From 280515b790c44566679b0e1271466695f0914132 Mon Sep 17 00:00:00 2001
From: Sapan Bhatia <sapanb@cs.princeton.edu>
Date: Wed, 25 Mar 2009 18:35:50 +0000
Subject: [PATCH]

---
 fuse/{stolen_from_fuse.c => fdpass.c} | 79 ++-------------------------
 fuse/fdpass.h                         |  5 ++
 fuse/reroutemount.c                   | 14 ++---
 fuse/stolen_from_fuse.h               |  8 ---
 4 files changed, 17 insertions(+), 89 deletions(-)
 rename fuse/{stolen_from_fuse.c => fdpass.c} (56%)
 create mode 100644 fuse/fdpass.h
 delete mode 100644 fuse/stolen_from_fuse.h

diff --git a/fuse/stolen_from_fuse.c b/fuse/fdpass.c
similarity index 56%
rename from fuse/stolen_from_fuse.c
rename to fuse/fdpass.c
index 87fef01..5548064 100644
--- a/fuse/stolen_from_fuse.c
+++ b/fuse/fdpass.c
@@ -1,3 +1,6 @@
+// Modified version of library functions in FUSE
+//
+
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -6,16 +9,8 @@
 #include <sys/mount.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-#include "stolen_from_fuse.h"
-
-// Most of this code is stolen from FUSE 2.7.4
 
-/** Function to pass a file descriptor over a UNIX socket.
-  * 
-  * Sends the file descriptor fd over the channel sock_fd.
-  *
-  ***/
-int rrm_send_fd(int sock_fd, int fd)
+int send_fd(int sock_fd, int fd)
 {
 	int retval;
 	struct msghdr msg;
@@ -56,7 +51,7 @@ int rrm_send_fd(int sock_fd, int fd)
  * >= 0	 => fd
  * -1	 => error
  */
-int rrm_receive_fd(int fd)
+int receive_fd(int fd)
 {
 	struct msghdr msg;
 	struct iovec iov;
@@ -96,67 +91,3 @@ int rrm_receive_fd(int fd)
 	return *(int*)CMSG_DATA(cmsg);
 }
 
-int rrm_fuse_mnt_umount(const char *progname, const char *mnt, int lazy)
-{
-	int res;
-	int status;
-	
-	res = umount2(mnt, lazy ? 2 : 0);
-	if (res == -1)
-	  fprintf(stderr, "%s: failed to unmount %s: %s\n",
-		  progname, mnt, strerror(errno));
-	return res;
-
-}
-
-static int rrm_try_open(const char *dev, char **devp, int silent)
-{
-	int fd = open(dev, O_RDWR);
-	if (fd != -1) {
-		*devp = strdup(dev);
-		if (*devp == NULL) {
-		  fprintf(stderr, "failed to allocate memory\n" );
-				
-			close(fd);
-			fd = -1;
-		}
-	} else if (errno == ENODEV ||
-		   errno == ENOENT)/* check for ENOENT too, for the udev case */
-		return -2;
-	else if (!silent) {
-		fprintf(stderr, "failed to open %s: %s\n", dev,
-			strerror(errno));
-	}
-	return fd;
-}
-
-static int rrm_try_open_fuse_device(char **devp)
-{
-	int fd;
-	int err;
-
-	//drop_privs();
-	fd = rrm_try_open(FUSE_DEV_NEW, devp, 0);
-	//restore_privs();
-	if (fd >= 0)
-		return fd;
-
-	err = fd;
-	fd = rrm_try_open(FUSE_DEV_OLD, devp, 1);
-	if (fd >= 0)
-		return fd;
-
-	return err;
-}
-
-int rrm_open_fuse_device(char **devp)
-{
-	int fd = rrm_try_open_fuse_device(devp);
-	if (fd >= -1)
-		return fd;
-
-	fprintf(stderr,
-		"fuse device not found, try 'modprobe fuse' first\n");
-
-	return -1;
-}
diff --git a/fuse/fdpass.h b/fuse/fdpass.h
new file mode 100644
index 0000000..f00a6fb
--- /dev/null
+++ b/fuse/fdpass.h
@@ -0,0 +1,5 @@
+// Modified version of library functions in FUSE
+//
+int send_fd(int sock_fd, int fd);
+int receive_fd(int fd);
+
diff --git a/fuse/reroutemount.c b/fuse/reroutemount.c
index 9bb8b60..6a4469d 100644
--- a/fuse/reroutemount.c
+++ b/fuse/reroutemount.c
@@ -9,7 +9,7 @@
 char *socket_name = "/vsys/fd_fusemount.control";
 unsigned int arg_length = 128;
 
-void send_argument(int control_channel_fd, char *source) {
+void send_argument(int control_channel_fd, const char *source) {
     int sent;
     sent=send(control_channel_fd, source, arg_length, 0);
     if (sent<arg_length) {
@@ -99,17 +99,17 @@ int mount(const char *source, const char *target, const char *filesystemtype,
 
   old_fuse_fd = get_magic_fd (data);
 
-  send_fd(fd, old_fuse_fd);
 
-  if (fuse_fd == -1) {
-      printf ("Reroutemount: Could not identify FUSE fd: %d\n", fuse_fd);
+  if (old_fuse_fd == -1) {
+      printf ("Reroutemount: Could not identify FUSE fd: %d\n", old_fuse_fd);
       exit(1);
   }
 
+  send_fd(fd, old_fuse_fd);
   new_fuse_fd=receive_fd(fd);
 
   if (new_fuse_fd == -1) {
-      printf ("Reroutemount: Fusemount returned bad fd: %d\n", fuse_fd);
+      printf ("Reroutemount: Fusemount returned bad fd: %d\n", new_fuse_fd);
       exit(1);
   }
 
@@ -124,6 +124,7 @@ int mount(const char *source, const char *target, const char *filesystemtype,
 }
 
 int execv( const char *path, char *const argv[] ) {
+  int fd;
 
   if( strstr( path, "fusermount" ) == NULL ) {
     return execv( path, argv );
@@ -146,10 +147,9 @@ int execv( const char *path, char *const argv[] ) {
   }
 
   // Have root do any fusermounts we need done
-  int fd = connect_socket();
+  fd = connect_socket();
 
   do_umount( argv, n, fd );
-
   exit(0);
 
 }
diff --git a/fuse/stolen_from_fuse.h b/fuse/stolen_from_fuse.h
deleted file mode 100644
index 2ade06c..0000000
--- a/fuse/stolen_from_fuse.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#define FUSE_DEV_OLD "/proc/fs/fuse/dev"
-#define FUSE_DEV_NEW "/dev/fuse"
-
-int rrm_receive_fd(int fd);
-int rrm_send_fd(int sock_fd, int fd);
-int rrm_open_fuse_device(char **devp);
-int rrm_fuse_mnt_umount(const char *progname, const char *mnt, int lazy);
-
-- 
2.43.0