linux/fs/nfs/fs_context.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/fs/nfs/fs_context.c
 *
 * Copyright (C) 1992 Rick Sladkey
 *
 * NFS mount handling.
 *
 * Split from fs/nfs/super.c by David Howells <dhowells@redhat.com>
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/nfs4_mount.h>
#include "nfs.h"
#include "internal.h"

#define NFSDBG_FACILITY		NFSDBG_MOUNT

#if IS_ENABLED(CONFIG_NFS_V3)
#define NFS_DEFAULT_VERSION 3
#else
#define NFS_DEFAULT_VERSION 2
#endif

#define NFS_MAX_CONNECTIONS 16

enum nfs_param {
	Opt_ac,
	Opt_acdirmax,
	Opt_acdirmin,
	Opt_acl,
	Opt_acregmax,
	Opt_acregmin,
	Opt_actimeo,
	Opt_addr,
	Opt_bg,
	Opt_bsize,
	Opt_clientaddr,
	Opt_cto,
	Opt_fg,
	Opt_fscache,
	Opt_hard,
	Opt_intr,
	Opt_local_lock,
	Opt_lock,
	Opt_lookupcache,
	Opt_migration,
	Opt_minorversion,
	Opt_mountaddr,
	Opt_mounthost,
	Opt_mountport,
	Opt_mountproto,
	Opt_mountvers,
	Opt_namelen,
	Opt_nconnect,
	Opt_port,
	Opt_posix,
	Opt_proto,
	Opt_rdirplus,
	Opt_rdma,
	Opt_resvport,
	Opt_retrans,
	Opt_retry,
	Opt_rsize,
	Opt_sec,
	Opt_sharecache,
	Opt_sloppy,
	Opt_soft,
	Opt_softerr,
	Opt_source,
	Opt_tcp,
	Opt_timeo,
	Opt_udp,
	Opt_v,
	Opt_vers,
	Opt_wsize,
};

static const struct fs_parameter_spec nfs_param_specs[] = {
	fsparam_flag_no("ac",		Opt_ac),
	fsparam_u32   ("acdirmax",	Opt_acdirmax),
	fsparam_u32   ("acdirmin",	Opt_acdirmin),
	fsparam_flag_no("acl",		Opt_acl),
	fsparam_u32   ("acregmax",	Opt_acregmax),
	fsparam_u32   ("acregmin",	Opt_acregmin),
	fsparam_u32   ("actimeo",	Opt_actimeo),
	fsparam_string("addr",		Opt_addr),
	fsparam_flag  ("bg",		Opt_bg),
	fsparam_u32   ("bsize",		Opt_bsize),
	fsparam_string("clientaddr",	Opt_clientaddr),
	fsparam_flag_no("cto",		Opt_cto),
	fsparam_flag  ("fg",		Opt_fg),
	__fsparam(fs_param_is_string, "fsc",		Opt_fscache,
		  fs_param_neg_with_no|fs_param_v_optional),
	fsparam_flag  ("hard",		Opt_hard),
	__fsparam(fs_param_is_flag, "intr",		Opt_intr,
		  fs_param_neg_with_no|fs_param_deprecated),
	fsparam_enum  ("local_lock",	Opt_local_lock),
	fsparam_flag_no("lock",		Opt_lock),
	fsparam_enum  ("lookupcache",	Opt_lookupcache),
	fsparam_flag_no("migration",	Opt_migration),
	fsparam_u32   ("minorversion",	Opt_minorversion),
	fsparam_string("mountaddr",	Opt_mountaddr),
	fsparam_string("mounthost",	Opt_mounthost),
	fsparam_u32   ("mountport",	Opt_mountport),
	fsparam_string("mountproto",	Opt_mountproto),
	fsparam_u32   ("mountvers",	Opt_mountvers),
	fsparam_u32   ("namlen",	Opt_namelen),
	fsparam_u32   ("nconnect",	Opt_nconnect),
	fsparam_string("nfsvers",	Opt_vers),
	fsparam_u32   ("port",		Opt_port),
	fsparam_flag_no("posix",	Opt_posix),
	fsparam_string("proto",		Opt_proto),
	fsparam_flag_no("rdirplus",	Opt_rdirplus),
	fsparam_flag  ("rdma",		Opt_rdma),
	fsparam_flag_no("resvport",	Opt_resvport),
	fsparam_u32   ("retrans",	Opt_retrans),
	fsparam_string("retry",		Opt_retry),
	fsparam_u32   ("rsize",		Opt_rsize),
	fsparam_string("sec",		Opt_sec),
	fsparam_flag_no("sharecache",	Opt_sharecache),
	fsparam_flag  ("sloppy",	Opt_sloppy),
	fsparam_flag  ("soft",		Opt_soft),
	fsparam_flag  ("softerr",	Opt_softerr),
	fsparam_string("source",	Opt_source),
	fsparam_flag  ("tcp",		Opt_tcp),
	fsparam_u32   ("timeo",		Opt_timeo),
	fsparam_flag  ("udp",		Opt_udp),
	fsparam_flag  ("v2",		Opt_v),
	fsparam_flag  ("v3",		Opt_v),
	fsparam_flag  ("v4",		Opt_v),
	fsparam_flag  ("v4.0",		Opt_v),
	fsparam_flag  ("v4.1",		Opt_v),
	fsparam_flag  ("v4.2",		Opt_v),
	fsparam_string("vers",		Opt_vers),
	fsparam_u32   ("wsize",		Opt_wsize),
	{}
};

