summaryrefslogblamecommitdiffstats
path: root/net/openvswitch/conntrack.c
blob: cd94f925495a5ef6b6d2192961a0c97d6ac1764f (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194














                                                                      


                       
                             
                   
                          
                                            
                                             
                                              
                                              
                                              

                                              
                          
 





                                         





                         

                   

  





                                                      
                                                         


                                       

  





                                                                           

                                             
                                           

                                      
                      
                                                         
                     
                              
                   
                                                              
                            
                                
                           
                                                                                
      

  
























                                                                             

                                                                   

                                                                     



















                                                                       















                                                 








                                         








                                                    




                                                                       

                                                               


                                                                      


                                                            
                                                     

 



                                                                              
                                                








                                                                   
                                                                  

                                                                     
 

                                
                                           
                                               
























                                                                             
                                                                       

                                         
                               

 
                                                                        


                                                                           

                                                        
                                                                    

                                                                    








                                                                
                                                                  

                                              


                                                                        

                                                  
                                     
                                                                   





                                                          


                                                            

                                           
         
                                                  

 


                                                                               

                                                                        
                                                        

 





                                                                         
 
                                                                      


                                                    
                                                                    

                                 
                                                   
                                                                    

                                 
                                                     

                                                                           

                                 
                                   





                                                             
                                                      









                                                                               
                                                      






                                                                         


                 
                                                                       

                                                 
                                        

                     


                                                  

                                                                


                                        
                 


                         

 
                                                                        
 
                                  





                                           





                                                                               
                                                    




                                                                          







                                                                      

                                        
                

                               












                                                                    
 
                                                                         
                                                    


                                                 






















                                                                         
 


                 







                                                        
                



















                                                    
                        
 


                                                                             


                                                             
                              






                                                                 











                                                                               

 


                                                                          



                                                                     
                


                                                                          

                                                                   
                                                



                                                      
                                     
                                                        
                                                                            

                                                                     
                                                         


                                                
                                   
                 
 
                                                       
                                                       

                
                               















                                                                         
                                        
 
                                                                                 
                            



























                                                                              

 

















                                                                               
                                                                             


                                     

                                                                             


                                                                           
                                                                
 

                                          
                           
 

                                                                   



                                                                    



                                                                       
                                                              





                                                                              






                                                     






                                                                               
                                               


                  



























                                                                               
                                                                              



                                                                  


                                      
                                


                                     




                                                                        
                             
 



                                                            






                                                                             






                                                                             

                                                  


                                        
 
                           

 






                                                                      
                                                                




                                                               
                                    









                                                                  

                                                       




                                                                           

                                                                













                                                                             

                                                                  
                                  




























                                                                            
                                                   










                                                                
                                                  




















                                                                          
                                                  





























                                                                           





                                                                            

                                                                             


                                                            
                                                        



































                                                                           
                                                                             

                                                                           
                                                                             

                                      
                                                                    







                                                                              




                                                           




                                                    
                                                
                        


                                                        

                                                                
                                                            
                                                        

                 
                                                   
                                     
                                       
 



                                                                               
                                  


                                                              
         
 
                                     








                                                                              
                                     
                   
                                                                        




                                                                               












                                                                               








                                                                           











                                                                  






                                                                              



                                                                      


                                                                        
                                                                           
                                                                          







                                                           
                                                     


                                                        



                 
                                                                  


                 

                                                  




                                    


















































































                                                                               




                                                                  

                                      





                                                   




                                                                            






                                                                             
                                                                    






                                                       













                                                                             




                                                                             
                                                                



                                                       




                                                                      

                                                            

                                                                     











                                                                              





























                                                                     


                                                                          








                                                               
                                    
 



                                        





                                                                     
                         
                                                         



                                                         
                                                   

                               


                   










                                                              












                                                                               
                                                          
                    
                                                




                                                 



                                                  


                 


























                                                                               
                                                                                 




                                                                     
                                                                                                








                                                                    
                                                                                        







                                                                           

                                                                 

































                                                                             
                                                                           




                                       
                                                                          





                                                             
                                                                                                              





                                                                         
                                                                                                       
















                                                                       
                                                                            
                                                               
                                                                       

                                                            

                                                                       

                                                                         
                                                




                                                                       

                                                            


                                                                               
                                                  





                                           

                           






                                                                             


                                                       







                                                                                                                


                                              

                                            





                                                       



                                                           



                                                                           



                                           
                                 

                                                               
 



                                                                             
                                               


                              






                                                                           








                                                          




                                                         






                                                                     













                                                                              







                                                                           
                                                           





                                                    


                                                   
                                                     
                                             



                                                                       








                                                                  
                                  














                                                             
                                                     








                                                                         




                                                                    





                                                                   

                                                          

                 
                                       


                   




















                                                                     

                                                     






                                                                         

                                                            







                                                                            



























                                                                       








                                                                   


                                                                      



                                                                 
                                                                         


                                                                 
                                                     
                                                    

                                                                     
                                 




                                                           



                                                                        



                                                              








                                                         




                                                                    
                            
                                                         
                        
                                             
 
 





























































































































































































































































































































































































































                                                                               
 
                                                                               

                                                               
                                                 




                                                                  





                                               





                                                               



                                              


                                       
/*
 * Copyright (c) 2015 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 */

#include <linux/module.h>
#include <linux/openvswitch.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/sctp.h>
#include <linux/static_key.h>
#include <net/ip.h>
#include <net/genetlink.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_count.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include <net/ipv6_frag.h>

#ifdef CONFIG_NF_NAT_NEEDED
#include <linux/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_nat_l3proto.h>
#endif

