Merge remote-tracking branch 'origin/master' into nuke_nca

[unleashed.git] / kernel / fs / sockfs / socksyscalls.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved.
 * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
 * Copyright 2015, Joyent, Inc.  All rights reserved.
 */

#include <sys/types.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/cred.h>
#include <sys/kmem.h>
#include <sys/sysmacros.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/debug.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/file.h>
#include <sys/user.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/sunddi.h>
#include <sys/esunddi.h>
#include <sys/flock.h>
#include <sys/modctl.h>
#include <sys/cmn_err.h>
#include <sys/vmsystm.h>
#include <sys/policy.h>
#include <sys/limits.h>

#include <sys/socket.h>
#include <sys/socketvar.h>

#include <sys/isa_defs.h>
#include <sys/inttypes.h>
#include <sys/systm.h>
#include <sys/cpuvar.h>
#include <sys/filio.h>
#include <sys/sendfile.h>
#include <sys/ddi.h>
#include <vm/seg.h>
#include <vm/seg_map.h>
#include <vm/seg_kpm.h>

#include "sockcommon.h"
#include "sockfilter_impl.h"
#include "socktpi.h"

#ifdef SOCK_TEST
int do_useracc = 1;             /* Controlled by setting SO_DEBUG to 4 */
#else
#define do_useracc      1
#endif /* SOCK_TEST */

extern int      xnet_truncate_print;

/*
 * Kernel component of socket creation.
 *
 * First the library calls this with a NULL devpath. If this fails
 * to find a transport (using solookup) the library will look in /etc/netconfig
 * for the appropriate transport. If one is found it will pass in the
 * devpath for the kernel to use.
 */
int
so_socket(int family, int type_w_flags, int protocol, char *devpath)
{
        struct sonode *so;
        vnode_t *vp;
        struct file *fp;
        int fd;
        int error;
        int type;

        type = type_w_flags & SOCK_TYPE_MASK;
        type_w_flags &= ~SOCK_TYPE_MASK;
        if (type_w_flags & ~(SOCK_CLOEXEC|SOCK_NDELAY|SOCK_NONBLOCK))
                return (set_errno(EINVAL));

        if (devpath != NULL) {
                char *buf;
                size_t kdevpathlen = 0;

                buf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
                if ((error = copyinstr(devpath, buf,
                    MAXPATHLEN, &kdevpathlen)) != 0) {
                        kmem_free(buf, MAXPATHLEN);
                        return (set_errno(error));
                }
                so = socket_create(family, type, protocol, buf, NULL,
                    SOCKET_SLEEP, CRED(), &error);
                kmem_free(buf, MAXPATHLEN);
        } else {
                so = socket_create(family, type, protocol, NULL, NULL,
                    SOCKET_SLEEP, CRED(), &error);
        }
        if (so == NULL)
                return (set_errno(error));

        /* Allocate a file descriptor for the socket */
        vp = SOTOV(so);
        if (error = falloc(vp, FWRITE|FREAD, &fp, &fd)) {
                (void) socket_close(so, 0, CRED());
                socket_destroy(so);
                return (set_errno(error));
        }

        /*
         * Now fill in the entries that falloc reserved
         */
        if (type_w_flags & SOCK_NDELAY) {
                so->so_state |= SS_NDELAY;
                fp->f_flag |= FNDELAY;
        }
        if (type_w_flags & SOCK_NONBLOCK) {
                so->so_state |= SS_NONBLOCK;
                fp->f_flag |= FNONBLOCK;
        }
        mutex_exit(&fp->f_tlock);
        setf(fd, fp);
        if ((type_w_flags & SOCK_CLOEXEC) != 0) {
                f_setfd(fd, FD_CLOEXEC);
        }

        return (fd);
}

/*
 * Map from a file descriptor to a socket node.
 * Returns with the file descriptor held i.e. the caller has to
 * use releasef when done with the file descriptor.
 */
struct sonode *
getsonode(int sock, int *errorp, file_t **fpp)
{
        file_t *fp;
        vnode_t *vp;
        struct sonode *so;

        if ((fp = getf(sock)) == NULL) {
                *errorp = EBADF;
                eprintline(*errorp);
                return (NULL);
        }
        vp = fp->f_vnode;
        /* Check if it is a socket */
        if (vp->v_type != VSOCK) {
                releasef(sock);
                *errorp = ENOTSOCK;
                eprintline(*errorp);
                return (NULL);
        }
        /*
         * Use the stream head to find the real socket vnode.
         * This is needed when namefs sits above sockfs.
         */
        if (vp->v_stream) {
                ASSERT(vp->v_stream->sd_vnode);
                vp = vp->v_stream->sd_vnode;

                so = VTOSO(vp);
                if (so->so_is_stream) {
                        releasef(sock);
                        *errorp = ENOTSOCK;
                        eprintsoline(so, *errorp);
                        return (NULL);
                }
        } else {
                so = VTOSO(vp);
        }
        if (fpp)
                *fpp = fp;
        return (so);
}

/*
 * Allocate and copyin a sockaddr.
 * Ensures NULL termination for AF_UNIX addresses by extending them
 * with one NULL byte if need be. Verifies that the length is not
 * excessive to prevent an application from consuming all of kernel
 * memory. Returns NULL when an error occurred.
 */
static struct sockaddr *
copyin_name(struct sonode *so, struct sockaddr *name, socklen_t *namelenp,
            int *errorp)
{
        char    *faddr;
        size_t  namelen = (size_t)*namelenp;

        ASSERT(namelen != 0);
        if (namelen > SO_MAXARGSIZE) {
                *errorp = EINVAL;
                eprintsoline(so, *errorp);
                return (NULL);
        }

        faddr = (char *)kmem_alloc(namelen, KM_SLEEP);
        if (copyin(name, faddr, namelen)) {
                kmem_free(faddr, namelen);
                *errorp = EFAULT;
                eprintsoline(so, *errorp);
                return (NULL);
        }

        /*
         * Add space for NULL termination if needed.
         * Do a quick check if the last byte is NUL.
         */
        if (so->so_family == AF_UNIX && faddr[namelen - 1] != '\0') {
                /* Check if there is any NULL termination */
                size_t  i;
                int foundnull = 0;

                for (i = sizeof (name->sa_family); i < namelen; i++) {
                        if (faddr[i] == '\0') {
                                foundnull = 1;
                                break;
                        }
                }
                if (!foundnull) {
                        /* Add extra byte for NUL padding */
                        char *nfaddr;

                        nfaddr = (char *)kmem_alloc(namelen + 1, KM_SLEEP);
                        bcopy(faddr, nfaddr, namelen);
                        kmem_free(faddr, namelen);

                        /* NUL terminate */
                        nfaddr[namelen] = '\0';
                        namelen++;
                        ASSERT((socklen_t)namelen == namelen);
                        *namelenp = (socklen_t)namelen;
                        faddr = nfaddr;
                }
        }
        return ((struct sockaddr *)faddr);
}

/*
 * Copy from kaddr/klen to uaddr/ulen. Updates ulenp if non-NULL.
 */
static int
copyout_arg(void *uaddr, socklen_t ulen, void *ulenp,
                void *kaddr, socklen_t klen)
{
        if (uaddr != NULL) {
                if (ulen > klen)
                        ulen = klen;

                if (ulen != 0) {
                        if (copyout(kaddr, uaddr, ulen))
                                return (EFAULT);
                }
        } else
                ulen = 0;

        if (ulenp != NULL) {
                if (copyout(&ulen, ulenp, sizeof (ulen)))
                        return (EFAULT);
        }
        return (0);
}

/*
 * Copy from kaddr/klen to uaddr/ulen. Updates ulenp if non-NULL.
 * If klen is greater than ulen it still uses the non-truncated
 * klen to update ulenp.
 */
static int
copyout_name(void *uaddr, socklen_t ulen, void *ulenp,
                void *kaddr, socklen_t klen)
{
        if (uaddr != NULL) {
                if (ulen >= klen)
                        ulen = klen;
                else if (ulen != 0 && xnet_truncate_print) {
                        printf("sockfs: truncating copyout of address using "
                            "XNET semantics for pid = %d. Lengths %d, %d\n",
                            curproc->p_pid, klen, ulen);
                }

                if (ulen != 0) {
                        if (copyout(kaddr, uaddr, ulen))
                                return (EFAULT);
                } else
                        klen = 0;
        } else
                klen = 0;

        if (ulenp != NULL) {
                if (copyout(&klen, ulenp, sizeof (klen)))
                        return (EFAULT);
        }
        return (0);
}

/*
 * The socketpair() code in libsocket creates two sockets (using
 * the /etc/netconfig fallback if needed) before calling this routine
 * to connect the two sockets together.
 *
 * For a SOCK_STREAM socketpair a listener is needed - in that case this
 * routine will create a new file descriptor as part of accepting the
 * connection. The library socketpair() will check if svs[2] has changed
 * in which case it will close the changed fd.
 *
 * Note that this code could use the TPI feature of accepting the connection
 * on the listening endpoint. However, that would require significant changes
 * to soaccept.
 */
int
so_socketpair(int sv[2])
{
        int svs[2];
        struct sonode *so1, *so2;
        int error;
        int orig_flags;
        struct sockaddr_ux *name;
        size_t namelen;
        sotpi_info_t *sti1;
        sotpi_info_t *sti2;

        dprint(1, ("so_socketpair(%p)\n", (void *)sv));

        error = useracc(sv, sizeof (svs), B_WRITE);
        if (error && do_useracc)
                return (set_errno(EFAULT));

        if (copyin(sv, svs, sizeof (svs)))
                return (set_errno(EFAULT));

        if ((so1 = getsonode(svs[0], &error, NULL)) == NULL)
                return (set_errno(error));

        if ((so2 = getsonode(svs[1], &error, NULL)) == NULL) {
                releasef(svs[0]);
                return (set_errno(error));
        }

        if (so1->so_family != AF_UNIX || so2->so_family != AF_UNIX) {
                error = EOPNOTSUPP;
                goto done;
        }

        sti1 = SOTOTPI(so1);
        sti2 = SOTOTPI(so2);

        /*
         * The code below makes assumptions about the "sockfs" implementation.
         * So make sure that the correct implementation is really used.
         */
        ASSERT(so1->so_ops == &sotpi_sonodeops);
        ASSERT(so2->so_ops == &sotpi_sonodeops);

        if (so1->so_type == SOCK_DGRAM) {
                /*
                 * Bind both sockets and connect them with each other.
                 * Need to allocate name/namelen for soconnect.
                 */
                error = socket_bind(so1, NULL, 0, _SOBIND_UNSPEC, CRED());
                if (error) {
                        eprintsoline(so1, error);
                        goto done;
                }
                error = socket_bind(so2, NULL, 0, _SOBIND_UNSPEC, CRED());
                if (error) {
                        eprintsoline(so2, error);
                        goto done;
                }
                namelen = sizeof (struct sockaddr_ux);
                name = kmem_alloc(namelen, KM_SLEEP);
                name->sou_family = AF_UNIX;
                name->sou_addr = sti2->sti_ux_laddr;
                error = socket_connect(so1,
                    (struct sockaddr *)name,
                    (socklen_t)namelen,
                    0, _SOCONNECT_NOXLATE, CRED());
                if (error) {
                        kmem_free(name, namelen);
                        eprintsoline(so1, error);
                        goto done;
                }
                name->sou_addr = sti1->sti_ux_laddr;
                error = socket_connect(so2,
                    (struct sockaddr *)name,
                    (socklen_t)namelen,
                    0, _SOCONNECT_NOXLATE, CRED());
                kmem_free(name, namelen);
                if (error) {
                        eprintsoline(so2, error);
                        goto done;
                }
                releasef(svs[0]);
                releasef(svs[1]);
        } else {
                /*
                 * Bind both sockets, with so1 being a listener.
                 * Connect so2 to so1 - nonblocking to avoid waiting for
                 * soaccept to complete.
                 * Accept a connection on so1. Pass out the new fd as sv[0].
                 * The library will detect the changed fd and close
                 * the original one.
                 */
                struct sonode *nso;
                struct vnode *nvp;
                struct file *nfp;
                int nfd;