enum {
	Opt_local_lock_all,
	Opt_local_lock_flock,
	Opt_local_lock_none,
	Opt_local_lock_posix,
};

enum {
	Opt_lookupcache_all,
	Opt_lookupcache_none,
	Opt_lookupcache_positive,
};

static const struct fs_parameter_enum nfs_param_enums[] = {
	{ Opt_local_lock,	"all",		Opt_local_lock_all },
	{ Opt_local_lock,	"flock",	Opt_local_lock_flock },
	{ Opt_local_lock,	"none",		Opt_local_lock_none },
	{ Opt_local_lock,	"posix",	Opt_local_lock_posix },
	{ Opt_lookupcache,	"all",		Opt_lookupcache_all },
	{ Opt_lookupcache,	"none",		Opt_lookupcache_none },
	{ Opt_lookupcache,	"pos",		Opt_lookupcache_positive },
	{ Opt_lookupcache,	"positive",	Opt_lookupcache_positive },
	{}
};

static const struct fs_parameter_description nfs_fs_parameters = {
	.name		= "nfs",
	.specs		= nfs_param_specs,
	.enums		= nfs_param_enums,
};

enum {
	Opt_vers_2,
	Opt_vers_3,
	Opt_vers_4,
	Opt_vers_4_0,
	Opt_vers_4_1,
	Opt_vers_4_2,
};

static const struct constant_table nfs_vers_tokens[] = {
	{ "2",		Opt_vers_2 },
	{ "3",		Opt_vers_3 },
	{ "4",		Opt_vers_4 },
	{ "4.0",	Opt_vers_4_0 },
	{ "4.1",	Opt_vers_4_1 },
	{ "4.2",	Opt_vers_4_2 },
};

enum {
	Opt_xprt_rdma,
	Opt_xprt_rdma6,
	Opt_xprt_tcp,
	Opt_xprt_tcp6,
	Opt_xprt_udp,
	Opt_xprt_udp6,
	nr__Opt_xprt
};

static const struct constant_table nfs_xprt_protocol_tokens[nr__Opt_xprt] = {
	{ "rdma",	Opt_xprt_rdma },
	{ "rdma6",	Opt_xprt_rdma6 },
	{ "tcp",	Opt_xprt_tcp },
	{ "tcp6",	Opt_xprt_tcp6 },
	{ "udp",	Opt_xprt_udp },
	{ "udp6",	Opt_xprt_udp6 },
};

enum {
	Opt_sec_krb5,
	Opt_sec_krb5i,
	Opt_sec_krb5p,
	Opt_sec_lkey,
	Opt_sec_lkeyi,
	Opt_sec_lkeyp,
	Opt_sec_none,
	Opt_sec_spkm,
	Opt_sec_spkmi,
	Opt_sec_spkmp,
	Opt_sec_sys,
	nr__Opt_sec
};

static const struct constant_table nfs_secflavor_tokens[] = {
	{ "krb5",	Opt_sec_krb5 },
	{ "krb5i",	Opt_sec_krb5i },
	{ "krb5p",	Opt_sec_krb5p },
	{ "lkey",	Opt_sec_lkey },
	{ "lkeyi",	Opt_sec_lkeyi },
	{ "lkeyp",	Opt_sec_lkeyp },
	{ "none",	Opt_sec_none },
	{ "null",	Opt_sec_none },
	{ "spkm3",	Opt_sec_spkm },
	{ "spkm3i",	Opt_sec_spkmi },
	{ "spkm3p",	Opt_sec_spkmp },
	{ "sys",	Opt_sec_sys },
};

struct nfs_fs_context *nfs_alloc_parsed_mount_data(void)
{
	struct nfs_fs_context *ctx;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (ctx) {
		ctx->timeo		= NFS_UNSPEC_TIMEO;
		ctx->retrans		= NFS_UNSPEC_RETRANS;
		ctx->acregmin		= NFS_DEF_ACREGMIN;
		ctx->acregmax		= NFS_DEF_ACREGMAX;
		ctx->acdirmin		= NFS_DEF_ACDIRMIN;
		ctx->acdirmax		= NFS_DEF_ACDIRMAX;
		ctx->mount_server.port	= NFS_UNSPEC_PORT;
		ctx->nfs_server.port	= NFS_UNSPEC_PORT;
		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
		ctx->selected_flavor	= RPC_AUTH_MAXFLAVOR;
		ctx->minorversion	= 0;
		ctx->need_mount	= true;
		ctx->net		= current->nsproxy->net_ns;
		ctx->lsm_opts = NULL;
	}
	return ctx;
}

void nfs_free_parsed_mount_data(struct nfs_fs_context *ctx)
{
	if (ctx) {
		kfree(ctx->client_address);
		kfree(ctx->mount_server.hostname);
		kfree(ctx->nfs_server.export_path);
		kfree(ctx->nfs_server.hostname);
		kfree(ctx->fscache_uniq);
		security_free_mnt_opts(&ctx->lsm_opts);
		kfree(ctx);
	}
}

