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tor/src/feature/dircache/dircache.c

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/* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2018, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#define DIRCACHE_PRIVATE
#include "core/or/or.h"
#include "app/config/config.h"
#include "core/mainloop/connection.h"
#include "core/or/relay.h"
#include "feature/dirauth/dirvote.h"
#include "feature/dirauth/authmode.h"
#include "feature/dirauth/process_descs.h"
#include "feature/dircache/conscache.h"
#include "feature/dircache/consdiffmgr.h"
#include "feature/dircache/dircache.h"
#include "feature/dircache/dirserv.h"
#include "feature/dircommon/directory.h"
#include "feature/dircommon/fp_pair.h"
#include "feature/hs/hs_cache.h"
#include "feature/nodelist/authcert.h"
#include "feature/nodelist/networkstatus.h"
#include "feature/nodelist/routerlist.h"
#include "feature/relay/routermode.h"
#include "feature/rend/rendcache.h"
#include "feature/stats/geoip_stats.h"
#include "feature/stats/rephist.h"
#include "lib/compress/compress.h"
#include "feature/dircache/cached_dir_st.h"
#include "feature/dircommon/dir_connection_st.h"
#include "feature/nodelist/authority_cert_st.h"
#include "feature/nodelist/networkstatus_st.h"
#include "feature/nodelist/routerinfo_st.h"
/** Maximum size, in bytes, for any directory object that we're accepting
* as an upload. */
#define MAX_DIR_UL_SIZE ((1<<24)-1) /* 16MB-1 */
/** HTTP cache control: how long do we tell proxies they can cache each
* kind of document we serve? */
#define FULL_DIR_CACHE_LIFETIME (60*60)
#define RUNNINGROUTERS_CACHE_LIFETIME (20*60)
#define DIRPORTFRONTPAGE_CACHE_LIFETIME (20*60)
#define NETWORKSTATUS_CACHE_LIFETIME (5*60)
#define ROUTERDESC_CACHE_LIFETIME (30*60)
#define ROUTERDESC_BY_DIGEST_CACHE_LIFETIME (48*60*60)
#define ROBOTS_CACHE_LIFETIME (24*60*60)
#define MICRODESC_CACHE_LIFETIME (48*60*60)
/** Parse an HTTP request string <b>headers</b> of the form
* \verbatim
* "\%s [http[s]://]\%s HTTP/1..."
* \endverbatim
* If it's well-formed, strdup the second \%s into *<b>url</b>, and
* nul-terminate it. If the url doesn't start with "/tor/", rewrite it
* so it does. Return 0.
* Otherwise, return -1.
*/
STATIC int
parse_http_url(const char *headers, char **url)
{
char *command = NULL;
if (parse_http_command(headers, &command, url) < 0) {
return -1;
}
if (strcmpstart(*url, "/tor/")) {
char *new_url = NULL;
tor_asprintf(&new_url, "/tor%s%s",
*url[0] == '/' ? "" : "/",
*url);
tor_free(*url);
*url = new_url;
}
tor_free(command);
return 0;
}
/** Create an http response for the client <b>conn</b> out of
* <b>status</b> and <b>reason_phrase</b>. Write it to <b>conn</b>.
*/
static void
write_short_http_response(dir_connection_t *conn, int status,
const char *reason_phrase)
{
char *buf = NULL;
char *datestring = NULL;
IF_BUG_ONCE(!reason_phrase) { /* bullet-proofing */
reason_phrase = "unspecified";
}
if (server_mode(get_options())) {
/* include the Date: header, but only if we're a relay or bridge */
char datebuf[RFC1123_TIME_LEN+1];
format_rfc1123_time(datebuf, time(NULL));
tor_asprintf(&datestring, "Date: %s\r\n", datebuf);
}
tor_asprintf(&buf, "HTTP/1.0 %d %s\r\n%s\r\n",
status, reason_phrase, datestring?datestring:"");
log_debug(LD_DIRSERV,"Wrote status 'HTTP/1.0 %d %s'", status, reason_phrase);
connection_buf_add(buf, strlen(buf), TO_CONN(conn));
tor_free(datestring);
tor_free(buf);
}
/** Write the header for an HTTP/1.0 response onto <b>conn</b>-\>outbuf,
* with <b>type</b> as the Content-Type.
*
* If <b>length</b> is nonnegative, it is the Content-Length.
* If <b>encoding</b> is provided, it is the Content-Encoding.
* If <b>cache_lifetime</b> is greater than 0, the content may be cached for
* up to cache_lifetime seconds. Otherwise, the content may not be cached. */
static void
write_http_response_header_impl(dir_connection_t *conn, ssize_t length,
const char *type, const char *encoding,
const char *extra_headers,
long cache_lifetime)
{
char date[RFC1123_TIME_LEN+1];
time_t now = time(NULL);
buf_t *buf = buf_new_with_capacity(1024);
tor_assert(conn);
format_rfc1123_time(date, now);
buf_add_printf(buf, "HTTP/1.0 200 OK\r\nDate: %s\r\n", date);
if (type) {
buf_add_printf(buf, "Content-Type: %s\r\n", type);
}
if (!is_local_addr(&conn->base_.addr)) {
/* Don't report the source address for a nearby/private connection.
* Otherwise we tend to mis-report in cases where incoming ports are
* being forwarded to a Tor server running behind the firewall. */
buf_add_printf(buf, X_ADDRESS_HEADER "%s\r\n", conn->base_.address);
}
if (encoding) {
buf_add_printf(buf, "Content-Encoding: %s\r\n", encoding);
}
if (length >= 0) {
buf_add_printf(buf, "Content-Length: %ld\r\n", (long)length);
}
if (cache_lifetime > 0) {
char expbuf[RFC1123_TIME_LEN+1];
format_rfc1123_time(expbuf, (time_t)(now + cache_lifetime));
/* We could say 'Cache-control: max-age=%d' here if we start doing
* http/1.1 */
buf_add_printf(buf, "Expires: %s\r\n", expbuf);
} else if (cache_lifetime == 0) {
/* We could say 'Cache-control: no-cache' here if we start doing
* http/1.1 */
buf_add_string(buf, "Pragma: no-cache\r\n");
}
if (extra_headers) {
buf_add_string(buf, extra_headers);
}
buf_add_string(buf, "\r\n");
connection_buf_add_buf(TO_CONN(conn), buf);
buf_free(buf);
}
/** As write_http_response_header_impl, but translates method into
* encoding */
static void
write_http_response_headers(dir_connection_t *conn, ssize_t length,
compress_method_t method,
const char *extra_headers, long cache_lifetime)
{
write_http_response_header_impl(conn, length,
"text/plain",
compression_method_get_name(method),
extra_headers,
cache_lifetime);
}
/** As write_http_response_headers, but assumes extra_headers is NULL */
static void
write_http_response_header(dir_connection_t *conn, ssize_t length,
compress_method_t method,
long cache_lifetime)
{
write_http_response_headers(conn, length, method, NULL, cache_lifetime);
}
/** Array of compression methods to use (if supported) for serving
* precompressed data, ordered from best to worst. */
static compress_method_t srv_meth_pref_precompressed[] = {
LZMA_METHOD,
ZSTD_METHOD,
ZLIB_METHOD,
GZIP_METHOD,
NO_METHOD
};
/** Array of compression methods to use (if supported) for serving
* streamed data, ordered from best to worst. */
static compress_method_t srv_meth_pref_streaming_compression[] = {
ZSTD_METHOD,
ZLIB_METHOD,
GZIP_METHOD,
NO_METHOD
};
/** Parse the compression methods listed in an Accept-Encoding header <b>h</b>,
* and convert them to a bitfield where compression method x is supported if
* and only if 1 &lt;&lt; x is set in the bitfield. */
STATIC unsigned
parse_accept_encoding_header(const char *h)
{
unsigned result = (1u << NO_METHOD);
smartlist_t *methods = smartlist_new();
smartlist_split_string(methods, h, ",",
SPLIT_SKIP_SPACE|SPLIT_STRIP_SPACE|SPLIT_IGNORE_BLANK, 0);
SMARTLIST_FOREACH_BEGIN(methods, const char *, m) {
compress_method_t method = compression_method_get_by_name(m);
if (method != UNKNOWN_METHOD) {
tor_assert(((unsigned)method) < 8*sizeof(unsigned));
result |= (1u << method);
}
} SMARTLIST_FOREACH_END(m);
SMARTLIST_FOREACH_BEGIN(methods, char *, m) {
tor_free(m);
} SMARTLIST_FOREACH_END(m);
smartlist_free(methods);
return result;
}
/** Decide whether a client would accept the consensus we have.