                /*
                 * We could simply call socket_listen() here (which would do the
                 * binding automatically) if the code didn't rely on passing
                 * _SOBIND_NOXLATE to the TPI implementation of socket_bind().
                 */
                error = socket_bind(so1, NULL, 0, _SOBIND_UNSPEC|
                    _SOBIND_NOXLATE|_SOBIND_LISTEN|_SOBIND_SOCKETPAIR,
                    CRED());
                if (error) {
                        eprintsoline(so1, error);
                        goto done;
                }
                error = socket_bind(so2, NULL, 0, _SOBIND_UNSPEC, CRED());
                if (error) {
                        eprintsoline(so2, error);
                        goto done;
                }

                namelen = sizeof (struct sockaddr_ux);
                name = kmem_alloc(namelen, KM_SLEEP);
                name->sou_family = AF_UNIX;
                name->sou_addr = sti1->sti_ux_laddr;
                error = socket_connect(so2,
                    (struct sockaddr *)name,
                    (socklen_t)namelen,
                    FNONBLOCK, _SOCONNECT_NOXLATE, CRED());
                kmem_free(name, namelen);
                if (error) {
                        if (error != EINPROGRESS) {
                                eprintsoline(so2, error); goto done;
                        }
                }

                error = socket_accept(so1, 0, CRED(), &nso);
                if (error) {
                        eprintsoline(so1, error);
                        goto done;
                }

                /* wait for so2 being SS_CONNECTED ignoring signals */
                mutex_enter(&so2->so_lock);
                error = sowaitconnected(so2, 0, 1);
                mutex_exit(&so2->so_lock);
                if (error != 0) {
                        (void) socket_close(nso, 0, CRED());
                        socket_destroy(nso);
                        eprintsoline(so2, error);
                        goto done;
                }

                nvp = SOTOV(nso);
                if (error = falloc(nvp, FWRITE|FREAD, &nfp, &nfd)) {
                        (void) socket_close(nso, 0, CRED());
                        socket_destroy(nso);
                        eprintsoline(nso, error);
                        goto done;
                }
                /*
                 * copy over FNONBLOCK and FNDELAY flags should they exist
                 */
                if (so1->so_state & SS_NONBLOCK)
                        nfp->f_flag |= FNONBLOCK;
                if (so1->so_state & SS_NDELAY)
                        nfp->f_flag |= FNDELAY;

                /*
                 * fill in the entries that falloc reserved
                 */
                mutex_exit(&nfp->f_tlock);
                setf(nfd, nfp);

                /*
                 * get the original flags before we release
                 */
                VERIFY(f_getfd_error(svs[0], &orig_flags) == 0);

                releasef(svs[0]);
                releasef(svs[1]);

                /*
                 * If FD_CLOEXEC was set on the filedescriptor we're
                 * swapping out, we should set it on the new one too.
                 */
                if (orig_flags & FD_CLOEXEC) {
                        f_setfd(nfd, FD_CLOEXEC);
                }

                /*
                 * The socketpair library routine will close the original
                 * svs[0] when this code passes out a different file
                 * descriptor.
                 */
                svs[0] = nfd;

                if (copyout(svs, sv, sizeof (svs))) {
                        (void) closeandsetf(nfd, NULL);
                        eprintline(EFAULT);
                        return (set_errno(EFAULT));
                }
        }
        return (0);

done:
        releasef(svs[0]);
        releasef(svs[1]);
        return (set_errno(error));
}

int
bind(int sock, struct sockaddr *name, socklen_t namelen)
{
        struct sonode *so;
        int error;

        dprint(1, ("bind(%d, %p, %d)\n",
            sock, (void *)name, namelen));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                return (set_errno(error));

        /* Allocate and copyin name */
        /*
         * X/Open test does not expect EFAULT with NULL name and non-zero
         * namelen.
         */
        if (name != NULL && namelen != 0) {
                ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                name = copyin_name(so, name, &namelen, &error);
                if (name == NULL) {
                        releasef(sock);
                        return (set_errno(error));
                }
        } else {
                name = NULL;
                namelen = 0;
        }

        error = socket_bind(so, name, namelen, 0, CRED());
done:
        releasef(sock);
        if (name != NULL)
                kmem_free(name, (size_t)namelen);

        if (error)
                return (set_errno(error));
        return (0);
}

int
listen(int sock, int backlog)
{
        struct sonode *so;
        int error;

        dprint(1, ("listen(%d, %d)\n",
            sock, backlog));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                return (set_errno(error));

        error = socket_listen(so, backlog, CRED());

        releasef(sock);
        if (error)
                return (set_errno(error));
        return (0);
}

int
accept(int sock, struct sockaddr *name, socklen_t *namelenp, int flags)
{
        struct sonode *so;
        file_t *fp;
        int error;
        socklen_t namelen;
        struct sonode *nso;
        struct vnode *nvp;
        struct file *nfp;
        int nfd;
        int ssflags;
        struct sockaddr *addrp;
        socklen_t addrlen;

        dprint(1, ("accept(%d, %p, %p)\n",
            sock, (void *)name, (void *)namelenp));

        if (flags & ~(SOCK_CLOEXEC|SOCK_NONBLOCK|SOCK_NDELAY)) {
                return (set_errno(EINVAL));
        }

        /* Translate SOCK_ flags to their SS_ variant */
        ssflags = 0;
        if (flags & SOCK_NONBLOCK)
                ssflags |= SS_NONBLOCK;
        if (flags & SOCK_NDELAY)
                ssflags |= SS_NDELAY;

        if ((so = getsonode(sock, &error, &fp)) == NULL)
                return (set_errno(error));

        if (name != NULL) {
                ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                if (copyin(namelenp, &namelen, sizeof (namelen))) {
                        releasef(sock);
                        return (set_errno(EFAULT));
                }
                if (namelen != 0) {
                        error = useracc(name, (size_t)namelen, B_WRITE);
                        if (error && do_useracc) {
                                releasef(sock);
                                return (set_errno(EFAULT));
                        }
                } else
                        name = NULL;
        } else {
                namelen = 0;
        }

        /*
         * Allocate the user fd before socket_accept() in order to
         * catch EMFILE errors before calling socket_accept().
         */
        if ((nfd = ufalloc(0)) == -1) {
                eprintsoline(so, EMFILE);
                releasef(sock);
                return (set_errno(EMFILE));
        }
        error = socket_accept(so, fp->f_flag, CRED(), &nso);
        if (error) {
                setf(nfd, NULL);
                releasef(sock);
                return (set_errno(error));
        }

        nvp = SOTOV(nso);

        ASSERT(MUTEX_NOT_HELD(&nso->so_lock));
        if (namelen != 0) {
                addrlen = so->so_max_addr_len;
                addrp = (struct sockaddr *)kmem_alloc(addrlen, KM_SLEEP);

                if ((error = socket_getpeername(nso, (struct sockaddr *)addrp,
                    &addrlen, B_TRUE, CRED())) == 0) {
                        error = copyout_name(name, namelen, namelenp,
                            addrp, addrlen);
                } else {
                        ASSERT(error == EINVAL || error == ENOTCONN);
                        error = ECONNABORTED;
                }
                kmem_free(addrp, so->so_max_addr_len);
        }

        if (error) {
                setf(nfd, NULL);
                (void) socket_close(nso, 0, CRED());
                socket_destroy(nso);
                releasef(sock);
                return (set_errno(error));
        }
        if (error = falloc(NULL, FWRITE|FREAD, &nfp, NULL)) {
                setf(nfd, NULL);
                (void) socket_close(nso, 0, CRED());
                socket_destroy(nso);
                eprintsoline(so, error);
                releasef(sock);
                return (set_errno(error));
        }
        /*
         * fill in the entries that falloc reserved
         */
        nfp->f_vnode = nvp;
        mutex_exit(&nfp->f_tlock);
        setf(nfd, nfp);

        /*
         * Act on SOCK_CLOEXEC from flags
         */
        if (flags & SOCK_CLOEXEC) {
                f_setfd(nfd, FD_CLOEXEC);
        }

        /*
         * Copy FNDELAY and FNONBLOCK from listener to acceptor
         * and from ssflags
         */
        if ((ssflags | so->so_state) & (SS_NDELAY|SS_NONBLOCK)) {
                uint_t oflag = nfp->f_flag;
                int arg = 0;

                if ((ssflags | so->so_state) & SS_NONBLOCK)
                        arg |= FNONBLOCK;
                else if ((ssflags | so->so_state) & SS_NDELAY)
                        arg |= FNDELAY;

                /*
                 * This code is a simplification of the F_SETFL code in fcntl()
                 * Ignore any errors from VOP_SETFL.
                 */
                if ((error = VOP_SETFL(nvp, oflag, arg, nfp->f_cred, NULL))
                    != 0) {
                        eprintsoline(so, error);
                        error = 0;
                } else {
                        mutex_enter(&nfp->f_tlock);
                        nfp->f_flag &= ~FMASK | (FREAD|FWRITE);
                        nfp->f_flag |= arg;
                        mutex_exit(&nfp->f_tlock);
                }
        }
        releasef(sock);
        return (nfd);
}

int
connect(int sock, struct sockaddr *name, socklen_t namelen)
{
        struct sonode *so;
        file_t *fp;
        int error;

        dprint(1, ("connect(%d, %p, %d)\n",
            sock, (void *)name, namelen));

        if ((so = getsonode(sock, &error, &fp)) == NULL)
                return (set_errno(error));

        /* Allocate and copyin name */
        if (namelen != 0) {
                ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                name = copyin_name(so, name, &namelen, &error);
                if (name == NULL) {
                        releasef(sock);
                        return (set_errno(error));
                }
        } else
                name = NULL;

        error = socket_connect(so, name, namelen, fp->f_flag, 0, CRED());
        releasef(sock);
        if (name)
                kmem_free(name, (size_t)namelen);
        if (error)
                return (set_errno(error));
        return (0);
}

int
shutdown(int sock, int how)
{
        struct sonode *so;
        int error;

        dprint(1, ("shutdown(%d, %d)\n",
            sock, how));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                return (set_errno(error));

        error = socket_shutdown(so, how, CRED());

        releasef(sock);
        if (error)
                return (set_errno(error));
        return (0);
}

/*
 * Common receive routine.
 */
static ssize_t
recvit(int sock,
        struct nmsghdr *msg,
        struct uio *uiop,
        int flags,
        socklen_t *namelenp,
        socklen_t *controllenp,
        int *flagsp)
{
        struct sonode *so;
        file_t *fp;
        void *name;
        socklen_t namelen;
        void *control;
        socklen_t controllen;
        ssize_t len;
        int error;

        if ((so = getsonode(sock, &error, &fp)) == NULL)
                return (set_errno(error));

        len = uiop->uio_resid;
        uiop->uio_fmode = fp->f_flag;
        uiop->uio_extflg = UIO_COPY_CACHED;

        name = msg->msg_name;
        namelen = msg->msg_namelen;
        control = msg->msg_control;
        controllen = msg->msg_controllen;

        msg->msg_flags = flags & (MSG_OOB | MSG_PEEK | MSG_WAITALL |
            MSG_DONTWAIT);

        error = socket_recvmsg(so, msg, uiop, CRED());
        if (error) {
                releasef(sock);
                return (set_errno(error));
        }
        lwp_stat_update(LWP_STAT_MSGRCV, 1);
        releasef(sock);

        error = copyout_name(name, namelen, namelenp,
            msg->msg_name, msg->msg_namelen);
        if (error)
                goto err;

        if (flagsp != NULL) {
                /*
                 * Determine MSG_CTRUNC. sorecvmsg sets MSG_CTRUNC only
                 * when controllen is zero and there is control data to
                 * copy out.
                 */
                if (controllen != 0 &&
                    (msg->msg_controllen > controllen || control == NULL)) {
                        dprint(1, ("recvit: CTRUNC %d %d %p\n",
                            msg->msg_controllen, controllen, control));

