Esempio n. 1
0
int
sosend(struct socket *so, 
       struct mbuf *nam,      /* sockaddr, if UDP socket, NULL if TCP */
       char  *data,           /* data to send */
       int   *data_length,    /* IN/OUT  length of (remaining) data */
       int   flags)
{
   struct mbuf *head = (struct mbuf *)NULL;
   struct mbuf *m;
   int   space;
   int   resid;
   int   len;
   int   error = 0;
   int   dontroute;
   int   first = 1;

   resid = *data_length;

   /*
    * In theory resid should be unsigned.
    * However, space must be signed, as it might be less than 0
    * if we over-committed, and we must use a signed comparison
    * of space and resid.  On the other hand, a negative resid
    * causes us to loop sending 0-length segments to the protocol.
    */
   if (resid < 0)
      return (EINVAL);

   INET_TRACE (INETM_IO, ("INET:sosend: so %lx resid %d sb_hiwat %d so_state %x\n",
               so, resid, so->so_snd.sb_hiwat, so->so_state));

   if (sosendallatonce(so) && (resid > (int)so->so_snd.sb_hiwat))
      return (EMSGSIZE);

   dontroute = (flags & MSG_DONTROUTE) &&
               ((so->so_options & SO_DONTROUTE) == 0) &&
               (so->so_proto->pr_flags & PR_ATOMIC);

#define     snderr(errno)     {  error =  errno;   goto  release; }

restart:
   sblock(&so->so_snd);
   do 
   {
      if (so->so_error) 
      {
         error = so->so_error;
         so->so_error = 0;          /* ??? */
         goto release;
      }
      if (so->so_state & SS_CANTSENDMORE)
         snderr(EPIPE);
      if ((so->so_state & SS_ISCONNECTED) == 0) 
      {
         if (so->so_proto->pr_flags & PR_CONNREQUIRED)
            snderr(ENOTCONN);
         if (nam == 0)
            snderr(EDESTADDRREQ);
      }
      if (flags & MSG_OOB)
         space = 1024;
      else 
      {
         space = (int)sbspace(&so->so_snd);
         if ((sosendallatonce(so) && (space < resid)) ||
             ((resid >= CLBYTES) && (space < CLBYTES) &&
              (so->so_snd.sb_cc >= CLBYTES) &&
              ((so->so_state & SS_NBIO) == 0) &&
              ((flags & MSG_DONTWAIT) == 0)))
         {
            if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT))
            {
               if (first)
                  error = EWOULDBLOCK;
               goto release;
            }
            sbunlock(&so->so_snd);
            sbwait(&so->so_snd);
            goto restart;
         }
      }
      if ( space <= 0 ) 
      {
         /* no space in socket send buffer - see if we can wait */
         if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT))
         {
            if (first)     /* report first error */
               error = EWOULDBLOCK;
            goto release;
         }
         /* If blocking socket, let someone else run */
         sbunlock(&so->so_snd);
         sbwait(&so->so_snd);
         goto restart;
      }

      while (space > 0) 
      {
         len = resid;
         if ( so->so_type == SOCK_STREAM )
         {
            m = m_getwithdata(MT_TXDATA, len);
            if (!m)   
               snderr(ENOBUFS);
            MEMCPY(m->m_data, data, len);
            so->so_snd.sb_flags |= SB_MBCOMP;   /* allow compression */
         }
         else
         {
            m = m_get (M_WAIT, MT_TXDATA);
            m->m_data = data;
         }
         INET_TRACE (INETM_IO,
          ("sosend:got %d bytes so %lx mlen %d, off %d mtod %x\n",
             len, so, m->m_len, m->m_off, mtod (m, caddr_t)));

