| 1 | /* |
| 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
| 3 | * Copyright (c) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * Development of this code funded by Astaro AG (http://www.astaro.com/) |
| 10 | */ |
| 11 | |
| 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 | |
| 22 | static const char *nft_log_null_prefix = ""; |
| 23 | |
| 24 | struct nft_log { |
| 25 | struct nf_loginfo loginfo; |
| 26 | char *prefix; |
| 27 | }; |
| 28 | |
| 29 | static 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 | |
| 39 | static 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 | |
| 48 | static 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 | |
| 116 | static 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 | |
| 133 | static 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 | |
| 170 | nla_put_failure: |
| 171 | return -1; |
| 172 | } |
| 173 | |
| 174 | static struct nft_expr_type nft_log_type; |
| 175 | static 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 | |
| 184 | static 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 | |
| 192 | static int __init nft_log_module_init(void) |
| 193 | { |
| 194 | return nft_register_expr(&nft_log_type); |
| 195 | } |
| 196 | |
| 197 | static void __exit nft_log_module_exit(void) |
| 198 | { |
| 199 | nft_unregister_expr(&nft_log_type); |
| 200 | } |
| 201 | |
| 202 | module_init(nft_log_module_init); |
| 203 | module_exit(nft_log_module_exit); |
| 204 | |
| 205 | MODULE_LICENSE("GPL"); |
| 206 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 207 | MODULE_ALIAS_NFT_EXPR("log"); |