cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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qmi_interface.c (21465B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2017 Linaro Ltd.
      4 */
      5#include <linux/kernel.h>
      6#include <linux/module.h>
      7#include <linux/device.h>
      8#include <linux/qrtr.h>
      9#include <linux/net.h>
     10#include <linux/completion.h>
     11#include <linux/idr.h>
     12#include <linux/string.h>
     13#include <net/sock.h>
     14#include <linux/workqueue.h>
     15#include <linux/soc/qcom/qmi.h>
     16
     17static struct socket *qmi_sock_create(struct qmi_handle *qmi,
     18				      struct sockaddr_qrtr *sq);
     19
     20/**
     21 * qmi_recv_new_server() - handler of NEW_SERVER control message
     22 * @qmi:	qmi handle
     23 * @service:	service id of the new server
     24 * @instance:	instance id of the new server
     25 * @node:	node of the new server
     26 * @port:	port of the new server
     27 *
     28 * Calls the new_server callback to inform the client about a newly registered
     29 * server matching the currently registered service lookup.
     30 */
     31static void qmi_recv_new_server(struct qmi_handle *qmi,
     32				unsigned int service, unsigned int instance,
     33				unsigned int node, unsigned int port)
     34{
     35	struct qmi_ops *ops = &qmi->ops;
     36	struct qmi_service *svc;
     37	int ret;
     38
     39	if (!ops->new_server)
     40		return;
     41
     42	/* Ignore EOF marker */
     43	if (!node && !port)
     44		return;
     45
     46	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
     47	if (!svc)
     48		return;
     49
     50	svc->service = service;
     51	svc->version = instance & 0xff;
     52	svc->instance = instance >> 8;
     53	svc->node = node;
     54	svc->port = port;
     55
     56	ret = ops->new_server(qmi, svc);
     57	if (ret < 0)
     58		kfree(svc);
     59	else
     60		list_add(&svc->list_node, &qmi->lookup_results);
     61}
     62
     63/**
     64 * qmi_recv_del_server() - handler of DEL_SERVER control message
     65 * @qmi:	qmi handle
     66 * @node:	node of the dying server, a value of -1 matches all nodes
     67 * @port:	port of the dying server, a value of -1 matches all ports
     68 *
     69 * Calls the del_server callback for each previously seen server, allowing the
     70 * client to react to the disappearing server.
     71 */
     72static void qmi_recv_del_server(struct qmi_handle *qmi,
     73				unsigned int node, unsigned int port)
     74{
     75	struct qmi_ops *ops = &qmi->ops;
     76	struct qmi_service *svc;
     77	struct qmi_service *tmp;
     78
     79	list_for_each_entry_safe(svc, tmp, &qmi->lookup_results, list_node) {
     80		if (node != -1 && svc->node != node)
     81			continue;
     82		if (port != -1 && svc->port != port)
     83			continue;
     84
     85		if (ops->del_server)
     86			ops->del_server(qmi, svc);
     87
     88		list_del(&svc->list_node);
     89		kfree(svc);
     90	}
     91}
     92
     93/**
     94 * qmi_recv_bye() - handler of BYE control message
     95 * @qmi:	qmi handle
     96 * @node:	id of the dying node
     97 *
     98 * Signals the client that all previously registered services on this node are
     99 * now gone and then calls the bye callback to allow the client further
    100 * cleaning up resources associated with this remote.
    101 */
    102static void qmi_recv_bye(struct qmi_handle *qmi,
    103			 unsigned int node)
    104{
    105	struct qmi_ops *ops = &qmi->ops;
    106
    107	qmi_recv_del_server(qmi, node, -1);
    108
    109	if (ops->bye)
    110		ops->bye(qmi, node);
    111}
    112
    113/**
    114 * qmi_recv_del_client() - handler of DEL_CLIENT control message
    115 * @qmi:	qmi handle
    116 * @node:	node of the dying client
    117 * @port:	port of the dying client
    118 *
    119 * Signals the client about a dying client, by calling the del_client callback.