                        msg->msg_flags |= MSG_CTRUNC;
                }
                if (copyout(&msg->msg_flags, flagsp,
                    sizeof (msg->msg_flags))) {
                        error = EFAULT;
                        goto err;
                }
        }
        /*
         * Note: This MUST be done last. There can be no "goto err" after this
         * point since it could make so_closefds run twice on some part
         * of the file descriptor array.
         */
        if (controllen != 0) {
                error = copyout_arg(control, controllen, controllenp,
                    msg->msg_control, msg->msg_controllen);
                if (error)
                        goto err;

                if (msg->msg_controllen > controllen || control == NULL) {
                        if (control == NULL)
                                controllen = 0;
                        so_closefds(msg->msg_control, msg->msg_controllen,
                            controllen);
                }
        }
        if (msg->msg_namelen != 0)
                kmem_free(msg->msg_name, (size_t)msg->msg_namelen);
        if (msg->msg_controllen != 0)
                kmem_free(msg->msg_control, (size_t)msg->msg_controllen);
        return (len - uiop->uio_resid);

err:
        /*
         * If we fail and the control part contains file descriptors
         * we have to close the fd's.
         */
        if (msg->msg_controllen != 0)
                so_closefds(msg->msg_control, msg->msg_controllen, 0);
        if (msg->msg_namelen != 0)
                kmem_free(msg->msg_name, (size_t)msg->msg_namelen);
        if (msg->msg_controllen != 0)
                kmem_free(msg->msg_control, (size_t)msg->msg_controllen);
        return (set_errno(error));
}

/*
 * Native system call
 */
ssize_t
recv(int sock, void *buffer, size_t len, int flags)
{
        struct nmsghdr lmsg;
        struct uio auio;
        struct iovec aiov[1];

        dprint(1, ("recv(%d, %p, %ld, %d)\n",
            sock, buffer, len, flags));

        if ((ssize_t)len < 0) {
                return (set_errno(EINVAL));
        }

        aiov[0].iov_base = buffer;
        aiov[0].iov_len = len;
        auio.uio_loffset = 0;
        auio.uio_iov = aiov;
        auio.uio_iovcnt = 1;
        auio.uio_resid = len;
        auio.uio_segflg = UIO_USERSPACE;
        auio.uio_limit = 0;

        lmsg.msg_namelen = 0;
        lmsg.msg_controllen = 0;
        lmsg.msg_flags = 0;
        return (recvit(sock, &lmsg, &auio, flags, NULL, NULL, NULL));
}

ssize_t
recvfrom(int sock, void *buffer, size_t len, int flags,
        struct sockaddr *name, socklen_t *namelenp)
{
        struct nmsghdr lmsg;
        struct uio auio;
        struct iovec aiov[1];

        dprint(1, ("recvfrom(%d, %p, %ld, %d, %p, %p)\n",
            sock, buffer, len, flags, (void *)name, (void *)namelenp));

        if ((ssize_t)len < 0) {
                return (set_errno(EINVAL));
        }

        aiov[0].iov_base = buffer;
        aiov[0].iov_len = len;
        auio.uio_loffset = 0;
        auio.uio_iov = aiov;
        auio.uio_iovcnt = 1;
        auio.uio_resid = len;
        auio.uio_segflg = UIO_USERSPACE;
        auio.uio_limit = 0;

        lmsg.msg_name = (char *)name;
        if (namelenp != NULL) {
                if (copyin(namelenp, &lmsg.msg_namelen,
                    sizeof (lmsg.msg_namelen)))
                        return (set_errno(EFAULT));
        } else {
                lmsg.msg_namelen = 0;
        }
        lmsg.msg_controllen = 0;
        lmsg.msg_flags = 0;

        return (recvit(sock, &lmsg, &auio, flags, namelenp, NULL, NULL));
}

ssize_t
recvmsg(int sock, struct nmsghdr *msg, int flags)
{
        STRUCT_DECL(nmsghdr, u_lmsg);
        STRUCT_HANDLE(nmsghdr, umsgptr);
        struct nmsghdr lmsg;
        struct uio auio;
        struct iovec buf[IOV_MAX_STACK], *aiov = buf;
        ssize_t iovsize = 0;
        int iovcnt;
        ssize_t len, rval;
        int i;
        int *flagsp;
        model_t model;

        dprint(1, ("recvmsg(%d, %p, %d)\n",
            sock, (void *)msg, flags));

        model = get_udatamodel();
        STRUCT_INIT(u_lmsg, model);
        STRUCT_SET_HANDLE(umsgptr, model, msg);

        if (copyin(msg, STRUCT_BUF(u_lmsg), STRUCT_SIZE(u_lmsg)))
                return (set_errno(EFAULT));
        flagsp = STRUCT_FADDR(umsgptr, msg_flags);

        /*
         * Code below us will kmem_alloc memory and hang it
         * off msg_control and msg_name fields. This forces
         * us to copy the structure to its native form.
         */
        lmsg.msg_name = STRUCT_FGETP(u_lmsg, msg_name);
        lmsg.msg_namelen = STRUCT_FGET(u_lmsg, msg_namelen);
        lmsg.msg_iov = STRUCT_FGETP(u_lmsg, msg_iov);
        lmsg.msg_iovlen = STRUCT_FGET(u_lmsg, msg_iovlen);
        lmsg.msg_control = STRUCT_FGETP(u_lmsg, msg_control);
        lmsg.msg_controllen = STRUCT_FGET(u_lmsg, msg_controllen);
        lmsg.msg_flags = STRUCT_FGET(u_lmsg, msg_flags);

        iovcnt = lmsg.msg_iovlen;

        if (iovcnt < 0 || iovcnt > IOV_MAX)
                return (set_errno(EMSGSIZE));

        if (iovcnt > IOV_MAX_STACK) {
                iovsize = iovcnt * sizeof (struct iovec);
                aiov = kmem_alloc(iovsize, KM_SLEEP);
        }

#ifdef _SYSCALL32_IMPL
        /*
         * 32-bit callers need to have their iovec expanded, while ensuring
         * that they can't move more than 2Gbytes of data in a single call.
         */
        if (model == DATAMODEL_ILP32) {
                struct iovec32 buf32[IOV_MAX_STACK], *aiov32 = buf32;
                ssize_t iov32size;
                ssize32_t count32;

                iov32size = iovcnt * sizeof (struct iovec32);
                if (iovsize != 0)
                        aiov32 = kmem_alloc(iov32size, KM_SLEEP);

                if (copyin((struct iovec32 *)lmsg.msg_iov, aiov32, iov32size)) {
                        if (iovsize != 0) {
                                kmem_free(aiov32, iov32size);
                                kmem_free(aiov, iovsize);
                        }

                        return (set_errno(EFAULT));
                }

                count32 = 0;
                for (i = 0; i < iovcnt; i++) {
                        ssize32_t iovlen32;

                        iovlen32 = aiov32[i].iov_len;
                        count32 += iovlen32;
                        if (iovlen32 < 0 || count32 < 0) {
                                if (iovsize != 0) {
                                        kmem_free(aiov32, iov32size);
                                        kmem_free(aiov, iovsize);
                                }

                                return (set_errno(EINVAL));
                        }

                        aiov[i].iov_len = iovlen32;
                        aiov[i].iov_base =
                            (caddr_t)(uintptr_t)aiov32[i].iov_base;
                }

                if (iovsize != 0)
                        kmem_free(aiov32, iov32size);
        } else
#endif /* _SYSCALL32_IMPL */
        if (copyin(lmsg.msg_iov, aiov, iovcnt * sizeof (struct iovec))) {
                if (iovsize != 0)
                        kmem_free(aiov, iovsize);

                return (set_errno(EFAULT));
        }
        len = 0;
        for (i = 0; i < iovcnt; i++) {
                ssize_t iovlen = aiov[i].iov_len;
                len += iovlen;
                if (iovlen < 0 || len < 0) {
                        if (iovsize != 0)
                                kmem_free(aiov, iovsize);

                        return (set_errno(EINVAL));
                }
        }
        auio.uio_loffset = 0;
        auio.uio_iov = aiov;
        auio.uio_iovcnt = iovcnt;
        auio.uio_resid = len;
        auio.uio_segflg = UIO_USERSPACE;
        auio.uio_limit = 0;

        if (lmsg.msg_control != NULL &&
            (do_useracc == 0 ||
            useracc(lmsg.msg_control, lmsg.msg_controllen,
            B_WRITE) != 0)) {
                if (iovsize != 0)
                        kmem_free(aiov, iovsize);

                return (set_errno(EFAULT));
        }

        rval = recvit(sock, &lmsg, &auio, flags,
            STRUCT_FADDR(umsgptr, msg_namelen),
            STRUCT_FADDR(umsgptr, msg_controllen), flagsp);

        if (iovsize != 0)
                kmem_free(aiov, iovsize);

        return (rval);
}

/*
 * Common send function.
 */
static ssize_t
sendit(int sock, struct nmsghdr *msg, struct uio *uiop, int flags)
{
        struct sonode *so;
        file_t *fp;
        void *name;
        socklen_t namelen;
        void *control;
        socklen_t controllen;
        ssize_t len;
        int error;

        if ((so = getsonode(sock, &error, &fp)) == NULL)
                return (set_errno(error));

        uiop->uio_fmode = fp->f_flag;

        if (so->so_family == AF_UNIX)
                uiop->uio_extflg = UIO_COPY_CACHED;
        else
                uiop->uio_extflg = UIO_COPY_DEFAULT;

        /* Allocate and copyin name and control */
        name = msg->msg_name;
        namelen = msg->msg_namelen;
        if (name != NULL && namelen != 0) {
                ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                name = copyin_name(so,
                    (struct sockaddr *)name,
                    &namelen, &error);
                if (name == NULL)
                        goto done3;
                /* copyin_name null terminates addresses for AF_UNIX */
                msg->msg_namelen = namelen;
                msg->msg_name = name;
        } else {
                msg->msg_name = name = NULL;
                msg->msg_namelen = namelen = 0;
        }

        control = msg->msg_control;
        controllen = msg->msg_controllen;
        if ((control != NULL) && (controllen != 0)) {
                /*
                 * Verify that the length is not excessive to prevent
                 * an application from consuming all of kernel memory.
                 */
                if (controllen > SO_MAXARGSIZE) {
                        error = EINVAL;
                        goto done2;
                }
                control = kmem_alloc(controllen, KM_SLEEP);

                ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                if (copyin(msg->msg_control, control, controllen)) {
                        error = EFAULT;
                        goto done1;
                }
                msg->msg_control = control;
        } else {
                msg->msg_control = control = NULL;
                msg->msg_controllen = controllen = 0;
        }

        len = uiop->uio_resid;
        msg->msg_flags = flags;

        error = socket_sendmsg(so, msg, uiop, CRED());
done1:
        if (control != NULL)
                kmem_free(control, controllen);
done2:
        if (name != NULL)
                kmem_free(name, namelen);
done3:
        if (error != 0) {
                releasef(sock);
                return (set_errno(error));
        }
        lwp_stat_update(LWP_STAT_MSGSND, 1);
        releasef(sock);
        return (len - uiop->uio_resid);
}

/*
 * Native system call
 */
ssize_t
send(int sock, void *buffer, size_t len, int flags)
{
        struct nmsghdr lmsg;
        struct uio auio;
        struct iovec aiov[1];

        dprint(1, ("send(%d, %p, %ld, %d)\n",
            sock, buffer, len, flags));

        if ((ssize_t)len < 0) {
                return (set_errno(EINVAL));
        }

        aiov[0].iov_base = buffer;
        aiov[0].iov_len = len;
        auio.uio_loffset = 0;
        auio.uio_iov = aiov;
        auio.uio_iovcnt = 1;
        auio.uio_resid = len;
        auio.uio_segflg = UIO_USERSPACE;
        auio.uio_limit = 0;

        lmsg.msg_name = NULL;
        lmsg.msg_control = NULL;
        return (sendit(sock, &lmsg, &auio, flags));
}

ssize_t
sendmsg(int sock, struct nmsghdr *msg, int flags)
{
        struct nmsghdr lmsg;
        STRUCT_DECL(nmsghdr, u_lmsg);
        struct uio auio;
        struct iovec buf[IOV_MAX_STACK], *aiov = buf;
        ssize_t iovsize = 0;
        int iovcnt;
        ssize_t len, rval;
        int i;
        model_t model;

        dprint(1, ("sendmsg(%d, %p, %d)\n", sock, (void *)msg, flags));

        model = get_udatamodel();
        STRUCT_INIT(u_lmsg, model);

        if (copyin(msg, (char *)STRUCT_BUF(u_lmsg),
            STRUCT_SIZE(u_lmsg)))
                return (set_errno(EFAULT));
        /*
         * Code below us will kmem_alloc memory and hang it
         * off msg_control and msg_name fields. This forces
         * us to copy the structure to its native form.
         */
        lmsg.msg_name = STRUCT_FGETP(u_lmsg, msg_name);
        lmsg.msg_namelen = STRUCT_FGET(u_lmsg, msg_namelen);
        lmsg.msg_iov = STRUCT_FGETP(u_lmsg, msg_iov);
        lmsg.msg_iovlen = STRUCT_FGET(u_lmsg, msg_iovlen);
        lmsg.msg_control = STRUCT_FGETP(u_lmsg, msg_control);
        lmsg.msg_controllen = STRUCT_FGET(u_lmsg, msg_controllen);
        lmsg.msg_flags = STRUCT_FGET(u_lmsg, msg_flags);

        iovcnt = lmsg.msg_iovlen;

        if (iovcnt < 0 || iovcnt > IOV_MAX)
                return (set_errno(EMSGSIZE));

        if (iovcnt > IOV_MAX_STACK) {
                iovsize = iovcnt * sizeof (struct iovec);
                aiov = kmem_alloc(iovsize, KM_SLEEP);
        }

