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- #define PROTOVER_PRIVATE
- #include "protover.h"
- #include "compat.h"
- #include "torlog.h"
- 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. */
- static const struct {
- protocol_type_t protover_type;
- const char *name;
- } PROTOCOL_NAMES[] = {
- { PRT_LINK, "Link" },
- { PRT_LINKAUTH, "LinkAuth" },
- { PRT_RELAY, "Relay" },
- { PRT_HSMID, "HSMid" },
- { PRT_DIRCACHE, "DirCache" },
- { PRT_HSDIR, "HSDir" },
- { PRT_DESC, "Desc" },
- { PRT_MICRODESC, "Microdesc"},
- { PRT_CONS, "Cons" }
- };
- #define N_PROTOCOL_NAMES ARRAY_LENGTH(PROTOCOL_NAMES)
- /**
- * 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;
- }
- tor_assert_nonfatal_unreached_once();
- return "UNKNOWN";
- }
- /**
- * 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);
- }
- /**
- * 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
- /* 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, UINT32_MAX, &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 */
- high = (uint32_t) tor_parse_ulong(s, 10, 0, UINT32_MAX, &ok, &next);
- if (!ok)
- goto error;
- if (next != end_of_range)
- goto error;
- done:
- *high_out = high;
- *low_out = low;
- return 0;
- error:
- 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;
- 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;
- }
- if (range->low > range->high) {
- 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;
- }
- /**
- * 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 the canonical string containing the list of protocols
- * that we support. */
- const char *
- get_supported_protocols(void)
- {
- return
- "Cons=1-2 "
- "Desc=1-2 "
- "DirCache=1 "
- "HSDir=1 "
- "HSMid=1 "
- "Link=1-4 "
- "LinkAuth=1 "
- "Microdesc=1-2 "
- "Relay=1-2";
- }
- /** The protocols from 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(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(chunks, tor_strdup(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;
- }
- /** 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;
- if (!s) {
- return 1;
- }
- smartlist_t *entries = parse_protocol_list(s);
- 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;
- }
- continue;
- }
- SMARTLIST_FOREACH_BEGIN(ent->ranges, const proto_range_t *, range) {
- uint32_t i;
- for (i = range->low; i <= range->high; ++i) {
- if (!protover_is_supported_here(tp, i)) {
- goto unsupported;
- }
- }
- } SMARTLIST_FOREACH_END(range);
- continue;
- unsupported:
- all_supported = 0;
- smartlist_add(missing, (void*) ent);
- } SMARTLIST_FOREACH_END(ent);
- if (missing_out && !all_supported) {
- tor_assert(0 != smartlist_len(missing));
- *missing_out = encode_protocol_list(missing);
- }
- smartlist_free(missing);
- SMARTLIST_FOREACH(entries, proto_entry_t *, ent, proto_entry_free(ent));
- smartlist_free(entries);
- return all_supported;
- }
- static int
- protocol_list_contains(const smartlist_t *protos,
- protocol_type_t pr, uint32_t ver)
- {
- if (BUG(protos == NULL)) {
- return 0;
- }
- const char *pr_name = protocol_type_to_str(pr);
- if (BUG(pr_name == NULL)) {
- 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);
- return 0;
- }
- 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;
- }
- }
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