/* Copyright (c) 2016-2018, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file protover.c * \brief Versioning information for different pieces of the Tor protocol. * * Starting in version 0.2.9.3-alpha, Tor places separate version numbers on * each of the different components of its protocol. Relays use these numbers * to advertise what versions of the protocols they can support, and clients * use them to find what they can ask a given relay to do. Authorities vote * on the supported protocol versions for each relay, and also vote on the * which protocols you should have to support in order to be on the Tor * network. All Tor instances use these required/recommended protocol versions * to tell what level of support for recent protocols each relay has, and * to decide whether they should be running given their current protocols. * * The main advantage of these protocol versions numbers over using Tor * version numbers is that they allow different implementations of the Tor * protocols to develop independently, without having to claim compatibility * with specific versions of Tor. **/ #define PROTOVER_PRIVATE #include "core/or/or.h" #include "core/or/protover.h" #include "feature/nodelist/routerparse.h" #ifndef HAVE_RUST static const smartlist_t *get_supported_protocol_list(void); static int protocol_list_contains(const smartlist_t *protos, protocol_type_t pr, uint32_t ver); /** Mapping between protocol type string and protocol type. */ /// C_RUST_COUPLED: src/rust/protover/protover.rs `PROTOCOL_NAMES` static const struct { protocol_type_t protover_type; const char *name; } PROTOCOL_NAMES[] = { { PRT_LINK, "Link" }, { PRT_LINKAUTH, "LinkAuth" }, { PRT_RELAY, "Relay" }, { PRT_DIRCACHE, "DirCache" }, { PRT_HSDIR, "HSDir" }, { PRT_HSINTRO, "HSIntro" }, { PRT_HSREND, "HSRend" }, { PRT_DESC, "Desc" }, { PRT_MICRODESC, "Microdesc"}, { PRT_CONS, "Cons" } }; #define N_PROTOCOL_NAMES ARRAY_LENGTH(PROTOCOL_NAMES) /* Maximum allowed length of any single subprotocol name. */ // C_RUST_COUPLED: src/rust/protover/protover.rs // `MAX_PROTOCOL_NAME_LENGTH` static const unsigned MAX_PROTOCOL_NAME_LENGTH = 100; /** * Given a protocol_type_t, return the corresponding string used in * descriptors. */ STATIC const char * protocol_type_to_str(protocol_type_t pr) { unsigned i; for (i=0; i < N_PROTOCOL_NAMES; ++i) { if (PROTOCOL_NAMES[i].protover_type == pr) return PROTOCOL_NAMES[i].name; } /* LCOV_EXCL_START */ tor_assert_nonfatal_unreached_once(); return "UNKNOWN"; /* LCOV_EXCL_STOP */ } /** * Given a string, find the corresponding protocol type and store it in * pr_out. Return 0 on success, -1 on failure. */ STATIC int str_to_protocol_type(const char *s, protocol_type_t *pr_out) { if (BUG(!pr_out)) return -1; unsigned i; for (i=0; i < N_PROTOCOL_NAMES; ++i) { if (0 == strcmp(s, PROTOCOL_NAMES[i].name)) { *pr_out = PROTOCOL_NAMES[i].protover_type; return 0; } } return -1; } /** * Release all space held by a single proto_entry_t structure */ STATIC void proto_entry_free_(proto_entry_t *entry) { if (!entry) return; tor_free(entry->name); SMARTLIST_FOREACH(entry->ranges, proto_range_t *, r, tor_free(r)); smartlist_free(entry->ranges); tor_free(entry); } /** The largest possible protocol version. */ #define MAX_PROTOCOL_VERSION (UINT32_MAX-1) /** * Given a string s and optional end-of-string pointer * end_of_range, parse the protocol range and store it in * low_out and high_out. A protocol range has the format U, or * U-U, where U is an unsigned 32-bit integer. */ static int parse_version_range(const char *s, const char *end_of_range, uint32_t *low_out, uint32_t *high_out) { uint32_t low, high; char *next = NULL; int ok; tor_assert(high_out); tor_assert(low_out); if (BUG(!end_of_range)) end_of_range = s + strlen(s); // LCOV_EXCL_LINE /* A range must start with a digit. */ if (!TOR_ISDIGIT(*s)) { goto error; } /* Note that this wouldn't be safe if we didn't know that eventually, * we'd hit a NUL */ low = (uint32_t) tor_parse_ulong(s, 10, 0, MAX_PROTOCOL_VERSION, &ok, &next); if (!ok) goto error; if (next > end_of_range) goto error; if (next == end_of_range) { high = low; goto done; } if (*next != '-') goto error; s = next+1; /* ibid */ if (!TOR_ISDIGIT(*s)) { goto error; } high = (uint32_t) tor_parse_ulong(s, 10, 0, MAX_PROTOCOL_VERSION, &ok, &next); if (!ok) goto error; if (next != end_of_range) goto error; if (low > high) goto error; done: *high_out = high; *low_out = low; return 0; error: return -1; } /** Parse a single protocol entry from s up to an optional * end_of_entry pointer, and return that protocol entry. Return NULL * on error. * * A protocol entry has a keyword, an = sign, and zero or more ranges. */ static proto_entry_t * parse_single_entry(const char *s, const char *end_of_entry) { proto_entry_t *out = tor_malloc_zero(sizeof(proto_entry_t)); const char *equals; out->ranges = smartlist_new(); if (BUG (!end_of_entry)) end_of_entry = s + strlen(s); // LCOV_EXCL_LINE /* There must be an =. */ equals = memchr(s, '=', end_of_entry - s); if (!equals) goto error; /* The name must be nonempty */ if (equals == s) goto error; /* The name must not be longer than MAX_PROTOCOL_NAME_LENGTH. */ if (equals - s > (int)MAX_PROTOCOL_NAME_LENGTH) { log_warn(LD_NET, "When parsing a protocol entry, I got a very large " "protocol name. This is possibly an attack or a bug, unless " "the Tor network truly supports protocol names larger than " "%ud characters. The offending string was: %s", MAX_PROTOCOL_NAME_LENGTH, escaped(out->name)); goto error; } out->name = tor_strndup(s, equals-s); tor_assert(equals < end_of_entry); s = equals + 1; while (s < end_of_entry) { const char *comma = memchr(s, ',', end_of_entry-s); proto_range_t *range = tor_malloc_zero(sizeof(proto_range_t)); if (! comma) comma = end_of_entry; smartlist_add(out->ranges, range); if (parse_version_range(s, comma, &range->low, &range->high) < 0) { goto error; } s = comma; while (*s == ',' && s < end_of_entry) ++s; } return out; error: proto_entry_free(out); return NULL; } /** * Parse the protocol list from s and return it as a smartlist of * proto_entry_t */ STATIC smartlist_t * parse_protocol_list(const char *s) { smartlist_t *entries = smartlist_new(); while (*s) { /* Find the next space or the NUL. */ const char *end_of_entry = strchr(s, ' '); proto_entry_t *entry; if (!end_of_entry) end_of_entry = s + strlen(s); entry = parse_single_entry(s, end_of_entry); if (! entry) goto error; smartlist_add(entries, entry); s = end_of_entry; while (*s == ' ') ++s; } return entries; error: SMARTLIST_FOREACH(entries, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(entries); return NULL; } /** * Return true if the unparsed protover in s would contain a protocol * name longer than MAX_PROTOCOL_NAME_LENGTH, and false otherwise. */ bool protover_contains_long_protocol_names(const char *s) { smartlist_t *list = parse_protocol_list(s); if (!list) return true; /* yes, has a dangerous name */ SMARTLIST_FOREACH(list, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(list); return false; /* no, looks fine */ } /** * Given a protocol type and version number, return true iff we know * how to speak that protocol. */ int protover_is_supported_here(protocol_type_t pr, uint32_t ver) { const smartlist_t *ours = get_supported_protocol_list(); return protocol_list_contains(ours, pr, ver); } /** * Return true iff "list" encodes a protocol list that includes support for * the indicated protocol and version. */ int protocol_list_supports_protocol(const char *list, protocol_type_t tp, uint32_t version) { /* NOTE: This is a pretty inefficient implementation. If it ever shows * up in profiles, we should memoize it. */ smartlist_t *protocols = parse_protocol_list(list); if (!protocols) { return 0; } int contains = protocol_list_contains(protocols, tp, version); SMARTLIST_FOREACH(protocols, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(protocols); return contains; } /** * Return true iff "list" encodes a protocol list that includes support for * the indicated protocol and version, or some later version. */ int protocol_list_supports_protocol_or_later(const char *list, protocol_type_t tp, uint32_t version) { /* NOTE: This is a pretty inefficient implementation. If it ever shows * up in profiles, we should memoize it. */ smartlist_t *protocols = parse_protocol_list(list); if (!protocols) { return 0; } const char *pr_name = protocol_type_to_str(tp); int contains = 0; SMARTLIST_FOREACH_BEGIN(protocols, proto_entry_t *, proto) { if (strcasecmp(proto->name, pr_name)) continue; SMARTLIST_FOREACH_BEGIN(proto->ranges, const proto_range_t *, range) { if (range->high >= version) { contains = 1; goto found; } } SMARTLIST_FOREACH_END(range); } SMARTLIST_FOREACH_END(proto); found: SMARTLIST_FOREACH(protocols, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(protocols); return contains; } /** Return the canonical string containing the list of protocols * that we support. */ /// C_RUST_COUPLED: src/rust/protover/protover.rs `SUPPORTED_PROTOCOLS` const char * protover_get_supported_protocols(void) { return "Cons=1-2 " "Desc=1-2 " "DirCache=1-2 " "HSDir=1-2 " "HSIntro=3-4 " "HSRend=1-2 " "Link=1-5 " "LinkAuth=1,3 " "Microdesc=1-2 " "Relay=1-2"; } /** The protocols from protover_get_supported_protocols(), as parsed into a * list of proto_entry_t values. Access this via * get_supported_protocol_list. */ static smartlist_t *supported_protocol_list = NULL; /** Return a pointer to a smartlist of proto_entry_t for the protocols * we support. */ static const smartlist_t * get_supported_protocol_list(void) { if (PREDICT_UNLIKELY(supported_protocol_list == NULL)) { supported_protocol_list = parse_protocol_list(protover_get_supported_protocols()); } return supported_protocol_list; } /** * Given a protocol entry, encode it at the end of the smartlist chunks * as one or more newly allocated strings. */ static void proto_entry_encode_into(smartlist_t *chunks, const proto_entry_t *entry) { smartlist_add_asprintf(chunks, "%s=", entry->name); SMARTLIST_FOREACH_BEGIN(entry->ranges, proto_range_t *, range) { const char *comma = ""; if (range_sl_idx != 0) comma = ","; if (range->low == range->high) { smartlist_add_asprintf(chunks, "%s%lu", comma, (unsigned long)range->low); } else { smartlist_add_asprintf(chunks, "%s%lu-%lu", comma, (unsigned long)range->low, (unsigned long)range->high); } } SMARTLIST_FOREACH_END(range); } /** Given a list of space-separated proto_entry_t items, * encode it into a newly allocated space-separated string. */ STATIC char * encode_protocol_list(const smartlist_t *sl) { const char *separator = ""; smartlist_t *chunks = smartlist_new(); SMARTLIST_FOREACH_BEGIN(sl, const proto_entry_t *, ent) { smartlist_add_strdup(chunks, separator); proto_entry_encode_into(chunks, ent); separator = " "; } SMARTLIST_FOREACH_END(ent); char *result = smartlist_join_strings(chunks, "", 0, NULL); SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp)); smartlist_free(chunks); return result; } /* We treat any protocol list with more than this many subprotocols in it * as a DoS attempt. */ /// C_RUST_COUPLED: src/rust/protover/protover.rs /// `MAX_PROTOCOLS_TO_EXPAND` static const int MAX_PROTOCOLS_TO_EXPAND = (1<<16); /** Voting helper: Given a list of proto_entry_t, return a newly allocated * smartlist of newly allocated strings, one for each included protocol * version. (So 'Foo=3,5-7' expands to a list of 'Foo=3', 'Foo=5', 'Foo=6', * 'Foo=7'.) * * Do not list any protocol version more than once. * * Return NULL if the list would be too big. */ static smartlist_t * expand_protocol_list(const smartlist_t *protos) { smartlist_t *expanded = smartlist_new(); if (!protos) return expanded; SMARTLIST_FOREACH_BEGIN(protos, const proto_entry_t *, ent) { const char *name = ent->name; if (strlen(name) > MAX_PROTOCOL_NAME_LENGTH) { log_warn(LD_NET, "When expanding a protocol entry, I got a very large " "protocol name. This is possibly an attack or a bug, unless " "the Tor network truly supports protocol names larger than " "%ud characters. The offending string was: %s", MAX_PROTOCOL_NAME_LENGTH, escaped(name)); continue; } SMARTLIST_FOREACH_BEGIN(ent->ranges, const proto_range_t *, range) { uint32_t u; for (u = range->low; u <= range->high; ++u) { smartlist_add_asprintf(expanded, "%s=%lu", name, (unsigned long)u); if (smartlist_len(expanded) > MAX_PROTOCOLS_TO_EXPAND) goto too_many; } } SMARTLIST_FOREACH_END(range); } SMARTLIST_FOREACH_END(ent); smartlist_sort_strings(expanded); smartlist_uniq_strings(expanded); // This makes voting work. do not remove return expanded; too_many: SMARTLIST_FOREACH(expanded, char *, cp, tor_free(cp)); smartlist_free(expanded); return NULL; } /** Voting helper: compare two singleton proto_entry_t items by version * alone. (A singleton item is one with a single range entry where * low==high.) */ static int cmp_single_ent_by_version(const void **a_, const void **b_) { const proto_entry_t *ent_a = *a_; const proto_entry_t *ent_b = *b_; tor_assert(smartlist_len(ent_a->ranges) == 1); tor_assert(smartlist_len(ent_b->ranges) == 1); const proto_range_t *a = smartlist_get(ent_a->ranges, 0); const proto_range_t *b = smartlist_get(ent_b->ranges, 0); tor_assert(a->low == a->high); tor_assert(b->low == b->high); if (a->low < b->low) { return -1; } else if (a->low == b->low) { return 0; } else { return 1; } } /** Voting helper: Given a list of singleton protocol strings (of the form * Foo=7), return a canonical listing of all the protocol versions listed, * with as few ranges as possible, with protocol versions sorted lexically and * versions sorted in numerically increasing order, using as few range entries * as possible. **/ static char * contract_protocol_list(const smartlist_t *proto_strings) { if (smartlist_len(proto_strings) == 0) { return tor_strdup(""); } // map from name to list of single-version entries strmap_t *entry_lists_by_name = strmap_new(); // list of protocol names smartlist_t *all_names = smartlist_new(); // list of strings for the output we're building smartlist_t *chunks = smartlist_new(); // Parse each item and stick it entry_lists_by_name. Build // 'all_names' at the same time. SMARTLIST_FOREACH_BEGIN(proto_strings, const char *, s) { if (BUG(!s)) continue;// LCOV_EXCL_LINE proto_entry_t *ent = parse_single_entry(s, s+strlen(s)); if (BUG(!ent)) continue; // LCOV_EXCL_LINE smartlist_t *lst = strmap_get(entry_lists_by_name, ent->name); if (!lst) { smartlist_add(all_names, ent->name); lst = smartlist_new(); strmap_set(entry_lists_by_name, ent->name, lst); } smartlist_add(lst, ent); } SMARTLIST_FOREACH_END(s); // We want to output the protocols sorted by their name. smartlist_sort_strings(all_names); SMARTLIST_FOREACH_BEGIN(all_names, const char *, name) { const int first_entry = (name_sl_idx == 0); smartlist_t *lst = strmap_get(entry_lists_by_name, name); tor_assert(lst); // Sort every entry with this name by version. They are // singletons, so there can't be overlap. smartlist_sort(lst, cmp_single_ent_by_version); if (! first_entry) smartlist_add_strdup(chunks, " "); /* We're going to construct this entry from the ranges. */ proto_entry_t *entry = tor_malloc_zero(sizeof(proto_entry_t)); entry->ranges = smartlist_new(); entry->name = tor_strdup(name); // Now, find all the ranges of versions start..end where // all of start, start+1, start+2, ..end are included. int start_of_cur_series = 0; while (start_of_cur_series < smartlist_len(lst)) { const proto_entry_t *ent = smartlist_get(lst, start_of_cur_series); const proto_range_t *range = smartlist_get(ent->ranges, 0); const uint32_t ver_low = range->low; uint32_t ver_high = ver_low; int idx; for (idx = start_of_cur_series+1; idx < smartlist_len(lst); ++idx) { ent = smartlist_get(lst, idx); range = smartlist_get(ent->ranges, 0); if (range->low != ver_high + 1) break; ver_high += 1; } // Now idx is either off the end of the list, or the first sequence // break in the list. start_of_cur_series = idx; proto_range_t *new_range = tor_malloc_zero(sizeof(proto_range_t)); new_range->low = ver_low; new_range->high = ver_high; smartlist_add(entry->ranges, new_range); } proto_entry_encode_into(chunks, entry); proto_entry_free(entry); } SMARTLIST_FOREACH_END(name); // Build the result... char *result = smartlist_join_strings(chunks, "", 0, NULL); // And free all the stuff we allocated. SMARTLIST_FOREACH_BEGIN(all_names, const char *, name) { smartlist_t *lst = strmap_get(entry_lists_by_name, name); tor_assert(lst); SMARTLIST_FOREACH(lst, proto_entry_t *, e, proto_entry_free(e)); smartlist_free(lst); } SMARTLIST_FOREACH_END(name); strmap_free(entry_lists_by_name, NULL); smartlist_free(all_names); SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp)); smartlist_free(chunks); return result; } /** * Protocol voting implementation. * * Given a list of strings describing protocol versions, return a newly * allocated string encoding all of the protocols that are listed by at * least threshold of the inputs. * * The string is minimal and sorted according to the rules of * contract_protocol_list above. */ char * protover_compute_vote(const smartlist_t *list_of_proto_strings, int threshold) { if (smartlist_len(list_of_proto_strings) == 0) { return tor_strdup(""); } smartlist_t *all_entries = smartlist_new(); // First, parse the inputs and break them into singleton entries. SMARTLIST_FOREACH_BEGIN(list_of_proto_strings, const char *, vote) { smartlist_t *unexpanded = parse_protocol_list(vote); if (! unexpanded) { log_warn(LD_NET, "I failed with parsing a protocol list from " "an authority. The offending string was: %s", escaped(vote)); continue; } smartlist_t *this_vote = expand_protocol_list(unexpanded); if (this_vote == NULL) { log_warn(LD_NET, "When expanding a protocol list from an authority, I " "got too many protocols. This is possibly an attack or a bug, " "unless the Tor network truly has expanded to support over %d " "different subprotocol versions. The offending string was: %s", MAX_PROTOCOLS_TO_EXPAND, escaped(vote)); } else { smartlist_add_all(all_entries, this_vote); smartlist_free(this_vote); } SMARTLIST_FOREACH(unexpanded, proto_entry_t *, e, proto_entry_free(e)); smartlist_free(unexpanded); } SMARTLIST_FOREACH_END(vote); if (smartlist_len(all_entries) == 