not needed, but shannon's a perfectionist

[unix-history] / usr / src / sys / kern / uipc_socket.c

/*      uipc_socket.c   4.74    83/05/18        */

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/file.h"
#include "../h/inode.h"
#include "../h/buf.h"
#include "../h/mbuf.h"
#include "../h/protosw.h"
#include "../h/socket.h"
#include "../h/socketvar.h"
#include "../h/stat.h"
#include "../h/ioctl.h"
#include "../h/uio.h"
#include "../net/route.h"
#include "../net/if.h"

/*
* Socket operation routines.
* These routines are called by the routines in
* sys_socket.c or from a system process, and
* implement the semantics of socket operations by
* switching out to the protocol specific routines.
*/

/*ARGSUSED*/
socreate(dom, aso, type, proto)
       struct socket **aso;
       int type, proto;
{
       register struct protosw *prp;
       register struct socket *so;
       struct mbuf *m;
       int error;

       if (proto)
               prp = pffindproto(dom, proto);
       else
               prp = pffindtype(dom, type);
       if (prp == 0)
               return (EPROTONOSUPPORT);
       if (prp->pr_type != type)
               return (EPROTOTYPE);
       m = m_getclr(M_WAIT, MT_SOCKET);
       if (m == 0)
               return (ENOBUFS);
       so = mtod(m, struct socket *);
       so->so_options = SO_LINGER;
       so->so_state = 0;
       so->so_type = type;
       if (u.u_uid == 0)
               so->so_state = SS_PRIV;
       so->so_proto = prp;
       error = (*prp->pr_usrreq)(so, PRU_ATTACH,
           (struct mbuf *)0, (struct mbuf *)0);
       if (error) {
               so->so_state |= SS_NOFDREF;
               sofree(so);
               return (error);
       }
       *aso = so;
       return (0);
}

sobind(so, nam)
       struct socket *so;
       struct mbuf *nam;
{
       int s = splnet();
       int error;

       error =
           (*so->so_proto->pr_usrreq)(so, PRU_BIND, (struct mbuf *)0, nam);
       splx(s);
       return (error);
}

solisten(so, backlog)
       struct socket *so;
       int backlog;
{
       int s = splnet();
       int error;

       error = (*so->so_proto->pr_usrreq)(so, PRU_LISTEN,
           (struct mbuf *)0, (struct mbuf *)0);
       if (error) {
               splx(s);
               return (error);
       }
       if (so->so_q == 0) {
               so->so_q = so;
               so->so_q0 = so;
               so->so_options |= SO_ACCEPTCONN;
       }
       if (backlog < 0)
               backlog = 0;
#define SOMAXCONN       5
       so->so_qlimit = MIN(backlog, SOMAXCONN);
       so->so_options |= SO_NEWFDONCONN;
       splx(s);
       return (0);
}

sofree(so)
       struct socket *so;
{

       if (so->so_head) {
               if (!soqremque(so, 0) && !soqremque(so, 1))
                       panic("sofree dq");
               so->so_head = 0;
       }
       if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
               return;
       sbrelease(&so->so_snd);
       sbrelease(&so->so_rcv);
       (void) m_free(dtom(so));
}

/*
* Close a socket on last file table reference removal.
* Initiate disconnect if connected.
* Free socket when disconnect complete.
*/
soclose(so, exiting)
       register struct socket *so;
       int exiting;
{
       int s = splnet();               /* conservative */
       int error;

       if (so->so_options & SO_ACCEPTCONN) {
               while (so->so_q0 != so)
                       (void) soabort(so->so_q0);
               while (so->so_q != so)
                       (void) soabort(so->so_q);
       }
       if (so->so_pcb == 0)
               goto discard;
       if (exiting)
               so->so_options |= SO_KEEPALIVE;
       if (so->so_state & SS_ISCONNECTED) {
               if ((so->so_state & SS_ISDISCONNECTING) == 0) {
                       error = sodisconnect(so, (struct mbuf *)0);
                       if (error) {
                               if (exiting)
                                       goto drop;
                               splx(s);
                               return (error);
                       }
               }
               if (so->so_options & SO_LINGER) {
                       if ((so->so_state & SS_ISDISCONNECTING) &&
                           (so->so_state & SS_NBIO) &&
                           exiting == 0)
                               return (EINPROGRESS);
                       /* should use tsleep here, for at most linger */
                       while (so->so_state & SS_ISCONNECTED)
                               sleep((caddr_t)&so->so_timeo, PZERO+1);
               }
       }
drop:
       if (so->so_pcb) {
               error = (*so->so_proto->pr_usrreq)(so, PRU_DETACH,
                   (struct mbuf *)0, (struct mbuf *)0);
               if (exiting == 0 && error) {
                       splx(s);
                       return (error);
               }
       }
discard:
       if (so->so_state & SS_NOFDREF)
               panic("soclose: NOFDREF");
       so->so_state |= SS_NOFDREF;
       sofree(so);
       splx(s);
       return (0);
}