    120 */
    121static void qmi_recv_del_client(struct qmi_handle *qmi,
    122				unsigned int node, unsigned int port)
    123{
    124	struct qmi_ops *ops = &qmi->ops;
    125
    126	if (ops->del_client)
    127		ops->del_client(qmi, node, port);
    128}
    129
    130static void qmi_recv_ctrl_pkt(struct qmi_handle *qmi,
    131			      const void *buf, size_t len)
    132{
    133	const struct qrtr_ctrl_pkt *pkt = buf;
    134
    135	if (len < sizeof(struct qrtr_ctrl_pkt)) {
    136		pr_debug("ignoring short control packet\n");
    137		return;
    138	}
    139
    140	switch (le32_to_cpu(pkt->cmd)) {
    141	case QRTR_TYPE_BYE:
    142		qmi_recv_bye(qmi, le32_to_cpu(pkt->client.node));
    143		break;
    144	case QRTR_TYPE_NEW_SERVER:
    145		qmi_recv_new_server(qmi,
    146				    le32_to_cpu(pkt->server.service),
    147				    le32_to_cpu(pkt->server.instance),
    148				    le32_to_cpu(pkt->server.node),
    149				    le32_to_cpu(pkt->server.port));
    150		break;
    151	case QRTR_TYPE_DEL_SERVER:
    152		qmi_recv_del_server(qmi,
    153				    le32_to_cpu(pkt->server.node),
    154				    le32_to_cpu(pkt->server.port));
    155		break;
    156	case QRTR_TYPE_DEL_CLIENT:
    157		qmi_recv_del_client(qmi,
    158				    le32_to_cpu(pkt->client.node),
    159				    le32_to_cpu(pkt->client.port));
    160		break;
    161	}
    162}
    163
    164static void qmi_send_new_lookup(struct qmi_handle *qmi, struct qmi_service *svc)
    165{
    166	struct qrtr_ctrl_pkt pkt;
    167	struct sockaddr_qrtr sq;
    168	struct msghdr msg = { };
    169	struct kvec iv = { &pkt, sizeof(pkt) };
    170	int ret;
    171
    172	memset(&pkt, 0, sizeof(pkt));
    173	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_LOOKUP);
    174	pkt.server.service = cpu_to_le32(svc->service);
    175	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
    176
    177	sq.sq_family = qmi->sq.sq_family;
    178	sq.sq_node = qmi->sq.sq_node;
    179	sq.sq_port = QRTR_PORT_CTRL;
    180
    181	msg.msg_name = &sq;
    182	msg.msg_namelen = sizeof(sq);
    183
    184	mutex_lock(&qmi->sock_lock);
    185	if (qmi->sock) {
    186		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
    187		if (ret < 0)
    188			pr_err("failed to send lookup registration: %d\n", ret);
    189	}
    190	mutex_unlock(&qmi->sock_lock);
    191}
    192
    193/**
    194 * qmi_add_lookup() - register a new lookup with the name service
    195 * @qmi:	qmi handle
    196 * @service:	service id of the request
    197 * @instance:	instance id of the request
    198 * @version:	version number of the request
    199 *
    200 * Registering a lookup query with the name server will cause the name server
    201 * to send NEW_SERVER and DEL_SERVER control messages to this socket as
    202 * matching services are registered.
    203 *
    204 * Return: 0 on success, negative errno on failure.
    205 */
    206int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
    207		   unsigned int version, unsigned int instance)
    208{
    209	struct qmi_service *svc;
    210
    211	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
    212	if (!svc)
    213		return -ENOMEM;
    214
    215	svc->service = service;
    216	svc->version = version;
    217	svc->instance = instance;
    218
    219	list_add(&svc->list_node, &qmi->lookups);
    220
    221	qmi_send_new_lookup(qmi, svc);
    222
    223	return 0;
    224}
    225EXPORT_SYMBOL(qmi_add_lookup);
    226
    227static void qmi_send_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
    228{
    229	struct qrtr_ctrl_pkt pkt;
    230	struct sockaddr_qrtr sq;
    231	struct msghdr msg = { };
    232	struct kvec iv = { &pkt, sizeof(pkt) };
    233	int ret;
    234
    235	memset(&pkt, 0, sizeof(pkt));
    236	pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_SERVER);
    237	pkt.server.service = cpu_to_le32(svc->service);
    238	pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
    239	pkt.server.node = cpu_to_le32(qmi->sq.sq_node);
    240	pkt.server.port = cpu_to_le32(qmi->sq.sq_port);
    241
    242	sq.sq_family = qmi->sq.sq_family;
    243	sq.sq_node = qmi->sq.sq_node;
    244	sq.sq_port = QRTR_PORT_CTRL;
    245
    246	msg.msg_name = &sq;
    247	msg.msg_namelen = sizeof(sq);
    248
    249	mutex_lock(&qmi->sock_lock);
    250	if (qmi->sock) {
    251		ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
    252		if (ret < 0)
    253			pr_err("send service registration failed: %d\n", ret);
    254	}
    255	mutex_unlock(&qmi->sock_lock);
    256}
    257
    258/**
    259 * qmi_add_server() - register a service with the name service
    260 * @qmi:	qmi handle
    261 * @service:	type of the service
    262 * @instance:	instance of the service
    263 * @version:	version of the service
    264 *
    265 * Register a new service with the name service. This allows clients to find
    266 * and start sending messages to the client associated with @qmi.
