[apple/xnu.git] / bsd / kern / kpi_socket.c

/*
 * Copyright (c) 2003-2011 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#define __KPI__
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/mbuf.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/uio_internal.h>
#include <kern/lock.h>
#include <netinet/in.h>
#include <libkern/OSAtomic.h>

extern int soclose_locked(struct socket *so);
extern void soclose_wait_locked(struct socket *so);
extern int so_isdstlocal(struct socket *so);

errno_t sock_send_internal(
        socket_t                        sock,
        const struct msghdr     *msg,
        mbuf_t                          data,
        int                                     flags,
        size_t                          *sentlen);

typedef void    (*so_upcall)(struct socket *, caddr_t , int );


errno_t
sock_accept(
        socket_t                sock,
        struct sockaddr *from,
        int                             fromlen,
        int                             flags,
        sock_upcall             callback,
        void*                   cookie,
        socket_t                *new_sock)
{
        struct sockaddr *sa;
        struct socket *new_so;
        lck_mtx_t *mutex_held;
        int     dosocklock;
        errno_t error = 0;
        
        if (sock == NULL || new_sock == NULL) return EINVAL;
        socket_lock(sock, 1);
        if ((sock->so_options & SO_ACCEPTCONN) == 0) {
                socket_unlock(sock, 1);
                return EINVAL;
        }
        if ((flags & ~(MSG_DONTWAIT)) != 0) {
                socket_unlock(sock, 1);
                return ENOTSUP;
        }
        if (((flags & MSG_DONTWAIT) != 0 || (sock->so_state & SS_NBIO) != 0) &&
                sock->so_comp.tqh_first == NULL) {
                socket_unlock(sock, 1);
                return EWOULDBLOCK;
        }

        if (sock->so_proto->pr_getlock != NULL)  {
                mutex_held = (*sock->so_proto->pr_getlock)(sock, 0);
                dosocklock = 1;
        }
        else {
                mutex_held = sock->so_proto->pr_domain->dom_mtx;
                dosocklock = 0;
        }
        
        while (TAILQ_EMPTY(&sock->so_comp) && sock->so_error == 0) {
                if (sock->so_state & SS_CANTRCVMORE) {
                        sock->so_error = ECONNABORTED;
                        break;
                }
                error = msleep((caddr_t)&sock->so_timeo, mutex_held, PSOCK | PCATCH, "sock_accept", NULL);
                if (error) {
                        socket_unlock(sock, 1);
                        return (error);
                }
        }
        if (sock->so_error) {
                error = sock->so_error;
                sock->so_error = 0;
                socket_unlock(sock, 1);
                return (error);
        }
        
        new_so = TAILQ_FIRST(&sock->so_comp);
        TAILQ_REMOVE(&sock->so_comp, new_so, so_list);
        sock->so_qlen--;

        /*
         * Pass the pre-accepted socket to any interested socket filter(s).
         * Upon failure, the socket would have been closed by the callee.
         */
        if (new_so->so_filt != NULL) {
                /*
                 * Temporarily drop the listening socket's lock before we
                 * hand off control over to the socket filter(s), but keep
                 * a reference so that it won't go away.  We'll grab it
                 * again once we're done with the filter(s).
                 */
                socket_unlock(sock, 0);
                if ((error = soacceptfilter(new_so)) != 0) {
                        /* Drop reference on listening socket */
                        sodereference(sock);
                        return (error);
                }
                socket_lock(sock, 0);
        }

        if (dosocklock) {
                lck_mtx_assert(new_so->so_proto->pr_getlock(new_so, 0),
                                           LCK_MTX_ASSERT_NOTOWNED);
                socket_lock(new_so, 1);
        }
        
        new_so->so_state &= ~SS_COMP;
        new_so->so_head = NULL;
        (void) soacceptlock(new_so, &sa, 0);
        
        socket_unlock(sock, 1); /* release the head */

        if (callback) {
                new_so->so_upcall = (so_upcall) callback;
                new_so->so_upcallarg = cookie;
                new_so->so_rcv.sb_flags |= SB_UPCALL;
#if CONFIG_SOWUPCALL
                new_so->so_snd.sb_flags |= SB_UPCALL;
#endif
        }
        
        if (sa && from)
        {
                if (fromlen > sa->sa_len) fromlen = sa->sa_len;
                memcpy(from, sa, fromlen);
        }
        if (sa) FREE(sa, M_SONAME);