*
* Clients can say they only want a consensus if it's signed by more
* than half the authorities in a list. They pass this list in
* the url as "...consensus/<b>fpr</b>+<b>fpr</b>+<b>fpr</b>".
*
* <b>fpr</b> may be an abbreviated fingerprint, i.e. only a left substring
* of the full authority identity digest. (Only strings of even length,
* i.e. encodings of full bytes, are handled correctly. In the case
* of an odd number of hex digits the last one is silently ignored.)
*
* Returns 1 if more than half of the requested authorities signed the
* consensus, 0 otherwise.
*/
static int
client_likes_consensus(const struct consensus_cache_entry_t *ent,
const char *want_url)
{
smartlist_t *voters = smartlist_new();
int need_at_least;
int have = 0;
if (consensus_cache_entry_get_voter_id_digests(ent, voters) != 0) {
smartlist_free(voters);
return 1; // We don't know the voters; assume the client won't mind. */
}
smartlist_t *want_authorities = smartlist_new();
dir_split_resource_into_fingerprints(want_url, want_authorities, NULL, 0);
need_at_least = smartlist_len(want_authorities)/2+1;
SMARTLIST_FOREACH_BEGIN(want_authorities, const char *, want_digest) {
SMARTLIST_FOREACH_BEGIN(voters, const char *, digest) {
if (!strcasecmpstart(digest, want_digest)) {
have++;
break;
};
} SMARTLIST_FOREACH_END(digest);
/* early exit, if we already have enough */
if (have >= need_at_least)
break;
} SMARTLIST_FOREACH_END(want_digest);
SMARTLIST_FOREACH(want_authorities, char *, d, tor_free(d));
smartlist_free(want_authorities);
SMARTLIST_FOREACH(voters, char *, cp, tor_free(cp));
smartlist_free(voters);
return (have >= need_at_least);
}
/** Return the compression level we should use for sending a compressed
* response of size <b>n_bytes</b>. */
STATIC compression_level_t
choose_compression_level(ssize_t n_bytes)
{
if (! have_been_under_memory_pressure()) {
return HIGH_COMPRESSION; /* we have plenty of RAM. */
} else if (n_bytes < 0) {
return HIGH_COMPRESSION; /* unknown; might be big. */
} else if (n_bytes < 1024) {
return LOW_COMPRESSION;
} else if (n_bytes < 2048) {
return MEDIUM_COMPRESSION;
} else {
return HIGH_COMPRESSION;
}
}
/** Information passed to handle a GET request. */
typedef struct get_handler_args_t {
/** Bitmask of compression methods that the client said (or implied) it
* supported. */
unsigned compression_supported;
/** If nonzero, the time included an if-modified-since header with this
* value. */
time_t if_modified_since;
/** String containing the requested URL or resource. */
const char *url;
/** String containing the HTTP headers */
const char *headers;
} get_handler_args_t;
/** Entry for handling an HTTP GET request.
*
* This entry matches a request if "string" is equal to the requested
* resource, or if "is_prefix" is true and "string" is a prefix of the
* requested resource.
*
* The 'handler' function is called to handle the request. It receives
* an arguments structure, and must return 0 on success or -1 if we should
* close the connection.
**/
typedef struct url_table_ent_s {
const char *string;
int is_prefix;
int (*handler)(dir_connection_t *conn, const get_handler_args_t *args);
} url_table_ent_t;
static int handle_get_frontpage(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_current_consensus(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_status_vote(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_microdesc(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_descriptor(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_keys(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_hs_descriptor_v2(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_robots(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_networkstatus_bridges(dir_connection_t *conn,
const get_handler_args_t *args);
/** Table for handling GET requests. */
static const url_table_ent_t url_table[] = {
{ "/tor/", 0, handle_get_frontpage },
{ "/tor/status-vote/current/consensus", 1, handle_get_current_consensus },
{ "/tor/status-vote/current/", 1, handle_get_status_vote },
{ "/tor/status-vote/next/", 1, handle_get_status_vote },
{ "/tor/micro/d/", 1, handle_get_microdesc },
{ "/tor/server/", 1, handle_get_descriptor },
{ "/tor/extra/", 1, handle_get_descriptor },
{ "/tor/keys/", 1, handle_get_keys },
{ "/tor/rendezvous2/", 1, handle_get_hs_descriptor_v2 },
{ "/tor/hs/3/", 1, handle_get_hs_descriptor_v3 },
{ "/tor/robots.txt", 0, handle_get_robots },
{ "/tor/networkstatus-bridges", 0, handle_get_networkstatus_bridges },
{ NULL, 0, NULL },
};
/** 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.
