nexmon – Rev 1
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/*
* lib/netfilter/ct.c Conntrack
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
* Copyright (c) 2007 Philip Craig <philipc@snapgear.com>
* Copyright (c) 2007 Secure Computing Corporation
* Copyright (c= 2008 Patrick McHardy <kaber@trash.net>
*/
/**
* @ingroup nfnl
* @defgroup ct Conntrack
* @brief
* @{
*/
#include <byteswap.h>
#include <sys/types.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <netlink-local.h>
#include <netlink/attr.h>
#include <netlink/netfilter/nfnl.h>
#include <netlink/netfilter/ct.h>
static struct nl_cache_ops nfnl_ct_ops;
#if __BYTE_ORDER == __BIG_ENDIAN
static uint64_t ntohll(uint64_t x)
{
return x;
}
#elif __BYTE_ORDER == __LITTLE_ENDIAN
static uint64_t ntohll(uint64_t x)
{
return __bswap_64(x);
}
#endif
static struct nla_policy ct_policy[CTA_MAX+1] = {
[CTA_TUPLE_ORIG] = { .type = NLA_NESTED },
[CTA_TUPLE_REPLY] = { .type = NLA_NESTED },
[CTA_STATUS] = { .type = NLA_U32 },
[CTA_PROTOINFO] = { .type = NLA_NESTED },
//[CTA_HELP]
//[CTA_NAT_SRC]
[CTA_TIMEOUT] = { .type = NLA_U32 },
[CTA_MARK] = { .type = NLA_U32 },
[CTA_COUNTERS_ORIG] = { .type = NLA_NESTED },
[CTA_COUNTERS_REPLY] = { .type = NLA_NESTED },
[CTA_USE] = { .type = NLA_U32 },
[CTA_ID] = { .type = NLA_U32 },
//[CTA_NAT_DST]
};
static struct nla_policy ct_tuple_policy[CTA_TUPLE_MAX+1] = {
[CTA_TUPLE_IP] = { .type = NLA_NESTED },
[CTA_TUPLE_PROTO] = { .type = NLA_NESTED },
};
static struct nla_policy ct_ip_policy[CTA_IP_MAX+1] = {
[CTA_IP_V4_SRC] = { .type = NLA_U32 },
[CTA_IP_V4_DST] = { .type = NLA_U32 },
[CTA_IP_V6_SRC] = { .minlen = 16 },
[CTA_IP_V6_DST] = { .minlen = 16 },
};
static struct nla_policy ct_proto_policy[CTA_PROTO_MAX+1] = {
[CTA_PROTO_NUM] = { .type = NLA_U8 },
[CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
[CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
[CTA_PROTO_ICMP_ID] = { .type = NLA_U16 },
[CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 },
[CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 },
[CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
[CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
[CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
};
static struct nla_policy ct_protoinfo_policy[CTA_PROTOINFO_MAX+1] = {
[CTA_PROTOINFO_TCP] = { .type = NLA_NESTED },
};
static struct nla_policy ct_protoinfo_tcp_policy[CTA_PROTOINFO_TCP_MAX+1] = {
[CTA_PROTOINFO_TCP_STATE] = { .type = NLA_U8 },
[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] = { .type = NLA_U8 },
[CTA_PROTOINFO_TCP_WSCALE_REPLY] = { .type = NLA_U8 },
[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL] = { .minlen = 2 },