#include "datapath.h"
#include "conntrack.h"
#include "flow.h"
#include "flow_netlink.h"

struct ovs_ct_len_tbl {
	int maxlen;
	int minlen;
};

/* Metadata mark for masked write to conntrack mark */
struct md_mark {
	u32 value;
	u32 mask;
};

/* Metadata label for masked write to conntrack label. */
struct md_labels {
	struct ovs_key_ct_labels value;
	struct ovs_key_ct_labels mask;
};

enum ovs_ct_nat {
	OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
	OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
	OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
};

/* Conntrack action context for execution. */
struct ovs_conntrack_info {
	struct nf_conntrack_helper *helper;
	struct nf_conntrack_zone zone;
	struct nf_conn *ct;
	u8 commit : 1;
	u8 nat : 3;                 /* enum ovs_ct_nat */
	u8 force : 1;
	u8 have_eventmask : 1;
	u16 family;
	u32 eventmask;              /* Mask of 1 << IPCT_*. */
	struct md_mark mark;
	struct md_labels labels;
#ifdef CONFIG_NF_NAT_NEEDED
	struct nf_nat_range2 range;  /* Only present for SRC NAT and DST NAT. */
#endif
};

#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
#define OVS_CT_LIMIT_UNLIMITED	0
#define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
#define CT_LIMIT_HASH_BUCKETS 512
static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);

struct ovs_ct_limit {
	/* Elements in ovs_ct_limit_info->limits hash table */
	struct hlist_node hlist_node;
	struct rcu_head rcu;
	u16 zone;
	u32 limit;
};

struct ovs_ct_limit_info {
	u32 default_limit;
	struct hlist_head *limits;
	struct nf_conncount_data *data;
};

static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
	[OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
};
#endif

static bool labels_nonzero(const struct ovs_key_ct_labels *labels);

static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);

static u16 key_to_nfproto(const struct sw_flow_key *key)
{
	switch (ntohs(key->eth.type)) {
	case ETH_P_IP:
		return NFPROTO_IPV4;
	case ETH_P_IPV6:
		return NFPROTO_IPV6;
	default:
		return NFPROTO_UNSPEC;
	}
}

/* Map SKB connection state into the values used by flow definition. */
static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
{
	u8 ct_state = OVS_CS_F_TRACKED;

	switch (ctinfo) {
	case IP_CT_ESTABLISHED_REPLY:
	case IP_CT_RELATED_REPLY:
		ct_state |= OVS_CS_F_REPLY_DIR;
		break;
	default:
		break;
	}

	switch (ctinfo) {
	case IP_CT_ESTABLISHED:
	case IP_CT_ESTABLISHED_REPLY:
		ct_state |= OVS_CS_F_ESTABLISHED;
		break;
	case IP_CT_RELATED:
	case IP_CT_RELATED_REPLY:
		ct_state |= OVS_CS_F_RELATED;
		break;
	case IP_CT_NEW:
		ct_state |= OVS_CS_F_NEW;
		break;
	default:
		break;
	}

	return ct_state;
}

static u32 ovs_ct_get_mark(const struct nf_conn *ct)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
	return ct ? ct->mark : 0;
#else
	return 0;
#endif
}

/* Guard against conntrack labels max size shrinking below 128 bits. */
#if NF_CT_LABELS_MAX_SIZE < 16
#error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
#endif

static void ovs_ct_get_labels(const struct nf_conn *ct,
			      struct ovs_key_ct_labels *labels)
{
	struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;

	if (cl)
		memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
	else
		memset(labels, 0, OVS_CT_LABELS_LEN);
}

static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
					const struct nf_conntrack_tuple *orig,
					u8 icmp_proto)
{
	key->ct_orig_proto = orig->dst.protonum;
	if (orig->dst.protonum == icmp_proto) {
		key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
		key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
	} else {
		key->ct.orig_tp.src = orig->src.u.all;
		key->ct.orig_tp.dst = orig->dst.u.all;
	}
}

static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
				const struct nf_conntrack_zone *zone,
				const struct nf_conn *ct)
{
	key->ct_state = state;
	key->ct_zone = zone->id;
	key->ct.mark = ovs_ct_get_mark(ct);
	ovs_ct_get_labels(ct, &key->ct.labels);

	if (ct) {
		const struct nf_conntrack_tuple *orig;

		/* Use the master if we have one. */
		if (ct->master)
			ct = ct->master;
		orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;

		/* IP version must match with the master connection. */
		if (key->eth.type == htons(ETH_P_IP) &&
		    nf_ct_l3num(ct) == NFPROTO_IPV4) {
			key->ipv4.ct_orig.src = orig->src.u3.ip;
			key->ipv4.ct_orig.dst = orig->dst.u3.ip;
			__ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
			return;
		} else if (key->eth.type == htons(ETH_P_IPV6) &&
			   !sw_flow_key_is_nd(key) &&
			   nf_ct_l3num(ct) == NFPROTO_IPV6) {
			key->ipv6.ct_orig.src = orig->src.u3.in6;
			key->ipv6.ct_orig.dst = orig->dst.u3.in6;
			__ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
			return;
		}
	}
	/* Clear 'ct_orig_proto' to mark the non-existence of conntrack
	 * original direction key fields.
	 */
	key->ct_orig_proto = 0;
}

