net/netlink: Add NETLINK_NETFILTER's CONNTRACK support

Now we only supports conntrack info from NAT entries, to let our apps in user space know the mapping status in NAT.

Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
This commit is contained in:
Zhe Weng 2024-03-20 11:22:24 +08:00 committed by Xiang Xiao
parent 9b77bb16c9
commit 3a844d8dd7
9 changed files with 959 additions and 1 deletions

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@ -437,6 +437,160 @@
#define RTM_F_CLONED 0x200 /* This route is cloned */
/* Attribute definitions for struct nfattr **********************************/
/* Macros to handle attribute lists */
#define NFNL_NFA_NEST 0x8000
#define NFA_TYPE(attr) ((attr)->nfa_type & 0x7fff)
#define NFA_MASK (sizeof(uint32_t) - 1)
#define NFA_ALIGN(n) (((n) + NFA_MASK) & ~NFA_MASK)
#define NFA_OK(nfa, n) \
((n) >= (int)sizeof(struct nfattr) && \
(nfa)->nfa_len >= sizeof(struct nfattr) && \
(nfa)->nfa_len <= (n))
#define NFA_NEXT(nfa, attrlen) \
((attrlen) -= NFA_ALIGN((nfa)->nfa_len), \
(FAR struct nfattr *)(((FAR char *)(nfa)) + NFA_ALIGN((nfa)->nfa_len)))
#define NFA_LENGTH(len) ((sizeof(struct nfattr)) + (len))
#define NFA_SPACE(len) NFA_ALIGN(NFA_LENGTH(len))
#define NFA_DATA(nfa) ((FAR void *)(((FAR char *)(nfa)) + NFA_LENGTH(0)))
#define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0))
/* Definitions for struct nfgenmsg ******************************************/
#define NFM_NFA(n) ((FAR struct nfattr *) \
(((FAR char *)(n)) + \
NLMSG_ALIGN(sizeof(struct nfgenmsg))))
#define NFM_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct nfgenmsg))
/* Definitions for NETLINK_NETFILTER ****************************************/
#define NFNETLINK_V0 0
/* netfilter netlink message types are split in two pieces:
* 8 bit subsystem, 8bit operation.
*/
#define NFNL_SUBSYS_ID(x) (((x) & 0xff00) >> 8)
#define NFNL_MSG_TYPE(x) ((x) & 0x00ff)
/* subsystems */
#define NFNL_SUBSYS_NONE 0
#define NFNL_SUBSYS_CTNETLINK 1
#define NFNL_SUBSYS_CTNETLINK_EXP 2
#define NFNL_SUBSYS_QUEUE 3
#define NFNL_SUBSYS_ULOG 4
#define NFNL_SUBSYS_OSF 5
#define NFNL_SUBSYS_IPSET 6
#define NFNL_SUBSYS_ACCT 7
#define NFNL_SUBSYS_CTNETLINK_TIMEOUT 8
#define NFNL_SUBSYS_CTHELPER 9
#define NFNL_SUBSYS_NFTABLES 10
#define NFNL_SUBSYS_NFT_COMPAT 11
#define NFNL_SUBSYS_HOOK 12
#define NFNL_SUBSYS_COUNT 13
/* NETLINK_NETFILTER: subsystem CTNL (ip conntrack netlink) message types */
#define IPCTNL_MSG_CT_NEW 0
#define IPCTNL_MSG_CT_GET 1
#define IPCTNL_MSG_CT_DELETE 2
#define IPCTNL_MSG_CT_GET_CTRZERO 3
#define IPCTNL_MSG_CT_GET_STATS_CPU 4
#define IPCTNL_MSG_CT_GET_STATS 5
#define IPCTNL_MSG_CT_GET_DYING 6
#define IPCTNL_MSG_CT_GET_UNCONFIRMED 7
#define IPCTNL_MSG_MAX 8
/* NETLINK_NETFILTER: Conntrack attributes */
#define CTA_UNSPEC 0
#define CTA_TUPLE_ORIG 1
#define CTA_TUPLE_REPLY 2
#define CTA_STATUS 3
#define CTA_PROTOINFO 4
#define CTA_HELP 5
#define CTA_NAT_SRC 6
#define CTA_TIMEOUT 7
#define CTA_MARK 8
#define CTA_COUNTERS_ORIG 9
#define CTA_COUNTERS_REPLY 10
