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12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/netlink.h>
16#include <linux/netfilter.h>
17#include <linux/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables.h>
19#include <net/netfilter/nf_log.h>
20#include <linux/netdevice.h>
21
22static const char *nft_log_null_prefix = "";
23
24struct nft_log {
25 struct nf_loginfo loginfo;
26 char *prefix;
27};
28
29static void nft_log_eval(const struct nft_expr *expr,
30 struct nft_regs *regs,
31 const struct nft_pktinfo *pkt)
32{
33 const struct nft_log *priv = nft_expr_priv(expr);
34
35 nf_log_packet(pkt->net, pkt->pf, pkt->hook, pkt->skb, pkt->in,
36 pkt->out, &priv->loginfo, "%s", priv->prefix);
37}
38
39static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
40 [NFTA_LOG_GROUP] = { .type = NLA_U16 },
41 [NFTA_LOG_PREFIX] = { .type = NLA_STRING },
42 [NFTA_LOG_SNAPLEN] = { .type = NLA_U32 },
43 [NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 },
44 [NFTA_LOG_LEVEL] = { .type = NLA_U32 },
45 [NFTA_LOG_FLAGS] = { .type = NLA_U32 },
46};
47
48static int nft_log_init(const struct nft_ctx *ctx,
49 const struct nft_expr *expr,
50 const struct nlattr * const tb[])
51{
52 struct nft_log *priv = nft_expr_priv(expr);
53 struct nf_loginfo *li = &priv->loginfo;
54 const struct nlattr *nla;
55 int ret;
56
57 nla = tb[NFTA_LOG_PREFIX];
58 if (nla != NULL) {
59 priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
60 if (priv->prefix == NULL)
61 return -ENOMEM;
62 nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
63 } else {
64 priv->prefix = (char *)nft_log_null_prefix;
65 }
66
67 li->type = NF_LOG_TYPE_LOG;
68 if (tb[NFTA_LOG_LEVEL] != NULL &&
69 tb[NFTA_LOG_GROUP] != NULL)
70 return -EINVAL;
71 if (tb[NFTA_LOG_GROUP] != NULL)
72 li->type = NF_LOG_TYPE_ULOG;
73
74 switch (li->type) {
75 case NF_LOG_TYPE_LOG:
76 if (tb[NFTA_LOG_LEVEL] != NULL) {
77 li->u.log.level =
78 ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL]));
79 } else {
80 li->u.log.level = LOGLEVEL_WARNING;
81 }
82 if (tb[NFTA_LOG_FLAGS] != NULL) {
83 li->u.log.logflags =
84 ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
85 }
86 break;
87 case NF_LOG_TYPE_ULOG:
88 li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
89 if (tb[NFTA_LOG_SNAPLEN] != NULL) {
90 li->u.ulog.copy_len =
91 ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
92 }
93 if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
94 li->u.ulog.qthreshold =
95 ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
96 }
97 break;
98 }
99
100 if (ctx->afi->family == NFPROTO_INET) {
101 ret = nf_logger_find_get(NFPROTO_IPV4, li->type);
102 if (ret < 0)
103 return ret;
104
105 ret = nf_logger_find_get(NFPROTO_IPV6, li->type);
106 if (ret < 0) {
107 nf_logger_put(NFPROTO_IPV4, li->type);
108 return ret;
109 }
110 return 0;
111 }
112
113 return nf_logger_find_get(ctx->afi->family, li->type);
114}
115
116static void nft_log_destroy(const struct nft_ctx *ctx,
117 const struct nft_expr *expr)
118{
119 struct nft_log *priv = nft_expr_priv(expr);
120 struct nf_loginfo *li = &priv->loginfo;
121
122 if (priv->prefix != nft_log_null_prefix)
123 kfree(priv->prefix);
124
125 if (ctx->afi->family == NFPROTO_INET) {
126 nf_logger_put(NFPROTO_IPV4, li->type);
127 nf_logger_put(NFPROTO_IPV6, li->type);
128 } else {
129 nf_logger_put(ctx->afi->family, li->type);
130 }
131}
132
133static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)
134{
135 const struct nft_log *priv = nft_expr_priv(expr);
136 const struct nf_loginfo *li = &priv->loginfo;
137
138 if (priv->prefix != nft_log_null_prefix)
139 if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
140 goto nla_put_failure;
141 switch (li->type) {
142 case NF_LOG_TYPE_LOG:
143 if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
144 goto nla_put_failure;
145
146 if (li->u.log.logflags) {
147 if (nla_put_be32(skb, NFTA_LOG_FLAGS,
148 htonl(li->u.log.logflags)))
149 goto nla_put_failure;
150 }
151 break;
152 case NF_LOG_TYPE_ULOG:
153 if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
154 goto nla_put_failure;
155
156 if (li->u.ulog.copy_len) {
157 if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
158 htonl(li->u.ulog.copy_len)))
159 goto nla_put_failure;
160 }
161 if (li->u.ulog.qthreshold) {
162 if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
163 htons(li->u.ulog.qthreshold)))
164 goto nla_put_failure;
165 }
166 break;
167 }
168 return 0;
169
170nla_put_failure:
171 return -1;
172}
173
174static struct nft_expr_type nft_log_type;
175static const struct nft_expr_ops nft_log_ops = {
176 .type = &nft_log_type,
177 .size = NFT_EXPR_SIZE(sizeof(struct nft_log)),
178 .eval = nft_log_eval,
179 .init = nft_log_init,
180 .destroy = nft_log_destroy,
181 .dump = nft_log_dump,
182};
183
184static struct nft_expr_type nft_log_type __read_mostly = {
185 .name = "log",
186 .ops = &nft_log_ops,
187 .policy = nft_log_policy,
188 .maxattr = NFTA_LOG_MAX,
189 .owner = THIS_MODULE,
190};
191
192static int __init nft_log_module_init(void)
193{
194 return nft_register_expr(&nft_log_type);
195}
196
197static void __exit nft_log_module_exit(void)
198{
199 nft_unregister_expr(&nft_log_type);
200}
201
202module_init(nft_log_module_init);
203module_exit(nft_log_module_exit);
204
205MODULE_LICENSE("GPL");
206MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
207MODULE_ALIAS_NFT_EXPR("log");
208