* Return 0 if we handled this successfully, or -1 if we need to close
* the connection. */
MOCK_IMPL(STATIC int,
directory_handle_command_get,(dir_connection_t *conn, const char *headers,
const char *req_body, size_t req_body_len))
{
char *url, *url_mem, *header;
time_t if_modified_since = 0;
int zlib_compressed_in_url;
unsigned compression_methods_supported;
/* We ignore the body of a GET request. */
(void)req_body;
(void)req_body_len;
log_debug(LD_DIRSERV,"Received GET command.");
conn->base_.state = DIR_CONN_STATE_SERVER_WRITING;
if (parse_http_url(headers, &url) < 0) {
write_short_http_response(conn, 400, "Bad request");
return 0;
}
if ((header = http_get_header(headers, "If-Modified-Since: "))) {
struct tm tm;
if (parse_http_time(header, &tm) == 0) {
if (tor_timegm(&tm, &if_modified_since)<0) {
if_modified_since = 0;
} else {
log_debug(LD_DIRSERV, "If-Modified-Since is '%s'.", escaped(header));
}
}
/* The correct behavior on a malformed If-Modified-Since header is to
* act as if no If-Modified-Since header had been given. */
tor_free(header);
}
log_debug(LD_DIRSERV,"rewritten url as '%s'.", escaped(url));
url_mem = url;
{
size_t url_len = strlen(url);
zlib_compressed_in_url = url_len > 2 && !strcmp(url+url_len-2, ".z");
if (zlib_compressed_in_url) {
url[url_len-2] = '\0';
}
}
if ((header = http_get_header(headers, "Accept-Encoding: "))) {
compression_methods_supported = parse_accept_encoding_header(header);
tor_free(header);
} else {
compression_methods_supported = (1u << NO_METHOD);
}
if (zlib_compressed_in_url) {
compression_methods_supported |= (1u << ZLIB_METHOD);
}
/* Remove all methods that we don't both support. */
compression_methods_supported &= tor_compress_get_supported_method_bitmask();
get_handler_args_t args;
args.url = url;
args.headers = headers;
args.if_modified_since = if_modified_since;
args.compression_supported = compression_methods_supported;
int i, result = -1;
for (i = 0; url_table[i].string; ++i) {
int match;
if (url_table[i].is_prefix) {
match = !strcmpstart(url, url_table[i].string);
} else {
match = !strcmp(url, url_table[i].string);
}
if (match) {
result = url_table[i].handler(conn, &args);
goto done;
}
}
/* we didn't recognize the url */
write_short_http_response(conn, 404, "Not found");
result = 0;
done:
tor_free(url_mem);
return result;
}
/** Helper function for GET / or GET /tor/
*/
static int
handle_get_frontpage(dir_connection_t *conn, const get_handler_args_t *args)
{
(void) args; /* unused */
const char *frontpage = get_dirportfrontpage();
if (frontpage) {
size_t dlen;
dlen = strlen(frontpage);
/* Let's return a disclaimer page (users shouldn't use V1 anymore,
and caches don't fetch '/', so this is safe). */
/* [We don't check for write_bucket_low here, since we want to serve
* this page no matter what.] */
write_http_response_header_impl(conn, dlen, "text/html", "identity",
NULL, DIRPORTFRONTPAGE_CACHE_LIFETIME);
connection_buf_add(frontpage, dlen, TO_CONN(conn));
} else {
write_short_http_response(conn, 404, "Not found");
}
return 0;
}
/** Warn that the cached consensus <b>consensus</b> of type
* <b>flavor</b> is too old and will not be served to clients. Rate-limit the
* warning to avoid logging an entry on every request.
*/
static void
warn_consensus_is_too_old(const struct consensus_cache_entry_t *consensus,
const char *flavor, time_t now)
{
#define TOO_OLD_WARNING_INTERVAL (60*60)
static ratelim_t warned = RATELIM_INIT(TOO_OLD_WARNING_INTERVAL);
char timestamp[ISO_TIME_LEN+1];
time_t valid_until;
char *dupes;
if (consensus_cache_entry_get_valid_until(consensus, &valid_until))
return;
if ((dupes = rate_limit_log(&warned, now))) {
format_local_iso_time(timestamp, valid_until);
log_warn(LD_DIRSERV, "Our %s%sconsensus is too old, so we will not "
"serve it to clients. It was valid until %s local time and we "
"continued to serve it for up to 24 hours after it expired.%s",
flavor ? flavor : "", flavor ? " " : "", timestamp, dupes);
tor_free(dupes);
}
}
/**
* Parse a single hex-encoded sha3-256 digest from <b>hex</b> into
* <b>digest</b>. Return 0 on success. On failure, report that the hash came
* from <b>location</b>, report that we are taking <b>action</b> with it, and
* return -1.
*/
static int
parse_one_diff_hash(uint8_t *digest, const char *hex, const char *location,
const char *action)
{
if (base16_decode((char*)digest, DIGEST256_LEN, hex, strlen(hex)) ==
DIGEST256_LEN) {
return 0;
} else {
log_fn(LOG_PROTOCOL_WARN, LD_DIR,
"%s contained bogus digest %s; %s.",
location, escaped(hex), action);
return -1;
}
}
/** If there is an X-Or-Diff-From-Consensus header included in <b>headers</b>,
* set <b>digest_out<b> to a new smartlist containing every 256-bit
* hex-encoded digest listed in that header and return 0. Otherwise return
* -1. */
static int
parse_or_diff_from_header(smartlist_t **digests_out, const char *headers)
{
char *hdr = http_get_header(headers, X_OR_DIFF_FROM_CONSENSUS_HEADER);
if (hdr == NULL) {
return -1;
}
smartlist_t *hex_digests = smartlist_new();
*digests_out = smartlist_new();
smartlist_split_string(hex_digests, hdr, " ",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
SMARTLIST_FOREACH_BEGIN(hex_digests, const char *, hex) {
uint8_t digest[DIGEST256_LEN];
if (!parse_one_diff_hash(digest, hex, "X-Or-Diff-From-Consensus header",
"ignoring")) {
smartlist_add(*digests_out, tor_memdup(digest, sizeof(digest)));
}
} SMARTLIST_FOREACH_END(hex);
SMARTLIST_FOREACH(hex_digests, char *, cp, tor_free(cp));
smartlist_free(hex_digests);
tor_free(hdr);
return 0;
}
/** Fallback compression method. The fallback compression method is used in
* case a client requests a non-compressed document. We only store compressed
* documents, so we use this compression method to fetch the document and let
* the spooling system do the streaming decompression.
*/
#define FALLBACK_COMPRESS_METHOD ZLIB_METHOD
/**
* Try to find the best consensus diff possible in order to serve a client
* request for a diff from one of the consensuses in <b>digests</b> to the
* current consensus of flavor <b>flav</b>. The client supports the
* compression methods listed in the <b>compression_methods</b> bitfield:
* place the method chosen (if any) into <b>compression_used_out</b>.
*/
static struct consensus_cache_entry_t *
find_best_diff(const smartlist_t *digests, int flav,
unsigned compression_methods,
compress_method_t *compression_used_out)
{
struct consensus_cache_entry_t *result = NULL;
SMARTLIST_FOREACH_BEGIN(digests, const uint8_t *, diff_from) {
unsigned u;
for (u = 0; u < ARRAY_LENGTH(srv_meth_pref_precompressed); ++u) {
compress_method_t method = srv_meth_pref_precompressed[u];
if (0 == (compression_methods & (1u<<method)))
continue; // client doesn't like this one, or we don't have it.
if (consdiffmgr_find_diff_from(&result, flav, DIGEST_SHA3_256,
diff_from, DIGEST256_LEN,
method) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = method;
return result;
}
}
} SMARTLIST_FOREACH_END(diff_from);
SMARTLIST_FOREACH_BEGIN(digests, const uint8_t *, diff_from) {
if (consdiffmgr_find_diff_from(&result, flav, DIGEST_SHA3_256, diff_from,
DIGEST256_LEN, FALLBACK_COMPRESS_METHOD) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = FALLBACK_COMPRESS_METHOD;
return result;
}
} SMARTLIST_FOREACH_END(diff_from);
return NULL;
}
/** Lookup the cached consensus document by the flavor found in <b>flav</b>.
