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
|
/*
* (C) 2015 by Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <libnetfilter_log/libnetfilter_log.h>
#include <errno.h>
#include "internal.h"
/**
* \defgroup nlmsg Netlink message helper functions
* @{
*/
/**
* nflog_nlmsg_put_header - reserve and prepare room for nflog Netlink header
* \param buf memory already allocated to store the Netlink header
* \param type message type one of the enum nfulnl_msg_types
* \param family protocol family to be an object of
* \param qnum queue number to be an object of
*
* This function creates Netlink header in the memory buffer passed
* as parameter that will send to nfnetlink log. This function
* returns a pointer to the Netlink header structure.
*/
struct nlmsghdr *
nflog_nlmsg_put_header(char *buf, uint8_t type, uint8_t family, uint16_t qnum)
{
struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
struct nfgenmsg *nfg;
nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | type;
nlh->nlmsg_flags = NLM_F_REQUEST;
nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
nfg->nfgen_family = family;
nfg->version = NFNETLINK_V0;
nfg->res_id = htons(qnum);
return nlh;
}
/**
* nflog_attr_put_cfg_mode - add a mode attribute to nflog netlink message
* \param nlh pointer to the netlink message
* \param mode copy mode defined in linux/netfilter/nfnetlink_log.h
* \param range copy range
*
* this function returns -1 and errno is explicitly set on error.
* On success, this function returns 1.
*/
int nflog_attr_put_cfg_mode(struct nlmsghdr *nlh, uint8_t mode, uint32_t range)
{
struct nfulnl_msg_config_mode nfmode = {
.copy_mode = mode,
.copy_range = htonl(range)
};
mnl_attr_put(nlh, NFULA_CFG_MODE, sizeof(nfmode), &nfmode);
/* it may returns -1 in future */
return 0;
}
/**
* nflog_attr_put_cfg_cmd - add a cmd attribute to nflog netlink message
* \param nlh pointer to the netlink message
* \param cmd command one of the enum nfulnl_msg_config_cmds
*
* this function returns -1 and errno is explicitly set on error.
* On success, this function returns 1.
*/
int nflog_attr_put_cfg_cmd(struct nlmsghdr *nlh, uint8_t cmd)
{
struct nfulnl_msg_config_cmd nfcmd = {
.command = cmd
};
mnl_attr_put(nlh, NFULA_CFG_CMD, sizeof(nfcmd), &nfcmd);
/* it may returns -1 in future */
return 0;
}
static int nflog_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_HWTYPE: /* hardware type */
case NFULA_HWLEN: /* hardware header length */
if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
return MNL_CB_ERROR;
break;
case NFULA_MARK: /* __u32 nfmark */
case NFULA_IFINDEX_INDEV: /* __u32 ifindex */
case NFULA_IFINDEX_OUTDEV: /* __u32 ifindex */
case NFULA_IFINDEX_PHYSINDEV: /* __u32 ifindex */
case NFULA_IFINDEX_PHYSOUTDEV: /* __u32 ifindex */
case NFULA_UID: /* user id of socket */
case NFULA_SEQ: /* instance-local sequence number */
case NFULA_SEQ_GLOBAL: /* global sequence number */
case NFULA_GID: /* group id of socket */
case NFULA_CT_INFO: /* enum ip_conntrack_info */
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
return MNL_CB_ERROR;
break;
case NFULA_PACKET_HDR:
if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
sizeof(struct nfulnl_msg_packet_hdr)) < 0) {
return MNL_CB_ERROR;
}
break;
case NFULA_TIMESTAMP: /* nfulnl_msg_packet_timestamp */
if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
sizeof(struct nfulnl_msg_packet_timestamp)) < 0) {
return MNL_CB_ERROR;
}
break;
case NFULA_HWADDR: /* nfulnl_msg_packet_hw */
if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
sizeof(struct nfulnl_msg_packet_hw)) < 0) {
return MNL_CB_ERROR;
}
break;
case NFULA_PREFIX: /* string prefix */
if (mnl_attr_validate(attr, MNL_TYPE_NUL_STRING) < 0)
return MNL_CB_ERROR;
break;
case NFULA_HWHEADER: /* hardware header */
case NFULA_PAYLOAD: /* opaque data payload */
case NFULA_CT: /* nf_conntrack_netlink.h */
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
/**
* nflog_nlmsg_parse - set nlattrs from netlink message
* \param nlh netlink message that you want to read.
* \param attr pointer to the array of nlattr which size is NFULA_MAX + 1
*
* This function returns MNL_CB_ERROR if any error occurs, or MNL_CB_OK on
* success.
*/
int nflog_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr **attr)
{
return mnl_attr_parse(nlh, sizeof(struct nfgenmsg),
nflog_parse_attr_cb, attr);
}
/**
* nflog_nlmsg_snprintf - print a nflog nlattrs to a buffer
* \param buf buffer used to build the printable nflog
* \param bufsiz size of the buffer
* \param nlh netlink message (to get queue num in the futuer)
* \param attr pointer to a nflog attrs
* \param type print message type in enum nflog_output_type
* \param flags The flag that tell what to print into the buffer
*
* This function supports the following type - flags:
*
* type: NFLOG_OUTPUT_XML
* - NFLOG_XML_PREFIX: include the string prefix
* - NFLOG_XML_HW: include the hardware link layer address
* - NFLOG_XML_MARK: include the packet mark
* - NFLOG_XML_DEV: include the device information
* - NFLOG_XML_PHYSDEV: include the physical device information
* - NFLOG_XML_PAYLOAD: include the payload (in hexadecimal)
* - NFLOG_XML_TIME: include the timestamp
* - NFLOG_XML_ALL: include all the logging information (all flags set)
*
* You can combine this flags with an binary OR.
*
* this function returns -1 and errno is explicitly set in case of
* failure, otherwise the length of the string that would have been
* printed into the buffer (in case that there is enough room in
* it). See snprintf() return value for more information.
*/
int nflog_nlmsg_snprintf(char *buf, size_t bufsiz, const struct nlmsghdr *nlh,
struct nlattr **attr, enum nflog_output_type type,
uint32_t flags)
{
/* This is a hack to re-use the existing old API code. */
struct nflog_data nfad = {
.nfa = (struct nfattr **)&attr[1],
};
int ret;
switch (type) {
case NFLOG_OUTPUT_XML:
ret = nflog_snprintf_xml(buf, bufsiz, &nfad, flags);
break;
default:
ret = -1;
errno = EOPNOTSUPP;
break;
}
return ret;
}
/**
* @}
*/
|
