1 /* 2 * Copyright (c) 2005 Jeffrey M. Hsu. All rights reserved. 3 * Copyright (c) 1982, 1986, 1988, 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93 31 * $FreeBSD: src/sys/kern/uipc_socket2.c,v 1.55.2.17 2002/08/31 19:04:55 dwmalone Exp $ 32 */ 33 34 #include "opt_param.h" 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/domain.h> 38 #include <sys/file.h> /* for maxfiles */ 39 #include <sys/kernel.h> 40 #include <sys/ktr.h> 41 #include <sys/proc.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/protosw.h> 45 #include <sys/resourcevar.h> 46 #include <sys/stat.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/socketops.h> 50 #include <sys/signalvar.h> 51 #include <sys/sysctl.h> 52 #include <sys/event.h> 53 54 #include <sys/msgport2.h> 55 #include <sys/socketvar2.h> 56 57 #include <net/netisr2.h> 58 59 #ifndef KTR_SOWAKEUP 60 #define KTR_SOWAKEUP KTR_ALL 61 #endif 62 KTR_INFO_MASTER(sowakeup); 63 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_start, 0, "newconn sorwakeup start"); 64 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_end, 1, "newconn sorwakeup end"); 65 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_wakeupstart, 2, "newconn wakeup start"); 66 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_wakeupend, 3, "newconn wakeup end"); 67 #define logsowakeup(name) KTR_LOG(sowakeup_ ## name) 68 69 int maxsockets; 70 71 /* 72 * Primitive routines for operating on sockets and socket buffers 73 */ 74 75 u_long sb_max = SB_MAX; 76 u_long sb_max_adj = 77 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */ 78 79 static u_long sb_efficiency = 8; /* parameter for sbreserve() */ 80 81 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC"); 82 83 /* 84 * soacceptreuse allows bind() a local port (e.g. for listen() purposes) 85 * to ignore any connections still accepted from a prior listen(). 86 */ 87 static int soacceptreuse = 1; 88 SYSCTL_INT(_kern_ipc, OID_AUTO, soaccept_reuse, CTLFLAG_RW, 89 &soacceptreuse, 0, "Allow quick reuse of local port"); 90 91 /************************************************************************ 92 * signalsockbuf procedures * 93 ************************************************************************/ 94 95 /* 96 * Wait for data to arrive at/drain from a socket buffer. 97 * 98 * NOTE: Caller must generally hold the ssb_lock (client side lock) since 99 * WAIT/WAKEUP only works for one client at a time. 100 * 101 * NOTE: Caller always retries whatever operation it was waiting on. 102 */ 103 int 104 ssb_wait(struct signalsockbuf *ssb) 105 { 106 uint32_t flags; 107 int pflags; 108 int error; 109 110 pflags = (ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH; 111 112 for (;;) { 113 flags = ssb->ssb_flags; 114 cpu_ccfence(); 115 116 /* 117 * WAKEUP and WAIT interlock each other. We can catch the 118 * race by checking to see if WAKEUP has already been set, 119 * and only setting WAIT if WAKEUP is clear. 120 */ 121 if (flags & SSB_WAKEUP) { 122 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 123 flags & ~SSB_WAKEUP)) { 124 error = 0; 125 break; 126 } 127 continue; 128 } 129 130 /* 131 * Only set WAIT if WAKEUP is clear. 