1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)uipc_usrreq.c 7.31 (Berkeley) 03/13/92 8 */ 9 10 #include "param.h" 11 #include "proc.h" 12 #include "filedesc.h" 13 #include "domain.h" 14 #include "protosw.h" 15 #include "socket.h" 16 #include "socketvar.h" 17 #include "unpcb.h" 18 #include "un.h" 19 #include "namei.h" 20 #include "vnode.h" 21 #include "file.h" 22 #include "stat.h" 23 #include "mbuf.h" 24 25 /* 26 * Unix communications domain. 27 * 28 * TODO: 29 * SEQPACKET, RDM 30 * rethink name space problems 31 * need a proper out-of-band 32 */ 33 struct sockaddr sun_noname = { sizeof(sun_noname), AF_UNIX }; 34 ino_t unp_ino; /* prototype for fake inode numbers */ 35 36 /*ARGSUSED*/ 37 uipc_usrreq(so, req, m, nam, control) 38 struct socket *so; 39 int req; 40 struct mbuf *m, *nam, *control; 41 { 42 struct unpcb *unp = sotounpcb(so); 43 register struct socket *so2; 44 register int error = 0; 45 struct proc *p = curproc; /* XXX */ 46 47 if (req == PRU_CONTROL) 48 return (EOPNOTSUPP); 49 if (req != PRU_SEND && control && control->m_len) { 50 error = EOPNOTSUPP; 51 goto release; 52 } 53 if (unp == 0 && req != PRU_ATTACH) { 54 error = EINVAL; 55 goto release; 56 } 57 switch (req) { 58 59 case PRU_ATTACH: 60 if (unp) { 61 error = EISCONN; 62 break; 63 } 64 error = unp_attach(so); 65 break; 66 67 case PRU_DETACH: 68 unp_detach(unp); 69 break; 70 71 case PRU_BIND: 72 error = unp_bind(unp, nam, p); 73 break; 74 75 case PRU_LISTEN: 76 if (unp->unp_vnode == 0) 77 error = EINVAL; 78 break; 79 80 case PRU_CONNECT: 81 error = unp_connect(so, nam, p); 82 break; 83 84 case PRU_CONNECT2: 85 error = unp_connect2(so, (struct socket *)nam); 86 break; 87 88 case PRU_DISCONNECT: 89 unp_disconnect(unp); 90 break; 91 92 case PRU_ACCEPT: 93 /* 94 * Pass back name of connected socket, 95 * if it was bound and we are still connected 96 * (our peer may have closed already!). 97 */ 98 if (unp->unp_conn && unp->unp_conn->unp_addr) { 99 nam->m_len = unp->unp_conn->unp_addr->m_len; 100 bcopy(mtod(unp->unp_conn->unp_addr, caddr_t), 101 mtod(nam, caddr_t), (unsigned)nam->m_len); 102 } else { 103 nam->m_len = sizeof(sun_noname); 104 *(mtod(nam, struct sockaddr *)) = sun_noname; 105 } 106 break; 107 108 case PRU_SHUTDOWN: 109 socantsendmore(so); 110 unp_shutdown(unp); 111 break; 112 113 case PRU_RCVD: 114 switch (so->so_type) { 115 116 case SOCK_DGRAM: 117 panic("uipc 1"); 118 /*NOTREACHED*/ 119 120 case SOCK_STREAM: 121 #define rcv (&so->so_rcv) 122 #define snd (&so2->so_snd) 123 if (unp->unp_conn == 0) 124 break; 125 so2 = unp->unp_conn->unp_socket; 126 /* 127 * Adjust backpressure on sender 128 * and wakeup any waiting to write. 129 */ 130 snd->sb_mbmax += unp->unp_mbcnt - rcv->sb_mbcnt; 131 unp->unp_mbcnt = rcv->sb_mbcnt; 132 snd->sb_hiwat += unp->unp_cc - rcv->sb_cc; 133 unp->unp_cc = rcv->sb_cc; 134 sowwakeup(so2); 135 #undef snd 136 #undef rcv 137 break; 138 139 default: 140 panic("uipc 2"); 141 } 142 break; 143 144 case PRU_SEND: 145 if (control && (error = unp_internalize(control, p))) 146 break; 147 switch (so->so_type) { 148 149 case SOCK_DGRAM: { 150 struct sockaddr *from; 151 152 if (nam) { 153 if (unp->unp_conn) { 154 error = EISCONN; 155 break; 156 } 157 error = unp_connect(so, nam, p); 158 if (error) 159 break; 160 } else { 161 if (unp->unp_conn == 0) { 162 error = ENOTCONN; 163 break; 164 } 165 } 166 so2 = unp->unp_conn->unp_socket; 167 if (unp->unp_addr) 168 from = mtod(unp->unp_addr, struct sockaddr *); 169 else 170 from = &sun_noname; 171 if (sbappendaddr(&so2->so_rcv, from, m, control)) { 172 sorwakeup(so2); 173 m = 0; 174 control = 0; 175 } else 176 error = ENOBUFS; 177 if (nam) 178 unp_disconnect(unp); 179 break; 180 } 181 182 case SOCK_STREAM: 183 #define rcv (&so2->so_rcv) 184 #define snd (&so->so_snd) 185 if (so->so_state & SS_CANTSENDMORE) { 186 error = EPIPE; 187 break; 188 } 189 if (unp->unp_conn == 0) 190 panic("uipc 3"); 191 so2 = unp->unp_conn->unp_socket; 192 /* 193 * Send to paired receive port, and then reduce 194 * send buffer hiwater marks to maintain backpressure. 195 * Wake up readers. 196 */ 197 if (control) { 198 if (sbappendcontrol(rcv, m, control)) 199 control = 0; 200 } else 201 sbappend(rcv, m); 202 snd->sb_mbmax -= 203 rcv->sb_mbcnt - unp->unp_conn->unp_mbcnt; 204 unp->unp_conn->unp_mbcnt = rcv->sb_mbcnt; 205 snd->sb_hiwat -= rcv->sb_cc - unp->unp_conn->unp_cc; 206 unp->unp_conn->unp_cc = rcv->sb_cc; 207 sorwakeup(so2); 208 m = 0; 209 #undef snd 210 #undef rcv 211 break; 212 213 default: 214 panic("uipc 4"); 215 } 216 break; 217 218 case PRU_ABORT: 219 unp_drop(unp, ECONNABORTED); 220 break; 221 222 case PRU_SENSE: 223 ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat; 224 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) { 225 so2 = unp->unp_conn->unp_socket; 226 ((struct stat *) m)->st_blksize += so2->so_rcv.sb_cc; 227 } 228 ((struct stat *) m)->st_dev = NODEV; 229 if (unp->unp_ino == 0) 230 unp->unp_ino = unp_ino++; 231 ((struct stat *) m)->st_ino = unp->unp_ino; 232 return (0); 233 234 case PRU_RCVOOB: 235 return (EOPNOTSUPP); 236 237 case PRU_SENDOOB: 238 error = EOPNOTSUPP; 239 break; 240 241 case PRU_SOCKADDR: 242 if (unp->unp_addr) { 243 nam->m_len = unp->unp_addr->m_len; 244 bcopy(mtod(unp->unp_addr, caddr_t), 245 mtod(nam, caddr_t), (unsigned)nam->m_len); 246 } else 247 nam->m_len = 0; 248 break; 249 250 case PRU_PEERADDR: 251 if (unp->unp_conn && unp->unp_conn->unp_addr) { 252 nam->m_len = unp->unp_conn->unp_addr->m_len; 253 bcopy(mtod(unp->unp_conn->unp_addr, caddr_t), 254 mtod(nam, caddr_t), (unsigned)nam->m_len); 255 } else 256 nam->m_len = 0; 257 break; 258 259 case PRU_SLOWTIMO: 260 break; 261 262 default: 263 panic("piusrreq"); 264 } 265 release: 266 if (control) 267 m_freem(control); 268 if (m) 269 m_freem(m); 270 return (error); 271 } 272 273 /* 274 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 275 * for stream sockets, although the total for sender and receiver is 276 * actually only PIPSIZ. 277 * Datagram sockets really use the sendspace as the maximum datagram size, 278 * and don't really want to reserve the sendspace. Their recvspace should 279 * be large enough for at least one max-size datagram plus address. 280 */ 281 #define PIPSIZ 4096 282 u_long unpst_sendspace = PIPSIZ; 283 u_long unpst_recvspace = PIPSIZ; 284 u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 285 u_long unpdg_recvspace = 4*1024; 286 287 int unp_rights; /* file descriptors in flight */ 288 289 unp_attach(so) 290 struct socket *so; 291 { 292 register struct mbuf *m; 293 register struct unpcb *unp; 294 int error; 295 296 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 297 switch (so->so_type) { 298 299 case SOCK_STREAM: 300 error = soreserve(so, unpst_sendspace, unpst_recvspace); 