* The preferred set of compression methods should be listed in the
* <b>compression_methods</b> bitfield. The compression method chosen (if any)
* is stored in <b>compression_used_out</b>. */
static struct consensus_cache_entry_t *
find_best_consensus(int flav,
unsigned compression_methods,
compress_method_t *compression_used_out)
{
struct consensus_cache_entry_t *result = NULL;
unsigned u;
for (u = 0; u < ARRAY_LENGTH(srv_meth_pref_precompressed); ++u) {
compress_method_t method = srv_meth_pref_precompressed[u];
if (0 == (compression_methods & (1u<<method)))
continue;
if (consdiffmgr_find_consensus(&result, flav,
method) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = method;
return result;
}
}
if (consdiffmgr_find_consensus(&result, flav,
FALLBACK_COMPRESS_METHOD) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = FALLBACK_COMPRESS_METHOD;
return result;
}
return NULL;
}
/** Try to find the best supported compression method possible from a given
* <b>compression_methods</b>. Return NO_METHOD if no mutually supported
* compression method could be found. */
static compress_method_t
find_best_compression_method(unsigned compression_methods, int stream)
{
unsigned u;
compress_method_t *methods;
size_t length;
if (stream) {
methods = srv_meth_pref_streaming_compression;
length = ARRAY_LENGTH(srv_meth_pref_streaming_compression);
} else {
methods = srv_meth_pref_precompressed;
length = ARRAY_LENGTH(srv_meth_pref_precompressed);
}
for (u = 0; u < length; ++u) {
compress_method_t method = methods[u];
if (compression_methods & (1u<<method))
return method;
}
return NO_METHOD;
}
/** Check if any of the digests in <b>digests</b> matches the latest consensus
* flavor (given in <b>flavor</b>) that we have available. */
static int
digest_list_contains_best_consensus(consensus_flavor_t flavor,
const smartlist_t *digests)
{
const networkstatus_t *ns = NULL;
if (digests == NULL)
return 0;
ns = networkstatus_get_latest_consensus_by_flavor(flavor);
if (ns == NULL)
return 0;
SMARTLIST_FOREACH_BEGIN(digests, const uint8_t *, digest) {
if (tor_memeq(ns->digest_sha3_as_signed, digest, DIGEST256_LEN))
return 1;
} SMARTLIST_FOREACH_END(digest);
return 0;
}
/** Encodes the results of parsing a consensus request to figure out what
* consensus, and possibly what diffs, the user asked for. */
typedef struct {
/** name of the flavor to retrieve. */
char *flavor;
/** flavor to retrive, as enum. */
consensus_flavor_t flav;
/** plus-separated list of authority fingerprints; see
* client_likes_consensus(). Aliases the URL in the request passed to
* parse_consensus_request(). */
const char *want_fps;
/** Optionally, a smartlist of sha3 digests-as-signed of the consensuses
* to return a diff from. */
smartlist_t *diff_from_digests;
/** If true, never send a full consensus. If there is no diff, send
* a 404 instead. */
int diff_only;
} parsed_consensus_request_t;
/** Remove all data held in <b>req</b>. Do not free <b>req</b> itself, since
* it is stack-allocated. */
static void
parsed_consensus_request_clear(parsed_consensus_request_t *req)
{
if (!req)
return;
tor_free(req->flavor);
if (req->diff_from_digests) {
SMARTLIST_FOREACH(req->diff_from_digests, uint8_t *, d, tor_free(d));
smartlist_free(req->diff_from_digests);
}
memset(req, 0, sizeof(parsed_consensus_request_t));
}
/**
* Parse the URL and relevant headers of <b>args</b> for a current-consensus
* request to learn what flavor of consensus we want, what keys it must be
* signed with, and what diffs we would accept (or demand) instead. Return 0
* on success and -1 on failure.
*/
static int
parse_consensus_request(parsed_consensus_request_t *out,
const get_handler_args_t *args)
{
const char *url = args->url;
memset(out, 0, sizeof(parsed_consensus_request_t));
out->flav = FLAV_NS;
const char CONSENSUS_URL_PREFIX[] = "/tor/status-vote/current/consensus/";
const char CONSENSUS_FLAVORED_PREFIX[] =
"/tor/status-vote/current/consensus-";
/* figure out the flavor if any, and who we wanted to sign the thing */
const char *after_flavor = NULL;
if (!strcmpstart(url, CONSENSUS_FLAVORED_PREFIX)) {
const char *f, *cp;
f = url + strlen(CONSENSUS_FLAVORED_PREFIX);
cp = strchr(f, '/');
if (cp) {
after_flavor = cp+1;
out->flavor = tor_strndup(f, cp-f);
} else {
out->flavor = tor_strdup(f);
}
int flav = networkstatus_parse_flavor_name(out->flavor);
if (flav < 0)
flav = FLAV_NS;
out->flav = flav;
} else {
if (!strcmpstart(url, CONSENSUS_URL_PREFIX))
after_flavor = url+strlen(CONSENSUS_URL_PREFIX);
}
/* see whether we've been asked explicitly for a diff from an older
* consensus. (The user might also have said that a diff would be okay,
* via X-Or-Diff-From-Consensus */
const char DIFF_COMPONENT[] = "diff/";
char *diff_hash_in_url = NULL;
if (after_flavor && !strcmpstart(after_flavor, DIFF_COMPONENT)) {
after_flavor += strlen(DIFF_COMPONENT);
const char *cp = strchr(after_flavor, '/');
if (cp) {
diff_hash_in_url = tor_strndup(after_flavor, cp-after_flavor);
out->want_fps = cp+1;
} else {
diff_hash_in_url = tor_strdup(after_flavor);
out->want_fps = NULL;
}
} else {
out->want_fps = after_flavor;
}
if (diff_hash_in_url) {
uint8_t diff_from[DIGEST256_LEN];
out->diff_from_digests = smartlist_new();
out->diff_only = 1;
int ok = !parse_one_diff_hash(diff_from, diff_hash_in_url, "URL",
"rejecting");
tor_free(diff_hash_in_url);
if (ok) {
smartlist_add(out->diff_from_digests,
tor_memdup(diff_from, DIGEST256_LEN));
} else {
return -1;
}
} else {
parse_or_diff_from_header(&out->diff_from_digests, args->headers);
}
return 0;
}
/** Helper function for GET /tor/status-vote/current/consensus
*/
static int
handle_get_current_consensus(dir_connection_t *conn,
const get_handler_args_t *args)
{
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 0);
const time_t if_modified_since = args->if_modified_since;
int clear_spool = 0;
/* v3 network status fetch. */
long lifetime = NETWORKSTATUS_CACHE_LIFETIME;
time_t now = time(NULL);
parsed_consensus_request_t req;
if (parse_consensus_request(&req, args) < 0) {
write_short_http_response(conn, 404, "Couldn't parse request");
goto done;
}
if (digest_list_contains_best_consensus(req.flav,
req.diff_from_digests)) {
write_short_http_response(conn, 304, "Not modified");
geoip_note_ns_response(GEOIP_REJECT_NOT_MODIFIED);
goto done;
}
struct consensus_cache_entry_t *cached_consensus = NULL;
compress_method_t compression_used = NO_METHOD;
if (req.diff_from_digests) {
