commit 1cde3e2776dc879ce7ca876e0616d8d10d6f1702 Author: Andrea Shepard andrea@torproject.org Date: Fri Jun 17 22:35:58 2016 +0000

Add multiple descriptor dump support for dump_desc() in routerparse.c; fixes bug 18322 --- src/or/config.c | 1 + src/or/main.c | 1 + src/or/or.h | 5 ++ src/or/routerparse.c | 211 ++++++++++++++++++++++++++++++++++++++++++++++++--- src/or/routerparse.h | 2 + 5 files changed, 211 insertions(+), 9 deletions(-)

diff --git a/src/or/config.c b/src/or/config.c index cdd4f10..275be28 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -212,6 +212,7 @@ static config_var_t option_vars_[] = { V(CountPrivateBandwidth, BOOL, "0"), V(DataDirectory, FILENAME, NULL), V(DataDirectoryGroupReadable, BOOL, "0"), + V(DetailedLogForUnparseableDescriptors, MEMUNIT, "0 bytes"), V(DisableNetwork, BOOL, "0"), V(DirAllowPrivateAddresses, BOOL, "0"), V(TestingAuthDirTimeToLearnReachability, INTERVAL, "30 minutes"), diff --git a/src/or/main.c b/src/or/main.c index 4de2e70..3291570 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -3146,6 +3146,7 @@ tor_free_all(int postfork) scheduler_free_all(); nodelist_free_all(); microdesc_free_all(); + routerparse_free_all(); ext_orport_free_all(); control_free_all(); sandbox_free_getaddrinfo_cache(); diff --git a/src/or/or.h b/src/or/or.h index ea38022..364699f 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -4498,6 +4498,11 @@ typedef struct {

/** Autobool: Do we try to retain capabilities if we can? */ int KeepBindCapabilities; + + /** If > 0, maximum total size of unparseable descriptors to log + * during the lifetime of this Tor process. + */ + uint64_t DetailedLogForUnparseableDescriptors; } or_options_t;

/** Persistent state for an onion router, as saved to disk. */ diff --git a/src/or/routerparse.c b/src/or/routerparse.c index 6550fa6..5ad6549 100644 --- a/src/or/routerparse.c +++ b/src/or/routerparse.c @@ -587,6 +587,99 @@ static int check_signature_token(const char *digest,

/** Last time we dumped a descriptor to disk. */ static time_t last_desc_dumped = 0; +/** List of dumped descriptors for FIFO cleanup purposes */ +static smartlist_t *descs_dumped = NULL; +/** Total size of dumped descriptors for FIFO cleanup */ +static size_t len_descs_dumped = 0; + +typedef struct { + char *filename; + size_t len; + time_t timestamp; +} dumped_desc_t; + +/** Dump desc FIFO/cleanup; take ownership of the given filename, add it to + * the FIFO, and clean up the oldest entries to the extent they exceed the + * configured cap. */ +static void +dump_desc_fifo_add_and_clean(char *filename, size_t len, time_t now) +{ + dumped_desc_t *ent = NULL, *tmp; + size_t max_len; + + if (descs_dumped == NULL) { + /* We better have no length, then */ + tor_assert(len_descs_dumped == 0); + /* Make a smartlist */ + descs_dumped = smartlist_new(); + } + + /* Make a new entry to put this one in */ + ent = tor_malloc_zero(sizeof(*ent)); + ent->filename = filename; + ent->len = len; + ent->timestamp = now; + + /* Do we need to do some cleanup? */ + if (get_options()->DetailedLogForUnparseableDescriptors > 0) { + max_len = get_options()->DetailedLogForUnparseableDescriptors; + /* Iterate over the list until we've freed enough space */ + while (len_descs_dumped + len > max_len && + smartlist_len(descs_dumped) > 0) { + /* Get the oldest thing on the list */ + tmp = (dumped_desc_t *)(smartlist_get(descs_dumped, 0)); + /* + * Check if it matches the filename we just added, so we don't + * delete something we just emitted if we get repeated identical + * descriptors. + */ + if (strcmp(tmp->filename, filename) != 0) { + /* Delete it and adjust the length counter */ + unlink(tmp->filename); + tor_assert(len_descs_dumped >= tmp->len); + len_descs_dumped -= tmp->len; + log_info(LD_DIR, "Deleting old unparseable descriptor dump %s due to " + "space limits", tmp->filename); + } else { + /* + * Don't delete, but do adjust the counter since we will bump it + * later + */ + tor_assert(len_descs_dumped >= tmp->len); + len_descs_dumped -= tmp->len; + log_info(LD_DIR, "Replacing old descriptor dump %s with new identical" + " one", tmp->filename); + } + /* Free it and remove it from the list */ + smartlist_del_keeporder(descs_dumped, 0); + tor_free(tmp->filename); + tor_free(tmp); + } + } + + /* Append our entry to the end of the list and bump the counter */ + smartlist_add(descs_dumped, ent); + len_descs_dumped += len; +} + +/** Clean up on exit; just memory, leave the dumps behind + */ +static void +dump_desc_fifo_cleanup(void) +{ + if (descs_dumped) { + /* Free each descriptor */ + SMARTLIST_FOREACH_BEGIN(descs_dumped, dumped_desc_t *, ent) { + tor_assert(ent); + tor_free(ent->filename); + tor_free(ent); + } SMARTLIST_FOREACH_END(ent); + /* Free the list */ + smartlist_free(descs_dumped); + descs_dumped = NULL; + len_descs_dumped = 0; + } +}

