resolver: full ares support

Signed-off-by: hexian000 <hexian000@outlook.com>

README.md

@@ -87,9 +87,9 @@ If you downloaded a *-static build in the [Releases](https://github.com/hexian00
 
 ```sh
 # Debian & Ubuntu
-sudo apt install -y libev4
+sudo apt install libev4 libc-ares2
 # OpenWRT
-opkg install libev
+opkg install libev libcares
 ```
 
 *Lua is always statically linked.*
@@ -99,7 +99,9 @@ opkg install libev
 
 ```sh
 # Debian & Ubuntu
-sudo apt install -y libev-dev liblua5.4-dev
+sudo apt install libev-dev liblua5.4-dev libc-ares-dev
+# Alpine Linux
+apk add libev-dev lua5.4-dev c-ares-dev
 ```
 
 ### Building with CMake

ruleset.lua

@@ -34,6 +34,8 @@ _G.redirect_name = {
 _G.redirect = {
     -- redirect API address, or loopback will be rejected
     [1] = {match.exact("127.0.1.1:80"), rule.redirect("127.0.1.1:9080")},
+    -- redirect TCP DNS to local cache
+    [2] = {match.exact("1.1.1.1:53"), rule.redirect("127.0.0.53:53")},
     -- no default action, go to _G.route
     [0] = nil
 }

src/CMakeLists.txt

@@ -61,11 +61,10 @@ if(BUILD_STATIC OR LINK_STATIC_LIBS)
 else()
     find_library(LIBEV_LIBRARY NAMES ev)
 endif()
-if((EXISTS ${LIBEV_INCLUDE_DIR}) AND (EXISTS ${LIBEV_LIBRARY}))
-    message(STATUS "libev: ${LIBEV_LIBRARY}")
-else()
+if((NOT EXISTS ${LIBEV_INCLUDE_DIR}) OR (NOT EXISTS ${LIBEV_LIBRARY}))
     message(FATAL_ERROR "libev not found")
 endif()
+message(STATUS "libev: ${LIBEV_LIBRARY}")
 target_include_directories(neosocksd SYSTEM PRIVATE ${LIBEV_INCLUDE_DIR})
 target_link_libraries(neosocksd PRIVATE ${LIBEV_LIBRARY})
 
@@ -76,14 +75,14 @@ if(BUILD_STATIC OR LINK_STATIC_LIBS)
 else()
     find_library(LIBCARES_LIBRARY NAMES cares)
 endif()
-if((EXISTS ${LIBCARES_INCLUDE_DIR}) AND (EXISTS ${LIBCARES_LIBRARY}))
-    message(STATUS "c-ares: ${LIBCARES_LIBRARY}")
-    set(WITH_CARES ON)
+if((NOT EXISTS ${LIBCARES_INCLUDE_DIR}) OR (NOT EXISTS ${LIBCARES_LIBRARY}))
+    message(WARNING "c-ares not found, asynchronous name resolution is unavailable")
 else()
-    message(FATAL_ERROR "c-ares not found")
+    message(STATUS "c-ares: ${LIBCARES_LIBRARY}")
+    set(WITH_CARES 1)
+    target_include_directories(neosocksd SYSTEM PRIVATE ${LIBCARES_INCLUDE_DIR})
+    target_link_libraries(neosocksd PRIVATE ${LIBCARES_LIBRARY})
 endif()
-target_include_directories(neosocksd SYSTEM PRIVATE ${LIBCARES_INCLUDE_DIR})
-target_link_libraries(neosocksd PRIVATE ${LIBCARES_LIBRARY})
 
 # find lua
 find_path(LUA_INCLUDE_DIR
@@ -103,11 +102,10 @@ find_library(LUA_LIBRARY
     lib/lua53 lib/lua5.3 lib/lua-5.3
     lib/lua lib
 )
-if((EXISTS ${LUA_INCLUDE_DIR}) AND (EXISTS ${LUA_LIBRARY}))
-    message(STATUS "Lua: ${LUA_LIBRARY}")
-else()
+if((NOT EXISTS ${LUA_INCLUDE_DIR}) OR (NOT EXISTS ${LUA_LIBRARY}))
     message(FATAL_ERROR "Lua not found")
 endif()
+message(STATUS "Lua: ${LUA_LIBRARY}")
 target_include_directories(neosocksd SYSTEM PRIVATE ${LUA_INCLUDE_DIR})
 target_link_libraries(neosocksd PRIVATE ${LUA_LIBRARY} ${CMAKE_DL_LIBS})
 

src/conf.h

@@ -9,10 +9,12 @@
 struct config {
 	const char *listen;
 	const char *forward;
-	const char *nameserver;
 	const char *restapi;
 	const char *ruleset;
 	const char *user_name;
+#if WITH_CARES
+	const char *nameserver;
+#endif
 #if WITH_NETDEVICE
 	const char *netdev;
 #endif

src/dialer.c

@@ -1,17 +1,17 @@
 #include "dialer.h"
-#include "net/http.h"
-#include "proto/domain.h"
-#include "resolver.h"
 #include "utils/buffer.h"
 #include "utils/serialize.h"
 #include "utils/slog.h"
 #include "utils/check.h"
 #include "net/addr.h"
 #include "net/url.h"
+#include "net/http.h"
+#include "proto/domain.h"
 #include "proto/socks.h"
 #include "conf.h"
 #include "sockutil.h"
 #include "util.h"
+#include "resolver.h"
 