        /*
         * If the socket has been marked as inactive by sosetdefunct(),
         * disallow further operations on it.
         */
        if (new_so->so_flags & SOF_DEFUNCT) {
                (void) sodefunct(current_proc(), new_so,
                    SHUTDOWN_SOCKET_LEVEL_DISCONNECT_INTERNAL);
        }
        *new_sock = new_so;
        if (dosocklock) 
                socket_unlock(new_so, 1);
        return error;
}

errno_t
sock_bind(
        socket_t                                sock,
        const struct sockaddr   *to)
{
        int     error = 0;
        struct sockaddr *sa = NULL;
        struct sockaddr_storage ss;
        boolean_t want_free = TRUE;

        if (sock == NULL || to == NULL) 
                return EINVAL;
        
        if (to->sa_len > sizeof(ss)) {
                MALLOC(sa, struct sockaddr *, to->sa_len, M_SONAME, M_WAITOK);
                if (sa == NULL)
                        return ENOBUFS;
        } else {
                sa = (struct sockaddr *)&ss;
                want_free = FALSE;
        }
        memcpy(sa, to, to->sa_len);

        error = sobind(sock, sa);
        
        if (sa != NULL && want_free == TRUE)
                FREE(sa, M_SONAME);     

        return error;
}

errno_t
sock_connect(
        socket_t                                sock,
        const struct sockaddr   *to,
        int                                             flags)
{
        int     error = 0;
        lck_mtx_t *mutex_held;
        struct sockaddr *sa = NULL;
        struct sockaddr_storage ss;
        boolean_t want_free = TRUE;
        
        if (sock == NULL || to == NULL) return EINVAL;
        
        if (to->sa_len > sizeof(ss)) {
                MALLOC(sa, struct sockaddr *, to->sa_len, M_SONAME,
                        (flags & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK);
                if (sa == NULL)
                        return ENOBUFS;
        } else {
                sa = (struct sockaddr *)&ss;
                want_free = FALSE;
        }
        memcpy(sa, to, to->sa_len);

        socket_lock(sock, 1);

        if ((sock->so_state & SS_ISCONNECTING) &&
                ((sock->so_state & SS_NBIO) != 0 ||
                 (flags & MSG_DONTWAIT) != 0)) {
                error = EALREADY;
                goto out;
        }
        error = soconnectlock(sock, sa, 0);
        if (!error) {
                if ((sock->so_state & SS_ISCONNECTING) &&
                        ((sock->so_state & SS_NBIO) != 0 || (flags & MSG_DONTWAIT) != 0)) {
                        error = EINPROGRESS;
                        goto out;
                }
                
                if (sock->so_proto->pr_getlock != NULL)  
                        mutex_held = (*sock->so_proto->pr_getlock)(sock, 0);
                else 
                        mutex_held = sock->so_proto->pr_domain->dom_mtx;

                while ((sock->so_state & SS_ISCONNECTING) && sock->so_error == 0) {
                        error = msleep((caddr_t)&sock->so_timeo, mutex_held, PSOCK | PCATCH,
                                "sock_connect", NULL);
                        if (error)
                                break;
                }
                
                if (error == 0) {
                        error = sock->so_error;
                        sock->so_error = 0;
                }
        }
        else {
                sock->so_state &= ~SS_ISCONNECTING;
        }
out:
        socket_unlock(sock, 1);

        if (sa != NULL && want_free == TRUE)
                FREE(sa, M_SONAME);
                
        return error;
}

errno_t
sock_connectwait(
        socket_t                                sock,
        const struct timeval    *tv)
{
        lck_mtx_t * mutex_held;
        errno_t retval = 0;
        struct timespec ts;
        
        socket_lock(sock, 1);
        
        // Check if we're already connected or if we've already errored out
        if ((sock->so_state & SS_ISCONNECTING) == 0 || sock->so_error) {
                if (sock->so_error) {
                        retval = sock->so_error;
                        sock->so_error = 0;
                }
                else {
                        if ((sock->so_state & SS_ISCONNECTED) != 0)
                                retval = 0;
                        else
                                retval = EINVAL;
                }
                goto done;
        }
        
