);
connection_mark_for_close(conn);
} else {
connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_END,
NULL, 0, conn->cpath_layer);
}
return 0;
#else
if (buf_datalen(conn->inbuf) && connection_state_is_open(conn)) {
/* it still has stuff to process. don't let it die yet. */
return 0;
}
log_fn(LOG_INFO,"conn (fd %d) reached eof. Closing.", conn->s);
if (!conn->marked_for_close) {
/* only mark it if not already marked. it's possible to
* get the 'end' right around when the client hangs up on us. */
connection_edge_end(conn, END_STREAM_REASON_DONE, conn->cpath_layer);
if (conn->socks_request) /* eof, so don't send a socks reply back */
conn->socks_request->has_finished = 1;
connection_mark_for_close(conn);
}
return 0;
#endif
}
/** Handle new bytes on conn->inbuf based on state:
* - If it's waiting for socks info, try to read another step of the
* socks handshake out of conn->inbuf.
* - If it's open, then package more relay cells from the stream.
* - Else, leave the bytes on inbuf alone for now.
*
* Mark and return -1 if there was an unexpected error with the conn,
* else return 0.
*/
int
connection_edge_process_inbuf(connection_t *conn, int package_partial)
{
tor_assert(conn);
tor_assert(CONN_IS_EDGE(conn));
switch (conn->state) {
case AP_CONN_STATE_SOCKS_WAIT:
if (connection_ap_handshake_process_socks(conn) < 0) {
/* already marked */
return -1;
}
return 0;
case AP_CONN_STATE_OPEN:
case EXIT_CONN_STATE_OPEN:
if (connection_edge_package_raw_inbuf(conn, package_partial) < 0) {
/* (We already sent an end cell if possible) */
connection_mark_for_close(conn);
return -1;
}
return 0;
case EXIT_CONN_STATE_CONNECTING:
case AP_CONN_STATE_RENDDESC_WAIT:
case AP_CONN_STATE_CIRCUIT_WAIT:
case AP_CONN_STATE_CONNECT_WAIT:
case AP_CONN_STATE_RESOLVE_WAIT:
case AP_CONN_STATE_CONTROLLER_WAIT:
log_fn(LOG_INFO,"data from edge while in '%s' state. Leaving it on buffer.",
conn_state_to_string(conn->type, conn->state));
return 0;
}
log_fn(LOG_WARN,"Bug: Got unexpected state %d. Closing.",conn->state);
tor_fragile_assert();
connection_edge_end(conn, END_STREAM_REASON_INTERNAL, conn->cpath_layer);
connection_mark_for_close(conn);
return -1;
}
/** This edge needs to be closed, because its circuit has closed.
* Mark it for close and return 0.
*/
int
connection_edge_destroy(uint16_t circ_id, connection_t *conn)
{
tor_assert(CONN_IS_EDGE(conn));
if (!conn->marked_for_close) {
log_fn(LOG_INFO,"CircID %d: At an edge. Marking connection for close.",
circ_id);
if (conn->type == CONN_TYPE_AP) {
connection_mark_unattached_ap(conn, END_STREAM_REASON_DESTROY);
} else {
conn->has_sent_end = 1; /* we're closing the circuit, nothing to send to */
connection_mark_for_close(conn);
conn->hold_open_until_flushed = 1;
}
}
conn->cpath_layer = NULL;
conn->on_circuit = NULL;
return 0;
}
/** Send a relay end cell from stream <b>conn</b> to conn's circuit,
* with a destination of cpath_layer. (If cpath_layer is NULL, the
* destination is the circuit's origin.) Mark the relay end cell as
* closing because of <b>reason</b>.
*
* Return -1 if this function has already been called on this conn,
* else return 0.
*/
int
connection_edge_end(connection_t *conn, char reason, crypt_path_t *cpath_layer)
{
char payload[5];
size_t payload_len=1;
circuit_t *circ;
if (conn->has_sent_end) {
log_fn(LOG_WARN,"Harmless bug: Calling connection_edge_end (reason %d) on an already ended stream?", reason);
tor_fragile_assert();
return -1;
}
if (conn->marked_for_close) {
log_fn(LOG_WARN,"Bug: called on conn that's already marked for close at %s:%d.",
conn->marked_for_close_file, conn->marked_for_close);
return 0;
}
payload[0] = reason;
if (reason == END_STREAM_REASON_EXITPOLICY) {
/* this is safe even for rend circs, because they never fail
* because of exitpolicy */
set_uint32(payload+1, htonl(conn->addr));
set_uint32(payload+5, htonl(MAX_DNS_ENTRY_AGE)); /* XXXXfill with a real TTL*/
payload_len += 8;
}
circ = circuit_get_by_edge_conn(conn);
if (circ && !circ->marked_for_close) {
log_fn(LOG_DEBUG,"Marking conn (fd %d) and sending end.",conn->s);
connection_edge_send_command(conn, circ, RELAY_COMMAND_END,
payload, payload_len, cpath_layer);
} else {
log_fn(LOG_DEBUG,"Marking conn (fd %d); no circ to send end.",conn->s);
}
conn->has_sent_end = 1;
return 0;
}
/** An error has just occured on an operation on an edge connection
* <b>conn</b>. Extract the errno; convert it to an end reason, and send
* an appropriate relay end cell to <b>cpath_layer</b>.
**/
int
connection_edge_end_errno(connection_t *conn, crypt_path_t *cpath_layer)
{
uint8_t reason;
tor_assert(conn);
reason = (uint8_t)errno_to_end_reason(tor_socket_errno(conn->s));
return connection_edge_end(conn, reason, cpath_layer);
}
/** Connection <b>conn</b> has finished writing and has no bytes left on
* its outbuf.
*
* If it's in state 'open', stop writing, consider responding with a
* sendme, and return.
* Otherwise, stop writing and return.
*
* If <b>conn</b> is broken, mark it for close and return -1, else
* return 0.
*/
int
connection_edge_finished_flushing(connection_t *conn)
{
tor_assert(conn);
tor_assert(CONN_IS_EDGE(conn));
switch (conn->state) {
case AP_CONN_STATE_OPEN:
case EXIT_CONN_STATE_OPEN:
connection_stop_writing(conn);
connection_edge_consider_sending_sendme(conn);
return 0;
case AP_CONN_STATE_SOCKS_WAIT:
case AP_CONN_STATE_RENDDESC_WAIT:
case AP_CONN_STATE_CIRCUIT_WAIT:
case AP_CONN_STATE_CONNECT_WAIT:
case AP_CONN_STATE_CONTROLLER_WAIT:
connection_stop_writing(conn);
return 0;
default:
log_fn(LOG_WARN,"BUG: called in unexpected state %d.", conn->state);
tor_fragile_assert();
return -1;
}
return 0;
}
/** Connected handler for exit connections: start writing pending
* data, deliver 'CONNECTED' relay cells as appropriate, and check
* any pending data that may have been received. */
int
connection_edge_finished_connecting(connection_t *conn)
{
char valbuf[INET_NTOA_BUF_LEN];
struct in_addr in;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_EXIT);
tor_assert(conn->state == EXIT_CONN_STATE_CONNECTING);
in.s_addr = htonl(conn->addr);
tor_inet_ntoa(&in,valbuf,sizeof(valbuf));
log_fn(LOG_INFO,"Exit connection to %s:%u (%s) established.",
safe_str(conn->address),conn->port,safe_str(valbuf));
conn->state = EXIT_CONN_STATE_OPEN;
connection_watch_events(conn, EV_READ); /* stop writing, continue reading */
if (connection_wants_to_flush(conn)) /* in case there are any queued relay cells */
connection_start_writing(conn);
/* deliver a 'connected' relay cell back through the circuit. */
if (connection_edge_is_rendezvous_stream(conn)) {
if (connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_CONNECTED, NULL, 0, conn->cpath_layer) < 0)
return 0; /* circuit is closed, don't continue */
} else {
char connected_payload[8];
set_uint32(connected_payload, htonl(conn->addr));
set_uint32(connected_payload+4,
htonl(MAX_DNS_ENTRY_AGE)); /* XXXX fill with a real TTL */
if (connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_CONNECTED, connected_payload, 8, conn->cpath_layer) < 0)
return 0; /* circuit is closed, don't continue */
}
tor_assert(conn->package_window > 0);
/* in case the server has written anything */
return connection_edge_process_inbuf(conn, 1);
}
/** Find all general-purpose AP streams waiting for a response that sent
* their begin/resolve cell >=15 seconds ago. Detach from their current circuit,
* and mark their current circuit as unsuitable for new streams. Then call
* connection_ap_handshake_attach_circuit() to attach to a new circuit (if
* available) or launch a new one.
