[tor-commits] [tor/master] Merge branch 'maint-0.3.4'
nickm at torproject.org
nickm at torproject.org
Fri Sep 21 13:36:45 UTC 2018
commit 9b0a17a74f5d8cd7c5d8a07dd275e7d96bd4fd35
Merge: 96d1f2e6d e818a7190
Author: Nick Mathewson <nickm at torproject.org>
Date: Fri Sep 21 09:36:31 2018 -0400
Merge branch 'maint-0.3.4'
changes/bug27316 | 3 +++
src/core/or/protover.c | 15 +++++++++++++++
src/test/test_protover.c | 4 ++++
3 files changed, 22 insertions(+)
diff --cc src/core/or/protover.c
index 0f6f0e79f,000000000..f0791366f
mode 100644,000000..100644
--- a/src/core/or/protover.c
+++ b/src/core/or/protover.c
@@@ -1,927 -1,0 +1,942 @@@
+/* 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"
+#include "lib/tls/tortls.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
+ * <b>pr_out</b>. 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 <b>s</b> and optional end-of-string pointer
+ * <b>end_of_range</b>, parse the protocol range and store it in
+ * <b>low_out</b> and <b>high_out</b>. 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;
+}
+
++static int
++is_valid_keyword(const char *s, size_t n)
++{
++ for (size_t i = 0; i < n; i++) {
++ if (!TOR_ISALNUM(s[i]) && s[i] != '-')
++ return 0;
++ }
++ return 1;
++}
++
+/** Parse a single protocol entry from <b>s</b> up to an optional
+ * <b>end_of_entry</b> 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;
+ }
++
++ /* The name must contain only alphanumeric characters and hyphens. */
++ if (!is_valid_keyword(s, equals-s))
++ 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 <b>s</b> 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 <b>s</b> 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 "
+#ifdef HAVE_WORKING_TOR_TLS_GET_TLSSECRETS
+ "LinkAuth=1,3 "
+#else
+ "LinkAuth=3 "
+#endif
+ "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 <b>chunks</b>
+ * 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 <b>threshold</b> 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 <b>s</b> is
+ * one that we support, and false otherwise. If <b>missing_out</b> 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
+ * <b>pr</b>=<b>ver</b> 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
+ * <b>version</b>, 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) */
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