         *data_length -= len;
         resid -= len;
         data += len;
         m->m_len = len;
         if (head == (struct mbuf *)NULL)
            head = m;
         if (error)
            goto release;
         if (*data_length <= 0)
            break;
      }

      if (dontroute)
         so->so_options |= SO_DONTROUTE;

      so->so_req = (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND;
      error = (*so->so_proto->pr_usrreq)(so, head, nam);

      if (dontroute)
         so->so_options &= ~SO_DONTROUTE;

      head = (struct mbuf *)NULL;
      first = 0;
   } while ((resid != 0) && (error == 0));

release:
   sbunlock(&so->so_snd);  
   if (head)
      m_freem(head);
   return error;
}
Esempio n. 2
0
/*
 * Slightly changed version of sosend()
 */
static int
kttcp_sosend(struct socket *so, unsigned long long slen,
	     unsigned long long *done, struct lwp *l, int flags)
{
	struct mbuf **mp, *m, *top;
	long space, len, mlen;
	int error, dontroute, atomic;
	long long resid;

	atomic = sosendallatonce(so);
	resid = slen;
	top = NULL;
	/*
	 * In theory resid should be unsigned.
	 * However, space must be signed, as it might be less than 0
	 * if we over-committed, and we must use a signed comparison
	 * of space and resid.  On the other hand, a negative resid
	 * causes us to loop sending 0-length segments to the protocol.
	 */
	if (resid < 0) {
		error = EINVAL;
		goto out;
	}
	dontroute =
	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
	    (so->so_proto->pr_flags & PR_ATOMIC);
	l->l_ru.ru_msgsnd++;
#define	snderr(errno)	{ error = errno; goto release; }
	solock(so);
 restart:
	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
		goto out;
	do {
		if (so->so_state & SS_CANTSENDMORE)
			snderr(EPIPE);
		if (so->so_error) {
			error = so->so_error;
			so->so_error = 0;
			goto release;
		}
		if ((so->so_state & SS_ISCONNECTED) == 0) {
			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
				snderr(ENOTCONN);
			} else {
				snderr(EDESTADDRREQ);
			}
		}
		space = sbspace(&so->so_snd);
		if (flags & MSG_OOB)
			space += 1024;
		if ((atomic && resid > so->so_snd.sb_hiwat))
			snderr(EMSGSIZE);
		if (space < resid && (atomic || space < so->so_snd.sb_lowat)) {
			if (so->so_state & SS_NBIO)
				snderr(EWOULDBLOCK);
			SBLASTRECORDCHK(&so->so_rcv,
			    "kttcp_soreceive sbwait 1");
			SBLASTMBUFCHK(&so->so_rcv,
			    "kttcp_soreceive sbwait 1");
			sbunlock(&so->so_snd);
			error = sbwait(&so->so_snd);
			if (error)
				goto out;
			goto restart;
		}
		mp = &top;
		do {
			sounlock(so);
			do {
				if (top == 0) {
					m = m_gethdr(M_WAIT, MT_DATA);
					mlen = MHLEN;
					m->m_pkthdr.len = 0;
					m->m_pkthdr.rcvif = NULL;
				} else {
					m = m_get(M_WAIT, MT_DATA);
					mlen = MLEN;
				}
				if (resid >= MINCLSIZE && space >= MCLBYTES) {
					m_clget(m, M_WAIT);
					if ((m->m_flags & M_EXT) == 0)
						goto nopages;
					mlen = MCLBYTES;
#ifdef	MAPPED_MBUFS
					len = lmin(MCLBYTES, resid);
#else
					if (atomic && top == 0) {
						len = lmin(MCLBYTES - max_hdr,
						    resid);
						m->m_data += max_hdr;
					} else
						len = lmin(MCLBYTES, resid);
#endif
					space -= len;
				} else {
nopages:
					len = lmin(lmin(mlen, resid), space);
					space -= len;
					/*
					 * For datagram protocols, leave room
					 * for protocol headers in first mbuf.
					 */
					if (atomic && top == 0 && len < mlen)
						MH_ALIGN(m, len);
				}
				resid -= len;
				m->m_len = len;
				*mp = m;
				top->m_pkthdr.len += len;
				if (error)
					goto release;
				mp = &m->m_next;
				if (resid <= 0) {
					if (flags & MSG_EOR)
						top->m_flags |= M_EOR;
					break;
				}
			} while (space > 0 && atomic);
			solock(so);

