net/netfilter/nft_queue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2013 Eric Leblond <eric@regit.org>
   4  *
   5  * Development of this code partly funded by OISF
   6  * (http://www.openinfosecfoundation.org/)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/netlink.h>
  13 #include <linux/jhash.h>
  14 #include <linux/netfilter.h>
  15 #include <linux/netfilter/nf_tables.h>
  16 #include <net/netfilter/nf_tables.h>
  17 #include <net/netfilter/nf_queue.h>
  18
  19 static u32 jhash_initval __read_mostly;
  20
  21 struct nft_queue {
  22         enum nft_registers      sreg_qnum:8;
  23         u16                     queuenum;
  24         u16                     queues_total;
  25         u16                     flags;
  26 };
  27
  28 static void nft_queue_eval(const struct nft_expr *expr,
  29                            struct nft_regs *regs,
  30                            const struct nft_pktinfo *pkt)
  31 {
  32         struct nft_queue *priv = nft_expr_priv(expr);
  33         u32 queue = priv->queuenum;
  34         u32 ret;
  35
  36         if (priv->queues_total > 1) {
  37                 if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT) {
  38                         int cpu = raw_smp_processor_id();
  39
  40                         queue = priv->queuenum + cpu % priv->queues_total;
  41                 } else {
  42                         queue = nfqueue_hash(pkt->skb, queue,
  43                                              priv->queues_total, nft_pf(pkt),
  44                                              jhash_initval);
  45                 }
  46         }
  47
  48         ret = NF_QUEUE_NR(queue);
  49         if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
  50                 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
  51
  52         regs->verdict.code = ret;
  53 }
  54
  55 static void nft_queue_sreg_eval(const struct nft_expr *expr,
  56                                 struct nft_regs *regs,
  57                                 const struct nft_pktinfo *pkt)
  58 {
  59         struct nft_queue *priv = nft_expr_priv(expr);
  60         u32 queue, ret;
  61
  62         queue = regs->data[priv->sreg_qnum];
  63
  64         ret = NF_QUEUE_NR(queue);
  65         if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
  66                 ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
  67
  68         regs->verdict.code = ret;
  69 }
  70
  71 static const struct nla_policy nft_queue_policy[NFTA_QUEUE_MAX + 1] = {
  72         [NFTA_QUEUE_NUM]        = { .type = NLA_U16 },
  73         [NFTA_QUEUE_TOTAL]      = { .type = NLA_U16 },
  74         [NFTA_QUEUE_FLAGS]      = { .type = NLA_U16 },
  75         [NFTA_QUEUE_SREG_QNUM]  = { .type = NLA_U32 },
  76 };
  77
  78 static int nft_queue_init(const struct nft_ctx *ctx,
  79                           const struct nft_expr *expr,
  80                           const struct nlattr * const tb[])
  81 {
  82         struct nft_queue *priv = nft_expr_priv(expr);
  83         u32 maxid;
  84
  85         priv->queuenum = ntohs(nla_get_be16(tb[NFTA_QUEUE_NUM]));
  86
  87         if (tb[NFTA_QUEUE_TOTAL])
  88                 priv->queues_total = ntohs(nla_get_be16(tb[NFTA_QUEUE_TOTAL]));
  89         else
  90                 priv->queues_total = 1;
  91
  92         if (priv->queues_total == 0)
  93                 return -EINVAL;
  94
  95         maxid = priv->queues_total - 1 + priv->queuenum;
  96         if (maxid > U16_MAX)
  97                 return -ERANGE;
  98
  99         if (tb[NFTA_QUEUE_FLAGS]) {
 100                 priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
 101                 if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
 102                         return -EINVAL;
 103         }
 104         return 0;
 105 }
 106
 107 static int nft_queue_sreg_init(const struct nft_ctx *ctx,
