2 * An implementation of key value pair (KVP) functionality for Linux.
5 * Copyright (C) 2010, Novell, Inc.
6 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
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.
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
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.
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/net.h>
26 #include <linux/nls.h>
27 #include <linux/connector.h>
28 #include <linux/workqueue.h>
29 #include <linux/hyperv.h>
34 * Global state maintained for transaction that is being processed.
35 * Note that only one transaction can be active at any point in time.
37 * This state is set when we receive a request from the host; we
38 * cleanup this state when the transaction is completed - when we respond
39 * to the host with the key value.
43 bool active; /* transaction status - active or not */
44 int recv_len; /* number of bytes received. */
45 struct hv_kvp_msg *kvp_msg; /* current message */
46 struct vmbus_channel *recv_channel; /* chn we got the request */
47 u64 recv_req_id; /* request ID. */
48 void *kvp_context; /* for the channel callback */
52 * Before we can accept KVP messages from the host, we need
53 * to handshake with the user level daemon. This state tracks
54 * if we are in the handshake phase.
56 static bool in_hand_shake = true;
59 * This state maintains the version number registered by the daemon.
61 static int dm_reg_value;
63 static void kvp_send_key(struct work_struct *dummy);
66 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
67 static void kvp_work_func(struct work_struct *dummy);
68 static void kvp_register(int);
70 static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
71 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
73 static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
74 static const char kvp_name[] = "kvp_kernel_module";
75 static u8 *recv_buffer;
77 * Register the kernel component with the user-level daemon.
78 * As part of this registration, pass the LIC version number.
82 kvp_register(int reg_value)
86 struct hv_kvp_msg *kvp_msg;
89 msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
92 kvp_msg = (struct hv_kvp_msg *)msg->data;
93 version = kvp_msg->body.kvp_register.version;
94 msg->id.idx = CN_KVP_IDX;
95 msg->id.val = CN_KVP_VAL;
97 kvp_msg->kvp_hdr.operation = reg_value;
98 strcpy(version, HV_DRV_VERSION);
99 msg->len = sizeof(struct hv_kvp_msg);
100 cn_netlink_send(msg, 0, GFP_ATOMIC);
105 kvp_work_func(struct work_struct *dummy)
108 * If the timer fires, the user-mode component has not responded;
109 * process the pending transaction.
111 kvp_respond_to_host(NULL, HV_E_FAIL);
114 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
118 switch (msg->kvp_hdr.operation) {
119 case KVP_OP_REGISTER:
120 dm_reg_value = KVP_OP_REGISTER;
121 pr_info("KVP: IP injection functionality not available\n");
122 pr_info("KVP: Upgrade the KVP daemon\n");
124 case KVP_OP_REGISTER1:
125 dm_reg_value = KVP_OP_REGISTER1;
128 pr_info("KVP: incompatible daemon\n");
129 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
130 KVP_OP_REGISTER1, msg->kvp_hdr.operation);
136 * We have a compatible daemon; complete the handshake.
138 pr_info("KVP: user-mode registering done.\n");
139 kvp_register(dm_reg_value);
140 kvp_transaction.active = false;
141 if (kvp_transaction.kvp_context)
142 hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
149 * Callback when data is received from user mode.
153 kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
155 struct hv_kvp_msg *message;
156 struct hv_kvp_msg_enumerate *data;
159 message = (struct hv_kvp_msg *)msg->data;
162 * If we are negotiating the version information
163 * with the daemon; handle that first.
167 if (kvp_handle_handshake(message))
168 in_hand_shake = false;
173 * Based on the version of the daemon, we propagate errors from the
174 * daemon differently.
177 data = &message->body.kvp_enum_data;
179 switch (dm_reg_value) {
180 case KVP_OP_REGISTER:
182 * Null string is used to pass back error condition.
184 if (data->data.key[0] == 0)
188 case KVP_OP_REGISTER1:
190 * We use the message header information from
191 * the user level daemon to transmit errors.
193 error = message->error;
198 * Complete the transaction by forwarding the key value
199 * to the host. But first, cancel the timeout.
201 if (cancel_delayed_work_sync(&kvp_work))
202 kvp_respond_to_host(message, error);
206 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
208 struct hv_kvp_msg *in = in_msg;
209 struct hv_kvp_ip_msg *out = out_msg;
213 case KVP_OP_GET_IP_INFO:
215 * Transform all parameters into utf16 encoding.
