[PATCH 08/13] NFS: Add functions to parse nfs mount options to fs/nfs/super.c

[PATCH 08/13] NFS: Add functions to parse nfs mount options to fs/nfs/super.c

[Chuck Lever]

For NFSv2 and NFSv3 mount options.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/super.c |  449 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 449 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 1974648..a9f698b 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -514,6 +514,455 @@ static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
 	shrink_submounts(vfsmnt, &nfs_automount_list);
 }
 
+
+static match_table_t nfs_tokens = {
+	{Opt_userspace, "bg"},
+	{Opt_userspace, "fg"},
+	{Opt_soft, "soft"},
+	{Opt_hard, "hard"},
+	{Opt_intr, "intr"},
+	{Opt_nointr, "nointr"},
+	{Opt_posix, "posix"},
+	{Opt_noposix, "noposix"},
+	{Opt_cto, "cto"},
+	{Opt_nocto, "nocto"},
+	{Opt_ac, "ac"},
+	{Opt_noac, "noac"},
+	{Opt_lock, "lock"},
+	{Opt_nolock, "nolock"},
+	{Opt_v2, "v2"},
+	{Opt_v3, "v3"},
+	{Opt_udp, "udp"},
+	{Opt_tcp, "tcp"},
+	{Opt_acl, "acl"},
+	{Opt_noacl, "noacl"},
+
+	{Opt_port, "port=%u"},
+	{Opt_rsize, "rsize=%u"},
+	{Opt_wsize, "wsize=%u"},
+	{Opt_timeo, "timeo=%u"},
+	{Opt_retrans, "retrans=%u"},
+	{Opt_acregmin, "acregmin=%u"},
+	{Opt_acregmax, "acregmax=%u"},
+	{Opt_acdirmin, "acdirmin=%u"},
+	{Opt_acdirmax, "acdirmax=%u"},
+	{Opt_actimeo, "actimeo=%u"},
+	{Opt_userspace, "retry=%u"},
+	{Opt_namelen, "namlen=%u"},
+	{Opt_mountport, "mountport=%u"},
+	{Opt_mountprog, "mountprog=%u"},
+	{Opt_mountvers, "mountvers=%u"},
+	{Opt_nfsprog, "nfsprog=%u"},
+	{Opt_nfsvers, "nfsvers=%u"},
+	{Opt_nfsvers, "vers=%u"},
+
+	{Opt_sec, "sec=%s"},
+	{Opt_proto, "proto=%s"},
+	{Opt_addr, "addr=%s"},
+	{Opt_mounthost, "mounthost=%s"},
+	{Opt_context, "context=%s"},
+
+	{Opt_err, NULL},
+};
+
+static int nfs_parse_options(char *raw, struct nfs_mount_args *mnt)
+{
+	char *p, *string;
+
+	if (!raw) {
+		dprintk("NFS: mount options string was NULL.\n");
+		return 1;
+	}
+
+	while ((p = strsep (&raw, ",")) != NULL) {
+		substring_t args[MAX_OPT_ARGS];
+		int option, token;
+
+		if (!*p)
+			continue;
+		token = match_token(p, nfs_tokens, args);
+
+		dprintk("NFS:   nfs mount option '%s': parsing token %d\n",
+			p, token);
+
+		switch (token) {
+		case Opt_soft:
+			mnt->nmd.flags |= NFS_MOUNT_SOFT;
+			break;
+		case Opt_hard:
+			mnt->nmd.flags &= ~NFS_MOUNT_SOFT;
+			break;
+		case Opt_intr:
+			mnt->nmd.flags |= NFS_MOUNT_INTR;
+			break;
+		case Opt_nointr:
+			mnt->nmd.flags &= ~NFS_MOUNT_INTR;
+			break;
+		case Opt_posix:
+			mnt->nmd.flags |= NFS_MOUNT_POSIX;
+			break;
+		case Opt_noposix:
+			mnt->nmd.flags &= ~NFS_MOUNT_POSIX;
+			break;
+		case Opt_cto:
+			mnt->nmd.flags &= ~NFS_MOUNT_NOCTO;
+			break;
+		case Opt_nocto:
+			mnt->nmd.flags |= NFS_MOUNT_NOCTO;
+			break;
+		case Opt_ac:
+			mnt->nmd.flags &= ~NFS_MOUNT_NOAC;
