target/linux/generic/pending-4.9/600-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 diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
  11 index 5f446cd9f3fd..4c1856b5151f 100644
  12 --- a/net/netfilter/nf_conntrack_standalone.c
  13 +++ b/net/netfilter/nf_conntrack_standalone.c
  14 @@ -17,6 +17,7 @@
  15  #include <linux/percpu.h>
  16  #include <linux/netdevice.h>
  17  #include <linux/security.h>
  18 +#include <linux/inet.h>
  19  #include <net/net_namespace.h>
  20  #ifdef CONFIG_SYSCTL
  21  #include <linux/sysctl.h>
  22 @@ -298,10 +299,66 @@ static int ct_open(struct inode *inode, struct file *file)
  23                         sizeof(struct ct_iter_state));
  24  }
  25
  26 +struct kill_request {
  27 +       u16 family;
  28 +       union nf_inet_addr addr;
  29 +};
  30 +
  31 +static int kill_matching(struct nf_conn *i, void *data)
  32 +{
  33 +       struct kill_request *kr = data;
  34 +       struct nf_conntrack_tuple *t1 = &i->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
  35 +       struct nf_conntrack_tuple *t2 = &i->tuplehash[IP_CT_DIR_REPLY].tuple;
  36 +
  37 +       if (!kr->family)
  38 +               return 1;
  39 +
  40 +       if (t1->src.l3num != kr->family)
  41 +               return 0;
  42 +
  43 +       return (nf_inet_addr_cmp(&kr->addr, &t1->src.u3) ||
  44 +               nf_inet_addr_cmp(&kr->addr, &t1->dst.u3) ||
  45 +               nf_inet_addr_cmp(&kr->addr, &t2->src.u3) ||
  46 +               nf_inet_addr_cmp(&kr->addr, &t2->dst.u3));
  47 +}
  48 +
  49 +static ssize_t ct_file_write(struct file *file, const char __user *buf,
  50 +                            size_t count, loff_t *ppos)
  51 +{
  52 +       struct seq_file *seq = file->private_data;
  53 +       struct net *net = seq_file_net(seq);
  54 +       struct kill_request kr = { };
  55 +       char req[INET6_ADDRSTRLEN] = { };
  56 +
  57 +       if (count == 0)
  58 +               return 0;
  59 +
  60 +       if (count >= INET6_ADDRSTRLEN)
  61 +               count = INET6_ADDRSTRLEN - 1;
  62 +
  63 +       if (copy_from_user(req, buf, count))
  64 +               return -EFAULT;
  65 +
  66 +       if (strnchr(req, count, ':')) {
  67 +               kr.family = AF_INET6;
  68 +               if (!in6_pton(req, count, (void *)&kr.addr, '\n', NULL))
  69 +                       return -EINVAL;
  70 +       } else if (strnchr(req, count, '.')) {
  71 +               kr.family = AF_INET;
  72 +               if (!in4_pton(req, count, (void *)&kr.addr, '\n', NULL))
  73 +                       return -EINVAL;
  74 +       }
  75 +
  76 +       nf_ct_iterate_cleanup(net, kill_matching, &kr, 0, 0);
  77 +
  78 +       return count;
  79 +}
  80 +
  81  static const struct file_operations ct_file_ops = {
  82         .owner   = THIS_MODULE,
  83         .open    = ct_open,
  84         .read    = seq_read,
  85 +       .write   = ct_file_write,
  86         .llseek  = seq_lseek,
  87         .release = seq_release_net,
  88  };
  89 @@ -405,7 +462,7 @@ static int nf_conntrack_standalone_init_proc(struct net *net)
  90         kuid_t root_uid;
  91         kgid_t root_gid;
  92
  93 -       pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
  94 +       pde = proc_create("nf_conntrack", 0660, net->proc_net, &ct_file_ops);
  95         if (!pde)
  96                 goto out_nf_conntrack;
  97
  98 --
  99 2.11.0
 100