net/netfilter/nft_queue.c

   1 /*
   2  * Copyright (c) 2013 Eric Leblond <eric@regit.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Development of this code partly funded by OISF
   9  * (http://www.openinfosecfoundation.org/)
  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/jhash.h>
  17 #include <linux/netfilter.h>
  18 #include <linux/netfilter/nf_tables.h>
  19 #include <net/netfilter/nf_tables.h>
  20 #include <net/netfilter/nf_queue.h>
  21
  22 static u32 jhash_initval __read_mostly;
  23
  24 struct nft_queue {
  25         enum nft_registers      sreg_qnum:8;
  26         u16                     queuenum;
  27         u16                     queues_total;
  28         u16                     flags;
  29 };
  30
  31 static void nft_queue_eval(const struct nft_expr *expr,
  32                            struct nft_regs *regs,
  33                            const struct nft_pktinfo *pkt)
  34 {
  35         struct nft_queue *priv = nft_expr_priv(expr);
  36         u32 queue = priv->queuenum;
  37         u32 ret;
  38
  39         if (priv->queues_total > 1) {
  40                 if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT) {
  41                         int cpu = raw_smp_processor_id();
  42
  43                         queue = priv->queuenum + cpu % priv->queues_total;
  44                 } else {
  45                         queue = nfqueue_hash(pkt->skb, queue,
  46                                              priv->queues_total, nft_pf(pkt),
  47                                              jhash_initval);
  48                 }
  49         }
  50
  51         ret = NF_QUEUE_NR(queue);
  52         if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
  53                 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
  54
  55         regs->verdict.code = ret;
  56 }
  57
  58 static void nft_queue_sreg_eval(const struct nft_expr *expr,
  59                                 struct nft_regs *regs,
  60                                 const struct nft_pktinfo *pkt)
  61 {
  62         struct nft_queue *priv = nft_expr_priv(expr);
  63         u32 queue, ret;
  64
  65         queue = regs->data[priv->sreg_qnum];
  66
  67         ret = NF_QUEUE_NR(queue);
  68         if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
  69                 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
  70
  71         regs->verdict.code = ret;
  72 }
  73
  74 static const struct nla_policy nft_queue_policy[NFTA_QUEUE_MAX + 1] = {
  75         [NFTA_QUEUE_NUM]        = { .type = NLA_U16 },
  76         [NFTA_QUEUE_TOTAL]      = { .type = NLA_U16 },
  77         [NFTA_QUEUE_FLAGS]      = { .type = NLA_U16 },
  78         [NFTA_QUEUE_SREG_QNUM]  = { .type = NLA_U32 },
  79 };
  80
  81 static int nft_queue_init(const struct nft_ctx *ctx,
  82                           const struct nft_expr *expr,
  83                           const struct nlattr * const tb[])
  84 {
  85         struct nft_queue *priv = nft_expr_priv(expr);
  86         u32 maxid;
  87
  88         priv->queuenum = ntohs(nla_get_be16(tb[NFTA_QUEUE_NUM]));
  89
  90         if (tb[NFTA_QUEUE_TOTAL])
  91                 priv->queues_total = ntohs(nla_get_be16(tb[NFTA_QUEUE_TOTAL]));
  92         else
  93                 priv->queues_total = 1;
  94
  95         if (priv->queues_total == 0)
  96                 return -EINVAL;
  97
  98         maxid = priv->queues_total - 1 + priv->queuenum;
  99         if (maxid > U16_MAX)
 100                 return -ERANGE;
 101
 102         if (tb[NFTA_QUEUE_FLAGS]) {
 103                 priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
 104                 if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
 105                         return -EINVAL;
 106         }
 107         return 0;
 108 }
 109
 110 static int nft_queue_sreg_init(const struct nft_ctx *ctx,