cached_consensus = find_best_diff(req.diff_from_digests, req.flav,
args->compression_supported,
&compression_used);
}
if (req.diff_only && !cached_consensus) {
write_short_http_response(conn, 404, "No such diff available");
// XXXX warn_consensus_is_too_old(v, req.flavor, now);
geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND);
goto done;
}
if (! cached_consensus) {
cached_consensus = find_best_consensus(req.flav,
args->compression_supported,
&compression_used);
}
time_t fresh_until, valid_until;
int have_fresh_until = 0, have_valid_until = 0;
if (cached_consensus) {
have_fresh_until =
!consensus_cache_entry_get_fresh_until(cached_consensus, &fresh_until);
have_valid_until =
!consensus_cache_entry_get_valid_until(cached_consensus, &valid_until);
}
if (cached_consensus && have_valid_until &&
!networkstatus_valid_until_is_reasonably_live(valid_until, now)) {
write_short_http_response(conn, 404, "Consensus is too old");
warn_consensus_is_too_old(cached_consensus, req.flavor, now);
geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND);
goto done;
}
if (cached_consensus && req.want_fps &&
!client_likes_consensus(cached_consensus, req.want_fps)) {
write_short_http_response(conn, 404, "Consensus not signed by sufficient "
"number of requested authorities");
geoip_note_ns_response(GEOIP_REJECT_NOT_ENOUGH_SIGS);
goto done;
}
conn->spool = smartlist_new();
clear_spool = 1;
{
spooled_resource_t *spooled;
if (cached_consensus) {
spooled = spooled_resource_new_from_cache_entry(cached_consensus);
smartlist_add(conn->spool, spooled);
}
}
lifetime = (have_fresh_until && fresh_until > now) ? fresh_until - now : 0;
size_t size_guess = 0;
int n_expired = 0;
dirserv_spool_remove_missing_and_guess_size(conn, if_modified_since,
compress_method != NO_METHOD,
&size_guess,
&n_expired);
if (!smartlist_len(conn->spool) && !n_expired) {
write_short_http_response(conn, 404, "Not found");
geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND);
goto done;
} else if (!smartlist_len(conn->spool)) {
write_short_http_response(conn, 304, "Not modified");
geoip_note_ns_response(GEOIP_REJECT_NOT_MODIFIED);
goto done;
}
if (global_write_bucket_low(TO_CONN(conn), size_guess, 2)) {
log_debug(LD_DIRSERV,
"Client asked for network status lists, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_short_http_response(conn, 503, "Directory busy, try again later");
geoip_note_ns_response(GEOIP_REJECT_BUSY);
goto done;
}
tor_addr_t addr;
if (tor_addr_parse(&addr, (TO_CONN(conn))->address) >= 0) {
geoip_note_client_seen(GEOIP_CLIENT_NETWORKSTATUS,
&addr, NULL,
time(NULL));
geoip_note_ns_response(GEOIP_SUCCESS);
/* Note that a request for a network status has started, so that we
* can measure the download time later on. */
if (conn->dirreq_id)
geoip_start_dirreq(conn->dirreq_id, size_guess, DIRREQ_TUNNELED);
else
geoip_start_dirreq(TO_CONN(conn)->global_identifier, size_guess,
DIRREQ_DIRECT);
}
/* Use this header to tell caches that the response depends on the
* X-Or-Diff-From-Consensus header (or lack thereof). */
const char vary_header[] = "Vary: X-Or-Diff-From-Consensus\r\n";
clear_spool = 0;
// The compress_method might have been NO_METHOD, but we store the data
// compressed. Decompress them using `compression_used`. See fallback code in
// find_best_consensus() and find_best_diff().
write_http_response_headers(conn, -1,
compress_method == NO_METHOD ?
NO_METHOD : compression_used,
vary_header,
smartlist_len(conn->spool) == 1 ? lifetime : 0);
if (compress_method == NO_METHOD && smartlist_len(conn->spool))
conn->compress_state = tor_compress_new(0, compression_used,
HIGH_COMPRESSION);
/* Prime the connection with some data. */
const int initial_flush_result = connection_dirserv_flushed_some(conn);
tor_assert_nonfatal(initial_flush_result == 0);
goto done;
done:
parsed_consensus_request_clear(&req);
if (clear_spool) {
dir_conn_clear_spool(conn);
}
return 0;
}
/** Helper function for GET /tor/status-vote/{current,next}/...
*/
static int
handle_get_status_vote(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
{
ssize_t body_len = 0;
ssize_t estimated_len = 0;
int lifetime = 60; /* XXXX?? should actually use vote intervals. */
/* This smartlist holds strings that we can compress on the fly. */
smartlist_t *items = smartlist_new();
/* This smartlist holds cached_dir_t objects that have a precompressed
* deflated version. */
smartlist_t *dir_items = smartlist_new();
dirvote_dirreq_get_status_vote(url, items, dir_items);
if (!smartlist_len(dir_items) && !smartlist_len(items)) {
write_short_http_response(conn, 404, "Not found");
goto vote_done;
}
/* We're sending items from at most one kind of source */
tor_assert_nonfatal(smartlist_len(items) == 0 ||
smartlist_len(dir_items) == 0);
int streaming;
unsigned mask;
if (smartlist_len(items)) {
/* We're taking strings and compressing them on the fly. */
streaming = 1;
mask = ~0u;
} else {
/* We're taking cached_dir_t objects. We only have them uncompressed
* or deflated. */
streaming = 0;
mask = (1u<<NO_METHOD) | (1u<<ZLIB_METHOD);
}
const compress_method_t compress_method = find_best_compression_method(
args->compression_supported&mask, streaming);
SMARTLIST_FOREACH(dir_items, cached_dir_t *, d,
body_len += compress_method != NO_METHOD ?
d->dir_compressed_len : d->dir_len);
estimated_len += body_len;
SMARTLIST_FOREACH(items, const char *, item, {
size_t ln = strlen(item);
if (compress_method != NO_METHOD) {
estimated_len += ln/2;
} else {
body_len += ln; estimated_len += ln;
}
});
if (global_write_bucket_low(TO_CONN(conn), estimated_len, 2)) {
write_short_http_response(conn, 503, "Directory busy, try again later");
goto vote_done;
}
write_http_response_header(conn, body_len ? body_len : -1,
compress_method,
lifetime);
if (smartlist_len(items)) {
if (compress_method != NO_METHOD) {
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(estimated_len));
SMARTLIST_FOREACH(items, const char *, c,
connection_buf_add_compress(c, strlen(c), conn, 0));
connection_buf_add_compress("", 0, conn, 1);
} else {
SMARTLIST_FOREACH(items, const char *, c,
connection_buf_add(c, strlen(c), TO_CONN(conn)));
}
} else {
SMARTLIST_FOREACH(dir_items, cached_dir_t *, d,
connection_buf_add(compress_method != NO_METHOD ?
d->dir_compressed : d->dir,
compress_method != NO_METHOD ?
d->dir_compressed_len : d->dir_len,
TO_CONN(conn)));
}
vote_done:
smartlist_free(items);
smartlist_free(dir_items);
goto done;
}
done:
return 0;
}
/** Helper function for GET /tor/micro/d/...
