1 files changed, 481 insertions, 0 deletions

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
new file mode 100644
index 000000000000..d271df9df2b2
--- /dev/null
+++ b/fs/nfs/callback_xdr.c
@@ -0,0 +1,481 @@
+/*
+ * linux/fs/nfs/callback_xdr.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback encode/decode procedures
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include "callback.h"
+
+#define CB_OP_TAGLEN_MAXSZ      (512)
+#define CB_OP_HDR_RES_MAXSZ     (2 + CB_OP_TAGLEN_MAXSZ)
+#define CB_OP_GETATTR_BITMAP_MAXSZ      (4)
+#define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
+                                CB_OP_GETATTR_BITMAP_MAXSZ + \
+                                2 + 2 + 3 + 3)
+#define CB_OP_RECALL_RES_MAXSZ  (CB_OP_HDR_RES_MAXSZ)
+
+#define NFSDBG_FACILITY NFSDBG_CALLBACK
+
+typedef unsigned (*callback_process_op_t)(void *, void *);
+typedef unsigned (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
+typedef unsigned (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
+
+
+struct callback_op {
+        callback_process_op_t process_op;
+        callback_decode_arg_t decode_args;
+        callback_encode_res_t encode_res;
+        long res_maxsize;
+};
+
+static struct callback_op callback_ops[];
+
+static int nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
+{
+        return htonl(NFS4_OK);
+}
+
+static int nfs4_decode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy)
+{
+        return xdr_argsize_check(rqstp, p);
+}
+
+static int nfs4_encode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy)
+{
+        return xdr_ressize_check(rqstp, p);
+}
+
+static uint32_t *read_buf(struct xdr_stream *xdr, int nbytes)
+{
+        uint32_t *p;
+
+        p = xdr_inline_decode(xdr, nbytes);
+        if (unlikely(p == NULL))
+                printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
+        return p;
+}
+
+static unsigned decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
+{
+        uint32_t *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;
+
+        return 0;
+}
+
+static unsigned decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+        uint32_t *p;
+
+        p = read_buf(xdr, 4);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        fh->size = ntohl(*p);
+        if (fh->size > NFS4_FHSIZE)
+                return htonl(NFS4ERR_BADHANDLE);
+        p = read_buf(xdr, fh->size);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        memcpy(&fh->data[0], p, fh->size);
+        memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
+        return 0;
+}
+
+static unsigned decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
+{
+        uint32_t *p;
+        unsigned int attrlen;
+
+        p = read_buf(xdr, 4);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        attrlen = ntohl(*p);
+        p = read_buf(xdr, attrlen << 2);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        if (likely(attrlen > 0))
+                bitmap[0] = ntohl(*p++);
+        if (attrlen > 1)
+                bitmap[1] = ntohl(*p);
+        return 0;
+}
+
+static unsigned decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+        uint32_t *p;
+
+        p = read_buf(xdr, 16);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        memcpy(stateid->data, p, 16);
+        return 0;
+}
+
+static unsigned decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
+{
+        uint32_t *p;
+        unsigned int minor_version;
+        unsigned status;
+
+        status = decode_string(xdr, &hdr->taglen, &hdr->tag);
+        if (unlikely(status != 0))
+                return status;
+        /* We do not like overly long tags! */
+        if (hdr->taglen > CB_OP_TAGLEN_MAXSZ-12 || hdr->taglen < 0) {
+                printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
+                                __FUNCTION__, hdr->taglen);
+                return htonl(NFS4ERR_RESOURCE);
+        }
+        p = read_buf(xdr, 12);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        minor_version = ntohl(*p++);
+        /* Check minor version is zero. */
+        if (minor_version != 0) {
+                printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n",
+                                __FUNCTION__, minor_version);
+                return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+        }
+        hdr->callback_ident = ntohl(*p++);
+        hdr->nops = ntohl(*p);
+        return 0;
+}
+
+static unsigned decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
+{
+        uint32_t *p;
+        p = read_buf(xdr, 4);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        *op = ntohl(*p);
+        return 0;
+}
+
+static unsigned decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
+{
+        unsigned status;
+
+        status = decode_fh(xdr, &args->fh);
+        if (unlikely(status != 0))
+                goto out;
+        args->addr = &rqstp->rq_addr;
+        status = decode_bitmap(xdr, args->bitmap);
