1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * File: pep.c 4 * 5 * Phonet pipe protocol end point socket 6 * 7 * Copyright (C) 2008 Nokia Corporation. 8 * 9 * Author: Rémi Denis-Courmont 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/sched/signal.h> 14 #include <linux/slab.h> 15 #include <linux/socket.h> 16 #include <net/sock.h> 17 #include <net/tcp_states.h> 18 #include <asm/ioctls.h> 19 20 #include <linux/phonet.h> 21 #include <linux/module.h> 22 #include <net/phonet/phonet.h> 23 #include <net/phonet/pep.h> 24 #include <net/phonet/gprs.h> 25 26 /* sk_state values: 27 * TCP_CLOSE sock not in use yet 28 * TCP_CLOSE_WAIT disconnected pipe 29 * TCP_LISTEN listening pipe endpoint 30 * TCP_SYN_RECV connected pipe in disabled state 31 * TCP_ESTABLISHED connected pipe in enabled state 32 * 33 * pep_sock locking: 34 * - sk_state, hlist: sock lock needed 35 * - listener: read only 36 * - pipe_handle: read only 37 */ 38 39 #define CREDITS_MAX 10 40 #define CREDITS_THR 7 41 42 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */ 43 44 /* Get the next TLV sub-block. */ 45 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen, 46 void *buf) 47 { 48 void *data = NULL; 49 struct { 50 u8 sb_type; 51 u8 sb_len; 52 } *ph, h; 53 int buflen = *plen; 54 55 ph = skb_header_pointer(skb, 0, 2, &h); 56 if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len)) 57 return NULL; 58 ph->sb_len -= 2; 59 *ptype = ph->sb_type; 60 *plen = ph->sb_len; 61 62 if (buflen > ph->sb_len) 63 buflen = ph->sb_len; 64 data = skb_header_pointer(skb, 2, buflen, buf); 65 __skb_pull(skb, 2 + ph->sb_len); 66 return data; 67 } 68 69 static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload, 70 int len, gfp_t priority) 71 { 72 struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority); 73 if (!skb) 74 return NULL; 75 skb_set_owner_w(skb, sk); 76 77 skb_reserve(skb, MAX_PNPIPE_HEADER); 78 __skb_put(skb, len); 79 skb_copy_to_linear_data(skb, payload, len); 80 __skb_push(skb, sizeof(struct pnpipehdr)); 81 skb_reset_transport_header(skb); 82 return skb; 83 } 84 85 static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code, 86 const void *data, int len, gfp_t priority) 87 { 88 const struct pnpipehdr *oph = pnp_hdr(oskb); 89 struct pnpipehdr *ph; 90 struct sk_buff *skb; 91 struct sockaddr_pn peer; 92 93 skb = pep_alloc_skb(sk, data, len, priority); 94 if (!skb) 95 return -ENOMEM; 96 97 ph = pnp_hdr(skb); 98 ph->utid = oph->utid; 99 ph->message_id = oph->message_id + 1; /* REQ -> RESP */ 100 ph->pipe_handle = oph->pipe_handle; 101 ph->error_code = code; 102 103 pn_skb_get_src_sockaddr(oskb, &peer); 104 return pn_skb_send(sk, skb, &peer); 105 } 106 107 static int pep_indicate(struct sock *sk, u8 id, u8 code, 108 const void *data, int len, gfp_t priority) 109 { 110 struct pep_sock *pn = pep_sk(sk); 111 struct pnpipehdr *ph; 112 struct sk_buff *skb; 113 114 skb = pep_alloc_skb(sk, data, len, priority); 115 if (!skb) 116 return -ENOMEM; 117 118 ph = pnp_hdr(skb); 119 ph->utid = 0; 120 ph->message_id = id; 121 ph->pipe_handle = pn->pipe_handle; 122 ph->error_code = code; 123 return pn_skb_send(sk, skb, NULL); 124 } 125 126 #define PAD 0x00 127 128 static int pipe_handler_request(struct sock *sk, u8 id, u8 code, 129 const void *data, int len) 130 { 131 struct pep_sock *pn = pep_sk(sk); 132 struct pnpipehdr *ph; 133 struct sk_buff *skb; 134 135 skb = pep_alloc_skb(sk, data, len, GFP_KERNEL); 136 if (!skb) 137 return -ENOMEM; 138 139 ph = pnp_hdr(skb); 140 ph->utid = id; /* whatever */ 141 ph->message_id = id; 142 ph->pipe_handle = pn->pipe_handle; 143 ph->error_code = code; 144 return pn_skb_send(sk, skb, NULL); 145 } 146 147 static int pipe_handler_send_created_ind(struct sock *sk) 148 { 149 struct pep_sock *pn = pep_sk(sk); 150 u8 data[4] = { 151 PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2), 152 pn->tx_fc, pn->rx_fc, 153 }; 154 155 return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */, 156 data, 4, GFP_ATOMIC); 157 } 158 159 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb) 160 { 161 static const u8 data[20] = { 162 PAD, PAD, PAD, 2 /* sub-blocks */, 163 PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD, 164 PN_MULTI_CREDIT_FLOW_CONTROL, 165 PN_ONE_CREDIT_FLOW_CONTROL, 166 PN_LEGACY_FLOW_CONTROL, 