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Rewrite the core of parse_short_policy() to be faster.
The old implementation did some funky out-of-order lexing, and tended to parse every port twice if the %d-%d pattern didn't match. Closes ticket 28853.
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changes/ticket28853
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changes/ticket28853
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@ -0,0 +1,3 @@
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o Minor features (performance):
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- Replace parse_short_policy() with a faster implementation, to improve
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microdescriptor parsing time. Closes ticket 28853.
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@ -2720,7 +2720,7 @@ parse_short_policy(const char *summary)
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int is_accept;
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int n_entries;
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short_policy_entry_t entries[MAX_EXITPOLICY_SUMMARY_LEN]; /* overkill */
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const char *next;
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char *next;
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if (!strcmpstart(summary, "accept ")) {
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is_accept = 1;
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@ -2735,57 +2735,56 @@ parse_short_policy(const char *summary)
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n_entries = 0;
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for ( ; *summary; summary = next) {
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const char *comma = strchr(summary, ',');
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unsigned low, high;
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char dummy;
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char ent_buf[32];
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size_t len;
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next = comma ? comma+1 : strchr(summary, '\0');
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len = comma ? (size_t)(comma - summary) : strlen(summary);
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if (n_entries == MAX_EXITPOLICY_SUMMARY_LEN) {
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log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Impossibly long policy summary %s",
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escaped(orig_summary));
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return NULL;
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}
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if (! TOR_ISDIGIT(*summary) || len > (sizeof(ent_buf)-1)) {
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/* unrecognized entry format. skip it. */
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continue;
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}
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if (len < 1) {
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/* empty; skip it. */
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/* XXX This happens to be unreachable, since if len==0, then *summary is
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* ',' or '\0', and the TOR_ISDIGIT test above would have failed. */
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continue;
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unsigned low, high;
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int ok;
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low = (unsigned) tor_parse_ulong(summary, 10, 1, 65535, &ok, &next);
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if (!ok) {
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if (! TOR_ISDIGIT(*summary) || *summary == ',') {
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/* Unrecognized format: skip it. */
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goto skip_ent;
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} else {
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goto bad_ent;
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}
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}
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memcpy(ent_buf, summary, len);
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ent_buf[len] = '\0';
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switch (*next) {
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case ',':
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++next;
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/* fall through */
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case '\0':
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high = low;
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break;
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case '-':
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high = (unsigned) tor_parse_ulong(next+1, 10, low, 65535, &ok, &next);
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if (!ok)
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goto bad_ent;
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if (tor_sscanf(ent_buf, "%u-%u%c", &low, &high, &dummy) == 2) {
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if (low<1 || low>65535 || high<1 || high>65535 || low>high) {
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log_fn(LOG_PROTOCOL_WARN, LD_DIR,
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"Found bad entry in policy summary %s", escaped(orig_summary));
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return NULL;
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}
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} else if (tor_sscanf(ent_buf, "%u%c", &low, &dummy) == 1) {
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if (low<1 || low>65535) {
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log_fn(LOG_PROTOCOL_WARN, LD_DIR,
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"Found bad entry in policy summary %s", escaped(orig_summary));
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return NULL;
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}
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high = low;
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} else {
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log_fn(LOG_PROTOCOL_WARN, LD_DIR,"Found bad entry in policy summary %s",
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escaped(orig_summary));
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return NULL;
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if (*next == ',')
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++next;
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else if (*next != '\0')
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goto bad_ent;
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break;
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default:
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goto bad_ent;
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}
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entries[n_entries].min_port = low;
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entries[n_entries].max_port = high;
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n_entries++;
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continue;
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skip_ent:
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next = strchr(next, ',');
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if (!next)
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break;
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++next;
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}
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if (n_entries == 0) {
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@ -2806,6 +2805,11 @@ parse_short_policy(const char *summary)
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result->n_entries = n_entries;
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memcpy(result->entries, entries, sizeof(short_policy_entry_t)*n_entries);
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return result;
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bad_ent:
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log_fn(LOG_PROTOCOL_WARN, LD_DIR,"Found bad entry in policy summary %s",
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escaped(orig_summary));
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return NULL;
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}
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/** Write <b>policy</b> back out into a string. */
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