libnl  3.2.28
queue_msg.c
1 /*
2  * lib/netfilter/queue_msg.c Netfilter Queue Messages
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation version 2.1
7  * of the License.
8  *
9  * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
10  * Copyright (c) 2010 Karl Hiramoto <karl@hiramoto.org>
11  */
12 
13 /**
14  * @ingroup nfnl
15  * @defgroup queue Queue
16  * @brief
17  * @{
18  */
19 
20 #include <sys/types.h>
21 #include <linux/netfilter/nfnetlink_queue.h>
22 
23 #include <netlink-private/netlink.h>
24 #include <netlink/attr.h>
25 #include <netlink/netfilter/nfnl.h>
26 #include <netlink/netfilter/queue_msg.h>
27 #include <byteswap.h>
28 
29 static struct nl_cache_ops nfnl_queue_msg_ops;
30 
31 #if __BYTE_ORDER == __BIG_ENDIAN
32 static uint64_t ntohll(uint64_t x)
33 {
34  return x;
35 }
36 #elif __BYTE_ORDER == __LITTLE_ENDIAN
37 static uint64_t ntohll(uint64_t x)
38 {
39  return bswap_64(x);
40 }
41 #endif
42 
43 static struct nla_policy queue_policy[NFQA_MAX+1] = {
44  [NFQA_PACKET_HDR] = {
45  .minlen = sizeof(struct nfqnl_msg_packet_hdr),
46  },
47  [NFQA_VERDICT_HDR] = {
48  .minlen = sizeof(struct nfqnl_msg_verdict_hdr),
49  },
50  [NFQA_MARK] = { .type = NLA_U32 },
51  [NFQA_TIMESTAMP] = {
52  .minlen = sizeof(struct nfqnl_msg_packet_timestamp),
53  },
54  [NFQA_IFINDEX_INDEV] = { .type = NLA_U32 },
55  [NFQA_IFINDEX_OUTDEV] = { .type = NLA_U32 },
56  [NFQA_IFINDEX_PHYSINDEV] = { .type = NLA_U32 },
57  [NFQA_IFINDEX_PHYSOUTDEV] = { .type = NLA_U32 },
58  [NFQA_HWADDR] = {
59  .minlen = sizeof(struct nfqnl_msg_packet_hw),
60  },
61 };
62 
63 int nfnlmsg_queue_msg_parse(struct nlmsghdr *nlh,
64  struct nfnl_queue_msg **result)
65 {
66  struct nfnl_queue_msg *msg;
67  struct nlattr *tb[NFQA_MAX+1];
68  struct nlattr *attr;
69  int err;
70 
71  msg = nfnl_queue_msg_alloc();
72  if (!msg)
73  return -NLE_NOMEM;
74 
75  msg->ce_msgtype = nlh->nlmsg_type;
76 
77  err = nlmsg_parse(nlh, sizeof(struct nfgenmsg), tb, NFQA_MAX,
78  queue_policy);
79  if (err < 0)
80  goto errout;
81 
82  nfnl_queue_msg_set_group(msg, nfnlmsg_res_id(nlh));
83  nfnl_queue_msg_set_family(msg, nfnlmsg_family(nlh));
84 
85  attr = tb[NFQA_PACKET_HDR];
86  if (attr) {
87  struct nfqnl_msg_packet_hdr *hdr = nla_data(attr);
88 
89  nfnl_queue_msg_set_packetid(msg, ntohl(hdr->packet_id));
90  if (hdr->hw_protocol)
91  nfnl_queue_msg_set_hwproto(msg, hdr->hw_protocol);
92  nfnl_queue_msg_set_hook(msg, hdr->hook);
93  }
94 
95  attr = tb[NFQA_MARK];
96  if (attr)
97  nfnl_queue_msg_set_mark(msg, ntohl(nla_get_u32(attr)));
98 
99  attr = tb[NFQA_TIMESTAMP];
100  if (attr) {
101  struct nfqnl_msg_packet_timestamp *timestamp = nla_data(attr);
102  struct timeval tv;
103 
104  tv.tv_sec = ntohll(timestamp->sec);
105  tv.tv_usec = ntohll(timestamp->usec);
106  nfnl_queue_msg_set_timestamp(msg, &tv);
107  }
108 
109  attr = tb[NFQA_IFINDEX_INDEV];
110  if (attr)
111  nfnl_queue_msg_set_indev(msg, ntohl(nla_get_u32(attr)));
112 
113  attr = tb[NFQA_IFINDEX_OUTDEV];
114  if (attr)
115  nfnl_queue_msg_set_outdev(msg, ntohl(nla_get_u32(attr)));
116 
117  attr = tb[NFQA_IFINDEX_PHYSINDEV];
118  if (attr)
119  nfnl_queue_msg_set_physindev(msg, ntohl(nla_get_u32(attr)));
120 
121  attr = tb[NFQA_IFINDEX_PHYSOUTDEV];
122  if (attr)
123  nfnl_queue_msg_set_physoutdev(msg, ntohl(nla_get_u32(attr)));
124 
125  attr = tb[NFQA_HWADDR];
126  if (attr) {
127  struct nfqnl_msg_packet_hw *hw = nla_data(attr);
128 
129  nfnl_queue_msg_set_hwaddr(msg, hw->hw_addr,
130  ntohs(hw->hw_addrlen));
131  }
132 
