[tor-commits] [tor/master] Protover: simplify implementation structure to use 64-bit property
ahf at torproject.org
ahf at torproject.org
Wed Oct 28 15:17:13 UTC 2020
commit 33fb51a111da68352183437332a8f01a4a57571d
Author: Nick Mathewson <nickm at torproject.org>
Date: Wed Oct 14 13:05:00 2020 -0400
Protover: simplify implementation structure to use 64-bit property
Now that prop318 is in, we can simplify our representation for
protocol range sets to just be a bitmask.
---
changes/ticket40133_more | 3 +
src/core/or/protover.c | 550 +++++++++++++++--------------------------------
src/core/or/protover.h | 12 +-
src/test/test_protover.c | 38 +---
4 files changed, 181 insertions(+), 422 deletions(-)
diff --git a/changes/ticket40133_more b/changes/ticket40133_more
new file mode 100644
index 0000000000..569409e336
--- /dev/null
+++ b/changes/ticket40133_more
@@ -0,0 +1,3 @@
+ o Minor features (subprotocol versions):
+ - Use the new limitations on subprotocol versions due to proposal
+ 318 to simplify our implementation. Part of ticket 40133.
diff --git a/src/core/or/protover.c b/src/core/or/protover.c
index 712e264314..5a87ade3da 100644
--- a/src/core/or/protover.c
+++ b/src/core/or/protover.c
@@ -33,6 +33,8 @@
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);
+static const proto_entry_t *find_entry_by_name(const smartlist_t *protos,
+ const char *name);
/** Mapping between protocol type string and protocol type. */
/// C_RUST_COUPLED: src/rust/protover/protover.rs `PROTOCOL_NAMES`
@@ -82,27 +84,6 @@ protocol_type_to_str(protocol_type_t pr)
/* 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
*/
@@ -112,8 +93,6 @@ 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);
}
@@ -194,6 +173,23 @@ is_valid_keyword(const char *s, size_t n)
return 1;
}
+/** The x'th bit in a bitmask. */
+#define BIT(x) (UINT64_C(1)<<(x))
+
+/**
+ * Return a bitmask so that bits 'low' through 'high' inclusive are set,
+ * and all other bits are cleared.
+ **/
+static uint64_t
+bitmask_for_range(uint32_t low, uint32_t high)
+{
+ uint64_t mask = ~(uint64_t)0;
+ mask <<= 63 - high;
+ mask >>= 63 - high + low;
+ mask <<= low;
+ return mask;
+}
+
/** 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.
@@ -205,8 +201,6 @@ 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
@@ -240,15 +234,16 @@ parse_single_entry(const char *s, const char *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) {
+ uint32_t low=0, high=0;
+ if (parse_version_range(s, comma, &low, &high) < 0) {
goto error;
}
+ out->bitmask |= bitmask_for_range(low,high);
+
s = comma;
// Skip the comma separator between ranges. Don't ignore a trailing comma.
if (s < (end_of_entry - 1))
@@ -372,15 +367,15 @@ protocol_list_supports_protocol_or_later(const char *list,
const char *pr_name = protocol_type_to_str(tp);
int contains = 0;
+ const uint64_t mask = bitmask_for_range(version, 63);
+
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);
+ if (0 != (proto->bitmask & mask)) {
+ contains = 1;
+ goto found;
+ }
} SMARTLIST_FOREACH_END(proto);
found:
@@ -436,6 +431,23 @@ get_supported_protocol_list(void)
return supported_protocol_list;
}
+/** Return the number of trailing zeros in x. Undefined if x is 0. */
+static int
+trailing_zeros(uint64_t x)
+{
+#ifdef __GNUC__
+ return __builtin_ctzll((unsigned long long)x);
+#else
+ int i;
+ for (i = 0; i <= 64; ++i) {
+ if (x&1)
+ return i;
+ x>>=1;
+ }
+ return i;
+#endif
+}
+
/**
* Given a protocol entry, encode it at the end of the smartlist <b>chunks</b>
* as one or more newly allocated strings.
