Various cleanups and bugfixes for the NFSv4 client XDR code.
v2: Add documentation to the generic helpers
v3: Fix a bug in xdr_stream_encode_opaque (Whoops!)
v4: Add a "maxlen" argument to xdr_stream_decode_opaque_inline() to perform
size sanity checking on all objects coming from the server.
Replace the string decoder in the callback XDR
Add cleanups for the owner/group attribute decoding
Trond Myklebust (8):
SUNRPC: Add generic helpers for xdr_stream encode/decode
NFSv4: Replace ad-hoc xdr encode/decode helpers with xdr_stream_*
generics
NFSv4: Replace the open coded decode_opaque_inline() with the new
generic
NFSv4: Replace callback string decode function with a generic
NFSv4: Fix the underestimation of delegation XDR space reservation
NFSv4: Remove bogus "struct nfs_client" argument from decode_ace()
SUNRPC: Add a helper function xdr_stream_decode_string_dup()
NFSv4: Clean up owner/group attribute decode
fs/nfs/callback_xdr.c | 38 ++-----
fs/nfs/flexfilelayout/flexfilelayout.c | 5 +-
fs/nfs/nfs4xdr.c | 185 ++++++++++++++-------------------
include/linux/sunrpc/xdr.h | 179 +++++++++++++++++++++++++++++++
net/sunrpc/xdr.c | 34 ++++++
5 files changed, 302 insertions(+), 139 deletions(-)
--
2.9.3
Add some generic helpers for encoding/decoding opaque structures and
basic u32/u64.
Signed-off-by: Trond Myklebust <[email protected]>
---
include/linux/sunrpc/xdr.h | 177 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 177 insertions(+)
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 56c48c884a24..af41484212e5 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -242,6 +242,183 @@ extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
+/**
+ * xdr_align_size - Calculate padded size of an object
+ * @n: Size of an object being XDR encoded (in bytes)
+ *
+ * Return value:
+ * Size (in bytes) of the object including xdr padding
+ */
+static inline size_t
+xdr_align_size(size_t n)
+{
+ const size_t mask = sizeof(__u32) - 1;
+
+ return (n + mask) & ~mask;
+}
+
+/**
+ * xdr_stream_encode_u32 - Encode a 32-bit integer
+ * @xdr: pointer to xdr_stream
+ * @n: integer to encode
+ *
+ * Return values:
+ * On success, returns length in bytes of XDR buffer consumed
+ * %-ENOBUFS on XDR buffer overflow
+ */
+static inline ssize_t
+xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
+{
+ const size_t len = sizeof(n);
+ __be32 *p = xdr_reserve_space(xdr, len);
+
+ if (unlikely(!p))
+ return -ENOBUFS;
+ *p = cpu_to_be32(n);
+ return len;
+}
+
+/**
+ * xdr_stream_encode_u64 - Encode a 64-bit integer
+ * @xdr: pointer to xdr_stream
+ * @n: 64-bit integer to encode
+ *
+ * Return values:
+ * On success, returns length in bytes of XDR buffer consumed
+ * %-ENOBUFS on XDR buffer overflow
+ */
+static inline ssize_t
+xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
+{
+ const size_t len = sizeof(n);
+ __be32 *p = xdr_reserve_space(xdr, len);
+
+ if (unlikely(!p))
+ return -ENOBUFS;
+ xdr_encode_hyper(p, n);
+ return len;
+}
+
+/**
+ * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
+ * @xdr: pointer to xdr_stream
+ * @ptr: pointer to opaque data object
+ * @len: size of object pointed to by @ptr
+ *
+ * Return values:
+ * On success, returns length in bytes of XDR buffer consumed
+ * %-ENOBUFS on XDR buffer overflow
+ */
+static inline ssize_t
+xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
+{
+ __be32 *p = xdr_reserve_space(xdr, len);
+
+ if (unlikely(!p))
+ return -ENOBUFS;
+ xdr_encode_opaque_fixed(p, ptr, len);
+ return xdr_align_size(len);
+}
+
+/**
+ * xdr_stream_encode_opaque - Encode variable length opaque xdr data
+ * @xdr: pointer to xdr_stream
+ * @ptr: pointer to opaque data object
+ * @len: size of object pointed to by @ptr
+ *
+ * Return values:
+ * On success, returns length in bytes of XDR buffer consumed
+ * %-ENOBUFS on XDR buffer overflow
+ */
+static inline ssize_t
+xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
+{
+ size_t count = sizeof(__u32) + xdr_align_size(len);
+ __be32 *p = xdr_reserve_space(xdr, count);
+
+ if (unlikely(!p))
+ return -ENOBUFS;
+ xdr_encode_opaque(p, ptr, len);
+ return count;
+}
+
+/**
+ * xdr_stream_decode_u32 - Decode a 32-bit integer
+ * @xdr: pointer to xdr_stream