			if (so->so_state & SS_CANTSENDMORE)
				snderr(EPIPE);
			if (dontroute)
				so->so_options |= SO_DONTROUTE;
			if (resid > 0)
				so->so_state |= SS_MORETOCOME;
			if (flags & MSG_OOB)
				error = (*so->so_proto->pr_usrreqs->pr_sendoob)(so,
				    top, NULL);
			else
				error = (*so->so_proto->pr_usrreqs->pr_send)(so,
				    top, NULL, NULL, l);
			if (dontroute)
				so->so_options &= ~SO_DONTROUTE;
			if (resid > 0)
				so->so_state &= ~SS_MORETOCOME;
			top = 0;
			mp = &top;
			if (error)
				goto release;
		} while (resid && space > 0);
	} while (resid);

 release:
	sbunlock(&so->so_snd);
 out:
 	sounlock(so);
	if (top)
		m_freem(top);
	*done = slen - resid;
#if 0
	printf("sosend: error %d slen %llu resid %lld\n", error, slen, resid);
#endif
	return (error);
}
Esempio n. 3
0
static int
kttcp_soreceive(struct socket *so, unsigned long long slen,
    unsigned long long *done, struct lwp *l, int *flagsp)
{
	struct mbuf *m, **mp;
	int flags, len, error, offset, moff, type;
	long long orig_resid, resid;
	const struct protosw *pr;
	struct mbuf *nextrecord;

	pr = so->so_proto;
	mp = NULL;
	type = 0;
	resid = orig_resid = slen;
	if (flagsp)
		flags = *flagsp &~ MSG_EOR;
	else
 		flags = 0;
	if (flags & MSG_OOB) {
		m = m_get(M_WAIT, MT_DATA);
		solock(so);
		error = (*pr->pr_usrreqs->pr_recvoob)(so, m, flags & MSG_PEEK);
		sounlock(so);
		if (error)
			goto bad;
		do {
			resid -= min(resid, m->m_len);
			m = m_free(m);
		} while (resid && error == 0 && m);
 bad:
		if (m)
			m_freem(m);
		return (error);
	}
	if (mp)
		*mp = NULL;
	solock(so);
 restart:
	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0)
		return (error);
	m = so->so_rcv.sb_mb;
	/*
	 * If we have less data than requested, block awaiting more
	 * (subject to any timeout) if:
	 *   1. the current count is less than the low water mark,
	 *   2. MSG_WAITALL is set, and it is possible to do the entire
	 *	receive operation at once if we block (resid <= hiwat), or
	 *   3. MSG_DONTWAIT is not set.
	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
	 * we have to do the receive in sections, and thus risk returning
	 * a short count if a timeout or signal occurs after we start.
	 */
	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
	    so->so_rcv.sb_cc < resid) &&
	    (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
	    ((flags & MSG_WAITALL) && resid <= so->so_rcv.sb_hiwat)) &&
	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
#ifdef DIAGNOSTIC
		if (m == NULL && so->so_rcv.sb_cc)
			panic("receive 1");
#endif
		if (so->so_error) {
			if (m)
				goto dontblock;
			error = so->so_error;
			if ((flags & MSG_PEEK) == 0)
				so->so_error = 0;
			goto release;
		}
		if (so->so_state & SS_CANTRCVMORE) {
			if (m)
				goto dontblock;
			else
				goto release;
		}
		for (; m; m = m->m_next)
			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
				m = so->so_rcv.sb_mb;
				goto dontblock;
			}
		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
			error = ENOTCONN;
			goto release;
		}
		if (resid == 0)
			goto release;
		if ((so->so_state & SS_NBIO) ||
		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
			error = EWOULDBLOCK;
			goto release;
		}
		sbunlock(&so->so_rcv);
		error = sbwait(&so->so_rcv);
		if (error) {
			sounlock(so);
			return (error);
		}
		goto restart;
	}
 dontblock:
	/*
	 * On entry here, m points to the first record of the socket buffer.
	 * While we process the initial mbufs containing address and control
	 * info, we save a copy of m->m_nextpkt into nextrecord.
	 */
#ifdef notyet /* XXXX */
	if (uio->uio_lwp)
		uio->uio_lwp->l_ru.ru_msgrcv++;
#endif
	KASSERT(m == so->so_rcv.sb_mb);
	SBLASTRECORDCHK(&so->so_rcv, "kttcp_soreceive 1");
	SBLASTMBUFCHK(&so->so_rcv, "kttcp_soreceive 1");
	nextrecord = m->m_nextpkt;
	if (pr->pr_flags & PR_ADDR) {
#ifdef DIAGNOSTIC
		if (m->m_type != MT_SONAME)
			panic("receive 1a");
#endif
		orig_resid = 0;
		if (flags & MSG_PEEK) {
			m = m->m_next;
		} else {
			sbfree(&so->so_rcv, m);
			MFREE(m, so->so_rcv.sb_mb);
			m = so->so_rcv.sb_mb;
		}
	}
	while (m && m->m_type == MT_CONTROL && error == 0) {
		if (flags & MSG_PEEK) {
			m = m->m_next;
		} else {
			sbfree(&so->so_rcv, m);
			MFREE(m, so->so_rcv.sb_mb);
			m = so->so_rcv.sb_mb;
		}
	}

