// 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_fhs_status_sz (1) #define MNT_fhandle_sz XDR_QUADLEN(NFS2_FHSIZE) #define MNT_fhandle3_sz (1 + 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_fhandle_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 * * Uses default timeout parameters specified by underlying transport. 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) { 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 = info->sap, .addrsize = info->salen, .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; 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 = 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, };