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|
/* Copyright 2004 Roger Dingledine */
/* See LICENSE for licensing information */
/* $Id$ */
/**
* \file rendservice.c
* \brief The hidden-service side of rendezvous functionality.
**/
#include "or.h"
static circuit_t *find_intro_circuit(routerinfo_t *router, const char *pk_digest);
/** Represents the mapping from a virtual port of a rendezvous service to
* a real port on some IP.
*/
typedef struct rend_service_port_config_t {
uint16_t virtual_port;
uint16_t real_port;
uint32_t real_address;
} rend_service_port_config_t;
/** Try to maintain this many intro points per service if possible. */
#define NUM_INTRO_POINTS 3
/** If we can't build our intro circuits, don't retry for this long. */
#define INTRO_CIRC_RETRY_PERIOD 60*15
/** Don't try to build more than this many circuits before giving up
* for a while.*/
#define MAX_INTRO_CIRCS_PER_PERIOD 20
/** Represents a single hidden service running at this OP. */
typedef struct rend_service_t {
/** Fields specified in config file */
char *directory; /**< where in the filesystem it stores it */
smartlist_t *ports; /**< List of rend_service_port_config_t */
char *intro_prefer_nodes; /**< comma-separated list of nicknames */
char *intro_exclude_nodes; /**< comma-separated list of nicknames */
/* Other fields */
crypto_pk_env_t *private_key;
char service_id[REND_SERVICE_ID_LEN+1];
char pk_digest[DIGEST_LEN];
smartlist_t *intro_nodes; /**< list of nicknames for intro points we have,
* or are trying to establish. */
time_t intro_period_started;
int n_intro_circuits_launched; /**< count of intro circuits we have
* established in this period. */
rend_service_descriptor_t *desc;
int desc_is_dirty;
} rend_service_t;
/** A list of rend_service_t's for services run on this OP.
*/
static smartlist_t *rend_service_list = NULL;
/** Release the storage held by <b>service</b>.
*/
static void rend_service_free(rend_service_t *service)
{
if (!service) return;
tor_free(service->directory);
SMARTLIST_FOREACH(service->ports, void*, p, tor_free(p));
smartlist_free(service->ports);
if (service->private_key)
crypto_free_pk_env(service->private_key);
tor_free(service->intro_prefer_nodes);
tor_free(service->intro_exclude_nodes);
SMARTLIST_FOREACH(service->intro_nodes, void*, p, tor_free(p));
smartlist_free(service->intro_nodes);
if (service->desc)
rend_service_descriptor_free(service->desc);
tor_free(service);
}
/** Release all the storage held in rend_service_list, and allocate a new,
* empty rend_service_list.
*/
static void rend_service_free_all(void)
{
if (!rend_service_list) {
rend_service_list = smartlist_create();
return;
}
SMARTLIST_FOREACH(rend_service_list, rend_service_t*, ptr,
rend_service_free(ptr));
smartlist_free(rend_service_list);
rend_service_list = smartlist_create();
}
/** Validate <b>service</b> and add it to rend_service_list if possible.
*/
static void add_service(rend_service_t *service)
{
int i;
rend_service_port_config_t *p;
struct in_addr addr;
if (!service->intro_prefer_nodes)
service->intro_prefer_nodes = tor_strdup("");
if (!service->intro_exclude_nodes)
service->intro_exclude_nodes = tor_strdup("");
if (!smartlist_len(service->ports)) {
log_fn(LOG_WARN, "Hidden service with no ports configured; ignoring.");
rend_service_free(service);
} else {
smartlist_set_capacity(service->ports, -1);
smartlist_add(rend_service_list, service);
log_fn(LOG_DEBUG,"Configuring service with directory %s",service->directory);
for (i = 0; i < smartlist_len(service->ports); ++i) {
p = smartlist_get(service->ports, i);
addr.s_addr = htonl(p->real_address);
log_fn(LOG_DEBUG,"Service maps port %d to %s:%d",
p->virtual_port, inet_ntoa(addr), p->real_port);
}
}
}
/** Parses a real-port to virtual-port mapping and returns a new
* rend_service_port_config_t.
*
* The format is: VirtualPort (IP|RealPort|IP:RealPort)?