+			break;
+		case Opt_noac:
+			mnt->nmd.flags |= NFS_MOUNT_NOAC;
+			break;
+		case Opt_lock:
+			mnt->nmd.flags &= ~NFS_MOUNT_NONLM;
+			break;
+		case Opt_nolock:
+			mnt->nmd.flags |= NFS_MOUNT_NONLM;
+			break;
+		case Opt_v2:
+			mnt->nmd.flags &= ~NFS_MOUNT_VER3;
+			break;
+		case Opt_v3:
+			mnt->nmd.flags |= NFS_MOUNT_VER3;
+			break;
+		case Opt_udp:
+			mnt->nmd.flags &= ~NFS_MOUNT_TCP;
+			break;
+		case Opt_tcp:
+			mnt->nmd.flags |= NFS_MOUNT_TCP;
+			break;
+		case Opt_acl:
+			mnt->nmd.flags &= ~NFS_MOUNT_NOACL;
+			break;
+		case Opt_noacl:
+			mnt->nmd.flags |= NFS_MOUNT_NOACL;
+			break;
+
+		case Opt_port:
+			if (match_int(args, &option))
+				return 0;
+			if (option < 0 || option > 65535)
+				return 0;
+			mnt->nmd.addr.sin_port = htonl(option);
+			break;
+		case Opt_rsize:
+			if (match_int(args, &mnt->nmd.rsize))
+				return 0;
+			break;
+		case Opt_wsize:
+			if (match_int(args, &mnt->nmd.wsize))
+				return 0;
+			break;
+		case Opt_timeo:
+			if (match_int(args, &mnt->nmd.timeo))
+				return 0;
+			break;
+		case Opt_retrans:
+			if (match_int(args, &mnt->nmd.retrans))
+				return 0;
+			break;
+		case Opt_acregmin:
+			if (match_int(args, &mnt->nmd.acregmin))
+				return 0;
+			break;
+		case Opt_acregmax:
+			if (match_int(args, &mnt->nmd.acregmax))
+				return 0;
+			break;
+		case Opt_acdirmin:
+			if (match_int(args, &mnt->nmd.acdirmin))
+				return 0;
+			break;
+		case Opt_acdirmax:
+			if (match_int(args, &mnt->nmd.acdirmax))
+				return 0;
+			break;
+		case Opt_actimeo:
+			if (match_int(args, &option))
+				return 0;
+			if (option < 0)
+				return 0;
+			mnt->nmd.acregmin =
+			mnt->nmd.acregmax =
+			mnt->nmd.acdirmin =
+			mnt->nmd.acdirmax = option;
+			break;
+		case Opt_namelen:
+			if (match_int(args, &mnt->nmd.namlen))
+				return 0;
+			break;
+		case Opt_mountport:
+			if (match_int(args, &option))
+				return 0;
+			if (option < 0 || option > 65535)
+				return 0;
+			mnt->mnthost.sin_port = htonl(option);
+			break;
+		case Opt_mountprog:
+			if (match_int(args, &option))
+				return 0;
+			if (option < 0)
+				return 0;
+			mnt->mntprog = option;
+			break;
+		case Opt_mountvers:
+			if (match_int(args, &option))
+				return 0;
+			if (option < 0)
+				return 0;
+			mnt->mntvers = option;
+			break;
+		case Opt_nfsprog:
+			if (match_int(args, &option))
+				return 0;
+			if (option < 0)
+				return 0;
+			mnt->nfsprog = option;
+			break;
+		case Opt_nfsvers:
+			if (match_int(args, &option))
+				return 0;
+			switch (option) {
+			case 2:
+				mnt->nmd.flags &= ~NFS_MOUNT_VER3;
+				break;
+			case 3:
+				mnt->nmd.flags |= NFS_MOUNT_VER3;
+				break;
+			default:
+				goto out_unrec_vers;
+			}
+			break;
+
+		case Opt_sec: {
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			token = match_token(string, nfs_sec_tokens, args);
