diff options
| -rw-r--r-- | changes/bug6177 | 3 | ||||
| -rw-r--r-- | src/or/Makefile.am | 1 | ||||
| -rw-r--r-- | src/or/replaycache.c | 215 | ||||
| -rw-r--r-- | src/or/replaycache.h | 66 | ||||
| -rw-r--r-- | src/test/Makefile.am | 1 | ||||
| -rw-r--r-- | src/test/test.c | 2 | ||||
| -rw-r--r-- | src/test/test_replay.c | 184 |
7 files changed, 472 insertions, 0 deletions
diff --git a/changes/bug6177 b/changes/bug6177 new file mode 100644 index 0000000000..c900c27bdd --- /dev/null +++ b/changes/bug6177 @@ -0,0 +1,3 @@ + o Minor features: + - Add replaycache_t structure, functions and unit tests, for future use + in refactoring rend_service_introduce() for bug 6177. diff --git a/src/or/Makefile.am b/src/or/Makefile.am index 3cc789a1be..70a0cb02dc 100644 --- a/src/or/Makefile.am +++ b/src/or/Makefile.am @@ -48,6 +48,7 @@ libtor_a_SOURCES = \ rendmid.c \ rendservice.c \ rephist.c \ + replaycache.c \ router.c \ routerlist.c \ routerparse.c \ diff --git a/src/or/replaycache.c b/src/or/replaycache.c new file mode 100644 index 0000000000..09104a9373 --- /dev/null +++ b/src/or/replaycache.c @@ -0,0 +1,215 @@ + /* Copyright (c) 2012, The Tor Project, Inc. */ + /* See LICENSE for licensing information */ + +/* + * \file replaycache.c + * + * \brief Self-scrubbing replay cache for rendservice.c + */ + +#define REPLAYCACHE_PRIVATE + +#include "or.h" +#include "replaycache.h" + +/** Free the replaycache r and all of its entries. + */ + +void +replaycache_free(replaycache_t *r) +{ + if (!r) { + log_info(LD_BUG, "replaycache_free() called on NULL"); + return; + } + + if (r->digests_seen) digestmap_free(r->digests_seen, _tor_free); + + tor_free(r); +} + +/** Allocate a new, empty replay detection cache, where horizon is the time + * for entries to age out and interval is the time after which the cache + * should be scrubbed for old entries. + */ + +replaycache_t * +replaycache_new(time_t horizon, time_t interval) +{ + replaycache_t *r = NULL; + + if (horizon < 0) { + log_info(LD_BUG, "replaycache_new() called with negative" + " horizon parameter"); + goto err; + } + + if (interval < 0) { + log_info(LD_BUG, "replaycache_new() called with negative interval" + " parameter"); + interval = 0; + } + + r = tor_malloc(sizeof(*r)); + r->scrub_interval = interval; + r->scrubbed = 0; + r->horizon = horizon; + r->digests_seen = digestmap_new(); + + err: + return r; +} + +/** See documentation for replaycache_add_and_test() + */ + +int +replaycache_add_and_test_internal( + time_t present, replaycache_t *r, const void *data, int len, + time_t *elapsed) +{ + int rv = 0; + char digest[DIGEST_LEN]; + time_t *access_time; + + /* sanity check */ + if (present <= 0 || !r || !data || len <= 0) { + log_info(LD_BUG, "replaycache_add_and_test_internal() called with stupid" + " parameters; please fix this."); + goto done; + } + + /* compute digest */ + crypto_digest(digest, (const char *)data, len); + + /* check map */ + access_time = digestmap_get(r->digests_seen, digest); + + /* seen before? */ + if (access_time != NULL) { + /* + * If it's far enough in the past, no hit. If the horizon is zero, we + * never expire. + */ + if (*access_time >= present - r->horizon || r->horizon == 0) { + /* replay cache hit, return 1 */ + rv = 1; + /* If we want to output an elapsed time, do so */ + if (elapsed) { + if (present >= *access_time) { + *elapsed = present - *access_time; + } else { + /* We shouldn't really be seeing hits from the future, but... */ + *elapsed = 0; + } + } + } + /* + * If it's ahead of the cached time, update + */ + if (*access_time < present) { + *access_time = present; + } + } else { + /* No, so no hit and update the digest map with the current time */ + access_time = tor_malloc(sizeof(*access_time)); + *access_time = present; + digestmap_set(r->digests_seen, digest, access_time); + } + + /* now scrub the cache if it's time */ + replaycache_scrub_if_needed_internal(present, r); + + done: + return rv; +} + +/** See documentation for replaycache_scrub_if_needed() + */ + +void +replaycache_scrub_if_needed_internal(time_t present, replaycache_t *r) +{ + digestmap_iter_t *itr = NULL; + const char *digest; + void *valp; + time_t *access_time; + char scrub_this; + + /* sanity check */ + if (!r || !