Switch from using pipes to socketpairs for communication between

sftp/scp and ssh, and between sshd and its subprocesses. This saves
a file descriptor per session and apparently makes userland ppp over
ssh work; ok markus@ deraadt@

3 files changed, 3 insertions, 69 deletions

diff --git a/usr.bin/ssh/includes.h b/usr.bin/ssh/includes.h
index 5a1a0de1b5c..7b0fcb5d0a7 100644
--- a/usr.bin/ssh/includes.h
+++ b/usr.bin/ssh/includes.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: includes.h,v 1.39 2006/03/25 22:22:43 djm Exp $ */
+/* $OpenBSD: includes.h,v 1.40 2006/04/20 21:53:44 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -39,10 +39,4 @@
 
 #include "version.h"
 
-/*
- * Define this to use pipes instead of socketpairs for communicating with the
- * client program.  Socketpairs do not seem to work on all systems.
- */
-#define USE_PIPES 1
-
 #endif				/* INCLUDES_H */
diff --git a/usr.bin/ssh/session.c b/usr.bin/ssh/session.c
index 763542662c0..faf70dd4b0c 100644
--- a/usr.bin/ssh/session.c
+++ b/usr.bin/ssh/session.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: session.c,v 1.202 2006/03/25 13:17:02 djm Exp $ */
+/* $OpenBSD: session.c,v 1.203 2006/04/20 21:53:44 djm Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -379,20 +379,12 @@ do_exec_no_pty(Session *s, const char *command)
 {
 	pid_t pid;
 
-#ifdef USE_PIPES
-	int pin[2], pout[2], perr[2];
-	/* Allocate pipes for communicating with the program. */
-	if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
-		packet_disconnect("Could not create pipes: %.100s",
-				  strerror(errno));
-#else /* USE_PIPES */
 	int inout[2], err[2];
 	/* Uses socket pairs to communicate with the program. */
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 	    socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 		packet_disconnect("Could not create socket pairs: %.100s",
 				  strerror(errno));
-#endif /* USE_PIPES */
 	if (s == NULL)
 		fatal("do_exec_no_pty: no session");
 
@@ -412,28 +404,6 @@ do_exec_no_pty(Session *s, const char *command)
 		if (setsid() < 0)
 			error("setsid failed: %.100s", strerror(errno));
 
-#ifdef USE_PIPES
-		/*
-		 * Redirect stdin.  We close the parent side of the socket
-		 * pair, and make the child side the standard input.
-		 */
-		close(pin[1]);
-		if (dup2(pin[0], 0) < 0)
-			perror("dup2 stdin");
-		close(pin[0]);
-
-		/* Redirect stdout. */
-		close(pout[0]);
-		if (dup2(pout[1], 1) < 0)
-			perror("dup2 stdout");
-		close(pout[1]);
-
-		/* Redirect stderr. */
-		close(perr[0]);
-		if (dup2(perr[1], 2) < 0)
-			perror("dup2 stderr");
-		close(perr[1]);
-#else /* USE_PIPES */
 		/*
 		 * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 		 * use the same socket, as some programs (particularly rdist)
@@ -447,7 +417,6 @@ do_exec_no_pty(Session *s, const char *command)
 			perror("dup2 stdout");
 		if (dup2(err[0], 2) < 0)	/* stderr */
 			perror("dup2 stderr");
-#endif /* USE_PIPES */
 
 		/* Do processing for the child (exec command etc). */
 		do_child(s, command);
@@ -458,24 +427,7 @@ do_exec_no_pty(Session *s, const char *command)
 	s->pid = pid;
 	/* Set interactive/non-interactive mode. */
 	packet_set_interactive(s->display != NULL);
-#ifdef USE_PIPES
-	/* We are the parent.  Close the child sides of the pipes. */
-	close(pin[0]);
-	close(pout[1]);
-	close(perr[1]);
 
-	if (compat20) {
-		if (s->is_subsystem) {
-			close(perr[0]);
-			perr[0] = -1;
-		}
-		session_set_fds(s, pin[1], pout[0], perr[0]);
-	} else {
-		/* Enter the interactive session. */
-		server_loop(pid, pin[1], pout[0], perr[0]);
-		/* server_loop has closed pin[1], pout[0], and perr[0]. */
-	}
-#else /* USE_PIPES */
 	/* We are the parent.  Close the child sides of the socket pairs. */
 	close(inout[0]);
 	close(err[0]);
@@ -490,7 +442,6 @@ do_exec_no_pty(Session *s, const char *command)
 		server_loop(pid, inout[1], inout[1], err[1]);
 		/* server_loop has closed inout[1] and err[1]. */
 	}
-#endif /* USE_PIPES */
 }
 
 /*
diff --git a/usr.bin/ssh/sftp.c b/usr.bin/ssh/sftp.c
index 91592b20598..392a2de1fd4 100644
--- a/usr.bin/ssh/sftp.c
+++ b/usr.bin/ssh/sftp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.80 2006/03/27 23:15:46 djm Exp $ */
+/* $OpenBSD: sftp.c,v 1.81 2006/04/20 21:53:44 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -1361,23 +1361,12 @@ connect_to_server(char *path, char **args, int *in, int *out)
 {
 	int c_in, c_out;
 
-#ifdef USE_PIPES
-	int pin[2], pout[2];
-
-	if ((pipe(pin) == -1) || (pipe(pout) == -1))
-		fatal("pipe: %s", strerror(errno));
-	*in = pin[0];
-	*out = pout[1];
-	c_in = pout[0];
-	c_out = pin[1];
-#else /* USE_PIPES */
 	int inout[2];
 
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) == -1)
 		fatal("socketpair: %s", strerror(errno));
 	*in = *out = inout[0];
 	c_in = c_out = inout[1];
-#endif /* USE_PIPES */
 
 	if ((sshpid = fork()) == -1)
 		fatal("fork: %s", strerror(errno));