[CTA_PROTOINFO_TCP_FLAGS_REPLY] = { .minlen = 2 },
};
static struct nla_policy ct_counters_policy[CTA_COUNTERS_MAX+1] = {
[CTA_COUNTERS_PACKETS] = { .type = NLA_U64 },
[CTA_COUNTERS_BYTES] = { .type = NLA_U64 },
[CTA_COUNTERS32_PACKETS]= { .type = NLA_U32 },
[CTA_COUNTERS32_BYTES] = { .type = NLA_U32 },
};
static int ct_parse_ip(struct nfnl_ct *ct, int repl, struct nlattr *attr)
{
struct nlattr *tb[CTA_IP_MAX+1];
struct nl_addr *addr;
int err;
err = nla_parse_nested(tb, CTA_IP_MAX, attr, ct_ip_policy);
if (err < 0)
goto errout;
if (tb[CTA_IP_V4_SRC]) {
addr = nl_addr_alloc_attr(tb[CTA_IP_V4_SRC], AF_INET);
if (addr == NULL)
goto errout_enomem;
err = nfnl_ct_set_src(ct, repl, addr);
nl_addr_put(addr);
if (err < 0)
goto errout;
}
if (tb[CTA_IP_V4_DST]) {
addr = nl_addr_alloc_attr(tb[CTA_IP_V4_DST], AF_INET);
if (addr == NULL)
goto errout_enomem;
err = nfnl_ct_set_dst(ct, repl, addr);
nl_addr_put(addr);
if (err < 0)
goto errout;
}
if (tb[CTA_IP_V6_SRC]) {
addr = nl_addr_alloc_attr(tb[CTA_IP_V6_SRC], AF_INET6);
if (addr == NULL)
goto errout_enomem;
err = nfnl_ct_set_src(ct, repl, addr);
nl_addr_put(addr);
if (err < 0)
goto errout;
}
if (tb[CTA_IP_V6_DST]) {
addr = nl_addr_alloc_attr(tb[CTA_IP_V6_DST], AF_INET6);
if (addr == NULL)
goto errout_enomem;
err = nfnl_ct_set_dst(ct, repl, addr);
nl_addr_put(addr);
if (err < 0)
goto errout;
}
return 0;
errout_enomem:
err = -NLE_NOMEM;
errout:
return err;
}
static int ct_parse_proto(struct nfnl_ct *ct, int repl, struct nlattr *attr)
{
struct nlattr *tb[CTA_PROTO_MAX+1];
int err;
err = nla_parse_nested(tb, CTA_PROTO_MAX, attr, ct_proto_policy);
if (err < 0)
return err;
if (!repl && tb[CTA_PROTO_NUM])
nfnl_ct_set_proto(ct, nla_get_u8(tb[CTA_PROTO_NUM]));
if (tb[CTA_PROTO_SRC_PORT])
nfnl_ct_set_src_port(ct, repl,
ntohs(nla_get_u16(tb[CTA_PROTO_SRC_PORT])));
if (tb[CTA_PROTO_DST_PORT])
nfnl_ct_set_dst_port(ct, repl,
ntohs(nla_get_u16(tb[CTA_PROTO_DST_PORT])));
if (tb[CTA_PROTO_ICMP_ID])
nfnl_ct_set_icmp_id(ct, repl,
ntohs(nla_get_u16(tb[CTA_PROTO_ICMP_ID])));
if (tb[CTA_PROTO_ICMP_TYPE])
nfnl_ct_set_icmp_type(ct, repl,
nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]));
if (tb[CTA_PROTO_ICMP_CODE])
nfnl_ct_set_icmp_code(ct, repl,
nla_get_u8(tb[CTA_PROTO_ICMP_CODE]));
return 0;
}
static int ct_parse_tuple(struct nfnl_ct *ct, int repl, struct nlattr *attr)
{
struct nlattr *tb[CTA_TUPLE_MAX+1];
int err;
err = nla_parse_nested(tb, CTA_TUPLE_MAX, attr, ct_tuple_policy);
if (err < 0)
return err;
if (tb[CTA_TUPLE_IP]) {
err = ct_parse_ip(ct, repl, tb[CTA_TUPLE_IP]);
if (err < 0)
return err;
}
if (tb[CTA_TUPLE_PROTO]) {
err = ct_parse_proto(ct, repl, tb[CTA_TUPLE_PROTO]);
if (err < 0)