/*
* Must be called at splnet...
*/
soabort(so)
       struct socket *so;
{
       int error;

       error = (*so->so_proto->pr_usrreq)(so, PRU_ABORT,
          (struct mbuf *)0, (struct mbuf *)0);
       return (error);
}

/*ARGSUSED*/
sostat(so, ub)
       struct socket *so;
       struct stat *ub;
{
       struct stat sb;

       bzero((caddr_t)&sb, sizeof (sb));               /* XXX */
       (void) copyout((caddr_t)&sb, (caddr_t)ub, sizeof (sb));/* XXX */
       return (0);                                     /* XXX */
}

soaccept(so, nam)
       struct socket *so;
       struct mbuf *nam;
{
       int s = splnet();
       int error;

       if ((so->so_state & SS_NOFDREF) == 0)
               panic("soaccept: !NOFDREF");
       so->so_state &= ~SS_NOFDREF;
       error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT,
           (struct mbuf *)0, nam);
       splx(s);
       return (error);
}

soconnect(so, nam)
       struct socket *so;
       struct mbuf *nam;
{
       int s = splnet();
       int error;

       if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) {
               error = EISCONN;
               goto bad;
       }
       error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,
           (struct mbuf *)0, nam);
bad:
       splx(s);
       return (error);
}

sodisconnect(so, nam)
       struct socket *so;
       struct mbuf *nam;
{
       int s = splnet();
       int error;

       if ((so->so_state & SS_ISCONNECTED) == 0) {
               error = ENOTCONN;
               goto bad;
       }
       if (so->so_state & SS_ISDISCONNECTING) {
               error = EALREADY;
               goto bad;
       }
       error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
           (struct mbuf *)0, nam);
bad:
       splx(s);
       return (error);
}

/*
* 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.
*/
sosend(so, nam, uio, flags)
       register struct socket *so;
       struct mbuf *nam;
       struct uio *uio;
       int flags;
{
       struct mbuf *top = 0;
       register struct mbuf *m, **mp = &top;
       register int len;
       int error = 0, space, s, dontroute;

       if (sosendallatonce(so) && uio->uio_resid > so->so_snd.sb_hiwat)
               return (EMSGSIZE);
       dontroute = (flags & SOF_DONTROUTE) &&
               (so->so_options & SO_DONTROUTE) == 0 &&
               (so->so_proto->pr_flags & PR_ATOMIC);
restart:
       sblock(&so->so_snd);
#define snderr(errno)   { error = errno; splx(s); goto release; }

       u.u_ru.ru_msgsnd++;
again:
       s = splnet();
       if (so->so_state & SS_CANTSENDMORE) {
               psignal(u.u_procp, SIGPIPE);
               snderr(EPIPE);
       }
       if (so->so_error) {
               error = so->so_error;
               so->so_error = 0;                               /* ??? */
               splx(s);
               goto release;
       }
       if ((so->so_state & SS_ISCONNECTED) == 0) {
               if (so->so_proto->pr_flags & PR_CONNREQUIRED)
                       snderr(ENOTCONN);
               if (nam == 0)
                       snderr(EDESTADDRREQ);
       }
       if (top) {
               if (dontroute)
                       so->so_options |= SO_DONTROUTE;
               error = (*so->so_proto->pr_usrreq)(so,
                   (flags & SOF_OOB) ? PRU_SENDOOB : PRU_SEND,
                   top, (caddr_t)nam);
               if (dontroute)
                       so->so_options &= ~SO_DONTROUTE;
               top = 0;
               if (error) {
                       splx(s);
                       goto release;
               }
               mp = &top;
       }
       if (uio->uio_resid == 0) {
               splx(s);
               goto release;
       }
       if (flags & SOF_OOB)
               space = 1024;
       else {
               space = sbspace(&so->so_snd);
               if (space <= 0 ||
                   sosendallatonce(so) && space < uio->uio_resid) {
                       if (so->so_state & SS_NBIO)
                               snderr(EWOULDBLOCK);
                       sbunlock(&so->so_snd);
                       sbwait(&so->so_snd);
                       splx(s);
                       goto restart;
               }
       }
       splx(s);
       while (uio->uio_resid > 0 && space > 0) {
               register struct iovec *iov = uio->uio_iov;

               if (iov->iov_len == 0) {
                       uio->uio_iov++;
                       uio->uio_iovcnt--;
                       if (uio->uio_iovcnt < 0)
                               panic("sosend");
                       continue;
               }
               MGET(m, M_WAIT, MT_DATA);
               if (m == NULL) {
                       error = ENOBUFS;                        /* SIGPIPE? */
                       goto release;
               }
               if (iov->iov_len >= CLBYTES && space >= CLBYTES) {
                       register struct mbuf *p;
                       MCLGET(p, 1);
                       if (p == 0)
                               goto nopages;
                       m->m_off = (int)p - (int)m;
                       len = CLBYTES;
               } else {
nopages:
                       len = MIN(MLEN, iov->iov_len);
               }
               (void) uiomove(mtod(m, caddr_t), len, UIO_WRITE, uio);
               m->m_len = len;
               *mp = m;
               mp = &m->m_next;
               if (flags & SOF_OOB)
                       space -= len;
               else
                       space = sbspace(&so->so_snd);
       }
       goto again;

