Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 51 insertions, 0 deletions

diff --git a/tools/virtiofsd/passthrough_helpers.h b/tools/virtiofsd/passthrough_helpers.h
new file mode 100644
index 000000000..0b98275ed
--- /dev/null
+++ b/tools/virtiofsd/passthrough_helpers.h
@@ -0,0 +1,51 @@
+/*
+ * FUSE: Filesystem in Userspace
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE
+ */
+
+/*
+ * Creates files on the underlying file system in response to a FUSE_MKNOD
+ * operation
+ */
+static int mknod_wrapper(int dirfd, const char *path, const char *link,
+                         int mode, dev_t rdev)
+{
+    int res;
+
+    if (S_ISREG(mode)) {
+        res = openat(dirfd, path, O_CREAT | O_EXCL | O_WRONLY, mode);
+        if (res >= 0) {
+            res = close(res);
+        }
+    } else if (S_ISDIR(mode)) {
+        res = mkdirat(dirfd, path, mode);
+    } else if (S_ISLNK(mode) && link != NULL) {
+        res = symlinkat(link, dirfd, path);
+    } else if (S_ISFIFO(mode)) {
+        res = mkfifoat(dirfd, path, mode);
+    } else {
+        res = mknodat(dirfd, path, mode, rdev);
+    }
+
+    return res;
+}