132 */ 133 tsleep_interlock(&ssb->ssb_cc, pflags); 134 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 135 flags | SSB_WAIT)) { 136 error = tsleep(&ssb->ssb_cc, pflags | PINTERLOCKED, 137 "sbwait", ssb->ssb_timeo); 138 break; 139 } 140 } 141 return (error); 142 } 143 144 /* 145 * Lock a sockbuf already known to be locked; 146 * return any error returned from sleep (EINTR). 147 */ 148 int 149 _ssb_lock(struct signalsockbuf *ssb) 150 { 151 uint32_t flags; 152 int pflags; 153 int error; 154 155 pflags = (ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH; 156 157 for (;;) { 158 flags = ssb->ssb_flags; 159 cpu_ccfence(); 160 if (flags & SSB_LOCK) { 161 tsleep_interlock(&ssb->ssb_flags, pflags); 162 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 163 flags | SSB_WANT)) { 164 error = tsleep(&ssb->ssb_flags, 165 pflags | PINTERLOCKED, 166 "sblock", 0); 167 if (error) 168 break; 169 } 170 } else { 171 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 172 flags | SSB_LOCK)) { 173 lwkt_gettoken(&ssb->ssb_token); 174 error = 0; 175 break; 176 } 177 } 178 } 179 return (error); 180 } 181 182 /* 183 * This does the same for sockbufs. Note that the xsockbuf structure, 184 * since it is always embedded in a socket, does not include a self 185 * pointer nor a length. We make this entry point public in case 186 * some other mechanism needs it. 187 */ 188 void 189 ssbtoxsockbuf(struct signalsockbuf *ssb, struct xsockbuf *xsb) 190 { 191 xsb->sb_cc = ssb->ssb_cc; 192 xsb->sb_hiwat = ssb->ssb_hiwat; 193 xsb->sb_mbcnt = ssb->ssb_mbcnt; 194 xsb->sb_mbmax = ssb->ssb_mbmax; 195 xsb->sb_lowat = ssb->ssb_lowat; 196 xsb->sb_flags = ssb->ssb_flags; 197 xsb->sb_timeo = ssb->ssb_timeo; 198 } 199 200 201 /************************************************************************ 202 * Procedures which manipulate socket state flags, wakeups, etc. * 203 ************************************************************************ 204 * 205 * Normal sequence from the active (originating) side is that 206 * soisconnecting() is called during processing of connect() call, resulting 207 * in an eventual call to soisconnected() if/when the connection is 208 * established. When the connection is torn down soisdisconnecting() is 209 * called during processing of disconnect() call, and soisdisconnected() is 210 * called when the connection to the peer is totally severed. 211 * 212 * The semantics of these routines are such that connectionless protocols 213 * can call soisconnected() and soisdisconnected() only, bypassing the 214 * in-progress calls when setting up a ``connection'' takes no time. 215 * 216 * From the passive side, a socket is created with two queues of sockets: 217 * so_incomp for connections in progress and so_comp for connections 218 * already made and awaiting user acceptance. As a protocol is preparing 219 * incoming connections, it creates a socket structure queued on so_incomp 220 * by calling sonewconn(). When the connection is established, 221 * soisconnected() is called, and transfers the socket structure to so_comp, 222 * making it available to accept(). 223 * 224 * If a socket is closed with sockets on either so_incomp or so_comp, these 225 * sockets are dropped. 226 * 227 * If higher level protocols are implemented in the kernel, the wakeups 228 * done here will sometimes cause software-interrupt process scheduling. 