1 /* Copyright (C) 1994-2021 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <errno.h>
19 #include <string.h>
20 #include <sys/socket.h>
21 #include <hurd.h>
22 #include <hurd/fd.h>
23 #include <hurd/socket.h>
24 #include <sysdep-cancel.h>
25 
26 /* Read N bytes into BUF through socket FD.
27    If ADDR is not NULL, fill in *ADDR_LEN bytes of it with tha address of
28    the sender, and store the actual size of the address in *ADDR_LEN.
29    Returns the number of bytes read or -1 for errors.  */
30 ssize_t
__recvfrom(int fd,void * buf,size_t n,int flags,__SOCKADDR_ARG addrarg,socklen_t * addr_len)31 __recvfrom (int fd, void *buf, size_t n, int flags, __SOCKADDR_ARG addrarg,
32 	    socklen_t *addr_len)
33 {
34   error_t err;
35   mach_port_t addrport;
36   char *bufp = buf;
37   mach_msg_type_number_t nread = n;
38   mach_port_t *ports;
39   mach_msg_type_number_t nports = 0;
40   char *cdata = NULL;
41   mach_msg_type_number_t clen = 0;
42   struct sockaddr *addr = addrarg.__sockaddr__;
43   int cancel_oldtype;
44 
45   cancel_oldtype = LIBC_CANCEL_ASYNC();
46   err = HURD_DPORT_USE_CANCEL (fd, __socket_recv (port, &addrport,
47 						  flags, &bufp, &nread,
48 						  &ports, &nports,
49 						  &cdata, &clen,
50 						  &flags,
51 						  n));
52   LIBC_CANCEL_RESET (cancel_oldtype);
53 
54   if (err)
55     return __hurd_sockfail (fd, flags, err);
56 
57   /* Get address data for the returned address port if requested.  */
58   if (addr != NULL && addrport != MACH_PORT_NULL)
59     {
60       char *buf = (char *) addr;
61       mach_msg_type_number_t buflen = *addr_len;
62       int type;
63 
64       cancel_oldtype = LIBC_CANCEL_ASYNC();
65       err = __socket_whatis_address (addrport, &type, &buf, &buflen);
66       LIBC_CANCEL_RESET (cancel_oldtype);
67       if (err == EOPNOTSUPP)
68 	/* If the protocol server can't tell us the address, just return a
69 	   zero-length one.  */
70 	{
71 	  buf = (char *)addr;
72 	  buflen = 0;
73 	  err = 0;
74 	}
75 
76       if (err)
77 	{
78 	  __mach_port_deallocate (__mach_task_self (), addrport);
79 	  return __hurd_sockfail (fd, flags, err);
80 	}
81 
82       if (*addr_len > buflen)
83 	*addr_len = buflen;
84 
85       if (buf != (char *) addr)
86 	{
87 	  memcpy (addr, buf, *addr_len);
88 	  __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);
89 	}
90 
91       if (buflen > 0)
92 	addr->sa_family = type;
93     }
94   else if (addr_len != NULL)
95     *addr_len = 0;
96 
97   __mach_port_deallocate (__mach_task_self (), addrport);
98 
99   /* Toss control data; we don't care.  */
100   __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);
101 
102   if (bufp != buf)
103     {
104       memcpy (buf, bufp, nread);
105       __vm_deallocate (__mach_task_self (), (vm_address_t) bufp, nread);
106     }
107 
108   return nread;
109 }
110 
111 weak_alias (__recvfrom, recvfrom)
112