1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * NFS server support for local clients to bypass network stack
4 *
5 * Copyright (C) 2014 Weston Andros Adamson <dros@primarydata.com>
6 * Copyright (C) 2019 Trond Myklebust <trond.myklebust@hammerspace.com>
7 * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
8 * Copyright (C) 2024 NeilBrown <neilb@suse.de>
9 */
10
11 #include <linux/exportfs.h>
12 #include <linux/sunrpc/svcauth.h>
13 #include <linux/sunrpc/clnt.h>
14 #include <linux/nfs.h>
15 #include <linux/nfs_common.h>
16 #include <linux/nfslocalio.h>
17 #include <linux/nfs_fs.h>
18 #include <linux/nfs_xdr.h>
19 #include <linux/string.h>
20
21 #include "nfsd.h"
22 #include "vfs.h"
23 #include "netns.h"
24 #include "filecache.h"
25 #include "cache.h"
26
27 static const struct nfsd_localio_operations nfsd_localio_ops = {
28 .nfsd_serv_try_get = nfsd_serv_try_get,
29 .nfsd_serv_put = nfsd_serv_put,
30 .nfsd_open_local_fh = nfsd_open_local_fh,
31 .nfsd_file_put_local = nfsd_file_put_local,
32 .nfsd_file_file = nfsd_file_file,
33 };
34
35 void nfsd_localio_ops_init(void)
36 {
37 nfs_to = &nfsd_localio_ops;
38 }
39
40 /**
41 * nfsd_open_local_fh - lookup a local filehandle @nfs_fh and map to nfsd_file
42 *
43 * @net: 'struct net' to get the proper nfsd_net required for LOCALIO access
44 * @dom: 'struct auth_domain' required for LOCALIO access
45 * @rpc_clnt: rpc_clnt that the client established
46 * @cred: cred that the client established
47 * @nfs_fh: filehandle to lookup
48 * @fmode: fmode_t to use for open
49 *
50 * This function maps a local fh to a path on a local filesystem.
51 * This is useful when the nfs client has the local server mounted - it can
52 * avoid all the NFS overhead with reads, writes and commits.
53 *
54 * On successful return, returned nfsd_file will have its nf_net member
55 * set. Caller (NFS client) is responsible for calling nfsd_serv_put and
56 * nfsd_file_put (via nfs_to_nfsd_file_put_local).
57 */
58 struct nfsd_file *
59 nfsd_open_local_fh(struct net *net, struct auth_domain *dom,
60 struct rpc_clnt *rpc_clnt, const struct cred *cred,
61 const struct nfs_fh *nfs_fh, const fmode_t fmode)
62 {
63 int mayflags = NFSD_MAY_LOCALIO;
64 struct svc_cred rq_cred;
65 struct svc_fh fh;
66 struct nfsd_file *localio;
67 __be32 beres;
68
69 if (nfs_fh->size > NFS4_FHSIZE)
70 return ERR_PTR(-EINVAL);
71
72 /* nfs_fh -> svc_fh */
73 fh_init(&fh, NFS4_FHSIZE);
74 fh.fh_handle.fh_size = nfs_fh->size;
75 memcpy(fh.fh_handle.fh_raw, nfs_fh->data, nfs_fh->size);
76
77 if (fmode & FMODE_READ)
78 mayflags |= NFSD_MAY_READ;
79 if (fmode & FMODE_WRITE)
80 mayflags |= NFSD_MAY_WRITE;
81
82 svcauth_map_clnt_to_svc_cred_local(rpc_clnt, cred, &rq_cred);
83
84 beres = nfsd_file_acquire_local(net, &rq_cred, dom,
85 &fh, mayflags, &localio);
86 if (beres)
87 localio = ERR_PTR(nfs_stat_to_errno(be32_to_cpu(beres)));
88
89 fh_put(&fh);
90 if (rq_cred.cr_group_info)
91 put_group_info(rq_cred.cr_group_info);
92
93 return localio;
94 }
95 EXPORT_SYMBOL_GPL(nfsd_open_local_fh);
96
97 /*
98 * UUID_IS_LOCAL XDR functions
99 */
100
101 static __be32 localio_proc_null(struct svc_rqst *rqstp)
102 {
103 return rpc_success;
104 }
105
106 struct localio_uuidarg {
107 uuid_t uuid;
108 };
109
110 static __be32 localio_proc_uuid_is_local(struct svc_rqst *rqstp)
111 {
112 struct localio_uuidarg *argp = rqstp->rq_argp;
113 struct net *net = SVC_NET(rqstp);
114 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
115
116 nfs_uuid_is_local(&argp->uuid, &nn->local_clients,
117 net, rqstp->rq_client, THIS_MODULE);
118
119 return rpc_success;
120 }
121
122 static bool localio_decode_uuidarg(struct svc_rqst *rqstp,
123 struct xdr_stream *xdr)
124 {
125 struct localio_uuidarg *argp = rqstp->rq_argp;
126 u8 uuid[UUID_SIZE];
127
128 if (decode_opaque_fixed(xdr, uuid, UUID_SIZE))
129 return false;
130 import_uuid(&argp->uuid, uuid);
131
132 return true;
133 }
134
135 static const struct svc_procedure localio_procedures1[] = {
136 [LOCALIOPROC_NULL] = {
137 .pc_func = localio_proc_null,
138 .pc_decode = nfssvc_decode_voidarg,
139 .pc_encode = nfssvc_encode_voidres,
140 .pc_argsize = sizeof(struct nfsd_voidargs),
141 .pc_ressize = sizeof(struct nfsd_voidres),
142 .pc_cachetype = RC_NOCACHE,
143 .pc_xdrressize = 0,
144 .pc_name = "NULL",
145 },
146 [LOCALIOPROC_UUID_IS_LOCAL] = {
147 .pc_func = localio_proc_uuid_is_local,
148 .pc_decode = localio_decode_uuidarg,
149 .pc_encode = nfssvc_encode_voidres,
150 .pc_argsize = sizeof(struct localio_uuidarg),
151 .pc_argzero = sizeof(struct localio_uuidarg),
152 .pc_ressize = sizeof(struct nfsd_voidres),
153 .pc_cachetype = RC_NOCACHE,
154 .pc_name = "UUID_IS_LOCAL",
155 },
156 };
157
158 #define LOCALIO_NR_PROCEDURES ARRAY_SIZE(localio_procedures1)
159 static DEFINE_PER_CPU_ALIGNED(unsigned long,
160 localio_count[LOCALIO_NR_PROCEDURES]);
161 const struct svc_version localio_version1 = {
162 .vs_vers = 1,
163 .vs_nproc = LOCALIO_NR_PROCEDURES,
164 .vs_proc = localio_procedures1,
165 .vs_dispatch = nfsd_dispatch,
166 .vs_count = localio_count,
167 .vs_xdrsize = XDR_QUADLEN(UUID_SIZE),
168 .vs_hidden = true,
169 };
170
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