/*
 * Sanity-check a server address provided by the mount command.
 *
 * Address family must be initialized, and address must not be
 * the ANY address for that family.
 */
static int nfs_verify_server_address(struct sockaddr *addr)
{
	switch (addr->sa_family) {
	case AF_INET: {
		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
	}
	case AF_INET6: {
		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
		return !ipv6_addr_any(sa);
	}
	}

	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
	return 0;
}

/*
 * Sanity check the NFS transport protocol.
 *
 */
static void nfs_validate_transport_protocol(struct nfs_fs_context *ctx)
{
	switch (ctx->nfs_server.protocol) {
	case XPRT_TRANSPORT_UDP:
	case XPRT_TRANSPORT_TCP:
	case XPRT_TRANSPORT_RDMA:
		break;
	default:
		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
	}
}

/*
 * For text based NFSv2/v3 mounts, the mount protocol transport default
 * settings should depend upon the specified NFS transport.
 */
static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
{
	nfs_validate_transport_protocol(ctx);

	if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
	    ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
			return;
	switch (ctx->nfs_server.protocol) {
	case XPRT_TRANSPORT_UDP:
		ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
		break;
	case XPRT_TRANSPORT_TCP:
	case XPRT_TRANSPORT_RDMA:
		ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
	}
}

/*
 * Add 'flavor' to 'auth_info' if not already present.
 * Returns true if 'flavor' ends up in the list, false otherwise
 */
static int nfs_auth_info_add(struct nfs_fs_context *ctx,
			     struct nfs_auth_info *auth_info,
			     rpc_authflavor_t flavor)
{
	unsigned int i;
	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);

	/* make sure this flavor isn't already in the list */
	for (i = 0; i < auth_info->flavor_len; i++) {
		if (flavor == auth_info->flavors[i])
			return 0;
	}

	if (auth_info->flavor_len + 1 >= max_flavor_len) {
		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
		return -EINVAL;
	}

	auth_info->flavors[auth_info->flavor_len++] = flavor;
	return 0;
}

/*
 * Parse the value of the 'sec=' option.
 */
static int nfs_parse_security_flavors(struct nfs_fs_context *ctx,
				      struct fs_parameter *param)
{
	rpc_authflavor_t pseudoflavor;
	char *string = param->string, *p;
	int ret;

	dfprintk(MOUNT, "NFS: parsing %s=%s option\n", param->key, param->string);

	while ((p = strsep(&string, ":")) != NULL) {
		if (!*p)
			continue;
		switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
		case Opt_sec_none:
			pseudoflavor = RPC_AUTH_NULL;
			break;
		case Opt_sec_sys:
			pseudoflavor = RPC_AUTH_UNIX;
			break;
		case Opt_sec_krb5:
			pseudoflavor = RPC_AUTH_GSS_KRB5;
			break;
		case Opt_sec_krb5i:
			pseudoflavor = RPC_AUTH_GSS_KRB5I;
			break;
		case Opt_sec_krb5p:
			pseudoflavor = RPC_AUTH_GSS_KRB5P;
			break;
		case Opt_sec_lkey:
			pseudoflavor = RPC_AUTH_GSS_LKEY;
			break;
		case Opt_sec_lkeyi:
			pseudoflavor = RPC_AUTH_GSS_LKEYI;
			break;
		case Opt_sec_lkeyp:
			pseudoflavor = RPC_AUTH_GSS_LKEYP;
			break;
		case Opt_sec_spkm:
			pseudoflavor = RPC_AUTH_GSS_SPKM;
			break;
		case Opt_sec_spkmi:
			pseudoflavor = RPC_AUTH_GSS_SPKMI;
			break;
		case Opt_sec_spkmp:
			pseudoflavor = RPC_AUTH_GSS_SPKMP;
			break;
		default:
			dfprintk(MOUNT,
				 "NFS: sec= option '%s' not recognized\n", p);
			return -EINVAL;
		}

		ret = nfs_auth_info_add(ctx, &ctx->auth_info, pseudoflavor);
		if (ret < 0)
			return ret;
	}

