Rémi Denis-Courmont | 9641458 | 2008-10-05 11:15:13 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * File: pep.c |
| 3 | * |
| 4 | * Phonet pipe protocol end point socket |
| 5 | * |
| 6 | * Copyright (C) 2008 Nokia Corporation. |
| 7 | * |
| 8 | * Author: Rémi Denis-Courmont <remi.denis-courmont@nokia.com> |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * version 2 as published by the Free Software Foundation. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, but |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with this program; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA |
| 22 | * 02110-1301 USA |
| 23 | */ |
| 24 | |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/socket.h> |
| 27 | #include <net/sock.h> |
| 28 | #include <net/tcp_states.h> |
| 29 | #include <asm/ioctls.h> |
| 30 | |
| 31 | #include <linux/phonet.h> |
| 32 | #include <net/phonet/phonet.h> |
| 33 | #include <net/phonet/pep.h> |
| 34 | |
| 35 | /* sk_state values: |
| 36 | * TCP_CLOSE sock not in use yet |
| 37 | * TCP_CLOSE_WAIT disconnected pipe |
| 38 | * TCP_LISTEN listening pipe endpoint |
| 39 | * TCP_SYN_RECV connected pipe in disabled state |
| 40 | * TCP_ESTABLISHED connected pipe in enabled state |
| 41 | * |
| 42 | * pep_sock locking: |
| 43 | * - sk_state, ackq, hlist: sock lock needed |
| 44 | * - listener: read only |
| 45 | * - pipe_handle: read only |
| 46 | */ |
| 47 | |
| 48 | #define CREDITS_MAX 10 |
| 49 | #define CREDITS_THR 7 |
| 50 | |
| 51 | static const struct sockaddr_pn pipe_srv = { |
| 52 | .spn_family = AF_PHONET, |
| 53 | .spn_resource = 0xD9, /* pipe service */ |
| 54 | }; |
| 55 | |
| 56 | #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */ |
| 57 | |
| 58 | /* Get the next TLV sub-block. */ |
| 59 | static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen, |
| 60 | void *buf) |
| 61 | { |
| 62 | void *data = NULL; |
| 63 | struct { |
| 64 | u8 sb_type; |
| 65 | u8 sb_len; |
| 66 | } *ph, h; |
| 67 | int buflen = *plen; |
| 68 | |
| 69 | ph = skb_header_pointer(skb, 0, 2, &h); |
| 70 | if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len)) |
| 71 | return NULL; |
| 72 | ph->sb_len -= 2; |
| 73 | *ptype = ph->sb_type; |
| 74 | *plen = ph->sb_len; |
| 75 | |
| 76 | if (buflen > ph->sb_len) |
| 77 | buflen = ph->sb_len; |
| 78 | data = skb_header_pointer(skb, 2, buflen, buf); |
| 79 | __skb_pull(skb, 2 + ph->sb_len); |
| 80 | return data; |
| 81 | } |
| 82 | |
| 83 | static int pep_reply(struct sock *sk, struct sk_buff *oskb, |
| 84 | u8 code, const void *data, int len, gfp_t priority) |
| 85 | { |
| 86 | const struct pnpipehdr *oph = pnp_hdr(oskb); |
| 87 | struct pnpipehdr *ph; |
| 88 | struct sk_buff *skb; |
| 89 | |
| 90 | skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority); |
| 91 | if (!skb) |
| 92 | return -ENOMEM; |
| 93 | skb_set_owner_w(skb, sk); |
| 94 | |
| 95 | skb_reserve(skb, MAX_PNPIPE_HEADER); |
| 96 | __skb_put(skb, len); |
| 97 | skb_copy_to_linear_data(skb, data, len); |
| 98 | __skb_push(skb, sizeof(*ph)); |
| 99 | skb_reset_transport_header(skb); |
| 100 | ph = pnp_hdr(skb); |
| 101 | ph->utid = oph->utid; |
| 102 | ph->message_id = oph->message_id + 1; /* REQ -> RESP */ |
| 103 | ph->pipe_handle = oph->pipe_handle; |
| 104 | ph->error_code = code; |
| 105 | |
| 106 | return pn_skb_send(sk, skb, &pipe_srv); |
| 107 | } |
| 108 | |
| 109 | #define PAD 0x00 |
| 110 | static int pep_accept_conn(struct sock *sk, struct sk_buff *skb) |
| 111 | { |
| 112 | static const u8 data[20] = { |
| 113 | PAD, PAD, PAD, 2 /* sub-blocks */, |
