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freebsd-dev/sys/kern/uipc_syscalls.c
Alfred Perlstein 426da3bcfb SMP Lock struct file, filedesc and the global file list. 
Seigo Tanimura (tanimura) posted the initial delta.

I've polished it quite a bit reducing the need for locking and
adapting it for KSE.

Locks:

1 mutex in each filedesc
   protects all the fields.
   protects "struct file" initialization, while a struct file
     is being changed from &badfileops -> &pipeops or something
     the filedesc should be locked.

1 mutex in each struct file
   protects the refcount fields.
   doesn't protect anything else.
   the flags used for garbage collection have been moved to
     f_gcflag which was the FILLER short, this doesn't need
     locking because the garbage collection is a single threaded
     container.
  could likely be made to use a pool mutex.

1 sx lock for the global filelist.

struct file *	fhold(struct file *fp);
        /* increments reference count on a file */

struct file *	fhold_locked(struct file *fp);
        /* like fhold but expects file to locked */

struct file *	ffind_hold(struct thread *, int fd);
        /* finds the struct file in thread, adds one reference and
                returns it unlocked */

struct file *	ffind_lock(struct thread *, int fd);
        /* ffind_hold, but returns file locked */

I still have to smp-safe the fget cruft, I'll get to that asap.
2002-01-13 11:58:06 +00:00

1958 lines
41 KiB
C
Raw Blame History

/*
* Copyright (c) 1982, 1986, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* sendfile(2) and related extensions:
* Copyright (c) 1998, David Greenman. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)uipc_syscalls.c 8.4 (Berkeley) 2/21/94
* $FreeBSD$
*/
#include "opt_compat.h"
#include "opt_ktrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysproto.h>
#include <sys/malloc.h>
#include <sys/filedesc.h>
#include <sys/event.h>
#include <sys/proc.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/lock.h>
#include <sys/mount.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
static void sf_buf_init(void *arg);
SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL)
static struct sf_buf *sf_buf_alloc(void);
static void sf_buf_free(caddr_t addr, void *args);
static int sendit __P((struct thread *td, int s, struct msghdr *mp, int flags));
static int recvit __P((struct thread *td, int s, struct msghdr *mp,
caddr_t namelenp));
static int accept1 __P((struct thread *td, struct accept_args *uap, int compat));
static int getsockname1 __P((struct thread *td, struct getsockname_args *uap,
int compat));
static int getpeername1 __P((struct thread *td, struct getpeername_args *uap,
int compat));
/*
* Expanded sf_freelist head. Really an SLIST_HEAD() in disguise, with the
* sf_freelist head with the sf_lock mutex.
*/
static struct {
SLIST_HEAD(, sf_buf) sf_head;
struct mtx sf_lock;
} sf_freelist;
static vm_offset_t sf_base;
static struct sf_buf *sf_bufs;
static u_int sf_buf_alloc_want;
/*
* System call interface to the socket abstraction.
*/
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#define COMPAT_OLDSOCK
#endif
extern struct fileops socketops;
/*
* MPSAFE
*/
int
socket(td, uap)
struct thread *td;
register struct socket_args /* {
int domain;
int type;
int protocol;
} */ *uap;
{
struct filedesc *fdp;
struct socket *so;
struct file *fp;
int fd, error;
mtx_lock(&Giant);
fdp = td->td_proc->p_fd;
error = falloc(td, &fp, &fd);
if (error)
goto done2;
fhold(fp);
error = socreate(uap->domain, &so, uap->type, uap->protocol,
td->td_proc->p_ucred, td);
FILEDESC_LOCK(fdp);
if (error) {
if (fdp->fd_ofiles[fd] == fp) {
fdp->fd_ofiles[fd] = NULL;
FILEDESC_UNLOCK(fdp);
fdrop(fp, td);
} else
FILEDESC_UNLOCK(fdp);
} else {
fp->f_data = (caddr_t)so; /* already has ref count */
fp->f_flag = FREAD|FWRITE;
fp->f_ops = &socketops;
fp->f_type = DTYPE_SOCKET;
FILEDESC_UNLOCK(fdp);
td->td_retval[0] = fd;
}
fdrop(fp, td);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
bind(td, uap)
struct thread *td;
register struct bind_args /* {
int s;
caddr_t name;
int namelen;
} */ *uap;
{
struct socket *so;
struct sockaddr *sa;
int error;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->s, &so, NULL)) != 0)
goto done2;
if ((error = getsockaddr(&sa, uap->name, uap->namelen)) != 0)
goto done1;
error = sobind(so, sa, td);
FREE(sa, M_SONAME);
done1:
fputsock(so);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
listen(td, uap)
struct thread *td;
register struct listen_args /* {
int s;
int backlog;
} */ *uap;
{
struct socket *so;
int error;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->s, &so, NULL)) == 0) {
error = solisten(so, uap->backlog, td);
fputsock(so);
}
mtx_unlock(&Giant);
return(error);
}
/*
* accept1()
* MPSAFE
*/
static int
accept1(td, uap, compat)
struct thread *td;
register struct accept_args /* {
int s;
caddr_t name;
int *anamelen;
} */ *uap;
int compat;
{
struct filedesc *fdp;
struct file *nfp = NULL;
struct sockaddr *sa;
int namelen, error, s;
struct socket *head, *so;
int fd;
u_int fflag;
mtx_lock(&Giant);
fdp = td->td_proc->p_fd;
if (uap->name) {
error = copyin((caddr_t)uap->anamelen, (caddr_t)&namelen,
sizeof (namelen));
if(error)
goto done2;
}
error = fgetsock(td, uap->s, &head, &fflag);
if (error)
goto done2;
s = splnet();
if ((head->so_options & SO_ACCEPTCONN) == 0) {
splx(s);
error = EINVAL;
goto done;
}
if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->so_comp)) {
splx(s);
error = EWOULDBLOCK;
goto done;
}
while (TAILQ_EMPTY(&head->so_comp) && head->so_error == 0) {
if (head->so_state & SS_CANTRCVMORE) {
head->so_error = ECONNABORTED;
break;
}
error = tsleep((caddr_t)&head->so_timeo, PSOCK | PCATCH,
"accept", 0);
if (error) {
splx(s);
goto done;
}
}
if (head->so_error) {
error = head->so_error;
head->so_error = 0;
splx(s);
goto done;
}
/*
* At this point we know that there is at least one connection
* ready to be accepted. Remove it from the queue prior to
* allocating the file descriptor for it since falloc() may
* block allowing another process to accept the connection
* instead.