	return 0;
}

static int nfs_parse_version_string(struct nfs_fs_context *ctx,
				    const char *string)
{
	ctx->flags &= ~NFS_MOUNT_VER3;
	switch (lookup_constant(nfs_vers_tokens, string, -1)) {
	case Opt_vers_2:
		ctx->version = 2;
		break;
	case Opt_vers_3:
		ctx->flags |= NFS_MOUNT_VER3;
		ctx->version = 3;
		break;
	case Opt_vers_4:
		/* Backward compatibility option. In future,
		 * the mount program should always supply
		 * a NFSv4 minor version number.
		 */
		ctx->version = 4;
		break;
	case Opt_vers_4_0:
		ctx->version = 4;
		ctx->minorversion = 0;
		break;
	case Opt_vers_4_1:
		ctx->version = 4;
		ctx->minorversion = 1;
		break;
	case Opt_vers_4_2:
		ctx->version = 4;
		ctx->minorversion = 2;
		break;
	default:
		dfprintk(MOUNT, "NFS:   Unsupported NFS version\n");
		return -EINVAL;
	}
	return 0;
}

/*
 * Parse a single mount parameter.
 */
static int nfs_fs_context_parse_param(struct nfs_fs_context *ctx,
				      struct fs_parameter *param)
{
	struct fs_parse_result result;
	unsigned short protofamily, mountfamily;
	unsigned int len;
	int ret, opt;

	dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", param->key);

	opt = fs_parse(NULL, &nfs_fs_parameters, param, &result);
	if (opt < 0)
		return ctx->sloppy ? 1 : opt;

	switch (opt) {
		/*
		 * boolean options:  foo/nofoo
		 */
	case Opt_soft:
		ctx->flags |= NFS_MOUNT_SOFT;
		ctx->flags &= ~NFS_MOUNT_SOFTERR;
		break;
	case Opt_softerr:
		ctx->flags |= NFS_MOUNT_SOFTERR;
		ctx->flags &= ~NFS_MOUNT_SOFT;
		break;
	case Opt_hard:
		ctx->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
		break;
	case Opt_posix:
		if (result.negated)
			ctx->flags &= ~NFS_MOUNT_POSIX;
		else
			ctx->flags |= NFS_MOUNT_POSIX;
		break;
	case Opt_cto:
		if (result.negated)
			ctx->flags |= NFS_MOUNT_NOCTO;
		else
			ctx->flags &= ~NFS_MOUNT_NOCTO;
		break;
	case Opt_ac:
		if (result.negated)
			ctx->flags |= NFS_MOUNT_NOAC;
		else
			ctx->flags &= ~NFS_MOUNT_NOAC;
		break;
	case Opt_lock:
		if (result.negated) {
			ctx->flags |= NFS_MOUNT_NONLM;
			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
		} else {
			ctx->flags &= ~NFS_MOUNT_NONLM;
			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
		}
		break;
	case Opt_udp:
		ctx->flags &= ~NFS_MOUNT_TCP;
		ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
		break;
	case Opt_tcp:
		ctx->flags |= NFS_MOUNT_TCP;
		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
		break;
	case Opt_rdma:
		ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
		ctx->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
		xprt_load_transport(param->key);
		break;
	case Opt_acl:
		if (result.negated)
			ctx->flags |= NFS_MOUNT_NOACL;
		else
			ctx->flags &= ~NFS_MOUNT_NOACL;
		break;
	case Opt_rdirplus:
		if (result.negated)
			ctx->flags |= NFS_MOUNT_NORDIRPLUS;
		else
			ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
		break;
	case Opt_sharecache:
		if (result.negated)
			ctx->flags |= NFS_MOUNT_UNSHARED;
		else
			ctx->flags &= ~NFS_MOUNT_UNSHARED;
		break;
	case Opt_resvport:
		if (result.negated)
			ctx->flags |= NFS_MOUNT_NORESVPORT;
		else
			ctx->flags &= ~NFS_MOUNT_NORESVPORT;
		break;
	case Opt_fscache:
		kfree(ctx->fscache_uniq);
		ctx->fscache_uniq = param->string;
		param->string = NULL;
		if (result.negated)
			ctx->options &= ~NFS_OPTION_FSCACHE;
		else
			ctx->options |= NFS_OPTION_FSCACHE;
		break;
	case Opt_migration:
		if (result.negated)
			ctx->options &= ~NFS_OPTION_MIGRATION;
		else
			ctx->options |= NFS_OPTION_MIGRATION;
		break;

