From: Alan T. DeKok <aland@freeradius.org>
Date: Mon, 4 Jun 2018 01:21:50 +0000 (-0400)
Subject: allow for partial writes to sockets.
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=41b5ea24b4bf60fa60ac01529c3ad5b4fd637932;p=thirdparty%2Ffreeradius-server.git

allow for partial writes to sockets.

When that happens, save how much we've written, and remember
to keep doing the writes later.
---

diff --git a/src/lib/io/network.c b/src/lib/io/network.c
index b955749b387..2abd0971f5b 100644
--- a/src/lib/io/network.c
+++ b/src/lib/io/network.c
@@ -80,6 +80,7 @@ typedef struct fr_network_socket_t {
 	fr_message_set_t	*ms;			//!< message buffers for this socket.
 	fr_channel_data_t	*cd;			//!< cached in case of allocation & read error
 	size_t			leftover;		//!< leftover data from a previous read
+	size_t			written;		//!< however much we did in a partial write
 
 	fr_channel_data_t	*pending;		//!< the currently pending partial packet
 	fr_heap_t		*waiting;		//!< packets waiting to be written
@@ -588,6 +589,12 @@ static void fr_network_write(UNUSED fr_event_list_t *el, UNUSED int sockfd, UNUS
 
 	rad_assert(s->pending != NULL);
 
+	/*
+	 *	@todo - this code is much the same as in
+	 *	fr_network_post_event().  Fix it so we only have one
+	 *	copy!
+	 */
+
 	/*
 	 *	Start with the currently pending message, and then
 	 *	work through the priority heap.
@@ -609,6 +616,23 @@ static void fr_network_write(UNUSED fr_event_list_t *el, UNUSED int sockfd, UNUS
 			 *	pending message to the current one.
 			 */
 			if (errno == EWOULDBLOCK) {
+				s->pending = 0;
+
+			save_pending:
+				/*
+				 *	s->pending MUST be localized.
+				 *	Other messages in the list
+				 *	MUST NOT have been localized
+				 *	yet.
+				 */
+				if (cd->m.status != FR_MESSAGE_LOCALIZED) {
+					fr_message_t *lm;
+
+					MEM(lm = fr_message_localize(s, &cd->m, sizeof(*cd)));
+					fr_message_done(&cd->m);
+
+					cd = (fr_channel_data_t *) lm;
+				}
 				s->pending = cd;
 				return;
 			}
@@ -631,13 +655,15 @@ static void fr_network_write(UNUSED fr_event_list_t *el, UNUSED int sockfd, UNUS
 		}
 
 		/*
-		 *
-		 We MUST have written all of the data.  It is
-		 *	up to the app_io->write() function to track
-		 *	any partially written data.
+		 *	If we've done a partial write, localize the message and continue.
 		 */
-		rad_assert((size_t) rcode == cd->m.data_size);
+		if ((rcode > 0) && ((size_t) rcode < cd->m.data_size)) {
+			s->written = rcode;
+			goto save_pending;
+		}
+
 		s->pending = NULL;
+		s->written = 0;
 
 		/*
 		 *	Reset for the next message.
@@ -1202,6 +1228,9 @@ static void fr_network_post_event(UNUSED fr_event_list_t *el, UNUSED struct time
 					      cd->reply.request_time,
 					      cd->m.data, cd->m.data_size, 0);
 		if (rcode < 0) {
+			s->pending = 0;
+
+		save_pending:
 			if (errno == EWOULDBLOCK) {
 				if (fr_event_fd_insert(nr, nr->el, s->fd,
 						       fr_network_read,
@@ -1245,14 +1274,18 @@ static void fr_network_post_event(UNUSED fr_event_list_t *el, UNUSED struct time
 		}
 
 		/*
-		 *	We MUST have written all of the data.  It is
-		 *	up to the app_io->write() function to track
-		 *	any partially written data.
+		 *	If there's a partial write, save the write
+		 *	callback for later.
 		 */
-		rad_assert(!rcode || (size_t) rcode == cd->m.data_size);
+		if ((rcode > 0) && ((size_t) rcode < cd->m.data_size)) {
+			s->written = rcode;
+			goto save_pending;
+		}
 
 		DEBUG3("Sending reply to socket %d", s->fd);
 		fr_message_done(&cd->m);
+		s->pending = NULL;
+		s->written = 0;
 
 		/*
 		 *	As a special case, allow write() to return