	/*
	 * If m is non-NULL, we have some data to read.  From now on,
	 * make sure to keep sb_lastrecord consistent when working on
	 * the last packet on the chain (nextrecord == NULL) and we
	 * change m->m_nextpkt.
	 */
	if (m) {
		if ((flags & MSG_PEEK) == 0) {
			m->m_nextpkt = nextrecord;
			/*
			 * If nextrecord == NULL (this is a single chain),
			 * then sb_lastrecord may not be valid here if m
			 * was changed earlier.
			 */
			if (nextrecord == NULL) {
				KASSERT(so->so_rcv.sb_mb == m);
				so->so_rcv.sb_lastrecord = m;
			}
		}
		type = m->m_type;
		if (type == MT_OOBDATA)
			flags |= MSG_OOB;
	} else {
		if ((flags & MSG_PEEK) == 0) {
			KASSERT(so->so_rcv.sb_mb == m);
			so->so_rcv.sb_mb = nextrecord;
			SB_EMPTY_FIXUP(&so->so_rcv);
		}
	}
	SBLASTRECORDCHK(&so->so_rcv, "kttcp_soreceive 2");
	SBLASTMBUFCHK(&so->so_rcv, "kttcp_soreceive 2");

	moff = 0;
	offset = 0;
	while (m && resid > 0 && error == 0) {
		if (m->m_type == MT_OOBDATA) {
			if (type != MT_OOBDATA)
				break;
		} else if (type == MT_OOBDATA)
			break;
#ifdef DIAGNOSTIC
		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
			panic("receive 3");
#endif
		so->so_state &= ~SS_RCVATMARK;
		len = resid;
		if (so->so_oobmark && len > so->so_oobmark - offset)
			len = so->so_oobmark - offset;
		if (len > m->m_len - moff)
			len = m->m_len - moff;
		/*
		 * If mp is set, just pass back the mbufs.
		 * Otherwise copy them out via the uio, then free.
		 * Sockbuf must be consistent here (points to current mbuf,
		 * it points to next record) when we drop priority;
		 * we must note any additions to the sockbuf when we
		 * block interrupts again.
		 */
		resid -= len;
		if (len == m->m_len - moff) {
			if (m->m_flags & M_EOR)
				flags |= MSG_EOR;
			if (flags & MSG_PEEK) {
				m = m->m_next;
				moff = 0;
			} else {
				nextrecord = m->m_nextpkt;
				sbfree(&so->so_rcv, m);
				if (mp) {
					*mp = m;
					mp = &m->m_next;
					so->so_rcv.sb_mb = m = m->m_next;
					*mp = NULL;
				} else {
					MFREE(m, so->so_rcv.sb_mb);
					m = so->so_rcv.sb_mb;
				}
				/*
				 * If m != NULL, we also know that
				 * so->so_rcv.sb_mb != NULL.
