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/* Copyright (C) 2001-2023 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 <sys/un.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <hurd/ifsock.h>
#include <hurd/socket.h>
#include <sysdep-cancel.h>
#include "hurd/hurdsocket.h"
/* Send a message described MESSAGE on socket FD.
Returns the number of bytes sent, or -1 for errors. */
ssize_t
__libc_sendmsg (int fd, const struct msghdr *message, int flags)
{
error_t err = 0;
struct cmsghdr *cmsg;
mach_port_t *ports = NULL;
mach_msg_type_number_t nports = 0;
int *fds, nfds;
struct sockaddr_un *addr = message->msg_name;
socklen_t addr_len = message->msg_namelen;
addr_port_t aport = MACH_PORT_NULL;
union
{
char *ptr;
vm_address_t addr;
} data = { .ptr = NULL };
char data_buf[2048];
mach_msg_type_number_t len;
vm_size_t amount;
int dealloc = 0;
int socketrpc = 0;
int i;
/* Find the total number of bytes to be written. */
len = 0;
for (i = 0; i < message->msg_iovlen; i++)
{
if (message->msg_iov[i].iov_len > 0)
{
/* As an optimization, if we only have a single non-empty
iovec, we set DATA and LEN from it. */
if (len == 0)
data.ptr = message->msg_iov[i].iov_base;
else
data.ptr = NULL;
len += message->msg_iov[i].iov_len;
}
}
if (data.ptr == NULL)
{
size_t to_copy;
char *buf;
/* Allocate a temporary buffer to hold the data. For small
amounts of data, we allocate a buffer on the stack. Larger
amounts of data are stored in a page-aligned buffer. The
limit of 2048 bytes is inspired by the MiG stubs. */
if (len > 2048)
{
err = __vm_allocate (__mach_task_self (), &data.addr, len, 1);
if (err)
{
__set_errno (err);
return -1;
}
dealloc = 1;
}
else
data.ptr = data_buf;
/* Copy the data into DATA. */
to_copy = len;
buf = data.ptr;
for (i = 0; i < len; i++)
{
#define min(a, b) ((a) > (b) ? (b) : (a))
size_t copy = min (message->msg_iov[i].iov_len, to_copy);
buf = __mempcpy (buf, message->msg_iov[i].iov_base, copy);
to_copy -= copy;
if (to_copy == 0)
break;
}
}
/* Allocate enough room for ports. */
cmsg = CMSG_FIRSTHDR (message);
for (; cmsg; cmsg = CMSG_NXTHDR ((struct msghdr *) message, cmsg))
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
nports += (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr)))
/ sizeof (int);
if (nports)
ports = __alloca (nports * sizeof (mach_port_t));
nports = 0;
for (cmsg = CMSG_FIRSTHDR (message);
cmsg;
cmsg = CMSG_NXTHDR ((struct msghdr *) message, cmsg))
{
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
{
/* SCM_RIGHTS support: send FDs. */
fds = (int *) CMSG_DATA (cmsg);
nfds = (cmsg->cmsg_len - CMSG_ALIGN (sizeof (struct cmsghdr)))
/ sizeof (int);
for (i = 0; i < nfds; i++)
{
err = HURD_DPORT_USE
(fds[i],
({
err = __io_restrict_auth (port, &ports[nports],
0, 0, 0, 0);
if (! err)
nports++;
/* We pass the flags in the control data. */
fds[i] = descriptor->flags;
err;
}));
if (err)
goto out;
}
}
}
if (addr)
{
if (addr->sun_family == AF_LOCAL)
{
char *name = _hurd_sun_path_dupa (addr, addr_len);
/* For the local domain, we must look up the name as a file
and talk to it with the ifsock protocol. */
file_t file = __file_name_lookup (name, 0, 0);
if (file == MACH_PORT_NULL)
{
err = errno;
goto out;
}
err = __ifsock_getsockaddr (file, &aport);
__mach_port_deallocate (__mach_task_self (), file);
if (err == MIG_BAD_ID || err == EOPNOTSUPP)
/* The file did not grok the ifsock protocol. */
err = ENOTSOCK;
if (err)
goto out;
}
else
err = EIEIO;
}
err = HURD_DPORT_USE_CANCEL (fd,
({
if (err)
err = __socket_create_address (port,
addr->sun_family,
(char *) addr,
addr_len,
&aport);
if (! err)
{
/* Send the data. */
int cancel_oldtype = LIBC_CANCEL_ASYNC();
err = __socket_send (port, aport,
flags, data.ptr, len,
ports,
MACH_MSG_TYPE_COPY_SEND,
nports,
message->msg_control,
message->msg_controllen,
&amount);
LIBC_CANCEL_RESET (cancel_oldtype);
__mach_port_deallocate (__mach_task_self (),
aport);
}
err;
}));
socketrpc = 1;
out:
for (i = 0; i < nports; i++)
__mach_port_deallocate (__mach_task_self (), ports[i]);
if (dealloc)
__vm_deallocate (__mach_task_self (), data.addr, len);
if (socketrpc)
return err ? __hurd_sockfail (fd, flags, err) : amount;
else
return __hurd_fail (err);
}
weak_alias (__libc_sendmsg, sendmsg)
weak_alias (__libc_sendmsg, __sendmsg)
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