/** For debugging purposes, dump unparseable descriptor *<b>desc</b> of * type *<b>type</b> to file $DATADIR/unparseable-desc. Do not write more @@ -598,19 +691,112 @@ dump_desc(const char *desc, const char *type) time_t now = time(NULL); tor_assert(desc); tor_assert(type); - if (!last_desc_dumped || last_desc_dumped + 60 < now) { - char *debugfile = get_datadir_fname("unparseable-desc"); - size_t filelen = 50 + strlen(type) + strlen(desc); - char *content = tor_malloc_zero(filelen); - tor_snprintf(content, filelen, "Unable to parse descriptor of type " - "%s:\n%s", type, desc); + /* Are we dumping this one to a file? */ + int dumping_this_one; + /* + * Are we including the hash in the filename and using the + * FIFO mechanism? + */ + int dumping_by_hash; + /* Emit an "Unable to parse descriptor..." prefix? */ + int emit_prefix; + size_t len; + /* The SHA256 of the string */ + uint8_t digest_sha256[DIGEST256_LEN]; + char digest_sha256_hex[HEX_DIGEST256_LEN+1]; + /* Filename to log it to */ + char *debugfile, *debugfile_base; + /* Expected length of file */ + size_t filelen; + /* File content */ + char *content; + + /* Get the hash for logging purposes anyway */ + len = strlen(desc); + if (crypto_digest256((char *)digest_sha256, desc, len, + DIGEST_SHA256) != 0) { + log_info(LD_DIR, + "Unable to parse descriptor of type %s, and unable to even hash" + " it!", type); + goto err; + } + + base16_encode(digest_sha256_hex, sizeof(digest_sha256_hex), + (const char *)digest_sha256, sizeof(digest_sha256)); + + if (get_options()->DetailedLogForUnparseableDescriptors > 0) { + /* Okay, we're logging to a fresh file named by hash for each one */ + dumping_by_hash = 1; + dumping_this_one = 1; + /* + * Detailed logging mechanism will mention type and hash in the main log; + * don't clutter up the files with anything but the exact dump. + */ + emit_prefix = 0; + tor_asprintf(&debugfile_base, "unparseable-desc.%s", digest_sha256_hex); + debugfile = get_datadir_fname(debugfile_base); + } else if (!last_desc_dumped || last_desc_dumped + 60 < now) { + /* Simple mechanism, check so we don't dump too often */ + dumping_by_hash = 0; + dumping_this_one = 1; + emit_prefix = 1; + debugfile_base = tor_strdup("unparseable-desc"); + debugfile = get_datadir_fname(debugfile_base); + } else { + /* No logging of the full descriptor this time */ + dumping_by_hash = 0; + dumping_this_one = 0; + emit_prefix = 1; + debugfile_base = NULL; + debugfile = NULL; + } + + if (dumping_this_one) { + if (emit_prefix) filelen = 50 + strlen(type) + len; + else filelen = len; + + /* Get content pointing at what we're writing */ + if (emit_prefix) { + content = tor_malloc_zero(filelen); + tor_snprintf(content, filelen, "Unable to parse descriptor of type " + "%s:\n%s", type, desc); + } else { + content = tor_strdup(desc); + } + + /* Write it, and tell the main log about it */ write_str_to_file(debugfile, content, 1); - log_info(LD_DIR, "Unable to parse descriptor of type %s. See file " - "unparseable-desc in data directory for details.", type); + log_info(LD_DIR, + "Unable to parse descriptor of type %s with hash %s and length " + "%lu. See file %s in data directory for details.", + type, digest_sha256_hex, (unsigned long)len, debugfile_base); + + /* Free our in-memory copy if necessary */ tor_free(content); - tor_free(debugfile); + last_desc_dumped = now; + + /* Give it to the FIFO and clean up as needed, if we're using one */ + if (dumping_by_hash) { + dump_desc_fifo_add_and_clean(debugfile, filelen, now); + /* Since we handed ownership over, don't free debugfile later */ + debugfile = NULL; + } + } else { + /* Just log that it happened without dumping */ + log_info(LD_DIR, + "Unable to parse descriptor of type %s with hash %s and length " + "%lu. Descriptor not dumped since we just dumped one %u seconds " + "ago.", + type, digest_sha256_hex, (unsigned long)len, + (unsigned int)(now - last_desc_dumped)); } + + if (debugfile_base != NULL) tor_free(debugfile_base); + if (debugfile != NULL) tor_free(debugfile); + + err: + return; }

/** Set <b>digest</b> to the SHA-1 digest of the hash of the directory in @@ -5468,3 +5654,10 @@ rend_parse_client_keys(strmap_t *parsed_clients, const char *ckstr) return result; }

+/** Clean up all data structures used by routerparse.c at exit */ +void +routerparse_free_all(void) +{ + dump_desc_fifo_cleanup(); +} + diff --git a/src/or/routerparse.h b/src/or/routerparse.h index c46eb1c..69160d1 100644 --- a/src/or/routerparse.h +++ b/src/or/routerparse.h @@ -85,6 +85,8 @@ int rend_parse_introduction_points(rend_service_descriptor_t *parsed, size_t intro_points_encoded_size); int rend_parse_client_keys(strmap_t *parsed_clients, const char *str);

+void routerparse_free_all(void); + #ifdef ROUTERPARSE_PRIVATE STATIC int routerstatus_parse_guardfraction(const char *guardfraction_str, networkstatus_t *vote,