        // copied translation from timeval to hertz from SO_RCVTIMEO handling
        if (tv->tv_sec < 0 || tv->tv_sec > SHRT_MAX / hz ||
                tv->tv_usec < 0 || tv->tv_usec >= 1000000) {
                retval = EDOM;
                goto done;
        }
        
        ts.tv_sec = tv->tv_sec;
        ts.tv_nsec = (tv->tv_usec * NSEC_PER_USEC);
        if ( (ts.tv_sec + (ts.tv_nsec/NSEC_PER_SEC))/100  >  SHRT_MAX)  {
                retval = EDOM;
                goto done;
        }
        
        if (sock->so_proto->pr_getlock != NULL)  
                mutex_held = (*sock->so_proto->pr_getlock)(sock, 0);
        else 
                mutex_held = sock->so_proto->pr_domain->dom_mtx;

        msleep((caddr_t)&sock->so_timeo, mutex_held, PSOCK, "sock_connectwait", &ts);
        
        // Check if we're still waiting to connect
        if ((sock->so_state & SS_ISCONNECTING) && sock->so_error == 0) {
                retval = EINPROGRESS;
                goto done;
        }
        
        if (sock->so_error) {
                retval = sock->so_error;
                sock->so_error = 0;
        }
        
done:
        socket_unlock(sock, 1);
        return retval;
}

errno_t
sock_nointerrupt(
        socket_t        sock,
        int                     on)
{
        socket_lock(sock, 1);

        if (on) {
                sock->so_rcv.sb_flags |= SB_NOINTR; // This isn't safe
                sock->so_snd.sb_flags |= SB_NOINTR; // This isn't safe
        }
        else {
                sock->so_rcv.sb_flags &= ~SB_NOINTR; // This isn't safe
                sock->so_snd.sb_flags &= ~SB_NOINTR; // This isn't safe
        }

        socket_unlock(sock, 1);

        return 0;
}

errno_t
sock_getpeername(socket_t sock, struct sockaddr *peername, int peernamelen)
{
        int error;
        struct sockaddr *sa = NULL;

        if (sock == NULL || peername == NULL || peernamelen < 0)
                return (EINVAL);

        socket_lock(sock, 1);
        if (!(sock->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING))) {
                socket_unlock(sock, 1);
                return (ENOTCONN);
        }
        error = sogetaddr_locked(sock, &sa, 1);
        socket_unlock(sock, 1);
        if (error == 0) {
                if (peernamelen > sa->sa_len)
                        peernamelen = sa->sa_len;
                memcpy(peername, sa, peernamelen);
                FREE(sa, M_SONAME);
        }
        return (error);
}

errno_t
sock_getsockname(socket_t sock, struct sockaddr *sockname, int socknamelen)
{
        int error;
        struct sockaddr *sa = NULL;

        if (sock == NULL || sockname == NULL || socknamelen < 0)
                return (EINVAL);

        socket_lock(sock, 1);
        error = sogetaddr_locked(sock, &sa, 0);
        socket_unlock(sock, 1);
        if (error == 0) {
                if (socknamelen > sa->sa_len)
                        socknamelen = sa->sa_len;
                memcpy(sockname, sa, socknamelen);
                FREE(sa, M_SONAME);
        }
        return (error);
}

__private_extern__ int
sogetaddr_locked(struct socket *so, struct sockaddr **psa, int peer)
{
        int error;

        if (so == NULL || psa == NULL)
                return (EINVAL);

        *psa = NULL;
        error = peer ? so->so_proto->pr_usrreqs->pru_peeraddr(so, psa) :
            so->so_proto->pr_usrreqs->pru_sockaddr(so, psa);

        if (error == 0 && *psa == NULL) {
                error = ENOMEM;
        } else if (error != 0 && *psa != NULL) {
                FREE(*psa, M_SONAME);
                *psa = NULL;
        }
        return (error);
}

errno_t
sock_getaddr(socket_t sock, struct sockaddr **psa, int peer)
{
        int error;

        if (sock == NULL || psa == NULL)
                return (EINVAL);

        socket_lock(sock, 1);
        error = sogetaddr_locked(sock, psa, peer);
        socket_unlock(sock, 1);
        
        return (error);
}

void
sock_freeaddr(struct sockaddr *sa)
{
        if (sa != NULL)
                FREE(sa, M_SONAME);
}