    267 *
    268 * Return: 0 on success, negative errno on failure.
    269 */
    270int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
    271		   unsigned int version, unsigned int instance)
    272{
    273	struct qmi_service *svc;
    274
    275	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
    276	if (!svc)
    277		return -ENOMEM;
    278
    279	svc->service = service;
    280	svc->version = version;
    281	svc->instance = instance;
    282
    283	list_add(&svc->list_node, &qmi->services);
    284
    285	qmi_send_new_server(qmi, svc);
    286
    287	return 0;
    288}
    289EXPORT_SYMBOL(qmi_add_server);
    290
    291/**
    292 * qmi_txn_init() - allocate transaction id within the given QMI handle
    293 * @qmi:	QMI handle
    294 * @txn:	transaction context
    295 * @ei:		description of how to decode a matching response (optional)
    296 * @c_struct:	pointer to the object to decode the response into (optional)
    297 *
    298 * This allocates a transaction id within the QMI handle. If @ei and @c_struct
    299 * are specified any responses to this transaction will be decoded as described
    300 * by @ei into @c_struct.
    301 *
    302 * A client calling qmi_txn_init() must call either qmi_txn_wait() or
    303 * qmi_txn_cancel() to free up the allocated resources.
    304 *
    305 * Return: Transaction id on success, negative errno on failure.
    306 */
    307int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
    308		 struct qmi_elem_info *ei, void *c_struct)
    309{
    310	int ret;
    311
    312	memset(txn, 0, sizeof(*txn));
    313
    314	mutex_init(&txn->lock);
    315	init_completion(&txn->completion);
    316	txn->qmi = qmi;
    317	txn->ei = ei;
    318	txn->dest = c_struct;
    319
    320	mutex_lock(&qmi->txn_lock);
    321	ret = idr_alloc_cyclic(&qmi->txns, txn, 0, U16_MAX, GFP_KERNEL);
    322	if (ret < 0)
    323		pr_err("failed to allocate transaction id\n");
    324
    325	txn->id = ret;
    326	mutex_unlock(&qmi->txn_lock);
    327
    328	return ret;
    329}
    330EXPORT_SYMBOL(qmi_txn_init);
    331
    332/**
    333 * qmi_txn_wait() - wait for a response on a transaction
    334 * @txn:	transaction handle
    335 * @timeout:	timeout, in jiffies
    336 *
    337 * If the transaction is decoded by the means of @ei and @c_struct the return
    338 * value will be the returned value of qmi_decode_message(), otherwise it's up
    339 * to the specified message handler to fill out the result.
    340 *
    341 * Return: the transaction response on success, negative errno on failure.
    342 */
    343int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout)
    344{
    345	struct qmi_handle *qmi = txn->qmi;
    346	int ret;
    347
    348	ret = wait_for_completion_timeout(&txn->completion, timeout);
    349
    350	mutex_lock(&qmi->txn_lock);
    351	mutex_lock(&txn->lock);
    352	idr_remove(&qmi->txns, txn->id);
    353	mutex_unlock(&txn->lock);
    354	mutex_unlock(&qmi->txn_lock);
    355
    356	if (ret == 0)
    357		return -ETIMEDOUT;
    358	else
    359		return txn->result;
    360}
    361EXPORT_SYMBOL(qmi_txn_wait);
    362
    363/**
    364 * qmi_txn_cancel() - cancel an ongoing transaction
    365 * @txn:	transaction id
    366 */
    367void qmi_txn_cancel(struct qmi_txn *txn)
    368{
    369	struct qmi_handle *qmi = txn->qmi;
    370
    371	mutex_lock(&qmi->txn_lock);
    372	mutex_lock(&txn->lock);
    373	idr_remove(&qmi->txns, txn->id);
    374	mutex_unlock(&txn->lock);
    375	mutex_unlock(&qmi->txn_lock);
    376}
    377EXPORT_SYMBOL(qmi_txn_cancel);
    378
    379/**
    380 * qmi_invoke_handler() - find and invoke a handler for a message
    381 * @qmi:	qmi handle
    382 * @sq:		sockaddr of the sender
    383 * @txn:	transaction object for the message
    384 * @buf:	buffer containing the message
    385 * @len:	length of @buf
    386 *
    387 * Find handler and invoke handler for the incoming message.
