The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_socket.c

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    1 /*      $NetBSD: uipc_socket.c,v 1.302 2022/04/09 23:52:22 riastradh Exp $      */
    2 
    3 /*
    4  * Copyright (c) 2002, 2007, 2008, 2009 The NetBSD Foundation, Inc.
    5  * All rights reserved.
    6  *
    7  * This code is derived from software contributed to The NetBSD Foundation
    8  * by Jason R. Thorpe of Wasabi Systems, Inc, and by Andrew Doran.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   29  * POSSIBILITY OF SUCH DAMAGE.
   30  */
   31 
   32 /*
   33  * Copyright (c) 2004 The FreeBSD Foundation
   34  * Copyright (c) 2004 Robert Watson
   35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
   36  *      The Regents of the University of California.  All rights reserved.
   37  *
   38  * Redistribution and use in source and binary forms, with or without
   39  * modification, are permitted provided that the following conditions
   40  * are met:
   41  * 1. Redistributions of source code must retain the above copyright
   42  *    notice, this list of conditions and the following disclaimer.
   43  * 2. Redistributions in binary form must reproduce the above copyright
   44  *    notice, this list of conditions and the following disclaimer in the
   45  *    documentation and/or other materials provided with the distribution.
   46  * 3. Neither the name of the University nor the names of its contributors
   47  *    may be used to endorse or promote products derived from this software
   48  *    without specific prior written permission.
   49  *
   50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   60  * SUCH DAMAGE.
   61  *
   62  *      @(#)uipc_socket.c       8.6 (Berkeley) 5/2/95
   63  */
   64 
   65 /*
   66  * Socket operation routines.
   67  *
   68  * These routines are called by the routines in sys_socket.c or from a
   69  * system process, and implement the semantics of socket operations by
   70  * switching out to the protocol specific routines.
   71  */
   72 
   73 #include <sys/cdefs.h>
   74 __KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.302 2022/04/09 23:52:22 riastradh Exp $");
   75 
   76 #ifdef _KERNEL_OPT
   77 #include "opt_compat_netbsd.h"
   78 #include "opt_sock_counters.h"
   79 #include "opt_sosend_loan.h"
   80 #include "opt_mbuftrace.h"
   81 #include "opt_somaxkva.h"
   82 #include "opt_multiprocessor.h" /* XXX */
   83 #include "opt_sctp.h"
   84 #endif
   85 
   86 #include <sys/param.h>
   87 #include <sys/systm.h>
   88 #include <sys/proc.h>
   89 #include <sys/file.h>
   90 #include <sys/filedesc.h>
   91 #include <sys/kmem.h>
   92 #include <sys/mbuf.h>
   93 #include <sys/domain.h>
   94 #include <sys/kernel.h>
   95 #include <sys/protosw.h>
   96 #include <sys/socket.h>
   97 #include <sys/socketvar.h>
   98 #include <sys/signalvar.h>
   99 #include <sys/resourcevar.h>
  100 #include <sys/uidinfo.h>
  101 #include <sys/event.h>
  102 #include <sys/poll.h>
  103 #include <sys/kauth.h>
  104 #include <sys/mutex.h>
  105 #include <sys/condvar.h>
  106 #include <sys/kthread.h>
  107 #include <sys/compat_stub.h>
  108 
  109 #include <compat/sys/time.h>
  110 #include <compat/sys/socket.h>
  111 
  112 #include <uvm/uvm_extern.h>
  113 #include <uvm/uvm_loan.h>
  114 #include <uvm/uvm_page.h>
  115 
  116 #ifdef SCTP
  117 #include <netinet/sctp_route.h>
  118 #endif
  119 
  120 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
  121 
  122 extern const struct fileops socketops;
  123 
  124 static int      sooptions;
  125 extern int      somaxconn;                      /* patchable (XXX sysctl) */
  126 int             somaxconn = SOMAXCONN;
  127 kmutex_t        *softnet_lock;
  128 
  129 #ifdef SOSEND_COUNTERS
  130 #include <sys/device.h>
  131 
  132 static struct evcnt sosend_loan_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
  133     NULL, "sosend", "loan big");
  134 static struct evcnt sosend_copy_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
  135     NULL, "sosend", "copy big");
  136 static struct evcnt sosend_copy_small = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
  137     NULL, "sosend", "copy small");
  138 static struct evcnt sosend_kvalimit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
  139     NULL, "sosend", "kva limit");
  140 
  141 #define SOSEND_COUNTER_INCR(ev)         (ev)->ev_count++
  142 
  143 EVCNT_ATTACH_STATIC(sosend_loan_big);
  144 EVCNT_ATTACH_STATIC(sosend_copy_big);
  145 EVCNT_ATTACH_STATIC(sosend_copy_small);
  146 EVCNT_ATTACH_STATIC(sosend_kvalimit);
  147 #else
  148 
  149 #define SOSEND_COUNTER_INCR(ev)         /* nothing */
  150 
  151 #endif /* SOSEND_COUNTERS */
  152 
  153 #if defined(SOSEND_NO_LOAN) || defined(MULTIPROCESSOR)
  154 int sock_loan_thresh = -1;
  155 #else
  156 int sock_loan_thresh = 4096;
  157 #endif
  158 
  159 static kmutex_t so_pendfree_lock;
  160 static struct mbuf *so_pendfree = NULL;
  161 
  162 #ifndef SOMAXKVA
  163 #define SOMAXKVA (16 * 1024 * 1024)
  164 #endif
  165 int somaxkva = SOMAXKVA;
  166 static int socurkva;
  167 static kcondvar_t socurkva_cv;
  168 
  169 #ifndef SOFIXEDBUF
  170 #define SOFIXEDBUF true
  171 #endif
  172 bool sofixedbuf = SOFIXEDBUF;
  173 
  174 static kauth_listener_t socket_listener;
  175 
  176 #define SOCK_LOAN_CHUNK         65536
  177 
  178 static void sopendfree_thread(void *);
  179 static kcondvar_t pendfree_thread_cv;
  180 static lwp_t *sopendfree_lwp;
  181 
  182 static void sysctl_kern_socket_setup(void);
  183 static struct sysctllog *socket_sysctllog;
  184 
  185 static vsize_t
  186 sokvareserve(struct socket *so, vsize_t len)
  187 {
  188         int error;
  189 
  190         mutex_enter(&so_pendfree_lock);
  191         while (socurkva + len > somaxkva) {
  192                 SOSEND_COUNTER_INCR(&sosend_kvalimit);
  193                 error = cv_wait_sig(&socurkva_cv, &so_pendfree_lock);
  194                 if (error) {
  195                         len = 0;
  196                         break;
  197                 }
  198         }
  199         socurkva += len;
  200         mutex_exit(&so_pendfree_lock);
  201         return len;
  202 }
  203 
  204 static void
  205 sokvaunreserve(vsize_t len)
  206 {
  207 
  208         mutex_enter(&so_pendfree_lock);
  209         socurkva -= len;
  210         cv_broadcast(&socurkva_cv);
  211         mutex_exit(&so_pendfree_lock);
  212 }
  213 
  214 /*
  215  * sokvaalloc: allocate kva for loan.
  216  */
  217 vaddr_t
  218 sokvaalloc(vaddr_t sva, vsize_t len, struct socket *so)
  219 {
  220         vaddr_t lva;
  221 
  222         if (sokvareserve(so, len) == 0)
  223                 return 0;
  224 
  225         lva = uvm_km_alloc(kernel_map, len, atop(sva) & uvmexp.colormask,
  226             UVM_KMF_COLORMATCH | UVM_KMF_VAONLY | UVM_KMF_WAITVA);
  227         if (lva == 0) {
  228                 sokvaunreserve(len);
  229                 return 0;
  230         }
  231 
  232         return lva;
  233 }
  234 
  235 /*
  236  * sokvafree: free kva for loan.
  237  */
  238 void
  239 sokvafree(vaddr_t sva, vsize_t len)
  240 {
  241 
  242         uvm_km_free(kernel_map, sva, len, UVM_KMF_VAONLY);
  243         sokvaunreserve(len);
  244 }
  245 
  246 static void
  247 sodoloanfree(struct vm_page **pgs, void *buf, size_t size)
  248 {
  249         vaddr_t sva, eva;
  250         vsize_t len;
  251         int npgs;
  252 
  253         KASSERT(pgs != NULL);
  254 
  255         eva = round_page((vaddr_t) buf + size);
  256         sva = trunc_page((vaddr_t) buf);
  257         len = eva - sva;
  258         npgs = len >> PAGE_SHIFT;
  259 
  260         pmap_kremove(sva, len);
  261         pmap_update(pmap_kernel());
  262         uvm_unloan(pgs, npgs, UVM_LOAN_TOPAGE);
  263         sokvafree(sva, len);
  264 }
  265 
  266 /*
  267  * sopendfree_thread: free mbufs on "pendfree" list. Unlock and relock
  268  * so_pendfree_lock when freeing mbufs.
  269  */
  270 static void
  271 sopendfree_thread(void *v)
  272 {
  273         struct mbuf *m, *next;
  274         size_t rv;
  275 
  276         mutex_enter(&so_pendfree_lock);
  277 
  278         for (;;) {
  279                 rv = 0;
  280                 while (so_pendfree != NULL) {
  281                         m = so_pendfree;
  282                         so_pendfree = NULL;
  283                         mutex_exit(&so_pendfree_lock);
  284 
  285                         for (; m != NULL; m = next) {
  286                                 next = m->m_next;
  287                                 KASSERT((~m->m_flags & (M_EXT|M_EXT_PAGES)) ==
  288                                     0);
  289                                 KASSERT(m->m_ext.ext_refcnt == 0);
  290 
  291                                 rv += m->m_ext.ext_size;
  292                                 sodoloanfree(m->m_ext.ext_pgs, m->m_ext.ext_buf,
  293                                     m->m_ext.ext_size);
  294                                 pool_cache_put(mb_cache, m);
  295                         }
  296 
  297                         mutex_enter(&so_pendfree_lock);
  298                 }
  299                 if (rv)
  300                         cv_broadcast(&socurkva_cv);
  301                 cv_wait(&pendfree_thread_cv, &so_pendfree_lock);
  302         }
  303         panic("sopendfree_thread");
  304         /* NOTREACHED */
  305 }
  306 
  307 void
  308 soloanfree(struct mbuf *m, void *buf, size_t size, void *arg)
  309 {
  310 
  311         KASSERT(m != NULL);
  312 
  313         /*
  314          * postpone freeing mbuf.
  315          *
  316          * we can't do it in interrupt context
  317          * because we need to put kva back to kernel_map.
