Avoid duplicate downloads by (fp,sk) and by fp for authority certs when bootstrapping (4f7daf11) · Commits · Legacy / gitolite / user / andrea / Tor

src/or/routerlist.c

+70 −29

Original line number	Diff line number	Diff line
		@@ -660,8 +660,57 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now)
		missing_cert_digests = smartlist_new();
		missing_id_digests = smartlist_new();

		/*
		* First, we get the lists of already pending downloads so we don't
		* duplicate effort.
		*/
		list_pending_downloads(pending_id, DIR_PURPOSE_FETCH_CERTIFICATE, "fp/");
		list_pending_fpsk_downloads(pending_cert);

		/*
		* Now, we download any trusted authority certs we don't have by
		* identity digest only. This gets the latest cert for that authority.
		*/
		SMARTLIST_FOREACH_BEGIN(trusted_dir_servers, trusted_dir_server_t *, ds) {
		int found = 0;
		if (!(ds->type & V3_DIRINFO))
		continue;
		if (smartlist_digest_isin(missing_id_digests, ds->v3_identity_digest))
		continue;
		cl = get_cert_list(ds->v3_identity_digest);
		SMARTLIST_FOREACH_BEGIN(cl->certs, authority_cert_t *, cert) {
		if (now < cert->expires) {
		/* It's not expired, and we weren't looking for something to
		* verify a consensus with. Call it done. */
		download_status_reset(&(cl->dl_status_by_id));
		/* No sense trying to download it specifically by signing key hash */
		download_status_reset_by_sk_in_cl(cl, cert->signing_key_digest);
		found = 1;
		break;
		}
		} SMARTLIST_FOREACH_END(cert);
		if (!found &&
		download_status_is_ready(&(cl->dl_status_by_id), now,
		MAX_CERT_DL_FAILURES) &&
		!digestmap_get(pending_id, ds->v3_identity_digest)) {
		log_info(LD_DIR,
		"No current certificate known for authority %s "
		"(ID digest %s); launching request.",
		ds->nickname, hex_str(ds->v3_identity_digest, DIGEST_LEN));
		smartlist_add(missing_id_digests, ds->v3_identity_digest);
		}
		} SMARTLIST_FOREACH_END(ds);

		/*
		* Next, if we have a consensus, scan through it and look for anything
		* signed with a key from a cert we don't have. Those get downloaded
		* by (fp,sk) pair, but if we don't know any certs at all for the fp
		* (identity digest), and it's one of the trusted dir server certs
		* we started off above or a pending download in pending_id, don't
		* try to get it yet. Most likely, the one we'll get for that will
		* have the right signing key too, and we'd just be downloading
		* redundantly.
		*/
		if (status) {
		SMARTLIST_FOREACH_BEGIN(status->voters, networkstatus_voter_info_t *,
		voter) {
		@@ -671,7 +720,28 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now)
		if (!cache &&
		!trusteddirserver_get_by_v3_auth_digest(voter->identity_digest))
		continue; /* We are not a cache, and we don't know this authority.*/

		/*
		* If we don't know any cert for this authority, and a download by ID
		* is pending or we added it to missing_id_digests above, skip this
		* one for now to avoid duplicate downloads.
		*/
		cl = get_cert_list(voter->identity_digest);
		if (smartlist_len(cl->certs) == 0) {
		/* We have no certs at all for this one */

		/* Do we have a download of one pending? */
		if (digestmap_get(pending_id, voter->identity_digest))
		continue;

		/*
		* Are we about to launch a download of one due to the trusted
		* dir server check above?
		*/
		if (smartlist_digest_isin(missing_id_digests, voter->identity_digest))
		continue;
		}

		SMARTLIST_FOREACH_BEGIN(voter->sigs, document_signature_t *, sig) {
		cert = authority_cert_get_by_digests(voter->identity_digest,
		sig->signing_key_digest);
		@@ -718,35 +788,6 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now)
		} SMARTLIST_FOREACH_END(sig);
		} SMARTLIST_FOREACH_END(voter);
		}
		SMARTLIST_FOREACH_BEGIN(trusted_dir_servers, trusted_dir_server_t *, ds) {
		int found = 0;
		if (!(ds->type & V3_DIRINFO))
		continue;
		if (smartlist_digest_isin(missing_id_digests, ds->v3_identity_digest))
		continue;
		cl = get_cert_list(ds->v3_identity_digest);
		SMARTLIST_FOREACH(cl->certs, authority_cert_t *, cert, {
		if (now < cert->expires) {
		/* It's not expired, and we weren't looking for something to
		* verify a consensus with. Call it done. */
		download_status_reset(&(cl->dl_status_by_id));
		/* No sense trying to download it specifically by signing key hash */
		download_status_reset_by_sk_in_cl(cl, cert->signing_key_digest);
		found = 1;
		break;
		}
		});
		if (!found &&
		download_status_is_ready(&(cl->dl_status_by_id), now,
		MAX_CERT_DL_FAILURES) &&
		!digestmap_get(pending_id, ds->v3_identity_digest)) {
		log_info(LD_DIR,
		"No current certificate known for authority %s "
		"(ID digest %s); launching request.",
		ds->nickname, hex_str(ds->v3_identity_digest, DIGEST_LEN));
		smartlist_add(missing_id_digests, ds->v3_identity_digest);
		}
		} SMARTLIST_FOREACH_END(ds);

		/* Do downloads by identity digest */
		if (smartlist_len(missing_id_digests) > 0) {