// SPDX-License-Identifier: GPL-2.0 /* * XDR support for nfsd * * Copyright (C) 1995, 1996 Olaf Kirch */ #include "vfs.h" #include "xdr.h" #include "auth.h" /* * Mapping of S_IF* types to NFS file types */ static const u32 nfs_ftypes[] = { NFNON, NFCHR, NFCHR, NFBAD, NFDIR, NFBAD, NFBLK, NFBAD, NFREG, NFBAD, NFLNK, NFBAD, NFSOCK, NFBAD, NFLNK, NFBAD, }; /* * Basic NFSv2 data types (RFC 1094 Section 2.3) */ /** * svcxdr_encode_stat - Encode an NFSv2 status code * @xdr: XDR stream * @status: status value to encode * * Return values: * %false: Send buffer space was exhausted * %true: Success */ bool svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status) { __be32 *p; p = xdr_reserve_space(xdr, sizeof(status)); if (!p) return false; *p = status; return true; } /** * svcxdr_decode_fhandle - Decode an NFSv2 file handle * @xdr: XDR stream positioned at an encoded NFSv2 FH * @fhp: OUT: filled-in server file handle * * Return values: * %false: The encoded file handle was not valid * %true: @fhp has been initialized */ bool svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp) { __be32 *p; p = xdr_inline_decode(xdr, NFS_FHSIZE); if (!p) return false; fh_init(fhp, NFS_FHSIZE); memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE); fhp->fh_handle.fh_size = NFS_FHSIZE; return true; } static bool svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp) { __be32 *p; p = xdr_reserve_space(xdr, NFS_FHSIZE); if (!p) return false; memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE); return true; } static __be32 * encode_timeval(__be32 *p, const struct timespec64 *time) { *p++ = cpu_to_be32((u32)time->tv_sec); if (time->tv_nsec) *p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC); else *p++ = xdr_zero; return p; } static bool svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len) { u32 size, i; __be32 *p; char *c; if (xdr_stream_decode_u32(xdr, &size) < 0) return false; if (size == 0 || size > NFS_MAXNAMLEN) return false; p = xdr_inline_decode(xdr, size); if (!p) return false; *len = size; *name = (char *)p; for (i = 0, c = *name; i < size; i++, c++) if (*c == '\0' || *c == '/') return false; return true; } static bool svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp, char **name, unsigned int *len) { return svcxdr_decode_fhandle(xdr, fhp) && svcxdr_decode_filename(xdr, name, len); } static bool svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct iattr *iap) { u32 tmp1, tmp2; __be32 *p; p = xdr_inline_decode(xdr, XDR_UNIT * 8); if (!p) return false; iap->ia_valid = 0; /* * Some Sun clients put 0xffff in the mode field when they * mean 0xffffffff. */ tmp1 = be32_to_cpup(p++); if (tmp1 != (u32)-1 && tmp1 != 0xffff) { iap->ia_valid |= ATTR_MODE; iap->ia_mode = tmp1; } tmp1 = be32_to_cpup(p++); if (tmp1 != (u32)-1) { iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1); if (uid_valid(iap->ia_uid)) iap->ia_valid |= ATTR_UID; } tmp1 = be32_to_cpup(p++); if (tmp1 != (u32)-1) { iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1); if (gid_valid(iap->ia_gid)) iap->ia_valid |= ATTR_GID; } tmp1 = be32_to_cpup(p++); if (tmp1 != (u32)-1) { iap->ia_valid |= ATTR_SIZE; iap->ia_size = tmp1; } tmp1 = be32_to_cpup(p++); tmp2 = be32_to_cpup(p++); if (tmp1 != (u32)-1 && tmp2 != (u32)-1) { iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET; iap->ia_atime.tv_sec = tmp1; iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC; } tmp1 = be32_to_cpup(p++); tmp2 = be32_to_cpup(p++); if (tmp1 != (u32)-1 && tmp2 != (u32)-1) { iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET; iap->ia_mtime.tv_sec = tmp1; iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC; /* * Passing the invalid value useconds=1000000 for mtime * is a Sun convention for "set both mtime and atime to * current server time". It's needed to make permissions * checks for the "touch" program across v2 mounts to * Solaris and Irix boxes work correctly. See description of * sattr in section 6.1 of "NFS Illustrated" by * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5 */ if (tmp2 == 1000000) iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET); } return true; } /** * svcxdr_encode_fattr - Encode NFSv2 file attributes * @rqstp: Context of a completed RPC transaction * @xdr: XDR stream * @fhp: File handle to encode * @stat: Attributes to encode * * Return values: * %false: Send buffer space was exhausted * %true: Success */ bool svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct svc_fh *fhp, const struct kstat *stat) { struct user_namespace *userns = nfsd_user_namespace(rqstp); struct dentry *dentry = fhp->fh_dentry; int type = stat->mode & S_IFMT; struct timespec64 time; __be32 *p; u32 fsid; p = xdr_reserve_space(xdr, XDR_UNIT * 17); if (!p) return false; *p++ = cpu_to_be32(nfs_ftypes[type >> 12]); *p++ = cpu_to_be32((u32)stat->mode); *p++ = cpu_to_be32((u32)stat->nlink); *p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid)); *p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid)); if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) *p++ = cpu_to_be32(NFS_MAXPATHLEN); else *p++ = cpu_to_be32((u32) stat->size); *p++ = cpu_to_be32((u32) stat->blksize); if (S_ISCHR(type) || S_ISBLK(type)) *p++ = cpu_to_be32(new_encode_dev(stat->rdev)); else *p++ = cpu_to_be32(0xffffffff); *p++ = cpu_to_be32((u32)stat->blocks); switch (fsid_source(fhp)) { case FSIDSOURCE_FSID: fsid = (u32)fhp->fh_export->ex_fsid; break; case FSIDSOURCE_UUID: fsid = ((u32 *)fhp->fh_export->ex_uuid)[0]; fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1]; fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2]; fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3]; break; default: fsid = new_encode_dev(stat->dev); break; } *p++ = cpu_to_be32(fsid); *p++ = cpu_to_be32((u32)stat->ino); p = encode_timeval(p, &stat->atime); time = stat->mtime; lease_get_mtime(d_inode(dentry), &time); p = encode_timeval(p, &time); encode_timeval(p, &stat->ctime); return true; } /* * XDR decode functions */ bool nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_fhandle *args = rqstp->rq_argp; return svcxdr_decode_fhandle(xdr, &args->fh); } bool nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_sattrargs *args = rqstp->rq_argp; return svcxdr_decode_fhandle(xdr, &args->fh) && svcxdr_decode_sattr(rqstp, xdr, &args->attrs); } bool nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_diropargs *args = rqstp->rq_argp; return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len); } bool nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_readargs *args = rqstp->rq_argp; u32 totalcount; if (!svcxdr_decode_fhandle(xdr, &args->fh)) return false; if (xdr_stream_decode_u32(xdr, &args->offset) < 0) return false; if (xdr_stream_decode_u32(xdr, &args->count) < 0) return false; /* totalcount is ignored */ if (xdr_stream_decode_u32(xdr, &totalcount) < 0) return false; return true; } bool nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_writeargs *args = rqstp->rq_argp; u32 beginoffset, totalcount; if (!svcxdr_decode_fhandle(xdr, &args->fh)) return false; /* beginoffset is ignored */ if (xdr_stream_decode_u32(xdr, &beginoffset) < 0) return false; if (xdr_stream_decode_u32(xdr, &args->offset) < 0) return false; /* totalcount is ignored */ if (xdr_stream_decode_u32(xdr, &totalcount) < 0) return false; /* opaque data */ if (xdr_stream_decode_u32(xdr, &args->len) < 0) return false; if (args->len > NFSSVC_MAXBLKSIZE_V2) return false; return xdr_stream_subsegment(xdr, &args->payload, args->len); } bool nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_createargs *args = rqstp->rq_argp; return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len) && svcxdr_decode_sattr(rqstp, xdr, &args->attrs); } bool nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_renameargs *args = rqstp->rq_argp; return svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen) && svcxdr_decode_diropargs(xdr, &args->tfh, &args->tname, &args->tlen); } bool nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_linkargs *args = rqstp->rq_argp; return svcxdr_decode_fhandle(xdr, &args->ffh) && svcxdr_decode_diropargs(xdr, &args->tfh, &args->tname, &args->tlen); } bool nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_symlinkargs *args = rqstp->rq_argp; struct kvec *head = rqstp->rq_arg.head; if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen)) return false; if (xdr_stream_decode_u32(xdr, &args->tlen) < 0) return false; if (args->tlen == 0) return false; args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); args->first.iov_base = xdr_inline_decode(xdr, args->tlen); if (!args->first.iov_base) return false; return svcxdr_decode_sattr(rqstp, xdr, &args->attrs); } bool nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_readdirargs *args = rqstp->rq_argp; if (!svcxdr_decode_fhandle(xdr, &args->fh)) return false; if (xdr_stream_decode_u32(xdr, &args->cookie) < 0) return false; if (xdr_stream_decode_u32(xdr, &args->count) < 0) return false; return true; } /* * XDR encode functions */ bool nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_stat *resp = rqstp->rq_resp; return svcxdr_encode_stat(xdr, resp->status); } bool nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_attrstat *resp = rqstp->rq_resp; if (!svcxdr_encode_stat(xdr, resp->status)) return false; switch (resp->status) { case nfs_ok: if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) return false; break; } return true; } bool nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_diropres *resp = rqstp->rq_resp; if (!svcxdr_encode_stat(xdr, resp->status)) return false; switch (resp->status) { case nfs_ok: if (!svcxdr_encode_fhandle(xdr, &resp->fh)) return false; if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) return false; break; } return true; } bool nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_readlinkres *resp = rqstp->rq_resp; struct kvec *head = rqstp->rq_res.head; if (!svcxdr_encode_stat(xdr, resp->status)) return false; switch (resp->status) { case nfs_ok: if (xdr_stream_encode_u32(xdr, resp->len) < 0) return false; svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0, resp->len); if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0) return false; break; } return true; } bool nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_readres *resp = rqstp->rq_resp; struct kvec *head = rqstp->rq_res.head; if (!svcxdr_encode_stat(xdr, resp->status)) return false; switch (resp->status) { case nfs_ok: if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) return false; if (xdr_stream_encode_u32(xdr, resp->count) < 0) return false; svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages, rqstp->rq_res.page_base, resp->count); if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0) return false; break; } return true; } bool nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_readdirres *resp = rqstp->rq_resp; struct xdr_buf *dirlist = &resp->dirlist; if (!svcxdr_encode_stat(xdr, resp->status)) return false; switch (resp->status) { case nfs_ok: svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0, dirlist->len); /* no more entries */ if (xdr_stream_encode_item_absent(xdr) < 0) return false; if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0) return false; break; } return true; } bool nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd_statfsres *resp = rqstp->rq_resp; struct kstatfs *stat = &resp->stats; __be32 *p; if (!svcxdr_encode_stat(xdr, resp->status)) return false; switch (resp->status) { case nfs_ok: p = xdr_reserve_space(xdr, XDR_UNIT * 5); if (!p) return false; *p++ = cpu_to_be32(NFSSVC_MAXBLKSIZE_V2); *p++ = cpu_to_be32(stat->f_bsize); *p++ = cpu_to_be32(stat->f_blocks); *p++ = cpu_to_be32(stat->f_bfree); *p = cpu_to_be32(stat->f_bavail); break; } return true; } /** * nfssvc_encode_nfscookie - Encode a directory offset cookie * @resp: readdir result context * @offset: offset cookie to encode * * The buffer space for the offset cookie has already been reserved * by svcxdr_encode_entry_common(). */ void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset) { __be32 cookie = cpu_to_be32(offset); if (!resp->cookie_offset) return; write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie, sizeof(cookie)); resp->cookie_offset = 0; } static bool svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name, int namlen, loff_t offset, u64 ino) { struct xdr_buf *dirlist = &resp->dirlist; struct xdr_stream *xdr = &resp->xdr; if (xdr_stream_encode_item_present(xdr) < 0) return false; /* fileid */ if (xdr_stream_encode_u32(xdr, (u32)ino) < 0) return false; /* name */ if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0) return false; /* cookie */ resp->cookie_offset = dirlist->len; if (xdr_stream_encode_u32(xdr, ~0U) < 0) return false; return true; } /** * nfssvc_encode_entry - encode one NFSv2 READDIR entry * @data: directory context * @name: name of the object to be encoded * @namlen: length of that name, in bytes * @offset: the offset of the previous entry * @ino: the fileid of this entry * @d_type: unused * * Return values: * %0: Entry was successfully encoded. * %-EINVAL: An encoding problem occured, secondary status code in resp->common.err * * On exit, the following fields are updated: * - resp->xdr * - resp->common.err * - resp->cookie_offset */ int nfssvc_encode_entry(void *data, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct readdir_cd *ccd = data; struct nfsd_readdirres *resp = container_of(ccd, struct nfsd_readdirres, common); unsigned int starting_length = resp->dirlist.len; /* The offset cookie for the previous entry */ nfssvc_encode_nfscookie(resp, offset); if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino)) goto out_toosmall; xdr_commit_encode(&resp->xdr); resp->common.err = nfs_ok; return 0; out_toosmall: resp->cookie_offset = 0; resp->common.err = nfserr_toosmall; resp->dirlist.len = starting_length; return -EINVAL; } /* * XDR release functions */ void nfssvc_release_attrstat(struct svc_rqst *rqstp) { struct nfsd_attrstat *resp = rqstp->rq_resp; fh_put(&resp->fh); } void nfssvc_release_diropres(struct svc_rqst *rqstp) { struct nfsd_diropres *resp = rqstp->rq_resp; fh_put(&resp->fh); } void nfssvc_release_readres(struct svc_rqst *rqstp) { struct nfsd_readres *resp = rqstp->rq_resp; fh_put(&resp->fh); }