net/qrtr/ns.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright (c) 2015, Sony Mobile Communications Inc.
   4  * Copyright (c) 2013, The Linux Foundation. All rights reserved.
   5  * Copyright (c) 2020, Linaro Ltd.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/qrtr.h>
  10 #include <linux/workqueue.h>
  11 #include <net/sock.h>
  12
  13 #include "qrtr.h"
  14
  15 #include <trace/events/sock.h>
  16 #define CREATE_TRACE_POINTS
  17 #include <trace/events/qrtr.h>
  18
  19 static DEFINE_XARRAY(nodes);
  20
  21 static struct {
  22         struct socket *sock;
  23         struct sockaddr_qrtr bcast_sq;
  24         struct list_head lookups;
  25         struct workqueue_struct *workqueue;
  26         struct work_struct work;
  27         int local_node;
  28 } qrtr_ns;
  29
  30 static const char * const qrtr_ctrl_pkt_strings[] = {
  31         [QRTR_TYPE_HELLO]       = "hello",
  32         [QRTR_TYPE_BYE]         = "bye",
  33         [QRTR_TYPE_NEW_SERVER]  = "new-server",
  34         [QRTR_TYPE_DEL_SERVER]  = "del-server",
  35         [QRTR_TYPE_DEL_CLIENT]  = "del-client",
  36         [QRTR_TYPE_RESUME_TX]   = "resume-tx",
  37         [QRTR_TYPE_EXIT]        = "exit",
  38         [QRTR_TYPE_PING]        = "ping",
  39         [QRTR_TYPE_NEW_LOOKUP]  = "new-lookup",
  40         [QRTR_TYPE_DEL_LOOKUP]  = "del-lookup",
  41 };
  42
  43 struct qrtr_server_filter {
  44         unsigned int service;
  45         unsigned int instance;
  46         unsigned int ifilter;
  47 };
  48
  49 struct qrtr_lookup {
  50         unsigned int service;
  51         unsigned int instance;
  52
  53         struct sockaddr_qrtr sq;
  54         struct list_head li;
  55 };
  56
  57 struct qrtr_server {
  58         unsigned int service;
  59         unsigned int instance;
  60
  61         unsigned int node;
  62         unsigned int port;
  63
  64         struct list_head qli;
  65 };
  66
  67 struct qrtr_node {
  68         unsigned int id;
  69         struct xarray servers;
  70 };
  71
  72 static struct qrtr_node *node_get(unsigned int node_id)
  73 {
  74         struct qrtr_node *node;
  75
  76         node = xa_load(&nodes, node_id);
  77         if (node)
  78                 return node;
  79
  80         /* If node didn't exist, allocate and insert it to the tree */
  81         node = kzalloc(sizeof(*node), GFP_KERNEL);
  82         if (!node)
  83                 return NULL;
  84
  85         node->id = node_id;
  86         xa_init(&node->servers);
  87
  88         if (xa_store(&nodes, node_id, node, GFP_KERNEL)) {
  89                 kfree(node);
  90                 return NULL;
  91         }
  92
  93         return node;
  94 }
  95
  96 static int server_match(const struct qrtr_server *srv,
  97                         const struct qrtr_server_filter *f)
  98 {
  99         unsigned int ifilter = f->ifilter;
 100
 101         if (f->service != 0 && srv->service != f->service)
 102                 return 0;
 103         if (!ifilter && f->instance)
 104                 ifilter = ~0;
 105
 106         return (srv->instance & ifilter) == f->instance;
 107 }
 108
 109 static int service_announce_new(struct sockaddr_qrtr *dest,
 110                                 struct qrtr_server *srv)
 111 {
 112         struct qrtr_ctrl_pkt pkt;
 113         struct msghdr msg = { };
 114         struct kvec iv;
 115
 116         trace_qrtr_ns_service_announce_new(srv->service, srv->instance,
 117                                            srv->node, srv->port);
 118
 119         iv.iov_base = &pkt;
 120         iv.iov_len = sizeof(pkt);
 121
 122         memset(&pkt, 0, sizeof(pkt));
 123         pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_SERVER);
 124         pkt.server.service = cpu_to_le32(srv->service);
 125         pkt.server.instance = cpu_to_le32(srv->instance);
 126         pkt.server.node = cpu_to_le32(srv->node);
 127         pkt.server.port = cpu_to_le32(srv->port);
 128
 129         msg.msg_name = (struct sockaddr *)dest;
 130         msg.msg_namelen = sizeof(*dest);
