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 * $DragonFly: src/sys/kern/uipc_socket2.c,v 1.33 2008/09/02 16:17:52 dillon Exp $ 33 */ 34 35 #include "opt_param.h" 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/domain.h> 39 #include <sys/file.h> /* for maxfiles */ 40 #include <sys/kernel.h> 41 #include <sys/ktr.h> 42 #include <sys/proc.h> 43 #include <sys/malloc.h> 44 #include <sys/mbuf.h> 45 #include <sys/protosw.h> 46 #include <sys/resourcevar.h> 47 #include <sys/stat.h> 48 #include <sys/socket.h> 49 #include <sys/socketvar.h> 50 #include <sys/socketops.h> 51 #include <sys/signalvar.h> 52 #include <sys/sysctl.h> 53 #include <sys/event.h> 54 55 #include <sys/thread2.h> 56 #include <sys/msgport2.h> 57 #include <sys/socketvar2.h> 58 59 #include <net/netisr2.h> 60 61 #ifndef KTR_SOWAKEUP 62 #define KTR_SOWAKEUP KTR_ALL 63 #endif 64 KTR_INFO_MASTER(sowakeup); 65 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_start, 0, "newconn sorwakeup start"); 66 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_end, 1, "newconn sorwakeup end"); 67 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_wakeupstart, 2, "newconn wakeup start"); 68 KTR_INFO(KTR_SOWAKEUP, sowakeup, nconn_wakeupend, 3, "newconn wakeup end"); 69 #define logsowakeup(name) KTR_LOG(sowakeup_ ## name) 70 71 int maxsockets; 72 73 /* 74 * Primitive routines for operating on sockets and socket buffers 75 */ 76 77 u_long sb_max = SB_MAX; 78 u_long sb_max_adj = 79 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */ 80 81 static u_long sb_efficiency = 8; /* parameter for sbreserve() */ 82 83 /************************************************************************ 84 * signalsockbuf procedures * 85 ************************************************************************/ 86 87 /* 88 * Wait for data to arrive at/drain from a socket buffer. 89 * 90 * NOTE: Caller must generally hold the ssb_lock (client side lock) since 91 * WAIT/WAKEUP only works for one client at a time. 92 * 93 * NOTE: Caller always retries whatever operation it was waiting on. 94 */ 95 int 96 ssb_wait(struct signalsockbuf *ssb) 97 { 98 uint32_t flags; 99 int pflags; 100 int error; 101 102 pflags = (ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH; 103 104 for (;;) { 105 flags = ssb->ssb_flags; 106 cpu_ccfence(); 107 108 /* 109 * WAKEUP and WAIT interlock each other. We can catch the 110 * race by checking to see if WAKEUP has already been set, 111 * and only setting WAIT if WAKEUP is clear. 112 */ 113 if (flags & SSB_WAKEUP) { 114 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 115 flags & ~SSB_WAKEUP)) { 116 error = 0; 117 break; 118 } 119 continue; 120 } 121 122 /* 123 * Only set WAIT if WAKEUP is clear. 124 */ 125 tsleep_interlock(&ssb->ssb_cc, pflags); 126 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 127 flags | SSB_WAIT)) { 128 error = tsleep(&ssb->ssb_cc, pflags | PINTERLOCKED, 129 "sbwait", ssb->ssb_timeo); 130 break; 131 } 132 } 133 return (error); 134 } 135 136 /* 137 * Lock a sockbuf already known to be locked; 138 * return any error returned from sleep (EINTR). 139 */ 140 int 141 _ssb_lock(struct signalsockbuf *ssb) 142 { 143 uint32_t flags; 144 int pflags; 145 int error; 146 147 pflags = (ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH; 148 149 for (;;) { 150 flags = ssb->ssb_flags; 151 cpu_ccfence(); 152 if (flags & SSB_LOCK) { 153 tsleep_interlock(&ssb->ssb_flags, pflags); 154 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 155 flags | SSB_WANT)) { 156 error = tsleep(&ssb->ssb_flags, 157 pflags | PINTERLOCKED, 158 "sblock", 0); 159 if (error) 160 break; 161 } 162 } else { 163 