*/
so = TAILQ_FIRST(&head->so_comp);
TAILQ_REMOVE(&head->so_comp, so, so_list);
head->so_qlen--;
error = falloc(td, &nfp, &fd);
if (error) {
/*
* Probably ran out of file descriptors. Put the
* unaccepted connection back onto the queue and
* do another wakeup so some other process might
* have a chance at it.
*/
TAILQ_INSERT_HEAD(&head->so_comp, so, so_list);
head->so_qlen++;
wakeup_one(&head->so_timeo);
splx(s);
goto done;
}
fhold(nfp);
td->td_retval[0] = fd;
/* connection has been removed from the listen queue */
KNOTE(&head->so_rcv.sb_sel.si_note, 0);
so->so_state &= ~SS_COMP;
so->so_head = NULL;
if (head->so_sigio != NULL)
fsetown(fgetown(head->so_sigio), &so->so_sigio);
FILE_LOCK(nfp);
soref(so); /* file descriptor reference */
nfp->f_data = (caddr_t)so; /* nfp has ref count from falloc */
nfp->f_flag = fflag;
nfp->f_ops = &socketops;
nfp->f_type = DTYPE_SOCKET;
FILE_UNLOCK(nfp);
sa = 0;
error = soaccept(so, &sa);
if (error) {
/*
* return a namelen of zero for older code which might
* ignore the return value from accept.
*/
if (uap->name != NULL) {
namelen = 0;
(void) copyout((caddr_t)&namelen,
(caddr_t)uap->anamelen, sizeof(*uap->anamelen));
}
goto noconnection;
}
if (sa == NULL) {
namelen = 0;
if (uap->name)
goto gotnoname;
splx(s);
error = 0;
goto done;
}
if (uap->name) {
/* check sa_len before it is destroyed */
if (namelen > sa->sa_len)
namelen = sa->sa_len;
#ifdef COMPAT_OLDSOCK
if (compat)
((struct osockaddr *)sa)->sa_family =
sa->sa_family;
#endif
error = copyout(sa, (caddr_t)uap->name, (u_int)namelen);
if (!error)
gotnoname:
error = copyout((caddr_t)&namelen,
(caddr_t)uap->anamelen, sizeof (*uap->anamelen));
}
noconnection:
if (sa)
FREE(sa, M_SONAME);
/*
* close the new descriptor, assuming someone hasn't ripped it
* out from under us.
*/
if (error) {
FILEDESC_LOCK(fdp);
if (fdp->fd_ofiles[fd] == nfp) {
fdp->fd_ofiles[fd] = NULL;
FILEDESC_UNLOCK(fdp);
fdrop(nfp, td);
} else {
FILEDESC_UNLOCK(fdp);
}
}
splx(s);
/*
* Release explicitly held references before returning.
*/
done:
if (nfp != NULL)
fdrop(nfp, td);
fputsock(head);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE (accept1() is MPSAFE)
*/
int
accept(td, uap)
struct thread *td;
struct accept_args *uap;
{
return (accept1(td, uap, 0));
}
#ifdef COMPAT_OLDSOCK
/*
* MPSAFE (accept1() is MPSAFE)
*/
int
oaccept(td, uap)
struct thread *td;
struct accept_args *uap;
{
return (accept1(td, uap, 1));
}
#endif /* COMPAT_OLDSOCK */
/*
* MPSAFE
*/
/* ARGSUSED */
int
connect(td, uap)
struct thread *td;
register struct connect_args /* {
int s;
caddr_t name;
int namelen;
} */ *uap;
{
struct socket *so;
struct sockaddr *sa;
int error, s;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->s, &so, NULL)) != 0)
goto done2;
if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
error = EALREADY;
goto done1;
}
error = getsockaddr(&sa, uap->name, uap->namelen);
if (error)
goto done1;
error = soconnect(so, sa, td);
if (error)
goto bad;
if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
FREE(sa, M_SONAME);
error = EINPROGRESS;
goto done1;
}
s = splnet();
while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
error = tsleep((caddr_t)&so->so_timeo, PSOCK | PCATCH, "connec", 0);
if (error)
break;
}
if (error == 0) {
error = so->so_error;
so->so_error = 0;
}
splx(s);
bad:
so->so_state &= ~SS_ISCONNECTING;
FREE(sa, M_SONAME);
if (error == ERESTART)
error = EINTR;
done1:
fputsock(so);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
int
socketpair(td, uap)
struct thread *td;
register struct socketpair_args /* {
int domain;
int type;
int protocol;
int *rsv;
} */ *uap;
{
register struct filedesc *fdp = td->td_proc->p_fd;
struct file *fp1, *fp2;
struct socket *so1, *so2;
int fd, error, sv[2];
mtx_lock(&Giant);
error = socreate(uap->domain, &so1, uap->type, uap->protocol,
td->td_proc->p_ucred, td);
if (error)
goto done2;
error = socreate(uap->domain, &so2, uap->type, uap->protocol,
td->td_proc->p_ucred, td);
if (error)
goto free1;
error = falloc(td, &fp1, &fd);
if (error)
goto free2;
fhold(fp1);
sv[0] = fd;
fp1->f_data = (caddr_t)so1; /* so1 already has ref count */
error = falloc(td, &fp2, &fd);
if (error)
goto free3;
fhold(fp2);
fp2->f_data = (caddr_t)so2; /* so2 already has ref count */
sv[1] = fd;
error = soconnect2(so1, so2);
if (error)
goto free4;
if (uap->type == SOCK_DGRAM) {
/*
* Datagram socket connection is asymmetric.