		/*
		 * options that take numeric values
		 */
	case Opt_port:
		if (result.uint_32 > USHRT_MAX)
			goto out_of_bounds;
		ctx->nfs_server.port = result.uint_32;
		break;
	case Opt_rsize:
		ctx->rsize = result.uint_32;
		break;
	case Opt_wsize:
		ctx->wsize = result.uint_32;
		break;
	case Opt_bsize:
		ctx->bsize = result.uint_32;
		break;
	case Opt_timeo:
		if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
			goto out_of_bounds;
		ctx->timeo = result.uint_32;
		break;
	case Opt_retrans:
		if (result.uint_32 > INT_MAX)
			goto out_of_bounds;
		ctx->retrans = result.uint_32;
		break;
	case Opt_acregmin:
		ctx->acregmin = result.uint_32;
		break;
	case Opt_acregmax:
		ctx->acregmax = result.uint_32;
		break;
	case Opt_acdirmin:
		ctx->acdirmin = result.uint_32;
		break;
	case Opt_acdirmax:
		ctx->acdirmax = result.uint_32;
		break;
	case Opt_actimeo:
		ctx->acregmin = result.uint_32;
		ctx->acregmax = result.uint_32;
		ctx->acdirmin = result.uint_32;
		ctx->acdirmax = result.uint_32;
		break;
	case Opt_namelen:
		ctx->namlen = result.uint_32;
		break;
	case Opt_mountport:
		if (result.uint_32 > USHRT_MAX)
			goto out_of_bounds;
		ctx->mount_server.port = result.uint_32;
		break;
	case Opt_mountvers:
		if (result.uint_32 < NFS_MNT_VERSION ||
		    result.uint_32 > NFS_MNT3_VERSION)
			goto out_of_bounds;
		ctx->mount_server.version = result.uint_32;
		break;
	case Opt_minorversion:
		if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
			goto out_of_bounds;
		ctx->minorversion = result.uint_32;
		break;

		/*
		 * options that take text values
		 */
	case Opt_v:
		ret = nfs_parse_version_string(ctx, param->key + 1);
		if (ret < 0)
			return ret;
		break;
	case Opt_vers:
		ret = nfs_parse_version_string(ctx, param->string);
		if (ret < 0)
			return ret;
		break;
	case Opt_sec:
		ret = nfs_parse_security_flavors(ctx, param);
		if (ret < 0)
			return ret;
		break;

	case Opt_proto:
		protofamily = AF_INET;
		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
		case Opt_xprt_udp6:
			protofamily = AF_INET6;
			/* fall through */
		case Opt_xprt_udp:
			ctx->flags &= ~NFS_MOUNT_TCP;
			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
			break;
		case Opt_xprt_tcp6:
			protofamily = AF_INET6;
			/* fall through */
		case Opt_xprt_tcp:
			ctx->flags |= NFS_MOUNT_TCP;
			ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
			break;
		case Opt_xprt_rdma6:
			protofamily = AF_INET6;
			/* fall through */
		case Opt_xprt_rdma:
			/* vector side protocols to TCP */
			ctx->flags |= NFS_MOUNT_TCP;
			ctx->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
			xprt_load_transport(param->string);
			break;
		default:
			dfprintk(MOUNT, "NFS:   unrecognized transport protocol\n");
			return -EINVAL;
		}

		ctx->protofamily = protofamily;
		break;

	case Opt_mountproto:
		mountfamily = AF_INET;
		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
		case Opt_xprt_udp6:
			mountfamily = AF_INET6;
			/* fall through */
		case Opt_xprt_udp:
			ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
			break;
		case Opt_xprt_tcp6:
			mountfamily = AF_INET6;
			/* fall through */
		case Opt_xprt_tcp:
			ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
			break;
		case Opt_xprt_rdma: /* not used for side protocols */
		default:
			dfprintk(MOUNT, "NFS:   unrecognized transport protocol\n");
			return -EINVAL;
		}
		ctx->mountfamily = mountfamily;
		break;

	case Opt_addr:
		len = rpc_pton(ctx->net, param->string, param->size,
			       &ctx->nfs_server.address,
			       sizeof(ctx->nfs_server._address));
		if (len == 0)
			goto out_invalid_address;
		ctx->nfs_server.addrlen = len;
		break;
	case Opt_clientaddr:
		kfree(ctx->client_address);
		ctx->client_address = param->string;
		param->string = NULL;
		break;
	case Opt_mounthost:
		kfree(ctx->mount_server.hostname);
		ctx->mount_server.hostname = param->string;
		param->string = NULL;
		break;
	case Opt_mountaddr:
		len = rpc_pton(ctx->net, param->string, param->size,
			       &ctx->mount_server.address,
			       sizeof(ctx->mount_server._address));
		if (len == 0)
			goto out_invalid_address;
		ctx->mount_server.addrlen = len;
		break;
	case Opt_nconnect:
		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
			goto out_of_bounds;
		ctx->nfs_server.nconnect = result.uint_32;
		break;
	case Opt_lookupcache:
		switch (result.uint_32) {
		case Opt_lookupcache_all:
			ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
			break;
		case Opt_lookupcache_positive:
			ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
			break;
		case Opt_lookupcache_none:
			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
			break;
		default:
			goto out_invalid_value;
		}
		break;
	case Opt_local_lock:
		switch (result.uint_32) {
		case Opt_local_lock_all:
			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
				       NFS_MOUNT_LOCAL_FCNTL);
			break;
		case Opt_local_lock_flock:
			ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
			break;
		case Opt_local_lock_posix:
			ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
			break;
		case Opt_local_lock_none:
			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
					NFS_MOUNT_LOCAL_FCNTL);
			break;
		default:
			goto out_invalid_value;
		}
		break;