167 PAD, 168 PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD, 169 PN_MULTI_CREDIT_FLOW_CONTROL, 170 PN_ONE_CREDIT_FLOW_CONTROL, 171 PN_LEGACY_FLOW_CONTROL, 172 PAD, 173 }; 174 175 might_sleep(); 176 return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data), 177 GFP_KERNEL); 178 } 179 180 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code, 181 gfp_t priority) 182 { 183 static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ }; 184 WARN_ON(code == PN_PIPE_NO_ERROR); 185 return pep_reply(sk, skb, code, data, sizeof(data), priority); 186 } 187 188 /* Control requests are not sent by the pipe service and have a specific 189 * message format. */ 190 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code, 191 gfp_t priority) 192 { 193 const struct pnpipehdr *oph = pnp_hdr(oskb); 194 struct sk_buff *skb; 195 struct pnpipehdr *ph; 196 struct sockaddr_pn dst; 197 u8 data[4] = { 198 oph->pep_type, /* PEP type */ 199 code, /* error code, at an unusual offset */ 200 PAD, PAD, 201 }; 202 203 skb = pep_alloc_skb(sk, data, 4, priority); 204 if (!skb) 205 return -ENOMEM; 206 207 ph = pnp_hdr(skb); 208 ph->utid = oph->utid; 209 ph->message_id = PNS_PEP_CTRL_RESP; 210 ph->pipe_handle = oph->pipe_handle; 211 ph->data0 = oph->data[0]; /* CTRL id */ 212 213 pn_skb_get_src_sockaddr(oskb, &dst); 214 return pn_skb_send(sk, skb, &dst); 215 } 216 217 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority) 218 { 219 u8 data[4] = { type, PAD, PAD, status }; 220 221 return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON, 222 data, 4, priority); 223 } 224 225 /* Send our RX flow control information to the sender. 226 * Socket must be locked. */ 227 static void pipe_grant_credits(struct sock *sk, gfp_t priority) 228 { 229 struct pep_sock *pn = pep_sk(sk); 230 231 BUG_ON(sk->sk_state != TCP_ESTABLISHED); 232 233 switch (pn->rx_fc) { 234 case PN_LEGACY_FLOW_CONTROL: /* TODO */ 235 break; 236 case PN_ONE_CREDIT_FLOW_CONTROL: 237 if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL, 238 PEP_IND_READY, priority) == 0) 239 pn->rx_credits = 1; 240 break; 241 case PN_MULTI_CREDIT_FLOW_CONTROL: 242 if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX) 243 break; 244 if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS, 245 CREDITS_MAX - pn->rx_credits, 246 priority) == 0) 247 pn->rx_credits = CREDITS_MAX; 248 break; 249 } 250 } 251 252 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) 253 { 254 struct pep_sock *pn = pep_sk(sk); 255 struct pnpipehdr *hdr; 256 int wake = 0; 257 258 if (!pskb_may_pull(skb, sizeof(*hdr) + 4)) 259 return -EINVAL; 260 261 hdr = pnp_hdr(skb); 262 if (hdr->pep_type != PN_PEP_TYPE_COMMON) { 263 net_dbg_ratelimited("Phonet unknown PEP type: %u\n", 264 (unsigned int)hdr->pep_type); 265 return -EOPNOTSUPP; 266 } 267 268 switch (hdr->data[0]) { 269 case PN_PEP_IND_FLOW_CONTROL: 270 switch (pn->tx_fc) { 271 case PN_LEGACY_FLOW_CONTROL: 272 switch (hdr->data[3]) { 273 case PEP_IND_BUSY: 274 atomic_set(&pn->tx_credits, 0); 275 break; 276 case PEP_IND_READY: 277 atomic_set(&pn->tx_credits, wake = 1); 278 break; 279 } 280 break; 281 case PN_ONE_CREDIT_FLOW_CONTROL: 282 if (hdr->data[3] == PEP_IND_READY) 283 atomic_set(&pn->tx_credits, wake = 1); 284 break; 285 } 286 break; 287 288 case PN_PEP_IND_ID_MCFC_GRANT_CREDITS: 289 if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL) 290 break; 291 atomic_add(wake = hdr->data[3], &pn->tx_credits); 292 break; 293 294 default: 295 net_dbg_ratelimited("Phonet unknown PEP indication: %u\n", 296 (unsigned int)hdr->data[0]); 297 return -EOPNOTSUPP; 298 } 299 if (wake) 300 sk->sk_write_space(sk); 301 return 0; 302 } 303 304 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb) 305 { 306 struct pep_sock *pn = pep_sk(sk); 307 struct pnpipehdr *hdr = pnp_hdr(skb); 308 u8 n_sb = hdr->data0; 309 310 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL; 311 __skb_pull(skb, sizeof(*hdr)); 312 while (n_sb > 0) { 313 u8 type, buf[2], len = sizeof(buf); 314 u8 *data = pep_get_sb(skb, &type, &len, buf); 315 316 if (data == NULL) 317 return -EINVAL; 318 switch (type) { 319 case PN_PIPE_SB_NEGOTIATED_FC: 320 if (len < 2 || (data[0] | data[1]) > 3) 321 break; 322 pn->tx_fc = data[0] & 3; 323 pn->rx_fc = data[1] & 3; 324 break; 