May 2017 - tor-commits - lists.torproject.org

[tor/master] Split consensus-request parsing into a separate function
by nickm＠torproject.org 15 May '17

15 May '17

commit 4531fdbbff4ac5127d3de421903ccf2fe2171097 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu May 4 11:13:44 2017 -0400 Split consensus-request parsing into a separate function This ought to make the control flow a tiny bit more readable. --- src/or/directory.c | 131 +++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 96 insertions(+), 35 deletions(-) diff --git a/src/or/directory.c b/src/or/directory.c index 71ae274..4537d79 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -3822,43 +3822,75 @@ find_best_compression_method(unsigned compression_methods, int stream) return NO_METHOD; } -/** Helper function for GET /tor/status-vote/current/consensus +/** 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 req. Do not free req 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 args 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 -handle_get_current_consensus(dir_connection_t *conn, - const get_handler_args_t *args) +parse_consensus_request(parsed_consensus_request_t *out, + const get_handler_args_t *args) { const char *url = args->url; - 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; + memset(out, 0, sizeof(parsed_consensus_request_t)); + out->flav = FLAV_NS; - time_t now = time(NULL); - const char *want_fps = NULL, *after_flavor = NULL; - char *flavor = NULL; - int 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; - flavor = tor_strndup(f, cp-f); + out->flavor = tor_strndup(f, cp-f); } else { - flavor = tor_strdup(f); + out->flavor = tor_strdup(f); } - flav = networkstatus_parse_flavor_name(flavor); + 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); @@ -3874,44 +3906,74 @@ handle_get_current_consensus(dir_connection_t *conn, const char *cp = strchr(after_flavor, '/'); if (cp) { diff_hash_in_url = tor_strndup(after_flavor, cp-after_flavor); - want_fps = cp+1; + out->want_fps = cp+1; } else { diff_hash_in_url = tor_strdup(after_flavor); - want_fps = NULL; + out->want_fps = NULL; } } else { - want_fps = after_flavor; + out->want_fps = after_flavor; } - struct consensus_cache_entry_t *cached_consensus = NULL; - smartlist_t *diff_from_digests = NULL; - compress_method_t compression_used = NO_METHOD; if (diff_hash_in_url) { uint8_t diff_from[DIGEST256_LEN]; - diff_from_digests = smartlist_new(); + out->diff_from_digests = smartlist_new(); + out->diff_only = 1; if (!parse_one_diff_hash(diff_from, diff_hash_in_url, "URL", "rejecting")) { - smartlist_add(diff_from_digests, tor_memdup(diff_from, DIGEST256_LEN)); + smartlist_add(out->diff_from_digests, + tor_memdup(diff_from, DIGEST256_LEN)); + } else { + return -1; } - } else if (!parse_or_diff_from_header(&diff_from_digests, args->headers)) { - tor_assert(diff_from_digests); + } else { + parse_or_diff_from_header(&out->diff_from_digests, args->headers); } - if (diff_from_digests) { - cached_consensus = find_best_diff(diff_from_digests, flav, + 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); + const char *want_fps = NULL; + parsed_consensus_request_t req; + + if (parse_consensus_request(&req, args) < 0) { + write_http_status_line(conn, 404, "Couldn't parse request"); + 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 (diff_hash_in_url && !cached_consensus) { + if (req.diff_only && !cached_consensus) { write_http_status_line(conn, 404, "No such diff available"); - // XXXX warn_consensus_is_too_old(v, flavor, now); + // 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(flav, + cached_consensus = find_best_consensus(req.flav, args->compression_supported, &compression_used); } @@ -3928,7 +3990,7 @@ handle_get_current_consensus(dir_connection_t *conn, if (cached_consensus && have_valid_until && !networkstatus_valid_until_is_reasonably_live(valid_until, now)) { write_http_status_line(conn, 404, "Consensus is too old"); - warn_consensus_is_too_old(cached_consensus, flavor, now); + warn_consensus_is_too_old(cached_consensus, req.flavor, now); geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND); goto done; } @@ -4014,8 +4076,7 @@ handle_get_current_consensus(dir_connection_t *conn, goto done; done: - tor_free(flavor); - tor_free(diff_hash_in_url); + parsed_consensus_request_clear(&req); if (clear_spool) { dir_conn_clear_spool(conn); }