errno_t
sock_getsockopt(
        socket_t        sock,
        int                     level,
        int                     optname,
        void            *optval,
        int                     *optlen)
{
        int                             error = 0;
        struct sockopt  sopt;
        
        if (sock == NULL || optval == NULL || optlen == NULL) return EINVAL;
        sopt.sopt_dir = SOPT_GET;
        sopt.sopt_level = level;
        sopt.sopt_name = optname;
        sopt.sopt_val = CAST_USER_ADDR_T(optval); 
        sopt.sopt_valsize = *optlen;
        sopt.sopt_p = kernproc;
        error = sogetopt(sock, &sopt); /* will lock socket */
        if (error == 0) *optlen = sopt.sopt_valsize;
        return error;
}

errno_t
sock_ioctl(
        socket_t        sock,
        unsigned long request,
        void *argp)
{
        return soioctl(sock, request, argp, kernproc); /* will lock socket */
}

errno_t
sock_setsockopt(
        socket_t        sock,
        int                     level,
        int                     optname,
        const void      *optval,
        int                     optlen)
{
        struct sockopt  sopt;
        
        if (sock == NULL || optval == NULL) return EINVAL;
        sopt.sopt_dir = SOPT_SET;
        sopt.sopt_level = level;
        sopt.sopt_name = optname;
        sopt.sopt_val = CAST_USER_ADDR_T(optval);
        sopt.sopt_valsize = optlen;
        sopt.sopt_p = kernproc;
        return sosetopt(sock, &sopt); /* will lock socket */
}

/*
 * This follows the recommended mappings between DSCP code points and WMM access classes
 */
static u_int32_t so_tc_from_dscp(u_int8_t dscp);
static u_int32_t
so_tc_from_dscp(u_int8_t dscp)
{
        u_int32_t tc;

        if (dscp >= 0x30 && dscp <= 0x3f)
                tc = SO_TC_VO;
        else if (dscp >= 0x20 && dscp <= 0x2f)
                tc = SO_TC_VI;
        else if (dscp >= 0x08 && dscp <= 0x17)
                tc = SO_TC_BK;
        else
                tc = SO_TC_BE;

        return (tc);
}

errno_t
sock_settclassopt(
        socket_t        sock,
        const void      *optval,
        size_t          optlen) {

        errno_t error = 0;
        struct sockopt sopt;
        int sotc;

        if (sock == NULL || optval == NULL || optlen != sizeof(int)) return EINVAL;

        socket_lock(sock, 1);
        if (!(sock->so_state & SS_ISCONNECTED)) {
                /* If the socket is not connected then we don't know 
                 * if the destination is on LAN  or not. Skip
                 * setting traffic class in this case
                 */
                error = ENOTCONN;
                goto out;
        }

        if (sock->so_proto == NULL || sock->so_proto->pr_domain == NULL || sock->so_pcb == NULL) {
                error = EINVAL;
                goto out;
        }

        /*
         * Set the socket traffic class based on the passed DSCP code point
         * regardless of the scope of the destination
         */
        sotc = so_tc_from_dscp((*(const int *)optval) >> 2);

        sopt.sopt_dir = SOPT_SET;
        sopt.sopt_val = CAST_USER_ADDR_T(&sotc);
        sopt.sopt_valsize = sizeof(sotc);
        sopt.sopt_p = kernproc;
        sopt.sopt_level = SOL_SOCKET;
        sopt.sopt_name = SO_TRAFFIC_CLASS;

        socket_unlock(sock, 0);
        error = sosetopt(sock, &sopt);
        socket_lock(sock, 0);

        if (error != 0) {
                printf("sock_settclassopt: sosetopt SO_TRAFFIC_CLASS failed %d\n", error);
                goto out;
        }

        /* Check if the destination address is LAN or link local address.
         * We do not want to set traffic class bits if the destination
         * is not local 
         */ 
        if (!so_isdstlocal(sock)) {
                goto out;
        }

        sopt.sopt_dir = SOPT_SET;
        sopt.sopt_val = CAST_USER_ADDR_T(optval);
        sopt.sopt_valsize = optlen;
        sopt.sopt_p = kernproc;

        switch (sock->so_proto->pr_domain->dom_family) {
        case AF_INET:
                sopt.sopt_level = IPPROTO_IP;
                sopt.sopt_name = IP_TOS;
                break;
        case AF_INET6:
                sopt.sopt_level = IPPROTO_IPV6;
                sopt.sopt_name = IPV6_TCLASS;
                break;
        default:
                error = EINVAL;
                goto out;
        }
        
