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freebsd-nq/sys/kern/uipc_syscalls.c
Bosko Milekic 4bde2ac539 Fix is a similar race condition as existed in the mbuf code. When we go 
into an interruptable sleep and we increment a sleep count, we make sure
that we are the thread that will decrement the count when we wakeup.
Otherwise, what happens is that if we get interrupted (signal) and we
have to wake up, but before we get our mutex, some thread that wants
to wake us up detects that the count is non-zero and so enters wakeup_one(),
but there's nothing on the sleep queue and so we don't get woken up. The
thread will still decrement the sleep count, which is bad because we will
also decrement it again later (as we got interrupted) and are already off
the sleep queue.
2001-03-08 19:21:45 +00:00

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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.
* 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/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/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>
#include <sys/lock.h>
#include <sys/mount.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 proc *p, int s, struct msghdr *mp, int flags));
static int recvit __P((struct proc *p, int s, struct msghdr *mp,
caddr_t namelenp));
static int accept1 __P((struct proc *p, struct accept_args *uap, int compat));
static int getsockname1 __P((struct proc *p, struct getsockname_args *uap,
int compat));
static int getpeername1 __P((struct proc *p, 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;
int
socket(p, uap)
struct proc *p;
register struct socket_args /* {
int domain;
int type;
int protocol;
} */ *uap;
{
struct filedesc *fdp = p->p_fd;
struct socket *so;
struct file *fp;
int fd, error;
error = falloc(p, &fp, &fd);
if (error)
return (error);
fhold(fp);
error = socreate(uap->domain, &so, uap->type, uap->protocol, p);
if (error) {
if (fdp->fd_ofiles[fd] == fp) {
fdp->fd_ofiles[fd] = NULL;
fdrop(fp, p);
}
} else {
fp->f_data = (caddr_t)so;
fp->f_flag = FREAD|FWRITE;
fp->f_ops = &socketops;
fp->f_type = DTYPE_SOCKET;
p->p_retval[0] = fd;
}
fdrop(fp, p);
return (error);
}
/* ARGSUSED */
int
bind(p, uap)
struct proc *p;
register struct bind_args /* {
int s;
caddr_t name;
int namelen;
} */ *uap;
{
struct file *fp;
struct sockaddr *sa;
int error;
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
return (error);
error = getsockaddr(&sa, uap->name, uap->namelen);
if (error) {
fdrop(fp, p);
return (error);
}
error = sobind((struct socket *)fp->f_data, sa, p);
FREE(sa, M_SONAME);
fdrop(fp, p);
return (error);
}
/* ARGSUSED */
int
listen(p, uap)
struct proc *p;
register struct listen_args /* {
int s;
int backlog;
} */ *uap;
{
struct file *fp;
int error;
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
return (error);
error = solisten((struct socket *)fp->f_data, uap->backlog, p);
fdrop(fp, p);
return(error);
}
static int
accept1(p, uap, compat)
struct proc *p;
register struct accept_args /* {
int s;
caddr_t name;
int *anamelen;
} */ *uap;
int compat;
{
struct filedesc *fdp = p->p_fd;
struct file *lfp = NULL;
struct file *nfp = NULL;
struct sockaddr *sa;
int namelen, error, s;
struct socket *head, *so;
int fd;
short fflag; /* type must match fp->f_flag */
if (uap->name) {
error = copyin((caddr_t)uap->anamelen, (caddr_t)&namelen,
sizeof (namelen));
if(error)
return (error);
}
error = holdsock(fdp, uap->s, &lfp);
if (error)
return (error);
s = splnet();
head = (struct socket *)lfp->f_data;
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--;
fflag = lfp->f_flag;
error = falloc(p, &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);
p->p_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);
nfp->f_data = (caddr_t)so;
nfp->f_flag = fflag;
nfp->f_ops = &socketops;
nfp->f_type = DTYPE_SOCKET;
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) {
if (fdp->fd_ofiles[fd] == nfp) {
fdp->fd_ofiles[fd] = NULL;
fdrop(nfp, p);
}
}
splx(s);
/*
* Release explicitly held references before returning.
