*** empty log message ***

5 files changed, 238 insertions, 61 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 40f7014..0247d11 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -8,7 +8,7 @@ lib_LTLIBRARIES = libfuse.la libulockmgr.la
 if BSD
 mount_source = mount_bsd.c
 else
-mount_source = mount.c
+mount_source = mount.c mount_util.c mount_util.h
 endif
 
 if ICONV
diff --git a/lib/helper.c b/lib/helper.c
index a1e9eb0..e6bfc4d 100644
--- a/lib/helper.c
+++ b/lib/helper.c
@@ -180,13 +180,6 @@ int fuse_daemonize(int foreground)
             perror("fuse: failed to daemonize program\n");
             return -1;
         }
-    } else {
-        /* Ensure consistant behavior across debug and normal modes */
-        res = chdir("/");
-        if (res == -1) {
-            perror("fuse: failed to change working directory to /\n");
-            return -1;
-        }
     }
     return 0;
 }
diff --git a/lib/mount.c b/lib/mount.c
index 5232737..3ca5e7e 100644
--- a/lib/mount.c
+++ b/lib/mount.c
@@ -10,6 +10,7 @@
 #include "fuse_i.h"
 #include "fuse_opt.h"
 #include "fuse_common_compat.h"
+#include "mount_util.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -52,7 +53,6 @@ struct mount_opts {
     int flags;
     int nonempty;
     int blkdev;
-    int large_read;
     char *fsname;
     char *mtab_opts;
     char *fusermount_opts;
@@ -67,13 +67,12 @@ static const struct fuse_opt fuse_mount_opts[] = {
     FUSE_MOUNT_OPT("nonempty",          nonempty),
     FUSE_MOUNT_OPT("blkdev",            blkdev),
     FUSE_MOUNT_OPT("fsname=%s",         fsname),
-    FUSE_MOUNT_OPT("large_read",        large_read),
     FUSE_OPT_KEY("allow_other",         KEY_KERN_OPT),
     FUSE_OPT_KEY("allow_root",          KEY_ALLOW_ROOT),
     FUSE_OPT_KEY("nonempty",            KEY_FUSERMOUNT_OPT),
     FUSE_OPT_KEY("blkdev",              KEY_FUSERMOUNT_OPT),
     FUSE_OPT_KEY("fsname=",             KEY_FUSERMOUNT_OPT),
-    FUSE_OPT_KEY("large_read",          KEY_FUSERMOUNT_OPT),
+    FUSE_OPT_KEY("large_read",          KEY_KERN_OPT),
     FUSE_OPT_KEY("blksize=",            KEY_KERN_OPT),
     FUSE_OPT_KEY("default_permissions", KEY_KERN_OPT),
     FUSE_OPT_KEY("max_read=",           KEY_KERN_OPT),
@@ -356,34 +355,6 @@ int fuse_mount_compat22(const char *mountpoint, const char *opts)
     return rv;
 }
 
-static int add_mount(const char *fsname, const char *mnt, const char *type,
-                     const char *opts)
-{
-    int res;
-    int status;
-
-    res = fork();
-    if (res == -1) {
-        perror("fork");
-        return -1;
-    }
-    if (res == 0) {
-        setuid(geteuid());
-        execl("/bin/mount", "/bin/mount", "-i", "-f", "-t", type, "-o", opts,
-              fsname, mnt, NULL);
-        perror("execl /bin/mount");
-        exit(1);
-    }
-    res = waitpid(res, &status, 0);
-    if (res == -1) {
-        perror("waitpid");
-        return -1;
-    }
-    if (status != 0)
-        return -1;
-
-    return 0;
-}
 
 static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
                           const char *mnt_opts)
@@ -395,20 +366,29 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
     int fd;
     int res;
 
