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tor/src/or/control.c

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/* Copyright 2004-2005 Roger Dingledine, Nick Mathewson. */
/* See LICENSE for licensing information */
/* $Id$ */
const char control_c_id[] = "$Id$";
/**
* \file control.c
*
* \brief Implementation for Tor's control-socket interface.
*/
#include "or.h"
/* Protocol outline: a bidirectional stream, over which each side
* sends a series of messages. Each message has a two-byte length field,
* a two-byte typecode, and a variable-length body whose length is
* given in the length field.
*
* By default, the server only sends messages in response to client messages.
* Every client message gets a message in response. The client may, however,
* _request_ that other messages be delivered asynchronously.
*
*
* Every message type is either client-only or server-only, and every
* server message type is either synchronous-only (only occurs in
* response to a client request) or asynchronous-only (never is an
* answer to a client request.
*
* See control-spec.txt for full details.
*/
/* Recognized message type codes. */
#define CONTROL_CMD_ERROR 0x0000
#define CONTROL_CMD_DONE 0x0001
#define CONTROL_CMD_SETCONF 0x0002
#define CONTROL_CMD_GETCONF 0x0003
#define CONTROL_CMD_CONFVALUE 0x0004
#define CONTROL_CMD_SETEVENTS 0x0005
#define CONTROL_CMD_EVENT 0x0006
#define CONTROL_CMD_AUTHENTICATE 0x0007
#define CONTROL_CMD_SAVECONF 0x0008
#define CONTROL_CMD_SIGNAL 0x0009
#define CONTROL_CMD_MAPADDRESS 0x000A
#define CONTROL_CMD_GETINFO 0x000B
#define CONTROL_CMD_INFOVALUE 0x000C
#define CONTROL_CMD_EXTENDCIRCUIT 0x000D
#define CONTROL_CMD_ATTACHSTREAM 0x000E
#define CONTROL_CMD_POSTDESCRIPTOR 0x000F
#define CONTROL_CMD_FRAGMENTHEADER 0x0010
#define CONTROL_CMD_FRAGMENT 0x0011
#define CONTROL_CMD_REDIRECTSTREAM 0x0012
#define CONTROL_CMD_CLOSESTREAM 0x0013
#define CONTROL_CMD_CLOSECIRCUIT 0x0014
#define _CONTROL_CMD_MAX_RECOGNIZED 0x0014
/* Recognized error codes. */
#define ERR_UNSPECIFIED 0x0000
#define ERR_INTERNAL 0x0001
#define ERR_UNRECOGNIZED_TYPE 0x0002
#define ERR_SYNTAX 0x0003
#define ERR_UNRECOGNIZED_CONFIG_KEY 0x0004
#define ERR_INVALID_CONFIG_VALUE 0x0005
#define ERR_UNRECOGNIZED_EVENT_CODE 0x0006
#define ERR_UNAUTHORIZED 0x0007
#define ERR_REJECTED_AUTHENTICATION 0x0008
#define ERR_RESOURCE_EXHAUSETED 0x0009
#define ERR_NO_STREAM 0x000A
#define ERR_NO_CIRC 0x000B
#define ERR_NO_ROUTER 0x000C
/* Recognized asynchronous event types. */
#define _EVENT_MIN 0x0001
#define EVENT_CIRCUIT_STATUS 0x0001
#define EVENT_STREAM_STATUS 0x0002
#define EVENT_OR_CONN_STATUS 0x0003
#define EVENT_BANDWIDTH_USED 0x0004
#define EVENT_LOG_OBSOLETE 0x0005
#define EVENT_NEW_DESC 0x0006
#define EVENT_DEBUG_MSG 0x0007
#define EVENT_INFO_MSG 0x0008
#define EVENT_NOTICE_MSG 0x0009
#define EVENT_WARN_MSG 0x000A
#define EVENT_ERR_MSG 0x000B
#define _EVENT_MAX 0x000B
/** Array mapping from message type codes to human-readable message
* type names. */
static const char * CONTROL_COMMANDS[_CONTROL_CMD_MAX_RECOGNIZED+1] = {
"error",
"done",
"setconf",
"getconf",
"confvalue",
"setevents",
"events",
"authenticate",
"saveconf",
"signal",
"mapaddress",
"getinfo",
"infovalue",
"extendcircuit",
"attachstream",
"postdescriptor",
"fragmentheader",
"fragment",
};
/** Bitfield: The bit 1&lt;&lt;e is set if <b>any</b> open control
* connection is interested in events of type <b>e</b>. We use this
* so that we can decide to skip generating event messages that nobody
* has interest in without having to walk over the global connection
* list to find out.
**/
static uint32_t global_event_mask = 0;
/** Macro: true if any control connection is interested in events of type
* <b>e</b>. */
#define EVENT_IS_INTERESTING(e) (global_event_mask & (1<<(e)))
/** If we're using cookie-type authentication, how long should our cookies be?