*
* IP defaults to 127.0.0.1; RealPort defaults to VirtualPort.
*/
static rend_service_port_config_t *parse_port_config(const char *string)
{
int virtport, realport, r;
struct in_addr addr;
char *endptr, *colon, *addrstring;
rend_service_port_config_t *result;
virtport = (int) strtol(string, &endptr, 10);
if (endptr == string) {
log_fn(LOG_WARN, "Missing port in hidden service port configuration");
return NULL;
}
if (virtport < 1 || virtport > 65535) {
log_fn(LOG_WARN, "Port out of range in hidden service port configuration");
return NULL;
}
string = endptr + strspn(endptr, " \t");
if (!*string) {
/* No addr:port part; use default. */
realport = virtport;
addr.s_addr = htonl(0x7F000001u); /* 127.0.0.1 */
} else {
colon = strchr(string, ':');
if (colon) {
/* Try to parse addr:port. */
addrstring = tor_strndup(string, colon-string);
r = tor_inet_aton(addrstring, &addr);
tor_free(addrstring);
if (!r) {
log_fn(LOG_WARN,"Unparseable address in hidden service port configuration");
return NULL;
}
realport = strtol(colon+1, &endptr, 10);
if (*endptr) {
log_fn(LOG_WARN,"Unparseable or missing port in hidden service port configuration.");
return NULL;
}
} else if (strchr(string, '.') && tor_inet_aton(string, &addr)) {
/* We have addr; use deafult port. */
realport = virtport;
} else {
/* No addr:port, no addr -- must be port. */
realport = strtol(string, &endptr, 10);
if (*endptr) {
log_fn(LOG_WARN, "Unparseable of missing port in hidden service port configuration.");
return NULL;
}
addr.s_addr = htonl(0x7F000001u); /* Default to 127.0.0.1 */
}
}
if (realport < 1 || realport > 65535) {
log_fn(LOG_WARN, "Port out of range in hidden service port configuration.");
return NULL;
}
result = tor_malloc(sizeof(rend_service_port_config_t));
result->virtual_port = virtport;
result->real_port = realport;
result->real_address = (uint32_t) ntohl(addr.s_addr);
return result;
}
/** Set up rend_service_list, based on the values of HiddenServiceDir and
* HiddenServicePort in <b>options</b>. Return 0 on success and -1 on
* failure.
*/
int rend_config_services(or_options_t *options)
{
struct config_line_t *line;
rend_service_t *service = NULL;
rend_service_port_config_t *portcfg;
rend_service_free_all();
for (line = options->RendConfigLines; line; line = line->next) {
if (!strcasecmp(line->key, "HiddenServiceDir")) {
if (service)
add_service(service);
service = tor_malloc_zero(sizeof(rend_service_t));
service->directory = tor_strdup(line->value);
service->ports = smartlist_create();
service->intro_nodes = smartlist_create();
service->intro_period_started = time(NULL);
continue;
}
if (!service) {
log_fn(LOG_WARN, "HiddenServicePort with no preceeding HiddenServiceDir directive");
rend_service_free(service);
return -1;
}
if (!strcasecmp(line->key, "HiddenServicePort")) {
portcfg = parse_port_config(line->value);
if (!portcfg) {
rend_service_free(service);
return -1;
}
smartlist_add(service->ports, portcfg);
} else if (!strcasecmp(line->key, "HiddenServiceNodes")) {
if (service->intro_prefer_nodes) {
log_fn(LOG_WARN, "Got multiple HiddenServiceNodes lines for a single service");
return -1;
}
service->intro_prefer_nodes = tor_strdup(line->value);
} else {
tor_assert(!strcasecmp(line->key, "HiddenServiceExcludeNodes"));
if (service->intro_exclude_nodes) {
log_fn(LOG_WARN, "Got multiple HiddenServiceExcludedNodes lines for a single service");
return -1;
}
service->intro_exclude_nodes = tor_strdup(line->value);
}
}
if (service)
add_service(service);
return 0;
}
/** Replace the old value of <b>service</b>-\>desc with one that reflects
* the other fields in service.
