NFSv4: Send implementation id with exchange_id

Send the nfs implementation id in EXCHANGE_ID requests unless the module
parameter nfs.send_implementation_id is 0.

This adds a CONFIG variable for the nii_domain that defaults to "kernel.org".

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 51 insertions, 2 deletions

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index ee86cfcd6c33..7bce64c7060e 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -99,6 +99,18 @@ config PNFS_OBJLAYOUT
         depends on NFS_FS && NFS_V4_1 && SCSI_OSD_ULD
         default m
 
+config NFS_V4_1_IMPLEMENTATION_ID_DOMAIN
+        string "NFSv4.1 Implementation ID Domain"
+        depends on NFS_V4_1
+        default "kernel.org"
+        help
+          This option defines the domain portion of the implementation ID that
+          may be sent in the NFS exchange_id operation.  The value must be in
+          the format of a DNS domain name and should be set to the DNS domain
+          name of the distribution.
+          If the NFS client is unchanged from the upstream kernel, this
+          option should be set to the default "kernel.org".
+
 config ROOT_NFS
         bool "Root file system on NFS"
         depends on NFS_FS=y && IP_PNP
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index ae7834366712..d824aedb1237 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -44,6 +44,8 @@
 #include <linux/pagemap.h>
 #include <linux/proc_fs.h>
 #include <linux/kdev_t.h>
+#include <linux/module.h>
+#include <linux/utsname.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/msg_prot.h>
 #include <linux/sunrpc/gss_api.h>
@@ -271,7 +273,12 @@ static int nfs4_stat_to_errno(int);
                                 1 /* flags */ + \
                                 1 /* spa_how */ + \
                                 0 /* SP4_NONE (for now) */ + \
-                                1 /* zero implemetation id array */)
+                                1 /* implementation id array of size 1 */ + \
+                                1 /* nii_domain */ + \
+                                XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+                                1 /* nii_name */ + \
+                                XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+                                3 /* nii_date */)
 #define decode_exchange_id_maxsz (op_decode_hdr_maxsz + \
                                 2 /* eir_clientid */ + \
                                 1 /* eir_sequenceid */ + \
@@ -838,6 +845,12 @@ const u32 nfs41_maxread_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
                                     XDR_UNIT);
 #endif /* CONFIG_NFS_V4_1 */
 
+static unsigned short send_implementation_id = 1;
+
+module_param(send_implementation_id, ushort, 0644);
+MODULE_PARM_DESC(send_implementation_id,
+                "Send implementation ID with NFSv4.1 exchange_id");
+
 static const umode_t nfs_type2fmt[] = {
         [NF4BAD] = 0,
         [NF4REG] = S_IFREG,
@@ -1766,6 +1779,8 @@ static void encode_exchange_id(struct xdr_stream *xdr,
                                struct compound_hdr *hdr)
 {
         __be32 *p;
+        char impl_name[NFS4_OPAQUE_LIMIT];
+        int len = 0;
 
         p = reserve_space(xdr, 4 + sizeof(args->verifier->data));
         *p++ = cpu_to_be32(OP_EXCHANGE_ID);
@@ -1776,7 +1791,29 @@ static void encode_exchange_id(struct xdr_stream *xdr,
         p = reserve_space(xdr, 12);
         *p++ = cpu_to_be32(args->flags);
         *p++ = cpu_to_be32(0);  /* zero length state_protect4_a */
-        *p = cpu_to_be32(0);    /* zero length implementation id array */
+
+        if (send_implementation_id &&
+            sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN) > 1 &&
+            sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN)
+                <= NFS4_OPAQUE_LIMIT + 1)
+                len = snprintf(impl_name, sizeof(impl_name), "%s %s %s %s",
+                               utsname()->sysname, utsname()->release,
+                               utsname()->version, utsname()->machine);
+
+        if (len > 0) {
+                *p = cpu_to_be32(1);    /* implementation id array length=1 */
+
+                encode_string(xdr,
+                        sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN) - 1,
+                        CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN);
+                encode_string(xdr, len, impl_name);
+                /* just send zeros for nii_date - the date is in nii_name */
+                p = reserve_space(xdr, 12);
+                p = xdr_encode_hyper(p, 0);
+                *p = cpu_to_be32(0);
+        } else
+                *p = cpu_to_be32(0);    /* implementation id array length=0 */
+
         hdr->nops++;
         hdr->replen += decode_exchange_id_maxsz;
 }