/* Copyright 2001,2002,2003 Roger Dingledine. */
/* See LICENSE for licensing information */
/* $Id$ */
#include "or.h"
/**
* \file directory.c
* \brief Implement directory HTTP protocol.
**/
/* In-points to directory.c:
*
* - directory_post_to_dirservers(), called from
* router_upload_dir_desc_to_dirservers() in router.c
* upload_service_descriptor() in rendservice.c
* - directory_get_from_dirserver(), called from
* rend_client_refetch_renddesc() in rendclient.c
* run_scheduled_events() in main.c
* do_hup() in main.c
* - connection_dir_process_inbuf(), called from
* connection_process_inbuf() in connection.c
* - connection_dir_finished_flushing(), called from
* connection_finished_flushing() in connection.c
* - connection_dir_finished_connecting(), called from
* connection_finished_connecting() in connection.c
*/
static void
directory_initiate_command(routerinfo_t *router, uint8_t purpose,
const char *payload, int payload_len);
static void directory_send_command(connection_t *conn, int purpose,
const char *payload, int payload_len);
static int directory_handle_command(connection_t *conn);
/********* START VARIABLES **********/
extern or_options_t options; /* command-line and config-file options */
/** URL for publishing rendezvous descriptors. */
char rend_publish_string[] = "/rendezvous/publish";
/** Prefix for downloading rendezvous descriptors. */
char rend_fetch_url[] = "/rendezvous/";
#define MAX_HEADERS_SIZE 50000
#define MAX_BODY_SIZE 500000
/********* END VARIABLES ************/
/** Start a connection to every known directory server, using
* connection purpose 'purpose' and uploading the payload 'payload'
* (length 'payload_len'). The purpose should be one of
* 'DIR_PURPOSE_UPLOAD_DIR' or 'DIR_PURPOSE_UPLOAD_RENDDESC'.
*/
void
directory_post_to_dirservers(uint8_t purpose, const char *payload,
int payload_len)
{
int i;
routerinfo_t *router;
routerlist_t *rl;
router_get_routerlist(&rl);
if(!rl)
return;
for(i=0; i < smartlist_len(rl->routers); i++) {
router = smartlist_get(rl->routers, i);
if(router->is_trusted_dir)
directory_initiate_command(router, purpose, payload, payload_len);
}
}
/** Start a connection to a random running directory server, using
* connection purpose 'purpose' requesting 'payload' (length
* 'payload_len'). The purpose should be one of
* 'DIR_PURPOSE_FETCH_DIR' or 'DIR_PURPOSE_FETCH_RENDDESC'.
*/
void
directory_get_from_dirserver(uint8_t purpose, const char *payload,
int payload_len)
{
routerinfo_t *ds;
if (purpose == DIR_PURPOSE_FETCH_DIR) {
if (advertised_server_mode()) {
/* only ask authdirservers, and don't ask myself */
ds = router_pick_directory_server(1, 1);
} else {
/* anybody with a non-zero dirport will do */
ds = router_pick_directory_server(0, 1);
}
} else { // (purpose == DIR_PURPOSE_FETCH_RENDDESC)
/* only ask authdirservers, any of them will do */
ds = router_pick_directory_server(1, 0);
}
if (!ds) { /* no viable dirserver found */
log_fn(LOG_WARN,"No running dirservers known. Not trying. (purpose %d)", purpose);
return;
}
directory_initiate_command(ds, purpose, payload, payload_len);
}
/** Launch a new connection to the directory server router to upload or
* download a service or rendezvous descriptor. purpose determines what
* kind of directory connection we're launching, and must be one of
* DIR_PURPOSE_{FETCH|UPLOAD}_{DIR|RENDDESC}.
*
* When uploading, payload and payload_len determine the content
* of the HTTP post. When fetching a rendezvous descriptor, payload
* and payload_len are the service ID we want to fetch.