(r->digests_seen)) { + log_info(LD_BUG, "replaycache_scrub_if_needed_internal() called with" + " stupid parameters; please fix this."); + return; + } + + /* scrub time yet? (scrubbed == 0 indicates never scrubbed before) */ + if (present - r->scrubbed < r->scrub_interval && r->scrubbed > 0) return; + + /* if we're never expiring, don't bother scrubbing */ + if (r->horizon == 0) return; + + /* okay, scrub time */ + itr = digestmap_iter_init(r->digests_seen); + while (!digestmap_iter_done(itr)) { + scrub_this = 0; + digestmap_iter_get(itr, &digest, &valp); + access_time = (time_t *)valp; + if (access_time) { + /* aged out yet? */ + if (*access_time < present - r->horizon) scrub_this = 1; + } else { + /* Buh? Get rid of it, anyway */ + log_info(LD_BUG, "replaycache_scrub_if_needed_internal() saw a NULL" + " entry in the digestmap."); + scrub_this = 1; + } + + if (scrub_this) { + /* Advance the iterator and remove this one */ + itr = digestmap_iter_next_rmv(r->digests_seen, itr); + /* Free the value removed */ + tor_free(access_time); + } else { + /* Just advance the iterator */ + itr = digestmap_iter_next(r->digests_seen, itr); + } + } + + /* update scrubbed timestamp */ + if (present > r->scrubbed) r->scrubbed = present; +} + +/** Test the buffer of length len point to by data against the replay cache r; + * the digest of the buffer will be added to the cache at the current time, + * and the function will return 1 if it was already seen within the cache's + * horizon, or 0 otherwise. + */ + +int +replaycache_add_and_test(replaycache_t *r, const void *data, int len) +{ + return replaycache_add_and_test_internal(time(NULL), r, data, len, NULL); +} + +/** Like replaycache_add_and_test(), but if it's a hit also return the time + * elapsed since this digest was last seen. + */ + +int +replaycache_add_test_and_elapsed( + replaycache_t *r, const void *data, int len, time_t *elapsed) +{ + return replaycache_add_and_test_internal(time(NULL), r, data, len, elapsed); +} + +/** Scrub aged entries out of r if sufficiently long has elapsed since r was + * last scrubbed. + */ + +void +replaycache_scrub_if_needed(replaycache_t *r) +{ + replaycache_scrub_if_needed_internal(time(NULL), r); +} + diff --git a/src/or/replaycache.h b/src/or/replaycache.h new file mode 100644 index 0000000000..9f3107c513 --- /dev/null +++ b/src/or/replaycache.h @@ -0,0 +1,66 @@ +/* Copyright (c) 2012, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file replaycache.h + * \brief Header file for replaycache.c. + **/ + +#ifndef _TOR_REPLAYCACHE_H +#define _TOR_REPLAYCACHE_H + +typedef struct replaycache_s replaycache_t; + +#ifdef REPLAYCACHE_PRIVATE + +struct replaycache_s { + /* Scrub interval */ + time_t scrub_interval; + /* Last scrubbed */ + time_t scrubbed; + /* + * Horizon + * (don't return true on digests in the cache but older than this) + */ + time_t horizon; + /* + * Digest map: keys are digests, values are times the digest was last seen + */ + digestmap_t *digests_seen; +}; + +#endif /* REPLAYCACHE_PRIVATE */ + +/* replaycache_t free/new */ + +void replaycache_free(replaycache_t *r); +replaycache_t * replaycache_new(time_t horizon, time_t interval); + +#ifdef REPLAYCACHE_PRIVATE + +/* + * replaycache_t internal functions: + * + * These take the time to treat as the present as an argument for easy unit + * testing. For everything else, use the wrappers below instead. + */ + +int replaycache_add_and_test_internal( + time_t present, replaycache_t *r, const void *data, int len, + time_t *elapsed); +void replaycache_scrub_if_needed_internal( + time_t present, replaycache_t *r); + +#endif /* REPLAYCACHE_PRIVATE */ + +/* + * replaycache_t methods + */ + +int replaycache_add_and_test(replaycache_t *r, const void *data, int len); +int replaycache_add_test_and_elapsed( + replaycache_t *r, const void *data, int len, time_t *elapsed); +void replaycache_scrub_if_needed(replaycache_t *r); + +#endif + diff --git a/src/test/Makefile.am b/src/test/Makefile.am index 31a464ee7a..3606686df2 100644 --- a/src/test/Makefile.am +++ b/src/test/Makefile.am @@ -20,6 +20,7 @@ test_SOURCES = \ test_dir.c \ test_microdesc.c \ test_pt.c \ + test_replay.c \ test_util.c \ test_config.c \ tinytest.c diff --git a/src/test/test.c b/src/test/test.c index 6bf2d28d90..1162b5c74f 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -1863,6 +1863,7 @@ extern struct