*/
#define AUTHENTICATION_COOKIE_LEN 32
/** If true, we've set authentication_cookie to a secret code and
* stored it to disk. */
static int authentication_cookie_is_set = 0;
static char authentication_cookie[AUTHENTICATION_COOKIE_LEN];
static void update_global_event_mask(void);
static void send_control_message(connection_t *conn, uint16_t type,
uint32_t len, const char *body);
static void send_control_done(connection_t *conn);
static void send_control_done2(connection_t *conn, const char *msg, size_t len);
static void send_control_error(connection_t *conn, uint16_t error,
const char *message);
static void send_control_event(uint16_t event, uint32_t len, const char *body);
static int handle_control_setconf(connection_t *conn, uint32_t len,
char *body);
static int handle_control_getconf(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_setevents(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_authenticate(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_saveconf(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_signal(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_mapaddress(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_getinfo(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_extendcircuit(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_attachstream(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_postdescriptor(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_redirectstream(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_closestream(connection_t *conn, uint32_t len,
const char *body);
static int handle_control_closecircuit(connection_t *conn, uint32_t len,
const char *body);
/** Given a possibly invalid message type code <b>cmd</b>, return a
* human-readable string equivalent. */
static INLINE const char *
control_cmd_to_string(uint16_t cmd)
{
return (cmd<=_CONTROL_CMD_MAX_RECOGNIZED) ? CONTROL_COMMANDS[cmd] : "Unknown";
}
static INLINE int
event_to_log_severity(int event)
{
switch (event) {
case EVENT_DEBUG_MSG: return LOG_DEBUG;
case EVENT_INFO_MSG: return LOG_INFO;
case EVENT_NOTICE_MSG: return LOG_NOTICE;
case EVENT_WARN_MSG: return LOG_WARN;
case EVENT_ERR_MSG: return LOG_ERR;
default: return -1;
}
}
static INLINE int
log_severity_to_event(int severity)
{
switch (severity) {
case LOG_DEBUG: return EVENT_DEBUG_MSG;
case LOG_INFO: return EVENT_INFO_MSG;
case LOG_NOTICE: return EVENT_NOTICE_MSG;
case LOG_WARN: return EVENT_WARN_MSG;
case LOG_ERR: return EVENT_ERR_MSG;
default: return -1;
}
}
/** Set <b>global_event_mask</b> to the bitwise OR of each live control
* connection's event_mask field. */
static void update_global_event_mask(void)
{
connection_t **conns;
int n_conns, i;
global_event_mask = 0;
get_connection_array(&conns, &n_conns);
for (i = 0; i < n_conns; ++i) {
if (conns[i]->type == CONN_TYPE_CONTROL &&
conns[i]->state == CONTROL_CONN_STATE_OPEN) {
global_event_mask |= conns[i]->event_mask;
}
}
adjust_event_log_severity();
}
void adjust_event_log_severity(void) {
int i;
int min_log_event=EVENT_ERR_MSG, max_log_event=EVENT_DEBUG_MSG;
for (i = EVENT_DEBUG_MSG; i <= EVENT_ERR_MSG; ++i) {
if (EVENT_IS_INTERESTING(i)) {
min_log_event = i;
break;
}
}
for (i = EVENT_ERR_MSG; i >= EVENT_DEBUG_MSG; --i) {
if (EVENT_IS_INTERESTING(i)) {
max_log_event = i;
break;
}
}
if (EVENT_IS_INTERESTING(EVENT_LOG_OBSOLETE)) {
if (min_log_event > EVENT_NOTICE_MSG)
min_log_event = EVENT_NOTICE_MSG;
if (max_log_event < EVENT_ERR_MSG)
max_log_event = EVENT_ERR_MSG;
}
change_callback_log_severity(event_to_log_severity(min_log_event),
event_to_log_severity(max_log_event),
control_event_logmsg);
}
/** Send a message of type <b>type</b> containing <b>len</b> bytes
* from <b>body</b> along the control connection <b>conn</b> */
static void
send_control_message(connection_t *conn, uint16_t type, uint32_t len,
const char *body)
{
char buf[10];
tor_assert(conn);
tor_assert(len || !body);
tor_assert(type <= _CONTROL_CMD_MAX_RECOGNIZED);
if (len < 65536) {
set_uint16(buf, htons(len));
set_uint16(buf+2, htons(type));
connection_write_to_buf(buf, 4, conn);
if (len)
connection_write_to_buf(body, len, conn);
} else {
set_uint16(buf, htons(65535));
set_uint16(buf+2, htons(CONTROL_CMD_FRAGMENTHEADER));
set_uint16(buf+4, htons(type));
set_uint32(buf+6, htonl(len));
connection_write_to_buf(buf, 10, conn);
connection_write_to_buf(body, 65535-6, conn);
len -= (65535-6);
body += (65535-6);
while (len) {
size_t chunklen = (len<65535)?len:65535;
set_uint16(buf, htons((uint16_t)chunklen));
set_uint16(buf+2, htons(CONTROL_CMD_FRAGMENT));
connection_write_to_buf(buf, 4, conn);
connection_write_to_buf(body, chunklen, conn);
len -= chunklen;
body += chunklen;
}
}
}
/** Send a "DONE" message down the control connection <b>conn</b> */
static void
send_control_done(connection_t *conn)
{