				 */
				KASSERT(so->so_rcv.sb_mb == m);
				if (m) {
					m->m_nextpkt = nextrecord;
					if (nextrecord == NULL)
						so->so_rcv.sb_lastrecord = m;
				} else {
					so->so_rcv.sb_mb = nextrecord;
					SB_EMPTY_FIXUP(&so->so_rcv);
				}
				SBLASTRECORDCHK(&so->so_rcv,
				    "kttcp_soreceive 3");
				SBLASTMBUFCHK(&so->so_rcv,
				    "kttcp_soreceive 3");
			}
		} else {
			if (flags & MSG_PEEK)
				moff += len;
			else {
				if (mp) {
					sounlock(so);
					*mp = m_copym(m, 0, len, M_WAIT);
					solock(so);
				}
				m->m_data += len;
				m->m_len -= len;
				so->so_rcv.sb_cc -= len;
			}
		}
		if (so->so_oobmark) {
			if ((flags & MSG_PEEK) == 0) {
				so->so_oobmark -= len;
				if (so->so_oobmark == 0) {
					so->so_state |= SS_RCVATMARK;
					break;
				}
			} else {
				offset += len;
				if (offset == so->so_oobmark)
					break;
			}
		}
		if (flags & MSG_EOR)
			break;
		/*
		 * If the MSG_WAITALL flag is set (for non-atomic socket),
		 * we must not quit until "uio->uio_resid == 0" or an error
		 * termination.  If a signal/timeout occurs, return
		 * with a short count but without error.
		 * Keep sockbuf locked against other readers.
		 */
		while (flags & MSG_WAITALL && m == NULL && resid > 0 &&
		    !sosendallatonce(so) && !nextrecord) {
			if (so->so_error || so->so_state & SS_CANTRCVMORE)
				break;
			/*
			 * If we are peeking and the socket receive buffer is
			 * full, stop since we can't get more data to peek at.
			 */
			if ((flags & MSG_PEEK) && sbspace(&so->so_rcv) <= 0)
				break;
			/*
			 * If we've drained the socket buffer, tell the
			 * protocol in case it needs to do something to
			 * get it filled again.
			 */
			if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb) {
				(*pr->pr_usrreqs->pr_rcvd)(so, flags, l);
			}
			SBLASTRECORDCHK(&so->so_rcv,
			    "kttcp_soreceive sbwait 2");
			SBLASTMBUFCHK(&so->so_rcv,
			    "kttcp_soreceive sbwait 2");
			error = sbwait(&so->so_rcv);
			if (error) {
				sbunlock(&so->so_rcv);
				sounlock(so);
				return (0);
			}
			if ((m = so->so_rcv.sb_mb) != NULL)
				nextrecord = m->m_nextpkt;
		}
	}