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 164 flags | SSB_LOCK)) { 165 lwkt_gettoken(&ssb->ssb_token); 166 error = 0; 167 break; 168 } 169 } 170 } 171 return (error); 172 } 173 174 /* 175 * This does the same for sockbufs. Note that the xsockbuf structure, 176 * since it is always embedded in a socket, does not include a self 177 * pointer nor a length. We make this entry point public in case 178 * some other mechanism needs it. 179 */ 180 void 181 ssbtoxsockbuf(struct signalsockbuf *ssb, struct xsockbuf *xsb) 182 { 183 xsb->sb_cc = ssb->ssb_cc; 184 xsb->sb_hiwat = ssb->ssb_hiwat; 185 xsb->sb_mbcnt = ssb->ssb_mbcnt; 186 xsb->sb_mbmax = ssb->ssb_mbmax; 187 xsb->sb_lowat = ssb->ssb_lowat; 188 xsb->sb_flags = ssb->ssb_flags; 189 xsb->sb_timeo = ssb->ssb_timeo; 190 } 191 192 193 /************************************************************************ 194 * Procedures which manipulate socket state flags, wakeups, etc. * 195 ************************************************************************ 196 * 197 * Normal sequence from the active (originating) side is that 198 * soisconnecting() is called during processing of connect() call, resulting 199 * in an eventual call to soisconnected() if/when the connection is 200 * established. When the connection is torn down soisdisconnecting() is 201 * called during processing of disconnect() call, and soisdisconnected() is 202 * called when the connection to the peer is totally severed. 203 * 204 * The semantics of these routines are such that connectionless protocols 205 * can call soisconnected() and soisdisconnected() only, bypassing the 206 * in-progress calls when setting up a ``connection'' takes no time. 207 * 208 * From the passive side, a socket is created with two queues of sockets: 209 * so_incomp for connections in progress and so_comp for connections 210 * already made and awaiting user acceptance. As a protocol is preparing 211 * incoming connections, it creates a socket structure queued on so_incomp 212 * by calling sonewconn(). When the connection is established, 213 * soisconnected() is called, and transfers the socket structure to so_comp, 214 * making it available to accept(). 215 * 216 * If a socket is closed with sockets on either so_incomp or so_comp, these 217 * sockets are dropped. 218 * 219 * If higher level protocols are implemented in the kernel, the wakeups 220 * done here will sometimes cause software-interrupt process scheduling. 221 */ 222 223 void 224 soisconnecting(struct socket *so) 225 { 226 soclrstate(so, SS_ISCONNECTED | SS_ISDISCONNECTING); 227 sosetstate(so, SS_ISCONNECTING); 228 } 229 230 void 231 soisconnected(struct socket *so) 232 { 233 struct socket *head; 234 235 while ((head = so->so_head) != NULL) { 236 lwkt_getpooltoken(head); 237 if (so->so_head == head) 238 break; 239 lwkt_relpooltoken(head); 240 } 241 242 soclrstate(so, SS_ISCONNECTING | SS_ISDISCONNECTING | SS_ISCONFIRMING); 243 sosetstate(so, SS_ISCONNECTED); 244 if (head && (so->so_state & SS_INCOMP)) { 245 if ((so->so_options & SO_ACCEPTFILTER) != 0) { 246 so->so_upcall = head->so_accf->so_accept_filter->accf_callback; 247 so->so_upcallarg = head->so_accf->so_accept_filter_arg; 248 atomic_set_int(&so->so_rcv.ssb_flags, SSB_UPCALL); 249 so->so_options &= ~SO_ACCEPTFILTER; 250 so->so_upcall(so, so->so_upcallarg, 0); 251 lwkt_relpooltoken(head); 252 return; 253 } 254 255 /* 256 * Listen socket are not per-cpu. 257 */ 258 TAILQ_REMOVE(&head->so_incomp, so, so_list); 259 head->so_incqlen--; 260 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); 261 head->so_qlen++; 262 sosetstate(so, SS_COMP); 263 soclrstate(so, SS_INCOMP); 264 265 /* 266 * XXX head may be on a different protocol thread. 