From: Felix Fietkau Subject: netfilter: add support for flushing conntrack via /proc lede-commit 8193bbe59a74d34d6a26d4a8cb857b1952905314 Signed-off-by: Felix Fietkau --- net/netfilter/nf_conntrack_standalone.c | 59 ++++++++++++++++++++++++++++++++- 1 file changed, 58 insertions(+), 1 deletion(-) --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #ifdef CONFIG_SYSCTL #include @@ -458,6 +459,58 @@ static int ct_cpu_seq_show(struct seq_fi return 0; } +struct kill_request { + u16 family; + union nf_inet_addr addr; +}; + +static int kill_matching(struct nf_conn *i, void *data) +{ + struct kill_request *kr = data; + struct nf_conntrack_tuple *t1 = &i->tuplehash[IP_CT_DIR_ORIGINAL].tuple; + struct nf_conntrack_tuple *t2 = &i->tuplehash[IP_CT_DIR_REPLY].tuple; + + if (!kr->family) + return 1; + + if (t1->src.l3num != kr->family) + return 0; + + return (nf_inet_addr_cmp(&kr->addr, &t1->src.u3) || + nf_inet_addr_cmp(&kr->addr, &t1->dst.u3) || + nf_inet_addr_cmp(&kr->addr, &t2->src.u3) || + nf_inet_addr_cmp(&kr->addr, &t2->dst.u3)); +} + +static int ct_file_write(struct file *file, char *buf, size_t count) +{ + struct seq_file *seq = file->private_data; + struct nf_ct_iter_data iter_data; + struct kill_request kr = { }; + + if (count == 0) + return 0; + + if (count >= INET6_ADDRSTRLEN) + count = INET6_ADDRSTRLEN - 1; + + if (strnchr(buf, count, ':')) { + kr.family = AF_INET6; + if (!in6_pton(buf, count, (void *)&kr.addr, '\n', NULL)) + return -EINVAL; + } else if (strnchr(buf, count, '.')) { + kr.family = AF_INET; + if (!in4_pton(buf, count, (void *)&kr.addr, '\n', NULL)) + return -EINVAL; + } + + iter_data.net = seq_file_net(seq); + iter_data.data = &kr; + nf_ct_iterate_cleanup_net(kill_matching, &iter_data); + + return 0; +} + static const struct seq_operations ct_cpu_seq_ops = { .start = ct_cpu_seq_start, .next = ct_cpu_seq_next, @@ -471,8 +524,9 @@ static int nf_conntrack_standalone_init_ kuid_t root_uid; kgid_t root_gid; - pde = proc_create_net("nf_conntrack", 0440, net->proc_net, &ct_seq_ops, - sizeof(struct ct_iter_state)); + pde = proc_create_net_data_write("nf_conntrack", 0440, net->proc_net, + &ct_seq_ops, &ct_file_write, + sizeof(struct ct_iter_state), NULL); if (!pde) goto out_nf_conntrack;