+out:
+        dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
+        return status;
+}
+
+static unsigned decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
+{
+        uint32_t *p;
+        unsigned status;
+
+        args->addr = &rqstp->rq_addr;
+        status = decode_stateid(xdr, &args->stateid);
+        if (unlikely(status != 0))
+                goto out;
+        p = read_buf(xdr, 4);
+        if (unlikely(p == NULL)) {
+                status = htonl(NFS4ERR_RESOURCE);
+                goto out;
+        }
+        args->truncate = ntohl(*p);
+        status = decode_fh(xdr, &args->fh);
+out:
+        dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
+        return 0;
+}
+
+static unsigned encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
+{
+        uint32_t *p;
+
+        p = xdr_reserve_space(xdr, 4 + len);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        xdr_encode_opaque(p, str, len);
+        return 0;
+}
+
+#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
+#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
+static unsigned encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, uint32_t **savep)
+{
+        uint32_t bm[2];
+        uint32_t *p;
+
+        bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
+        bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
+        if (bm[1] != 0) {
+                p = xdr_reserve_space(xdr, 16);
+                if (unlikely(p == NULL))
+                        return htonl(NFS4ERR_RESOURCE);
+                *p++ = htonl(2);
+                *p++ = bm[0];
+                *p++ = bm[1];
+        } else if (bm[0] != 0) {
+                p = xdr_reserve_space(xdr, 12);
+                if (unlikely(p == NULL))
+                        return htonl(NFS4ERR_RESOURCE);
+                *p++ = htonl(1);
+                *p++ = bm[0];
+        } else {
+                p = xdr_reserve_space(xdr, 8);
+                if (unlikely(p == NULL))
+                        return htonl(NFS4ERR_RESOURCE);
+                *p++ = htonl(0);
+        }
+        *savep = p;
+        return 0;
+}
+
+static unsigned encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
+{
+        uint32_t *p;
+
+        if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
+                return 0;
+        p = xdr_reserve_space(xdr, 8);
+        if (unlikely(p == 0))
+                return htonl(NFS4ERR_RESOURCE);
+        p = xdr_encode_hyper(p, change);
+        return 0;
+}
+
+static unsigned encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
+{
+        uint32_t *p;
+
+        if (!(bitmap[0] & FATTR4_WORD0_SIZE))
+                return 0;
+        p = xdr_reserve_space(xdr, 8);
+        if (unlikely(p == 0))
+                return htonl(NFS4ERR_RESOURCE);
+        p = xdr_encode_hyper(p, size);
+        return 0;
+}
+
+static unsigned encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
+{
+        uint32_t *p;
+
+        p = xdr_reserve_space(xdr, 12);
+        if (unlikely(p == 0))
+                return htonl(NFS4ERR_RESOURCE);
+        p = xdr_encode_hyper(p, time->tv_sec);
+        *p = htonl(time->tv_nsec);
+        return 0;
+}
+
+static unsigned encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
+{
+        if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
+                return 0;
+        return encode_attr_time(xdr,time);
+}
+
+static unsigned encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
+{
+        if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
+                return 0;
+        return encode_attr_time(xdr,time);
+}
+
+static unsigned encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
+{
+        unsigned status;
+
+        hdr->status = xdr_reserve_space(xdr, 4);
+        if (unlikely(hdr->status == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        status = encode_string(xdr, hdr->taglen, hdr->tag);
+        if (unlikely(status != 0))
+                return status;
+        hdr->nops = xdr_reserve_space(xdr, 4);
+        if (unlikely(hdr->nops == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        return 0;
+}
+
+static unsigned encode_op_hdr(struct xdr_stream *xdr, uint32_t op, uint32_t res)
+{
+        uint32_t *p;
+        
+        p = xdr_reserve_space(xdr, 8);
+        if (unlikely(p == NULL))
+                return htonl(NFS4ERR_RESOURCE);
+        *p++ = htonl(op);
+        *p = res;
+        return 0;
+}
+
+static unsigned encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
+{
+        uint32_t *savep;
+        unsigned status = res->status;
+        
+        if (unlikely(status != 0))
+                goto out;
+        status = encode_attr_bitmap(xdr, res->bitmap, &savep);
+        if (unlikely(status != 0))
+                goto out;
+        status = encode_attr_change(xdr, res->bitmap, res->change_attr);
+        if (unlikely(status != 0))
+                goto out;
+        status = encode_attr_size(xdr, res->bitmap, res->size);