| 114 | PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD, |
| 115 | PN_MULTI_CREDIT_FLOW_CONTROL, |
| 116 | PN_ONE_CREDIT_FLOW_CONTROL, |
| 117 | PN_LEGACY_FLOW_CONTROL, |
| 118 | PAD, |
| 119 | PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD, |
| 120 | PN_MULTI_CREDIT_FLOW_CONTROL, |
| 121 | PN_ONE_CREDIT_FLOW_CONTROL, |
| 122 | PN_LEGACY_FLOW_CONTROL, |
| 123 | PAD, |
| 124 | }; |
| 125 | |
| 126 | might_sleep(); |
| 127 | return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data), |
| 128 | GFP_KERNEL); |
| 129 | } |
| 130 | |
| 131 | static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code) |
| 132 | { |
| 133 | static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ }; |
| 134 | WARN_ON(code == PN_PIPE_NO_ERROR); |
| 135 | return pep_reply(sk, skb, code, data, sizeof(data), GFP_ATOMIC); |
| 136 | } |
| 137 | |
| 138 | /* Control requests are not sent by the pipe service and have a specific |
| 139 | * message format. */ |
| 140 | static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code) |
| 141 | { |
| 142 | const struct pnpipehdr *oph = pnp_hdr(oskb); |
| 143 | struct sk_buff *skb; |
| 144 | struct pnpipehdr *ph; |
| 145 | struct sockaddr_pn dst; |
| 146 | |
| 147 | skb = alloc_skb(MAX_PNPIPE_HEADER + 4, GFP_ATOMIC); |
| 148 | if (!skb) |
| 149 | return -ENOMEM; |
| 150 | skb_set_owner_w(skb, sk); |
| 151 | |
| 152 | skb_reserve(skb, MAX_PHONET_HEADER); |
| 153 | ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4); |
| 154 | |
| 155 | ph->utid = oph->utid; |
| 156 | ph->message_id = PNS_PEP_CTRL_RESP; |
| 157 | ph->pipe_handle = oph->pipe_handle; |
| 158 | ph->data[0] = oph->data[1]; /* CTRL id */ |
| 159 | ph->data[1] = oph->data[0]; /* PEP type */ |
| 160 | ph->data[2] = code; /* error code, at an usual offset */ |
| 161 | ph->data[3] = PAD; |
| 162 | ph->data[4] = PAD; |
| 163 | |
| 164 | pn_skb_get_src_sockaddr(oskb, &dst); |
| 165 | return pn_skb_send(sk, skb, &dst); |
| 166 | } |
| 167 | |
| 168 | static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority) |
| 169 | { |
| 170 | struct pep_sock *pn = pep_sk(sk); |
| 171 | struct pnpipehdr *ph; |
| 172 | struct sk_buff *skb; |
| 173 | |
| 174 | skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority); |
| 175 | if (!skb) |
| 176 | return -ENOMEM; |
| 177 | skb_set_owner_w(skb, sk); |
| 178 | |
| 179 | skb_reserve(skb, MAX_PNPIPE_HEADER + 4); |
| 180 | __skb_push(skb, sizeof(*ph) + 4); |
| 181 | skb_reset_transport_header(skb); |
| 182 | ph = pnp_hdr(skb); |
| 183 | ph->utid = 0; |
| 184 | ph->message_id = PNS_PEP_STATUS_IND; |
| 185 | ph->pipe_handle = pn->pipe_handle; |
| 186 | ph->pep_type = PN_PEP_TYPE_COMMON; |
| 187 | ph->data[1] = type; |
| 188 | ph->data[2] = PAD; |
| 189 | ph->data[3] = PAD; |
| 190 | ph->data[4] = status; |
| 191 | |
| 192 | return pn_skb_send(sk, skb, &pipe_srv); |
| 193 | } |
| 194 | |
| 195 | /* Send our RX flow control information to the sender. |
| 196 | * Socket must be locked. */ |
| 197 | static void pipe_grant_credits(struct sock *sk) |
| 198 | { |
| 199 | struct pep_sock *pn = pep_sk(sk); |
| 200 | |
| 201 | BUG_ON(sk->sk_state != TCP_ESTABLISHED); |
| 202 | |
| 203 | switch (pn->rx_fc) { |
| 204 | case PN_LEGACY_FLOW_CONTROL: /* TODO */ |
| 205 | break; |
| 206 | case PN_ONE_CREDIT_FLOW_CONTROL: |
| 207 | pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL, |
| 208 | PEP_IND_READY, GFP_ATOMIC); |
| 209 | pn->rx_credits = 1; |
| 210 | break; |
| 211 | case PN_MULTI_CREDIT_FLOW_CONTROL: |
| 212 | if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX) |
| 213 | break; |
