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245ba56a KS |
1 | /* |
2 | * An implementation of key value pair (KVP) functionality for Linux. | |
3 | * | |
4 | * | |
5 | * Copyright (C) 2010, Novell, Inc. | |
6 | * Author : K. Y. Srinivasan <ksrinivasan@novell.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License version 2 as published | |
10 | * by the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
15 | * NON INFRINGEMENT. See the GNU General Public License for more | |
16 | * details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
21 | * | |
22 | */ | |
af7a5b6e | 23 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
245ba56a KS |
24 | |
25 | #include <linux/net.h> | |
26 | #include <linux/nls.h> | |
27 | #include <linux/connector.h> | |
28 | #include <linux/workqueue.h> | |
46a97191 | 29 | #include <linux/hyperv.h> |
245ba56a | 30 | |
245ba56a KS |
31 | #include "hv_kvp.h" |
32 | ||
33 | ||
34 | ||
35 | /* | |
36 | * Global state maintained for transaction that is being processed. | |
37 | * Note that only one transaction can be active at any point in time. | |
38 | * | |
39 | * This state is set when we receive a request from the host; we | |
40 | * cleanup this state when the transaction is completed - when we respond | |
41 | * to the host with the key value. | |
42 | */ | |
43 | ||
44 | static struct { | |
45 | bool active; /* transaction status - active or not */ | |
46 | int recv_len; /* number of bytes received. */ | |
e2bb6537 | 47 | int index; /* current index */ |
245ba56a KS |
48 | struct vmbus_channel *recv_channel; /* chn we got the request */ |
49 | u64 recv_req_id; /* request ID. */ | |
50 | } kvp_transaction; | |
51 | ||
e2bb6537 | 52 | static void kvp_send_key(struct work_struct *dummy); |
245ba56a | 53 | |
76e5f813 S |
54 | #define TIMEOUT_FIRED 1 |
55 | ||
245ba56a KS |
56 | static void kvp_respond_to_host(char *key, char *value, int error); |
57 | static void kvp_work_func(struct work_struct *dummy); | |
58 | static void kvp_register(void); | |
59 | ||
60 | static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func); | |
e2bb6537 | 61 | static DECLARE_WORK(kvp_sendkey_work, kvp_send_key); |
245ba56a KS |
62 | |
63 | static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL }; | |
64 | static const char kvp_name[] = "kvp_kernel_module"; | |
245ba56a KS |
65 | static u8 *recv_buffer; |
66 | /* | |
67 | * Register the kernel component with the user-level daemon. | |
68 | * As part of this registration, pass the LIC version number. | |
69 | */ | |
70 | ||
71 | static void | |
72 | kvp_register(void) | |
73 | { | |
74 | ||
75 | struct cn_msg *msg; | |
76 | ||
77 | msg = kzalloc(sizeof(*msg) + strlen(HV_DRV_VERSION) + 1 , GFP_ATOMIC); | |
78 | ||
79 | if (msg) { | |
80 | msg->id.idx = CN_KVP_IDX; | |
81 | msg->id.val = CN_KVP_VAL; | |
82 | msg->seq = KVP_REGISTER; | |
83 | strcpy(msg->data, HV_DRV_VERSION); | |
84 | msg->len = strlen(HV_DRV_VERSION) + 1; | |
85 | cn_netlink_send(msg, 0, GFP_ATOMIC); | |
86 | kfree(msg); | |
87 | } | |
88 | } | |
89 | static void | |
90 | kvp_work_func(struct work_struct *dummy) | |
91 | { | |
92 | /* | |
93 | * If the timer fires, the user-mode component has not responded; | |
94 | * process the pending transaction. | |
95 | */ | |
76e5f813 | 96 | kvp_respond_to_host("Unknown key", "Guest timed out", TIMEOUT_FIRED); |
245ba56a KS |
97 | } |
98 | ||
99 | /* | |
100 | * Callback when data is received from user mode. | |
101 | */ | |
102 | ||
103 | static void | |
104 | kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) | |
105 | { | |
106 | struct hv_ku_msg *message; | |
107 | ||
108 | message = (struct hv_ku_msg *)msg->data; | |
109 | if (msg->seq == KVP_REGISTER) { | |
af7a5b6e | 110 | pr_info("KVP: user-mode registering done.\n"); |
245ba56a KS |
111 | kvp_register(); |
112 | } | |
113 | ||