*/
static int
handle_get_microdesc(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
int clear_spool = 1;
{
conn->spool = smartlist_new();
dir_split_resource_into_spoolable(url+strlen("/tor/micro/d/"),
DIR_SPOOL_MICRODESC,
conn->spool, NULL,
DSR_DIGEST256|DSR_BASE64|DSR_SORT_UNIQ);
size_t size_guess = 0;
dirserv_spool_remove_missing_and_guess_size(conn, 0,
compress_method != NO_METHOD,
&size_guess, NULL);
if (smartlist_len(conn->spool) == 0) {
write_short_http_response(conn, 404, "Not found");
goto done;
}
if (global_write_bucket_low(TO_CONN(conn), size_guess, 2)) {
log_info(LD_DIRSERV,
"Client asked for server descriptors, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_short_http_response(conn, 503, "Directory busy, try again later");
goto done;
}
clear_spool = 0;
write_http_response_header(conn, -1,
compress_method,
MICRODESC_CACHE_LIFETIME);
if (compress_method != NO_METHOD)
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(size_guess));
const int initial_flush_result = connection_dirserv_flushed_some(conn);
tor_assert_nonfatal(initial_flush_result == 0);
goto done;
}
done:
if (clear_spool) {
dir_conn_clear_spool(conn);
}
return 0;
}
/** Helper function for GET /tor/{server,extra}/...
*/
static int
handle_get_descriptor(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
const or_options_t *options = get_options();
int clear_spool = 1;
if (!strcmpstart(url,"/tor/server/") ||
(!options->BridgeAuthoritativeDir &&
!options->BridgeRelay && !strcmpstart(url,"/tor/extra/"))) {
int res;
const char *msg = NULL;
int cache_lifetime = 0;
int is_extra = !strcmpstart(url,"/tor/extra/");
url += is_extra ? strlen("/tor/extra/") : strlen("/tor/server/");
dir_spool_source_t source;
time_t publish_cutoff = 0;
if (!strcmpstart(url, "d/")) {
source =
is_extra ? DIR_SPOOL_EXTRA_BY_DIGEST : DIR_SPOOL_SERVER_BY_DIGEST;
} else {
source =
is_extra ? DIR_SPOOL_EXTRA_BY_FP : DIR_SPOOL_SERVER_BY_FP;
/* We only want to apply a publish cutoff when we're requesting
* resources by fingerprint. */
publish_cutoff = time(NULL) - ROUTER_MAX_AGE_TO_PUBLISH;
}
conn->spool = smartlist_new();
res = dirserv_get_routerdesc_spool(conn->spool, url,
source,
connection_dir_is_encrypted(conn),
&msg);
if (!strcmpstart(url, "all")) {
cache_lifetime = FULL_DIR_CACHE_LIFETIME;
} else if (smartlist_len(conn->spool) == 1) {
cache_lifetime = ROUTERDESC_BY_DIGEST_CACHE_LIFETIME;
}
size_t size_guess = 0;
int n_expired = 0;
dirserv_spool_remove_missing_and_guess_size(conn, publish_cutoff,
compress_method != NO_METHOD,
&size_guess, &n_expired);
/* If we are the bridge authority and the descriptor is a bridge
* descriptor, remember that we served this descriptor for desc stats. */
/* XXXX it's a bit of a kludge to have this here. */
if (get_options()->BridgeAuthoritativeDir &&
source == DIR_SPOOL_SERVER_BY_FP) {
SMARTLIST_FOREACH_BEGIN(conn->spool, spooled_resource_t *, spooled) {
const routerinfo_t *router =
router_get_by_id_digest((const char *)spooled->digest);
/* router can be NULL here when the bridge auth is asked for its own
* descriptor. */
if (router && router->purpose == ROUTER_PURPOSE_BRIDGE)
rep_hist_note_desc_served(router->cache_info.identity_digest);
} SMARTLIST_FOREACH_END(spooled);
}
if (res < 0 || size_guess == 0 || smartlist_len(conn->spool) == 0) {
if (msg == NULL)
msg = "Not found";
write_short_http_response(conn, 404, msg);
} else {
if (global_write_bucket_low(TO_CONN(conn), size_guess, 2)) {
log_info(LD_DIRSERV,
"Client asked for server descriptors, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_short_http_response(conn, 503,
"Directory busy, try again later");
dir_conn_clear_spool(conn);
goto done;
}
write_http_response_header(conn, -1, compress_method, cache_lifetime);
if (compress_method != NO_METHOD)
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(size_guess));
clear_spool = 0;
/* Prime the connection with some data. */
int initial_flush_result = connection_dirserv_flushed_some(conn);
tor_assert_nonfatal(initial_flush_result == 0);
}
goto done;
}
done:
if (clear_spool)
dir_conn_clear_spool(conn);
return 0;
}
/** Helper function for GET /tor/keys/...