/* Update 'key' based on skb->_nfct.  If 'post_ct' is true, then OVS has
 * previously sent the packet to conntrack via the ct action.  If
 * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
 * initialized from the connection status.
 */
static void ovs_ct_update_key(const struct sk_buff *skb,
			      const struct ovs_conntrack_info *info,
			      struct sw_flow_key *key, bool post_ct,
			      bool keep_nat_flags)
{
	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	u8 state = 0;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct) {
		state = ovs_ct_get_state(ctinfo);
		/* All unconfirmed entries are NEW connections. */
		if (!nf_ct_is_confirmed(ct))
			state |= OVS_CS_F_NEW;
		/* OVS persists the related flag for the duration of the
		 * connection.
		 */
		if (ct->master)
			state |= OVS_CS_F_RELATED;
		if (keep_nat_flags) {
			state |= key->ct_state & OVS_CS_F_NAT_MASK;
		} else {
			if (ct->status & IPS_SRC_NAT)
				state |= OVS_CS_F_SRC_NAT;
			if (ct->status & IPS_DST_NAT)
				state |= OVS_CS_F_DST_NAT;
		}
		zone = nf_ct_zone(ct);
	} else if (post_ct) {
		state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
		if (info)
			zone = &info->zone;
	}
	__ovs_ct_update_key(key, state, zone, ct);
}

/* This is called to initialize CT key fields possibly coming in from the local
 * stack.
 */
void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
{
	ovs_ct_update_key(skb, NULL, key, false, false);
}

#define IN6_ADDR_INITIALIZER(ADDR) \
	{ (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \
	  (ADDR).s6_addr32[2], (ADDR).s6_addr32[3] }

int ovs_ct_put_key(const struct sw_flow_key *swkey,
		   const struct sw_flow_key *output, struct sk_buff *skb)
{
	if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
		return -EMSGSIZE;

	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
		return -EMSGSIZE;

	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
		return -EMSGSIZE;

	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
		    &output->ct.labels))
		return -EMSGSIZE;

	if (swkey->ct_orig_proto) {
		if (swkey->eth.type == htons(ETH_P_IP)) {
			struct ovs_key_ct_tuple_ipv4 orig = {
				output->ipv4.ct_orig.src,
				output->ipv4.ct_orig.dst,
				output->ct.orig_tp.src,
				output->ct.orig_tp.dst,
				output->ct_orig_proto,
			};
			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
				    sizeof(orig), &orig))
				return -EMSGSIZE;
		} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
			struct ovs_key_ct_tuple_ipv6 orig = {
				IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src),
				IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst),
				output->ct.orig_tp.src,
				output->ct.orig_tp.dst,
				output->ct_orig_proto,
			};
			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
				    sizeof(orig), &orig))
				return -EMSGSIZE;
		}
	}

	return 0;
}

static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
			   u32 ct_mark, u32 mask)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
	u32 new_mark;

	new_mark = ct_mark | (ct->mark & ~(mask));
	if (ct->mark != new_mark) {
		ct->mark = new_mark;
		if (nf_ct_is_confirmed(ct))
			nf_conntrack_event_cache(IPCT_MARK, ct);
		key->ct.mark = new_mark;
	}

	return 0;
#else
	return -ENOTSUPP;
#endif
}

static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
{
	struct nf_conn_labels *cl;

	cl = nf_ct_labels_find(ct);
	if (!cl) {
		nf_ct_labels_ext_add(ct);
		cl = nf_ct_labels_find(ct);
	}

	return cl;
}

/* Initialize labels for a new, yet to be committed conntrack entry.  Note that
 * since the new connection is not yet confirmed, and thus no-one else has
 * access to it's labels, we simply write them over.
 */
static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
			      const struct ovs_key_ct_labels *labels,
			      const struct ovs_key_ct_labels *mask)
{
	struct nf_conn_labels *cl, *master_cl;
	bool have_mask = labels_nonzero(mask);

	/* Inherit master's labels to the related connection? */
	master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;

	if (!master_cl && !have_mask)
		return 0;   /* Nothing to do. */

	cl = ovs_ct_get_conn_labels(ct);
	if (!cl)
		return -ENOSPC;

	/* Inherit the master's labels, if any. */
	if (master_cl)
		*cl = *master_cl;

	if (have_mask) {
		u32 *dst = (u32 *)cl->bits;
		int i;

		for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
			dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
				(labels->ct_labels_32[i]
				 & mask->ct_labels_32[i]);
	}

	/* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
	 * IPCT_LABEL bit is set in the event cache.
	 */
	nf_conntrack_event_cache(IPCT_LABEL, ct);

	memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);

	return 0;
}

static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
			     const struct ovs_key_ct_labels *labels,
			     const struct ovs_key_ct_labels *mask)
{
	struct nf_conn_labels *cl;
	int err;

	cl = ovs_ct_get_conn_labels(ct);
	if (!cl)
		return -ENOSPC;

	err = nf_connlabels_replace(ct, labels->ct_labels_32,
				    mask->ct_labels_32,
				    OVS_CT_LABELS_LEN_32);
	if (err)
		return err;

	memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);

	return 0;
}

/* 'skb' should already be pulled to nh_ofs. */
static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
{
	const struct nf_conntrack_helper *helper;
	const struct nf_conn_help *help;
	enum ip_conntrack_info ctinfo;
	unsigned int protoff;
	struct nf_conn *ct;
	int err;

	ct = nf_ct_get(skb, &ctinfo);
	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
		return NF_ACCEPT;

	help = nfct_help(ct);
	if (!help)
		return NF_ACCEPT;

	helper = rcu_dereference(help->helper);
	if (!helper)
		return NF_ACCEPT;

	switch (proto) {
	case NFPROTO_IPV4:
		protoff = ip_hdrlen(skb);
		break;
	case NFPROTO_IPV6: {
		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
		__be16 frag_off;
		int ofs;

