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freebsd-skq/sys/kern/uipc_syscalls.c
rwatson 576b26bafd Integrate accept locking from rwatson_netperf, introducing a new 
global mutex, accept_mtx, which serializes access to the following
fields across all sockets:

          so_qlen          so_incqlen         so_qstate
          so_comp          so_incomp          so_list
          so_head

While providing only coarse granularity, this approach avoids lock
order issues between sockets by avoiding ownership of the fields
by a specific socket and its per-socket mutexes.

While here, rewrite soclose(), sofree(), soaccept(), and
sonewconn() to add assertions, close additional races and  address
lock order concerns.  In particular:

- Reorganize the optimistic concurrency behavior in accept1() to
  always allocate a file descriptor with falloc() so that if we do
  find a socket, we don't have to encounter the "Oh, there wasn't
  a socket" race that can occur if falloc() sleeps in the current
  code, which broke inbound accept() ordering, not to mention
  requiring backing out socket state changes in a way that raced
  with the protocol level.  We may want to add a lockless read of
  the queue state if polling of empty queues proves to be important
  to optimize.

- In accept1(), soref() the socket while holding the accept lock
  so that the socket cannot be free'd in a race with the protocol
  layer.  Likewise in netgraph equivilents of the accept1() code.

- In sonewconn(), loop waiting for the queue to be small enough to
  insert our new socket once we've committed to inserting it, or
  races can occur that cause the incomplete socket queue to
  overfill.  In the previously implementation, it was sufficient
  to simply tested once since calling soabort() didn't release
  synchronization permitting another thread to insert a socket as
  we discard a previous one.

- In soclose()/sofree()/et al, it is the responsibility of the
  caller to remove a socket from the incomplete connection queue
  before calling soabort(), which prevents soabort() from having
  to walk into the accept socket to release the socket from its
  queue, and avoids races when releasing the accept mutex to enter
  soabort(), permitting soabort() to avoid lock ordering issues
  with the caller.

- Generally cluster accept queue related operations together
  throughout these functions in order to facilitate locking.

Annotate new locking in socketvar.h.
2004-06-02 04:15:39 +00:00

2078 lines
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/*
* 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.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include "opt_ktrace.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mac.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/filio.h>
#include <sys/mount.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/sf_buf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.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 int sendit(struct thread *td, int s, struct msghdr *mp, int flags);
static int recvit(struct thread *td, int s, struct msghdr *mp, void *namelenp);
static int accept1(struct thread *td, struct accept_args *uap, int compat);
static int do_sendfile(struct thread *td, struct sendfile_args *uap, int compat);
static int getsockname1(struct thread *td, struct getsockname_args *uap,
int compat);
static int getpeername1(struct thread *td, struct getpeername_args *uap,
int compat);
/*
* NSFBUFS-related variables and associated sysctls
*/
int nsfbufs;
int nsfbufspeak;
int nsfbufsused;
SYSCTL_DECL(_kern_ipc);
SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufs, CTLFLAG_RDTUN, &nsfbufs, 0,
"Maximum number of sendfile(2) sf_bufs available");
SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufspeak, CTLFLAG_RD, &nsfbufspeak, 0,
"Number of sendfile(2) sf_bufs at peak usage");
SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufsused, CTLFLAG_RD, &nsfbufsused, 0,
"Number of sendfile(2) sf_bufs in use");
/*
* System call interface to the socket abstraction.