114 | if (msg->seq == KVP_USER_SET) { | |
115 | /* | |
116 | * Complete the transaction by forwarding the key value | |
117 | * to the host. But first, cancel the timeout. | |
118 | */ | |
119 | if (cancel_delayed_work_sync(&kvp_work)) | |
120 | kvp_respond_to_host(message->kvp_key, | |
121 | message->kvp_value, | |
122 | !strlen(message->kvp_key)); | |
123 | } | |
124 | } | |
125 | ||
e2bb6537 S |
126 | static void |
127 | kvp_send_key(struct work_struct *dummy) | |
245ba56a KS |
128 | { |
129 | struct cn_msg *msg; | |
e2bb6537 | 130 | int index = kvp_transaction.index; |
245ba56a KS |
131 | |
132 | msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC); | |
133 | ||
134 | if (msg) { | |
135 | msg->id.idx = CN_KVP_IDX; | |
136 | msg->id.val = CN_KVP_VAL; | |
137 | msg->seq = KVP_KERNEL_GET; | |
138 | ((struct hv_ku_msg *)msg->data)->kvp_index = index; | |
139 | msg->len = sizeof(struct hv_ku_msg); | |
140 | cn_netlink_send(msg, 0, GFP_ATOMIC); | |
141 | kfree(msg); | |
245ba56a | 142 | } |
e2bb6537 | 143 | return; |
245ba56a KS |
144 | } |
145 | ||
146 | /* | |
147 | * Send a response back to the host. | |
148 | */ | |
149 | ||
150 | static void | |
151 | kvp_respond_to_host(char *key, char *value, int error) | |
152 | { | |
153 | struct hv_kvp_msg *kvp_msg; | |
154 | struct hv_kvp_msg_enumerate *kvp_data; | |
155 | char *key_name; | |
156 | struct icmsg_hdr *icmsghdrp; | |
157 | int keylen, valuelen; | |
158 | u32 buf_len; | |
159 | struct vmbus_channel *channel; | |
160 | u64 req_id; | |
161 | ||
162 | /* | |
163 | * If a transaction is not active; log and return. | |
164 | */ | |
165 | ||
166 | if (!kvp_transaction.active) { | |
167 | /* | |
168 | * This is a spurious call! | |
169 | */ | |
af7a5b6e | 170 | pr_warn("KVP: Transaction not active\n"); |
245ba56a KS |
171 | return; |
172 | } | |
173 | /* | |
174 | * Copy the global state for completing the transaction. Note that | |
175 | * only one transaction can be active at a time. | |
176 | */ | |
177 | ||
178 | buf_len = kvp_transaction.recv_len; | |
179 | channel = kvp_transaction.recv_channel; | |
180 | req_id = kvp_transaction.recv_req_id; | |
181 | ||
76e5f813 S |
182 | kvp_transaction.active = false; |
183 | ||
4e65f6e8 S |
184 | if (channel->onchannel_callback == NULL) |
185 | /* | |
186 | * We have raced with util driver being unloaded; | |
187 | * silently return. | |
188 | */ | |
189 | return; | |
190 | ||
245ba56a KS |
191 | icmsghdrp = (struct icmsg_hdr *) |
192 | &recv_buffer[sizeof(struct vmbuspipe_hdr)]; | |
193 | kvp_msg = (struct hv_kvp_msg *) | |
194 | &recv_buffer[sizeof(struct vmbuspipe_hdr) + | |
195 | sizeof(struct icmsg_hdr)]; | |
196 | kvp_data = &kvp_msg->kvp_data; | |
197 | key_name = key; | |
198 | ||
199 | /* | |
200 | * If the error parameter is set, terminate the host's enumeration. | |
201 | */ | |
202 | if (error) { | |
203 | /* | |
204 | * We don't support this index or the we have timedout; | |
205 | * terminate the host-side iteration by returning an error. | |
206 | */ | |
207 | icmsghdrp->status = HV_E_FAIL; | |
208 | goto response_done; | |
209 | } | |
210 | ||
211 | /* | |
212 | * The windows host expects the key/value pair to be encoded | |
213 | * in utf16. | |
214 | */ | |
215 | keylen = utf8s_to_utf16s(key_name, strlen(key_name), | |
216 | (wchar_t *)kvp_data->data.key); | |
217 | kvp_data->data.key_size = 2*(keylen + 1); /* utf16 encoding */ | |
218 | valuelen = utf8s_to_utf16s(value, strlen(value), | |
219 | (wchar_t *)kvp_data->data.value); | |
220 | kvp_data->data.value_size = 2*(valuelen + 1); /* utf16 encoding */ | |
221 | ||
222 | kvp_data->data.value_type = REG_SZ; /* all our values are strings */ | |
223 | icmsghdrp->status = HV_S_OK; | |
224 | ||
225 | response_done: | |
226 | icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; | |
227 | ||
