Add sosend_dgram(), a greatly reduced and simplified version of sosend()

intended for use solely with atomic datagram socket types, and relies
on the previous break-out of sosend_copyin().  Changes to allow UDP to
optionally use this instead of sosend() will be committed as a
follow-up.
This commit is contained in:
Robert Watson 2006-01-13 10:22:01 +00:00
parent 1f313773f3
commit b8ae1cd619
2 changed files with 158 additions and 2 deletions

View File

@ -716,7 +716,159 @@ sosend_copyin(struct uio *uio, struct mbuf **retmp, int atomic, long *space,
}
#define SBLOCKWAIT(f) (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
#define snderr(errno) { error = (errno); goto release; }
int
sosend_dgram(so, addr, uio, top, control, flags, td)
struct socket *so;
struct sockaddr *addr;
struct uio *uio;
struct mbuf *top;
struct mbuf *control;
int flags;
struct thread *td;
{
long space, resid;
int clen = 0, error, dontroute;
int atomic = sosendallatonce(so) || top;
KASSERT(so->so_type == SOCK_DGRAM, ("sodgram_send: !SOCK_DGRAM"));
KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
("sodgram_send: !PR_ATOMIC"));
if (uio != NULL)
resid = uio->uio_resid;
else
resid = top->m_pkthdr.len;
/*
* In theory resid should be unsigned.
* However, space must be signed, as it might be less than 0
* if we over-committed, and we must use a signed comparison
* of space and resid. On the other hand, a negative resid
* causes us to loop sending 0-length segments to the protocol.
*
* Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
* type sockets since that's an error.
*/
if (resid < 0) {
error = EINVAL;
goto out;
}
dontroute =
(flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
if (td != NULL)
td->td_proc->p_stats->p_ru.ru_msgsnd++;
if (control != NULL)
clen = control->m_len;
SOCKBUF_LOCK(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EPIPE;
goto out;
}
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
if ((so->so_state & SS_ISCONNECTED) == 0) {
/*
* `sendto' and `sendmsg' is allowed on a connection-
* based socket if it supports implied connect.
* Return ENOTCONN if not connected and no address is
* supplied.
*/
if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
if ((so->so_state & SS_ISCONFIRMING) == 0 &&
!(resid == 0 && clen != 0)) {
SOCKBUF_UNLOCK(&so->so_snd);
error = ENOTCONN;
goto out;
}
} else if (addr == NULL) {
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
error = ENOTCONN;
else
error = EDESTADDRREQ;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
}
/*
* Do we need MSG_OOB support in SOCK_DGRAM? Signs here may be a
* problem and need fixing.
*/
space = sbspace(&so->so_snd);
if (flags & MSG_OOB)
space += 1024;
space -= clen;
if (resid > space) {
error = EMSGSIZE;
goto out;
}
SOCKBUF_UNLOCK(&so->so_snd);
if (uio == NULL) {
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
} else {
error = sosend_copyin(uio, &top, atomic, &space, flags);
if (error)
goto out;
resid = uio->uio_resid;
}
KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
/*
* XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
* than with.
*/
if (dontroute) {
SOCK_LOCK(so);
so->so_options |= SO_DONTROUTE;
SOCK_UNLOCK(so);
}
/*
* XXX all the SBS_CANTSENDMORE checks previously
* done could be out of date. We could have recieved
* a reset packet in an interrupt or maybe we slept
* while doing page faults in uiomove() etc. We could
* probably recheck again inside the locking protection
* here, but there are probably other places that this
* also happens. We must rethink this.
*/
error = (*so->so_proto->pr_usrreqs->pru_send)(so,
(flags & MSG_OOB) ? PRUS_OOB :
/*
* If the user set MSG_EOF, the protocol
* understands this flag and nothing left to
* send then use PRU_SEND_EOF instead of PRU_SEND.
*/
((flags & MSG_EOF) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) &&
(resid <= 0)) ?
PRUS_EOF :
/* If there is more to send set PRUS_MORETOCOME */
(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
top, addr, control, td);
if (dontroute) {
SOCK_LOCK(so);
so->so_options &= ~SO_DONTROUTE;
SOCK_UNLOCK(so);
}
clen = 0;
control = NULL;
top = NULL;
out:
if (top != NULL)
m_freem(top);
if (control != NULL)
m_freem(control);
return (error);
}
/*
* Send on a socket.
@ -735,7 +887,7 @@ sosend_copyin(struct uio *uio, struct mbuf **retmp, int atomic, long *space,
* must check for short counts if EINTR/ERESTART are returned.
* Data and control buffers are freed on return.
*/
#define snderr(errno) { error = (errno); goto release; }
int
sosend(so, addr, uio, top, control, flags, td)
struct socket *so;
@ -897,6 +1049,7 @@ sosend(so, addr, uio, top, control, flags, td)
m_freem(control);
return (error);
}
#undef snderr
/*
* The part of soreceive() that implements reading non-inline out-of-band

View File

@ -533,6 +533,9 @@ void sorflush(struct socket *so);
int sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags,
struct thread *td);
int sosend_dgram(struct socket *so, struct sockaddr *addr,
struct uio *uio, struct mbuf *top, struct mbuf *control,
int flags, struct thread *td);
int sosetopt(struct socket *so, struct sockopt *sopt);
int soshutdown(struct socket *so, int how);
void sotoxsocket(struct socket *so, struct xsocket *xso);