*
* For rendezvous streams, simply give up after 45 seconds (with no
* retry attempt).
*/
void
connection_ap_expire_beginning(void)
{
connection_t **carray;
connection_t *conn;
circuit_t *circ;
int n, i;
time_t now = time(NULL);
or_options_t *options = get_options();
get_connection_array(&carray, &n);
for (i = 0; i < n; ++i) {
conn = carray[i];
if (conn->type != CONN_TYPE_AP)
continue;
if (conn->state == AP_CONN_STATE_CONTROLLER_WAIT) {
if (now - conn->timestamp_lastread >= 120) {
log_fn(LOG_NOTICE, "Closing unattached stream.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_TIMEOUT);
}
continue;
}
else if (conn->state != AP_CONN_STATE_RESOLVE_WAIT &&
conn->state != AP_CONN_STATE_CONNECT_WAIT)
continue;
if (now - conn->timestamp_lastread < 15)
continue;
circ = circuit_get_by_edge_conn(conn);
if (!circ) { /* it's vanished? */
log_fn(LOG_INFO,"Conn is waiting (address %s), but lost its circ.",
safe_str(conn->socks_request->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TIMEOUT);
continue;
}
if (circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
if (now - conn->timestamp_lastread > 45) {
log_fn(LOG_NOTICE,"Rend stream is %d seconds late. Giving up on address '%s'.",
(int)(now - conn->timestamp_lastread),
safe_str(conn->socks_request->address));
connection_edge_end(conn, END_STREAM_REASON_TIMEOUT, conn->cpath_layer);
connection_mark_unattached_ap(conn, END_STREAM_REASON_TIMEOUT);
}
continue;
}
tor_assert(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL);
log_fn(LOG_NOTICE,"Stream is %d seconds late on address '%s'. Retrying.",
(int)(now - conn->timestamp_lastread),
safe_str(conn->socks_request->address));
circuit_log_path(LOG_NOTICE, circ);
/* send an end down the circuit */
connection_edge_end(conn, END_STREAM_REASON_TIMEOUT, conn->cpath_layer);
/* un-mark it as ending, since we're going to reuse it */
conn->has_sent_end = 0;
/* kludge to make us not try this circuit again, yet to allow
* current streams on it to survive if they can: make it
* unattractive to use for new streams */
tor_assert(circ->timestamp_dirty);
circ->timestamp_dirty -= options->MaxCircuitDirtiness;
/* give our stream another 15 seconds to try */
conn->timestamp_lastread += 15;
/* move it back into 'pending' state, and try to attach. */
if (connection_ap_detach_retriable(conn, circ)<0) {
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
}
} /* end for */
}
/** Tell any AP streams that are waiting for a new circuit that one is
* available.
*/
void
connection_ap_attach_pending(void)
{
connection_t **carray;
connection_t *conn;
int n, i;
get_connection_array(&carray, &n);
for (i = 0; i < n; ++i) {
conn = carray[i];
if (conn->marked_for_close ||
conn->type != CONN_TYPE_AP ||
conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
continue;
if (connection_ap_handshake_attach_circuit(conn) < 0) {
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
}
}
}
/** The AP connection <b>conn</b> has just failed while attaching or
* sending a BEGIN or resolving on <b>circ</b>, but another circuit
* might work. Detach the circuit, and either reattach it, launch a
* new circuit, tell the controller, or give up as a appropriate.
*
* Returns -1 on err, 1 on success, 0 on not-yet-sure.
*/
int
connection_ap_detach_retriable(connection_t *conn, circuit_t *circ)
{
control_event_stream_status(conn, STREAM_EVENT_FAILED_RETRIABLE);
conn->timestamp_lastread = time(NULL);
if (! get_options()->LeaveStreamsUnattached) {
conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
circuit_detach_stream(circ,conn);
return connection_ap_handshake_attach_circuit(conn);
} else {
conn->state = AP_CONN_STATE_CONTROLLER_WAIT;
circuit_detach_stream(circ,conn);
return 0;
}
}
/** A client-side struct to remember requests to rewrite addresses
* to new addresses. These structs make up a tree, with addressmap
* below as its root.
*
* There are 5 ways to set an address mapping:
* - A MapAddress command from the controller [permanent]
* - An AddressMap directive in the torrc [permanent]
* - When a TrackHostExits torrc directive is triggered [temporary]
* - When a dns resolve succeeds [temporary]
* - When a dns resolve fails [temporary]
*
* When an addressmap request is made but one is already registered,
* the new one is replaced only if the currently registered one has
* no "new_address" (that is, it's in the process of dns resolve),
* or if the new one is permanent (expires==0 or 1).
*
* (We overload the 'expires' field, using "0" for mappings set via
* the configuration file, "1" for mappings set from the control
* interface, and other values for DNS mappings that can expire.)
*/
typedef struct {
char *new_address;
time_t expires;
int num_resolve_failures;
} addressmap_entry_t;
typedef struct {
char *ipv4_address;
char *hostname_address;
} virtaddress_entry_t;
/** The tree of client-side address rewrite instructions. */
static strmap_t *addressmap=NULL;
/**
* Tree mapping addresses to which virtual address, if any, we
* assigned them to.
*
* We maintain the following invariant: if [A,B] is in
* virtaddress_reversemap, then B must be a virtual address, and [A,B]
* must be in addressmap. We do not require that the converse hold:
* if it fails, then we could end up mapping two virtual addresses to
* the same address, which is no disaster.