@@ -445,20 +457,30 @@ 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);
+ uint64_t mask = entry->bitmask;
+ int shift = 0; // how much have we shifted by so far?
+ bool first = true;
+ while (mask) {
+ const char *comma = first ? "" : ",";
+ if (first) {
+ first = false;
+ }
+ int zeros = trailing_zeros(mask);
+ mask >>= zeros;
+ shift += zeros;
+ int ones = !mask ? 64 : trailing_zeros(~mask);
+ if (ones == 1) {
+ smartlist_add_asprintf(chunks, "%s%d", comma, shift);
} else {
- smartlist_add_asprintf(chunks, "%s%lu-%lu",
- comma, (unsigned long)range->low,
- (unsigned long)range->high);
+ smartlist_add_asprintf(chunks, "%s%d-%d", comma,
+ shift, shift + ones - 1);
}
- } SMARTLIST_FOREACH_END(range);
+ if (ones == 64) {
+ break; // avoid undefined behavior; can't shift by 64.
+ }
+ mask >>= ones;
+ shift += ones;
+ }
}
/** Given a list of space-separated proto_entry_t items,
@@ -484,192 +506,6 @@ encode_protocol_list(const smartlist_t *sl)
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.
*
@@ -684,13 +520,18 @@ char *
protover_compute_vote(const smartlist_t *list_of_proto_strings,
int threshold)
{
+ // we use u8 counters below.
+ tor_assert(smartlist_len(list_of_proto_strings) < 256);
+
if (smartlist_len(list_of_proto_strings) == 0) {
return tor_strdup("");
}
- smartlist_t *all_entries = smartlist_new();
+ smartlist_t *parsed = smartlist_new(); // smartlist of smartlist of entries
+ smartlist_t *proto_names = smartlist_new(); // smartlist of strings
+ smartlist_t *result = smartlist_new(); // smartlist of entries
- // First, parse the inputs and break them into singleton entries.
+ // First, parse the inputs, and accumulate a list of protocol names.
SMARTLIST_FOREACH_BEGIN(list_of_proto_strings, const char *, vote) {
smartlist_t *unexpanded = parse_protocol_list(vote);
if (! unexpanded) {
@@ -699,54 +540,62 @@ protover_compute_vote(const smartlist_t *list_of_proto_strings,
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_BEGIN(unexpanded, const proto_entry_t *, ent) {
+ if (!smartlist_contains_string(proto_names,ent->name)) {
+ smartlist_add(proto_names, ent->name);
+ }
+ } SMARTLIST_FOREACH_END(ent);
+ smartlist_add(parsed, 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);
+ // Sort the list of names.
+ smartlist_sort_strings(proto_names);
+
+ // For each named protocol, compute the consensus.
+ //
+ // This is not super-efficient, but it's not critical path.
+ SMARTLIST_FOREACH_BEGIN(proto_names, const char *, name) {
+ uint8_t counts[64];
+ memset(counts, 0, sizeof(counts));
+ // Count how many votes we got for each bit.
+ SMARTLIST_FOREACH_BEGIN(parsed, const smartlist_t *, vote) {
+ const proto_entry_t *ent = find_entry_by_name(vote, name);
+ if (! ent)
+ continue;
+
+ for (int i = 0; i < 64; ++i) {
+ if ((ent->bitmask & BIT(i)) != 0) {
+ ++ counts[i];
+ }
+ }
+ } SMARTLIST_FOREACH_END(vote);
- // 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 ;
+ uint64_t result_bitmask = 0;
+ for (int i = 0; i < 64; ++i) {
+ if (counts[i] >= threshold) {
+ result_bitmask |= BIT(i);
+ }
}
- } SMARTLIST_FOREACH_END(ent);
+ if (result_bitmask != 0) {
+ proto_entry_t *newent = tor_malloc_zero(sizeof(proto_entry_t));
+ newent->name = tor_strdup(name);
+ newent->bitmask = result_bitmask;
+ smartlist_add(result, newent);
+ }
+ } SMARTLIST_FOREACH_END(name);
- if (n_times >= threshold && cur_entry)
- smartlist_add(include_entries, (void*)cur_entry);
+ char *consensus = encode_protocol_list(result);
- // 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);
+ SMARTLIST_FOREACH(result, proto_entry_t *, ent, proto_entry_free(ent));
+ smartlist_free(result);
+ smartlist_free(proto_names); // no need to free members; they are aliases.
