1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <time.h>
5
6 #include <libmnl/libmnl.h>
7 #include <libnetfilter_conntrack/libnetfilter_conntrack.h>
8
9 struct callback_args {
10 struct mnl_socket *nl;
11 unsigned int seq;
12 int bit;
13 };
14
set_label(struct nf_conntrack * ct,struct callback_args * cbargs)15 static void set_label(struct nf_conntrack *ct, struct callback_args *cbargs)
16 {
17 struct nfct_bitmask *b = (void *) nfct_get_attr(ct, ATTR_CONNLABELS);
18 int bit = cbargs->bit;
19 char buf[MNL_SOCKET_BUFFER_SIZE];
20 struct nlmsghdr *nlh;
21 struct nfgenmsg *nfh;
22
23 if (b) {
24 if (bit < 0)
25 b = nfct_bitmask_new(0);
26 else if (nfct_bitmask_test_bit(b, bit))
27 return;
28 } else {
29 b = nfct_bitmask_new(0);
30 }
31
32 if (!b)
33 return;
34 if (bit >= 0)
35 nfct_bitmask_set_bit(b, bit);
36 nfct_set_attr(ct, ATTR_CONNLABELS, b);
37
38 if (bit >= 0) {
39 b = nfct_bitmask_new(bit);
40 if (b) {
41 nfct_bitmask_set_bit(b, bit);
42 nfct_set_attr(ct, ATTR_CONNLABELS_MASK, b);
43 }
44 }
45
46 cbargs->seq++;
47
48 nlh = mnl_nlmsg_put_header(buf);
49 nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_NEW;
50 nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE;
51 nlh->nlmsg_seq = cbargs->seq;
52
53 nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
54 nfh->nfgen_family = nfct_get_attr_u8(ct, ATTR_L3PROTO);
55 nfh->version = NFNETLINK_V0;
56 nfh->res_id = 0;
57
58 nfct_nlmsg_build(nlh, ct);
59
60 if (mnl_socket_sendto(cbargs->nl, nlh, nlh->nlmsg_len) < 0)
61 perror("mnl_socket_sendto");
62 }
63
data_cb(const struct nlmsghdr * nlh,void * data)64 static int data_cb(const struct nlmsghdr *nlh, void *data)
65 {
66 struct nf_conntrack *ct;
67 char buf[4096];
68
69 ct = nfct_new();
70 if (ct == NULL)
71 return MNL_CB_OK;
72
73 nfct_nlmsg_parse(nlh, ct);
74
75 nfct_snprintf(buf, sizeof(buf), ct, NFCT_T_UNKNOWN, NFCT_O_DEFAULT, 0);
76 printf("%s\n", buf);
77
78 set_label(ct, data);
79
80 nfct_destroy(ct);
81
82 return MNL_CB_OK;
83 }
84
show_labels(struct nfct_labelmap * l)85 static void show_labels(struct nfct_labelmap *l)
86 {
87 unsigned int i = 0;
88 const char *name;
89
90 if (l) {
91 fputs("usage: program label, configured labels are:\n", stderr);
92 while ((name = nfct_labelmap_get_name(l, i))) {
93 if (*name)
94 fprintf(stderr, "%s -> bit %d\n", name, i);
95 i++;
96 }
97 } else {
98 fputs("no labels configured, usage: program bit\n", stderr);
99 }
100 exit(1);
101 }
102
sock_nl_create(void)103 static struct mnl_socket *sock_nl_create(void)
104 {
105 struct mnl_socket *nl;
106
107 nl = mnl_socket_open(NETLINK_NETFILTER);
108 if (nl == NULL) {
109 perror("mnl_socket_open");
110 exit(EXIT_FAILURE);
111 }
112
113 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
114 perror("mnl_socket_bind");
115 exit(EXIT_FAILURE);
116 }
117
118 return nl;
119 }
120
main(int argc,char * argv[])121 int main(int argc, char *argv[])
122 {
123 struct mnl_socket *nl;
124 struct nlmsghdr *nlh;
125 struct nfgenmsg *nfh;
126 char buf[MNL_SOCKET_BUFFER_SIZE];
127 unsigned int seq, portid;
128 struct callback_args cbargs;
129 int ret;
130 struct nfct_labelmap *l = nfct_labelmap_new(NULL);
131
132 if (argc < 2)
133 show_labels(l);
134
135 cbargs.bit = l ? nfct_labelmap_get_bit(l, argv[1]) : -1;
136
137 if (cbargs.bit < 0) {
138 cbargs.bit = atoi(argv[1]);
139 if (cbargs.bit == 0 && argv[1][0] != '0')
140 show_labels(l);
141 }
142
143 if (cbargs.bit < 0)
144 puts("will clear all labels");
145 else
146 printf("will set label bit %d\n", cbargs.bit);
147
148 nl = sock_nl_create();
149 portid = mnl_socket_get_portid(nl);
150
151 nlh = mnl_nlmsg_put_header(buf);
152 nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET;
153 nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
154 nlh->nlmsg_seq = seq = time(NULL);
155
156 nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
157 nfh->nfgen_family = AF_UNSPEC;
158 nfh->version = NFNETLINK_V0;
159 nfh->res_id = 0;
160
161
162 ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
163 if (ret == -1) {
164 perror("mnl_socket_sendto");
165 exit(EXIT_FAILURE);
166 }
167
168 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
169
170
171 cbargs.nl = sock_nl_create();
172 cbargs.seq = seq;
173
174 while (ret > 0) {
175 ret = mnl_cb_run(buf, ret, seq, portid, data_cb, &cbargs);
176 if (ret <= MNL_CB_STOP)
177 break;
178 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
179 }
180 if (ret == -1) {
181 perror("mnl_socket_recvfrom");
182 exit(EXIT_FAILURE);
183 }
184
185 if (l)
186 nfct_labelmap_destroy(l);
187 mnl_socket_close(nl);
188
189 return 0;
190 }
191