    388 */
    389static void qmi_invoke_handler(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
    390			       struct qmi_txn *txn, const void *buf, size_t len)
    391{
    392	const struct qmi_msg_handler *handler;
    393	const struct qmi_header *hdr = buf;
    394	void *dest;
    395	int ret;
    396
    397	if (!qmi->handlers)
    398		return;
    399
    400	for (handler = qmi->handlers; handler->fn; handler++) {
    401		if (handler->type == hdr->type &&
    402		    handler->msg_id == hdr->msg_id)
    403			break;
    404	}
    405
    406	if (!handler->fn)
    407		return;
    408
    409	dest = kzalloc(handler->decoded_size, GFP_KERNEL);
    410	if (!dest)
    411		return;
    412
    413	ret = qmi_decode_message(buf, len, handler->ei, dest);
    414	if (ret < 0)
    415		pr_err("failed to decode incoming message\n");
    416	else
    417		handler->fn(qmi, sq, txn, dest);
    418
    419	kfree(dest);
    420}
    421
    422/**
    423 * qmi_handle_net_reset() - invoked to handle ENETRESET on a QMI handle
    424 * @qmi:	the QMI context
    425 *
    426 * As a result of registering a name service with the QRTR all open sockets are
    427 * flagged with ENETRESET and this function will be called. The typical case is
    428 * the initial boot, where this signals that the local node id has been
    429 * configured and as such any bound sockets needs to be rebound. So close the
    430 * socket, inform the client and re-initialize the socket.
    431 *
    432 * For clients it's generally sufficient to react to the del_server callbacks,
    433 * but server code is expected to treat the net_reset callback as a "bye" from
    434 * all nodes.
    435 *
    436 * Finally the QMI handle will send out registration requests for any lookups
    437 * and services.
    438 */
    439static void qmi_handle_net_reset(struct qmi_handle *qmi)
    440{
    441	struct sockaddr_qrtr sq;
    442	struct qmi_service *svc;
    443	struct socket *sock;
    444
    445	sock = qmi_sock_create(qmi, &sq);
    446	if (IS_ERR(sock))
    447		return;
    448
    449	mutex_lock(&qmi->sock_lock);
    450	sock_release(qmi->sock);
    451	qmi->sock = NULL;
    452	mutex_unlock(&qmi->sock_lock);
    453
    454	qmi_recv_del_server(qmi, -1, -1);
    455
    456	if (qmi->ops.net_reset)
    457		qmi->ops.net_reset(qmi);
    458
    459	mutex_lock(&qmi->sock_lock);
    460	qmi->sock = sock;
    461	qmi->sq = sq;
    462	mutex_unlock(&qmi->sock_lock);
    463
    464	list_for_each_entry(svc, &qmi->lookups, list_node)
    465		qmi_send_new_lookup(qmi, svc);
    466
    467	list_for_each_entry(svc, &qmi->services, list_node)
    468		qmi_send_new_server(qmi, svc);
    469}
    470
    471static void qmi_handle_message(struct qmi_handle *qmi,
    472			       struct sockaddr_qrtr *sq,
    473			       const void *buf, size_t len)
    474{
    475	const struct qmi_header *hdr;
    476	struct qmi_txn tmp_txn;
    477	struct qmi_txn *txn = NULL;
    478	int ret;
    479
    480	if (len < sizeof(*hdr)) {
    481		pr_err("ignoring short QMI packet\n");
    482		return;
    483	}
    484
    485	hdr = buf;
    486
    487	/* If this is a response, find the matching transaction handle */
    488	if (hdr->type == QMI_RESPONSE) {
    489		mutex_lock(&qmi->txn_lock);
    490		txn = idr_find(&qmi->txns, hdr->txn_id);
    491
    492		/* Ignore unexpected responses */
    493		if (!txn) {
    494			mutex_unlock(&qmi->txn_lock);
    495			return;
    496		}
    497
    498		mutex_lock(&txn->lock);
    499		mutex_unlock(&qmi->txn_lock);
    500