+ SMARTLIST_FOREACH_BEGIN(parsed, smartlist_t *, v) {
+ SMARTLIST_FOREACH(v, proto_entry_t *, ent, proto_entry_free(ent));
+ smartlist_free(v);
+ } SMARTLIST_FOREACH_END(v);
+ smartlist_free(parsed);
- return result;
+ return consensus;
}
/** Return true if every protocol version described in the string <b>s</b> is
@@ -755,19 +604,10 @@ protover_compute_vote(const smartlist_t *list_of_proto_strings,
*
* If the protocol version string is unparseable, treat it as if it defines no
* protocols, and return 1.
- *
- * 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;
}
@@ -778,101 +618,37 @@ protover_all_supported(const char *s, char **missing_out)
" from the consensus", escaped(s));
return 1;
}
-
- missing_some = smartlist_new();
- missing_completely = smartlist_new();
+ const smartlist_t *supported = get_supported_protocol_list();
+ smartlist_t *missing = 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;
+ const proto_entry_t *mine = find_entry_by_name(supported, ent->name);
+ if (mine == NULL) {
+ if (ent->bitmask != 0) {
+ proto_entry_t *m = tor_malloc_zero(sizeof(proto_entry_t));
+ m->name = tor_strdup(ent->name);
+ m->bitmask = ent->bitmask;
+ smartlist_add(missing, m);
}
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);
- } else {
- tor_free(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);
- }
- } SMARTLIST_FOREACH_END(range);
-
- continue;
-
- unsupported:
- all_supported = 0;
- smartlist_add(missing_completely, (void*) ent);
+ uint64_t missing_mask = ent->bitmask & ~mine->bitmask;
+ if (missing_mask != 0) {
+ proto_entry_t *m = tor_malloc_zero(sizeof(proto_entry_t));
+ m->name = tor_strdup(ent->name);
+ m->bitmask = missing_mask;
+ smartlist_add(missing, m);
+ }
} 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);
+ const int all_supported = (smartlist_len(missing) == 0);
+ if (!all_supported && missing_out) {
+ *missing_out = encode_protocol_list(missing);
}
- 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(missing, proto_entry_t *, ent, proto_entry_free(ent));
+ smartlist_free(missing);
SMARTLIST_FOREACH(entries, proto_entry_t *, ent, proto_entry_free(ent));
smartlist_free(entries);
@@ -880,6 +656,23 @@ protover_all_supported(const char *s, char **missing_out)
return all_supported;
}
+/** Helper: return the member of 'protos' whose name is
+ * 'name', or NULL if there is no such member. */
+static const proto_entry_t *
+find_entry_by_name(const smartlist_t *protos, const char *name)
+{
+ if (!protos) {
+ return NULL;
+ }
+ SMARTLIST_FOREACH_BEGIN(protos, const proto_entry_t *, ent) {
+ if (!strcmp(ent->name, name)) {
+ return ent;
+ }
+ } SMARTLIST_FOREACH_END(ent);
+
+ return NULL;
+}
+
/** Helper: Given a list of proto_entry_t, return true iff
* <b>pr</b>=<b>ver</b> is included in that list. */
static int
@@ -893,17 +686,14 @@ protocol_list_contains(const smartlist_t *protos,
if (BUG(pr_name == NULL)) {
return 0; // LCOV_EXCL_LINE
}
+ if (ver > MAX_PROTOCOL_VERSION) {
+ return 0;
+ }
- 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);
-
+ const proto_entry_t *ent = find_entry_by_name(protos, pr_name);
+ if (ent) {
+ return (ent->bitmask & BIT(ver)) != 0;
+ }
return 0;
}
diff --git a/src/core/or/protover.h b/src/core/or/protover.h
index 24008f46b9..88fcbb0b61 100644
--- a/src/core/or/protover.h
+++ b/src/core/or/protover.h
@@ -86,13 +86,6 @@ int protocol_list_supports_protocol_or_later(const char *list,
void protover_free_all(void);
#ifdef PROTOVER_PRIVATE
-/** Represents a range of subprotocols of a given type. All subprotocols
- * between <b>low</b> and <b>high</b> inclusive are included. */
-typedef struct proto_range_t {
- uint32_t low;
- uint32_t high;
-} proto_range_t;
-
/** Represents a set of ranges of subprotocols of a given type. */
typedef struct proto_entry_t {
/** The name of the protocol.