		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
				       &frag_off);
		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
			pr_debug("proto header not found\n");
			return NF_ACCEPT;
		}
		protoff = ofs;
		break;
	}
	default:
		WARN_ONCE(1, "helper invoked on non-IP family!");
		return NF_DROP;
	}

	err = helper->help(skb, protoff, ct, ctinfo);
	if (err != NF_ACCEPT)
		return err;

	/* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
	 * FTP with NAT) adusting the TCP payload size when mangling IP
	 * addresses and/or port numbers in the text-based control connection.
	 */
	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
	    !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
		return NF_DROP;
	return NF_ACCEPT;
}

/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 * value if 'skb' is freed.
 */
static int handle_fragments(struct net *net, struct sw_flow_key *key,
			    u16 zone, struct sk_buff *skb)
{
	struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
	int err;

	if (key->eth.type == htons(ETH_P_IP)) {
		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;

		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
		err = ip_defrag(net, skb, user);
		if (err)
			return err;

		ovs_cb.mru = IPCB(skb)->frag_max_size;
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
	} else if (key->eth.type == htons(ETH_P_IPV6)) {
		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;

		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
		err = nf_ct_frag6_gather(net, skb, user);
		if (err) {
			if (err != -EINPROGRESS)
				kfree_skb(skb);
			return err;
		}

		key->ip.proto = ipv6_hdr(skb)->nexthdr;
		ovs_cb.mru = IP6CB(skb)->frag_max_size;
#endif
	} else {
		kfree_skb(skb);
		return -EPFNOSUPPORT;
	}

	key->ip.frag = OVS_FRAG_TYPE_NONE;
	skb_clear_hash(skb);
	skb->ignore_df = 1;
	*OVS_CB(skb) = ovs_cb;

	return 0;
}

static struct nf_conntrack_expect *
ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
		   u16 proto, const struct sk_buff *skb)
{
	struct nf_conntrack_tuple tuple;
	struct nf_conntrack_expect *exp;

	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
		return NULL;

	exp = __nf_ct_expect_find(net, zone, &tuple);
	if (exp) {
		struct nf_conntrack_tuple_hash *h;

		/* Delete existing conntrack entry, if it clashes with the
		 * expectation.  This can happen since conntrack ALGs do not
		 * check for clashes between (new) expectations and existing
		 * conntrack entries.  nf_conntrack_in() will check the
		 * expectations only if a conntrack entry can not be found,
		 * which can lead to OVS finding the expectation (here) in the
		 * init direction, but which will not be removed by the
		 * nf_conntrack_in() call, if a matching conntrack entry is
		 * found instead.  In this case all init direction packets
		 * would be reported as new related packets, while reply
		 * direction packets would be reported as un-related
		 * established packets.
		 */
		h = nf_conntrack_find_get(net, zone, &tuple);
		if (h) {
			struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);

			nf_ct_delete(ct, 0, 0);
			nf_conntrack_put(&ct->ct_general);
		}
	}

	return exp;
}

/* This replicates logic from nf_conntrack_core.c that is not exported. */
static enum ip_conntrack_info
ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
{
	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);

	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
		return IP_CT_ESTABLISHED_REPLY;
	/* Once we've had two way comms, always ESTABLISHED. */
	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
		return IP_CT_ESTABLISHED;
	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
		return IP_CT_RELATED;
	return IP_CT_NEW;
}

/* Find an existing connection which this packet belongs to without
 * re-attributing statistics or modifying the connection state.  This allows an
 * skb->_nfct lost due to an upcall to be recovered during actions execution.
 *
 * Must be called with rcu_read_lock.
 *
 * On success, populates skb->_nfct and returns the connection.  Returns NULL
 * if there is no existing entry.
 */
static struct nf_conn *
ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
		     u8 l3num, struct sk_buff *skb, bool natted)
{
	struct nf_conntrack_tuple tuple;
	struct nf_conntrack_tuple_hash *h;
	struct nf_conn *ct;

	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
			       net, &tuple)) {
		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
		return NULL;
	}

	/* Must invert the tuple if skb has been transformed by NAT. */
	if (natted) {
		struct nf_conntrack_tuple inverse;

		if (!nf_ct_invert_tuplepr(&inverse, &tuple)) {
			pr_debug("ovs_ct_find_existing: Inversion failed!\n");
			return NULL;
		}
		tuple = inverse;
	}

	/* look for tuple match */
	h = nf_conntrack_find_get(net, zone, &tuple);
	if (!h)
		return NULL;   /* Not found. */

	ct = nf_ct_tuplehash_to_ctrack(h);

	/* Inverted packet tuple matches the reverse direction conntrack tuple,
	 * select the other tuplehash to get the right 'ctinfo' bits for this
	 * packet.
	 */
	if (natted)
		h = &ct->tuplehash[!h->tuple.dst.dir];

	nf_ct_set(skb, ct, ovs_ct_get_info(h));
	return ct;
}

static
struct nf_conn *ovs_ct_executed(struct net *net,
				const struct sw_flow_key *key,
				const struct ovs_conntrack_info *info,
				struct sk_buff *skb,
				bool *ct_executed)
{
	struct nf_conn *ct = NULL;

	/* If no ct, check if we have evidence that an existing conntrack entry
	 * might be found for this skb.  This happens when we lose a skb->_nfct
	 * due to an upcall, or if the direction is being forced.  If the
	 * connection was not confirmed, it is not cached and needs to be run
	 * through conntrack again.
	 */
	*ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
		       !(key->ct_state & OVS_CS_F_INVALID) &&
		       (key->ct_zone == info->zone.id);

	if (*ct_executed || (!key->ct_state && info->force)) {
		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
					  !!(key->ct_state &
					  OVS_CS_F_NAT_MASK));
	}

	return ct;
}

/* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
static bool skb_nfct_cached(struct net *net,
			    const struct sw_flow_key *key,
			    const struct ovs_conntrack_info *info,
			    struct sk_buff *skb)
{
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	bool ct_executed = true;

	ct = nf_ct_get(skb, &ctinfo);
	if (!ct)
		ct = ovs_ct_executed(net, key, info, skb, &ct_executed);

	if (ct)
		nf_ct_get(skb, &ctinfo);
	else
		return false;

	if (!net_eq(net, read_pnet(&ct->ct_net)))
		return false;
	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
		return false;
	if (info->helper) {
		struct nf_conn_help *help;