    501		if (txn->dest && txn->ei) {
    502			ret = qmi_decode_message(buf, len, txn->ei, txn->dest);
    503			if (ret < 0)
    504				pr_err("failed to decode incoming message\n");
    505
    506			txn->result = ret;
    507			complete(&txn->completion);
    508		} else  {
    509			qmi_invoke_handler(qmi, sq, txn, buf, len);
    510		}
    511
    512		mutex_unlock(&txn->lock);
    513	} else {
    514		/* Create a txn based on the txn_id of the incoming message */
    515		memset(&tmp_txn, 0, sizeof(tmp_txn));
    516		tmp_txn.id = hdr->txn_id;
    517
    518		qmi_invoke_handler(qmi, sq, &tmp_txn, buf, len);
    519	}
    520}
    521
    522static void qmi_data_ready_work(struct work_struct *work)
    523{
    524	struct qmi_handle *qmi = container_of(work, struct qmi_handle, work);
    525	struct qmi_ops *ops = &qmi->ops;
    526	struct sockaddr_qrtr sq;
    527	struct msghdr msg = { .msg_name = &sq, .msg_namelen = sizeof(sq) };
    528	struct kvec iv;
    529	ssize_t msglen;
    530
    531	for (;;) {
    532		iv.iov_base = qmi->recv_buf;
    533		iv.iov_len = qmi->recv_buf_size;
    534
    535		mutex_lock(&qmi->sock_lock);
    536		if (qmi->sock)
    537			msglen = kernel_recvmsg(qmi->sock, &msg, &iv, 1,
    538						iv.iov_len, MSG_DONTWAIT);
    539		else
    540			msglen = -EPIPE;
    541		mutex_unlock(&qmi->sock_lock);
    542		if (msglen == -EAGAIN)
    543			break;
    544
    545		if (msglen == -ENETRESET) {
    546			qmi_handle_net_reset(qmi);
    547
    548			/* The old qmi->sock is gone, our work is done */
    549			break;
    550		}
    551
    552		if (msglen < 0) {
    553			pr_err("qmi recvmsg failed: %zd\n", msglen);
    554			break;
    555		}
    556
    557		if (sq.sq_node == qmi->sq.sq_node &&
    558		    sq.sq_port == QRTR_PORT_CTRL) {
    559			qmi_recv_ctrl_pkt(qmi, qmi->recv_buf, msglen);
    560		} else if (ops->msg_handler) {
    561			ops->msg_handler(qmi, &sq, qmi->recv_buf, msglen);
    562		} else {
    563			qmi_handle_message(qmi, &sq, qmi->recv_buf, msglen);
    564		}
    565	}
    566}
    567
    568static void qmi_data_ready(struct sock *sk)
    569{
    570	struct qmi_handle *qmi = sk->sk_user_data;
    571
    572	/*
    573	 * This will be NULL if we receive data while being in
    574	 * qmi_handle_release()
    575	 */
    576	if (!qmi)
    577		return;
    578
    579	queue_work(qmi->wq, &qmi->work);
    580}
    581
    582static struct socket *qmi_sock_create(struct qmi_handle *qmi,
    583				      struct sockaddr_qrtr *sq)
    584{
    585	struct socket *sock;
    586	int ret;
    587
    588	ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
    589			       PF_QIPCRTR, &sock);
    590	if (ret < 0)
    591		return ERR_PTR(ret);
    592
    593	ret = kernel_getsockname(sock, (struct sockaddr *)sq);
    594	if (ret < 0) {
    595		sock_release(sock);
    596		return ERR_PTR(ret);
    597	}
    598
    599	sock->sk->sk_user_data = qmi;
    600	sock->sk->sk_data_ready = qmi_data_ready;
    601	sock->sk->sk_error_report = qmi_data_ready;
    602
    603	return sock;
    604}
    605
    606/**
    607 * qmi_handle_init() - initialize a QMI client handle
    608 * @qmi:	QMI handle to initialize
    609 * @recv_buf_size: maximum size of incoming message
    610 * @ops:	reference to callbacks for QRTR notifications
    611 * @handlers:	NULL-terminated list of QMI message handlers
    612 *
    613 * This initializes the QMI client handle to allow sending and receiving QMI
    614 * messages. As messages are received the appropriate handler will be invoked.