*/
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#define COMPAT_OLDSOCK
#endif
/*
* 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;
fdp = td->td_proc->p_fd;
error = falloc(td, &fp, &fd);
if (error)
return (error);
/* An extra reference on `fp' has been held for us by falloc(). */
NET_LOCK_GIANT();
error = socreate(uap->domain, &so, uap->type, uap->protocol,
td->td_ucred, td);
NET_UNLOCK_GIANT();
FILEDESC_LOCK(fdp);
if (error) {
if (fdp->fd_ofiles[fd] == fp) {
fdp->fd_ofiles[fd] = NULL;
fdunused(fdp, fd);
FILEDESC_UNLOCK(fdp);
fdrop(fp, td);
} else {
FILEDESC_UNLOCK(fdp);
}
} else {
fp->f_data = 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);
return (error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
bind(td, uap)
struct thread *td;
register struct bind_args /* {
int s;
caddr_t name;
int namelen;
} */ *uap;
{
struct sockaddr *sa;
int error;
if ((error = getsockaddr(&sa, uap->name, uap->namelen)) != 0)
return (error);
return (kern_bind(td, uap->s, sa));
}
int
kern_bind(td, fd, sa)
struct thread *td;
int fd;
struct sockaddr *sa;
{
struct socket *so;
int error;
NET_LOCK_GIANT();
if ((error = fgetsock(td, fd, &so, NULL)) != 0)
goto done2;
#ifdef MAC
error = mac_check_socket_bind(td->td_ucred, so, sa);
if (error)
goto done1;
#endif
error = sobind(so, sa, td);
#ifdef MAC
done1:
#endif
fputsock(so);
done2:
NET_UNLOCK_GIANT();
FREE(sa, M_SONAME);
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;
NET_LOCK_GIANT();
if ((error = fgetsock(td, uap->s, &so, NULL)) == 0) {
#ifdef MAC
error = mac_check_socket_listen(td->td_ucred, so);
if (error)
goto done;
#endif
error = solisten(so, uap->backlog, td);
#ifdef MAC
done:
#endif
fputsock(so);
}
NET_UNLOCK_GIANT();
return(error);
}
/*
* accept1()
* MPSAFE
*/
static int
accept1(td, uap, compat)
struct thread *td;
register struct accept_args /* {
int s;
struct sockaddr * __restrict name;
socklen_t * __restrict anamelen;
} */ *uap;
int compat;
{
struct filedesc *fdp;
struct file *nfp = NULL;
struct sockaddr *sa;
socklen_t namelen;
int error;
struct socket *head, *so;
int fd;
u_int fflag;
pid_t pgid;
int tmp;
fdp = td->td_proc->p_fd;
if (uap->name) {
error = copyin(uap->anamelen, &namelen, sizeof (namelen));
if(error)
return (error);
if (namelen < 0)
return (EINVAL);
}
NET_LOCK_GIANT();
error = fgetsock(td, uap->s, &head, &fflag);
if (error)
goto done2;
if ((head->so_options & SO_ACCEPTCONN) == 0) {
error = EINVAL;
goto done;
}
error = falloc(td, &nfp, &fd);
if (error)
goto done;
ACCEPT_LOCK();
if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->so_comp)) {
ACCEPT_UNLOCK();
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 = msleep(&head->so_timeo, &accept_mtx, PSOCK | PCATCH,
"accept", 0);
if (error) {
ACCEPT_UNLOCK();
goto done;
}
}
if (head->so_error) {
error = head->so_error;
head->so_error = 0;
ACCEPT_UNLOCK();
goto done;
}
so = TAILQ_FIRST(&head->so_comp);
KASSERT(!(so->so_qstate & SQ_INCOMP), ("accept1: so SQ_INCOMP"));
KASSERT(so->so_qstate & SQ_COMP, ("accept1: so not SQ_COMP"));
soref(so); /* file descriptor reference */
TAILQ_REMOVE(&head->so_comp, so, so_list);
head->so_qlen--;
so->so_qstate &= ~SQ_COMP;
so->so_head = NULL;
ACCEPT_UNLOCK();
/* An extra reference on `nfp' has been held for us by falloc(). */
td->td_retval[0] = fd;
/* connection has been removed from the listen queue */
KNOTE(&head->so_rcv.sb_sel.si_note, 0);
pgid = fgetown(&head->so_sigio);
if (pgid != 0)
fsetown(pgid, &so->so_sigio);
FILE_LOCK(nfp);
nfp->f_data = so; /* nfp has ref count from falloc */
nfp->f_flag = fflag;
nfp->f_ops = &socketops;
nfp->f_type = DTYPE_SOCKET;
FILE_UNLOCK(nfp);
/* Sync socket nonblocking/async state with file flags */
tmp = fflag & FNONBLOCK;
(void) fo_ioctl(nfp, FIONBIO, &tmp, td->td_ucred, td);
tmp = fflag & FASYNC;
(void) fo_ioctl(nfp, FIOASYNC, &tmp, td->td_ucred, td);
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(&namelen,
uap->anamelen, sizeof(*uap->anamelen));
}
goto noconnection;
}
if (sa == NULL) {
namelen = 0;
if (uap->name)
goto gotnoname;
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, uap->name, (u_int)namelen);
if (!error)
gotnoname:
error = copyout(&namelen,
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;
fdunused(fdp, fd);
FILEDESC_UNLOCK(fdp);
fdrop(nfp, td);
} else {
FILEDESC_UNLOCK(fdp);
}
}
/*
* Release explicitly held references before returning.