229 */ 230 231 void 232 soisconnecting(struct socket *so) 233 { 234 soclrstate(so, SS_ISCONNECTED | SS_ISDISCONNECTING); 235 sosetstate(so, SS_ISCONNECTING); 236 } 237 238 void 239 soisconnected(struct socket *so) 240 { 241 struct socket *head; 242 243 while ((head = so->so_head) != NULL) { 244 lwkt_getpooltoken(head); 245 if (so->so_head == head) 246 break; 247 lwkt_relpooltoken(head); 248 } 249 250 soclrstate(so, SS_ISCONNECTING | SS_ISDISCONNECTING | SS_ISCONFIRMING); 251 sosetstate(so, SS_ISCONNECTED); 252 if (head && (so->so_state & SS_INCOMP)) { 253 if ((so->so_options & SO_ACCEPTFILTER) != 0) { 254 so->so_upcall = head->so_accf->so_accept_filter->accf_callback; 255 so->so_upcallarg = head->so_accf->so_accept_filter_arg; 256 atomic_set_int(&so->so_rcv.ssb_flags, SSB_UPCALL); 257 so->so_options &= ~SO_ACCEPTFILTER; 258 so->so_upcall(so, so->so_upcallarg, 0); 259 lwkt_relpooltoken(head); 260 return; 261 } 262 263 /* 264 * Listen socket are not per-cpu. 265 */ 266 KKASSERT((so->so_state & (SS_COMP | SS_INCOMP)) == SS_INCOMP); 267 TAILQ_REMOVE(&head->so_incomp, so, so_list); 268 head->so_incqlen--; 269 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); 270 head->so_qlen++; 271 sosetstate(so, SS_COMP); 272 soclrstate(so, SS_INCOMP); 273 274 /* 275 * XXX head may be on a different protocol thread. 276 * sorwakeup()->sowakeup() is hacked atm. 277 */ 278 sorwakeup(head); 279 wakeup_one(&head->so_timeo); 280 } else { 281 wakeup(&so->so_timeo); 282 sorwakeup(so); 283 sowwakeup(so); 284 } 285 if (head) 286 lwkt_relpooltoken(head); 287 } 288 289 void 290 soisdisconnecting(struct socket *so) 291 { 292 soclrstate(so, SS_ISCONNECTING); 293 sosetstate(so, SS_ISDISCONNECTING | SS_CANTRCVMORE | SS_CANTSENDMORE); 294 wakeup((caddr_t)&so->so_timeo); 295 sowwakeup(so); 296 sorwakeup(so); 297 } 298 299 void 300 soisdisconnected(struct socket *so) 301 { 302 soclrstate(so, SS_ISCONNECTING | SS_ISCONNECTED | SS_ISDISCONNECTING); 303 sosetstate(so, SS_CANTRCVMORE | SS_CANTSENDMORE | SS_ISDISCONNECTED); 304 wakeup((caddr_t)&so->so_timeo); 305 sbdrop(&so->so_snd.sb, so->so_snd.ssb_cc); 306 sowwakeup(so); 307 sorwakeup(so); 308 } 309 310 void 311 soisreconnecting(struct socket *so) 312 { 313 soclrstate(so, SS_ISDISCONNECTING | SS_ISDISCONNECTED | 314 SS_CANTRCVMORE | SS_CANTSENDMORE); 315 sosetstate(so, SS_ISCONNECTING); 316 } 317 318 void 319 soisreconnected(struct socket *so) 320 { 321 soclrstate(so, SS_ISDISCONNECTED | SS_CANTRCVMORE | SS_CANTSENDMORE); 322 soisconnected(so); 323 } 324 325 /* 326 * Set or change the message port a socket receives commands on. 327 * 328 * XXX 329 */ 330 void 331 sosetport(struct socket *so, lwkt_port_t port) 332 { 333 so->so_port = port; 334 } 335 336 /* 337 * When an attempt at a new connection is noted on a socket 338 * which accepts connections, sonewconn is called. If the 339 * connection is possible (subject to space constraints, etc.) 340 * then we allocate a new structure, propoerly linked into the 341 * data structure of the original socket, and return this. 342 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 343 * 344 * The new socket is returned with one ref and so_pcb assigned. 