+ * @ptr: location to store integer
+ *
+ * Return values:
+ * %0 on success
+ * %-ENOBUFS on XDR buffer overflow
+ */
+static inline ssize_t
+xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
+{
+ const size_t count = sizeof(*ptr);
+ __be32 *p = xdr_inline_decode(xdr, count);
+
+ if (unlikely(!p))
+ return -ENOBUFS;
+ *ptr = be32_to_cpup(p);
+ return 0;
+}
+
+/**
+ * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
+ * @xdr: pointer to xdr_stream
+ * @ptr: location to store data
+ * @len: size of buffer pointed to by @ptr
+ *
+ * Return values:
+ * On success, returns size of object stored in @ptr
+ * %-ENOBUFS on XDR buffer overflow
+ */
+static inline ssize_t
+xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
+{
+ __be32 *p = xdr_inline_decode(xdr, len);
+
+ if (unlikely(!p))
+ return -ENOBUFS;
+ xdr_decode_opaque_fixed(p, ptr, len);
+ return len;
+}
+
+/**
+ * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
+ * @xdr: pointer to xdr_stream
+ * @ptr: location to store pointer to opaque data
+ * @maxlen: maximum acceptable object size
+ *
+ * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
+ * buffer has been destroyed, or even after calling xdr_inline_decode()
+ * on @xdr. It is therefore expected that the object it points to should
+ * be processed immediately.
+ *
+ * Return values:
+ * On success, returns size of object stored in *@ptr
+ * %-ENOBUFS on XDR buffer overflow
+ * %-E2BIG if the size of the object would exceed @maxlen
+ */
+static inline ssize_t
+xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
+{
+ __be32 *p;
+ __u32 len;
+
+ *ptr = NULL;
+ if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
+ return -ENOBUFS;
+ if (len != 0) {
+ p = xdr_inline_decode(xdr, len);
+ if (unlikely(!p))
+ return -ENOBUFS;
+ if (unlikely(len > maxlen))
+ return -E2BIG;
+ *ptr = p;
+ }
+ return len;
+}
#endif /* __KERNEL__ */
#endif /* _SUNRPC_XDR_H_ */
--
2.9.3
Also ensure that we always check that the size of the decoded object
matches the expectation that it must be smaller than NFS4_OPAQUE_LIMIT.
This should be true for all the current users of decode_opaque_inline(),
including decode_ace(), decode_pathname(), decode_attr_fs_locations()
and decode_exchange_id().
Note that this allows us to get rid of a number of existing checks in
decode_exchange_id(),
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/nfs4xdr.c | 29 ++++++++---------------------
1 file changed, 8 insertions(+), 21 deletions(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 5f0a6fcd0030..4c40098c184b 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3050,20 +3050,15 @@ static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char **string)
{
- __be32 *p;
-
- p = xdr_inline_decode(xdr, 4);
- if (unlikely(!p))
- goto out_overflow;
- *len = be32_to_cpup(p);
- p = xdr_inline_decode(xdr, *len);
- if (unlikely(!p))
- goto out_overflow;
- *string = (char *)p;
+ ssize_t ret = xdr_stream_decode_opaque_inline(xdr, (void **)string,
+ NFS4_OPAQUE_LIMIT);
+ if (unlikely(ret < 0)) {
+ if (ret == -ENOBUFS)
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+ }
+ *len = ret;
return 0;
-out_overflow:
- print_overflow_msg(__func__, xdr);
- return -EIO;
}
static int decode_compound_hdr(struct xdr_stream *xdr, struct compound_hdr *hdr)
@@ -5645,8 +5640,6 @@ static int decode_exchange_id(struct xdr_stream *xdr,
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->server_owner->major_id, dummy_str, dummy);
res->server_owner->major_id_sz = dummy;
@@ -5654,8 +5647,6 @@ static int decode_exchange_id(struct xdr_stream *xdr,
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->server_scope->server_scope, dummy_str, dummy);
res->server_scope->server_scope_sz = dummy;
@@ -5670,16 +5661,12 @@ static int decode_exchange_id(struct xdr_stream *xdr,
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->impl_id->domain, dummy_str, dummy);
/* nii_name */
status = decode_opaque_inline(xdr, &dummy, &dummy_str);
if (unlikely(status))
return status;
- if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
- return -EIO;
memcpy(res->impl_id->name, dummy_str, dummy);
/* nii_date */
--
2.9.3
Account for the "space_limit" field in struct open_write_delegation4.