    615 *
    616 * Return: 0 on success, negative errno on failure.
    617 */
    618int qmi_handle_init(struct qmi_handle *qmi, size_t recv_buf_size,
    619		    const struct qmi_ops *ops,
    620		    const struct qmi_msg_handler *handlers)
    621{
    622	int ret;
    623
    624	mutex_init(&qmi->txn_lock);
    625	mutex_init(&qmi->sock_lock);
    626
    627	idr_init(&qmi->txns);
    628
    629	INIT_LIST_HEAD(&qmi->lookups);
    630	INIT_LIST_HEAD(&qmi->lookup_results);
    631	INIT_LIST_HEAD(&qmi->services);
    632
    633	INIT_WORK(&qmi->work, qmi_data_ready_work);
    634
    635	qmi->handlers = handlers;
    636	if (ops)
    637		qmi->ops = *ops;
    638
    639	/* Make room for the header */
    640	recv_buf_size += sizeof(struct qmi_header);
    641	/* Must also be sufficient to hold a control packet */
    642	if (recv_buf_size < sizeof(struct qrtr_ctrl_pkt))
    643		recv_buf_size = sizeof(struct qrtr_ctrl_pkt);
    644
    645	qmi->recv_buf_size = recv_buf_size;
    646	qmi->recv_buf = kzalloc(recv_buf_size, GFP_KERNEL);
    647	if (!qmi->recv_buf)
    648		return -ENOMEM;
    649
    650	qmi->wq = alloc_workqueue("qmi_msg_handler", WQ_UNBOUND, 1);
    651	if (!qmi->wq) {
    652		ret = -ENOMEM;
    653		goto err_free_recv_buf;
    654	}
    655
    656	qmi->sock = qmi_sock_create(qmi, &qmi->sq);
    657	if (IS_ERR(qmi->sock)) {
    658		if (PTR_ERR(qmi->sock) == -EAFNOSUPPORT) {
    659			ret = -EPROBE_DEFER;
    660		} else {
    661			pr_err("failed to create QMI socket\n");
    662			ret = PTR_ERR(qmi->sock);
    663		}
    664		goto err_destroy_wq;
    665	}
    666
    667	return 0;
    668
    669err_destroy_wq:
    670	destroy_workqueue(qmi->wq);
    671err_free_recv_buf:
    672	kfree(qmi->recv_buf);
    673
    674	return ret;
    675}
    676EXPORT_SYMBOL(qmi_handle_init);
    677
    678/**
    679 * qmi_handle_release() - release the QMI client handle
    680 * @qmi:	QMI client handle
    681 *
    682 * This closes the underlying socket and stops any handling of QMI messages.
    683 */
    684void qmi_handle_release(struct qmi_handle *qmi)
    685{
    686	struct socket *sock = qmi->sock;
    687	struct qmi_service *svc, *tmp;
    688
    689	sock->sk->sk_user_data = NULL;
    690	cancel_work_sync(&qmi->work);
    691
    692	qmi_recv_del_server(qmi, -1, -1);
    693
    694	mutex_lock(&qmi->sock_lock);
    695	sock_release(sock);
    696	qmi->sock = NULL;
    697	mutex_unlock(&qmi->sock_lock);
    698
    699	destroy_workqueue(qmi->wq);
    700
    701	idr_destroy(&qmi->txns);
    702
    703	kfree(qmi->recv_buf);
    704
    705	/* Free registered lookup requests */
    706	list_for_each_entry_safe(svc, tmp, &qmi->lookups, list_node) {
    707		list_del(&svc->list_node);
    708		kfree(svc);
    709	}
    710
    711	/* Free registered service information */
    712	list_for_each_entry_safe(svc, tmp, &qmi->services, list_node) {
    713		list_del(&svc->list_node);
    714		kfree(svc);
    715	}
    716}
    717EXPORT_SYMBOL(qmi_handle_release);
    718
    719/**
    720 * qmi_send_message() - send a QMI message
    721 * @qmi:	QMI client handle
    722 * @sq:		destination sockaddr
    723 * @txn:	transaction object to use for the message
    724 * @type:	type of message to send
    725 * @msg_id:	message id
    726 * @len:	max length of the QMI message
    727 * @ei:		QMI message description
    728 * @c_struct:	object to be encoded
    729 *
    730 * This function encodes @c_struct using @ei into a message of type @type,
    731 * with @msg_id and @txn into a buffer of maximum size @len, and sends this to
    732 * @sq.