send_control_message(conn, CONTROL_CMD_DONE, 0, NULL);
}
static void send_control_done2(connection_t *conn, const char *msg, size_t len)
{
if (len==0)
len = strlen(msg);
send_control_message(conn, CONTROL_CMD_DONE, len, msg);
}
/** Send an error message with error code <b>error</b> and body
* <b>message</b> down the connection <b>conn</b> */
static void
send_control_error(connection_t *conn, uint16_t error, const char *message)
{
char buf[256];
size_t len;
set_uint16(buf, htons(error));
len = strlen(message);
tor_assert(len < (256-2));
memcpy(buf+2, message, len);
send_control_message(conn, CONTROL_CMD_ERROR, (uint16_t)(len+2), buf);
}
/** Send an 'event' message of event type <b>event</b>, containing
* <b>len</b> bytes in <b>body</b> to every control connection that
* is interested in it. */
static void
send_control_event(uint16_t event, uint32_t len, const char *body)
{
connection_t **conns;
int n_conns, i;
size_t buflen;
char *buf;
buflen = len + 2;
buf = tor_malloc_zero(buflen);
set_uint16(buf, htons(event));
memcpy(buf+2, body, len);
get_connection_array(&conns, &n_conns);
for (i = 0; i < n_conns; ++i) {
if (conns[i]->type == CONN_TYPE_CONTROL &&
conns[i]->state == CONTROL_CONN_STATE_OPEN &&
conns[i]->event_mask & (1<<event)) {
send_control_message(conns[i], CONTROL_CMD_EVENT, buflen, buf);
if (event == EVENT_ERR_MSG) {
_connection_controller_force_write(conns[i]);
}
}
}
tor_free(buf);
}
/** Called when we receive a SETCONF message: parse the body and try
* to update our configuration. Reply with a DONE or ERROR message. */
static int
handle_control_setconf(connection_t *conn, uint32_t len, char *body)
{
int r;
struct config_line_t *lines=NULL;
if (config_get_lines(body, &lines) < 0) {
log_fn(LOG_WARN,"Controller gave us config lines we can't parse.");
send_control_error(conn, ERR_SYNTAX, "Couldn't parse configuration");
return 0;
}
if ((r=config_trial_assign(lines, 1)) < 0) {
log_fn(LOG_WARN,"Controller gave us config lines that didn't validate.");
if (r==-1) {
send_control_error(conn, ERR_UNRECOGNIZED_CONFIG_KEY,
"Unrecognized option");
} else {
send_control_error(conn, ERR_INVALID_CONFIG_VALUE,"Invalid option value");
}
config_free_lines(lines);
return 0;
}
config_free_lines(lines);
if (options_act() < 0) { /* acting on them failed. die. */
log_fn(LOG_ERR,"Acting on config options left us in a broken state. Dying.");
exit(1);
}
send_control_done(conn);
return 0;
}
/** Called when we receive a GETCONF message. Parse the request, and
* reply with a CONFVALUE or an ERROR message */
static int
handle_control_getconf(connection_t *conn, uint32_t body_len, const char *body)
{
smartlist_t *questions = NULL;
smartlist_t *answers = NULL;
char *msg = NULL;
size_t msg_len;
or_options_t *options = get_options();
questions = smartlist_create();
smartlist_split_string(questions, body, "\n",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
answers = smartlist_create();
SMARTLIST_FOREACH(questions, const char *, q,
{
int recognized = config_option_is_recognized(q);
if (!recognized) {
send_control_error(conn, ERR_UNRECOGNIZED_CONFIG_KEY, q);
goto done;
} else {
struct config_line_t *answer = config_get_assigned_option(options,q);
while (answer) {
struct config_line_t *next;
size_t alen = strlen(answer->key)+strlen(answer->value)+3;
char *astr = tor_malloc(alen);
tor_snprintf(astr, alen, "%s %s\n", answer->key, answer->value);
smartlist_add(answers, astr);
next = answer->next;
tor_free(answer->key);
tor_free(answer->value);
tor_free(answer);
answer = next;
}
}
});
msg = smartlist_join_strings(answers, "", 0, &msg_len);
send_control_message(conn, CONTROL_CMD_CONFVALUE,
(uint16_t)msg_len, msg_len?msg:NULL);
done:
if (answers) SMARTLIST_FOREACH(answers, char *, cp, tor_free(cp));
if (questions) SMARTLIST_FOREACH(questions, char *, cp, tor_free(cp));
smartlist_free(answers);
smartlist_free(questions);
tor_free(msg);
return 0;
}
/** Called when we get a SETEVENTS message: update conn->event_mask,
* and reply with DONE or ERROR. */
static int
handle_control_setevents(connection_t *conn, uint32_t len, const char *body)
{
uint16_t event_code;
uint32_t event_mask = 0;
if (len % 2) {
send_control_error(conn, ERR_SYNTAX,
"Odd number of bytes in setevents message");
return 0;
}
for (; len; len -= 2, body += 2) {
event_code = ntohs(get_uint16(body));
if (event_code < _EVENT_MIN || event_code > _EVENT_MAX) {
send_control_error(conn, ERR_UNRECOGNIZED_EVENT_CODE,
"Unrecognized event code");
return 0;
}
event_mask |= (1 << event_code);
}
conn->event_mask = event_mask;
update_global_event_mask();
send_control_done(conn);
return 0;
}
/** Decode the hashed, base64'd password stored in <b>hashed</b>. If
* <b>buf</b> is provided, store the hashed password in the first
* S2K_SPECIFIER_LEN+DIGEST_LEN bytes of <b>buf</b>. Return 0 on
* success, -1 on failure.
