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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
96518518 | 2 | /* |
ef1f7df9 | 3 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
09d27b88 | 4 | * Copyright (c) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org> |
96518518 | 5 | * |
96518518 PM |
6 | * Development of this code funded by Astaro AG (http://www.astaro.com/) |
7 | */ | |
8 | ||
1a893b44 | 9 | #include <linux/audit.h> |
96518518 PM |
10 | #include <linux/kernel.h> |
11 | #include <linux/init.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/netlink.h> | |
14 | #include <linux/netfilter.h> | |
15 | #include <linux/netfilter/nf_tables.h> | |
1a893b44 PS |
16 | #include <net/ipv6.h> |
17 | #include <net/ip.h> | |
96518518 PM |
18 | #include <net/netfilter/nf_tables.h> |
19 | #include <net/netfilter/nf_log.h> | |
20 | #include <linux/netdevice.h> | |
21 | ||
22 | static const char *nft_log_null_prefix = ""; | |
23 | ||
24 | struct nft_log { | |
25 | struct nf_loginfo loginfo; | |
26 | char *prefix; | |
96518518 PM |
27 | }; |
28 | ||
1a893b44 PS |
29 | static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) |
30 | { | |
31 | struct iphdr _iph; | |
32 | const struct iphdr *ih; | |
33 | ||
34 | ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph); | |
35 | if (!ih) | |
36 | return false; | |
37 | ||
38 | audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", | |
39 | &ih->saddr, &ih->daddr, ih->protocol); | |
40 | ||
41 | return true; | |
42 | } | |
43 | ||
44 | static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb) | |
45 | { | |
46 | struct ipv6hdr _ip6h; | |
47 | const struct ipv6hdr *ih; | |
48 | u8 nexthdr; | |
49 | __be16 frag_off; | |
50 | ||
51 | ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h); | |
52 | if (!ih) | |
53 | return false; | |
54 | ||
55 | nexthdr = ih->nexthdr; | |
56 | ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off); | |
57 | ||
58 | audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", | |
59 | &ih->saddr, &ih->daddr, nexthdr); | |
60 | ||
61 | return true; | |
62 | } | |
63 | ||
64 | static void nft_log_eval_audit(const struct nft_pktinfo *pkt) | |
65 | { | |
66 | struct sk_buff *skb = pkt->skb; | |
67 | struct audit_buffer *ab; | |
68 | int fam = -1; | |
69 | ||
70 | if (!audit_enabled) | |
71 | return; | |
72 | ||
73 | ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT); | |
74 | if (!ab) | |
75 | return; | |
76 | ||
77 | audit_log_format(ab, "mark=%#x", skb->mark); | |
78 | ||
79 | switch (nft_pf(pkt)) { | |
80 | case NFPROTO_BRIDGE: | |
81 | switch (eth_hdr(skb)->h_proto) { | |
82 | case htons(ETH_P_IP): | |
83 | fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; | |
84 | break; | |
85 | case htons(ETH_P_IPV6): | |
86 | fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; | |
87 | break; | |
88 | } | |
89 | break; | |
90 | case NFPROTO_IPV4: | |
91 | fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; | |
92 | break; | |
93 | case NFPROTO_IPV6: | |
94 | fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; | |
95 | break; | |
96 | } | |
97 | ||
98 | if (fam == -1) | |
99 | audit_log_format(ab, " saddr=? daddr=? proto=-1"); | |
100 | ||
101 | audit_log_end(ab); | |
102 | } | |
103 | ||
96518518 | 104 | static void nft_log_eval(const struct nft_expr *expr, |
a55e22e9 | 105 | struct nft_regs *regs, |
96518518 PM |
106 | const struct nft_pktinfo *pkt) |
107 | { | |
108 | const struct nft_log *priv = nft_expr_priv(expr); | |
96518518 | 109 | |
1a893b44 | 110 | if (priv->loginfo.type == NF_LOG_TYPE_LOG && |
7eced5ab | 111 | priv->loginfo.u.log.level == NFT_LOGLEVEL_AUDIT) { |
1a893b44 PS |
112 | nft_log_eval_audit(pkt); |
113 | return; | |
114 | } | |
115 | ||
0e5a1c7e PNA |