1 0

[tor/master] Prop140, continued: accept "diff/<HASH>" in URLs, per proposal.
by nickm＠torproject.org 15 May '17

15 May '17

commit eb3c8d376dc240642f784830a9aec3fa95200764 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu May 4 10:53:22 2017 -0400 Prop140, continued: accept "diff/<HASH>" in URLs, per proposal. --- src/or/directory.c | 86 +++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 69 insertions(+), 17 deletions(-) diff --git a/src/or/directory.c b/src/or/directory.c index a5121eb..71ae274 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -3661,6 +3661,27 @@ warn_consensus_is_too_old(const struct consensus_cache_entry_t *consensus, } } +/** + * Parse a single hex-encoded sha3-256 digest from hex into + * digest. Return 0 on success. On failure, report that the hash came + * from location, report that we are taking action 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 headers, * set digest_out to a new smartlist containing every 256-bit * hex-encoded digest listed in that header and return 0. Otherwise return @@ -3678,13 +3699,9 @@ parse_or_diff_from_header(smartlist_t **digests_out, const char *headers) SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1); SMARTLIST_FOREACH_BEGIN(hex_digests, const char *, hex) { uint8_t digest[DIGEST256_LEN]; - if (base16_decode((char*)digest, sizeof(digest), hex, strlen(hex)) == - 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))); - } else { - log_fn(LOG_PROTOCOL_WARN, LD_DIR, - "X-Or-Diff-From-Consensus header contained bogus digest %s; " - "ignoring.", escaped(hex)); } } SMARTLIST_FOREACH_END(hex); SMARTLIST_FOREACH(hex_digests, char *, cp, tor_free(cp)); @@ -3821,18 +3838,20 @@ handle_get_current_consensus(dir_connection_t *conn, long lifetime = NETWORKSTATUS_CACHE_LIFETIME; time_t now = time(NULL); - const char *want_fps = NULL; + const char *want_fps = NULL, *after_flavor = NULL; char *flavor = NULL; int flav = FLAV_NS; -#define CONSENSUS_URL_PREFIX "/tor/status-vote/current/consensus/" -#define CONSENSUS_FLAVORED_PREFIX "/tor/status-vote/current/consensus-" + 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 */ if (!strcmpstart(url, CONSENSUS_FLAVORED_PREFIX)) { const char *f, *cp; f = url + strlen(CONSENSUS_FLAVORED_PREFIX); cp = strchr(f, '/'); if (cp) { - want_fps = cp+1; + after_flavor = cp+1; flavor = tor_strndup(f, cp-f); } else { flavor = tor_strdup(f); @@ -3842,19 +3861,53 @@ handle_get_current_consensus(dir_connection_t *conn, flav = FLAV_NS; } else { if (!strcmpstart(url, CONSENSUS_URL_PREFIX)) - want_fps = url+strlen(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); + want_fps = cp+1; + } else { + diff_hash_in_url = tor_strdup(after_flavor); + want_fps = NULL; + } + } else { + want_fps = after_flavor; } struct consensus_cache_entry_t *cached_consensus = NULL; smartlist_t *diff_from_digests = NULL; compress_method_t compression_used = NO_METHOD; - if (!parse_or_diff_from_header(&diff_from_digests, args->headers)) { + if (diff_hash_in_url) { + uint8_t diff_from[DIGEST256_LEN]; + diff_from_digests = smartlist_new(); + if (!parse_one_diff_hash(diff_from, diff_hash_in_url, "URL", + "rejecting")) { + smartlist_add(diff_from_digests, tor_memdup(diff_from, DIGEST256_LEN)); + } + } else if (!parse_or_diff_from_header(&diff_from_digests, args->headers)) { tor_assert(diff_from_digests); + } + + if (diff_from_digests) { cached_consensus = find_best_diff(diff_from_digests, flav, args->compression_supported, &compression_used); - SMARTLIST_FOREACH(diff_from_digests, uint8_t *, d, tor_free(d)); - smartlist_free(diff_from_digests); + } + + if (diff_hash_in_url && !cached_consensus) { + write_http_status_line(conn, 404, "No such diff available"); + // XXXX warn_consensus_is_too_old(v, flavor, now); + geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND); + goto done; } if (! cached_consensus) { @@ -3877,7 +3930,6 @@ handle_get_current_consensus(dir_connection_t *conn, write_http_status_line(conn, 404, "Consensus is too old"); warn_consensus_is_too_old(cached_consensus, flavor, now); geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND); - tor_free(flavor); goto done; } @@ -3886,7 +3938,6 @@ handle_get_current_consensus(dir_connection_t *conn, write_http_status_line(conn, 404, "Consensus not signed by sufficient " "number of requested authorities"); geoip_note_ns_response(GEOIP_REJECT_NOT_ENOUGH_SIGS); - tor_free(flavor); goto done; } @@ -3898,7 +3949,6 @@ handle_get_current_consensus(dir_connection_t *conn, spooled = spooled_resource_new_from_cache_entry(cached_consensus); smartlist_add(conn->spool, spooled); } - tor_free(flavor); } lifetime = (have_fresh_until && fresh_until > now) ? fresh_until - now : 0; @@ -3964,6 +4014,8 @@ handle_get_current_consensus(dir_connection_t *conn, goto done; done: + tor_free(flavor); + tor_free(diff_hash_in_url); if (clear_spool) { dir_conn_clear_spool(conn); }

