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-rw-r--r--fs/nfs/mount_clnt.c544
1 files changed, 544 insertions, 0 deletions
diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
new file mode 100644
index 000000000..68e76b626
--- /dev/null
+++ b/fs/nfs/mount_clnt.c
@@ -0,0 +1,544 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * In-kernel MOUNT protocol client
+ *
+ * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/nfs_fs.h>
+#include "internal.h"
+
+#define NFSDBG_FACILITY NFSDBG_MOUNT
+
+/*
+ * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
+ */
+#define MNTPATHLEN (1024)
+
+/*
+ * XDR data type sizes
+ */
+#define encode_dirpath_sz (1 + XDR_QUADLEN(MNTPATHLEN))
+#define MNT_status_sz (1)
+#define MNT_fhandle_sz XDR_QUADLEN(NFS2_FHSIZE)
+#define MNT_fhandlev3_sz XDR_QUADLEN(NFS3_FHSIZE)
+#define MNT_authflav3_sz (1 + NFS_MAX_SECFLAVORS)
+
+/*
+ * XDR argument and result sizes
+ */
+#define MNT_enc_dirpath_sz encode_dirpath_sz
+#define MNT_dec_mountres_sz (MNT_status_sz + MNT_fhandle_sz)
+#define MNT_dec_mountres3_sz (MNT_status_sz + MNT_fhandlev3_sz + \
+ MNT_authflav3_sz)
+
+/*
+ * Defined by RFC 1094, section A.5
+ */
+enum {
+ MOUNTPROC_NULL = 0,
+ MOUNTPROC_MNT = 1,
+ MOUNTPROC_DUMP = 2,
+ MOUNTPROC_UMNT = 3,
+ MOUNTPROC_UMNTALL = 4,
+ MOUNTPROC_EXPORT = 5,
+};
+
+/*
+ * Defined by RFC 1813, section 5.2
+ */
+enum {
+ MOUNTPROC3_NULL = 0,
+ MOUNTPROC3_MNT = 1,
+ MOUNTPROC3_DUMP = 2,
+ MOUNTPROC3_UMNT = 3,
+ MOUNTPROC3_UMNTALL = 4,
+ MOUNTPROC3_EXPORT = 5,
+};
+
+static const struct rpc_program mnt_program;
+
+/*
+ * Defined by OpenGroup XNFS Version 3W, chapter 8
+ */
+enum mountstat {
+ MNT_OK = 0,
+ MNT_EPERM = 1,
+ MNT_ENOENT = 2,
+ MNT_EACCES = 13,
+ MNT_EINVAL = 22,
+};
+
+static struct {
+ u32 status;
+ int errno;
+} mnt_errtbl[] = {
+ { .status = MNT_OK, .errno = 0, },
+ { .status = MNT_EPERM, .errno = -EPERM, },
+ { .status = MNT_ENOENT, .errno = -ENOENT, },
+ { .status = MNT_EACCES, .errno = -EACCES, },
+ { .status = MNT_EINVAL, .errno = -EINVAL, },
+};
+
+/*
+ * Defined by RFC 1813, section 5.1.5
+ */
+enum mountstat3 {
+ MNT3_OK = 0, /* no error */
+ MNT3ERR_PERM = 1, /* Not owner */
+ MNT3ERR_NOENT = 2, /* No such file or directory */
+ MNT3ERR_IO = 5, /* I/O error */
+ MNT3ERR_ACCES = 13, /* Permission denied */
+ MNT3ERR_NOTDIR = 20, /* Not a directory */
+ MNT3ERR_INVAL = 22, /* Invalid argument */
+ MNT3ERR_NAMETOOLONG = 63, /* Filename too long */
+ MNT3ERR_NOTSUPP = 10004, /* Operation not supported */
+ MNT3ERR_SERVERFAULT = 10006, /* A failure on the server */
+};
+
+static struct {
+ u32 status;
+ int errno;
+} mnt3_errtbl[] = {
+ { .status = MNT3_OK, .errno = 0, },
+ { .status = MNT3ERR_PERM, .errno = -EPERM, },
+ { .status = MNT3ERR_NOENT, .errno = -ENOENT, },
+ { .status = MNT3ERR_IO, .errno = -EIO, },
+ { .status = MNT3ERR_ACCES, .errno = -EACCES, },
+ { .status = MNT3ERR_NOTDIR, .errno = -ENOTDIR, },
+ { .status = MNT3ERR_INVAL, .errno = -EINVAL, },
+ { .status = MNT3ERR_NAMETOOLONG, .errno = -ENAMETOOLONG, },
+ { .status = MNT3ERR_NOTSUPP, .errno = -ENOTSUPP, },
+ { .status = MNT3ERR_SERVERFAULT, .errno = -EREMOTEIO, },
+};
+
+struct mountres {
+ int errno;
+ struct nfs_fh *fh;
+ unsigned int *auth_count;
+ rpc_authflavor_t *auth_flavors;
+};
+
+struct mnt_fhstatus {
+ u32 status;
+ struct nfs_fh *fh;
+};
+
+/**
+ * nfs_mount - Obtain an NFS file handle for the given host and path
+ * @info: pointer to mount request arguments
+ * @timeo: deciseconds the mount waits for a response before it retries
+ * @retrans: number of times the mount retries a request
+ *
+ * Uses timeout parameters specified by caller. On successful return, the
+ * auth_flavs list and auth_flav_len will be populated with the list from the
+ * server or a faked-up list if the server didn't provide one.
