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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 err;
56
57 li->type = NF_LOG_TYPE_LOG;
58 if (tb[NFTA_LOG_LEVEL] != NULL &&
59 tb[NFTA_LOG_GROUP] != NULL)
60 return -EINVAL;
61 if (tb[NFTA_LOG_GROUP] != NULL)
62 li->type = NF_LOG_TYPE_ULOG;
63
64 nla = tb[NFTA_LOG_PREFIX];
65 if (nla != NULL) {
66 priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
67 if (priv->prefix == NULL)
68 return -ENOMEM;
69 nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
70 } else {
71 priv->prefix = (char *)nft_log_null_prefix;
72 }
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 (li->u.log.level > LOGLEVEL_DEBUG) {
83 err = -EINVAL;
84 goto err1;
85 }
86
87 if (tb[NFTA_LOG_FLAGS] != NULL) {
88 li->u.log.logflags =
89 ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
90 }
91 break;
92 case NF_LOG_TYPE_ULOG:
93 li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
94 if (tb[NFTA_LOG_SNAPLEN] != NULL) {
95 li->u.ulog.flags |= NF_LOG_F_COPY_LEN;
96 li->u.ulog.copy_len =
97 ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
98 }
99 if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
100 li->u.ulog.qthreshold =
101 ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
102 }
103 break;
104 }
105
106 err = nf_logger_find_get(ctx->afi->family, li->type);
107 if (err < 0)
108 goto err1;
109
110 return 0;
111
112err1:
113 if (priv->prefix != nft_log_null_prefix)
114 kfree(priv->prefix);
115 return err;
116}
117
118static void nft_log_destroy(const struct nft_ctx *ctx,
119 const struct nft_expr *expr)
120{
121 struct nft_log *priv = nft_expr_priv(expr);
122 struct nf_loginfo *li = &priv->loginfo;
123
124 if (priv->prefix != nft_log_null_prefix)
125 kfree(priv->prefix);
126
127 nf_logger_put(ctx->afi->family, li->type);
128}
129
130static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)
131{
132 const struct nft_log *priv = nft_expr_priv(expr);
133 const struct nf_loginfo *li = &priv->loginfo;
134
135 if (priv->prefix != nft_log_null_prefix)
136 if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
137 goto nla_put_failure;
138 switch (li->type) {
139 case NF_LOG_TYPE_LOG:
140 if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
141 goto nla_put_failure;
142
143 if (li->u.log.logflags) {
144 if (nla_put_be32(skb, NFTA_LOG_FLAGS,
145 htonl(li->u.log.logflags)))
146 goto nla_put_failure;
147 }
148 break;
149 case NF_LOG_TYPE_ULOG:
150 if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
151 goto nla_put_failure;
152
153 if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) {
154 if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
155 htonl(li->u.ulog.copy_len)))
156 goto nla_put_failure;
157 }
158 if (li->u.ulog.qthreshold) {
159 if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
160 htons(li->u.ulog.qthreshold)))
161 goto nla_put_failure;
162 }
163 break;
164 }
165 return 0;
166
167nla_put_failure:
168 return -1;
169}
170
171static struct nft_expr_type nft_log_type;
172static const struct nft_expr_ops nft_log_ops = {
173 .type = &nft_log_type,
174 .size = NFT_EXPR_SIZE(sizeof(struct nft_log)),
175 .eval = nft_log_eval,
176 .init = nft_log_init,
177 .destroy = nft_log_destroy,
178 .dump = nft_log_dump,
179};
180
181static struct nft_expr_type nft_log_type __read_mostly = {
182 .name = "log",
183 .ops = &nft_log_ops,
184 .policy = nft_log_policy,
185 .maxattr = NFTA_LOG_MAX,
186 .owner = THIS_MODULE,
187};
188
189static int __init nft_log_module_init(void)
190{
191 return nft_register_expr(&nft_log_type);
192}
193
194static void __exit nft_log_module_exit(void)
195{
196 nft_unregister_expr(&nft_log_type);
197}
198
199module_init(nft_log_module_init);
200module_exit(nft_log_module_exit);
201
202MODULE_LICENSE("GPL");
203MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
204MODULE_ALIAS_NFT_EXPR("log");
205
