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connection_edge.h
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1/* Copyright (c) 2001 Matej Pfajfar.
2 * Copyright (c) 2001-2004, Roger Dingledine.
3 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
4 * Copyright (c) 2007-2021, The Tor Project, Inc. */
5/* See LICENSE for licensing information */
6
7/**
8 * \file connection_edge.h
9 * \brief Header file for connection_edge.c.
10 **/
11
12#ifndef TOR_CONNECTION_EDGE_H
13#define TOR_CONNECTION_EDGE_H
14
16
19
21
25
29
30#define EXIT_CONN_STATE_MIN_ 1
31/** State for an exit connection: waiting for response from DNS farm. */
32#define EXIT_CONN_STATE_RESOLVING 1
33/** State for an exit connection: waiting for connect() to finish. */
34#define EXIT_CONN_STATE_CONNECTING 2
35/** State for an exit connection: open and ready to transmit data. */
36#define EXIT_CONN_STATE_OPEN 3
37/** State for an exit connection: waiting to be removed. */
38#define EXIT_CONN_STATE_RESOLVEFAILED 4
39#define EXIT_CONN_STATE_MAX_ 4
40
41/* The AP state values must be disjoint from the EXIT state values. */
42#define AP_CONN_STATE_MIN_ 5
43/** State for a SOCKS connection: waiting for SOCKS request. */
44#define AP_CONN_STATE_SOCKS_WAIT 5
45/** State for a SOCKS connection: got a y.onion URL; waiting to receive
46 * rendezvous descriptor. */
47#define AP_CONN_STATE_RENDDESC_WAIT 6
48/** The controller will attach this connection to a circuit; it isn't our
49 * job to do so. */
50#define AP_CONN_STATE_CONTROLLER_WAIT 7
51/** State for a SOCKS connection: waiting for a completed circuit. */
52#define AP_CONN_STATE_CIRCUIT_WAIT 8
53/** State for a SOCKS connection: sent BEGIN, waiting for CONNECTED. */
54#define AP_CONN_STATE_CONNECT_WAIT 9
55/** State for a SOCKS connection: sent RESOLVE, waiting for RESOLVED. */
56#define AP_CONN_STATE_RESOLVE_WAIT 10
57/** State for a SOCKS connection: ready to send and receive. */
58#define AP_CONN_STATE_OPEN 11
59/** State for a transparent natd connection: waiting for original
60 * destination. */
61#define AP_CONN_STATE_NATD_WAIT 12
62/** State for an HTTP tunnel: waiting for an HTTP CONNECT command. */
63#define AP_CONN_STATE_HTTP_CONNECT_WAIT 13
64#define AP_CONN_STATE_MAX_ 13
65
66#define EXIT_PURPOSE_MIN_ 1
67/** This exit stream wants to do an ordinary connect. */
68#define EXIT_PURPOSE_CONNECT 1
69/** This exit stream wants to do a resolve (either normal or reverse). */
70#define EXIT_PURPOSE_RESOLVE 2
71#define EXIT_PURPOSE_MAX_ 2
72
73/** True iff the AP_CONN_STATE_* value <b>s</b> means that the corresponding
74 * edge connection is not attached to any circuit. */
75#define AP_CONN_STATE_IS_UNATTACHED(s) \
76 ((s) <= AP_CONN_STATE_CIRCUIT_WAIT || (s) == AP_CONN_STATE_NATD_WAIT)
77
78#define connection_mark_unattached_ap(conn, endreason) \
79 connection_mark_unattached_ap_((conn), (endreason), __LINE__, SHORT_FILE__)
80
81/** Possible return values for parse_extended_hostname. */
82typedef enum hostname_type_t {
83 BAD_HOSTNAME,
84 EXIT_HOSTNAME,
85 NORMAL_HOSTNAME,
86 ONION_V3_HOSTNAME,
88
90 (entry_connection_t *conn, int endreason,
91 int line, const char *file));
94 int package_partial);
96int connection_edge_end(edge_connection_t *conn, uint8_t reason);
98void connection_edge_end_close(edge_connection_t *conn, uint8_t reason);
102
104
107void connection_reapply_exit_policy(config_line_t *changes);
108
109MOCK_DECL(int,
112
114 char *address, uint16_t port,
115 const char *digest,