*/
error = soconnect2(so2, so1);
if (error)
goto free4;
}
FILE_LOCK(fp1);
fp1->f_flag = FREAD|FWRITE;
fp1->f_ops = &socketops;
fp1->f_type = DTYPE_SOCKET;
FILE_UNLOCK(fp1);
FILE_LOCK(fp2);
fp2->f_flag = FREAD|FWRITE;
fp2->f_ops = &socketops;
fp2->f_type = DTYPE_SOCKET;
FILE_UNLOCK(fp2);
error = copyout((caddr_t)sv, (caddr_t)uap->rsv, 2 * sizeof (int));
fdrop(fp1, td);
fdrop(fp2, td);
goto done2;
free4:
FILEDESC_LOCK(fdp);
if (fdp->fd_ofiles[sv[1]] == fp2) {
fdp->fd_ofiles[sv[1]] = NULL;
FILEDESC_UNLOCK(fdp);
fdrop(fp2, td);
} else
FILEDESC_UNLOCK(fdp);
fdrop(fp2, td);
free3:
FILEDESC_LOCK(fdp);
if (fdp->fd_ofiles[sv[0]] == fp1) {
fdp->fd_ofiles[sv[0]] = NULL;
FILEDESC_UNLOCK(fdp);
fdrop(fp1, td);
} else
FILEDESC_UNLOCK(fdp);
fdrop(fp1, td);
free2:
(void)soclose(so2);
free1:
(void)soclose(so1);
done2:
mtx_unlock(&Giant);
return (error);
}
static int
sendit(td, s, mp, flags)
register struct thread *td;
int s;
register struct msghdr *mp;
int flags;
{
struct uio auio;
register struct iovec *iov;
register int i;
struct mbuf *control;
struct sockaddr *to = NULL;
int len, error;
struct socket *so;
#ifdef KTRACE
struct iovec *ktriov = NULL;
struct uio ktruio;
#endif
if ((error = fgetsock(td, s, &so, NULL)) != 0)
return (error);
auio.uio_iov = mp->msg_iov;
auio.uio_iovcnt = mp->msg_iovlen;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_rw = UIO_WRITE;
auio.uio_td = td;
auio.uio_offset = 0; /* XXX */
auio.uio_resid = 0;
iov = mp->msg_iov;
for (i = 0; i < mp->msg_iovlen; i++, iov++) {
if ((auio.uio_resid += iov->iov_len) < 0) {
error = EINVAL;
goto bad;
}
}
if (mp->msg_name) {
error = getsockaddr(&to, mp->msg_name, mp->msg_namelen);
if (error)
goto bad;
}
if (mp->msg_control) {
if (mp->msg_controllen < sizeof(struct cmsghdr)
#ifdef COMPAT_OLDSOCK
&& mp->msg_flags != MSG_COMPAT
#endif
) {
error = EINVAL;
goto bad;
}
error = sockargs(&control, mp->msg_control,
mp->msg_controllen, MT_CONTROL);
if (error)
goto bad;
#ifdef COMPAT_OLDSOCK
if (mp->msg_flags == MSG_COMPAT) {
register struct cmsghdr *cm;
M_PREPEND(control, sizeof(*cm), M_TRYWAIT);
if (control == 0) {
error = ENOBUFS;
goto bad;
} else {
cm = mtod(control, struct cmsghdr *);
cm->cmsg_len = control->m_len;
cm->cmsg_level = SOL_SOCKET;
cm->cmsg_type = SCM_RIGHTS;
}
}
#endif
} else {
control = 0;
}
#ifdef KTRACE
if (KTRPOINT(td->td_proc, KTR_GENIO)) {
int iovlen = auio.uio_iovcnt * sizeof (struct iovec);
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
ktruio = auio;
}
#endif
len = auio.uio_resid;
error = so->so_proto->pr_usrreqs->pru_sosend(so, to, &auio, 0, control,
flags, td);
if (error) {
if (auio.uio_resid != len && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE) {
PROC_LOCK(td->td_proc);
psignal(td->td_proc, SIGPIPE);
PROC_UNLOCK(td->td_proc);
}
}
if (error == 0)
td->td_retval[0] = len - auio.uio_resid;
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0) {
ktruio.uio_iov = ktriov;
ktruio.uio_resid = td->td_retval[0];
ktrgenio(td->td_proc->p_tracep, s, UIO_WRITE, &ktruio, error);
}
FREE(ktriov, M_TEMP);
}
#endif
bad:
fputsock(so);
if (to)
FREE(to, M_SONAME);
return (error);
}
/*
* MPSAFE
*/
int
sendto(td, uap)
struct thread *td;
register struct sendto_args /* {
int s;
caddr_t buf;
size_t len;
int flags;
caddr_t to;
int tolen;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
int error;
msg.msg_name = uap->to;
msg.msg_namelen = uap->tolen;
msg.msg_iov = &aiov;
msg.msg_iovlen = 1;
msg.msg_control = 0;
#ifdef COMPAT_OLDSOCK
msg.msg_flags = 0;
#endif
aiov.iov_base = uap->buf;
aiov.iov_len = uap->len;
mtx_lock(&Giant);
error = sendit(td, uap->s, &msg, uap->flags);
mtx_unlock(&Giant);
return (error);
}
#ifdef COMPAT_OLDSOCK
/*
* MPSAFE
*/
int
osend(td, uap)
struct thread *td;
register struct osend_args /* {
int s;
caddr_t buf;
int len;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
int error;
msg.msg_name = 0;
msg.msg_namelen = 0;
msg.msg_iov = &aiov;
msg.msg_iovlen = 1;
aiov.iov_base = uap->buf;
aiov.iov_len = uap->len;
msg.msg_control = 0;
msg.msg_flags = 0;
mtx_lock(&Giant);
error = sendit(td, uap->s, &msg, uap->flags);
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