Fixes: 2cebf82883f4 ("NFSv4: Fix the underestimate of NFSv4 open request size")
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/nfs4xdr.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 4c40098c184b..91c386c09bf3 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -169,8 +169,10 @@ static int nfs4_stat_to_errno(int);
open_owner_id_maxsz + \
encode_opentype_maxsz + \
encode_claim_null_maxsz)
+#define decode_space_limit_maxsz (3)
#define decode_ace_maxsz (3 + nfs4_owner_maxsz)
#define decode_delegation_maxsz (1 + decode_stateid_maxsz + 1 + \
+ decode_space_limit_maxsz + \
decode_ace_maxsz)
#define decode_change_info_maxsz (5)
#define decode_open_maxsz (op_decode_hdr_maxsz + \
--
2.9.3
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/callback_xdr.c | 8 ++------
fs/nfs/flexfilelayout/flexfilelayout.c | 5 +----
fs/nfs/nfs4xdr.c | 33 +++++++++------------------------
3 files changed, 12 insertions(+), 34 deletions(-)
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index eb094c6011d8..e732a65db546 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -582,12 +582,8 @@ static __be32 decode_notify_lock_args(struct svc_rqst *rqstp, struct xdr_stream
static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
{
- __be32 *p;
-
- p = xdr_reserve_space(xdr, 4 + len);
- if (unlikely(p == NULL))
- return htonl(NFS4ERR_RESOURCE);
- xdr_encode_opaque(p, str, len);
+ if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
+ return cpu_to_be32(NFS4ERR_RESOURCE);
return 0;
}
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index 42e3e9daa328..471efdc2589d 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1966,10 +1966,7 @@ static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
static void
encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
{
- __be32 *p;
-
- p = xdr_reserve_space(xdr, len);
- xdr_encode_opaque_fixed(p, buf, len);
+ WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
}
static void
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index e9255cb453e6..5f0a6fcd0030 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -924,34 +924,22 @@ static __be32 *reserve_space(struct xdr_stream *xdr, size_t nbytes)
static void encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
{
- __be32 *p;
-
- p = xdr_reserve_space(xdr, len);
- xdr_encode_opaque_fixed(p, buf, len);
+ WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
}
static void encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
{
- __be32 *p;
-
- p = reserve_space(xdr, 4 + len);
- xdr_encode_opaque(p, str, len);
+ WARN_ON_ONCE(xdr_stream_encode_opaque(xdr, str, len) < 0);
}
static void encode_uint32(struct xdr_stream *xdr, u32 n)
{
- __be32 *p;
-
- p = reserve_space(xdr, 4);
- *p = cpu_to_be32(n);
+ WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
}
static void encode_uint64(struct xdr_stream *xdr, u64 n)
{
- __be32 *p;
-
- p = reserve_space(xdr, 8);
- xdr_encode_hyper(p, n);
+ WARN_ON_ONCE(xdr_stream_encode_u64(xdr, n) < 0);
}
static void encode_nfs4_seqid(struct xdr_stream *xdr,
@@ -4294,15 +4282,12 @@ static int decode_access(struct xdr_stream *xdr, u32 *supported, u32 *access)
static int decode_opaque_fixed(struct xdr_stream *xdr, void *buf, size_t len)
{
- __be32 *p;
-
- p = xdr_inline_decode(xdr, len);
- if (likely(p)) {
- memcpy(buf, p, len);
- return 0;
+ ssize_t ret = xdr_stream_decode_opaque_fixed(xdr, buf, len);
+ if (unlikely(ret < 0)) {
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
}
- print_overflow_msg(__func__, xdr);
- return -EIO;
+ return 0;
}
static int decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
--
2.9.3
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/nfs4xdr.c | 117 +++++++++++++++++++++++++++----------------------------
1 file changed, 57 insertions(+), 60 deletions(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index f5df18f99bd4..afe7f40add05 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3875,45 +3875,50 @@ static int decode_attr_nlink(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t
return -EIO;
}