1 0

[tor/master] Try not to mess up caches with the X-Or-Diff-From-Consensus header
by nickm＠torproject.org 15 May '17

15 May '17

commit da6b00443c266f1f0928ae02c3832123cbaa9455 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu May 4 11:25:33 2017 -0400 Try not to mess up caches with the X-Or-Diff-From-Consensus header --- src/or/directory.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/src/or/directory.c b/src/or/directory.c index 4537d79..aca3030 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -3288,8 +3288,9 @@ write_http_response_header_impl(dir_connection_t *conn, ssize_t length, /** As write_http_response_header_impl, but sets encoding and content-typed * based on whether the response will be compressed or not. */ static void -write_http_response_header(dir_connection_t *conn, ssize_t length, - compress_method_t method, long cache_lifetime) +write_http_response_headers(dir_connection_t *conn, ssize_t length, + compress_method_t method, + const char *extra_headers, long cache_lifetime) { const char *methodname = compression_method_get_name(method); const char *doctype; @@ -3300,10 +3301,19 @@ write_http_response_header(dir_connection_t *conn, ssize_t length, write_http_response_header_impl(conn, length, doctype, methodname, - NULL, + 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[] = { @@ -4056,14 +4066,19 @@ handle_get_current_consensus(dir_connection_t *conn, 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_header(conn, -1, + 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)

1 0

[tor/master] Dircache protocol version 2 adds support for diffs
by nickm＠torproject.org 15 May '17

15 May '17

commit f9d8ade91242a702589e4e2ff2a280836fabb4da Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu May 4 11:39:39 2017 -0400 Dircache protocol version 2 adds support for diffs --- src/or/protover.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/or/protover.c b/src/or/protover.c index ee58927..1a3e69b 100644 --- a/src/or/protover.c +++ b/src/or/protover.c @@ -288,7 +288,7 @@ protover_get_supported_protocols(void) return "Cons=1-2 " "Desc=1-2 " - "DirCache=1 " + "DirCache=1-2 " "HSDir=1-2 " "HSIntro=3-4 " "HSRend=1-2 "

1 0

[tor/master] Test fix: always set address in new_dir_conn()
by nickm＠torproject.org 15 May '17