345 * The reference is implied by so_pcb. 346 */ 347 struct socket * 348 sonewconn_faddr(struct socket *head, int connstatus, 349 const struct sockaddr *faddr, boolean_t keep_ref) 350 { 351 struct socket *so; 352 struct socket *sp; 353 struct pru_attach_info ai; 354 355 if (head->so_qlen > 3 * head->so_qlimit / 2) 356 return (NULL); 357 so = soalloc(1, head->so_proto); 358 if (so == NULL) 359 return (NULL); 360 361 /* 362 * Set the port prior to attaching the inpcb to the current 363 * cpu's protocol thread (which should be the current thread 364 * but might not be in all cases). This serializes any pcb ops 365 * which occur to our cpu allowing us to complete the attachment 366 * without racing anything. 367 */ 368 if (head->so_proto->pr_flags & PR_SYNC_PORT) 369 sosetport(so, &netisr_sync_port); 370 else 371 sosetport(so, netisr_cpuport(mycpuid)); 372 if ((head->so_options & SO_ACCEPTFILTER) != 0) 373 connstatus = 0; 374 so->so_head = head; 375 so->so_type = head->so_type; 376 so->so_options = head->so_options &~ SO_ACCEPTCONN; 377 so->so_linger = head->so_linger; 378 379 /* 380 * NOTE: Clearing NOFDREF implies referencing the so with 381 * soreference(). 382 */ 383 so->so_state = head->so_state | SS_NOFDREF | SS_ASSERTINPROG; 384 so->so_cred = crhold(head->so_cred); 385 ai.sb_rlimit = NULL; 386 ai.p_ucred = NULL; 387 ai.fd_rdir = NULL; /* jail code cruft XXX JH */ 388 389 /* 390 * Reserve space and call pru_attach. We can direct-call the 391 * function since we're already in the protocol thread. 392 */ 393 if (soreserve(so, head->so_snd.ssb_hiwat, 394 head->so_rcv.ssb_hiwat, NULL) || 395 so_pru_attach_direct(so, 0, &ai)) { 396 so->so_head = NULL; 397 soclrstate(so, SS_ASSERTINPROG); 398 sofree(so); /* remove implied pcb ref */ 399 return (NULL); 400 } 401 KKASSERT(((so->so_proto->pr_flags & PR_ASYNC_RCVD) == 0 && 402 so->so_refs == 2) || /* attach + our base ref */ 403 ((so->so_proto->pr_flags & PR_ASYNC_RCVD) && 404 so->so_refs == 3)); /* + async rcvd ref */ 405 if (keep_ref) { 406 /* 407 * Keep the reference; caller will free it. 408 */ 409 } else { 410 sofree(so); 411 } 412 KKASSERT(so->so_port != NULL); 413 so->so_rcv.ssb_lowat = head->so_rcv.ssb_lowat; 414 so->so_snd.ssb_lowat = head->so_snd.ssb_lowat; 415 so->so_rcv.ssb_timeo = head->so_rcv.ssb_timeo; 416 so->so_snd.ssb_timeo = head->so_snd.ssb_timeo; 417 418 if (head->so_rcv.ssb_flags & SSB_AUTOLOWAT) 419 so->so_rcv.ssb_flags |= SSB_AUTOLOWAT; 420 else 421 so->so_rcv.ssb_flags &= ~SSB_AUTOLOWAT; 422 423 if (head->so_snd.ssb_flags & SSB_AUTOLOWAT) 424 so->so_snd.ssb_flags |= SSB_AUTOLOWAT; 425 else 426 so->so_snd.ssb_flags &= ~SSB_AUTOLOWAT; 427 428 if (head->so_rcv.ssb_flags & SSB_AUTOSIZE) 429 so->so_rcv.ssb_flags |= SSB_AUTOSIZE; 430 else 431 so->so_rcv.ssb_flags &= ~SSB_AUTOSIZE; 432 433 if (head->so_snd.ssb_flags & SSB_AUTOSIZE) 434 so->so_snd.ssb_flags |= SSB_AUTOSIZE; 435 else 436 so->so_snd.ssb_flags &= ~SSB_AUTOSIZE; 437 438 /* 439 * Save the faddr, if the information is provided and 440 * the protocol can perform the saving opertation. 