    733 *
    734 * Return: 0 on success, negative errno on failure.
    735 */
    736static ssize_t qmi_send_message(struct qmi_handle *qmi,
    737				struct sockaddr_qrtr *sq, struct qmi_txn *txn,
    738				int type, int msg_id, size_t len,
    739				struct qmi_elem_info *ei, const void *c_struct)
    740{
    741	struct msghdr msghdr = {};
    742	struct kvec iv;
    743	void *msg;
    744	int ret;
    745
    746	msg = qmi_encode_message(type,
    747				 msg_id, &len,
    748				 txn->id, ei,
    749				 c_struct);
    750	if (IS_ERR(msg))
    751		return PTR_ERR(msg);
    752
    753	iv.iov_base = msg;
    754	iv.iov_len = len;
    755
    756	if (sq) {
    757		msghdr.msg_name = sq;
    758		msghdr.msg_namelen = sizeof(*sq);
    759	}
    760
    761	mutex_lock(&qmi->sock_lock);
    762	if (qmi->sock) {
    763		ret = kernel_sendmsg(qmi->sock, &msghdr, &iv, 1, len);
    764		if (ret < 0)
    765			pr_err("failed to send QMI message\n");
    766	} else {
    767		ret = -EPIPE;
    768	}
    769	mutex_unlock(&qmi->sock_lock);
    770
    771	kfree(msg);
    772
    773	return ret < 0 ? ret : 0;
    774}
    775
    776/**
    777 * qmi_send_request() - send a request QMI message
    778 * @qmi:	QMI client handle
    779 * @sq:		destination sockaddr
    780 * @txn:	transaction object to use for the message
    781 * @msg_id:	message id
    782 * @len:	max length of the QMI message
    783 * @ei:		QMI message description
    784 * @c_struct:	object to be encoded
    785 *
    786 * Return: 0 on success, negative errno on failure.
    787 */
    788ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
    789			 struct qmi_txn *txn, int msg_id, size_t len,
    790			 struct qmi_elem_info *ei, const void *c_struct)
    791{
    792	return qmi_send_message(qmi, sq, txn, QMI_REQUEST, msg_id, len, ei,
    793				c_struct);
    794}
    795EXPORT_SYMBOL(qmi_send_request);
    796
    797/**
    798 * qmi_send_response() - send a response QMI message
    799 * @qmi:	QMI client handle
    800 * @sq:		destination sockaddr
    801 * @txn:	transaction object to use for the message
    802 * @msg_id:	message id
    803 * @len:	max length of the QMI message
    804 * @ei:		QMI message description
    805 * @c_struct:	object to be encoded
    806 *
    807 * Return: 0 on success, negative errno on failure.
    808 */
    809ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
    810			  struct qmi_txn *txn, int msg_id, size_t len,
    811			  struct qmi_elem_info *ei, const void *c_struct)
    812{
    813	return qmi_send_message(qmi, sq, txn, QMI_RESPONSE, msg_id, len, ei,
    814				c_struct);
    815}
    816EXPORT_SYMBOL(qmi_send_response);
    817
    818/**
    819 * qmi_send_indication() - send an indication QMI message
    820 * @qmi:	QMI client handle
    821 * @sq:		destination sockaddr
    822 * @msg_id:	message id
    823 * @len:	max length of the QMI message
    824 * @ei:		QMI message description
    825 * @c_struct:	object to be encoded
    826 *
    827 * Return: 0 on success, negative errno on failure.
    828 */
    829ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
    830			    int msg_id, size_t len, struct qmi_elem_info *ei,
    831			    const void *c_struct)
    832{
    833	struct qmi_txn txn;
    834	ssize_t rval;
    835	int ret;
    836
    837	ret = qmi_txn_init(qmi, &txn, NULL, NULL);
    838	if (ret < 0)
    839		return ret;
    840
    841	rval = qmi_send_message(qmi, sq, &txn, QMI_INDICATION, msg_id, len, ei,
    842				c_struct);
    843
    844	/* We don't care about future messages on this txn */
    845	qmi_txn_cancel(&txn);
    846
    847	return rval;
    848}
    849EXPORT_SYMBOL(qmi_send_indication);