@@ -101,8 +94,9 @@ typedef struct proto_entry_t {
* we don't recognize yet, so it's a char* rather than a protocol_type_t.)
*/
char *name;
- /** Smartlist of proto_range_t */
- struct smartlist_t *ranges;
+ /** Bitmask of supported protocols. Version 'x' is included in this
+ * entry if and only if bit '1<<x' is set here. */
+ uint64_t bitmask;
} proto_entry_t;
#if !defined(HAVE_RUST) && defined(TOR_UNIT_TESTS)
diff --git a/src/test/test_protover.c b/src/test/test_protover.c
index f129aa7f1c..be3aeb5e40 100644
--- a/src/test/test_protover.c
+++ b/src/test/test_protover.c
@@ -39,53 +39,25 @@ test_protover_parse(void *arg)
tt_int_op(smartlist_len(elts), OP_EQ, 4);
const proto_entry_t *e;
- const proto_range_t *r;
e = smartlist_get(elts, 0);
tt_str_op(e->name, OP_EQ, "Foo");
- tt_int_op(smartlist_len(e->ranges), OP_EQ, 2);
- {
- r = smartlist_get(e->ranges, 0);
- tt_int_op(r->low, OP_EQ, 1);
- tt_int_op(r->high, OP_EQ, 1);
-
- r = smartlist_get(e->ranges, 1);
- tt_int_op(r->low, OP_EQ, 3);
- tt_int_op(r->high, OP_EQ, 3);
- }
+ tt_int_op(e->bitmask, OP_EQ, 0x0a);
e = smartlist_get(elts, 1);
tt_str_op(e->name, OP_EQ, "Bar");
- tt_int_op(smartlist_len(e->ranges), OP_EQ, 1);
- {
- r = smartlist_get(e->ranges, 0);
- tt_int_op(r->low, OP_EQ, 3);
- tt_int_op(r->high, OP_EQ, 3);
- }
+ tt_int_op(e->bitmask, OP_EQ, 0x08);
e = smartlist_get(elts, 2);
tt_str_op(e->name, OP_EQ, "Baz");
- tt_int_op(smartlist_len(e->ranges), OP_EQ, 0);
+ tt_int_op(e->bitmask, OP_EQ, 0x00);
e = smartlist_get(elts, 3);
tt_str_op(e->name, OP_EQ, "Quux");
- tt_int_op(smartlist_len(e->ranges), OP_EQ, 3);
- {
- r = smartlist_get(e->ranges, 0);
- tt_int_op(r->low, OP_EQ, 9);
- tt_int_op(r->high, OP_EQ, 12);
-
- r = smartlist_get(e->ranges, 1);
- tt_int_op(r->low, OP_EQ, 14);
- tt_int_op(r->high, OP_EQ, 14);
-
- r = smartlist_get(e->ranges, 2);
- tt_int_op(r->low, OP_EQ, 15);
- tt_int_op(r->high, OP_EQ, 16);
- }
+ tt_int_op(e->bitmask, OP_EQ, 0x1de00);
re_encoded = encode_protocol_list(elts);
tt_assert(re_encoded);
- tt_str_op(re_encoded, OP_EQ, orig);
+ tt_str_op(re_encoded, OP_EQ, "Foo=1,3 Bar=3 Baz= Quux=9-12,14-16");
done:
if (elts)
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