116 int session_group,
117 int isolation_flags,
118 int use_begindir, int want_onehop);
120 size_t replylen,
121 int endreason);
123 (entry_connection_t *conn,
124 int answer_type,
125 size_t answer_len,
126 const uint8_t *answer,
127 int ttl,
128 time_t expires));
130 const tor_addr_t *answer,
131 int ttl,
132 time_t expires);
133
139 const node_t *exit);
142void connection_ap_attach_pending(int retry);
144 const char *file, int line);
145#define connection_ap_mark_as_pending_circuit(c) \
146 connection_ap_mark_as_pending_circuit_((c), __FILE__, __LINE__)
149 entry_connection_t *entry_conn);
150
151#define CONNECTION_AP_EXPECT_NONPENDING(c) do { \
152 if (ENTRY_TO_CONN(c)->state == AP_CONN_STATE_CIRCUIT_WAIT) { \
153 log_warn(LD_BUG, "At %s:%d: %p was unexpectedly in circuit_wait.", \
154 __FILE__, __LINE__, (c)); \
155 connection_ap_mark_as_non_pending_circuit(c); \
156 } \
157 } while (0)
158void connection_ap_fail_onehop(const char *failed_digest,
159 cpath_build_state_t *build_state);
162 origin_circuit_t *circ,
163 int reason);
165
166int address_is_invalid_destination(const char *address, int client);
167
169 (entry_connection_t *conn,
170 origin_circuit_t *circ,
171 crypt_path_t *cpath));
173 origin_circuit_t *circ,
174 crypt_path_t *cpath);
175
176#if defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H)
177int get_pf_socket(void);
178#endif
179
181 const origin_circuit_t *circ);
183 origin_circuit_t *circ,
184 int dry_run);
187
188void connection_edge_free_all(void);
189
190void connection_ap_warn_and_unmark_if_pending_circ(
191 entry_connection_t *entry_conn,
192 const char *where);
193
194/** Lowest value for DNS ttl clipping excluding the random addition. */
195#define MIN_DNS_TTL (5*60)
196/** Highest value for DNS ttl clipping excluding the random addition. */
197#define MAX_DNS_TTL (60*60)
198/** How long do we keep DNS cache entries before purging them (regardless of
199 * their TTL)? */
200#define MAX_DNS_ENTRY_AGE (3*60*60)
201/** How long do we cache/tell clients to cache DNS records when no TTL is
202 * known? */
203#define DEFAULT_DNS_TTL (30*60)
204/** How much should we +- each TTL to make it fuzzy with uniform sampling at
205 * exits? The value 4 minutes was chosen so that the lowest possible clip is
206 * 60s. Such low clips were used in the past for all TTLs due to a bug in Tor,
207 * see "The effect of DNS on Tor's Anonymity" by Greschbach et al. In other
208 * words, sampling such low clips is unlikely to cause any breakage at exits.
209 */
210#define FUZZY_DNS_TTL (4*60)
211
212uint32_t clip_dns_ttl(uint32_t ttl);
213uint32_t clip_dns_fuzzy_ttl(uint32_t ttl);
214
216 streamid_t stream_id);
218 streamid_t stream_id);
220 streamid_t stream_id);
222 streamid_t stream_id);
224 streamid_t stream_id);
226
228struct half_edge_t;
229void half_edge_free_(struct half_edge_t *he);
230#define half_edge_free(he) \
231 FREE_AND_NULL(half_edge_t, half_edge_free_, (he))
232
233/** @name Begin-cell flags
234 *
235 * These flags are used in RELAY_BEGIN cells to change the default behavior
236 * of the cell.
237 *
238 * @{
239 **/
240/** When this flag is set, the client is willing to get connected to IPv6
241 * addresses */
242#define BEGIN_FLAG_IPV6_OK (1u<<0)
243/** When this flag is set, the client DOES NOT support connecting to IPv4
244 * addresses. (The sense of this flag is inverted from IPV6_OK, so that the
245 * old default behavior of Tor is equivalent to having all flags set to 0.)
