xref: /linux/fs/nfs/mount_clnt.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * linux/fs/nfs/mount_clnt.c
3  *
4  * MOUNT client to support NFSroot.
5  *
6  * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/socket.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/uio.h>
14 #include <linux/net.h>
15 #include <linux/in.h>
16 #include <linux/sunrpc/clnt.h>
17 #include <linux/sunrpc/xprt.h>
18 #include <linux/sunrpc/sched.h>
19 #include <linux/nfs_fs.h>
20 
21 #ifdef RPC_DEBUG
22 # define NFSDBG_FACILITY	NFSDBG_ROOT
23 #endif
24 
25 /*
26 #define MOUNT_PROGRAM		100005
27 #define MOUNT_VERSION		1
28 #define MOUNT_MNT		1
29 #define MOUNT_UMNT		3
30  */
31 
32 static struct rpc_clnt *	mnt_create(char *, struct sockaddr_in *,
33 								int, int);
34 static struct rpc_program	mnt_program;
35 
36 struct mnt_fhstatus {
37 	unsigned int		status;
38 	struct nfs_fh *		fh;
39 };
40 
41 /*
42  * Obtain an NFS file handle for the given host and path
43  */
44 int
45 nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
46 		int version, int protocol)
47 {
48 	struct rpc_clnt		*mnt_clnt;
49 	struct mnt_fhstatus	result = {
50 		.fh		= fh
51 	};
52 	struct rpc_message msg	= {
53 		.rpc_argp	= path,
54 		.rpc_resp	= &result,
55 	};
56 	char			hostname[32];
57 	int			status;
58 
59 	dprintk("NFS:      nfs_mount(%08x:%s)\n",
60 			(unsigned)ntohl(addr->sin_addr.s_addr), path);
61 
62 	sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr->sin_addr.s_addr));
63 	mnt_clnt = mnt_create(hostname, addr, version, protocol);
64 	if (IS_ERR(mnt_clnt))
65 		return PTR_ERR(mnt_clnt);
66 
67 	if (version == NFS_MNT3_VERSION)
68 		msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
69 	else
70 		msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
71 
72 	status = rpc_call_sync(mnt_clnt, &msg, 0);
73 	return status < 0? status : (result.status? -EACCES : 0);
74 }
75 
76 static struct rpc_clnt *
77 mnt_create(char *hostname, struct sockaddr_in *srvaddr, int version,
78 		int protocol)
79 {
80 	struct rpc_xprt	*xprt;
81 	struct rpc_clnt	*clnt;
82 
83 	xprt = xprt_create_proto(protocol, srvaddr, NULL);
84 	if (IS_ERR(xprt))
85 		return (struct rpc_clnt *)xprt;
86 
87 	clnt = rpc_create_client(xprt, hostname,
88 				&mnt_program, version,
89 				RPC_AUTH_UNIX);
90 	if (!IS_ERR(clnt)) {
91 		clnt->cl_softrtry = 1;
92 		clnt->cl_oneshot  = 1;
93 		clnt->cl_intr = 1;
94 	}
95 	return clnt;
96 }
97 
98 /*
99  * XDR encode/decode functions for MOUNT
100  */
101 static int
102 xdr_encode_dirpath(struct rpc_rqst *req, u32 *p, const char *path)
103 {
104 	p = xdr_encode_string(p, path);
105 
106 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
107 	return 0;
108 }
109 
110 static int
111 xdr_decode_fhstatus(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
112 {
113 	struct nfs_fh *fh = res->fh;
114 
115 	if ((res->status = ntohl(*p++)) == 0) {
116 		fh->size = NFS2_FHSIZE;
117 		memcpy(fh->data, p, NFS2_FHSIZE);
118 	}
119 	return 0;
120 }
121 
122 static int
123 xdr_decode_fhstatus3(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
124 {
125 	struct nfs_fh *fh = res->fh;
126 
127 	if ((res->status = ntohl(*p++)) == 0) {
128 		int size = ntohl(*p++);
129 		if (size <= NFS3_FHSIZE) {
130 			fh->size = size;
131 			memcpy(fh->data, p, size);
132 		} else
133 			res->status = -EBADHANDLE;
134 	}
135 	return 0;
136 }
137 
138 #define MNT_dirpath_sz		(1 + 256)
139 #define MNT_fhstatus_sz		(1 + 8)
140 
141 static struct rpc_procinfo	mnt_procedures[] = {
142 [MNTPROC_MNT] = {
143 	  .p_proc		= MNTPROC_MNT,
144 	  .p_encode		= (kxdrproc_t) xdr_encode_dirpath,
145 	  .p_decode		= (kxdrproc_t) xdr_decode_fhstatus,
146 	  .p_bufsiz		= MNT_dirpath_sz << 2,
147 	  .p_statidx		= MNTPROC_MNT,
148 	  .p_name		= "MOUNT",
149 	},
150 };
151 
152 static struct rpc_procinfo mnt3_procedures[] = {
153 [MOUNTPROC3_MNT] = {
154 	  .p_proc		= MOUNTPROC3_MNT,
155 	  .p_encode		= (kxdrproc_t) xdr_encode_dirpath,
156 	  .p_decode		= (kxdrproc_t) xdr_decode_fhstatus3,
157 	  .p_bufsiz		= MNT_dirpath_sz << 2,
158 	  .p_statidx		= MOUNTPROC3_MNT,
159 	  .p_name		= "MOUNT",
160 	},
161 };
162 
163 
164 static struct rpc_version	mnt_version1 = {
165 		.number		= 1,
166 		.nrprocs 	= 2,
167 		.procs 		= mnt_procedures
168 };
169 
170 static struct rpc_version       mnt_version3 = {
171 		.number		= 3,
172 		.nrprocs	= 2,
173 		.procs		= mnt3_procedures
174 };
175 
176 static struct rpc_version *	mnt_version[] = {
177 	NULL,
178 	&mnt_version1,
179 	NULL,
180 	&mnt_version3,
181 };
182 
183 static struct rpc_stat		mnt_stats;
184 
185 static struct rpc_program	mnt_program = {
186 	.name		= "mount",
187 	.number		= NFS_MNT_PROGRAM,
188 	.nrvers		= ARRAY_SIZE(mnt_version),
189 	.version	= mnt_version,
190 	.stats		= &mnt_stats,
191 };
192