/* * linux/fs/nfsd/nfs4callback.c * * Copyright (c) 2001 The Regents of the University of Michigan. * All rights reserved. * * Kendrick Smith * Andy Adamson * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include "nfsd.h" #include "state.h" #define NFSDDBG_FACILITY NFSDDBG_PROC #define NFSPROC4_CB_NULL 0 #define NFSPROC4_CB_COMPOUND 1 #define NFS4_STATEID_SIZE 16 /* Index of predefined Linux callback client operations */ enum { NFSPROC4_CLNT_CB_NULL = 0, NFSPROC4_CLNT_CB_RECALL, NFSPROC4_CLNT_CB_SEQUENCE, }; enum nfs_cb_opnum4 { OP_CB_RECALL = 4, OP_CB_SEQUENCE = 11, }; #define NFS4_MAXTAGLEN 20 #define NFS4_enc_cb_null_sz 0 #define NFS4_dec_cb_null_sz 0 #define cb_compound_enc_hdr_sz 4 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2)) #define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2) #define cb_sequence_enc_sz (sessionid_sz + 4 + \ 1 /* no referring calls list yet */) #define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4) #define op_enc_sz 1 #define op_dec_sz 2 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2)) #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2) #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \ cb_sequence_enc_sz + \ 1 + enc_stateid_sz + \ enc_nfs4_fh_sz) #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \ cb_sequence_dec_sz + \ op_dec_sz) struct nfs4_rpc_args { void *args_op; struct nfsd4_cb_sequence args_seq; }; /* * Generic encode routines from fs/nfs/nfs4xdr.c */ static inline __be32 * xdr_writemem(__be32 *p, const void *ptr, int nbytes) { int tmp = XDR_QUADLEN(nbytes); if (!tmp) return p; p[tmp-1] = 0; memcpy(p, ptr, nbytes); return p + tmp; } #define WRITE32(n) *p++ = htonl(n) #define WRITEMEM(ptr,nbytes) do { \ p = xdr_writemem(p, ptr, nbytes); \ } while (0) #define RESERVE_SPACE(nbytes) do { \ p = xdr_reserve_space(xdr, nbytes); \ if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \ BUG_ON(!p); \ } while (0) /* * Generic decode routines from fs/nfs/nfs4xdr.c */ #define DECODE_TAIL \ status = 0; \ out: \ return status; \ xdr_error: \ dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \ status = -EIO; \ goto out #define READ32(x) (x) = ntohl(*p++) #define READ64(x) do { \ (x) = (u64)ntohl(*p++) << 32; \ (x) |= ntohl(*p++); \ } while (0) #define READTIME(x) do { \ p++; \ (x.tv_sec) = ntohl(*p++); \ (x.tv_nsec) = ntohl(*p++); \ } while (0) #define READ_BUF(nbytes) do { \ p = xdr_inline_decode(xdr, nbytes); \ if (!p) { \ dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \ __func__, __LINE__); \ return -EIO; \ } \ } while (0) struct nfs4_cb_compound_hdr { /* args */ u32 ident; /* minorversion 0 only */ u32 nops; __be32 *nops_p; u32 minorversion; /* res */ int status; u32 taglen; char *tag; }; static struct { int stat; int errno; } nfs_cb_errtbl[] = { { NFS4_OK, 0 }, { NFS4ERR_PERM, EPERM }, { NFS4ERR_NOENT, ENOENT }, { NFS4ERR_IO, EIO }, { NFS4ERR_NXIO, ENXIO }, { NFS4ERR_ACCESS, EACCES }, { NFS4ERR_EXIST, EEXIST }, { NFS4ERR_XDEV, EXDEV }, { NFS4ERR_NOTDIR, ENOTDIR }, { NFS4ERR_ISDIR, EISDIR }, { NFS4ERR_INVAL, EINVAL }, { NFS4ERR_FBIG, EFBIG }, { NFS4ERR_NOSPC, ENOSPC }, { NFS4ERR_ROFS, EROFS }, { NFS4ERR_MLINK, EMLINK }, { NFS4ERR_NAMETOOLONG, ENAMETOOLONG }, { NFS4ERR_NOTEMPTY, ENOTEMPTY }, { NFS4ERR_DQUOT, EDQUOT }, { NFS4ERR_STALE, ESTALE }, { NFS4ERR_BADHANDLE, EBADHANDLE }, { NFS4ERR_BAD_COOKIE, EBADCOOKIE }, { NFS4ERR_NOTSUPP, ENOTSUPP }, { NFS4ERR_TOOSMALL, ETOOSMALL }, { NFS4ERR_SERVERFAULT, ESERVERFAULT }, { NFS4ERR_BADTYPE, EBADTYPE }, { NFS4ERR_LOCKED, EAGAIN }, { NFS4ERR_RESOURCE, EREMOTEIO }, { NFS4ERR_SYMLINK, ELOOP }, { NFS4ERR_OP_ILLEGAL, EOPNOTSUPP }, { NFS4ERR_DEADLOCK, EDEADLK }, { -1, EIO } }; static int nfs_cb_stat_to_errno(int stat) { int i; for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { if (nfs_cb_errtbl[i].stat == stat) return nfs_cb_errtbl[i].errno; } /* If we cannot translate the error, the recovery routines should * handle it. * Note: remaining NFSv4 error codes have values > 10000, so