325 } 326 n_sb--; 327 } 328 return 0; 329 } 330 331 /* Queue an skb to a connected sock. 332 * Socket lock must be held. */ 333 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb) 334 { 335 struct pep_sock *pn = pep_sk(sk); 336 struct pnpipehdr *hdr = pnp_hdr(skb); 337 struct sk_buff_head *queue; 338 int err = 0; 339 340 BUG_ON(sk->sk_state == TCP_CLOSE_WAIT); 341 342 switch (hdr->message_id) { 343 case PNS_PEP_CONNECT_REQ: 344 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC); 345 break; 346 347 case PNS_PEP_DISCONNECT_REQ: 348 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); 349 sk->sk_state = TCP_CLOSE_WAIT; 350 if (!sock_flag(sk, SOCK_DEAD)) 351 sk->sk_state_change(sk); 352 break; 353 354 case PNS_PEP_ENABLE_REQ: 355 /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */ 356 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); 357 break; 358 359 case PNS_PEP_RESET_REQ: 360 switch (hdr->state_after_reset) { 361 case PN_PIPE_DISABLE: 362 pn->init_enable = 0; 363 break; 364 case PN_PIPE_ENABLE: 365 pn->init_enable = 1; 366 break; 367 default: /* not allowed to send an error here!? */ 368 err = -EINVAL; 369 goto out; 370 } 371 fallthrough; 372 case PNS_PEP_DISABLE_REQ: 373 atomic_set(&pn->tx_credits, 0); 374 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); 375 break; 376 377 case PNS_PEP_CTRL_REQ: 378 if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) { 379 atomic_inc(&sk->sk_drops); 380 break; 381 } 382 __skb_pull(skb, 4); 383 queue = &pn->ctrlreq_queue; 384 goto queue; 385 386 case PNS_PIPE_ALIGNED_DATA: 387 __skb_pull(skb, 1); 388 fallthrough; 389 case PNS_PIPE_DATA: 390 __skb_pull(skb, 3); /* Pipe data header */ 391 if (!pn_flow_safe(pn->rx_fc)) { 392 err = sock_queue_rcv_skb(sk, skb); 393 if (!err) 394 return NET_RX_SUCCESS; 395 err = -ENOBUFS; 396 break; 397 } 398 399 if (pn->rx_credits == 0) { 400 atomic_inc(&sk->sk_drops); 401 err = -ENOBUFS; 402 break; 403 } 404 pn->rx_credits--; 405 queue = &sk->sk_receive_queue; 406 goto queue; 407 408 case PNS_PEP_STATUS_IND: 409 pipe_rcv_status(sk, skb); 410 break; 411 412 case PNS_PIPE_REDIRECTED_IND: 413 err = pipe_rcv_created(sk, skb); 414 break; 415 416 case PNS_PIPE_CREATED_IND: 417 err = pipe_rcv_created(sk, skb); 418 if (err) 419 break; 420 fallthrough; 421 case PNS_PIPE_RESET_IND: 422 if (!pn->init_enable) 423 break; 424 fallthrough; 425 case PNS_PIPE_ENABLED_IND: 426 if (!pn_flow_safe(pn->tx_fc)) { 427 atomic_set(&pn->tx_credits, 1); 428 sk->sk_write_space(sk); 429 } 430 if (sk->sk_state == TCP_ESTABLISHED) 431 break; /* Nothing to do */ 432 sk->sk_state = TCP_ESTABLISHED; 433 pipe_grant_credits(sk, GFP_ATOMIC); 434 break; 435 436 case PNS_PIPE_DISABLED_IND: 437 sk->sk_state = TCP_SYN_RECV; 438 pn->rx_credits = 0; 439 break; 440 441 default: 442 net_dbg_ratelimited("Phonet unknown PEP message: %u\n", 443 hdr->message_id); 444 err = -EINVAL; 445 } 446 out: 447 kfree_skb(skb); 448 return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS; 449 450 queue: 451 skb->dev = NULL; 452 skb_set_owner_r(skb, sk); 453 skb_queue_tail(queue, skb); 454 if (!sock_flag(sk, SOCK_DEAD)) 455 sk->sk_data_ready(sk); 456 return NET_RX_SUCCESS; 457 } 458 459 /* Destroy connected sock. */ 460 static void pipe_destruct(struct sock *sk) 461 { 462 struct pep_sock *pn = pep_sk(sk); 463 464 skb_queue_purge(&sk->sk_receive_queue); 465 skb_queue_purge(&pn->ctrlreq_queue); 466 } 467 468 static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n) 469 { 470 unsigned int i; 471 u8 final_fc = PN_NO_FLOW_CONTROL; 472 473 for (i = 0; i < n; i++) { 474 u8 fc = fcs[i]; 475 476 if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL) 477 final_fc = fc; 478 } 479 return final_fc; 480 } 481 482 static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb) 483 { 484 struct pep_sock *pn = pep_sk(sk); 485 struct pnpipehdr *hdr; 486 u8 n_sb; 487 488 if (!pskb_pull(skb, sizeof(*hdr) + 4)) 489 return -EINVAL; 490 491 hdr = pnp_hdr(skb); 492 if (hdr->error_code != PN_PIPE_NO_ERROR) 493 return -ECONNREFUSED; 494 495 /* Parse sub-blocks */ 496 n_sb = hdr->data[3]; 497 while (n_sb > 0) { 498 u8 type, buf[6], len = sizeof(buf); 499 const u8 *data = pep_get_sb(skb, &type, &len, buf); 500 501 if (data == NULL) 502 return -EINVAL; 503 504 switch (type) { 505 