*/
int
decode_hashed_password(char *buf, const char *hashed)
{
char decoded[64];
if (base64_decode(decoded, sizeof(decoded), hashed, strlen(hashed))
!= S2K_SPECIFIER_LEN+DIGEST_LEN) {
return -1;
}
if (buf)
memcpy(buf, decoded, sizeof(decoded));
return 0;
}
/** Called when we get an AUTHENTICATE message. Check whether the
* authentication is valid, and if so, update the connection's state to
* OPEN. Reply with DONE or ERROR.
*/
static int
handle_control_authenticate(connection_t *conn, uint32_t len, const char *body)
{
or_options_t *options = get_options();
if (options->CookieAuthentication) {
if (len == AUTHENTICATION_COOKIE_LEN &&
!memcmp(authentication_cookie, body, len)) {
goto ok;
}
} else if (options->HashedControlPassword) {
char expected[S2K_SPECIFIER_LEN+DIGEST_LEN];
char received[DIGEST_LEN];
if (decode_hashed_password(expected, options->HashedControlPassword)<0) {
log_fn(LOG_WARN,"Couldn't decode HashedControlPassword: invalid base64");
goto err;
}
secret_to_key(received,DIGEST_LEN,body,len,expected);
if (!memcmp(expected+S2K_SPECIFIER_LEN, received, DIGEST_LEN))
goto ok;
goto err;
} else {
if (len == 0) {
/* if Tor doesn't demand any stronger authentication, then
* the controller can get in with a blank auth line. */
goto ok;
}
goto err;
}
err:
send_control_error(conn, ERR_REJECTED_AUTHENTICATION,"Authentication failed");
return 0;
ok:
log_fn(LOG_INFO, "Authenticated control connection (%d)", conn->s);
send_control_done(conn);
conn->state = CONTROL_CONN_STATE_OPEN;
return 0;
}
static int
handle_control_saveconf(connection_t *conn, uint32_t len,
const char *body)
{
if (save_current_config()<0) {
send_control_error(conn, ERR_INTERNAL,
"Unable to write configuration to disk.");
} else {
send_control_done(conn);
}
return 0;
}
static int
handle_control_signal(connection_t *conn, uint32_t len,
const char *body)
{
if (len != 1) {
send_control_error(conn, ERR_SYNTAX,
"Body of SIGNAL command too long or too short.");
} else if (control_signal_act((uint8_t)body[0]) < 0) {
send_control_error(conn, ERR_SYNTAX, "Unrecognized signal number.");
} else {
send_control_done(conn);
}
return 0;
}
static int
handle_control_mapaddress(connection_t *conn, uint32_t len, const char *body)
{
smartlist_t *elts;
smartlist_t *lines;
smartlist_t *reply;
char *r;
size_t sz;
lines = smartlist_create();
elts = smartlist_create();
reply = smartlist_create();
smartlist_split_string(lines, body, "\n",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
SMARTLIST_FOREACH(lines, char *, line,
{
tor_strlower(line);
smartlist_split_string(elts, line, " ", 0, 2);
if (smartlist_len(elts) == 2) {
const char *from = smartlist_get(elts,0);
const char *to = smartlist_get(elts,1);
if (!is_plausible_address(from)) {
log_fn(LOG_WARN,"Skipping invalid argument '%s' in MapAddress msg",from);
} else if (!is_plausible_address(to)) {
log_fn(LOG_WARN,"Skipping invalid argument '%s' in MapAddress msg",to);
} else if (!strcmp(from, ".") || !strcmp(from, "0.0.0.0")) {
const char *addr = addressmap_register_virtual_address(
strcmp(from,".") ? RESOLVED_TYPE_HOSTNAME : RESOLVED_TYPE_IPV4,
tor_strdup(to));
if (!addr) {
log_fn(LOG_WARN,
"Unable to allocate address for '%s' in MapAddress msg",line);
} else {
size_t anslen = strlen(addr)+strlen(to)+2;
char *ans = tor_malloc(anslen);
tor_snprintf(ans, anslen, "%s %s", addr, to);
smartlist_add(reply, ans);
}
} else {
addressmap_register(from, tor_strdup(to), 1);
smartlist_add(reply, tor_strdup(line));
}
} else {
log_fn(LOG_WARN, "Skipping MapAddress line with wrong number of items.");
}
SMARTLIST_FOREACH(elts, char *, cp, tor_free(cp));
smartlist_clear(elts);
});
SMARTLIST_FOREACH(lines, char *, cp, tor_free(cp));
smartlist_free(lines);
smartlist_free(elts);
r = smartlist_join_strings(reply, "\n", 1, &sz);
send_control_done2(conn,r,sz);
SMARTLIST_FOREACH(reply, char *, cp, tor_free(cp));
smartlist_free(reply);
tor_free(r);
return 0;
}
/** Lookup the 'getinfo' entry <b>question</b>, and return
* the answer in <b>*answer</b> (or NULL if key not recognized).