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

soreceive(so, aname, uio, flags)
       register struct socket *so;
       struct mbuf **aname;
       struct uio *uio;
       int flags;
{
       register struct mbuf *m, *n;
       int len;
       int eor, s, error = 0, moff, tomark;

       if (flags & SOF_OOB) {
               m = m_get(M_WAIT, MT_DATA);
               if (m == NULL)
                       return (ENOBUFS);
               error = (*so->so_proto->pr_usrreq)(so, PRU_RCVOOB,
                   m, (struct mbuf *)0);
               if (error)
                       goto bad;
               do {
                       len = uio->uio_resid;
                       if (len > m->m_len)
                               len = m->m_len;
                       error =
                           uiomove(mtod(m, caddr_t), (int)len, UIO_READ, uio);
                       m = m_free(m);
               } while (uio->uio_resid && error == 0 && m);
bad:
               if (m)
                       m_freem(m);
               return (error);
       }

restart:
       sblock(&so->so_rcv);
       s = splnet();

#define rcverr(errno)   { error = errno; splx(s); goto release; }
       if (so->so_rcv.sb_cc == 0) {
               if (so->so_error) {
                       error = so->so_error;
                       so->so_error = 0;
                       splx(s);
                       goto release;
               }
               if (so->so_state & SS_CANTRCVMORE) {
                       splx(s);
                       goto release;
               }
               if ((so->so_state & SS_ISCONNECTED) == 0 &&
                   (so->so_proto->pr_flags & PR_CONNREQUIRED))
                       rcverr(ENOTCONN);
               if (so->so_state & SS_NBIO)
                       rcverr(EWOULDBLOCK);
               sbunlock(&so->so_rcv);
               sbwait(&so->so_rcv);
               splx(s);
               goto restart;
       }
       u.u_ru.ru_msgrcv++;
       m = so->so_rcv.sb_mb;
       if (m == 0)
               panic("receive");
       if (so->so_proto->pr_flags & PR_ADDR) {
               if ((flags & SOF_PREVIEW) == 0) {
                       so->so_rcv.sb_cc -= m->m_len;
                       so->so_rcv.sb_mbcnt -= MSIZE;
               }
               if (aname) {
                       if (flags & SOF_PREVIEW) {
                               *aname = m_copy(m, 0, m->m_len);
                               if (*aname == NULL)
                                       panic("receive 2");
                       } else
                               *aname = m;
                       m = m->m_next;
                       (*aname)->m_next = 0;
               } else
                       if (flags & SOF_PREVIEW)
                               m = m->m_next;
                       else
                               m = m_free(m);
               if (m == 0)
                       panic("receive 3");
               if ((flags & SOF_PREVIEW) == 0)
                       so->so_rcv.sb_mb = m;
       }
       eor = 0;
       moff = 0;
       tomark = so->so_oobmark;
       do {
               if (uio->uio_resid <= 0)
                       break;
               len = uio->uio_resid;
               so->so_state &= ~SS_RCVATMARK;
               if (tomark && len > tomark)
                       len = tomark;
               if (moff+len > m->m_len - moff)
                       len = m->m_len - moff;
               splx(s);
               error =
                   uiomove(mtod(m, caddr_t) + moff, (int)len, UIO_READ, uio);
               s = splnet();
               if (len == m->m_len) {
                       eor = (int)m->m_act;
                       if (flags & SOF_PREVIEW)
                               m = m->m_next;
                       else {
                               sbfree(&so->so_rcv, m);
                               MFREE(m, n);
                               m = n;
                               so->so_rcv.sb_mb = m;
                       }
                       moff = 0;
               } else {
                       if (flags & SOF_PREVIEW)
                               moff += len;
                       else {
                               m->m_off += len;
                               m->m_len -= len;
                               so->so_rcv.sb_cc -= len;
                       }
               }
               if ((flags & SOF_PREVIEW) == 0 && so->so_oobmark) {
                       so->so_oobmark -= len;
                       if (so->so_oobmark == 0) {
                               so->so_state |= SS_RCVATMARK;
                               break;
                       }
               }
               if (tomark) {
                       tomark -= len;
                       if (tomark == 0)
                               break;
               }
       } while (m && error == 0 && !eor);
       if (flags & SOF_PREVIEW)
               goto release;
       if ((so->so_proto->pr_flags & PR_ATOMIC) && eor == 0)
               do {
                       if (m == 0)
                               panic("receive 4");
                       sbfree(&so->so_rcv, m);
                       eor = (int)m->m_act;
                       so->so_rcv.sb_mb = m->m_next;
                       MFREE(m, n);
                       m = n;
               } while (eor == 0);
       if ((so->so_proto->pr_flags & PR_WANTRCVD) && so->so_pcb)
               (*so->so_proto->pr_usrreq)(so, PRU_RCVD,
                   (struct mbuf *)0, (struct mbuf *)0);
release:
       sbunlock(&so->so_rcv);
       splx(s);
       return (error);
}