0) { smartlist_free(all_entries); return tor_strdup(""); } // Now sort the singleton entries smartlist_sort_strings(all_entries); // Now find all the strings that appear at least 'threshold' times. smartlist_t *include_entries = smartlist_new(); const char *cur_entry = smartlist_get(all_entries, 0); int n_times = 0; SMARTLIST_FOREACH_BEGIN(all_entries, const char *, ent) { if (!strcmp(ent, cur_entry)) { n_times++; } else { if (n_times >= threshold && cur_entry) smartlist_add(include_entries, (void*)cur_entry); cur_entry = ent; n_times = 1 ; } } SMARTLIST_FOREACH_END(ent); if (n_times >= threshold && cur_entry) smartlist_add(include_entries, (void*)cur_entry); // Finally, compress that list. char *result = contract_protocol_list(include_entries); smartlist_free(include_entries); SMARTLIST_FOREACH(all_entries, char *, cp, tor_free(cp)); smartlist_free(all_entries); return result; } /** Return true if every protocol version described in the string s is * one that we support, and false otherwise. If missing_out is * provided, set it to the list of protocols we do not support. * * NOTE: This is quadratic, but we don't do it much: only a few times per * consensus. Checking signatures should be way more expensive than this * ever would be. **/ int protover_all_supported(const char *s, char **missing_out) { int all_supported = 1; smartlist_t *missing_some; smartlist_t *missing_completely; smartlist_t *missing_all; if (!s) { return 1; } smartlist_t *entries = parse_protocol_list(s); if (BUG(entries == NULL)) { log_warn(LD_NET, "Received an unparseable protocol list %s" " from the consensus", escaped(s)); return 1; } missing_some = smartlist_new(); missing_completely = smartlist_new(); SMARTLIST_FOREACH_BEGIN(entries, const proto_entry_t *, ent) { protocol_type_t tp; if (str_to_protocol_type(ent->name, &tp) < 0) { if (smartlist_len(ent->ranges)) { goto unsupported; } continue; } SMARTLIST_FOREACH_BEGIN(ent->ranges, const proto_range_t *, range) { proto_entry_t *unsupported = tor_malloc_zero(sizeof(proto_entry_t)); proto_range_t *versions = tor_malloc_zero(sizeof(proto_range_t)); uint32_t i; unsupported->name = tor_strdup(ent->name); unsupported->ranges = smartlist_new(); for (i = range->low; i <= range->high; ++i) { if (!protover_is_supported_here(tp, i)) { if (versions->low == 0 && versions->high == 0) { versions->low = i; /* Pre-emptively add the high now, just in case we're in a single * version range (e.g. "Link=999"). */ versions->high = i; } /* If the last one to be unsupported is one less than the current * one, we're in a continuous range, so set the high field. */ if ((versions->high && versions->high == i - 1) || /* Similarly, if the last high wasn't set and we're currently * one higher than the low, add current index as the highest * known high. */ (!versions->high && versions->low == i - 1)) { versions->high = i; continue; } } else { /* If we hit a supported version, and we previously had a range, * we've hit a non-continuity. Copy the previous range and add it to * the unsupported->ranges list and zero-out the previous range for * the next iteration. */ if (versions->low != 0 && versions->high != 0) { proto_range_t *versions_to_add = tor_malloc(sizeof(proto_range_t)); versions_to_add->low = versions->low; versions_to_add->high = versions->high; smartlist_add(unsupported->ranges, versions_to_add); versions->low = 0; versions->high = 0; } } } /* Once we've run out of versions to check, see if we had any unsupported * ones and, if so, add them to unsupported->ranges. */ if (versions->low != 0 && versions->high != 0) { smartlist_add(unsupported->ranges, versions); } /* Finally, if we had