  318          */
  319 
  320         mutex_enter(&so_pendfree_lock);
  321         m->m_next = so_pendfree;
  322         so_pendfree = m;
  323         cv_signal(&pendfree_thread_cv);
  324         mutex_exit(&so_pendfree_lock);
  325 }
  326 
  327 static long
  328 sosend_loan(struct socket *so, struct uio *uio, struct mbuf *m, long space)
  329 {
  330         struct iovec *iov = uio->uio_iov;
  331         vaddr_t sva, eva;
  332         vsize_t len;
  333         vaddr_t lva;
  334         int npgs, error;
  335         vaddr_t va;
  336         int i;
  337 
  338         if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace))
  339                 return 0;
  340 
  341         if (iov->iov_len < (size_t) space)
  342                 space = iov->iov_len;
  343         if (space > SOCK_LOAN_CHUNK)
  344                 space = SOCK_LOAN_CHUNK;
  345 
  346         eva = round_page((vaddr_t) iov->iov_base + space);
  347         sva = trunc_page((vaddr_t) iov->iov_base);
  348         len = eva - sva;
  349         npgs = len >> PAGE_SHIFT;
  350 
  351         KASSERT(npgs <= M_EXT_MAXPAGES);
  352 
  353         lva = sokvaalloc(sva, len, so);
  354         if (lva == 0)
  355                 return 0;
  356 
  357         error = uvm_loan(&uio->uio_vmspace->vm_map, sva, len,
  358             m->m_ext.ext_pgs, UVM_LOAN_TOPAGE);
  359         if (error) {
  360                 sokvafree(lva, len);
  361                 return 0;
  362         }
  363 
  364         for (i = 0, va = lva; i < npgs; i++, va += PAGE_SIZE)
  365                 pmap_kenter_pa(va, VM_PAGE_TO_PHYS(m->m_ext.ext_pgs[i]),
  366                     VM_PROT_READ, 0);
  367         pmap_update(pmap_kernel());
  368 
  369         lva += (vaddr_t) iov->iov_base & PAGE_MASK;
  370 
  371         MEXTADD(m, (void *) lva, space, M_MBUF, soloanfree, so);
  372         m->m_flags |= M_EXT_PAGES | M_EXT_ROMAP;
  373 
  374         uio->uio_resid -= space;
  375         /* uio_offset not updated, not set/used for write(2) */
  376         uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + space;
  377         uio->uio_iov->iov_len -= space;
  378         if (uio->uio_iov->iov_len == 0) {
  379                 uio->uio_iov++;
  380                 uio->uio_iovcnt--;
  381         }
  382 
  383         return space;
  384 }
  385 
  386 static int
  387 socket_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
  388     void *arg0, void *arg1, void *arg2, void *arg3)
  389 {
  390         int result;
  391         enum kauth_network_req req;
  392 
  393         result = KAUTH_RESULT_DEFER;
  394         req = (enum kauth_network_req)(uintptr_t)arg0;
  395 
  396         if ((action != KAUTH_NETWORK_SOCKET) &&
  397             (action != KAUTH_NETWORK_BIND))
  398                 return result;
  399 
  400         switch (req) {
  401         case KAUTH_REQ_NETWORK_BIND_PORT:
  402                 result = KAUTH_RESULT_ALLOW;
  403                 break;
  404 
  405         case KAUTH_REQ_NETWORK_SOCKET_DROP: {
  406                 /* Normal users can only drop their own connections. */
  407                 struct socket *so = (struct socket *)arg1;
  408 
  409                 if (so->so_cred && proc_uidmatch(cred, so->so_cred) == 0)
  410                         result = KAUTH_RESULT_ALLOW;
  411 
  412                 break;
  413                 }
  414 
  415         case KAUTH_REQ_NETWORK_SOCKET_OPEN:
  416                 /* We allow "raw" routing/bluetooth sockets to anyone. */
  417                 switch ((u_long)arg1) {
  418                 case PF_ROUTE:
  419                 case PF_OROUTE:
  420                 case PF_BLUETOOTH:
  421                 case PF_CAN:
  422                         result = KAUTH_RESULT_ALLOW;
  423                         break;
  424                 default:
  425                         /* Privileged, let secmodel handle this. */
  426                         if ((u_long)arg2 == SOCK_RAW)
  427                                 break;
  428                         result = KAUTH_RESULT_ALLOW;
  429                         break;
  430                 }
  431                 break;
  432 
  433         case KAUTH_REQ_NETWORK_SOCKET_CANSEE:
  434                 result = KAUTH_RESULT_ALLOW;
  435 
  436                 break;
  437 
  438         default:
  439                 break;
  440         }
  441 
  442         return result;
  443 }
  444 
  445 void
  446 soinit(void)
  447 {
  448 
  449         sysctl_kern_socket_setup();
  450 
  451 #ifdef SCTP
  452         /* Update the SCTP function hooks if necessary*/
  453 
  454         vec_sctp_add_ip_address = sctp_add_ip_address;
  455         vec_sctp_delete_ip_address = sctp_delete_ip_address; 
  456 #endif
  457 
  458         mutex_init(&so_pendfree_lock, MUTEX_DEFAULT, IPL_VM);
  459         softnet_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
  460         cv_init(&socurkva_cv, "sokva");
  461         cv_init(&pendfree_thread_cv, "sopendfr");
  462         soinit2();
  463 
  464         /* Set the initial adjusted socket buffer size. */
  465         if (sb_max_set(sb_max))
  466                 panic("bad initial sb_max value: %lu", sb_max);
  467 
  468         socket_listener = kauth_listen_scope(KAUTH_SCOPE_NETWORK,
  469             socket_listener_cb, NULL);
  470 }
  471 
  472 void
  473 soinit1(void)
  474 {
  475         int error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
  476             sopendfree_thread, NULL, &sopendfree_lwp, "sopendfree");
  477         if (error)
  478                 panic("soinit1 %d", error);
  479 }
  480 
  481 /*
  482  * socreate: create a new socket of the specified type and the protocol.
  483  *
  484  * => Caller may specify another socket for lock sharing (must not be held).
  485  * => Returns the new socket without lock held.
  486  */
  487 int
  488 socreate(int dom, struct socket **aso, int type, int proto, struct lwp *l,
  489     struct socket *lockso)
  490 {
  491         const struct protosw *prp;
  492         struct socket *so;
  493         uid_t uid;
  494         int error;
  495         kmutex_t *lock;
  496 
  497         error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_SOCKET,
  498             KAUTH_REQ_NETWORK_SOCKET_OPEN, KAUTH_ARG(dom), KAUTH_ARG(type),
  499             KAUTH_ARG(proto));
  500         if (error != 0)
  501                 return error;
  502 
  503         if (proto)
  504                 prp = pffindproto(dom, proto, type);
  505         else
  506                 prp = pffindtype(dom, type);
  507         if (prp == NULL) {
  508                 /* no support for domain */
  509                 if (pffinddomain(dom) == 0)
  510                         return EAFNOSUPPORT;
  511                 /* no support for socket type */
  512                 if (proto == 0 && type != 0)
  513                         return EPROTOTYPE;
  514                 return EPROTONOSUPPORT;
  515         }
  516         if (prp->pr_usrreqs == NULL)
  517                 return EPROTONOSUPPORT;
  518         if (prp->pr_type != type)
  519                 return EPROTOTYPE;
  520 
  521         so = soget(true);
  522         so->so_type = type;
  523         so->so_proto = prp;
  524         so->so_send = sosend;
  525         so->so_receive = soreceive;
  526         so->so_options = sooptions;
  527 #ifdef MBUFTRACE
  528         so->so_rcv.sb_mowner = &prp->pr_domain->dom_mowner;
  529         so->so_snd.sb_mowner = &prp->pr_domain->dom_mowner;
  530         so->so_mowner = &prp->pr_domain->dom_mowner;
  531 #endif
  532         uid = kauth_cred_geteuid(l->l_cred);
  533         so->so_uidinfo = uid_find(uid);
  534         so->so_egid = kauth_cred_getegid(l->l_cred);
  535         so->so_cpid = l->l_proc->p_pid;
  536 
  537         /*
  538          * Lock assigned and taken during PCB attach, unless we share
  539          * the lock with another socket, e.g. socketpair(2) case.
  540          */
  541         if (lockso) {
  542                 /*
  543                  * lockso->so_lock should be stable at this point, so
  544                  * no need for atomic_load_*.
  545                  */
  546                 lock = lockso->so_lock;
  547                 so->so_lock = lock;
  548                 mutex_obj_hold(lock);
  549                 mutex_enter(lock);
  550         }
  551 
  552         /* Attach the PCB (returns with the socket lock held). */
  553         error = (*prp->pr_usrreqs->pr_attach)(so, proto);
  554         KASSERT(solocked(so));
  555 
  556         if (error) {
  557                 KASSERT(so->so_pcb == NULL);
  558                 so->so_state |= SS_NOFDREF;
  559                 sofree(so);
  560                 return error;
  561         }
  562         so->so_cred = kauth_cred_dup(l->l_cred);
  563         sounlock(so);
  564 
  565         *aso = so;
  566         return 0;
  567 }
  568 
  569 /*
  570  * fsocreate: create a socket and a file descriptor associated with it.
  571  *
  572  * => On success, write file descriptor to fdout and return zero.
  573  * => On failure, return non-zero; *fdout will be undefined.
  574  */
  575 int
  576 fsocreate(int domain, struct socket **sop, int type, int proto, int *fdout)
  577 {
  578         lwp_t *l = curlwp;
  579         int error, fd, flags;
  580         struct socket *so;
  581         struct file *fp;
  582 
  583         if ((error = fd_allocfile(&fp, &fd)) != 0) {
  584                 return error;
  585         }
  586         flags = type & SOCK_FLAGS_MASK;
  587         fd_set_exclose(l, fd, (flags & SOCK_CLOEXEC) != 0);
  588         fp->f_flag = FREAD|FWRITE|((flags & SOCK_NONBLOCK) ? FNONBLOCK : 0)|
  589             ((flags & SOCK_NOSIGPIPE) ? FNOSIGPIPE : 0);
  590         fp->f_type = DTYPE_SOCKET;
  591         fp->f_ops = &socketops;
  592 
  593         type &= ~SOCK_FLAGS_MASK;
  594         error = socreate(domain, &so, type, proto, l, NULL);
  595         if (error) {
  596                 fd_abort(curproc, fp, fd);
  597                 return error;
  598         }
  599         if (flags & SOCK_NONBLOCK) {
  600                 so->so_state |= SS_NBIO;
  601         }
  602         fp->f_socket = so;
  603         fd_affix(curproc, fp, fd);
  604 
  605         if (sop != NULL) {
  606                 *sop = so;
  607         }
  608         *fdout = fd;
  609         return error;
  610 }
  611 
  612 int
  613 sofamily(const struct socket *so)
  614 {
  615         const struct protosw *pr;
  616         const struct domain *dom;
  617 
  618         if ((pr = so->so_proto) == NULL)
  619                 return AF_UNSPEC;
  620         if ((dom = pr->pr_domain) == NULL)
  621                 return AF_UNSPEC;
  622         return dom->dom_family;
  623 }
  624 
  625 int
  626 sobind(struct socket *so, struct sockaddr *nam, struct lwp *l)
  627 {
  628         int error;
  629 
  630         solock(so);
  631         if (nam->sa_family != so->so_proto->pr_domain->dom_family) {
  632                 sounlock(so);
  633                 return EAFNOSUPPORT;
  634         }
  635         error = (*so->so_proto->pr_usrreqs->pr_bind)(so, nam, l);
  636         sounlock(so);
  637         return error;
  638 }
  639 
  640 int
  641 solisten(struct socket *so, int backlog, struct lwp *l)
  642 {
  643         int error;
  644         short oldopt, oldqlimit;
  645 
  646         solock(so);
  647         if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
  648             SS_ISDISCONNECTING)) != 0) {
  649                 sounlock(so);
  650                 return EINVAL;
  651         }
  652         oldopt = so->so_options;
  653         oldqlimit = so->so_qlimit;
  654         if (TAILQ_EMPTY(&so->so_q))
  655                 so->so_options |= SO_ACCEPTCONN;
  656         if (backlog < 0)
  657                 backlog = 0;
  658         so->so_qlimit = uimin(backlog, somaxconn);
  659 
  660         error = (*so->so_proto->pr_usrreqs->pr_listen)(so, l);
  661         if (error != 0) {
  662                 so->so_options = oldopt;
  663                 so->so_qlimit = oldqlimit;
  664                 sounlock(so);
  665                 return error;
  666         }
  667         sounlock(so);
  668         return 0;
  669 }
  670 
  671 void
  672 sofree(struct socket *so)
  673 {
  674         u_int refs;
  675 
  676         KASSERT(solocked(so));
  677 
  678         if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0) {
  679                 sounlock(so);
  680                 return;
  681         }
  682         if (so->so_head) {
  683                 /*
  684                  * We must not decommission a socket that's on the accept(2)
  685                  * queue.  If we do, then accept(2) may hang after select(2)
  686                  * indicated that the listening socket was ready.