| 214 | if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS, |
| 215 | CREDITS_MAX - pn->rx_credits, |
| 216 | GFP_ATOMIC) == 0) |
| 217 | pn->rx_credits = CREDITS_MAX; |
| 218 | break; |
| 219 | } |
| 220 | } |
| 221 | |
| 222 | static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) |
| 223 | { |
| 224 | struct pep_sock *pn = pep_sk(sk); |
| 225 | struct pnpipehdr *hdr = pnp_hdr(skb); |
| 226 | |
| 227 | if (!pskb_may_pull(skb, sizeof(*hdr) + 4)) |
| 228 | return -EINVAL; |
| 229 | |
| 230 | if (hdr->data[0] != PN_PEP_TYPE_COMMON) { |
| 231 | LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n", |
| 232 | (unsigned)hdr->data[0]); |
| 233 | return -EOPNOTSUPP; |
| 234 | } |
| 235 | |
| 236 | switch (hdr->data[1]) { |
| 237 | case PN_PEP_IND_FLOW_CONTROL: |
| 238 | switch (pn->tx_fc) { |
| 239 | case PN_LEGACY_FLOW_CONTROL: |
| 240 | switch (hdr->data[4]) { |
| 241 | case PEP_IND_BUSY: |
| 242 | pn->tx_credits = 0; |
| 243 | break; |
| 244 | case PEP_IND_READY: |
| 245 | pn->tx_credits = 1; |
| 246 | break; |
| 247 | } |
| 248 | break; |
| 249 | case PN_ONE_CREDIT_FLOW_CONTROL: |
| 250 | if (hdr->data[4] == PEP_IND_READY) |
| 251 | pn->tx_credits = 1; |
| 252 | break; |
| 253 | } |
| 254 | break; |
| 255 | |
| 256 | case PN_PEP_IND_ID_MCFC_GRANT_CREDITS: |
| 257 | if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL) |
| 258 | break; |
| 259 | if (pn->tx_credits + hdr->data[4] > 0xff) |
| 260 | pn->tx_credits = 0xff; |
| 261 | else |
| 262 | pn->tx_credits += hdr->data[4]; |
| 263 | break; |
| 264 | |
| 265 | default: |
| 266 | LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n", |
| 267 | (unsigned)hdr->data[1]); |
| 268 | return -EOPNOTSUPP; |
| 269 | } |
| 270 | if (pn->tx_credits) |
| 271 | sk->sk_write_space(sk); |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb) |
| 276 | { |
| 277 | struct pep_sock *pn = pep_sk(sk); |
| 278 | struct pnpipehdr *hdr = pnp_hdr(skb); |
| 279 | u8 n_sb = hdr->data[0]; |
| 280 | |
| 281 | pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL; |
| 282 | __skb_pull(skb, sizeof(*hdr)); |
| 283 | while (n_sb > 0) { |
| 284 | u8 type, buf[2], len = sizeof(buf); |
| 285 | u8 *data = pep_get_sb(skb, &type, &len, buf); |
| 286 | |
| 287 | if (data == NULL) |
| 288 | return -EINVAL; |
| 289 | switch (type) { |
| 290 | case PN_PIPE_SB_NEGOTIATED_FC: |
| 291 | if (len < 2 || (data[0] | data[1]) > 3) |
| 292 | break; |
| 293 | pn->tx_fc = data[0] & 3; |
| 294 | pn->rx_fc = data[1] & 3; |
| 295 | break; |
| 296 | } |
| 297 | n_sb--; |
| 298 | } |
| 299 | return 0; |
| 300 | } |
| 301 | |
| 302 | /* Queue an skb to a connected sock. |
| 303 | * Socket lock must be held. */ |
| 304 | static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb) |
| 305 | { |
| 306 | struct pep_sock *pn = pep_sk(sk); |
| 307 | struct pnpipehdr *hdr = pnp_hdr(skb); |
| 308 | int err = 0; |
| 309 | |
| 310 | BUG_ON(sk->sk_state == TCP_CLOSE_WAIT); |
| 311 | |
| 312 | switch (hdr->message_id) { |
| 313 | case PNS_PEP_CONNECT_REQ: |
| 314 | pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE); |
| 315 | break; |
| 316 | |
| 317 | case PNS_PEP_DISCONNECT_REQ: |
| 318 | pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); |
| 319 | sk->sk_state = TCP_CLOSE_WAIT; |
| 320 | if (!sock_flag(sk, SOCK_DEAD)) |
| 321 | sk->sk_state_change(sk); |
| 322 | break; |
| 323 | |
| 324 | case PNS_PEP_ENABLE_REQ: |
| 325 | /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */ |
| 326 | pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); |
| 327 | break; |
| 328 | |