		/*
		 * Special options
		 */
	case Opt_sloppy:
		ctx->sloppy = true;
		dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
		break;
	}

	return 0;

out_invalid_value:
	printk(KERN_INFO "NFS: Bad mount option value specified\n");
	return -EINVAL;
out_invalid_address:
	printk(KERN_INFO "NFS: Bad IP address specified\n");
	return -EINVAL;
out_of_bounds:
	printk(KERN_INFO "NFS: Value for '%s' out of range\n", param->key);
	return -ERANGE;
}

/* cribbed from generic_parse_monolithic and vfs_parse_fs_string */
static int nfs_fs_context_parse_option(struct nfs_fs_context *ctx, char *p)
{
	int ret;
	char *key = p, *value;
	size_t v_size = 0;
	struct fs_parameter param;

	memset(&param, 0, sizeof(param));
	value = strchr(key, '=');
	if (value && value != key) {
		*value++ = 0;
		v_size = strlen(value);
	}
	param.key = key;
	param.type = fs_value_is_flag;
	param.size = v_size;
	if (v_size > 0) {
		param.type = fs_value_is_string;
		param.string = kmemdup_nul(value, v_size, GFP_KERNEL);
		if (!param.string)
			return -ENOMEM;
	}
	ret = nfs_fs_context_parse_param(ctx, &param);
	kfree(param.string);
	return ret;
}

/*
 * Error-check and convert a string of mount options from user space into
 * a data structure.  The whole mount string is processed; bad options are
 * skipped as they are encountered.  If there were no errors, return 1;
 * otherwise return 0 (zero).
 */
int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
{
	char *p;
	int rc, sloppy = 0, invalid_option = 0;

	if (!raw) {
		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
		return 1;
	}
	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);

	rc = security_sb_eat_lsm_opts(raw, &ctx->lsm_opts);
	if (rc)
		goto out_security_failure;

	while ((p = strsep(&raw, ",")) != NULL) {
		if (!*p)
			continue;
		if (nfs_fs_context_parse_option(ctx, p) < 0)
			invalid_option = true;
	}

	if (!sloppy && invalid_option)
		return 0;

	if (ctx->minorversion && ctx->version != 4)
		goto out_minorversion_mismatch;

	if (ctx->options & NFS_OPTION_MIGRATION &&
	    (ctx->version != 4 || ctx->minorversion != 0))
		goto out_migration_misuse;

	/*
	 * verify that any proto=/mountproto= options match the address
	 * families in the addr=/mountaddr= options.
	 */
	if (ctx->protofamily != AF_UNSPEC &&
	    ctx->protofamily != ctx->nfs_server.address.sa_family)
		goto out_proto_mismatch;

	if (ctx->mountfamily != AF_UNSPEC) {
		if (ctx->mount_server.addrlen) {
			if (ctx->mountfamily != ctx->mount_server.address.sa_family)
				goto out_mountproto_mismatch;
		} else {
			if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
				goto out_mountproto_mismatch;
		}
	}

	return 1;

out_minorversion_mismatch:
	printk(KERN_INFO "NFS: mount option vers=%u does not support "
			 "minorversion=%u\n", ctx->version, ctx->minorversion);
	return 0;
out_mountproto_mismatch:
	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
			 "option\n");
	return 0;
out_proto_mismatch:
	printk(KERN_INFO "NFS: server address does not match proto= option\n");
	return 0;
out_migration_misuse:
	printk(KERN_INFO
		"NFS: 'migration' not supported for this NFS version\n");
	return -EINVAL;
out_security_failure:
	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
	return 0;
}

/*
 * Split "dev_name" into "hostname:export_path".
 *
 * The leftmost colon demarks the split between the server's hostname
 * and the export path.  If the hostname starts with a left square
 * bracket, then it may contain colons.
 *
 * Note: caller frees hostname and export path, even on error.
 */
static int nfs_parse_devname(struct nfs_fs_context *ctx,
			     const char *dev_name,
			     size_t maxnamlen, size_t maxpathlen)
{
	size_t len;
	char *end;

	if (unlikely(!dev_name || !*dev_name)) {
		dfprintk(MOUNT, "NFS: device name not specified\n");
		return -EINVAL;
	}

	/* Is the host name protected with square brakcets? */
	if (*dev_name == '[') {
		end = strchr(++dev_name, ']');
		if (end == NULL || end[1] != ':')
			goto out_bad_devname;

		len = end - dev_name;
		end++;
	} else {
		char *comma;

		end = strchr(dev_name, ':');
		if (end == NULL)
			goto out_bad_devname;
		len = end - dev_name;

		/* kill possible hostname list: not supported */
		comma = strchr(dev_name, ',');
		if (comma != NULL && comma < end)
			len = comma - dev_name;
	}

	if (len > maxnamlen)
		goto out_hostname;

	/* N.B. caller will free nfs_server.hostname in all cases */
	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
	if (!ctx->nfs_server.hostname)
		goto out_nomem;
	len = strlen(++end);
	if (len > maxpathlen)
		goto out_path;
	ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
	if (!ctx->nfs_server.export_path)
		goto out_nomem;

