unfs3: Add a NFSv3 user mode server for use with runqemu

The user mode nfs server allows the use of runqemu without any root
privileges and may even be accelerated with kvm.

Example:

runqemu-extract-sdk tmp-eglibc/deploy/images/qemux86-64/core-image-minimal-qemux86-64.tar.bz2 rootfs

runqemu qemux86-64 `pwd`/rootfs nographic slirp kvm

[YOCTO #5639]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/meta/recipes-devtools/unfs3/unfs3/relative_max_socket_path_len.patch b/meta/recipes-devtools/unfs3/unfs3/relative_max_socket_path_len.patch
new file mode 100644
index 0000000000..17ad7b6feb
--- /dev/null
+++ b/meta/recipes-devtools/unfs3/unfs3/relative_max_socket_path_len.patch
@@ -0,0 +1,74 @@
+nfs.c: Allow max sa.sun_path for a localdomain socket with the user nfs-server
+
+There is a hard limit for the kernel of 108 characters for a
+localdomain socket name.  To avoid problems with the user nfs
+server it should maximize the number of characters by using
+a relative path on the server side.
+
+Previously the nfs-server used the absolute path name passed to
+the sa.sunpath arg for binding the socket and this has caused
+problems for both the X server and UST binaries which make
+heavy use of named sockets with long names.
+
+Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
+
+Upstream-Status: Pending
+
+---
+ nfs.c |   29 +++++++++++++++++++++++++++--
+ 1 file changed, 27 insertions(+), 2 deletions(-)
+
+--- a/nfs.c
++++ b/nfs.c
+@@ -672,6 +672,7 @@ SYMLINK3res *nfsproc3_symlink_3_svc(SYML
+ }
+ 
+ #ifndef WIN32
++static char pathbuf_tmp[NFS_MAXPATHLEN + NFS_MAXNAMLEN + 1];
+ 
+ /*
+  * create Unix socket
+@@ -680,17 +681,41 @@ static int mksocket(const char *path, mo
+ {
+     int res, sock;
+     struct sockaddr_un addr;
++    unsigned int len = strlen(path);
+ 
+     sock = socket(PF_UNIX, SOCK_STREAM, 0);
+-    addr.sun_family = AF_UNIX;
+-    strcpy(addr.sun_path, path);
+     res = sock;
+     if (res != -1) {
++	addr.sun_family = AF_UNIX;
++	if (len < sizeof(addr.sun_path) -1) {
++	    strcpy(addr.sun_path, path);
++	} else {
++	    char *ptr;
++	    res = -1;
++	    if (len >= sizeof(path))
++		goto out;
++	    strcpy(pathbuf_tmp, path);
++	    ptr = strrchr(pathbuf_tmp,'/');
++	    if (ptr) {
++		*ptr = '\0';
++		ptr++;
++		if (chdir(pathbuf_tmp))
++		    goto out;
++	    } else {
++		ptr = pathbuf_tmp;
++	    }
++	    if (strlen(ptr) >= sizeof(addr.sun_path))
++		goto out;
++	    strcpy(addr.sun_path, ptr);
++	}
+ 	umask(~mode);
+ 	res =
+ 	    bind(sock, (struct sockaddr *) &addr,
+ 		 sizeof(addr.sun_family) + strlen(addr.sun_path));
+ 	umask(0);
++out:
++	if (chdir("/"))
++	    fprintf(stderr, "Internal failure to chdir /\n");
+ 	close(sock);
+     }
+     return res;