 108                                const struct nft_expr *expr,
 109                                const struct nlattr * const tb[])
 110 {
 111         struct nft_queue *priv = nft_expr_priv(expr);
 112         int err;
 113
 114         priv->sreg_qnum = nft_parse_register(tb[NFTA_QUEUE_SREG_QNUM]);
 115         err = nft_validate_register_load(priv->sreg_qnum, sizeof(u32));
 116         if (err < 0)
 117                 return err;
 118
 119         if (tb[NFTA_QUEUE_FLAGS]) {
 120                 priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
 121                 if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
 122                         return -EINVAL;
 123                 if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT)
 124                         return -EOPNOTSUPP;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static int nft_queue_dump(struct sk_buff *skb, const struct nft_expr *expr)
 131 {
 132         const struct nft_queue *priv = nft_expr_priv(expr);
 133
 134         if (nla_put_be16(skb, NFTA_QUEUE_NUM, htons(priv->queuenum)) ||
 135             nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)) ||
 136             nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
 137                 goto nla_put_failure;
 138
 139         return 0;
 140
 141 nla_put_failure:
 142         return -1;
 143 }
 144
 145 static int
 146 nft_queue_sreg_dump(struct sk_buff *skb, const struct nft_expr *expr)
 147 {
 148         const struct nft_queue *priv = nft_expr_priv(expr);
 149
 150         if (nft_dump_register(skb, NFTA_QUEUE_SREG_QNUM, priv->sreg_qnum) ||
 151             nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
 152                 goto nla_put_failure;
 153
 154         return 0;
 155
 156 nla_put_failure:
 157         return -1;
 158 }
 159
 160 static struct nft_expr_type nft_queue_type;
 161 static const struct nft_expr_ops nft_queue_ops = {
 162         .type           = &nft_queue_type,
 163         .size           = NFT_EXPR_SIZE(sizeof(struct nft_queue)),
 164         .eval           = nft_queue_eval,
 165         .init           = nft_queue_init,
 166         .dump           = nft_queue_dump,
 167 };
 168
 169 static const struct nft_expr_ops nft_queue_sreg_ops = {
 170         .type           = &nft_queue_type,
 171         .size           = NFT_EXPR_SIZE(sizeof(struct nft_queue)),
 172         .eval           = nft_queue_sreg_eval,
 173         .init           = nft_queue_sreg_init,
 174         .dump           = nft_queue_sreg_dump,
 175 };
 176
 177 static const struct nft_expr_ops *
 178 nft_queue_select_ops(const struct nft_ctx *ctx,
 179                      const struct nlattr * const tb[])
 180 {
 181         if (tb[NFTA_QUEUE_NUM] && tb[NFTA_QUEUE_SREG_QNUM])
 182                 return ERR_PTR(-EINVAL);
 183
 184         init_hashrandom(&jhash_initval);
 185
 186         if (tb[NFTA_QUEUE_NUM])
 187                 return &nft_queue_ops;
 188
 189         if (tb[NFTA_QUEUE_SREG_QNUM])
 190                 return &nft_queue_sreg_ops;
 191
 192         return ERR_PTR(-EINVAL);
 193 }
 194
 195 static struct nft_expr_type nft_queue_type __read_mostly = {
 196         .name           = "queue",
 197         .select_ops     = nft_queue_select_ops,
 198         .policy         = nft_queue_policy,
 199         .maxattr        = NFTA_QUEUE_MAX,
 200         .owner          = THIS_MODULE,
 201 };
 202
 203 static int __init nft_queue_module_init(void)
 204 {
 205         return nft_register_expr(&nft_queue_type);
 206 }
 207
 208 static void __exit nft_queue_module_exit(void)
 209 {
 210         nft_unregister_expr(&nft_queue_type);
 211 }
 212
 213 module_init(nft_queue_module_init);
 214 module_exit(nft_queue_module_exit);
 215
 216 MODULE_LICENSE("GPL");
 217 MODULE_AUTHOR("Eric Leblond <eric@regit.org>");
 218 MODULE_ALIAS_NFT_EXPR("queue");