-    /* For now silently fall back to fusermount if something doesn't work */
-
-    /* FIXME: check non-empty mountpoint*/
-
-    if (mo->large_read)
-        return -1;
-
     res = lstat(mnt, &stbuf);
-    if (res == -1)
+    if (res == -1) {
+        fprintf(stderr ,"fuse: failed to access mountpoint %s: %s\n",
+                mnt, strerror(errno));
         return -1;
+    }
+
+    if (!mo->nonempty) {
+        res = fuse_mnt_check_empty("fuse", mnt, stbuf.st_mode, stbuf.st_size);
+        if (res == -1)
+            return -1;
+    }
 
     fd = open(devname, O_RDWR);
-    if (fd == -1)
+    if (fd == -1) {
+        if (errno == ENODEV || errno == ENOENT)
+            fprintf(stderr,
+                    "fuse: device not found, try 'modprobe fuse' first\n");
+        else
+            fprintf(stderr, "fuse: failed to open %s: %s\n", devname,
+                    strerror(errno));
         return -1;
+    }
 
     if (mo->fsname)
         devname = mo->fsname;
@@ -416,24 +396,42 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
     snprintf(tmp, sizeof(tmp),  "fd=%i,rootmode=%o,user_id=%i,group_id=%i", fd,
              stbuf.st_mode & S_IFMT, getuid(), getgid());
 
-    if (fuse_opt_add_opt(&mo->kernel_opts, tmp) == -1) {
-        close(fd);
-        return -1;
-    }
+    res = fuse_opt_add_opt(&mo->kernel_opts, tmp);
+    if (res == -1)
+        goto out_close;
+
     res = mount(devname, mnt, type, mo->flags, mo->kernel_opts);
     if (res == -1) {
-        close(fd);
-        return -1;
+        /*
+         * Maybe kernel doesn't support unprivileged mounts, in this
+         * case try falling back to fusermount
+         */
+        if (errno == EPERM)
+            res = -2;
+        else
+            perror("fuse: mount failed");
+        goto out_close;
     }
+
     if (geteuid() == 0) {
-        res = add_mount(devname, mnt, type, mnt_opts);
-        if (res == -1) {
-            umount2(mnt, 2); /* lazy umount */
-            close(fd);
-            return -1;
-        }
+        char *newmnt = fuse_mnt_resolve_path("fuse", mnt);
+        res = -1;
+        if (!newmnt)
+            goto out_umount;
+
+        res = fuse_mnt_add_mount("fuse", devname, newmnt, type, mnt_opts);
+        free(newmnt);
+        if (res == -1)
+            goto out_umount;
     }
+
     return fd;
+
+ out_umount:
+    umount2(mnt, 2); /* lazy umount */
+ out_close:
+    close(fd);
+    return res;
 }
 
 static int get_mnt_flag_opts(char **mnt_optsp, int flags)
@@ -481,7 +479,7 @@ int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
         goto out;
 