int
osendmsg(td, uap)
struct thread *td;
register struct osendmsg_args /* {
int s;
caddr_t msg;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov[UIO_SMALLIOV], *iov;
int error;
mtx_lock(&Giant);
error = copyin(uap->msg, (caddr_t)&msg, sizeof (struct omsghdr));
if (error)
goto done2;
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV) {
error = EMSGSIZE;
goto done2;
}
MALLOC(iov, struct iovec *,
sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
M_WAITOK);
} else {
iov = aiov;
}
error = copyin((caddr_t)msg.msg_iov, (caddr_t)iov,
(unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
if (error)
goto done;
msg.msg_flags = MSG_COMPAT;
msg.msg_iov = iov;
error = sendit(td, uap->s, &msg, uap->flags);
done:
if (iov != aiov)
FREE(iov, M_IOV);
done2:
mtx_unlock(&Giant);
return (error);
}
#endif
/*
* MPSAFE
*/
int
sendmsg(td, uap)
struct thread *td;
register struct sendmsg_args /* {
int s;
caddr_t msg;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov[UIO_SMALLIOV], *iov;
int error;
mtx_lock(&Giant);
error = copyin(uap->msg, (caddr_t)&msg, sizeof (msg));
if (error)
goto done2;
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV) {
error = EMSGSIZE;
goto done2;
}
MALLOC(iov, struct iovec *,
sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
M_WAITOK);
} else {
iov = aiov;
}
if (msg.msg_iovlen &&
(error = copyin((caddr_t)msg.msg_iov, (caddr_t)iov,
(unsigned)(msg.msg_iovlen * sizeof (struct iovec)))))
goto done;
msg.msg_iov = iov;
#ifdef COMPAT_OLDSOCK
msg.msg_flags = 0;
#endif
error = sendit(td, uap->s, &msg, uap->flags);
done:
if (iov != aiov)
FREE(iov, M_IOV);
done2:
mtx_unlock(&Giant);
return (error);
}
static int
recvit(td, s, mp, namelenp)
register struct thread *td;
int s;
register struct msghdr *mp;
caddr_t namelenp;
{
struct uio auio;
register struct iovec *iov;
register int i;
int len, error;
struct mbuf *m, *control = 0;
caddr_t ctlbuf;
struct socket *so;
struct sockaddr *fromsa = 0;
#ifdef KTRACE
struct iovec *ktriov = NULL;
struct uio ktruio;
#endif
if ((error = fgetsock(td, s, &so, NULL)) != 0)
return (error);
auio.uio_iov = mp->msg_iov;
auio.uio_iovcnt = mp->msg_iovlen;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_rw = UIO_READ;
auio.uio_td = td;
auio.uio_offset = 0; /* XXX */
auio.uio_resid = 0;
iov = mp->msg_iov;
for (i = 0; i < mp->msg_iovlen; i++, iov++) {
if ((auio.uio_resid += iov->iov_len) < 0) {
fputsock(so);
return (EINVAL);
}
}
#ifdef KTRACE
if (KTRPOINT(td->td_proc, KTR_GENIO)) {
int iovlen = auio.uio_iovcnt * sizeof (struct iovec);
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
ktruio = auio;
}
#endif
len = auio.uio_resid;
error = so->so_proto->pr_usrreqs->pru_soreceive(so, &fromsa, &auio,
(struct mbuf **)0, mp->msg_control ? &control : (struct mbuf **)0,
&mp->msg_flags);
if (error) {
if (auio.uio_resid != len && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
}
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0) {
ktruio.uio_iov = ktriov;
ktruio.uio_resid = len - auio.uio_resid;
ktrgenio(td->td_proc->p_tracep, s, UIO_READ, &ktruio, error);
}
FREE(ktriov, M_TEMP);
}
#endif
if (error)
goto out;
td->td_retval[0] = len - auio.uio_resid;
if (mp->msg_name) {
len = mp->msg_namelen;
if (len <= 0 || fromsa == 0)
len = 0;
else {
#ifndef MIN
#define MIN(a,b) ((a)>(b)?(b):(a))
#endif
/* save sa_len before it is destroyed by MSG_COMPAT */
len = MIN(len, fromsa->sa_len);
#ifdef COMPAT_OLDSOCK
if (mp->msg_flags & MSG_COMPAT)
((struct osockaddr *)fromsa)->sa_family =
fromsa->sa_family;
#endif
error = copyout(fromsa,
(caddr_t)mp->msg_name, (unsigned)len);
if (error)
goto out;
}
mp->msg_namelen = len;
if (namelenp &&
(error = copyout((caddr_t)&len, namelenp, sizeof (int)))) {
#ifdef COMPAT_OLDSOCK
if (mp->msg_flags & MSG_COMPAT)
error = 0; /* old recvfrom didn't check */
else
#endif
goto out;
}
}
if (mp->msg_control) {
#ifdef COMPAT_OLDSOCK
/*
* We assume that old recvmsg calls won't receive access
* rights and other control info, esp. as control info
* is always optional and those options didn't exist in 4.3.
* If we receive rights, trim the cmsghdr; anything else
* is tossed.