 #include <ev.h>
 #include <errno.h>
@@ -175,6 +175,9 @@ static void dialer_cancel(struct dialer *restrict d, struct ev_loop *loop)
 	switch (d->state) {
 	case STATE_INIT:
 		break;
+	case STATE_RESOLVE:
+		resolve_cancel(&d->resolve_query);
+		/* fallthrough */
 	case STATE_CONNECT:
 	case STATE_HANDSHAKE1:
 	case STATE_HANDSHAKE2: {
@@ -760,16 +763,15 @@ static bool connect_sa(
 	return true;
 }
 
-static void
-resolve_cb(struct ev_loop *loop, const struct sockaddr *sa, void *data)
+static void resolve_cb(struct ev_loop *loop, void *data)
 {
 	struct dialer *restrict d = data;
-	const struct domain_name *restrict domain =
-		d->req->num_proxy > 0 ? &d->req->proxy[0].addr.domain :
-					&d->req->addr.domain;
+	const struct dialaddr *restrict addr =
+		d->req->num_proxy > 0 ? &d->req->proxy[0].addr : &d->req->addr;
+	const struct sockaddr *sa = resolve_get(&d->resolve_query);
 	if (sa == NULL) {
-		LOGE_F("name resolution failed: \"%.*s\"", (int)domain->len,
-		       domain->name);
+		LOGE_F("name resolution failed: \"%.*s\"",
+		       (int)addr->domain.len, addr->domain.name);
 		return;
 	}
 
@@ -787,11 +789,13 @@ resolve_cb(struct ev_loop *loop, const struct sockaddr *sa, void *data)
 		FAIL();
 	}
 
-	if (LOGLEVEL(LOG_LEVEL_DEBUG)) {
+	if (LOGLEVEL(LOG_LEVEL_VERBOSE)) {
+		char node_str[addr->domain.len + 1 + 5 + 1];
+		dialaddr_format(addr, node_str, sizeof(node_str));
 		char addr_str[64];
 		format_sa(sa, addr_str, sizeof(addr_str));
-		LOG_F(LOG_LEVEL_DEBUG, "resolve: \"%.*s\" is \"%s\"",
-		      (int)domain->len, domain->name, addr_str);
+		LOG_F(LOG_LEVEL_VERBOSE, "resolve: \"%s\" is %s", node_str,
+		      addr_str);
 	}
 
 	if (!connect_sa(d, loop, sa)) {
@@ -864,7 +868,17 @@ bool dialer_start(
 		memcpy(host, addr->domain.name, addr->domain.len);
 		host[addr->domain.len] = '\0';
 		d->state = STATE_RESOLVE;
-		resolver_do(loop, host, d->conf->resolve_pf, resolve_cb, d);
+		struct resolve_query *q = &d->resolve_query;
+		resolve_init(
+			G.resolver, q,
+			(struct event_cb){
+				.cb = resolve_cb,
+				.ctx = d,
+			});
+		const int family = d->conf->resolve_pf;
+		if (!resolve_start(q, host, NULL, family)) {
+			return false;
+		}
 	} break;
 	default:
 		FAIL();

src/dialer.h

@@ -5,7 +5,7 @@
 #include "proto/socks.h"
 #include "utils/minmax.h"
 #include "utils/buffer.h"
-#include "net/url.h"
+#include "resolver.h"
 #include "sockutil.h"
 #include "util.h"
 
@@ -74,6 +74,7 @@ struct dialer {
 	const struct config *conf;
 	struct event_cb done_cb;
 	struct dialreq *req;
+	struct resolve_query resolve_query;
 	size_t jump;
 	int state;
 	enum dialer_error err;

src/forward.c

@@ -2,22 +2,21 @@
  * This code is licensed under MIT license (see LICENSE for details) */
 
 #include "forward.h"
+#include "utils/check.h"
+#include "utils/slog.h"
 #include "conf.h"
+#include "util.h"
 #include "server.h"
 #include "dialer.h"
 #include "sockutil.h"
 #include "transfer.h"
-#include "util.h"
-#include "utils/check.h"
-#include "utils/slog.h"
 
 #include <ev.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
 #include <unistd.h>
 
 #include <assert.h>
-#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>

src/http.c

@@ -4,11 +4,11 @@
 #include "http.h"
 #include "http_impl.h"
 #include "net/http.h"
-#include "server.h"
 #include "utils/minmax.h"
 #include "utils/buffer.h"
 #include "utils/slog.h"
 #include "utils/check.h"
+#include "server.h"
 #include "transfer.h"
 #include "dialer.h"
 #include "util.h"

src/http_api.c

@@ -2,11 +2,14 @@
 #include "net/url.h"
 #include "utils/formats.h"
 #include "utils/slog.h"
+#include "resolver.h"
 #include "ruleset.h"
 