*/
static void rend_service_update_descriptor(rend_service_t *service)
{
rend_service_descriptor_t *d;
circuit_t *circ;
int i,n;
routerinfo_t *router;
if (service->desc) {
rend_service_descriptor_free(service->desc);
service->desc = NULL;
}
d = service->desc = tor_malloc(sizeof(rend_service_descriptor_t));
d->pk = crypto_pk_dup_key(service->private_key);
d->timestamp = time(NULL);
n = smartlist_len(service->intro_nodes);
d->n_intro_points = 0;
d->intro_points = tor_malloc(sizeof(char*)*n);
for (i=0; i < n; ++i) {
router = router_get_by_nickname(smartlist_get(service->intro_nodes, i));
circ = find_intro_circuit(router, service->pk_digest);
if (circ && circ->purpose == CIRCUIT_PURPOSE_S_INTRO) {
/* We have an entirely established intro circuit. */
d->intro_points[d->n_intro_points++] = tor_strdup(router->nickname);
}
}
}
/** Load and/or generate private keys for all hidden services. Return 0 on
* success, -1 on failure.
*/
int rend_service_load_keys(void)
{
int i;
rend_service_t *s;
char fname[512];
char buf[128];
for (i=0; i < smartlist_len(rend_service_list); ++i) {
s = smartlist_get(rend_service_list,i);
if (s->private_key)
continue;
log_fn(LOG_INFO, "Loading hidden-service keys from '%s'", s->directory);
/* Check/create directory */
if (check_private_dir(s->directory, 1) < 0)
return -1;
/* Load key */
if (strlcpy(fname,s->directory,sizeof(fname)) >= sizeof(fname) ||
strlcat(fname,"/private_key",sizeof(fname)) >= sizeof(fname)) {
log_fn(LOG_WARN, "Directory name too long: '%s'", s->directory);
return -1;
}
s->private_key = init_key_from_file(fname);
if (!s->private_key)
return -1;
/* Create service file */
if (rend_get_service_id(s->private_key, s->service_id)<0) {
log_fn(LOG_WARN, "Couldn't encode service ID");
return -1;
}
if (crypto_pk_get_digest(s->private_key, s->pk_digest)<0) {
log_fn(LOG_WARN, "Couldn't compute hash of public key");
return -1;
}
if (strlcpy(fname,s->directory,sizeof(fname)) >= sizeof(fname) ||
strlcat(fname,"/hostname",sizeof(fname)) >= sizeof(fname)) {
log_fn(LOG_WARN, "Directory name too long: '%s'", s->directory);
return -1;
}
sprintf(buf, "%s.onion\n", s->service_id);
if (write_str_to_file(fname,buf)<0)
return -1;
}
return 0;
}
/** Return the service whose public key has a digest of <b>digest</b>. Return
* NULL if no such service exists.
*/
static rend_service_t *
rend_service_get_by_pk_digest(const char* digest)
{
SMARTLIST_FOREACH(rend_service_list, rend_service_t*, s,
if (!memcmp(s->pk_digest,digest,DIGEST_LEN)) return s);
return NULL;
}
/******
* Handle cells
******/
/** Respond to an INTRODUCE2 cell by launching a circuit to the chosen
* rendezvous points.
