1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/compat.c
4 *
5 * Kernel compatibililty routines for e.g. 32 bit syscall support
6 * on 64 bit kernels.
7 *
8 * Copyright (C) 2002 Stephen Rothwell, IBM Corporation
9 * Copyright (C) 1997-2000 Jakub Jelinek (jakub@redhat.com)
10 * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
11 * Copyright (C) 2001,2002 Andi Kleen, SuSE Labs
12 * Copyright (C) 2003 Pavel Machek (pavel@ucw.cz)
13 */
14
15 #include <linux/compat.h>
16 #include <linux/nfs4_mount.h>
17 #include <linux/syscalls.h>
18 #include <linux/slab.h>
19 #include <linux/uaccess.h>
20 #include "internal.h"
21
22 struct compat_nfs_string {
23 compat_uint_t len;
24 compat_uptr_t data;
25 };
26
compat_nfs_string(struct nfs_string * dst,struct compat_nfs_string * src)27 static inline void compat_nfs_string(struct nfs_string *dst,
28 struct compat_nfs_string *src)
29 {
30 dst->data = compat_ptr(src->data);
31 dst->len = src->len;
32 }
33
34 struct compat_nfs4_mount_data_v1 {
35 compat_int_t version;
36 compat_int_t flags;
37 compat_int_t rsize;
38 compat_int_t wsize;
39 compat_int_t timeo;
40 compat_int_t retrans;
41 compat_int_t acregmin;
42 compat_int_t acregmax;
43 compat_int_t acdirmin;
44 compat_int_t acdirmax;
45 struct compat_nfs_string client_addr;
46 struct compat_nfs_string mnt_path;
47 struct compat_nfs_string hostname;
48 compat_uint_t host_addrlen;
49 compat_uptr_t host_addr;
50 compat_int_t proto;
51 compat_int_t auth_flavourlen;
52 compat_uptr_t auth_flavours;
53 };
54
do_nfs4_super_data_conv(void * raw_data)55 static int do_nfs4_super_data_conv(void *raw_data)
56 {
57 int version = *(compat_uint_t *) raw_data;
58
59 if (version == 1) {
60 struct compat_nfs4_mount_data_v1 *raw = raw_data;
61 struct nfs4_mount_data *real = raw_data;
62
63 /* copy the fields backwards */
64 real->auth_flavours = compat_ptr(raw->auth_flavours);
65 real->auth_flavourlen = raw->auth_flavourlen;
66 real->proto = raw->proto;
67 real->host_addr = compat_ptr(raw->host_addr);
68 real->host_addrlen = raw->host_addrlen;
69 compat_nfs_string(&real->hostname, &raw->hostname);
70 compat_nfs_string(&real->mnt_path, &raw->mnt_path);
71 compat_nfs_string(&real->client_addr, &raw->client_addr);
72 real->acdirmax = raw->acdirmax;
73 real->acdirmin = raw->acdirmin;
74 real->acregmax = raw->acregmax;
75 real->acregmin = raw->acregmin;
76 real->retrans = raw->retrans;
77 real->timeo = raw->timeo;
78 real->wsize = raw->wsize;
79 real->rsize = raw->rsize;
80 real->flags = raw->flags;
81 real->version = raw->version;
82 }
83
84 return 0;
85 }
86
87 #define NFS4_NAME "nfs4"
88
COMPAT_SYSCALL_DEFINE5(mount,const char __user *,dev_name,const char __user *,dir_name,const char __user *,type,compat_ulong_t,flags,const void __user *,data)89 COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
90 const char __user *, dir_name,
91 const char __user *, type, compat_ulong_t, flags,
92 const void __user *, data)
93 {
94 char *kernel_type;
95 void *options;
96 char *kernel_dev;
97 int retval;
98
99 kernel_type = copy_mount_string(type);
100 retval = PTR_ERR(kernel_type);
101 if (IS_ERR(kernel_type))
102 goto out;
103
104 kernel_dev = copy_mount_string(dev_name);
105 retval = PTR_ERR(kernel_dev);
106 if (IS_ERR(kernel_dev))
107 goto out1;
108
109 options = copy_mount_options(data);
110 retval = PTR_ERR(options);
111 if (IS_ERR(options))
112 goto out2;
113
114 if (kernel_type && options) {
115 if (!strcmp(kernel_type, NFS4_NAME)) {
116 retval = -EINVAL;
117 if (do_nfs4_super_data_conv(options))
118 goto out3;
119 }
120 }
121
122 retval = do_mount(kernel_dev, dir_name, kernel_type, flags, options);
123
124 out3:
125 kfree(options);
126 out2:
127 kfree(kernel_dev);
128 out1:
129 kfree(kernel_type);
130 out:
131 return retval;
132 }
133