case PN_PIPE_SB_REQUIRED_FC_TX: 506 if (len < 2 || len < data[0]) 507 break; 508 pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2); 509 break; 510 511 case PN_PIPE_SB_PREFERRED_FC_RX: 512 if (len < 2 || len < data[0]) 513 break; 514 pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2); 515 break; 516 517 } 518 n_sb--; 519 } 520 521 return pipe_handler_send_created_ind(sk); 522 } 523 524 static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb) 525 { 526 struct pnpipehdr *hdr = pnp_hdr(skb); 527 528 if (hdr->error_code != PN_PIPE_NO_ERROR) 529 return -ECONNREFUSED; 530 531 return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */, 532 NULL, 0, GFP_ATOMIC); 533 534 } 535 536 static void pipe_start_flow_control(struct sock *sk) 537 { 538 struct pep_sock *pn = pep_sk(sk); 539 540 if (!pn_flow_safe(pn->tx_fc)) { 541 atomic_set(&pn->tx_credits, 1); 542 sk->sk_write_space(sk); 543 } 544 pipe_grant_credits(sk, GFP_ATOMIC); 545 } 546 547 /* Queue an skb to an actively connected sock. 548 * Socket lock must be held. */ 549 static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb) 550 { 551 struct pep_sock *pn = pep_sk(sk); 552 struct pnpipehdr *hdr = pnp_hdr(skb); 553 int err = NET_RX_SUCCESS; 554 555 switch (hdr->message_id) { 556 case PNS_PIPE_ALIGNED_DATA: 557 __skb_pull(skb, 1); 558 fallthrough; 559 case PNS_PIPE_DATA: 560 __skb_pull(skb, 3); /* Pipe data header */ 561 if (!pn_flow_safe(pn->rx_fc)) { 562 err = sock_queue_rcv_skb(sk, skb); 563 if (!err) 564 return NET_RX_SUCCESS; 565 err = NET_RX_DROP; 566 break; 567 } 568 569 if (pn->rx_credits == 0) { 570 atomic_inc(&sk->sk_drops); 571 err = NET_RX_DROP; 572 break; 573 } 574 pn->rx_credits--; 575 skb->dev = NULL; 576 skb_set_owner_r(skb, sk); 577 skb_queue_tail(&sk->sk_receive_queue, skb); 578 if (!sock_flag(sk, SOCK_DEAD)) 579 sk->sk_data_ready(sk); 580 return NET_RX_SUCCESS; 581 582 case PNS_PEP_CONNECT_RESP: 583 if (sk->sk_state != TCP_SYN_SENT) 584 break; 585 if (!sock_flag(sk, SOCK_DEAD)) 586 sk->sk_state_change(sk); 587 if (pep_connresp_rcv(sk, skb)) { 588 sk->sk_state = TCP_CLOSE_WAIT; 589 break; 590 } 591 if (pn->init_enable == PN_PIPE_DISABLE) 592 sk->sk_state = TCP_SYN_RECV; 593 else { 594 sk->sk_state = TCP_ESTABLISHED; 595 pipe_start_flow_control(sk); 596 } 597 break; 598 599 case PNS_PEP_ENABLE_RESP: 600 if (sk->sk_state != TCP_SYN_SENT) 601 break; 602 603 if (pep_enableresp_rcv(sk, skb)) { 604 sk->sk_state = TCP_CLOSE_WAIT; 605 break; 606 } 607 608 sk->sk_state = TCP_ESTABLISHED; 609 pipe_start_flow_control(sk); 610 break; 611 612 case PNS_PEP_DISCONNECT_RESP: 613 /* sock should already be dead, nothing to do */ 614 break; 615 616 case PNS_PEP_STATUS_IND: 617 pipe_rcv_status(sk, skb); 618 break; 619 } 620 kfree_skb(skb); 621 return err; 622 } 623 624 /* Listening sock must be locked */ 625 static struct sock *pep_find_pipe(const struct hlist_head *hlist, 626 const struct sockaddr_pn *dst, 627 u8 pipe_handle) 628 { 629 struct sock *sknode; 630 u16 dobj = pn_sockaddr_get_object(dst); 631 632 sk_for_each(sknode, hlist) { 633 struct pep_sock *pnnode = pep_sk(sknode); 634 635 /* Ports match, but addresses might not: */ 636 if (pnnode->pn_sk.sobject != dobj) 637 continue; 638 if (pnnode->pipe_handle != pipe_handle) 639 continue; 640 if (sknode->sk_state == TCP_CLOSE_WAIT) 641 continue; 642 643 sock_hold(sknode); 644 return sknode; 645 } 646 return NULL; 647 } 648 649 /* 650 * Deliver an skb to a listening sock. 651 * Socket lock must be held. 652 * We then queue the skb to the right connected sock (if any). 653 */ 654 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb) 655 { 656 struct pep_sock *pn = pep_sk(sk); 657 struct sock *sknode; 658 struct pnpipehdr *hdr; 659 struct sockaddr_pn dst; 660 u8 pipe_handle; 661 662 if (!pskb_may_pull(skb, sizeof(*hdr))) 663 goto drop; 664 665 hdr = pnp_hdr(skb); 666 pipe_handle = hdr->pipe_handle; 667 if (pipe_handle == PN_PIPE_INVALID_HANDLE) 668 goto drop; 669 670 pn_skb_get_dst_sockaddr(skb, &dst); 671 672 /* Look for an existing pipe handle */ 673 sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle); 674 if (sknode) 675 return sk_receive_skb(sknode, skb, 1); 676 677 switch (hdr->message_id) { 678 case PNS_PEP_CONNECT_REQ: 679 if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) { 