246 **/
247#define BEGIN_FLAG_IPV4_NOT_OK (1u<<1)
248/** When this flag is set, if we find both an IPv4 and an IPv6 address,
249 * we use the IPv6 address. Otherwise we use the IPv4 address. */
250#define BEGIN_FLAG_IPV6_PREFERRED (1u<<2)
251/**@}*/
252
253#ifdef CONNECTION_EDGE_PRIVATE
254
255STATIC bool parse_extended_hostname(char *address, hostname_type_t *type_out);
256
257/** A parsed BEGIN or BEGIN_DIR cell */
258typedef struct begin_cell_t {
259 /** The address the client has asked us to connect to, or NULL if this is
260 * a BEGIN_DIR cell*/
261 char *address;
262 /** The flags specified in the BEGIN cell's body. One or more of
263 * BEGIN_FLAG_*. */
264 uint32_t flags;
265 /** The client's requested port. */
266 uint16_t port;
267 /** The client's requested Stream ID */
268 uint16_t stream_id;
269 /** True iff this is a BEGIN_DIR cell. */
270 unsigned is_begindir : 1;
271} begin_cell_t;
272
273STATIC int begin_cell_parse(const relay_msg_t *msg, begin_cell_t *bcell,
274 uint8_t *end_reason_out);
275STATIC int connected_cell_format_payload(uint8_t *payload_out,
276 const tor_addr_t *addr,
277 uint32_t ttl);
278
279typedef struct {
280 /** Original address, after we lowercased it but before we started
281 * mapping it.
282 */
283 char orig_address[MAX_SOCKS_ADDR_LEN];
284 /** True iff the address has been automatically remapped to a local
285 * address in VirtualAddrNetwork. (Only set true when we do a resolve
286 * and get a virtual address; not when we connect to the address.) */
287 int automap;
288 /** If this connection has a .exit address, who put it there? */
289 addressmap_entry_source_t exit_source;
290 /** If we've rewritten the address, when does this map expire? */
291 time_t map_expires;
292 /** If we should close the connection, this is the end_reason to pass
293 * to connection_mark_unattached_ap */
294 int end_reason;
295 /** True iff we should close the connection, either because of error or
296 * because of successful early RESOLVED reply. */
297 int should_close;
298} rewrite_result_t;
299
300STATIC void connection_ap_handshake_rewrite(entry_connection_t *conn,
301 rewrite_result_t *out);
302
304STATIC void export_hs_client_circuit_id(edge_connection_t *edge_conn,
305 hs_circuit_id_protocol_t protocol);
306
307struct half_edge_t;
309 origin_circuit_t *circ);
311 const smartlist_t *half_conns,
313#endif /* defined(CONNECTION_EDGE_PRIVATE) */
314
315#endif /* !defined(TOR_CONNECTION_EDGE_H) */
Header for confline.c.
STATIC int connection_ap_process_http_connect(entry_connection_t *conn)
STATIC int connected_cell_format_payload(uint8_t *payload_out, const tor_addr_t *addr, uint32_t ttl)
STATIC int begin_cell_parse(const relay_msg_t *msg, begin_cell_t *bcell, uint8_t *end_reason_out)
STATIC bool parse_extended_hostname(char *address, hostname_type_t *type_out)
STATIC void connection_half_edge_add(const edge_connection_t *conn, origin_circuit_t *circ)
STATIC half_edge_t * connection_half_edge_find_stream_id(const smartlist_t *half_conns, streamid_t stream_id)
int connection_edge_compatible_with_circuit(const entry_connection_t *conn, const origin_circuit_t *circ)
int connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn, origin_circuit_t *circ, crypt_path_t *cpath)
int connection_half_edge_is_valid_data(const smartlist_t *half_conns, streamid_t stream_id)
const entry_connection_t * CONST_TO_ENTRY_CONN(const connection_t *)
void connection_ap_mark_as_waiting_for_renddesc(entry_connection_t *entry_conn)
edge_connection_t * TO_EDGE_CONN(connection_t *)
void connection_mark_unattached_ap_(entry_connection_t *conn, int endreason, int line, const char *file)
void connection_ap_about_to_close(entry_connection_t *edge_conn)
const entry_connection_t * CONST_EDGE_TO_ENTRY_CONN(const edge_connection_t *)
void connection_edge_free_all(void)
void connection_ap_mark_as_pending_circuit_(entry_connection_t *entry_conn, const char *file, int line)
void connection_ap_mark_as_non_pending_circuit(entry_connection_t *entry_conn)