*/
static int
handle_get_keys(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
const time_t if_modified_since = args->if_modified_since;
{
smartlist_t *certs = smartlist_new();
ssize_t len = -1;
if (!strcmp(url, "/tor/keys/all")) {
authority_cert_get_all(certs);
} else if (!strcmp(url, "/tor/keys/authority")) {
authority_cert_t *cert = get_my_v3_authority_cert();
if (cert)
smartlist_add(certs, cert);
} else if (!strcmpstart(url, "/tor/keys/fp/")) {
smartlist_t *fps = smartlist_new();
dir_split_resource_into_fingerprints(url+strlen("/tor/keys/fp/"),
fps, NULL,
DSR_HEX|DSR_SORT_UNIQ);
SMARTLIST_FOREACH(fps, char *, d, {
authority_cert_t *c = authority_cert_get_newest_by_id(d);
if (c) smartlist_add(certs, c);
tor_free(d);
});
smartlist_free(fps);
} else if (!strcmpstart(url, "/tor/keys/sk/")) {
smartlist_t *fps = smartlist_new();
dir_split_resource_into_fingerprints(url+strlen("/tor/keys/sk/"),
fps, NULL,
DSR_HEX|DSR_SORT_UNIQ);
SMARTLIST_FOREACH(fps, char *, d, {
authority_cert_t *c = authority_cert_get_by_sk_digest(d);
if (c) smartlist_add(certs, c);
tor_free(d);
});
smartlist_free(fps);
} else if (!strcmpstart(url, "/tor/keys/fp-sk/")) {
smartlist_t *fp_sks = smartlist_new();
dir_split_resource_into_fingerprint_pairs(url+strlen("/tor/keys/fp-sk/"),
fp_sks);
SMARTLIST_FOREACH(fp_sks, fp_pair_t *, pair, {
authority_cert_t *c = authority_cert_get_by_digests(pair->first,
pair->second);
if (c) smartlist_add(certs, c);
tor_free(pair);
});
smartlist_free(fp_sks);
} else {
write_short_http_response(conn, 400, "Bad request");
goto keys_done;
}
if (!smartlist_len(certs)) {
write_short_http_response(conn, 404, "Not found");
goto keys_done;
}
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
if (c->cache_info.published_on < if_modified_since)
SMARTLIST_DEL_CURRENT(certs, c));
if (!smartlist_len(certs)) {
write_short_http_response(conn, 304, "Not modified");
goto keys_done;
}
len = 0;
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
len += c->cache_info.signed_descriptor_len);
if (global_write_bucket_low(TO_CONN(conn),
compress_method != NO_METHOD ? len/2 : len,
2)) {
write_short_http_response(conn, 503, "Directory busy, try again later");
goto keys_done;
}
write_http_response_header(conn,
compress_method != NO_METHOD ? -1 : len,
compress_method,
60*60);
if (compress_method != NO_METHOD) {
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(len));
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
connection_buf_add_compress(
c->cache_info.signed_descriptor_body,
c->cache_info.signed_descriptor_len,
conn, 0));
connection_buf_add_compress("", 0, conn, 1);
} else {
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
connection_buf_add(c->cache_info.signed_descriptor_body,
c->cache_info.signed_descriptor_len,
TO_CONN(conn)));
}
keys_done:
smartlist_free(certs);
goto done;
}
done:
return 0;
}
/** Helper function for GET /tor/rendezvous2/
*/
static int
handle_get_hs_descriptor_v2(dir_connection_t *conn,
const get_handler_args_t *args)
{
const char *url = args->url;
if (connection_dir_is_encrypted(conn)) {
/* Handle v2 rendezvous descriptor fetch request. */
const char *descp;
const char *query = url + strlen("/tor/rendezvous2/");
if (rend_valid_descriptor_id(query)) {
log_info(LD_REND, "Got a v2 rendezvous descriptor request for ID '%s'",
safe_str(escaped(query)));
switch (rend_cache_lookup_v2_desc_as_dir(query, &descp)) {
case 1: /* valid */
write_http_response_header(conn, strlen(descp), NO_METHOD, 0);
connection_buf_add(descp, strlen(descp), TO_CONN(conn));
break;
case 0: /* well-formed but not present */
write_short_http_response(conn, 404, "Not found");
break;
case -1: /* not well-formed */
write_short_http_response(conn, 400, "Bad request");
break;
}
} else { /* not well-formed */
write_short_http_response(conn, 400, "Bad request");
}
goto done;
} else {
/* Not encrypted! */
write_short_http_response(conn, 404, "Not found");
}
done:
return 0;
}
/** Helper function for GET /tor/hs/3/<z>. Only for version 3.
*/
STATIC int
handle_get_hs_descriptor_v3(dir_connection_t *conn,
const get_handler_args_t *args)
{
int retval;
const char *desc_str = NULL;
const char *pubkey_str = NULL;
const char *url = args->url;
/* Reject unencrypted dir connections */
if (!connection_dir_is_encrypted(conn)) {
write_short_http_response(conn, 404, "Not found");
goto done;
}
/* After the path prefix follows the base64 encoded blinded pubkey which we
* use to get the descriptor from the cache. Skip the prefix and get the
* pubkey. */
tor_assert(!strcmpstart(url, "/tor/hs/3/"));
pubkey_str = url + strlen("/tor/hs/3/");
retval = hs_cache_lookup_as_dir(HS_VERSION_THREE,
pubkey_str, &desc_str);
if (retval <= 0 || desc_str == NULL) {
write_short_http_response(conn, 404, "Not found");
goto done;
}
/* Found requested descriptor! Pass it to this nice client. */
write_http_response_header(conn, strlen(desc_str), NO_METHOD, 0);
connection_buf_add(desc_str, strlen(desc_str), TO_CONN(conn));
done:
return 0;
}
/** Helper function for GET /tor/networkstatus-bridges
*/
static int
handle_get_networkstatus_bridges(dir_connection_t *conn,
const get_handler_args_t *args)
{
const char *headers = args->headers;
const or_options_t *options = get_options();
if (options->BridgeAuthoritativeDir &&
options->BridgePassword_AuthDigest_ &&
connection_dir_is_encrypted(conn)) {
char *status;
char digest[DIGEST256_LEN];
char *header = http_get_header(headers, "Authorization: Basic ");
if (header)
crypto_digest256(digest, header, strlen(header), DIGEST_SHA256);
/* now make sure the password is there and right */
if (!header ||
tor_memneq(digest,
options->BridgePassword_AuthDigest_, DIGEST256_LEN)) {
write_short_http_response(conn, 404, "Not found");
tor_free(header);
goto done;
}
tor_free(header);
/* all happy now. send an answer. */
status = networkstatus_getinfo_by_purpose("bridge", time(NULL));
size_t dlen = strlen(status);
write_http_response_header(conn, dlen, NO_METHOD, 0);
connection_buf_add(status, dlen, TO_CONN(conn));
tor_free(status);
goto done;
}
done:
return 0;
}
/** Helper function for GET robots.txt or /tor/robots.txt */
static int
handle_get_robots(dir_connection_t *conn, const get_handler_args_t *args)
{
(void)args;
{
const char robots[] = "User-agent: *\r\nDisallow: /\r\n";
size_t len = strlen(robots);
write_http_response_header(conn, len, NO_METHOD, ROBOTS_CACHE_LIFETIME);
connection_buf_add(robots, len, TO_CONN(conn));
}
return 0;
}
/* Given the <b>url</b> from a POST request, try to extract the version number
* using the provided <b>prefix</b>. The version should be after the prefix and
* ending with the separator "/". For instance:
* /tor/hs/3/publish
*
* On success, <b>end_pos</b> points to the position right after the version
* was found. On error, it is set to NULL.