#define CTA_USE 11
#define CTA_ID 12
#define CTA_NAT_DST 13
#define CTA_TUPLE_MASTER 14
#define CTA_SEQ_ADJ_ORIG 15
#define CTA_NAT_SEQ_ADJ_ORIG CTA_SEQ_ADJ_ORIG
#define CTA_SEQ_ADJ_REPLY 16
#define CTA_NAT_SEQ_ADJ_REPLY CTA_SEQ_ADJ_REPLY
#define CTA_ZONE 18
#define CTA_SECCTX 19
#define CTA_TIMESTAMP 20
#define CTA_MARK_MASK 21
#define CTA_LABELS 22
#define CTA_LABELS_MASK 23
#define CTA_SYNPROXY 24
#define CTA_FILTER 25
#define CTA_STATUS_MASK 26
#define CTA_MAX 26
/* NETLINK_NETFILTER: Conntrack tuple attributes */
#define CTA_TUPLE_UNSPEC 0
#define CTA_TUPLE_IP 1
#define CTA_TUPLE_PROTO 2
#define CTA_TUPLE_ZONE 3
#define CTA_TUPLE_MAX 3
/* NETLINK_NETFILTER: Conntrack IP attributes */
#define CTA_IP_UNSPEC 0
#define CTA_IP_V4_SRC 1
#define CTA_IP_V4_DST 2
#define CTA_IP_V6_SRC 3
#define CTA_IP_V6_DST 4
#define CTA_IP_MAX 4
/* NETLINK_NETFILTER: Conntrack protocol attributes */
#define CTA_PROTO_UNSPEC 0
#define CTA_PROTO_NUM 1
#define CTA_PROTO_SRC_PORT 2
#define CTA_PROTO_DST_PORT 3
#define CTA_PROTO_ICMP_ID 4
#define CTA_PROTO_ICMP_TYPE 5
#define CTA_PROTO_ICMP_CODE 6
#define CTA_PROTO_ICMPV6_ID 7
#define CTA_PROTO_ICMPV6_TYPE 8
#define CTA_PROTO_ICMPV6_CODE 9
#define CTA_PROTO_MAX 9
/* NFnetlink multicast groups (userspace) */
#define NF_NETLINK_CONNTRACK_NEW 0x00000001
#define NF_NETLINK_CONNTRACK_UPDATE 0x00000002
#define NF_NETLINK_CONNTRACK_DESTROY 0x00000004
#define NF_NETLINK_CONNTRACK_EXP_NEW 0x00000008
#define NF_NETLINK_CONNTRACK_EXP_UPDATE 0x00000010
#define NF_NETLINK_CONNTRACK_EXP_DESTROY 0x00000020
/* NFnetlink multicast groups */
#define NFNLGRP_NONE 0
#define NFNLGRP_CONNTRACK_NEW 1
#define NFNLGRP_CONNTRACK_UPDATE 2
#define NFNLGRP_CONNTRACK_DESTROY 3
#define NFNLGRP_CONNTRACK_EXP_NEW 4
#define NFNLGRP_CONNTRACK_EXP_UPDATE 5
#define NFNLGRP_CONNTRACK_EXP_DESTROY 6
#define NFNLGRP_NFTABLES 7
#define NFNLGRP_ACCT_QUOTA 8
#define NFNLGRP_NFTRACE 9
#define NFNLGRP_MAX 9
/****************************************************************************
* Public Type Definitions
****************************************************************************/
@ -584,6 +738,25 @@ struct nla_bitfield32
uint32_t selector;
};
/* NETLINK_NETFILTER Message Structures *************************************/
/* These attributes should be manipulated using only the NFA_* */
struct nfattr
{
uint16_t nfa_len;
uint16_t nfa_type;
};
/* General form of address family dependent message. */
struct nfgenmsg
{
uint8_t nfgen_family; /* AF_xxx */
uint8_t version; /* nfnetlink version */
uint16_t res_id; /* resource id */
};
/****************************************************************************
* Neighbor Discovery userland options
*/

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@ -33,6 +33,7 @@
#include <nuttx/nuttx.h>
#include "nat/nat.h"
#include "netlink/netlink.h"
#ifdef CONFIG_NET_NAT44
@ -145,6 +146,10 @@ ipv4_nat_entry_create(uint8_t protocol,
hashtable_add(g_nat44_outbound, &entry->hash_outbound,
ipv4_nat_outbound_key(local_ip, local_port, protocol));