217 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
218 strlen((char *)in->body.kvp_ip_val.ip_addr),
220 (wchar_t *)out->kvp_ip_val.ip_addr,
225 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
226 strlen((char *)in->body.kvp_ip_val.sub_net),
228 (wchar_t *)out->kvp_ip_val.sub_net,
233 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
234 strlen((char *)in->body.kvp_ip_val.gate_way),
236 (wchar_t *)out->kvp_ip_val.gate_way,
241 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
242 strlen((char *)in->body.kvp_ip_val.dns_addr),
244 (wchar_t *)out->kvp_ip_val.dns_addr,
249 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
250 strlen((char *)in->body.kvp_ip_val.adapter_id),
252 (wchar_t *)out->kvp_ip_val.adapter_id,
257 out->kvp_ip_val.dhcp_enabled =
258 in->body.kvp_ip_val.dhcp_enabled;
259 out->kvp_ip_val.addr_family =
260 in->body.kvp_ip_val.addr_family;
266 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
268 struct hv_kvp_ip_msg *in = in_msg;
269 struct hv_kvp_msg *out = out_msg;
272 case KVP_OP_SET_IP_INFO:
274 * Transform all parameters into utf8 encoding.
276 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
279 (__u8 *)out->body.kvp_ip_val.ip_addr,
282 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
285 (__u8 *)out->body.kvp_ip_val.sub_net,
288 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
291 (__u8 *)out->body.kvp_ip_val.gate_way,
294 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
297 (__u8 *)out->body.kvp_ip_val.dns_addr,
300 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
303 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
306 (__u8 *)out->body.kvp_ip_val.adapter_id,
307 MAX_ADAPTER_ID_SIZE);
309 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
317 kvp_send_key(struct work_struct *dummy)
320 struct hv_kvp_msg *message;
321 struct hv_kvp_msg *in_msg;
322 __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
323 __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
327 msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
331 msg->id.idx = CN_KVP_IDX;
332 msg->id.val = CN_KVP_VAL;
334 message = (struct hv_kvp_msg *)msg->data;
335 message->kvp_hdr.operation = operation;
336 message->kvp_hdr.pool = pool;
337 in_msg = kvp_transaction.kvp_msg;
340 * The key/value strings sent from the host are encoded in
341 * in utf16; convert it to utf8 strings.
342 * The host assures us that the utf16 strings will not exceed
343 * the max lengths specified. We will however, reserve room
344 * for the string terminating character - in the utf16s_utf8s()
345 * function we limit the size of the buffer where the converted
346 * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
347 * that the strings can be properly terminated!
350 switch (message->kvp_hdr.operation) {
351 case KVP_OP_SET_IP_INFO:
352 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
354 case KVP_OP_GET_IP_INFO:
355 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
358 switch (in_msg->body.kvp_set.data.value_type) {
361 * The value is a string - utf16 encoding.
363 message->body.kvp_set.data.value_size =
365 (wchar_t *)in_msg->body.kvp_set.data.value,
366 in_msg->body.kvp_set.data.value_size,
368 message->body.kvp_set.data.value,
369 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
374 * The value is a 32 bit scalar.
375 * We save this as a utf8 string.
377 val32 = in_msg->body.kvp_set.data.value_u32;
378 message->body.kvp_set.data.value_size =
379 sprintf(message->body.kvp_set.data.value,
385 * The value is a 64 bit scalar.
386 * We save this as a utf8 string.
388 val64 = in_msg->body.kvp_set.data.value_u64;
389 message->body.kvp_set.data.value_size =
390 sprintf(message->body.kvp_set.data.value,
396 message->body.kvp_set.data.key_size =
398 (wchar_t *)in_msg->body.kvp_set.data.key,
399 in_msg->body.kvp_set.data.key_size,
401 message->body.kvp_set.data.key,
402 HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
406 message->body.kvp_delete.key_size =
408 (wchar_t *)in_msg->body.kvp_delete.key,
409 in_msg->body.kvp_delete.key_size,
411 message->body.kvp_delete.key,
412 HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
415 case KVP_OP_ENUMERATE:
416 message->body.kvp_enum_data.index =
417 in_msg->body.kvp_enum_data.index;
421 msg->len = sizeof(struct hv_kvp_msg);
422 cn_netlink_send(msg, 0, GFP_ATOMIC);
429 * Send a response back to the host.
433 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
435 struct hv_kvp_msg *kvp_msg;
436 struct hv_kvp_exchg_msg_value *kvp_data;
439 struct icmsg_hdr *icmsghdrp;
443 struct vmbus_channel *channel;
448 * If a transaction is not active; log and return.
451 if (!kvp_transaction.active) {
453 * This is a spurious call!
455 pr_warn("KVP: Transaction not active\n");
459 * Copy the global state for completing the transaction. Note that
460 * only one transaction can be active at a time.