*/
if (control && mp->msg_flags & MSG_COMPAT) {
if (mtod(control, struct cmsghdr *)->cmsg_level !=
SOL_SOCKET ||
mtod(control, struct cmsghdr *)->cmsg_type !=
SCM_RIGHTS) {
mp->msg_controllen = 0;
goto out;
}
control->m_len -= sizeof (struct cmsghdr);
control->m_data += sizeof (struct cmsghdr);
}
#endif
len = mp->msg_controllen;
m = control;
mp->msg_controllen = 0;
ctlbuf = (caddr_t) mp->msg_control;
while (m && len > 0) {
unsigned int tocopy;
if (len >= m->m_len)
tocopy = m->m_len;
else {
mp->msg_flags |= MSG_CTRUNC;
tocopy = len;
}
if ((error = copyout((caddr_t)mtod(m, caddr_t),
ctlbuf, tocopy)) != 0)
goto out;
ctlbuf += tocopy;
len -= tocopy;
m = m->m_next;
}
mp->msg_controllen = ctlbuf - (caddr_t)mp->msg_control;
}
out:
fputsock(so);
if (fromsa)
FREE(fromsa, M_SONAME);
if (control)
m_freem(control);
return (error);
}
/*
* MPSAFE
*/
int
recvfrom(td, uap)
struct thread *td;
register struct recvfrom_args /* {
int s;
caddr_t buf;
size_t len;
int flags;
caddr_t from;
int *fromlenaddr;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
int error;
mtx_lock(&Giant);
if (uap->fromlenaddr) {
error = copyin((caddr_t)uap->fromlenaddr,
(caddr_t)&msg.msg_namelen, sizeof (msg.msg_namelen));
if (error)
goto done2;
} else {
msg.msg_namelen = 0;
}
msg.msg_name = uap->from;
msg.msg_iov = &aiov;
msg.msg_iovlen = 1;
aiov.iov_base = uap->buf;
aiov.iov_len = uap->len;
msg.msg_control = 0;
msg.msg_flags = uap->flags;
error = recvit(td, uap->s, &msg, (caddr_t)uap->fromlenaddr);
done2:
mtx_unlock(&Giant);
return(error);
}
#ifdef COMPAT_OLDSOCK
/*
* MPSAFE
*/
int
orecvfrom(td, uap)
struct thread *td;
struct recvfrom_args *uap;
{
uap->flags |= MSG_COMPAT;
return (recvfrom(td, uap));
}
#endif
#ifdef COMPAT_OLDSOCK
/*
* MPSAFE
*/
int
orecv(td, uap)
struct thread *td;
register struct orecv_args /* {
int s;
caddr_t buf;
int len;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
int error;
mtx_lock(&Giant);
msg.msg_name = 0;
msg.msg_namelen = 0;
msg.msg_iov = &aiov;
msg.msg_iovlen = 1;
aiov.iov_base = uap->buf;
aiov.iov_len = uap->len;
msg.msg_control = 0;
msg.msg_flags = uap->flags;
error = recvit(td, uap->s, &msg, (caddr_t)0);
mtx_unlock(&Giant);
return (error);
}
/*
* Old recvmsg. This code takes advantage of the fact that the old msghdr
* overlays the new one, missing only the flags, and with the (old) access
* rights where the control fields are now.
*
* MPSAFE
*/
int
orecvmsg(td, uap)
struct thread *td;
register struct orecvmsg_args /* {
int s;
struct omsghdr *msg;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov[UIO_SMALLIOV], *iov;
int error;
error = copyin((caddr_t)uap->msg, (caddr_t)&msg,
sizeof (struct omsghdr));
if (error)
return (error);
mtx_lock(&Giant);
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV) {
error = EMSGSIZE;
goto done2;
}
MALLOC(iov, struct iovec *,
sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
M_WAITOK);
} else {
iov = aiov;
}
msg.msg_flags = uap->flags | MSG_COMPAT;
error = copyin((caddr_t)msg.msg_iov, (caddr_t)iov,
(unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
if (error)
goto done;
msg.msg_iov = iov;
error = recvit(td, uap->s, &msg, (caddr_t)&uap->msg->msg_namelen);
if (msg.msg_controllen && error == 0)
error = copyout((caddr_t)&msg.msg_controllen,
(caddr_t)&uap->msg->msg_accrightslen, sizeof (int));
done:
if (iov != aiov)
FREE(iov, M_IOV);
done2:
mtx_unlock(&Giant);
return (error);
}
#endif
/*
* MPSAFE
*/
int
recvmsg(td, uap)
struct thread *td;
register struct recvmsg_args /* {
int s;
struct msghdr *msg;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov[UIO_SMALLIOV], *uiov, *iov;
register int error;
mtx_lock(&Giant);
error = copyin((caddr_t)uap->msg, (caddr_t)&msg, sizeof (msg));
if (error)
goto done2;
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV) {
error = EMSGSIZE;
goto done2;
}
MALLOC(iov, struct iovec *,
sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
M_WAITOK);
} else {
iov = aiov;
}
#ifdef COMPAT_OLDSOCK
msg.msg_flags = uap->flags &~ MSG_COMPAT;
#else
msg.msg_flags = uap->flags;
#endif
uiov = msg.msg_iov;
msg.msg_iov = iov;
error = copyin((caddr_t)uiov, (caddr_t)iov,
(unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
if (error)
goto done;
error = recvit(td, uap->s, &msg, (caddr_t)0);
if (!error) {
msg.msg_iov = uiov;
error = copyout((caddr_t)&msg, (caddr_t)uap->msg, sizeof(msg));
}
done:
if (iov != aiov)
FREE(iov, M_IOV);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
shutdown(td, uap)
struct thread *td;
register struct shutdown_args /* {
int s;
int how;
} */ *uap;
{
struct socket *so;
int error;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->s, &so, NULL)) == 0) {
error = soshutdown(so, uap->how);
fputsock(so);
}
mtx_unlock(&Giant);
return(error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
setsockopt(td, uap)
struct thread *td;
register struct setsockopt_args /* {
int s;
int level;
int name;
caddr_t val;
int valsize;
} */ *uap;
{
struct socket *so;
struct sockopt sopt;
int error;
if (uap->val == 0 && uap->valsize != 0)
return (EFAULT);
if (uap->valsize < 0)
return (EINVAL);
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->s, &so, NULL)) == 0) {
sopt.sopt_dir = SOPT_SET;
sopt.sopt_level = uap->level;
sopt.sopt_name = uap->name;
sopt.sopt_val = uap->val;
sopt.sopt_valsize = uap->valsize;
sopt.sopt_td = td;
error = sosetopt(so, &sopt);
fputsock(so);
}
mtx_unlock(&Giant);
return(error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
getsockopt(td, uap)
struct thread *td;
register struct getsockopt_args /* {
int s;
int level;
int name;
caddr_t val;
int *avalsize;
} */ *uap;
{
int valsize, error;
struct socket *so;
struct sockopt sopt;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->s, &so, NULL)) != 0)
goto done2;
if (uap->val) {
error = copyin((caddr_t)uap->avalsize, (caddr_t)&valsize,
sizeof (valsize));
if (error)
goto done1;
if (valsize < 0) {
error = EINVAL;
goto done1;
}
} else {
valsize = 0;
}
sopt.sopt_dir = SOPT_GET;
sopt.sopt_level = uap->level;
sopt.sopt_name = uap->name;
sopt.sopt_val = uap->val;
sopt.sopt_valsize = (size_t)valsize; /* checked non-negative above */
sopt.sopt_td = td;
error = sogetopt(so, &sopt);
if (error == 0) {
valsize = sopt.sopt_valsize;
error = copyout((caddr_t)&valsize,
(caddr_t)uap->avalsize, sizeof (valsize));
}
done1:
fputsock(so);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* getsockname1() - Get socket name.