should * not conflict with native Linux error codes. */ return stat; } /* * XDR encode */ static void encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr) { __be32 * p; RESERVE_SPACE(16); WRITE32(0); /* tag length is always 0 */ WRITE32(hdr->minorversion); WRITE32(hdr->ident); hdr->nops_p = p; WRITE32(hdr->nops); } static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr) { *hdr->nops_p = htonl(hdr->nops); } static void encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp, struct nfs4_cb_compound_hdr *hdr) { __be32 *p; int len = dp->dl_fh.fh_size; RESERVE_SPACE(12+sizeof(dp->dl_stateid) + len); WRITE32(OP_CB_RECALL); WRITE32(dp->dl_stateid.si_generation); WRITEMEM(&dp->dl_stateid.si_opaque, sizeof(stateid_opaque_t)); WRITE32(0); /* truncate optimization not implemented */ WRITE32(len); WRITEMEM(&dp->dl_fh.fh_base, len); hdr->nops++; } static void encode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *args, struct nfs4_cb_compound_hdr *hdr) { __be32 *p; if (hdr->minorversion == 0) return; RESERVE_SPACE(1 + NFS4_MAX_SESSIONID_LEN + 20); WRITE32(OP_CB_SEQUENCE); WRITEMEM(args->cbs_clp->cl_sessionid.data, NFS4_MAX_SESSIONID_LEN); WRITE32(args->cbs_clp->cl_cb_seq_nr); WRITE32(0); /* slotid, always 0 */ WRITE32(0); /* highest slotid always 0 */ WRITE32(0); /* cachethis always 0 */ WRITE32(0); /* FIXME: support referring_call_lists */ hdr->nops++; } static int nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p) { struct xdr_stream xdrs, *xdr = &xdrs; xdr_init_encode(&xdrs, &req->rq_snd_buf, p); RESERVE_SPACE(0); return 0; } static int nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_rpc_args *rpc_args) { struct xdr_stream xdr; struct nfs4_delegation *args = rpc_args->args_op; struct nfs4_cb_compound_hdr hdr = { .ident = args->dl_ident, .minorversion = rpc_args->args_seq.cbs_minorversion, }; xdr_init_encode(&xdr, &req->rq_snd_buf, p); encode_cb_compound_hdr(&xdr, &hdr); encode_cb_sequence(&xdr, &rpc_args->args_seq, &hdr); encode_cb_recall(&xdr, args, &hdr); encode_cb_nops(&hdr); return 0; } static int decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){ __be32 *p; READ_BUF(8); READ32(hdr->status); READ32(hdr->taglen); READ_BUF(hdr->taglen + 4); hdr->tag = (char *)p; p += XDR_QUADLEN(hdr->taglen); READ32(hdr->nops); return 0; } static int decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected) { __be32 *p; u32 op; int32_t nfserr; READ_BUF(8); READ32(op); if (op != expected) { dprintk("NFSD: decode_cb_op_hdr: Callback server returned " " operation %d but we issued a request for %d\n", op, expected); return -EIO; } READ32(nfserr); if (nfserr != NFS_OK) return -nfs_cb_stat_to_errno(nfserr); return 0; } /* * Our current back channel implmentation supports a single backchannel * with a single slot. */ static int decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res, struct rpc_rqst *rqstp) { struct nfs4_sessionid id; int status; u32 dummy; __be32 *p; if (res->cbs_minorversion == 0) return 0; status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE); if (status) return status; /* * If the server returns different values for sessionID, slotID or * sequence number, the server is looney tunes. */ status = -ESERVERFAULT; READ_BUF(NFS4_MAX_SESSIONID_LEN + 16); memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN); p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); if (memcmp(id.data, res->cbs_clp->cl_sessionid.data, NFS4_MAX_SESSIONID_LEN)) { dprintk("%s Invalid session id\n", __func__); goto out; } READ32(dummy); if (dummy != res->cbs_clp->cl_cb_seq_nr) { dprintk("%s Invalid sequence number\n", __func__); goto out; } READ32(dummy); /* slotid must be 0 */ if (dummy != 0) { dprintk("%s Invalid slotid\n", __func__); goto out; } /* FIXME: process highest slotid and target highest slotid */ status = 0; out: return status; } static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p) { return 0; } static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p, struct