267 * sorwakeup()->sowakeup() is hacked atm. 268 */ 269 sorwakeup(head); 270 wakeup_one(&head->so_timeo); 271 } else { 272 wakeup(&so->so_timeo); 273 sorwakeup(so); 274 sowwakeup(so); 275 } 276 if (head) 277 lwkt_relpooltoken(head); 278 } 279 280 void 281 soisdisconnecting(struct socket *so) 282 { 283 soclrstate(so, SS_ISCONNECTING); 284 sosetstate(so, SS_ISDISCONNECTING | SS_CANTRCVMORE | SS_CANTSENDMORE); 285 wakeup((caddr_t)&so->so_timeo); 286 sowwakeup(so); 287 sorwakeup(so); 288 } 289 290 void 291 soisdisconnected(struct socket *so) 292 { 293 soclrstate(so, SS_ISCONNECTING | SS_ISCONNECTED | SS_ISDISCONNECTING); 294 sosetstate(so, SS_CANTRCVMORE | SS_CANTSENDMORE | SS_ISDISCONNECTED); 295 wakeup((caddr_t)&so->so_timeo); 296 sbdrop(&so->so_snd.sb, so->so_snd.ssb_cc); 297 sowwakeup(so); 298 sorwakeup(so); 299 } 300 301 void 302 soisreconnecting(struct socket *so) 303 { 304 soclrstate(so, SS_ISDISCONNECTING | SS_ISDISCONNECTED | 305 SS_CANTRCVMORE | SS_CANTSENDMORE); 306 sosetstate(so, SS_ISCONNECTING); 307 } 308 309 void 310 soisreconnected(struct socket *so) 311 { 312 soclrstate(so, SS_ISDISCONNECTED | SS_CANTRCVMORE | SS_CANTSENDMORE); 313 soisconnected(so); 314 } 315 316 /* 317 * Set or change the message port a socket receives commands on. 318 * 319 * XXX 320 */ 321 void 322 sosetport(struct socket *so, lwkt_port_t port) 323 { 324 so->so_port = port; 325 } 326 327 /* 328 * When an attempt at a new connection is noted on a socket 329 * which accepts connections, sonewconn is called. If the 330 * connection is possible (subject to space constraints, etc.) 331 * then we allocate a new structure, propoerly linked into the 332 * data structure of the original socket, and return this. 333 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 334 * 335 * The new socket is returned with one ref and so_pcb assigned. 336 * The reference is implied by so_pcb. 337 */ 338 struct socket * 339 sonewconn_faddr(struct socket *head, int connstatus, 340 const struct sockaddr *faddr) 341 { 342 struct socket *so; 343 struct socket *sp; 344 struct pru_attach_info ai; 345 346 if (head->so_qlen > 3 * head->so_qlimit / 2) 347 return (NULL); 348 so = soalloc(1, head->so_proto); 349 if (so == NULL) 350 return (NULL); 351 352 /* 353 * Set the port prior to attaching the inpcb to the current 354 * cpu's protocol thread (which should be the current thread 355 * but might not be in all cases). This serializes any pcb ops 356 * which occur to our cpu allowing us to complete the attachment 357 * without racing anything. 358 */ 359 if (head->so_proto->pr_flags & PR_SYNC_PORT) 360 sosetport(so, &netisr_sync_port); 361 else 362 sosetport(so, netisr_cpuport(mycpuid)); 363 if ((head->so_options & SO_ACCEPTFILTER) != 0) 364 connstatus = 0; 365 so->so_head = head; 366 so->so_type = head->so_type; 367 so->so_options = head->so_options &~ SO_ACCEPTCONN; 368 so->so_linger = head->so_linger; 369 370 /* 371 * NOTE: Clearing NOFDREF implies referencing the so with 372 * soreference(). 373 */ 374 so->so_state = head->so_state | SS_NOFDREF | SS_ASSERTINPROG; 375 so->so_cred = crhold(head->so_cred); 376 ai.sb_rlimit = NULL; 377 ai.p_ucred = NULL; 378 ai.fd_rdir = NULL; /* jail code cruft XXX JH */ 379 380 /* 381 * Reserve space and call pru_attach. We can direct-call the 382 * function since we're already in the protocol thread. 