441 */ 442 if (faddr != NULL && so->so_proto->pr_usrreqs->pru_savefaddr != NULL) 443 so->so_proto->pr_usrreqs->pru_savefaddr(so, faddr); 444 445 lwkt_getpooltoken(head); 446 if (connstatus) { 447 KKASSERT((so->so_state & (SS_INCOMP | SS_COMP)) == 0); 448 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); 449 head->so_qlen++; 450 /* 451 * Set connstatus within head token, so that the accepted 452 * socket will have connstatus (SS_ISCONNECTED) set. 453 */ 454 if (soacceptreuse) 455 connstatus |= SS_ACCEPTMECH; 456 sosetstate(so, SS_COMP | connstatus); 457 } else { 458 if (head->so_incqlen > head->so_qlimit) { 459 sp = TAILQ_FIRST(&head->so_incomp); 460 KKASSERT((sp->so_state & (SS_INCOMP | SS_COMP)) == 461 SS_INCOMP); 462 TAILQ_REMOVE(&head->so_incomp, sp, so_list); 463 head->so_incqlen--; 464 soclrstate(sp, SS_INCOMP); 465 soabort_async(sp, TRUE); 466 } 467 KKASSERT((so->so_state & (SS_INCOMP | SS_COMP)) == 0); 468 TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list); 469 head->so_incqlen++; 470 sosetstate(so, SS_INCOMP | SS_ACCEPTMECH); 471 } 472 /* 473 * Clear SS_ASSERTINPROG within head token, so that it will not 474 * race against accept-close or abort for "synchronous" sockets, 475 * e.g. unix socket, on other CPUs. 476 */ 477 soclrstate(so, SS_ASSERTINPROG); 478 lwkt_relpooltoken(head); 479 480 if (connstatus) { 481 /* 482 * XXX head may be on a different protocol thread. 483 * sorwakeup()->sowakeup() is hacked atm. 484 */ 485 logsowakeup(nconn_start); 486 sorwakeup(head); 487 logsowakeup(nconn_end); 488 489 logsowakeup(nconn_wakeupstart); 490 wakeup((caddr_t)&head->so_timeo); 491 logsowakeup(nconn_wakeupend); 492 } 493 return (so); 494 } 495 496 struct socket * 497 sonewconn(struct socket *head, int connstatus) 498 { 499 return sonewconn_faddr(head, connstatus, NULL, FALSE /* don't ref */); 500 } 501 502 /* 503 * Socantsendmore indicates that no more data will be sent on the 504 * socket; it would normally be applied to a socket when the user 505 * informs the system that no more data is to be sent, by the protocol 506 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 507 * will be received, and will normally be applied to the socket by a 508 * protocol when it detects that the peer will send no more data. 509 * Data queued for reading in the socket may yet be read. 510 */ 511 void 512 socantsendmore(struct socket *so) 513 { 514 sosetstate(so, SS_CANTSENDMORE); 515 sowwakeup(so); 516 } 517 518 void 519 socantrcvmore(struct socket *so) 520 { 521 sosetstate(so, SS_CANTRCVMORE); 522 sorwakeup(so); 523 } 524 525 /* 526 * Wakeup processes waiting on a socket buffer. Do asynchronous notification 527 * via SIGIO if the socket has the SS_ASYNC flag set. 528 * 529 * For users waiting on send/recv try to avoid unnecessary context switch 530 * thrashing. Particularly for senders of large buffers (needs to be 531 * extended to sel and aio? XXX) 532 * 533 * WARNING! Can be called on a foreign socket from the wrong protocol 534 * thread. aka is called on the 'head' listen socket when 535 * a new connection comes in. 536 */ 537 538 void 539 sowakeup(struct socket *so, struct signalsockbuf *ssb) 540 { 541 uint32_t flags; 542 543 /* 544 * Atomically check the flags. When no special features are being 545 * used, WAIT is clear, and WAKEUP is already set, we can simply 546 * return. The upcoming synchronous waiter will not block. 