Improve behaviour when flushing out after a process has exited.

--HG--
branch : channel-fix
extra : convert_revision : e73ee8f7ae404a9355685c30828a0ad4524031bc

1 files changed, 18 insertions, 1 deletions

diff --git a/common-session.c b/common-session.c
index a16d1f9..6e1abf3 100644
--- a/common-session.c
+++ b/common-session.c
@@ -61,6 +61,12 @@ void common_session_init(int sock, char* remotehost) {
 
 	ses.connecttimeout = 0;
 	
+	if (pipe(ses.signal_pipe) < 0) {
+		dropbear_exit("signal pipe failed");
+	}
+	setnonblocking(ses.signal_pipe[0]);
+	setnonblocking(ses.signal_pipe[1]);
+	
 	kexfirstinitialise(); /* initialise the kex state */
 
 	ses.writepayload = buf_new(MAX_TRANS_PAYLOAD_LEN);
@@ -108,7 +114,6 @@ void common_session_init(int sock, char* remotehost) {
 
 	ses.allowprivport = 0;
 
-
 	TRACE(("leave session_init"))
 }
 
@@ -132,6 +137,10 @@ void session_loop(void(*loophandler)()) {
 				FD_SET(ses.sock, &writefd);
 			}
 		}
+		
+		/* We get woken up when signal handlers write to this pipe.
+		   SIGCHLD in svr-chansession is the only one currently. */
+		FD_SET(ses.signal_pipe[0], &readfd);
 
 		/* set up for channels which require reading/writing */
 		if (ses.dataallowed) {
@@ -155,6 +164,14 @@ void session_loop(void(*loophandler)()) {
 			FD_ZERO(&writefd);
 			FD_ZERO(&readfd);
 		}
+		
+		/* We'll just empty out the pipe if required. We don't do
+		any thing with the data, since the pipe's purpose is purely to
+		wake up the select() above. */
+		if (FD_ISSET(ses.signal_pipe[0], &readfd)) {
+			char x;
+			while (read(ses.signal_pipe[0], &x, 1) > 0) {}
+		}
 
 		/* check for auth timeout, rekeying required etc */
 		checktimeouts();