return err;
}
return 0;
}
static int ct_parse_protoinfo_tcp(struct nfnl_ct *ct, struct nlattr *attr)
{
struct nlattr *tb[CTA_PROTOINFO_TCP_MAX+1];
int err;
err = nla_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, attr,
ct_protoinfo_tcp_policy);
if (err < 0)
return err;
if (tb[CTA_PROTOINFO_TCP_STATE])
nfnl_ct_set_tcp_state(ct,
nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]));
return 0;
}
static int ct_parse_protoinfo(struct nfnl_ct *ct, struct nlattr *attr)
{
struct nlattr *tb[CTA_PROTOINFO_MAX+1];
int err;
err = nla_parse_nested(tb, CTA_PROTOINFO_MAX, attr,
ct_protoinfo_policy);
if (err < 0)
return err;
if (tb[CTA_PROTOINFO_TCP]) {
err = ct_parse_protoinfo_tcp(ct, tb[CTA_PROTOINFO_TCP]);
if (err < 0)
return err;
}
return 0;
}
static int ct_parse_counters(struct nfnl_ct *ct, int repl, struct nlattr *attr)
{
struct nlattr *tb[CTA_COUNTERS_MAX+1];
int err;
err = nla_parse_nested(tb, CTA_COUNTERS_MAX, attr, ct_counters_policy);
if (err < 0)
return err;
if (tb[CTA_COUNTERS_PACKETS])
nfnl_ct_set_packets(ct, repl,
ntohll(nla_get_u64(tb[CTA_COUNTERS_PACKETS])));
if (tb[CTA_COUNTERS32_PACKETS])
nfnl_ct_set_packets(ct, repl,
ntohl(nla_get_u32(tb[CTA_COUNTERS32_PACKETS])));
if (tb[CTA_COUNTERS_BYTES])
nfnl_ct_set_bytes(ct, repl,
ntohll(nla_get_u64(tb[CTA_COUNTERS_BYTES])));
if (tb[CTA_COUNTERS32_BYTES])
nfnl_ct_set_bytes(ct, repl,
ntohl(nla_get_u32(tb[CTA_COUNTERS32_BYTES])));
return 0;
}
int nfnlmsg_ct_group(struct nlmsghdr *nlh)
{
switch (nfnlmsg_subtype(nlh)) {
case IPCTNL_MSG_CT_NEW:
if (nlh->nlmsg_flags & (NLM_F_CREATE|NLM_F_EXCL))
return NFNLGRP_CONNTRACK_NEW;
else
return NFNLGRP_CONNTRACK_UPDATE;
case IPCTNL_MSG_CT_DELETE:
return NFNLGRP_CONNTRACK_DESTROY;
default:
return NFNLGRP_NONE;
}
}
int nfnlmsg_ct_parse(struct nlmsghdr *nlh, struct nfnl_ct **result)
{
struct nfnl_ct *ct;
struct nlattr *tb[CTA_MAX+1];
int err;
ct = nfnl_ct_alloc();
if (!ct)
return -NLE_NOMEM;
ct->ce_msgtype = nlh->nlmsg_type;
err = nlmsg_parse(nlh, sizeof(struct nfgenmsg), tb, CTA_MAX,
ct_policy);
if (err < 0)
goto errout;
nfnl_ct_set_family(ct, nfnlmsg_family(nlh));
if (tb[CTA_TUPLE_ORIG]) {
err = ct_parse_tuple(ct, 0, tb[CTA_TUPLE_ORIG]);
if (err < 0)
goto errout;
}
if (tb[CTA_TUPLE_REPLY]) {
err = ct_parse_tuple(ct, 1, tb[CTA_TUPLE_REPLY]);
if (err < 0)
goto errout;
}
if (tb[CTA_PROTOINFO]) {
err = ct_parse_protoinfo(ct, tb[CTA_PROTOINFO]);
if (err < 0)
goto errout;
}
if (tb[CTA_STATUS])
nfnl_ct_set_status(ct, ntohl(nla_get_u32(tb[CTA_STATUS])));
if (tb[CTA_TIMEOUT])
nfnl_ct_set_timeout(ct, ntohl(nla_get_u32(tb[CTA_TIMEOUT])));
if (tb[CTA_MARK])
nfnl_ct_set_mark(ct, ntohl(nla_get_u32(tb[CTA_MARK])));
if (tb[CTA_USE])