+#include <stdint.h>
+
 static void handle_ruleset_stats(struct http_ctx *restrict ctx, const double dt)
 {
-	struct ruleset *restrict ruleset = ctx->s->ruleset;
+	struct ruleset *restrict ruleset = G.ruleset;
 	if (ruleset == NULL) {
 		return;
 	}
@@ -68,6 +71,8 @@ static void http_handle_stats(
 	const struct server *restrict s_ = ctx->s->data;
 	const struct server_stats *restrict stats = &s_->stats;
 	const struct listener_stats *restrict lstats = &s_->l.stats;
+	const struct resolver_stats *restrict resolv_stats =
+		resolver_stats(G.resolver);
 	const ev_tstamp now = ev_now(loop);
 	const double uptime = now - stats->started;
 	const time_t server_time = time(NULL);
@@ -91,6 +96,8 @@ static void http_handle_stats(
 
 	const double uptime_hrs = uptime / 3600.0;
 	const double avgreq_hrs = (double)(stats->num_request) / uptime_hrs;
+	const double avgresolv_hrs =
+		(double)(resolv_stats->num_query) / uptime_hrs;
 	FORMAT_BYTES(avgbw_up, ((double)stats->byt_up) / uptime_hrs);
 	FORMAT_BYTES(avgbw_down, ((double)stats->byt_down) / uptime_hrs);
 
@@ -99,22 +106,25 @@ static void http_handle_stats(
 		"Server Time         : %s\n"
 		"Uptime              : %s\n"
 		"Num Sessions        : %zu (+%zu)\n"
-		"Listener Accepts    : %ju (+%ju rejected)\n"
-		"Requests            : %ju (+%ju)\n"
-		"Avg Requests        : %.1f/hrs\n"
+		"Conn Accepts        : %ju (+%ju)\n"
+		"Requests            : %ju (+%ju), %.1f/hrs\n"
+		"Name Resolves       : %ju (+%ju), %.1f/hrs\n"
 		"Traffic             : Up %s, Down %s\n"
 		"Avg Bandwidth       : Up %s/hrs, Down %s/hrs\n",
 		timestamp, str_uptime, stats->num_sessions, stats->num_halfopen,
 		lstats->num_serve, num_reject, stats->num_success,
-		stats->num_request - stats->num_success, avgreq_hrs, xfer_up,
-		xfer_down, avgbw_up, avgbw_down);
+		stats->num_request - stats->num_success, avgreq_hrs,
+		resolv_stats->num_success,
+		resolv_stats->num_query - resolv_stats->num_success,
+		avgresolv_hrs, xfer_up, xfer_down, avgbw_up, avgbw_down);
 
 	if (stateless) {
 		return;
 	}
 
 	static struct {
 		uintmax_t num_success;
+		uintmax_t num_failure;
 		uintmax_t xfer_up, xfer_down;
 		uintmax_t num_accept;
 		uintmax_t num_reject;
@@ -133,18 +143,22 @@ static void http_handle_stats(
 		(double)(lstats->num_accept - last.num_accept) / dt;
 	const double reject_rate = (double)(num_reject - last.num_reject) / dt;
 
+	const uintmax_t num_failure = stats->num_request - stats->num_success;
 	const double success_rate =
 		(double)(stats->num_success - last.num_success) / dt;
+	const double failure_rate =
+		(double)(num_failure - last.num_failure) / dt;
 
 	BUF_APPENDF(
 		ctx->wbuf,
-		"Incoming Conns      : %.1f/s (%+.1f/s rejected)\n"
-		"Request Success     : %.1f/s\n"
+		"Accept Rate         : %.1f/s (%+.1f/s)\n"
+		"Request Rate        : %.1f/s (%+.1f/s)\n"
 		"Bandwidth           : Up %s/s, Down %s/s\n",
-		accept_rate, reject_rate, success_rate, xfer_rate_up,
-		xfer_rate_down);
+		accept_rate, reject_rate, success_rate, failure_rate,
+		xfer_rate_up, xfer_rate_down);
 
 	last.num_success = stats->num_success;
+	last.num_failure = num_failure;
 	last.xfer_up = stats->byt_up;
 	last.xfer_down = stats->byt_down;
 	last.num_accept = lstats->num_accept;
@@ -181,7 +195,7 @@ static void http_handle_ruleset(
 	struct url *restrict uri)
 {
 	UNUSED(loop);
-	struct ruleset *ruleset = ctx->s->ruleset;
+	struct ruleset *ruleset = G.ruleset;
 	if (ruleset == NULL) {
 		RESPHDR_POST(ctx->wbuf, HTTP_INTERNAL_SERVER_ERROR);
 		BUF_APPENDF(

src/http_proxy.c

@@ -65,8 +65,7 @@ static bool proxy_dial(
 	struct http_ctx *restrict ctx, struct ev_loop *loop,
 	const char *addr_str)
 {
-	struct server *restrict s = ctx->s;
-	struct ruleset *ruleset = s->ruleset;
+	struct ruleset *ruleset = G.ruleset;
 
 	struct dialreq *req = NULL;
 	if (ruleset == NULL) {