        socket_unlock(sock, 1);
        return sosetopt(sock, &sopt);
out:
        socket_unlock(sock, 1);
        return error;
}

errno_t
sock_gettclassopt(
        socket_t        sock,
        void            *optval,
        size_t          *optlen) {

        errno_t         error = 0;
        struct sockopt  sopt;
        
        if (sock == NULL || optval == NULL || optlen == NULL) return EINVAL;

        sopt.sopt_dir = SOPT_GET;
        sopt.sopt_val = CAST_USER_ADDR_T(optval); 
        sopt.sopt_valsize = *optlen;
        sopt.sopt_p = kernproc;

        socket_lock(sock, 1);
        if (sock->so_proto == NULL || sock->so_proto->pr_domain == NULL) {
                socket_unlock(sock, 1);
                return EINVAL;
        }

        switch (sock->so_proto->pr_domain->dom_family) {
        case AF_INET:
                sopt.sopt_level = IPPROTO_IP;
                sopt.sopt_name = IP_TOS;
                break;
        case AF_INET6:
                sopt.sopt_level = IPPROTO_IPV6;
                sopt.sopt_name = IPV6_TCLASS;
                break;
        default:
                socket_unlock(sock, 1);
                return EINVAL;

        }
        socket_unlock(sock, 1);
        error = sogetopt(sock, &sopt); /* will lock socket */
        if (error == 0) *optlen = sopt.sopt_valsize;
        return error;
}

errno_t
sock_listen(
        socket_t        sock,
        int                     backlog)
{
        if (sock == NULL) return EINVAL;
        return solisten(sock, backlog); /* will lock socket */
}

static errno_t
sock_receive_internal(
        socket_t                sock,
        struct msghdr           *msg,
        mbuf_t                  *data,
        int                     flags,
        size_t                  *recvdlen)
{
        uio_t           auio;
        struct mbuf     *control = NULL;
        int                     error = 0;
        int                     length = 0;
        struct sockaddr *fromsa;
        char            uio_buf[ UIO_SIZEOF((msg != NULL) ? msg->msg_iovlen : 0) ];
        
        if (sock == NULL) return EINVAL;
        
        auio = uio_createwithbuffer(((msg != NULL) ? msg->msg_iovlen : 0), 
                                                                  0, UIO_SYSSPACE, UIO_READ, 
                                                                  &uio_buf[0], sizeof(uio_buf));
        if (msg && data == NULL) {
                int i;
                struct iovec *tempp = msg->msg_iov;
                
                for (i = 0; i < msg->msg_iovlen; i++) {
                        uio_addiov(auio, CAST_USER_ADDR_T((tempp + i)->iov_base), (tempp + i)->iov_len);
                }
                if (uio_resid(auio) < 0) return EINVAL;
        }
        else {
                uio_setresid(auio, (uio_resid(auio) + *recvdlen));
        }
        length = uio_resid(auio);
        
        if (recvdlen)
                *recvdlen = 0;

        /* let pru_soreceive handle the socket locking */       
        error = sock->so_proto->pr_usrreqs->pru_soreceive(sock, &fromsa, auio,
            data, (msg && msg->msg_control) ? &control : NULL, &flags);
        if (error) goto cleanup;
        
        if (recvdlen)
                *recvdlen = length - uio_resid(auio);
        if (msg) {
                msg->msg_flags = flags;
                
                if (msg->msg_name)
                {
                        int salen;
                        salen = msg->msg_namelen;
                        if (msg->msg_namelen > 0 && fromsa != 0)
                        {
                                salen = MIN(salen, fromsa->sa_len);
                                memcpy(msg->msg_name, fromsa,
                                        msg->msg_namelen > fromsa->sa_len ? fromsa->sa_len :  msg->msg_namelen);
                        }
                }
                
                if (msg->msg_control)
                {
                        struct mbuf*    m = control;
                        u_char*                 ctlbuf = msg->msg_control;
                        int                             clen = msg->msg_controllen;
                        msg->msg_controllen = 0;
                        