*/
int
rend_service_introduce(circuit_t *circuit, const char *request, int request_len)
{
char *ptr, *rp_nickname, *r_cookie;
char buf[RELAY_PAYLOAD_SIZE];
char keys[DIGEST_LEN+CPATH_KEY_MATERIAL_LEN]; /* Holds KH, Df, Db, Kf, Kb */
rend_service_t *service;
int len, keylen;
crypto_dh_env_t *dh = NULL;
circuit_t *launched = NULL;
crypt_path_t *cpath = NULL;
char serviceid[REND_SERVICE_ID_LEN+1];
char hexcookie[9];
if (base32_encode(serviceid, REND_SERVICE_ID_LEN+1,
circuit->rend_pk_digest,10)) {
return -1;
}
log_fn(LOG_INFO, "Received INTRODUCE2 cell for service %s on circ %d",
serviceid, circuit->n_circ_id);
if (circuit->purpose != CIRCUIT_PURPOSE_S_INTRO) {
log_fn(LOG_WARN, "Got an INTRODUCE2 over a non-introduction circuit %d",
circuit->n_circ_id);
return -1;
}
/* min key length plus digest length plus nickname length */
if (request_len < DIGEST_LEN+REND_COOKIE_LEN+(MAX_NICKNAME_LEN+1)+
DH_KEY_LEN+42){
log_fn(LOG_WARN, "Got a truncated INTRODUCE2 cell on circ %d",
circuit->n_circ_id);
return -1;
}
/* first DIGEST_LEN bytes of request is service pk digest */
service = rend_service_get_by_pk_digest(request);
if (!service) {
log_fn(LOG_WARN, "Got an INTRODUCE2 cell for an unrecognized service %s",
serviceid);
return -1;
}
if (memcmp(circuit->rend_pk_digest, request, DIGEST_LEN)) {
if (base32_encode(serviceid, REND_SERVICE_ID_LEN+1, request, 10)) {
return -1;
}
log_fn(LOG_WARN, "Got an INTRODUCE2 cell for the wrong service (%s)",
serviceid);
return -1;
}
keylen = crypto_pk_keysize(service->private_key);
if (request_len < keylen+DIGEST_LEN) {
log_fn(LOG_WARN, "PK-encrypted portion of INTRODUCE2 cell was truncated");
return -1;
}
/* Next N bytes is encrypted with service key */
len = crypto_pk_private_hybrid_decrypt(
service->private_key,request+DIGEST_LEN,request_len-DIGEST_LEN,buf,
PK_PKCS1_OAEP_PADDING,1);
if (len<0) {
log_fn(LOG_WARN, "Couldn't decrypt INTRODUCE2 cell");
return -1;
}
ptr=memchr(buf,0,MAX_NICKNAME_LEN+1);
if (!ptr || ptr == buf) {
log_fn(LOG_WARN, "Couldn't find a null-padded nickname in INTRODUCE2 cell");
return -1;
}
if ((int)strspn(buf,LEGAL_NICKNAME_CHARACTERS) != ptr-buf) {
log_fn(LOG_WARN, "Nickname in INTRODUCE2 cell contains illegal character.");
return -1;
}
/* Okay, now we know that the nickname is at the start of the buffer. */
rp_nickname = buf;
ptr = buf+(MAX_NICKNAME_LEN+1);
len -= (MAX_NICKNAME_LEN+1);
if (len != REND_COOKIE_LEN+DH_KEY_LEN) {
log_fn(LOG_WARN, "Bad length for INTRODUCE2 cell.");
return -1;
}
r_cookie = ptr;
hex_encode(r_cookie,4,hexcookie);
/* Try DH handshake... */
dh = crypto_dh_new();
if (!dh || crypto_dh_generate_public(dh)<0) {
log_fn(LOG_WARN, "Couldn't build DH state or generate public key");
goto err;
}
if (crypto_dh_compute_secret(dh, ptr+REND_COOKIE_LEN, DH_KEY_LEN, keys,
DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
log_fn(LOG_WARN, "Couldn't complete DH handshake");
goto err;
}
/* Launch a circuit to alice's chosen rendezvous point.
*/
launched = circuit_launch_new(CIRCUIT_PURPOSE_S_CONNECT_REND, rp_nickname);
log_fn(LOG_INFO,
"Accepted intro; launching circuit to '%s' (cookie %s) for service %s",
rp_nickname, hexcookie, serviceid);
if (!launched) {
log_fn(LOG_WARN,
"Can't launch circuit to rendezvous point '%s' for service %s",
rp_nickname, serviceid);
return -1;
}
tor_assert(launched->build_state);
/* Fill in the circuit's state. */
memcpy(launched->rend_pk_digest, circuit->rend_pk_digest,
DIGEST_LEN);
memcpy(launched->rend_cookie, r_cookie, REND_COOKIE_LEN);
strcpy(launched->rend_query, service->service_id);
launched->build_state->pending_final_cpath = cpath =
tor_malloc_zero(sizeof(crypt_path_t));
cpath->handshake_state = dh;
dh = NULL;
if (circuit_init_cpath_crypto(cpath,keys+DIGEST_LEN,1)<0)
goto err;
memcpy(cpath->handshake_digest, keys, DIGEST_LEN);
return 0;
err:
if (dh) crypto_dh_free(dh);
if (launched) circuit_mark_for_close(launched);
return -1;
}
/** How many times will a hidden service operator attempt to connect to
* a requested rendezvous point before giving up? */
#define MAX_REND_FAILURES 3
/** Called when we fail building a rendezvous circuit at some point other
* than the last hop: launches a new circuit to the same rendezvous point.