*
* MPSAFE
*/
/* ARGSUSED */
static int
getsockname1(td, uap, compat)
struct thread *td;
register struct getsockname_args /* {
int fdes;
caddr_t asa;
int *alen;
} */ *uap;
int compat;
{
struct socket *so;
struct sockaddr *sa;
int len, error;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->fdes, &so, NULL)) != 0)
goto done2;
error = copyin((caddr_t)uap->alen, (caddr_t)&len, sizeof (len));
if (error)
goto done1;
sa = 0;
error = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, &sa);
if (error)
goto bad;
if (sa == 0) {
len = 0;
goto gotnothing;
}
len = MIN(len, sa->sa_len);
#ifdef COMPAT_OLDSOCK
if (compat)
((struct osockaddr *)sa)->sa_family = sa->sa_family;
#endif
error = copyout(sa, (caddr_t)uap->asa, (u_int)len);
if (error == 0)
gotnothing:
error = copyout((caddr_t)&len, (caddr_t)uap->alen,
sizeof (len));
bad:
if (sa)
FREE(sa, M_SONAME);
done1:
fputsock(so);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
int
getsockname(td, uap)
struct thread *td;
struct getsockname_args *uap;
{
return (getsockname1(td, uap, 0));
}
#ifdef COMPAT_OLDSOCK
/*
* MPSAFE
*/
int
ogetsockname(td, uap)
struct thread *td;
struct getsockname_args *uap;
{
return (getsockname1(td, uap, 1));
}
#endif /* COMPAT_OLDSOCK */
/*
* getpeername1() - Get name of peer for connected socket.
*
* MPSAFE
*/
/* ARGSUSED */
static int
getpeername1(td, uap, compat)
struct thread *td;
register struct getpeername_args /* {
int fdes;
caddr_t asa;
int *alen;
} */ *uap;
int compat;
{
struct socket *so;
struct sockaddr *sa;
int len, error;
mtx_lock(&Giant);
if ((error = fgetsock(td, uap->fdes, &so, NULL)) != 0)
goto done2;
if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
error = ENOTCONN;
goto done1;
}
error = copyin((caddr_t)uap->alen, (caddr_t)&len, sizeof (len));
if (error)
goto done1;
sa = 0;
error = (*so->so_proto->pr_usrreqs->pru_peeraddr)(so, &sa);
if (error)
goto bad;
if (sa == 0) {
len = 0;
goto gotnothing;
}
len = MIN(len, sa->sa_len);
#ifdef COMPAT_OLDSOCK
if (compat)
((struct osockaddr *)sa)->sa_family =
sa->sa_family;
#endif
error = copyout(sa, (caddr_t)uap->asa, (u_int)len);
if (error)
goto bad;
gotnothing:
error = copyout((caddr_t)&len, (caddr_t)uap->alen, sizeof (len));
bad:
if (sa)
FREE(sa, M_SONAME);
done1:
fputsock(so);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* MPSAFE
*/
int
getpeername(td, uap)
struct thread *td;
struct getpeername_args *uap;
{
return (getpeername1(td, uap, 0));
}
#ifdef COMPAT_OLDSOCK
/*
* MPSAFE
*/
int
ogetpeername(td, uap)
struct thread *td;
struct ogetpeername_args *uap;
{
/* XXX uap should have type `getpeername_args *' to begin with. */
return (getpeername1(td, (struct getpeername_args *)uap, 1));
}
#endif /* COMPAT_OLDSOCK */
int
sockargs(mp, buf, buflen, type)
struct mbuf **mp;
caddr_t buf;
int buflen, type;
{
register struct sockaddr *sa;
register struct mbuf *m;
int error;
if ((u_int)buflen > MLEN) {
#ifdef COMPAT_OLDSOCK
if (type == MT_SONAME && (u_int)buflen <= 112)
buflen = MLEN; /* unix domain compat. hack */
else
#endif
return (EINVAL);
}
m = m_get(M_TRYWAIT, type);
if (m == NULL)
return (ENOBUFS);
m->m_len = buflen;
error = copyin(buf, mtod(m, caddr_t), (u_int)buflen);
if (error)
(void) m_free(m);
else {
*mp = m;
if (type == MT_SONAME) {
sa = mtod(m, struct sockaddr *);
#if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
sa->sa_family = sa->sa_len;
#endif
sa->sa_len = buflen;
}
}
return (error);
}
int
getsockaddr(namp, uaddr, len)
struct sockaddr **namp;
caddr_t uaddr;
size_t len;
{
struct sockaddr *sa;
int error;
if (len > SOCK_MAXADDRLEN)
return ENAMETOOLONG;
MALLOC(sa, struct sockaddr *, len, M_SONAME, M_WAITOK);
error = copyin(uaddr, sa, len);
if (error) {
FREE(sa, M_SONAME);
} else {
#if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
sa->sa_family = sa->sa_len;
#endif
sa->sa_len = len;
*namp = sa;
}
return error;
}
/*
* Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
* XXX - The sf_buf functions are currently private to sendfile(2), so have
* been made static, but may be useful in the future for doing zero-copy in
* other parts of the networking code.