*/
done:
if (nfp != NULL)
fdrop(nfp, p);
fdrop(lfp, p);
return (error);
}
int
accept(p, uap)
struct proc *p;
struct accept_args *uap;
{
return (accept1(p, uap, 0));
}
#ifdef COMPAT_OLDSOCK
int
oaccept(p, uap)
struct proc *p;
struct accept_args *uap;
{
return (accept1(p, uap, 1));
}
#endif /* COMPAT_OLDSOCK */
/* ARGSUSED */
int
connect(p, uap)
struct proc *p;
register struct connect_args /* {
int s;
caddr_t name;
int namelen;
} */ *uap;
{
struct file *fp;
register struct socket *so;
struct sockaddr *sa;
int error, s;
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
return (error);
so = (struct socket *)fp->f_data;
if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
error = EALREADY;
goto done;
}
error = getsockaddr(&sa, uap->name, uap->namelen);
if (error)
goto done;
error = soconnect(so, sa, p);
if (error)
goto bad;
if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
FREE(sa, M_SONAME);
error = EINPROGRESS;
goto done;
}
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;
done:
fdrop(fp, p);
return (error);
}
int
socketpair(p, uap)
struct proc *p;
register struct socketpair_args /* {
int domain;
int type;
int protocol;
int *rsv;
} */ *uap;
{
register struct filedesc *fdp = p->p_fd;
struct file *fp1, *fp2;
struct socket *so1, *so2;
int fd, error, sv[2];
error = socreate(uap->domain, &so1, uap->type, uap->protocol, p);
if (error)
return (error);
error = socreate(uap->domain, &so2, uap->type, uap->protocol, p);
if (error)
goto free1;
error = falloc(p, &fp1, &fd);
if (error)
goto free2;
fhold(fp1);
sv[0] = fd;
fp1->f_data = (caddr_t)so1;
error = falloc(p, &fp2, &fd);
if (error)
goto free3;
fhold(fp2);
fp2->f_data = (caddr_t)so2;
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;
}
fp1->f_flag = fp2->f_flag = FREAD|FWRITE;
fp1->f_ops = fp2->f_ops = &socketops;
fp1->f_type = fp2->f_type = DTYPE_SOCKET;
error = copyout((caddr_t)sv, (caddr_t)uap->rsv, 2 * sizeof (int));
fdrop(fp1, p);
fdrop(fp2, p);
return (error);
free4:
if (fdp->fd_ofiles[sv[1]] == fp2) {
fdp->fd_ofiles[sv[1]] = NULL;
fdrop(fp2, p);
}
fdrop(fp2, p);
free3:
if (fdp->fd_ofiles[sv[0]] == fp1) {
fdp->fd_ofiles[sv[0]] = NULL;
fdrop(fp1, p);
}
fdrop(fp1, p);
free2:
(void)soclose(so2);
free1:
(void)soclose(so1);
return (error);
}
static int
sendit(p, s, mp, flags)
register struct proc *p;
int s;
register struct msghdr *mp;
int flags;
{
struct file *fp;
struct uio auio;
register struct iovec *iov;
register int i;
struct mbuf *control;
struct sockaddr *to;
int len, error;
struct socket *so;
#ifdef KTRACE
struct iovec *ktriov = NULL;
struct uio ktruio;
#endif
error = holdsock(p->p_fd, s, &fp);
if (error)
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_procp = p;
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) {
fdrop(fp, p);
return (EINVAL);
}
}
if (mp->msg_name) {
error = getsockaddr(&to, mp->msg_name, mp->msg_namelen);
if (error) {
fdrop(fp, p);
return (error);
}
} else {
to = 0;
}
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(p, 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;
so = (struct socket *)fp->f_data;
error = so->so_proto->pr_usrreqs->pru_sosend(so, to, &auio, 0, control,
flags, p);
if (error) {
if (auio.uio_resid != len && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE) {
PROC_LOCK(p);
psignal(p, SIGPIPE);
PROC_UNLOCK(p);
}
}
if (error == 0)
p->p_retval[0] = len - auio.uio_resid;
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0) {
ktruio.uio_iov = ktriov;
ktruio.uio_resid = p->p_retval[0];
ktrgenio(p->p_tracep, s, UIO_WRITE, &ktruio, error);
}
FREE(ktriov, M_TEMP);
}
#endif
bad:
fdrop(fp, p);
if (to)
FREE(to, M_SONAME);
return (error);
}
int
sendto(p, uap)
struct proc *p;
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;
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;
return (sendit(p, uap->s, &msg, uap->flags));
}
#ifdef COMPAT_OLDSOCK
int
osend(p, uap)
struct proc *p;
register struct osend_args /* {
int s;
caddr_t buf;
int len;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
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;
return (sendit(p, uap->s, &msg, uap->flags));
}
int
osendmsg(p, uap)
struct proc *p;
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, (caddr_t)&msg, sizeof (struct omsghdr));
if (error)
return (error);
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
return (EMSGSIZE);
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(p, uap->s, &msg, uap->flags);