*/
static void
directory_initiate_command(routerinfo_t *router, uint8_t purpose,
const char *payload, int payload_len)
{
connection_t *conn;
tor_assert(router);
tor_assert(router->dir_port);
switch (purpose)
{
case DIR_PURPOSE_FETCH_DIR:
log_fn(LOG_DEBUG,"initiating directory fetch");
break;
case DIR_PURPOSE_FETCH_RENDDESC:
log_fn(LOG_DEBUG,"initiating hidden-service descriptor fetch");
break;
case DIR_PURPOSE_UPLOAD_DIR:
log_fn(LOG_DEBUG,"initiating server descriptor upload");
break;
case DIR_PURPOSE_UPLOAD_RENDDESC:
log_fn(LOG_DEBUG,"initiating hidden-service descriptor upload");
break;
default:
log_fn(LOG_ERR, "Unrecognized directory connection purpose.");
tor_assert(0);
}
conn = connection_new(CONN_TYPE_DIR);
/* set up conn so it's got all the data we need to remember */
conn->addr = router->addr;
conn->port = router->dir_port;
conn->address = tor_strdup(router->address);
conn->nickname = tor_strdup(router->nickname);
tor_assert(router->identity_pkey);
conn->identity_pkey = crypto_pk_dup_key(router->identity_pkey);
crypto_pk_get_digest(conn->identity_pkey, conn->identity_digest);
conn->purpose = purpose;
/* give it an initial state */
conn->state = DIR_CONN_STATE_CONNECTING;
if(purpose == DIR_PURPOSE_FETCH_DIR ||
purpose == DIR_PURPOSE_UPLOAD_DIR) {
/* then we want to connect directly */
switch(connection_connect(conn, conn->address, conn->addr, conn->port)) {
case -1:
router_mark_as_down(conn->identity_digest); /* don't try him again */
if(purpose == DIR_PURPOSE_FETCH_DIR && !all_directory_servers_down()) {
log_fn(LOG_INFO,"Giving up on dirserver %s; trying another.", conn->nickname);
directory_get_from_dirserver(purpose, payload, payload_len);
}
connection_free(conn);
return;
case 1:
conn->state = DIR_CONN_STATE_CLIENT_SENDING; /* start flushing conn */
/* fall through */
case 0:
/* queue the command on the outbuf */
directory_send_command(conn, purpose, payload, payload_len);
connection_watch_events(conn, POLLIN | POLLOUT | POLLERR);
/* writable indicates finish, readable indicates broken link,
error indicates broken link in windowsland. */
}
} else { /* we want to connect via tor */
/* make an AP connection
* populate it and add it at the right state
* socketpair and hook up both sides
*/
conn->s = connection_ap_make_bridge(conn->address, conn->port);
if(conn->s < 0) {
log_fn(LOG_WARN,"Making AP bridge to dirserver failed.");
connection_mark_for_close(conn);
return;
}
conn->state = DIR_CONN_STATE_CLIENT_SENDING;
connection_add(conn);
/* queue the command on the outbuf */
directory_send_command(conn, purpose, payload, payload_len);
connection_watch_events(conn, POLLIN | POLLOUT | POLLERR);
}
}
/** Queue an appropriate HTTP command on conn-\>outbuf. The args
* purpose, payload, and payload_len are as in
* directory_initiate_command.