680 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, 681 GFP_ATOMIC); 682 break; 683 } 684 skb_queue_head(&sk->sk_receive_queue, skb); 685 sk_acceptq_added(sk); 686 if (!sock_flag(sk, SOCK_DEAD)) 687 sk->sk_data_ready(sk); 688 return NET_RX_SUCCESS; 689 690 case PNS_PEP_DISCONNECT_REQ: 691 pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); 692 break; 693 694 case PNS_PEP_CTRL_REQ: 695 pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC); 696 break; 697 698 case PNS_PEP_RESET_REQ: 699 case PNS_PEP_ENABLE_REQ: 700 case PNS_PEP_DISABLE_REQ: 701 /* invalid handle is not even allowed here! */ 702 break; 703 704 default: 705 if ((1 << sk->sk_state) 706 & ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT)) 707 /* actively connected socket */ 708 return pipe_handler_do_rcv(sk, skb); 709 } 710 drop: 711 kfree_skb(skb); 712 return NET_RX_SUCCESS; 713 } 714 715 static int pipe_do_remove(struct sock *sk) 716 { 717 struct pep_sock *pn = pep_sk(sk); 718 struct pnpipehdr *ph; 719 struct sk_buff *skb; 720 721 skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL); 722 if (!skb) 723 return -ENOMEM; 724 725 ph = pnp_hdr(skb); 726 ph->utid = 0; 727 ph->message_id = PNS_PIPE_REMOVE_REQ; 728 ph->pipe_handle = pn->pipe_handle; 729 ph->data0 = PAD; 730 return pn_skb_send(sk, skb, NULL); 731 } 732 733 /* associated socket ceases to exist */ 734 static void pep_sock_close(struct sock *sk, long timeout) 735 { 736 struct pep_sock *pn = pep_sk(sk); 737 int ifindex = 0; 738 739 sock_hold(sk); /* keep a reference after sk_common_release() */ 740 sk_common_release(sk); 741 742 lock_sock(sk); 743 if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) { 744 if (sk->sk_backlog_rcv == pipe_do_rcv) 745 /* Forcefully remove dangling Phonet pipe */ 746 pipe_do_remove(sk); 747 else 748 pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD, 749 NULL, 0); 750 } 751 sk->sk_state = TCP_CLOSE; 752 753 ifindex = pn->ifindex; 754 pn->ifindex = 0; 755 release_sock(sk); 756 757 if (ifindex) 758 gprs_detach(sk); 759 sock_put(sk); 760 } 761 762 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp, 763 bool kern) 764 { 765 struct pep_sock *pn = pep_sk(sk), *newpn; 766 struct sock *newsk = NULL; 767 struct sk_buff *skb; 768 struct pnpipehdr *hdr; 769 struct sockaddr_pn dst, src; 770 int err; 771 u16 peer_type; 772 u8 pipe_handle, enabled, n_sb; 773 u8 aligned = 0; 774 775 skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp); 776 if (!skb) 777 return NULL; 778 779 lock_sock(sk); 780 if (sk->sk_state != TCP_LISTEN) { 781 err = -EINVAL; 782 goto drop; 783 } 784 sk_acceptq_removed(sk); 785 786 err = -EPROTO; 787 if (!pskb_may_pull(skb, sizeof(*hdr) + 4)) 788 goto drop; 789 790 hdr = pnp_hdr(skb); 791 pipe_handle = hdr->pipe_handle; 792 switch (hdr->state_after_connect) { 793 case PN_PIPE_DISABLE: 794 enabled = 0; 795 break; 796 case PN_PIPE_ENABLE: 797 enabled = 1; 798 break; 799 default: 800 pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM, 801 GFP_KERNEL); 802 goto drop; 803 } 804 peer_type = hdr->other_pep_type << 8; 805 806 /* Parse sub-blocks (options) */ 807 n_sb = hdr->data[3]; 808 while (n_sb > 0) { 809 u8 type, buf[1], len = sizeof(buf); 810 const u8 *data = pep_get_sb(skb, &type, &len, buf); 811 812 if (data == NULL) 813 goto drop; 814 switch (type) { 815 case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE: 816 if (len < 1) 817 goto drop; 818 peer_type = (peer_type & 0xff00) | data[0]; 819 break; 820 case PN_PIPE_SB_ALIGNED_DATA: 821 aligned = data[0] != 0; 822 break; 823 } 824 n_sb--; 825 } 826 827 /* Check for duplicate pipe handle */ 828 newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle); 829 if (unlikely(newsk)) { 830 __sock_put(newsk); 831 newsk = NULL; 832 pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL); 833 goto drop; 834 } 835 836 /* Create a new to-be-accepted sock */ 837 newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot, 838 kern); 839 if (!newsk) { 840 pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL); 841 err = -ENOBUFS; 842 goto drop; 843 } 844 845 sock_init_data(NULL, newsk); 846 newsk->sk_state = TCP_SYN_RECV; 847 newsk->sk_backlog_rcv = pipe_do_rcv; 848 newsk->sk_protocol = sk->sk_protocol; 849 newsk->sk_destruct = pipe_destruct; 850 