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1 | /* |
2 | * This file implement the Wireless Extensions priv API. | |
3 | * | |
4 | * Authors : Jean Tourrilhes - HPL - <jt@hpl.hp.com> | |
5 | * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved. | |
6 | * Copyright 2009 Johannes Berg <johannes@sipsolutions.net> | |
7 | * | |
8 | * (As all part of the Linux kernel, this file is GPL) | |
9 | */ | |
10 | #include <linux/wireless.h> | |
11 | #include <linux/netdevice.h> | |
12 | #include <net/iw_handler.h> | |
13 | #include <net/wext.h> | |
14 | ||
15 | int iw_handler_get_private(struct net_device * dev, | |
16 | struct iw_request_info * info, | |
17 | union iwreq_data * wrqu, | |
18 | char * extra) | |
19 | { | |
20 | /* Check if the driver has something to export */ | |
21 | if ((dev->wireless_handlers->num_private_args == 0) || | |
22 | (dev->wireless_handlers->private_args == NULL)) | |
23 | return -EOPNOTSUPP; | |
24 | ||
25 | /* Check if there is enough buffer up there */ | |
26 | if (wrqu->data.length < dev->wireless_handlers->num_private_args) { | |
27 | /* User space can't know in advance how large the buffer | |
28 | * needs to be. Give it a hint, so that we can support | |
29 | * any size buffer we want somewhat efficiently... */ | |
30 | wrqu->data.length = dev->wireless_handlers->num_private_args; | |
31 | return -E2BIG; | |
32 | } | |
33 | ||
34 | /* Set the number of available ioctls. */ | |
35 | wrqu->data.length = dev->wireless_handlers->num_private_args; | |
36 | ||
37 | /* Copy structure to the user buffer. */ | |
38 | memcpy(extra, dev->wireless_handlers->private_args, | |
39 | sizeof(struct iw_priv_args) * wrqu->data.length); | |
40 | ||
41 | return 0; | |
42 | } | |
43 | ||
44 | /* Size (in bytes) of the various private data types */ | |
45 | static const char iw_priv_type_size[] = { | |
46 | 0, /* IW_PRIV_TYPE_NONE */ | |
47 | 1, /* IW_PRIV_TYPE_BYTE */ | |
48 | 1, /* IW_PRIV_TYPE_CHAR */ | |
49 | 0, /* Not defined */ | |
50 | sizeof(__u32), /* IW_PRIV_TYPE_INT */ | |
51 | sizeof(struct iw_freq), /* IW_PRIV_TYPE_FLOAT */ | |
52 | sizeof(struct sockaddr), /* IW_PRIV_TYPE_ADDR */ | |
53 | 0, /* Not defined */ | |
54 | }; | |
55 | ||
56 | static int get_priv_size(__u16 args) | |
57 | { | |
58 | int num = args & IW_PRIV_SIZE_MASK; | |
59 | int type = (args & IW_PRIV_TYPE_MASK) >> 12; | |
60 | ||
61 | return num * iw_priv_type_size[type]; | |
62 | } | |
63 | ||
64 | static int adjust_priv_size(__u16 args, struct iw_point *iwp) | |
65 | { | |
66 | int num = iwp->length; | |
67 | int max = args & IW_PRIV_SIZE_MASK; | |
68 | int type = (args & IW_PRIV_TYPE_MASK) >> 12; | |
69 | ||
70 | /* Make sure the driver doesn't goof up */ | |
71 | if (max < num) | |
72 | num = max; | |
73 | ||
74 | return num * iw_priv_type_size[type]; | |
75 | } | |
76 | ||
77 | /* | |
78 | * Wrapper to call a private Wireless Extension handler. | |
79 | * We do various checks and also take care of moving data between | |
80 | * user space and kernel space. | |
81 | * It's not as nice and slimline as the standard wrapper. The cause | |
82 | * is struct iw_priv_args, which was not really designed for the | |
83 | * job we are going here. | |
84 | * | |
85 | * IMPORTANT : This function prevent to set and get data on the same | |
86 | * IOCTL and enforce the SET/GET convention. Not doing it would be | |
87 | * far too hairy... | |
88 | * If you need to set and get data at the same time, please don't use | |
89 | * a iw_handler but process it in your ioctl handler (i.e. use the | |
90 | * old driver API). | |
91 | */ | |
92 | static int get_priv_descr_and_size(struct net_device *dev, unsigned int cmd, | |
93 | const struct iw_priv_args **descrp) | |
94 | { | |
95 | const struct iw_priv_args *descr; | |
96 | int i, extra_size; | |
97 | ||
98 | descr = NULL; | |
99 | for (i = 0; i < dev->wireless_handlers->num_private_args; i++) { | |
100 | if (cmd == dev->wireless_handlers->private_args[i].cmd) { | |
101 | descr = &dev->wireless_handlers->private_args[i]; | |
102 | break; | |
103 | } | |
104 | } | |
105 | ||
106 | extra_size = 0; | |
107 | if (descr) { | |
108 | if (IW_IS_SET(cmd)) { | |
109 | int offset = 0; /* For sub-ioctls */ | |
110 | /* Check for sub-ioctl handler */ | |
111 | if (descr->name[0] == '\0') | |
112 | /* Reserve one int for sub-ioctl index */ | |
113 | offset = sizeof(__u32); | |
114 | ||
115 | /* Size of set arguments */ | |
116 | extra_size = get_priv_size(descr->set_args); | |