  687                  */
  688                 if (!soqremque(so, 0)) {
  689                         sounlock(so);
  690                         return;
  691                 }
  692         }
  693         if (so->so_rcv.sb_hiwat)
  694                 (void)chgsbsize(so->so_uidinfo, &so->so_rcv.sb_hiwat, 0,
  695                     RLIM_INFINITY);
  696         if (so->so_snd.sb_hiwat)
  697                 (void)chgsbsize(so->so_uidinfo, &so->so_snd.sb_hiwat, 0,
  698                     RLIM_INFINITY);
  699         sbrelease(&so->so_snd, so);
  700         KASSERT(!cv_has_waiters(&so->so_cv));
  701         KASSERT(!cv_has_waiters(&so->so_rcv.sb_cv));
  702         KASSERT(!cv_has_waiters(&so->so_snd.sb_cv));
  703         sorflush(so);
  704         refs = so->so_aborting; /* XXX */
  705         /* Remove acccept filter if one is present. */
  706         if (so->so_accf != NULL)
  707                 (void)accept_filt_clear(so);
  708         sounlock(so);
  709         if (refs == 0)          /* XXX */
  710                 soput(so);
  711 }
  712 
  713 /*
  714  * soclose: close a socket on last file table reference removal.
  715  * Initiate disconnect if connected.  Free socket when disconnect complete.
  716  */
  717 int
  718 soclose(struct socket *so)
  719 {
  720         struct socket *so2;
  721         int error = 0;
  722 
  723         solock(so);
  724         if (so->so_options & SO_ACCEPTCONN) {
  725                 for (;;) {
  726                         if ((so2 = TAILQ_FIRST(&so->so_q0)) != 0) {
  727                                 KASSERT(solocked2(so, so2));
  728                                 (void) soqremque(so2, 0);
  729                                 /* soabort drops the lock. */
  730                                 (void) soabort(so2);
  731                                 solock(so);
  732                                 continue;
  733                         }
  734                         if ((so2 = TAILQ_FIRST(&so->so_q)) != 0) {
  735                                 KASSERT(solocked2(so, so2));
  736                                 (void) soqremque(so2, 1);
  737                                 /* soabort drops the lock. */
  738                                 (void) soabort(so2);
  739                                 solock(so);
  740                                 continue;
  741                         }
  742                         break;
  743                 }
  744         }
  745         if (so->so_pcb == NULL)
  746                 goto discard;
  747         if (so->so_state & SS_ISCONNECTED) {
  748                 if ((so->so_state & SS_ISDISCONNECTING) == 0) {
  749                         error = sodisconnect(so);
  750                         if (error)
  751                                 goto drop;
  752                 }
  753                 if (so->so_options & SO_LINGER) {
  754                         if ((so->so_state & (SS_ISDISCONNECTING|SS_NBIO)) ==
  755                             (SS_ISDISCONNECTING|SS_NBIO))
  756                                 goto drop;
  757                         while (so->so_state & SS_ISCONNECTED) {
  758                                 error = sowait(so, true, so->so_linger * hz);
  759                                 if (error)
  760                                         break;
  761                         }
  762                 }
  763         }
  764  drop:
  765         if (so->so_pcb) {
  766                 KASSERT(solocked(so));
  767                 (*so->so_proto->pr_usrreqs->pr_detach)(so);
  768         }
  769  discard:
  770         KASSERT((so->so_state & SS_NOFDREF) == 0);
  771         kauth_cred_free(so->so_cred);
  772         so->so_cred = NULL;
  773         so->so_state |= SS_NOFDREF;
  774         sofree(so);
  775         return error;
  776 }
  777 
  778 /*
  779  * Must be called with the socket locked..  Will return with it unlocked.
  780  */
  781 int
  782 soabort(struct socket *so)
  783 {
  784         u_int refs;
  785         int error;
  786 
  787         KASSERT(solocked(so));
  788         KASSERT(so->so_head == NULL);
  789 
  790         so->so_aborting++;              /* XXX */
  791         error = (*so->so_proto->pr_usrreqs->pr_abort)(so);
  792         refs = --so->so_aborting;       /* XXX */
  793         if (error || (refs == 0)) {
  794                 sofree(so);
  795         } else {
  796                 sounlock(so);
  797         }
  798         return error;
  799 }
  800 
  801 int
  802 soaccept(struct socket *so, struct sockaddr *nam)
  803 {
  804         int error;
  805 
  806         KASSERT(solocked(so));
  807         KASSERT((so->so_state & SS_NOFDREF) != 0);
  808 
  809         so->so_state &= ~SS_NOFDREF;
  810         if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
  811             (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
  812                 error = (*so->so_proto->pr_usrreqs->pr_accept)(so, nam);
  813         else
  814                 error = ECONNABORTED;
  815 
  816         return error;
  817 }
  818 
  819 int
  820 soconnect(struct socket *so, struct sockaddr *nam, struct lwp *l)
  821 {
  822         int error;
  823 
  824         KASSERT(solocked(so));
  825 
  826         if (so->so_options & SO_ACCEPTCONN)
  827                 return EOPNOTSUPP;
  828         /*
  829          * If protocol is connection-based, can only connect once.
  830          * Otherwise, if connected, try to disconnect first.
  831          * This allows user to disconnect by connecting to, e.g.,
  832          * a null address.
  833          */
  834         if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
  835             ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
  836             (error = sodisconnect(so)))) {
  837                 error = EISCONN;
  838         } else {
  839                 if (nam->sa_family != so->so_proto->pr_domain->dom_family) {
  840                         return EAFNOSUPPORT;
  841                 }
  842                 error = (*so->so_proto->pr_usrreqs->pr_connect)(so, nam, l);
  843         }
  844 
  845         return error;
  846 }
  847 
  848 int
  849 soconnect2(struct socket *so1, struct socket *so2)
  850 {
  851         KASSERT(solocked2(so1, so2));
  852 
  853         return (*so1->so_proto->pr_usrreqs->pr_connect2)(so1, so2);
  854 }
  855 
  856 int
  857 sodisconnect(struct socket *so)
  858 {
  859         int error;
  860 
  861         KASSERT(solocked(so));
  862 
  863         if ((so->so_state & SS_ISCONNECTED) == 0) {
  864                 error = ENOTCONN;
  865         } else if (so->so_state & SS_ISDISCONNECTING) {
  866                 error = EALREADY;
  867         } else {
  868                 error = (*so->so_proto->pr_usrreqs->pr_disconnect)(so);
  869         }
  870         return error;
  871 }
  872 
  873 #define SBLOCKWAIT(f)   (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
  874 /*
  875  * Send on a socket.
  876  * If send must go all at once and message is larger than
  877  * send buffering, then hard error.
  878  * Lock against other senders.
  879  * If must go all at once and not enough room now, then
  880  * inform user that this would block and do nothing.
  881  * Otherwise, if nonblocking, send as much as possible.
  882  * The data to be sent is described by "uio" if nonzero,
  883  * otherwise by the mbuf chain "top" (which must be null
  884  * if uio is not).  Data provided in mbuf chain must be small
  885  * enough to send all at once.
  886  *
  887  * Returns nonzero on error, timeout or signal; callers
  888  * must check for short counts if EINTR/ERESTART are returned.
  889  * Data and control buffers are freed on return.
  890  */
  891 int
  892 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
  893         struct mbuf *top, struct mbuf *control, int flags, struct lwp *l)
  894 {
  895         struct mbuf **mp, *m;
  896         long space, len, resid, clen, mlen;
  897         int error, s, dontroute, atomic;
  898         short wakeup_state = 0;
  899 
  900         clen = 0;
  901 
  902         /*
  903          * solock() provides atomicity of access.  splsoftnet() prevents
  904          * protocol processing soft interrupts from interrupting us and
  905          * blocking (expensive).
  906          */
  907         s = splsoftnet();
  908         solock(so);
  909         atomic = sosendallatonce(so) || top;
  910         if (uio)
  911                 resid = uio->uio_resid;
  912         else
  913                 resid = top->m_pkthdr.len;
  914         /*
  915          * In theory resid should be unsigned.
  916          * However, space must be signed, as it might be less than 0
  917          * if we over-committed, and we must use a signed comparison
  918          * of space and resid.  On the other hand, a negative resid
  919          * causes us to loop sending 0-length segments to the protocol.
  920          */
  921         if (resid < 0) {
  922                 error = EINVAL;
  923                 goto out;
  924         }
  925         dontroute =
  926             (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
  927             (so->so_proto->pr_flags & PR_ATOMIC);
  928         l->l_ru.ru_msgsnd++;
  929         if (control)
  930                 clen = control->m_len;
  931  restart:
  932         if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
  933                 goto out;
  934         do {
  935                 if (so->so_state & SS_CANTSENDMORE) {
  936                         error = EPIPE;
  937                         goto release;
  938                 }
  939                 if (so->so_error) {
  940                         error = so->so_error;
  941                         if ((flags & MSG_PEEK) == 0)
  942                                 so->so_error = 0;
  943                         goto release;
  944                 }
  945                 if ((so->so_state & SS_ISCONNECTED) == 0) {
  946                         if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
  947                                 if (resid || clen == 0) {
  948                                         error = ENOTCONN;
  949                                         goto release;
  950                                 }
  951                         } else if (addr == NULL) {
  952                                 error = EDESTADDRREQ;
  953                                 goto release;
  954                         }
  955                 }
  956                 space = sbspace(&so->so_snd);
  957                 if (flags & MSG_OOB)
  958                         space += 1024;
  959                 if ((atomic && resid > so->so_snd.sb_hiwat) ||
  960                     clen > so->so_snd.sb_hiwat) {
  961                         error = EMSGSIZE;
  962                         goto release;
  963                 }
  964                 if (space < resid + clen &&
  965                     (atomic || space < so->so_snd.sb_lowat || space < clen)) {
  966                         if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
  967                                 error = EWOULDBLOCK;
  968                                 goto release;
  969                         }
  970                         sbunlock(&so->so_snd);
  971                         if (wakeup_state & SS_RESTARTSYS) {
  972                                 error = ERESTART;
  973                                 goto out;
  974                         }
  975                         error = sbwait(&so->so_snd);
  976                         if (error)
  977                                 goto out;
  978                         wakeup_state = so->so_state;
  979                         goto restart;
  980                 }
  981                 wakeup_state = 0;
  982                 mp = &top;
  983                 space -= clen;
  984                 do {
  985                         if (uio == NULL) {
  986                                 /*
  987                                  * Data is prepackaged in "top".
  988                                  */
  989                                 resid = 0;
  990                                 if (flags & MSG_EOR)
  991                                         top->m_flags |= M_EOR;
  992                         } else do {
  993                                 sounlock(so);
  994                                 splx(s);
  995                                 if (top == NULL) {
  996                                         m = m_gethdr(M_WAIT, MT_DATA);
  997                                         mlen = MHLEN;
  998                                         m->m_pkthdr.len = 0;
  999                                         m_reset_rcvif(m);
 1000                                 } else {
 1001                                         m = m_get(M_WAIT, MT_DATA);
 1002                                         mlen = MLEN;
 1003                                 }
 1004                                 MCLAIM(m, so->so_snd.sb_mowner);
 1005                                 if (sock_loan_thresh >= 0 &&
 1006                                     uio->uio_iov->iov_len >= sock_loan_thresh &&
 1007                                     space >= sock_loan_thresh &&
 1008                                     (len = sosend_loan(so, uio, m,
 1009                                                        space)) != 0) {
 1010                                         SOSEND_COUNTER_INCR(&sosend_loan_big);
 1011                                         space -= len;
 1012                                         goto have_data;
 1013                                 }
 1014                                 if (resid >= MINCLSIZE && space >= MCLBYTES) {
 1015                                         SOSEND_COUNTER_INCR(&sosend_copy_big);
 1016                                         m_clget(m, M_DONTWAIT);
 1017                                         if ((m->m_flags & M_EXT) == 0)
 1018                                                 goto nopages;
 1019                                         mlen = MCLBYTES;
 1020                                         if (atomic && top == 0) {
 1021                                                 len = lmin(MCLBYTES - max_hdr,
 1022                                                     resid);
 1023                                                 m->m_data += max_hdr;
 1024                                         } else
 1025                                                 len = lmin(MCLBYTES, resid);
 1026                                         space -= len;
 1027                                 } else {
 1028  nopages:
 1029                                         SOSEND_COUNTER_INCR(&sosend_copy_small);
 1030                                         len = lmin(lmin(mlen, resid), space);
 1031                                         space -= len;
 1032                                         /*
 1033                                          * For datagram protocols, leave room
 1034                                          * for protocol headers in first mbuf.