*/
void
rend_service_relaunch_rendezvous(circuit_t *oldcirc)
{
circuit_t *newcirc;
cpath_build_state_t *newstate, *oldstate;
/* XXXX assert type and build_state */
if (!oldcirc->build_state ||
oldcirc->build_state->failure_count > MAX_REND_FAILURES) {
log_fn(LOG_INFO,"Attempt to build circuit to %s for rendezvous has failed too many times; giving up.",
oldcirc->build_state->chosen_exit);
return;
}
log_fn(LOG_INFO,"Reattempting rendezvous circuit to %s",
oldcirc->build_state->chosen_exit);
newcirc = circuit_launch_new(CIRCUIT_PURPOSE_S_CONNECT_REND,
oldcirc->build_state->chosen_exit);
if (!newcirc) {
log_fn(LOG_WARN,"Couldn't relaunch rendezvous circuit to %s",
oldcirc->build_state->chosen_exit);
return;
}
oldstate = oldcirc->build_state;
newstate = newcirc->build_state;
tor_assert(newstate && oldstate);
newstate->failure_count = oldstate->failure_count+1;
newstate->pending_final_cpath = oldstate->pending_final_cpath;
oldstate->pending_final_cpath = NULL;
memcpy(newcirc->rend_query, oldcirc->rend_query, REND_SERVICE_ID_LEN+1);
memcpy(newcirc->rend_pk_digest, oldcirc->rend_pk_digest, DIGEST_LEN);
memcpy(newcirc->rend_cookie, oldcirc->rend_cookie, REND_COOKIE_LEN);
}
/** Launch a circuit to serve as an introduction point for the service
* <b>service</b> at the introduction point <b>nickname</b>
*/
static int
rend_service_launch_establish_intro(rend_service_t *service, const char *nickname)
{
circuit_t *launched;
log_fn(LOG_INFO, "Launching circuit to introduction point %s for service %s",
nickname, service->service_id);
++service->n_intro_circuits_launched;
launched = circuit_launch_new(CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, nickname);
if (!launched) {
log_fn(LOG_WARN, "Can't launch circuit to establish introduction at '%s'",
nickname);
return -1;
}
strcpy(launched->rend_query, service->service_id);
memcpy(launched->rend_pk_digest, service->pk_digest, DIGEST_LEN);
return 0;
}
/** Called when we're done building a circuit to an introduction point:
* sends a RELAY_ESTABLISH_INTRO cell.
*/
void
rend_service_intro_has_opened(circuit_t *circuit)
{
rend_service_t *service;
int len, r;
char buf[RELAY_PAYLOAD_SIZE];
char auth[DIGEST_LEN + 9];
char serviceid[REND_SERVICE_ID_LEN+1];
tor_assert(circuit->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
tor_assert(CIRCUIT_IS_ORIGIN(circuit) && circuit->cpath);
if (base32_encode(serviceid, REND_SERVICE_ID_LEN+1,
circuit->rend_pk_digest,10)) {
tor_assert(0);
}
service = rend_service_get_by_pk_digest(circuit->rend_pk_digest);
if (!service) {
log_fn(LOG_WARN, "Unrecognized service ID %s on introduction circuit %d",
serviceid, circuit->n_circ_id);
goto err;
}
log_fn(LOG_INFO,
"Established circuit %d as introduction point for service %s",
circuit->n_circ_id, serviceid);
/* Build the payload for a RELAY_ESTABLISH_INTRO cell. */
len = crypto_pk_asn1_encode(service->private_key, buf+2,
RELAY_PAYLOAD_SIZE-2);
set_uint16(buf, htons((uint16_t)len));
len += 2;
memcpy(auth, circuit->cpath->prev->handshake_digest, DIGEST_LEN);
memcpy(auth+DIGEST_LEN, "INTRODUCE", 9);
if (crypto_digest(auth, DIGEST_LEN+9, buf+len))
goto err;
len += 20;
r = crypto_pk_private_sign_digest(service->private_key, buf, len, buf+len);
if (r<0) {
log_fn(LOG_WARN, "Couldn't sign introduction request");
goto err;
}
len += r;