133  attr = tb[NFQA_PAYLOAD];
134  if (attr) {
135  err = nfnl_queue_msg_set_payload(msg, nla_data(attr),
136  nla_len(attr));
137  if (err < 0)
138  goto errout;
139  }
140 
141  *result = msg;
142  return 0;
143 
144 errout:
145  nfnl_queue_msg_put(msg);
146  return err;
147 }
148 
149 static int queue_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
150  struct nlmsghdr *nlh, struct nl_parser_param *pp)
151 {
152  struct nfnl_queue_msg *msg;
153  int err;
154 
155  if ((err = nfnlmsg_queue_msg_parse(nlh, &msg)) < 0)
156  return err;
157 
158  err = pp->pp_cb((struct nl_object *) msg, pp);
159  nfnl_queue_msg_put(msg);
160  return err;
161 }
162 
163 /** @} */
164 
165 static struct nl_msg *
166 __nfnl_queue_msg_build_verdict(const struct nfnl_queue_msg *msg,
167  uint8_t type)
168 {
169  struct nl_msg *nlmsg;
170  struct nfqnl_msg_verdict_hdr verdict;
171 
172  nlmsg = nfnlmsg_alloc_simple(NFNL_SUBSYS_QUEUE, type, 0,
173  nfnl_queue_msg_get_family(msg),
174  nfnl_queue_msg_get_group(msg));
175  if (nlmsg == NULL)
176  return NULL;
177 
178  verdict.id = htonl(nfnl_queue_msg_get_packetid(msg));
179  verdict.verdict = htonl(nfnl_queue_msg_get_verdict(msg));
180  if (nla_put(nlmsg, NFQA_VERDICT_HDR, sizeof(verdict), &verdict) < 0)
181  goto nla_put_failure;
182 
183  if (nfnl_queue_msg_test_mark(msg) &&
184  nla_put_u32(nlmsg, NFQA_MARK,
185  ntohl(nfnl_queue_msg_get_mark(msg))) < 0)
186  goto nla_put_failure;
187 
188  return nlmsg;
189 
190 nla_put_failure:
191  nlmsg_free(nlmsg);
192  return NULL;
193 }
194 
195 struct nl_msg *
196 nfnl_queue_msg_build_verdict(const struct nfnl_queue_msg *msg)
197 {
198  return __nfnl_queue_msg_build_verdict(msg, NFQNL_MSG_VERDICT);
199 }
200 
201 struct nl_msg *
202 nfnl_queue_msg_build_verdict_batch(const struct nfnl_queue_msg *msg)
203 {
204  return __nfnl_queue_msg_build_verdict(msg, NFQNL_MSG_VERDICT_BATCH);
205 }
206 
207 /**
208 * Send a message verdict/mark
209 * @arg nlh netlink messsage header
210 * @arg msg queue msg
211 * @return 0 on OK or error code
212 */
213 int nfnl_queue_msg_send_verdict(struct nl_sock *nlh,
214  const struct nfnl_queue_msg *msg)
215 {
216  struct nl_msg *nlmsg;
217  int err;
218 
219  nlmsg = nfnl_queue_msg_build_verdict(msg);
220  if (nlmsg == NULL)
221  return -NLE_NOMEM;
222 
223  err = nl_send_auto_complete(nlh, nlmsg);
224  nlmsg_free(nlmsg);
225  if (err < 0)
226  return err;
227  return wait_for_ack(nlh);
228 }
229 
230 /**
231 * Send a message batched verdict/mark
232 * @arg nlh netlink messsage header
233 * @arg msg queue msg
234 * @return 0 on OK or error code
235 */
236 int nfnl_queue_msg_send_verdict_batch(struct nl_sock *nlh,
237  const struct nfnl_queue_msg *msg)
238 {
239  struct nl_msg *nlmsg;
240  int err;
241 
242  nlmsg = nfnl_queue_msg_build_verdict_batch(msg);
243  if (nlmsg == NULL)
244  return -NLE_NOMEM;
245 
246  err = nl_send_auto_complete(nlh, nlmsg);
247  nlmsg_free(nlmsg);
248  if (err < 0)
249  return err;
250  return wait_for_ack(nlh);
251 }
252 
253 /**
254 * Send a message verdict including the payload
255 * @arg nlh netlink messsage header
256 * @arg msg queue msg
257 * @arg payload_data packet payload data
258 * @arg payload_len payload length
259 * @return 0 on OK or error code
260 */
261 int nfnl_queue_msg_send_verdict_payload(struct nl_sock *nlh,
262  const struct nfnl_queue_msg *msg,
263  const void *payload_data, unsigned payload_len)
264 {
265  struct nl_msg *nlmsg;
266  int err;
267  struct iovec iov[3];
268  struct nlattr nla;
269 
270  nlmsg = nfnl_queue_msg_build_verdict(msg);
271  if (nlmsg == NULL)
272  return -NLE_NOMEM;
273 
274  memset(iov, 0, sizeof(iov));
275 
276  iov[0].iov_base = (void *) nlmsg_hdr(nlmsg);
277  iov[0].iov_len = nlmsg_hdr(nlmsg)->nlmsg_len;
278 
279  nla.nla_type = NFQA_PAYLOAD;
280  nla.nla_len = payload_len + sizeof(nla);
281  nlmsg_hdr(nlmsg)->nlmsg_len += nla.nla_len;
282 
283  iov[1].iov_base = (void *) &nla;
284  iov[1].iov_len = sizeof(nla);
285 
286  iov[2].iov_base = (void *) payload_data;
287  iov[2].iov_len = NLA_ALIGN(payload_len);
288 
289  nl_complete_msg(nlh, nlmsg);
290  err = nl_send_iovec(nlh, nlmsg, iov, 3);
291 
292  nlmsg_free(nlmsg);
293  if (err < 0)
294  return err;
295  return wait_for_ack(nlh);
296 }
297 
298 #define NFNLMSG_QUEUE_TYPE(type) NFNLMSG_TYPE(NFNL_SUBSYS_QUEUE, (type))
299 static struct nl_cache_ops nfnl_queue_msg_ops = {
300  .co_name = "netfilter/queue_msg",
301  .co_hdrsize = NFNL_HDRLEN,
302  .co_msgtypes = {
303  { NFNLMSG_QUEUE_TYPE(NFQNL_MSG_PACKET), NL_ACT_NEW, "new" },
304  END_OF_MSGTYPES_LIST,
305  },
306  .co_protocol = NETLINK_NETFILTER,
307  .co_msg_parser = queue_msg_parser,
308  .co_obj_ops = &queue_msg_obj_ops,
309 };
310 
311 static void __init nfnl_msg_queue_init(void)
312 {
313  nl_cache_mngt_register(&nfnl_queue_msg_ops);
314 }
315 
316 static void __exit nfnl_queue_msg_exit(void)
317 {
318  nl_cache_mngt_unregister(&nfnl_queue_msg_ops);
319 }
320 
321 /** @} */
int nl_send_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
Definition: nl.c:1252
void nlmsg_free(struct nl_msg *msg)
Release a reference from an netlink message.
Definition: msg.c:558
void nl_complete_msg(struct nl_sock *sk, struct nl_msg *msg)
Finalize Netlink message.
Definition: nl.c:485
int nl_cache_mngt_unregister(struct nl_cache_ops *ops)
Unregister a set of cache operations.
Definition: cache_mngt.c:287
Attribute validation policy.
Definition: attr.h:67
uint32_t nla_get_u32(const struct nlattr *nla)
Return payload of 32 bit integer attribute.
Definition: attr.c:699
int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[], int maxtype, struct nla_policy *policy)
parse attributes of a netlink message
Definition: msg.c:213
int nl_cache_mngt_register(struct nl_cache_ops *ops)
Register a set of cache operations.
Definition: cache_mngt.c:252
struct nlmsghdr * nlmsg_hdr(struct nl_msg *n)
Return actual netlink message.
Definition: msg.c:536
void * nla_data(const struct nlattr *nla)
Return pointer to the payload section.
Definition: attr.c:120
int nl_send_iovec(struct nl_sock *sk, struct nl_msg *msg, struct iovec *iov, unsigned iovlen)
Transmit Netlink message (taking IO vector)
Definition: nl.c:377
int nla_len(const struct nlattr *nla)
Return length of the payload .
Definition: attr.c:131
uint8_t nfnlmsg_family(struct nlmsghdr *nlh)
Get netfilter family from message.
Definition: nfnl.c:150
uint16_t minlen
Minimal length of payload required.
Definition: attr.h:72
int nla_put_u32(struct nl_msg *msg, int attrtype, uint32_t value)
Add 32 bit integer attribute to netlink message.
Definition: attr.c:688
32 bit integer
Definition: attr.h:41
int nla_put(struct nl_msg *msg, int attrtype, int datalen, const void *data)
Add a unspecific attribute to netlink message.
Definition: attr.c:497
struct nl_msg * nfnlmsg_alloc_simple(uint8_t subsys_id, uint8_t type, int flags, uint8_t family, uint16_t res_id)
Allocate a new netfilter netlink message.
Definition: nfnl.c:201
uint16_t nfnlmsg_res_id(struct nlmsghdr *nlh)
Get netfilter resource id from message.
Definition: nfnl.c:161