 1035                                          */
 1036                                         if (atomic && top == 0 && len < mlen)
 1037                                                 m_align(m, len);
 1038                                 }
 1039                                 error = uiomove(mtod(m, void *), (int)len, uio);
 1040  have_data:
 1041                                 resid = uio->uio_resid;
 1042                                 m->m_len = len;
 1043                                 *mp = m;
 1044                                 top->m_pkthdr.len += len;
 1045                                 s = splsoftnet();
 1046                                 solock(so);
 1047                                 if (error != 0)
 1048                                         goto release;
 1049                                 mp = &m->m_next;
 1050                                 if (resid <= 0) {
 1051                                         if (flags & MSG_EOR)
 1052                                                 top->m_flags |= M_EOR;
 1053                                         break;
 1054                                 }
 1055                         } while (space > 0 && atomic);
 1056 
 1057                         if (so->so_state & SS_CANTSENDMORE) {
 1058                                 error = EPIPE;
 1059                                 goto release;
 1060                         }
 1061                         if (dontroute)
 1062                                 so->so_options |= SO_DONTROUTE;
 1063                         if (resid > 0)
 1064                                 so->so_state |= SS_MORETOCOME;
 1065                         if (flags & MSG_OOB) {
 1066                                 error = (*so->so_proto->pr_usrreqs->pr_sendoob)(
 1067                                     so, top, control);
 1068                         } else {
 1069                                 error = (*so->so_proto->pr_usrreqs->pr_send)(so,
 1070                                     top, addr, control, l);
 1071                         }
 1072                         if (dontroute)
 1073                                 so->so_options &= ~SO_DONTROUTE;
 1074                         if (resid > 0)
 1075                                 so->so_state &= ~SS_MORETOCOME;
 1076                         clen = 0;
 1077                         control = NULL;
 1078                         top = NULL;
 1079                         mp = &top;
 1080                         if (error != 0)
 1081                                 goto release;
 1082                 } while (resid && space > 0);
 1083         } while (resid);
 1084 
 1085  release:
 1086         sbunlock(&so->so_snd);
 1087  out:
 1088         sounlock(so);
 1089         splx(s);
 1090         if (top)
 1091                 m_freem(top);
 1092         if (control)
 1093                 m_freem(control);
 1094         return error;
 1095 }
 1096 
 1097 /*
 1098  * Following replacement or removal of the first mbuf on the first
 1099  * mbuf chain of a socket buffer, push necessary state changes back
 1100  * into the socket buffer so that other consumers see the values
 1101  * consistently.  'nextrecord' is the caller's locally stored value of
 1102  * the original value of sb->sb_mb->m_nextpkt which must be restored
 1103  * when the lead mbuf changes.  NOTE: 'nextrecord' may be NULL.
 1104  */
 1105 static void
 1106 sbsync(struct sockbuf *sb, struct mbuf *nextrecord)
 1107 {
 1108 
 1109         KASSERT(solocked(sb->sb_so));
 1110 
 1111         /*
 1112          * First, update for the new value of nextrecord.  If necessary,
 1113          * make it the first record.
 1114          */
 1115         if (sb->sb_mb != NULL)
 1116                 sb->sb_mb->m_nextpkt = nextrecord;
 1117         else
 1118                 sb->sb_mb = nextrecord;
 1119 
 1120         /*
 1121          * Now update any dependent socket buffer fields to reflect
 1122          * the new state.  This is an inline of SB_EMPTY_FIXUP, with
 1123          * the addition of a second clause that takes care of the
 1124          * case where sb_mb has been updated, but remains the last
 1125          * record.
 1126          */
 1127         if (sb->sb_mb == NULL) {
 1128                 sb->sb_mbtail = NULL;
 1129                 sb->sb_lastrecord = NULL;
 1130         } else if (sb->sb_mb->m_nextpkt == NULL)
 1131                 sb->sb_lastrecord = sb->sb_mb;
 1132 }
 1133 
 1134 /*
 1135  * Implement receive operations on a socket.
 1136  *
 1137  * We depend on the way that records are added to the sockbuf by sbappend*. In
 1138  * particular, each record (mbufs linked through m_next) must begin with an
 1139  * address if the protocol so specifies, followed by an optional mbuf or mbufs
 1140  * containing ancillary data, and then zero or more mbufs of data.
 1141  *
 1142  * In order to avoid blocking network interrupts for the entire time here, we
 1143  * splx() while doing the actual copy to user space. Although the sockbuf is
 1144  * locked, new data may still be appended, and thus we must maintain
 1145  * consistency of the sockbuf during that time.
 1146  *
 1147  * The caller may receive the data as a single mbuf chain by supplying an mbuf
 1148  * **mp0 for use in returning the chain. The uio is then used only for the
 1149  * count in uio_resid.
 1150  */
 1151 int
 1152 soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
 1153     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
 1154 {
 1155         struct lwp *l = curlwp;
 1156         struct mbuf *m, **mp, *mt;
 1157         size_t len, offset, moff, orig_resid;
 1158         int atomic, flags, error, s, type;
 1159         const struct protosw *pr;
 1160         struct mbuf *nextrecord;
 1161         int mbuf_removed = 0;
 1162         const struct domain *dom;
 1163         short wakeup_state = 0;
 1164 
 1165         pr = so->so_proto;
 1166         atomic = pr->pr_flags & PR_ATOMIC;
 1167         dom = pr->pr_domain;
 1168         mp = mp0;
 1169         type = 0;
 1170         orig_resid = uio->uio_resid;
 1171 
 1172         if (paddr != NULL)
 1173                 *paddr = NULL;
 1174         if (controlp != NULL)
 1175                 *controlp = NULL;
 1176         if (flagsp != NULL)
 1177                 flags = *flagsp &~ MSG_EOR;
 1178         else
 1179                 flags = 0;
 1180 
 1181         if (flags & MSG_OOB) {
 1182                 m = m_get(M_WAIT, MT_DATA);
 1183                 solock(so);
 1184                 error = (*pr->pr_usrreqs->pr_recvoob)(so, m, flags & MSG_PEEK);
 1185                 sounlock(so);
 1186                 if (error)
 1187                         goto bad;
 1188                 do {
 1189                         error = uiomove(mtod(m, void *),
 1190                             MIN(uio->uio_resid, m->m_len), uio);
 1191                         m = m_free(m);
 1192                 } while (uio->uio_resid > 0 && error == 0 && m);
 1193 bad:
 1194                 if (m != NULL)
 1195                         m_freem(m);
 1196                 return error;
 1197         }
 1198         if (mp != NULL)
 1199                 *mp = NULL;
 1200 
 1201         /*
 1202          * solock() provides atomicity of access.  splsoftnet() prevents
 1203          * protocol processing soft interrupts from interrupting us and
 1204          * blocking (expensive).
 1205          */
 1206         s = splsoftnet();
 1207         solock(so);
 1208 restart:
 1209         if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0) {
 1210                 sounlock(so);
 1211                 splx(s);
 1212                 return error;
 1213         }
 1214         m = so->so_rcv.sb_mb;
 1215 
 1216         /*
 1217          * If we have less data than requested, block awaiting more
 1218          * (subject to any timeout) if:
 1219          *   1. the current count is less than the low water mark,
 1220          *   2. MSG_WAITALL is set, and it is possible to do the entire
 1221          *      receive operation at once if we block (resid <= hiwat), or
 1222          *   3. MSG_DONTWAIT is not set.
 1223          * If MSG_WAITALL is set but resid is larger than the receive buffer,
 1224          * we have to do the receive in sections, and thus risk returning
 1225          * a short count if a timeout or signal occurs after we start.
 1226          */
 1227         if (m == NULL ||
 1228             ((flags & MSG_DONTWAIT) == 0 &&
 1229              so->so_rcv.sb_cc < uio->uio_resid &&
 1230              (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
 1231               ((flags & MSG_WAITALL) &&
 1232                uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
 1233              m->m_nextpkt == NULL && !atomic)) {
 1234 #ifdef DIAGNOSTIC
 1235                 if (m == NULL && so->so_rcv.sb_cc)
 1236                         panic("receive 1");
 1237 #endif
 1238                 if (so->so_error || so->so_rerror) {
 1239                         u_short *e;
 1240                         if (m != NULL)
 1241                                 goto dontblock;
 1242                         e = so->so_error ? &so->so_error : &so->so_rerror;
 1243                         error = *e;
 1244                         if ((flags & MSG_PEEK) == 0)
 1245                                 *e = 0;
 1246                         goto release;
 1247                 }
 1248                 if (so->so_state & SS_CANTRCVMORE) {
 1249                         if (m != NULL)
 1250                                 goto dontblock;
 1251                         else
 1252                                 goto release;
 1253                 }
 1254                 for (; m != NULL; m = m->m_next)
 1255                         if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
 1256                                 m = so->so_rcv.sb_mb;
 1257                                 goto dontblock;
 1258                         }
 1259                 if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
 1260                     (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
 1261                         error = ENOTCONN;
 1262                         goto release;
 1263                 }
 1264                 if (uio->uio_resid == 0)
 1265                         goto release;
 1266                 if ((so->so_state & SS_NBIO) ||
 1267                     (flags & (MSG_DONTWAIT|MSG_NBIO))) {
 1268                         error = EWOULDBLOCK;
 1269                         goto release;
 1270                 }
 1271                 SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
 1272                 SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
 1273                 sbunlock(&so->so_rcv);
 1274                 if (wakeup_state & SS_RESTARTSYS)
 1275                         error = ERESTART;
 1276                 else
 1277                         error = sbwait(&so->so_rcv);
 1278                 if (error != 0) {
 1279                         sounlock(so);
 1280                         splx(s);
 1281                         return error;
 1282                 }
 1283                 wakeup_state = so->so_state;
 1284                 goto restart;
 1285         }
 1286 
 1287 dontblock:
 1288         /*
 1289          * On entry here, m points to the first record of the socket buffer.
 1290          * From this point onward, we maintain 'nextrecord' as a cache of the
 1291          * pointer to the next record in the socket buffer.  We must keep the
 1292          * various socket buffer pointers and local stack versions of the
 1293          * pointers in sync, pushing out modifications before dropping the
 1294          * socket lock, and re-reading them when picking it up.
 1295          *
 1296          * Otherwise, we will race with the network stack appending new data
 1297          * or records onto the socket buffer by using inconsistent/stale
 1298          * versions of the field, possibly resulting in socket buffer
 1299          * corruption.
 1300          *
 1301          * By holding the high-level sblock(), we prevent simultaneous
 1302          * readers from pulling off the front of the socket buffer.
 1303          */
 1304         if (l != NULL)
 1305                 l->l_ru.ru_msgrcv++;
 1306         KASSERT(m == so->so_rcv.sb_mb);
 1307         SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
 1308         SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
 1309         nextrecord = m->m_nextpkt;
 1310 
 1311         if (pr->pr_flags & PR_ADDR) {
 1312                 KASSERT(m->m_type == MT_SONAME);
 1313                 orig_resid = 0;
 1314                 if (flags & MSG_PEEK) {
 1315                         if (paddr)
 1316                                 *paddr = m_copym(m, 0, m->m_len, M_DONTWAIT);
 1317                         m = m->m_next;
 1318                 } else {
 1319                         sbfree(&so->so_rcv, m);
 1320                         mbuf_removed = 1;
 1321                         if (paddr != NULL) {
 1322                                 *paddr = m;
 1323                                 so->so_rcv.sb_mb = m->m_next;
 1324                                 m->m_next = NULL;
 1325                                 m = so->so_rcv.sb_mb;
 1326                         } else {
 1327                                 m = so->so_rcv.sb_mb = m_free(m);
 1328                         }
 1329                         sbsync(&so->so_rcv, nextrecord);
 1330                 }
 1331         }
 1332 
 1333         if (pr->pr_flags & PR_ADDR_OPT) {
 1334                 /*
 1335                  * For SCTP we may be getting a whole message OR a partial
 1336                  * delivery.