		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
		if (help && rcu_access_pointer(help->helper) != info->helper)
			return false;
	}
	/* Force conntrack entry direction to the current packet? */
	if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
		/* Delete the conntrack entry if confirmed, else just release
		 * the reference.
		 */
		if (nf_ct_is_confirmed(ct))
			nf_ct_delete(ct, 0, 0);

		nf_conntrack_put(&ct->ct_general);
		nf_ct_set(skb, NULL, 0);
		return false;
	}

	return ct_executed;
}

#ifdef CONFIG_NF_NAT_NEEDED
/* Modelled after nf_nat_ipv[46]_fn().
 * range is only used for new, uninitialized NAT state.
 * Returns either NF_ACCEPT or NF_DROP.
 */
static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
			      enum ip_conntrack_info ctinfo,
			      const struct nf_nat_range2 *range,
			      enum nf_nat_manip_type maniptype)
{
	int hooknum, nh_off, err = NF_ACCEPT;

	nh_off = skb_network_offset(skb);
	skb_pull_rcsum(skb, nh_off);

	/* See HOOK2MANIP(). */
	if (maniptype == NF_NAT_MANIP_SRC)
		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
	else
		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */

	switch (ctinfo) {
	case IP_CT_RELATED:
	case IP_CT_RELATED_REPLY:
		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
		    skb->protocol == htons(ETH_P_IP) &&
		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
							   hooknum))
				err = NF_DROP;
			goto push;
		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
			   skb->protocol == htons(ETH_P_IPV6)) {
			__be16 frag_off;
			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
			int hdrlen = ipv6_skip_exthdr(skb,
						      sizeof(struct ipv6hdr),
						      &nexthdr, &frag_off);

			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
				if (!nf_nat_icmpv6_reply_translation(skb, ct,
								     ctinfo,
								     hooknum,
								     hdrlen))
					err = NF_DROP;
				goto push;
			}
		}
		/* Non-ICMP, fall thru to initialize if needed. */
		/* fall through */
	case IP_CT_NEW:
		/* Seen it before?  This can happen for loopback, retrans,
		 * or local packets.
		 */
		if (!nf_nat_initialized(ct, maniptype)) {
			/* Initialize according to the NAT action. */
			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
				/* Action is set up to establish a new
				 * mapping.
				 */
				? nf_nat_setup_info(ct, range, maniptype)
				: nf_nat_alloc_null_binding(ct, hooknum);
			if (err != NF_ACCEPT)
				goto push;
		}
		break;

	case IP_CT_ESTABLISHED:
	case IP_CT_ESTABLISHED_REPLY:
		break;

	default:
		err = NF_DROP;
		goto push;
	}

	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
push:
	skb_push(skb, nh_off);
	skb_postpush_rcsum(skb, skb->data, nh_off);

	return err;
}

static void ovs_nat_update_key(struct sw_flow_key *key,
			       const struct sk_buff *skb,
			       enum nf_nat_manip_type maniptype)
{
	if (maniptype == NF_NAT_MANIP_SRC) {
		__be16 src;

		key->ct_state |= OVS_CS_F_SRC_NAT;
		if (key->eth.type == htons(ETH_P_IP))
			key->ipv4.addr.src = ip_hdr(skb)->saddr;
		else if (key->eth.type == htons(ETH_P_IPV6))
			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
			       sizeof(key->ipv6.addr.src));
		else
			return;

		if (key->ip.proto == IPPROTO_UDP)
			src = udp_hdr(skb)->source;
		else if (key->ip.proto == IPPROTO_TCP)
			src = tcp_hdr(skb)->source;
		else if (key->ip.proto == IPPROTO_SCTP)
			src = sctp_hdr(skb)->source;
		else
			return;

		key->tp.src = src;
	} else {
		__be16 dst;

		key->ct_state |= OVS_CS_F_DST_NAT;
		if (key->eth.type == htons(ETH_P_IP))
			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
		else if (key->eth.type == htons(ETH_P_IPV6))
			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
			       sizeof(key->ipv6.addr.dst));
		else
			return;

		if (key->ip.proto == IPPROTO_UDP)
			dst = udp_hdr(skb)->dest;
		else if (key->ip.proto == IPPROTO_TCP)
			dst = tcp_hdr(skb)->dest;
		else if (key->ip.proto == IPPROTO_SCTP)
			dst = sctp_hdr(skb)->dest;
		else
			return;

		key->tp.dst = dst;
	}
}

/* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
		      const struct ovs_conntrack_info *info,
		      struct sk_buff *skb, struct nf_conn *ct,
		      enum ip_conntrack_info ctinfo)
{
	enum nf_nat_manip_type maniptype;
	int err;

	/* Add NAT extension if not confirmed yet. */
	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
		return NF_ACCEPT;   /* Can't NAT. */