testcase_t dir_tests[]; extern struct testcase_t microdesc_tests[]; extern struct testcase_t pt_tests[]; extern struct testcase_t config_tests[]; +extern struct testcase_t replaycache_tests[]; static struct testgroup_t testgroups[] = { { "", test_array }, @@ -1875,6 +1876,7 @@ static struct testgroup_t testgroups[] = { { "dir/md/", microdesc_tests }, { "pt/", pt_tests }, { "config/", config_tests }, + { "replaycache/", replaycache_tests }, END_OF_GROUPS }; diff --git a/src/test/test_replay.c b/src/test/test_replay.c new file mode 100644 index 0000000000..217b5554d5 --- /dev/null +++ b/src/test/test_replay.c @@ -0,0 +1,184 @@ +/* Copyright (c) 2012, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#define REPLAYCACHE_PRIVATE + +#include "orconfig.h" +#include "or.h" +#include "replaycache.h" +#include "test.h" + +static const char *test_buffer = + "Lorem ipsum dolor sit amet, consectetur adipisici elit, sed do eiusmod" + " tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim" + " veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea" + " commodo consequat. Duis aute irure dolor in reprehenderit in voluptate" + " velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint" + " occaecat cupidatat non proident, sunt in culpa qui officia deserunt" + " mollit anim id est laborum."; + +static void +test_replaycache_alloc(void) +{ + replaycache_t *r = NULL; + + r = replaycache_new(600, 300); + test_assert(r != NULL); + if (!r) goto done; + + done: + if (r) replaycache_free(r); + + return; +} + +static void +test_replaycache_miss(void) +{ + replaycache_t *r = NULL; + int result; + + r = replaycache_new(600, 300); + test_assert(r != NULL); + if (!r) goto done; + + result = + replaycache_add_and_test_internal(1200, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 0); + + done: + if (r) replaycache_free(r); + + return; +} + +static void +test_replaycache_hit(void) +{ + replaycache_t *r = NULL; + int result; + + r = replaycache_new(600, 300); + test_assert(r != NULL); + if (!r) goto done; + + result = + replaycache_add_and_test_internal(1200, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 0); + + result = + replaycache_add_and_test_internal(1300, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 1); + + done: + if (r) replaycache_free(r); + + return; +} + +static void +test_replaycache_age(void) +{ + replaycache_t *r = NULL; + int result; + + r = replaycache_new(600, 300); + test_assert(r != NULL); + if (!r) goto done; + + result = + replaycache_add_and_test_internal(1200, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 0); + + result = + replaycache_add_and_test_internal(1300, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 1); + + result = + replaycache_add_and_test_internal(3000, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 0); + + done: + if (r) replaycache_free(r); + + return; +} + +static void +test_replaycache_elapsed(void) +{ + replaycache_t *r = NULL; + int result; + time_t elapsed; + + r = replaycache_new(600, 300); + test_assert(r != NULL); + if (!r) goto done; + + result = + replaycache_add_and_test_internal(1200, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 0); + + result = + replaycache_add_and_test_internal(1300, r, test_buffer, + strlen(test_buffer), &elapsed); + test_eq(result, 1); + test_eq(elapsed, 100); + + done: + if (r) replaycache_free(r); + + return; +} + +static void +test_replaycache_noexpire(void) +{ + replaycache_t *r = NULL; + int result; + + r = replaycache_new(0, 0); + test_assert(r != NULL); + if (!r) goto done; + + result = + replaycache_add_and_test_internal(1200, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 0); + + result = + replaycache_add_and_test_internal(1300, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 1); + + result = + replaycache_add_and_test_internal(3000, r, test_buffer, + strlen(test_buffer), NULL); + test_eq(result, 1); + + done: + if (r) replaycache_free(r); + + return; +} + +#define REPLAYCACHE_LEGACY(name) \ + { #name, legacy_test_helper, 0, &legacy_setup, test_replaycache_ ## name } + +struct testcase_t replaycache_tests[] = { + REPLAYCACHE_LEGACY(alloc), + REPLAYCACHE_LEGACY(miss), + REPLAYCACHE_LEGACY(hit), + REPLAYCACHE_LEGACY(age), + REPLAYCACHE_LEGACY(elapsed), + REPLAYCACHE_LEGACY(noexpire), + END_OF_TESTCASES +}; + |