	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", ctx->nfs_server.export_path);
	return 0;

out_bad_devname:
	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
	return -EINVAL;

out_nomem:
	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
	return -ENOMEM;

out_hostname:
	dfprintk(MOUNT, "NFS: server hostname too long\n");
	return -ENAMETOOLONG;

out_path:
	dfprintk(MOUNT, "NFS: export pathname too long\n");
	return -ENAMETOOLONG;
}

/*
 * Parse monolithic NFS2/NFS3 mount data
 * - fills in the mount root filehandle
 *
 * For option strings, 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 proto=udp after proto=tcp, v2 after v3,
 *   mountproto=tcp after mountproto=udp, and so on
 */
static int nfs23_validate_mount_data(void *options,
				     struct nfs_fs_context *ctx,
				     struct nfs_fh *mntfh,
				     const char *dev_name)
{
	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;

	if (data == NULL)
		goto out_no_data;

	ctx->version = NFS_DEFAULT_VERSION;
	switch (data->version) {
	case 1:
		data->namlen = 0; /* fall through */
	case 2:
		data->bsize = 0; /* fall through */
	case 3:
		if (data->flags & NFS_MOUNT_VER3)
			goto out_no_v3;
		data->root.size = NFS2_FHSIZE;
		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
		/* Turn off security negotiation */
		extra_flags |= NFS_MOUNT_SECFLAVOUR;
		/* fall through */
	case 4:
		if (data->flags & NFS_MOUNT_SECFLAVOUR)
			goto out_no_sec;
		/* fall through */
	case 5:
		memset(data->context, 0, sizeof(data->context));
		/* fall through */
	case 6:
		if (data->flags & NFS_MOUNT_VER3) {
			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
				goto out_invalid_fh;
			mntfh->size = data->root.size;
			ctx->version = 3;
		} else {
			mntfh->size = NFS2_FHSIZE;
			ctx->version = 2;
		}


		memcpy(mntfh->data, data->root.data, mntfh->size);
		if (mntfh->size < sizeof(mntfh->data))
			memset(mntfh->data + mntfh->size, 0,
			       sizeof(mntfh->data) - mntfh->size);

		/*
		 * Translate to nfs_fs_context, which nfs_fill_super
		 * can deal with.
		 */
		ctx->flags	= data->flags & NFS_MOUNT_FLAGMASK;
		ctx->flags	|= extra_flags;
		ctx->rsize	= data->rsize;
		ctx->wsize	= data->wsize;
		ctx->timeo	= data->timeo;
		ctx->retrans	= data->retrans;
		ctx->acregmin	= data->acregmin;
		ctx->acregmax	= data->acregmax;
		ctx->acdirmin	= data->acdirmin;
		ctx->acdirmax	= data->acdirmax;
		ctx->need_mount	= false;

		memcpy(sap, &data->addr, sizeof(data->addr));
		ctx->nfs_server.addrlen = sizeof(data->addr);
		ctx->nfs_server.port = ntohs(data->addr.sin_port);
		if (sap->sa_family != AF_INET ||
		    !nfs_verify_server_address(sap))
			goto out_no_address;

		if (!(data->flags & NFS_MOUNT_TCP))
			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
		/* N.B. caller will free nfs_server.hostname in all cases */
		ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
		ctx->namlen		= data->namlen;
		ctx->bsize		= data->bsize;

		if (data->flags & NFS_MOUNT_SECFLAVOUR)
			ctx->selected_flavor = data->pseudoflavor;
		else
			ctx->selected_flavor = RPC_AUTH_UNIX;
		if (!ctx->nfs_server.hostname)
			goto out_nomem;

		if (!(data->flags & NFS_MOUNT_NONLM))
			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
					 NFS_MOUNT_LOCAL_FCNTL);
		else
			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
					NFS_MOUNT_LOCAL_FCNTL);
		/*
		 * The legacy version 6 binary mount data from userspace has a
		 * field used only to transport selinux information into the
		 * the kernel.  To continue to support that functionality we
		 * have a touch of selinux knowledge here in the NFS code. The
		 * userspace code converted context=blah to just blah so we are
		 * converting back to the full string selinux understands.
		 */
		if (data->context[0]){
#ifdef CONFIG_SECURITY_SELINUX
			int rc;
			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
			rc = security_add_mnt_opt("context", data->context,
					strlen(data->context), ctx->lsm_opts);
			if (rc)
				return rc;
#else
			return -EINVAL;
#endif
		}

		break;
	default:
		return NFS_TEXT_DATA;
	}

	return 0;

out_no_data:
	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
	return -EINVAL;

out_no_v3:
	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
		 data->version);
	return -EINVAL;

out_no_sec:
	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
	return -EINVAL;

out_nomem:
	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
	return -ENOMEM;

out_no_address:
	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
	return -EINVAL;

out_invalid_fh:
	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
	return -EINVAL;
}