done:
if (iov != aiov)
FREE(iov, M_IOV);
return (error);
}
#endif
int
sendmsg(p, uap)
struct proc *p;
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, (caddr_t)&msg, sizeof (msg));
if (error)
return (error);
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
return (EMSGSIZE);
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(p, uap->s, &msg, uap->flags);
done:
if (iov != aiov)
FREE(iov, M_IOV);
return (error);
}
static int
recvit(p, s, mp, namelenp)
register struct proc *p;
int s;
register struct msghdr *mp;
caddr_t namelenp;
{
struct file *fp;
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
error = holdsock(p->p_fd, s, &fp);
if (error)
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_procp = p;
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) {
fdrop(fp, p);
return (EINVAL);
}
}
#ifdef KTRACE
if (KTRPOINT(p, 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;
so = (struct socket *)fp->f_data;
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(p->p_tracep, s, UIO_READ, &ktruio, error);
}
FREE(ktriov, M_TEMP);
}
#endif
if (error)
goto out;
p->p_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:
fdrop(fp, p);
if (fromsa)
FREE(fromsa, M_SONAME);
if (control)
m_freem(control);
return (error);
}
int
recvfrom(p, uap)
struct proc *p;
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;
if (uap->fromlenaddr) {
error = copyin((caddr_t)uap->fromlenaddr,
(caddr_t)&msg.msg_namelen, sizeof (msg.msg_namelen));
if (error)
return (error);
} 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;
return (recvit(p, uap->s, &msg, (caddr_t)uap->fromlenaddr));
}
#ifdef COMPAT_OLDSOCK
int
orecvfrom(p, uap)
struct proc *p;
struct recvfrom_args *uap;
{
uap->flags |= MSG_COMPAT;
return (recvfrom(p, uap));
}
#endif
#ifdef COMPAT_OLDSOCK
int
orecv(p, uap)
struct proc *p;
register struct orecv_args /* {
int s;
caddr_t buf;
int len;
int flags;
} */ *uap;
{
struct msghdr msg;
struct iovec aiov;
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;
return (recvit(p, uap->s, &msg, (caddr_t)0));
}
/*
* 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.
*/
int
orecvmsg(p, uap)
struct proc *p;
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);
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
return (EMSGSIZE);
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(p, 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);
return (error);
}
#endif
int
recvmsg(p, uap)
struct proc *p;
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((caddr_t)uap->msg, (caddr_t)&msg, sizeof (msg));
if (error)
return (error);
if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
return (EMSGSIZE);
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(p, 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);
return (error);
}
/* ARGSUSED */
int
shutdown(p, uap)
struct proc *p;
register struct shutdown_args /* {
int s;
int how;
} */ *uap;
{
struct file *fp;
int error;
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
return (error);
error = soshutdown((struct socket *)fp->f_data, uap->how);
fdrop(fp, p);
return(error);
}
/* ARGSUSED */
int
setsockopt(p, uap)
struct proc *p;
register struct setsockopt_args /* {
int s;
int level;
int name;
caddr_t val;
int valsize;
} */ *uap;
{
struct file *fp;
struct sockopt sopt;
int error;
if (uap->val == 0 && uap->valsize != 0)
return (EFAULT);
if (uap->valsize < 0)
return (EINVAL);
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
return (error);
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_p = p;
error = sosetopt((struct socket *)fp->f_data, &sopt);
fdrop(fp, p);
return(error);
}
/* ARGSUSED */
int
getsockopt(p, uap)
struct proc *p;
register struct getsockopt_args /* {
int s;
int level;
int name;
caddr_t val;
int *avalsize;
} */ *uap;
{
int valsize, error;
struct file *fp;
struct sockopt sopt;
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
return (error);
if (uap->val) {
error = copyin((caddr_t)uap->avalsize, (caddr_t)&valsize,
sizeof (valsize));
if (error) {
fdrop(fp, p);
return (error);
}
if (valsize < 0) {
fdrop(fp, p);
return (EINVAL);
}
} 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_p = p;
error = sogetopt((struct socket *)fp->f_data, &sopt);
if (error == 0) {
valsize = sopt.sopt_valsize;
error = copyout((caddr_t)&valsize,
(caddr_t)uap->avalsize, sizeof (valsize));
}
fdrop(fp, p);
return (error);
}
/*
* Get socket name.