#ifdef _SYSCALL32_IMPL
        /*
         * 32-bit callers need to have their iovec expanded, while ensuring
         * that they can't move more than 2Gbytes of data in a single call.
         */
        if (model == DATAMODEL_ILP32) {
                struct iovec32 buf32[IOV_MAX_STACK], *aiov32 = buf32;
                ssize_t iov32size;
                ssize32_t count32;

                iov32size = iovcnt * sizeof (struct iovec32);
                if (iovsize != 0)
                        aiov32 = kmem_alloc(iov32size, KM_SLEEP);

                if (iovcnt != 0 &&
                    copyin((struct iovec32 *)lmsg.msg_iov, aiov32, iov32size)) {
                        if (iovsize != 0) {
                                kmem_free(aiov32, iov32size);
                                kmem_free(aiov, iovsize);
                        }

                        return (set_errno(EFAULT));
                }

                count32 = 0;
                for (i = 0; i < iovcnt; i++) {
                        ssize32_t iovlen32;

                        iovlen32 = aiov32[i].iov_len;
                        count32 += iovlen32;
                        if (iovlen32 < 0 || count32 < 0) {
                                if (iovsize != 0) {
                                        kmem_free(aiov32, iov32size);
                                        kmem_free(aiov, iovsize);
                                }

                                return (set_errno(EINVAL));
                        }

                        aiov[i].iov_len = iovlen32;
                        aiov[i].iov_base =
                            (caddr_t)(uintptr_t)aiov32[i].iov_base;
                }

                if (iovsize != 0)
                        kmem_free(aiov32, iov32size);
        } else
#endif /* _SYSCALL32_IMPL */
        if (iovcnt != 0 &&
            copyin(lmsg.msg_iov, aiov,
            (unsigned)iovcnt * sizeof (struct iovec))) {
                if (iovsize != 0)
                        kmem_free(aiov, iovsize);

                return (set_errno(EFAULT));
        }
        len = 0;
        for (i = 0; i < iovcnt; i++) {
                ssize_t iovlen = aiov[i].iov_len;
                len += iovlen;
                if (iovlen < 0 || len < 0) {
                        if (iovsize != 0)
                                kmem_free(aiov, iovsize);

                        return (set_errno(EINVAL));
                }
        }
        auio.uio_loffset = 0;
        auio.uio_iov = aiov;
        auio.uio_iovcnt = iovcnt;
        auio.uio_resid = len;
        auio.uio_segflg = UIO_USERSPACE;
        auio.uio_limit = 0;

        rval = sendit(sock, &lmsg, &auio, flags);

        if (iovsize != 0)
                kmem_free(aiov, iovsize);

        return (rval);
}

ssize_t
sendto(int sock, void *buffer, size_t len, int flags,
    struct sockaddr *name, socklen_t namelen)
{
        struct nmsghdr lmsg;
        struct uio auio;
        struct iovec aiov[1];

        dprint(1, ("sendto(%d, %p, %ld, %d, %p, %d)\n",
            sock, buffer, len, flags, (void *)name, namelen));

        if ((ssize_t)len < 0) {
                return (set_errno(EINVAL));
        }

        aiov[0].iov_base = buffer;
        aiov[0].iov_len = len;
        auio.uio_loffset = 0;
        auio.uio_iov = aiov;
        auio.uio_iovcnt = 1;
        auio.uio_resid = len;
        auio.uio_segflg = UIO_USERSPACE;
        auio.uio_limit = 0;

        lmsg.msg_name = (char *)name;
        lmsg.msg_namelen = namelen;
        lmsg.msg_control = NULL;
        return (sendit(sock, &lmsg, &auio, flags));
}

int
getpeername(int sock, struct sockaddr *name, socklen_t *namelenp)
{
        struct sonode *so;
        int error;
        socklen_t namelen;
        socklen_t sock_addrlen;
        struct sockaddr *sock_addrp;

        dprint(1, ("getpeername(%d, %p, %p)\n",
            sock, (void *)name, (void *)namelenp));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                goto bad;

        ASSERT(MUTEX_NOT_HELD(&so->so_lock));
        if (copyin(namelenp, &namelen, sizeof (namelen)) ||
            (name == NULL && namelen != 0)) {
                error = EFAULT;
                goto rel_out;
        }
        sock_addrlen = so->so_max_addr_len;
        sock_addrp = (struct sockaddr *)kmem_alloc(sock_addrlen, KM_SLEEP);

        if ((error = socket_getpeername(so, sock_addrp, &sock_addrlen,
            B_FALSE, CRED())) == 0) {
                ASSERT(sock_addrlen <= so->so_max_addr_len);
                error = copyout_name(name, namelen, namelenp,
                    (void *)sock_addrp, sock_addrlen);
        }
        kmem_free(sock_addrp, so->so_max_addr_len);
rel_out:
        releasef(sock);
bad:    return (error != 0 ? set_errno(error) : 0);
}

int
getsockname(int sock, struct sockaddr *name,
                socklen_t *namelenp)
{
        struct sonode *so;
        int error;
        socklen_t namelen, sock_addrlen;
        struct sockaddr *sock_addrp;

        dprint(1, ("getsockname(%d, %p, %p)\n",
            sock, (void *)name, (void *)namelenp));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                goto bad;

        ASSERT(MUTEX_NOT_HELD(&so->so_lock));
        if (copyin(namelenp, &namelen, sizeof (namelen)) ||
            (name == NULL && namelen != 0)) {
                error = EFAULT;
                goto rel_out;
        }

        sock_addrlen = so->so_max_addr_len;
        sock_addrp = (struct sockaddr *)kmem_alloc(sock_addrlen, KM_SLEEP);
        if ((error = socket_getsockname(so, sock_addrp, &sock_addrlen,
            CRED())) == 0) {
                ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                ASSERT(sock_addrlen <= so->so_max_addr_len);
                error = copyout_name(name, namelen, namelenp,
                    (void *)sock_addrp, sock_addrlen);
        }
        kmem_free(sock_addrp, so->so_max_addr_len);
rel_out:
        releasef(sock);
bad:    return (error != 0 ? set_errno(error) : 0);
}

int
getsockopt(int sock,
        int level,
        int option_name,
        void *option_value,
        socklen_t *option_lenp)
{
        struct sonode *so;
        socklen_t optlen, optlen_res;
        void *optval;
        int error;

        dprint(1, ("getsockopt(%d, %d, %d, %p, %p)\n",
            sock, level, option_name, option_value, (void *)option_lenp));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                return (set_errno(error));

        ASSERT(MUTEX_NOT_HELD(&so->so_lock));
        if (copyin(option_lenp, &optlen, sizeof (optlen))) {
                releasef(sock);
                return (set_errno(EFAULT));
        }
        /*
         * Verify that the length is not excessive to prevent
         * an application from consuming all of kernel memory.
         */
        if (optlen > SO_MAXARGSIZE) {
                error = EINVAL;
                releasef(sock);
                return (set_errno(error));
        }
        optval = kmem_alloc(optlen, KM_SLEEP);
        optlen_res = optlen;
        error = socket_getsockopt(so, level, option_name, optval,
            &optlen_res, 0, CRED());
        releasef(sock);
        if (error) {
                kmem_free(optval, optlen);
                return (set_errno(error));
        }
        error = copyout_arg(option_value, optlen, option_lenp,
            optval, optlen_res);
        kmem_free(optval, optlen);
        if (error)
                return (set_errno(error));
        return (0);
}

int
setsockopt(int sock,
        int level,
        int option_name,
        void *option_value,
        socklen_t option_len)
{
        struct sonode *so;
        intptr_t buffer[2];
        void *optval = NULL;
        int error;

        dprint(1, ("setsockopt(%d, %d, %d, %p, %d)\n",
            sock, level, option_name, option_value, option_len));

        if ((so = getsonode(sock, &error, NULL)) == NULL)
                return (set_errno(error));

        if (option_value != NULL) {
                if (option_len != 0) {
                        /*
                         * Verify that the length is not excessive to prevent
                         * an application from consuming all of kernel memory.
                         */
                        if (option_len > SO_MAXARGSIZE) {
                                error = EINVAL;
                                goto done2;
                        }
                        optval = option_len <= sizeof (buffer) ?
                            &buffer : kmem_alloc((size_t)option_len, KM_SLEEP);
                        ASSERT(MUTEX_NOT_HELD(&so->so_lock));
                        if (copyin(option_value, optval, (size_t)option_len)) {
                                error = EFAULT;
                                goto done1;
                        }
                }
        } else
                option_len = 0;

        error = socket_setsockopt(so, level, option_name, optval,
            (t_uscalar_t)option_len, CRED());
done1:
        if (optval != buffer)
                kmem_free(optval, (size_t)option_len);
done2:
        releasef(sock);
        if (error)
                return (set_errno(error));
        return (0);
}

static int
sockconf_add_sock(int family, int type, int protocol, char *name)
{
        int error = 0;
        char *kdevpath = NULL;
        char *kmodule = NULL;
        char *buf = NULL;
        size_t pathlen = 0;
        struct sockparams *sp;

        if (name == NULL)
                return (EINVAL);
        /*
         * Copyin the name.
         * This also makes it possible to check for too long pathnames.
         * Compress the space needed for the name before passing it
         * to soconfig - soconfig will store the string until
         * the configuration is removed.
         */
        buf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        if ((error = copyinstr(name, buf, MAXPATHLEN, &pathlen)) != 0) {
                kmem_free(buf, MAXPATHLEN);
                return (error);
        }
        if (strncmp(buf, "/dev", strlen("/dev")) == 0) {
                /* For device */
                kdevpath = kmem_alloc(pathlen, KM_SLEEP);
                bcopy(buf, kdevpath, pathlen);
                kdevpath[pathlen - 1] = '\0';
        } else {
                /* For socket module */
                kmodule = kmem_alloc(pathlen, KM_SLEEP);
                bcopy(buf, kmodule, pathlen);
                kmodule[pathlen - 1] = '\0';
                pathlen = 0;
        }
        kmem_free(buf, MAXPATHLEN);

