target/linux/generic/pending-4.9/610-netfilter_match_bypass_default_checks.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: kernel: add a new version of my netfilter speedup patches for linux 2.6.39 and 3.0
   3
   4 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   5 ---
   6  include/uapi/linux/netfilter_ipv4/ip_tables.h |  1 +
   7  net/ipv4/netfilter/ip_tables.c                | 37 +++++++++++++++++++++++++++
   8  2 files changed, 38 insertions(+)
   9
  10 diff --git a/include/uapi/linux/netfilter_ipv4/ip_tables.h b/include/uapi/linux/netfilter_ipv4/ip_tables.h
  11 index d0da53d96d93..f279daa13c0f 100644
  12 --- a/include/uapi/linux/netfilter_ipv4/ip_tables.h
  13 +++ b/include/uapi/linux/netfilter_ipv4/ip_tables.h
  14 @@ -88,6 +88,7 @@ struct ipt_ip {
  15  #define IPT_F_FRAG             0x01    /* Set if rule is a fragment rule */
  16  #define IPT_F_GOTO             0x02    /* Set if jump is a goto */
  17  #define IPT_F_MASK             0x03    /* All possible flag bits mask. */
  18 +#define IPT_F_NO_DEF_MATCH     0x80    /* Internal: no default match rules present */
  19
  20  /* Values for "inv" field in struct ipt_ip. */
  21  #define IPT_INV_VIA_IN         0x01    /* Invert the sense of IN IFACE. */
  22 diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
  23 index 7c00ce90adb8..d919350a0e8b 100644
  24 --- a/net/ipv4/netfilter/ip_tables.c
  25 +++ b/net/ipv4/netfilter/ip_tables.c
  26 @@ -58,6 +58,9 @@ ip_packet_match(const struct iphdr *ip,
  27  {
  28         unsigned long ret;
  29
  30 +       if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
  31 +               return true;
  32 +
  33         if (NF_INVF(ipinfo, IPT_INV_SRCIP,
  34                     (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) ||
  35             NF_INVF(ipinfo, IPT_INV_DSTIP,
  36 @@ -88,6 +91,29 @@ ip_packet_match(const struct iphdr *ip,
  37         return true;
  38  }
  39
  40 +static void
  41 +ip_checkdefault(struct ipt_ip *ip)
  42 +{
  43 +       static const char iface_mask[IFNAMSIZ] = {};
  44 +
  45 +       if (ip->invflags || ip->flags & IPT_F_FRAG)
  46 +               return;
  47 +
  48 +       if (memcmp(ip->iniface_mask, iface_mask, IFNAMSIZ) != 0)
  49 +               return;
  50 +
  51 +       if (memcmp(ip->outiface_mask, iface_mask, IFNAMSIZ) != 0)
  52 +               return;
  53 +
  54 +       if (ip->smsk.s_addr || ip->dmsk.s_addr)
  55 +               return;
  56 +
  57 +       if (ip->proto)
  58 +               return;
  59 +
  60 +       ip->flags |= IPT_F_NO_DEF_MATCH;
  61 +}
  62 +
  63  static bool
  64  ip_checkentry(const struct ipt_ip *ip)
  65  {
  66 @@ -545,6 +571,8 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
  67         struct xt_entry_match *ematch;
  68         unsigned long pcnt;
  69
  70 +       ip_checkdefault(&e->ip);
  71 +
  72         pcnt = xt_percpu_counter_alloc();
  73         if (IS_ERR_VALUE(pcnt))
  74                 return -ENOMEM;
  75 @@ -824,6 +852,7 @@ copy_entries_to_user(unsigned int total_size,
  76         const struct xt_table_info *private = table->private;
  77         int ret = 0;
  78         const void *loc_cpu_entry;
  79 +       u8 flags;
  80
  81         counters = alloc_counters(table);
  82         if (IS_ERR(counters))
  83 @@ -851,6 +880,14 @@ copy_entries_to_user(unsigned int total_size,
  84                         goto free_counters;
  85                 }
  86
  87 +               flags = e->ip.flags & IPT_F_MASK;
  88 +               if (copy_to_user(userptr + off
  89 +                                + offsetof(struct ipt_entry, ip.flags),
  90 +                                &flags, sizeof(flags)) != 0) {
  91 +                       ret = -EFAULT;
  92 +                       goto free_counters;
  93 +               }
  94 +
  95                 for (i = sizeof(struct ipt_entry);
  96                      i < e->target_offset;
  97                      i += m->u.match_size) {
  98 --
  99 2.11.0
 100