xref: /openbmc/linux/fs/nfs/mount_clnt.c (revision 367b8112)
1 /*
2  * In-kernel MOUNT protocol client
3  *
4  * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
5  */
6 
7 #include <linux/types.h>
8 #include <linux/socket.h>
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/uio.h>
12 #include <linux/net.h>
13 #include <linux/in.h>
14 #include <linux/sunrpc/clnt.h>
15 #include <linux/sunrpc/sched.h>
16 #include <linux/nfs_fs.h>
17 #include "internal.h"
18 
19 #ifdef RPC_DEBUG
20 # define NFSDBG_FACILITY	NFSDBG_MOUNT
21 #endif
22 
23 static struct rpc_program	mnt_program;
24 
25 struct mnt_fhstatus {
26 	u32 status;
27 	struct nfs_fh *fh;
28 };
29 
30 /**
31  * nfs_mount - Obtain an NFS file handle for the given host and path
32  * @addr: pointer to server's address
33  * @len: size of server's address
34  * @hostname: name of server host, or NULL
35  * @path: pointer to string containing export path to mount
36  * @version: mount version to use for this request
37  * @protocol: transport protocol to use for thie request
38  * @fh: pointer to location to place returned file handle
39  *
40  * Uses default timeout parameters specified by underlying transport.
41  */
42 int nfs_mount(struct sockaddr *addr, size_t len, char *hostname, char *path,
43 	      int version, int protocol, struct nfs_fh *fh)
44 {
45 	struct mnt_fhstatus	result = {
46 		.fh		= fh
47 	};
48 	struct rpc_message msg	= {
49 		.rpc_argp	= path,
50 		.rpc_resp	= &result,
51 	};
52 	struct rpc_create_args args = {
53 		.protocol	= protocol,
54 		.address	= addr,
55 		.addrsize	= len,
56 		.servername	= hostname,
57 		.program	= &mnt_program,
58 		.version	= version,
59 		.authflavor	= RPC_AUTH_UNIX,
60 		.flags		= 0,
61 	};
62 	struct rpc_clnt		*mnt_clnt;
63 	int			status;
64 
65 	dprintk("NFS: sending MNT request for %s:%s\n",
66 		(hostname ? hostname : "server"), path);
67 
68 	mnt_clnt = rpc_create(&args);
69 	if (IS_ERR(mnt_clnt))
70 		goto out_clnt_err;
71 
72 	if (version == NFS_MNT3_VERSION)
73 		msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
74 	else
75 		msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
76 
77 	status = rpc_call_sync(mnt_clnt, &msg, 0);
78 	rpc_shutdown_client(mnt_clnt);
79 
80 	if (status < 0)
81 		goto out_call_err;
82 	if (result.status != 0)
83 		goto out_mnt_err;
84 
85 	dprintk("NFS: MNT request succeeded\n");
86 	status = 0;
87 
88 out:
89 	return status;
90 
91 out_clnt_err:
92 	status = PTR_ERR(mnt_clnt);
93 	dprintk("NFS: failed to create RPC client, status=%d\n", status);
94 	goto out;
95 
96 out_call_err:
97 	dprintk("NFS: failed to start MNT request, status=%d\n", status);
98 	goto out;
99 
100 out_mnt_err:
101 	dprintk("NFS: MNT server returned result %d\n", result.status);
102 	status = nfs_stat_to_errno(result.status);
103 	goto out;
104 }
105 
106 /*
107  * XDR encode/decode functions for MOUNT
108  */
109 static int xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p,
110 			      const char *path)
111 {
112 	p = xdr_encode_string(p, path);
113 
114 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
115 	return 0;
116 }
117 
118 static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
119 			       struct mnt_fhstatus *res)
120 {
121 	struct nfs_fh *fh = res->fh;
122 
123 	if ((res->status = ntohl(*p++)) == 0) {
124 		fh->size = NFS2_FHSIZE;
125 		memcpy(fh->data, p, NFS2_FHSIZE);
126 	}
127 	return 0;
128 }
129 
130 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
131 				struct mnt_fhstatus *res)
132 {
133 	struct nfs_fh *fh = res->fh;
134 	unsigned size;
135 
136 	if ((res->status = ntohl(*p++)) == 0) {
137 		size = ntohl(*p++);
138 		if (size <= NFS3_FHSIZE && size != 0) {
139 			fh->size = size;
140 			memcpy(fh->data, p, size);
141 		} else
142 			res->status = -EBADHANDLE;
143 	}
144 	return 0;
145 }
146 
147 #define MNT_dirpath_sz		(1 + 256)
148 #define MNT_fhstatus_sz		(1 + 8)
149 #define MNT_fhstatus3_sz	(1 + 16)
150 
151 static struct rpc_procinfo mnt_procedures[] = {
152 	[MNTPROC_MNT] = {
153 		.p_proc		= MNTPROC_MNT,
154 		.p_encode	= (kxdrproc_t) xdr_encode_dirpath,
155 		.p_decode	= (kxdrproc_t) xdr_decode_fhstatus,
156 		.p_arglen	= MNT_dirpath_sz,
157 		.p_replen	= MNT_fhstatus_sz,
158 		.p_statidx	= MNTPROC_MNT,
159 		.p_name		= "MOUNT",
160 	},
161 };
162 
163 static struct rpc_procinfo mnt3_procedures[] = {
164 	[MOUNTPROC3_MNT] = {
165 		.p_proc		= MOUNTPROC3_MNT,
166 		.p_encode	= (kxdrproc_t) xdr_encode_dirpath,
167 		.p_decode	= (kxdrproc_t) xdr_decode_fhstatus3,
168 		.p_arglen	= MNT_dirpath_sz,
169 		.p_replen	= MNT_fhstatus3_sz,
170 		.p_statidx	= MOUNTPROC3_MNT,
171 		.p_name		= "MOUNT",
172 	},
173 };
174 
175 
176 static struct rpc_version mnt_version1 = {
177 	.number		= 1,
178 	.nrprocs	= 2,
179 	.procs		= mnt_procedures,
180 };
181 
182 static struct rpc_version mnt_version3 = {
183 	.number		= 3,
184 	.nrprocs	= 2,
185 	.procs		= mnt3_procedures,
186 };
187 
188 static struct rpc_version *mnt_version[] = {
189 	NULL,
190 	&mnt_version1,
191 	NULL,
192 	&mnt_version3,
193 };
194 
195 static struct rpc_stat mnt_stats;
196 
197 static struct rpc_program mnt_program = {
198 	.name		= "mount",
199 	.number		= NFS_MNT_PROGRAM,
200 	.nrvers		= ARRAY_SIZE(mnt_version),
201 	.version	= mnt_version,
202 	.stats		= &mnt_stats,
203 };
204