383 */ 384 if (soreserve(so, head->so_snd.ssb_hiwat, 385 head->so_rcv.ssb_hiwat, NULL) || 386 so_pru_attach_direct(so, 0, &ai)) { 387 so->so_head = NULL; 388 soclrstate(so, SS_ASSERTINPROG); 389 sofree(so); /* remove implied pcb ref */ 390 return (NULL); 391 } 392 KKASSERT(((so->so_proto->pr_flags & PR_ASYNC_RCVD) == 0 && 393 so->so_refs == 2) || /* attach + our base ref */ 394 ((so->so_proto->pr_flags & PR_ASYNC_RCVD) && 395 so->so_refs == 3)); /* + async rcvd ref */ 396 sofree(so); 397 KKASSERT(so->so_port != NULL); 398 so->so_rcv.ssb_lowat = head->so_rcv.ssb_lowat; 399 so->so_snd.ssb_lowat = head->so_snd.ssb_lowat; 400 so->so_rcv.ssb_timeo = head->so_rcv.ssb_timeo; 401 so->so_snd.ssb_timeo = head->so_snd.ssb_timeo; 402 403 if (head->so_rcv.ssb_flags & SSB_AUTOLOWAT) 404 so->so_rcv.ssb_flags |= SSB_AUTOLOWAT; 405 else 406 so->so_rcv.ssb_flags &= ~SSB_AUTOLOWAT; 407 408 if (head->so_snd.ssb_flags & SSB_AUTOLOWAT) 409 so->so_snd.ssb_flags |= SSB_AUTOLOWAT; 410 else 411 so->so_snd.ssb_flags &= ~SSB_AUTOLOWAT; 412 413 if (head->so_rcv.ssb_flags & SSB_AUTOSIZE) 414 so->so_rcv.ssb_flags |= SSB_AUTOSIZE; 415 else 416 so->so_rcv.ssb_flags &= ~SSB_AUTOSIZE; 417 418 if (head->so_snd.ssb_flags & SSB_AUTOSIZE) 419 so->so_snd.ssb_flags |= SSB_AUTOSIZE; 420 else 421 so->so_snd.ssb_flags &= ~SSB_AUTOSIZE; 422 423 /* 424 * Save the faddr, if the information is provided and 425 * the protocol can perform the saving opertation. 426 */ 427 if (faddr != NULL && so->so_proto->pr_usrreqs->pru_savefaddr != NULL) 428 so->so_proto->pr_usrreqs->pru_savefaddr(so, faddr); 429 430 lwkt_getpooltoken(head); 431 if (connstatus) { 432 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); 433 sosetstate(so, SS_COMP); 434 head->so_qlen++; 435 } else { 436 if (head->so_incqlen > head->so_qlimit) { 437 sp = TAILQ_FIRST(&head->so_incomp); 438 TAILQ_REMOVE(&head->so_incomp, sp, so_list); 439 head->so_incqlen--; 440 soclrstate(sp, SS_INCOMP); 441 sp->so_head = NULL; 442 soabort_async(sp); 443 } 444 TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list); 445 sosetstate(so, SS_INCOMP); 446 head->so_incqlen++; 447 } 448 lwkt_relpooltoken(head); 449 if (connstatus) { 450 /* 451 * XXX head may be on a different protocol thread. 452 * sorwakeup()->sowakeup() is hacked atm. 453 */ 454 logsowakeup(nconn_start); 455 sorwakeup(head); 456 logsowakeup(nconn_end); 457 458 logsowakeup(nconn_wakeupstart); 459 wakeup((caddr_t)&head->so_timeo); 460 logsowakeup(nconn_wakeupend); 461 462 sosetstate(so, connstatus); 463 } 464 soclrstate(so, SS_ASSERTINPROG); 465 return (so); 466 } 467 468 struct socket * 469 sonewconn(struct socket *head, int connstatus) 470 { 471 return sonewconn_faddr(head, connstatus, NULL); 472 } 473 474 /* 475 * Socantsendmore indicates that no more data will be sent on the 476 * socket; it would normally be applied to a socket when the user 477 * informs the system that no more data is to be sent, by the protocol 478 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 479 * will be received, and will normally be applied to the socket by a 480 * protocol when it detects that the peer will send no more data. 481 * Data queued for reading in the socket may yet be read. 482 */ 483 void 484 socantsendmore(struct socket *so) 485 { 486 sosetstate(so, SS_CANTSENDMORE); 487 sowwakeup(so); 488 } 489 490 void 491 socantrcvmore(struct socket *so) 492 { 493 sosetstate(so, SS_CANTRCVMORE); 494 sorwakeup(so); 495 } 496 497 /* 498 * Wakeup processes waiting on a socket buffer. Do asynchronous notification 499 * via SIGIO if the socket has the SS_ASYNC flag set. 500 * 501 * For users waiting on send/recv try to avoid unnecessary context switch 502 * thrashing. Particularly for senders of large buffers (needs to be 503 * extended to sel and aio? XXX) 504 * 505 * WARNING! Can be called on a foreign socket from the wrong protocol 506 * thread. aka is called on the 'head' listen socket when 507 * a new connection comes in. 508 */ 509 510 void 511 sowakeup(struct socket *so, struct signalsockbuf *ssb) 512 { 513 struct kqinfo *kqinfo = &ssb->ssb_kq; 514 uint32_t flags; 515 516 /* 517 * Atomically check the flags. When no special features are being 518 * used, WAIT is clear, and WAKEUP is already set, we can simply 519 * return. The upcoming synchronous waiter will not block. 