        /* sockparams_create frees mod name and devpath upon failure */
        sp = sockparams_create(family, type, protocol, kmodule,
            kdevpath, pathlen, 0, KM_SLEEP, &error);
        if (sp != NULL) {
                error = sockparams_add(sp);
                if (error != 0)
                        sockparams_destroy(sp);
        }

        return (error);
}

static int
sockconf_remove_sock(int family, int type, int protocol)
{
        return (sockparams_delete(family, type, protocol));
}

static int
sockconfig_remove_filter(const char *uname)
{
        char kname[SOF_MAXNAMELEN];
        size_t len;
        int error;
        sof_entry_t *ent;

        if ((error = copyinstr(uname, kname, SOF_MAXNAMELEN, &len)) != 0)
                return (error);

        ent = sof_entry_remove_by_name(kname);
        if (ent == NULL)
                return (ENXIO);

        mutex_enter(&ent->sofe_lock);
        ASSERT(!(ent->sofe_flags & SOFEF_CONDEMED));
        if (ent->sofe_refcnt == 0) {
                mutex_exit(&ent->sofe_lock);
                sof_entry_free(ent);
        } else {
                /* let the last socket free the filter */
                ent->sofe_flags |= SOFEF_CONDEMED;
                mutex_exit(&ent->sofe_lock);
        }

        return (0);
}

static int
sockconfig_add_filter(const char *uname, void *ufilpropp)
{
        struct sockconfig_filter_props filprop;
        sof_entry_t *ent;
        int error;
        size_t tuplesz, len;
        char hintbuf[SOF_MAXNAMELEN];

        ent = kmem_zalloc(sizeof (sof_entry_t), KM_SLEEP);
        mutex_init(&ent->sofe_lock, NULL, MUTEX_DEFAULT, NULL);

        if ((error = copyinstr(uname, ent->sofe_name, SOF_MAXNAMELEN,
            &len)) != 0) {
                sof_entry_free(ent);
                return (error);
        }

        if (get_udatamodel() == DATAMODEL_NATIVE) {
                if (copyin(ufilpropp, &filprop, sizeof (filprop)) != 0) {
                        sof_entry_free(ent);
                        return (EFAULT);
                }
        }
#ifdef  _SYSCALL32_IMPL
        else {
                struct sockconfig_filter_props32 filprop32;

                if (copyin(ufilpropp, &filprop32, sizeof (filprop32)) != 0) {
                        sof_entry_free(ent);
                        return (EFAULT);
                }
                filprop.sfp_modname = (char *)(uintptr_t)filprop32.sfp_modname;
                filprop.sfp_autoattach = filprop32.sfp_autoattach;
                filprop.sfp_hint = filprop32.sfp_hint;
                filprop.sfp_hintarg = (char *)(uintptr_t)filprop32.sfp_hintarg;
                filprop.sfp_socktuple_cnt = filprop32.sfp_socktuple_cnt;
                filprop.sfp_socktuple =
                    (sof_socktuple_t *)(uintptr_t)filprop32.sfp_socktuple;
        }
#endif  /* _SYSCALL32_IMPL */

        if ((error = copyinstr(filprop.sfp_modname, ent->sofe_modname,
            sizeof (ent->sofe_modname), &len)) != 0) {
                sof_entry_free(ent);
                return (error);
        }

        /*
         * A filter must specify at least one socket tuple.
         */
        if (filprop.sfp_socktuple_cnt == 0 ||
            filprop.sfp_socktuple_cnt > SOF_MAXSOCKTUPLECNT) {
                sof_entry_free(ent);
                return (EINVAL);
        }
        ent->sofe_flags = filprop.sfp_autoattach ? SOFEF_AUTO : SOFEF_PROG;
        ent->sofe_hint = filprop.sfp_hint;

        /*
         * Verify the hint, and copy in the hint argument, if necessary.
         */
        switch (ent->sofe_hint) {
        case SOF_HINT_BEFORE:
        case SOF_HINT_AFTER:
                if ((error = copyinstr(filprop.sfp_hintarg, hintbuf,
                    sizeof (hintbuf), &len)) != 0) {
                        sof_entry_free(ent);
                        return (error);
                }
                ent->sofe_hintarg = kmem_alloc(len, KM_SLEEP);
                bcopy(hintbuf, ent->sofe_hintarg, len);
                /* FALLTHRU */
        case SOF_HINT_TOP:
        case SOF_HINT_BOTTOM:
                /* hints cannot be used with programmatic filters */
                if (ent->sofe_flags & SOFEF_PROG) {
                        sof_entry_free(ent);
                        return (EINVAL);
                }
                break;
        case SOF_HINT_NONE:
                break;
        default:
                /* bad hint value */
                sof_entry_free(ent);
                return (EINVAL);
        }

        ent->sofe_socktuple_cnt = filprop.sfp_socktuple_cnt;
        tuplesz = sizeof (sof_socktuple_t) * ent->sofe_socktuple_cnt;
        ent->sofe_socktuple = kmem_alloc(tuplesz, KM_SLEEP);

        if (get_udatamodel() == DATAMODEL_NATIVE) {
                if (copyin(filprop.sfp_socktuple, ent->sofe_socktuple,
                    tuplesz)) {
                        sof_entry_free(ent);
                        return (EFAULT);
                }
        }
#ifdef  _SYSCALL32_IMPL
        else {
                int i;
                caddr_t data = (caddr_t)filprop.sfp_socktuple;
                sof_socktuple_t *tup = ent->sofe_socktuple;
                sof_socktuple32_t tup32;

                tup = ent->sofe_socktuple;
                for (i = 0; i < ent->sofe_socktuple_cnt; i++, tup++) {
                        ASSERT(tup < ent->sofe_socktuple + tuplesz);

                        if (copyin(data, &tup32, sizeof (tup32)) != 0) {
                                sof_entry_free(ent);
                                return (EFAULT);
                        }
                        tup->sofst_family = tup32.sofst_family;
                        tup->sofst_type = tup32.sofst_type;
                        tup->sofst_protocol = tup32.sofst_protocol;

                        data += sizeof (tup32);
                }
        }
#endif  /* _SYSCALL32_IMPL */

        /* Sockets can start using the filter as soon as the filter is added */
        if ((error = sof_entry_add(ent)) != 0)
                sof_entry_free(ent);

        return (error);
}

/*
 * Socket configuration system call. It is used to add and remove
 * socket types.
 */
int
sockconfig(int cmd, void *arg1, void *arg2, void *arg3, void *arg4)
{
        int error = 0;

        if (secpolicy_net_config(CRED(), B_FALSE) != 0)
                return (set_errno(EPERM));

        switch (cmd) {
        case SOCKCONFIG_ADD_SOCK:
                error = sockconf_add_sock((int)(uintptr_t)arg1,
                    (int)(uintptr_t)arg2, (int)(uintptr_t)arg3, arg4);
                break;
        case SOCKCONFIG_REMOVE_SOCK:
                error = sockconf_remove_sock((int)(uintptr_t)arg1,
                    (int)(uintptr_t)arg2, (int)(uintptr_t)arg3);
                break;
        case SOCKCONFIG_ADD_FILTER:
                error = sockconfig_add_filter((const char *)arg1, arg2);
                break;
        case SOCKCONFIG_REMOVE_FILTER:
                error = sockconfig_remove_filter((const char *)arg1);
                break;
        case SOCKCONFIG_GET_SOCKTABLE:
                error = sockparams_copyout_socktable((int)(uintptr_t)arg1);
                break;
        default:
#ifdef  DEBUG
                cmn_err(CE_NOTE, "sockconfig: unkonwn subcommand %d", cmd);
#endif
                error = EINVAL;
                break;
        }

        if (error != 0) {
                eprintline(error);
                return (set_errno(error));
        }
        return (0);
}


/*
 * Sendfile is implemented through two schemes, direct I/O or by
 * caching in the filesystem page cache. We cache the input file by
 * default and use direct I/O only if sendfile_max_size is set
 * appropriately as explained below. Note that this logic is consistent
 * with other filesystems where caching is turned on by default
 * unless explicitly turned off by using the DIRECTIO ioctl.
 *
 * We choose a slightly different scheme here. One can turn off
 * caching by setting sendfile_max_size to 0. One can also enable
 * caching of files <= sendfile_max_size by setting sendfile_max_size
 * to an appropriate value. By default sendfile_max_size is set to the
 * maximum value so that all files are cached. In future, we may provide
 * better interfaces for caching the file.
 *
 * Sendfile through Direct I/O (Zero copy)
 * --------------------------------------
 *
 * As disks are normally slower than the network, we can't have a
 * single thread that reads the disk and writes to the network. We
 * need to have parallelism. This is done by having the sendfile
 * thread create another thread that reads from the filesystem
 * and queues it for network processing. In this scheme, the data
 * is never copied anywhere i.e it is zero copy unlike the other
 * scheme.
 *
 * We have a sendfile queue (snfq) where each sendfile
 * request (snf_req_t) is queued for processing by a thread. Number
 * of threads is dynamically allocated and they exit if they are idling
 * beyond a specified amount of time. When each request (snf_req_t) is
 * processed by a thread, it produces a number of mblk_t structures to
 * be consumed by the sendfile thread. snf_deque and snf_enque are
 * used for consuming and producing mblks. Size of the filesystem
 * read is determined by the tunable (sendfile_read_size). A single
 * mblk holds sendfile_read_size worth of data (except the last
 * read of the file) which is sent down as a whole to the network.
 * sendfile_read_size is set to 1 MB as this seems to be the optimal
 * value for the UFS filesystem backed by a striped storage array.
 *
 * Synchronisation between read (producer) and write (consumer) threads.
 * --------------------------------------------------------------------
 *
 * sr_lock protects sr_ib_head and sr_ib_tail. The lock is held while
 * adding and deleting items in this list. Error can happen anytime
 * during read or write. There could be unprocessed mblks in the
 * sr_ib_XXX list when a read or write error occurs. Whenever error
 * is encountered, we need two things to happen :
 *
 * a) One of the threads need to clean the mblks.
 * b) When one thread encounters an error, the other should stop.
 *
 * For (a), we don't want to penalize the reader thread as it could do
 * some useful work processing other requests. For (b), the error can
 * be detected by examining sr_read_error or sr_write_error.
 * sr_lock protects sr_read_error and sr_write_error. If both reader and
 * writer encounters error, we need to report the write error back to
 * the application as that's what would have happened if the operations
 * were done sequentially. With this in mind, following should work :
 *
 *      - Check for errors before read or write.
 *      - If the reader encounters error, set the error in sr_read_error.
 *        Check sr_write_error, if it is set, send cv_signal as it is
 *        waiting for reader to complete. If it is not set, the writer
 *        is either running sinking data to the network or blocked
 *        because of flow control. For handling the latter case, we
 *        always send a signal. In any case, it will examine sr_read_error
 *        and return. sr_read_error is marked with SR_READ_DONE to tell
 *        the writer that the reader is done in all the cases.
 *      - If the writer encounters error, set the error in sr_write_error.
 *        The reader thread is either blocked because of flow control or
 *        running reading data from the disk. For the former, we need to
 *        wakeup the thread. Again to keep it simple, we always wake up
 *        the reader thread. Then, wait for the read thread to complete
 *        if it is not done yet. Cleanup and return.
 *
 * High and low water marks for the read thread.
 * --------------------------------------------
 *
 * If sendfile() is used to send data over a slow network, we need to
 * make sure that the read thread does not produce data at a faster
 * rate than the network. This can happen if the disk is faster than
 * the network. In such a case, we don't want to build a very large queue.
 * But we would still like to get all of the network throughput possible.
 * This implies that network should never block waiting for data.
 * As there are lot of disk throughput/network throughput combinations
 * possible, it is difficult to come up with an accurate number.
 * A typical 10K RPM disk has a max seek latency 17ms and rotational
 * latency of 3ms for reading a disk block. Thus, the total latency to
 * initiate a new read, transfer data from the disk and queue for
 * transmission would take about a max of 25ms. Todays max transfer rate
 * for network is 100MB/sec. If the thread is blocked because of flow
 * control, it would take 25ms to get new data ready for transmission.
 * We have to make sure that network is not idling, while we are initiating
 * new transfers. So, at 100MB/sec, to keep network busy we would need
 * 2.5MB of data. Rounding off, we keep the low water mark to be 3MB of data.
 * We need to pick a high water mark so that the woken up thread would
 * do considerable work before blocking again to prevent thrashing. Currently,
 * we pick this to be 10 times that of the low water mark.
 *
 * Sendfile with segmap caching (One copy from page cache to mblks).
 * ----------------------------------------------------------------
 *
 * We use the segmap cache for caching the file, if the size of file
 * is <= sendfile_max_size. In this case we don't use threads as VM
 * is reasonably fast enough to keep up with the network. If the underlying
 * transport allows, we call segmap_getmapflt() to map MAXBSIZE (8K) worth
 * of data into segmap space, and use the virtual address from segmap
 * directly through desballoc() to avoid copy. Once the transport is done
 * with the data, the mapping will be released through segmap_release()
 * called by the call-back routine.
 *
 * If zero-copy is not allowed by the transport, we simply call VOP_READ()
 * to copy the data from the filesystem into our temporary network buffer.
 *
 * To disable caching, set sendfile_max_size to 0.
 */

uint_t sendfile_read_size = 1024 * 1024;
#define SENDFILE_REQ_LOWAT      3 * 1024 * 1024
uint_t sendfile_req_lowat = SENDFILE_REQ_LOWAT;
uint_t sendfile_req_hiwat = 10 * SENDFILE_REQ_LOWAT;
struct sendfile_stats sf_stats;
struct sendfile_queue *snfq;
clock_t snfq_timeout;
off64_t sendfile_max_size;

static void snf_enque(snf_req_t *, mblk_t *);
static mblk_t *snf_deque(snf_req_t *);

void
sendfile_init(void)
{
        snfq = kmem_zalloc(sizeof (struct sendfile_queue), KM_SLEEP);

        mutex_init(&snfq->snfq_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&snfq->snfq_cv, NULL, CV_DEFAULT, NULL);
        snfq->snfq_max_threads = max_ncpus;
        snfq_timeout = SNFQ_TIMEOUT;
        /* Cache all files by default. */
        sendfile_max_size = MAXOFFSET_T;
}

