diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-09 13:58:04 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-09 13:58:04 -0700 |
commit | 7a6b60441f02f6e22e7c0936ef16fa3f51832a48 (patch) | |
tree | 9e1661d21e52bdf30f2c0261e8a5ee0b175abb65 /fs/nfsd/nfs4xdr.c | |
parent | 8d3e09b43312991c503478bf0f5f99e92c23ccf1 (diff) | |
parent | b297fed699ad9e50315b27e78de42ac631c9990d (diff) |
Merge tag 'nfsd-5.9' of git://git.linux-nfs.org/projects/cel/cel-2.6
Pull NFS server updates from Chuck Lever:
"Highlights:
- Support for user extended attributes on NFS (RFC 8276)
- Further reduce unnecessary NFSv4 delegation recalls
Notable fixes:
- Fix recent krb5p regression
- Address a few resource leaks and a rare NULL dereference
Other:
- De-duplicate RPC/RDMA error handling and other utility functions
- Replace storage and display of kernel memory addresses by tracepoints"
* tag 'nfsd-5.9' of git://git.linux-nfs.org/projects/cel/cel-2.6: (38 commits)
svcrdma: CM event handler clean up
svcrdma: Remove transport reference counting
svcrdma: Fix another Receive buffer leak
SUNRPC: Refresh the show_rqstp_flags() macro
nfsd: netns.h: delete a duplicated word
SUNRPC: Fix ("SUNRPC: Add "@len" parameter to gss_unwrap()")
nfsd: avoid a NULL dereference in __cld_pipe_upcall()
nfsd4: a client's own opens needn't prevent delegations
nfsd: Use seq_putc() in two functions
svcrdma: Display chunk completion ID when posting a rw_ctxt
svcrdma: Record send_ctxt completion ID in trace_svcrdma_post_send()
svcrdma: Introduce Send completion IDs
svcrdma: Record Receive completion ID in svc_rdma_decode_rqst
svcrdma: Introduce Receive completion IDs
svcrdma: Introduce infrastructure to support completion IDs
svcrdma: Add common XDR encoders for RDMA and Read segments
svcrdma: Add common XDR decoders for RDMA and Read segments
SUNRPC: Add helpers for decoding list discriminators symbolically
svcrdma: Remove declarations for functions long removed
svcrdma: Clean up trace_svcrdma_send_failed() tracepoint
...
Diffstat (limited to 'fs/nfsd/nfs4xdr.c')
-rw-r--r-- | fs/nfsd/nfs4xdr.c | 531 |
1 files changed, 501 insertions, 30 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 996ac01ee977..259d5ad0e3f4 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -41,6 +41,8 @@ #include <linux/pagemap.h> #include <linux/sunrpc/svcauth_gss.h> #include <linux/sunrpc/addr.h> +#include <linux/xattr.h> +#include <uapi/linux/xattr.h> #include "idmap.h" #include "acl.h" @@ -257,6 +259,44 @@ svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len) return p; } +static __be32 +svcxdr_construct_vector(struct nfsd4_compoundargs *argp, struct kvec *head, + struct page ***pagelist, u32 buflen) +{ + int avail; + int len; + int pages; + + /* Sorry .. no magic macros for this.. * + * READ_BUF(write->wr_buflen); + * SAVEMEM(write->wr_buf, write->wr_buflen); + */ + avail = (char *)argp->end - (char *)argp->p; + if (avail + argp->pagelen < buflen) { + dprintk("NFSD: xdr error (%s:%d)\n", + __FILE__, __LINE__); + return nfserr_bad_xdr; + } + head->iov_base = argp->p; + head->iov_len = avail; + *pagelist = argp->pagelist; + + len = XDR_QUADLEN(buflen) << 2; + if (len >= avail) { + len -= avail; + + pages = len >> PAGE_SHIFT; + argp->pagelist += pages; + argp->pagelen -= pages * PAGE_SIZE; + len -= pages * PAGE_SIZE; + + next_decode_page(argp); + } + argp->p += XDR_QUADLEN(len); + + return 0; +} + /** * savemem - duplicate a chunk of memory for later processing * @argp: NFSv4 compound argument structure to be freed with @@ -1265,8 +1305,6 @@ nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify static __be32 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) { - int avail; - int len; DECODE_HEAD; status = nfsd4_decode_stateid(argp, &write->wr_stateid); @@ -1279,34 +1317,10 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) goto xdr_error; write->wr_buflen = be32_to_cpup(p++); - /* Sorry .. no magic macros for this.. * - * READ_BUF(write->wr_buflen); - * SAVEMEM(write->wr_buf, write->wr_buflen); - */ - avail = (char*)argp->end - (char*)argp->p; - if (avail + argp->pagelen < write->wr_buflen) { - dprintk("NFSD: xdr error (%s:%d)\n", - __FILE__, __LINE__); - goto xdr_error; - } - write->wr_head.iov_base = p; - write->wr_head.iov_len = avail; - write->wr_pagelist = argp->pagelist; - - len = XDR_QUADLEN(write->wr_buflen) << 2; - if (len >= avail) { - int pages; - - len -= avail; - - pages = len >> PAGE_SHIFT; - argp->pagelist += pages; - argp->pagelen -= pages * PAGE_SIZE; - len -= pages * PAGE_SIZE; - - next_decode_page(argp); - } - argp->p += XDR_QUADLEN(len); + status = svcxdr_construct_vector(argp, &write->wr_head, + &write->wr_pagelist, write->wr_buflen); + if (status) + return status; DECODE_TAIL; } @@ -1865,6 +1879,208 @@ nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek) DECODE_TAIL; } +/* + * XDR data that is more than PAGE_SIZE in size is normally part of a + * read or write. However, the size of extended attributes is limited + * by the maximum request size, and then further limited by the underlying + * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX + * is 64k). Since there is no kvec- or page-based interface to xattrs, + * and we're not dealing with contiguous pages, we need to do some copying. + */ + +/* + * Decode data into buffer. Uses head and pages constructed by + * svcxdr_construct_vector. + */ +static __be32 +nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct kvec *head, + struct page **pages, char **bufp, u32 buflen) +{ + char *tmp, *dp; + u32 len; + + if (buflen <= head->iov_len) { + /* + * We're in luck, the head has enough space. Just return + * the head, no need for copying. + */ + *bufp = head->iov_base; + return 0; + } + + tmp = svcxdr_tmpalloc(argp, buflen); + if (tmp == NULL) + return nfserr_jukebox; + + dp = tmp; + memcpy(dp, head->iov_base, head->iov_len); + buflen -= head->iov_len; + dp += head->iov_len; + + while (buflen > 0) { + len = min_t(u32, buflen, PAGE_SIZE); + memcpy(dp, page_address(*pages), len); + + buflen -= len; + dp += len; + pages++; + } + + *bufp = tmp; + return 0; +} + +/* + * Get a user extended attribute name from the XDR buffer. + * It will not have the "user." prefix, so prepend it. + * Lastly, check for nul characters in the name. + */ +static __be32 +nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep) +{ + DECODE_HEAD; + char *name, *sp, *dp; + u32 namelen, cnt; + + READ_BUF(4); + namelen = be32_to_cpup(p++); + + if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN)) + return nfserr_nametoolong; + + if (namelen == 0) + goto xdr_error; + + READ_BUF(namelen); + + name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1); + if (!name) + return nfserr_jukebox; + + memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN); + + /* + * Copy the extended attribute name over while checking for 0 + * characters. + */ + sp = (char *)p; + dp = name + XATTR_USER_PREFIX_LEN; + cnt = namelen; + + while (cnt-- > 0) { + if (*sp == '\0') + goto xdr_error; + *dp++ = *sp++; + } + *dp = '\0'; + + *namep = name; + + DECODE_TAIL; +} + +/* + * A GETXATTR op request comes without a length specifier. We just set the + * maximum length for the reply based on XATTR_SIZE_MAX and the maximum + * channel reply size. nfsd_getxattr will probe the length of the xattr, + * check it against getxa_len, and allocate + return the value. + */ +static __be32 +nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp, + struct nfsd4_getxattr *getxattr) +{ + __be32 status; + u32 maxcount; + + status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name); + if (status) + return status; + + maxcount = svc_max_payload(argp->rqstp); + maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount); + + getxattr->getxa_len = maxcount; + + return status; +} + +static __be32 +nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp, + struct nfsd4_setxattr *setxattr) +{ + DECODE_HEAD; + u32 flags, maxcount, size; + struct kvec head; + struct