520 */ 521 flags = atomic_fetchadd_int(&ssb->ssb_flags, 0); 522 if ((flags & SSB_NOTIFY_MASK) == 0) { 523 if (flags & SSB_WAKEUP) 524 return; 525 } 526 527 /* 528 * Check conditions, set the WAKEUP flag, and clear and signal if 529 * the WAIT flag is found to be set. This interlocks against the 530 * client side. 531 */ 532 for (;;) { 533 long space; 534 535 flags = ssb->ssb_flags; 536 cpu_ccfence(); 537 if (ssb->ssb_flags & SSB_PREALLOC) 538 space = ssb_space_prealloc(ssb); 539 else 540 space = ssb_space(ssb); 541 542 if ((ssb == &so->so_snd && space >= ssb->ssb_lowat) || 543 (ssb == &so->so_rcv && ssb->ssb_cc >= ssb->ssb_lowat) || 544 (ssb == &so->so_snd && (so->so_state & SS_CANTSENDMORE)) || 545 (ssb == &so->so_rcv && (so->so_state & SS_CANTRCVMORE)) 546 ) { 547 if (atomic_cmpset_int(&ssb->ssb_flags, flags, 548 (flags | SSB_WAKEUP) & ~SSB_WAIT)) { 549 if (flags & SSB_WAIT) 550 wakeup(&ssb->ssb_cc); 551 break; 552 } 553 } else { 554 break; 555 } 556 } 557 558 /* 559 * Misc other events 560 */ 561 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL) 562 pgsigio(so->so_sigio, SIGIO, 0); 563 if (ssb->ssb_flags & SSB_UPCALL) 564 (*so->so_upcall)(so, so->so_upcallarg, MB_DONTWAIT); 565 KNOTE(&kqinfo->ki_note, 0); 566 567 /* 568 * This is a bit of a hack. Multiple threads can wind up scanning 569 * ki_mlist concurrently due to the fact that this function can be 570 * called on a foreign socket, so we can't afford to block here. 571 * 572 * We need the pool token for (so) (likely the listne socket if 573 * SSB_MEVENT is set) because the predicate function may have 574 * to access the accept queue. 575 */ 576 if (ssb->ssb_flags & SSB_MEVENT) { 577 struct netmsg_so_notify *msg, *nmsg; 578 579 lwkt_getpooltoken(so); 580 TAILQ_FOREACH_MUTABLE(msg, &kqinfo->ki_mlist, nm_list, nmsg) { 581 if (msg->nm_predicate(msg)) { 582 TAILQ_REMOVE(&kqinfo->ki_mlist, msg, nm_list); 583 lwkt_replymsg(&msg->base.lmsg, 584 msg->base.lmsg.ms_error); 585 } 586 } 587 if (TAILQ_EMPTY(&ssb->ssb_kq.ki_mlist)) 588 atomic_clear_int(&ssb->ssb_flags, SSB_MEVENT); 589 lwkt_relpooltoken(so); 590 } 591 } 592 593 /* 594 * Socket buffer (struct signalsockbuf) utility routines. 595 * 596 * Each socket contains two socket buffers: one for sending data and 597 * one for receiving data. Each buffer contains a queue of mbufs, 598 * information about the number of mbufs and amount of data in the 599 * queue, and other fields allowing kevent()/select()/poll() statements 600 * and notification on data availability to be implemented. 601 * 602 * Data stored in a socket buffer is maintained as a list of records. 603 * Each record is a list of mbufs chained together with the m_next 604 * field. Records are chained together with the m_nextpkt field. The upper 605 * level routine soreceive() expects the following conventions to be 606 * observed when placing information in the receive buffer: 607 * 608 * 1. If the protocol requires each message be preceded by the sender's 609 * name, then a record containing that name must be present before 610 * any associated data (mbuf's must be of type MT_SONAME). 