if (connection_edge_send_command(NULL, circuit,RELAY_COMMAND_ESTABLISH_INTRO,
buf, len, circuit->cpath->prev)<0) {
log_fn(LOG_WARN,
"Couldn't send introduction request for service %s on circuit %d",
serviceid, circuit->n_circ_id);
goto err;
}
return;
err:
circuit_mark_for_close(circuit);
}
/** Called when we get an INTRO_ESTABLISHED cell; mark the circuit as a
* live introduction point, and note that the service descriptor is
* now out-of-date.*/
int
rend_service_intro_established(circuit_t *circuit, const char *request, int request_len)
{
rend_service_t *service;
if (circuit->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) {
log_fn(LOG_WARN, "received INTRO_ESTABLISHED cell on non-intro circuit");
goto err;
}
service = rend_service_get_by_pk_digest(circuit->rend_pk_digest);
if (!service) {
log_fn(LOG_WARN, "Unknown service on introduction circuit %d",
circuit->n_circ_id);
goto err;
}
service->desc_is_dirty = 1;
circuit->purpose = CIRCUIT_PURPOSE_S_INTRO;
return 0;
err:
circuit_mark_for_close(circuit);
return -1;
}
/** Called once a circuit to a rendezvous point is established: sends a
* RELAY_COMMAND_RENDEZVOUS1 cell.
*/
void
rend_service_rendezvous_has_opened(circuit_t *circuit)
{
rend_service_t *service;
char buf[RELAY_PAYLOAD_SIZE];
crypt_path_t *hop;
char serviceid[REND_SERVICE_ID_LEN+1];
char hexcookie[9];
tor_assert(circuit->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND);
tor_assert(circuit->cpath);
tor_assert(circuit->build_state);
hop = circuit->build_state->pending_final_cpath;
tor_assert(hop);
hex_encode(circuit->rend_cookie, 4, hexcookie);
if (base32_encode(serviceid, REND_SERVICE_ID_LEN+1,
circuit->rend_pk_digest,10)) {
tor_assert(0);
}
log_fn(LOG_INFO,
"Done building circuit %d to rendezvous with cookie %s for service %s",
circuit->n_circ_id, hexcookie, serviceid);
service = rend_service_get_by_pk_digest(circuit->rend_pk_digest);
if (!service) {
log_fn(LOG_WARN, "Internal error: unrecognized service ID on introduction circuit");
goto err;
}
/* All we need to do is send a RELAY_RENDEZVOUS1 cell... */
memcpy(buf, circuit->rend_cookie, REND_COOKIE_LEN);
if (crypto_dh_get_public(hop->handshake_state,
buf+REND_COOKIE_LEN, DH_KEY_LEN)<0) {
log_fn(LOG_WARN,"Couldn't get DH public key");
goto err;
}
memcpy(buf+REND_COOKIE_LEN+DH_KEY_LEN, hop->handshake_digest,
DIGEST_LEN);
/* Send the cell */
if (connection_edge_send_command(NULL, circuit, RELAY_COMMAND_RENDEZVOUS1,
buf, REND_COOKIE_LEN+DH_KEY_LEN+DIGEST_LEN,
circuit->cpath->prev)<0) {
log_fn(LOG_WARN, "Couldn't send RENDEZVOUS1 cell");
goto err;
}
crypto_dh_free(hop->handshake_state);
hop->handshake_state = NULL;
/* Append the cpath entry. */
hop->state = CPATH_STATE_OPEN;
/* set the windows to default. these are the windows
* that bob thinks alice has.
*/
hop->package_window = CIRCWINDOW_START;
hop->deliver_window = CIRCWINDOW_START;
onion_append_to_cpath(&circuit->cpath, hop);
circuit->build_state->pending_final_cpath = NULL; /* prevent double-free */
/* Change the circuit purpose. */
circuit->purpose = CIRCUIT_PURPOSE_S_REND_JOINED;
return;
err:
circuit_mark_for_close(circuit);
}
/*
* Manage introduction points
*/
/** Return the (possibly non-open) introduction circuit ending at
* <b>router</b> for the service whose public key is <b>pk_digest</b>. Return
* NULL if no such service is found.
