/* * 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 "nfs4_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 = NULL; 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 = &callback_ops[0]; unsigned int op_nr = OP_CB_ILLEGAL; unsigned int status = 0; long maxlen; unsigned res; dprintk("%s: start\n", __FUNCTION__); status = decode_op_hdr(xdr_in, &op_nr); if (likely(status == 0)) { switch (op_nr) { case OP_CB_GETATTR: case OP_CB_RECALL: op = &callback_ops[op_nr]; break; default: op_nr = OP_CB_ILLEGAL; op = &callback_ops[0]; status = htonl(NFS4ERR_OP_ILLEGAL); } } 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); 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; hdr_res.nops = NULL; 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, };