int connection_ap_rewrite_and_attach_if_allowed(entry_connection_t *conn, origin_circuit_t *circ, crypt_path_t *cpath)
uint32_t clip_dns_fuzzy_ttl(uint32_t ttl)
int connection_exit_begin_resolve(const relay_msg_t *msg, or_circuit_t *circ)
entry_connection_t * connection_ap_make_link(connection_t *partner, char *address, uint16_t port, const char *digest, int session_group, int isolation_flags, int use_begindir, int want_onehop)
void connection_ap_expire_beginning(void)
void connection_ap_fail_onehop(const char *failed_digest, cpath_build_state_t *build_state)
int connection_ap_detach_retriable(entry_connection_t *conn, origin_circuit_t *circ, int reason)
void connection_ap_rescan_and_attach_pending(void)
int connection_ap_can_use_exit(const entry_connection_t *conn, const node_t *exit)
int connection_ap_handshake_send_begin(entry_connection_t *ap_conn)
int address_is_invalid_destination(const char *address, int client)
Definition: addressmap.c:1082
void connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply, size_t replylen, int endreason)
int connection_half_edge_is_valid_end(smartlist_t *half_conns, streamid_t stream_id)
hostname_type_t
uint32_t clip_dns_ttl(uint32_t ttl)
bool connection_half_edges_waiting(const origin_circuit_t *circ)
void half_edge_free_(struct half_edge_t *he)
int connection_ap_process_transparent(entry_connection_t *conn)
void connection_edge_end_close(edge_connection_t *conn, uint8_t reason)
int connection_edge_destroy(circid_t circ_id, edge_connection_t *conn)
int connection_edge_finished_flushing(edge_connection_t *conn)
void circuit_clear_isolation(origin_circuit_t *circ)
void connection_exit_about_to_close(edge_connection_t *edge_conn)
int connection_half_edge_is_valid_connected(const smartlist_t *half_conns, streamid_t stream_id)
int connection_exit_begin_conn(const relay_msg_t *msg, circuit_t *circ)
int connection_edge_flushed_some(edge_connection_t *conn)
int connection_ap_handshake_send_resolve(entry_connection_t *ap_conn)
void connection_ap_handshake_socks_resolved_addr(entry_connection_t *conn, const tor_addr_t *answer, int ttl, time_t expires)
int connection_edge_update_circuit_isolation(const entry_connection_t *conn, origin_circuit_t *circ, int dry_run)
int connection_edge_reached_eof(edge_connection_t *conn)
entry_connection_t * TO_ENTRY_CONN(connection_t *)
int connection_half_edge_is_valid_resolved(smartlist_t *half_conns, streamid_t stream_id)
int connection_edge_finished_connecting(edge_connection_t *conn)
int connection_edge_end_errno(edge_connection_t *conn)
int connection_edge_end(edge_connection_t *conn, uint8_t reason)
void connection_ap_attach_pending(int retry)
size_t half_streams_get_total_allocation(void)
int connection_half_edge_is_valid_sendme(const smartlist_t *half_conns, streamid_t stream_id)
int connection_edge_is_rendezvous_stream(const edge_connection_t *conn)
entry_connection_t * EDGE_TO_ENTRY_CONN(edge_connection_t *)
void connection_ap_handshake_socks_resolved(entry_connection_t *conn, int answer_type, size_t answer_len, const uint8_t *answer, int ttl, time_t expires)
void connection_entry_set_controller_wait(entry_connection_t *conn)
streamid_t get_unique_stream_id_by_circ(origin_circuit_t *circ)
const edge_connection_t * CONST_TO_EDGE_CONN(const connection_t *)
void circuit_discard_optional_exit_enclaves(extend_info_t *info)
void connection_exit_connect(edge_connection_t *conn)
int connection_edge_process_inbuf(edge_connection_t *conn, int package_partial)
Header file containing service data for the HS subsystem.
hs_circuit_id_protocol_t
Definition: hs_service.h:203
addressmap_entry_source_t
Definition: or.h:1006
uint32_t circid_t
Definition: or.h:579
uint16_t streamid_t
Definition: or.h:581
A relay message which contains a relay command and parameters, if any, that is from a relay cell.
streamid_t stream_id
Definition: half_edge_st.h:24
Definition: node_st.h:34
Macros to implement mocking and selective exposure for the test code.
#define STATIC
Definition: testsupport.h:32
#define MOCK_DECL(rv, funcname, arglist)
Definition: testsupport.h:127