#ifdef CONFIG_NETLINK_NETFILTER
netlink_conntrack_notify(IPCTNL_MSG_CT_NEW, PF_INET, entry);
#endif
return entry;
}
@ -175,6 +180,10 @@ static void ipv4_nat_entry_delete(FAR ipv4_nat_entry_t *entry)
entry->local_port,
entry->protocol));
#ifdef CONFIG_NETLINK_NETFILTER
netlink_conntrack_notify(IPCTNL_MSG_CT_DELETE, PF_INET, entry);
#endif
kmm_free(entry);
}

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@ -34,6 +34,7 @@
#include "inet/inet.h"
#include "nat/nat.h"
#include "netlink/netlink.h"
#ifdef CONFIG_NET_NAT66
@ -135,6 +136,10 @@ ipv6_nat_entry_create(uint8_t protocol, const net_ipv6addr_t external_ip,
hashtable_add(g_nat66_outbound, &entry->hash_outbound,
ipv6_nat_hash_key(local_ip, local_port, protocol));
#ifdef CONFIG_NETLINK_NETFILTER
netlink_conntrack_notify(IPCTNL_MSG_CT_NEW, PF_INET6, entry);
#endif
return entry;
}
@ -168,6 +173,10 @@ static void ipv6_nat_entry_delete(FAR ipv6_nat_entry_t *entry)
entry->local_port,
entry->protocol));
#ifdef CONFIG_NETLINK_NETFILTER
netlink_conntrack_notify(IPCTNL_MSG_CT_DELETE, PF_INET6, entry);
#endif
kmm_free(entry);
}

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@ -27,5 +27,9 @@ if(CONFIG_NET_NETLINK)
list(APPEND SRCS netlink_route.c netlink_attr.c)
endif()
if(CONFIG_NETLINK_NETFILTER)
list(APPEND SRCS netlink_netfilter.c)
endif()
target_sources(net PRIVATE ${SRCS})
endif()

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@ -117,6 +117,15 @@ config NETLINK_VALIDATE_POLICY
you pass in are valid.
endif # NETLINK_ROUTE
config NETLINK_NETFILTER
bool "Netlink Netfilter protocol"
default n
depends on NET_NAT
---help---
Support the NETLINK_NETFILTER protocol option, mainly
for conntrack with NAT.
endmenu # Netlink Protocols
endif # NET_NETLINK
endmenu # Netlink Socket Support

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@ -29,6 +29,10 @@ ifeq ($(CONFIG_NETLINK_ROUTE),y)
NET_CSRCS += netlink_route.c netlink_attr.c
endif
ifeq ($(CONFIG_NETLINK_NETFILTER),y)
NET_CSRCS += netlink_netfilter.c
endif
# Include netlink build support
DEPPATH += --dep-path netlink

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@ -543,7 +543,40 @@ int nla_parse(FAR struct nlattr **tb, int maxtype,
FAR const struct nlattr *head,
int len, FAR const struct nla_policy *policy,
FAR struct netlink_ext_ack *extack);
#endif
#endif /* CONFIG_NETLINK_ROUTE */
/****************************************************************************
* Name: netlink_netfilter_sendto
*
* Description:
* Perform the sendto() operation for the NETLINK_NETFILTER protocol.
*
****************************************************************************/
#ifdef CONFIG_NETLINK_NETFILTER
ssize_t netlink_netfilter_sendto(NETLINK_HANDLE handle,
FAR const struct nlmsghdr *nlmsg,
size_t len, int flags,
FAR const struct sockaddr_nl *to,
socklen_t tolen);
/****************************************************************************
* Name: netlink_conntrack_notify
*
* Description:
* Perform the conntrack broadcast for the NETLINK_NETFILTER protocol.