*/
static void
sf_buf_init(void *arg)
{
int i;
mtx_init(&sf_freelist.sf_lock, "sf_bufs list lock", MTX_DEF);
mtx_lock(&sf_freelist.sf_lock);
SLIST_INIT(&sf_freelist.sf_head);
sf_base = kmem_alloc_pageable(kernel_map, nsfbufs * PAGE_SIZE);
sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
M_NOWAIT | M_ZERO);
for (i = 0; i < nsfbufs; i++) {
sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
SLIST_INSERT_HEAD(&sf_freelist.sf_head, &sf_bufs[i], free_list);
}
sf_buf_alloc_want = 0;
mtx_unlock(&sf_freelist.sf_lock);
}
/*
* Get an sf_buf from the freelist. Will block if none are available.
*/
static struct sf_buf *
sf_buf_alloc()
{
struct sf_buf *sf;
int error;
mtx_lock(&sf_freelist.sf_lock);
while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
sf_buf_alloc_want++;
error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
"sfbufa", 0);
sf_buf_alloc_want--;
/*
* If we got a signal, don't risk going back to sleep.
*/
if (error)
break;
}
if (sf != NULL)
SLIST_REMOVE_HEAD(&sf_freelist.sf_head, free_list);
mtx_unlock(&sf_freelist.sf_lock);
return (sf);
}
#define dtosf(x) (&sf_bufs[((uintptr_t)(x) - (uintptr_t)sf_base) >> PAGE_SHIFT])
/*
* Detatch mapped page and release resources back to the system.
*/
static void
sf_buf_free(caddr_t addr, void *args)
{
struct sf_buf *sf;
struct vm_page *m;
GIANT_REQUIRED;
sf = dtosf(addr);
pmap_qremove((vm_offset_t)addr, 1);
m = sf->m;
vm_page_unwire(m, 0);
/*
* Check for the object going away on us. This can
* happen since we don't hold a reference to it.
* If so, we're responsible for freeing the page.
*/
if (m->wire_count == 0 && m->object == NULL)
vm_page_free(m);
sf->m = NULL;
mtx_lock(&sf_freelist.sf_lock);
SLIST_INSERT_HEAD(&sf_freelist.sf_head, sf, free_list);
if (sf_buf_alloc_want > 0)
wakeup_one(&sf_freelist);
mtx_unlock(&sf_freelist.sf_lock);
}
/*
* sendfile(2)
*
* MPSAFE
*
* int sendfile(int fd, int s, off_t offset, size_t nbytes,
* struct sf_hdtr *hdtr, off_t *sbytes, int flags)
*
* Send a file specified by 'fd' and starting at 'offset' to a socket
* specified by 's'. Send only 'nbytes' of the file or until EOF if
* nbytes == 0. Optionally add a header and/or trailer to the socket
* output. If specified, write the total number of bytes sent into *sbytes.
*
*/
int
sendfile(struct thread *td, struct sendfile_args *uap)
{
struct vnode *vp;
struct vm_object *obj;
struct socket *so = NULL;
struct mbuf *m;
struct sf_buf *sf;
struct vm_page *pg;
struct writev_args nuap;
struct sf_hdtr hdtr;
off_t off, xfsize, sbytes = 0;
int error, s;
mtx_lock(&Giant);
/*
* The descriptor must be a regular file and have a backing VM object.
*/
if ((error = fgetvp_read(td, uap->fd, &vp)) != 0)
goto done;
if (vp->v_type != VREG || VOP_GETVOBJECT(vp, &obj) != 0) {
error = EINVAL;
goto done;
}
if ((error = fgetsock(td, uap->s, &so, NULL)) != 0)
goto done;
if (so->so_type != SOCK_STREAM) {
error = EINVAL;
goto done;
}
if ((so->so_state & SS_ISCONNECTED) == 0) {
error = ENOTCONN;
goto done;
}
if (uap->offset < 0) {
error = EINVAL;
goto done;
}
/*
* If specified, get the pointer to the sf_hdtr struct for
* any headers/trailers.
*/
if (uap->hdtr != NULL) {
error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
if (error)
goto done;
/*
* Send any headers. Wimp out and use writev(2).
*/
if (hdtr.headers != NULL) {
nuap.fd = uap->s;
nuap.iovp = hdtr.headers;
nuap.iovcnt = hdtr.hdr_cnt;
error = writev(td, &nuap);
if (error)
goto done;
sbytes += td->td_retval[0];
}
}
/*
* Protect against multiple writers to the socket.
*/
(void) sblock(&so->so_snd, M_WAITOK);
/*
* Loop through the pages in the file, starting with the requested
* offset. Get a file page (do I/O if necessary), map the file page
* into an sf_buf, attach an mbuf header to the sf_buf, and queue
* it on the socket.
*/
for (off = uap->offset; ; off += xfsize, sbytes += xfsize) {
vm_pindex_t pindex;
vm_offset_t pgoff;
pindex = OFF_TO_IDX(off);
retry_lookup:
/*
* Calculate the amount to transfer. Not to exceed a page,
* the EOF, or the passed in nbytes.
*/
xfsize = obj->un_pager.vnp.vnp_size - off;
if (xfsize > PAGE_SIZE)
xfsize = PAGE_SIZE;
pgoff = (vm_offset_t)(off & PAGE_MASK);
if (PAGE_SIZE - pgoff < xfsize)
xfsize = PAGE_SIZE - pgoff;
if (uap->nbytes && xfsize > (uap->nbytes - sbytes))
xfsize = uap->nbytes - sbytes;
if (xfsize <= 0)
break;
/*
* Optimize the non-blocking case by looking at the socket space
* before going to the extra work of constituting the sf_buf.