 1337                  */
 1338                 if (m->m_type == MT_SONAME) {
 1339                         orig_resid = 0;
 1340                         if (flags & MSG_PEEK) {
 1341                                 if (paddr)
 1342                                         *paddr = m_copym(m, 0, m->m_len, M_DONTWAIT);
 1343                                 m = m->m_next;
 1344                         } else {
 1345                                 sbfree(&so->so_rcv, m);
 1346                                 mbuf_removed = 1;
 1347                                 if (paddr) {
 1348                                         *paddr = m;
 1349                                         so->so_rcv.sb_mb = m->m_next;
 1350                                         m->m_next = 0;
 1351                                         m = so->so_rcv.sb_mb;
 1352                                 } else {
 1353                                         m = so->so_rcv.sb_mb = m_free(m);
 1354                                 }
 1355                                 sbsync(&so->so_rcv, nextrecord);
 1356                         }
 1357                 }
 1358         }
 1359 
 1360         /*
 1361          * Process one or more MT_CONTROL mbufs present before any data mbufs
 1362          * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
 1363          * just copy the data; if !MSG_PEEK, we call into the protocol to
 1364          * perform externalization (or freeing if controlp == NULL).
 1365          */
 1366         if (__predict_false(m != NULL && m->m_type == MT_CONTROL)) {
 1367                 struct mbuf *cm = NULL, *cmn;
 1368                 struct mbuf **cme = &cm;
 1369 
 1370                 do {
 1371                         if (flags & MSG_PEEK) {
 1372                                 if (controlp != NULL) {
 1373                                         *controlp = m_copym(m, 0, m->m_len, M_DONTWAIT);
 1374                                         controlp = (*controlp == NULL ? NULL :
 1375                                             &(*controlp)->m_next);
 1376                                 }
 1377                                 m = m->m_next;
 1378                         } else {
 1379                                 sbfree(&so->so_rcv, m);
 1380                                 so->so_rcv.sb_mb = m->m_next;
 1381                                 m->m_next = NULL;
 1382                                 *cme = m;
 1383                                 cme = &(*cme)->m_next;
 1384                                 m = so->so_rcv.sb_mb;
 1385                         }
 1386                 } while (m != NULL && m->m_type == MT_CONTROL);
 1387                 if ((flags & MSG_PEEK) == 0)
 1388                         sbsync(&so->so_rcv, nextrecord);
 1389 
 1390                 for (; cm != NULL; cm = cmn) {
 1391                         cmn = cm->m_next;
 1392                         cm->m_next = NULL;
 1393                         type = mtod(cm, struct cmsghdr *)->cmsg_type;
 1394                         if (controlp != NULL) {
 1395                                 if (dom->dom_externalize != NULL &&
 1396                                     type == SCM_RIGHTS) {
 1397                                         sounlock(so);
 1398                                         splx(s);
 1399                                         error = (*dom->dom_externalize)(cm, l,
 1400                                             (flags & MSG_CMSG_CLOEXEC) ?
 1401                                             O_CLOEXEC : 0);
 1402                                         s = splsoftnet();
 1403                                         solock(so);
 1404                                 }
 1405                                 *controlp = cm;
 1406                                 while (*controlp != NULL)
 1407                                         controlp = &(*controlp)->m_next;
 1408                         } else {
 1409                                 /*
 1410                                  * Dispose of any SCM_RIGHTS message that went
 1411                                  * through the read path rather than recv.
 1412                                  */
 1413                                 if (dom->dom_dispose != NULL &&
 1414                                     type == SCM_RIGHTS) {
 1415                                         sounlock(so);
 1416                                         (*dom->dom_dispose)(cm);
 1417                                         solock(so);
 1418                                 }
 1419                                 m_freem(cm);
 1420                         }
 1421                 }
 1422                 if (m != NULL)
 1423                         nextrecord = so->so_rcv.sb_mb->m_nextpkt;
 1424                 else
 1425                         nextrecord = so->so_rcv.sb_mb;
 1426                 orig_resid = 0;
 1427         }
 1428 
 1429         /* If m is non-NULL, we have some data to read. */
 1430         if (__predict_true(m != NULL)) {
 1431                 type = m->m_type;
 1432                 if (type == MT_OOBDATA)
 1433                         flags |= MSG_OOB;
 1434         }
 1435         SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
 1436         SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
 1437 
 1438         moff = 0;
 1439         offset = 0;
 1440         while (m != NULL && uio->uio_resid > 0 && error == 0) {
 1441                 /*
 1442                  * If the type of mbuf has changed, end the receive
 1443                  * operation and do a short read.
 1444                  */
 1445                 if (m->m_type == MT_OOBDATA) {
 1446                         if (type != MT_OOBDATA)
 1447                                 break;
 1448                 } else if (type == MT_OOBDATA) {
 1449                         break;
 1450                 } else if (m->m_type == MT_CONTROL) {
 1451                         break;
 1452                 }
 1453 #ifdef DIAGNOSTIC
 1454                 else if (m->m_type != MT_DATA && m->m_type != MT_HEADER) {
 1455                         panic("%s: m_type=%d", __func__, m->m_type);
 1456                 }
 1457 #endif
 1458 
 1459                 so->so_state &= ~SS_RCVATMARK;
 1460                 wakeup_state = 0;
 1461                 len = uio->uio_resid;
 1462                 if (so->so_oobmark && len > so->so_oobmark - offset)
 1463                         len = so->so_oobmark - offset;
 1464                 if (len > m->m_len - moff)
 1465                         len = m->m_len - moff;
 1466 
 1467                 /*
 1468                  * If mp is set, just pass back the mbufs.
 1469                  * Otherwise copy them out via the uio, then free.
 1470                  * Sockbuf must be consistent here (points to current mbuf,
 1471                  * it points to next record) when we drop priority;
 1472                  * we must note any additions to the sockbuf when we
 1473                  * block interrupts again.
 1474                  */
 1475                 if (mp == NULL) {
 1476                         SBLASTRECORDCHK(&so->so_rcv, "soreceive uiomove");
 1477                         SBLASTMBUFCHK(&so->so_rcv, "soreceive uiomove");
 1478                         sounlock(so);
 1479                         splx(s);
 1480                         error = uiomove(mtod(m, char *) + moff, len, uio);
 1481                         s = splsoftnet();
 1482                         solock(so);
 1483                         if (error != 0) {
 1484                                 /*
 1485                                  * If any part of the record has been removed
 1486                                  * (such as the MT_SONAME mbuf, which will
 1487                                  * happen when PR_ADDR, and thus also
 1488                                  * PR_ATOMIC, is set), then drop the entire
 1489                                  * record to maintain the atomicity of the
 1490                                  * receive operation.
 1491                                  *
 1492                                  * This avoids a later panic("receive 1a")
 1493                                  * when compiled with DIAGNOSTIC.
 1494                                  */
 1495                                 if (m && mbuf_removed && atomic)
 1496                                         (void) sbdroprecord(&so->so_rcv);
 1497 
 1498                                 goto release;
 1499                         }
 1500                 } else {
 1501                         uio->uio_resid -= len;
 1502                 }
 1503 
 1504                 if (len == m->m_len - moff) {
 1505                         if (m->m_flags & M_EOR)
 1506                                 flags |= MSG_EOR;
 1507 #ifdef SCTP
 1508                         if (m->m_flags & M_NOTIFICATION)
 1509                                 flags |= MSG_NOTIFICATION;
 1510 #endif
 1511                         if (flags & MSG_PEEK) {
 1512                                 m = m->m_next;
 1513                                 moff = 0;
 1514                         } else {
 1515                                 nextrecord = m->m_nextpkt;
 1516                                 sbfree(&so->so_rcv, m);
 1517                                 if (mp) {
 1518                                         *mp = m;
 1519                                         mp = &m->m_next;
 1520                                         so->so_rcv.sb_mb = m = m->m_next;
 1521                                         *mp = NULL;
 1522                                 } else {
 1523                                         m = so->so_rcv.sb_mb = m_free(m);
 1524                                 }
 1525                                 /*
 1526                                  * If m != NULL, we also know that
 1527                                  * so->so_rcv.sb_mb != NULL.
 1528                                  */
 1529                                 KASSERT(so->so_rcv.sb_mb == m);
 1530                                 if (m) {
 1531                                         m->m_nextpkt = nextrecord;
 1532                                         if (nextrecord == NULL)
 1533                                                 so->so_rcv.sb_lastrecord = m;
 1534                                 } else {
 1535                                         so->so_rcv.sb_mb = nextrecord;
 1536                                         SB_EMPTY_FIXUP(&so->so_rcv);
 1537                                 }
 1538                                 SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
 1539                                 SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
 1540                         }
 1541                 } else if (flags & MSG_PEEK) {
 1542                         moff += len;
 1543                 } else {
 1544                         if (mp != NULL) {
 1545                                 mt = m_copym(m, 0, len, M_NOWAIT);
 1546                                 if (__predict_false(mt == NULL)) {
 1547                                         sounlock(so);
 1548                                         mt = m_copym(m, 0, len, M_WAIT);
 1549                                         solock(so);
 1550                                 }
 1551                                 *mp = mt;
 1552                         }
 1553                         m->m_data += len;
 1554                         m->m_len -= len;
 1555                         so->so_rcv.sb_cc -= len;
 1556                 }
 1557 
 1558                 if (so->so_oobmark) {
 1559                         if ((flags & MSG_PEEK) == 0) {
 1560                                 so->so_oobmark -= len;
 1561                                 if (so->so_oobmark == 0) {
 1562                                         so->so_state |= SS_RCVATMARK;
 1563                                         break;
 1564                                 }
 1565                         } else {
 1566                                 offset += len;
 1567                                 if (offset == so->so_oobmark)
 1568                                         break;
 1569                         }
 1570                 } else {
 1571                         so->so_state &= ~SS_POLLRDBAND;
 1572                 }
 1573                 if (flags & MSG_EOR)
 1574                         break;
 1575 
 1576                 /*
 1577                  * If the MSG_WAITALL flag is set (for non-atomic socket),
 1578                  * we must not quit until "uio->uio_resid == 0" or an error
 1579                  * termination.  If a signal/timeout occurs, return
 1580                  * with a short count but without error.
 1581                  * Keep sockbuf locked against other readers.
 1582                  */
 1583                 while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
 1584                     !sosendallatonce(so) && !nextrecord) {
 1585                         if (so->so_error || so->so_rerror ||
 1586                             so->so_state & SS_CANTRCVMORE)
 1587                                 break;
 1588                         /*
 1589                          * If we are peeking and the socket receive buffer is
 1590                          * full, stop since we can't get more data to peek at.
 1591                          */
 1592                         if ((flags & MSG_PEEK) && sbspace(&so->so_rcv) <= 0)
 1593                                 break;
 1594                         /*
 1595                          * If we've drained the socket buffer, tell the
 1596                          * protocol in case it needs to do something to
 1597                          * get it filled again.