*/
done:
if (nfp != NULL)
fdrop(nfp, td);
fputsock(head);
done2:
NET_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 sockaddr *sa;
int error;
error = getsockaddr(&sa, uap->name, uap->namelen);
if (error)
return (error);
return (kern_connect(td, uap->s, sa));
}
int
kern_connect(td, fd, sa)
struct thread *td;
int fd;
struct sockaddr *sa;
{
struct socket *so;
int error, s;
int interrupted = 0;
NET_LOCK_GIANT();
if ((error = fgetsock(td, fd, &so, NULL)) != 0)
goto done2;
if (so->so_state & SS_ISCONNECTING) {
error = EALREADY;
goto done1;
}
#ifdef MAC
error = mac_check_socket_connect(td->td_ucred, so, sa);
if (error)
goto bad;
#endif
error = soconnect(so, sa, td);
if (error)
goto bad;
if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
error = EINPROGRESS;
goto done1;
}
s = splnet();
while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
error = tsleep(&so->so_timeo, PSOCK | PCATCH, "connec", 0);
if (error) {
if (error == EINTR || error == ERESTART)
interrupted = 1;
break;
}
}
if (error == 0) {
error = so->so_error;
so->so_error = 0;
}
splx(s);
bad:
if (!interrupted)
so->so_state &= ~SS_ISCONNECTING;
if (error == ERESTART)
error = EINTR;
done1:
fputsock(so);
done2:
NET_UNLOCK_GIANT();
FREE(sa, M_SONAME);
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];
NET_LOCK_GIANT();
error = socreate(uap->domain, &so1, uap->type, uap->protocol,
td->td_ucred, td);
if (error)
goto done2;
error = socreate(uap->domain, &so2, uap->type, uap->protocol,
td->td_ucred, td);
if (error)
goto free1;
/* On success extra reference to `fp1' and 'fp2' is set by falloc. */
error = falloc(td, &fp1, &fd);
if (error)
goto free2;
sv[0] = fd;
fp1->f_data = so1; /* so1 already has ref count */
error = falloc(td, &fp2, &fd);
if (error)
goto free3;
fp2->f_data = 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(sv, 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;
fdunused(fdp, sv[1]);
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;
fdunused(fdp, sv[0]);
FILEDESC_UNLOCK(fdp);
fdrop(fp1, td);
} else {
FILEDESC_UNLOCK(fdp);
}
fdrop(fp1, td);
free2:
(void)soclose(so2);
free1:
(void)soclose(so1);
done2:
NET_UNLOCK_GIANT();
return (error);
}
static int
sendit(td, s, mp, flags)
register struct thread *td;
int s;
register struct msghdr *mp;
int flags;
{
struct mbuf *control;
struct sockaddr *to;
int error;
if (mp->msg_name != NULL) {
error = getsockaddr(&to, mp->msg_name, mp->msg_namelen);
if (error) {
to = NULL;
goto bad;
}
mp->msg_name = to;
} else {
to = NULL;
}
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 = NULL;
}
error = kern_sendit(td, s, mp, flags, control);
bad:
if (to)
FREE(to, M_SONAME);
return (error);
}
int
kern_sendit(td, s, mp, flags, control)
struct thread *td;
int s;
struct msghdr *mp;
int flags;
struct mbuf *control;
{
struct uio auio;
struct iovec *iov;
struct socket *so;
int i;
int len, error;
#ifdef KTRACE
struct iovec *ktriov = NULL;
struct uio ktruio;
int iovlen;
#endif
NET_LOCK_GIANT();
if ((error = fgetsock(td, s, &so, NULL)) != 0)
goto bad2;
#ifdef MAC
error = mac_check_socket_send(td->td_ucred, so);
if (error)
goto bad;
#endif
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;
}
}
#ifdef KTRACE
if (KTRPOINT(td, KTR_GENIO)) {
iovlen = auio.uio_iovcnt * sizeof (struct iovec);
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy(auio.uio_iov, ktriov, iovlen);
ktruio = auio;
}
#endif
len = auio.uio_resid;
error = so->so_proto->pr_usrreqs->pru_sosend(so, mp->msg_name, &auio,
0, control, flags, td);
if (error) {
if (auio.uio_resid != len && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
/* Generation of SIGPIPE can be controlled per socket */
if (error == EPIPE && !(so->so_options & SO_NOSIGPIPE)) {
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(s, UIO_WRITE, &ktruio, error);
}
FREE(ktriov, M_TEMP);
