dialer: fix socks5 forwarding

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

src/dialer.c

@@ -120,28 +120,29 @@ int dialaddr_format(
 	FAIL();
 }
 
-struct dialreq *dialreq_new(const size_t max_proxy)
+struct dialreq *dialreq_new(const size_t num_proxy)
 {
 	struct dialreq *restrict req = malloc(
-		sizeof(struct dialreq) + sizeof(struct proxy_req) * max_proxy);
+		sizeof(struct dialreq) + sizeof(struct proxy_req) * num_proxy);
 	if (req == NULL) {
 		return NULL;
 	}
-	req->num_proxy = 0;
+	req->num_proxy = num_proxy;
 	return req;
 }
 
-bool dialreq_proxy(
-	struct dialreq *restrict req, const char *proxy_uri, size_t len)
+bool dialreq_setproxy(
+	struct dialreq *restrict req, const size_t i, const char *proxy_uri,
+	const size_t urilen)
 {
 	/* should be more than enough */
-	if (len >= 1024) {
+	if (urilen >= 1024) {
 		LOGE_F("proxy uri is too long: \"%s\"", proxy_uri);
 		return false;
 	}
-	char buf[len + 1];
-	memcpy(buf, proxy_uri, len);
-	buf[len] = '\0';
+	char buf[urilen + 1];
+	memcpy(buf, proxy_uri, urilen);
+	buf[urilen] = '\0';
 	struct url uri;
 	if (!url_parse(buf, &uri)) {
 		LOGE_F("unable to parse uri: \"%s\"", proxy_uri);
@@ -163,14 +164,12 @@ bool dialreq_proxy(
 		LOGE_F("dialer: unknown scheme \"%s\"", uri.scheme);
 		return false;
 	}
-	const size_t n = req->num_proxy;
-	struct proxy_req *restrict proxy = &req->proxy[n];
+	struct proxy_req *restrict proxy = &req->proxy[i];
 	proxy->proto = protocol;
 	const size_t hostlen = strlen(uri.host);
 	if (!dialaddr_set(&proxy->addr, uri.host, hostlen)) {
 		return false;
 	}
-	req->num_proxy = n + 1;
 	return true;
 }
 
@@ -179,10 +178,10 @@ struct dialreq *dialreq_parse(const char *csv)
 	const size_t len = strlen(csv);
 	char buf[len + 1];
 	memcpy(buf, csv, len + 1);
-	size_t n = 1;
+	size_t n = 0;
 	for (size_t i = 0; i < len; i++) {
 		if (buf[i] == ',') {
-			n++;
+			++n;
 		}
 	}
 	struct dialreq *req = dialreq_new(n);
@@ -193,6 +192,7 @@ struct dialreq *dialreq_parse(const char *csv)
 	bool direct = true;
 	for (char *tok = strtok(buf, ","); tok != NULL;
 	     tok = strtok(NULL, ",")) {
+		LOGE_F("tok: %s", tok);
 		if (direct) {
 			if (!dialaddr_set(&req->addr, tok, strlen(tok))) {
 				dialreq_free(req);
@@ -201,7 +201,7 @@ struct dialreq *dialreq_parse(const char *csv)
 			direct = false;
 			continue;
 		}
-		if (!dialreq_proxy(req, tok, strlen(tok))) {
+		if (!dialreq_setproxy(req, --n, tok, strlen(tok))) {
 			dialreq_free(req);
 			return NULL;
 		}
@@ -560,12 +560,13 @@ static int recv_socks4a_rsp(struct dialer *restrict d)
 static int recv_socks5_rsp(struct dialer *restrict d)
 {
 	assert(d->state == STATE_HANDSHAKE2);
-	const size_t rsplen = sizeof(struct socks5_hdr) +
-			      sizeof(struct in6_addr) + sizeof(in_port_t);
-	if (d->buf.len < rsplen) {
-		return (int)(rsplen - d->buf.len);
-	}
 	const unsigned char *hdr = d->buf.data;
+	const size_t len = d->buf.len;
+	size_t expected = sizeof(struct socks5_hdr);
+	if (len < expected) {
+		return (int)(expected - len) + 1;
+	}
+
 	const uint8_t version =
 		read_uint8(hdr + offsetof(struct socks5_hdr, version));
 	if (version != SOCKS5) {
@@ -578,8 +579,24 @@ static int recv_socks5_rsp(struct dialer *restrict d)
 		LOGE_F("SOCKS5 failure: %" PRIu8, command);
 		return -1;
 	}
+	const uint8_t addrtype =
+		read_uint8(hdr + offsetof(struct socks5_hdr, addrtype));
+	switch (addrtype) {
+	case SOCKS5ADDR_IPV4:
+		expected += sizeof(struct in_addr) + sizeof(in_port_t);
+		break;
+	case SOCKS5ADDR_IPV6:
+		expected += sizeof(struct in6_addr) + sizeof(in_port_t);
+		break;
+	default:
+		LOGE_F("SOCKS5 invalid addrtype: %" PRIu8, addrtype);
+		return -1;
+	}
+	if (len < expected) {
+		return (int)(expected - len);
+	}
 	/* protocol finished, remove header */
-	if (!consume_rcvbuf(d, rsplen)) {
+	if (!consume_rcvbuf(d, expected)) {
 		return -1;
 	}
 	return 0;
@@ -609,7 +626,11 @@ static int recv_socks5_auth(struct dialer *restrict d)
 	if (!consume_rcvbuf(d, rsplen)) {
 		return -1;
 	}
+	BUF_CONSUME(d->buf, rsplen);
 	d->state = STATE_HANDSHAKE2;
+	if (!send_proxy_req(d)) {
+		return -1;
+	}
 	return recv_socks5_rsp(d);
 }
 