     res = fuse_mount_sys(mountpoint, &mo, mnt_opts);
-    if (res == -1) {
+    if (res == -2) {
         if (mo.fusermount_opts && 
             fuse_opt_add_opt(&mnt_opts, mo.fusermount_opts) == -1)
             goto out;
diff --git a/lib/mount_util.c b/lib/mount_util.c
new file mode 100644
index 0000000..852e264
--- /dev/null
+++ b/lib/mount_util.c
@@ -0,0 +1,171 @@
+/*
+    FUSE: Filesystem in Userspace
+    Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
+
+    This program can be distributed under the terms of the GNU LGPL.
+    See the file COPYING.LIB.
+*/
+
+#include "mount_util.h"
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <errno.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+int fuse_mnt_add_mount(const char *progname, const char *fsname,
+                       const char *mnt, const char *type, const char *opts)
+{
+    int res;
+    int status;
+
+    res = fork();
+    if (res == -1) {
+        fprintf(stderr, "%s: fork: %s\n", progname, strerror(errno));
+        return -1;
+    }
+    if (res == 0) {
+        char templ[] = "/tmp/fusermountXXXXXX";
+        char *tmp;
+
+        setuid(geteuid());
+
+        /* 
+         * hide in a directory, where mount isn't able to resolve
+         * fsname as a valid path
+         */
+        tmp = mkdtemp(templ);
+        if (!tmp) {
+            fprintf(stderr, "%s: failed to create temporary directory\n",
+                    progname);
+            exit(1);
+        }
+        if (mkdir(tmp, 0) == -1) {
+            fprintf(stderr, "%s: failed to mkdir %s: %s\n", progname, tmp,
+                    strerror(errno));
+            exit(1);
+        }
+        if (chdir(tmp)) {
+            fprintf(stderr, "%s: failed to chdir to %s: %s\n",
+                    progname, tmp, strerror(errno));
+            exit(1);
+        }
+        rmdir(tmp);
+        execl("/bin/mount", "/bin/mount", "-i", "-f", "-t", type, "-o", opts,
+              fsname, mnt, NULL);
+        fprintf(stderr, "%s: failed to execute /bin/mount: %s\n", progname,
+                strerror(errno));
+        exit(1);
+    }
+    res = waitpid(res, &status, 0);
+    if (res == -1) {
+        fprintf(stderr, "%s: waitpid: %s\n", progname, strerror(errno));
+        return -1;
+    }
+    if (status != 0)
+        return -1;
+
+    return 0;
+}
+
+char *fuse_mnt_resolve_path(const char *progname, const char *orig)
+{
+    char buf[PATH_MAX];
+    char *copy;
+    char *dst;
+    char *end;
+    char *lastcomp;
+    const char *toresolv;
+
+    if (!orig[0]) {
+        fprintf(stderr, "%s: invalid mountpoint '%s'\n", progname, orig);
+        return NULL;
+    }
+
+    copy = strdup(orig);
+    if (copy == NULL) {
+        fprintf(stderr, "%s: failed to allocate memory\n", progname);
+        return NULL;
+    }
+
+    toresolv = copy;
+    lastcomp = NULL;
+    for (end = copy + strlen(copy) - 1; end > copy && *end == '/'; end --);
+    if (end[0] != '/') {
+        char *tmp;
+        end[1] = '\0';
+        tmp = strrchr(copy, '/');
+        if (tmp == NULL) {
+            lastcomp = copy;
+            toresolv = ".";
+        } else {
+            lastcomp = tmp + 1;
+            if (tmp == copy)
+                toresolv = "/";
+        }
+        if (strcmp(lastcomp, ".") == 0 || strcmp(lastcomp, "..") == 0) {
+            lastcomp = NULL;
+            toresolv = copy;
+        }
+        else if (tmp)
+            tmp[0] = '\0';
+    }
+    if (realpath(toresolv, buf) == NULL) {
+        fprintf(stderr, "%s: bad mount point %s: %s\n", progname, orig,
+                strerror(errno));
+        free(copy);
+        return NULL;
+    }
+    if (lastcomp == NULL)
+        dst = strdup(buf);
+    else {
+        dst = (char *) malloc(strlen(buf) + 1 + strlen(lastcomp) + 1);
+        if (dst) {
+            unsigned buflen = strlen(buf);
+            if (buflen && buf[buflen-1] == '/')
+                sprintf(dst, "%s%s", buf, lastcomp);
+            else
+                sprintf(dst, "%s/%s", buf, lastcomp);
+        }
+    }
+    free(copy);
+    if (dst == NULL)
+        fprintf(stderr, "%s: failed to allocate memory\n", progname);
+    return dst;
+}
+
+int fuse_mnt_check_empty(const char *progname, const char *mnt,
+                         mode_t rootmode, off_t rootsize)
+{
+    int isempty = 1;
+
+    if (S_ISDIR(rootmode)) {
+        struct dirent *ent;
+        DIR *dp = opendir(mnt);
+        if (dp == NULL) {
+            fprintf(stderr, "%s: failed to open mountpoint for reading: %s\n",
+                    progname, strerror(errno));
+            return -1;
+        }
+        while ((ent = readdir(dp)) != NULL) {
+            if (strcmp(ent->d_name, ".") != 0 &&
+                strcmp(ent->d_name, "..") != 0) {
+                isempty = 0;
+                break;
+            }
+        }
+        closedir(dp);
+    } else if (rootsize)
+        isempty = 0;
+
+    if (!isempty) {
+        fprintf(stderr, "%s: mountpoint is not empty\n", progname);
+        fprintf(stderr, "%s: if you are sure this is safe, use the 'nonempty' mount option\n", progname);
+        return -1;
+    }
+    return 0;
+}
diff --git a/lib/mount_util.h b/lib/mount_util.h
new file mode 100644
index 0000000..d341df7
--- /dev/null
+++ b/lib/mount_util.h
@@ -0,0 +1,15 @@
+/*
+    FUSE: Filesystem in Userspace
+    Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
+
+    This program can be distributed under the terms of the GNU LGPL.
+    See the file COPYING.LIB.
+*/
+
+#include <sys/types.h>
+
+int fuse_mnt_add_mount(const char *progname, const char *fsname,
+                       const char *mnt, const char *type, const char *opts);
+char *fuse_mnt_resolve_path(const char *progname, const char *orig);
+int fuse_mnt_check_empty(const char *progname, const char *mnt,
+                         mode_t rootmode, off_t rootsize);