}
#endif
bad:
fputsock(so);
bad2:
NET_UNLOCK_GIANT();
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;
error = sendit(td, uap->s, &msg, uap->flags);
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;
error = sendit(td, uap->s, &msg, uap->flags);
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;
error = copyin(uap->msg, &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(msg.msg_iov, 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:
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;
error = copyin(uap->msg, &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(msg.msg_iov, 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:
return (error);
}
static int
recvit(td, s, mp, namelenp)
register struct thread *td;
int s;
register struct msghdr *mp;
void *namelenp;
{
struct uio auio;
register struct iovec *iov;
register int i;
socklen_t len;
int 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;
int iovlen;
#endif
NET_LOCK_GIANT();
if ((error = fgetsock(td, s, &so, NULL)) != 0) {
NET_UNLOCK_GIANT();
return (error);
}
#ifdef MAC
error = mac_check_socket_receive(td->td_ucred, so);
if (error) {
fputsock(so);
NET_UNLOCK_GIANT();
return (error);
}
#endif
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);
NET_UNLOCK_GIANT();
return (EINVAL);
}
}
#ifdef KTRACE
if (KTRPOINT(td, KTR_GENIO)) {
iovlen = auio.uio_iovcnt * sizeof (struct iovec);
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy(auio.uio_iov, 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 != (int)len && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
}
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0) {
ktruio.uio_iov = ktriov;
ktruio.uio_resid = (int)len - auio.uio_resid;
ktrgenio(s, UIO_READ, &ktruio, error);
}
FREE(ktriov, M_TEMP);
}
#endif
if (error)
goto out;
td->td_retval[0] = (int)len - auio.uio_resid;
if (mp->msg_name) {
len = mp->msg_namelen;
if (len <= 0 || fromsa == 0)
len = 0;
else {
/* 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, mp->msg_name, (unsigned)len);
if (error)
goto out;
}
mp->msg_namelen = len;
if (namelenp &&
(error = copyout(&len, namelenp, sizeof (socklen_t)))) {
#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 = 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(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);
NET_UNLOCK_GIANT();
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;
struct sockaddr * __restrict from;
socklen_t * __restrict fromlenaddr;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
int error;
if (uap->fromlenaddr) {
error = copyin(uap->fromlenaddr,
&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, uap->fromlenaddr);
done2:
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;
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, NULL);
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(uap->msg, &msg, sizeof (struct omsghdr));
if (error)
return (error);
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(msg.msg_iov, iov,
(unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
if (error)
goto done;
msg.msg_iov = iov;
error = recvit(td, uap->s, &msg, &uap->msg->msg_namelen);
if (msg.msg_controllen && error == 0)
error = copyout(&msg.msg_controllen,
&uap->msg->msg_accrightslen, sizeof (int));
done:
if (iov != aiov)
FREE(iov, M_IOV);
done2:
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;
error = copyin(uap->msg, &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(uiov, iov,
(unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
if (error)
goto done;
error = recvit(td, uap->s, &msg, NULL);
if (!error) {
msg.msg_iov = uiov;
error = copyout(&msg, uap->msg, sizeof(msg));
}
done:
if (iov != aiov)
FREE(iov, M_IOV);
done2:
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;
NET_LOCK_GIANT();
if ((error = fgetsock(td, uap->s, &so, NULL)) == 0) {