**/
static strmap_t *virtaddress_reversemap=NULL;
/** Initialize addressmap. */
void
addressmap_init(void)
{
addressmap = strmap_new();
virtaddress_reversemap = strmap_new();
}
/** Free the memory associated with the addressmap entry <b>_ent</b>. */
static void
addressmap_ent_free(void *_ent)
{
addressmap_entry_t *ent = _ent;
tor_free(ent->new_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b> */
static void
addressmap_virtaddress_ent_free(void *_ent)
{
virtaddress_entry_t *ent = _ent;
tor_free(ent->ipv4_address);
tor_free(ent->hostname_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b> */
static void
addressmap_virtaddress_remove(const char *addr, addressmap_entry_t *ent)
{
if (ent && ent->new_address && address_is_in_virtual_range(ent->new_address)) {
virtaddress_entry_t *ve =
strmap_get(virtaddress_reversemap, ent->new_address);
/*log_fn(LOG_NOTICE,"remove reverse mapping for %s",ent->new_address);*/
if (ve) {
if (!strcmp(addr, ve->ipv4_address))
tor_free(ve->ipv4_address);
if (!strcmp(addr, ve->hostname_address))
tor_free(ve->hostname_address);
if (!ve->ipv4_address && !ve->hostname_address) {
tor_free(ve);
strmap_remove(virtaddress_reversemap, ent->new_address);
}
}
}
}
/* DOCDOC */
static void
addressmap_ent_remove(const char *addr, addressmap_entry_t *ent)
{
addressmap_virtaddress_remove(addr, ent);
addressmap_ent_free(ent);
}
/** Remove all entries from the addressmap that were set via the
* configuration file or the command line. */
void
addressmap_clear_configured(void)
{
addressmap_get_mappings(NULL, 0, 0);
}
/** Remove all entries from the addressmap that are set to expire, ever. */
void
addressmap_clear_transient(void)
{
addressmap_get_mappings(NULL, 2, TIME_MAX);
}
/** Clean out entries from the addressmap cache that were
* added long enough ago that they are no longer valid.
*/
void
addressmap_clean(time_t now)
{
addressmap_get_mappings(NULL, 2, now);
}
/** Free all the elements in the addressmap, and free the addressmap
* itself. */
void
addressmap_free_all(void)
{
strmap_free(addressmap, addressmap_ent_free);
addressmap = NULL;
strmap_free(virtaddress_reversemap, addressmap_virtaddress_ent_free);
}
/** Look at address, and rewrite it until it doesn't want any
* more rewrites; but don't get into an infinite loop.
* Don't write more than maxlen chars into address.
*/
void
addressmap_rewrite(char *address, size_t maxlen)
{
addressmap_entry_t *ent;
int rewrites;
for (rewrites = 0; rewrites < 16; rewrites++) {
ent = strmap_get(addressmap, address);
if (!ent || !ent->new_address)
return; /* done, no rewrite needed */
log_fn(LOG_INFO, "Addressmap: rewriting '%s' to '%s'",
safe_str(address), safe_str(ent->new_address));
strlcpy(address, ent->new_address, maxlen);
}
log_fn(LOG_WARN,"Loop detected: we've rewritten '%s' 16 times! Using it as-is.",
safe_str(address));
/* it's fine to rewrite a rewrite, but don't loop forever */
}
/** Return 1 if <b>address</b> is already registered, else return 0 */
int
addressmap_already_mapped(const char *address)
{
return strmap_get(addressmap, address) ? 1 : 0;
}
/** Register a request to map <b>address</b> to <b>new_address</b>,
* which will expire on <b>expires</b> (or 0 if never expires from
* config file, 1 if never expires from controller, 2 if never expires
* (virtual address mapping) from the controller.)
*
* <b>new_address</b> should be a newly dup'ed string, which we'll use or
* free as appropriate. We will leave address alone.
*
* If <b>new_address</b> is NULL, or equal to <b>address</b>, remove
* any mappings that exist from <b>address</b>.
*/
void
addressmap_register(const char *address, char *new_address, time_t expires)
{
addressmap_entry_t *ent;
ent = strmap_get(addressmap, address);
if (!new_address || !strcasecmp(address,new_address)) {
/* Remove the mapping, if any. */
tor_free(new_address);
if (ent) {
addressmap_ent_remove(address,ent);
strmap_remove(addressmap, address);
}
return;
}
if (!ent) { /* make a new one and register it */
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
strmap_set(addressmap, address, ent);
} else if (ent->new_address) { /* we need to clean up the old mapping. */
if (expires > 1) {
log_fn(LOG_INFO,"Temporary addressmap ('%s' to '%s') not performed, since it's already mapped to '%s'",
safe_str(address), safe_str(new_address), safe_str(ent->new_address));
tor_free(new_address);
return;
}
if (address_is_in_virtual_range(ent->new_address) &&
expires != 2) {
/* XXX This isn't the perfect test; we want to avoid removing
* mappings set from the control interface _as virtual mapping */
addressmap_virtaddress_remove(address, ent);
}
tor_free(ent->new_address);
} /* else { we have an in-progress resolve with no mapping. } */
ent->new_address = new_address;
ent->expires = expires==2 ? 1 : expires;
ent->num_resolve_failures = 0;
log_fn(LOG_INFO, "Addressmap: (re)mapped '%s' to '%s'",
safe_str(address), safe_str(ent->new_address));
control_event_address_mapped(address, ent->new_address, expires);
}
/** An attempt to resolve <b>address</b> failed at some OR.
* Increment the number of resolve failures we have on record
* for it, and then return that number.
*/
int
client_dns_incr_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (!ent) {
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
ent->expires = time(NULL)+MAX_DNS_ENTRY_AGE;
strmap_set(addressmap,address,ent);
}
++ent->num_resolve_failures;
log_fn(LOG_INFO,"Address %s now has %d resolve failures.",
safe_str(address), ent->num_resolve_failures);
return ent->num_resolve_failures;
}
/** If <b>address</b> is in the client dns addressmap, reset
* the number of resolve failures we have on record for it.
* This is used when we fail a stream because it won't resolve:
* otherwise future attempts on that address will only try once.
*/
void
client_dns_clear_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (ent)
ent->num_resolve_failures = 0;
}
/** Record the fact that <b>address</b> resolved to <b>val</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds.
*/
void
client_dns_set_addressmap(const char *address, uint32_t val, const char *exitname,
int ttl)
{
struct in_addr in;
char extendedaddress[MAX_SOCKS_ADDR_LEN+MAX_HEX_NICKNAME_LEN+10];
char valbuf[INET_NTOA_BUF_LEN];
char extendedval[INET_NTOA_BUF_LEN+MAX_HEX_NICKNAME_LEN+10];
tor_assert(address); tor_assert(val);
if (ttl<0 || ttl>MAX_DNS_ENTRY_AGE)
ttl = MAX_DNS_ENTRY_AGE;
if (tor_inet_aton(address, &in))
return; /* If address was an IP address already, don't add a mapping. */
in.s_addr = htonl(val);
tor_inet_ntoa(&in,valbuf,sizeof(valbuf));
if (exitname) {
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s.%s.exit", address, exitname);
tor_snprintf(extendedval, sizeof(extendedval),
"%s.%s.exit", valbuf, exitname);
} else {
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s", address);
tor_snprintf(extendedval, sizeof(extendedval),
"%s", valbuf);
}
addressmap_register(extendedaddress, tor_strdup(extendedval), time(NULL) + ttl);
}
/* Currently, we hand out 127.192.0.1 through 127.254.254.254.
* These addresses should map to localhost, so even if the
* application accidentally tried to connect to them directly (not
* via Tor), it wouldn't get too far astray.
*
* Eventually, we should probably make this configurable.