547 */ 548 flags = atomic_fetchadd_int(&ssb->ssb_flags, 0); 549 if ((flags & SSB_NOTIFY_MASK) == 0) { 550 if (flags & SSB_WAKEUP) 551 return; 552 } 553 554 /* 555 * Check conditions, set the WAKEUP flag, and clear and signal if 556 * the WAIT flag is found to be set. This interlocks against the 557 * client side. 558 */ 559 for (;;) { 560 long space; 561 562 flags = ssb->ssb_flags; 563 cpu_ccfence(); 564 if (ssb->ssb_flags & SSB_PREALLOC) 565 space = ssb_space_prealloc(ssb); 566 else 567 space = ssb_space(ssb); 568 569 if ((ssb == &so->so_snd && space >= ssb->ssb_lowat) || 570 (ssb == &so->so_rcv && ssb->ssb_cc >= ssb->ssb_lowat) || 571 (ssb == &so->so_snd && (so->so_state & SS_CANTSENDMORE)) || 572 (ssb == &so->so_rcv && (so->so_state & SS_CANTRCVMORE)) 573 ) { 574 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 575 (flags | SSB_WAKEUP) & ~SSB_WAIT)) { 576 if (flags & SSB_WAIT) 577 wakeup(&ssb->ssb_cc); 578 break; 579 } 580 } else { 581 break; 582 } 583 } 584 585 /* 586 * Misc other events 587 */ 588 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL) 589 pgsigio(so->so_sigio, SIGIO, 0); 590 if (ssb->ssb_flags & SSB_UPCALL) 591 (*so->so_upcall)(so, so->so_upcallarg, M_NOWAIT); 592 KNOTE(&ssb->ssb_kq.ki_note, 0); 593 594 /* 595 * This is a bit of a hack. Multiple threads can wind up scanning 596 * ssb_mlist concurrently due to the fact that this function can be 597 * called on a foreign socket, so we can't afford to block here. 598 * 599 * We need the pool token for (so) (likely the listne socket if 600 * SSB_MEVENT is set) because the predicate function may have 601 * to access the accept queue. 602 */ 603 if (ssb->ssb_flags & SSB_MEVENT) { 604 struct netmsg_so_notify *msg, *nmsg; 605 606 lwkt_getpooltoken(so); 607 TAILQ_FOREACH_MUTABLE(msg, &ssb->ssb_mlist, nm_list, nmsg) { 608 if (msg->nm_predicate(msg)) { 609 TAILQ_REMOVE(&ssb->ssb_mlist, msg, nm_list); 610 lwkt_replymsg(&msg->base.lmsg, 611 msg->base.lmsg.ms_error); 612 } 613 } 614 if (TAILQ_EMPTY(&ssb->ssb_mlist)) 615 atomic_clear_int(&ssb->ssb_flags, SSB_MEVENT); 616 lwkt_relpooltoken(so); 617 } 618 } 619 620 /* 621 * Socket buffer (struct signalsockbuf) utility routines. 622 * 623 * Each socket contains two socket buffers: one for sending data and 624 * one for receiving data. Each buffer contains a queue of mbufs, 625 * information about the number of mbufs and amount of data in the 626 * queue, and other fields allowing kevent()/select()/poll() statements 627 * and notification on data availability to be implemented. 628 * 629 * Data stored in a socket buffer is maintained as a list of records. 630 * Each record is a list of mbufs chained together with the m_next 631 * field. Records are chained together with the m_nextpkt field. The upper 632 * level routine soreceive() expects the following conventions to be 633 * observed when placing information in the receive buffer: 634 * 635 * 1. If the protocol requires each message be preceded by the sender's 636 * name, then a record containing that name must be present before 637 * any associated data (mbuf's must be of type MT_SONAME). 638 * 2. If the protocol supports the exchange of ``access rights'' (really 639 * just additional data associated with the message), and there are 640 * ``rights'' to be received, then a record containing this data 641 * should be present (mbuf's must be of type MT_RIGHTS). 642 * 3. If a name or rights record exists, then it must be followed by 643 * a data record, perhaps of zero length. 644 * 645 * Before using a new socket structure it is first necessary to reserve 646 * buffer space to the socket, by calling sbreserve(). This should commit 647 * some of the available buffer space in the system buffer pool for the 648 * socket (currently, it does nothing but enforce limits). The space 649 * should be released by calling ssb_release() when the socket is destroyed. 