* Return 0 if success, or -1 if internal error. */
static int
handle_getinfo_helper(const char *question, char **answer)
{
*answer = NULL; /* unrecognized key by default */
if (!strcmp(question, "version")) {
*answer = tor_strdup(VERSION);
} else if (!strcmpstart(question, "desc/id/")) {
routerinfo_t *ri = router_get_by_hexdigest(question+strlen("desc/id/"));
if (ri && ri->signed_descriptor)
*answer = tor_strdup(ri->signed_descriptor);
} else if (!strcmpstart(question, "desc/name/")) {
routerinfo_t *ri = router_get_by_nickname(question+strlen("desc/name/"));
if (ri && ri->signed_descriptor)
*answer = tor_strdup(ri->signed_descriptor);
} else if (!strcmp(question, "network-status")) {
routerlist_t *routerlist;
router_get_routerlist(&routerlist);
if (!routerlist || !routerlist->routers ||
list_server_status(routerlist->routers, NULL, answer) < 0) {
return -1;
}
} else if (!strcmpstart(question, "addr-mappings/")) {
time_t min_e, max_e;
smartlist_t *mappings;
if (!strcmp(question, "addr-mappings/all")) {
min_e = 0; max_e = TIME_MAX;
} else if (!strcmp(question, "addr-mappings/cache")) {
min_e = 2; max_e = TIME_MAX;
} else if (!strcmp(question, "addr-mappings/config")) {
min_e = 0; max_e = 0;
} else if (!strcmp(question, "addr-mappings/control")) {
min_e = 1; max_e = 1;
} else {
return 0;
}
mappings = smartlist_create();
addressmap_get_mappings(mappings, min_e, max_e);
*answer = smartlist_join_strings(mappings, "\n", 1, NULL);
SMARTLIST_FOREACH(mappings, char *, cp, tor_free(cp));
smartlist_free(mappings);
}
return 0;
}
static int
handle_control_getinfo(connection_t *conn, uint32_t len, const char *body)
{
smartlist_t *questions = NULL;
smartlist_t *answers = NULL;
char *msg = NULL, *ans;
size_t msg_len;
questions = smartlist_create();
smartlist_split_string(questions, body, "\n",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
answers = smartlist_create();
SMARTLIST_FOREACH(questions, const char *, q,
{
if (handle_getinfo_helper(q, &ans) < 0) {
send_control_error(conn, ERR_INTERNAL, body);
goto done;
} if (!ans) {
send_control_error(conn, ERR_UNRECOGNIZED_CONFIG_KEY, body);
goto done;
}
smartlist_add(answers, tor_strdup(q));
smartlist_add(answers, ans);
});
msg = smartlist_join_strings2(answers, "\0", 1, 1, &msg_len);
tor_assert(msg_len > 0); /* it will at least be terminated */
send_control_message(conn, CONTROL_CMD_INFOVALUE,
msg_len, msg);
done:
if (answers) SMARTLIST_FOREACH(answers, char *, cp, tor_free(cp));
if (questions) SMARTLIST_FOREACH(questions, char *, cp, tor_free(cp));
smartlist_free(answers);
smartlist_free(questions);
tor_free(msg);
return 0;
}
static int
handle_control_extendcircuit(connection_t *conn, uint32_t len,
const char *body)
{
smartlist_t *router_nicknames, *routers;
uint32_t circ_id;
circuit_t *circ;
char reply[4];
if (len<5) {
send_control_error(conn, ERR_SYNTAX, "extendcircuit message too short");
return 0;
}
router_nicknames = smartlist_create();
routers = smartlist_create();
smartlist_split_string(router_nicknames, body+4, ",", 0, 0);
SMARTLIST_FOREACH(router_nicknames, const char *, n,
{
routerinfo_t *r = router_get_by_nickname(n);
if (!r) {
send_control_error(conn, ERR_NO_ROUTER, n);
goto done;
}
smartlist_add(routers, r);
});
if (!smartlist_len(routers)) {
send_control_error(conn, ERR_SYNTAX, "No router names provided");
goto done;
}
circ_id = ntohl(get_uint32(body));
if (!circ_id) {
/* start a new circuit */
circ = circuit_init(CIRCUIT_PURPOSE_C_GENERAL, 0, 0, 0);
} else {
circ = circuit_get_by_global_id(circ_id);
if (!circ) {
send_control_error(conn, ERR_NO_CIRC,
"No circuit found with given ID");
goto done;
}
}
/* now circ refers to something that is ready to be extended */
SMARTLIST_FOREACH(routers, routerinfo_t *, r,
{
circuit_append_new_exit(circ, r);
});
/* now that we've populated the cpath, start extending */
if (!circ_id) {
if (circuit_handle_first_hop(circ) < 0) {
circuit_mark_for_close(circ);
send_control_error(conn, ERR_INTERNAL, "couldn't start circuit");
goto done;
}
} else {
if (circ->state == CIRCUIT_STATE_OPEN) {
circ->state = CIRCUIT_STATE_BUILDING;
if (circuit_send_next_onion_skin(circ) < 0) {
log_fn(LOG_INFO,"send_next_onion_skin failed; circuit marked for closing.");
circuit_mark_for_close(circ);
send_control_error(conn, ERR_INTERNAL, "couldn't send onion skin");
