1 // SPDX-License-Identifier: GPL-2.0 2 /* net/atm/svc.c - ATM SVC sockets */ 3 4 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */ 5 6 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ 7 8 #include <linux/string.h> 9 #include <linux/net.h> /* struct socket, struct proto_ops */ 10 #include <linux/errno.h> /* error codes */ 11 #include <linux/kernel.h> /* printk */ 12 #include <linux/skbuff.h> 13 #include <linux/wait.h> 14 #include <linux/sched/signal.h> 15 #include <linux/fcntl.h> /* O_NONBLOCK */ 16 #include <linux/init.h> 17 #include <linux/atm.h> /* ATM stuff */ 18 #include <linux/atmsap.h> 19 #include <linux/atmsvc.h> 20 #include <linux/atmdev.h> 21 #include <linux/bitops.h> 22 #include <net/sock.h> /* for sock_no_* */ 23 #include <linux/uaccess.h> 24 #include <linux/export.h> 25 26 #include "resources.h" 27 #include "common.h" /* common for PVCs and SVCs */ 28 #include "signaling.h" 29 #include "addr.h" 30 31 static int svc_create(struct net *net, struct socket *sock, int protocol, 32 int kern); 33 34 /* 35 * Note: since all this is still nicely synchronized with the signaling demon, 36 * there's no need to protect sleep loops with clis. If signaling is 37 * moved into the kernel, that would change. 38 */ 39 40 41 static int svc_shutdown(struct socket *sock, int how) 42 { 43 return 0; 44 } 45 46 static void svc_disconnect(struct atm_vcc *vcc) 47 { 48 DEFINE_WAIT(wait); 49 struct sk_buff *skb; 50 struct sock *sk = sk_atm(vcc); 51 52 pr_debug("%p\n", vcc); 53 if (test_bit(ATM_VF_REGIS, &vcc->flags)) { 54 sigd_enq(vcc, as_close, NULL, NULL, NULL); 55 for (;;) { 56 prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE); 57 if (test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd) 58 break; 59 schedule(); 60 } 61 finish_wait(sk_sleep(sk), &wait); 62 } 63 /* beware - socket is still in use by atmsigd until the last 64 as_indicate has been answered */ 65 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { 66 atm_return(vcc, skb->truesize); 67 pr_debug("LISTEN REL\n"); 68 sigd_enq2(NULL, as_reject, vcc, NULL, NULL, &vcc->qos, 0); 69 dev_kfree_skb(skb); 70 } 71 clear_bit(ATM_VF_REGIS, &vcc->flags); 72 /* ... may retry later */ 73 } 74 75 static int svc_release(struct socket *sock) 76 { 77 struct sock *sk = sock->sk; 78 struct atm_vcc *vcc; 79 80 if (sk) { 81 vcc = ATM_SD(sock); 82 pr_debug("%p\n", vcc); 83 clear_bit(ATM_VF_READY, &vcc->flags); 84 /* 85 * VCC pointer is used as a reference, 86 * so we must not free it (thereby subjecting it to re-use) 87 * before all pending connections are closed 88 */ 89 svc_disconnect(vcc); 90 vcc_release(sock); 91 } 92 return 0; 93 } 94 95 static int svc_bind(struct socket *sock, struct sockaddr *sockaddr, 96 int sockaddr_len) 97 { 98 DEFINE_WAIT(wait); 99 struct sock *sk = sock->sk; 100 struct sockaddr_atmsvc *addr; 101 struct atm_vcc *vcc; 102 int error; 103 104 if (sockaddr_len != sizeof(struct sockaddr_atmsvc)) 105 return -EINVAL; 106 lock_sock(sk); 107 if (sock->state == SS_CONNECTED) { 108 error = -EISCONN; 109 goto out; 110 } 111 if (sock->state != SS_UNCONNECTED) { 112 error = -EINVAL; 113 goto out; 114 } 115 vcc = ATM_SD(sock); 116 addr = (struct sockaddr_atmsvc *) sockaddr; 117 if (addr->sas_family != AF_ATMSVC) { 118 error = -EAFNOSUPPORT; 119 goto out; 120 } 121 clear_bit(ATM_VF_BOUND, &vcc->flags); 122 /* failing rebind will kill old binding */ 123 /* @@@ check memory (de)allocation on rebind */ 124 if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) { 125 error = -EBADFD; 126 goto out; 127 } 128 vcc->local = *addr; 129 set_bit(ATM_VF_WAITING, &vcc->flags); 130 sigd_enq(vcc, as_bind, NULL, NULL, &vcc->local); 131 for (;;) { 132 prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE); 133 if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd) 134 break; 135 schedule(); 136 } 137 finish_wait(sk_sleep(sk), &wait); 138 clear_bit(ATM_VF_REGIS, &vcc->flags); /* doesn't count */ 139 if (!sigd) { 140 error = -EUNATCH; 141 goto out; 142 } 143 if (!sk->sk_err) 144 set_bit(ATM_VF_BOUND, &vcc->flags); 145 error = -sk->sk_err; 146 out: 147 release_sock(sk); 148 return error; 149 } 150 151 static int svc_connect(struct socket *sock, struct sockaddr *sockaddr, 152 int sockaddr_len, int flags) 153 { 154 DEFINE_WAIT(wait); 155 struct sock *sk = sock->sk; 156 struct sockaddr_atmsvc *addr; 157 struct atm_vcc *vcc = ATM_SD(sock); 158 int error; 159 160 pr_debug("%p\n", vcc); 161 lock_sock(sk); 162 if (sockaddr_len != sizeof(struct sockaddr_atmsvc)) { 163 error = -EINVAL; 164 goto out; 165 } 166 167 switch (sock->state) { 168 default: 169 error = -EINVAL; 170 goto out; 171 case SS_CONNECTED: 172 error = -EISCONN; 173 goto out; 174 case SS_CONNECTING: 175 if (test_bit(ATM_VF_WAITING, &vcc->flags)) { 176 error = -EALREADY; 177 goto out; 178 } 179 sock->state = SS_UNCONNECTED; 180 if (sk->sk_err) { 181 error = -sk->sk_err; 182 goto out; 183 } 184 break; 185 case SS_UNCONNECTED: 186 addr = (struct sockaddr_atmsvc *) sockaddr; 187 if (addr->sas_family != AF_ATMSVC) { 188 error = -EAFNOSUPPORT; 189 goto out; 190 } 191 if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) { 192 error = -EBADFD; 193 goto out; 194 } 195 if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS || 196 vcc->qos.rxtp.traffic_class == ATM_ANYCLASS) { 197 error = -EINVAL; 198 goto out; 199 } 200 if (!vcc->qos.txtp.traffic_class && 201 !vcc->qos.rxtp.traffic_class) { 202 error = -EINVAL; 203 goto out; 204 } 205 vcc->remote = *addr; 206 set_bit(ATM_VF_WAITING, &vcc->flags); 207 sigd_enq(vcc, as_connect, NULL, NULL, &vcc->remote); 208 if (flags & O_NONBLOCK) { 209 sock->state = SS_CONNECTING; 210 error = -EINPROGRESS; 211 goto out; 212 } 213 error = 0; 214 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 215 while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) { 216 schedule(); 217 if (!signal_pending(current)) { 218 prepare_to_wait(sk_sleep(sk), &wait, 219 TASK_INTERRUPTIBLE); 220 continue; 221 } 222 