Fix smtp proto

We enable readcb for srvdst to relay the 220 smtp greeting from the
server to the client, otherwise the conn stalls.
Related with issue #18 too.

src/protoautossl.c

@@ -128,7 +128,7 @@ protoautossl_conn_connect(pxy_conn_ctx_t *ctx)
 
 	/* initiate connection */
 	if (bufferevent_socket_connect(ctx->srvdst.bev, (struct sockaddr *)&ctx->dstaddr, ctx->dstaddrlen) == -1) {
-		log_err_level_printf(LOG_CRIT, "bufferevent_socket_connect for srvdst failed\n");
+		log_err_level_printf(LOG_CRIT, "protoautossl_conn_connect: bufferevent_socket_connect for srvdst failed\n");
 		log_fine("bufferevent_socket_connect for srvdst failed");
 		// @attention Do not try to term/close conns or do anything else with conn ctx on the thrmgr thread after setting event callbacks and/or socket connect. Just return 0.
 	}

src/protosmtp.c

@@ -26,6 +26,7 @@
  */
 
 #include "protosmtp.h"
+#include "prototcp.h"
 #include "protossl.h"
 
 #include <string.h>
@@ -91,11 +92,86 @@ protosmtp_validate(pxy_conn_ctx_t *ctx, char *packet
 	return 0;
 }
 
+static int NONNULL(1) WUNRES
+protosmtp_conn_connect(pxy_conn_ctx_t *ctx)
+{
+	log_finest("ENTER");
+
+	/* create server-side socket and eventbuffer */
+	if (ctx->protoctx->proto == PROTO_SMTP) {
+		if (prototcp_setup_srvdst(ctx) == -1) {
+			return -1;
+		}
+	} else {
+		if (protossl_setup_srvdst(ctx) == -1) {
+			return -1;
+		}
+	}
+
+	// Conn setup is successful, so add the conn to the conn list of its thread now
+	pxy_thrmgr_add_conn(ctx);
+
+	// We enable readcb for srvdst to relay the 220 smtp greeting from the server to the client, otherwise the conn stalls
+	bufferevent_setcb(ctx->srvdst.bev, pxy_bev_readcb, pxy_bev_writecb, pxy_bev_eventcb, ctx);
+	bufferevent_enable(ctx->srvdst.bev, EV_READ|EV_WRITE);
+	
+	/* initiate connection */
+	if (bufferevent_socket_connect(ctx->srvdst.bev, (struct sockaddr *)&ctx->dstaddr, ctx->dstaddrlen) == -1) {
+		log_err_level_printf(LOG_CRIT, "protosmtp_conn_connect: bufferevent_socket_connect for srvdst failed\n");
+		log_fine("bufferevent_socket_connect for srvdst failed");
+		// @attention Do not try to term/close conns or do anything else with conn ctx on the thrmgr thread after setting event callbacks and/or socket connect.
+	}
+	return 0;
+}
+
+static void NONNULL(1)
+protosmtp_bev_readcb_srvdst(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
+{
+	log_finest_va("ENTER, size=%zu", evbuffer_get_length(bufferevent_get_input(bev)));
+
+	// Make sure src.bev exists
+	if (ctx->src.bev) {
+		if (prototcp_try_send_userauth_msg(ctx->src.bev, ctx)) {
+			return;
+		}
+	}
+
+	if (ctx->src.closed) {
+		pxy_discard_inbuf(bev);
+		return;
+	}
+
+	struct evbuffer *inbuf = bufferevent_get_input(bev);
+	struct evbuffer *outbuf = bufferevent_get_output(ctx->src.bev);
+	evbuffer_add_buffer(outbuf, inbuf);
+	pxy_try_set_watermark(bev, ctx, ctx->src.bev);
+}
+
+static void NONNULL(1)
+protosmtp_bev_readcb(struct bufferevent *bev, void *arg)
+{
+	pxy_conn_ctx_t *ctx = arg;
+
+	if (bev == ctx->src.bev) {
+		prototcp_bev_readcb_src(bev, ctx);
+	} else if (bev == ctx->dst.bev) {
+		prototcp_bev_readcb_dst(bev, ctx);
+	} else if (bev == ctx->srvdst.bev) {
+		protosmtp_bev_readcb_srvdst(bev, ctx);
+	} else {
+		log_err_printf("protosmtp_bev_readcb: UNKWN conn end\n");
+	}
+}
+
 protocol_t
 protosmtp_setup(pxy_conn_ctx_t *ctx)
 {
 	ctx->protoctx->proto = PROTO_SMTP;
 