*/
static void directory_send_command(connection_t *conn, int purpose,
const char *payload, int payload_len) {
char fetchwholedir[] = "GET / HTTP/1.0\r\n\r\n";
char fetchrunninglist[] = "GET /running-routers HTTP/1.0\r\n\r\n";
char tmp[8192];
tor_assert(conn && conn->type == CONN_TYPE_DIR);
switch(purpose) {
case DIR_PURPOSE_FETCH_DIR:
tor_assert(payload == NULL);
connection_write_to_buf(fetchwholedir, strlen(fetchwholedir), conn);
break;
case DIR_PURPOSE_FETCH_RUNNING_LIST:
tor_assert(payload == NULL);
connection_write_to_buf(fetchrunninglist, strlen(fetchrunninglist), conn);
break;
case DIR_PURPOSE_UPLOAD_DIR:
tor_assert(payload);
snprintf(tmp, sizeof(tmp), "POST / HTTP/1.0\r\nContent-Length: %d\r\n\r\n",
payload_len);
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(payload, payload_len, conn);
break;
case DIR_PURPOSE_FETCH_RENDDESC:
tor_assert(payload);
/* this must be true or we wouldn't be doing the lookup */
tor_assert(payload_len <= REND_SERVICE_ID_LEN);
/* This breaks the function abstraction. */
memcpy(conn->rend_query, payload, payload_len);
conn->rend_query[payload_len] = 0;
snprintf(tmp, sizeof(tmp), "GET %s%s HTTP/1.0\r\n\r\n", rend_fetch_url, payload);
connection_write_to_buf(tmp, strlen(tmp), conn);
break;
case DIR_PURPOSE_UPLOAD_RENDDESC:
tor_assert(payload);
snprintf(tmp, sizeof(tmp),
"POST %s HTTP/1.0\r\nContent-Length: %d\r\n\r\n", rend_publish_string, payload_len);
connection_write_to_buf(tmp, strlen(tmp), conn);
/* could include nuls, need to write it separately */
connection_write_to_buf(payload, payload_len, conn);
break;
}
}
/** Parse an HTTP request string headers of the form "\%s \%s HTTP/1..."
* If it's well-formed, point *url to the second \%s,
* null-terminate it (this modifies headers!) and return 0.
* Otherwise, return -1.
*/
static int
parse_http_url(char *headers, char **url)
{
char *s, *tmp;
s = (char *)eat_whitespace_no_nl(headers);
if (!*s) return -1;
s = (char *)find_whitespace(s); /* get past GET/POST */
if (!*s) return -1;
s = (char *)eat_whitespace_no_nl(s);
if (!*s) return -1;
tmp = s; /* this is it, assuming it's valid */
s = (char *)find_whitespace(s);
if (!*s) return -1;
*s = 0;
*url = tmp;
return 0;
}
/** Parse an HTTP response string headers of the form
* "HTTP/1.\%d \%d\%s\r\n...".
* If it's well-formed, assign *code, point *message to the first
* non-space character after code if there is one and message is non-NULL
* (else leave it alone), and return 0.
* Otherwise, return -1.
*/
static int
parse_http_response(char *headers, int *code, char **message)
{
int n1, n2;
tor_assert(headers && code);
while(isspace((int)*headers)) headers++; /* tolerate leading whitespace */
if(sscanf(headers, "HTTP/1.%d %d", &n1, &n2) < 2 ||
(n1 != 0 && n1 != 1) ||
(n2 < 100 || n2 >= 600)) {
log_fn(LOG_WARN,"Failed to parse header '%s'",headers);
return -1;
}
*code = n2;
if(message) {
/* XXX should set *message correctly */
}
return 0;
}
/** We are a client, and we've finished reading the server's
* response. Parse and it and act appropriately.
*
* Return -1 if an error has occurred, or 0 normally. The caller
* will take care of marking the connection for close.