 131
 132         return kernel_sendmsg(qrtr_ns.sock, &msg, &iv, 1, sizeof(pkt));
 133 }
 134
 135 static void service_announce_del(struct sockaddr_qrtr *dest,
 136                                  struct qrtr_server *srv)
 137 {
 138         struct qrtr_ctrl_pkt pkt;
 139         struct msghdr msg = { };
 140         struct kvec iv;
 141         int ret;
 142
 143         trace_qrtr_ns_service_announce_del(srv->service, srv->instance,
 144                                            srv->node, srv->port);
 145
 146         iv.iov_base = &pkt;
 147         iv.iov_len = sizeof(pkt);
 148
 149         memset(&pkt, 0, sizeof(pkt));
 150         pkt.cmd = cpu_to_le32(QRTR_TYPE_DEL_SERVER);
 151         pkt.server.service = cpu_to_le32(srv->service);
 152         pkt.server.instance = cpu_to_le32(srv->instance);
 153         pkt.server.node = cpu_to_le32(srv->node);
 154         pkt.server.port = cpu_to_le32(srv->port);
 155
 156         msg.msg_name = (struct sockaddr *)dest;
 157         msg.msg_namelen = sizeof(*dest);
 158
 159         ret = kernel_sendmsg(qrtr_ns.sock, &msg, &iv, 1, sizeof(pkt));
 160         if (ret < 0 && ret != -ENODEV)
 161                 pr_err("failed to announce del service\n");
 162
 163         return;
 164 }
 165
 166 static void lookup_notify(struct sockaddr_qrtr *to, struct qrtr_server *srv,
 167                           bool new)
 168 {
 169         struct qrtr_ctrl_pkt pkt;
 170         struct msghdr msg = { };
 171         struct kvec iv;
 172         int ret;
 173
 174         iv.iov_base = &pkt;
 175         iv.iov_len = sizeof(pkt);
 176
 177         memset(&pkt, 0, sizeof(pkt));
 178         pkt.cmd = new ? cpu_to_le32(QRTR_TYPE_NEW_SERVER) :
 179                         cpu_to_le32(QRTR_TYPE_DEL_SERVER);
 180         if (srv) {
 181                 pkt.server.service = cpu_to_le32(srv->service);
 182                 pkt.server.instance = cpu_to_le32(srv->instance);
 183                 pkt.server.node = cpu_to_le32(srv->node);
 184                 pkt.server.port = cpu_to_le32(srv->port);
 185         }
 186
 187         msg.msg_name = (struct sockaddr *)to;
 188         msg.msg_namelen = sizeof(*to);
 189
 190         ret = kernel_sendmsg(qrtr_ns.sock, &msg, &iv, 1, sizeof(pkt));
 191         if (ret < 0 && ret != -ENODEV)
 192                 pr_err("failed to send lookup notification\n");
 193 }
 194
 195 static int announce_servers(struct sockaddr_qrtr *sq)
 196 {
 197         struct qrtr_server *srv;
 198         struct qrtr_node *node;
 199         unsigned long index;
 200         int ret;
 201
 202         node = node_get(qrtr_ns.local_node);
 203         if (!node)
 204                 return 0;
 205
 206         /* Announce the list of servers registered in this node */
 207         xa_for_each(&node->servers, index, srv) {
 208                 ret = service_announce_new(sq, srv);
 209                 if (ret < 0) {
 210                         if (ret == -ENODEV)
 211                                 continue;
 212
 213                         pr_err("failed to announce new service\n");
 214                         return ret;
 215                 }
 216         }
 217         return 0;
 218 }
 219
 220 static struct qrtr_server *server_add(unsigned int service,
 221                                       unsigned int instance,
 222                                       unsigned int node_id,
 223                                       unsigned int port)
 224 {
 225         struct qrtr_server *srv;
 226         struct qrtr_server *old;
 227         struct qrtr_node *node;
 228
 229         if (!service || !port)
 230                 return NULL;
 231
 232         srv = kzalloc(sizeof(*srv), GFP_KERNEL);
 233         if (!srv)
 234                 return NULL;
 235
 236         srv->service = service;
 237         srv->instance = instance;
 238         srv->node = node_id;
 239         srv->port = port;
 240
 241         node = node_get(node_id);
 242         if (!node)
 243                 goto err;
 244