| 329 | case PNS_PEP_RESET_REQ: |
| 330 | switch (hdr->state_after_reset) { |
| 331 | case PN_PIPE_DISABLE: |
| 332 | pn->init_enable = 0; |
| 333 | break; |
| 334 | case PN_PIPE_ENABLE: |
| 335 | pn->init_enable = 1; |
| 336 | break; |
| 337 | default: /* not allowed to send an error here!? */ |
| 338 | err = -EINVAL; |
| 339 | goto out; |
| 340 | } |
| 341 | /* fall through */ |
| 342 | case PNS_PEP_DISABLE_REQ: |
| 343 | pn->tx_credits = 0; |
| 344 | pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); |
| 345 | break; |
| 346 | |
| 347 | case PNS_PEP_CTRL_REQ: |
| 348 | /* TODO */ |
| 349 | pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR); |
| 350 | break; |
| 351 | |
| 352 | case PNS_PIPE_DATA: |
| 353 | __skb_pull(skb, 3); /* Pipe data header */ |
| 354 | if (!pn_flow_safe(pn->rx_fc)) { |
| 355 | err = sock_queue_rcv_skb(sk, skb); |
| 356 | if (!err) |
| 357 | return 0; |
| 358 | break; |
| 359 | } |
| 360 | |
| 361 | if (pn->rx_credits == 0) { |
| 362 | err = -ENOBUFS; |
| 363 | break; |
| 364 | } |
| 365 | pn->rx_credits--; |
| 366 | skb->dev = NULL; |
| 367 | skb_set_owner_r(skb, sk); |
| 368 | err = skb->len; |
| 369 | skb_queue_tail(&sk->sk_receive_queue, skb); |
| 370 | if (!sock_flag(sk, SOCK_DEAD)) |
| 371 | sk->sk_data_ready(sk, err); |
| 372 | return 0; |
| 373 | |
| 374 | case PNS_PEP_STATUS_IND: |
| 375 | pipe_rcv_status(sk, skb); |
| 376 | break; |
| 377 | |
| 378 | case PNS_PIPE_REDIRECTED_IND: |
| 379 | err = pipe_rcv_created(sk, skb); |
| 380 | break; |
| 381 | |
| 382 | case PNS_PIPE_CREATED_IND: |
| 383 | err = pipe_rcv_created(sk, skb); |
| 384 | if (err) |
| 385 | break; |
| 386 | /* fall through */ |
| 387 | case PNS_PIPE_RESET_IND: |
| 388 | if (!pn->init_enable) |
| 389 | break; |
| 390 | /* fall through */ |
| 391 | case PNS_PIPE_ENABLED_IND: |
| 392 | if (!pn_flow_safe(pn->tx_fc)) { |
| 393 | pn->tx_credits = 1; |
| 394 | sk->sk_write_space(sk); |
| 395 | } |
| 396 | if (sk->sk_state == TCP_ESTABLISHED) |
| 397 | break; /* Nothing to do */ |
| 398 | sk->sk_state = TCP_ESTABLISHED; |
| 399 | pipe_grant_credits(sk); |
| 400 | break; |
| 401 | |
| 402 | case PNS_PIPE_DISABLED_IND: |
| 403 | sk->sk_state = TCP_SYN_RECV; |
| 404 | pn->rx_credits = 0; |
| 405 | break; |
| 406 | |
| 407 | default: |
| 408 | LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n", |
| 409 | hdr->message_id); |
| 410 | err = -EINVAL; |
| 411 | } |
| 412 | out: |
| 413 | kfree_skb(skb); |
| 414 | return err; |
| 415 | } |
| 416 | |
| 417 | /* Destroy connected sock. */ |
| 418 | static void pipe_destruct(struct sock *sk) |
| 419 | { |
| 420 | skb_queue_purge(&sk->sk_receive_queue); |
| 421 | } |
| 422 | |
| 423 | static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb) |
| 424 | { |
| 425 | struct sock *newsk; |
| 426 | struct pep_sock *newpn, *pn = pep_sk(sk); |
| 427 | struct pnpipehdr *hdr; |
| 428 | struct sockaddr_pn dst; |
| 429 | u16 peer_type; |
| 430 | u8 pipe_handle, enabled, n_sb; |
| 431 | |
| 432 | if (!pskb_pull(skb, sizeof(*hdr) + 4)) |
| 433 | return -EINVAL; |
| 434 | |
| 435 | hdr = pnp_hdr(skb); |
| 436 | pipe_handle = hdr->pipe_handle; |
| 437 | switch (hdr->state_after_connect) { |
| 438 | case PN_PIPE_DISABLE: |
| 439 | enabled = 0; |
| 440 | break; |
| 441 | case PN_PIPE_ENABLE: |
| 442 | enabled = 1; |
| 443 | break; |
| 444 | default: |
| 445 | pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM); |
| 446 | return -EINVAL; |
| 447 | } |
| 448 | peer_type = hdr->other_pep_type << 8; |
| 449 | |
| 450 | if (unlikely(sk->sk_state != TCP_LISTEN) || sk_acceptq_is_full(sk)) { |