*
* Input Parameters:
* type - The type of the message, IPCTNL_MSG_CT_*
* domain - The domain of the message
* nat_entry - The NAT entry
*
****************************************************************************/
void netlink_conntrack_notify(uint8_t type, uint8_t domain,
FAR const void *nat_entry);
#endif /* CONFIG_NETLINK_NETFILTER */
#undef EXTERN
#ifdef __cplusplus

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@ -0,0 +1,703 @@
/****************************************************************************
* net/netlink/netlink_netfilter.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <debug.h>
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <netpacket/netlink.h>
#include <nuttx/kmalloc.h>
#include <nuttx/net/net.h>
#include <nuttx/net/icmp.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/netlink.h>
#include "inet/inet.h"
#include "nat/nat.h"
#include "netlink/netlink.h"
#include "utils/utils.h"
#ifdef CONFIG_NETLINK_NETFILTER
/****************************************************************************
* Private Types
****************************************************************************/
struct nfnl_sendto_request_s
{
struct nlmsghdr hdr;
struct nfgenmsg msg;
};
struct nfnl_info_s
{
NETLINK_HANDLE handle;
FAR const struct nfnl_sendto_request_s *req;
};
struct nfnl_ipv4addr_s
{
struct nfattr attr;
in_addr_t addr;
};
struct nfnl_ipv6addr_s
{
struct nfattr attr;
net_ipv6addr_t addr;
};
struct nfnl_attr_u8_s
{
struct nfattr attr;
uint8_t value;
uint8_t pad[3];
};
struct nfnl_attr_u16_s
{
struct nfattr attr;
uint16_t value;
uint16_t pad[1];
};
/* Struct of a conntrack tuple
* +------+--------------+-----------------+
* | attr | CTA_TUPLE_IP | CTA_TUPLE_PROTO |
* +------+--------------+-----------------+
*/
/* CTA_TUPLE_IP definitions */
struct conntrack_tuple_ipv4_s
{
struct nfattr attr;
struct nfnl_ipv4addr_s src;
struct nfnl_ipv4addr_s dst;
};
struct conntrack_tuple_ipv6_s
{
struct nfattr attr;
struct nfnl_ipv6addr_s src;
struct nfnl_ipv6addr_s dst;
};
/* CTA_TUPLE_PROTO definitions */
struct conntrack_tuple_tcpudp_s
{
struct nfattr attr;
struct nfnl_attr_u8_s proto;
struct nfnl_attr_u16_s sport;
struct nfnl_attr_u16_s dport;
};
struct conntrack_tuple_icmp_s
{
struct nfattr attr;
struct nfnl_attr_u8_s proto;
struct nfnl_attr_u16_s id;
struct nfnl_attr_u8_s type;
struct nfnl_attr_u8_s code;
};
/* Struct of a conntrack response
* +-----+-----+-----------------+----------------+
* | hdr | msg | tuple of origin | tuple of reply |
* +-----+-----+-----------------+----------------+
*/
struct conntrack_recvfrom_response_s
{
struct nlmsghdr hdr;
struct nfgenmsg msg;
uint8_t data[1];
};
#define SIZEOF_CTNL_RECVFROM_RESPONSE_S(n) \
(sizeof(struct conntrack_recvfrom_response_s) + (n) - 1)
struct conntrack_recvfrom_rsplist_s
{
sq_entry_t flink;
struct conntrack_recvfrom_response_s payload;
};
#define SIZEOF_CTNL_RECVFROM_RSPLIST_S(n) \
(sizeof(struct conntrack_recvfrom_rsplist_s) + (n) - 1)
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: netlink_conntrack_tuple_size
*
* Description:
* Get the size of a CTA_TUPLE. Struct of a conntrack tuple:
* +------+--------------+-----------------+
* | attr | CTA_TUPLE_IP | CTA_TUPLE_PROTO |
* +------+--------------+-----------------+
*
* Input Parameters:
* domain - The domain of the tuple
* proto - The protocol of the tuple
*
* Returned Value:
* The size of the tuple.
*
****************************************************************************/
static ssize_t netlink_conntrack_tuple_size(uint8_t domain, uint8_t proto)
{
size_t size = sizeof(struct nfattr);
switch (domain)
{
case PF_INET:
size += sizeof(struct conntrack_tuple_ipv4_s);
break;
case PF_INET6:
size += sizeof(struct conntrack_tuple_ipv6_s);
break;
default:
return -EINVAL;
}
switch (proto)
{
case IPPROTO_TCP:
case IPPROTO_UDP:
size += sizeof(struct conntrack_tuple_tcpudp_s);
break;
case IPPROTO_ICMP:
case IPPROTO_ICMP6:
size += sizeof(struct conntrack_tuple_icmp_s);
break;
default:
return -EINVAL;
}
return size;
}
/****************************************************************************
* Name: netlink_conntrack_fill_ip
*
* Description:
* Fill the data of a CTA_TUPLE_IP.