error = soshutdown(so, uap->how);
fputsock(so);
}
NET_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);
NET_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);
}
NET_UNLOCK_GIANT();
return(error);
}
/*
* MPSAFE
*/
/* ARGSUSED */
int
getsockopt(td, uap)
struct thread *td;
register struct getsockopt_args /* {
int s;
int level;
int name;
void * __restrict val;
socklen_t * __restrict avalsize;
} */ *uap;
{
socklen_t valsize;
int error;
struct socket *so;
struct sockopt sopt;
NET_LOCK_GIANT();
if ((error = fgetsock(td, uap->s, &so, NULL)) != 0)
goto done2;
if (uap->val) {
error = copyin(uap->avalsize, &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(&valsize, uap->avalsize, sizeof (valsize));
}
done1:
fputsock(so);
done2:
NET_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;
struct sockaddr * __restrict asa;
socklen_t * __restrict alen;
} */ *uap;
int compat;
{
struct socket *so;
struct sockaddr *sa;
socklen_t len;
int error;
NET_LOCK_GIANT();
if ((error = fgetsock(td, uap->fdes, &so, NULL)) != 0)
goto done2;
error = copyin(uap->alen, &len, sizeof (len));
if (error)
goto done1;
if (len < 0) {
error = EINVAL;
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, uap->asa, (u_int)len);
if (error == 0)
gotnothing:
error = copyout(&len, uap->alen, sizeof (len));
bad:
if (sa)
FREE(sa, M_SONAME);
done1:
fputsock(so);
done2:
NET_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;
struct sockaddr * __restrict asa;
socklen_t * __restrict alen;
} */ *uap;
int compat;
{
struct socket *so;
struct sockaddr *sa;
socklen_t len;
int error;
NET_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(uap->alen, &len, sizeof (len));
if (error)
goto done1;
if (len < 0) {
error = EINVAL;
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, uap->asa, (u_int)len);
if (error)
goto bad;
gotnothing:
error = copyout(&len, uap->alen, sizeof (len));
bad:
if (sa)
FREE(sa, M_SONAME);
done1:
fputsock(so);
done2:
NET_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);
if (len < offsetof(struct sockaddr, sa_data[0]))
return (EINVAL);
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);
}
/*
* Detach mapped page and release resources back to the system.
*/
void
sf_buf_mext(void *addr, void *args)
{
vm_page_t m;
m = sf_buf_page(args);
sf_buf_free(args);
vm_page_lock_queues();
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);
vm_page_unlock_queues();
}
/*
* 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)
{
return (do_sendfile(td, uap, 0));
}
#ifdef COMPAT_FREEBSD4
int
freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap)
{
struct sendfile_args args;
args.fd = uap->fd;
args.s = uap->s;
args.offset = uap->offset;
args.nbytes = uap->nbytes;
args.hdtr = uap->hdtr;
args.sbytes = uap->sbytes;
args.flags = uap->flags;
return (do_sendfile(td, &args, 1));
}
#endif /* COMPAT_FREEBSD4 */
static int
do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
{
struct vnode *vp;
struct vm_object *obj;
struct socket *so = NULL;
struct mbuf *m, *m_header = NULL;
struct sf_buf *sf;
struct vm_page *pg;
struct writev_args nuap;
struct sf_hdtr hdtr;
struct uio hdr_uio;
off_t off, xfsize, hdtr_size, sbytes = 0;
int error, s, headersize = 0, headersent = 0;
struct iovec *hdr_iov = NULL;
mtx_lock(&Giant);
hdtr_size = 0;
/*
* The descriptor must be a regular file and have a backing VM object.
*/
if ((error = fgetvp_read(td, uap->fd, &vp)) != 0)
goto done;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
if (vp->v_type != VREG || VOP_GETVOBJECT(vp, &obj) != 0) {
error = EINVAL;
VOP_UNLOCK(vp, 0, td);
goto done;
}
VOP_UNLOCK(vp, 0, td);
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;
}
#ifdef MAC
error = mac_check_socket_send(td->td_ucred, so);
if (error)
goto done;
#endif
/*
* 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.
