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/* Copyright (C) 2001-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <hurd/socket.h>
#include <sysdep-cancel.h>
/* Receive a message as described by MESSAGE from socket FD.
Returns the number of bytes read or -1 for errors. */
ssize_t
__libc_recvmsg (int fd, struct msghdr *message, int flags)
{
error_t err;
addr_port_t aport;
char *data = NULL;
mach_msg_type_number_t len = 0;
mach_port_t *ports, *newports = NULL;
mach_msg_type_number_t nports = 0;
struct cmsghdr *cmsg;
char *cdata = NULL;
mach_msg_type_number_t clen = 0;
size_t amount;
char *buf;
int nfds, *opened_fds = NULL;
int i, ii, j;
int newfds;
int cancel_oldtype;
error_t reauthenticate (mach_port_t port, mach_port_t *result)
{
error_t err;
mach_port_t ref;
ref = __mach_reply_port ();
int cancel_oldtype;
cancel_oldtype = LIBC_CANCEL_ASYNC();
do
err = __io_reauthenticate (port, ref, MACH_MSG_TYPE_MAKE_SEND);
while (err == EINTR);
if (!err)
do
err = __USEPORT_CANCEL (AUTH, __auth_user_authenticate (port,
ref, MACH_MSG_TYPE_MAKE_SEND,
result));
while (err == EINTR);
LIBC_CANCEL_RESET (cancel_oldtype);
__mach_port_destroy (__mach_task_self (), ref);
return err;
}
/* Find the total number of bytes to be read. */
amount = 0;
for (i = 0; i < message->msg_iovlen; i++)
{
amount += message->msg_iov[i].iov_len;
/* As an optimization, we set the initial values of DATA and LEN
from the first non-empty iovec. This kicks-in in the case
where the whole packet fits into that iovec buffer. */
if (data == NULL && message->msg_iov[i].iov_len > 0)
{
data = message->msg_iov[i].iov_base;
len = message->msg_iov[i].iov_len;
}
}
buf = data;
cancel_oldtype = LIBC_CANCEL_ASYNC();
err = HURD_DPORT_USE_CANCEL (fd, __socket_recv (port, &aport,
flags, &data, &len,
&ports, &nports,
&cdata, &clen,
&message->msg_flags, amount));
LIBC_CANCEL_RESET (cancel_oldtype);
if (err)
return __hurd_sockfail (fd, flags, err);
if (message->msg_name != NULL && aport != MACH_PORT_NULL)
{
char *buf = message->msg_name;
mach_msg_type_number_t buflen = message->msg_namelen;
int type;
cancel_oldtype = LIBC_CANCEL_ASYNC();
err = __socket_whatis_address (aport, &type, &buf, &buflen);
LIBC_CANCEL_RESET (cancel_oldtype);
if (err == EOPNOTSUPP)
/* If the protocol server can't tell us the address, just return a
zero-length one. */
{
buf = message->msg_name;
buflen = 0;
err = 0;
}
if (err)
{
__mach_port_deallocate (__mach_task_self (), aport);
return __hurd_sockfail (fd, flags, err);
}
if (message->msg_namelen > buflen)
message->msg_namelen = buflen;
if (buf != message->msg_name)
{
memcpy (message->msg_name, buf, message->msg_namelen);
__vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);
}
if (buflen > 0)
((struct sockaddr *) message->msg_name)->sa_family = type;
}
else if (message->msg_name != NULL)
message->msg_namelen = 0;
__mach_port_deallocate (__mach_task_self (), aport);
if (buf == data)
buf += len;
else
{
/* Copy the data into MSG. */
if (len > amount)
message->msg_flags |= MSG_TRUNC;
else
amount = len;
buf = data;
for (i = 0; i < message->msg_iovlen; i++)
{
#define min(a, b) ((a) > (b) ? (b) : (a))
size_t copy = min (message->msg_iov[i].iov_len, amount);
memcpy (message->msg_iov[i].iov_base, buf, copy);
buf += copy;
amount -= copy;
if (len == 0)
break;
}
__vm_deallocate (__mach_task_self (), (vm_address_t) data, len);
}
/* Copy the control message into MSG. */
if (clen > message->msg_controllen)
message->msg_flags |= MSG_CTRUNC;
else
message->msg_controllen = clen;
memcpy (message->msg_control, cdata, message->msg_controllen);
if (nports > 0)
{
newports = __alloca (nports * sizeof (mach_port_t));
opened_fds = __alloca (nports * sizeof (int));
}
/* This counts how many ports we processed completely. */
i = 0;
/* This counts how many new fds we create. */
newfds = 0;
for (cmsg = CMSG_FIRSTHDR (message);
cmsg;
cmsg = CMSG_NXTHDR (message, cmsg))
{
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
{
/* SCM_RIGHTS support. */
/* The fd's flags are passed in the control data. */
int *fds = (int *) CMSG_DATA (cmsg);
nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr)))
/ sizeof (int);
for (j = 0; j < nfds; j++)
{
err = reauthenticate (ports[i], &newports[newfds]);
if (err)
goto cleanup;
fds[j] = opened_fds[newfds] = _hurd_intern_fd (newports[newfds],
fds[j], 0);
if (fds[j] == -1)
{
err = errno;
__mach_port_deallocate (__mach_task_self (), newports[newfds]);
goto cleanup;
}
i++;
newfds++;
}
}
}
for (i = 0; i < nports; i++)
__mach_port_deallocate (mach_task_self (), ports[i]);
__vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);
return (buf - data);
cleanup:
/* Clean up all the file descriptors from port 0 to i-1. */
if (nports > 0)
{
ii = 0;
newfds = 0;
for (cmsg = CMSG_FIRSTHDR (message);
cmsg;
cmsg = CMSG_NXTHDR (message, cmsg))
{
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
{
nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr)))
/ sizeof (int);
for (j = 0; j < nfds && ii < i; j++, ii++, newfds++)
{
_hurd_fd_close (_hurd_fd_get (opened_fds[newfds]));
__mach_port_deallocate (__mach_task_self (), newports[newfds]);
__mach_port_deallocate (__mach_task_self (), ports[ii]);
}
}
}
}
__vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);
return __hurd_fail (err);
}
weak_alias (__libc_recvmsg, recvmsg)
weak_alias (__libc_recvmsg, __recvmsg)
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