                        while (m && clen > 0)
                        {
                                unsigned int tocopy;
                                if (clen >= m->m_len)
                                {
                                        tocopy = m->m_len;
                                }
                                else
                                {
                                        msg->msg_flags |= MSG_CTRUNC;
                                        tocopy = clen;
                                }
                                memcpy(ctlbuf, mtod(m, caddr_t), tocopy);
                                ctlbuf += tocopy;
                                clen -= tocopy;
                                m = m->m_next;
                        }
                        msg->msg_controllen = (uintptr_t)ctlbuf - (uintptr_t)msg->msg_control;
                }
        }

cleanup:
        if (control) m_freem(control);
        if (fromsa) FREE(fromsa, M_SONAME);
        return error;
}

errno_t
sock_receive(
        socket_t                sock,
        struct msghdr   *msg,
        int                             flags,
        size_t                  *recvdlen)
{
        if ((msg == NULL) ||
                (msg->msg_iovlen < 1) ||
                (msg->msg_iov[0].iov_len == 0) ||
                (msg->msg_iov[0].iov_base == NULL))
                return EINVAL;
        return sock_receive_internal(sock, msg, NULL, flags, recvdlen);
}

errno_t
sock_receivembuf(
        socket_t                sock,
        struct msghdr   *msg,
        mbuf_t                  *data,
        int                             flags,
        size_t                  *recvlen)
{
        if (data == NULL || recvlen == 0 || *recvlen <= 0 || (msg &&
                (msg->msg_iov != NULL || msg->msg_iovlen != 0)))
                return EINVAL;
        return sock_receive_internal(sock, msg, data, flags, recvlen);
}

errno_t
sock_send_internal(
        socket_t                        sock,
        const struct msghdr     *msg,
        mbuf_t                          data,
        int                                     flags,
        size_t                          *sentlen)
{
        uio_t                   auio = NULL;
        struct mbuf             *control = NULL;
        int                             error = 0;
        int                             datalen = 0;
        char                    uio_buf[ UIO_SIZEOF((msg != NULL ? msg->msg_iovlen : 1)) ];
        
        if (sock == NULL) {
                error = EINVAL;
                goto errorout;
        }
        
        if (data == 0 && msg != NULL) {
                struct iovec *tempp = msg->msg_iov;

                auio = uio_createwithbuffer(msg->msg_iovlen, 0, UIO_SYSSPACE, UIO_WRITE, 
                                                                  &uio_buf[0], sizeof(uio_buf));
                if (tempp != NULL)
                {
                        int i;
                        
                        for (i = 0; i < msg->msg_iovlen; i++) {
                                uio_addiov(auio, CAST_USER_ADDR_T((tempp + i)->iov_base), (tempp + i)->iov_len);
                        }
                        
                        if (uio_resid(auio) < 0) {
                                error = EINVAL;
                                goto errorout;
                        }
                }
        }
        
        if (sentlen)
                *sentlen = 0;
        
        if (auio)
                datalen = uio_resid(auio);
        else
                datalen = data->m_pkthdr.len;
        
        if (msg && msg->msg_control)
        {
                if ((size_t)msg->msg_controllen < sizeof(struct cmsghdr)) return EINVAL;
                if ((size_t)msg->msg_controllen > MLEN) return EINVAL;
                control = m_get(M_NOWAIT, MT_CONTROL);
                if (control == NULL) {
                        error = ENOMEM;
                        goto errorout;
                }
                memcpy(mtod(control, caddr_t), msg->msg_control, msg->msg_controllen);
                control->m_len = msg->msg_controllen;
        }
        
        error = sock->so_proto->pr_usrreqs->pru_sosend(sock, msg != NULL ?
            (struct sockaddr*)msg->msg_name : NULL, auio, data, control, flags);

        /*
         * Residual data is possible in the case of IO vectors but not
         * in the mbuf case since the latter is treated as atomic send.
         * If pru_sosend() consumed a portion of the iovecs data and
         * the error returned is transient, treat it as success; this
         * is consistent with sendit() behavior.
         */
        if (auio != NULL && uio_resid(auio) != datalen &&
            (error == ERESTART || error == EINTR || error == EWOULDBLOCK))
                error = 0;

        if (error == 0 && sentlen != NULL) {
                if (auio != NULL)
                        *sentlen = datalen - uio_resid(auio);
                else
                        *sentlen = datalen;
        }
        
        return error;