something unsupported, add it to the list of * missing_some things and mark that there was something missing. */ if (smartlist_len(unsupported->ranges) != 0) { smartlist_add(missing_some, (void*) unsupported); all_supported = 0; } else { proto_entry_free(unsupported); tor_free(versions); } } SMARTLIST_FOREACH_END(range); continue; unsupported: all_supported = 0; smartlist_add(missing_completely, (void*) ent); } SMARTLIST_FOREACH_END(ent); /* We keep the two smartlists separate so that we can free the proto_entry_t * we created and put in missing_some, so here we add them together to build * the string. */ missing_all = smartlist_new(); smartlist_add_all(missing_all, missing_some); smartlist_add_all(missing_all, missing_completely); if (missing_out && !all_supported) { tor_assert(smartlist_len(missing_all) != 0); *missing_out = encode_protocol_list(missing_all); } SMARTLIST_FOREACH(missing_some, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(missing_some); smartlist_free(missing_completely); smartlist_free(missing_all); SMARTLIST_FOREACH(entries, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(entries); return all_supported; } /** Helper: Given a list of proto_entry_t, return true iff * pr=ver is included in that list. */ static int protocol_list_contains(const smartlist_t *protos, protocol_type_t pr, uint32_t ver) { if (BUG(protos == NULL)) { return 0; // LCOV_EXCL_LINE } const char *pr_name = protocol_type_to_str(pr); if (BUG(pr_name == NULL)) { return 0; // LCOV_EXCL_LINE } SMARTLIST_FOREACH_BEGIN(protos, const proto_entry_t *, ent) { if (strcasecmp(ent->name, pr_name)) continue; /* name matches; check the ranges */ SMARTLIST_FOREACH_BEGIN(ent->ranges, const proto_range_t *, range) { if (ver >= range->low && ver <= range->high) return 1; } SMARTLIST_FOREACH_END(range); } SMARTLIST_FOREACH_END(ent); return 0; } /** Return a string describing the protocols supported by tor version * version, or an empty string if we cannot tell. * * Note that this is only used to infer protocols for Tor versions that * can't declare their own. **/ /// C_RUST_COUPLED: src/rust/protover/protover.rs `compute_for_old_tor` const char * protover_compute_for_old_tor(const char *version) { if (version == NULL) { /* No known version; guess the oldest series that is still supported. */ version = "0.2.5.15"; } if (tor_version_as_new_as(version, FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS)) { return ""; } else if (tor_version_as_new_as(version, "0.2.9.1-alpha")) { /* 0.2.9.1-alpha HSRend=2 */ return "Cons=1-2 Desc=1-2 DirCache=1 HSDir=1 HSIntro=3 HSRend=1-2 " "Link=1-4 LinkAuth=1 " "Microdesc=1-2 Relay=1-2"; } else if (tor_version_as_new_as(version, "0.2.7.5")) { /* 0.2.7-stable added Desc=2, Microdesc=2, Cons=2, which indicate * ed25519 support. We'll call them present only in "stable" 027, * though. */ return "Cons=1-2 Desc=1-2 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 " "Link=1-4 LinkAuth=1 " "Microdesc=1-2 Relay=1-2"; } else if (tor_version_as_new_as(version, "0.2.4.19")) { /* No currently supported Tor server versions are older than this, or * lack these protocols. */ return "Cons=1 Desc=1 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 " "Link=1-4 LinkAuth=1 " "Microdesc=1 Relay=1-2"; } else { /* Cannot infer protocols. */ return ""; } } /** * Release all storage held by static fields in protover.c */ void protover_free_all(void) { if (supported_protocol_list) { smartlist_t *entries = supported_protocol_list; SMARTLIST_FOREACH(entries, proto_entry_t *, ent, proto_entry_free(ent)); smartlist_free(entries); supported_protocol_list = NULL; } } #endif /* !defined(HAVE_RUST) */