/*
 * Queues a mblk_t for network processing.
 */
static void
snf_enque(snf_req_t *sr, mblk_t *mp)
{
        mp->b_next = NULL;
        mutex_enter(&sr->sr_lock);
        if (sr->sr_mp_head == NULL) {
                sr->sr_mp_head = sr->sr_mp_tail = mp;
                cv_signal(&sr->sr_cv);
        } else {
                sr->sr_mp_tail->b_next = mp;
                sr->sr_mp_tail = mp;
        }
        sr->sr_qlen += MBLKL(mp);
        while ((sr->sr_qlen > sr->sr_hiwat) &&
            (sr->sr_write_error == 0)) {
                sf_stats.ss_full_waits++;
                cv_wait(&sr->sr_cv, &sr->sr_lock);
        }
        mutex_exit(&sr->sr_lock);
}

/*
 * De-queues a mblk_t for network processing.
 */
static mblk_t *
snf_deque(snf_req_t *sr)
{
        mblk_t *mp;

        mutex_enter(&sr->sr_lock);
        /*
         * If we have encountered an error on read or read is
         * completed and no more mblks, return NULL.
         * We need to check for NULL sr_mp_head also as
         * the reads could have completed and there is
         * nothing more to come.
         */
        if (((sr->sr_read_error & ~SR_READ_DONE) != 0) ||
            ((sr->sr_read_error & SR_READ_DONE) &&
            sr->sr_mp_head == NULL)) {
                mutex_exit(&sr->sr_lock);
                return (NULL);
        }
        /*
         * To start with neither SR_READ_DONE is marked nor
         * the error is set. When we wake up from cv_wait,
         * following are the possibilities :
         *
         *      a) sr_read_error is zero and mblks are queued.
         *      b) sr_read_error is set to SR_READ_DONE
         *         and mblks are queued.
         *      c) sr_read_error is set to SR_READ_DONE
         *         and no mblks.
         *      d) sr_read_error is set to some error other
         *         than SR_READ_DONE.
         */

        while ((sr->sr_read_error == 0) && (sr->sr_mp_head == NULL)) {
                sf_stats.ss_empty_waits++;
                cv_wait(&sr->sr_cv, &sr->sr_lock);
        }
        /* Handle (a) and (b) first  - the normal case. */
        if (((sr->sr_read_error & ~SR_READ_DONE) == 0) &&
            (sr->sr_mp_head != NULL)) {
                mp = sr->sr_mp_head;
                sr->sr_mp_head = mp->b_next;
                sr->sr_qlen -= MBLKL(mp);
                if (sr->sr_qlen < sr->sr_lowat)
                        cv_signal(&sr->sr_cv);
                mutex_exit(&sr->sr_lock);
                mp->b_next = NULL;
                return (mp);
        }
        /* Handle (c) and (d). */
        mutex_exit(&sr->sr_lock);
        return (NULL);
}

/*
 * Reads data from the filesystem and queues it for network processing.
 */
void
snf_async_read(snf_req_t *sr)
{
        size_t iosize;
        u_offset_t fileoff;
        u_offset_t size;
        int ret_size;
        int error;
        file_t *fp;
        mblk_t *mp;
        struct vnode *vp;
        int extra = 0;
        int maxblk = 0;
        int wroff = 0;
        struct sonode *so;

        fp = sr->sr_fp;
        size = sr->sr_file_size;
        fileoff = sr->sr_file_off;

        /*
         * Ignore the error for filesystems that doesn't support DIRECTIO.
         */
        (void) VOP_IOCTL(fp->f_vnode, _FIODIRECTIO, DIRECTIO_ON, 0,
            kcred, NULL, NULL);

        vp = sr->sr_vp;
        if (vp->v_type == VSOCK) {
                stdata_t *stp;

                /*
                 * Get the extra space to insert a header and a trailer.
                 */
                so = VTOSO(vp);
                stp = vp->v_stream;
                if (stp == NULL) {
                        wroff = so->so_proto_props.sopp_wroff;
                        maxblk = so->so_proto_props.sopp_maxblk;
                        extra = wroff + so->so_proto_props.sopp_tail;
                } else {
                        wroff = (int)(stp->sd_wroff);
                        maxblk = (int)(stp->sd_maxblk);
                        extra = wroff + (int)(stp->sd_tail);
                }
        }

        while ((size != 0) && (sr->sr_write_error == 0)) {

                iosize = (int)MIN(sr->sr_maxpsz, size);

                /*
                 * Socket filters can limit the mblk size,
                 * so limit reads to maxblk if there are
                 * filters present.
                 */
                if (vp->v_type == VSOCK &&
                    so->so_filter_active > 0 && maxblk != INFPSZ)
                        iosize = (int)MIN(iosize, maxblk);

                if (is_system_labeled()) {
                        mp = allocb_cred(iosize + extra, CRED(),
                            curproc->p_pid);
                } else {
                        mp = allocb(iosize + extra, BPRI_MED);
                }
                if (mp == NULL) {
                        error = EAGAIN;
                        break;
                }

                mp->b_rptr += wroff;

                ret_size = soreadfile(fp, mp->b_rptr, fileoff, &error, iosize);

                /* Error or Reached EOF ? */
                if ((error != 0) || (ret_size == 0)) {
                        freeb(mp);
                        break;
                }
                mp->b_wptr = mp->b_rptr + ret_size;

                snf_enque(sr, mp);
                size -= ret_size;
                fileoff += ret_size;
        }
        (void) VOP_IOCTL(fp->f_vnode, _FIODIRECTIO, DIRECTIO_OFF, 0,
            kcred, NULL, NULL);
        mutex_enter(&sr->sr_lock);
        sr->sr_read_error = error;
        sr->sr_read_error |= SR_READ_DONE;
        cv_signal(&sr->sr_cv);
        mutex_exit(&sr->sr_lock);
}

void
snf_async_thread(void)
{
        snf_req_t *sr;
        callb_cpr_t cprinfo;
        clock_t time_left = 1;

        CALLB_CPR_INIT(&cprinfo, &snfq->snfq_lock, callb_generic_cpr, "snfq");

        mutex_enter(&snfq->snfq_lock);
        for (;;) {
                /*
                 * If we didn't find a entry, then block until woken up
                 * again and then look through the queues again.
                 */
                while ((sr = snfq->snfq_req_head) == NULL) {
                        CALLB_CPR_SAFE_BEGIN(&cprinfo);
                        if (time_left <= 0) {
                                snfq->snfq_svc_threads--;
                                CALLB_CPR_EXIT(&cprinfo);
                                thread_exit();
                                /* NOTREACHED */
                        }
                        snfq->snfq_idle_cnt++;

                        time_left = cv_reltimedwait(&snfq->snfq_cv,
                            &snfq->snfq_lock, snfq_timeout, TR_CLOCK_TICK);
                        snfq->snfq_idle_cnt--;

                        CALLB_CPR_SAFE_END(&cprinfo, &snfq->snfq_lock);
                }
                snfq->snfq_req_head = sr->sr_next;
                snfq->snfq_req_cnt--;
                mutex_exit(&snfq->snfq_lock);
                snf_async_read(sr);
                mutex_enter(&snfq->snfq_lock);
        }
}


snf_req_t *
create_thread(int operation, struct vnode *vp, file_t *fp,
    u_offset_t fileoff, u_offset_t size)
{
        snf_req_t *sr;
        stdata_t *stp;

        sr = (snf_req_t *)kmem_zalloc(sizeof (snf_req_t), KM_SLEEP);

        sr->sr_vp = vp;
        sr->sr_fp = fp;
        stp = vp->v_stream;

        /*
         * store sd_qn_maxpsz into sr_maxpsz while we have stream head.
         * stream might be closed before thread returns from snf_async_read.
         */
        if (stp != NULL && stp->sd_qn_maxpsz > 0) {
                sr->sr_maxpsz = MIN(MAXBSIZE, stp->sd_qn_maxpsz);
        } else {
                sr->sr_maxpsz = MAXBSIZE;
        }

        sr->sr_operation = operation;
        sr->sr_file_off = fileoff;
        sr->sr_file_size = size;
        sr->sr_hiwat = sendfile_req_hiwat;
        sr->sr_lowat = sendfile_req_lowat;
        mutex_init(&sr->sr_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&sr->sr_cv, NULL, CV_DEFAULT, NULL);
        /*
         * See whether we need another thread for servicing this
         * request. If there are already enough requests queued
         * for the threads, create one if not exceeding
         * snfq_max_threads.
         */
        mutex_enter(&snfq->snfq_lock);
        if (snfq->snfq_req_cnt >= snfq->snfq_idle_cnt &&
            snfq->snfq_svc_threads < snfq->snfq_max_threads) {
                (void) thread_create(NULL, 0, &snf_async_thread, 0, 0, &p0,
                    TS_RUN, minclsyspri);
                snfq->snfq_svc_threads++;
        }
        if (snfq->snfq_req_head == NULL) {
                snfq->snfq_req_head = snfq->snfq_req_tail = sr;
                cv_signal(&snfq->snfq_cv);
        } else {
                snfq->snfq_req_tail->sr_next = sr;
                snfq->snfq_req_tail = sr;
        }
        snfq->snfq_req_cnt++;
        mutex_exit(&snfq->snfq_lock);
        return (sr);
}

int
snf_direct_io(file_t *fp, file_t *rfp, u_offset_t fileoff, u_offset_t size,
    ssize_t *count)
{
        snf_req_t *sr;
        mblk_t *mp;
        int iosize;
        int error = 0;
        short fflag;
        struct vnode *vp;
        int ksize;
        struct nmsghdr msg;

        ksize = 0;
        *count = 0;
        bzero(&msg, sizeof (msg));

        vp = fp->f_vnode;
        fflag = fp->f_flag;
        if ((sr = create_thread(READ_OP, vp, rfp, fileoff, size)) == NULL)
                return (EAGAIN);

        /*
         * We check for read error in snf_deque. It has to check
         * for successful READ_DONE and return NULL, and we might
         * as well make an additional check there.
         */
        while ((mp = snf_deque(sr)) != NULL) {

                if (ISSIG(curthread, JUSTLOOKING)) {
                        freeb(mp);
                        error = EINTR;
                        break;
                }
                iosize = MBLKL(mp);

                error = socket_sendmblk(VTOSO(vp), &msg, fflag, CRED(), &mp);

                if (error != 0) {
                        if (mp != NULL)
                                freeb(mp);
                        break;
                }
                ksize += iosize;
        }
        *count = ksize;

        mutex_enter(&sr->sr_lock);
        sr->sr_write_error = error;
        /* Look at the big comments on why we cv_signal here. */
        cv_signal(&sr->sr_cv);

        /* Wait for the reader to complete always. */
        while (!(sr->sr_read_error & SR_READ_DONE)) {
                cv_wait(&sr->sr_cv, &sr->sr_lock);
        }
        /* If there is no write error, check for read error. */
        if (error == 0)
                error = (sr->sr_read_error & ~SR_READ_DONE);

        if (error != 0) {
                mblk_t *next_mp;

                mp = sr->sr_mp_head;
                while (mp != NULL) {
                        next_mp = mp->b_next;
                        mp->b_next = NULL;
                        freeb(mp);
                        mp = next_mp;
                }
        }
        mutex_exit(&sr->sr_lock);
        kmem_free(sr, sizeof (snf_req_t));
        return (error);
}

/* Maximum no.of pages allocated by vpm for sendfile at a time */
#define SNF_VPMMAXPGS   (VPMMAXPGS/2)