*/
static int
connection_dir_client_reached_eof(connection_t *conn)
{
char *body;
char *headers;
int body_len=0;
int status_code;
switch(fetch_from_buf_http(conn->inbuf,
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_DIR_SIZE)) {
case -1: /* overflow */
log_fn(LOG_WARN,"'fetch' response too large. Failing.");
return -1;
case 0:
log_fn(LOG_INFO,"'fetch' response not all here, but we're at eof. Closing.");
return -1;
/* case 1, fall through */
}
if(parse_http_response(headers, &status_code, NULL) < 0) {
log_fn(LOG_WARN,"Unparseable headers. Closing.");
free(body); free(headers);
return -1;
}
if(conn->purpose == DIR_PURPOSE_FETCH_DIR) {
/* fetch/process the directory to learn about new routers. */
log_fn(LOG_INFO,"Received directory (size %d):\n%s", body_len, body);
if(status_code == 503 || body_len == 0) {
log_fn(LOG_INFO,"Empty directory. Ignoring.");
free(body); free(headers);
return 0;
}
if(status_code != 200) {
log_fn(LOG_WARN,"Received http status code %d from dirserver. Failing.",
status_code);
free(body); free(headers);
return -1;
}
if(router_load_routerlist_from_directory(body, NULL) < 0){
log_fn(LOG_INFO,"...but parsing failed. Ignoring.");
} else {
log_fn(LOG_INFO,"updated routers.");
}
directory_has_arrived(); /* do things we've been waiting to do */
}
if(conn->purpose == DIR_PURPOSE_FETCH_RUNNING_LIST) {
running_routers_t *rrs;
routerlist_t *rl;
/* just update our list of running routers, if this list is new info */
log_fn(LOG_INFO,"Received running-routers list (size %d):\n%s", body_len, body);
if(status_code != 200) {
log_fn(LOG_WARN,"Received http status code %d from dirserver. Failing.",
status_code);
free(body); free(headers);
return -1;
}
if (!(rrs = router_parse_runningrouters(body))) {
log_fn(LOG_WARN, "Can't parse runningrouters list");
free(body); free(headers);
return -1;
}
router_get_routerlist(&rl);
routerlist_update_from_runningrouters(rl,rrs);
running_routers_free(rrs);
}
if(conn->purpose == DIR_PURPOSE_UPLOAD_DIR) {
switch(status_code) {
case 200:
log_fn(LOG_INFO,"eof (status 200) after uploading server descriptor: finished.");
break;
case 400:
log_fn(LOG_WARN,"http status 400 (bad request) response from dirserver. Malformed server descriptor?");
break;
case 403:
log_fn(LOG_WARN,"http status 403 (unapproved server) response from dirserver. Is your clock skewed? Have you mailed us your identity fingerprint? Are you using the right key? See README.");
break;
default:
log_fn(LOG_WARN,"http status %d response unrecognized.", status_code);
break;
}
}
if(conn->purpose == DIR_PURPOSE_FETCH_RENDDESC) {
log_fn(LOG_INFO,"Received rendezvous descriptor (size %d, status code %d)",
body_len, status_code);
switch(status_code) {
case 200:
if(rend_cache_store(body, body_len) < 0) {
log_fn(LOG_WARN,"Failed to store rendezvous descriptor.");
/* alice's ap_stream will notice when connection_mark_for_close
* cleans it up */
} else {
/* success. notify pending connections about this. */
rend_client_desc_fetched(conn->rend_query, 1);
conn->purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC;
}
break;
case 404:
/* not there. pending connections will be notified when
* connection_mark_for_close cleans it up. */
break;
case 400:
log_fn(LOG_WARN,"http status 400 (bad request). Dirserver didn't like our rendezvous query?");
break;
}
}
if(conn->purpose == DIR_PURPOSE_UPLOAD_RENDDESC) {
switch(status_code) {
case 200:
log_fn(LOG_INFO,"eof (status 200) after uploading rendezvous descriptor: finished.");
break;
case 400:
log_fn(LOG_WARN,"http status 400 (bad request) response from dirserver. Malformed rendezvous descriptor?");
break;
default:
log_fn(LOG_WARN,"http status %d response unrecognized.", status_code);
break;
}
}
free(body); free(headers);
return 0;
}
/** Read handler for directory connections. (That's connections to
* directory servers and connections at directory servers.)
*/
int connection_dir_process_inbuf(connection_t *conn) {
int retval;
tor_assert(conn && conn->type == CONN_TYPE_DIR);
/* Directory clients write, then read data until they receive EOF;
* directory servers read data until they get an HTTP command, then
* write their response (when it's finished flushing, they mark for
* close).
