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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 struct net *net = dev_net(pkt->in ? pkt->in : pkt->out);
35
36 nf_log_packet(net, pkt->ops->pf, pkt->ops->hooknum, pkt->skb, pkt->in,
37 pkt->out, &priv->loginfo, "%s", priv->prefix);
38}
39
40static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
41 [NFTA_LOG_GROUP] = { .type = NLA_U16 },
42 [NFTA_LOG_PREFIX] = { .type = NLA_STRING },
43 [NFTA_LOG_SNAPLEN] = { .type = NLA_U32 },
44 [NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 },
45 [NFTA_LOG_LEVEL] = { .type = NLA_U32 },
46 [NFTA_LOG_FLAGS] = { .type = NLA_U32 },
47};
48
49static int nft_log_init(const struct nft_ctx *ctx,
50 const struct nft_expr *expr,
51 const struct nlattr * const tb[])
52{
53 struct nft_log *priv = nft_expr_priv(expr);
54 struct nf_loginfo *li = &priv->loginfo;
55 const struct nlattr *nla;
56 int ret;
57
58 nla = tb[NFTA_LOG_PREFIX];
59 if (nla != NULL) {
60 priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
61 if (priv->prefix == NULL)
62 return -ENOMEM;
63 nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
64 } else {
65 priv->prefix = (char *)nft_log_null_prefix;
66 }
67
68 li->type = NF_LOG_TYPE_LOG;
69 if (tb[NFTA_LOG_LEVEL] != NULL &&
70 tb[NFTA_LOG_GROUP] != NULL)
71 return -EINVAL;
72 if (tb[NFTA_LOG_GROUP] != NULL)
73 li->type = NF_LOG_TYPE_ULOG;
74
75 switch (li->type) {
76 case NF_LOG_TYPE_LOG:
77 if (tb[NFTA_LOG_LEVEL] != NULL) {
78 li->u.log.level =
79 ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL]));
80 } else {
81 li->u.log.level = LOGLEVEL_WARNING;
82 }
83 if (tb[NFTA_LOG_FLAGS] != NULL) {
84 li->u.log.logflags =
85 ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
86 }
87 break;
88 case NF_LOG_TYPE_ULOG:
89 li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
90 if (tb[NFTA_LOG_SNAPLEN] != NULL) {
91 li->u.ulog.copy_len =
92 ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
93 }
94 if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
95 li->u.ulog.qthreshold =
96 ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
97 }
98 break;
99 }
100
101 if (ctx->afi->family == NFPROTO_INET) {
102 ret = nf_logger_find_get(NFPROTO_IPV4, li->type);
103 if (ret < 0)
104 return ret;
105
106 ret = nf_logger_find_get(NFPROTO_IPV6, li->type);
107 if (ret < 0) {
108 nf_logger_put(NFPROTO_IPV4, li->type);
109 return ret;
110 }
111 return 0;
112 }
113
114 return nf_logger_find_get(ctx->afi->family, li->type);
115}
116
117static void nft_log_destroy(const struct nft_ctx *ctx,
118 const struct nft_expr *expr)
119{
120 struct nft_log *priv = nft_expr_priv(expr);
121 struct nf_loginfo *li = &priv->loginfo;
122
123 if (priv->prefix != nft_log_null_prefix)
124 kfree(priv->prefix);
125
126 if (ctx->afi->family == NFPROTO_INET) {
127 nf_logger_put(NFPROTO_IPV4, li->type);
128 nf_logger_put(NFPROTO_IPV6, li->type);
129 } else {
130 nf_logger_put(ctx->afi->family, li->type);
131 }
132}
133
134static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)
135{
136 const struct nft_log *priv = nft_expr_priv(expr);
137 const struct nf_loginfo *li = &priv->loginfo;
138
139 if (priv->prefix != nft_log_null_prefix)
140 if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
141 goto nla_put_failure;
142 switch (li->type) {
143 case NF_LOG_TYPE_LOG:
144 if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
145 goto nla_put_failure;
146
147 if (li->u.log.logflags) {
148 if (nla_put_be32(skb, NFTA_LOG_FLAGS,
149 htonl(li->u.log.logflags)))
150 goto nla_put_failure;
151 }
152 break;
153 case NF_LOG_TYPE_ULOG:
154 if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
155 goto nla_put_failure;
156
157 if (li->u.ulog.copy_len) {
158 if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
159 htonl(li->u.ulog.copy_len)))
160 goto nla_put_failure;
161 }
162 if (li->u.ulog.qthreshold) {
163 if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
164 htons(li->u.ulog.qthreshold)))
165 goto nla_put_failure;
166 }
167 break;
168 }
169 return 0;
170
171nla_put_failure:
172 return -1;
173}
174
175static struct nft_expr_type nft_log_type;
176static const struct nft_expr_ops nft_log_ops = {
177 .type = &nft_log_type,
178 .size = NFT_EXPR_SIZE(sizeof(struct nft_log)),
179 .eval = nft_log_eval,
180 .init = nft_log_init,
181 .destroy = nft_log_destroy,
182 .dump = nft_log_dump,
183};
184
185static struct nft_expr_type nft_log_type __read_mostly = {
186 .name = "log",
187 .ops = &nft_log_ops,
188 .policy = nft_log_policy,
189 .maxattr = NFTA_LOG_MAX,
190 .owner = THIS_MODULE,
191};
192
193static int __init nft_log_module_init(void)
194{
195 return nft_register_expr(&nft_log_type);
196}
197
198static void __exit nft_log_module_exit(void)
199{
200 nft_unregister_expr(&nft_log_type);
201}
202
203module_init(nft_log_module_init);
204module_exit(nft_log_module_exit);
205
206MODULE_LICENSE("GPL");
207MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
208MODULE_ALIAS_NFT_EXPR("log");
209