+			kfree(string);
+
+			mnt->nmd.flags |= NFS_MOUNT_SECFLAVOUR;
+
+			switch (token) {
+			case Opt_sec_none:
+				mnt->nmd.flags &= ~NFS_MOUNT_SECFLAVOUR;
+				mnt->nmd.pseudoflavor = RPC_AUTH_NULL;
+				break;
+			case Opt_sec_sys:
+				mnt->nmd.flags &= ~NFS_MOUNT_SECFLAVOUR;
+				mnt->nmd.pseudoflavor = RPC_AUTH_UNIX;
+				break;
+			case Opt_sec_krb5:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_KRB5;
+				break;
+			case Opt_sec_krb5i:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_KRB5I;
+				break;
+			case Opt_sec_krb5p:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_KRB5P;
+				break;
+			case Opt_sec_lkey:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_LKEY;
+				break;
+			case Opt_sec_lkeyi:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_LKEYI;
+				break;
+			case Opt_sec_lkeyp:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_LKEYP;
+				break;
+			case Opt_sec_spkm:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_SPKM;
+				break;
+			case Opt_sec_spkmi:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_SPKMI;
+				break;
+			case Opt_sec_spkmp:
+				mnt->nmd.pseudoflavor = RPC_AUTH_GSS_SPKMP;
+				break;
+			default:
+				goto out_unrec_sec;
+			}
+			break;
+			}
+		case Opt_proto:
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			if (strcmp(string, "udp") == 0) {
+				mnt->nmd.flags &= ~NFS_MOUNT_TCP;
+				kfree(string);
+				break;
+			}
+			if (strcmp(string, "tcp") == 0) {
+				mnt->nmd.flags |= NFS_MOUNT_TCP;
+				kfree(string);
+				break;
+			}
+			goto out_unrec_xprt;
+		case Opt_addr:
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			mnt->nmd.addr.sin_family = AF_INET;
+			mnt->nmd.addr.sin_addr.s_addr = in_aton(string);
+			kfree(string);
+			break;
+		case Opt_mounthost:
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			mnt->mnthost.sin_family = AF_INET;
+			mnt->mnthost.sin_addr.s_addr = in_aton(string);
+			kfree(string);
+			mnt->use_mnthost = 1;
+			break;
+		case Opt_context:
+			match_strcpy(mnt->nmd.context, args);
+			break;
+
+		case Opt_userspace:
+		case Opt_deprecated:
+			break;
+
+		default:
+			goto out_unknown;
+		}
+	}
+
+	return 1;
+
+out_nomem:
+	printk(KERN_INFO "NFS: not enough memory to parse option\n");
+	return 0;
+
+out_unrec_vers:
+	printk(KERN_INFO "NFS: unrecognized NFS version number\n");
+	return 0;
+
+out_unrec_xprt:
+	printk(KERN_INFO "NFS: unrecognized transport protocol\n");
+	return 0;
+
+out_unrec_sec:
+	printk(KERN_INFO "NFS: unrecognized security flavor\n");
+	return 0;
+
+out_unknown:
+	printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
+	return 0;
+}
+
+/*
+ * Use the remote server's MOUNT service to request the NFS file handle
+ * corresponding to the provided path.
+ */
+static int nfs_try_mount(struct nfs_mount_data *nmd, char *path)
+{
+	struct nfs_mount_args *args;