| 451 | pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE); |
| 452 | return -ENOBUFS; |
| 453 | } |
| 454 | |
| 455 | /* Parse sub-blocks (options) */ |
| 456 | n_sb = hdr->data[4]; |
| 457 | while (n_sb > 0) { |
| 458 | u8 type, buf[1], len = sizeof(buf); |
| 459 | const u8 *data = pep_get_sb(skb, &type, &len, buf); |
| 460 | |
| 461 | if (data == NULL) |
| 462 | return -EINVAL; |
| 463 | switch (type) { |
| 464 | case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE: |
| 465 | if (len < 1) |
| 466 | return -EINVAL; |
| 467 | peer_type = (peer_type & 0xff00) | data[0]; |
| 468 | break; |
| 469 | } |
| 470 | n_sb--; |
| 471 | } |
| 472 | |
| 473 | skb = skb_clone(skb, GFP_ATOMIC); |
| 474 | if (!skb) |
| 475 | return -ENOMEM; |
| 476 | |
| 477 | /* Create a new to-be-accepted sock */ |
| 478 | newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_ATOMIC, sk->sk_prot); |
| 479 | if (!newsk) { |
| 480 | kfree_skb(skb); |
| 481 | return -ENOMEM; |
| 482 | } |
| 483 | sock_init_data(NULL, newsk); |
| 484 | newsk->sk_state = TCP_SYN_RECV; |
| 485 | newsk->sk_backlog_rcv = pipe_do_rcv; |
| 486 | newsk->sk_protocol = sk->sk_protocol; |
| 487 | newsk->sk_destruct = pipe_destruct; |
| 488 | |
| 489 | newpn = pep_sk(newsk); |
| 490 | pn_skb_get_dst_sockaddr(skb, &dst); |
| 491 | newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst); |
| 492 | newpn->pn_sk.resource = pn->pn_sk.resource; |
| 493 | newpn->pipe_handle = pipe_handle; |
| 494 | newpn->peer_type = peer_type; |
| 495 | newpn->rx_credits = newpn->tx_credits = 0; |
| 496 | newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL; |
| 497 | newpn->init_enable = enabled; |
| 498 | |
| 499 | BUG_ON(!skb_queue_empty(&newsk->sk_receive_queue)); |
| 500 | skb_queue_head(&newsk->sk_receive_queue, skb); |
| 501 | if (!sock_flag(sk, SOCK_DEAD)) |
| 502 | sk->sk_data_ready(sk, 0); |
| 503 | |
| 504 | sk_acceptq_added(sk); |
| 505 | sk_add_node(newsk, &pn->ackq); |
| 506 | return 0; |
| 507 | } |
| 508 | |
| 509 | /* Listening sock must be locked */ |
| 510 | static struct sock *pep_find_pipe(const struct hlist_head *hlist, |
| 511 | const struct sockaddr_pn *dst, |
| 512 | u8 pipe_handle) |
| 513 | { |
| 514 | struct hlist_node *node; |
| 515 | struct sock *sknode; |
| 516 | u16 dobj = pn_sockaddr_get_object(dst); |
| 517 | |
| 518 | sk_for_each(sknode, node, hlist) { |
| 519 | struct pep_sock *pnnode = pep_sk(sknode); |
| 520 | |
| 521 | /* Ports match, but addresses might not: */ |
| 522 | if (pnnode->pn_sk.sobject != dobj) |
| 523 | continue; |
| 524 | if (pnnode->pipe_handle != pipe_handle) |
| 525 | continue; |
| 526 | if (sknode->sk_state == TCP_CLOSE_WAIT) |
| 527 | continue; |
| 528 | |
| 529 | sock_hold(sknode); |
| 530 | return sknode; |
| 531 | } |
| 532 | return NULL; |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * Deliver an skb to a listening sock. |
| 537 | * Socket lock must be held. |
| 538 | * We then queue the skb to the right connected sock (if any). |
| 539 | */ |
| 540 | static int pep_do_rcv(struct sock *sk, struct sk_buff *skb) |
| 541 | { |
| 542 | struct pep_sock *pn = pep_sk(sk); |
| 543 | struct sock *sknode; |
| 544 | struct pnpipehdr *hdr = pnp_hdr(skb); |
| 545 | struct sockaddr_pn dst; |
| 546 | int err = NET_RX_SUCCESS; |
| 547 | u8 pipe_handle; |
| 548 | |
| 549 | if (!pskb_may_pull(skb, sizeof(*hdr))) |
| 550 | goto drop; |
| 551 | |
| 552 | hdr = pnp_hdr(skb); |
| 553 | pipe_handle = hdr->pipe_handle; |
| 554 | if (pipe_handle == PN_PIPE_INVALID_HANDLE) |
| 555 | goto drop; |
| 556 | |
