r11726@Kushana: nickm | 2006-12-28 16:24:06 -0500

 Expose a function from eventdns.c to set options without having to make a fake configuration file.  Also, add more settable options


svn:r9202

src/or/eventdns.c

@@ -295,7 +295,7 @@ static int global_max_nameserver_timeout = 3;
 static const struct timeval global_nameserver_timeouts[] = {{10, 0}, {60, 0}, {300, 0}, {900, 0}, {3600, 0}};
 static const int global_nameserver_timeouts_length = sizeof(global_nameserver_timeouts)/sizeof(struct timeval);
 
-const char *const evdns_error_strings[] = {"no error", "The name server was unable to interpret the query", "The name server suffered an internal error", "The requested domain name does not exist", "The name server refused to reply to the request"};
+static const char *const evdns_error_strings[] = {"no error", "The name server was unable to interpret the query", "The name server suffered an internal error", "The requested domain name does not exist", "The name server refused to reply to the request"};
 
 static struct nameserver *nameserver_pick(void);
 static void evdns_request_insert(struct request *req, struct request **head);
@@ -2490,6 +2490,64 @@ strtoint(const char *const str) {
 	return r;
 }
 
+// helper version of atoi that returns -1 on error and clips to bounds.
+static int
+strtoint_clipped(const char *const str, int min, int max)
+{
+	int r = strtoint(str);
+	if (r == -1)
+		return r;
+	else if (r<min)
+		return min;
+	else if (r>max)
+		return max;
+	else
+		return r;
+}
+
+// exported function
+int
+evdns_set_option(const char *option, const char *val, int flags)
+{
+	if (!strncmp(option, "ndots:", 6)) {
+		const int ndots = strtoint(val);
+		if (ndots == -1) return -1;
+		if (!(flags & DNS_OPTION_SEARCH)) return 0;
+		log(EVDNS_LOG_DEBUG, "Setting ndots to %d", ndots);
+		if (!global_search_state) global_search_state = search_state_new();
+		if (!global_search_state) return -1;
+		global_search_state->ndots = ndots;
+	} else if (!strncmp(option, "timeout:", 8)) {
+		const int timeout = strtoint(val);
+		if (timeout == -1) return -1;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		log(EVDNS_LOG_DEBUG, "Setting timeout to %d", timeout);
+		global_timeout.tv_sec = timeout;
+	} else if (!strncmp(option, "max-timeouts:", 12)) {
+		const int maxtimeout = strtoint_clipped(val, 1, 255);
+		if (maxtimeout == -1) return -1;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		log(EVDNS_LOG_DEBUG, "Setting maximum allowed timeouts to %d",
+			maxtimeout);
+		global_max_nameserver_timeout = maxtimeout;
+	} else if (!strncmp(option, "max-inflight:", 13)) {
+		const int maxinflight = strtoint_clipped(val, 1, 65000);
+		if (maxinflight == -1) return -1;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		log(EVDNS_LOG_DEBUG, "Setting maximum inflight requests to %d",
+			maxinflight);
+		global_max_requests_inflight = maxinflight;
+	} else if (!strncmp(option, "attempts:", 9)) {
+		int retries = strtoint(val);
+		if (retries == -1) return -1;
+		if (retries > 255) retries = 255;
+		if (!(flags & DNS_OPTION_MISC)) return 0;
+		log(EVDNS_LOG_DEBUG, "Setting retries to %d", retries);
+		global_max_retransmits = retries;
+	}
+	return 0;
+}
+
 static void
 resolv_conf_parse_line(char *const start, int flags) {
 	char *strtok_state;
@@ -2523,30 +2581,9 @@ resolv_conf_parse_line(char *const start, int flags) {
 		search_reverse();
 	} else if (!strcmp(first_token, "options")) {
 		const char *option;
-
 		while ((option = NEXT_TOKEN)) {
-			if (!strncmp(option, "ndots:", 6)) {
-				const int ndots = strtoint(&option[6]);
-				if (ndots == -1) continue;
-				if (!(flags & DNS_OPTION_SEARCH)) continue;
-				log(EVDNS_LOG_DEBUG, "Setting ndots to %d", ndots);
-				if (!global_search_state) global_search_state = search_state_new();
-								if (!global_search_state) return;
-				global_search_state->ndots = ndots;
-			} else if (!strncmp(option, "timeout:", 8)) {
-				const int timeout = strtoint(&option[8]);
-				if (timeout == -1) continue;
-				if (!(flags & DNS_OPTION_MISC)) continue;
-				log(EVDNS_LOG_DEBUG, "Setting timeout to %d", timeout);
-				global_timeout.tv_sec = timeout;
-			} else if (!strncmp(option, "attempts:", 9)) {
-				int retries = strtoint(&option[9]);
-				if (retries == -1) continue;
-				if (retries > 255) retries = 255;
-				if (!(flags & DNS_OPTION_MISC)) continue;
-				log(EVDNS_LOG_DEBUG, "Setting retries to %d", retries);
-				global_max_retransmits = retries;
-			}
+			const char *val = strchr(option, ':');
+            evdns_set_option(option, val ? val+1 : "", flags);
 		}
 	}
 #undef NEXT_TOKEN

src/or/eventdns.h

@@ -269,6 +269,7 @@ struct in_addr;
 struct in6_addr;
 int evdns_resolve_reverse(struct in_addr *in, int flags, evdns_callback_type callback, void *ptr);
 int evdns_resolve_reverse_ipv6(struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr);
+int evdns_set_option(const char *option, const char *val, int flags);
 int evdns_resolv_conf_parse(int flags, const char *);
 #ifdef MS_WINDOWS
 int evdns_config_windows_nameservers(void);