pr_debug("*ABORT*\n"); 223 /* 224 * This is tricky: 225 * Kernel ---close--> Demon 226 * Kernel <--close--- Demon 227 * or 228 * Kernel ---close--> Demon 229 * Kernel <--error--- Demon 230 * or 231 * Kernel ---close--> Demon 232 * Kernel <--okay---- Demon 233 * Kernel <--close--- Demon 234 */ 235 sigd_enq(vcc, as_close, NULL, NULL, NULL); 236 while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) { 237 prepare_to_wait(sk_sleep(sk), &wait, 238 TASK_INTERRUPTIBLE); 239 schedule(); 240 } 241 if (!sk->sk_err) 242 while (!test_bit(ATM_VF_RELEASED, &vcc->flags) && 243 sigd) { 244 prepare_to_wait(sk_sleep(sk), &wait, 245 TASK_INTERRUPTIBLE); 246 schedule(); 247 } 248 clear_bit(ATM_VF_REGIS, &vcc->flags); 249 clear_bit(ATM_VF_RELEASED, &vcc->flags); 250 clear_bit(ATM_VF_CLOSE, &vcc->flags); 251 /* we're gone now but may connect later */ 252 error = -EINTR; 253 break; 254 } 255 finish_wait(sk_sleep(sk), &wait); 256 if (error) 257 goto out; 258 if (!sigd) { 259 error = -EUNATCH; 260 goto out; 261 } 262 if (sk->sk_err) { 263 error = -sk->sk_err; 264 goto out; 265 } 266 } 267 268 vcc->qos.txtp.max_pcr = SELECT_TOP_PCR(vcc->qos.txtp); 269 vcc->qos.txtp.pcr = 0; 270 vcc->qos.txtp.min_pcr = 0; 271 272 error = vcc_connect(sock, vcc->itf, vcc->vpi, vcc->vci); 273 if (!error) 274 sock->state = SS_CONNECTED; 275 else 276 (void)svc_disconnect(vcc); 277 out: 278 release_sock(sk); 279 return error; 280 } 281 282 static int svc_listen(struct socket *sock, int backlog) 283 { 284 DEFINE_WAIT(wait); 285 struct sock *sk = sock->sk; 286 struct atm_vcc *vcc = ATM_SD(sock); 287 int error; 288 289 pr_debug("%p\n", vcc); 290 lock_sock(sk); 291 /* let server handle listen on unbound sockets */ 292 if (test_bit(ATM_VF_SESSION, &vcc->flags)) { 293 error = -EINVAL; 294 goto out; 295 } 296 if (test_bit(ATM_VF_LISTEN, &vcc->flags)) { 297 error = -EADDRINUSE; 298 goto out; 299 } 300 set_bit(ATM_VF_WAITING, &vcc->flags); 301 sigd_enq(vcc, as_listen, NULL, NULL, &vcc->local); 302 for (;;) { 303 prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE); 304 if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd) 305 break; 306 schedule(); 307 } 308 finish_wait(sk_sleep(sk), &wait); 309 if (!sigd) { 310 error = -EUNATCH; 311 goto out; 312 } 313 set_bit(ATM_VF_LISTEN, &vcc->flags); 314 vcc_insert_socket(sk); 315 sk->sk_max_ack_backlog = backlog > 0 ? backlog : ATM_BACKLOG_DEFAULT; 316 error = -sk->sk_err; 317 out: 318 release_sock(sk); 319 return error; 320 } 321 322 static int svc_accept(struct socket *sock, struct socket *newsock, int flags, 323 bool kern) 324 { 325 struct sock *sk = sock->sk; 326 struct sk_buff *skb; 327 struct atmsvc_msg *msg; 328 struct atm_vcc *old_vcc = ATM_SD(sock); 329 struct atm_vcc *new_vcc; 330 int error; 331 332 lock_sock(sk); 333 334 error = svc_create(sock_net(sk), newsock, 0, kern); 335 if (error) 336 goto out; 337 338 new_vcc = ATM_SD(newsock); 339 340 pr_debug("%p -> %p\n", old_vcc, new_vcc); 341 while (1) { 342 DEFINE_WAIT(wait); 343 344 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 345 while (!