goto done;
}
}
}
set_uint32(reply, htonl(circ->global_identifier));
send_control_done2(conn, reply, sizeof(reply));
done:
SMARTLIST_FOREACH(router_nicknames, char *, n, tor_free(n));
smartlist_free(router_nicknames);
smartlist_free(routers);
return 0;
}
static int handle_control_attachstream(connection_t *conn, uint32_t len,
const char *body)
{
uint32_t conn_id;
uint32_t circ_id;
connection_t *ap_conn;
circuit_t *circ;
if (len < 8) {
send_control_error(conn, ERR_SYNTAX, "attachstream message too short");
return 0;
}
conn_id = ntohl(get_uint32(body));
circ_id = ntohl(get_uint32(body+4));
if (!(ap_conn = connection_get_by_global_id(conn_id))) {
send_control_error(conn, ERR_NO_STREAM,
"No connection found with given ID");
return 0;
}
if (ap_conn->state != AP_CONN_STATE_CONTROLLER_WAIT) {
send_control_error(conn, ERR_NO_STREAM,
"Connection was not managed by controller.");
return 0;
}
if (!circ_id) {
ap_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
if (connection_ap_handshake_attach_circuit(ap_conn)<0)
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_CANT_ATTACH);
send_control_done(conn);
return 0;
}
if (!(circ = circuit_get_by_global_id(circ_id))) {
send_control_error(conn, ERR_NO_CIRC, "No circuit found with given ID");
return 0;
}
if (circ->state != CIRCUIT_STATE_OPEN) {
send_control_error(conn, ERR_INTERNAL, "Refuse to attach stream to non-open circ.");
return 0;
}
if (connection_ap_handshake_attach_chosen_circuit(ap_conn, circ) != 1) {
send_control_error(conn, ERR_INTERNAL, "Unable to attach stream.");
return 0;
}
send_control_done(conn);
return 0;
}
static int
handle_control_postdescriptor(connection_t *conn, uint32_t len,
const char *body)
{
const char *msg;
switch (router_load_single_router(body, &msg)) {
case -1:
send_control_error(conn,ERR_SYNTAX,msg?msg: "Could not parse descriptor");
break;
case 0:
send_control_done2(conn,msg?msg: "Descriptor not added",0);
break;
case 1:
send_control_done(conn);
break;
}
return 0;
}
static int
handle_control_redirectstream(connection_t *conn, uint32_t len,
const char *body)
{
connection_t *ap_conn;
uint32_t conn_id;
if (len < 6) {
send_control_error(conn, ERR_SYNTAX, "redirectstream message too short");
return 0;
}
conn_id = ntohl(get_uint32(body));
if (!(ap_conn = connection_get_by_global_id(conn_id))
|| ap_conn->state != CONN_TYPE_AP
|| !ap_conn->socks_request) {
send_control_error(conn, ERR_NO_STREAM,
"No AP connection found with given ID");
return 0;
}
strlcpy(ap_conn->socks_request->address, body+4,
sizeof(ap_conn->socks_request->address));
send_control_done(conn);
return 0;
}
static int
handle_control_closestream(connection_t *conn, uint32_t len,
const char *body)
{
uint32_t conn_id;
connection_t *ap_conn;
uint8_t reason;
if (len < 6) {
send_control_error(conn, ERR_SYNTAX, "closestream message too short");
return 0;
}
conn_id = ntohl(get_uint32(body));
reason = *(uint8_t*)(body+4);
if (!(ap_conn = connection_get_by_global_id(conn_id))
|| ap_conn->state != CONN_TYPE_AP
|| !ap_conn->socks_request) {
send_control_error(conn, ERR_NO_STREAM,
"No AP connection found with given ID");
return 0;
}
connection_mark_unattached_ap(ap_conn, reason);
send_control_done(conn);
return 0;
}
static int
handle_control_closecircuit(connection_t *conn, uint32_t len,
const char *body)
{
uint32_t circ_id;
circuit_t *circ;
int safe;
if (len < 5) {
send_control_error(conn, ERR_SYNTAX, "closecircuit message too short");
return 0;
}
circ_id = ntohl(get_uint32(body));
safe = (*(uint8_t*)(body+4)) & 1;
if (!(circ = circuit_get_by_global_id(circ_id))) {
send_control_error(conn, ERR_NO_CIRC,
"No circuit found with given ID");
return 0;
}
if (!safe || !circ->p_streams) {
circuit_mark_for_close(circ);
}
send_control_done(conn);
return 0;
}
/** Called when <b>conn</b> has no more bytes left on its outbuf. */
int
connection_control_finished_flushing(connection_t *conn) {
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_CONTROL);
connection_stop_writing(conn);
return 0;
}
/** Called when <b>conn</b> has gotten its socket closed. */
int connection_control_reached_eof(connection_t *conn) {
log_fn(LOG_INFO,"Control connection reached EOF. Closing.");
connection_mark_for_close(conn);
return 0;
}
/** Called when <b>conn</b> has received more bytes on its inbuf.