*/
#define MIN_UNUSED_IPV4 0x7fc00001u
#define MAX_UNUSED_IPV4 0x7ffefefeu
/**
* Return true iff <b>addr</b> is likely to have been returned by
* client_dns_get_unused_address.
**/
static int
address_is_in_virtual_range(const char *addr)
{
struct in_addr in;
tor_assert(addr);
if (!strcasecmpend(addr, ".virtual")) {
return 1;
} else if (tor_inet_aton(addr, &in)) {
uint32_t a = ntohl(in.s_addr);
if (a >= MIN_UNUSED_IPV4 && a <= MAX_UNUSED_IPV4)
return 1;
}
return 0;
}
/** Return a newly allocated string holding an address of <b>type</b>
* (one of RESOLVED_TYPE_{IPV4|HOSTNAME}) that has not yet been mapped,
* and that is very unlikely to be the address of any real host.
*/
static char *
addressmap_get_virtual_address(int type)
{
char buf[64];
static uint32_t next_ipv4 = MIN_UNUSED_IPV4;
struct in_addr in;
if (type == RESOLVED_TYPE_HOSTNAME) {
char rand[10];
do {
crypto_rand(rand, sizeof(rand));
base32_encode(buf,sizeof(buf),rand,sizeof(rand));
strlcat(buf, ".virtual", sizeof(buf));
} while (strmap_get(addressmap, buf));
return tor_strdup(buf);
} else if (type == RESOLVED_TYPE_IPV4) {
while (1) {
/* Don't hand out any .0 or .255 address. */
while ((next_ipv4 & 0xff) == 0 ||
(next_ipv4 & 0xff) == 0xff)
++next_ipv4;
in.s_addr = htonl(next_ipv4);
tor_inet_ntoa(&in, buf, sizeof(buf));
if (!strmap_get(addressmap, buf))
break;
++next_ipv4;
if (next_ipv4 > MAX_UNUSED_IPV4)
next_ipv4 = MIN_UNUSED_IPV4;
}
return tor_strdup(buf);
} else {
log_fn(LOG_WARN, "Called with unsupported address type (%d)",
type);
return NULL;
}
}
/** A controller has requested that we map some address of type
* <b>type</b> to the address <b>new_address</b>. Choose an address
* that is unlikely to be used, and map it, and return it in a newly
* allocated string. If another address of the same type is already
* mapped to <b>new_address</b>, try to return a copy of that address.
*
* The string in <b>new_address</b> may be freed, or inserted into a map
* as appropriate.
**/
const char *
addressmap_register_virtual_address(int type, char *new_address)
{
char **addrp;
virtaddress_entry_t *vent;
tor_assert(new_address);
tor_assert(addressmap);
tor_assert(virtaddress_reversemap);
vent = strmap_get(virtaddress_reversemap, new_address);
if (!vent) {
vent = tor_malloc_zero(sizeof(virtaddress_entry_t));
strmap_set(virtaddress_reversemap, new_address, vent);
}
addrp = (type == RESOLVED_TYPE_IPV4) ?
&vent->ipv4_address : &vent->hostname_address;
if (*addrp) {
addressmap_entry_t *ent = strmap_get(addressmap, *addrp);
if (ent && ent->new_address && !strcasecmp(new_address, ent->new_address)) {
tor_free(new_address);
return tor_strdup(*addrp);
} else
log_fn(LOG_WARN, "Internal confusion: I thought that '%s' was mapped to by '%s', but '%s' really maps to '%s'. This is a harmless bug.",
safe_str(new_address), safe_str(*addrp), safe_str(*addrp),
ent?safe_str(ent->new_address):"(nothing)");
}
tor_free(*addrp);
*addrp = addressmap_get_virtual_address(type);
addressmap_register(*addrp, new_address, 2);
#if 0
{
/* Try to catch possible bugs */
addressmap_entry_t *ent;
ent = strmap_get(addressmap, *addrp);
tor_assert(ent);
tor_assert(!strcasecmp(ent->new_address,new_address));
vent = strmap_get(virtaddress_reversemap, new_address);
tor_assert(vent);
tor_assert(!strcasecmp(*addrp,
(type == RESOLVED_TYPE_IPV4) ?
vent->ipv4_address : vent->hostname_address));
log_fn(LOG_INFO, "Map from %s to %s okay.",
safe_str(*addrp),safe_str(new_address));
}
#endif
return *addrp;
}
/** Return 1 if <b>address</b> has funny characters in it like
* colons. Return 0 if it's fine.
*/
static int
address_is_invalid_destination(const char *address)
{
/* FFFF should flesh this out */
if (strchr(address,':'))
return 1;
return 0;
}
/** Iterate over all address mapings which have expiry times between
* min_expires and max_expires, inclusive. If sl is provided, add an
* "old-addr new-addr" string to sl for each mapping. If sl is NULL,
* remove the mappings.
*/
void
addressmap_get_mappings(smartlist_t *sl, time_t min_expires, time_t max_expires)
{
strmap_iter_t *iter;
const char *key;
void *_val;
addressmap_entry_t *val;
if (!addressmap)
addressmap_init();
for (iter = strmap_iter_init(addressmap); !strmap_iter_done(iter); ) {
strmap_iter_get(iter, &key, &_val);
val = _val;
if (val->expires >= min_expires && val->expires <= max_expires) {
if (!sl) {
addressmap_ent_remove(key, val);
iter = strmap_iter_next_rmv(addressmap,iter);
continue;
} else if (val->new_address) {
size_t len = strlen(key)+strlen(val->new_address)+2;
char *line = tor_malloc(len);
tor_snprintf(line, len, "%s %s", key, val->new_address);
smartlist_add(sl, line);
}
}
iter = strmap_iter_next(addressmap,iter);
}
}
/** connection_edge_process_inbuf() found a conn in state
* socks_wait. See if conn->inbuf has the right bytes to proceed with
* the socks handshake.
*
* If the handshake is complete, and it's for a general circuit, then
* try to attach it to a circuit (or launch one as needed). If it's for
* a rendezvous circuit, then fetch a rendezvous descriptor first (or
* attach/launch a circuit if the rendezvous descriptor is already here
* and fresh enough).
*
* Return -1 if an unexpected error with conn (and it should be marked
* for close), else return 0.
*/
static int
connection_ap_handshake_process_socks(connection_t *conn)
{
socks_request_t *socks;
int sockshere;
hostname_type_t addresstype;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_AP);
tor_assert(conn->state == AP_CONN_STATE_SOCKS_WAIT);
tor_assert(conn->socks_request);
socks = conn->socks_request;
log_fn(LOG_DEBUG,"entered.");
sockshere = fetch_from_buf_socks(conn->inbuf, socks);
if (sockshere == 0) {
if (socks->replylen) {
connection_write_to_buf(socks->reply, socks->replylen, conn);
socks->replylen = 0; /* zero it out so we can do another round of negotiation */
} else {
log_fn(LOG_DEBUG,"socks handshake not all here yet.");
}
return 0;
} else if (sockshere == -1) {
if (socks->replylen) { /* we should send reply back */
log_fn(LOG_DEBUG,"reply is already set for us. Using it.");
connection_ap_handshake_socks_reply(conn, socks->reply, socks->replylen,
SOCKS5_GENERAL_ERROR);
} else {
log_fn(LOG_WARN,"Fetching socks handshake failed. Closing.");
connection_ap_handshake_socks_reply(conn, NULL, 0, SOCKS5_GENERAL_ERROR);
}
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return -1;
} /* else socks handshake is done, continue processing */
tor_strlower(socks->address); /* normalize it */
/* For address map controls, remap the address */
addressmap_rewrite(socks->address, sizeof(socks->address));
if (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.