| 557 | pn_skb_get_dst_sockaddr(skb, &dst); |
| 558 | |
| 559 | /* Look for an existing pipe handle */ |
| 560 | sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle); |
| 561 | if (sknode) |
| 562 | return sk_receive_skb(sknode, skb, 1); |
| 563 | |
| 564 | /* Look for a pipe handle pending accept */ |
| 565 | sknode = pep_find_pipe(&pn->ackq, &dst, pipe_handle); |
| 566 | if (sknode) { |
| 567 | sock_put(sknode); |
| 568 | if (net_ratelimit()) |
| 569 | printk(KERN_WARNING"Phonet unconnected PEP ignored"); |
| 570 | err = NET_RX_DROP; |
| 571 | goto drop; |
| 572 | } |
| 573 | |
| 574 | switch (hdr->message_id) { |
| 575 | case PNS_PEP_CONNECT_REQ: |
| 576 | err = pep_connreq_rcv(sk, skb); |
| 577 | break; |
| 578 | |
| 579 | case PNS_PEP_DISCONNECT_REQ: |
| 580 | pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); |
| 581 | break; |
| 582 | |
| 583 | case PNS_PEP_CTRL_REQ: |
| 584 | pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE); |
| 585 | break; |
| 586 | |
| 587 | case PNS_PEP_RESET_REQ: |
| 588 | case PNS_PEP_ENABLE_REQ: |
| 589 | case PNS_PEP_DISABLE_REQ: |
| 590 | /* invalid handle is not even allowed here! */ |
| 591 | default: |
| 592 | err = NET_RX_DROP; |
| 593 | } |
| 594 | drop: |
| 595 | kfree_skb(skb); |
| 596 | return err; |
| 597 | } |
| 598 | |
| 599 | /* associated socket ceases to exist */ |
| 600 | static void pep_sock_close(struct sock *sk, long timeout) |
| 601 | { |
| 602 | struct pep_sock *pn = pep_sk(sk); |
| 603 | |
| 604 | sk_common_release(sk); |
| 605 | |
| 606 | lock_sock(sk); |
| 607 | if (sk->sk_state == TCP_LISTEN) { |
| 608 | /* Destroy the listen queue */ |
| 609 | struct sock *sknode; |
| 610 | struct hlist_node *p, *n; |
| 611 | |
| 612 | sk_for_each_safe(sknode, p, n, &pn->ackq) |
| 613 | sk_del_node_init(sknode); |
| 614 | sk->sk_state = TCP_CLOSE; |
| 615 | } |
| 616 | release_sock(sk); |
| 617 | } |
| 618 | |
| 619 | static int pep_wait_connreq(struct sock *sk, int noblock) |
| 620 | { |
| 621 | struct task_struct *tsk = current; |
| 622 | struct pep_sock *pn = pep_sk(sk); |
| 623 | long timeo = sock_rcvtimeo(sk, noblock); |
| 624 | |
| 625 | for (;;) { |
| 626 | DEFINE_WAIT(wait); |
| 627 | |
| 628 | if (sk->sk_state != TCP_LISTEN) |
| 629 | return -EINVAL; |
| 630 | if (!hlist_empty(&pn->ackq)) |
| 631 | break; |
| 632 | if (!timeo) |
| 633 | return -EWOULDBLOCK; |
| 634 | if (signal_pending(tsk)) |
| 635 | return sock_intr_errno(timeo); |
| 636 | |
| 637 | prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait, |
| 638 | TASK_INTERRUPTIBLE); |
| 639 | release_sock(sk); |
| 640 | timeo = schedule_timeout(timeo); |
| 641 | lock_sock(sk); |
| 642 | finish_wait(&sk->sk_socket->wait, &wait); |
| 643 | } |
| 644 | |
| 645 | return 0; |
| 646 | } |
| 647 | |
| 648 | static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp) |
| 649 | { |
| 650 | struct pep_sock *pn = pep_sk(sk); |
| 651 | struct sock *newsk = NULL; |
| 652 | struct sk_buff *oskb; |
| 653 | int err; |
| 654 | |
| 655 | lock_sock(sk); |
| 656 | err = pep_wait_connreq(sk, flags & O_NONBLOCK); |
| 657 | if (err) |
| 658 | goto out; |
| 659 | |
| 660 | newsk = __sk_head(&pn->ackq); |
| 661 | |
| 662 | oskb = skb_dequeue(&newsk->sk_receive_queue); |
| 663 | err = pep_accept_conn(newsk, oskb); |
| 664 | if (err) { |
| 665 | skb_queue_head(&newsk->sk_receive_queue, oskb); |
| 666 | newsk = NULL; |
| 667 | goto out; |
| 668 | } |
| 669 | |
| 670 | sock_hold(sk); |
| 671 | pep_sk(newsk)->listener = sk; |
| 672 | |
| 673 | sock_hold(newsk); |
| 674 | sk_del_node_init(newsk); |
| 675 | sk_acceptq_removed(sk); |