 245         /* Delete the old server on the same port */
 246         old = xa_store(&node->servers, port, srv, GFP_KERNEL);
 247         if (old) {
 248                 if (xa_is_err(old)) {
 249                         pr_err("failed to add server [0x%x:0x%x] ret:%d\n",
 250                                srv->service, srv->instance, xa_err(old));
 251                         goto err;
 252                 } else {
 253                         kfree(old);
 254                 }
 255         }
 256
 257         trace_qrtr_ns_server_add(srv->service, srv->instance,
 258                                  srv->node, srv->port);
 259
 260         return srv;
 261
 262 err:
 263         kfree(srv);
 264         return NULL;
 265 }
 266
 267 static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
 268 {
 269         struct qrtr_lookup *lookup;
 270         struct qrtr_server *srv;
 271         struct list_head *li;
 272
 273         srv = xa_load(&node->servers, port);
 274         if (!srv)
 275                 return -ENOENT;
 276
 277         xa_erase(&node->servers, port);
 278
 279         /* Broadcast the removal of local servers */
 280         if (srv->node == qrtr_ns.local_node && bcast)
 281                 service_announce_del(&qrtr_ns.bcast_sq, srv);
 282
 283         /* Announce the service's disappearance to observers */
 284         list_for_each(li, &qrtr_ns.lookups) {
 285                 lookup = container_of(li, struct qrtr_lookup, li);
 286                 if (lookup->service && lookup->service != srv->service)
 287                         continue;
 288                 if (lookup->instance && lookup->instance != srv->instance)
 289                         continue;
 290
 291                 lookup_notify(&lookup->sq, srv, false);
 292         }
 293
 294         kfree(srv);
 295
 296         return 0;
 297 }
 298
 299 static int say_hello(struct sockaddr_qrtr *dest)
 300 {
 301         struct qrtr_ctrl_pkt pkt;
 302         struct msghdr msg = { };
 303         struct kvec iv;
 304         int ret;
 305
 306         iv.iov_base = &pkt;
 307         iv.iov_len = sizeof(pkt);
 308
 309         memset(&pkt, 0, sizeof(pkt));
 310         pkt.cmd = cpu_to_le32(QRTR_TYPE_HELLO);
 311
 312         msg.msg_name = (struct sockaddr *)dest;
 313         msg.msg_namelen = sizeof(*dest);
 314
 315         ret = kernel_sendmsg(qrtr_ns.sock, &msg, &iv, 1, sizeof(pkt));
 316         if (ret < 0)
 317                 pr_err("failed to send hello msg\n");
 318
 319         return ret;
 320 }
 321
 322 /* Announce the list of servers registered on the local node */
 323 static int ctrl_cmd_hello(struct sockaddr_qrtr *sq)
 324 {
 325         int ret;
 326
 327         ret = say_hello(sq);
 328         if (ret < 0)
 329                 return ret;
 330
 331         return announce_servers(sq);
 332 }
 333
 334 static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
 335 {
 336         struct qrtr_node *local_node;
 337         struct qrtr_ctrl_pkt pkt;
 338         struct qrtr_server *srv;
 339         struct sockaddr_qrtr sq;
 340         struct msghdr msg = { };
 341         struct qrtr_node *node;
 342         unsigned long index;
 343         struct kvec iv;
 344         int ret;
 345
 346         iv.iov_base = &pkt;
 347         iv.iov_len = sizeof(pkt);
 348
 349         node = node_get(from->sq_node);
 350         if (!node)
 351                 return 0;
 352
 353         /* Advertise removal of this client to all servers of remote node */
 354         xa_for_each(&node->servers, index, srv)
 355                 server_del(node, srv->port, true);
 356
 357         /* Advertise the removal of this client to all local servers */
 358         local_node = node_get(qrtr_ns.local_node);
 359         if (!local_node)
 360                 return 0;
 361
 362         memset(&pkt, 0, sizeof(pkt));
 363         pkt.cmd = cpu_to_le32(QRTR_TYPE_BYE);
 364         pkt.client.node = cpu_to_le32(from->sq_node);
 365
 366         xa_for_each(&local_node->servers, index, srv) {
 367                 sq.sq_family = AF_QIPCRTR;