 1598                          */
 1599                         if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb)
 1600                                 (*pr->pr_usrreqs->pr_rcvd)(so, flags, l);
 1601                         SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
 1602                         SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
 1603                         if (wakeup_state & SS_RESTARTSYS)
 1604                                 error = ERESTART;
 1605                         else
 1606                                 error = sbwait(&so->so_rcv);
 1607                         if (error != 0) {
 1608                                 sbunlock(&so->so_rcv);
 1609                                 sounlock(so);
 1610                                 splx(s);
 1611                                 return 0;
 1612                         }
 1613                         if ((m = so->so_rcv.sb_mb) != NULL)
 1614                                 nextrecord = m->m_nextpkt;
 1615                         wakeup_state = so->so_state;
 1616                 }
 1617         }
 1618 
 1619         if (m && atomic) {
 1620                 flags |= MSG_TRUNC;
 1621                 if ((flags & MSG_PEEK) == 0)
 1622                         (void) sbdroprecord(&so->so_rcv);
 1623         }
 1624         if ((flags & MSG_PEEK) == 0) {
 1625                 if (m == NULL) {
 1626                         /*
 1627                          * First part is an inline SB_EMPTY_FIXUP().  Second
 1628                          * part makes sure sb_lastrecord is up-to-date if
 1629                          * there is still data in the socket buffer.
 1630                          */
 1631                         so->so_rcv.sb_mb = nextrecord;
 1632                         if (so->so_rcv.sb_mb == NULL) {
 1633                                 so->so_rcv.sb_mbtail = NULL;
 1634                                 so->so_rcv.sb_lastrecord = NULL;
 1635                         } else if (nextrecord->m_nextpkt == NULL)
 1636                                 so->so_rcv.sb_lastrecord = nextrecord;
 1637                 }
 1638                 SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
 1639                 SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
 1640                 if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
 1641                         (*pr->pr_usrreqs->pr_rcvd)(so, flags, l);
 1642         }
 1643         if (orig_resid == uio->uio_resid && orig_resid &&
 1644             (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
 1645                 sbunlock(&so->so_rcv);
 1646                 goto restart;
 1647         }
 1648 
 1649         if (flagsp != NULL)
 1650                 *flagsp |= flags;
 1651 release:
 1652         sbunlock(&so->so_rcv);
 1653         sounlock(so);
 1654         splx(s);
 1655         return error;
 1656 }
 1657 
 1658 int
 1659 soshutdown(struct socket *so, int how)
 1660 {
 1661         const struct protosw *pr;
 1662         int error;
 1663 
 1664         KASSERT(solocked(so));
 1665 
 1666         pr = so->so_proto;
 1667         if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
 1668                 return EINVAL;
 1669 
 1670         if (how == SHUT_RD || how == SHUT_RDWR) {
 1671                 sorflush(so);
 1672                 error = 0;
 1673         }
 1674         if (how == SHUT_WR || how == SHUT_RDWR)
 1675                 error = (*pr->pr_usrreqs->pr_shutdown)(so);
 1676 
 1677         return error;
 1678 }
 1679 
 1680 void
 1681 sorestart(struct socket *so)
 1682 {
 1683         /*
 1684          * An application has called close() on an fd on which another
 1685          * of its threads has called a socket system call.
 1686          * Mark this and wake everyone up, and code that would block again
 1687          * instead returns ERESTART.
 1688          * On system call re-entry the fd is validated and EBADF returned.
 1689          * Any other fd will block again on the 2nd syscall.
 1690          */
 1691         solock(so);
 1692         so->so_state |= SS_RESTARTSYS;
 1693         cv_broadcast(&so->so_cv);
 1694         cv_broadcast(&so->so_snd.sb_cv);
 1695         cv_broadcast(&so->so_rcv.sb_cv);
 1696         sounlock(so);
 1697 }
 1698 
 1699 void
 1700 sorflush(struct socket *so)
 1701 {
 1702         struct sockbuf *sb, asb;
 1703         const struct protosw *pr;
 1704 
 1705         KASSERT(solocked(so));
 1706 
 1707         sb = &so->so_rcv;
 1708         pr = so->so_proto;
 1709         socantrcvmore(so);
 1710         sb->sb_flags |= SB_NOINTR;
 1711         (void )sblock(sb, M_WAITOK);
 1712         sbunlock(sb);
 1713         asb = *sb;
 1714         /*
 1715          * Clear most of the sockbuf structure, but leave some of the
 1716          * fields valid.
 1717          */
 1718         memset(&sb->sb_startzero, 0,
 1719             sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
 1720         if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose) {
 1721                 sounlock(so);
 1722                 (*pr->pr_domain->dom_dispose)(asb.sb_mb);
 1723                 solock(so);
 1724         }
 1725         sbrelease(&asb, so);
 1726 }
 1727 
 1728 /*
 1729  * internal set SOL_SOCKET options
 1730  */
 1731 static int
 1732 sosetopt1(struct socket *so, const struct sockopt *sopt)
 1733 {
 1734         int error, opt;
 1735         int optval = 0; /* XXX: gcc */
 1736         struct linger l;
 1737         struct timeval tv;
 1738 
 1739         opt = sopt->sopt_name;
 1740 
 1741         switch (opt) {
 1742 
 1743         case SO_ACCEPTFILTER:
 1744                 error = accept_filt_setopt(so, sopt);
 1745                 KASSERT(solocked(so));
 1746                 break;
 1747 
 1748         case SO_LINGER:
 1749                 error = sockopt_get(sopt, &l, sizeof(l));
 1750                 solock(so);
 1751                 if (error)
 1752                         break;
 1753                 if (l.l_linger < 0 || l.l_linger > USHRT_MAX ||
 1754                     l.l_linger > (INT_MAX / hz)) {
 1755                         error = EDOM;
 1756                         break;
 1757                 }
 1758                 so->so_linger = l.l_linger;
 1759                 if (l.l_onoff)
 1760                         so->so_options |= SO_LINGER;
 1761                 else
 1762                         so->so_options &= ~SO_LINGER;
 1763                 break;
 1764 
 1765         case SO_DEBUG:
 1766         case SO_KEEPALIVE:
 1767         case SO_DONTROUTE:
 1768         case SO_USELOOPBACK:
 1769         case SO_BROADCAST:
 1770         case SO_REUSEADDR:
 1771         case SO_REUSEPORT:
 1772         case SO_OOBINLINE:
 1773         case SO_TIMESTAMP:
 1774         case SO_NOSIGPIPE:
 1775         case SO_RERROR:
 1776                 error = sockopt_getint(sopt, &optval);
 1777                 solock(so);
 1778                 if (error)
 1779                         break;
 1780                 if (optval)
 1781                         so->so_options |= opt;
 1782                 else
 1783                         so->so_options &= ~opt;
 1784                 break;
 1785 
 1786         case SO_SNDBUF:
 1787         case SO_RCVBUF:
 1788         case SO_SNDLOWAT:
 1789         case SO_RCVLOWAT:
 1790                 error = sockopt_getint(sopt, &optval);
 1791                 solock(so);
 1792                 if (error)
 1793                         break;
 1794 
 1795                 /*
 1796                  * Values < 1 make no sense for any of these
 1797                  * options, so disallow them.
 1798                  */
 1799                 if (optval < 1) {
 1800                         error = EINVAL;
 1801                         break;
 1802                 }
 1803 
 1804                 switch (opt) {
 1805                 case SO_SNDBUF:
 1806                         if (sbreserve(&so->so_snd, (u_long)optval, so) == 0) {
 1807                                 error = ENOBUFS;
 1808                                 break;
 1809                         }
 1810                         if (sofixedbuf)
 1811                                 so->so_snd.sb_flags &= ~SB_AUTOSIZE;
 1812                         break;
 1813 
 1814                 case SO_RCVBUF:
 1815                         if (sbreserve(&so->so_rcv, (u_long)optval, so) == 0) {
 1816                                 error = ENOBUFS;
 1817                                 break;
 1818                         }
 1819                         if (sofixedbuf)
 1820                                 so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
 1821                         break;
 1822 
 1823                 /*
 1824                  * Make sure the low-water is never greater than
 1825                  * the high-water.
 1826                  */
 1827                 case SO_SNDLOWAT:
 1828                         if (optval > so->so_snd.sb_hiwat)
 1829                                 optval = so->so_snd.sb_hiwat;
 1830 
 1831                         so->so_snd.sb_lowat = optval;
 1832                         break;
 1833 
 1834                 case SO_RCVLOWAT:
 1835                         if (optval > so->so_rcv.sb_hiwat)
 1836                                 optval = so->so_rcv.sb_hiwat;
 1837 
 1838                         so->so_rcv.sb_lowat = optval;
 1839                         break;
 1840                 }
 1841                 break;
 1842 
 1843         case SO_SNDTIMEO:
 1844         case SO_RCVTIMEO:
 1845                 solock(so);
 1846                 error = sockopt_get(sopt, &tv, sizeof(tv));
 1847                 if (error)
 1848                         break;
 1849 
 1850                 if (tv.tv_sec < 0 || tv.tv_usec < 0 || tv.tv_usec >= 1000000) {
 1851                         error = EDOM;
 1852                         break;
 1853                 }
 1854                 if (tv.tv_sec > (INT_MAX - tv.tv_usec / tick) / hz) {
 1855                         error = EDOM;
 1856                         break;
 1857                 }
 1858 
 1859                 optval = tv.tv_sec * hz + tv.tv_usec / tick;
 1860                 if (optval == 0 && tv.tv_usec != 0)
 1861                         optval = 1;
 1862 
 1863                 switch (opt) {
 1864                 case SO_SNDTIMEO:
 1865                         so->so_snd.sb_timeo = optval;
 1866                         break;
 1867                 case SO_RCVTIMEO:
 1868                         so->so_rcv.sb_timeo = optval;
 1869                         break;
 1870                 }
 1871                 break;
 1872 
 1873         default:
 1874                 MODULE_HOOK_CALL(uipc_socket_50_setopt1_hook,
 1875                     (opt, so, sopt), enosys(), error);
 1876                 if (error == ENOSYS || error == EPASSTHROUGH) {
 1877                         solock(so);
 1878                         error = ENOPROTOOPT;
 1879                 }
 1880                 break;
 1881         }
 1882         KASSERT(solocked(so));
 1883         return error;
 1884 }
 1885 
 1886 int
 1887 sosetopt(struct socket *so, struct sockopt *sopt)
 1888 {
 1889         int error, prerr;
 1890 
 1891         if (sopt->sopt_level == SOL_SOCKET) {
 1892                 error = sosetopt1(so, sopt);
 1893                 KASSERT(solocked(so));
 1894         } else {
 1895                 error = ENOPROTOOPT;
 1896                 solock(so);
 1897         }
 1898 
 1899         if ((error == 0 || error == ENOPROTOOPT) &&
 1900             so->so_proto != NULL && so->so_proto->pr_ctloutput != NULL) {
 1901                 /* give the protocol stack a shot */
 1902                 prerr = (*so->so_proto->pr_ctloutput)(PRCO_SETOPT, so, sopt);
 1903                 if (prerr == 0)
 1904                         error = 0;
 1905                 else if (prerr != ENOPROTOOPT)
 1906                         error = prerr;
 1907         }
 1908         sounlock(so);
 1909         return error;
 1910 }
 1911 
 1912 /*
 1913  * so_setsockopt() is a wrapper providing a sockopt structure for sosetopt()
 1914  */
 1915 int
 1916 so_setsockopt(struct lwp *l, struct socket *so, int level, int name,
 1917     const void *val, size_t valsize)
 1918 {
 1919         struct sockopt sopt;
 1920         int error;
 1921 
 1922         KASSERT(valsize == 0 || val != NULL);
 1923 
 1924         sockopt_init(&sopt, level, name, valsize);
 1925         sockopt_set(&sopt, val, valsize);
 1926 
 1927         error = sosetopt(so, &sopt);
 1928 
 1929         sockopt_destroy(&sopt);
 1930 
 1931         return error;
 1932 }
 1933 
 1934 /*
 1935  * internal get SOL_SOCKET options
 1936  */
 1937 static int
 1938 sogetopt1(struct socket *so, struct sockopt *sopt)
 1939 {
 1940         int error, optval, opt;
 1941         struct linger l;
 1942         struct timeval tv;
 1943 
 1944         switch ((opt = sopt->sopt_name)) {
 1945 
 1946         case SO_ACCEPTFILTER:
 1947                 error = accept_filt_getopt(so, sopt);
 1948                 break;
 1949 
 1950         case SO_LINGER:
 1951                 l.l_onoff = (so->so_options & SO_LINGER) ? 1 : 0;
 1952                 l.l_linger = so->so_linger;
 1953 
 1954                 error = sockopt_set(sopt, &l, sizeof(l));
 1955                 break;
 1956 
 1957         case SO_USELOOPBACK:
 1958         case SO_DONTROUTE:
 1959         case SO_DEBUG:
 1960         case SO_KEEPALIVE:
 1961         case SO_REUSEADDR:
 1962         case SO_REUSEPORT:
 1963         case SO_BROADCAST:
 1964         case SO_OOBINLINE:
 1965         case SO_TIMESTAMP:
 1966         case SO_NOSIGPIPE:
 1967         case SO_RERROR:
 1968         case SO_ACCEPTCONN:
 1969                 error = sockopt_setint(sopt, (so->so_options & opt) ? 1 : 0);
 1970                 break;
 1971 
 1972         case SO_TYPE:
 1973                 error = sockopt_setint(sopt, so->so_type);
 1974                 break;
 1975 
 1976         case SO_ERROR:
 1977                 if (so->so_error == 0) {
 1978                         so->so_error = so->so_rerror;
 1979                         so->so_rerror = 0;
 1980                 }
 1981                 error = sockopt_setint(sopt, so->so_error);
 1982                 so->so_error = 0;
 1983                 break;
 1984 
 1985         case SO_SNDBUF:
 1986                 error = sockopt_setint(sopt, so->so_snd.sb_hiwat);
 1987                 break;
 1988 
 1989         case SO_RCVBUF:
 1990                 error = sockopt_setint(sopt, so->so_rcv.sb_hiwat);
 1991                 break;
 1992 
 1993         case SO_SNDLOWAT:
 1994                 error = sockopt_setint(sopt, so->so_snd.sb_lowat);
 1995                 break;
 1996 
 1997         case SO_RCVLOWAT:
 1998                 error = sockopt_setint(sopt, so->so_rcv.sb_lowat);
 1999                 break;
 2000 
 2001         case SO_SNDTIMEO:
 2002         case SO_RCVTIMEO:
 2003                 optval = (opt == SO_SNDTIMEO ?
