Re: [PATCH 1/1] net: nfs: fix file handle length in NFSv3

[Andrew Davis]

On 3/26/24 4:34 AM, Sébastien Szymanski wrote:

The NFS protocol uses file handles to refer to file or directory.
In NFSv2 file handles have a fixed size of 32 bytes.
In NFSv3 file handles have a variable length up to 64 bytes. This is
also true for the MOUNT protocol. [1]
When the NFSv3 server replies with a file handle length > 32 bytes, U-Boot
only copies 32 bytes of that file handle and the next LOOKUP Call fails:

BIOS> nfs ${loadaddr} 192.168.1.51:/nfsroot/opos93dev-br/boot/Image
Using ethernet@428a0000 device
File transfer via NFS from server 192.168.1.51; our IP address is 192.168.1.133
Filename '/nfsroot/opos93dev-br/boot/Image'.
Load address: 0x80400000
Loading: *** ERROR: File lookup fail

done
BIOS>

Looking at this transfer in Wireshark, we can see that the server
replies with the following file handle:

     length: 36
     [hash (CRC-32): 0x230ac67b]
     FileHandle: 
0100070101005e000000000091763911f87c449fa73c298552db19ba0c9f60002980cfd2

and U-Boot sends the following file handle in the next LOOKUP Call:

     length: 32
     [hash (CRC-32): 0x6314131b]
     FileHandle: 
000000240100070101005e000000000091763911f87c449fa73c298552db19ba

Fix this by using a variable length file handle for dirfh.

[1] https://www.rfc-editor.org/rfc/rfc1813.html#page-106

Fixes: b0baca982048 ("net: NFS: Add NFSv3 support")
Signed-off-by: Sébastien Szymanski <sebastien.szyman...@armadeus.com>
---

Fixes NFS boot for me, thanks!

Tested-by: Andrew Davis <a...@ti.com>

  net/nfs.c | 18 +++++++++++++-----
  1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/net/nfs.c b/net/nfs.c
index 7a8887ef2368..c18282448ccd 100644
--- a/net/nfs.c
+++ b/net/nfs.c
@@ -57,7 +57,8 @@ static int nfs_offset = -1;
  static int nfs_len;
  static const ulong nfs_timeout = CONFIG_NFS_TIMEOUT;

-static char dirfh[NFS_FHSIZE]; /* NFSv2 / NFSv3 file handle of directory */

+static char dirfh[NFS3_FHSIZE]; /* NFSv2 / NFSv3 file handle of directory */
+static unsigned int dirfh3_length; /* (variable) length of dirfh when NFSv3 */
  static char filefh[NFS3_FHSIZE]; /* NFSv2 / NFSv3 file handle */
  static unsigned int filefh3_length;   /* (variable) length of filefh when 
NFSv3 */

@@ -377,9 +378,9 @@ static void nfs_lookup_req(char *fname) rpc_req(PROG_NFS, NFS_LOOKUP, data, len);

        } else {  /* NFS_V3 */
-               *p++ = htonl(NFS_FHSIZE);       /* Dir handle length */
-               memcpy(p, dirfh, NFS_FHSIZE);
-               p += (NFS_FHSIZE / 4);
+               *p++ = htonl(dirfh3_length);    /* Dir handle length */
+               memcpy(p, dirfh, dirfh3_length);
+               p += (dirfh3_length / 4);
                *p++ = htonl(fnamelen);
                if (fnamelen & 3)
                        *(p + fnamelen / 4) = 0;
@@ -565,7 +566,14 @@ static int nfs_mount_reply(uchar *pkt, unsigned len)

fs_mounted = 1;

        /*  NFSv2 and NFSv3 use same structure */
-       memcpy(dirfh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE);
+       if (choosen_nfs_version != NFS_V3) {
+               memcpy(dirfh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE);
+       } else {
+               dirfh3_length = ntohl(rpc_pkt.u.reply.data[1]);
+               if (dirfh3_length > NFS3_FHSIZE)
+                       dirfh3_length  = NFS3_FHSIZE;
+               memcpy(dirfh, rpc_pkt.u.reply.data + 2, dirfh3_length);
+       }

return 0;

  }