	/* Determine NAT type.
	 * Check if the NAT type can be deduced from the tracked connection.
	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
	 * when committing.
	 */
	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
	    ct->status & IPS_NAT_MASK &&
	    (ctinfo != IP_CT_RELATED || info->commit)) {
		/* NAT an established or related connection like before. */
		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
			/* This is the REPLY direction for a connection
			 * for which NAT was applied in the forward
			 * direction.  Do the reverse NAT.
			 */
			maniptype = ct->status & IPS_SRC_NAT
				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
		else
			maniptype = ct->status & IPS_SRC_NAT
				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
	} else if (info->nat & OVS_CT_SRC_NAT) {
		maniptype = NF_NAT_MANIP_SRC;
	} else if (info->nat & OVS_CT_DST_NAT) {
		maniptype = NF_NAT_MANIP_DST;
	} else {
		return NF_ACCEPT; /* Connection is not NATed. */
	}
	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);

	/* Mark NAT done if successful and update the flow key. */
	if (err == NF_ACCEPT)
		ovs_nat_update_key(key, skb, maniptype);

	return err;
}
#else /* !CONFIG_NF_NAT_NEEDED */
static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
		      const struct ovs_conntrack_info *info,
		      struct sk_buff *skb, struct nf_conn *ct,
		      enum ip_conntrack_info ctinfo)
{
	return NF_ACCEPT;
}
#endif

/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 * not done already.  Update key with new CT state after passing the packet
 * through conntrack.
 * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
 * set to NULL and 0 will be returned.
 */
static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
			   const struct ovs_conntrack_info *info,
			   struct sk_buff *skb)
{
	/* If we are recirculating packets to match on conntrack fields and
	 * committing with a separate conntrack action,  then we don't need to
	 * actually run the packet through conntrack twice unless it's for a
	 * different zone.
	 */
	bool cached = skb_nfct_cached(net, key, info, skb);
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	if (!cached) {
		struct nf_hook_state state = {
			.hook = NF_INET_PRE_ROUTING,
			.pf = info->family,
			.net = net,
		};
		struct nf_conn *tmpl = info->ct;
		int err;

		/* Associate skb with specified zone. */
		if (tmpl) {
			if (skb_nfct(skb))
				nf_conntrack_put(skb_nfct(skb));
			nf_conntrack_get(&tmpl->ct_general);
			nf_ct_set(skb, tmpl, IP_CT_NEW);
		}

		err = nf_conntrack_in(skb, &state);
		if (err != NF_ACCEPT)
			return -ENOENT;

		/* Clear CT state NAT flags to mark that we have not yet done
		 * NAT after the nf_conntrack_in() call.  We can actually clear
		 * the whole state, as it will be re-initialized below.
		 */
		key->ct_state = 0;

		/* Update the key, but keep the NAT flags. */
		ovs_ct_update_key(skb, info, key, true, true);
	}

	ct = nf_ct_get(skb, &ctinfo);
	if (ct) {
		/* Packets starting a new connection must be NATted before the
		 * helper, so that the helper knows about the NAT.  We enforce
		 * this by delaying both NAT and helper calls for unconfirmed
		 * connections until the committing CT action.  For later
		 * packets NAT and Helper may be called in either order.
		 *
		 * NAT will be done only if the CT action has NAT, and only
		 * once per packet (per zone), as guarded by the NAT bits in
		 * the key->ct_state.
		 */
		if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
		    (nf_ct_is_confirmed(ct) || info->commit) &&
		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
			return -EINVAL;
		}

		/* Userspace may decide to perform a ct lookup without a helper
		 * specified followed by a (recirculate and) commit with one.
		 * Therefore, for unconfirmed connections which we will commit,
		 * we need to attach the helper here.
		 */
		if (!nf_ct_is_confirmed(ct) && info->commit &&
		    info->helper && !nfct_help(ct)) {
			int err = __nf_ct_try_assign_helper(ct, info->ct,
							    GFP_ATOMIC);
			if (err)
				return err;
		}

		/* Call the helper only if:
		 * - nf_conntrack_in() was executed above ("!cached") for a
		 *   confirmed connection, or
		 * - When committing an unconfirmed connection.
		 */
		if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
			return -EINVAL;
		}
	}

	return 0;
}

/* Lookup connection and read fields into key. */
static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
			 const struct ovs_conntrack_info *info,
			 struct sk_buff *skb)
{
	struct nf_conntrack_expect *exp;

	/* If we pass an expected packet through nf_conntrack_in() the
	 * expectation is typically removed, but the packet could still be
	 * lost in upcall processing.  To prevent this from happening we
	 * perform an explicit expectation lookup.  Expected connections are
	 * always new, and will be passed through conntrack only when they are
	 * committed, as it is OK to remove the expectation at that time.
	 */
	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
	if (exp) {
		u8 state;

		/* NOTE: New connections are NATted and Helped only when
		 * committed, so we are not calling into NAT here.
		 */
		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
		__ovs_ct_update_key(key, state, &info->zone, exp->master);
	} else {
		struct nf_conn *ct;
		int err;

		err = __ovs_ct_lookup(net, key, info, skb);
		if (err)
			return err;

		ct = (struct nf_conn *)skb_nfct(skb);
		if (ct)
			nf_ct_deliver_cached_events(ct);
	}

	return 0;
}

static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
{
	size_t i;

	for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
		if (labels->ct_labels_32[i])
			return true;

	return false;
}

#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
static struct hlist_head *ct_limit_hash_bucket(
	const struct ovs_ct_limit_info *info, u16 zone)
{
	return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
}