nfnl_ct_set_use(ct, ntohl(nla_get_u32(tb[CTA_USE])));
if (tb[CTA_ID])
nfnl_ct_set_id(ct, ntohl(nla_get_u32(tb[CTA_ID])));
if (tb[CTA_COUNTERS_ORIG]) {
err = ct_parse_counters(ct, 0, tb[CTA_COUNTERS_ORIG]);
if (err < 0)
goto errout;
}
if (tb[CTA_COUNTERS_REPLY]) {
err = ct_parse_counters(ct, 1, tb[CTA_COUNTERS_REPLY]);
if (err < 0)
goto errout;
}
*result = ct;
return 0;
errout:
nfnl_ct_put(ct);
return err;
}
static int ct_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
struct nlmsghdr *nlh, struct nl_parser_param *pp)
{
struct nfnl_ct *ct;
int err;
if ((err = nfnlmsg_ct_parse(nlh, &ct)) < 0)
goto errout;
err = pp->pp_cb((struct nl_object *) ct, pp);
errout:
nfnl_ct_put(ct);
return err;
}
int nfnl_ct_dump_request(struct nl_sock *sk)
{
return nfnl_send_simple(sk, NFNL_SUBSYS_CTNETLINK, IPCTNL_MSG_CT_GET,
NLM_F_DUMP, AF_UNSPEC, 0);
}
static int ct_request_update(struct nl_cache *cache, struct nl_sock *sk)
{
return nfnl_ct_dump_request(sk);
}
static int nfnl_ct_build_tuple(struct nl_msg *msg, const struct nfnl_ct *ct,
int repl)
{
struct nlattr *tuple, *ip, *proto;
struct nl_addr *addr;
int family;
family = nfnl_ct_get_family(ct);
tuple = nla_nest_start(msg, repl ? CTA_TUPLE_REPLY : CTA_TUPLE_ORIG);
if (!tuple)
goto nla_put_failure;
ip = nla_nest_start(msg, CTA_TUPLE_IP);
if (!ip)
goto nla_put_failure;
addr = nfnl_ct_get_src(ct, repl);
if (addr)
NLA_PUT_ADDR(msg,
family == AF_INET ? CTA_IP_V4_SRC : CTA_IP_V6_SRC,
addr);
addr = nfnl_ct_get_dst(ct, repl);
if (addr)
NLA_PUT_ADDR(msg,
family == AF_INET ? CTA_IP_V4_DST : CTA_IP_V6_DST,
addr);
nla_nest_end(msg, ip);
proto = nla_nest_start(msg, CTA_TUPLE_PROTO);
if (!proto)
goto nla_put_failure;
if (nfnl_ct_test_proto(ct))
NLA_PUT_U8(msg, CTA_PROTO_NUM, nfnl_ct_get_proto(ct));
if (nfnl_ct_test_src_port(ct, repl))
NLA_PUT_U16(msg, CTA_PROTO_SRC_PORT,
htons(nfnl_ct_get_src_port(ct, repl)));
if (nfnl_ct_test_dst_port(ct, repl))
NLA_PUT_U16(msg, CTA_PROTO_DST_PORT,
htons(nfnl_ct_get_dst_port(ct, repl)));
if (nfnl_ct_test_icmp_id(ct, repl))
NLA_PUT_U16(msg, CTA_PROTO_ICMP_ID,
htons(nfnl_ct_get_icmp_id(ct, repl)));
if (nfnl_ct_test_icmp_type(ct, repl))
NLA_PUT_U8(msg, CTA_PROTO_ICMP_TYPE,
nfnl_ct_get_icmp_type(ct, repl));
if (nfnl_ct_test_icmp_code(ct, repl))
NLA_PUT_U8(msg, CTA_PROTO_ICMP_CODE,
nfnl_ct_get_icmp_code(ct, repl));
nla_nest_end(msg, proto);
nla_nest_end(msg, tuple);
return 0;
nla_put_failure:
return -NLE_MSGSIZE;
}
static int nfnl_ct_build_message(const struct nfnl_ct *ct, int cmd, int flags,
struct nl_msg **result)
{
struct nl_msg *msg;
int err;
msg = nfnlmsg_alloc_simple(NFNL_SUBSYS_CTNETLINK, cmd, flags,
nfnl_ct_get_family(ct), 0);
if (msg == NULL)
return -NLE_NOMEM;