463 buf_len = kvp_transaction.recv_len;
464 channel = kvp_transaction.recv_channel;
465 req_id = kvp_transaction.recv_req_id;
467 kvp_transaction.active = false;
469 icmsghdrp = (struct icmsg_hdr *)
470 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
472 if (channel->onchannel_callback == NULL)
474 * We have raced with util driver being unloaded;
479 icmsghdrp->status = error;
482 * If the error parameter is set, terminate the host's enumeration
487 * Something failed or we have timedout;
488 * terminate the current host-side iteration.
493 kvp_msg = (struct hv_kvp_msg *)
494 &recv_buffer[sizeof(struct vmbuspipe_hdr) +
495 sizeof(struct icmsg_hdr)];
497 switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
498 case KVP_OP_GET_IP_INFO:
499 ret = process_ob_ipinfo(msg_to_host,
500 (struct hv_kvp_ip_msg *)kvp_msg,
503 icmsghdrp->status = HV_E_FAIL;
506 case KVP_OP_SET_IP_INFO:
509 kvp_data = &kvp_msg->body.kvp_get.data;
520 kvp_data = &kvp_msg->body.kvp_enum_data.data;
521 key_name = msg_to_host->body.kvp_enum_data.data.key;
524 * The windows host expects the key/value pair to be encoded
525 * in utf16. Ensure that the key/value size reported to the host
526 * will be less than or equal to the MAX size (including the
527 * terminating character).
529 keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
530 (wchar_t *) kvp_data->key,
531 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
532 kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
535 value = msg_to_host->body.kvp_enum_data.data.value;
536 valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
537 (wchar_t *) kvp_data->value,
538 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
539 kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
542 * If the utf8s to utf16s conversion failed; notify host
545 if ((keylen < 0) || (valuelen < 0))
546 icmsghdrp->status = HV_E_FAIL;
548 kvp_data->value_type = REG_SZ; /* all our values are strings */
551 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
553 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
554 VM_PKT_DATA_INBAND, 0);
559 * This callback is invoked when we get a KVP message from the host.
560 * The host ensures that only one KVP transaction can be active at a time.
561 * KVP implementation in Linux needs to forward the key to a user-mde
562 * component to retrive the corresponding value. Consequently, we cannot
563 * respond to the host in the conext of this callback. Since the host
564 * guarantees that at most only one transaction can be active at a time,
565 * we stash away the transaction state in a set of global variables.
568 void hv_kvp_onchannelcallback(void *context)
570 struct vmbus_channel *channel = context;
574 struct hv_kvp_msg *kvp_msg;
576 struct icmsg_hdr *icmsghdrp;
577 struct icmsg_negotiate *negop = NULL;
579 if (kvp_transaction.active) {
581 * We will defer processing this callback once
582 * the current transaction is complete.
584 kvp_transaction.kvp_context = context;
588 vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
592 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
593 sizeof(struct vmbuspipe_hdr)];
595 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
596 vmbus_prep_negotiate_resp(icmsghdrp, negop,
597 recv_buffer, MAX_SRV_VER, MAX_SRV_VER);
599 kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
600 sizeof(struct vmbuspipe_hdr) +
601 sizeof(struct icmsg_hdr)];
604 * Stash away this global state for completing the
605 * transaction; note transactions are serialized.
608 kvp_transaction.recv_len = recvlen;
609 kvp_transaction.recv_channel = channel;
610 kvp_transaction.recv_req_id = requestid;
611 kvp_transaction.active = true;
612 kvp_transaction.kvp_msg = kvp_msg;
615 * Get the information from the
616 * user-mode component.
617 * component. This transaction will be
618 * completed when we get the value from
619 * the user-mode component.
620 * Set a timeout to deal with
621 * user-mode not responding.
623 schedule_work(&kvp_sendkey_work);
624 schedule_delayed_work(&kvp_work, 5*HZ);
630 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
631 | ICMSGHDRFLAG_RESPONSE;
633 vmbus_sendpacket(channel, recv_buffer,
635 VM_PKT_DATA_INBAND, 0);
641 hv_kvp_init(struct hv_util_service *srv)
645 err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
648 recv_buffer = srv->recv_buffer;
651 * When this driver loads, the user level daemon that
652 * processes the host requests may not yet be running.
653 * Defer processing channel callbacks until the daemon
656 kvp_transaction.active = true;
661 void hv_kvp_deinit(void)
663 cn_del_callback(&kvp_id);
664 cancel_delayed_work_sync(&kvp_work);
665 cancel_work_sync(&kvp_sendkey_work);