nfsd4_cb_sequence *seq) { struct xdr_stream xdr; struct nfs4_cb_compound_hdr hdr; int status; xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); status = decode_cb_compound_hdr(&xdr, &hdr); if (status) goto out; if (seq) { status = decode_cb_sequence(&xdr, seq, rqstp); if (status) goto out; } status = decode_cb_op_hdr(&xdr, OP_CB_RECALL); out: return status; } /* * RPC procedure tables */ #define PROC(proc, call, argtype, restype) \ [NFSPROC4_CLNT_##proc] = { \ .p_proc = NFSPROC4_CB_##call, \ .p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \ .p_decode = (kxdrproc_t) nfs4_xdr_##restype, \ .p_arglen = NFS4_##argtype##_sz, \ .p_replen = NFS4_##restype##_sz, \ .p_statidx = NFSPROC4_CB_##call, \ .p_name = #proc, \ } static struct rpc_procinfo nfs4_cb_procedures[] = { PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null), PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall), }; static struct rpc_version nfs_cb_version4 = { .number = 1, .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), .procs = nfs4_cb_procedures }; static struct rpc_version * nfs_cb_version[] = { NULL, &nfs_cb_version4, }; static struct rpc_program cb_program; static struct rpc_stat cb_stats = { .program = &cb_program }; #define NFS4_CALLBACK 0x40000000 static struct rpc_program cb_program = { .name = "nfs4_cb", .number = NFS4_CALLBACK, .nrvers = ARRAY_SIZE(nfs_cb_version), .version = nfs_cb_version, .stats = &cb_stats, .pipe_dir_name = "/nfsd4_cb", }; static int max_cb_time(void) { return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ; } /* Reference counting, callback cleanup, etc., all look racy as heck. * And why is cb_set an atomic? */ int setup_callback_client(struct nfs4_client *clp) { struct nfs4_cb_conn *cb = &clp->cl_cb_conn; struct rpc_timeout timeparms = { .to_initval = max_cb_time(), .to_retries = 0, }; struct rpc_create_args args = { .protocol = XPRT_TRANSPORT_TCP, .address = (struct sockaddr *) &cb->cb_addr, .addrsize = cb->cb_addrlen, .timeout = &timeparms, .program = &cb_program, .prognumber = cb->cb_prog, .version = nfs_cb_version[1]->number, .authflavor = clp->cl_flavor, .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), .client_name = clp->cl_principal, }; struct rpc_clnt *client; if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) return -EINVAL; if (cb->cb_minorversion) { args.bc_xprt = clp->cl_cb_xprt; args.protocol = XPRT_TRANSPORT_BC_TCP; } /* Create RPC client */ client = rpc_create(&args); if (IS_ERR(client)) { dprintk("NFSD: couldn't create callback client: %ld\n", PTR_ERR(client)); return PTR_ERR(client); } cb->cb_client = client; return 0; } static void warn_no_callback_path(struct nfs4_client *clp, int reason) { dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", (int)clp->cl_name.len, clp->cl_name.data, reason); } static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) { struct nfs4_client *clp = calldata; if (task->tk_status) warn_no_callback_path(clp, task->tk_status); else atomic_set(&clp->cl_cb_conn.cb_set, 1); put_nfs4_client(clp); } static const struct rpc_call_ops nfsd4_cb_probe_ops = { .rpc_call_done = nfsd4_cb_probe_done, }; static struct rpc_cred *callback_cred; int set_callback_cred(void) { callback_cred = rpc_lookup_machine_cred(); if (!callback_cred) return -ENOMEM; return 0; } void do_probe_callback(struct nfs4_client *clp) { struct nfs4_cb_conn *cb = &clp->cl_cb_conn; struct rpc_message msg = { .