650 */ 651 int 652 soreserve(struct socket *so, u_long sndcc, u_long rcvcc, struct rlimit *rl) 653 { 654 if (so->so_snd.ssb_lowat == 0) 655 atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOLOWAT); 656 if (ssb_reserve(&so->so_snd, sndcc, so, rl) == 0) 657 goto bad; 658 if (ssb_reserve(&so->so_rcv, rcvcc, so, rl) == 0) 659 goto bad2; 660 if (so->so_rcv.ssb_lowat == 0) 661 so->so_rcv.ssb_lowat = 1; 662 if (so->so_snd.ssb_lowat == 0) 663 so->so_snd.ssb_lowat = MCLBYTES; 664 if (so->so_snd.ssb_lowat > so->so_snd.ssb_hiwat) 665 so->so_snd.ssb_lowat = so->so_snd.ssb_hiwat; 666 return (0); 667 bad2: 668 ssb_release(&so->so_snd, so); 669 bad: 670 return (ENOBUFS); 671 } 672 673 static int 674 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS) 675 { 676 int error = 0; 677 u_long old_sb_max = sb_max; 678 679 error = SYSCTL_OUT(req, arg1, sizeof(int)); 680 if (error || !req->newptr) 681 return (error); 682 error = SYSCTL_IN(req, arg1, sizeof(int)); 683 if (error) 684 return (error); 685 if (sb_max < MSIZE + MCLBYTES) { 686 sb_max = old_sb_max; 687 return (EINVAL); 688 } 689 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES); 690 return (0); 691 } 692 693 /* 694 * Allot mbufs to a signalsockbuf. 695 * 696 * Attempt to scale mbmax so that mbcnt doesn't become limiting 697 * if buffering efficiency is near the normal case. 698 * 699 * sb_max only applies to user-sockets (where rl != NULL). It does 700 * not apply to kernel sockets or kernel-controlled sockets. Note 701 * that NFS overrides the sockbuf limits created when nfsd creates 702 * a socket. 703 */ 704 int 705 ssb_reserve(struct signalsockbuf *ssb, u_long cc, struct socket *so, 706 struct rlimit *rl) 707 { 708 /* 709 * rl will only be NULL when we're in an interrupt (eg, in tcp_input) 710 * or when called from netgraph (ie, ngd_attach) 711 */ 712 if (rl && cc > sb_max_adj) 713 cc = sb_max_adj; 714 if (!chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, cc, 715 rl ? rl->rlim_cur : RLIM_INFINITY)) { 716 return (0); 717 } 718 if (rl) 719 ssb->ssb_mbmax = min(cc * sb_efficiency, sb_max); 720 else 721 ssb->ssb_mbmax = cc * sb_efficiency; 722 723 /* 724 * AUTOLOWAT is set on send buffers and prevents large writes 725 * from generating a huge number of context switches. 726 */ 727 if (ssb->ssb_flags & SSB_AUTOLOWAT) { 728 ssb->ssb_lowat = ssb->ssb_hiwat / 4; 729 if (ssb->ssb_lowat < MCLBYTES) 730 ssb->ssb_lowat = MCLBYTES; 731 } 732 if (ssb->ssb_lowat > ssb->ssb_hiwat) 733 ssb->ssb_lowat = ssb->ssb_hiwat; 734 return (1); 735 } 736 737 /* 738 * Free mbufs held by a socket, and reserved mbuf space. 739 */ 740 void 741 ssb_release(struct signalsockbuf *ssb, struct socket *so) 742 { 743 sbflush(&ssb->sb); 744 (void)chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, 0, 745 RLIM_INFINITY); 746 ssb->ssb_mbmax = 0; 747 } 748 749 /* 750 * Some routines that return EOPNOTSUPP for entry points that are not 751 * supported by a protocol. Fill in as needed. 