 2004                      so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
 2005 
 2006                 memset(&tv, 0, sizeof(tv));
 2007                 tv.tv_sec = optval / hz;
 2008                 tv.tv_usec = (optval % hz) * tick;
 2009 
 2010                 error = sockopt_set(sopt, &tv, sizeof(tv));
 2011                 break;
 2012 
 2013         case SO_OVERFLOWED:
 2014                 error = sockopt_setint(sopt, so->so_rcv.sb_overflowed);
 2015                 break;
 2016 
 2017         default:
 2018                 MODULE_HOOK_CALL(uipc_socket_50_getopt1_hook,
 2019                     (opt, so, sopt), enosys(), error);
 2020                 if (error)
 2021                         error = ENOPROTOOPT;
 2022                 break;
 2023         }
 2024 
 2025         return error;
 2026 }
 2027 
 2028 int
 2029 sogetopt(struct socket *so, struct sockopt *sopt)
 2030 {
 2031         int error;
 2032 
 2033         solock(so);
 2034         if (sopt->sopt_level != SOL_SOCKET) {
 2035                 if (so->so_proto && so->so_proto->pr_ctloutput) {
 2036                         error = ((*so->so_proto->pr_ctloutput)
 2037                             (PRCO_GETOPT, so, sopt));
 2038                 } else
 2039                         error = (ENOPROTOOPT);
 2040         } else {
 2041                 error = sogetopt1(so, sopt);
 2042         }
 2043         sounlock(so);
 2044         return error;
 2045 }
 2046 
 2047 /*
 2048  * alloc sockopt data buffer buffer
 2049  *      - will be released at destroy
 2050  */
 2051 static int
 2052 sockopt_alloc(struct sockopt *sopt, size_t len, km_flag_t kmflag)
 2053 {
 2054         void *data;
 2055 
 2056         KASSERT(sopt->sopt_size == 0);
 2057 
 2058         if (len > sizeof(sopt->sopt_buf)) {
 2059                 data = kmem_zalloc(len, kmflag);
 2060                 if (data == NULL)
 2061                         return ENOMEM;
 2062                 sopt->sopt_data = data;
 2063         } else
 2064                 sopt->sopt_data = sopt->sopt_buf;
 2065 
 2066         sopt->sopt_size = len;
 2067         return 0;
 2068 }
 2069 
 2070 /*
 2071  * initialise sockopt storage
 2072  *      - MAY sleep during allocation
 2073  */
 2074 void
 2075 sockopt_init(struct sockopt *sopt, int level, int name, size_t size)
 2076 {
 2077 
 2078         memset(sopt, 0, sizeof(*sopt));
 2079 
 2080         sopt->sopt_level = level;
 2081         sopt->sopt_name = name;
 2082         (void)sockopt_alloc(sopt, size, KM_SLEEP);
 2083 }
 2084 
 2085 /*
 2086  * destroy sockopt storage
 2087  *      - will release any held memory references
 2088  */
 2089 void
 2090 sockopt_destroy(struct sockopt *sopt)
 2091 {
 2092 
 2093         if (sopt->sopt_data != sopt->sopt_buf)
 2094                 kmem_free(sopt->sopt_data, sopt->sopt_size);
 2095 
 2096         memset(sopt, 0, sizeof(*sopt));
 2097 }
 2098 
 2099 /*
 2100  * set sockopt value
 2101  *      - value is copied into sockopt
 2102  *      - memory is allocated when necessary, will not sleep
 2103  */
 2104 int
 2105 sockopt_set(struct sockopt *sopt, const void *buf, size_t len)
 2106 {
 2107         int error;
 2108 
 2109         if (sopt->sopt_size == 0) {
 2110                 error = sockopt_alloc(sopt, len, KM_NOSLEEP);
 2111                 if (error)
 2112                         return error;
 2113         }
 2114 
 2115         sopt->sopt_retsize = MIN(sopt->sopt_size, len);
 2116         if (sopt->sopt_retsize > 0) {
 2117                 memcpy(sopt->sopt_data, buf, sopt->sopt_retsize);
 2118         }
 2119 
 2120         return 0;
 2121 }
 2122 
 2123 /*
 2124  * common case of set sockopt integer value
 2125  */
 2126 int
 2127 sockopt_setint(struct sockopt *sopt, int val)
 2128 {
 2129 
 2130         return sockopt_set(sopt, &val, sizeof(int));
 2131 }
 2132 
 2133 /*
 2134  * get sockopt value
 2135  *      - correct size must be given
 2136  */
 2137 int
 2138 sockopt_get(const struct sockopt *sopt, void *buf, size_t len)
 2139 {
 2140 
 2141         if (sopt->sopt_size != len)
 2142                 return EINVAL;
 2143 
 2144         memcpy(buf, sopt->sopt_data, len);
 2145         return 0;
 2146 }
 2147 
 2148 /*
 2149  * common case of get sockopt integer value
 2150  */
 2151 int
 2152 sockopt_getint(const struct sockopt *sopt, int *valp)
 2153 {
 2154 
 2155         return sockopt_get(sopt, valp, sizeof(int));
 2156 }
 2157 
 2158 /*
 2159  * set sockopt value from mbuf
 2160  *      - ONLY for legacy code
 2161  *      - mbuf is released by sockopt
 2162  *      - will not sleep
 2163  */
 2164 int
 2165 sockopt_setmbuf(struct sockopt *sopt, struct mbuf *m)
 2166 {
 2167         size_t len;
 2168         int error;
 2169 
 2170         len = m_length(m);
 2171 
 2172         if (sopt->sopt_size == 0) {
 2173                 error = sockopt_alloc(sopt, len, KM_NOSLEEP);
 2174                 if (error)
 2175                         return error;
 2176         }
 2177 
 2178         sopt->sopt_retsize = MIN(sopt->sopt_size, len);
 2179         m_copydata(m, 0, sopt->sopt_retsize, sopt->sopt_data);
 2180         m_freem(m);
 2181 
 2182         return 0;
 2183 }
 2184 
 2185 /*
 2186  * get sockopt value into mbuf
 2187  *      - ONLY for legacy code
 2188  *      - mbuf to be released by the caller
 2189  *      - will not sleep
 2190  */
 2191 struct mbuf *
 2192 sockopt_getmbuf(const struct sockopt *sopt)
 2193 {
 2194         struct mbuf *m;
 2195 
 2196         if (sopt->sopt_size > MCLBYTES)
 2197                 return NULL;
 2198 
 2199         m = m_get(M_DONTWAIT, MT_SOOPTS);
 2200         if (m == NULL)
 2201                 return NULL;
 2202 
 2203         if (sopt->sopt_size > MLEN) {
 2204                 MCLGET(m, M_DONTWAIT);
 2205                 if ((m->m_flags & M_EXT) == 0) {
 2206                         m_free(m);
 2207                         return NULL;
 2208                 }
 2209         }
 2210 
 2211         memcpy(mtod(m, void *), sopt->sopt_data, sopt->sopt_size);
 2212         m->m_len = sopt->sopt_size;
 2213 
 2214         return m;
 2215 }
 2216 
 2217 void
 2218 sohasoutofband(struct socket *so)
 2219 {
 2220 
 2221         so->so_state |= SS_POLLRDBAND;
 2222         fownsignal(so->so_pgid, SIGURG, POLL_PRI, POLLPRI|POLLRDBAND, so);
 2223         selnotify(&so->so_rcv.sb_sel, POLLPRI | POLLRDBAND, NOTE_SUBMIT);
 2224 }
 2225 
 2226 static void
 2227 filt_sordetach(struct knote *kn)
 2228 {
 2229         struct socket *so;
 2230 
 2231         so = ((file_t *)kn->kn_obj)->f_socket;
 2232         solock(so);
 2233         if (selremove_knote(&so->so_rcv.sb_sel, kn))
 2234                 so->so_rcv.sb_flags &= ~SB_KNOTE;
 2235         sounlock(so);
 2236 }
 2237 
 2238 /*ARGSUSED*/
 2239 static int
 2240 filt_soread(struct knote *kn, long hint)
 2241 {
 2242         struct socket *so;
 2243         int rv;
 2244 
 2245         so = ((file_t *)kn->kn_obj)->f_socket;
 2246         if (hint != NOTE_SUBMIT)
 2247                 solock(so);
 2248         kn->kn_data = so->so_rcv.sb_cc;
 2249         if (so->so_state & SS_CANTRCVMORE) {
 2250                 knote_set_eof(kn, 0);
 2251                 kn->kn_fflags = so->so_error;
 2252                 rv = 1;
 2253         } else if (so->so_error || so->so_rerror)
 2254                 rv = 1;
 2255         else if (kn->kn_sfflags & NOTE_LOWAT)
 2256                 rv = (kn->kn_data >= kn->kn_sdata);
 2257         else
 2258                 rv = (kn->kn_data >= so->so_rcv.sb_lowat);
 2259         if (hint != NOTE_SUBMIT)
 2260                 sounlock(so);
 2261         return rv;
 2262 }
 2263 
 2264 static void
 2265 filt_sowdetach(struct knote *kn)
 2266 {
 2267         struct socket *so;
 2268 
 2269         so = ((file_t *)kn->kn_obj)->f_socket;
 2270         solock(so);
 2271         if (selremove_knote(&so->so_snd.sb_sel, kn))
 2272                 so->so_snd.sb_flags &= ~SB_KNOTE;
 2273         sounlock(so);
 2274 }
 2275 
 2276 /*ARGSUSED*/
 2277 static int
 2278 filt_sowrite(struct knote *kn, long hint)
 2279 {
 2280         struct socket *so;
 2281         int rv;
 2282 
 2283         so = ((file_t *)kn->kn_obj)->f_socket;
 2284         if (hint != NOTE_SUBMIT)
 2285                 solock(so);
 2286         kn->kn_data = sbspace(&so->so_snd);
 2287         if (so->so_state & SS_CANTSENDMORE) {
 2288                 knote_set_eof(kn, 0);
 2289                 kn->kn_fflags = so->so_error;
 2290                 rv = 1;
 2291         } else if (so->so_error)
 2292                 rv = 1;
 2293         else if (((so->so_state & SS_ISCONNECTED) == 0) &&
 2294             (so->so_proto->pr_flags & PR_CONNREQUIRED))
 2295                 rv = 0;
 2296         else if (kn->kn_sfflags & NOTE_LOWAT)
 2297                 rv = (kn->kn_data >= kn->kn_sdata);
 2298         else
 2299                 rv = (kn->kn_data >= so->so_snd.sb_lowat);
 2300         if (hint != NOTE_SUBMIT)
 2301                 sounlock(so);
 2302         return rv;
 2303 }
 2304 
 2305 static int
 2306 filt_soempty(struct knote *kn, long hint)
 2307 {
 2308         struct socket *so;
 2309         int rv;
 2310 
 2311         so = ((file_t *)kn->kn_obj)->f_socket;
 2312         if (hint != NOTE_SUBMIT)
 2313                 solock(so);
 2314         rv = (kn->kn_data = sbused(&so->so_snd)) == 0 ||
 2315              (so->so_options & SO_ACCEPTCONN) != 0;
 2316         if (hint != NOTE_SUBMIT)
 2317                 sounlock(so);
 2318         return rv;
 2319 }
 2320 
 2321 /*ARGSUSED*/
 2322 static int
 2323 filt_solisten(struct knote *kn, long hint)
 2324 {
 2325         struct socket *so;
 2326         int rv;
 2327 
 2328         so = ((file_t *)kn->kn_obj)->f_socket;
 2329 
 2330         /*
 2331          * Set kn_data to number of incoming connections, not
 2332          * counting partial (incomplete) connections.