/* Call with ovs_mutex */
static void ct_limit_set(const struct ovs_ct_limit_info *info,
			 struct ovs_ct_limit *new_ct_limit)
{
	struct ovs_ct_limit *ct_limit;
	struct hlist_head *head;

	head = ct_limit_hash_bucket(info, new_ct_limit->zone);
	hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
		if (ct_limit->zone == new_ct_limit->zone) {
			hlist_replace_rcu(&ct_limit->hlist_node,
					  &new_ct_limit->hlist_node);
			kfree_rcu(ct_limit, rcu);
			return;
		}
	}

	hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
}

/* Call with ovs_mutex */
static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
{
	struct ovs_ct_limit *ct_limit;
	struct hlist_head *head;
	struct hlist_node *n;

	head = ct_limit_hash_bucket(info, zone);
	hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
		if (ct_limit->zone == zone) {
			hlist_del_rcu(&ct_limit->hlist_node);
			kfree_rcu(ct_limit, rcu);
			return;
		}
	}
}

/* Call with RCU read lock */
static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
{
	struct ovs_ct_limit *ct_limit;
	struct hlist_head *head;

	head = ct_limit_hash_bucket(info, zone);
	hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
		if (ct_limit->zone == zone)
			return ct_limit->limit;
	}

	return info->default_limit;
}

static int ovs_ct_check_limit(struct net *net,
			      const struct ovs_conntrack_info *info,
			      const struct nf_conntrack_tuple *tuple)
{
	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
	const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
	u32 per_zone_limit, connections;
	u32 conncount_key;

	conncount_key = info->zone.id;

	per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
	if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
		return 0;

	connections = nf_conncount_count(net, ct_limit_info->data,
					 &conncount_key, tuple, &info->zone);
	if (connections > per_zone_limit)
		return -ENOMEM;

	return 0;
}
#endif

/* Lookup connection and confirm if unconfirmed. */
static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
			 const struct ovs_conntrack_info *info,
			 struct sk_buff *skb)
{
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	int err;

	err = __ovs_ct_lookup(net, key, info, skb);
	if (err)
		return err;

	/* The connection could be invalid, in which case this is a no-op.*/
	ct = nf_ct_get(skb, &ctinfo);
	if (!ct)
		return 0;

#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
	if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
		if (!nf_ct_is_confirmed(ct)) {
			err = ovs_ct_check_limit(net, info,
				&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
			if (err) {
				net_warn_ratelimited("openvswitch: zone: %u "
					"exceeds conntrack limit\n",
					info->zone.id);
				return err;
			}
		}
	}
#endif

	/* Set the conntrack event mask if given.  NEW and DELETE events have
	 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
	 * typically would receive many kinds of updates.  Setting the event
	 * mask allows those events to be filtered.  The set event mask will
	 * remain in effect for the lifetime of the connection unless changed
	 * by a further CT action with both the commit flag and the eventmask
	 * option. */
	if (info->have_eventmask) {
		struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);

		if (cache)
			cache->ctmask = info->eventmask;
	}

	/* Apply changes before confirming the connection so that the initial
	 * conntrack NEW netlink event carries the values given in the CT
	 * action.
	 */
	if (info->mark.mask) {
		err = ovs_ct_set_mark(ct, key, info->mark.value,
				      info->mark.mask);
		if (err)
			return err;
	}
	if (!nf_ct_is_confirmed(ct)) {
		err = ovs_ct_init_labels(ct, key, &info->labels.value,
					 &info->labels.mask);
		if (err)
			return err;
	} else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
		   labels_nonzero(&info->labels.mask)) {
		err = ovs_ct_set_labels(ct, key, &info->labels.value,
					&info->labels.mask);
		if (err)
			return err;
	}
	/* This will take care of sending queued events even if the connection
	 * is already confirmed.
	 */
	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
		return -EINVAL;

	return 0;
}

/* Trim the skb to the length specified by the IP/IPv6 header,
 * removing any trailing lower-layer padding. This prepares the skb
 * for higher-layer processing that assumes skb->len excludes padding
 * (such as nf_ip_checksum). The caller needs to pull the skb to the
 * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
 */
static int ovs_skb_network_trim(struct sk_buff *skb)
{
	unsigned int len;
	int err;

	switch (skb->protocol) {
	case htons(ETH_P_IP):
		len = ntohs(ip_hdr(skb)->tot_len);
		break;
	case htons(ETH_P_IPV6):
		len = sizeof(struct ipv6hdr)
			+ ntohs(ipv6_hdr(skb)->payload_len);
		break;
	default:
		len = skb->len;
	}

	err = pskb_trim_rcsum(skb, len);
	if (err)
		kfree_skb(skb);

	return err;
}

/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 * value if 'skb' is freed.
 */
int ovs_ct_execute(struct net *net, struct sk_buff *skb,
		   struct sw_flow_key *key,
		   const struct ovs_conntrack_info *info)
{
	int nh_ofs;
	int err;

	/* The conntrack module expects to be working at L3. */
	nh_ofs = skb_network_offset(skb);
	skb_pull_rcsum(skb, nh_ofs);

	err = ovs_skb_network_trim(skb);
	if (err)
		return err;

	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
		err = handle_fragments(net, key, info->zone.id, skb);
		if (err)
			return err;
	}

	if (info->commit)
		err = ovs_ct_commit(net, key, info, skb);
	else
		err = ovs_ct_lookup(net, key, info, skb);

	skb_push(skb, nh_ofs);
	skb_postpush_rcsum(skb, skb->data, nh_ofs);
	if (err)
		kfree_skb(skb);
	return err;
}

int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
{
	if (skb_nfct(skb)) {
		nf_conntrack_put(skb_nfct(skb));
		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
		ovs_ct_fill_key(skb, key);
	}

	return 0;
}

static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
			     const struct sw_flow_key *key, bool log)
{
	struct nf_conntrack_helper *helper;
	struct nf_conn_help *help;