117 | ||
118 | /* Does it fits in iwr ? */ | |
119 | if ((descr->set_args & IW_PRIV_SIZE_FIXED) && | |
120 | ((extra_size + offset) <= IFNAMSIZ)) | |
121 | extra_size = 0; | |
122 | } else { | |
123 | /* Size of get arguments */ | |
124 | extra_size = get_priv_size(descr->get_args); | |
125 | ||
126 | /* Does it fits in iwr ? */ | |
127 | if ((descr->get_args & IW_PRIV_SIZE_FIXED) && | |
128 | (extra_size <= IFNAMSIZ)) | |
129 | extra_size = 0; | |
130 | } | |
131 | } | |
132 | *descrp = descr; | |
133 | return extra_size; | |
134 | } | |
135 | ||
136 | static int ioctl_private_iw_point(struct iw_point *iwp, unsigned int cmd, | |
137 | const struct iw_priv_args *descr, | |
138 | iw_handler handler, struct net_device *dev, | |
139 | struct iw_request_info *info, int extra_size) | |
140 | { | |
141 | char *extra; | |
142 | int err; | |
143 | ||
144 | /* Check what user space is giving us */ | |
145 | if (IW_IS_SET(cmd)) { | |
146 | if (!iwp->pointer && iwp->length != 0) | |
147 | return -EFAULT; | |
148 | ||
149 | if (iwp->length > (descr->set_args & IW_PRIV_SIZE_MASK)) | |
150 | return -E2BIG; | |
151 | } else if (!iwp->pointer) | |
152 | return -EFAULT; | |
153 | ||
154 | extra = kmalloc(extra_size, GFP_KERNEL); | |
155 | if (!extra) | |
156 | return -ENOMEM; | |
157 | ||
158 | /* If it is a SET, get all the extra data in here */ | |
159 | if (IW_IS_SET(cmd) && (iwp->length != 0)) { | |
160 | if (copy_from_user(extra, iwp->pointer, extra_size)) { | |
161 | err = -EFAULT; | |
162 | goto out; | |
163 | } | |
164 | } | |
165 | ||
166 | /* Call the handler */ | |
167 | err = handler(dev, info, (union iwreq_data *) iwp, extra); | |
168 | ||
169 | /* If we have something to return to the user */ | |
170 | if (!err && IW_IS_GET(cmd)) { | |
171 | /* Adjust for the actual length if it's variable, | |
172 | * avoid leaking kernel bits outside. | |
173 | */ | |
174 | if (!(descr->get_args & IW_PRIV_SIZE_FIXED)) | |
175 | extra_size = adjust_priv_size(descr->get_args, iwp); | |
176 | ||
177 | if (copy_to_user(iwp->pointer, extra, extra_size)) | |
178 | err = -EFAULT; | |
179 | } | |
180 | ||
181 | out: | |
182 | kfree(extra); | |
183 | return err; | |
184 | } | |
185 | ||
186 | int ioctl_private_call(struct net_device *dev, struct iwreq *iwr, | |
187 | unsigned int cmd, struct iw_request_info *info, | |
188 | iw_handler handler) | |
189 | { | |
190 | int extra_size = 0, ret = -EINVAL; | |
191 | const struct iw_priv_args *descr; | |
192 | ||
193 | extra_size = get_priv_descr_and_size(dev, cmd, &descr); | |
194 | ||
195 | /* Check if we have a pointer to user space data or not. */ | |
196 | if (extra_size == 0) { | |
197 | /* No extra arguments. Trivial to handle */ | |
198 | ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u)); | |
199 | } else { | |
200 | ret = ioctl_private_iw_point(&iwr->u.data, cmd, descr, | |
201 | handler, dev, info, extra_size); | |
202 | } | |
203 | ||
204 | /* Call commit handler if needed and defined */ | |
205 | if (ret == -EIWCOMMIT) | |
206 | ret = call_commit_handler(dev); | |
207 | ||
208 | return ret; | |
209 | } | |
210 | ||
211 | #ifdef CONFIG_COMPAT | |
212 | int compat_private_call(struct net_device *dev, struct iwreq *iwr, | |
213 | unsigned int cmd, struct iw_request_info *info, | |
214 | iw_handler handler) | |
215 | { | |
216 | const struct iw_priv_args *descr; | |
217 | int ret, extra_size; | |
218 | ||
219 | extra_size = get_priv_descr_and_size(dev, cmd, &descr); | |
220 | ||
221 | /* Check if we have a pointer to user space data or not. */ | |
222 | if (extra_size == 0) { | |
223 | /* No extra arguments. Trivial to handle */ | |
224 | ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u)); | |
225 | } else { | |
226 | struct compat_iw_point *iwp_compat; | |
227 | struct iw_point iwp; | |
228 | ||
229 | iwp_compat = (struct compat_iw_point *) &iwr->u.data; | |
230 | iwp.pointer = compat_ptr(iwp_compat->pointer); | |
231 | iwp.length = iwp_compat->length; | |
232 | iwp.flags = iwp_compat->flags; | |
233 | ||
234 | ret = ioctl_private_iw_point(&iwp, cmd, descr, | |
235 | handler, dev, info, extra_size); | |
236 | ||
237 | iwp_compat->pointer = ptr_to_compat(iwp.pointer); | |
238 | iwp_compat->length = iwp.length; | |
239 | iwp_compat->flags = iwp.flags; | |
240 | } | |
241 | ||
242 | /* Call commit handler if needed and defined */ | |
243 | if (ret == -EIWCOMMIT) | |
244 | ret = call_commit_handler(dev); | |
245 | ||
246 | return ret; | |
247 | } | |
248 | #endif |