*/
int
connection_control_process_inbuf(connection_t *conn) {
uint32_t body_len;
uint16_t command_type;
char *body;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_CONTROL);
again:
/* Try to suck a control message from the buffer. */
switch (fetch_from_buf_control(conn->inbuf, &body_len, &command_type, &body))
{
case -1:
tor_free(body);
log_fn(LOG_WARN, "Error in control command. Failing.");
return -1;
case 0:
/* Control command not all here yet. Wait. */
return 0;
case 1:
/* We got a command. Process it. */
break;
default:
tor_assert(0);
}
/* We got a command. If we need authentication, only authentication
* commands will be considered. */
if (conn->state == CONTROL_CONN_STATE_NEEDAUTH &&
command_type != CONTROL_CMD_AUTHENTICATE) {
log_fn(LOG_WARN, "Rejecting '%s' command; authentication needed.",
control_cmd_to_string(command_type));
send_control_error(conn, ERR_UNAUTHORIZED, "Authentication required");
tor_free(body);
goto again;
}
/* Okay, we're willing to process the command. */
switch (command_type)
{
case CONTROL_CMD_SETCONF:
if (handle_control_setconf(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_GETCONF:
if (handle_control_getconf(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_SETEVENTS:
if (handle_control_setevents(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_AUTHENTICATE:
if (handle_control_authenticate(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_SAVECONF:
if (handle_control_saveconf(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_SIGNAL:
if (handle_control_signal(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_MAPADDRESS:
if (handle_control_mapaddress(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_GETINFO:
if (handle_control_getinfo(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_EXTENDCIRCUIT:
if (handle_control_extendcircuit(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_ATTACHSTREAM:
if (handle_control_attachstream(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_POSTDESCRIPTOR:
if (handle_control_postdescriptor(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_REDIRECTSTREAM:
if (handle_control_redirectstream(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_CLOSESTREAM:
if (handle_control_closestream(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_CLOSECIRCUIT:
if (handle_control_closecircuit(conn, body_len, body))
return -1;
break;
case CONTROL_CMD_ERROR:
case CONTROL_CMD_DONE:
case CONTROL_CMD_CONFVALUE:
case CONTROL_CMD_EVENT:
case CONTROL_CMD_INFOVALUE:
log_fn(LOG_WARN, "Received client-only '%s' command; ignoring.",
control_cmd_to_string(command_type));
send_control_error(conn, ERR_UNRECOGNIZED_TYPE,
"Command type only valid from server to tor client");
break;
case CONTROL_CMD_FRAGMENTHEADER:
case CONTROL_CMD_FRAGMENT:
log_fn(LOG_WARN, "Recieved command fragment out of order; ignoring.");
send_control_error(conn, ERR_SYNTAX, "Bad fragmentation on command.");
default:
log_fn(LOG_WARN, "Received unrecognized command type %d; ignoring.",
(int)command_type);
send_control_error(conn, ERR_UNRECOGNIZED_TYPE,
"Unrecognized command type");
break;
}
tor_free(body);
goto again; /* There might be more data. */
}
/** Something has happened to circuit <b>circ</b>: tell any interested
* control connections. */
int
control_event_circuit_status(circuit_t *circ, circuit_status_event_t tp)
{
char *path, *msg;
size_t path_len;
if (!EVENT_IS_INTERESTING(EVENT_CIRCUIT_STATUS))
return 0;
tor_assert(circ);
tor_assert(CIRCUIT_IS_ORIGIN(circ));
path = circuit_list_path(circ,0);
path_len = strlen(path);
msg = tor_malloc(1+4+path_len+1); /* event, circid, path, NUL. */
msg[0] = (uint8_t) tp;
set_uint32(msg+1, htonl(circ->global_identifier));
strlcpy(msg+5,path,path_len+1);
send_control_event(EVENT_CIRCUIT_STATUS, (uint32_t)(path_len+6), msg);
tor_free(path);
tor_free(msg);