611 * 2. If the protocol supports the exchange of ``access rights'' (really 612 * just additional data associated with the message), and there are 613 * ``rights'' to be received, then a record containing this data 614 * should be present (mbuf's must be of type MT_RIGHTS). 615 * 3. If a name or rights record exists, then it must be followed by 616 * a data record, perhaps of zero length. 617 * 618 * Before using a new socket structure it is first necessary to reserve 619 * buffer space to the socket, by calling sbreserve(). This should commit 620 * some of the available buffer space in the system buffer pool for the 621 * socket (currently, it does nothing but enforce limits). The space 622 * should be released by calling ssb_release() when the socket is destroyed. 623 */ 624 int 625 soreserve(struct socket *so, u_long sndcc, u_long rcvcc, struct rlimit *rl) 626 { 627 if (so->so_snd.ssb_lowat == 0) 628 atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOLOWAT); 629 if (ssb_reserve(&so->so_snd, sndcc, so, rl) == 0) 630 goto bad; 631 if (ssb_reserve(&so->so_rcv, rcvcc, so, rl) == 0) 632 goto bad2; 633 if (so->so_rcv.ssb_lowat == 0) 634 so->so_rcv.ssb_lowat = 1; 635 if (so->so_snd.ssb_lowat == 0) 636 so->so_snd.ssb_lowat = MCLBYTES; 637 if (so->so_snd.ssb_lowat > so->so_snd.ssb_hiwat) 638 so->so_snd.ssb_lowat = so->so_snd.ssb_hiwat; 639 return (0); 640 bad2: 641 ssb_release(&so->so_snd, so); 642 bad: 643 return (ENOBUFS); 644 } 645 646 static int 647 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS) 648 { 649 int error = 0; 650 u_long old_sb_max = sb_max; 651 652 error = SYSCTL_OUT(req, arg1, sizeof(int)); 653 if (error || !req->newptr) 654 return (error); 655 error = SYSCTL_IN(req, arg1, sizeof(int)); 656 if (error) 657 return (error); 658 if (sb_max < MSIZE + MCLBYTES) { 659 sb_max = old_sb_max; 660 return (EINVAL); 661 } 662 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES); 663 return (0); 664 } 665 666 /* 667 * Allot mbufs to a signalsockbuf. 668 * 669 * Attempt to scale mbmax so that mbcnt doesn't become limiting 670 * if buffering efficiency is near the normal case. 671 * 672 * sb_max only applies to user-sockets (where rl != NULL). It does 673 * not apply to kernel sockets or kernel-controlled sockets. Note 674 * that NFS overrides the sockbuf limits created when nfsd creates 675 * a socket. 676 */ 677 int 678 ssb_reserve(struct signalsockbuf *ssb, u_long cc, struct socket *so, 679 struct rlimit *rl) 680 { 681 /* 682 * rl will only be NULL when we're in an interrupt (eg, in tcp_input) 683 * or when called from netgraph (ie, ngd_attach) 684 */ 685 if (rl && cc > sb_max_adj) 686 cc = sb_max_adj; 687 if (!chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, cc, 688 rl ? rl->rlim_cur : RLIM_INFINITY)) { 689 return (0); 690 } 691 if (rl) 692 ssb->ssb_mbmax = min(cc * sb_efficiency, sb_max); 693 else 694 ssb->ssb_mbmax = cc * sb_efficiency; 695 696 /* 697 * AUTOLOWAT is set on send buffers and prevents large writes 698 * from generating a huge number of context switches. 699 */ 700 if (ssb->ssb_flags & SSB_AUTOLOWAT) { 701 ssb->ssb_lowat = ssb->ssb_hiwat / 4; 702 if (ssb->ssb_lowat < MCLBYTES) 703 ssb->ssb_lowat = MCLBYTES; 704 } 705 if (ssb->ssb_lowat > ssb->ssb_hiwat) 706 ssb->ssb_lowat = ssb->ssb_hiwat; 707 return (1); 708 } 709 710 /* 711 * Free mbufs held by a socket, and reserved mbuf space. 712 */ 713 void 714 ssb_release(struct signalsockbuf *ssb, struct socket *so) 715 { 716 sbflush(&ssb->sb); 717 (void)chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, 0, 718 RLIM_INFINITY); 719 ssb->ssb_mbmax = 0; 720 } 721 722 /* 723 * Some routines that return EOPNOTSUPP for entry points that are not 724 * supported by a protocol. Fill in as needed. 