+static ssize_t decode_nfs4_string(struct xdr_stream *xdr,
+ struct nfs4_string *name, gfp_t gfp_flags)
+{
+ ssize_t ret;
+
+ ret = xdr_stream_decode_string_dup(xdr, &name->data,
+ XDR_MAX_NETOBJ, gfp_flags);
+ name->len = 0;
+ if (ret > 0)
+ name->len = ret;
+ return ret;
+}
+
static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap,
const struct nfs_server *server, kuid_t *uid,
struct nfs4_string *owner_name)
{
- uint32_t len;
- __be32 *p;
- int ret = 0;
+ ssize_t len;
+ char *p;
*uid = make_kuid(&init_user_ns, -2);
if (unlikely(bitmap[1] & (FATTR4_WORD1_OWNER - 1U)))
return -EIO;
- if (likely(bitmap[1] & FATTR4_WORD1_OWNER)) {
- p = xdr_inline_decode(xdr, 4);
- if (unlikely(!p))
- goto out_overflow;
- len = be32_to_cpup(p);
- p = xdr_inline_decode(xdr, len);
- if (unlikely(!p))
- goto out_overflow;
- if (owner_name != NULL) {
- owner_name->data = kmemdup(p, len, GFP_NOWAIT);
- if (owner_name->data != NULL) {
- owner_name->len = len;
- ret = NFS_ATTR_FATTR_OWNER_NAME;
- }
- } else if (len < XDR_MAX_NETOBJ) {
- if (nfs_map_name_to_uid(server, (char *)p, len, uid) == 0)
- ret = NFS_ATTR_FATTR_OWNER;
- else
- dprintk("%s: nfs_map_name_to_uid failed!\n",
- __func__);
- } else
- dprintk("%s: name too long (%u)!\n",
- __func__, len);
- bitmap[1] &= ~FATTR4_WORD1_OWNER;
+ if (!(bitmap[1] & FATTR4_WORD1_OWNER))
+ return 0;
+ bitmap[1] &= ~FATTR4_WORD1_OWNER;
+
+ if (owner_name != NULL) {
+ len = decode_nfs4_string(xdr, owner_name, GFP_NOWAIT);
+ if (len <= 0)
+ goto out;
+ dprintk("%s: name=%s\n", __func__, owner_name->data);
+ return NFS_ATTR_FATTR_OWNER_NAME;
+ } else {
+ len = xdr_stream_decode_opaque_inline(xdr, (void **)&p,
+ XDR_MAX_NETOBJ);
+ if (len <= 0 || nfs_map_name_to_uid(server, p, len, uid) != 0)
+ goto out;
+ dprintk("%s: uid=%d\n", __func__, (int)from_kuid(&init_user_ns, *uid));
+ return NFS_ATTR_FATTR_OWNER;
}
- dprintk("%s: uid=%d\n", __func__, (int)from_kuid(&init_user_ns, *uid));
- return ret;
-out_overflow:
+out:
+ if (len != -ENOBUFS)
+ return 0;
print_overflow_msg(__func__, xdr);
return -EIO;
}
@@ -3922,41 +3927,33 @@ static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap,
const struct nfs_server *server, kgid_t *gid,
struct nfs4_string *group_name)
{
- uint32_t len;
- __be32 *p;
- int ret = 0;
+ ssize_t len;
+ char *p;
*gid = make_kgid(&init_user_ns, -2);
if (unlikely(bitmap[1] & (FATTR4_WORD1_OWNER_GROUP - 1U)))
return -EIO;
- if (likely(bitmap[1] & FATTR4_WORD1_OWNER_GROUP)) {
- p = xdr_inline_decode(xdr, 4);
- if (unlikely(!p))
- goto out_overflow;
- len = be32_to_cpup(p);
- p = xdr_inline_decode(xdr, len);
- if (unlikely(!p))
- goto out_overflow;
- if (group_name != NULL) {
- group_name->data = kmemdup(p, len, GFP_NOWAIT);
- if (group_name->data != NULL) {
- group_name->len = len;
- ret = NFS_ATTR_FATTR_GROUP_NAME;
- }
- } else if (len < XDR_MAX_NETOBJ) {
- if (nfs_map_group_to_gid(server, (char *)p, len, gid) == 0)
- ret = NFS_ATTR_FATTR_GROUP;
- else
- dprintk("%s: nfs_map_group_to_gid failed!\n",
- __func__);
- } else
- dprintk("%s: name too long (%u)!\n",
- __func__, len);
- bitmap[1] &= ~FATTR4_WORD1_OWNER_GROUP;
+ if (!(bitmap[1] & FATTR4_WORD1_OWNER_GROUP))
+ return 0;
+ bitmap[1] &= ~FATTR4_WORD1_OWNER_GROUP;
+
+ if (group_name != NULL) {
+ len = decode_nfs4_string(xdr, group_name, GFP_NOWAIT);
+ if (len <= 0)
+ goto out;
+ dprintk("%s: name=%s\n", __func__, group_name->data);
+ return NFS_ATTR_FATTR_OWNER_NAME;
+ } else {
+ len = xdr_stream_decode_opaque_inline(xdr, (void **)&p,
+ XDR_MAX_NETOBJ);
+ if (len <= 0 || nfs_map_group_to_gid(server, p, len, gid) != 0)
+ goto out;
+ dprintk("%s: gid=%d\n", __func__, (int)from_kgid(&init_user_ns, *gid));
+ return NFS_ATTR_FATTR_GROUP;
}
- dprintk("%s: gid=%d\n", __func__, (int)from_kgid(&init_user_ns, *gid));
- return ret;
-out_overflow:
+out:
+ if (len != -ENOBUFS)
+ return 0;
print_overflow_msg(__func__, xdr);
return -EIO;
}
--
2.9.3
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/callback_xdr.c | 30 ++++++++----------------------
1 file changed, 8 insertions(+), 22 deletions(-)