*
* Input Parameters:
* buf - The buffer to fill
* domain - The domain of the addresses
* src - The source address
* dst - The destination address
*
* Returned Value:
* The size of the filled data.
*
****************************************************************************/
static size_t netlink_conntrack_fill_ip(FAR void *buf, uint8_t domain,
FAR const void *src,
FAR const void *dst)
{
#ifdef CONFIG_NET_NAT44
if (domain == PF_INET)
{
FAR struct conntrack_tuple_ipv4_s *tuple_ipv4 = buf;
tuple_ipv4->attr.nfa_len = sizeof(struct conntrack_tuple_ipv4_s);
tuple_ipv4->attr.nfa_type = CTA_TUPLE_IP | NFNL_NFA_NEST;
tuple_ipv4->src.attr.nfa_len = NFA_LENGTH(sizeof(in_addr_t));
tuple_ipv4->src.attr.nfa_type = CTA_IP_V4_SRC;
net_ipv4addr_hdrcopy(&tuple_ipv4->src.addr, src);
tuple_ipv4->dst.attr.nfa_len = NFA_LENGTH(sizeof(in_addr_t));
tuple_ipv4->dst.attr.nfa_type = CTA_IP_V4_DST;
net_ipv4addr_hdrcopy(&tuple_ipv4->dst.addr, dst);
return tuple_ipv4->attr.nfa_len;
}
#endif
#ifdef CONFIG_NET_NAT66
if (domain == PF_INET6)
{
FAR struct conntrack_tuple_ipv6_s *tuple_ipv6 = buf;
tuple_ipv6->attr.nfa_len = sizeof(struct conntrack_tuple_ipv6_s);
tuple_ipv6->attr.nfa_type = CTA_TUPLE_IP | NFNL_NFA_NEST;
tuple_ipv6->src.attr.nfa_len = NFA_LENGTH(sizeof(net_ipv6addr_t));
tuple_ipv6->src.attr.nfa_type = CTA_IP_V6_SRC;
net_ipv6addr_hdrcopy(tuple_ipv6->src.addr, src);
tuple_ipv6->dst.attr.nfa_len = NFA_LENGTH(sizeof(net_ipv6addr_t));
tuple_ipv6->dst.attr.nfa_type = CTA_IP_V6_DST;
net_ipv6addr_hdrcopy(tuple_ipv6->dst.addr, dst);
return tuple_ipv6->attr.nfa_len;
}
#endif
return 0;
}
/****************************************************************************
* Name: netlink_conntrack_fill_proto
*
* Description:
* Fill the data of a CTA_TUPLE_PROTO.
*
* Input Parameters:
* buf - The buffer to fill
* proto - The protocol of the tuple
* sport - The source port
* dport - The destination port
* reply - True if the tuple is a reply
*
* Returned Value:
* The size of the filled data.
*
****************************************************************************/
static size_t netlink_conntrack_fill_proto(FAR void *buf, uint8_t proto,
uint16_t sport, uint16_t dport,
bool reply)
{
switch (proto)
{
#ifdef CONFIG_NET_TCP
case IPPROTO_TCP:
#endif
#ifdef CONFIG_NET_UDP
case IPPROTO_UDP:
#endif
#if defined(CONFIG_NET_TCP) || defined(CONFIG_NET_UDP)
{
FAR struct conntrack_tuple_tcpudp_s *tuple_tcpudp = buf;
tuple_tcpudp->attr.nfa_len =
sizeof(struct conntrack_tuple_tcpudp_s);
tuple_tcpudp->attr.nfa_type = CTA_TUPLE_PROTO | NFNL_NFA_NEST;
tuple_tcpudp->proto.attr.nfa_len = NFA_LENGTH(sizeof(uint8_t));
tuple_tcpudp->proto.attr.nfa_type = CTA_PROTO_NUM;
tuple_tcpudp->proto.value = proto;
tuple_tcpudp->sport.attr.nfa_len = NFA_LENGTH(sizeof(uint16_t));
tuple_tcpudp->sport.attr.nfa_type = CTA_PROTO_SRC_PORT;
tuple_tcpudp->sport.value = sport;
tuple_tcpudp->dport.attr.nfa_len = NFA_LENGTH(sizeof(uint16_t));
tuple_tcpudp->dport.attr.nfa_type = CTA_PROTO_DST_PORT;
tuple_tcpudp->dport.value = dport;