	if (m && pr->pr_flags & PR_ATOMIC) {
		flags |= MSG_TRUNC;
		if ((flags & MSG_PEEK) == 0)
			(void) sbdroprecord(&so->so_rcv);
	}
	if ((flags & MSG_PEEK) == 0) {
		if (m == NULL) {
			/*
			 * First part is an SB_EMPTY_FIXUP().  Second part
			 * makes sure sb_lastrecord is up-to-date if
			 * there is still data in the socket buffer.
			 */
			so->so_rcv.sb_mb = nextrecord;
			if (so->so_rcv.sb_mb == NULL) {
				so->so_rcv.sb_mbtail = NULL;
				so->so_rcv.sb_lastrecord = NULL;
			} else if (nextrecord->m_nextpkt == NULL)
				so->so_rcv.sb_lastrecord = nextrecord;
		}
		SBLASTRECORDCHK(&so->so_rcv, "kttcp_soreceive 4");
		SBLASTMBUFCHK(&so->so_rcv, "kttcp_soreceive 4");
		if (pr->pr_flags & PR_WANTRCVD && so->so_pcb) {
			(*pr->pr_usrreqs->pr_rcvd)(so, flags, l);
		}
	}
	if (orig_resid == resid && orig_resid &&
	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
		sbunlock(&so->so_rcv);
		goto restart;
	}

	if (flagsp)
		*flagsp |= flags;
 release:
	sbunlock(&so->so_rcv);
	sounlock(so);
	*done = slen - resid;
#if 0
	printf("soreceive: error %d slen %llu resid %lld\n", error, slen, resid);
#endif
	return (error);
}
Esempio n. 4
0
/*
 * Send on a socket.
 * If send must go all at once and message is larger than
 * send buffering, then hard error.
 * Lock against other senders.
 * If must go all at once and not enough room now, then
 * inform user that this would block and do nothing.
 * Otherwise, if nonblocking, send as much as possible.
 * The data to be sent is described by "uio" if nonzero,
 * otherwise by the mbuf chain "top" (which must be null
 * if uio is not).  Data provided in mbuf chain must be small
 * enough to send all at once.
 *
 * Returns nonzero on error, timeout or signal; callers
 * must check for short counts if EINTR/ERESTART are returned.
 * Data and control buffers are freed on return.
 */
int
sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
	struct mbuf *top, struct mbuf *control, int flags,
	struct thread *td)
{
	struct mbuf **mp;
	struct mbuf *m;
	size_t resid;
	int space, len;
	int clen = 0, error, dontroute, mlen;
	int atomic = sosendallatonce(so) || top;
	int pru_flags;

	if (uio) {
		resid = uio->uio_resid;
	} else {
		resid = (size_t)top->m_pkthdr.len;
#ifdef INVARIANTS
		len = 0;
		for (m = top; m; m = m->m_next)
			len += m->m_len;
		KKASSERT(top->m_pkthdr.len == len);
#endif
	}

	/*
	 * WARNING!  resid is unsigned, space and len are signed.  space
	 * 	     can wind up negative if the sockbuf is overcommitted.
	 *
	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
	 * type sockets since that's an error.
	 */
	if (so->so_type == SOCK_STREAM && (flags & MSG_EOR)) {
		error = EINVAL;
		goto out;
	}

	dontroute =
	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
	    (so->so_proto->pr_flags & PR_ATOMIC);
	if (td->td_lwp != NULL)
		td->td_lwp->lwp_ru.ru_msgsnd++;
	if (control)
		clen = control->m_len;
#define	gotoerr(errcode)	{ error = errcode; goto release; }

restart:
	error = ssb_lock(&so->so_snd, SBLOCKWAIT(flags));
	if (error)
		goto out;