+	int status, version, protocol;
+	struct sockaddr_in sin;
+	struct nfs_fh fh;
+
+	args = container_of(nmd, struct nfs_mount_args, nmd);
+	if (args->mntvers == 0) {
+		version = (args->nmd.flags & NFS_MOUNT_VER3) ?
+					NFS_MNT3_VERSION : NFS_MNT_VERSION;
+	} else
+		version = args->mntvers;
+	protocol = (args->nmd.flags & NFS_MOUNT_TCP) ?
+				IPPROTO_TCP : IPPROTO_UDP;
+
+	sin.sin_family = AF_INET;
+	if (args->use_mnthost == 0)
+		sin.sin_addr.s_addr = args->nmd.addr.sin_addr.s_addr;
+	else
+		sin.sin_addr.s_addr = args->mnthost.sin_addr.s_addr;
+	if (args->mntport == 0) {
+		status = rpcb_getport_sync(&sin, args->mntprog, version, protocol);
+		if (status < 0)
+			goto out_bind_err;
+		sin.sin_port = htons(status);
+	} else
+		sin.sin_port = htons(args->mntport);
+
+	sin.sin_addr.s_addr = args->nmd.addr.sin_addr.s_addr;
+	status = nfs_mount(&sin, path, &fh, version, protocol);
+	if (status < 0)
+		goto out_mnt_err;
+
+	args->nmd.root.size = fh.size;
+	memcpy(args->nmd.root.data, fh.data, fh.size);
+	return status;
+
+out_bind_err:
+	printk(KERN_INFO "NFS: unable to contact bind server on host %s\n",
+	       nmd->hostname);
+	return status;
+out_mnt_err:
+	printk(KERN_INFO "NFS: unable to contact NFS server on host %s\n",
+	       nmd->hostname);
+	return status;
+}
+
+/*
+ * Convert a string of nfs mount options into an nfs_mount_data struct.
+ *
+ * User space handles the following behaviors:
+ *
+ * + DNS: mapping server host name to IP address ("addr=" option)
+ *
+ * + failure mode: how to behave if a mount request can't be handled
+ *   immediately ("fg/bg" option)
+ *
+ * + retry: how often to retry a mount request ("retry=" option)
+ *
+ * + breaking back: trying UDP after TCP, and v2 after v3
+ *
+ * XXX: as far as I can tell, changing the NFS program is not really supported
+ *      in the NFS client.
+ *
+ */
+static struct nfs_mount_data *nfs_convert_mount_opts(const char *options)
+{
+	struct nfs_mount_args *args;
+
+	dprintk("NFS: nfs mount opts='%s'\n", options);
+
+	args = kzalloc(sizeof(*args), GFP_KERNEL);
+	if (args == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	args->nmd.version = 7;
+
+	args->nmd.flags = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
+	args->nmd.rsize = NFS_MAX_FILE_IO_SIZE;
+	args->nmd.wsize = NFS_MAX_FILE_IO_SIZE;
+	args->nmd.timeo = 600;		/* in tenths of a second */
+	args->nmd.retrans = 2;
+	args->nmd.acregmin = 3;
+	args->nmd.acregmax = 60;
+	args->nmd.acdirmin = 30;
+	args->nmd.acdirmax = 60;
+
+	args->nfsprog = NFS_PROGRAM;
+	args->use_mnthost = 0;
+	args->mntprog = NFS_MNT_PROGRAM;
+	args->mntvers = 0;
+	args->mntport = 0;
+
+	if (nfs_parse_options((char *) options, args) == 0)
+		goto out_err;
+
+	return &args->nmd;
+
+out_err:
+	kfree(args);
+	return ERR_PTR(-EINVAL);
+}
+
 /*
  * Sanity-check a server address provided by the mount command
  */

