diff options
Diffstat (limited to 'src/or/directory.c')
| -rw-r--r-- | src/or/directory.c | 69 |
1 files changed, 66 insertions, 3 deletions
diff --git a/src/or/directory.c b/src/or/directory.c index 7765c2102..f8f48ec74 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -37,6 +37,7 @@ const char directory_c_id[] = static void directory_send_command(dir_connection_t *conn, int purpose, int direct, const char *resource, const char *payload, size_t payload_len, + int supports_conditional_consensus, time_t if_modified_since); static int directory_handle_command(dir_connection_t *conn); static int body_is_plausible(const char *body, size_t body_len, int purpose); @@ -339,10 +340,13 @@ directory_get_from_dirserver(uint8_t dir_purpose, uint8_t router_purpose, /* want to ask a running bridge for which we have a descriptor. */ /* XXX021 we assume that all of our bridges can answer any * possible directory question. This won't be true forever. -RD */ + /* It certainly is not true with conditional consensus downloading, + * so, for now, never assume the server supports that. */ routerinfo_t *ri = choose_random_entry(NULL); if (ri) { directory_initiate_command(ri->address, ri->addr, ri->or_port, 0, + 0, /* don't use conditional consensus url */ 1, ri->cache_info.identity_digest, dir_purpose, router_purpose, @@ -464,6 +468,7 @@ directory_initiate_command_routerstatus(routerstatus_t *status, } directory_initiate_command(address, status->addr, status->or_port, status->dir_port, + status->version_supports_conditional_consensus, status->version_supports_begindir, status->identity_digest, dir_purpose, router_purpose, @@ -645,6 +650,7 @@ directory_command_should_use_begindir(or_options_t *options, uint32_t addr, void directory_initiate_command(const char *address, uint32_t addr, uint16_t or_port, uint16_t dir_port, + int supports_conditional_consensus, int supports_begindir, const char *digest, uint8_t dir_purpose, uint8_t router_purpose, int anonymized_connection, const char *resource, @@ -707,7 +713,9 @@ directory_initiate_command(const char *address, uint32_t addr, case 0: /* queue the command on the outbuf */ directory_send_command(conn, dir_purpose, 1, resource, - payload, payload_len, if_modified_since); + payload, payload_len, + supports_conditional_consensus, + if_modified_since); connection_watch_events(TO_CONN(conn), EV_READ | EV_WRITE); /* writable indicates finish, readable indicates broken link, error indicates broken link in windowsland. */ @@ -744,7 +752,9 @@ directory_initiate_command(const char *address, uint32_t addr, conn->_base.state = DIR_CONN_STATE_CLIENT_SENDING; /* queue the command on the outbuf */ directory_send_command(conn, dir_purpose, 0, resource, - payload, payload_len, if_modified_since); + payload, payload_len, + supports_conditional_consensus, + if_modified_since); connection_watch_events(TO_CONN(conn), EV_READ | EV_WRITE); connection_start_reading(TO_CONN(linked_conn)); } @@ -763,6 +773,55 @@ connection_dir_is_encrypted(dir_connection_t *conn) return TO_CONN(conn)->linked; } +/** Return the URL we should use for a consensus download. + * + * This url depends on whether or not the server we go to + * is sufficiently new to support conditional consensus downloading, + * i.e. GET .../consensus/<fpr>+<fpr>+<fpr> + */ +#define CONDITIONAL_CONSENSUS_FPR_LEN 3 +#if (CONDITIONAL_CONSENSUS_FPR_LEN > DIGEST_LEN) +#error "conditional consensus fingerprint length is larger than digest length +#endif +static char * +directory_get_consensus_url(int supports_conditional_consensus) +{ + char *url; + int len; + +#ifndef SUPPORTS_CONDITIONAL_CONSENSUS_SINCE_VERSION + supports_conditional_consensus = 0; +#endif + + if (supports_conditional_consensus) { + char *authority_id_list; + smartlist_t *authority_digets = smartlist_create(); + + SMARTLIST_FOREACH(router_get_trusted_dir_servers(), + trusted_dir_server_t *, ds, + { + char *hex = tor_malloc(2*CONDITIONAL_CONSENSUS_FPR_LEN+1); + base16_encode(hex, 2*CONDITIONAL_CONSENSUS_FPR_LEN+1, + ds->digest, CONDITIONAL_CONSENSUS_FPR_LEN); + smartlist_add(authority_digets, hex); + }); + authority_id_list = smartlist_join_strings(authority_digets, + "+", 0, NULL); + + len = strlen(authority_id_list)+64; + url = tor_malloc(len); + tor_snprintf(url, len, "/tor/status-vote/current/consensus/%s.z", + authority_id_list); + + SMARTLIST_FOREACH(authority_digets, char *, cp, tor_free(cp)); + smartlist_free(authority_digets); + tor_free(authority_id_list); + } else { + url = tor_strdup("/tor/status-vote/current/consensus.z"); + } + return url; +} + /** Queue an appropriate HTTP command on conn-\>outbuf. The other args * are as in directory_initiate_command. */ @@ -770,6 +829,7 @@ static void directory_send_command(dir_connection_t *conn, int purpose, int direct, const char *resource, const char *payload, size_t payload_len, + int supports_conditional_consensus, time_t if_modified_since) { char proxystring[256]; @@ -852,7 +912,10 @@ directory_send_command(dir_connection_t *conn, tor_assert(!resource); tor_assert(!payload); httpcommand = "GET"; - url = tor_strdup("/tor/status-vote/current/consensus.z"); + url = directory_get_consensus_url(supports_conditional_consensus); + /* XXX021: downgrade/remove once done with conditional consensus fu */ + log_notice(LD_DIR, "Downloading consensus from %s using %s", + hoststring, url); break; case DIR_PURPOSE_FETCH_CERTIFICATE: tor_assert(resource); |