From 51edc2517af40c42381f983f2aa7175853c1208e Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Mon, 18 May 2015 16:54:55 +0100
Subject: [PATCH] Implement IO in lua tcp.

---
 src/lua/lua_tcp.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)

diff --git a/src/lua/lua_tcp.c b/src/lua/lua_tcp.c
index 20330299e..a5fb6a882 100644
--- a/src/lua/lua_tcp.c
+++ b/src/lua/lua_tcp.c
@@ -27,6 +27,8 @@
 #include "dns.h"
 #include "utlist.h"
 
+static void lua_tcp_handler (int fd, short what, gpointer ud);
+
 LUA_FUNCTION_DEF (tcp, request);
 
 static const struct luaL_reg tcp_libf[] = {
@@ -43,6 +45,8 @@ struct lua_tcp_cbdata {
 	rspamd_inet_addr_t *addr;
 	rspamd_mempool_t *pool;
 	struct iovec *iov;
+	GString *in;
+	struct event ev;
 	gint fd;
 	gint cbref;
 	guint iovlen;
@@ -74,6 +78,7 @@ lua_tcp_fin (gpointer arg)
 	luaL_unref (cbd->L, LUA_REGISTRYINDEX, cbd->cbref);
 
 	if (cbd->fd != -1) {
+		event_del (&cbd->ev);
 		close (cbd->fd);
 	}
 
@@ -106,6 +111,158 @@ lua_tcp_push_error (struct lua_tcp_cbdata *cbd, const char *err)
 	}
 }
 
+static void
+lua_tcp_push_data (struct lua_tcp_cbdata *cbd, const gchar *str, gsize len)
+{
+	struct rspamd_lua_text *t;
+
+	lua_rawgeti (cbd->L, LUA_REGISTRYINDEX, cbd->cbref);
+	/* Error */
+	lua_pushnil (cbd->L);
+	/* Body */
+	t = lua_newuserdata (cbd->L, sizeof (*t));
+	rspamd_lua_setclass (cbd->L, "rspamd{text}", -1);
+	t->start = str;
+	t->len = len;
+
+	if (lua_pcall (cbd->L, 2, 0, 0) != 0) {
+		msg_info ("callback call failed: %s", lua_tostring (cbd->L, -1));
+	}
+
+	if (!cbd->partial) {
+		lua_tcp_maybe_free (cbd);
+	}
+}
+
+static void
+lua_tcp_write_helper (struct lua_tcp_cbdata *cbd)
+{
+	struct iovec *start;
+	guint niov, i;
+	gint flags = 0;
+	gsize remain;
+	gssize r;
+	struct iovec *cur_iov;
+	struct msghdr msg;
+
+	if (cbd->pos == cbd->total) {
+		goto call_finish_handler;
+	}
+
+	start = &cbd->iov[0];
+	niov = cbd->iovlen;
+	remain = cbd->pos;
+	/* We know that niov is small enough for that */
+	cur_iov = alloca (niov * sizeof (struct iovec));
+	memcpy (cur_iov, cbd->iov, niov * sizeof (struct iovec));
+	for (i = 0; i < cbd->iovlen && remain > 0; i++) {
+		/* Find out the first iov required */
+		start = &cur_iov[i];
+		if (start->iov_len <= remain) {
+			remain -= start->iov_len;
+			start = &cur_iov[i + 1];
+			niov--;
+		}
+		else {
+			start->iov_base = (void *)((char *)start->iov_base + remain);
+			start->iov_len -= remain;
+			remain = 0;
+		}
+	}
+
+	memset (&msg, 0, sizeof (msg));
+	msg.msg_iov = start;
+	msg.msg_iovlen = MIN (IOV_MAX, niov);
+	g_assert (niov > 0);
+#ifdef MSG_NOSIGNAL
+	flags = MSG_NOSIGNAL;
+#endif
+	r = sendmsg (cbd->fd, &msg, flags);
+
+	if (r == -1) {
+		lua_tcp_push_error (cbd, "IO write error");
+		lua_tcp_maybe_free (cbd);
+		return;
+	}
+	else {
+		cbd->pos += r;
+	}
+
+	if (cbd->pos >= cbd->total) {
+		goto call_finish_handler;
+	}
+	else {
+		/* Want to write more */
+		event_add (&cbd->ev, &cbd->tv);
+	}
+
+	return;
+
+call_finish_handler:
+
+	if (!cbd->partial) {
+		cbd->in = g_string_sized_new (BUFSIZ);
+		rspamd_mempool_add_destructor (cbd->pool, rspamd_gstring_free_hard,
+				cbd->in);
+	}
+
+	event_del (&cbd->ev);
+	event_set (&cbd->ev, cbd->fd, EV_READ | EV_PERSIST, lua_tcp_handler, cbd);
+	event_base_set (cbd->ev_base, &cbd->ev);
+	event_add (&cbd->ev, &cbd->tv);
+}
+
+static void
+lua_tcp_handler (int fd, short what, gpointer ud)
+{
+	struct lua_tcp_cbdata *cbd = ud;
+	gchar inbuf[BUFSIZ];
+	gssize r;
+
+	if (what == EV_READ) {
+		g_assert (cbd->partial || cbd->in != NULL);
+
+		r = read (cbd->fd, inbuf, sizeof (inbuf));
+
+		if (r <= 0) {
+			/*
+			 * We actually can have connection reset here, so we just check if
+			 * the cumulative buffer is not empty
+			 */
+			if (cbd->partial) {
+				if (r < 0) {
+					lua_tcp_push_error (cbd, strerror (errno));
+				}
+			}
+			else {
+				if (cbd->in->len > 0) {
+					lua_tcp_push_data (cbd, cbd->in->str, cbd->in->len);
+				}
+				else {
+					lua_tcp_push_error (cbd, "IO read error");
+				}
+			}
+
+			lua_tcp_maybe_free (cbd);
+		}
+		else {
+			if (cbd->partial) {
+				lua_tcp_push_data (cbd, inbuf, r);
+			}
+			else {
+				g_string_append_len (cbd->in, inbuf, r);
+			}
+		}
+	}
+	else if (what == EV_WRITE) {
+		lua_tcp_write_helper (cbd);
+	}
+	else {
+		lua_tcp_push_error (cbd, "IO timeout");
+		lua_tcp_maybe_free (cbd);
+	}
+}
+
 static gboolean
 lua_tcp_make_connection (struct lua_tcp_cbdata *cbd)
 {
@@ -120,6 +277,10 @@ lua_tcp_make_connection (struct lua_tcp_cbdata *cbd)
 	}
 	cbd->fd = fd;
 
+	event_set (&cbd->ev, cbd->fd, EV_WRITE, lua_tcp_handler, cbd);
+	event_base_set (cbd->ev_base, &cbd->ev);
+	event_add (&cbd->ev, &cbd->tv);
+
 	return TRUE;
 }
 
-- 
2.39.5