if ((err = nfnl_ct_build_tuple(msg, ct, 0)) < 0)
goto err_out;
*result = msg;
return 0;
err_out:
nlmsg_free(msg);
return err;
}
int nfnl_ct_build_add_request(const struct nfnl_ct *ct, int flags,
struct nl_msg **result)
{
return nfnl_ct_build_message(ct, IPCTNL_MSG_CT_NEW, flags, result);
}
int nfnl_ct_add(struct nl_sock *sk, const struct nfnl_ct *ct, int flags)
{
struct nl_msg *msg;
int err;
if ((err = nfnl_ct_build_add_request(ct, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
int nfnl_ct_build_delete_request(const struct nfnl_ct *ct, int flags,
struct nl_msg **result)
{
return nfnl_ct_build_message(ct, IPCTNL_MSG_CT_DELETE, flags, result);
}
int nfnl_ct_del(struct nl_sock *sk, const struct nfnl_ct *ct, int flags)
{
struct nl_msg *msg;
int err;
if ((err = nfnl_ct_build_delete_request(ct, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
int nfnl_ct_build_query_request(const struct nfnl_ct *ct, int flags,
struct nl_msg **result)
{
return nfnl_ct_build_message(ct, IPCTNL_MSG_CT_GET, flags, result);
}
int nfnl_ct_query(struct nl_sock *sk, const struct nfnl_ct *ct, int flags)
{
struct nl_msg *msg;
int err;
if ((err = nfnl_ct_build_query_request(ct, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
/**
* @name Cache Management
* @{
*/
/**
* Build a conntrack cache holding all conntrack currently in the kernel
* @arg sk Netlink socket.
* @arg result Pointer to store resulting cache.
*
* Allocates a new cache, initializes it properly and updates it to
* contain all conntracks currently in the kernel.
*
* @return 0 on success or a negative error code.
*/
int nfnl_ct_alloc_cache(struct nl_sock *sk, struct nl_cache **result)
{
return nl_cache_alloc_and_fill(&nfnl_ct_ops, sk, result);
}
/** @} */
/**
* @name Conntrack Addition
* @{
*/
/** @} */
static struct nl_af_group ct_groups[] = {
{ AF_UNSPEC, NFNLGRP_CONNTRACK_NEW },
{ AF_UNSPEC, NFNLGRP_CONNTRACK_UPDATE },
{ AF_UNSPEC, NFNLGRP_CONNTRACK_DESTROY },
{ END_OF_GROUP_LIST },
};
#define NFNLMSG_CT_TYPE(type) NFNLMSG_TYPE(NFNL_SUBSYS_CTNETLINK, (type))
static struct nl_cache_ops nfnl_ct_ops = {
.co_name = "netfilter/ct",
.co_hdrsize = NFNL_HDRLEN,
.co_msgtypes = {
{ NFNLMSG_CT_TYPE(IPCTNL_MSG_CT_NEW), NL_ACT_NEW, "new" },
{ NFNLMSG_CT_TYPE(IPCTNL_MSG_CT_GET), NL_ACT_GET, "get" },
{ NFNLMSG_CT_TYPE(IPCTNL_MSG_CT_DELETE), NL_ACT_DEL, "del" },
END_OF_MSGTYPES_LIST,
},
.co_protocol = NETLINK_NETFILTER,
.co_groups = ct_groups,
.co_request_update = ct_request_update,
.co_msg_parser = ct_msg_parser,
.co_obj_ops = &ct_obj_ops,
};
static void __init ct_init(void)
{
nl_cache_mngt_register(&nfnl_ct_ops);
}
static void __exit ct_exit(void)
{
nl_cache_mngt_unregister(&nfnl_ct_ops);
}
/** @} */