Re: [PATCH 08/13] NFS: Add functions to parse nfs mount options to fs/nfs/super.c

[Karel Zak]

On Mon, May 21, 2007 at 12:09:54PM -0400, Chuck Lever wrote:
> For NFSv2 and NFSv3 mount options.
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

 ....

> +static int nfs_parse_options(char *raw, struct nfs_mount_args *mnt)
> +{
> +	char *p, *string;
> +
> +	if (!raw) {
> +		dprintk("NFS: mount options string was NULL.\n");
> +		return 1;
> +	}
> +
> +	while ((p = strsep (&raw, ",")) != NULL) {
> +		substring_t args[MAX_OPT_ARGS];
> +		int option, token;
> +
> +		if (!*p)
> +			continue;
> +		token = match_token(p, nfs_tokens, args);

 ....

> +
> +		case Opt_context:
> +			match_strcpy(mnt->nmd.context, args);
> +			break;

 The userspace version (nfs-utils) of this code supports a quoted
 context strings. For example:

    context="aaa,bbb,ccc",hard

 It seems your code blindly parses a raw option string by ",".

    Karel

-- 
 Karel Zak  <kzak@redhat.com>

Re: [PATCH 08/13] NFS: Add functions to parse nfs mount options to fs/nfs/super.c

[Chuck Lever]

[-- Attachment #1: Type: text/plain, Size: 1115 bytes --]

Karel Zak wrote:
> On Mon, May 21, 2007 at 12:09:54PM -0400, Chuck Lever wrote:
>> For NFSv2 and NFSv3 mount options.
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> 
>  ....
> 
>> +static int nfs_parse_options(char *raw, struct nfs_mount_args *mnt)
>> +{
>> +	char *p, *string;
>> +
>> +	if (!raw) {
>> +		dprintk("NFS: mount options string was NULL.\n");
>> +		return 1;
>> +	}
>> +
>> +	while ((p = strsep (&raw, ",")) != NULL) {
>> +		substring_t args[MAX_OPT_ARGS];
>> +		int option, token;
>> +
>> +		if (!*p)
>> +			continue;
>> +		token = match_token(p, nfs_tokens, args);
> 
>  ....
> 
>> +
>> +		case Opt_context:
>> +			match_strcpy(mnt->nmd.context, args);
>> +			break;
> 
>  The userspace version (nfs-utils) of this code supports a quoted
>  context strings. For example:
> 
>     context="aaa,bbb,ccc",hard
> 
>  It seems your code blindly parses a raw option string by ",".

Karel-

I've never used the context= option, and didn't find any documentation 
describing how it was used.

Is there a clean example of how to use the in-kernel parser to handle 
quoted strings containing commas?

[-- Attachment #2: chuck.lever.vcf --]
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fn:Chuck Lever
n:Lever;Chuck
org:Oracle Corporation;Corporate Architecture: Linux Projects Group
adr:;;1015 Granger Avenue;Ann Arbor;MI;48104;USA
title:Principal Member of Staff
tel;work:+1 248 614 5091
x-mozilla-html:FALSE
url:http://oss.oracle.com/~cel/
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end:vcard

Re: [PATCH 08/13] NFS: Add functions to parse nfs mount options to fs/nfs/super.c

[Karel Zak]

On Tue, May 29, 2007 at 05:08:01PM -0400, Chuck Lever wrote:
> Karel Zak wrote:
> >On Mon, May 21, 2007 at 12:09:54PM -0400, Chuck Lever wrote:
> >>For NFSv2 and NFSv3 mount options.
> >>Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> >
> > ....
> >
> >>+static int nfs_parse_options(char *raw, struct nfs_mount_args *mnt)
> >>+{
> >>+	char *p, *string;
> >>+
> >>+	if (!raw) {
> >>+		dprintk("NFS: mount options string was NULL.\n");
> >>+		return 1;
> >>+	}
> >>+
> >>+	while ((p = strsep (&raw, ",")) != NULL) {
> >>+		substring_t args[MAX_OPT_ARGS];
> >>+		int option, token;
> >>+
> >>+		if (!*p)
> >>+			continue;
> >>+		token = match_token(p, nfs_tokens, args);
> >
> > ....
> >
> >>+
> >>+		case Opt_context:
> >>+			match_strcpy(mnt->nmd.context, args);
> >>+			break;
> >
> > The userspace version (nfs-utils) of this code supports a quoted
> > context strings. For example:
> >
> >    context="aaa,bbb,ccc",hard
> >
> > It seems your code blindly parses a raw option string by ",".
> 
> Karel-
> 
> I've never used the context= option, and didn't find any documentation 
> describing how it was used.

 That's SELinux stuff. See original discussion:

 http://thread.gmane.org/gmane.linux.redhat.security.lspp/1002/focus=1004

 There are also fscontext, defcontext and context for normal (non-NFS)
 mounts. See the mount.8 patch (where is basic docs):

 http://git.kernel.org/?p=utils/util-linux-ng/util-linux-ng.git;a=blobdiff;f=mount/mount.8;h=8ed5a11b77985c8da2dcac4602a67f8785a95070;hp=4692a42b3487b8e0db6dc0b7d17cfd214e8aefc8;hb=3a620ba4bffade41d81c429560c40bb65c9b81a7;hpb=6573c985a4077fa7d50ccb993bae177526fde8ec
 
> Is there a clean example of how to use the in-kernel parser to handle 
> quoted strings containing commas?

 Not sure.

 It was introduced by "[PATCH] SELinux: support mls categories for context
 mounts":

 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=3528a95322b5c1ce882ab723f175a1845430cd89

 The SELinux specific options are extracted from mount options by the
 sb_copy_data hook (fs/super.c, vfs_kern_mount()) -- that's probably
 transparent for all filesystems, maybe for your NFS options too. (I
 didn't study it in detail.)

    Karel

-- 
 Karel Zak  <kzak@redhat.com>