commit 1dc21b87904b527140446674876076f29c78b89f Author: George Kadianakis desnacked@riseup.net Date: Wed Aug 30 15:29:41 2017 +0300

prop224: Simplify HSDir set change algo.

Our logic for detecting hsdir set changes was needlessly compicated: we had to sort smartlists and compare them.

Instead, we can simplify things by employing the following logic: "We should reupload our descriptor if the latest HSDir set contains nodes that were not previously there" --- src/or/hs_service.c | 32 +++++++++++--------------------- src/or/hs_service.h | 2 +- 2 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/src/or/hs_service.c b/src/or/hs_service.c index 5ff118222..0fba0d7f9 100644 --- a/src/or/hs_service.c +++ b/src/or/hs_service.c @@ -1546,7 +1546,6 @@ service_desc_note_upload(hs_service_descriptor_t *desc, const node_t *hsdir)

if (!smartlist_contains_string(desc->previous_hsdirs, b64_digest)) { smartlist_add_strdup(desc->previous_hsdirs, b64_digest); - smartlist_sort_strings(desc->previous_hsdirs); } }

@@ -2366,9 +2365,8 @@ STATIC int service_desc_hsdirs_changed(const hs_service_t *service, const hs_service_descriptor_t *desc) { - int retval = 0; + int should_reupload = 0; smartlist_t *responsible_dirs = smartlist_new(); - smartlist_t *b64_responsible_dirs = smartlist_new();

/* No desc upload has happened yet: it will happen eventually */ if (!desc->previous_hsdirs || !smartlist_len(desc->previous_hsdirs)) { @@ -2379,32 +2377,24 @@ service_desc_hsdirs_changed(const hs_service_t *service, hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num, service->desc_next == desc, 0, responsible_dirs);

- /* Make a second list with their b64ed identity digests, so that we can - * compare it with out previous list of hsdirs */ + /* Check if any new hsdirs have been added to the responsible hsdirs set: + * Iterate over the list of new hsdirs, and reupload if any of them is not + * present in the list of previous hsdirs. + */ SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *, hsdir_rs) { char b64_digest[BASE64_DIGEST_LEN+1] = {0}; digest_to_base64(b64_digest, hsdir_rs->identity_digest); - smartlist_add_strdup(b64_responsible_dirs, b64_digest); - } SMARTLIST_FOREACH_END(hsdir_rs); - - /* Sort this new smartlist so that we can compare it with the other one */ - smartlist_sort_strings(b64_responsible_dirs);

- /* Check whether the set of HSDirs changed */ - if (!smartlist_strings_eq(b64_responsible_dirs, desc->previous_hsdirs)) { - log_info(LD_GENERAL, "Received new dirinfo and set of hsdirs changed!"); - retval = 1; - } else { - log_debug(LD_GENERAL, "No change in hsdir set!"); - } + if (!smartlist_contains_string(desc->previous_hsdirs, b64_digest)) { + should_reupload = 1; + break; + } + } SMARTLIST_FOREACH_END(hsdir_rs);

done: smartlist_free(responsible_dirs);

- SMARTLIST_FOREACH(b64_responsible_dirs, char*, s, tor_free(s)); - smartlist_free(b64_responsible_dirs); - - return retval; + return should_reupload; }

/* Return 1 if the given descriptor from the given service can be uploaded diff --git a/src/or/hs_service.h b/src/or/hs_service.h index 57717fc92..26f0bc000 100644 --- a/src/or/hs_service.h +++ b/src/or/hs_service.h @@ -133,7 +133,7 @@ typedef struct hs_service_descriptor_t { /** List of the responsible HSDirs (their b64ed identity digest) last time we * uploaded this descriptor. If the set of responsible HSDirs is different * from this list, this means we received new dirinfo and we need to - * reupload our descriptor. This list is always sorted lexicographically. */ + * reupload our descriptor. */ smartlist_t *previous_hsdirs; } hs_service_descriptor_t;