*/
/* ARGSUSED */
static int
getsockname1(p, uap, compat)
struct proc *p;
register struct getsockname_args /* {
int fdes;
caddr_t asa;
int *alen;
} */ *uap;
int compat;
{
struct file *fp;
register struct socket *so;
struct sockaddr *sa;
int len, error;
error = holdsock(p->p_fd, uap->fdes, &fp);
if (error)
return (error);
error = copyin((caddr_t)uap->alen, (caddr_t)&len, sizeof (len));
if (error) {
fdrop(fp, p);
return (error);
}
so = (struct socket *)fp->f_data;
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);
fdrop(fp, p);
return (error);
}
int
getsockname(p, uap)
struct proc *p;
struct getsockname_args *uap;
{
return (getsockname1(p, uap, 0));
}
#ifdef COMPAT_OLDSOCK
int
ogetsockname(p, uap)
struct proc *p;
struct getsockname_args *uap;
{
return (getsockname1(p, uap, 1));
}
#endif /* COMPAT_OLDSOCK */
/*
* Get name of peer for connected socket.
*/
/* ARGSUSED */
static int
getpeername1(p, uap, compat)
struct proc *p;
register struct getpeername_args /* {
int fdes;
caddr_t asa;
int *alen;
} */ *uap;
int compat;
{
struct file *fp;
register struct socket *so;
struct sockaddr *sa;
int len, error;
error = holdsock(p->p_fd, uap->fdes, &fp);
if (error)
return (error);
so = (struct socket *)fp->f_data;
if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
fdrop(fp, p);
return (ENOTCONN);
}
error = copyin((caddr_t)uap->alen, (caddr_t)&len, sizeof (len));
if (error) {
fdrop(fp, p);
return (error);
}
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);
fdrop(fp, p);
return (error);
}
int
getpeername(p, uap)
struct proc *p;
struct getpeername_args *uap;
{
return (getpeername1(p, uap, 0));
}
#ifdef COMPAT_OLDSOCK
int
ogetpeername(p, uap)
struct proc *p;
struct ogetpeername_args *uap;
{
/* XXX uap should have type `getpeername_args *' to begin with. */
return (getpeername1(p, (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;
}
/*
* holdsock() - load the struct file pointer associated
* with a socket into *fpp. If an error occurs, non-zero
* will be returned and *fpp will be set to NULL.
*/
int
holdsock(fdp, fdes, fpp)
struct filedesc *fdp;
int fdes;
struct file **fpp;
{
register struct file *fp = NULL;
int error = 0;
if ((unsigned)fdes >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[fdes]) == NULL) {
error = EBADF;
} else if (fp->f_type != DTYPE_SOCKET) {
error = ENOTSOCK;
fp = NULL;
} else {
fhold(fp);
}
*fpp = fp;
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;
}
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;
int s;
sf = dtosf(addr);
pmap_qremove((vm_offset_t)addr, 1);
m = sf->m;
s = splvm();
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);
splx(s);
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)
* 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 proc *p, struct sendfile_args *uap)
{
struct file *fp;
struct filedesc *fdp = p->p_fd;
struct vnode *vp;
struct vm_object *obj;
struct socket *so;
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 = 0, s;
vp = NULL;
/*
* Do argument checking. Must be a regular file in, stream
* type and connected socket out, positive offset.
*/
fp = holdfp(fdp, uap->fd, FREAD);
if (fp == NULL) {
error = EBADF;
goto done;
}
if (fp->f_type != DTYPE_VNODE) {
error = EINVAL;
goto done;
}
vp = (struct vnode *)fp->f_data;
vref(vp);
if (vp->v_type != VREG || VOP_GETVOBJECT(vp, &obj) != 0) {
error = EINVAL;
goto done;
}
fdrop(fp, p);
error = holdsock(p->p_fd, uap->s, &fp);
if (error)
goto done;
so = (struct socket *)fp->f_data;
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(p, &nuap);
if (error)
goto done;
sbytes += p->p_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_procp = p;
vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, p);
error = VOP_READ(vp, &auio, IO_VMIO | ((MAXBSIZE / bsize) << 16),
p->p_ucred);
VOP_UNLOCK(vp, 0, p);
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) {
s = splvm();
vm_page_unwire(pg, 0);
if (pg->wire_count == 0 && pg->object == NULL)
vm_page_free(pg);
splx(s);
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, p);
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(p, &nuap);
if (error)
goto done;
sbytes += p->p_retval[0];
}
done:
if (uap->sbytes != NULL) {
copyout(&sbytes, uap->sbytes, sizeof(off_t));
}
if (vp)
vrele(vp);
if (fp)
fdrop(fp, p);
return (error);
}
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