116 | nf_log_packet(nft_net(pkt), nft_pf(pkt), nft_hook(pkt), pkt->skb, |
117 | nft_in(pkt), nft_out(pkt), &priv->loginfo, "%s", | |
118 | priv->prefix); | |
96518518 PM |
119 | } |
120 | ||
121 | static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = { | |
122 | [NFTA_LOG_GROUP] = { .type = NLA_U16 }, | |
5ce6b04c LZ |
123 | [NFTA_LOG_PREFIX] = { .type = NLA_STRING, |
124 | .len = NF_LOG_PREFIXLEN - 1 }, | |
96518518 PM |
125 | [NFTA_LOG_SNAPLEN] = { .type = NLA_U32 }, |
126 | [NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 }, | |
09d27b88 PNA |
127 | [NFTA_LOG_LEVEL] = { .type = NLA_U32 }, |
128 | [NFTA_LOG_FLAGS] = { .type = NLA_U32 }, | |
96518518 PM |
129 | }; |
130 | ||
cefa31a9 FW |
131 | static int nft_log_modprobe(struct net *net, enum nf_log_type t) |
132 | { | |
133 | switch (t) { | |
134 | case NF_LOG_TYPE_LOG: | |
135 | return nft_request_module(net, "%s", "nf_log_syslog"); | |
136 | case NF_LOG_TYPE_ULOG: | |
137 | return nft_request_module(net, "%s", "nfnetlink_log"); | |
138 | case NF_LOG_TYPE_MAX: | |
139 | break; | |
140 | } | |
141 | ||
142 | return -ENOENT; | |
143 | } | |
144 | ||
96518518 PM |
145 | static int nft_log_init(const struct nft_ctx *ctx, |
146 | const struct nft_expr *expr, | |
147 | const struct nlattr * const tb[]) | |
148 | { | |
149 | struct nft_log *priv = nft_expr_priv(expr); | |
150 | struct nf_loginfo *li = &priv->loginfo; | |
151 | const struct nlattr *nla; | |
c2d9a429 LZ |
152 | int err; |
153 | ||
154 | li->type = NF_LOG_TYPE_LOG; | |
155 | if (tb[NFTA_LOG_LEVEL] != NULL && | |
156 | tb[NFTA_LOG_GROUP] != NULL) | |
157 | return -EINVAL; | |
ff107d27 | 158 | if (tb[NFTA_LOG_GROUP] != NULL) { |
c2d9a429 | 159 | li->type = NF_LOG_TYPE_ULOG; |
ff107d27 LZ |
160 | if (tb[NFTA_LOG_FLAGS] != NULL) |
161 | return -EINVAL; | |
162 | } | |
96518518 | 163 | |
96518518 PM |
164 | nla = tb[NFTA_LOG_PREFIX]; |
165 | if (nla != NULL) { | |
166 | priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL); | |
167 | if (priv->prefix == NULL) | |
168 | return -ENOMEM; | |
872f6903 | 169 | nla_strscpy(priv->prefix, nla, nla_len(nla) + 1); |
09d27b88 | 170 | } else { |
96518518 | 171 | priv->prefix = (char *)nft_log_null_prefix; |
09d27b88 | 172 | } |
96518518 | 173 | |
09d27b88 PNA |
174 | switch (li->type) { |
175 | case NF_LOG_TYPE_LOG: | |
176 | if (tb[NFTA_LOG_LEVEL] != NULL) { | |
177 | li->u.log.level = | |
5cbfda20 | 178 | ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL])); |
09d27b88 | 179 | } else { |
7eced5ab | 180 | li->u.log.level = NFT_LOGLEVEL_WARNING; |
09d27b88 | 181 | } |
7eced5ab | 182 | if (li->u.log.level > NFT_LOGLEVEL_AUDIT) { |
1bc4e013 LZ |
183 | err = -EINVAL; |
184 | goto err1; | |
185 | } | |
186 | ||
09d27b88 PNA |
187 | if (tb[NFTA_LOG_FLAGS] != NULL) { |
188 | li->u.log.logflags = | |
189 | ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS])); | |
ff107d27 LZ |
190 | if (li->u.log.logflags & ~NF_LOG_MASK) { |
191 | err = -EINVAL; | |
192 | goto err1; | |
193 | } | |
09d27b88 PNA |
194 | } |
195 | break; | |
196 | case NF_LOG_TYPE_ULOG: | |
96518518 | 197 | li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP])); |
09d27b88 | 198 | if (tb[NFTA_LOG_SNAPLEN] != NULL) { |
cc37c1ad | 199 | li->u.ulog.flags |= NF_LOG_F_COPY_LEN; |
09d27b88 PNA |
200 | li->u.ulog.copy_len = |
201 | ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN])); | |
202 | } | |
203 | if (tb[NFTA_LOG_QTHRESHOLD] != NULL) { | |
204 | li->u.ulog.qthreshold = | |
205 | ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD])); | |
206 | } | |
207 | break; | |
96518518 PM |
208 | } |
209 | ||
7eced5ab | 210 | if (li->u.log.level == NFT_LOGLEVEL_AUDIT) |
1a893b44 PS |
211 | return 0; |
212 | ||
36596dad | 213 | err = nf_logger_find_get(ctx->family, li->type); |