+        if (unlikely(status != 0))
+                goto out;
+        status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
+        if (unlikely(status != 0))
+                goto out;
+        status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
+        *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
+out:
+        dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
+        return status;
+}
+
+static unsigned process_op(struct svc_rqst *rqstp,
+                struct xdr_stream *xdr_in, void *argp,
+                struct xdr_stream *xdr_out, void *resp)
+{
+        struct callback_op *op;
+        unsigned int op_nr;
+        unsigned int status = 0;
+        long maxlen;
+        unsigned res;
+
+        dprintk("%s: start\n", __FUNCTION__);
+        status = decode_op_hdr(xdr_in, &op_nr);
+        if (unlikely(status != 0)) {
+                op_nr = OP_CB_ILLEGAL;
+                op = &callback_ops[0];
+        } else if (unlikely(op_nr != OP_CB_GETATTR && op_nr != OP_CB_RECALL)) {
+                op_nr = OP_CB_ILLEGAL;
+                op = &callback_ops[0];
+                status = htonl(NFS4ERR_OP_ILLEGAL);
+        } else
+                op = &callback_ops[op_nr];
+
+        maxlen = xdr_out->end - xdr_out->p;
+        if (maxlen > 0 && maxlen < PAGE_SIZE) {
+                if (likely(status == 0 && op->decode_args != NULL))
+                        status = op->decode_args(rqstp, xdr_in, argp);
+                if (likely(status == 0 && op->process_op != NULL))
+                        status = op->process_op(argp, resp);
+        } else
+                status = htonl(NFS4ERR_RESOURCE);
+
+        res = encode_op_hdr(xdr_out, op_nr, status);
+        if (status == 0)
+                status = res;
+        if (op->encode_res != NULL && status == 0)
+                status = op->encode_res(rqstp, xdr_out, resp);
+        dprintk("%s: done, status = %d\n", __FUNCTION__, status);
+        return status;
+}
+
+/*
+ * Decode, process and encode a COMPOUND
+ */
+static int nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
+{
+        struct cb_compound_hdr_arg hdr_arg;
+        struct cb_compound_hdr_res hdr_res;
+        struct xdr_stream xdr_in, xdr_out;
+        uint32_t *p;
+        unsigned int status;
+        unsigned int nops = 1;
+
+        dprintk("%s: start\n", __FUNCTION__);
+
+        xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
+
+        p = (uint32_t*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
+        rqstp->rq_res.head[0].iov_len = PAGE_SIZE;
+        xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
+
+        decode_compound_hdr_arg(&xdr_in, &hdr_arg);
+        hdr_res.taglen = hdr_arg.taglen;
+        hdr_res.tag = hdr_arg.tag;
+        encode_compound_hdr_res(&xdr_out, &hdr_res);
+
+        for (;;) {
+                status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
+                if (status != 0)
+                        break;
+                if (nops == hdr_arg.nops)
+                        break;
+                nops++;
+        }
+        *hdr_res.status = status;
+        *hdr_res.nops = htonl(nops);
+        dprintk("%s: done, status = %u\n", __FUNCTION__, status);
+        return rpc_success;
+}
+
+/*
+ * Define NFS4 callback COMPOUND ops.
+ */
+static struct callback_op callback_ops[] = {
+        [0] = {
+                .res_maxsize = CB_OP_HDR_RES_MAXSZ,
+        },
+        [OP_CB_GETATTR] = {
+                .process_op = (callback_process_op_t)nfs4_callback_getattr,
+                .decode_args = (callback_decode_arg_t)decode_getattr_args,
+                .encode_res = (callback_encode_res_t)encode_getattr_res,
+                .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
+        },
+        [OP_CB_RECALL] = {
+                .process_op = (callback_process_op_t)nfs4_callback_recall,
+                .decode_args = (callback_decode_arg_t)decode_recall_args,
+                .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
+        }
+};
+
+/*
+ * Define NFS4 callback procedures
+ */
+static struct svc_procedure nfs4_callback_procedures1[] = {
+        [CB_NULL] = {
+                .pc_func = nfs4_callback_null,
+                .pc_decode = (kxdrproc_t)nfs4_decode_void,
+                .pc_encode = (kxdrproc_t)nfs4_encode_void,
+                .pc_xdrressize = 1,
+        },
+        [CB_COMPOUND] = {
+                .pc_func = nfs4_callback_compound,
+                .pc_encode = (kxdrproc_t)nfs4_encode_void,
+                .pc_argsize = 256,
+                .pc_ressize = 256,
+                .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
+        }
+};
+
+struct svc_version nfs4_callback_version1 = {
+        .vs_vers = 1,
+        .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
+        .vs_proc = nfs4_callback_procedures1,
+        .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
+        .vs_dispatch = NULL,
+};
+