301 break; 302 303 case SOCK_DGRAM: 304 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 305 break; 306 307 default: 308 panic("unp_attach"); 309 } 310 if (error) 311 return (error); 312 } 313 m = m_getclr(M_DONTWAIT, MT_PCB); 314 if (m == NULL) 315 return (ENOBUFS); 316 unp = mtod(m, struct unpcb *); 317 so->so_pcb = (caddr_t)unp; 318 unp->unp_socket = so; 319 return (0); 320 } 321 322 unp_detach(unp) 323 register struct unpcb *unp; 324 { 325 326 if (unp->unp_vnode) { 327 unp->unp_vnode->v_socket = 0; 328 vrele(unp->unp_vnode); 329 unp->unp_vnode = 0; 330 } 331 if (unp->unp_conn) 332 unp_disconnect(unp); 333 while (unp->unp_refs) 334 unp_drop(unp->unp_refs, ECONNRESET); 335 soisdisconnected(unp->unp_socket); 336 unp->unp_socket->so_pcb = 0; 337 m_freem(unp->unp_addr); 338 (void) m_free(dtom(unp)); 339 if (unp_rights) 340 unp_gc(); 341 } 342 343 unp_bind(unp, nam, p) 344 struct unpcb *unp; 345 struct mbuf *nam; 346 struct proc *p; 347 { 348 struct sockaddr_un *soun = mtod(nam, struct sockaddr_un *); 349 register struct vnode *vp; 350 struct vattr vattr; 351 int error; 352 struct nameidata nd; 353 354 NDINIT(&nd, CREATE, FOLLOW | LOCKPARENT, UIO_SYSSPACE, 355 soun->sun_path, p); 356 if (unp->unp_vnode != NULL) 357 return (EINVAL); 358 if (nam->m_len == MLEN) { 359 if (*(mtod(nam, caddr_t) + nam->m_len - 1) != 0) 360 return (EINVAL); 361 } else 362 *(mtod(nam, caddr_t) + nam->m_len) = 0; 363 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 364 if (error = namei(&nd)) 365 return (error); 366 vp = nd.ni_vp; 367 if (vp != NULL) { 368 VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); 369 if (nd.ni_dvp == vp) 370 vrele(nd.ni_dvp); 371 else 372 vput(nd.ni_dvp); 373 vrele(vp); 374 return (EADDRINUSE); 375 } 376 VATTR_NULL(&vattr); 377 vattr.va_type = VSOCK; 378 vattr.va_mode = 0777; 379 LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE); 380 if (error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr)) 381 return (error); 382 vp = nd.ni_vp; 383 vp->v_socket = unp->unp_socket; 384 unp->unp_vnode = vp; 385 unp->unp_addr = m_copy(nam, 0, (int)M_COPYALL); 386 VOP_UNLOCK(vp); 387 return (0); 388 } 389 390 unp_connect(so, nam, p) 391 struct socket *so; 392 struct mbuf *nam; 393 struct proc *p; 394 { 395 register struct sockaddr_un *soun = mtod(nam, struct sockaddr_un *); 396 register struct vnode *vp; 397 register struct socket *so2, *so3; 398 struct unpcb *unp2, *unp3; 399 int error; 400 struct nameidata nd; 401 402 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, soun->sun_path, p); 403 if (nam->m_data + nam->m_len == &nam->m_dat[MLEN]) { /* XXX */ 404 if (*(mtod(nam, caddr_t) + nam->m_len - 1) != 0) 405 return (EMSGSIZE); 406 } else 407 *(mtod(nam, caddr_t) + nam->m_len) = 0; 408 if (error = namei(&nd)) 409 return (error); 410 vp = nd.ni_vp; 411 if (vp->v_type != VSOCK) { 412 error = ENOTSOCK; 413 goto bad; 414 } 415 if (error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p)) 416 goto bad; 417 so2 = vp->v_socket; 418 if (so2 == 0) { 419 error = ECONNREFUSED; 420 goto bad; 421 } 422 if (so->so_type != so2->so_type) { 423 error = EPROTOTYPE; 424 goto bad; 425 } 426 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 427 if ((so2->so_options & SO_ACCEPTCONN) == 0 || 428 (so3 = sonewconn(so2, 0)) == 0) { 429 error = ECONNREFUSED; 430 goto bad; 431 } 432 unp2 = sotounpcb(so2); 433 unp3 = sotounpcb(so3); 434 if (unp2->unp_addr) 435 unp3->unp_addr = 436 m_copy(unp2->unp_addr, 0, (int)M_COPYALL); 437 so2 = so3; 438 } 439 error = unp_connect2(so, so2); 440 bad: 441 vput(vp); 442 return (error); 443 } 444 445 unp_connect2(so, so2) 446 register struct socket *so; 447 register struct socket *so2; 448 { 449 register struct unpcb *unp = sotounpcb(so); 450 register struct unpcb *unp2; 451 452 if (so2->so_type != so->so_type) 453 return (EPROTOTYPE); 454 unp2 = sotounpcb(so2); 455 unp->unp_conn = unp2; 456 switch (so->so_type) { 457 458 case SOCK_DGRAM: 459 unp->unp_nextref = unp2->unp_refs; 460 unp2->unp_refs = unp; 461 soisconnected(so); 462 break; 463 464 case SOCK_STREAM: 465 unp2->unp_conn = unp; 466 soisconnected(so); 467 soisconnected(so2); 468 break; 469 470 default: 471 panic("unp_connect2"); 472 } 473 return (0); 474 } 475 476 unp_disconnect(unp) 477 struct unpcb *unp; 478 { 479 register struct unpcb *unp2 = unp->unp_conn; 480 481 if (unp2 == 0) 482 return; 483 unp->unp_conn = 0; 484 switch (unp->unp_socket->so_type) { 485 486 case SOCK_DGRAM: 487 if (unp2->unp_refs == unp) 488 unp2->unp_refs = unp->unp_nextref; 489 else { 490 unp2 = unp2->unp_refs; 491 for (;;) { 492 if (unp2 == 0) 493 panic("unp_disconnect"); 494 if (unp2->unp_nextref == unp) 495 break; 496 unp2 = unp2->unp_nextref; 497 } 498 unp2->unp_nextref = unp->unp_nextref; 499 } 500 unp->unp_nextref = 0; 501 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 502 break; 503 504 case SOCK_STREAM: 505 soisdisconnected(unp->unp_socket); 506 unp2->unp_conn = 0; 507 soisdisconnected(unp2->unp_socket); 508 break; 509 } 510 } 511 512 #ifdef notdef 513 unp_abort(unp) 514 struct unpcb *unp; 515 { 516 517 unp_detach(unp); 518 } 519 #endif 520 521 unp_shutdown(unp) 522 struct unpcb *unp; 523 { 524 struct socket *so; 525 526 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 527 (so = unp->unp_conn->unp_socket)) 528 socantrcvmore(so); 529 } 530 531 unp_drop(unp, errno) 532 struct unpcb *unp; 533 int errno; 534 { 535 struct socket *so = unp->unp_socket; 536 537 so->so_error = errno; 538 unp_disconnect(unp); 539 if (so->so_head) { 540 so->so_pcb = (caddr_t) 0; 541 m_freem(unp->unp_addr); 542 (void) m_free(dtom(unp)); 543 sofree(so); 544 } 545 } 546 547 #ifdef notdef 548 unp_drain() 549 { 550 551 } 552 #endif 553 554 unp_externalize(rights) 555 struct mbuf *rights; 556 { 557 struct proc *p = curproc; /* XXX */ 558 register int i; 559 register struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 560 register struct file **rp = (struct file **)(cm + 1); 561 register struct file *fp; 562 int newfds = (cm->cmsg_len - sizeof(*cm)) / sizeof (int); 563 int f; 564 565 if (fdavail(p, newfds)) { 566 for (i = 0; i < newfds; i++) { 567 fp = *rp; 568 unp_discard(fp); 569 *rp++ = 0; 570 } 571 return (EMSGSIZE); 572 } 573 for (i = 0; i < newfds; i++) { 574 if (fdalloc(p, 0, &f)) 575 panic("unp_externalize"); 576 fp = *rp; 577 p->p_fd->fd_ofiles[f] = fp; 578 fp->f_msgcount--; 579 unp_rights--; 580 *(int *)rp++ = f; 581 } 582 return (0); 583 } 584 585 unp_internalize(control, p) 586 struct mbuf *control; 587 struct proc *p; 588 { 589 struct filedesc *fdp = p->p_fd; 590 register struct cmsghdr *cm = mtod(control, struct cmsghdr *); 591 register struct file **rp; 592 register struct file *fp; 593 register int i, fd; 594 int