about summary refs log tree commit diff
path: root/sysdeps/mach/hurd/sendmsg.c
blob: e375e242ef1ae148c0dbb9a2f6a416a5257233c7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/* Copyright (C) 2001-2015 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 <http://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>

/* 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 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;
  mach_msg_type_number_t amount;
  int dealloc = 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;
	}
    }

  if (addr)
    {
      if (addr->sun_family == AF_LOCAL)
	{
	  /* 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 (addr->sun_path, 0, 0);
	  if (file == MACH_PORT_NULL)
	    {
	      if (dealloc)
		__vm_deallocate (__mach_task_self (), data.addr, len);
	      return -1;
	    }
	  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)
	    {
	      if (dealloc)
		__vm_deallocate (__mach_task_self (), data.addr, len);
	      return __hurd_fail (err);
	    }
	}
      else
	err = EIEIO;
    }

  err = HURD_DPORT_USE (fd,
			({
			  if (err)
			    err = __socket_create_address (port,
							   addr->sun_family,
							   (char *) addr,
							   addr_len,
							   &aport);
			  if (! err)
			    {
			      /* Send the data.  */
			      err = __socket_send (port, aport,
						   flags, data.ptr, len,
						   NULL,
						   MACH_MSG_TYPE_COPY_SEND, 0,
						   message->msg_control,
						   message->msg_controllen,
						   &amount);
			      __mach_port_deallocate (__mach_task_self (),
						      aport);
			    }
			  err;
			}));

  if (dealloc)
    __vm_deallocate (__mach_task_self (), data.addr, len);

  return err ? __hurd_sockfail (fd, flags, err) : amount;
}

weak_alias (__libc_sendmsg, sendmsg)
weak_alias (__libc_sendmsg, __sendmsg)