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
|
/* Copyright 2007-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
*
* 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 <assert.h> /* assert */
#include <errno.h> /* errno */
#include <stdlib.h> /* calloc, free */
#include <time.h> /* time */
#include <arpa/inet.h> /* hto* */
#include <libipset/linux_ip_set.h> /* enum ipset_cmd */
#include <libipset/debug.h> /* D() */
#include <libipset/session.h> /* ipset_session_handle */
#include <libipset/ui.h> /* IPSET_ENV_EXIST */
#include <libipset/utils.h> /* UNUSED */
#include <libipset/mnl.h> /* prototypes */
#ifndef NFNL_SUBSYS_IPSET
#define NFNL_SUBSYS_IPSET 6
#endif
/* Internal data structure for the kernel-userspace communication parameters */
struct ipset_handle {
struct mnl_socket *h; /* the mnl socket */
unsigned int seq; /* netlink message sequence number */
unsigned int portid; /* the socket port identifier */
mnl_cb_t *cb_ctl; /* control block callbacks */
void *data; /* data pointer */
};
/* Netlink flags of the commands */
static const uint16_t cmdflags[] = {
[IPSET_CMD_CREATE-1] = NLM_F_REQUEST|NLM_F_ACK|
NLM_F_CREATE|NLM_F_EXCL,
[IPSET_CMD_DESTROY-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_FLUSH-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_RENAME-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_SWAP-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_LIST-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_DUMP,
[IPSET_CMD_SAVE-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_DUMP,
[IPSET_CMD_ADD-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL,
[IPSET_CMD_DEL-1] = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL,
[IPSET_CMD_TEST-1] = NLM_F_REQUEST|NLM_F_ACK,
[IPSET_CMD_HEADER-1] = NLM_F_REQUEST,
[IPSET_CMD_TYPE-1] = NLM_F_REQUEST,
[IPSET_CMD_PROTOCOL-1] = NLM_F_REQUEST,
};
/**
* ipset_get_nlmsg_type - get ipset netlink message type
* @nlh: pointer to the netlink message header
*
* Returns the ipset netlink message type, i.e. the ipset command.
*/
int
ipset_get_nlmsg_type(const struct nlmsghdr *nlh)
{
return nlh->nlmsg_type & ~(NFNL_SUBSYS_IPSET << 8);
}
static void
ipset_mnl_fill_hdr(struct ipset_handle *handle, enum ipset_cmd cmd,
void *buffer, size_t len UNUSED, uint8_t envflags)
{
struct nlmsghdr *nlh;
struct nfgenmsg *nfg;
assert(handle);
assert(buffer);
assert(cmd > IPSET_CMD_NONE && cmd < IPSET_MSG_MAX);
nlh = mnl_nlmsg_put_header(buffer);
nlh->nlmsg_type = cmd | (NFNL_SUBSYS_IPSET << 8);
nlh->nlmsg_flags = cmdflags[cmd - 1];
if (envflags & IPSET_ENV_EXIST)
nlh->nlmsg_flags &= ~NLM_F_EXCL;
nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
nfg->nfgen_family = AF_INET;
nfg->version = NFNETLINK_V0;
nfg->res_id = htons(0);
}
static int
ipset_mnl_query(struct ipset_handle *handle, void *buffer, size_t len)
{
struct nlmsghdr *nlh = buffer;
int ret;
assert(handle);
assert(buffer);
nlh->nlmsg_seq = ++handle->seq;
#ifdef IPSET_DEBUG
ipset_debug_msg("sent", nlh, nlh->nlmsg_len);
#endif
if (mnl_socket_sendto(handle->h, nlh, nlh->nlmsg_len) < 0)
return -ECOMM;
ret = mnl_socket_recvfrom(handle->h, buffer, len);
#ifdef IPSET_DEBUG
ipset_debug_msg("received", buffer, ret);
#endif
while (ret > 0) {
ret = mnl_cb_run2(buffer, ret,
handle->seq, handle->portid,
handle->cb_ctl[NLMSG_MIN_TYPE],
handle->data,
handle->cb_ctl, NLMSG_MIN_TYPE);
D("nfln_cb_run2, ret: %d, errno %d", ret, errno);
if (ret <= 0)
break;
ret = mnl_socket_recvfrom(handle->h, buffer, len);
D("message received, ret: %d", ret);
}
return ret > 0 ? 0 : ret;
}
static struct ipset_handle *
ipset_mnl_init(mnl_cb_t *cb_ctl, void *data)
{
struct ipset_handle *handle;
assert(cb_ctl);
assert(data);
handle = calloc(1, sizeof(*handle));
if (!handle)
return NULL;
handle->h = mnl_socket_open(NETLINK_NETFILTER);
if (!handle->h)
goto free_handle;
if (mnl_socket_bind(handle->h, 0, MNL_SOCKET_AUTOPID) < 0)
goto close_nl;
handle->portid = mnl_socket_get_portid(handle->h);
handle->cb_ctl = cb_ctl;
handle->data = data;
handle->seq = time(NULL);
return handle;
close_nl:
mnl_socket_close(handle->h);
free_handle:
free(handle);
return NULL;
}
static int
ipset_mnl_fini(struct ipset_handle *handle)
{
assert(handle);
if (handle->h)
mnl_socket_close(handle->h);
free(handle);
return 0;
}
const struct ipset_transport ipset_mnl_transport = {
.init = ipset_mnl_init,
.fini = ipset_mnl_fini,
.fill_hdr = ipset_mnl_fill_hdr,
.query = ipset_mnl_query,
};
|