page **pagelist; + + READ_BUF(4); + flags = be32_to_cpup(p++); + + if (flags > SETXATTR4_REPLACE) + return nfserr_inval; + setxattr->setxa_flags = flags; + + status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name); + if (status) + return status; + + maxcount = svc_max_payload(argp->rqstp); + maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount); + + READ_BUF(4); + size = be32_to_cpup(p++); + if (size > maxcount) + return nfserr_xattr2big; + + setxattr->setxa_len = size; + if (size > 0) { + status = svcxdr_construct_vector(argp, &head, &pagelist, size); + if (status) + return status; + + status = nfsd4_vbuf_from_vector(argp, &head, pagelist, + &setxattr->setxa_buf, size); + } + + DECODE_TAIL; +} + +static __be32 +nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp, + struct nfsd4_listxattrs *listxattrs) +{ + DECODE_HEAD; + u32 maxcount; + + READ_BUF(12); + p = xdr_decode_hyper(p, &listxattrs->lsxa_cookie); + + /* + * If the cookie is too large to have even one user.x attribute + * plus trailing '\0' left in a maximum size buffer, it's invalid. + */ + if (listxattrs->lsxa_cookie >= + (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2))) + return nfserr_badcookie; + + maxcount = be32_to_cpup(p++); + if (maxcount < 8) + /* Always need at least 2 words (length and one character) */ + return nfserr_inval; + + maxcount = min(maxcount, svc_max_payload(argp->rqstp)); + listxattrs->lsxa_maxcount = maxcount; + + DECODE_TAIL; +} + +static __be32 +nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp, + struct nfsd4_removexattr *removexattr) +{ + return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name); +} + static __be32 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p) { @@ -1961,6 +2177,11 @@ static const nfsd4_dec nfsd4_dec_ops[] = { [OP_SEEK] = (nfsd4_dec)nfsd4_decode_seek, [OP_WRITE_SAME] = (nfsd4_dec)nfsd4_decode_notsupp, [OP_CLONE] = (nfsd4_dec)nfsd4_decode_clone, + /* RFC 8276 extended atributes operations */ + [OP_GETXATTR] = (nfsd4_dec)nfsd4_decode_getxattr, + [OP_SETXATTR] = (nfsd4_dec)nfsd4_decode_setxattr, + [OP_LISTXATTRS] = (nfsd4_dec)nfsd4_decode_listxattrs, + [OP_REMOVEXATTR] = (nfsd4_dec)nfsd4_decode_removexattr, }; static inline bool @@ -2992,6 +3213,15 @@ out_acl: } #endif + if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) { + p = xdr_reserve_space(xdr, 4); + if (!p) + goto out_resource; + err = xattr_supported_namespace(d_inode(dentry), + XATTR_USER_PREFIX); + *p++ = cpu_to_be32(err == 0); + } + attrlen = htonl(xdr->buf->len - attrlen_offset - 4); write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4); status = nfs_ok; @@ -4446,6 +4676,241 @@ nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p) return nfserr; } +/* + * Encode kmalloc-ed buffer in to XDR stream. + */ +static int +nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen) +{ + u32 cplen; + __be32 *p; + + cplen = min_t(unsigned long, buflen, + ((void *)xdr->end - (void *)xdr->p)); + p = xdr_reserve_space(xdr, cplen); + if (!p) + return nfserr_resource; + + memcpy(p, buf, cplen); + buf += cplen; + buflen -= cplen; + + while (buflen) { + cplen = min_t(u32, buflen, PAGE_SIZE); + p = xdr_reserve_space(xdr, cplen); + if (!p) + return nfserr_resource; + + memcpy(p, buf, cplen); + + if (cplen < PAGE_SIZE) { + /* + * We're done, with a length that wasn't page + * aligned, so possibly not word aligned. Pad + * any trailing bytes with 0. + */ + xdr_encode_opaque_fixed(p, NULL, cplen); + break; + } + + buflen -= PAGE_SIZE; + buf += PAGE_SIZE; + } + + return 0; +} + +static __be32 +nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_getxattr *getxattr) +{ + struct xdr_stream *xdr = &resp->xdr; + __be32 *p, err; + + p = xdr_reserve_space(xdr, 4); + if (!p) + return nfserr_resource; + + *p = cpu_to_be32(getxattr->getxa_len); + + if (getxattr->getxa_len == 0) + return 0; + + err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf, + getxattr->getxa_len); + + kvfree(getxattr->getxa_buf); + + return