*/
static circuit_t *
find_intro_circuit(routerinfo_t *router, const char *pk_digest)
{
circuit_t *circ = NULL;
while ((circ = circuit_get_next_by_pk_and_purpose(circ,pk_digest,
CIRCUIT_PURPOSE_S_INTRO))) {
tor_assert(circ->cpath);
if (circ->build_state->chosen_exit &&
!strcasecmp(circ->build_state->chosen_exit, router->nickname)) {
return circ;
}
}
circ = NULL;
while ((circ = circuit_get_next_by_pk_and_purpose(circ,pk_digest,
CIRCUIT_PURPOSE_S_ESTABLISH_INTRO))) {
tor_assert(circ->cpath);
if (circ->build_state->chosen_exit &&
!strcasecmp(circ->build_state->chosen_exit, router->nickname)) {
return circ;
}
}
return NULL;
}
/** If the directory servers don't have an up-to-date descriptor for
* <b>service</b>, encode and sign the service descriptor for <b>service</b>,
* and upload it to all the dirservers.
*/
static void
upload_service_descriptor(rend_service_t *service)
{
char *desc;
int desc_len;
if (!service->desc_is_dirty)
return;
/* Update the descriptor. */
rend_service_update_descriptor(service);
if (rend_encode_service_descriptor(service->desc,
service->private_key,
&desc, &desc_len)<0) {
log_fn(LOG_WARN, "Couldn't encode service descriptor; not uploading");
return;
}
/* Post it to the dirservers */
directory_post_to_dirservers(DIR_PURPOSE_UPLOAD_RENDDESC, desc, desc_len);
tor_free(desc);
service->desc_is_dirty = 0;
}
/* XXXX Make this longer once directories remember service descriptors across
* restarts.*/
#define MAX_SERVICE_PUBLICATION_INTERVAL (15*60)
/** For every service, check how many intro points it currently has, and:
* - Pick new intro points as necessary.
* - Launch circuits to any new intro points.
*/
void rend_services_introduce(void) {
int i,j,r;
routerinfo_t *router;
routerlist_t *rl;
rend_service_t *service;
char *intro;
int changed, prev_intro_nodes;
smartlist_t *intro_routers, *exclude_routers;
time_t now;
router_get_routerlist(&rl);
intro_routers = smartlist_create();
exclude_routers = smartlist_create();
now = time(NULL);
for (i=0; i< smartlist_len(rend_service_list); ++i) {
smartlist_clear(intro_routers);
service = smartlist_get(rend_service_list, i);
tor_assert(service);
changed = 0;
if (now > service->intro_period_started+INTRO_CIRC_RETRY_PERIOD) {
/* One period has elapsed; we can try building circuits again. */
service->intro_period_started = now;
service->n_intro_circuits_launched = 0;
} else if (service->n_intro_circuits_launched>=MAX_INTRO_CIRCS_PER_PERIOD){
/* We have failed too many times in this period; wait for the next
* one before we try again. */
continue;
}
/* Find out which introduction points we have in progress for this service. */
for (j=0;j< smartlist_len(service->intro_nodes); ++j) {
intro = smartlist_get(service->intro_nodes, j);
router = router_get_by_nickname(intro);
if (!router || !find_intro_circuit(router,service->pk_digest)) {
log_fn(LOG_INFO,"Giving up on %s as intro point for %s.",
intro, service->service_id);
smartlist_del(service->intro_nodes,j--);
changed = service->desc_is_dirty = 1;
}
smartlist_add(intro_routers, router);
}
/* We have enough intro points, and the intro points we thought we had were
* all connected.