228 | vmbus_sendpacket(channel, recv_buffer, buf_len, req_id, | |
415f2287 | 229 | VM_PKT_DATA_INBAND, 0); |
245ba56a | 230 | |
245ba56a KS |
231 | } |
232 | ||
233 | /* | |
234 | * This callback is invoked when we get a KVP message from the host. | |
235 | * The host ensures that only one KVP transaction can be active at a time. | |
236 | * KVP implementation in Linux needs to forward the key to a user-mde | |
237 | * component to retrive the corresponding value. Consequently, we cannot | |
238 | * respond to the host in the conext of this callback. Since the host | |
239 | * guarantees that at most only one transaction can be active at a time, | |
240 | * we stash away the transaction state in a set of global variables. | |
241 | */ | |
242 | ||
243 | void hv_kvp_onchannelcallback(void *context) | |
244 | { | |
245 | struct vmbus_channel *channel = context; | |
246 | u32 recvlen; | |
247 | u64 requestid; | |
248 | ||
249 | struct hv_kvp_msg *kvp_msg; | |
250 | struct hv_kvp_msg_enumerate *kvp_data; | |
251 | ||
252 | struct icmsg_hdr *icmsghdrp; | |
253 | struct icmsg_negotiate *negop = NULL; | |
254 | ||
255 | ||
245ba56a KS |
256 | vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE, &recvlen, &requestid); |
257 | ||
258 | if (recvlen > 0) { | |
245ba56a KS |
259 | icmsghdrp = (struct icmsg_hdr *)&recv_buffer[ |
260 | sizeof(struct vmbuspipe_hdr)]; | |
261 | ||
262 | if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) { | |
da0e9631 | 263 | vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer); |
245ba56a KS |
264 | } else { |
265 | kvp_msg = (struct hv_kvp_msg *)&recv_buffer[ | |
266 | sizeof(struct vmbuspipe_hdr) + | |
267 | sizeof(struct icmsg_hdr)]; | |
268 | ||
269 | kvp_data = &kvp_msg->kvp_data; | |
270 | ||
271 | /* | |
272 | * We only support the "get" operation on | |
273 | * "KVP_POOL_AUTO" pool. | |
274 | */ | |
275 | ||
276 | if ((kvp_msg->kvp_hdr.pool != KVP_POOL_AUTO) || | |
277 | (kvp_msg->kvp_hdr.operation != | |
278 | KVP_OP_ENUMERATE)) { | |
279 | icmsghdrp->status = HV_E_FAIL; | |
280 | goto callback_done; | |
281 | } | |
282 | ||
283 | /* | |
284 | * Stash away this global state for completing the | |
285 | * transaction; note transactions are serialized. | |
286 | */ | |
287 | kvp_transaction.recv_len = recvlen; | |
288 | kvp_transaction.recv_channel = channel; | |
289 | kvp_transaction.recv_req_id = requestid; | |
290 | kvp_transaction.active = true; | |
e2bb6537 | 291 | kvp_transaction.index = kvp_data->index; |
245ba56a KS |
292 | |
293 | /* | |
294 | * Get the information from the | |
295 | * user-mode component. | |
296 | * component. This transaction will be | |
297 | * completed when we get the value from | |
298 | * the user-mode component. | |
299 | * Set a timeout to deal with | |
300 | * user-mode not responding. | |
301 | */ | |
e2bb6537 S |
302 | schedule_work(&kvp_sendkey_work); |
303 | schedule_delayed_work(&kvp_work, 5*HZ); | |
245ba56a KS |
304 | |
305 | return; | |
306 | ||
307 | } | |
308 | ||
309 | callback_done: | |
310 | ||
311 | icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | |
312 | | ICMSGHDRFLAG_RESPONSE; | |
313 | ||
314 | vmbus_sendpacket(channel, recv_buffer, | |
315 | recvlen, requestid, | |
415f2287 | 316 | VM_PKT_DATA_INBAND, 0); |
245ba56a KS |
317 | } |
318 | ||
319 | } | |
320 | ||
321 | int | |
a29b643c | 322 | hv_kvp_init(struct hv_util_service *srv) |
245ba56a KS |
323 | { |
324 | int err; | |
325 | ||
326 | err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback); | |
327 | if (err) | |
328 | return err; | |
a29b643c | 329 | recv_buffer = srv->recv_buffer; |
245ba56a KS |
330 | |
331 | return 0; | |
332 | } | |
333 | ||
334 | void hv_kvp_deinit(void) | |
335 | { | |
336 | cn_del_callback(&kvp_id); | |
337 | cancel_delayed_work_sync(&kvp_work); | |
e2bb6537 | 338 | cancel_work_sync(&kvp_sendkey_work); |
245ba56a | 339 | } |