*/
if(conn->inbuf_reached_eof) {
if(conn->state != DIR_CONN_STATE_CLIENT_READING) {
log_fn(LOG_INFO,"conn reached eof, not reading. Closing.");
connection_close_immediate(conn); /* it was an error; give up on flushing */
connection_mark_for_close(conn);
return -1;
}
retval = connection_dir_client_reached_eof(conn);
connection_mark_for_close(conn);
return retval;
} /* endif 'reached eof' */
/* If we're on the dirserver side, look for a command. */
if(conn->state == DIR_CONN_STATE_SERVER_COMMAND_WAIT) {
if (directory_handle_command(conn) < 0) {
connection_mark_for_close(conn);
return -1;
}
return 0;
}
/* XXX for READ states, might want to make sure inbuf isn't too big */
log_fn(LOG_DEBUG,"Got data, not eof. Leaving on inbuf.");
return 0;
}
static char answer200[] = "HTTP/1.0 200 OK\r\n\r\n";
static char answer400[] = "HTTP/1.0 400 Bad request\r\n\r\n";
static char answer403[] = "HTTP/1.0 403 Unapproved server\r\n\r\n";
static char answer404[] = "HTTP/1.0 404 Not found\r\n\r\n";
static char answer503[] = "HTTP/1.0 503 Directory unavailable\r\n\r\n";
/** Helper function: called when a dirserver gets a complete HTTP GET
* request. Look for a request for a directory or for a rendezvous
* service descriptor. On finding one, write a response into
* conn-\>outbuf. If the request is unrecognized, send a 404.
* Always return 0. */
static int
directory_handle_command_get(connection_t *conn, char *headers,
char *body, int body_len)
{
size_t dlen;
const char *cp;
char *url;
char tmp[8192];
log_fn(LOG_DEBUG,"Received GET command.");
conn->state = DIR_CONN_STATE_SERVER_WRITING;
if (parse_http_url(headers, &url) < 0) {
connection_write_to_buf(answer400, strlen(answer400), conn);
return 0;
}
if(!strcmp(url,"/")) { /* directory fetch */
dlen = dirserv_get_directory(&cp);
if(dlen == 0) {
log_fn(LOG_WARN,"My directory is empty. Closing.");
connection_write_to_buf(answer503, strlen(answer503), conn);
return 0;
}
log_fn(LOG_DEBUG,"Dumping directory to client.");
snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: text/plain\r\n\r\n",
(int)dlen);
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(cp, strlen(cp), conn);
return 0;
}
if(!strcmp(url,"/running-routers")) { /* running-routers fetch */
if(!authdir_mode()) {
/* XXX008 for now, we don't cache running-routers. Reject. */
connection_write_to_buf(answer400, strlen(answer400), conn);
return 0;
}
dlen = dirserv_get_runningrouters(&cp);
if(dlen < 0) { /* we failed to create cp */
connection_write_to_buf(answer503, strlen(answer503), conn);
return 0;
}
snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: text/plain\r\n\r\n",
(int)dlen);
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(cp, strlen(cp), conn);
return 0;
}
if(!strncmp(url,rend_fetch_url,strlen(rend_fetch_url))) {
/* rendezvous descriptor fetch */
const char *descp;
int desc_len;
if(!authdir_mode()) {
/* We don't hand out rend descs. In fact, it could be a security
* risk, since rend_cache_lookup_desc() below would provide it
* if we're gone to the site recently, and 404 if we haven't.
*
* Reject. */
connection_write_to_buf(answer400, strlen(answer400), conn);
return 0;
}
switch(rend_cache_lookup_desc(url+strlen(rend_fetch_url), &descp, &desc_len)) {
case 1: /* valid */
snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: application/octet-stream\r\n\r\n",
desc_len); /* can't include descp here, because it's got nuls */
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(descp, desc_len, conn);
break;
case 0: /* well-formed but not present */
connection_write_to_buf(answer404, strlen(answer404), conn);
break;
case -1: /* not well-formed */
connection_write_to_buf(answer400, strlen(answer400), conn);
break;
}
return 0;
}
/* we didn't recognize the url */
connection_write_to_buf(answer404, strlen(answer404), conn);
return 0;
}
/** Helper function: called when a dirserver gets a complete HTTP POST
* request. Look for an uploaded server descriptor or rendezvous