*/
log_fn(LOG_WARN,"Missing mapping for virtual address '%s'. Refusing.",
socks->address); /* don't safe_str() this yet. */
connection_mark_unattached_ap(conn, END_STREAM_REASON_INTERNAL);
return -1;
}
/* 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);
if (addresstype == BAD_HOSTNAME) {
log_fn(LOG_WARN, "Invalid hostname %s; rejecting", socks->address);
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
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 (s) {
if (s[1] != '\0') {
conn->chosen_exit_name = tor_strdup(s+1);
*s = 0;
} else {
log_fn(LOG_WARN,"Malformed exit address '%s.exit'. Refusing.",
safe_str(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
} else {
struct in_addr in;
routerinfo_t *r = router_get_by_nickname(socks->address);
if (r) {
conn->chosen_exit_name = tor_strdup(socks->address);
/* XXXX Should this use server->address instead? */
in.s_addr = htonl(r->addr);
strlcpy(socks->address, inet_ntoa(in), sizeof(socks->address));
} else {
log_fn(LOG_WARN,
"Unrecognized server in exit address '%s.exit'. Refusing.",
safe_str(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
}
}
if (addresstype != ONION_HOSTNAME) {
/* not a hidden-service request (i.e. normal or .exit) */
if (address_is_invalid_destination(socks->address)) {
log_fn(LOG_WARN,"Destination '%s' seems to be an invalid hostname. Failing.",
safe_str(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
if (socks->command == SOCKS_COMMAND_RESOLVE) {
uint32_t answer;
struct in_addr in;
/* Reply to resolves immediately if we can. */
if (strlen(socks->address) > RELAY_PAYLOAD_SIZE) {
log_fn(LOG_WARN,"Address to be resolved is too large. Failing.");
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL,-1);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return -1;
}
if (tor_inet_aton(socks->address, &in)) { /* see if it's an IP already */
answer = in.s_addr; /* leave it in network order */
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
(char*)&answer,-1);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return 0;
}
rep_hist_note_used_resolve(time(NULL)); /* help predict this next time */
control_event_stream_status(conn, STREAM_EVENT_NEW_RESOLVE);
} else { /* socks->command == SOCKS_COMMAND_CONNECT */
if (socks->port == 0) {
log_fn(LOG_NOTICE,"Application asked to connect to port 0. Refusing.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
if (!conn->chosen_exit_name) {
/* see if we can find a suitable enclave exit */
routerinfo_t *r =
router_find_exact_exit_enclave(socks->address, socks->port);
if (r) {
log_fn(LOG_INFO,"Redirecting address %s to exit at enclave router %s",
safe_str(socks->address), r->nickname);
/* use the hex digest, not nickname, in case there are two
routers with this nickname */
conn->chosen_exit_name =
tor_strdup(hex_str(r->identity_digest, DIGEST_LEN));
}
}
rep_hist_note_used_port(socks->port, time(NULL)); /* help predict this next time */
control_event_stream_status(conn, STREAM_EVENT_NEW);
}
if (get_options()->LeaveStreamsUnattached) {
conn->state = AP_CONN_STATE_CONTROLLER_WAIT;
} else {
conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
if (connection_ap_handshake_attach_circuit(conn) < 0) {
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;
if (socks->command == SOCKS_COMMAND_RESOLVE) {
/* if it's a resolve request, fail it right now, rather than
* building all the circuits and then realizing it won't work. */
log_fn(LOG_WARN,"Resolve requests to hidden services not allowed. Failing.");
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL,-1);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return -1;
}
strlcpy(conn->rend_query, socks->address, sizeof(conn->rend_query));
log_fn(LOG_INFO,"Got a hidden service request for ID '%s'",
safe_str(conn->rend_query));
/* see if we already have it cached */
r = rend_cache_lookup_entry(conn->rend_query, -1, &entry);
if (r<0) {
log_fn(LOG_WARN,"Invalid service descriptor %s",
safe_str(conn->rend_query));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
if (r==0) {
conn->state = AP_CONN_STATE_RENDDESC_WAIT;
log_fn(LOG_INFO, "Unknown descriptor %s. Fetching.",
safe_str(conn->rend_query));
rend_client_refetch_renddesc(conn->rend_query);
return 0;
}
if (r>0) {
#define NUM_SECONDS_BEFORE_REFETCH (60*15)
if (time(NULL) - entry->received < NUM_SECONDS_BEFORE_REFETCH) {
conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
log_fn(LOG_INFO, "Descriptor is here and fresh enough. Great.");
if (connection_ap_handshake_attach_circuit(conn) < 0) {
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
return -1;
}
return 0;
} else {
conn->state = AP_CONN_STATE_RENDDESC_WAIT;
log_fn(LOG_INFO, "Stale descriptor %s. Refetching.",
safe_str(conn->rend_query));
rend_client_refetch_renddesc(conn->rend_query);
return 0;
}
}
}
return 0; /* unreached but keeps the compiler happy */
}
/** Iterate over the two bytes of stream_id until we get one that is not
* already in use; return it. Return 0 if can't get a unique stream_id.
*/
static uint16_t
get_unique_stream_id_by_circ(circuit_t *circ)
{
connection_t *tmpconn;
uint16_t test_stream_id;
uint32_t attempts=0;
again:
test_stream_id = circ->next_stream_id++;
if (++attempts > 1<<16) {
/* Make sure we don't loop forever if all stream_id's are used. */
log_fn(LOG_WARN,"No unused stream IDs. Failing.");
return 0;
}
if (test_stream_id == 0)
goto again;
for (tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream)
if (tmpconn->stream_id == test_stream_id)
goto again;
return test_stream_id;
}
/** Write a relay begin cell, using destaddr and destport from ap_conn's
* socks_request field, and send it down circ.
*
* If ap_conn is broken, mark it for close and return -1. Else return 0.
*/
int
connection_ap_handshake_send_begin(connection_t *ap_conn, circuit_t *circ)
{
char payload[CELL_PAYLOAD_SIZE];
int payload_len;
tor_assert(ap_conn->type == CONN_TYPE_AP);
tor_assert(ap_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
tor_assert(ap_conn->socks_request);
ap_conn->stream_id = get_unique_stream_id_by_circ(circ);
if (ap_conn->stream_id==0) {
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
circuit_mark_for_close(circ);
return -1;
}
tor_snprintf(payload,RELAY_PAYLOAD_SIZE, "%s:%d",
(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL) ?
ap_conn->socks_request->address : "",
ap_conn->socks_request->port);
payload_len = strlen(payload)+1;
log_fn(LOG_DEBUG,"Sending relay cell to begin stream %d.",ap_conn->stream_id);
if (connection_edge_send_command(ap_conn, circ, RELAY_COMMAND_BEGIN,
payload, payload_len, ap_conn->cpath_layer) < 0)
return -1; /* circuit is closed, don't continue */
ap_conn->package_window = STREAMWINDOW_START;
ap_conn->deliver_window = STREAMWINDOW_START;
ap_conn->state = AP_CONN_STATE_CONNECT_WAIT;
log_fn(LOG_INFO,"Address/port sent, ap socket %d, n_circ_id %d",
ap_conn->s, circ->n_circ_id);
control_event_stream_status(ap_conn, STREAM_EVENT_SENT_CONNECT);
return 0;
}
/** Write a relay resolve cell, using destaddr and destport from ap_conn's
* socks_request field, and send it down circ.
