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
|
/*
* Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <stdio.h>
#include <stdlib.h>
#include <net/if.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include <libmnl/libmnl.h>
#include <linux/rtnetlink.h>
#include <nftables.h>
#include <list.h>
#include <netlink.h>
#include <iface.h>
static LIST_HEAD(iface_list);
static bool iface_cache_init;
static int data_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, IFLA_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case IFLA_IFNAME:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
netlink_abi_error();
break;
default:
return MNL_CB_OK;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int data_cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[IFLA_MAX + 1] = {};
struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh);
struct iface *iface;
iface = xmalloc(sizeof(struct iface));
iface->ifindex = ifm->ifi_index;
mnl_attr_parse(nlh, sizeof(*ifm), data_attr_cb, tb);
snprintf(iface->name, IFNAMSIZ, "%s", mnl_attr_get_str(tb[IFLA_IFNAME]));
list_add(&iface->list, &iface_list);
return MNL_CB_OK;
}
static int iface_mnl_talk(struct mnl_socket *nl, uint32_t portid)
{
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct rtgenmsg *rt;
bool eintr = false;
uint32_t seq;
int ret;
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETLINK;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL);
rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
rt->rtgen_family = AF_PACKET;
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0)
return -1;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
if (ret == 0)
break;
if (ret < 0) {
if (errno != EINTR)
return ret;
/* process all pending messages before reporting EINTR */
eintr = true;
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (eintr) {
ret = -1;
errno = EINTR;
}
return ret;
}
void iface_cache_update(void)
{
struct mnl_socket *nl;
uint32_t portid;
int ret;
nl = mnl_socket_open(NETLINK_ROUTE);
if (nl == NULL)
netlink_init_error();
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0)
netlink_init_error();
portid = mnl_socket_get_portid(nl);
do {
ret = iface_mnl_talk(nl, portid);
} while (ret < 0 && errno == EINTR);
if (ret == -1)
netlink_init_error();
mnl_socket_close(nl);
iface_cache_init = true;
}
void iface_cache_release(void)
{
struct iface *iface, *next;
if (!iface_cache_init)
return;
list_for_each_entry_safe(iface, next, &iface_list, list) {
list_del(&iface->list);
free(iface);
}
iface_cache_init = false;
}
unsigned int nft_if_nametoindex(const char *name)
{
struct iface *iface;
if (!iface_cache_init)
iface_cache_update();
list_for_each_entry(iface, &iface_list, list) {
if (strncmp(name, iface->name, IFNAMSIZ) == 0)
return iface->ifindex;
}
return 0;
}
char *nft_if_indextoname(unsigned int ifindex, char *name)
{
struct iface *iface;
if (!iface_cache_init)
iface_cache_update();
list_for_each_entry(iface, &iface_list, list) {
if (iface->ifindex == ifindex) {
snprintf(name, IFNAMSIZ, "%s", iface->name);
return name;
}
}
return NULL;
}
|