(skb = skb_dequeue(&sk->sk_receive_queue)) && 346 sigd) { 347 if (test_bit(ATM_VF_RELEASED, &old_vcc->flags)) 348 break; 349 if (test_bit(ATM_VF_CLOSE, &old_vcc->flags)) { 350 error = -sk->sk_err; 351 break; 352 } 353 if (flags & O_NONBLOCK) { 354 error = -EAGAIN; 355 break; 356 } 357 release_sock(sk); 358 schedule(); 359 lock_sock(sk); 360 if (signal_pending(current)) { 361 error = -ERESTARTSYS; 362 break; 363 } 364 prepare_to_wait(sk_sleep(sk), &wait, 365 TASK_INTERRUPTIBLE); 366 } 367 finish_wait(sk_sleep(sk), &wait); 368 if (error) 369 goto out; 370 if (!skb) { 371 error = -EUNATCH; 372 goto out; 373 } 374 msg = (struct atmsvc_msg *)skb->data; 375 new_vcc->qos = msg->qos; 376 set_bit(ATM_VF_HASQOS, &new_vcc->flags); 377 new_vcc->remote = msg->svc; 378 new_vcc->local = msg->local; 379 new_vcc->sap = msg->sap; 380 error = vcc_connect(newsock, msg->pvc.sap_addr.itf, 381 msg->pvc.sap_addr.vpi, 382 msg->pvc.sap_addr.vci); 383 dev_kfree_skb(skb); 384 sk->sk_ack_backlog--; 385 if (error) { 386 sigd_enq2(NULL, as_reject, old_vcc, NULL, NULL, 387 &old_vcc->qos, error); 388 error = error == -EAGAIN ? -EBUSY : error; 389 goto out; 390 } 391 /* wait should be short, so we ignore the non-blocking flag */ 392 set_bit(ATM_VF_WAITING, &new_vcc->flags); 393 sigd_enq(new_vcc, as_accept, old_vcc, NULL, NULL); 394 for (;;) { 395 prepare_to_wait(sk_sleep(sk_atm(new_vcc)), &wait, 396 TASK_UNINTERRUPTIBLE); 397 if (!test_bit(ATM_VF_WAITING, &new_vcc->flags) || !sigd) 398 break; 399 release_sock(sk); 400 schedule(); 401 lock_sock(sk); 402 } 403 finish_wait(sk_sleep(sk_atm(new_vcc)), &wait); 404 if (!sigd) { 405 error = -EUNATCH; 406 goto out; 407 } 408 if (!sk_atm(new_vcc)->sk_err) 409 break; 410 if (sk_atm(new_vcc)->sk_err != ERESTARTSYS) { 411 error = -sk_atm(new_vcc)->sk_err; 412 goto out; 413 } 414 } 415 newsock->state = SS_CONNECTED; 416 out: 417 release_sock(sk); 418 return error; 419 } 420 421 static int svc_getname(struct socket *sock, struct sockaddr *sockaddr, 422 int peer) 423 { 424 struct sockaddr_atmsvc *addr; 425 426 addr = (struct sockaddr_atmsvc *) sockaddr; 427 memcpy(addr, peer ? &ATM_SD(sock)->remote : &ATM_SD(sock)->local, 428 sizeof(struct sockaddr_atmsvc)); 429 return sizeof(struct sockaddr_atmsvc); 430 } 431 432 int svc_change_qos(struct atm_vcc *vcc, struct atm_qos *qos) 433 { 434 struct sock *sk = sk_atm(vcc); 435 DEFINE_WAIT(wait); 436 437 set_bit(ATM_VF_WAITING, &vcc->flags); 438 sigd_enq2(vcc, as_modify, NULL, NULL, &vcc->local, qos, 0); 439 for (;;) { 440 prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE); 441 if (!test_bit(ATM_VF_WAITING, &vcc->flags) || 442 test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd) { 443 break; 444 } 445 schedule(); 446 } 447 finish_wait(sk_sleep(sk), &wait); 448 if (!sigd) 449 return -EUNATCH; 450 return -sk->sk_err; 451 } 452 453 static int svc_setsockopt(struct socket *sock, int level, int optname, 