return tuple_tcpudp->attr.nfa_len;
}
#endif
#ifdef CONFIG_NET_ICMP
case IPPROTO_ICMP:
#endif
#ifdef CONFIG_NET_ICMPv6
case IPPROTO_ICMP6:
#endif
#if defined(CONFIG_NET_ICMP) || defined(CONFIG_NET_ICMPv6)
{
FAR struct conntrack_tuple_icmp_s *tuple_icmp = buf;
tuple_icmp->attr.nfa_len = sizeof(struct conntrack_tuple_icmp_s);
tuple_icmp->attr.nfa_type = CTA_TUPLE_PROTO | NFNL_NFA_NEST;
tuple_icmp->proto.attr.nfa_len = NFA_LENGTH(sizeof(uint8_t));
tuple_icmp->proto.attr.nfa_type = CTA_PROTO_NUM;
tuple_icmp->proto.value = proto;
tuple_icmp->id.attr.nfa_len = NFA_LENGTH(sizeof(uint16_t));
tuple_icmp->id.value = reply ? dport : sport;
tuple_icmp->type.attr.nfa_len = NFA_LENGTH(sizeof(uint8_t));
tuple_icmp->code.attr.nfa_len = NFA_LENGTH(sizeof(uint8_t));
tuple_icmp->code.value = 0;
#ifdef CONFIG_NET_ICMP
if (proto == IPPROTO_ICMP)
{
tuple_icmp->id.attr.nfa_type = CTA_PROTO_ICMP_ID;
tuple_icmp->type.attr.nfa_type = CTA_PROTO_ICMP_TYPE;
tuple_icmp->type.value = reply ? ICMP_ECHO_REPLY :
ICMP_ECHO_REQUEST;
tuple_icmp->code.attr.nfa_type = CTA_PROTO_ICMP_CODE;
}
#endif
#ifdef CONFIG_NET_ICMPv6
if (proto == IPPROTO_ICMP6)
{
tuple_icmp->id.attr.nfa_type = CTA_PROTO_ICMPV6_ID;
tuple_icmp->type.attr.nfa_type = CTA_PROTO_ICMPV6_TYPE;
tuple_icmp->type.value = reply ? ICMPv6_ECHO_REPLY :
ICMPv6_ECHO_REQUEST;
tuple_icmp->code.attr.nfa_type = CTA_PROTO_ICMPV6_CODE;
}
#endif
return tuple_icmp->attr.nfa_len;
}
#endif
}
return 0;
}
/****************************************************************************
* Name: netlink_get_ipv4/ipv6_conntrack
*
* Description:
* Get the conntrack response corresponding to an NAT entry.
*
****************************************************************************/
static FAR struct netlink_response_s *
netlink_get_conntrack(FAR const struct nlmsghdr *req, uint16_t flags,
uint8_t type, uint8_t domain, uint8_t proto,
FAR const void *lipaddr, uint16_t lport,
FAR const void *eipaddr, uint16_t eport,
FAR const void *ripaddr, uint16_t rport)
{
FAR struct conntrack_recvfrom_rsplist_s *entry;
FAR struct nfattr *tuple;
ssize_t tuple_size = netlink_conntrack_tuple_size(domain, proto);
size_t offset = 0;
size_t allocsize;
size_t rspsize;
if (tuple_size < 0)
{
nerr("ERROR: Failed to get tuple size in response.\n");
return NULL;
}
rspsize = SIZEOF_CTNL_RECVFROM_RESPONSE_S(tuple_size * 2);
allocsize = SIZEOF_CTNL_RECVFROM_RSPLIST_S(tuple_size * 2);
entry = kmm_malloc(allocsize);
if (entry == NULL)
{
nerr("ERROR: Failed to allocate response buffer.\n");
return NULL;
}
entry->payload.hdr.nlmsg_len = rspsize;
entry->payload.hdr.nlmsg_type = type | (NFNL_SUBSYS_CTNETLINK << 8);
entry->payload.hdr.nlmsg_flags = flags;
entry->payload.hdr.nlmsg_seq = req ? req->nlmsg_seq : 0;
entry->payload.hdr.nlmsg_pid = req ? req->nlmsg_pid : 0;
entry->payload.msg.nfgen_family = domain;
entry->payload.msg.version = NFNETLINK_V0;
entry->payload.msg.res_id = 0;
/* CTA_TUPLE_ORIG */
tuple = (FAR struct nfattr *)&entry->payload.data[offset];
tuple->nfa_len = tuple_size;