 368                 sq.sq_node = srv->node;
 369                 sq.sq_port = srv->port;
 370
 371                 msg.msg_name = (struct sockaddr *)&sq;
 372                 msg.msg_namelen = sizeof(sq);
 373
 374                 ret = kernel_sendmsg(qrtr_ns.sock, &msg, &iv, 1, sizeof(pkt));
 375                 if (ret < 0 && ret != -ENODEV) {
 376                         pr_err("failed to send bye cmd\n");
 377                         return ret;
 378                 }
 379         }
 380         return 0;
 381 }
 382
 383 static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
 384                                unsigned int node_id, unsigned int port)
 385 {
 386         struct qrtr_node *local_node;
 387         struct qrtr_lookup *lookup;
 388         struct qrtr_ctrl_pkt pkt;
 389         struct msghdr msg = { };
 390         struct qrtr_server *srv;
 391         struct sockaddr_qrtr sq;
 392         struct qrtr_node *node;
 393         struct list_head *tmp;
 394         struct list_head *li;
 395         unsigned long index;
 396         struct kvec iv;
 397         int ret;
 398
 399         iv.iov_base = &pkt;
 400         iv.iov_len = sizeof(pkt);
 401
 402         /* Don't accept spoofed messages */
 403         if (from->sq_node != node_id)
 404                 return -EINVAL;
 405
 406         /* Local DEL_CLIENT messages comes from the port being closed */
 407         if (from->sq_node == qrtr_ns.local_node && from->sq_port != port)
 408                 return -EINVAL;
 409
 410         /* Remove any lookups by this client */
 411         list_for_each_safe(li, tmp, &qrtr_ns.lookups) {
 412                 lookup = container_of(li, struct qrtr_lookup, li);
 413                 if (lookup->sq.sq_node != node_id)
 414                         continue;
 415                 if (lookup->sq.sq_port != port)
 416                         continue;
 417
 418                 list_del(&lookup->li);
 419                 kfree(lookup);
 420         }
 421
 422         /* Remove the server belonging to this port but don't broadcast
 423          * DEL_SERVER. Neighbours would've already removed the server belonging
 424          * to this port due to the DEL_CLIENT broadcast from qrtr_port_remove().
 425          */
 426         node = node_get(node_id);
 427         if (node)
 428                 server_del(node, port, false);
 429
 430         /* Advertise the removal of this client to all local servers */
 431         local_node = node_get(qrtr_ns.local_node);
 432         if (!local_node)
 433                 return 0;
 434
 435         memset(&pkt, 0, sizeof(pkt));
 436         pkt.cmd = cpu_to_le32(QRTR_TYPE_DEL_CLIENT);
 437         pkt.client.node = cpu_to_le32(node_id);
 438         pkt.client.port = cpu_to_le32(port);
 439
 440         xa_for_each(&local_node->servers, index, srv) {
 441                 sq.sq_family = AF_QIPCRTR;
 442                 sq.sq_node = srv->node;
 443                 sq.sq_port = srv->port;
 444
 445                 msg.msg_name = (struct sockaddr *)&sq;
 446                 msg.msg_namelen = sizeof(sq);
 447
 448                 ret = kernel_sendmsg(qrtr_ns.sock, &msg, &iv, 1, sizeof(pkt));
 449                 if (ret < 0 && ret != -ENODEV) {
 450                         pr_err("failed to send del client cmd\n");
 451                         return ret;
 452                 }
 453         }
 454         return 0;
 455 }
 456
 457 static int ctrl_cmd_new_server(struct sockaddr_qrtr *from,
 458                                unsigned int service, unsigned int instance,
 459                                unsigned int node_id, unsigned int port)
 460 {
 461         struct qrtr_lookup *lookup;
 462         struct qrtr_server *srv;
 463         struct list_head *li;
 464         int ret = 0;
 465
 466         /* Ignore specified node and port for local servers */
 467         if (from->sq_node == qrtr_ns.local_node) {
 468                 node_id = from->sq_node;
 469                 port = from->sq_port;
 470         }
 471