| 676 | sk_add_node(newsk, &pn->hlist); |
| 677 | __sock_put(newsk); |
| 678 | |
| 679 | out: |
| 680 | release_sock(sk); |
| 681 | *errp = err; |
| 682 | return newsk; |
| 683 | } |
| 684 | |
| 685 | static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg) |
| 686 | { |
| 687 | int answ; |
| 688 | |
| 689 | switch (cmd) { |
| 690 | case SIOCINQ: |
| 691 | if (sk->sk_state == TCP_LISTEN) |
| 692 | return -EINVAL; |
| 693 | |
| 694 | lock_sock(sk); |
| 695 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
| 696 | answ = skb_peek(&sk->sk_receive_queue)->len; |
| 697 | else |
| 698 | answ = 0; |
| 699 | release_sock(sk); |
| 700 | return put_user(answ, (int __user *)arg); |
| 701 | } |
| 702 | |
| 703 | return -ENOIOCTLCMD; |
| 704 | } |
| 705 | |
| 706 | static int pep_init(struct sock *sk) |
| 707 | { |
| 708 | struct pep_sock *pn = pep_sk(sk); |
| 709 | |
| 710 | INIT_HLIST_HEAD(&pn->ackq); |
| 711 | INIT_HLIST_HEAD(&pn->hlist); |
| 712 | pn->pipe_handle = PN_PIPE_INVALID_HANDLE; |
| 713 | return 0; |
| 714 | } |
| 715 | |
| 716 | static int pep_sendmsg(struct kiocb *iocb, struct sock *sk, |
| 717 | struct msghdr *msg, size_t len) |
| 718 | { |
| 719 | struct pep_sock *pn = pep_sk(sk); |
| 720 | struct sk_buff *skb = NULL; |
| 721 | struct pnpipehdr *ph; |
| 722 | long timeo; |
| 723 | int flags = msg->msg_flags; |
| 724 | int err, done; |
| 725 | |
| 726 | if (msg->msg_flags & MSG_OOB || !(msg->msg_flags & MSG_EOR)) |
| 727 | return -EOPNOTSUPP; |
| 728 | |
| 729 | lock_sock(sk); |
| 730 | timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); |
| 731 | if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) { |
| 732 | err = -ENOTCONN; |
| 733 | goto out; |
| 734 | } |
| 735 | if (sk->sk_state != TCP_ESTABLISHED) { |
| 736 | /* Wait until the pipe gets to enabled state */ |
| 737 | disabled: |
| 738 | err = sk_stream_wait_connect(sk, &timeo); |
| 739 | if (err) |
| 740 | goto out; |
| 741 | |
| 742 | if (sk->sk_state == TCP_CLOSE_WAIT) { |
| 743 | err = -ECONNRESET; |
| 744 | goto out; |
| 745 | } |
| 746 | } |
| 747 | BUG_ON(sk->sk_state != TCP_ESTABLISHED); |
| 748 | |
| 749 | /* Wait until flow control allows TX */ |
| 750 | done = pn->tx_credits > 0; |
| 751 | while (!done) { |
| 752 | DEFINE_WAIT(wait); |
| 753 | |
| 754 | if (!timeo) { |
| 755 | err = -EAGAIN; |
| 756 | goto out; |
| 757 | } |
| 758 | if (signal_pending(current)) { |
| 759 | err = sock_intr_errno(timeo); |
| 760 | goto out; |
| 761 | } |
| 762 | |
| 763 | prepare_to_wait(&sk->sk_socket->wait, &wait, |
| 764 | TASK_INTERRUPTIBLE); |
| 765 | done = sk_wait_event(sk, &timeo, pn->tx_credits > 0); |
| 766 | finish_wait(&sk->sk_socket->wait, &wait); |
| 767 | |
| 768 | if (sk->sk_state != TCP_ESTABLISHED) |
| 769 | goto disabled; |
| 770 | } |
| 771 | |
| 772 | if (!skb) { |
| 773 | skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len, |
| 774 | flags & MSG_DONTWAIT, &err); |
| 775 | if (skb == NULL) |
| 776 | goto out; |
| 777 | skb_reserve(skb, MAX_PHONET_HEADER + 3); |
| 778 | |
| 779 | if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits) |
| 780 | goto disabled; /* sock_alloc_send_skb might sleep */ |
| 781 | } |
| 782 | |
| 783 | err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); |
| 784 | if (err < 0) |
| 785 | goto out; |
| 786 | |
| 787 | __skb_push(skb, 3); |
| 788 | skb_reset_transport_header(skb); |
| 789 | ph = pnp_hdr(skb); |
| 790 | ph->utid = 0; |
| 791 | ph->message_id = PNS_PIPE_DATA; |
| 792 | ph->pipe_handle = pn->pipe_handle; |
| 793 | if (pn_flow_safe(pn->tx_fc)) /* credit-based flow control */ |