454 char __user *optval, unsigned int optlen) 455 { 456 struct sock *sk = sock->sk; 457 struct atm_vcc *vcc = ATM_SD(sock); 458 int value, error = 0; 459 460 lock_sock(sk); 461 switch (optname) { 462 case SO_ATMSAP: 463 if (level != SOL_ATM || optlen != sizeof(struct atm_sap)) { 464 error = -EINVAL; 465 goto out; 466 } 467 if (copy_from_user(&vcc->sap, optval, optlen)) { 468 error = -EFAULT; 469 goto out; 470 } 471 set_bit(ATM_VF_HASSAP, &vcc->flags); 472 break; 473 case SO_MULTIPOINT: 474 if (level != SOL_ATM || optlen != sizeof(int)) { 475 error = -EINVAL; 476 goto out; 477 } 478 if (get_user(value, (int __user *)optval)) { 479 error = -EFAULT; 480 goto out; 481 } 482 if (value == 1) 483 set_bit(ATM_VF_SESSION, &vcc->flags); 484 else if (value == 0) 485 clear_bit(ATM_VF_SESSION, &vcc->flags); 486 else 487 error = -EINVAL; 488 break; 489 default: 490 error = vcc_setsockopt(sock, level, optname, optval, optlen); 491 } 492 493 out: 494 release_sock(sk); 495 return error; 496 } 497 498 static int svc_getsockopt(struct socket *sock, int level, int optname, 499 char __user *optval, int __user *optlen) 500 { 501 struct sock *sk = sock->sk; 502 int error = 0, len; 503 504 lock_sock(sk); 505 if (!__SO_LEVEL_MATCH(optname, level) || optname != SO_ATMSAP) { 506 error = vcc_getsockopt(sock, level, optname, optval, optlen); 507 goto out; 508 } 509 if (get_user(len, optlen)) { 510 error = -EFAULT; 511 goto out; 512 } 513 if (len != sizeof(struct atm_sap)) { 514 error = -EINVAL; 515 goto out; 516 } 517 if (copy_to_user(optval, &ATM_SD(sock)->sap, sizeof(struct atm_sap))) { 518 error = -EFAULT; 519 goto out; 520 } 521 out: 522 release_sock(sk); 523 return error; 524 } 525 526 static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr, 527 int sockaddr_len, int flags) 528 { 529 DEFINE_WAIT(wait); 530 struct sock *sk = sock->sk; 531 struct atm_vcc *vcc = ATM_SD(sock); 532 int error; 533 534 lock_sock(sk); 535 set_bit(ATM_VF_WAITING, &vcc->flags); 536 sigd_enq(vcc, as_addparty, NULL, NULL, 537 (struct sockaddr_atmsvc *) sockaddr); 538 if (flags & O_NONBLOCK) { 539 error = -EINPROGRESS; 540 goto out; 541 } 542 pr_debug("added wait queue\n"); 543 for (;;) { 544 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 545 if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd) 546 break; 547 schedule(); 548 } 549 finish_wait(sk_sleep(sk), &wait); 550 error = -xchg(&sk->sk_err_soft, 0); 551 out: 552 release_sock(sk); 553 return error; 554 } 555 556 static int svc_dropparty(struct socket *sock, int ep_ref) 557 { 558 DEFINE_WAIT(wait); 559 struct sock *sk = sock->sk; 560 struct atm_vcc *vcc = ATM_SD(sock); 561 int error; 562 563 lock_sock(sk); 564 set_bit(ATM_VF_WAITING, &vcc->flags); 565 sigd_enq2(vcc, as_dropparty, NULL, NULL, NULL, NULL, ep_ref); 566 for (;;) { 567 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 568 if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd) 569 break; 570 schedule(); 571 } 572 finish_wait(sk_sleep(sk), &wait); 