*
* If ap_conn is broken, mark it for close and return -1. Else return 0.
*/
int
connection_ap_handshake_send_resolve(connection_t *ap_conn, circuit_t *circ)
{
int payload_len;
const char *string_addr;
tor_assert(ap_conn->type == CONN_TYPE_AP);
tor_assert(ap_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
tor_assert(ap_conn->socks_request);
tor_assert(ap_conn->socks_request->command == SOCKS_COMMAND_RESOLVE);
tor_assert(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL);
ap_conn->stream_id = get_unique_stream_id_by_circ(circ);
if (ap_conn->stream_id==0) {
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
circuit_mark_for_close(circ);
return -1;
}
string_addr = ap_conn->socks_request->address;
payload_len = strlen(string_addr)+1;
tor_assert(payload_len <= RELAY_PAYLOAD_SIZE);
log_fn(LOG_DEBUG,"Sending relay cell to begin stream %d.",ap_conn->stream_id);
if (connection_edge_send_command(ap_conn, circ, RELAY_COMMAND_RESOLVE,
string_addr, payload_len, ap_conn->cpath_layer) < 0)
return -1; /* circuit is closed, don't continue */
ap_conn->state = AP_CONN_STATE_RESOLVE_WAIT;
log_fn(LOG_INFO,"Address sent for resolve, ap socket %d, n_circ_id %d",
ap_conn->s, circ->n_circ_id);
control_event_stream_status(ap_conn, STREAM_EVENT_SENT_RESOLVE);
return 0;
}
/** Make an AP connection_t, do a socketpair and attach one side
* to the conn, connection_add it, initialize it to circuit_wait,
* and call connection_ap_handshake_attach_circuit(conn) on it.
*
* Return the other end of the socketpair, or -1 if error.
*/
int
connection_ap_make_bridge(char *address, uint16_t port)
{
int fd[2];
connection_t *conn;
int err;
log_fn(LOG_INFO,"Making AP bridge to %s:%d ...",safe_str(address),port);
if ((err = tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) < 0) {
log(LOG_WARN,"Couldn't construct socketpair (%s). Network down? Delaying.",
tor_socket_strerror(-err));
return -1;
}
set_socket_nonblocking(fd[0]);
set_socket_nonblocking(fd[1]);
conn = connection_new(CONN_TYPE_AP);
conn->s = fd[0];
/* populate conn->socks_request */
/* leave version at zero, so the socks_reply is empty */
conn->socks_request->socks_version = 0;
conn->socks_request->has_finished = 0; /* waiting for 'connected' */
strlcpy(conn->socks_request->address, address,
sizeof(conn->socks_request->address));
conn->socks_request->port = port;
conn->socks_request->command = SOCKS_COMMAND_CONNECT;
conn->address = tor_strdup("(local bridge)");
conn->addr = 0;
conn->port = 0;
if (connection_add(conn) < 0) { /* no space, forget it */
connection_free(conn); /* this closes fd[0] */
tor_close_socket(fd[1]);
return -1;
}
conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
connection_start_reading(conn);
/* attaching to a dirty circuit is fine */
if (connection_ap_handshake_attach_circuit(conn) < 0) {
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
tor_close_socket(fd[1]);
return -1;
}
log_fn(LOG_INFO,"... AP bridge created and connected.");
return fd[1];
}
/** Send an answer to an AP connection that has requested a DNS lookup
* via SOCKS. The type should be one of RESOLVED_TYPE_(IPV4|IPV6) or
* -1 for unreachable; the answer should be in the format specified
* in the socks extensions document.
**/
void
connection_ap_handshake_socks_resolved(connection_t *conn,
int answer_type,
size_t answer_len,
const char *answer,
int ttl)
{
char buf[256];
size_t replylen;
if (answer_type == RESOLVED_TYPE_IPV4) {
uint32_t a = ntohl(get_uint32(answer));
if (a)
client_dns_set_addressmap(conn->socks_request->address, ntohl(a),
conn->chosen_exit_name, ttl);
}
if (conn->socks_request->socks_version == 4) {
buf[0] = 0x00; /* version */
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
buf[1] = 90; /* "Granted" */
set_uint16(buf+2, 0);
memcpy(buf+4, answer, 4); /* address */
replylen = SOCKS4_NETWORK_LEN;
} else {
buf[1] = 91; /* "error" */
memset(buf+2, 0, 6);
replylen = SOCKS4_NETWORK_LEN;
}
} else {
/* SOCKS5 */
buf[0] = 0x05; /* version */
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
buf[1] = SOCKS5_SUCCEEDED;
buf[2] = 0; /* reserved */
buf[3] = 0x01; /* IPv4 address type */
memcpy(buf+4, answer, 4); /* address */
set_uint16(buf+8, 0); /* port == 0. */
replylen = 10;
} else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
buf[1] = SOCKS5_SUCCEEDED;
buf[2] = 0; /* reserved */
buf[3] = 0x04; /* IPv6 address type */
memcpy(buf+4, answer, 16); /* address */
set_uint16(buf+20, 0); /* port == 0. */
replylen = 22;
} else {
buf[1] = SOCKS5_HOST_UNREACHABLE;
memset(buf+2, 0, 8);
replylen = 10;
}
}
connection_ap_handshake_socks_reply(conn, buf, replylen,
(answer_type == RESOLVED_TYPE_IPV4 ||
answer_type == RESOLVED_TYPE_IPV6) ?
SOCKS5_SUCCEEDED : SOCKS5_HOST_UNREACHABLE);
}
/** Send a socks reply to stream <b>conn</b>, using the appropriate
* socks version, etc, and mark <b>conn</b> as completed with SOCKS
* handshaking.
*
* If <b>reply</b> is defined, then write <b>replylen</b> bytes of it
* to conn and return, else reply based on <b>status</b>.
*
* If <b>reply</b> is undefined, <b>status</b> can't be 0.
*/
void
connection_ap_handshake_socks_reply(connection_t *conn, char *reply,
size_t replylen,
socks5_reply_status_t status) {
char buf[256];
tor_assert(conn->socks_request); /* make sure it's an AP stream */
control_event_stream_status(conn,
status==SOCKS5_SUCCEEDED ? STREAM_EVENT_SUCCEEDED : STREAM_EVENT_FAILED);
if (conn->socks_request->has_finished) {
log_fn(LOG_WARN, "Harmless bug: duplicate calls to connection_ap_handshake_socks_reply.");
return;
}
if (replylen) { /* we already have a reply in mind */
connection_write_to_buf(reply, replylen, conn);
conn->socks_request->has_finished = 1;
return;
}
if (conn->socks_request->socks_version == 4) {
memset(buf,0,SOCKS4_NETWORK_LEN);
#define SOCKS4_GRANTED 90
#define SOCKS4_REJECT 91
buf[1] = (status==SOCKS5_SUCCEEDED ? SOCKS4_GRANTED : SOCKS4_REJECT);
/* leave version, destport, destip zero */
connection_write_to_buf(buf, SOCKS4_NETWORK_LEN, conn);
} else if (conn->socks_request->socks_version == 5) {
buf[0] = 5; /* version 5 */
buf[1] = (char)status;
buf[2] = 0;
buf[3] = 1; /* ipv4 addr */
memset(buf+4,0,6); /* Set external addr/port to 0.