*/
if (!changed && smartlist_len(service->intro_nodes) >= NUM_INTRO_POINTS) {
/* We have all our intro points! Start a fresh period and reset the
* circuit count. */
service->intro_period_started = now;
service->n_intro_circuits_launched = 0;
continue;
}
/* Remember how many introduction circuits we started with. */
prev_intro_nodes = smartlist_len(service->intro_nodes);
smartlist_add_all(exclude_routers, intro_routers);
/* The directory is now here. Pick three ORs as intro points. */
for (j=prev_intro_nodes; j < NUM_INTRO_POINTS; ++j) {
router = router_choose_random_node(rl,
service->intro_prefer_nodes,
service->intro_exclude_nodes,
exclude_routers);
if (!router) {
log_fn(LOG_WARN, "Could only establish %d introduction points for %s",
smartlist_len(service->intro_nodes), service->service_id);
break;
}
changed = 1;
smartlist_add(intro_routers, router);
smartlist_add(exclude_routers, router);
smartlist_add(service->intro_nodes, tor_strdup(router->nickname));
log_fn(LOG_INFO,"Picked router %s as an intro point for %s.", router->nickname,
service->service_id);
}
/* Reset exclude_routers, for the next time around the loop. */
smartlist_clear(exclude_routers);
/* If there's no need to launch new circuits, stop here. */
if (!changed)
continue;
/* Establish new introduction points. */
for (j=prev_intro_nodes; j < smartlist_len(service->intro_nodes); ++j) {
intro = smartlist_get(service->intro_nodes, j);
r = rend_service_launch_establish_intro(service, intro);
if (r<0) {
log_fn(LOG_WARN, "Error launching circuit to node %s for service %s",
intro, service->service_id);
}
}
}
smartlist_free(intro_routers);
smartlist_free(exclude_routers);
}
/** Regenerate and upload rendezvous service descriptors for all
* services. If <b>force</b> is false, skip services where we've already
* uploaded an up-to-date copy; if <b>force</b> is true, regenerate and
* upload everything.
*/
void
rend_services_upload(int force)
{
int i;
rend_service_t *service;
for (i=0; i< smartlist_len(rend_service_list); ++i) {
service = smartlist_get(rend_service_list, i);
if (force)
service->desc_is_dirty = 1;
if (service->desc_is_dirty)
upload_service_descriptor(service);
}
}
/** Log the status of introduction points for all rendezvous services
* at log severity <b>serverity</b>.
*/
void
rend_service_dump_stats(int severity)
{
int i,j;
routerinfo_t *router;
rend_service_t *service;
char *nickname;
circuit_t *circ;
for (i=0; i < smartlist_len(rend_service_list); ++i) {
service = smartlist_get(rend_service_list, i);
log(severity, "Service configured in %s:", service->directory);
for (j=0; j < smartlist_len(service->intro_nodes); ++j) {
nickname = smartlist_get(service->intro_nodes, j);
router = router_get_by_nickname(smartlist_get(service->intro_nodes,j));
if (!router) {
log(severity, " Intro point at %s: unrecognized router",nickname);
continue;
}
circ = find_intro_circuit(router, service->pk_digest);
if (!circ) {
log(severity, " Intro point at %s: no circuit",nickname);
continue;
}
log(severity, " Intro point at %s: circuit is %s",nickname,
circuit_state_to_string[circ->state]);
}
}
}
/** Given <b>conn</b>, a rendezvous exit stream, look up the hidden service for
* 'circ', and look up the port and address based on conn-\>port.
* Assign the actual conn-\>addr and conn-\>port. Return -1 if failure,
* or 0 for success.
*/
int
rend_service_set_connection_addr_port(connection_t *conn, circuit_t *circ)
{
rend_service_t *service;
int i;
rend_service_port_config_t *p;
char serviceid[REND_SERVICE_ID_LEN+1];
tor_assert(circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED);
log_fn(LOG_DEBUG,"beginning to hunt for addr/port");
if (base32_encode(serviceid, REND_SERVICE_ID_LEN+1,
circ->rend_pk_digest,10)) {
log_fn(LOG_WARN,"bug: base32 failed");
return -1;
}
service = rend_service_get_by_pk_digest(circ->rend_pk_digest);
if (!service) {
log_fn(LOG_WARN, "Couldn't find any service associated with pk %s on rendezvous circuit %d; closing",
serviceid, circ->n_circ_id);
return -1;
}
for (i = 0; i < smartlist_len(service->ports); ++i) {
p = smartlist_get(service->ports, i);
if (conn->port == p->virtual_port) {
conn->addr = p->real_address;
conn->port = p->real_port;
return 0;
}
}
log_fn(LOG_INFO, "No virtual port mapping exists for port %d on service %s",
conn->port,serviceid);
return -1;
}
/*
Local Variables:
mode:c
indent-tabs-mode:nil
c-basic-offset:2
End:
*/
|