Merge pull request #434 from giuseppe/use-extended-override-xattr

main: use extended override xattr

.github/workflows/release.yaml

@@ -5,7 +5,7 @@ on:
 
 jobs:
   release:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
       with:

.github/workflows/test.yaml

@@ -4,23 +4,23 @@ on: [push, pull_request]
 
 jobs:
   build_job:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     name: Build on ${{ matrix.arch }}
 
     strategy:
       matrix:
         include:
           - arch: armv7
-            distro: ubuntu22.04
+            distro: ubuntu_latest
           - arch: aarch64
-            distro: ubuntu22.04
+            distro: ubuntu_latest
           - arch: s390x
-            distro: ubuntu22.04
+            distro: ubuntu_latest
           - arch: ppc64le
-            distro: ubuntu22.04
+            distro: ubuntu_latest
     steps:
       - uses: actions/checkout@v2.1.0
-      - uses: uraimo/run-on-arch-action@v2.7.2
+      - uses: uraimo/run-on-arch-action@v2.8.1
         name: Build
         id: build
         with:
@@ -49,7 +49,7 @@ jobs:
             fuse-overlayfs
 
   Test:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
@@ -90,7 +90,7 @@ jobs:
     - name: Archive build artifacts
       uses: actions/upload-artifact@v3
       with:
-        name: fuse-overlayfs-x86_64-ubuntu22.04
+        name: fuse-overlayfs-x86_64-ubuntu-latest
         path: |
           fuse-overlayfs
       if: ${{ matrix.test == 'ovl-whiteouts' }}

main.c

@@ -508,43 +508,26 @@ node_dirfd (struct ovl_node *n)
   return n->layer->fd;
 }
 
-static bool
-has_prefix (const char *str, const char *pref)
-{
-  while (1)
-    {
-      if (*pref == '\0')
-        return true;
-      if (*str == '\0')
-        return false;
-      if (*pref != *str)
-        return false;
-      str++;
-      pref++;
-    }
-  return false;
-}
-
 static bool
 can_access_xattr (const struct ovl_layer *l, const char *name)
 {
   return ! (has_prefix (name, XATTR_PREFIX)
             || has_prefix (name, PRIVILEGED_XATTR_PREFIX)
             || has_prefix (name, UNPRIVILEGED_XATTR_PREFIX)
-            || (l->stat_override_mode == STAT_OVERRIDE_CONTAINERS &&
+            || (l->stat_override_mode == STAT_OVERRIDE_CONTAINERS && has_prefix (name, XATTR_SECURITY_PREFIX)));
-                has_prefix (name, XATTR_SECURITY_PREFIX)));
 }
 
-static bool encoded_xattr_name (const struct ovl_layer *l, const char *name)
+static bool
+encoded_xattr_name (const struct ovl_layer *l, const char *name)
 {
-  return has_prefix (name, XATTR_CONTAINERS_OVERRIDE_PREFIX) &&
+  return has_prefix (name, XATTR_CONTAINERS_OVERRIDE_PREFIX) && ! can_access_xattr (l, name + sizeof (XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1);
-         ! can_access_xattr (l, name + sizeof(XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1);
 }
 
-static const char *decode_xattr_name (const struct ovl_layer *l, const char *name)
+static const char *
+decode_xattr_name (const struct ovl_layer *l, const char *name)
 {
   if (encoded_xattr_name (l, name))
-    return name + sizeof(XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1;
+    return name + sizeof (XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1;
 
   if (can_access_xattr (l, name))
     return name;
@@ -552,18 +535,18 @@ static const char *decode_xattr_name (const struct ovl_layer *l, const char *nam
   return NULL;
 }
 
-static const char *encode_xattr_name (const struct ovl_layer *l, char *buf,
+static const char *
-                                      const char *name)
+encode_xattr_name (const struct ovl_layer *l, char *buf,
+                   const char *name)
 {
   if (can_access_xattr (l, name))
     return name;
 