*/
if (hdtr.headers != NULL) {
hdr_uio.uio_td = td;
hdr_uio.uio_rw = UIO_WRITE;
error = uiofromiov(hdtr.headers, hdtr.hdr_cnt,
&hdr_uio);
if (error)
goto done;
/* Cache hdr_iov, m_uiotombuf may change it. */
hdr_iov = hdr_uio.uio_iov;
if (hdr_uio.uio_resid > 0) {
m_header = m_uiotombuf(&hdr_uio, M_DONTWAIT, 0);
if (m_header == NULL)
goto done;
headersize = m_header->m_pkthdr.len;
if (compat)
sbytes += headersize;
}
}
}
/*
* 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);
VM_OBJECT_LOCK(obj);
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;
VM_OBJECT_UNLOCK(obj);
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) {
if (m_header != NULL) {
m = m_header;
m_header = NULL;
goto retry_space;
} else
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;
}
VM_OBJECT_LOCK(obj);
/*
* 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 | VM_ALLOC_WIRED);
if (pg == NULL) {
VM_OBJECT_UNLOCK(obj);
VM_WAIT;
VM_OBJECT_LOCK(obj);
goto retry_lookup;
}
vm_page_lock_queues();
vm_page_wakeup(pg);
} else {
vm_page_lock_queues();
if (vm_page_sleep_if_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)) {
VM_OBJECT_UNLOCK(obj);
} else if (uap->flags & SF_NODISKIO) {
error = EBUSY;
} else {
int bsize, resid;
/*
* Ensure that our page is still around when the I/O
* completes.
*/
vm_page_io_start(pg);
vm_page_unlock_queues();
VM_OBJECT_UNLOCK(obj);
/*
* Get the page from backing store.
*/
bsize = vp->v_mount->mnt_stat.f_iosize;
vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
/*
* XXXMAC: Because we don't have fp->f_cred here,
* we pass in NOCRED. This is probably wrong, but
* is consistent with our original implementation.
*/
error = vn_rdwr(UIO_READ, vp, NULL, MAXBSIZE,
trunc_page(off), UIO_NOCOPY, IO_NODELOCKED |
IO_VMIO | ((MAXBSIZE / bsize) << IO_SEQSHIFT),
td->td_ucred, NOCRED, &resid, td);
VOP_UNLOCK(vp, 0, td);
if (error)
VM_OBJECT_LOCK(obj);
vm_page_lock_queues();
vm_page_io_finish(pg);
mbstat.sf_iocnt++;
}
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);
}
vm_page_unlock_queues();
VM_OBJECT_UNLOCK(obj);
sbunlock(&so->so_snd);
goto done;
}
vm_page_unlock_queues();
/*
* Get a sendfile buf. We usually wait as long as necessary,
* but this wait can be interrupted.
*/
if ((sf = sf_buf_alloc(pg, PCATCH)) == NULL) {
mbstat.sf_allocfail++;
vm_page_lock_queues();
vm_page_unwire(pg, 0);
if (pg->wire_count == 0 && pg->object == NULL)
vm_page_free(pg);
vm_page_unlock_queues();
sbunlock(&so->so_snd);
error = EINTR;
goto done;
}
/*
* Get an mbuf header and set it up as having external storage.
*/
if (m_header)
MGET(m, M_TRYWAIT, MT_DATA);
else
MGETHDR(m, M_TRYWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
sf_buf_mext((void *)sf_buf_kva(sf), sf);
sbunlock(&so->so_snd);
goto done;
}
/*
* Setup external storage for mbuf.
*/
MEXTADD(m, sf_buf_kva(sf), PAGE_SIZE, sf_buf_mext, sf, M_RDONLY,
EXT_SFBUF);
m->m_data = (char *)sf_buf_kva(sf) + pgoff;
m->m_pkthdr.len = m->m_len = xfsize;
if (m_header) {
m_cat(m_header, m);
m = m_header;
m_header = NULL;
m_fixhdr(m);
}
/*
* 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;
}
headersent = 1;
}
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;
if (compat)
sbytes += td->td_retval[0];
else
hdtr_size += td->td_retval[0];
}
done:
if (headersent) {
if (!compat)
hdtr_size += headersize;
} else {
if (compat)
sbytes -= headersize;
}
/*
* 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) {
if (!compat)
sbytes += hdtr_size;
copyout(&sbytes, uap->sbytes, sizeof(off_t));
}
if (vp)
vrele(vp);
if (so)
fputsock(so);
if (hdr_iov)
FREE(hdr_iov, M_IOV);
if (m_header)
m_freem(m_header);
mtx_unlock(&Giant);
if (error == ERESTART)
error = EINTR;
return (error);
}
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