The spec doesn't seem to say what to do here. -RD */
connection_write_to_buf(buf,10,conn);
}
/* If socks_version isn't 4 or 5, don't send anything.
* This can happen in the case of AP bridges. */
conn->socks_request->has_finished = 1;
return;
}
/** A relay 'begin' cell has arrived, and either we are an exit hop
* for the circuit, or we are the origin and it is a rendezvous begin.
*
* Launch a new exit connection and initialize things appropriately.
*
* If it's a rendezvous stream, call connection_exit_connect() on
* it.
*
* For general streams, call dns_resolve() on it first, and only call
* connection_exit_connect() if the dns answer is already known.
*
* Note that we don't call connection_add() on the new stream! We wait
* for connection_exit_connect() to do that.
*
* Return -1 if we want to tear down <b>circ</b>. Else return 0.
*/
int
connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
{
connection_t *n_stream;
relay_header_t rh;
char *address=NULL;
uint16_t port;
assert_circuit_ok(circ);
relay_header_unpack(&rh, cell->payload);
/* XXX currently we don't send an end cell back if we drop the
* begin because it's malformed.
*/
if (!memchr(cell->payload+RELAY_HEADER_SIZE, 0, rh.length)) {
log_fn(LOG_WARN,"relay begin cell has no \\0. Dropping.");
return 0;
}
if (parse_addr_port(cell->payload+RELAY_HEADER_SIZE,&address,NULL,&port)<0) {
log_fn(LOG_WARN,"Unable to parse addr:port in relay begin cell. Dropping.");
return 0;
}
if (port==0) {
log_fn(LOG_WARN,"Missing port in relay begin cell. Dropping.");
tor_free(address);
return 0;
}
log_fn(LOG_DEBUG,"Creating new exit connection.");
n_stream = connection_new(CONN_TYPE_EXIT);
n_stream->purpose = EXIT_PURPOSE_CONNECT;
n_stream->stream_id = rh.stream_id;
n_stream->port = port;
/* leave n_stream->s at -1, because it's not yet valid */
n_stream->package_window = STREAMWINDOW_START;
n_stream->deliver_window = STREAMWINDOW_START;
if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) {
log_fn(LOG_DEBUG,"begin is for rendezvous. configuring stream.");
n_stream->address = tor_strdup("(rendezvous)");
n_stream->state = EXIT_CONN_STATE_CONNECTING;
strlcpy(n_stream->rend_query, circ->rend_query,
sizeof(n_stream->rend_query));
tor_assert(connection_edge_is_rendezvous_stream(n_stream));
assert_circuit_ok(circ);
if (rend_service_set_connection_addr_port(n_stream, circ) < 0) {
log_fn(LOG_INFO,"Didn't find rendezvous service (port %d)",n_stream->port);
connection_edge_end(n_stream, END_STREAM_REASON_EXITPOLICY, n_stream->cpath_layer);
connection_free(n_stream);
circuit_mark_for_close(circ); /* knock the whole thing down, somebody screwed up */
tor_free(address);
return 0;
}
assert_circuit_ok(circ);
log_fn(LOG_DEBUG,"Finished assigning addr/port");
n_stream->cpath_layer = circ->cpath->prev; /* link it */
/* add it into the linked list of n_streams on this circuit */
n_stream->next_stream = circ->n_streams;
n_stream->on_circuit = circ;
circ->n_streams = n_stream;
assert_circuit_ok(circ);
connection_exit_connect(n_stream);
tor_free(address);
return 0;
}
tor_strlower(address);
n_stream->address = address;
n_stream->state = EXIT_CONN_STATE_RESOLVEFAILED;
/* default to failed, change in dns_resolve if it turns out not to fail */
if (we_are_hibernating()) {
connection_edge_end(n_stream, END_STREAM_REASON_HIBERNATING, n_stream->cpath_layer);
connection_free(n_stream);
return 0;
}
/* send it off to the gethostbyname farm */
switch (dns_resolve(n_stream)) {
case 1: /* resolve worked */
/* add it into the linked list of n_streams on this circuit */
n_stream->next_stream = circ->n_streams;
n_stream->on_circuit = circ;
circ->n_streams = n_stream;
assert_circuit_ok(circ);
connection_exit_connect(n_stream);
return 0;
case -1: /* resolve failed */
/* n_stream got freed. don't touch it. */
break;
case 0: /* resolve added to pending list */
/* add it into the linked list of resolving_streams on this circuit */
n_stream->next_stream = circ->resolving_streams;
n_stream->on_circuit = circ;
circ->resolving_streams = n_stream;
assert_circuit_ok(circ);
;
}
return 0;
}
/**
* Called when we receive a RELAY_RESOLVE cell 'cell' along the circuit 'circ';
* begin resolving the hostname, and (eventually) reply with a RESOLVED cell.
*/
int
connection_exit_begin_resolve(cell_t *cell, circuit_t *circ)
{
connection_t *dummy_conn;
relay_header_t rh;
assert_circuit_ok(circ);
relay_header_unpack(&rh, cell->payload);
/* This 'dummy_conn' only exists to remember the stream ID
* associated with the resolve request; and to make the
* implementation of dns.c more uniform. (We really only need to
* remember the circuit, the stream ID, and the hostname to be
* resolved; but if we didn't store them in a connection like this,
* the housekeeping in dns.c would get way more complicated.)
*/
dummy_conn = connection_new(CONN_TYPE_EXIT);
dummy_conn->stream_id = rh.stream_id;
dummy_conn->address = tor_strndup(cell->payload+RELAY_HEADER_SIZE,
rh.length);
dummy_conn->port = 0;
dummy_conn->state = EXIT_CONN_STATE_RESOLVEFAILED;
dummy_conn->purpose = EXIT_PURPOSE_RESOLVE;
/* send it off to the gethostbyname farm */
switch (dns_resolve(dummy_conn)) {
case -1: /* Impossible to resolve; a resolved cell was sent. */
/* Connection freed; don't touch it. */
return 0;
case 1: /* The result was cached; a resolved cell was sent. */
if (!dummy_conn->marked_for_close)
connection_free(dummy_conn);
return 0;
case 0: /* resolve added to pending list */
dummy_conn->next_stream = circ->resolving_streams;
dummy_conn->on_circuit = circ;
circ->resolving_streams = dummy_conn;
assert_circuit_ok(circ);
break;
}
return 0;
}
/** Connect to conn's specified addr and port. If it worked, conn
* has now been added to the connection_array.
*
* Send back a connected cell. Include the resolved IP of the destination
* address, but <em>only</em> if it's a general exit stream. (Rendezvous
* streams must not reveal what IP they connected to.)