+	ctx->protoctx->connectcb = protosmtp_conn_connect;
+
+	ctx->protoctx->bev_readcb = protosmtp_bev_readcb;
+
 	ctx->protoctx->validatecb = protosmtp_validate;
 
 	ctx->protoctx->arg = malloc(sizeof(protosmtp_ctx_t));
@@ -112,9 +188,10 @@ protosmtps_setup(pxy_conn_ctx_t *ctx)
 {
 	ctx->protoctx->proto = PROTO_SMTPS;
 
-	ctx->protoctx->connectcb = protossl_conn_connect;
+	ctx->protoctx->connectcb = protosmtp_conn_connect;
 	ctx->protoctx->fd_readcb = protossl_fd_readcb;
 	
+	ctx->protoctx->bev_readcb = protosmtp_bev_readcb;
 	ctx->protoctx->bev_eventcb = protossl_bev_eventcb;
 
 	ctx->protoctx->proto_free = protossl_free;

src/protossl.c

@@ -1256,7 +1256,7 @@ protossl_setup_srvdst_ssl(pxy_conn_ctx_t *ctx)
 	return 0;
 }
 
-static int NONNULL(1)
+int
 protossl_setup_srvdst(pxy_conn_ctx_t *ctx)
 {
 	if (protossl_setup_srvdst_ssl(ctx) == -1) {

src/protossl.h

@@ -52,6 +52,7 @@ int protossl_setup_dst_ssl_child(pxy_conn_child_ctx_t *) NONNULL(1);
 int protossl_setup_dst_new_bev_ssl_connecting_child(pxy_conn_child_ctx_t *) NONNULL(1);
 int protossl_setup_dst_child(pxy_conn_child_ctx_t *) NONNULL(1);
 
+int protossl_setup_srvdst(pxy_conn_ctx_t *ctx) NONNULL(1);
 int protossl_setup_srvdst_ssl(pxy_conn_ctx_t *) NONNULL(1);
 int protossl_setup_srvdst_new_bev_ssl_connecting(pxy_conn_ctx_t *) NONNULL(1);
 

src/prototcp.c

@@ -267,7 +267,7 @@ prototcp_try_validate_proto(struct bufferevent *bev, pxy_conn_ctx_t *ctx, struct
 	return 0;
 }
 
-static void NONNULL(1,2)
+void
 prototcp_bev_readcb_src(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
 {
 	log_finest_va("ENTER, size=%zu", evbuffer_get_length(bufferevent_get_input(bev)));
@@ -313,7 +313,7 @@ prototcp_bev_readcb_src(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
 	pxy_try_set_watermark(bev, ctx, ctx->dst.bev);
 }
 
-static void NONNULL(1)
+void
 prototcp_bev_readcb_dst(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
 {
 	log_finest_va("ENTER, size=%zu", evbuffer_get_length(bufferevent_get_input(bev)));

src/prototcp.h

@@ -38,6 +38,9 @@ int prototcp_try_send_userauth_msg(struct bufferevent *, pxy_conn_ctx_t *) NONNU
 int prototcp_try_close_unauth_conn(struct bufferevent *, pxy_conn_ctx_t *) NONNULL(1,2);
 int prototcp_try_close_protoerror_conn(struct bufferevent *, pxy_conn_ctx_t *) NONNULL(1,2);
 
+void prototcp_bev_readcb_src(struct bufferevent *, pxy_conn_ctx_t *) NONNULL(1,2);
+void prototcp_bev_readcb_dst(struct bufferevent *, pxy_conn_ctx_t *) NONNULL(1);
+
 void prototcp_bev_writecb_dst(struct bufferevent *, pxy_conn_ctx_t *) NONNULL(1);
 void prototcp_bev_writecb_srvdst(struct bufferevent *, pxy_conn_ctx_t *) NONNULL(1);