 472         srv = server_add(service, instance, node_id, port);
 473         if (!srv)
 474                 return -EINVAL;
 475
 476         if (srv->node == qrtr_ns.local_node) {
 477                 ret = service_announce_new(&qrtr_ns.bcast_sq, srv);
 478                 if (ret < 0) {
 479                         pr_err("failed to announce new service\n");
 480                         return ret;
 481                 }
 482         }
 483
 484         /* Notify any potential lookups about the new server */
 485         list_for_each(li, &qrtr_ns.lookups) {
 486                 lookup = container_of(li, struct qrtr_lookup, li);
 487                 if (lookup->service && lookup->service != service)
 488                         continue;
 489                 if (lookup->instance && lookup->instance != instance)
 490                         continue;
 491
 492                 lookup_notify(&lookup->sq, srv, true);
 493         }
 494
 495         return ret;
 496 }
 497
 498 static int ctrl_cmd_del_server(struct sockaddr_qrtr *from,
 499                                unsigned int service, unsigned int instance,
 500                                unsigned int node_id, unsigned int port)
 501 {
 502         struct qrtr_node *node;
 503
 504         /* Ignore specified node and port for local servers*/
 505         if (from->sq_node == qrtr_ns.local_node) {
 506                 node_id = from->sq_node;
 507                 port = from->sq_port;
 508         }
 509
 510         /* Local servers may only unregister themselves */
 511         if (from->sq_node == qrtr_ns.local_node && from->sq_port != port)
 512                 return -EINVAL;
 513
 514         node = node_get(node_id);
 515         if (!node)
 516                 return -ENOENT;
 517
 518         server_del(node, port, true);
 519
 520         return 0;
 521 }
 522
 523 static int ctrl_cmd_new_lookup(struct sockaddr_qrtr *from,
 524                                unsigned int service, unsigned int instance)
 525 {
 526         struct qrtr_server_filter filter;
 527         struct qrtr_lookup *lookup;
 528         struct qrtr_server *srv;
 529         struct qrtr_node *node;
 530         unsigned long node_idx;
 531         unsigned long srv_idx;
 532
 533         /* Accept only local observers */
 534         if (from->sq_node != qrtr_ns.local_node)
 535                 return -EINVAL;
 536
 537         lookup = kzalloc(sizeof(*lookup), GFP_KERNEL);
 538         if (!lookup)
 539                 return -ENOMEM;
 540
 541         lookup->sq = *from;
 542         lookup->service = service;
 543         lookup->instance = instance;
 544         list_add_tail(&lookup->li, &qrtr_ns.lookups);
 545
 546         memset(&filter, 0, sizeof(filter));
 547         filter.service = service;
 548         filter.instance = instance;
 549
 550         xa_for_each(&nodes, node_idx, node) {
 551                 xa_for_each(&node->servers, srv_idx, srv) {
 552                         if (!server_match(srv, &filter))
 553                                 continue;
 554
 555                         lookup_notify(from, srv, true);
 556                 }
 557         }
 558
 559         /* Empty notification, to indicate end of listing */
 560         lookup_notify(from, NULL, true);
 561
 562         return 0;
 563 }
 564
 565 static void ctrl_cmd_del_lookup(struct sockaddr_qrtr *from,
 566                                 unsigned int service, unsigned int instance)
 567 {
 568         struct qrtr_lookup *lookup;
 569         struct list_head *tmp;
 570         struct list_head *li;
 571
 572         list_for_each_safe(li, tmp, &qrtr_ns.lookups) {
 573                 lookup = container_of(li, struct qrtr_lookup, li);
 574                 if (lookup->sq.sq_node != from->sq_node)
 575                         continue;
 576                 if (lookup->sq.sq_port != from->sq_port)
 577                         continue;
 578                 if (lookup->service != service)
 579                         continue;
 580                 if (lookup->instance && lookup->instance != instance)