 111                                const struct nft_expr *expr,
 112                                const struct nlattr * const tb[])
 113 {
 114         struct nft_queue *priv = nft_expr_priv(expr);
 115         int err;
 116
 117         priv->sreg_qnum = nft_parse_register(tb[NFTA_QUEUE_SREG_QNUM]);
 118         err = nft_validate_register_load(priv->sreg_qnum, sizeof(u32));
 119         if (err < 0)
 120                 return err;
 121
 122         if (tb[NFTA_QUEUE_FLAGS]) {
 123                 priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
 124                 if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
 125                         return -EINVAL;
 126                 if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT)
 127                         return -EOPNOTSUPP;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int nft_queue_dump(struct sk_buff *skb, const struct nft_expr *expr)
 134 {
 135         const struct nft_queue *priv = nft_expr_priv(expr);
 136
 137         if (nla_put_be16(skb, NFTA_QUEUE_NUM, htons(priv->queuenum)) ||
 138             nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)) ||
 139             nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
 140                 goto nla_put_failure;
 141
 142         return 0;
 143
 144 nla_put_failure:
 145         return -1;
 146 }
 147
 148 static int
 149 nft_queue_sreg_dump(struct sk_buff *skb, const struct nft_expr *expr)
 150 {
 151         const struct nft_queue *priv = nft_expr_priv(expr);
 152
 153         if (nft_dump_register(skb, NFTA_QUEUE_SREG_QNUM, priv->sreg_qnum) ||
 154             nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
 155                 goto nla_put_failure;
 156
 157         return 0;
 158
 159 nla_put_failure:
 160         return -1;
 161 }
 162
 163 static struct nft_expr_type nft_queue_type;
 164 static const struct nft_expr_ops nft_queue_ops = {
 165         .type           = &nft_queue_type,
 166         .size           = NFT_EXPR_SIZE(sizeof(struct nft_queue)),
 167         .eval           = nft_queue_eval,
 168         .init           = nft_queue_init,
 169         .dump           = nft_queue_dump,
 170 };
 171
 172 static const struct nft_expr_ops nft_queue_sreg_ops = {
 173         .type           = &nft_queue_type,
 174         .size           = NFT_EXPR_SIZE(sizeof(struct nft_queue)),
 175         .eval           = nft_queue_sreg_eval,
 176         .init           = nft_queue_sreg_init,
 177         .dump           = nft_queue_sreg_dump,
 178 };
 179
 180 static const struct nft_expr_ops *
 181 nft_queue_select_ops(const struct nft_ctx *ctx,
 182                      const struct nlattr * const tb[])
 183 {
 184         if (tb[NFTA_QUEUE_NUM] && tb[NFTA_QUEUE_SREG_QNUM])
 185                 return ERR_PTR(-EINVAL);
 186
 187         init_hashrandom(&jhash_initval);
 188
 189         if (tb[NFTA_QUEUE_NUM])
 190                 return &nft_queue_ops;
 191
 192         if (tb[NFTA_QUEUE_SREG_QNUM])
 193                 return &nft_queue_sreg_ops;
 194
 195         return ERR_PTR(-EINVAL);
 196 }
 197
 198 static struct nft_expr_type nft_queue_type __read_mostly = {
 199         .name           = "queue",
 200         .select_ops     = nft_queue_select_ops,
 201         .policy         = nft_queue_policy,
 202         .maxattr        = NFTA_QUEUE_MAX,
 203         .owner          = THIS_MODULE,
 204 };
 205
 206 static int __init nft_queue_module_init(void)
 207 {
 208         return nft_register_expr(&nft_queue_type);
 209 }
 210
 211 static void __exit nft_queue_module_exit(void)
 212 {
 213         nft_unregister_expr(&nft_queue_type);
 214 }
 215
 216 module_init(nft_queue_module_init);
 217 module_exit(nft_queue_module_exit);
 218
 219 MODULE_LICENSE("GPL");
 220 MODULE_AUTHOR("Eric Leblond <eric@regit.org>");
 221 MODULE_ALIAS_NFT_EXPR("queue");