*/
void
connection_exit_connect(connection_t *conn)
{
uint32_t addr;
uint16_t port;
if (!connection_edge_is_rendezvous_stream(conn) &&
router_compare_to_my_exit_policy(conn)) {
log_fn(LOG_INFO,"%s:%d failed exit policy. Closing.",
safe_str(conn->address), conn->port);
connection_edge_end(conn, END_STREAM_REASON_EXITPOLICY, conn->cpath_layer);
circuit_detach_stream(circuit_get_by_edge_conn(conn), conn);
connection_free(conn);
return;
}
addr = conn->addr;
port = conn->port;
if (redirect_exit_list) {
SMARTLIST_FOREACH(redirect_exit_list, exit_redirect_t *, r,
{
if ((addr&r->mask)==(r->addr&r->mask) &&
(r->port_min <= port) && (port <= r->port_max)) {
struct in_addr in;
if (r->is_redirect) {
char tmpbuf[INET_NTOA_BUF_LEN];
addr = r->addr_dest;
port = r->port_dest;
in.s_addr = htonl(addr);
tor_inet_ntoa(&in, tmpbuf, sizeof(tmpbuf));
log_fn(LOG_DEBUG, "Redirecting connection from %s:%d to %s:%d",
safe_str(conn->address), conn->port, safe_str(tmpbuf), port);
}
break;
}
});
}
log_fn(LOG_DEBUG,"about to try connecting");
switch (connection_connect(conn, conn->address, addr, port)) {
case -1:
connection_edge_end_errno(conn, conn->cpath_layer);
circuit_detach_stream(circuit_get_by_edge_conn(conn), conn);
connection_free(conn);
return;
case 0:
conn->state = EXIT_CONN_STATE_CONNECTING;
connection_watch_events(conn, EV_WRITE | EV_READ);
/* writable indicates finish;
* readable/error indicates broken link in windowsland. */
return;
/* case 1: fall through */
}
conn->state = EXIT_CONN_STATE_OPEN;
if (connection_wants_to_flush(conn)) { /* in case there are any queued data cells */
log_fn(LOG_WARN,"Bug: newly connected conn had data waiting!");
// connection_start_writing(conn);
}
connection_watch_events(conn, EV_READ);
/* also, deliver a 'connected' cell back through the circuit. */
if (connection_edge_is_rendezvous_stream(conn)) { /* rendezvous stream */
/* don't send an address back! */
connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_CONNECTED,
NULL, 0, conn->cpath_layer);
} else { /* normal stream */
/* This must be the original address, not the redirected address. */
char connected_payload[8];
set_uint32(connected_payload, htonl(conn->addr));
set_uint32(connected_payload+4,
htonl(MAX_DNS_ENTRY_AGE)); /* XXXX fill with a real TTL */
connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_CONNECTED,
connected_payload, 8, conn->cpath_layer);
}
}
/** Return 1 if <b>conn</b> is a rendezvous stream, or 0 if
* it is a general stream.
*/
int
connection_edge_is_rendezvous_stream(connection_t *conn)
{
tor_assert(conn);
if (*conn->rend_query) /* XXX */
return 1;
return 0;
}
/** Return 1 if router <b>exit</b> is likely to allow stream <b>conn</b>
* to exit from it, or 0 if it probably will not allow it.
* (We might be uncertain if conn's destination address has not yet been
* resolved.)
*/
int
connection_ap_can_use_exit(connection_t *conn, routerinfo_t *exit)
{
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_AP);
tor_assert(conn->socks_request);
tor_assert(exit);
log_fn(LOG_DEBUG,"considering nickname %s, for address %s / port %d:",
exit->nickname, safe_str(conn->socks_request->address),
conn->socks_request->port);
/* If a particular exit node has been requested for the new connection,
* make sure the exit node of the existing circuit matches exactly.
*/
if (conn->chosen_exit_name) {
if (router_get_by_nickname(conn->chosen_exit_name) != exit) {
/* doesn't match */
log_fn(LOG_DEBUG,"Requested node '%s', considering node '%s'. No.",
conn->chosen_exit_name, exit->nickname);
return 0;
}
}
if (conn->socks_request->command != SOCKS_COMMAND_RESOLVE) {
struct in_addr in;
uint32_t addr = 0;
addr_policy_result_t r;
if (tor_inet_aton(conn->socks_request->address, &in))
addr = ntohl(in.s_addr);
r = router_compare_addr_to_addr_policy(addr, conn->socks_request->port,
exit->exit_policy);
if (r == ADDR_POLICY_REJECTED || r == ADDR_POLICY_PROBABLY_REJECTED)
return 0;
}
return 1;
}
/** A helper function for socks_policy_permits_address() below.
*
* Parse options->SocksPolicy in the same way that the exit policy
* is parsed, and put the processed version in &socks_policy.
* Ignore port specifiers.
*/
void
parse_socks_policy(void)
{
addr_policy_t *n;
if (socks_policy) {
addr_policy_free(socks_policy);
socks_policy = NULL;
}
config_parse_addr_policy(get_options()->SocksPolicy, &socks_policy, -1);
/* ports aren't used. */
for (n=socks_policy; n; n = n->next) {
n->prt_min = 1;
n->prt_max = 65535;
}
}
/** Free all storage held by our SOCKS allow policy
*/
void
free_socks_policy(void)
{
addr_policy_free(socks_policy);
socks_policy = NULL;
}
/** Return 1 if <b>addr</b> is permitted to connect to our socks port,
* based on <b>socks_policy</b>. Else return 0.
*/
int
socks_policy_permits_address(uint32_t addr)
{
int a;
if (!socks_policy) /* 'no socks policy' means 'accept' */
return 1;
a = router_compare_addr_to_addr_policy(addr, 1, socks_policy);
if (a==ADDR_POLICY_REJECTED)
return 0;
else if (a==ADDR_POLICY_ACCEPTED)
return 1;
log_fn(LOG_WARN, "Bug: Got unexpected 'maybe' answer from socks policy");
return 0;
}
/** Make connection redirection follow the provided list of
* exit_redirect_t */
void
set_exit_redirects(smartlist_t *lst)
{
if (redirect_exit_list) {
SMARTLIST_FOREACH(redirect_exit_list, exit_redirect_t *, p, tor_free(p));
smartlist_free(redirect_exit_list);
}
redirect_exit_list = lst;
}
/** If address is of the form "y.onion" with a well-formed handle y:
* Put a \code{'\0'} after y, lower-case it, and return ONION_HOSTNAME.
*
* If address is of the form "y.exit":
* Put a \code{'\0'} after y and return EXIT_HOSTNAME.
*
* Otherwise:
* Return NORMAL_HOSTNAME and change nothing.
*/
hostname_type_t
parse_extended_hostname(char *address)
{
char *s;
char query[REND_SERVICE_ID_LEN+1];
s = strrchr(address,'.');
if (!s) return 0; /* no dot, thus normal */
if (!strcmp(s+1,"exit")) {
*s = 0; /* null-terminate it */
return EXIT_HOSTNAME; /* .exit */
}
if (strcmp(s+1,"onion"))
return NORMAL_HOSTNAME; /* neither .exit nor .onion, thus normal */
/* so it is .onion */
*s = 0; /* null-terminate it */
if (strlcpy(query, address, REND_SERVICE_ID_LEN+1) >= REND_SERVICE_ID_LEN+1)
goto failed;
if (rend_valid_service_id(query)) {
return ONION_HOSTNAME; /* success */
}
failed:
/* otherwise, return to previous state and return 0 */
*s = '.';
return BAD_HOSTNAME;
}
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