target/linux/generic/pending-4.19/600-netfilter_conntrack_flush.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: netfilter: add support for flushing conntrack via /proc
   3
   4 lede-commit 8193bbe59a74d34d6a26d4a8cb857b1952905314
   5 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   6 ---
   7  net/netfilter/nf_conntrack_standalone.c | 59 ++++++++++++++++++++++++++++++++-
   8  1 file changed, 58 insertions(+), 1 deletion(-)
   9
  10 --- a/net/netfilter/nf_conntrack_standalone.c
  11 +++ b/net/netfilter/nf_conntrack_standalone.c
  12 @@ -9,6 +9,7 @@
  13  #include <linux/percpu.h>
  14  #include <linux/netdevice.h>
  15  #include <linux/security.h>
  16 +#include <linux/inet.h>
  17  #include <net/net_namespace.h>
  18  #ifdef CONFIG_SYSCTL
  19  #include <linux/sysctl.h>
  20 @@ -433,6 +434,56 @@ static int ct_cpu_seq_show(struct seq_fi
  21         return 0;
  22  }
  23
  24 +struct kill_request {
  25 +       u16 family;
  26 +       union nf_inet_addr addr;
  27 +};
  28 +
  29 +static int kill_matching(struct nf_conn *i, void *data)
  30 +{
  31 +       struct kill_request *kr = data;
  32 +       struct nf_conntrack_tuple *t1 = &i->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
  33 +       struct nf_conntrack_tuple *t2 = &i->tuplehash[IP_CT_DIR_REPLY].tuple;
  34 +
  35 +       if (!kr->family)
  36 +               return 1;
  37 +
  38 +       if (t1->src.l3num != kr->family)
  39 +               return 0;
  40 +
  41 +       return (nf_inet_addr_cmp(&kr->addr, &t1->src.u3) ||
  42 +               nf_inet_addr_cmp(&kr->addr, &t1->dst.u3) ||
  43 +               nf_inet_addr_cmp(&kr->addr, &t2->src.u3) ||
  44 +               nf_inet_addr_cmp(&kr->addr, &t2->dst.u3));
  45 +}
  46 +
  47 +static int ct_file_write(struct file *file, char *buf, size_t count)
  48 +{
  49 +       struct seq_file *seq = file->private_data;
  50 +       struct net *net = seq_file_net(seq);
  51 +       struct kill_request kr = { };
  52 +
  53 +       if (count == 0)
  54 +               return 0;
  55 +
  56 +       if (count >= INET6_ADDRSTRLEN)
  57 +               count = INET6_ADDRSTRLEN - 1;
  58 +
  59 +       if (strnchr(buf, count, ':')) {
  60 +               kr.family = AF_INET6;
  61 +               if (!in6_pton(buf, count, (void *)&kr.addr, '\n', NULL))
  62 +                       return -EINVAL;
  63 +       } else if (strnchr(buf, count, '.')) {
  64 +               kr.family = AF_INET;
  65 +               if (!in4_pton(buf, count, (void *)&kr.addr, '\n', NULL))
  66 +                       return -EINVAL;
  67 +       }
  68 +
  69 +       nf_ct_iterate_cleanup_net(net, kill_matching, &kr, 0, 0);
  70 +
  71 +       return 0;
  72 +}
  73 +
  74  static const struct seq_operations ct_cpu_seq_ops = {
  75         .start  = ct_cpu_seq_start,
  76         .next   = ct_cpu_seq_next,
  77 @@ -446,8 +497,9 @@ static int nf_conntrack_standalone_init_
  78         kuid_t root_uid;
  79         kgid_t root_gid;
  80
  81 -       pde = proc_create_net("nf_conntrack", 0440, net->proc_net, &ct_seq_ops,
  82 -                       sizeof(struct ct_iter_state));
  83 +       pde = proc_create_net_data_write("nf_conntrack", 0440, net->proc_net,
  84 +                                        &ct_seq_ops, &ct_file_write,
  85 +                                        sizeof(struct ct_iter_state), NULL);
  86         if (!pde)
  87                 goto out_nf_conntrack;
  88