*/
if ((so->so_state & SS_NBIO) && sbspace(&so->so_snd) <= 0) {
if (so->so_state & SS_CANTSENDMORE)
error = EPIPE;
else
error = EAGAIN;
sbunlock(&so->so_snd);
goto done;
}
/*
* Attempt to look up the page.
*
* Allocate if not found
*
* Wait and loop if busy.
*/
pg = vm_page_lookup(obj, pindex);
if (pg == NULL) {
pg = vm_page_alloc(obj, pindex, VM_ALLOC_NORMAL);
if (pg == NULL) {
VM_WAIT;
goto retry_lookup;
}
vm_page_wakeup(pg);
} else if (vm_page_sleep_busy(pg, TRUE, "sfpbsy")) {
goto retry_lookup;
}
/*
* Wire the page so it does not get ripped out from under
* us.
*/
vm_page_wire(pg);
/*
* If page is not valid for what we need, initiate I/O
*/
if (!pg->valid || !vm_page_is_valid(pg, pgoff, xfsize)) {
struct uio auio;
struct iovec aiov;
int bsize;
/*
* Ensure that our page is still around when the I/O
* completes.
*/
vm_page_io_start(pg);
/*
* Get the page from backing store.
*/
bsize = vp->v_mount->mnt_stat.f_iosize;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
aiov.iov_base = 0;
aiov.iov_len = MAXBSIZE;
auio.uio_resid = MAXBSIZE;
auio.uio_offset = trunc_page(off);
auio.uio_segflg = UIO_NOCOPY;
auio.uio_rw = UIO_READ;
auio.uio_td = td;
vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
error = VOP_READ(vp, &auio, IO_VMIO | ((MAXBSIZE / bsize) << 16),
td->td_proc->p_ucred);
VOP_UNLOCK(vp, 0, td);
vm_page_flag_clear(pg, PG_ZERO);
vm_page_io_finish(pg);
if (error) {
vm_page_unwire(pg, 0);
/*
* See if anyone else might know about this page.
* If not and it is not valid, then free it.
*/
if (pg->wire_count == 0 && pg->valid == 0 &&
pg->busy == 0 && !(pg->flags & PG_BUSY) &&
pg->hold_count == 0) {
vm_page_busy(pg);
vm_page_free(pg);
}
sbunlock(&so->so_snd);
goto done;
}
}
/*
* Get a sendfile buf. We usually wait as long as necessary,
* but this wait can be interrupted.
*/
if ((sf = sf_buf_alloc()) == NULL) {
vm_page_unwire(pg, 0);
if (pg->wire_count == 0 && pg->object == NULL)
vm_page_free(pg);
sbunlock(&so->so_snd);
error = EINTR;
goto done;
}
/*
* Allocate a kernel virtual page and insert the physical page
* into it.
*/
sf->m = pg;
pmap_qenter(sf->kva, &pg, 1);
/*
* Get an mbuf header and set it up as having external storage.
*/
MGETHDR(m, M_TRYWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
sf_buf_free((void *)sf->kva, NULL);
sbunlock(&so->so_snd);
goto done;
}
/*
* Setup external storage for mbuf.
*/
MEXTADD(m, sf->kva, PAGE_SIZE, sf_buf_free, NULL, M_RDONLY,
EXT_SFBUF);
m->m_data = (char *) sf->kva + pgoff;
m->m_pkthdr.len = m->m_len = xfsize;
/*
* Add the buffer to the socket buffer chain.
*/
s = splnet();
retry_space:
/*
* Make sure that the socket is still able to take more data.
* CANTSENDMORE being true usually means that the connection
* was closed. so_error is true when an error was sensed after
* a previous send.
* The state is checked after the page mapping and buffer
* allocation above since those operations may block and make
* any socket checks stale. From this point forward, nothing
* blocks before the pru_send (or more accurately, any blocking
* results in a loop back to here to re-check).
*/
if ((so->so_state & SS_CANTSENDMORE) || so->so_error) {
if (so->so_state & SS_CANTSENDMORE) {
error = EPIPE;
} else {
error = so->so_error;
so->so_error = 0;
}
m_freem(m);
sbunlock(&so->so_snd);
splx(s);
goto done;
}
/*
* Wait for socket space to become available. We do this just
* after checking the connection state above in order to avoid
* a race condition with sbwait().
*/
if (sbspace(&so->so_snd) < so->so_snd.sb_lowat) {
if (so->so_state & SS_NBIO) {
m_freem(m);
sbunlock(&so->so_snd);
splx(s);
error = EAGAIN;
goto done;
}
error = sbwait(&so->so_snd);
/*
* An error from sbwait usually indicates that we've
* been interrupted by a signal. If we've sent anything
* then return bytes sent, otherwise return the error.
*/
if (error) {
m_freem(m);
sbunlock(&so->so_snd);
splx(s);
goto done;
}
goto retry_space;
}
error = (*so->so_proto->pr_usrreqs->pru_send)(so, 0, m, 0, 0, td);
splx(s);
if (error) {
sbunlock(&so->so_snd);
goto done;
}
}
sbunlock(&so->so_snd);
/*
* Send trailers. Wimp out and use writev(2).
*/
if (uap->hdtr != NULL && hdtr.trailers != NULL) {
nuap.fd = uap->s;
nuap.iovp = hdtr.trailers;
nuap.iovcnt = hdtr.trl_cnt;
error = writev(td, &nuap);
if (error)
goto done;
sbytes += td->td_retval[0];
}
done:
/*
* If there was no error we have to clear td->td_retval[0]
* because it may have been set by writev.
*/
if (error == 0) {
td->td_retval[0] = 0;
}
if (uap->sbytes != NULL) {
copyout(&sbytes, uap->sbytes, sizeof(off_t));
}
if (vp)
vrele(vp);
if (so)
fputsock(so);
mtx_unlock(&Giant);
return (error);
}
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