* service descriptor. On finding one, process it and write a
* response into conn-\>outbuf. If the request is unrecognized, send a
* 404. Always return 0. */
static int
directory_handle_command_post(connection_t *conn, char *headers,
char *body, int body_len)
{
const char *cp;
char *url;
log_fn(LOG_DEBUG,"Received POST command.");
conn->state = DIR_CONN_STATE_SERVER_WRITING;
if(!authdir_mode()) {
/* we just provide cached directories; we don't want to
* receive anything. */
connection_write_to_buf(answer400, strlen(answer400), conn);
return 0;
}
if (parse_http_url(headers, &url) < 0) {
connection_write_to_buf(answer400, strlen(answer400), conn);
return 0;
}
log_fn(LOG_INFO,"url '%s' posted to us.", url);
if(!strcmp(url,"/")) { /* server descriptor post */
cp = body;
switch(dirserv_add_descriptor(&cp)) {
case -1:
/* malformed descriptor, or something wrong */
connection_write_to_buf(answer400, strlen(answer400), conn);
break;
case 0:
/* descriptor was well-formed but server has not been approved */
connection_write_to_buf(answer403, strlen(answer403), conn);
break;
case 1:
dirserv_get_directory(&cp); /* rebuild and write to disk */
connection_write_to_buf(answer200, strlen(answer200), conn);
break;
}
return 0;
}
if(!strncmp(url,rend_publish_string,strlen(rend_publish_string))) {
/* rendezvous descriptor post */
if(rend_cache_store(body, body_len) < 0)
connection_write_to_buf(answer400, strlen(answer400), conn);
else
connection_write_to_buf(answer200, strlen(answer200), conn);
return 0;
}
/* we didn't recognize the url */
connection_write_to_buf(answer404, strlen(answer404), conn);
return 0;
}
/** Called when a dirserver receives data on a directory connection;
* looks for an HTTP request. If the request is complete, remove it
* from the inbuf, try to process it; otherwise, leave it on the
* buffer. Return a 0 on success, or -1 on error.
*/
static int directory_handle_command(connection_t *conn) {
char *headers=NULL, *body=NULL;
int body_len=0;
int r;
tor_assert(conn && conn->type == CONN_TYPE_DIR);
switch(fetch_from_buf_http(conn->inbuf,
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_BODY_SIZE)) {
case -1: /* overflow */
log_fn(LOG_WARN,"input too large. Failing.");
return -1;
case 0:
log_fn(LOG_DEBUG,"command not all here yet.");
return 0;
/* case 1, fall through */
}
log_fn(LOG_DEBUG,"headers '%s', body '%s'.", headers, body);
if(!strncasecmp(headers,"GET",3))
r = directory_handle_command_get(conn, headers, body, body_len);
else if (!strncasecmp(headers,"POST",4))
r = directory_handle_command_post(conn, headers, body, body_len);
else {
log_fn(LOG_WARN,"Got headers '%s' with unknown command. Closing.", headers);
r = -1;
}
tor_free(headers); tor_free(body);
return r;
}
/** Write handler for directory connections; called when all data has
* been flushed. Close the connection or wait for a response as
* appropriate.
*/
int connection_dir_finished_flushing(connection_t *conn) {
tor_assert(conn && conn->type == CONN_TYPE_DIR);
switch(conn->state) {
case DIR_CONN_STATE_CLIENT_SENDING:
log_fn(LOG_DEBUG,"client finished sending command.");
conn->state = DIR_CONN_STATE_CLIENT_READING;
connection_stop_writing(conn);
return 0;
case DIR_CONN_STATE_SERVER_WRITING:
log_fn(LOG_INFO,"Finished writing server response. Closing.");
connection_mark_for_close(conn);
return 0;
default:
log_fn(LOG_WARN,"BUG: called in unexpected state %d.", conn->state);
return -1;
}
return 0;
}
/** Connected handler for directory connections: begin sending data to the
* server */
int connection_dir_finished_connecting(connection_t *conn)
{
tor_assert(conn && conn->type == CONN_TYPE_DIR);
tor_assert(conn->state == DIR_CONN_STATE_CONNECTING);
log_fn(LOG_INFO,"Dir connection to router %s:%u established.",
conn->address,conn->port);
conn->state = DIR_CONN_STATE_CLIENT_SENDING; /* start flushing conn */
return 0;
}
/*
Local Variables:
mode:c
indent-tabs-mode:nil
c-basic-offset:2
End:
*/