err; +} + +static __be32 +nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_setxattr *setxattr) +{ + struct xdr_stream *xdr = &resp->xdr; + __be32 *p; + + p = xdr_reserve_space(xdr, 20); + if (!p) + return nfserr_resource; + + encode_cinfo(p, &setxattr->setxa_cinfo); + + return 0; +} + +/* + * See if there are cookie values that can be rejected outright. + */ +static __be32 +nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs, + u32 *offsetp) +{ + u64 cookie = listxattrs->lsxa_cookie; + + /* + * If the cookie is larger than the maximum number we can fit + * in either the buffer we just got back from vfs_listxattr, or, + * XDR-encoded, in the return buffer, it's invalid. + */ + if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2)) + return nfserr_badcookie; + + if (cookie > (listxattrs->lsxa_maxcount / + (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4))) + return nfserr_badcookie; + + *offsetp = (u32)cookie; + return 0; +} + +static __be32 +nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_listxattrs *listxattrs) +{ + struct xdr_stream *xdr = &resp->xdr; + u32 cookie_offset, count_offset, eof; + u32 left, xdrleft, slen, count; + u32 xdrlen, offset; + u64 cookie; + char *sp; + __be32 status; + __be32 *p; + u32 nuser; + + eof = 1; + + status = nfsd4_listxattr_validate_cookie(listxattrs, &offset); + if (status) + goto out; + + /* + * Reserve space for the cookie and the name array count. Record + * the offsets to save them later. + */ + cookie_offset = xdr->buf->len; + count_offset = cookie_offset + 8; + p = xdr_reserve_space(xdr, 12); + if (!p) { + status = nfserr_resource; + goto out; + } + + count = 0; + left = listxattrs->lsxa_len; + sp = listxattrs->lsxa_buf; + nuser = 0; + + xdrleft = listxattrs->lsxa_maxcount; + + while (left > 0 && xdrleft > 0) { + slen = strlen(sp); + + /* + * Check if this a user. attribute, skip it if not. + */ + if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) + goto contloop; + + slen -= XATTR_USER_PREFIX_LEN; + xdrlen = 4 + ((slen + 3) & ~3); + if (xdrlen > xdrleft) { + if (count == 0) { + /* + * Can't even fit the first attribute name. + */ + status = nfserr_toosmall; + goto out; + } + eof = 0; + goto wreof; + } + + left -= XATTR_USER_PREFIX_LEN; + sp += XATTR_USER_PREFIX_LEN; + if (nuser++ < offset) + goto contloop; + + + p = xdr_reserve_space(xdr, xdrlen); + if (!p) { + status = nfserr_resource; + goto out; + } + + p = xdr_encode_opaque(p, sp, slen); + + xdrleft -= xdrlen; + count++; +contloop: + sp += slen + 1; + left -= slen + 1; + } + + /* + * If there were user attributes to copy, but we didn't copy + * any, the offset was too large (e.g. the cookie was invalid). + */ + if (nuser > 0 && count == 0) { + status = nfserr_badcookie; + goto out; + } + +wreof: + p = xdr_reserve_space(xdr, 4); + if (!p) { + status = nfserr_resource; + goto out; + } + *p = cpu_to_be32(eof); + + cookie = offset + count; + + write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8); + count = htonl(count); + write_bytes_to_xdr_buf(xdr->buf, count_offset, &count, 4); +out: + if (listxattrs->lsxa_len) + kvfree(listxattrs->lsxa_buf); + return status; +} + +static __be32 +nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_removexattr *removexattr) +{ + struct xdr_stream *xdr = &resp->xdr; + __be32 *p; + + p = xdr_reserve_space(xdr, 20); + if (!p) + return nfserr_resource; + + p = encode_cinfo(p, &removexattr->rmxa_cinfo); + return 0; +} + typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *); /* @@ -4535,6 +5000,12 @@ static const nfsd4_enc nfsd4_enc_ops[] = { [OP_SEEK] = (nfsd4_enc)nfsd4_encode_seek, [OP_WRITE_SAME] = (nfsd4_enc)nfsd4_encode_noop, [OP_CLONE] = (nfsd4_enc)nfsd4_encode_noop, + + /* RFC 8276 extended atributes operations */ + [OP_GETXATTR] = (nfsd4_enc)nfsd4_encode_getxattr, + [OP_SETXATTR] = (nfsd4_enc)nfsd4_encode_setxattr, + [OP_LISTXATTRS] = (nfsd4_enc)nfsd4_encode_listxattrs, + [OP_REMOVEXATTR] = (nfsd4_enc)nfsd4_encode_removexattr, }; /* |