cefa31a9 FW |
214 | if (err < 0) { |
215 | if (nft_log_modprobe(ctx->net, li->type) == -EAGAIN) | |
216 | err = -EAGAIN; | |
217 | ||
c2d9a429 | 218 | goto err1; |
cefa31a9 | 219 | } |
c2d9a429 LZ |
220 | |
221 | return 0; | |
222 | ||
223 | err1: | |
224 | if (priv->prefix != nft_log_null_prefix) | |
225 | kfree(priv->prefix); | |
226 | return err; | |
96518518 PM |
227 | } |
228 | ||
62472bce PM |
229 | static void nft_log_destroy(const struct nft_ctx *ctx, |
230 | const struct nft_expr *expr) | |
96518518 PM |
231 | { |
232 | struct nft_log *priv = nft_expr_priv(expr); | |
85d30e24 | 233 | struct nf_loginfo *li = &priv->loginfo; |
96518518 PM |
234 | |
235 | if (priv->prefix != nft_log_null_prefix) | |
236 | kfree(priv->prefix); | |
85d30e24 | 237 | |
7eced5ab | 238 | if (li->u.log.level == NFT_LOGLEVEL_AUDIT) |
1a893b44 PS |
239 | return; |
240 | ||
36596dad | 241 | nf_logger_put(ctx->family, li->type); |
96518518 PM |
242 | } |
243 | ||
244 | static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
245 | { | |
246 | const struct nft_log *priv = nft_expr_priv(expr); | |
247 | const struct nf_loginfo *li = &priv->loginfo; | |
248 | ||
249 | if (priv->prefix != nft_log_null_prefix) | |
250 | if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix)) | |
251 | goto nla_put_failure; | |
09d27b88 PNA |
252 | switch (li->type) { |
253 | case NF_LOG_TYPE_LOG: | |
254 | if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level))) | |
96518518 | 255 | goto nla_put_failure; |
09d27b88 PNA |
256 | |
257 | if (li->u.log.logflags) { | |
258 | if (nla_put_be32(skb, NFTA_LOG_FLAGS, | |
259 | htonl(li->u.log.logflags))) | |
260 | goto nla_put_failure; | |
261 | } | |
262 | break; | |
263 | case NF_LOG_TYPE_ULOG: | |
264 | if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group))) | |
96518518 | 265 | goto nla_put_failure; |
09d27b88 | 266 | |
cc37c1ad | 267 | if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) { |
09d27b88 PNA |
268 | if (nla_put_be32(skb, NFTA_LOG_SNAPLEN, |
269 | htonl(li->u.ulog.copy_len))) | |
270 | goto nla_put_failure; | |
271 | } | |
272 | if (li->u.ulog.qthreshold) { | |
273 | if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD, | |
274 | htons(li->u.ulog.qthreshold))) | |
275 | goto nla_put_failure; | |
276 | } | |
277 | break; | |
278 | } | |
96518518 PM |
279 | return 0; |
280 | ||
281 | nla_put_failure: | |
282 | return -1; | |
283 | } | |
284 | ||
ef1f7df9 PM |
285 | static struct nft_expr_type nft_log_type; |
286 | static const struct nft_expr_ops nft_log_ops = { | |
287 | .type = &nft_log_type, | |
96518518 | 288 | .size = NFT_EXPR_SIZE(sizeof(struct nft_log)), |
96518518 PM |
289 | .eval = nft_log_eval, |
290 | .init = nft_log_init, | |
291 | .destroy = nft_log_destroy, | |
292 | .dump = nft_log_dump, | |
ef1f7df9 PM |
293 | }; |
294 | ||
295 | static struct nft_expr_type nft_log_type __read_mostly = { | |
296 | .name = "log", | |
297 | .ops = &nft_log_ops, | |
96518518 PM |
298 | .policy = nft_log_policy, |
299 | .maxattr = NFTA_LOG_MAX, | |
ef1f7df9 | 300 | .owner = THIS_MODULE, |
96518518 PM |
301 | }; |
302 | ||
303 | static int __init nft_log_module_init(void) | |
304 | { | |
ef1f7df9 | 305 | return nft_register_expr(&nft_log_type); |
96518518 PM |
306 | } |
307 | ||
308 | static void __exit nft_log_module_exit(void) | |
309 | { | |
ef1f7df9 | 310 | nft_unregister_expr(&nft_log_type); |
96518518 PM |
311 | } |
312 | ||
313 | module_init(nft_log_module_init); | |
314 | module_exit(nft_log_module_exit); | |
315 | ||
316 | MODULE_LICENSE("GPL"); | |
317 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
318 | MODULE_ALIAS_NFT_EXPR("log"); | |
4cacc395 | 319 | MODULE_DESCRIPTION("Netfilter nf_tables log module"); |