soshutdown(so, how)
       struct socket *so;
       int how;
{

       how++;
       if (how & FREAD) {
               int s = splimp();
               socantrcvmore(so);
               sbflush(&so->so_rcv);
               splx(s);
       }
       if (how & FWRITE)
               return ((*so->so_proto->pr_usrreq)(so, PRU_SHUTDOWN,
                   (struct mbuf *)0, (struct mbuf *)0));
       return (0);
}

sosetopt(so, level, optname, m)
       struct socket *so;
       int level, optname;
       struct mbuf *m;
{

       if (level != SOL_SOCKET)
               return (EINVAL);        /* XXX */
       switch (optname) {

       case SO_DEBUG:
       case SO_KEEPALIVE:
       case SO_DONTROUTE:
       case SO_USELOOPBACK:
       case SO_REUSEADDR:
               so->so_options |= optname;
               break;

       case SO_LINGER:
               if (m == NULL || m->m_len != sizeof (int))
                       return (EINVAL);
               so->so_options |= SO_LINGER;
               so->so_linger = *mtod(m, int *);
               break;

       case SO_DONTLINGER:
               so->so_options &= ~SO_LINGER;
               so->so_linger = 0;
               break;

       default:
               return (EINVAL);
       }
       return (0);
}

sogetopt(so, level, optname, m)
       struct socket *so;
       int level, optname;
       struct mbuf *m;
{

       if (level != SOL_SOCKET)
               return (EINVAL);        /* XXX */
       switch (optname) {

       case SO_USELOOPBACK:
       case SO_DONTROUTE:
       case SO_DEBUG:
       case SO_KEEPALIVE:
       case SO_LINGER:
       case SO_REUSEADDR:
               if ((so->so_options & optname) == 0)
                       return (ENOPROTOOPT);
               if (optname == SO_LINGER && m != NULL) {
                       *mtod(m, int *) = so->so_linger;
                       m->m_len = sizeof (so->so_linger);
               }
               break;

       default:
               return (EINVAL);
       }
       return (0);
}

sohasoutofband(so)
       struct socket *so;
{

       if (so->so_pgrp == 0)
               return;
       if (so->so_pgrp > 0)
               gsignal(so->so_pgrp, SIGURG);
       else {
               struct proc *p = pfind(-so->so_pgrp);

               if (p)
                       psignal(p, SIGURG);
       }
}

/*ARGSUSED*/
soioctl(so, cmd, data)
       register struct socket *so;
       int cmd;
       register char *data;
{

       switch (cmd) {

       case FIONBIO:
               if (*(int *)data)
                       so->so_state |= SS_NBIO;
               else
                       so->so_state &= ~SS_NBIO;
               break;

       case FIOASYNC:
               if (*(int *)data)
                       so->so_state |= SS_ASYNC;
               else
                       so->so_state &= ~SS_ASYNC;
               break;

       case SIOCSPGRP:
               so->so_pgrp = *(int *)data;
               break;

       case SIOCGPGRP:
               *(int *)data = so->so_pgrp;
               break;

       case SIOCATMARK:
               *(int *)data = (so->so_state&SS_RCVATMARK) != 0;
               break;

       /* routing table update calls */
       case SIOCADDRT:
       case SIOCDELRT:
               if (!suser())
                       return (u.u_error);
               return (rtrequest(cmd, (struct rtentry *)data));

       /* interface parameter requests */
       case SIOCSIFADDR:
       case SIOCSIFFLAGS:
       case SIOCSIFDSTADDR:
               if (!suser())
                       return (u.u_error);
               return (ifrequest(cmd, data));

       case SIOCGIFADDR:
       case SIOCGIFFLAGS:
       case SIOCGIFDSTADDR:
               return (ifrequest(cmd, data));

       case SIOCGIFCONF:
               return (ifconf(cmd, data));

       /* type/protocol specific ioctls */
       default:
               return (ENOTTY);                /* XXX */
       }
       return (0);
}