851 newpn = pep_sk(newsk); 852 pn_skb_get_dst_sockaddr(skb, &dst); 853 pn_skb_get_src_sockaddr(skb, &src); 854 newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst); 855 newpn->pn_sk.dobject = pn_sockaddr_get_object(&src); 856 newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst); 857 sock_hold(sk); 858 newpn->listener = sk; 859 skb_queue_head_init(&newpn->ctrlreq_queue); 860 newpn->pipe_handle = pipe_handle; 861 atomic_set(&newpn->tx_credits, 0); 862 newpn->ifindex = 0; 863 newpn->peer_type = peer_type; 864 newpn->rx_credits = 0; 865 newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL; 866 newpn->init_enable = enabled; 867 newpn->aligned = aligned; 868 869 err = pep_accept_conn(newsk, skb); 870 if (err) { 871 __sock_put(sk); 872 sock_put(newsk); 873 newsk = NULL; 874 goto drop; 875 } 876 sk_add_node(newsk, &pn->hlist); 877 drop: 878 release_sock(sk); 879 kfree_skb(skb); 880 *errp = err; 881 return newsk; 882 } 883 884 static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len) 885 { 886 struct pep_sock *pn = pep_sk(sk); 887 int err; 888 u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD }; 889 890 if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE) 891 pn->pipe_handle = 1; /* anything but INVALID_HANDLE */ 892 893 err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ, 894 pn->init_enable, data, 4); 895 if (err) { 896 pn->pipe_handle = PN_PIPE_INVALID_HANDLE; 897 return err; 898 } 899 900 sk->sk_state = TCP_SYN_SENT; 901 902 return 0; 903 } 904 905 static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len) 906 { 907 int err; 908 909 err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD, 910 NULL, 0); 911 if (err) 912 return err; 913 914 sk->sk_state = TCP_SYN_SENT; 915 916 return 0; 917 } 918 919 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg) 920 { 921 struct pep_sock *pn = pep_sk(sk); 922 int answ; 923 int ret = -ENOIOCTLCMD; 924 925 switch (cmd) { 926 case SIOCINQ: 927 if (sk->sk_state == TCP_LISTEN) { 928 ret = -EINVAL; 929 break; 930 } 931 932 lock_sock(sk); 933 if (sock_flag(sk, SOCK_URGINLINE) && 934 !skb_queue_empty(&pn->ctrlreq_queue)) 935 answ = skb_peek(&pn->ctrlreq_queue)->len; 936 else if (!skb_queue_empty(&sk->sk_receive_queue)) 937 answ = skb_peek(&sk->sk_receive_queue)->len; 938 else 939 answ = 0; 940 release_sock(sk); 941 ret = put_user(answ, (int __user *)arg); 942 break; 943 944 case SIOCPNENABLEPIPE: 945 lock_sock(sk); 946 if (sk->sk_state == TCP_SYN_SENT) 947 ret = -EBUSY; 948 else if (sk->sk_state == TCP_ESTABLISHED) 949 ret = -EISCONN; 950 else if (!pn->pn_sk.sobject) 951 ret = -EADDRNOTAVAIL; 952 else 953 ret = pep_sock_enable(sk, NULL, 0); 954 release_sock(sk); 955 break; 956 } 957 958 return ret; 959 } 960 961 static int pep_init(struct sock *sk) 962 { 963 struct pep_sock *pn = pep_sk(sk); 964 965 sk->sk_destruct = pipe_destruct; 966 INIT_HLIST_HEAD(&pn->hlist); 967 pn->listener = NULL; 968 skb_queue_head_init(&pn->ctrlreq_queue); 969 atomic_set(&pn->tx_credits, 0); 970 pn->ifindex = 0; 971 pn->peer_type = 0; 972 pn->pipe_handle = PN_PIPE_INVALID_HANDLE; 973 pn->rx_credits = 0; 974 pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL; 975 pn->init_enable = 1; 976 pn->aligned = 0; 977 return 0; 978 } 979 980 static int pep_setsockopt(struct sock *sk, int level, int optname, 981 sockptr_t optval, unsigned int optlen) 982 { 983 struct pep_sock *pn = pep_sk(sk); 984 int val = 0, err = 0; 985 986 if (level != SOL_PNPIPE) 987 return -ENOPROTOOPT; 988 if (optlen >= sizeof(int)) { 989 if (copy_from_sockptr(&val, optval, sizeof(int))) 990 return -EFAULT; 991 } 992 993 lock_sock(sk); 994 switch (optname) { 995 case PNPIPE_ENCAP: 996 if (val && val != PNPIPE_ENCAP_IP) { 997 err = -EINVAL; 998 break; 999 } 1000 if (!pn->ifindex == !val) 1001 break; /* Nothing to do! */ 1002 if (!capable(CAP_NET_ADMIN)) { 1003 err = -EPERM; 1004 break; 1005 } 1006 if (val) { 1007 release_sock(sk); 1008 err = gprs_attach(sk); 1009 if (err > 0) { 1010 pn->ifindex = err; 1011 err = 0; 1012 } 1013 } else { 1014 pn->ifindex = 0; 1015 release_sock(sk); 1016 gprs_detach(sk); 1017 err = 0; 1018 } 1019 goto out_norel; 1020 1021 case PNPIPE_HANDLE: 1022 if ((sk->sk_state == TCP_CLOSE) && 1023 (val >= 0) && (val < PN_PIPE_INVALID_HANDLE)) 1024 pn->pipe_handle = val; 1025 else 1026 err = -EINVAL; 1027 break; 1028 1029 case PNPIPE_INITSTATE: 1030 pn->init_enable = !!val; 1031 break; 1032 1033 default: 1034 err = -ENOPROTOOPT; 1035 } 1036 release_sock(sk); 1037 1038 out_norel: 1039 return err; 1040 } 1041 1042 static int pep_getsockopt(struct sock *sk, int level, int optname, 1043 char __user *optval, int __user *optlen) 1044 { 1045 struct pep_sock *pn = pep_sk(sk); 1046 int len, val; 1047 1048 if (level != SOL_PNPIPE) 1049 return -ENOPROTOOPT; 1050 if (get_user(len, optlen)) 1051 return -EFAULT; 1052 1053 switch (optname) { 1054 case PNPIPE_ENCAP: 1055 val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE; 1056 break; 1057 1058 case PNPIPE_IFINDEX: 1059 val = pn->ifindex; 1060 break; 1061 1062 case PNPIPE_HANDLE: 1063 val = pn->pipe_handle; 1064 if (val == PN_PIPE_INVALID_HANDLE) 1065 return -EINVAL; 1066 break; 1067 1068 case PNPIPE_INITSTATE: 1069 val = pn->init_enable; 1070 break; 1071 1072 default: 1073 return -ENOPROTOOPT; 1074 } 1075 1076 len = min_t(unsigned int, sizeof(int), len); 1077 if (put_user(len, optlen)) 1078 return -EFAULT; 1079 if (put_user(val, (int __user *) optval)) 1080 return -EFAULT; 1081 return 0; 1082 } 1083 1084 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb) 1085 { 1086 struct pep_sock *pn = pep_sk(sk); 1087 struct pnpipehdr *ph; 1088 int err; 1089 1090 if (pn_flow_safe(pn->tx_fc) && 1091 !atomic_add_unless(&pn->tx_credits, -1, 0)) { 1092 kfree_skb(skb); 1093 return -ENOBUFS; 1094 } 1095 1096 skb_push(skb, 3 + pn->aligned); 1097 skb_reset_transport_header(skb); 1098 ph = pnp_hdr(skb); 1099 ph->utid = 0; 1100 if (pn->aligned) { 1101 ph->message_id = PNS_PIPE_ALIGNED_DATA; 1102 ph->data0 = 0; /* padding */ 1103 } else 1104 ph->message_id = PNS_PIPE_DATA; 1105 ph->pipe_handle = pn->pipe_handle; 1106 err = pn_skb_send(sk, skb, NULL); 1107 1108 if (err && pn_flow_safe(pn->tx_fc)) 1109 atomic_inc(&pn->tx_credits); 1110 return err; 1111 1112 } 1113 1114 static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1115 { 1116 struct pep_sock *pn = pep_sk(sk); 1117 struct sk_buff *skb; 1118 long timeo; 1119 int flags = msg->msg_flags; 1120 int err, done; 1121 1122 if (len > USHRT_MAX) 1123 return -EMSGSIZE; 1124 1125 if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL| 1126 MSG_CMSG_COMPAT)) || 1127 !(msg->msg_flags & MSG_EOR)) 1128 return -EOPNOTSUPP; 1129 1130 skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len, 1131 flags & MSG_DONTWAIT, &err); 1132 if (!skb) 1133 return err; 1134 1135 skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned); 1136 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1137 if (err < 0) 1138 goto outfree; 1139 1140 lock_sock(sk); 1141 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 1142 if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) { 1143 err = -ENOTCONN; 1144 goto out; 1145 } 1146 if (sk->sk_state != TCP_ESTABLISHED) { 1147 /* Wait until the pipe gets to enabled state */ 1148 disabled: 1149 err = sk_stream_wait_connect(sk, &timeo); 1150 if (err) 1151 goto out; 1152 1153 if (sk->sk_state == TCP_CLOSE_WAIT) { 1154 err = -ECONNRESET; 1155 goto out; 1156 } 1157 } 1158 BUG_ON(sk->sk_state != TCP_ESTABLISHED); 1159 1160 /* Wait until flow control allows TX */ 1161 done = atomic_read(&pn->tx_credits); 1162 while (!done) { 1163 DEFINE_WAIT_FUNC(wait, woken_wake_function); 1164 1165 if (!timeo) { 1166 err = -EAGAIN; 1167 goto out; 1168 } 1169 if (signal_pending(current)) { 1170 err = sock_intr_errno(timeo); 1171 goto out; 1172 } 1173 1174 add_wait_queue(sk_sleep(sk), &wait); 1175 done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits), &wait); 1176 remove_wait_queue(sk_sleep(sk), &wait); 1177 1178 if (sk->sk_state != TCP_ESTABLISHED) 1179 goto disabled; 1180 } 1181 1182 err = pipe_skb_send(sk, skb); 1183 if (err >= 0) 1184 err = len; /* success! */ 1185 skb = NULL; 1186 out: 1187 release_sock(sk); 1188 outfree: 1189 kfree_skb(skb); 1190 return err; 1191 } 1192 1193 int pep_writeable(struct sock *sk) 1194 { 1195 struct pep_sock *pn = pep_sk(sk); 1196 1197 return atomic_read(&pn->tx_credits); 1198 } 1199 1200 int pep_write(struct sock *sk, struct sk_buff *skb) 1201 { 1202 struct sk_buff *rskb, *fs; 1203 int flen = 0; 1204 1205 if (pep_sk(sk)->aligned) 1206 return