+ */
+int nfs_mount(struct nfs_mount_request *info, int timeo, int retrans)
+{
+ struct rpc_timeout mnt_timeout;
+ struct mountres result = {
+ .fh = info->fh,
+ .auth_count = info->auth_flav_len,
+ .auth_flavors = info->auth_flavs,
+ };
+ struct rpc_message msg = {
+ .rpc_argp = info->dirpath,
+ .rpc_resp = &result,
+ };
+ struct rpc_create_args args = {
+ .net = info->net,
+ .protocol = info->protocol,
+ .address = (struct sockaddr *)info->sap,
+ .addrsize = info->salen,
+ .timeout = &mnt_timeout,
+ .servername = info->hostname,
+ .program = &mnt_program,
+ .version = info->version,
+ .authflavor = RPC_AUTH_UNIX,
+ .cred = current_cred(),
+ };
+ struct rpc_clnt *mnt_clnt;
+ int status;
+
+ dprintk("NFS: sending MNT request for %s:%s\n",
+ (info->hostname ? info->hostname : "server"),
+ info->dirpath);
+
+ if (strlen(info->dirpath) > MNTPATHLEN)
+ return -ENAMETOOLONG;
+
+ if (info->noresvport)
+ args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+
+ nfs_init_timeout_values(&mnt_timeout, info->protocol, timeo, retrans);
+ mnt_clnt = rpc_create(&args);
+ if (IS_ERR(mnt_clnt))
+ goto out_clnt_err;
+
+ if (info->version == NFS_MNT3_VERSION)
+ msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
+ else
+ msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
+
+ status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
+ rpc_shutdown_client(mnt_clnt);
+
+ if (status < 0)
+ goto out_call_err;
+ if (result.errno != 0)
+ goto out_mnt_err;
+
+ dprintk("NFS: MNT request succeeded\n");
+ status = 0;
+
+ /*
+ * If the server didn't provide a flavor list, allow the
+ * client to try any flavor.
+ */
+ if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) {
+ dprintk("NFS: Faking up auth_flavs list\n");
+ info->auth_flavs[0] = RPC_AUTH_NULL;
+ *info->auth_flav_len = 1;
+ }
+out:
+ return status;
+
+out_clnt_err:
+ status = PTR_ERR(mnt_clnt);
+ dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
+ goto out;
+
+out_call_err:
+ dprintk("NFS: MNT request failed, status=%d\n", status);
+ goto out;
+
+out_mnt_err:
+ dprintk("NFS: MNT server returned result %d\n", result.errno);
+ status = result.errno;
+ goto out;
+}
+
+/**
+ * nfs_umount - Notify a server that we have unmounted this export
+ * @info: pointer to umount request arguments
+ *
+ * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
+ * use UDP.