tuple->nfa_type = CTA_TUPLE_ORIG | NFNL_NFA_NEST;
offset += sizeof(struct nfattr);
offset += netlink_conntrack_fill_ip(&entry->payload.data[offset], domain,
lipaddr, ripaddr);
offset += netlink_conntrack_fill_proto(&entry->payload.data[offset], proto,
lport, rport, false);
DEBUGASSERT(offset == tuple_size);
/* CTA_TUPLE_REPLY */
tuple = (FAR struct nfattr *)&entry->payload.data[offset];
tuple->nfa_len = tuple_size;
tuple->nfa_type = CTA_TUPLE_REPLY | NFNL_NFA_NEST;
offset += sizeof(struct nfattr);
offset += netlink_conntrack_fill_ip(&entry->payload.data[offset], domain,
ripaddr, eipaddr);
offset += netlink_conntrack_fill_proto(&entry->payload.data[offset], proto,
rport, eport, true);
DEBUGASSERT(offset == tuple_size * 2);
return (FAR struct netlink_response_s *)entry;
}
#ifdef CONFIG_NET_NAT44
static FAR struct netlink_response_s *
netlink_get_ipv4_conntrack(FAR const struct nlmsghdr *req,
FAR const ipv4_nat_entry_t *entry,
uint16_t flags, uint8_t type)
{
#ifndef CONFIG_NET_NAT44_SYMMETRIC
const in_addr_t any = INADDR_ANY;
#endif
return netlink_get_conntrack(req, flags, type, PF_INET, entry->protocol,
&entry->local_ip, entry->local_port,
&entry->external_ip, entry->external_port,
#ifdef CONFIG_NET_NAT44_SYMMETRIC
&entry->peer_ip, entry->peer_port
#else
&any, 0 /* Zero-address */
#endif
);
}
#endif
#ifdef CONFIG_NET_NAT66
static FAR struct netlink_response_s *
netlink_get_ipv6_conntrack(FAR const struct nlmsghdr *req,
FAR const ipv6_nat_entry_t *entry,
uint16_t flags, uint8_t type)
{
return netlink_get_conntrack(req, flags, type, PF_INET6, entry->protocol,
entry->local_ip, entry->local_port,
entry->external_ip, entry->external_port,
#ifdef CONFIG_NET_NAT66_SYMMETRIC
entry->peer_ip, entry->peer_port
#else
g_ipv6_unspecaddr, 0 /* Zero-address */
#endif
);
}
#endif
/****************************************************************************
* Name: netlink_add_ipv4/ipv6_conntrack
*
* Description:
* Add the conntrack response of an IPv4/IPv6 NAT entry.
*
****************************************************************************/
#ifdef CONFIG_NET_NAT44
static void netlink_add_ipv4_conntrack(FAR ipv4_nat_entry_t *entry,
FAR void *arg)
{
FAR struct nfnl_info_s *info = arg;
FAR struct netlink_response_s *resp;
uint16_t flags = NLM_F_MULTI | NLM_F_DUMP_FILTERED;
resp = netlink_get_ipv4_conntrack(&info->req->hdr, entry, flags,
IPCTNL_MSG_CT_NEW);
if (resp != NULL)
{
netlink_add_response(info->handle, resp);
}
}
#endif
#ifdef CONFIG_NET_NAT66
static void netlink_add_ipv6_conntrack(FAR ipv6_nat_entry_t *entry,
FAR void *arg)
{
FAR struct nfnl_info_s *info = arg;
FAR struct netlink_response_s *resp;
uint16_t flags = NLM_F_MULTI | NLM_F_DUMP_FILTERED;
resp = netlink_get_ipv6_conntrack(&info->req->hdr, entry, flags,
IPCTNL_MSG_CT_NEW);
if (resp != NULL)
{
netlink_add_response(info->handle, resp);
}
}
#endif
/****************************************************************************
* Name: netlink_list_conntrack
*
* Description:
* Return the entire NAT table.
