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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/* NHRP daemon Linux specific glue
* Copyright (c) 2014-2015 Timo Teräs
*/
#include "zebra.h"
#include <errno.h>
#include <linux/if_packet.h>
#include "nhrp_protocol.h"
#include "os.h"
#ifndef HAVE_STRLCPY
size_t strlcpy(char *__restrict dest,
const char *__restrict src, size_t destsize);
#endif
static int nhrp_socket_fd = -1;
int os_socket(void)
{
if (nhrp_socket_fd < 0)
nhrp_socket_fd =
socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_NHRP));
return nhrp_socket_fd;
}
int os_sendmsg(const uint8_t *buf, size_t len, int ifindex, const uint8_t *addr,
size_t addrlen, uint16_t protocol)
{
struct sockaddr_ll lladdr;
struct iovec iov = {
.iov_base = (void *)buf, .iov_len = len,
};
struct msghdr msg = {
.msg_name = &lladdr,
.msg_namelen = sizeof(lladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
int status, fd;
if (addrlen > sizeof(lladdr.sll_addr))
return -1;
memset(&lladdr, 0, sizeof(lladdr));
lladdr.sll_family = AF_PACKET;
lladdr.sll_protocol = htons(protocol);
lladdr.sll_ifindex = ifindex;
lladdr.sll_halen = addrlen;
memcpy(lladdr.sll_addr, addr, addrlen);
fd = os_socket();
if (fd < 0)
return -1;
status = sendmsg(fd, &msg, 0);
if (status < 0)
return -errno;
return status;
}
int os_recvmsg(uint8_t *buf, size_t *len, int *ifindex, uint8_t *addr,
size_t *addrlen)
{
struct sockaddr_ll lladdr;
struct iovec iov = {
.iov_base = buf, .iov_len = *len,
};
struct msghdr msg = {
.msg_name = &lladdr,
.msg_namelen = sizeof(lladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
int r;
r = recvmsg(nhrp_socket_fd, &msg, MSG_DONTWAIT);
if (r < 0)
return r;
*len = r;
*ifindex = lladdr.sll_ifindex;
if (*addrlen <= (size_t)lladdr.sll_addr) {
if (memcmp(lladdr.sll_addr, "\x00\x00\x00\x00", 4) != 0) {
memcpy(addr, lladdr.sll_addr, lladdr.sll_halen);
*addrlen = lladdr.sll_halen;
} else {
*addrlen = 0;
}
}
return 0;
}
static int linux_configure_arp(const char *iface, int on)
{
struct ifreq ifr;
strlcpy(ifr.ifr_name, iface, IFNAMSIZ);
if (ioctl(nhrp_socket_fd, SIOCGIFFLAGS, &ifr))
return -1;
if (on)
ifr.ifr_flags &= ~IFF_NOARP;
else
ifr.ifr_flags |= IFF_NOARP;
if (ioctl(nhrp_socket_fd, SIOCSIFFLAGS, &ifr))
return -1;
return 0;
}
static int linux_icmp_redirect_off(const char *iface)
{
char fname[PATH_MAX];
int fd, ret = -1;
snprintf(fname, sizeof(fname),
"/proc/sys/net/ipv4/conf/%s/send_redirects", iface);
fd = open(fname, O_WRONLY);
if (fd < 0)
return -1;
if (write(fd, "0\n", 2) == 2)
ret = 0;
close(fd);
return ret;
}
int os_configure_dmvpn(unsigned int ifindex, const char *ifname, int af)
{
int ret = 0;
switch (af) {
case AF_INET:
ret |= linux_icmp_redirect_off("all");
ret |= linux_icmp_redirect_off(ifname);
break;
}
ret |= linux_configure_arp(ifname, 1);
return ret;
}
|