725 */ 726 void 727 pr_generic_notsupp(netmsg_t msg) 728 { 729 lwkt_replymsg(&msg->lmsg, EOPNOTSUPP); 730 } 731 732 int 733 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio, 734 struct mbuf *top, struct mbuf *control, int flags, 735 struct thread *td) 736 { 737 if (top) 738 m_freem(top); 739 if (control) 740 m_freem(control); 741 return (EOPNOTSUPP); 742 } 743 744 int 745 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr, 746 struct uio *uio, struct sockbuf *sio, 747 struct mbuf **controlp, int *flagsp) 748 { 749 return (EOPNOTSUPP); 750 } 751 752 /* 753 * This isn't really a ``null'' operation, but it's the default one 754 * and doesn't do anything destructive. 755 */ 756 void 757 pru_sense_null(netmsg_t msg) 758 { 759 msg->sense.nm_stat->st_blksize = msg->base.nm_so->so_snd.ssb_hiwat; 760 lwkt_replymsg(&msg->lmsg, 0); 761 } 762 763 /* 764 * Make a copy of a sockaddr in a malloced buffer of type M_SONAME. Callers 765 * of this routine assume that it always succeeds, so we have to use a 766 * blockable allocation even though we might be called from a critical thread. 767 */ 768 struct sockaddr * 769 dup_sockaddr(const struct sockaddr *sa) 770 { 771 struct sockaddr *sa2; 772 773 sa2 = kmalloc(sa->sa_len, M_SONAME, M_INTWAIT); 774 bcopy(sa, sa2, sa->sa_len); 775 return (sa2); 776 } 777 778 /* 779 * Create an external-format (``xsocket'') structure using the information 780 * in the kernel-format socket structure pointed to by so. This is done 781 * to reduce the spew of irrelevant information over this interface, 782 * to isolate user code from changes in the kernel structure, and 783 * potentially to provide information-hiding if we decide that 784 * some of this information should be hidden from users. 785 */ 786 void 787 sotoxsocket(struct socket *so, struct xsocket *xso) 788 { 789 xso->xso_len = sizeof *xso; 790 xso->xso_so = so; 791 xso->so_type = so->so_type; 792 xso->so_options = so->so_options; 793 xso->so_linger = so->so_linger; 794 xso->so_state = so->so_state; 795 xso->so_pcb = so->so_pcb; 796 xso->xso_protocol = so->so_proto->pr_protocol; 797 xso->xso_family = so->so_proto->pr_domain->dom_family; 798 xso->so_qlen = so->so_qlen; 799 xso->so_incqlen = so->so_incqlen; 800 xso->so_qlimit = so->so_qlimit; 801 xso->so_timeo = so->so_timeo; 802 xso->so_error = so->so_error; 803 xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0; 804 xso->so_oobmark = so->so_oobmark; 805 ssbtoxsockbuf(&so->so_snd, &xso->so_snd); 806 ssbtoxsockbuf(&so->so_rcv, &xso->so_rcv); 807 xso->so_uid = so->so_cred->cr_uid; 808 } 809 810 /* 811 * Here is the definition of some of the basic objects in the kern.ipc 812 * branch of the MIB. 813 */ 814 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC"); 815 816 /* 817 * This takes the place of kern.maxsockbuf, which moved to kern.ipc. 818 * 819 * NOTE! sb_max only applies to user-created socket buffers. 820 */ 821 static int dummy; 822 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, ""); 823 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW, 824 &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size"); 825 SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD, 826 &maxsockets, 0, "Maximum number of sockets available"); 827 SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW, 828 &sb_efficiency, 0, 829 "Socket buffer limit scaler"); 830 831 /* 832 * Initialize maxsockets 833 */ 834 static void 835 init_maxsockets(void *ignored) 836 { 837 TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets); 838 maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters)); 839 } 840 SYSINIT(param, SI_BOOT1_TUNABLES, SI_ORDER_ANY, 841 init_maxsockets, NULL); 842 843