752 */ 753 void 754 pr_generic_notsupp(netmsg_t msg) 755 { 756 lwkt_replymsg(&msg->lmsg, EOPNOTSUPP); 757 } 758 759 int 760 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio, 761 struct mbuf *top, struct mbuf *control, int flags, 762 struct thread *td) 763 { 764 if (top) 765 m_freem(top); 766 if (control) 767 m_freem(control); 768 return (EOPNOTSUPP); 769 } 770 771 int 772 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr, 773 struct uio *uio, struct sockbuf *sio, 774 struct mbuf **controlp, int *flagsp) 775 { 776 return (EOPNOTSUPP); 777 } 778 779 /* 780 * This isn't really a ``null'' operation, but it's the default one 781 * and doesn't do anything destructive. 782 */ 783 void 784 pru_sense_null(netmsg_t msg) 785 { 786 msg->sense.nm_stat->st_blksize = msg->base.nm_so->so_snd.ssb_hiwat; 787 lwkt_replymsg(&msg->lmsg, 0); 788 } 789 790 /* 791 * Make a copy of a sockaddr in a malloced buffer of type M_SONAME. Callers 792 * of this routine assume that it always succeeds, so we have to use a 793 * blockable allocation even though we might be called from a critical thread. 794 */ 795 struct sockaddr * 796 dup_sockaddr(const struct sockaddr *sa) 797 { 798 struct sockaddr *sa2; 799 800 sa2 = kmalloc(sa->sa_len, M_SONAME, M_INTWAIT); 801 bcopy(sa, sa2, sa->sa_len); 802 return (sa2); 803 } 804 805 /* 806 * Create an external-format (``xsocket'') structure using the information 807 * in the kernel-format socket structure pointed to by so. This is done 808 * to reduce the spew of irrelevant information over this interface, 809 * to isolate user code from changes in the kernel structure, and 810 * potentially to provide information-hiding if we decide that 811 * some of this information should be hidden from users. 812 */ 813 void 814 sotoxsocket(struct socket *so, struct xsocket *xso) 815 { 816 xso->xso_len = sizeof *xso; 817 xso->xso_so = so; 818 xso->so_type = so->so_type; 819 xso->so_options = so->so_options; 820 xso->so_linger = so->so_linger; 821 xso->so_state = so->so_state; 822 xso->so_pcb = so->so_pcb; 823 xso->xso_protocol = so->so_proto->pr_protocol; 824 xso->xso_family = so->so_proto->pr_domain->dom_family; 825 xso->so_qlen = so->so_qlen; 826 xso->so_incqlen = so->so_incqlen; 827 xso->so_qlimit = so->so_qlimit; 828 xso->so_timeo = so->so_timeo; 829 xso->so_error = so->so_error; 830 xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0; 831 xso->so_oobmark = so->so_oobmark; 832 ssbtoxsockbuf(&so->so_snd, &xso->so_snd); 833 ssbtoxsockbuf(&so->so_rcv, &xso->so_rcv); 834 xso->so_uid = so->so_cred->cr_uid; 835 } 836 837 /* 838 * This takes the place of kern.maxsockbuf, which moved to kern.ipc. 839 * 840 * NOTE! sb_max only applies to user-created socket buffers. 841 */ 842 static int dummy; 843 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, ""); 844 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW, 845 &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size"); 846 SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD, 847 &maxsockets, 0, "Maximum number of sockets available"); 848 SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW, 849 &sb_efficiency, 0, 850 "Socket buffer limit scaler"); 851 852 /* 853 * Initialize maxsockets 854 */ 855 static void 856 init_maxsockets(void *ignored) 857 { 858 TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets); 859 maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters)); 860 } 861 SYSINIT(param, SI_BOOT1_TUNABLES, SI_ORDER_ANY, 862 init_maxsockets, NULL); 863 864