allow zero-length sends; fix race when blocking in uiomove

by getting EPIPE from usrreq if disconnected; M_WAIT is here

SCCS-vsn: sys/kern/uipc_socket.c 6.11

diff --git a/usr/src/sys/kern/uipc_socket.c b/usr/src/sys/kern/uipc_socket.c
index 856b9c8..095c6ef 100644 (file)
--- a/usr/src/sys/kern/uipc_socket.c
+++ b/usr/src/sys/kern/uipc_socket.c
@@ -1,4 +1,4 @@
-/*     uipc_socket.c   6.10    85/04/02        */
+/*     uipc_socket.c   6.11    85/05/27        */

 
 #include "param.h"
 #include "systm.h"
 
 #include "param.h"
 #include "systm.h"


@@ -55,8 +55,6 @@ socreate(dom, aso, type, proto)
        if (prp->pr_type != type)
                return (EPROTOTYPE);
        m = m_getclr(M_WAIT, MT_SOCKET);
        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 = 0;
        so->so_state = 0;
        so = mtod(m, struct socket *);
        so->so_options = 0;
        so->so_state = 0;


@@ -295,10 +293,8 @@ restart:
        sblock(&so->so_snd);
        do {
                s = splnet();
        sblock(&so->so_snd);
        do {
                s = splnet();

-               if (so->so_state & SS_CANTSENDMORE) {
-                       psignal(u.u_procp, SIGPIPE);
+               if (so->so_state & SS_CANTSENDMORE)

                        snderr(EPIPE);
                        snderr(EPIPE);

-               }

                if (so->so_error) {
                        error = so->so_error;
                        so->so_error = 0;                       /* ??? */
                if (so->so_error) {
                        error = so->so_error;
                        so->so_error = 0;                       /* ??? */


@@ -334,21 +330,10 @@ restart:
                }
                splx(s);
                mp = ⊤
                }
                splx(s);
                mp = ⊤

-               while (uio->uio_resid > 0 && space > 0) {
+               while (space > 0) {

                        register struct iovec *iov = uio->uio_iov;
 
                        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);
                        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 (iov->iov_len >= CLBYTES && space >= CLBYTES) {
                                register struct mbuf *p;
                                MCLGET(p, 1);


@@ -367,18 +352,24 @@ nopages:
                                goto release;
                        mp = &m->m_next;
                        space -= len;
                                goto release;
                        mp = &m->m_next;
                        space -= len;

+                       if (uio->uio_resid <= 0)
+                               break;
+                       while (uio->uio_iov->iov_len == 0) {
+                               uio->uio_iov++;
+                               uio->uio_iovcnt--;
+                               if (uio->uio_iovcnt <= 0)
+                                       panic("sosend");
+                       }

                }
                }

-               if (top) {
-                       if (dontroute)
-                               so->so_options |= SO_DONTROUTE;
-                       s = splnet();
-                       error = (*so->so_proto->pr_usrreq)(so,
-                           (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
-                           top, (caddr_t)nam, rights);
-                       splx(s);
-                       if (dontroute)
-                               so->so_options &= ~SO_DONTROUTE;
-               }
+               if (dontroute)
+                       so->so_options |= SO_DONTROUTE;
+               s = splnet();                                   /* XXX */
+               error = (*so->so_proto->pr_usrreq)(so,
+                   (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
+                   top, (caddr_t)nam, rights);
+               splx(s);
+               if (dontroute)
+                       so->so_options &= ~SO_DONTROUTE;

                top = 0;
                first = 0;
                if (error)
                top = 0;
                first = 0;
                if (error)


@@ -389,6 +380,8 @@ release:
        sbunlock(&so->so_snd);
        if (top)
                m_freem(top);
        sbunlock(&so->so_snd);
        if (top)
                m_freem(top);

+       if (error == EPIPE)
+               psignal(u.u_procp, SIGPIPE);

        return (error);
 }
 
        return (error);
 }
 


@@ -411,8 +404,6 @@ soreceive(so, aname, uio, flags, rightsp)
                *aname = 0;
        if (flags & MSG_OOB) {
                m = m_get(M_WAIT, MT_DATA);
                *aname = 0;
        if (flags & MSG_OOB) {
                m = m_get(M_WAIT, MT_DATA);

-               if (m == 0)
-                       return (ENOBUFS);

                error = (*pr->pr_usrreq)(so, PRU_RCVOOB,
                    m, (struct mbuf *)0, (struct mbuf *)0);
                if (error)
                error = (*pr->pr_usrreq)(so, PRU_RCVOOB,
                    m, (struct mbuf *)0, (struct mbuf *)0);
                if (error)


@@ -697,8 +688,6 @@ sogetopt(so, level, optname, mp)
                        return (ENOPROTOOPT);
        } else {
                m = m_get(M_WAIT, MT_SOOPTS);
                        return (ENOPROTOOPT);
        } else {
                m = m_get(M_WAIT, MT_SOOPTS);

-               if (m == NULL)
-                       return (ENOBUFS);

                switch (optname) {
 
                case SO_LINGER:
                switch (optname) {
 
                case SO_LINGER: