1/**
2 * \file
3 * This file implements the ipset module.  It can handle packets by putting
4 * the A and AAAA addresses that are configured in unbound.conf as type
5 * ipset (local-zone statements) into a firewall rule IPSet.  For firewall
6 * blacklist and whitelist usage.
7 */
8#include "config.h"
9#include "ipset/ipset.h"
10#include "util/regional.h"
11#include "util/net_help.h"
12#include "util/config_file.h"
13
14#include "services/cache/dns.h"
15
16#include "sldns/sbuffer.h"
17#include "sldns/wire2str.h"
18#include "sldns/parseutil.h"
19
20#include <libmnl/libmnl.h>
21#include <linux/netfilter/nfnetlink.h>
22#include <linux/netfilter/ipset/ip_set.h>
23
24#define BUFF_LEN 256
25
26/**
27 * Return an error
28 * @param qstate: our query state
29 * @param id: module id
30 * @param rcode: error code (DNS errcode).
31 * @return: 0 for use by caller, to make notation easy, like:
32 * 	return error_response(..).
33 */
34static int error_response(struct module_qstate* qstate, int id, int rcode) {
35	verbose(VERB_QUERY, "return error response %s",
36		sldns_lookup_by_id(sldns_rcodes, rcode)?
37		sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??");
38	qstate->return_rcode = rcode;
39	qstate->return_msg = NULL;
40	qstate->ext_state[id] = module_finished;
41	return 0;
42}
43
44static struct mnl_socket * open_mnl_socket() {
45	struct mnl_socket *mnl;
46
47	mnl = mnl_socket_open(NETLINK_NETFILTER);
48	if (!mnl) {
49		log_err("ipset: could not open netfilter.");
50		return NULL;
51	}
52
53	if (mnl_socket_bind(mnl, 0, MNL_SOCKET_AUTOPID) < 0) {
54		mnl_socket_close(mnl);
55		log_err("ipset: could not bind netfilter.");
56		return NULL;
57	}
58	return mnl;
59}
60
61static int add_to_ipset(struct mnl_socket *mnl, const char *setname, const void *ipaddr, int af) {
62	struct nlmsghdr *nlh;
63	struct nfgenmsg *nfg;
64	struct nlattr *nested[2];
65	static char buffer[BUFF_LEN];
66
67	if (strlen(setname) >= IPSET_MAXNAMELEN) {
68		errno = ENAMETOOLONG;
69		return -1;
70	}
71	if (af != AF_INET && af != AF_INET6) {
72		errno = EAFNOSUPPORT;
73		return -1;
74	}
75
76	nlh = mnl_nlmsg_put_header(buffer);
77	nlh->nlmsg_type = IPSET_CMD_ADD | (NFNL_SUBSYS_IPSET << 8);
78	nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL;
79
80	nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
81	nfg->nfgen_family = af;
82	nfg->version = NFNETLINK_V0;
83	nfg->res_id = htons(0);
84
85	mnl_attr_put_u8(nlh, IPSET_ATTR_PROTOCOL, IPSET_PROTOCOL);
86	mnl_attr_put(nlh, IPSET_ATTR_SETNAME, strlen(setname) + 1, setname);
87	nested[0] = mnl_attr_nest_start(nlh, IPSET_ATTR_DATA);
88	nested[1] = mnl_attr_nest_start(nlh, IPSET_ATTR_IP);
89	mnl_attr_put(nlh, (af == AF_INET ? IPSET_ATTR_IPADDR_IPV4 : IPSET_ATTR_IPADDR_IPV6)
90			| NLA_F_NET_BYTEORDER, (af == AF_INET ? sizeof(struct in_addr) : sizeof(struct in6_addr)), ipaddr);
91	mnl_attr_nest_end(nlh, nested[1]);
92	mnl_attr_nest_end(nlh, nested[0]);
93
94	if (mnl_socket_sendto(mnl, nlh, nlh->nlmsg_len) < 0) {
95		return -1;
96	}
97	return 0;
98}
99
100static void
101ipset_add_rrset_data(struct ipset_env *ie, struct mnl_socket *mnl,
102	struct packed_rrset_data *d, const char* setname, int af,
103	const char* dname)
104{
105	int ret;
106	size_t j, rr_len, rd_len;
107	uint8_t *rr_data;
108
109	/* to d->count, not d->rrsig_count, because we do not want to add the RRSIGs, only the addresses */
110	for (j = 0; j < d->count; j++) {
111		rr_len = d->rr_len[j];
112		rr_data = d->rr_data[j];
113
114		rd_len = sldns_read_uint16(rr_data);
115		if(af == AF_INET && rd_len != INET_SIZE)
116			continue;
117		if(af == AF_INET6 && rd_len != INET6_SIZE)
118			continue;
119		if (rr_len - 2 >= rd_len) {
120			if(verbosity >= VERB_QUERY) {
121				char ip[128];
122				if(inet_ntop(af, rr_data+2, ip, (socklen_t)sizeof(ip)) == 0)
123					snprintf(ip, sizeof(ip), "(inet_ntop_error)");
124				verbose(VERB_QUERY, "ipset: add %s to %s for %s", ip, setname, dname);
125			}
126			ret = add_to_ipset(mnl, setname, rr_data + 2, af);
127			if (ret < 0) {
128				log_err("ipset: could not add %s into %s", dname, setname);
129
130				mnl_socket_close(mnl);
131				ie->mnl = NULL;
132				break;
133			}
134		}
135	}
136}
137
138static int
139ipset_check_zones_for_rrset(struct module_env *env, struct ipset_env *ie,
140	struct mnl_socket *mnl, struct ub_packed_rrset_key *rrset,
141	const char *setname, int af)
142{
143	static char dname[BUFF_LEN];
144	const char *s;
145	int dlen, plen;
146
147	struct config_strlist *p;
148	struct packed_rrset_data *d;
149
150	dlen = sldns_wire2str_dname_buf(rrset->rk.dname, rrset->rk.dname_len, dname, BUFF_LEN);
151	if (dlen == 0) {
152		log_err("bad domain name");
153		return -1;
154	}
155	if (dname[dlen - 1] == '.') {
156		dlen--;
157	}
158
159	for (p = env->cfg->local_zones_ipset; p; p = p->next) {
160		plen = strlen(p->str);
161
162		if (dlen >= plen) {
163			s = dname + (dlen - plen);
164
165			if (strncasecmp(p->str, s, plen) == 0) {
166				d = (struct packed_rrset_data*)rrset->entry.data;
167				ipset_add_rrset_data(ie, mnl, d, setname,
168					af, dname);
169				break;
170			}
171		}
172	}
173	return 0;
174}
175
176static int ipset_update(struct module_env *env, struct dns_msg *return_msg, struct ipset_env *ie) {
177	struct mnl_socket *mnl;
178
179	size_t i;
180
181	const char *setname;
182
183	struct ub_packed_rrset_key *rrset;
184
185	int af;
186
187
188	mnl = (struct mnl_socket *)ie->mnl;
189	if (!mnl) {
190		// retry to create mnl socket
191		mnl = open_mnl_socket();
192		if (!mnl) {
193			return -1;
194		}
195
196		ie->mnl = mnl;
197	}
198
199	for (i = 0; i < return_msg->rep->rrset_count; ++i) {
200		setname = NULL;
201
202		rrset = return_msg->rep->rrsets[i];
203
204		if (rrset->rk.type == htons(LDNS_RR_TYPE_A)) {
205			af = AF_INET;
206			if ((ie->v4_enabled == 1)) {
207				setname = ie->name_v4;
208			}
209		} else {
210			af = AF_INET6;
211			if ((ie->v6_enabled == 1)) {
212				setname = ie->name_v6;
213			}
214		}
215
216		if (setname) {
217			if(ipset_check_zones_for_rrset(env, ie, mnl, rrset,
218				setname, af) == -1)
219				return -1;
220		}
221	}
222
223	return 0;
224}
225
226int ipset_init(struct module_env* env, int id) {
227	struct ipset_env *ipset_env;
228
229	ipset_env = (struct ipset_env *)calloc(1, sizeof(struct ipset_env));
230	if (!ipset_env) {
231		log_err("malloc failure");
232		return 0;
233	}
234
235	env->modinfo[id] = (void *)ipset_env;
236
237	ipset_env->mnl = NULL;
238
239	ipset_env->name_v4 = env->cfg->ipset_name_v4;
240	ipset_env->name_v6 = env->cfg->ipset_name_v6;
241
242	ipset_env->v4_enabled = !ipset_env->name_v4 || (strlen(ipset_env->name_v4) == 0) ? 0 : 1;
243	ipset_env->v6_enabled = !ipset_env->name_v6 || (strlen(ipset_env->name_v6) == 0) ? 0 : 1;
244
245	if ((ipset_env->v4_enabled < 1) && (ipset_env->v6_enabled < 1)) {
246		log_err("ipset: set name no configuration?");
247		return 0;
248	}
249
250	return 1;
251}
252
253void ipset_deinit(struct module_env *env, int id) {
254	struct mnl_socket *mnl;
255	struct ipset_env *ipset_env;
256
257	if (!env || !env->modinfo[id]) {
258		return;
259	}
260
261	ipset_env = (struct ipset_env *)env->modinfo[id];
262
263	mnl = (struct mnl_socket *)ipset_env->mnl;
264	if (mnl) {
265		mnl_socket_close(mnl);
266		ipset_env->mnl = NULL;
267	}
268
269	free(ipset_env);
270	env->modinfo[id] = NULL;
271}
272
273static int ipset_new(struct module_qstate* qstate, int id) {
274	struct ipset_qstate *iq = (struct ipset_qstate *)regional_alloc(
275		qstate->region, sizeof(struct ipset_qstate));
276	qstate->minfo[id] = iq;
277	if (!iq) {
278		return 0;
279	}
280
281	memset(iq, 0, sizeof(*iq));
282	/* initialise it */
283	/* TODO */
284
285	return 1;
286}
287
288void ipset_operate(struct module_qstate *qstate, enum module_ev event, int id,
289	struct outbound_entry *outbound) {
290	struct ipset_env *ie = (struct ipset_env *)qstate->env->modinfo[id];
291	struct ipset_qstate *iq = (struct ipset_qstate *)qstate->minfo[id];
292	verbose(VERB_QUERY, "ipset[module %d] operate: extstate:%s event:%s",
293		id, strextstate(qstate->ext_state[id]), strmodulevent(event));
294	if (iq) {
295		log_query_info(VERB_QUERY, "ipset operate: query", &qstate->qinfo);
296	}
297
298	/* perform ipset state machine */
299	if ((event == module_event_new || event == module_event_pass) && !iq) {
300		if (!ipset_new(qstate, id)) {
301			(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
302			return;
303		}
304		iq = (struct ipset_qstate*)qstate->minfo[id];
305	}
306
307	if (iq && (event == module_event_pass || event == module_event_new)) {
308		qstate->ext_state[id] = module_wait_module;
309		return;
310	}
311
312	if (iq && (event == module_event_moddone)) {
313		if (qstate->return_msg && qstate->return_msg->rep) {
314			ipset_update(qstate->env, qstate->return_msg, ie);
315		}
316		qstate->ext_state[id] = module_finished;
317		return;
318	}
319
320	if (iq && outbound) {
321		/* ipset does not need to process responses at this time
322		 * ignore it.
323		ipset_process_response(qstate, iq, ie, id, outbound, event);
324		*/
325		return;
326	}
327
328	if (event == module_event_error) {
329		verbose(VERB_ALGO, "got called with event error, giving up");
330		(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
331		return;
332	}
333
334	if (!iq && (event == module_event_moddone)) {
335		/* during priming, module done but we never started */
336		qstate->ext_state[id] = module_finished;
337		return;
338	}
339
340	log_err("bad event for ipset");
341	(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
342}
343
344void ipset_inform_super(struct module_qstate *ATTR_UNUSED(qstate),
345	int ATTR_UNUSED(id), struct module_qstate *ATTR_UNUSED(super)) {
346	/* ipset does not use subordinate requests at this time */
347	verbose(VERB_ALGO, "ipset inform_super was called");
348}
349
350void ipset_clear(struct module_qstate *qstate, int id) {
351	struct cachedb_qstate *iq;
352	if (!qstate) {
353		return;
354	}
355	iq = (struct cachedb_qstate *)qstate->minfo[id];
356	if (iq) {
357		/* free contents of iq */
358		/* TODO */
359	}
360	qstate->minfo[id] = NULL;
361}
362
363size_t ipset_get_mem(struct module_env *env, int id) {
364	struct ipset_env *ie = (struct ipset_env *)env->modinfo[id];
365	if (!ie) {
366		return 0;
367	}
368	return sizeof(*ie);
369}
370
371/**
372 * The ipset function block
373 */
374static struct module_func_block ipset_block = {
375	"ipset",
376	&ipset_init, &ipset_deinit, &ipset_operate,
377	&ipset_inform_super, &ipset_clear, &ipset_get_mem
378};
379
380struct module_func_block * ipset_get_funcblock(void) {
381	return &ipset_block;
382}
383
384