#if IS_ENABLED(CONFIG_NFS_V4)
static void nfs4_validate_mount_flags(struct nfs_fs_context *ctx)
{
	ctx->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
}

/*
 * Validate NFSv4 mount options
 */
static int nfs4_validate_mount_data(void *options,
				    struct nfs_fs_context *ctx,
				    const char *dev_name)
{
	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
	char *c;

	if (data == NULL)
		goto out_no_data;

	ctx->version = 4;

	switch (data->version) {
	case 1:
		if (data->host_addrlen > sizeof(ctx->nfs_server.address))
			goto out_no_address;
		if (data->host_addrlen == 0)
			goto out_no_address;
		ctx->nfs_server.addrlen = data->host_addrlen;
		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
			return -EFAULT;
		if (!nfs_verify_server_address(sap))
			goto out_no_address;
		ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);

		if (data->auth_flavourlen) {
			rpc_authflavor_t pseudoflavor;
			if (data->auth_flavourlen > 1)
				goto out_inval_auth;
			if (copy_from_user(&pseudoflavor,
					   data->auth_flavours,
					   sizeof(pseudoflavor)))
				return -EFAULT;
			ctx->selected_flavor = pseudoflavor;
		} else
			ctx->selected_flavor = RPC_AUTH_UNIX;

		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
		if (IS_ERR(c))
			return PTR_ERR(c);
		ctx->nfs_server.hostname = c;

		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
		if (IS_ERR(c))
			return PTR_ERR(c);
		ctx->nfs_server.export_path = c;
		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);

		c = strndup_user(data->client_addr.data, 16);
		if (IS_ERR(c))
			return PTR_ERR(c);
		ctx->client_address = c;

		/*
		 * Translate to nfs_fs_context, which nfs4_fill_super
		 * can deal with.
		 */

		ctx->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
		ctx->rsize	= data->rsize;
		ctx->wsize	= data->wsize;
		ctx->timeo	= data->timeo;
		ctx->retrans	= data->retrans;
		ctx->acregmin	= data->acregmin;
		ctx->acregmax	= data->acregmax;
		ctx->acdirmin	= data->acdirmin;
		ctx->acdirmax	= data->acdirmax;
		ctx->nfs_server.protocol = data->proto;
		nfs_validate_transport_protocol(ctx);
		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
			goto out_invalid_transport_udp;

		break;
	default:
		return NFS_TEXT_DATA;
	}

	return 0;

out_no_data:
	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
	return -EINVAL;

out_inval_auth:
	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
		 data->auth_flavourlen);
	return -EINVAL;

out_no_address:
	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
	return -EINVAL;

out_invalid_transport_udp:
	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
	return -EINVAL;
}

int nfs_validate_mount_data(struct file_system_type *fs_type,
			    void *options,
			    struct nfs_fs_context *ctx,
			    struct nfs_fh *mntfh,
			    const char *dev_name)
{
	if (fs_type == &nfs_fs_type)
		return nfs23_validate_mount_data(options, ctx, mntfh, dev_name);
	return nfs4_validate_mount_data(options, ctx, dev_name);
}
#else
int nfs_validate_mount_data(struct file_system_type *fs_type,
			    void *options,
			    struct nfs_fs_context *ctx,
			    struct nfs_fh *mntfh,
			    const char *dev_name)
{
	return nfs23_validate_mount_data(options, ctx, mntfh, dev_name);
}
#endif

int nfs_validate_text_mount_data(void *options,
				 struct nfs_fs_context *ctx,
				 const char *dev_name)
{
	int port = 0;
	int max_namelen = PAGE_SIZE;
	int max_pathlen = NFS_MAXPATHLEN;
	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;

	if (nfs_parse_mount_options((char *)options, ctx) == 0)
		return -EINVAL;

	if (!nfs_verify_server_address(sap))
		goto out_no_address;

	if (ctx->version == 4) {
#if IS_ENABLED(CONFIG_NFS_V4)
		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
			port = NFS_RDMA_PORT;
		else
			port = NFS_PORT;
		max_namelen = NFS4_MAXNAMLEN;
		max_pathlen = NFS4_MAXPATHLEN;
		nfs_validate_transport_protocol(ctx);
		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
			goto out_invalid_transport_udp;
		nfs4_validate_mount_flags(ctx);
#else
		goto out_v4_not_compiled;
#endif /* CONFIG_NFS_V4 */
	} else {
		nfs_set_mount_transport_protocol(ctx);
		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
			port = NFS_RDMA_PORT;
	}

	nfs_set_port(sap, &ctx->nfs_server.port, port);

	return nfs_parse_devname(ctx, dev_name, max_namelen, max_pathlen);

#if !IS_ENABLED(CONFIG_NFS_V4)
out_v4_not_compiled:
	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
	return -EPROTONOSUPPORT;
#else
out_invalid_transport_udp:
	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
	return -EINVAL;
#endif /* !CONFIG_NFS_V4 */

out_no_address:
	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
	return -EINVAL;
}