 581                         continue;
 582
 583                 list_del(&lookup->li);
 584                 kfree(lookup);
 585         }
 586 }
 587
 588 static void qrtr_ns_worker(struct work_struct *work)
 589 {
 590         const struct qrtr_ctrl_pkt *pkt;
 591         size_t recv_buf_size = 4096;
 592         struct sockaddr_qrtr sq;
 593         struct msghdr msg = { };
 594         unsigned int cmd;
 595         ssize_t msglen;
 596         void *recv_buf;
 597         struct kvec iv;
 598         int ret;
 599
 600         msg.msg_name = (struct sockaddr *)&sq;
 601         msg.msg_namelen = sizeof(sq);
 602
 603         recv_buf = kzalloc(recv_buf_size, GFP_KERNEL);
 604         if (!recv_buf)
 605                 return;
 606
 607         for (;;) {
 608                 iv.iov_base = recv_buf;
 609                 iv.iov_len = recv_buf_size;
 610
 611                 msglen = kernel_recvmsg(qrtr_ns.sock, &msg, &iv, 1,
 612                                         iv.iov_len, MSG_DONTWAIT);
 613
 614                 if (msglen == -EAGAIN)
 615                         break;
 616
 617                 if (msglen < 0) {
 618                         pr_err("error receiving packet: %zd\n", msglen);
 619                         break;
 620                 }
 621
 622                 pkt = recv_buf;
 623                 cmd = le32_to_cpu(pkt->cmd);
 624                 if (cmd < ARRAY_SIZE(qrtr_ctrl_pkt_strings) &&
 625                     qrtr_ctrl_pkt_strings[cmd])
 626                         trace_qrtr_ns_message(qrtr_ctrl_pkt_strings[cmd],
 627                                               sq.sq_node, sq.sq_port);
 628
 629                 ret = 0;
 630                 switch (cmd) {
 631                 case QRTR_TYPE_HELLO:
 632                         ret = ctrl_cmd_hello(&sq);
 633                         break;
 634                 case QRTR_TYPE_BYE:
 635                         ret = ctrl_cmd_bye(&sq);
 636                         break;
 637                 case QRTR_TYPE_DEL_CLIENT:
 638                         ret = ctrl_cmd_del_client(&sq,
 639                                         le32_to_cpu(pkt->client.node),
 640                                         le32_to_cpu(pkt->client.port));
 641                         break;
 642                 case QRTR_TYPE_NEW_SERVER:
 643                         ret = ctrl_cmd_new_server(&sq,
 644                                         le32_to_cpu(pkt->server.service),
 645                                         le32_to_cpu(pkt->server.instance),
 646                                         le32_to_cpu(pkt->server.node),
 647                                         le32_to_cpu(pkt->server.port));
 648                         break;
 649                 case QRTR_TYPE_DEL_SERVER:
 650                         ret = ctrl_cmd_del_server(&sq,
 651                                          le32_to_cpu(pkt->server.service),
 652                                          le32_to_cpu(pkt->server.instance),
 653                                          le32_to_cpu(pkt->server.node),
 654                                          le32_to_cpu(pkt->server.port));
 655                         break;
 656                 case QRTR_TYPE_EXIT:
 657                 case QRTR_TYPE_PING:
 658                 case QRTR_TYPE_RESUME_TX:
 659                         break;
 660                 case QRTR_TYPE_NEW_LOOKUP:
 661                         ret = ctrl_cmd_new_lookup(&sq,
 662                                          le32_to_cpu(pkt->server.service),
 663                                          le32_to_cpu(pkt->server.instance));
 664                         break;
 665                 case QRTR_TYPE_DEL_LOOKUP:
 666                         ctrl_cmd_del_lookup(&sq,
 667                                     le32_to_cpu(pkt->server.service),
 668                                     le32_to_cpu(pkt->server.instance));
 669                         break;
 670                 }
 671
 672                 if (ret < 0)
 673                         pr_err("failed while handling packet from %d:%d",