/*
 * Maximum no.of elements in the list returned by vpm, including
 * NULL for the last entry
 */
#define SNF_MAXVMAPS    (SNF_VPMMAXPGS + 1)

typedef struct {
        unsigned int    snfv_ref;
        frtn_t          snfv_frtn;
        vnode_t         *snfv_vp;
        struct vmap     snfv_vml[SNF_MAXVMAPS];
} snf_vmap_desbinfo;

typedef struct {
        frtn_t          snfi_frtn;
        caddr_t         snfi_base;
        uint_t          snfi_mapoff;
        size_t          snfi_len;
        vnode_t         *snfi_vp;
} snf_smap_desbinfo;

/*
 * The callback function used for vpm mapped mblks called when the last ref of
 * the mblk is dropped which normally occurs when TCP receives the ack. But it
 * can be the driver too due to lazy reclaim.
 */
void
snf_vmap_desbfree(snf_vmap_desbinfo *snfv)
{
        ASSERT(snfv->snfv_ref != 0);
        if (atomic_dec_32_nv(&snfv->snfv_ref) == 0) {
                vpm_unmap_pages(snfv->snfv_vml, S_READ);
                VN_RELE(snfv->snfv_vp);
                kmem_free(snfv, sizeof (snf_vmap_desbinfo));
        }
}

/*
 * The callback function used for segmap'ped mblks called when the last ref of
 * the mblk is dropped which normally occurs when TCP receives the ack. But it
 * can be the driver too due to lazy reclaim.
 */
void
snf_smap_desbfree(snf_smap_desbinfo *snfi)
{
        if (! IS_KPM_ADDR(snfi->snfi_base)) {
                /*
                 * We don't need to call segmap_fault(F_SOFTUNLOCK) for
                 * segmap_kpm as long as the latter never falls back to
                 * "use_segmap_range". (See segmap_getmapflt().)
                 *
                 * Using S_OTHER saves an redundant hat_setref() in
                 * segmap_unlock()
                 */
                (void) segmap_fault(kas.a_hat, segkmap,
                    (caddr_t)(uintptr_t)(((uintptr_t)snfi->snfi_base +
                    snfi->snfi_mapoff) & PAGEMASK), snfi->snfi_len,
                    F_SOFTUNLOCK, S_OTHER);
        }
        (void) segmap_release(segkmap, snfi->snfi_base, SM_DONTNEED);
        VN_RELE(snfi->snfi_vp);
        kmem_free(snfi, sizeof (*snfi));
}

/*
 * Use segmap or vpm instead of bcopy to send down a desballoca'ed, mblk.
 * When segmap is used, the mblk contains a segmap slot of no more
 * than MAXBSIZE.
 *
 * With vpm, a maximum of SNF_MAXVMAPS page-sized mappings can be obtained
 * in each iteration and sent by socket_sendmblk until an error occurs or
 * the requested size has been transferred. An mblk is esballoca'ed from
 * each mapped page and a chain of these mblk is sent to the transport layer.
 * vpm will be called to unmap the pages when all mblks have been freed by
 * free_func.
 *
 * At the end of the whole sendfile() operation, we wait till the data from
 * the last mblk is ack'ed by the transport before returning so that the
 * caller of sendfile() can safely modify the file content.
 */
int
snf_segmap(file_t *fp, vnode_t *fvp, u_offset_t fileoff, u_offset_t total_size,
    ssize_t *count, boolean_t nowait)
{
        caddr_t base;
        int mapoff;
        vnode_t *vp;
        mblk_t *mp = NULL;
        int chain_size;
        int error;
        clock_t deadlk_wait;
        short fflag;
        int ksize;
        struct vattr va;
        boolean_t dowait = B_FALSE;
        struct nmsghdr msg;

        vp = fp->f_vnode;
        fflag = fp->f_flag;
        ksize = 0;
        bzero(&msg, sizeof (msg));

        for (;;) {
                if (ISSIG(curthread, JUSTLOOKING)) {
                        error = EINTR;
                        break;
                }

                if (vpm_enable) {
                        snf_vmap_desbinfo *snfv;
                        mblk_t *nmp;
                        int mblk_size;
                        int maxsize;
                        int i;

                        mapoff = fileoff & PAGEOFFSET;
                        maxsize = MIN((SNF_VPMMAXPGS * PAGESIZE), total_size);

                        snfv = kmem_zalloc(sizeof (snf_vmap_desbinfo),
                            KM_SLEEP);

                        /*
                         * Get vpm mappings for maxsize with read access.
                         * If the pages aren't available yet, we get
                         * DEADLK, so wait and try again a little later using
                         * an increasing wait. We might be here a long time.
                         *
                         * If delay_sig returns EINTR, be sure to exit and
                         * pass it up to the caller.
                         */
                        deadlk_wait = 0;
                        while ((error = vpm_map_pages(fvp, fileoff,
                            (size_t)maxsize, (VPM_FETCHPAGE), snfv->snfv_vml,
                            SNF_MAXVMAPS, NULL, S_READ)) == EDEADLK) {
                                deadlk_wait += (deadlk_wait < 5) ? 1 : 4;
                                if ((error = delay_sig(deadlk_wait)) != 0) {
                                        break;
                                }
                        }
                        if (error != 0) {
                                kmem_free(snfv, sizeof (snf_vmap_desbinfo));
                                error = (error == EINTR) ? EINTR : EIO;
                                goto out;
                        }
                        snfv->snfv_frtn.free_func = snf_vmap_desbfree;
                        snfv->snfv_frtn.free_arg = (caddr_t)snfv;

                        /* Construct the mblk chain from the page mappings */
                        chain_size = 0;
                        for (i = 0; (snfv->snfv_vml[i].vs_addr != NULL) &&
                            total_size > 0; i++) {
                                ASSERT(chain_size < maxsize);
                                mblk_size = MIN(snfv->snfv_vml[i].vs_len -
                                    mapoff, total_size);
                                nmp = esballoca(
                                    (uchar_t *)snfv->snfv_vml[i].vs_addr +
                                    mapoff, mblk_size, BPRI_HI,
                                    &snfv->snfv_frtn);

                                /*
                                 * We return EAGAIN after unmapping the pages
                                 * if we cannot allocate the the head of the
                                 * chain. Otherwise, we continue sending the
                                 * mblks constructed so far.
                                 */
                                if (nmp == NULL) {
                                        if (i == 0) {
                                                vpm_unmap_pages(snfv->snfv_vml,
                                                    S_READ);
                                                kmem_free(snfv,
                                                    sizeof (snf_vmap_desbinfo));
                                                error = EAGAIN;
                                                goto out;
                                        }
                                        break;
                                }
                                /* Mark this dblk with the zero-copy flag */
                                nmp->b_datap->db_struioflag |= STRUIO_ZC;
                                nmp->b_wptr += mblk_size;
                                chain_size += mblk_size;
                                fileoff += mblk_size;
                                total_size -= mblk_size;
                                snfv->snfv_ref++;
                                mapoff = 0;
                                if (i > 0)
                                        linkb(mp, nmp);
                                else
                                        mp = nmp;
                        }
                        VN_HOLD(fvp);
                        snfv->snfv_vp = fvp;
                } else {
                        /* vpm not supported. fallback to segmap */
                        snf_smap_desbinfo *snfi;

                        mapoff = fileoff & MAXBOFFSET;
                        chain_size = MAXBSIZE - mapoff;
                        if (chain_size > total_size)
                                chain_size = total_size;
                        /*
                         * we don't forcefault because we'll call
                         * segmap_fault(F_SOFTLOCK) next.
                         *
                         * S_READ will get the ref bit set (by either
                         * segmap_getmapflt() or segmap_fault()) and page
                         * shared locked.
                         */
                        base = segmap_getmapflt(segkmap, fvp, fileoff,
                            chain_size, segmap_kpm ? SM_FAULT : 0, S_READ);

                        snfi = kmem_alloc(sizeof (*snfi), KM_SLEEP);
                        snfi->snfi_len = (size_t)roundup(mapoff+chain_size,
                            PAGESIZE)- (mapoff & PAGEMASK);
                        /*
                         * We must call segmap_fault() even for segmap_kpm
                         * because that's how error gets returned.
                         * (segmap_getmapflt() never fails but segmap_fault()
                         * does.)
                         *
                         * If the pages aren't available yet, we get
                         * DEADLK, so wait and try again a little later using
                         * an increasing wait. We might be here a long time.
                         *
                         * If delay_sig returns EINTR, be sure to exit and
                         * pass it up to the caller.
                         */
                        deadlk_wait = 0;
                        while ((error = FC_ERRNO(segmap_fault(kas.a_hat,
                            segkmap, (caddr_t)(uintptr_t)(((uintptr_t)base +
                            mapoff) & PAGEMASK), snfi->snfi_len, F_SOFTLOCK,
                            S_READ))) == EDEADLK) {
                                deadlk_wait += (deadlk_wait < 5) ? 1 : 4;
                                if ((error = delay_sig(deadlk_wait)) != 0) {
                                        break;
                                }
                        }
                        if (error != 0) {
                                (void) segmap_release(segkmap, base, 0);
                                kmem_free(snfi, sizeof (*snfi));
                                error = (error == EINTR) ? EINTR : EIO;
                                goto out;
                        }
                        snfi->snfi_frtn.free_func = snf_smap_desbfree;
                        snfi->snfi_frtn.free_arg = (caddr_t)snfi;
                        snfi->snfi_base = base;
                        snfi->snfi_mapoff = mapoff;
                        mp = esballoca((uchar_t *)base + mapoff, chain_size,
                            BPRI_HI, &snfi->snfi_frtn);

                        if (mp == NULL) {
                                (void) segmap_fault(kas.a_hat, segkmap,
                                    (caddr_t)(uintptr_t)(((uintptr_t)base +
                                    mapoff) & PAGEMASK), snfi->snfi_len,
                                    F_SOFTUNLOCK, S_OTHER);
                                (void) segmap_release(segkmap, base, 0);
                                kmem_free(snfi, sizeof (*snfi));
                                freemsg(mp);
                                error = EAGAIN;
                                goto out;
                        }
                        VN_HOLD(fvp);
                        snfi->snfi_vp = fvp;
                        mp->b_wptr += chain_size;

                        /* Mark this dblk with the zero-copy flag */
                        mp->b_datap->db_struioflag |= STRUIO_ZC;
                        fileoff += chain_size;
                        total_size -= chain_size;
                }

                if (total_size == 0 && !nowait) {
                        ASSERT(!dowait);
                        dowait = B_TRUE;
                        mp->b_datap->db_struioflag |= STRUIO_ZCNOTIFY;
                }
                VOP_RWUNLOCK(fvp, V_WRITELOCK_FALSE, NULL);
                error = socket_sendmblk(VTOSO(vp), &msg, fflag, CRED(), &mp);
                if (error != 0) {
                        /*
                         * mp contains the mblks that were not sent by
                         * socket_sendmblk. Use its size to update *count
                         */
                        *count = ksize + (chain_size - msgdsize(mp));
                        if (mp != NULL)
                                freemsg(mp);
                        return (error);
                }
                ksize += chain_size;
                if (total_size == 0)
                        goto done;

                (void) VOP_RWLOCK(fvp, V_WRITELOCK_FALSE, NULL);
                va.va_mask = AT_SIZE;
                error = VOP_GETATTR(fvp, &va, 0, kcred, NULL);
                if (error)
                        break;
                /* Read as much as possible. */
                if (fileoff >= va.va_size)
                        break;
                if (total_size + fileoff > va.va_size)
                        total_size = va.va_size - fileoff;
        }
out:
        VOP_RWUNLOCK(fvp, V_WRITELOCK_FALSE, NULL);
done:
        *count = ksize;
        if (dowait) {
                stdata_t *stp;

                stp = vp->v_stream;
                if (stp == NULL) {
                        struct sonode *so;
                        so = VTOSO(vp);
                        error = so_zcopy_wait(so);
                } else {
                        mutex_enter(&stp->sd_lock);
                        while (!(stp->sd_flag & STZCNOTIFY)) {
                                if (cv_wait_sig(&stp->sd_zcopy_wait,
                                    &stp->sd_lock) == 0) {
                                        error = EINTR;
                                        break;
                                }
                        }
                        stp->sd_flag &= ~STZCNOTIFY;
                        mutex_exit(&stp->sd_lock);
                }
        }
        return (error);
}

int
snf_cache(file_t *fp, vnode_t *fvp, u_offset_t fileoff, u_offset_t size,
    uint_t maxpsz, ssize_t *count)
{
        struct vnode *vp;
        mblk_t *mp;
        int iosize;
        int extra = 0;
        int error;
        short fflag;
        int ksize;
        int ioflag;
        struct uio auio;
        struct iovec aiov;
        struct vattr va;
        int maxblk = 0;
        int wroff = 0;
        struct sonode *so;
        struct nmsghdr msg;

        vp = fp->f_vnode;
        if (vp->v_type == VSOCK) {
                stdata_t *stp;