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL], .rpc_argp = clp, .rpc_cred = callback_cred }; int status; status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_SOFT, &nfsd4_cb_probe_ops, (void *)clp); if (status) { warn_no_callback_path(clp, status); put_nfs4_client(clp); } } /* * Set up the callback client and put a NFSPROC4_CB_NULL on the wire... */ void nfsd4_probe_callback(struct nfs4_client *clp) { int status; BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set)); status = setup_callback_client(clp); if (status) { warn_no_callback_path(clp, status); return; } /* the task holds a reference to the nfs4_client struct */ atomic_inc(&clp->cl_count); do_probe_callback(clp); } /* * There's currently a single callback channel slot. * If the slot is available, then mark it busy. Otherwise, set the * thread for sleeping on the callback RPC wait queue. */ static int nfsd41_cb_setup_sequence(struct nfs4_client *clp, struct rpc_task *task) { struct nfs4_rpc_args *args = task->tk_msg.rpc_argp; u32 *ptr = (u32 *)clp->cl_sessionid.data; int status = 0; dprintk("%s: %u:%u:%u:%u\n", __func__, ptr[0], ptr[1], ptr[2], ptr[3]); if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); dprintk("%s slot is busy\n", __func__); status = -EAGAIN; goto out; } /* * We'll need the clp during XDR encoding and decoding, * and the sequence during decoding to verify the reply */ args->args_seq.cbs_clp = clp; task->tk_msg.rpc_resp = &args->args_seq; out: dprintk("%s status=%d\n", __func__, status); return status; } /* * TODO: cb_sequence should support referring call lists, cachethis, multiple * slots, and mark callback channel down on communication errors. */ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) { struct nfs4_delegation *dp = calldata; struct nfs4_client *clp = dp->dl_client; struct nfs4_rpc_args *args = task->tk_msg.rpc_argp; u32 minorversion = clp->cl_cb_conn.cb_minorversion; int status = 0; args->args_seq.cbs_minorversion = minorversion; if (minorversion) { status = nfsd41_cb_setup_sequence(clp, task); if (status) { if (status != -EAGAIN) { /* terminate rpc task */ task->tk_status = status; task->tk_action = NULL; } return; } } rpc_call_start(task); } static void nfsd4_cb_done(struct rpc_task *task, void *calldata) { struct nfs4_delegation *dp = calldata; struct nfs4_client *clp = dp->dl_client; dprintk("%s: minorversion=%d\n", __func__, clp->cl_cb_conn.cb_minorversion); if (clp->cl_cb_conn.cb_minorversion) { /* No need for lock, access serialized in nfsd4_cb_prepare */ ++clp->cl_cb_seq_nr; clear_bit(0, &clp->cl_cb_slot_busy); rpc_wake_up_next(&clp->cl_cb_waitq); dprintk("%s: freed slot, new seqid=%d\n", __func__, clp->cl_cb_seq_nr); /* We're done looking into the sequence information */ task->tk_msg.rpc_resp = NULL; } } static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) { struct nfs4_delegation *dp = calldata; struct nfs4_client *clp = dp->dl_client; nfsd4_cb_done(task, calldata); switch (task->tk_status) { case -EIO: /* Network partition? */ atomic_set(&clp->cl_cb_conn.cb_set, 0); warn_no_callback_path(clp, task->tk_status); case -EBADHANDLE: case -NFS4ERR_BAD_STATEID: /* Race: client probably got cb_recall * before open reply granting delegation */ break; default: /* success, or error we can't handle */ goto done; } if (dp->dl_retries--) { rpc_delay(task, 2*HZ); task->tk_status = 0; rpc_restart_call(task); return; } else { atomic_set(&clp->cl_cb_conn.cb_set, 0); warn_no_callback_path(clp, task->tk_status); } done: kfree(task->tk_msg.rpc_argp); } static void nfsd4_cb_recall_release(void *calldata) { struct nfs4_delegation *dp = calldata; struct nfs4_client *clp = dp->dl_client; nfs4_put_delegation(dp); put_nfs4_client(clp); } static const struct rpc_call_ops nfsd4_cb_recall_ops = { .rpc_call_prepare = nfsd4_cb_prepare, .rpc_call_done = nfsd4_cb_recall_done, .rpc_release = nfsd4_cb_recall_release, }; /* * called with dp->dl_count inc'ed. */ void nfsd4_cb_recall(struct nfs4_delegation *dp) { struct nfs4_client *clp = dp->dl_client; struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client; struct nfs4_rpc_args *args; struct rpc_message msg = { .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL], .rpc_cred = callback_cred }; int status = -ENOMEM; args = kzalloc(sizeof(*args), GFP_KERNEL); if (!args) goto out; args->args_op = dp; msg.rpc_argp = args; dp->dl_retries = 1; status = rpc_call_async(clnt, &msg, RPC_TASK_SOFT, &nfsd4_cb_recall_ops, dp); out: if (status) { kfree(args); put_nfs4_client(clp); nfs4_put_delegation(dp); } }