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index e732a65db546..2ade5cb52b8e 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -83,23 +83,15 @@ static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
return p;
}
-static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
+static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
+ const char **str, size_t maxlen)
{
- __be32 *p;
-
- p = read_buf(xdr, 4);
- if (unlikely(p == NULL))
- return htonl(NFS4ERR_RESOURCE);
- *len = ntohl(*p);
-
- if (*len != 0) {
- p = read_buf(xdr, *len);
- if (unlikely(p == NULL))
- return htonl(NFS4ERR_RESOURCE);
- *str = (const char *)p;
- } else
- *str = NULL;
+ ssize_t err;
+ err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
+ if (err < 0)
+ return cpu_to_be32(NFS4ERR_RESOURCE);
+ *len = err;
return 0;
}
@@ -162,15 +154,9 @@ static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound
__be32 *p;
__be32 status;
- status = decode_string(xdr, &hdr->taglen, &hdr->tag);
+ status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
if (unlikely(status != 0))
return status;
- /* We do not like overly long tags! */
- if (hdr->taglen > CB_OP_TAGLEN_MAXSZ) {
- printk("NFS: NFSv4 CALLBACK %s: client sent tag of length %u\n",
- __func__, hdr->taglen);
- return htonl(NFS4ERR_RESOURCE);
- }
p = read_buf(xdr, 12);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
--
2.9.3
Create a helper function that decodes a xdr string object, allocates a memory
buffer and then store it as a NUL terminated string.
Signed-off-by: Trond Myklebust <[email protected]>
---
include/linux/sunrpc/xdr.h | 2 ++
net/sunrpc/xdr.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index af41484212e5..51d937466645 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -242,6 +242,8 @@ extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
+ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
+ size_t maxlen, gfp_t gfp_flags);
/**
* xdr_align_size - Calculate padded size of an object
* @n: Size of an object being XDR encoded (in bytes)
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 7f1071e103ca..6a7caab1c4a5 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1518,3 +1518,37 @@ xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
}
EXPORT_SYMBOL_GPL(xdr_process_buf);
+/**
+ * xdr_stream_decode_string_dup - Decode and duplicate variable length string
+ * @xdr: pointer to xdr_stream
+ * @str: location to store pointer to string
+ * @maxlen: maximum acceptable string length
+ * @gfp_flags: GFP mask to use
+ *
+ * Return values:
+ * On success, returns length of NUL-terminated string stored in *@ptr
+ * %-ENOBUFS on XDR buffer overflow
+ * %-ENOMEM on memory allocation failure
+ * %-E2BIG if the size of the string would exceed @maxlen
+ */
+ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
+ size_t maxlen, gfp_t gfp_flags)
+{
+ void *p;
+ ssize_t ret;
+
+ ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
+ if (ret > 0) {
+ char *s = kmalloc(ret + 1, gfp_flags);
+ if (s != NULL) {
+ memcpy(s, p, ret);
+ s[ret] = '\0';
+ *str = s;
+ return strlen(s);
+ }
+ ret = -ENOMEM;
+ }
+ *str = NULL;
+ return ret;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup);
--
2.9.3
We shouldn't need to force callers to carry an unused argument.
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/nfs4xdr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 91c386c09bf3..f5df18f99bd4 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3127,7 +3127,7 @@ static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
}
/* Dummy routine */
-static int decode_ace(struct xdr_stream *xdr, void *ace, struct nfs_client *clp)
+static int decode_ace(struct xdr_stream *xdr, void *ace)
{
__be32 *p;
unsigned int strlen;
@@ -5075,7 +5075,7 @@ static int decode_rw_delegation(struct xdr_stream *xdr,
if (decode_space_limit(xdr, &res->pagemod_limit) < 0)
return -EIO;
}
- return decode_ace(xdr, NULL, res->server->nfs_client);
+ return decode_ace(xdr, NULL);
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
--
2.9.3