+ */
+void nfs_umount(const struct nfs_mount_request *info)
+{
+ static const struct rpc_timeout nfs_umnt_timeout = {
+ .to_initval = 1 * HZ,
+ .to_maxval = 3 * HZ,
+ .to_retries = 2,
+ };
+ struct rpc_create_args args = {
+ .net = info->net,
+ .protocol = IPPROTO_UDP,
+ .address = (struct sockaddr *)info->sap,
+ .addrsize = info->salen,
+ .timeout = &nfs_umnt_timeout,
+ .servername = info->hostname,
+ .program = &mnt_program,
+ .version = info->version,
+ .authflavor = RPC_AUTH_UNIX,
+ .flags = RPC_CLNT_CREATE_NOPING,
+ .cred = current_cred(),
+ };
+ struct rpc_message msg = {
+ .rpc_argp = info->dirpath,
+ };
+ struct rpc_clnt *clnt;
+ int status;
+
+ if (strlen(info->dirpath) > MNTPATHLEN)
+ return;
+
+ if (info->noresvport)
+ args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+
+ clnt = rpc_create(&args);
+ if (IS_ERR(clnt))
+ goto out_clnt_err;
+
+ dprintk("NFS: sending UMNT request for %s:%s\n",
+ (info->hostname ? info->hostname : "server"), info->dirpath);
+
+ if (info->version == NFS_MNT3_VERSION)
+ msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
+ else
+ msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
+
+ status = rpc_call_sync(clnt, &msg, 0);
+ rpc_shutdown_client(clnt);
+
+ if (unlikely(status < 0))
+ goto out_call_err;
+
+ return;
+
+out_clnt_err:
+ dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
+ PTR_ERR(clnt));
+ return;
+
+out_call_err:
+ dprintk("NFS: UMNT request failed, status=%d\n", status);
+}
+
+/*
+ * XDR encode/decode functions for MOUNT
+ */
+
+static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
+{
+ const u32 pathname_len = strlen(pathname);
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4 + pathname_len);
+ xdr_encode_opaque(p, pathname, pathname_len);
+}
+
+static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
+ const void *dirpath)
+{
+ encode_mntdirpath(xdr, dirpath);
+}
+
+/*
+ * RFC 1094: "A non-zero status indicates some sort of error. In this
+ * case, the status is a UNIX error number." This can be problematic
+ * if the server and client use different errno values for the same
+ * error.
+ *
+ * However, the OpenGroup XNFS spec provides a simple mapping that is
+ * independent of local errno values on the server and the client.
+ */
+static int decode_status(struct xdr_stream *xdr, struct mountres *res)
+{
+ unsigned int i;
+ u32 status;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -EIO;
+ status = be32_to_cpup(p);
+
+ for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
+ if (mnt_errtbl[i].status == status) {
+ res->errno = mnt_errtbl[i].errno;
+ return 0;
+ }
+ }
+
+ dprintk("NFS: unrecognized MNT status code: %u\n", status);
+ res->errno = -EACCES;
+ return 0;
+}
+
+static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
+{
+ struct nfs_fh *fh = res->fh;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, NFS2_FHSIZE);
+ if (unlikely(p == NULL))
+ return -EIO;
+
+ fh->size = NFS2_FHSIZE;
+ memcpy(fh->data, p, NFS2_FHSIZE);
+ return 0;
+}
+
+static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ void *data)
+{
+ struct mountres *res = data;
+ int status;
+
+ status = decode_status(xdr, res);
+ if (unlikely(status != 0 || res->errno != 0))
+ return status;
+ return decode_fhandle(xdr, res);
+}
+
+static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
+{
+ unsigned int i;
+ u32 status;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -EIO;
+ status = be32_to_cpup(p);
+
+ for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