pipe_skb_send(sk, skb); 1207 1208 rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC); 1209 if (!rskb) { 1210 kfree_skb(skb); 1211 return -ENOMEM; 1212 } 1213 skb_shinfo(rskb)->frag_list = skb; 1214 rskb->len += skb->len; 1215 rskb->data_len += rskb->len; 1216 rskb->truesize += rskb->len; 1217 1218 /* Avoid nested fragments */ 1219 skb_walk_frags(skb, fs) 1220 flen += fs->len; 1221 skb->next = skb_shinfo(skb)->frag_list; 1222 skb_frag_list_init(skb); 1223 skb->len -= flen; 1224 skb->data_len -= flen; 1225 skb->truesize -= flen; 1226 1227 skb_reserve(rskb, MAX_PHONET_HEADER + 3); 1228 return pipe_skb_send(sk, rskb); 1229 } 1230 1231 struct sk_buff *pep_read(struct sock *sk) 1232 { 1233 struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue); 1234 1235 if (sk->sk_state == TCP_ESTABLISHED) 1236 pipe_grant_credits(sk, GFP_ATOMIC); 1237 return skb; 1238 } 1239 1240 static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 1241 int noblock, int flags, int *addr_len) 1242 { 1243 struct sk_buff *skb; 1244 int err; 1245 1246 if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL| 1247 MSG_NOSIGNAL|MSG_CMSG_COMPAT)) 1248 return -EOPNOTSUPP; 1249 1250 if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE))) 1251 return -ENOTCONN; 1252 1253 if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) { 1254 /* Dequeue and acknowledge control request */ 1255 struct pep_sock *pn = pep_sk(sk); 1256 1257 if (flags & MSG_PEEK) 1258 return -EOPNOTSUPP; 1259 skb = skb_dequeue(&pn->ctrlreq_queue); 1260 if (skb) { 1261 pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR, 1262 GFP_KERNEL); 1263 msg->msg_flags |= MSG_OOB; 1264 goto copy; 1265 } 1266 if (flags & MSG_OOB) 1267 return -EINVAL; 1268 } 1269 1270 skb = skb_recv_datagram(sk, flags, noblock, &err); 1271 lock_sock(sk); 1272 if (skb == NULL) { 1273 if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT) 1274 err = -ECONNRESET; 1275 release_sock(sk); 1276 return err; 1277 } 1278 1279 if (sk->sk_state == TCP_ESTABLISHED) 1280 pipe_grant_credits(sk, GFP_KERNEL); 1281 release_sock(sk); 1282 copy: 1283 msg->msg_flags |= MSG_EOR; 1284 if (skb->len > len) 1285 msg->msg_flags |= MSG_TRUNC; 1286 else 1287 len = skb->len; 1288 1289 err = skb_copy_datagram_msg(skb, 0, msg, len); 1290 if (!err) 1291 err = (flags & MSG_TRUNC) ? skb->len : len; 1292 1293 skb_free_datagram(sk, skb); 1294 return err; 1295 } 1296 1297 static void pep_sock_unhash(struct sock *sk) 1298 { 1299 struct pep_sock *pn = pep_sk(sk); 1300 struct sock *skparent = NULL; 1301 1302 lock_sock(sk); 1303 1304 if (pn->listener != NULL) { 1305 skparent = pn->listener; 1306 pn->listener = NULL; 1307 release_sock(sk); 1308 1309 pn = pep_sk(skparent); 1310 lock_sock(skparent); 1311 sk_del_node_init(sk); 1312 sk = skparent; 1313 } 1314 1315 /* Unhash a listening sock only when it is closed 1316 * and all of its active connected pipes are closed. */ 1317 if (hlist_empty(&pn->hlist)) 1318 pn_sock_unhash(&pn->pn_sk.sk); 1319 release_sock(sk); 1320 1321 if (skparent) 1322 sock_put(skparent); 1323 } 1324 1325 static struct proto pep_proto = { 1326 .close = pep_sock_close, 1327 .accept = pep_sock_accept, 1328 .connect = pep_sock_connect, 1329 .ioctl = pep_ioctl, 1330 .init = pep_init, 1331 .setsockopt = pep_setsockopt, 1332 .getsockopt = pep_getsockopt, 1333 .sendmsg = pep_sendmsg, 1334 .recvmsg = pep_recvmsg, 1335 .backlog_rcv = pep_do_rcv, 1336 .hash = pn_sock_hash, 1337 .unhash = pep_sock_unhash, 1338 .get_port = pn_sock_get_port, 1339 .obj_size = sizeof(struct pep_sock), 1340 .owner = THIS_MODULE, 1341 .name = "PNPIPE", 1342 }; 1343 1344 static const struct phonet_protocol pep_pn_proto = { 1345 .ops = &phonet_stream_ops, 1346 .prot = &pep_proto, 1347 .sock_type = SOCK_SEQPACKET, 1348 }; 1349 1350 static int __init pep_register(void) 1351 { 1352 return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto); 1353 } 1354 1355 static void __exit pep_unregister(void) 1356 { 1357 phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto); 1358 } 1359 1360 module_init(pep_register); 1361 module_exit(pep_unregister); 1362 MODULE_AUTHOR("Remi Denis-Courmont, Nokia"); 1363 MODULE_DESCRIPTION("Phonet pipe protocol"); 1364 MODULE_LICENSE("GPL"); 1365 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE); 1366