return 0;
}
/** Something has happened to the stream associated with AP connection
* <b>conn</b>: tell any interested control connections. */
int
control_event_stream_status(connection_t *conn, stream_status_event_t tp)
{
char *msg;
size_t len;
char buf[256], buf2[256];
tor_assert(conn->type == CONN_TYPE_AP);
tor_assert(conn->socks_request);
if (!EVENT_IS_INTERESTING(EVENT_STREAM_STATUS))
return 0;
if (conn->chosen_exit_name)
tor_snprintf(buf2, sizeof(buf2), ".%s.exit", conn->chosen_exit_name);
tor_snprintf(buf, sizeof(buf), "%s%s:%d",
conn->socks_request->address,
conn->chosen_exit_name ? buf2 : "",
conn->socks_request->port),
len = strlen(buf);
msg = tor_malloc(5+len+1);
msg[0] = (uint8_t) tp;
set_uint32(msg+1, htonl(conn->global_identifier));
strlcpy(msg+5, buf, len+1);
send_control_event(EVENT_STREAM_STATUS, (uint32_t)(5+len+1), msg);
tor_free(msg);
return 0;
}
/** Something has happened to the OR connection <b>conn</b>: tell any
* interested control connections. */
int
control_event_or_conn_status(connection_t *conn,or_conn_status_event_t tp)
{
char buf[HEX_DIGEST_LEN+3]; /* status, dollar, identity, NUL */
size_t len;
tor_assert(conn->type == CONN_TYPE_OR);
if (!EVENT_IS_INTERESTING(EVENT_OR_CONN_STATUS))
return 0;
buf[0] = (uint8_t)tp;
strlcpy(buf+1,conn->nickname,sizeof(buf)-1);
len = strlen(buf+1);
send_control_event(EVENT_OR_CONN_STATUS, (uint32_t)(len+1), buf);
return 0;
}
/** A second or more has elapsed: tell any interested control
* connections how much bandwidth we used. */
int
control_event_bandwidth_used(uint32_t n_read, uint32_t n_written)
{
char buf[8];
if (!EVENT_IS_INTERESTING(EVENT_BANDWIDTH_USED))
return 0;
set_uint32(buf, htonl(n_read));
set_uint32(buf+4, htonl(n_written));
send_control_event(EVENT_BANDWIDTH_USED, 8, buf);
return 0;
}
/** We got a log message: tell any interested control connections. */
void
control_event_logmsg(int severity, const char *msg)
{
int oldlog = EVENT_IS_INTERESTING(EVENT_LOG_OBSOLETE) &&
(severity == LOG_NOTICE || severity == LOG_WARN || severity == LOG_ERR);
int event = log_severity_to_event(severity);
if (event<0 || !EVENT_IS_INTERESTING(event))
event = 0;
if (oldlog || event) {
size_t len = strlen(msg);
if (event)
send_control_event(event, (uint32_t)(len+1), msg);
if (oldlog)
send_control_event(EVENT_LOG_OBSOLETE, (uint32_t)(len+1), msg);
}
}
/** Called whenever we receive new router descriptors: tell any
* interested control connections. <b>routers</b> is a list of
* DIGEST_LEN-byte identity digests.
*/
int control_event_descriptors_changed(smartlist_t *routers)
{
size_t len;
char *msg;
smartlist_t *identities;
char buf[HEX_DIGEST_LEN+1];
if (!EVENT_IS_INTERESTING(EVENT_NEW_DESC))
return 0;
identities = smartlist_create();
SMARTLIST_FOREACH(routers, routerinfo_t *, r,
{
base16_encode(buf,sizeof(buf),r->identity_digest,DIGEST_LEN);
smartlist_add(identities, tor_strdup(buf));
});
msg = smartlist_join_strings(identities, ",", 1, &len);
send_control_event(EVENT_NEW_DESC, len+1, msg);
SMARTLIST_FOREACH(identities, char *, cp, tor_free(cp));
smartlist_free(identities);
tor_free(msg);
return 0;
}
/** Choose a random authentication cookie and write it to disk.
* Anybody who can read the cookie from disk will be considered
* authorized to use the control connection. */
int
init_cookie_authentication(int enabled)
{
char fname[512];
if (!enabled) {
authentication_cookie_is_set = 0;
return 0;
}
tor_snprintf(fname, sizeof(fname), "%s/control_auth_cookie",
get_options()->DataDirectory);
crypto_rand(authentication_cookie, AUTHENTICATION_COOKIE_LEN);
authentication_cookie_is_set = 1;
if (write_bytes_to_file(fname, authentication_cookie,
AUTHENTICATION_COOKIE_LEN, 1)) {
log_fn(LOG_WARN,"Error writing authentication cookie.");
return -1;
}
return 0;
}
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