-  if (l->stat_override_mode != STAT_OVERRIDE_CONTAINERS ||
+  if (l->stat_override_mode != STAT_OVERRIDE_CONTAINERS || strlen (name) > XATTR_NAME_MAX + 1 - sizeof (XATTR_CONTAINERS_OVERRIDE_PREFIX))
-      strlen(name) > XATTR_NAME_MAX + 1 - sizeof(XATTR_CONTAINERS_OVERRIDE_PREFIX))
     return NULL;
 
-  strcpy(buf, XATTR_CONTAINERS_OVERRIDE_PREFIX);
+  strcpy (buf, XATTR_CONTAINERS_OVERRIDE_PREFIX);
-  strcpy(buf + sizeof(XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1, name);
+  strcpy (buf + sizeof (XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1, name);
 
   return buf;
 }
@@ -2645,8 +2628,7 @@ filter_xattrs_list (struct ovl_layer *l, char *buf, ssize_t len)
         {
           char *next = it;
 
-          next += encoded_xattr_name (l, it) ?
+          next += encoded_xattr_name (l, it) ? sizeof (XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1 : it_len;
-                  sizeof(XATTR_CONTAINERS_OVERRIDE_PREFIX) - 1 : it_len;
 
           memmove (it, next, buf + len - next);
           len -= it_len;
@@ -2742,7 +2724,7 @@ ovl_getxattr (fuse_req_t req, fuse_ino_t ino, const char *name, size_t size)
     }
 
   name = encode_xattr_name (node->layer, name_buf, name);
-  if (!name)
+  if (! name)
     {
       fuse_reply_err (req, ENODATA);
       return;
@@ -3551,12 +3533,12 @@ ovl_setxattr (fuse_req_t req, fuse_ino_t ino, const char *name,
       return;
     }
 
-    name = encode_xattr_name (node->layer, name_buf, name);
+  name = encode_xattr_name (node->layer, name_buf, name);
-    if (!name)
+  if (! name)
-      {
+    {
-        fuse_reply_err (req, EPERM);
+      fuse_reply_err (req, EPERM);
-        return;
+      return;
-      }
+    }
 
   if (! node->hidden)
     ret = direct_setxattr (node->layer, node->path, name, value, size, flags);
@@ -3619,12 +3601,12 @@ ovl_removexattr (fuse_req_t req, fuse_ino_t ino, const char *name)
       return;
     }
 
-    name = encode_xattr_name (node->layer, name_buf, name);
+  name = encode_xattr_name (node->layer, name_buf, name);
-    if (!name)
+  if (! name)
-      {
+    {
-        fuse_reply_err (req, EPERM);
+      fuse_reply_err (req, EPERM);
-        return;
+      return;
-      }
+    }
 
   if (! node->hidden)
     ret = direct_removexattr (node->layer, node->path, name);

tests/fedora-installs.sh

@@ -6,7 +6,7 @@ mkdir lower upper workdir merged
 
 fuse-overlayfs -o sync=0,lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
 
-docker run --rm -v $(pwd)/merged:/merged fedora dnf --installroot /merged --releasever 30 install -y glibc-common gedit
+docker run --rm -v $(pwd)/merged:/merged fedora dnf --use-host-config --installroot /merged --releasever 41 install -y glibc-common gedit
 
 umount merged
 
@@ -30,7 +30,7 @@ stat -c %A upper/suid | grep s
 stat -c %a upper/nosuid | grep -v s
 
 # Install some big packages
-docker run --rm -v $(pwd)/merged:/merged fedora dnf --installroot /merged --releasever 30 install -y emacs texlive
+docker run --rm -v $(pwd)/merged:/merged fedora dnf --use-host-config --installroot /merged --releasever 41 install -y emacs texlive
 
 docker run --rm -v $(pwd)/merged:/merged fedora sh -c 'rm /merged/usr/share/glib-2.0/schemas/gschemas.compiled; glib-compile-schemas /merged/usr/share/glib-2.0/schemas/'
 