@@ -666,18 +687,19 @@ static int dialer_recv(
 	LOG_BIN_F(
 		LOG_LEVEL_VERBOSE, d->buf.data, d->buf.len, "recv: %zu bytes",
 		d->buf.len);
-	const int want = recv_dispatch(d, req);
-	if (want < 0) {
-		return want;
-	} else if (want == 0) {
+	const int ret = recv_dispatch(d, req);
+	if (ret < 0) {
+		return ret;
+	} else if (ret == 0) {
 		socket_rcvlowat(d->fd, 1);
 		return 0;
 	}
-	if (d->buf.len + (size_t)want > d->buf.cap) {
+	const size_t want = d->buf.len + (size_t)ret;
+	if (want > d->buf.cap) {
 		LOGE("recv: header too long");
 		return -1;
 	}
-	socket_rcvlowat(fd, (size_t)nrecv + (size_t)want);
+	socket_rcvlowat(fd, want);
 	return 1;
 }
 

src/dialer.h

@@ -52,8 +52,9 @@ struct dialreq {
 	struct proxy_req proxy[];
 };
 
-struct dialreq *dialreq_new(size_t max_proxy);
-bool dialreq_proxy(struct dialreq *r, const char *proxy_uri, size_t len);
+struct dialreq *dialreq_new(size_t num_proxy);
+bool dialreq_setproxy(
+	struct dialreq *r, size_t i, const char *proxy_uri, size_t urilen);
 struct dialreq *dialreq_parse(const char *csv);
 void dialreq_free(struct dialreq *r);
 

src/ruleset.c

@@ -72,7 +72,7 @@ static struct dialreq *pop_dialreq(lua_State *restrict L, int n)
 		LOGE_F("ruleset: returned address #%d is not a string", 1);
 		return NULL;
 	}
-	struct dialreq *req = dialreq_new((size_t)n);
+	struct dialreq *req = dialreq_new((size_t)(n - 1));
 	if (req == NULL) {
 		LOGOOM();
 		return NULL;
@@ -90,7 +90,7 @@ static struct dialreq *pop_dialreq(lua_State *restrict L, int n)
 			dialreq_free(req);
 			return NULL;
 		}
-		if (!dialreq_proxy(req, s, len)) {
+		if (!dialreq_setproxy(req, i - 1, s, len)) {
 			LOGE_F("ruleset: returned address #%d is not valid",
 			       n - i);
 			dialreq_free(req);