*
* Return version on success else negative value. */
STATIC int
parse_hs_version_from_post(const char *url, const char *prefix,
const char **end_pos)
{
int ok;
unsigned long version;
const char *start;
char *end = NULL;
tor_assert(url);
tor_assert(prefix);
tor_assert(end_pos);
/* Check if the prefix does start the url. */
if (strcmpstart(url, prefix)) {
goto err;
}
/* Move pointer to the end of the prefix string. */
start = url + strlen(prefix);
/* Try this to be the HS version and if we are still at the separator, next
* will be move to the right value. */
version = tor_parse_long(start, 10, 0, INT_MAX, &ok, &end);
if (!ok) {
goto err;
}
*end_pos = end;
return (int) version;
err:
*end_pos = NULL;
return -1;
}
/* Handle the POST request for a hidden service descripror. The request is in
* <b>url</b>, the body of the request is in <b>body</b>. Return 200 on success
* else return 400 indicating a bad request. */
STATIC int
handle_post_hs_descriptor(const char *url, const char *body)
{
int version;
const char *end_pos;
tor_assert(url);
tor_assert(body);
version = parse_hs_version_from_post(url, "/tor/hs/", &end_pos);
if (version < 0) {
goto err;
}
/* We have a valid version number, now make sure it's a publish request. Use
* the end position just after the version and check for the command. */
if (strcmpstart(end_pos, "/publish")) {
goto err;
}
switch (version) {
case HS_VERSION_THREE:
if (hs_cache_store_as_dir(body) < 0) {
goto err;
}
log_info(LD_REND, "Publish request for HS descriptor handled "
"successfully.");
break;
default:
/* Unsupported version, return a bad request. */
goto err;
}
return 200;
err:
/* Bad request. */
return 400;
}
/** 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
* 400. Always return 0. */
MOCK_IMPL(STATIC int,
directory_handle_command_post,(dir_connection_t *conn, const char *headers,
const char *body, size_t body_len))
{
char *url = NULL;
const or_options_t *options = get_options();
log_debug(LD_DIRSERV,"Received POST command.");
conn->base_.state = DIR_CONN_STATE_SERVER_WRITING;
if (!public_server_mode(options)) {
log_info(LD_DIR, "Rejected dir post request from %s "
"since we're not a public relay.", conn->base_.address);
write_short_http_response(conn, 503, "Not acting as a public relay");
goto done;
}
if (parse_http_url(headers, &url) < 0) {
write_short_http_response(conn, 400, "Bad request");
return 0;
}
log_debug(LD_DIRSERV,"rewritten url as '%s'.", escaped(url));
/* Handle v2 rendezvous service publish request. */
if (connection_dir_is_encrypted(conn) &&
!strcmpstart(url,"/tor/rendezvous2/publish")) {
if (rend_cache_store_v2_desc_as_dir(body) < 0) {
log_warn(LD_REND, "Rejected v2 rend descriptor (body size %d) from %s.",
(int)body_len, conn->base_.address);
write_short_http_response(conn, 400,
"Invalid v2 service descriptor rejected");
} else {
write_short_http_response(conn, 200, "Service descriptor (v2) stored");
log_info(LD_REND, "Handled v2 rendezvous descriptor post: accepted");
}
goto done;
}
/* Handle HS descriptor publish request. */
/* XXX: This should be disabled with a consensus param until we want to
* the prop224 be deployed and thus use. */
if (connection_dir_is_encrypted(conn) && !strcmpstart(url, "/tor/hs/")) {
const char *msg = "HS descriptor stored successfully.";
/* We most probably have a publish request for an HS descriptor. */
int code = handle_post_hs_descriptor(url, body);
if (code != 200) {
msg = "Invalid HS descriptor. Rejected.";
}
write_short_http_response(conn, code, msg);
goto done;
}
if (!authdir_mode(options)) {
/* we just provide cached directories; we don't want to
* receive anything. */
write_short_http_response(conn, 400, "Nonauthoritative directory does not "
"accept posted server descriptors");
goto done;
}
if (authdir_mode(options) &&
!strcmp(url,"/tor/")) { /* server descriptor post */
const char *msg = "[None]";
uint8_t purpose = authdir_mode_bridge(options) ?
ROUTER_PURPOSE_BRIDGE : ROUTER_PURPOSE_GENERAL;
was_router_added_t r = dirserv_add_multiple_descriptors(body, body_len,
purpose, conn->base_.address, &msg);
tor_assert(msg);
if (r == ROUTER_ADDED_SUCCESSFULLY) {
write_short_http_response(conn, 200, msg);
} else if (WRA_WAS_OUTDATED(r)) {
write_http_response_header_impl(conn, -1, NULL, NULL,
"X-Descriptor-Not-New: Yes\r\n", -1);
} else {
log_info(LD_DIRSERV,
"Rejected router descriptor or extra-info from %s "
"(\"%s\").",
conn->base_.address, msg);
write_short_http_response(conn, 400, msg);
}
goto done;
}
if (authdir_mode_v3(options) &&
!strcmp(url,"/tor/post/vote")) { /* v3 networkstatus vote */
const char *msg = "OK";
int status;
if (dirvote_add_vote(body, &msg, &status)) {
write_short_http_response(conn, status, "Vote stored");
} else {
tor_assert(msg);
log_warn(LD_DIRSERV, "Rejected vote from %s (\"%s\").",
conn->base_.address, msg);
write_short_http_response(conn, status, msg);
}
goto done;
}
if (authdir_mode_v3(options) &&
!strcmp(url,"/tor/post/consensus-signature")) { /* sigs on consensus. */
const char *msg = NULL;
if (dirvote_add_signatures(body, conn->base_.address, &msg)>=0) {
write_short_http_response(conn, 200, msg?msg:"Signatures stored");
} else {
log_warn(LD_DIR, "Unable to store signatures posted by %s: %s",
conn->base_.address, msg?msg:"???");
write_short_http_response(conn, 400,
msg?msg:"Unable to store signatures");
}
goto done;
}
/* we didn't recognize the url */
write_short_http_response(conn, 404, "Not found");
done:
tor_free(url);
return 0;
}
/** If <b>headers</b> indicates that a proxy was involved, then rewrite
* <b>conn</b>-\>address to describe our best guess of the address that
* originated this HTTP request. */
static void
http_set_address_origin(const char *headers, connection_t *conn)
{
char *fwd;
fwd = http_get_header(headers, "Forwarded-For: ");
if (!fwd)
fwd = http_get_header(headers, "X-Forwarded-For: ");
if (fwd) {
tor_addr_t toraddr;
if (tor_addr_parse(&toraddr,fwd) == -1 ||
tor_addr_is_internal(&toraddr,0)) {
log_debug(LD_DIR, "Ignoring local/internal IP %s", escaped(fwd));
tor_free(fwd);
return;
}
tor_free(conn->address);
conn->address = tor_strdup(fwd);
tor_free(fwd);
}
}
/** 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.
*/
int
directory_handle_command(dir_connection_t *conn)
{
char *headers=NULL, *body=NULL;
size_t body_len=0;
int r;
tor_assert(conn);
tor_assert(conn->base_.type == CONN_TYPE_DIR);
switch (connection_fetch_from_buf_http(TO_CONN(conn),
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_DIR_UL_SIZE, 0)) {
case -1: /* overflow */
log_warn(LD_DIRSERV,
"Request too large from address '%s' to DirPort. Closing.",
safe_str(conn->base_.address));
return -1;
case 0:
log_debug(LD_DIRSERV,"command not all here yet.");
return 0;
/* case 1, fall through */
}
http_set_address_origin(headers, TO_CONN(conn));
// we should escape headers here as well,
// but we can't call escaped() twice, as it uses the same buffer
//log_debug(LD_DIRSERV,"headers %s, body %s.", headers, escaped(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_PROTOCOL_WARN, LD_PROTOCOL,
"Got headers %s with unknown command. Closing.",
escaped(headers));
r = -1;
}
tor_free(headers); tor_free(body);
return r;
}