/*
 * In cases where we detect an error before returning, we need to
 * free the mbuf chain if there is one. sosend (and pru_sosend) will
 * free the mbuf chain if they encounter an error.
 */
errorout:
        if (control)
                m_freem(control);
        if (data)
                m_freem(data);
        if (sentlen)
                *sentlen = 0;
        return error;
}

errno_t
sock_send(
        socket_t                        sock,
        const struct msghdr     *msg,
        int                                     flags,
        size_t                          *sentlen)
{
        if (msg == NULL || msg->msg_iov == NULL || msg->msg_iovlen < 1)
                return EINVAL;
        return sock_send_internal(sock, msg, NULL, flags, sentlen);
}

errno_t
sock_sendmbuf(
        socket_t                        sock,
        const struct msghdr     *msg,
        mbuf_t                          data,
        int                                     flags,
        size_t                          *sentlen)
{
        if (data == NULL || (msg &&
                (msg->msg_iov != NULL || msg->msg_iovlen != 0))) {
                if (data)
                        m_freem(data);
                return EINVAL;
        }
        return sock_send_internal(sock, msg, data, flags, sentlen);
}

errno_t
sock_shutdown(
        socket_t        sock,
        int                     how)
{
        if (sock == NULL) return EINVAL;
        return soshutdown(sock, how);
}


errno_t
sock_socket(
        int                             domain,
        int                             type,
        int                             protocol,
        sock_upcall             callback,
        void*                   context,
        socket_t                *new_so)
{
        int     error = 0;
        if (new_so == NULL) return EINVAL;
        /* socreate will create an initial so_count */
        error = socreate(domain, new_so, type, protocol);
        if (error == 0 && callback)
        {
                (*new_so)->so_rcv.sb_flags |= SB_UPCALL;
#if CONFIG_SOWUPCALL
                (*new_so)->so_snd.sb_flags |= SB_UPCALL;
#endif
                (*new_so)->so_upcall = (so_upcall)callback;
                (*new_so)->so_upcallarg = context;
                (*new_so)->last_pid = 0;
                (*new_so)->last_upid = 0;
        }
        return error;
}

void
sock_close(
        socket_t        sock)
{
        if (sock == NULL) return;
        soclose(sock);
}

/* Do we want this to be APPLE_PRIVATE API?: YES (LD 12/23/04)*/
void
sock_retain(
        socket_t        sock)
{
        if (sock == NULL) return;
        socket_lock(sock, 1);
        sock->so_retaincnt++;
        sock->so_usecount++;    /* add extra reference for holding the socket */
        socket_unlock(sock, 1);
}

/* Do we want this to be APPLE_PRIVATE API? */
void
sock_release(socket_t sock)
{
        if (sock == NULL)
                return;
        socket_lock(sock, 1);

        if (sock->so_upcallusecount)
                soclose_wait_locked(sock);

        sock->so_retaincnt--;
        if (sock->so_retaincnt < 0)
                panic("sock_release: negative retain count for sock=%p "
                    "cnt=%x\n", sock, sock->so_retaincnt);
        if ((sock->so_retaincnt == 0) && (sock->so_usecount == 2)) {
                /* close socket only if the FD is not holding it */
                soclose_locked(sock);
        } else {
                /* remove extra reference holding the socket */
                sock->so_usecount--;
        }
        socket_unlock(sock, 1);
}

errno_t
sock_setpriv(
        socket_t        sock,
        int                     on)
{
        if (sock == NULL) return EINVAL;
        socket_lock(sock, 1);
        if (on)
        {
                sock->so_state |= SS_PRIV;
        }
        else
        {
                sock->so_state &= ~SS_PRIV;
        }
        socket_unlock(sock, 1);
        return 0;
}

int
sock_isconnected(
        socket_t sock)
{
        int retval;
        socket_lock(sock, 1);
        retval = (sock->so_state & SS_ISCONNECTED) != 0;
        socket_unlock(sock, 1);
        return (retval);
}

int
sock_isnonblocking(
        socket_t sock)
{
        int retval;
        socket_lock(sock, 1);
        retval = (sock->so_state & SS_NBIO) != 0;
        socket_unlock(sock, 1);
        return (retval);
}

errno_t
sock_gettype(
        socket_t        sock,
        int                     *outDomain,
        int                     *outType,
        int                     *outProtocol)
{
        socket_lock(sock, 1);
        if (outDomain)
                *outDomain = sock->so_proto->pr_domain->dom_family;
        if (outType)
                *outType = sock->so_type;
        if (outProtocol)
                *outProtocol = sock->so_proto->pr_protocol;
        socket_unlock(sock, 1);
        return 0;
}