	do {
		if (so->so_state & SS_CANTSENDMORE)
			gotoerr(EPIPE);
		if (so->so_error) {
			error = so->so_error;
			so->so_error = 0;
			goto release;
		}
		if ((so->so_state & SS_ISCONNECTED) == 0) {
			/*
			 * `sendto' and `sendmsg' is allowed on a connection-
			 * based socket if it supports implied connect.
			 * Return ENOTCONN if not connected and no address is
			 * supplied.
			 */
			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
				    !(resid == 0 && clen != 0))
					gotoerr(ENOTCONN);
			} else if (addr == 0)
			    gotoerr(so->so_proto->pr_flags & PR_CONNREQUIRED ?
				   ENOTCONN : EDESTADDRREQ);
		}
		if ((atomic && resid > so->so_snd.ssb_hiwat) ||
		    clen > so->so_snd.ssb_hiwat) {
			gotoerr(EMSGSIZE);
		}
		space = ssb_space(&so->so_snd);
		if (flags & MSG_OOB)
			space += 1024;
		if ((space < 0 || (size_t)space < resid + clen) && uio &&
		    (atomic || space < so->so_snd.ssb_lowat || space < clen)) {
			if (flags & (MSG_FNONBLOCKING|MSG_DONTWAIT))
				gotoerr(EWOULDBLOCK);
			ssb_unlock(&so->so_snd);
			error = ssb_wait(&so->so_snd);
			if (error)
				goto out;
			goto restart;
		}
		mp = &top;
		space -= clen;
		do {
		    if (uio == NULL) {
			/*
			 * Data is prepackaged in "top".
			 */
			resid = 0;
			if (flags & MSG_EOR)
				top->m_flags |= M_EOR;
		    } else do {
			if (resid > INT_MAX)
				resid = INT_MAX;
			m = m_getl((int)resid, MB_WAIT, MT_DATA,
				   top == NULL ? M_PKTHDR : 0, &mlen);
			if (top == NULL) {
				m->m_pkthdr.len = 0;
				m->m_pkthdr.rcvif = NULL;
			}
			len = imin((int)szmin(mlen, resid), space);
			if (resid < MINCLSIZE) {
				/*
				 * For datagram protocols, leave room
				 * for protocol headers in first mbuf.
				 */
				if (atomic && top == 0 && len < mlen)
					MH_ALIGN(m, len);
			}
			space -= len;
			error = uiomove(mtod(m, caddr_t), (size_t)len, uio);
			resid = uio->uio_resid;
			m->m_len = len;
			*mp = m;
			top->m_pkthdr.len += len;
			if (error)
				goto release;
			mp = &m->m_next;
			if (resid == 0) {
				if (flags & MSG_EOR)
					top->m_flags |= M_EOR;
				break;
			}
		    } while (space > 0 && atomic);
		    if (dontroute)
			    so->so_options |= SO_DONTROUTE;
		    if (flags & MSG_OOB) {
		    	    pru_flags = PRUS_OOB;
		    } else if ((flags & MSG_EOF) &&
		    	       (so->so_proto->pr_flags & PR_IMPLOPCL) &&
			       (resid == 0)) {
			    /*
			     * If the user set MSG_EOF, the protocol
			     * understands this flag and nothing left to
			     * send then use PRU_SEND_EOF instead of PRU_SEND.
			     */
		    	    pru_flags = PRUS_EOF;
		    } else if (resid > 0 && space > 0) {
			    /* If there is more to send, set PRUS_MORETOCOME */
		    	    pru_flags = PRUS_MORETOCOME;
		    } else {
		    	    pru_flags = 0;
		    }
		    /*
		     * XXX all the SS_CANTSENDMORE checks previously
		     * done could be out of date.  We could have recieved
		     * a reset packet in an interrupt or maybe we slept
		     * while doing page faults in uiomove() etc. We could
		     * probably recheck again inside the splnet() protection
		     * here, but there are probably other places that this
		     * also happens.  We must rethink this.
		     */
		    error = so_pru_send(so, pru_flags, top, addr, control, td);
		    if (dontroute)
			    so->so_options &= ~SO_DONTROUTE;
		    clen = 0;
		    control = 0;
		    top = NULL;
		    mp = &top;
		    if (error)
			    goto release;
		} while (resid && space > 0);
	} while (resid);

release:
	ssb_unlock(&so->so_snd);
out:
	if (top)
		m_freem(top);
	if (control)
		m_freem(control);
	return (error);
}