*
****************************************************************************/
static int netlink_list_conntrack(NETLINK_HANDLE handle,
FAR const struct nfnl_sendto_request_s *req)
{
struct nfnl_info_s info;
uint8_t type = NFNL_MSG_TYPE(req->hdr.nlmsg_type);
if (type != IPCTNL_MSG_CT_GET)
{
return -ENOSYS;
}
info.handle = handle;
info.req = req;
switch (req->msg.nfgen_family)
{
#ifdef CONFIG_NET_NAT44
case AF_INET:
ipv4_nat_entry_foreach(netlink_add_ipv4_conntrack, &info);
break;
#endif
#ifdef CONFIG_NET_NAT66
case AF_INET6:
ipv6_nat_entry_foreach(netlink_add_ipv6_conntrack, &info);
break;
#endif
default:
return -ENOSYS;
}
return netlink_add_terminator(handle, &req->hdr, 0);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: netlink_netfilter_sendto
*
* Description:
* Perform the sendto() operation for the NETLINK_NETFILTER protocol.
*
****************************************************************************/
ssize_t netlink_netfilter_sendto(NETLINK_HANDLE handle,
FAR const struct nlmsghdr *nlmsg,
size_t len, int flags,
FAR const struct sockaddr_nl *to,
socklen_t tolen)
{
FAR const struct nfnl_sendto_request_s *req =
(FAR const struct nfnl_sendto_request_s *)nlmsg;
ssize_t ret = -ENOSYS;
uint8_t subsys;
DEBUGASSERT(handle != NULL && nlmsg != NULL &&
nlmsg->nlmsg_len >= sizeof(struct nlmsghdr) &&
len >= sizeof(struct nlmsghdr) &&
len >= nlmsg->nlmsg_len && to != NULL &&
tolen >= sizeof(struct sockaddr_nl));
/* Split subsys and type from nlmsg->nlmsg_type */
subsys = NFNL_SUBSYS_ID(nlmsg->nlmsg_type);
/* Handle according to the subsystem */
switch (subsys)
{
case NFNL_SUBSYS_CTNETLINK:
ret = netlink_list_conntrack(handle, req);
break;
}
/* On success, return the size of the request that was processed */
if (ret >= 0)
{
ret = len;
}
return ret;
}
/****************************************************************************
* Name: netlink_conntrack_notify
*
* Description:
* Perform the conntrack broadcast for the NETLINK_NETFILTER protocol.
*
* Input Parameters:
* type - The type of the message, IPCTNL_MSG_CT_*
* domain - The domain of the message
* nat_entry - The NAT entry
*
****************************************************************************/
void netlink_conntrack_notify(uint8_t type, uint8_t domain,
FAR const void *nat_entry)
{
FAR struct netlink_response_s *resp;
uint16_t flags;
int group;
switch (type)
{
case IPCTNL_MSG_CT_NEW:
group = NFNLGRP_CONNTRACK_NEW;
flags = NLM_F_EXCL | NLM_F_CREATE;
break;
case IPCTNL_MSG_CT_DELETE:
group = NFNLGRP_CONNTRACK_DESTROY;
flags = 0;
break;
default:
return;
}
switch (domain)
{
#ifdef CONFIG_NET_NAT44
case PF_INET:
resp = netlink_get_ipv4_conntrack(NULL, nat_entry, flags, type);
break;
#endif
#ifdef CONFIG_NET_NAT66
case PF_INET6:
resp = netlink_get_ipv6_conntrack(NULL, nat_entry, flags, type);
break;
#endif
default:
return;
}
if (resp != NULL)
{
netlink_add_broadcast(group, resp);
}
}
#endif /* CONFIG_NETLINK_NETFILTER */

View File

@ -129,6 +129,11 @@ static int netlink_setup(FAR struct socket *psock)
break;
#endif
#ifdef CONFIG_NETLINK_NETFILTER
case NETLINK_NETFILTER:
break;
#endif
default:
return -EPROTONOSUPPORT;
}
@ -621,6 +626,15 @@ static ssize_t netlink_sendmsg(FAR struct socket *psock,
break;
#endif
#ifdef CONFIG_NETLINK_NETFILTER
case NETLINK_NETFILTER:
ret = netlink_netfilter_sendto(conn, nlmsg,
msg->msg_iov->iov_len, flags,
(FAR const struct sockaddr_nl *)to,
tolen);
break;
#endif
default:
ret = -EOPNOTSUPP;
break;