| 794 | pn->tx_credits--; |
| 795 | |
| 796 | err = pn_skb_send(sk, skb, &pipe_srv); |
| 797 | if (err >= 0) |
| 798 | err = len; /* success! */ |
| 799 | skb = NULL; |
| 800 | out: |
| 801 | release_sock(sk); |
| 802 | kfree_skb(skb); |
| 803 | return err; |
| 804 | } |
| 805 | |
| 806 | static int pep_recvmsg(struct kiocb *iocb, struct sock *sk, |
| 807 | struct msghdr *msg, size_t len, int noblock, |
| 808 | int flags, int *addr_len) |
| 809 | { |
| 810 | struct sk_buff *skb; |
| 811 | int err; |
| 812 | |
| 813 | if (unlikely(flags & MSG_OOB)) |
| 814 | return -EOPNOTSUPP; |
| 815 | if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE))) |
| 816 | return -ENOTCONN; |
| 817 | |
| 818 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
| 819 | lock_sock(sk); |
| 820 | if (skb == NULL) { |
| 821 | if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT) |
| 822 | err = -ECONNRESET; |
| 823 | release_sock(sk); |
| 824 | return err; |
| 825 | } |
| 826 | |
| 827 | if (sk->sk_state == TCP_ESTABLISHED) |
| 828 | pipe_grant_credits(sk); |
| 829 | release_sock(sk); |
| 830 | |
| 831 | msg->msg_flags |= MSG_EOR; |
| 832 | |
| 833 | if (skb->len > len) |
| 834 | msg->msg_flags |= MSG_TRUNC; |
| 835 | else |
| 836 | len = skb->len; |
| 837 | |
| 838 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len); |
| 839 | if (!err) |
| 840 | err = (flags & MSG_TRUNC) ? skb->len : len; |
| 841 | |
| 842 | skb_free_datagram(sk, skb); |
| 843 | return err; |
| 844 | } |
| 845 | |
| 846 | static void pep_sock_unhash(struct sock *sk) |
| 847 | { |
| 848 | struct pep_sock *pn = pep_sk(sk); |
| 849 | struct sock *skparent = NULL; |
| 850 | |
| 851 | lock_sock(sk); |
| 852 | if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) { |
| 853 | skparent = pn->listener; |
| 854 | sk_del_node_init(sk); |
| 855 | release_sock(sk); |
| 856 | |
| 857 | sk = skparent; |
| 858 | pn = pep_sk(skparent); |
| 859 | lock_sock(sk); |
| 860 | } |
| 861 | /* Unhash a listening sock only when it is closed |
| 862 | * and all of its active connected pipes are closed. */ |
| 863 | if (hlist_empty(&pn->hlist)) |
| 864 | pn_sock_unhash(&pn->pn_sk.sk); |
| 865 | release_sock(sk); |
| 866 | |
| 867 | if (skparent) |
| 868 | sock_put(skparent); |
| 869 | } |
| 870 | |
| 871 | static struct proto pep_proto = { |
| 872 | .close = pep_sock_close, |
| 873 | .accept = pep_sock_accept, |
| 874 | .ioctl = pep_ioctl, |
| 875 | .init = pep_init, |
| 876 | .sendmsg = pep_sendmsg, |
| 877 | .recvmsg = pep_recvmsg, |
| 878 | .backlog_rcv = pep_do_rcv, |
| 879 | .hash = pn_sock_hash, |
| 880 | .unhash = pep_sock_unhash, |
| 881 | .get_port = pn_sock_get_port, |
| 882 | .obj_size = sizeof(struct pep_sock), |
| 883 | .owner = THIS_MODULE, |
| 884 | .name = "PNPIPE", |
| 885 | }; |
| 886 | |
| 887 | static struct phonet_protocol pep_pn_proto = { |
| 888 | .ops = &phonet_stream_ops, |
| 889 | .prot = &pep_proto, |
| 890 | .sock_type = SOCK_SEQPACKET, |
| 891 | }; |
| 892 | |
| 893 | static int __init pep_register(void) |
| 894 | { |
| 895 | return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto); |
| 896 | } |
| 897 | |
| 898 | static void __exit pep_unregister(void) |
| 899 | { |
| 900 | phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto); |
| 901 | } |
| 902 | |
| 903 | module_init(pep_register); |
| 904 | module_exit(pep_unregister); |
| 905 | MODULE_AUTHOR("Remi Denis-Courmont, Nokia"); |
| 906 | MODULE_DESCRIPTION("Phonet pipe protocol"); |
| 907 | MODULE_LICENSE("GPL"); |
| 908 | MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE); |