/*
 * Return the listening socket of a pre-accepted socket.  It returns the
 * listener (so_head) value of a given socket.  This is intended to be
 * called by a socket filter during a filter attach (sf_attach) callback.
 * The value returned by this routine is safe to be used only in the
 * context of that callback, because we hold the listener's lock across
 * the sflt_initsock() call.
 */
socket_t
sock_getlistener(socket_t sock)
{
        return (sock->so_head);
}

static inline void
sock_set_tcp_stream_priority(socket_t sock)
{
        if ((sock->so_proto->pr_domain->dom_family == AF_INET || 
                sock->so_proto->pr_domain->dom_family == AF_INET6) &&
                sock->so_proto->pr_type == SOCK_STREAM) {

                set_tcp_stream_priority(sock);

        }
}

/*
 * Caller must have ensured socket is valid and won't be going away.
 */
void
socket_set_traffic_mgt_flags_locked(socket_t sock, u_int32_t flags)
{
        (void) OSBitOrAtomic(flags, &sock->so_traffic_mgt_flags);
        sock_set_tcp_stream_priority(sock);
}

void
socket_set_traffic_mgt_flags(socket_t sock, u_int32_t flags)
{
        socket_lock(sock, 1);
        socket_set_traffic_mgt_flags_locked(sock, flags);
        socket_unlock(sock, 1);
}

/*
 * Caller must have ensured socket is valid and won't be going away.
 */
void
socket_clear_traffic_mgt_flags_locked(socket_t sock, u_int32_t flags)
{
        (void) OSBitAndAtomic(~flags, &sock->so_traffic_mgt_flags);
        sock_set_tcp_stream_priority(sock);
}

void
socket_clear_traffic_mgt_flags(socket_t sock, u_int32_t flags)
{
        socket_lock(sock, 1);
        socket_clear_traffic_mgt_flags_locked(sock, flags);
        socket_unlock(sock, 1);
}


/*
 * Caller must have ensured socket is valid and won't be going away.
 */
errno_t
socket_defunct(struct proc *p, socket_t so, int level)
{
        errno_t retval;

        if (level != SHUTDOWN_SOCKET_LEVEL_DISCONNECT_SVC &&
            level != SHUTDOWN_SOCKET_LEVEL_DISCONNECT_ALL)
                return (EINVAL);

        socket_lock(so, 1);
        /*
         * SHUTDOWN_SOCKET_LEVEL_DISCONNECT_SVC level is meant to tear down
         * all of mDNSResponder IPC sockets, currently those of AF_UNIX; note
         * that this is an implementation artifact of mDNSResponder.  We do
         * a quick test against the socket buffers for SB_UNIX, since that
         * would have been set by unp_attach() at socket creation time.
         */
        if (level == SHUTDOWN_SOCKET_LEVEL_DISCONNECT_SVC &&
            (so->so_rcv.sb_flags & so->so_snd.sb_flags & SB_UNIX) != SB_UNIX) {
                socket_unlock(so, 1);
                return (EOPNOTSUPP);
        }
        retval = sosetdefunct(p, so, level, TRUE);
        if (retval == 0)
                retval = sodefunct(p, so, level);
        socket_unlock(so, 1);
        return (retval);
}

errno_t
sock_setupcall(socket_t sock, sock_upcall callback, void* context)
{
        if (sock == NULL)
                return EINVAL;

        /*
         * Note that we don't wait for any in progress upcall to complete.
         */
        socket_lock(sock, 1);

        sock->so_upcall = (so_upcall) callback;
        sock->so_upcallarg = context;
        if (callback) {
                sock->so_rcv.sb_flags |= SB_UPCALL;
#if CONFIG_SOWUPCALL
                sock->so_snd.sb_flags |= SB_UPCALL;
#endif /* CONFIG_SOWUPCALL */
        } else {
                sock->so_rcv.sb_flags &= ~SB_UPCALL;
#if CONFIG_SOWUPCALL
                sock->so_snd.sb_flags &= ~SB_UPCALL;
#endif /* CONFIG_SOWUPCALL */
        }
        
        socket_unlock(sock, 1);

        return 0;
}