15 May '17

commit e1b3c1bbec0e78a41a79ed2d34abfb4a091393ea Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 15 18:00:38 2017 -0400 Test fix: always set address in new_dir_conn() --- src/test/test_dir_handle_get.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/src/test/test_dir_handle_get.c b/src/test/test_dir_handle_get.c index 7d40db4..75fe624 100644 --- a/src/test/test_dir_handle_get.c +++ b/src/test/test_dir_handle_get.c @@ -64,6 +64,7 @@ new_dir_conn(void) { dir_connection_t *conn = dir_connection_new(AF_INET); tor_addr_from_ipv4h(&conn->base_.addr, 0x7f000001); + TO_CONN(conn)->address = tor_strdup("127.0.0.1"); return conn; } @@ -1718,7 +1719,6 @@ test_dir_handle_get_status_vote_current_consensus_too_old(void *data) MOCK(networkstatus_get_latest_consensus_by_flavor, mock_ns_get_by_flavor); conn = new_dir_conn(); - TO_CONN(conn)->address = tor_strdup("127.0.0.1"); setup_capture_of_logs(LOG_WARN); @@ -1815,7 +1815,6 @@ status_vote_current_consensus_ns_test(char **header, char **body, tt_str_op("ab", OP_EQ, geoip_get_country_name(1)); conn = new_dir_conn(); - TO_CONN(conn)->address = tor_strdup("127.0.0.1"); tt_int_op(0, OP_EQ, directory_handle_command_get(conn, GET("/tor/status-vote/current/consensus-ns"), NULL, 0));

1 0

[tor/master] Merge branch 'prop140_aftermath_url_v3'
by nickm＠torproject.org 15 May '17

15 May '17

commit 6e2eb0afdb34955583ed231058adbe06c4625b0f Merge: afef059 e1b3c1b Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 15 18:05:32 2017 -0400 Merge branch 'prop140_aftermath_url_v3' src/or/directory.c | 210 +++++++++++++++++++++++++++++++++-------- src/or/protover.c | 2 +- src/test/test_dir_handle_get.c | 3 +- 3 files changed, 171 insertions(+), 44 deletions(-)

1 0

[tor/master] fix a memory leak
by nickm＠torproject.org 15 May '17

15 May '17

commit 460b9230263f0af40c08d8e97f5f13aa69127bf6 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 15 18:13:20 2017 -0400 fix a memory leak --- src/or/consdiffmgr.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/or/consdiffmgr.c b/src/or/consdiffmgr.c index 068f9c5..72a4f01 100644 --- a/src/or/consdiffmgr.c +++ b/src/or/consdiffmgr.c @@ -1758,6 +1758,7 @@ consensus_queue_compression_work(const char *consensus, config_line_prepend(&job->labels_in, LABEL_SIGNATORIES, signers); tor_free(signers); SMARTLIST_FOREACH(hexvoters, char *, cp, tor_free(cp)); + smartlist_free(hexvoters); } if (background_compression) {

1 0

[tor/master] remove a variable I missed
by nickm＠torproject.org 15 May '17

15 May '17

commit 294d80044dab3c682f61b239c79be3c261bcd0f2 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 15 18:16:58 2017 -0400 remove a variable I missed --- src/or/directory.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/src/or/directory.c b/src/or/directory.c index 15f7491..d954c06 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -3958,7 +3958,6 @@ handle_get_current_consensus(dir_connection_t *conn, long lifetime = NETWORKSTATUS_CACHE_LIFETIME; time_t now = time(NULL); - const char *want_fps = NULL; parsed_consensus_request_t req; if (parse_consensus_request(&req, args) < 0) { @@ -4005,8 +4004,8 @@ handle_get_current_consensus(dir_connection_t *conn, goto done; } - if (cached_consensus && want_fps && - !client_likes_consensus(cached_consensus, want_fps)) { + if (cached_consensus && req.want_fps && + !client_likes_consensus(cached_consensus, req.want_fps)) { write_http_status_line(conn, 404, "Consensus not signed by sufficient " "number of requested authorities"); geoip_note_ns_response(GEOIP_REJECT_NOT_ENOUGH_SIGS);

