projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 93557f53 JO |
1 | /* |
| 2 | * SNMP service broadcast connection tracking helper | |
| 3 | * | |
| 4 | * (c) 2011 Jiri Olsa <jolsa@redhat.com> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU General Public License | |
| 8 | * as published by the Free Software Foundation; either version | |
| 9 | * 2 of the License, or (at your option) any later version. | |
| 10 | */ | |
| 11 | #include <linux/kernel.h> | |
| 12 | #include <linux/module.h> | |
| 13 | #include <linux/init.h> | |
| 14 | #include <linux/in.h> | |
| 15 | ||
| 16 | #include <net/netfilter/nf_conntrack.h> | |
| 17 | #include <net/netfilter/nf_conntrack_helper.h> | |
| 18 | #include <net/netfilter/nf_conntrack_expect.h> | |
| 5a406b0c | 19 | #include <linux/netfilter/nf_conntrack_snmp.h> |
| 93557f53 JO |
20 | |
| 21 | #define SNMP_PORT 161 | |
| 22 | ||
| 23 | MODULE_AUTHOR("Jiri Olsa <jolsa@redhat.com>"); | |
| 24 | MODULE_DESCRIPTION("SNMP service broadcast connection tracking helper"); | |
| 25 | MODULE_LICENSE("GPL"); | |
| 26 | MODULE_ALIAS_NFCT_HELPER("snmp"); | |
| 27 | ||
| 28 | static unsigned int timeout __read_mostly = 30; | |
| 29 | module_param(timeout, uint, S_IRUSR); | |
| 30 | MODULE_PARM_DESC(timeout, "timeout for master connection/replies in seconds"); | |
| 31 | ||
| 32 | int (*nf_nat_snmp_hook)(struct sk_buff *skb, | |
| 33 | unsigned int protoff, | |
| 34 | struct nf_conn *ct, | |
| 35 | enum ip_conntrack_info ctinfo); | |
| 36 | EXPORT_SYMBOL_GPL(nf_nat_snmp_hook); | |
| 37 | ||
| 38 | static int snmp_conntrack_help(struct sk_buff *skb, unsigned int protoff, | |
| 39 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
| 40 | { | |
| 41 | typeof(nf_nat_snmp_hook) nf_nat_snmp; | |
| 42 | ||
| 43 | nf_conntrack_broadcast_help(skb, protoff, ct, ctinfo, timeout); | |
| 44 | ||
| 45 | nf_nat_snmp = rcu_dereference(nf_nat_snmp_hook); | |
| 46 | if (nf_nat_snmp && ct->status & IPS_NAT_MASK) | |
| 47 | return nf_nat_snmp(skb, protoff, ct, ctinfo); | |
| 48 | ||
| 49 | return NF_ACCEPT; | |
| 50 | } | |
| 51 | ||
| 52 | static struct nf_conntrack_expect_policy exp_policy = { | |
| 53 | .max_expected = 1, | |
| 54 | }; | |
| 55 | ||
| 56 | static struct nf_conntrack_helper helper __read_mostly = { | |
| 57 | .name = "snmp", | |
| 58 | .tuple.src.l3num = NFPROTO_IPV4, | |
| 59 | .tuple.src.u.udp.port = cpu_to_be16(SNMP_PORT), | |
| 60 | .tuple.dst.protonum = IPPROTO_UDP, | |
| 61 | .me = THIS_MODULE, | |
| 62 | .help = snmp_conntrack_help, | |
| 63 | .expect_policy = &exp_policy, | |
| 64 | }; | |
| 65 | ||
| 66 | static int __init nf_conntrack_snmp_init(void) | |
| 67 | { | |
| 68 | exp_policy.timeout = timeout; | |
| 69 | return nf_conntrack_helper_register(&helper); | |
| 70 | } | |
| 71 | ||
| 72 | static void __exit nf_conntrack_snmp_fini(void) | |
| 73 | { | |
| 74 | nf_conntrack_helper_unregister(&helper); | |
| 75 | } | |
| 76 | ||
| 77 | module_init(nf_conntrack_snmp_init); | |
| 78 | module_exit(nf_conntrack_snmp_fini); |