573 if (!sigd) { 574 error = -EUNATCH; 575 goto out; 576 } 577 error = -xchg(&sk->sk_err_soft, 0); 578 out: 579 release_sock(sk); 580 return error; 581 } 582 583 static int svc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 584 { 585 int error, ep_ref; 586 struct sockaddr_atmsvc sa; 587 struct atm_vcc *vcc = ATM_SD(sock); 588 589 switch (cmd) { 590 case ATM_ADDPARTY: 591 if (!test_bit(ATM_VF_SESSION, &vcc->flags)) 592 return -EINVAL; 593 if (copy_from_user(&sa, (void __user *) arg, sizeof(sa))) 594 return -EFAULT; 595 error = svc_addparty(sock, (struct sockaddr *)&sa, sizeof(sa), 596 0); 597 break; 598 case ATM_DROPPARTY: 599 if (!test_bit(ATM_VF_SESSION, &vcc->flags)) 600 return -EINVAL; 601 if (copy_from_user(&ep_ref, (void __user *) arg, sizeof(int))) 602 return -EFAULT; 603 error = svc_dropparty(sock, ep_ref); 604 break; 605 default: 606 error = vcc_ioctl(sock, cmd, arg); 607 } 608 609 return error; 610 } 611 612 #ifdef CONFIG_COMPAT 613 static int svc_compat_ioctl(struct socket *sock, unsigned int cmd, 614 unsigned long arg) 615 { 616 /* The definition of ATM_ADDPARTY uses the size of struct atm_iobuf. 617 But actually it takes a struct sockaddr_atmsvc, which doesn't need 618 compat handling. So all we have to do is fix up cmd... */ 619 if (cmd == COMPAT_ATM_ADDPARTY) 620 cmd = ATM_ADDPARTY; 621 622 if (cmd == ATM_ADDPARTY || cmd == ATM_DROPPARTY) 623 return svc_ioctl(sock, cmd, arg); 624 else 625 return vcc_compat_ioctl(sock, cmd, arg); 626 } 627 #endif /* CONFIG_COMPAT */ 628 629 static const struct proto_ops svc_proto_ops = { 630 .family = PF_ATMSVC, 631 .owner = THIS_MODULE, 632 633 .release = svc_release, 634 .bind = svc_bind, 635 .connect = svc_connect, 636 .socketpair = sock_no_socketpair, 637 .accept = svc_accept, 638 .getname = svc_getname, 639 .poll = vcc_poll, 640 .ioctl = svc_ioctl, 641 #ifdef CONFIG_COMPAT 642 .compat_ioctl = svc_compat_ioctl, 643 #endif 644 .listen = svc_listen, 645 .shutdown = svc_shutdown, 646 .setsockopt = svc_setsockopt, 647 .getsockopt = svc_getsockopt, 648 .sendmsg = vcc_sendmsg, 649 .recvmsg = vcc_recvmsg, 650 .mmap = sock_no_mmap, 651 .sendpage = sock_no_sendpage, 652 }; 653 654 655 static int svc_create(struct net *net, struct socket *sock, int protocol, 656 int kern) 657 { 658 int error; 659 660 if (!net_eq(net, &init_net)) 661 return -EAFNOSUPPORT; 662 663 sock->ops = &svc_proto_ops; 664 error = vcc_create(net, sock, protocol, AF_ATMSVC, kern); 665 if (error) 666 return error; 667 ATM_SD(sock)->local.sas_family = AF_ATMSVC; 668 ATM_SD(sock)->remote.sas_family = AF_ATMSVC; 669 return 0; 670 } 671 672 static const struct net_proto_family svc_family_ops = { 673 .family = PF_ATMSVC, 674 .create = svc_create, 675 .owner = THIS_MODULE, 676 }; 677 678 679 /* 680 * Initialize the ATM SVC protocol family 681 */ 682 683 int __init atmsvc_init(void) 684 { 685 return sock_register(&svc_family_ops); 686 } 687 688 void atmsvc_exit(void) 689 { 690 sock_unregister(PF_ATMSVC); 691 } 692