 674                                sq.sq_node, sq.sq_port);
 675         }
 676
 677         kfree(recv_buf);
 678 }
 679
 680 static void qrtr_ns_data_ready(struct sock *sk)
 681 {
 682         trace_sk_data_ready(sk);
 683
 684         queue_work(qrtr_ns.workqueue, &qrtr_ns.work);
 685 }
 686
 687 int qrtr_ns_init(void)
 688 {
 689         struct sockaddr_qrtr sq;
 690         int ret;
 691
 692         INIT_LIST_HEAD(&qrtr_ns.lookups);
 693         INIT_WORK(&qrtr_ns.work, qrtr_ns_worker);
 694
 695         ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
 696                                PF_QIPCRTR, &qrtr_ns.sock);
 697         if (ret < 0)
 698                 return ret;
 699
 700         ret = kernel_getsockname(qrtr_ns.sock, (struct sockaddr *)&sq);
 701         if (ret < 0) {
 702                 pr_err("failed to get socket name\n");
 703                 goto err_sock;
 704         }
 705
 706         qrtr_ns.workqueue = alloc_ordered_workqueue("qrtr_ns_handler", 0);
 707         if (!qrtr_ns.workqueue) {
 708                 ret = -ENOMEM;
 709                 goto err_sock;
 710         }
 711
 712         qrtr_ns.sock->sk->sk_data_ready = qrtr_ns_data_ready;
 713
 714         sq.sq_port = QRTR_PORT_CTRL;
 715         qrtr_ns.local_node = sq.sq_node;
 716
 717         ret = kernel_bind(qrtr_ns.sock, (struct sockaddr *)&sq, sizeof(sq));
 718         if (ret < 0) {
 719                 pr_err("failed to bind to socket\n");
 720                 goto err_wq;
 721         }
 722
 723         qrtr_ns.bcast_sq.sq_family = AF_QIPCRTR;
 724         qrtr_ns.bcast_sq.sq_node = QRTR_NODE_BCAST;
 725         qrtr_ns.bcast_sq.sq_port = QRTR_PORT_CTRL;
 726
 727         ret = say_hello(&qrtr_ns.bcast_sq);
 728         if (ret < 0)
 729                 goto err_wq;
 730
 731         /* As the qrtr ns socket owner and creator is the same module, we have
 732          * to decrease the qrtr module reference count to guarantee that it
 733          * remains zero after the ns socket is created, otherwise, executing
 734          * "rmmod" command is unable to make the qrtr module deleted after the
 735          *  qrtr module is inserted successfully.
 736          *
 737          * However, the reference count is increased twice in
 738          * sock_create_kern(): one is to increase the reference count of owner
 739          * of qrtr socket's proto_ops struct; another is to increment the
 740          * reference count of owner of qrtr proto struct. Therefore, we must
 741          * decrement the module reference count twice to ensure that it keeps
 742          * zero after server's listening socket is created. Of course, we
 743          * must bump the module reference count twice as well before the socket
 744          * is closed.
 745          */
 746         module_put(qrtr_ns.sock->ops->owner);
 747         module_put(qrtr_ns.sock->sk->sk_prot_creator->owner);
 748
 749         return 0;
 750
 751 err_wq:
 752         destroy_workqueue(qrtr_ns.workqueue);
 753 err_sock:
 754         sock_release(qrtr_ns.sock);
 755         return ret;
 756 }
 757 EXPORT_SYMBOL_GPL(qrtr_ns_init);
 758
 759 void qrtr_ns_remove(void)
 760 {
 761         cancel_work_sync(&qrtr_ns.work);
 762         destroy_workqueue(qrtr_ns.workqueue);
 763
 764         /* sock_release() expects the two references that were put during
 765          * qrtr_ns_init(). This function is only called during module remove,
 766          * so try_stop_module() has already set the refcnt to 0. Use
 767          * __module_get() instead of try_module_get() to successfully take two
 768          * references.
 769          */
 770         __module_get(qrtr_ns.sock->ops->owner);
 771         __module_get(qrtr_ns.sock->sk->sk_prot_creator->owner);
 772         sock_release(qrtr_ns.sock);
 773 }
 774 EXPORT_SYMBOL_GPL(qrtr_ns_remove);
 775
 776 MODULE_AUTHOR("Manivannan Sadhasivam <[email protected]>");
 777 MODULE_DESCRIPTION("Qualcomm IPC Router Nameservice");
 778 MODULE_LICENSE("Dual BSD/GPL");