                /*
                 * Get the extra space to insert a header and a trailer.
                 */
                so = VTOSO(vp);
                stp = vp->v_stream;
                if (stp == NULL) {
                        wroff = so->so_proto_props.sopp_wroff;
                        maxblk = so->so_proto_props.sopp_maxblk;
                        extra = wroff + so->so_proto_props.sopp_tail;
                } else {
                        wroff = (int)(stp->sd_wroff);
                        maxblk = (int)(stp->sd_maxblk);
                        extra = wroff + (int)(stp->sd_tail);
                }
        }
        bzero(&msg, sizeof (msg));
        fflag = fp->f_flag;
        ksize = 0;
        auio.uio_iov = &aiov;
        auio.uio_iovcnt = 1;
        auio.uio_segflg = UIO_SYSSPACE;
        auio.uio_llimit = MAXOFFSET_T;
        auio.uio_fmode = fflag;
        auio.uio_extflg = UIO_COPY_CACHED;
        ioflag = auio.uio_fmode & (FSYNC|FDSYNC|FRSYNC);
        /* If read sync is not asked for, filter sync flags */
        if ((ioflag & FRSYNC) == 0)
                ioflag &= ~(FSYNC|FDSYNC);
        for (;;) {
                if (ISSIG(curthread, JUSTLOOKING)) {
                        error = EINTR;
                        break;
                }
                iosize = (int)MIN(maxpsz, size);

                /*
                 * Socket filters can limit the mblk size,
                 * so limit reads to maxblk if there are
                 * filters present.
                 */
                if (vp->v_type == VSOCK &&
                    so->so_filter_active > 0 && maxblk != INFPSZ)
                        iosize = (int)MIN(iosize, maxblk);

                if (is_system_labeled()) {
                        mp = allocb_cred(iosize + extra, CRED(),
                            curproc->p_pid);
                } else {
                        mp = allocb(iosize + extra, BPRI_MED);
                }
                if (mp == NULL) {
                        error = EAGAIN;
                        break;
                }

                mp->b_rptr += wroff;

                aiov.iov_base = (caddr_t)mp->b_rptr;
                aiov.iov_len = iosize;
                auio.uio_loffset = fileoff;
                auio.uio_resid = iosize;

                error = VOP_READ(fvp, &auio, ioflag, fp->f_cred, NULL);
                iosize -= auio.uio_resid;

                if (error == EINTR && iosize != 0)
                        error = 0;

                if (error != 0 || iosize == 0) {
                        freeb(mp);
                        break;
                }
                mp->b_wptr = mp->b_rptr + iosize;

                VOP_RWUNLOCK(fvp, V_WRITELOCK_FALSE, NULL);

                error = socket_sendmblk(VTOSO(vp), &msg, fflag, CRED(), &mp);

                if (error != 0) {
                        *count = ksize;
                        if (mp != NULL)
                                freeb(mp);
                        return (error);
                }
                ksize += iosize;
                size -= iosize;
                if (size == 0)
                        goto done;

                fileoff += iosize;
                (void) VOP_RWLOCK(fvp, V_WRITELOCK_FALSE, NULL);
                va.va_mask = AT_SIZE;
                error = VOP_GETATTR(fvp, &va, 0, kcred, NULL);
                if (error)
                        break;
                /* Read as much as possible. */
                if (fileoff >= va.va_size)
                        size = 0;
                else if (size + fileoff > va.va_size)
                        size = va.va_size - fileoff;
        }
        VOP_RWUNLOCK(fvp, V_WRITELOCK_FALSE, NULL);
done:
        *count = ksize;
        return (error);
}

#if defined(_SYSCALL32_IMPL) || defined(_ILP32)
/*
 * Largefile support for 32 bit applications only.
 */
int
sosendfile64(file_t *fp, file_t *rfp, const struct ksendfilevec64 *sfv,
    ssize32_t *count32)
{
        ssize32_t sfv_len;
        u_offset_t sfv_off, va_size;
        struct vnode *vp, *fvp, *realvp;
        struct vattr va;
        stdata_t *stp;
        ssize_t count = 0;
        int error = 0;
        boolean_t dozcopy = B_FALSE;
        uint_t maxpsz;

        sfv_len = (ssize32_t)sfv->sfv_len;
        if (sfv_len < 0) {
                error = EINVAL;
                goto out;
        }

        if (sfv_len == 0) goto out;

        sfv_off = (u_offset_t)sfv->sfv_off;

        /* Same checks as in pread */
        if (sfv_off > MAXOFFSET_T) {
                error = EINVAL;
                goto out;
        }
        if (sfv_off + sfv_len > MAXOFFSET_T)
                sfv_len = (ssize32_t)(MAXOFFSET_T - sfv_off);

        /*
         * There are no more checks on sfv_len. So, we cast it to
         * u_offset_t and share the snf_direct_io/snf_cache code between
         * 32 bit and 64 bit.
         *
         * TODO: should do nbl_need_check() like read()?
         */
        if (sfv_len > sendfile_max_size) {
                sf_stats.ss_file_not_cached++;
                error = snf_direct_io(fp, rfp, sfv_off, (u_offset_t)sfv_len,
                    &count);
                goto out;
        }
        fvp = rfp->f_vnode;
        if (VOP_REALVP(fvp, &realvp, NULL) == 0)
                fvp = realvp;
        /*
         * Grab the lock as a reader to prevent the file size
         * from changing underneath.
         */
        (void) VOP_RWLOCK(fvp, V_WRITELOCK_FALSE, NULL);
        va.va_mask = AT_SIZE;
        error = VOP_GETATTR(fvp, &va, 0, kcred, NULL);
        va_size = va.va_size;
        if ((error != 0) || (va_size == 0) || (sfv_off >= va_size)) {
                VOP_RWUNLOCK(fvp, V_WRITELOCK_FALSE, NULL);
                goto out;
        }
        /* Read as much as possible. */
        if (sfv_off + sfv_len > va_size)
                sfv_len = va_size - sfv_off;

        vp = fp->f_vnode;
        stp = vp->v_stream;
        /*
         * When the NOWAIT flag is not set, we enable zero-copy only if the
         * transfer size is large enough. This prevents performance loss
         * when the caller sends the file piece by piece.
         */
        if (sfv_len >= MAXBSIZE && (sfv_len >= (va_size >> 1) ||
            (sfv->sfv_flag & SFV_NOWAIT) || sfv_len >= 0x1000000) &&
            !vn_has_flocks(fvp) && !(fvp->v_flag & VNOMAP)) {
                uint_t copyflag;
                copyflag = stp != NULL ? stp->sd_copyflag :
                    VTOSO(vp)->so_proto_props.sopp_zcopyflag;
                if ((copyflag & (STZCVMSAFE|STZCVMUNSAFE)) == 0) {
                        int on = 1;

                        if (socket_setsockopt(VTOSO(vp), SOL_SOCKET,
                            SO_SND_COPYAVOID, &on, sizeof (on), CRED()) == 0)
                                dozcopy = B_TRUE;
                } else {
                        dozcopy = copyflag & STZCVMSAFE;
                }
        }
        if (dozcopy) {
                sf_stats.ss_file_segmap++;
                error = snf_segmap(fp, fvp, sfv_off, (u_offset_t)sfv_len,
                    &count, ((sfv->sfv_flag & SFV_NOWAIT) != 0));
        } else {
                if (vp->v_type == VSOCK && stp == NULL) {
                        sonode_t *so = VTOSO(vp);
                        maxpsz = so->so_proto_props.sopp_maxpsz;
                } else if (stp != NULL) {
                        maxpsz = stp->sd_qn_maxpsz;
                } else {
                        maxpsz = maxphys;
                }

                if (maxpsz == INFPSZ)
                        maxpsz = maxphys;
                else
                        maxpsz = roundup(maxpsz, MAXBSIZE);
                sf_stats.ss_file_cached++;
                error = snf_cache(fp, fvp, sfv_off, (u_offset_t)sfv_len,
                    maxpsz, &count);
        }
out:
        releasef(sfv->sfv_fd);
        *count32 = (ssize32_t)count;
        return (error);
}
#endif

#ifdef _SYSCALL32_IMPL
/*
 * recv32(), recvfrom32(), send32(), sendto32(): intentionally return a
 * ssize_t rather than ssize32_t; see the comments above read32 for details.
 */

ssize_t
recv32(int32_t sock, caddr32_t buffer, size32_t len, int32_t flags)
{
        return (recv(sock, (void *)(uintptr_t)buffer, (ssize32_t)len, flags));
}

ssize_t
recvfrom32(int32_t sock, caddr32_t buffer, size32_t len, int32_t flags,
        caddr32_t name, caddr32_t namelenp)
{
        return (recvfrom(sock, (void *)(uintptr_t)buffer, (ssize32_t)len, flags,
            (void *)(uintptr_t)name, (void *)(uintptr_t)namelenp));
}

ssize_t
send32(int32_t sock, caddr32_t buffer, size32_t len, int32_t flags)
{
        return (send(sock, (void *)(uintptr_t)buffer, (ssize32_t)len, flags));
}

ssize_t
sendto32(int32_t sock, caddr32_t buffer, size32_t len, int32_t flags,
        caddr32_t name, socklen_t namelen)
{
        return (sendto(sock, (void *)(uintptr_t)buffer, (ssize32_t)len, flags,
            (void *)(uintptr_t)name, namelen));
}
#endif  /* _SYSCALL32_IMPL */

/*
 * Function wrappers (mostly around the sonode switch) for
 * backward compatibility.
 */

int
soaccept(struct sonode *so, int fflag, struct sonode **nsop)
{
        return (socket_accept(so, fflag, CRED(), nsop));
}

int
sobind(struct sonode *so, struct sockaddr *name, socklen_t namelen,
    int backlog, int flags)
{
        int     error;

        error = socket_bind(so, name, namelen, flags, CRED());
        if (error == 0 && backlog != 0)
                return (socket_listen(so, backlog, CRED()));

        return (error);
}

int
solisten(struct sonode *so, int backlog)
{
        return (socket_listen(so, backlog, CRED()));
}

int
soconnect(struct sonode *so, struct sockaddr *name, socklen_t namelen,
    int fflag, int flags)
{
        return (socket_connect(so, name, namelen, fflag, flags, CRED()));
}

int
sorecvmsg(struct sonode *so, struct nmsghdr *msg, struct uio *uiop)
{
        return (socket_recvmsg(so, msg, uiop, CRED()));
}

int
sosendmsg(struct sonode *so, struct nmsghdr *msg, struct uio *uiop)
{
        return (socket_sendmsg(so, msg, uiop, CRED()));
}

int
soshutdown(struct sonode *so, int how)
{
        return (socket_shutdown(so, how, CRED()));
}

int
sogetsockopt(struct sonode *so, int level, int option_name, void *optval,
    socklen_t *optlenp, int flags)
{
        return (socket_getsockopt(so, level, option_name, optval, optlenp,
            flags, CRED()));
}

int
sosetsockopt(struct sonode *so, int level, int option_name, const void *optval,
    t_uscalar_t optlen)
{
        return (socket_setsockopt(so, level, option_name, optval, optlen,
            CRED()));
}

/*
 * Because this is backward compatibility interface it only needs to be
 * able to handle the creation of TPI sockfs sockets.
 */
struct sonode *
socreate(struct sockparams *sp, int family, int type, int protocol,
    int *errorp)
{
        struct sonode *so;

        ASSERT(sp != NULL);

        so = sp->sp_smod_info->smod_sock_create_func(sp, family, type, protocol,
            SOCKET_SLEEP, errorp, CRED());
        if (so == NULL) {
                SOCKPARAMS_DEC_REF(sp);
        } else {
                if ((*errorp = SOP_INIT(so, NULL, CRED(), SOCKET_SLEEP)) == 0) {
                        /* Cannot fail, only bumps so_count */
                        (void) VOP_OPEN(&SOTOV(so), FREAD|FWRITE, CRED(), NULL);
                } else {
                        socket_destroy(so);
                        so = NULL;
                }
        }
        return (so);
}