 2333          */
 2334         if (hint != NOTE_SUBMIT)
 2335                 solock(so);
 2336         kn->kn_data = so->so_qlen;
 2337         rv = (kn->kn_data > 0);
 2338         if (hint != NOTE_SUBMIT)
 2339                 sounlock(so);
 2340         return rv;
 2341 }
 2342 
 2343 static const struct filterops solisten_filtops = {
 2344         .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
 2345         .f_attach = NULL,
 2346         .f_detach = filt_sordetach,
 2347         .f_event = filt_solisten,
 2348 };
 2349 
 2350 static const struct filterops soread_filtops = {
 2351         .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
 2352         .f_attach = NULL,
 2353         .f_detach = filt_sordetach,
 2354         .f_event = filt_soread,
 2355 };
 2356 
 2357 static const struct filterops sowrite_filtops = {
 2358         .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
 2359         .f_attach = NULL,
 2360         .f_detach = filt_sowdetach,
 2361         .f_event = filt_sowrite,
 2362 };
 2363 
 2364 static const struct filterops soempty_filtops = {
 2365         .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
 2366         .f_attach = NULL,
 2367         .f_detach = filt_sowdetach,
 2368         .f_event = filt_soempty,
 2369 };
 2370 
 2371 int
 2372 soo_kqfilter(struct file *fp, struct knote *kn)
 2373 {
 2374         struct socket *so;
 2375         struct sockbuf *sb;
 2376 
 2377         so = ((file_t *)kn->kn_obj)->f_socket;
 2378         solock(so);
 2379         switch (kn->kn_filter) {
 2380         case EVFILT_READ:
 2381                 if (so->so_options & SO_ACCEPTCONN)
 2382                         kn->kn_fop = &solisten_filtops;
 2383                 else
 2384                         kn->kn_fop = &soread_filtops;
 2385                 sb = &so->so_rcv;
 2386                 break;
 2387         case EVFILT_WRITE:
 2388                 kn->kn_fop = &sowrite_filtops;
 2389                 sb = &so->so_snd;
 2390                 break;
 2391         case EVFILT_EMPTY:
 2392                 kn->kn_fop = &soempty_filtops;
 2393                 sb = &so->so_snd;
 2394                 break;
 2395         default:
 2396                 sounlock(so);
 2397                 return EINVAL;
 2398         }
 2399         selrecord_knote(&sb->sb_sel, kn);
 2400         sb->sb_flags |= SB_KNOTE;
 2401         sounlock(so);
 2402         return 0;
 2403 }
 2404 
 2405 static int
 2406 sodopoll(struct socket *so, int events)
 2407 {
 2408         int revents;
 2409 
 2410         revents = 0;
 2411 
 2412         if (events & (POLLIN | POLLRDNORM))
 2413                 if (soreadable(so))
 2414                         revents |= events & (POLLIN | POLLRDNORM);
 2415 
 2416         if (events & (POLLOUT | POLLWRNORM))
 2417                 if (sowritable(so))
 2418                         revents |= events & (POLLOUT | POLLWRNORM);
 2419 
 2420         if (events & (POLLPRI | POLLRDBAND))
 2421                 if (so->so_state & SS_POLLRDBAND)
 2422                         revents |= events & (POLLPRI | POLLRDBAND);
 2423 
 2424         return revents;
 2425 }
 2426 
 2427 int
 2428 sopoll(struct socket *so, int events)
 2429 {
 2430         int revents = 0;
 2431 
 2432 #ifndef DIAGNOSTIC
 2433         /*
 2434          * Do a quick, unlocked check in expectation that the socket
 2435          * will be ready for I/O.  Don't do this check if DIAGNOSTIC,
 2436          * as the solocked() assertions will fail.
 2437          */
 2438         if ((revents = sodopoll(so, events)) != 0)
 2439                 return revents;
 2440 #endif
 2441 
 2442         solock(so);
 2443         if ((revents = sodopoll(so, events)) == 0) {
 2444                 if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
 2445                         selrecord(curlwp, &so->so_rcv.sb_sel);
 2446                         so->so_rcv.sb_flags |= SB_NOTIFY;
 2447                 }
 2448 
 2449                 if (events & (POLLOUT | POLLWRNORM)) {
 2450                         selrecord(curlwp, &so->so_snd.sb_sel);
 2451                         so->so_snd.sb_flags |= SB_NOTIFY;
 2452                 }
 2453         }
 2454         sounlock(so);
 2455 
 2456         return revents;
 2457 }
 2458 
 2459 struct mbuf **
 2460 sbsavetimestamp(int opt, struct mbuf **mp)
 2461 {
 2462         struct timeval tv;
 2463         int error;
 2464 
 2465         memset(&tv, 0, sizeof(tv));
 2466         microtime(&tv);
 2467 
 2468         MODULE_HOOK_CALL(uipc_socket_50_sbts_hook, (opt, &mp), enosys(), error);
 2469         if (error == 0)
 2470                 return mp;
 2471 
 2472         if (opt & SO_TIMESTAMP) {
 2473                 *mp = sbcreatecontrol(&tv, sizeof(tv),
 2474                     SCM_TIMESTAMP, SOL_SOCKET);
 2475                 if (*mp)
 2476                         mp = &(*mp)->m_next;
 2477         }
 2478         return mp;
 2479 }
 2480 
 2481 
 2482 #include <sys/sysctl.h>
 2483 
 2484 static int sysctl_kern_somaxkva(SYSCTLFN_PROTO);
 2485 static int sysctl_kern_sbmax(SYSCTLFN_PROTO);
 2486 
 2487 /*
 2488  * sysctl helper routine for kern.somaxkva.  ensures that the given
 2489  * value is not too small.
 2490  * (XXX should we maybe make sure it's not too large as well?)
 2491  */
 2492 static int
 2493 sysctl_kern_somaxkva(SYSCTLFN_ARGS)
 2494 {
 2495         int error, new_somaxkva;
 2496         struct sysctlnode node;
 2497 
 2498         new_somaxkva = somaxkva;
 2499         node = *rnode;
 2500         node.sysctl_data = &new_somaxkva;
 2501         error = sysctl_lookup(SYSCTLFN_CALL(&node));
 2502         if (error || newp == NULL)
 2503                 return error;
 2504 
 2505         if (new_somaxkva < (16 * 1024 * 1024)) /* sanity */
 2506                 return EINVAL;
 2507 
 2508         mutex_enter(&so_pendfree_lock);
 2509         somaxkva = new_somaxkva;
 2510         cv_broadcast(&socurkva_cv);
 2511         mutex_exit(&so_pendfree_lock);
 2512 
 2513         return error;
 2514 }
 2515 
 2516 /*
 2517  * sysctl helper routine for kern.sbmax. Basically just ensures that
 2518  * any new value is not too small.
 2519  */
 2520 static int
 2521 sysctl_kern_sbmax(SYSCTLFN_ARGS)
 2522 {
 2523         int error, new_sbmax;
 2524         struct sysctlnode node;
 2525 
 2526         new_sbmax = sb_max;
 2527         node = *rnode;
 2528         node.sysctl_data = &new_sbmax;
 2529         error = sysctl_lookup(SYSCTLFN_CALL(&node));
 2530         if (error || newp == NULL)
 2531                 return error;
 2532 
 2533         KERNEL_LOCK(1, NULL);
 2534         error = sb_max_set(new_sbmax);
 2535         KERNEL_UNLOCK_ONE(NULL);
 2536 
 2537         return error;
 2538 }
 2539 
 2540 /*
 2541  * sysctl helper routine for kern.sooptions. Ensures that only allowed
 2542  * options can be set.
 2543  */
 2544 static int
 2545 sysctl_kern_sooptions(SYSCTLFN_ARGS)
 2546 {
 2547         int error, new_options;
 2548         struct sysctlnode node;
 2549 
 2550         new_options = sooptions;
 2551         node = *rnode;
 2552         node.sysctl_data = &new_options;
 2553         error = sysctl_lookup(SYSCTLFN_CALL(&node));
 2554         if (error || newp == NULL)
 2555                 return error;
 2556 
 2557         if (new_options & ~SO_DEFOPTS)
 2558                 return EINVAL;
 2559 
 2560         sooptions = new_options;
 2561 
 2562         return 0;
 2563 }
 2564 
 2565 static void
 2566 sysctl_kern_socket_setup(void)
 2567 {
 2568 
 2569         KASSERT(socket_sysctllog == NULL);
 2570 
 2571         sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
 2572                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
 2573                        CTLTYPE_INT, "somaxkva",
 2574                        SYSCTL_DESCR("Maximum amount of kernel memory to be "
 2575                                     "used for socket buffers"),
 2576                        sysctl_kern_somaxkva, 0, NULL, 0,
 2577                        CTL_KERN, KERN_SOMAXKVA, CTL_EOL);
 2578 
 2579         sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
 2580                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
 2581                        CTLTYPE_BOOL, "sofixedbuf",
 2582                        SYSCTL_DESCR("Prevent scaling of fixed socket buffers"),
 2583                        NULL, 0, &sofixedbuf, 0,
 2584                        CTL_KERN, KERN_SOFIXEDBUF, CTL_EOL);
 2585 
 2586         sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
 2587                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
 2588                        CTLTYPE_INT, "sbmax",
 2589                        SYSCTL_DESCR("Maximum socket buffer size"),
 2590                        sysctl_kern_sbmax, 0, NULL, 0,
 2591                        CTL_KERN, KERN_SBMAX, CTL_EOL);
 2592 
 2593         sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
 2594                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
 2595                        CTLTYPE_INT, "sooptions",
 2596                        SYSCTL_DESCR("Default socket options"),
 2597                        sysctl_kern_sooptions, 0, NULL, 0,
 2598                        CTL_KERN, CTL_CREATE, CTL_EOL);
 2599 }

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