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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/* Determine whether interfaces use native transport. Linux version.
Copyright (C) 2007-2017 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; if not, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <errno.h>
#include <ifaddrs.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <sys/ioctl.h>
#include <asm/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <not-cancel.h>
#include "netlinkaccess.h"
void
__check_native (uint32_t a1_index, int *a1_native,
uint32_t a2_index, int *a2_native)
{
int fd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
struct sockaddr_nl nladdr;
memset (&nladdr, '\0', sizeof (nladdr));
nladdr.nl_family = AF_NETLINK;
socklen_t addr_len = sizeof (nladdr);
if (fd < 0
|| __bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) != 0
|| __getsockname (fd, (struct sockaddr *) &nladdr, &addr_len) != 0)
return;
pid_t pid = nladdr.nl_pid;
struct req
{
struct nlmsghdr nlh;
struct rtgenmsg g;
/* struct rtgenmsg consists of a single byte. This means there
are three bytes of padding included in the REQ definition.
We make them explicit here. */
char pad[3];
} req;
req.nlh.nlmsg_len = sizeof (req);
req.nlh.nlmsg_type = RTM_GETLINK;
req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
req.nlh.nlmsg_pid = 0;
req.nlh.nlmsg_seq = time (NULL);
req.g.rtgen_family = AF_UNSPEC;
assert (sizeof (req) - offsetof (struct req, pad) == 3);
memset (req.pad, '\0', sizeof (req.pad));
memset (&nladdr, '\0', sizeof (nladdr));
nladdr.nl_family = AF_NETLINK;
#ifdef PAGE_SIZE
/* Help the compiler optimize out the malloc call if PAGE_SIZE
is constant and smaller or equal to PTHREAD_STACK_MIN/4. */
const size_t buf_size = PAGE_SIZE;
#else
const size_t buf_size = __getpagesize ();
#endif
bool use_malloc = false;
char *buf;
if (__libc_use_alloca (buf_size))
buf = alloca (buf_size);
else
{
buf = malloc (buf_size);
if (buf != NULL)
use_malloc = true;
else
goto out_fail;
}
struct iovec iov = { buf, buf_size };
if (TEMP_FAILURE_RETRY (__sendto (fd, (void *) &req, sizeof (req), 0,
(struct sockaddr *) &nladdr,
sizeof (nladdr))) < 0)
goto out_fail;
bool done = false;
do
{
struct msghdr msg =
{
.msg_name = (void *) &nladdr,
.msg_namelen = sizeof (nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = NULL,
.msg_controllen = 0,
.msg_flags = 0
};
ssize_t read_len = TEMP_FAILURE_RETRY (__recvmsg (fd, &msg, 0));
__netlink_assert_response (fd, read_len);
if (read_len < 0)
goto out_fail;
if (msg.msg_flags & MSG_TRUNC)
goto out_fail;
struct nlmsghdr *nlmh;
for (nlmh = (struct nlmsghdr *) buf;
NLMSG_OK (nlmh, (size_t) read_len);
nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, read_len))
{
if (nladdr.nl_pid != 0 || (pid_t) nlmh->nlmsg_pid != pid
|| nlmh->nlmsg_seq != req.nlh.nlmsg_seq)
continue;
if (nlmh->nlmsg_type == RTM_NEWLINK)
{
struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlmh);
int native = (ifim->ifi_type != ARPHRD_TUNNEL6
&& ifim->ifi_type != ARPHRD_TUNNEL
&& ifim->ifi_type != ARPHRD_SIT);
if (a1_index == ifim->ifi_index)
{
*a1_native = native;
a1_index = 0xffffffffu;
}
if (a2_index == ifim->ifi_index)
{
*a2_native = native;
a2_index = 0xffffffffu;
}
if (a1_index == 0xffffffffu
&& a2_index == 0xffffffffu)
goto out;
}
else if (nlmh->nlmsg_type == NLMSG_DONE)
/* We found the end, leave the loop. */
done = true;
}
}
while (! done);
out:
close_not_cancel_no_status (fd);
return;
out_fail:
if (use_malloc)
free (buf);
}
|
