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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/* This example is placed in the public domain. */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_log.h>
static int parse_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
/* skip unsupported attribute in user-space */
if (mnl_attr_type_valid(attr, NFULA_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFULA_MARK:
case NFULA_IFINDEX_INDEV:
case NFULA_IFINDEX_OUTDEV:
case NFULA_IFINDEX_PHYSINDEV:
case NFULA_IFINDEX_PHYSOUTDEV:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case NFULA_TIMESTAMP:
if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
sizeof(struct nfulnl_msg_packet_timestamp)) < 0) {
perror("mnl_attr_validate2");
return MNL_CB_ERROR;
}
break;
case NFULA_HWADDR:
if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
sizeof(struct nfulnl_msg_packet_hw)) < 0) {
perror("mnl_attr_validate2");
return MNL_CB_ERROR;
}
break;
case NFULA_PREFIX:
if (mnl_attr_validate(attr, MNL_TYPE_NUL_STRING) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case NFULA_PAYLOAD:
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int log_cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[NFULA_MAX+1] = {};
struct nfulnl_msg_packet_hdr *ph = NULL;
const char *prefix = NULL;
uint32_t mark = 0;
mnl_attr_parse(nlh, sizeof(struct nfgenmsg), parse_attr_cb, tb);
if (tb[NFULA_PACKET_HDR])
ph = mnl_attr_get_payload(tb[NFULA_PACKET_HDR]);
if (tb[NFULA_PREFIX])
prefix = mnl_attr_get_str(tb[NFULA_PREFIX]);
if (tb[NFULA_MARK])
mark = ntohl(mnl_attr_get_u32(tb[NFULA_MARK]));
printf("log received (prefix=\"%s\" hw=0x%04x hook=%u mark=%u)\n",
prefix ? prefix : "", ntohs(ph->hw_protocol), ph->hook,
mark);
return MNL_CB_OK;
}
static struct nlmsghdr *
nflog_build_cfg_pf_request(char *buf, uint8_t command)
{
struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG;
nlh->nlmsg_flags = NLM_F_REQUEST;
struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
nfg->nfgen_family = AF_INET;
nfg->version = NFNETLINK_V0;
struct nfulnl_msg_config_cmd cmd = {
.command = command,
};
mnl_attr_put(nlh, NFULA_CFG_CMD, sizeof(cmd), &cmd);
return nlh;
}
static struct nlmsghdr *
nflog_build_cfg_request(char *buf, uint8_t command, int qnum)
{
struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG;
nlh->nlmsg_flags = NLM_F_REQUEST;
struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
nfg->nfgen_family = AF_INET;
nfg->version = NFNETLINK_V0;
nfg->res_id = htons(qnum);
struct nfulnl_msg_config_cmd cmd = {
.command = command,
};
mnl_attr_put(nlh, NFULA_CFG_CMD, sizeof(cmd), &cmd);
return nlh;
}
static struct nlmsghdr *
nflog_build_cfg_params(char *buf, uint8_t mode, int range, int qnum)
{
struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG;
nlh->nlmsg_flags = NLM_F_REQUEST;
struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
nfg->nfgen_family = AF_UNSPEC;
nfg->version = NFNETLINK_V0;
nfg->res_id = htons(qnum);
struct nfulnl_msg_config_mode params = {
.copy_range = htonl(range),
.copy_mode = mode,
};
mnl_attr_put(nlh, NFULA_CFG_MODE, sizeof(params), ¶ms);
return nlh;
}
int main(int argc, char *argv[])
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
int ret;
unsigned int portid, qnum;
if (argc != 2) {
printf("Usage: %s [queue_num]\n", argv[0]);
exit(EXIT_FAILURE);
}
qnum = atoi(argv[1]);
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) {
perror("mnl_socket_open");
exit(EXIT_FAILURE);
}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
perror("mnl_socket_bind");
exit(EXIT_FAILURE);
}
portid = mnl_socket_get_portid(nl);
nlh = nflog_build_cfg_pf_request(buf, NFULNL_CFG_CMD_PF_UNBIND);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_sendto");
exit(EXIT_FAILURE);
}
nlh = nflog_build_cfg_pf_request(buf, NFULNL_CFG_CMD_PF_BIND);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_sendto");
exit(EXIT_FAILURE);
}
nlh = nflog_build_cfg_request(buf, NFULNL_CFG_CMD_BIND, qnum);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_sendto");
exit(EXIT_FAILURE);
}
nlh = nflog_build_cfg_params(buf, NFULNL_COPY_PACKET, 0xFFFF, qnum);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_sendto");
exit(EXIT_FAILURE);
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
while (ret > 0) {
ret = mnl_cb_run(buf, ret, 0, portid, log_cb, NULL);
if (ret < 0){
perror("mnl_cb_run");
exit(EXIT_FAILURE);
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
}
mnl_socket_close(nl);
return 0;
}
|