oldfds; 595 596 if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET || 597 cm->cmsg_len != control->m_len) 598 return (EINVAL); 599 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int); 600 rp = (struct file **)(cm + 1); 601 for (i = 0; i < oldfds; i++) { 602 fd = *(int *)rp++; 603 if ((unsigned)fd >= fdp->fd_nfiles || 604 fdp->fd_ofiles[fd] == NULL) 605 return (EBADF); 606 } 607 rp = (struct file **)(cm + 1); 608 for (i = 0; i < oldfds; i++) { 609 fp = fdp->fd_ofiles[*(int *)rp]; 610 *rp++ = fp; 611 fp->f_count++; 612 fp->f_msgcount++; 613 unp_rights++; 614 } 615 return (0); 616 } 617 618 int unp_defer, unp_gcing; 619 int unp_mark(); 620 extern struct domain unixdomain; 621 622 unp_gc() 623 { 624 register struct file *fp; 625 register struct socket *so; 626 627 if (unp_gcing) 628 return; 629 unp_gcing = 1; 630 restart: 631 unp_defer = 0; 632 for (fp = filehead; fp; fp = fp->f_filef) 633 fp->f_flag &= ~(FMARK|FDEFER); 634 do { 635 for (fp = filehead; fp; fp = fp->f_filef) { 636 if (fp->f_count == 0) 637 continue; 638 if (fp->f_flag & FDEFER) { 639 fp->f_flag &= ~FDEFER; 640 unp_defer--; 641 } else { 642 if (fp->f_flag & FMARK) 643 continue; 644 if (fp->f_count == fp->f_msgcount) 645 continue; 646 fp->f_flag |= FMARK; 647 } 648 if (fp->f_type != DTYPE_SOCKET || 649 (so = (struct socket *)fp->f_data) == 0) 650 continue; 651 if (so->so_proto->pr_domain != &unixdomain || 652 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 653 continue; 654 #ifdef notdef 655 if (so->so_rcv.sb_flags & SB_LOCK) { 656 /* 657 * This is problematical; it's not clear 658 * we need to wait for the sockbuf to be 659 * unlocked (on a uniprocessor, at least), 660 * and it's also not clear what to do 661 * if sbwait returns an error due to receipt 662 * of a signal. If sbwait does return 663 * an error, we'll go into an infinite 664 * loop. Delete all of this for now. 665 */ 666 (void) sbwait(&so->so_rcv); 667 goto restart; 668 } 669 #endif 670 unp_scan(so->so_rcv.sb_mb, unp_mark); 671 } 672 } while (unp_defer); 673 for (fp = filehead; fp; fp = fp->f_filef) { 674 if (fp->f_count == 0) 675 continue; 676 if (fp->f_count == fp->f_msgcount && (fp->f_flag & FMARK) == 0) 677 while (fp->f_msgcount) 678 unp_discard(fp); 679 } 680 unp_gcing = 0; 681 } 682 683 unp_dispose(m) 684 struct mbuf *m; 685 { 686 int unp_discard(); 687 688 if (m) 689 unp_scan(m, unp_discard); 690 } 691 692 unp_scan(m0, op) 693 register struct mbuf *m0; 694 int (*op)(); 695 { 696 register struct mbuf *m; 697 register struct file **rp; 698 register struct cmsghdr *cm; 699 register int i; 700 int qfds; 701 702 while (m0) { 703 for (m = m0; m; m = m->m_next) 704 if (m->m_type == MT_CONTROL && 705 m->m_len >= sizeof(*cm)) { 706 cm = mtod(m, struct cmsghdr *); 707 if (cm->cmsg_level != SOL_SOCKET || 708 cm->cmsg_type != SCM_RIGHTS) 709 continue; 710 qfds = (cm->cmsg_len - sizeof *cm) 711 / sizeof (struct file *); 712 rp = (struct file **)(cm + 1); 713 for (i = 0; i < qfds; i++) 714 (*op)(*rp++); 715 break; /* XXX, but saves time */ 716 } 717 m0 = m0->m_act; 718 } 719 } 720 721 unp_mark(fp) 722 struct file *fp; 723 { 724 725 if (fp->f_flag & FMARK) 726 return; 727 unp_defer++; 728 fp->f_flag |= (FMARK|FDEFER); 729 } 730 731 unp_discard(fp) 732 struct file *fp; 733 { 734 735 fp->f_msgcount--; 736 unp_rights--; 737 (void) closef(fp, (struct proc *)NULL); 738 } 739