+ if (mnt3_errtbl[i].status == status) {
+ res->errno = mnt3_errtbl[i].errno;
+ return 0;
+ }
+ }
+
+ dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
+ res->errno = -EACCES;
+ return 0;
+}
+
+static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
+{
+ struct nfs_fh *fh = res->fh;
+ u32 size;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -EIO;
+
+ size = be32_to_cpup(p);
+ if (size > NFS3_FHSIZE || size == 0)
+ return -EIO;
+
+ p = xdr_inline_decode(xdr, size);
+ if (unlikely(p == NULL))
+ return -EIO;
+
+ fh->size = size;
+ memcpy(fh->data, p, size);
+ return 0;
+}
+
+static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
+{
+ rpc_authflavor_t *flavors = res->auth_flavors;
+ unsigned int *count = res->auth_count;
+ u32 entries, i;
+ __be32 *p;
+
+ if (*count == 0)
+ return 0;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -EIO;
+ entries = be32_to_cpup(p);
+ dprintk("NFS: received %u auth flavors\n", entries);
+ if (entries > NFS_MAX_SECFLAVORS)
+ entries = NFS_MAX_SECFLAVORS;
+
+ p = xdr_inline_decode(xdr, 4 * entries);
+ if (unlikely(p == NULL))
+ return -EIO;
+
+ if (entries > *count)
+ entries = *count;
+
+ for (i = 0; i < entries; i++) {
+ flavors[i] = be32_to_cpup(p++);
+ dprintk("NFS: auth flavor[%u]: %d\n", i, flavors[i]);
+ }
+ *count = i;
+
+ return 0;
+}
+
+static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ void *data)
+{
+ struct mountres *res = data;
+ int status;
+
+ status = decode_fhs_status(xdr, res);
+ if (unlikely(status != 0 || res->errno != 0))
+ return status;
+ status = decode_fhandle3(xdr, res);
+ if (unlikely(status != 0)) {
+ res->errno = -EBADHANDLE;
+ return 0;
+ }
+ return decode_auth_flavors(xdr, res);
+}
+
+static const struct rpc_procinfo mnt_procedures[] = {
+ [MOUNTPROC_MNT] = {
+ .p_proc = MOUNTPROC_MNT,
+ .p_encode = mnt_xdr_enc_dirpath,
+ .p_decode = mnt_xdr_dec_mountres,
+ .p_arglen = MNT_enc_dirpath_sz,
+ .p_replen = MNT_dec_mountres_sz,
+ .p_statidx = MOUNTPROC_MNT,
+ .p_name = "MOUNT",
+ },
+ [MOUNTPROC_UMNT] = {
+ .p_proc = MOUNTPROC_UMNT,
+ .p_encode = mnt_xdr_enc_dirpath,
+ .p_arglen = MNT_enc_dirpath_sz,
+ .p_statidx = MOUNTPROC_UMNT,
+ .p_name = "UMOUNT",
+ },
+};
+
+static const struct rpc_procinfo mnt3_procedures[] = {
+ [MOUNTPROC3_MNT] = {
+ .p_proc = MOUNTPROC3_MNT,
+ .p_encode = mnt_xdr_enc_dirpath,
+ .p_decode = mnt_xdr_dec_mountres3,
+ .p_arglen = MNT_enc_dirpath_sz,
+ .p_replen = MNT_dec_mountres3_sz,
+ .p_statidx = MOUNTPROC3_MNT,
+ .p_name = "MOUNT",
+ },
+ [MOUNTPROC3_UMNT] = {
+ .p_proc = MOUNTPROC3_UMNT,
+ .p_encode = mnt_xdr_enc_dirpath,
+ .p_arglen = MNT_enc_dirpath_sz,
+ .p_statidx = MOUNTPROC3_UMNT,
+ .p_name = "UMOUNT",
+ },
+};
+
+static unsigned int mnt_counts[ARRAY_SIZE(mnt_procedures)];
+static const struct rpc_version mnt_version1 = {
+ .number = 1,
+ .nrprocs = ARRAY_SIZE(mnt_procedures),
+ .procs = mnt_procedures,
+ .counts = mnt_counts,
+};
+
+static unsigned int mnt3_counts[ARRAY_SIZE(mnt3_procedures)];
+static const struct rpc_version mnt_version3 = {
+ .number = 3,
+ .nrprocs = ARRAY_SIZE(mnt3_procedures),
+ .procs = mnt3_procedures,
+ .counts = mnt3_counts,
+};
+
+static const struct rpc_version *mnt_version[] = {
+ NULL,
+ &mnt_version1,
+ NULL,
+ &mnt_version3,
+};
+
+static struct rpc_stat mnt_stats;
+
+static const struct rpc_program mnt_program = {
+ .name = "mount",
+ .number = NFS_MNT_PROGRAM,
+ .nrvers = ARRAY_SIZE(mnt_version),
+ .version = mnt_version,
+ .stats = &mnt_stats,
+};