@@ -48,7 +48,7 @@ mkdir upper workdir lower
 # fast_ino_check
 fuse-overlayfs -o fast_ino_check=1,sync=0,lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
 
-docker run --rm -v $(pwd)/merged:/merged fedora dnf --installroot /merged --releasever 30 install -y glibc-common gedit
+docker run --rm -v $(pwd)/merged:/merged fedora dnf --use-host-config --installroot /merged --releasever 41 install -y glibc-common gedit
 
 mkdir merged/a-directory
 

utils.c

@@ -224,16 +224,38 @@ open_fd_or_get_path (struct ovl_layer *l, const char *path, char *out, int *fd,
   return *fd;
 }
 
+int
+read_device (const char *s, dev_t *dev)
+{
+  unsigned int major, minor;
+  int ret;
+
+  while (*s == '-')
+    s++;
+
+  ret = sscanf (s, "%u-%u", &major, &minor);
+  if (ret != 2)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  *dev = makedev (major, minor);
+
+  return 0;
+}
+
 int
 override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *path, struct stat *st)
 {
   int ret;
   uid_t uid;
   gid_t gid;
-  mode_t mode;
+  mode_t mode = 0;
   char buf[64];
   cleanup_close int cleanup_fd = -1;
   const char *xattr_name;
+  cleanup_free char *type = NULL;
 
   switch (st->st_mode & S_IFMT)
     {
@@ -296,8 +318,45 @@ override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *pa
 
   buf[ret] = '\0';
 
-  ret = sscanf (buf, "%d:%d:%o", &uid, &gid, &mode);
+  ret = sscanf (buf, "%d:%d:%o:%ms", &uid, &gid, &mode, &type);
-  if (ret != 3)
+  if (ret == 4)
+    {
+      if (has_prefix (type, "dir"))
+        mode |= S_IFDIR;
+      else if (has_prefix (type, "file"))
+        mode |= S_IFREG;
+      else if (has_prefix (type, "symlink"))
+        mode |= S_IFLNK;
+      else if (has_prefix (type, "pipe"))
+        mode |= S_IFIFO;
+      else if (has_prefix (type, "socket"))
+        mode |= S_IFSOCK;
+      else if (has_prefix (type, "block"))
+        {
+          mode |= S_IFBLK;
+          ret = read_device (type + strlen ("block"), &st->st_rdev);
+          if (ret < 0)
+            return ret;
+        }
+      else if (has_prefix (type, "char"))
+        {
+          mode |= S_IFCHR;
+          ret = read_device (type + strlen ("char"), &st->st_rdev);
+          if (ret < 0)
+            return ret;
+        }
+      else
+        {
+          errno = EINVAL;
+          return -1;
+        }
+    }
+  else if (ret == 3)
+    {
+      /* If a type is not specified, keep the original one.  */
+      mode |= (st->st_mode & S_IFMT);
+    }
+  else
     {
       errno = EINVAL;
       return -1;
@@ -305,7 +364,24 @@ override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *pa
 
   st->st_uid = uid;
   st->st_gid = gid;
-  st->st_mode = (st->st_mode & S_IFMT) | mode;
+  st->st_mode = mode;
 
   return 0;
 }
+
+bool
+has_prefix (const char *str, const char *pref)
+{
+  while (1)
+    {
+      if (*pref == '\0')
+        return true;
+      if (*str == '\0')
+        return false;
+      if (*pref != *str)
+        return false;
+      str++;
+      pref++;
+    }
+  return false;
+}

utils.h

@@ -62,4 +62,6 @@ int safe_openat (int dirfd, const char *pathname, int flags, mode_t mode);
 
 int override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *path, struct stat *st);
 
+bool has_prefix (const char *str, const char *pref);
+
 #endif