1 0

[tor/master] Do not try to uncompress an empty spool
by nickm＠torproject.org 15 May '17

15 May '17

commit d3279d4304f5ebae0d1612e6c16d20e27b8e8790 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 15 18:13:38 2017 -0400 Do not try to uncompress an empty spool --- src/or/directory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/or/directory.c b/src/or/directory.c index aca3030..15f7491 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -4081,7 +4081,7 @@ handle_get_current_consensus(dir_connection_t *conn, vary_header, smartlist_len(conn->spool) == 1 ? lifetime : 0); - if (compress_method == NO_METHOD) + if (compress_method == NO_METHOD && smartlist_len(conn->spool)) conn->compress_state = tor_compress_new(0, compression_used, HIGH_COMPRESSION);

1 0

[tor/master] prop140 clients now only try to get diffs from recent consensuses
by nickm＠torproject.org 15 May '17

15 May '17

commit c9855928744a556ef882ef8409ba8b54afd11834 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu May 4 12:15:48 2017 -0400 prop140 clients now only try to get diffs from recent consensuses Rationale: If it's a year old, the relay won't have a diff to it. This is as specified in prop140 --- src/or/directory.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/src/or/directory.c b/src/or/directory.c index 67c28e1..20ff537 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -497,11 +497,23 @@ dir_consensus_request_set_additional_headers(directory_request_t *req, * period of 1 hour. */ const int DEFAULT_IF_MODIFIED_SINCE_DELAY = 180; + const int32_t DEFAULT_TRY_DIFF_FOR_CONSENSUS_NEWER = 72; + const int32_t MIN_TRY_DIFF_FOR_CONSENSUS_NEWER = 0; + const int32_t MAX_TRY_DIFF_FOR_CONSENSUS_NEWER = 8192; + const char TRY_DIFF_FOR_CONSENSUS_NEWER_NAME[] = + "try-diff-for-consensus-newer-than"; int flav = FLAV_NS; if (resource) flav = networkstatus_parse_flavor_name(resource); + int32_t max_age_for_diff = 3600 * + networkstatus_get_param(NULL, + TRY_DIFF_FOR_CONSENSUS_NEWER_NAME, + DEFAULT_TRY_DIFF_FOR_CONSENSUS_NEWER, + MIN_TRY_DIFF_FOR_CONSENSUS_NEWER, + MAX_TRY_DIFF_FOR_CONSENSUS_NEWER); + if (flav != -1) { /* IF we have a parsed consensus of this type, we can do an * if-modified-time based on it. */ @@ -517,8 +529,10 @@ dir_consensus_request_set_additional_headers(directory_request_t *req, ims_delay = (v->fresh_until - v->valid_after)/2; } if_modified_since = v->valid_after + ims_delay; - memcpy(or_diff_from, v->digest_sha3_as_signed, DIGEST256_LEN); - or_diff_from_is_set = 1; + if (v->valid_after >= approx_time() - max_age_for_diff) { + memcpy(or_diff_from, v->digest_sha3_as_signed, DIGEST256_LEN); + or_diff_from_is_set = 1; + } } } else { /* Otherwise it might be a consensus we don't parse, but which we @@ -528,8 +542,10 @@ dir_consensus_request_set_additional_headers(directory_request_t *req, * unparsed consensus, so we use the default. */ if (cd) { if_modified_since = cd->published + DEFAULT_IF_MODIFIED_SINCE_DELAY; - memcpy(or_diff_from, cd->digest_sha3_as_signed, DIGEST256_LEN); - or_diff_from_is_set = 1; + if (cd->published >= approx_time() - max_age_for_diff) { + memcpy(or_diff_from, cd->digest_sha3_as_signed, DIGEST256_LEN); + or_diff_from_is_set = 1; + } } }

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