	helper = nf_conntrack_helper_try_module_get(name, info->family,
						    key->ip.proto);
	if (!helper) {
		OVS_NLERR(log, "Unknown helper \"%s\"", name);
		return -EINVAL;
	}

	help = nf_ct_helper_ext_add(info->ct, GFP_KERNEL);
	if (!help) {
		nf_conntrack_helper_put(helper);
		return -ENOMEM;
	}

	rcu_assign_pointer(help->helper, helper);
	info->helper = helper;

	if (info->nat)
		request_module("ip_nat_%s", name);

	return 0;
}

#ifdef CONFIG_NF_NAT_NEEDED
static int parse_nat(const struct nlattr *attr,
		     struct ovs_conntrack_info *info, bool log)
{
	struct nlattr *a;
	int rem;
	bool have_ip_max = false;
	bool have_proto_max = false;
	bool ip_vers = (info->family == NFPROTO_IPV6);

	nla_for_each_nested(a, attr, rem) {
		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
			[OVS_NAT_ATTR_SRC] = {0, 0},
			[OVS_NAT_ATTR_DST] = {0, 0},
			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
						 sizeof(struct in6_addr)},
			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
						 sizeof(struct in6_addr)},
			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
		};
		int type = nla_type(a);

		if (type > OVS_NAT_ATTR_MAX) {
			OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
				  type, OVS_NAT_ATTR_MAX);
			return -EINVAL;
		}

		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
			OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
				  type, nla_len(a),
				  ovs_nat_attr_lens[type][ip_vers]);
			return -EINVAL;
		}

		switch (type) {
		case OVS_NAT_ATTR_SRC:
		case OVS_NAT_ATTR_DST:
			if (info->nat) {
				OVS_NLERR(log, "Only one type of NAT may be specified");
				return -ERANGE;
			}
			info->nat |= OVS_CT_NAT;
			info->nat |= ((type == OVS_NAT_ATTR_SRC)
					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
			break;

		case OVS_NAT_ATTR_IP_MIN:
			nla_memcpy(&info->range.min_addr, a,
				   sizeof(info->range.min_addr));
			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
			break;

		case OVS_NAT_ATTR_IP_MAX:
			have_ip_max = true;
			nla_memcpy(&info->range.max_addr, a,
				   sizeof(info->range.max_addr));
			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
			break;

		case OVS_NAT_ATTR_PROTO_MIN:
			info->range.min_proto.all = htons(nla_get_u16(a));
			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
			break;

		case OVS_NAT_ATTR_PROTO_MAX:
			have_proto_max = true;
			info->range.max_proto.all = htons(nla_get_u16(a));
			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
			break;

		case OVS_NAT_ATTR_PERSISTENT:
			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
			break;

		case OVS_NAT_ATTR_PROTO_HASH:
			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
			break;

		case OVS_NAT_ATTR_PROTO_RANDOM:
			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
			break;

		default:
			OVS_NLERR(log, "Unknown nat attribute (%d)", type);
			return -EINVAL;
		}
	}

	if (rem > 0) {
		OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
		return -EINVAL;
	}
	if (!info->nat) {
		/* Do not allow flags if no type is given. */
		if (info->range.flags) {
			OVS_NLERR(log,
				  "NAT flags may be given only when NAT range (SRC or DST) is also specified."
				  );
			return -EINVAL;
		}
		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
	} else if (!info->commit) {
		OVS_NLERR(log,
			  "NAT attributes may be specified only when CT COMMIT flag is also specified."
			  );
		return -EINVAL;
	}
	/* Allow missing IP_MAX. */
	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
		memcpy(&info->range.max_addr, &info->range.min_addr,
		       sizeof(info->range.max_addr));
	}
	/* Allow missing PROTO_MAX. */
	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
	    !have_proto_max) {
		info->range.max_proto.all = info->range.min_proto.all;
	}
	return 0;
}
#endif

static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
	[OVS_CT_ATTR_FORCE_COMMIT]	= { .minlen = 0, .maxlen = 0 },
	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
				    .maxlen = sizeof(u16) },
	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
				    .maxlen = sizeof(struct md_mark) },
	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
				    .maxlen = sizeof(struct md_labels) },
	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
				    .maxlen = NF_CT_HELPER_NAME_LEN },
#ifdef CONFIG_NF_NAT_NEEDED
	/* NAT length is checked when parsing the nested attributes. */
	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
#endif
	[OVS_CT_ATTR_EVENTMASK]	= { .minlen = sizeof(u32),
				    .maxlen = sizeof(u32) },
};

static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
		    const char **helper, bool log)
{
	struct nlattr *a;
	int rem;

	nla_for_each_nested(a, attr, rem) {
		int type = nla_type(a);
		int maxlen;
		int minlen;

		if (type > OVS_CT_ATTR_MAX) {
			OVS_NLERR(log,
				  "Unknown conntrack attr (type=%d, max=%d)",
				  type, OVS_CT_ATTR_MAX);
			return -EINVAL;
		}

		maxlen = ovs_ct_attr_lens[type].maxlen;
		minlen = ovs_ct_attr_lens[type].minlen;
		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
			OVS_NLERR(log,
				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
				  type, nla_len(a), maxlen);
			return -EINVAL;
		}

		switch (type) {
		case OVS_CT_ATTR_FORCE_COMMIT:
			info->force = true;
			/* fall through. */
		case OVS_CT_ATTR_COMMIT:
			info->commit = true;
			break;
#ifdef CONFIG_NF_CONNTRACK_ZONES
		case OVS_CT_ATTR_ZONE:
			info->zone.id = nla_get_u16(a);
			break;
#endif
#ifdef CONFIG_NF_CONNTRACK_MARK
		case OVS_CT_ATTR_MARK: {
			struct md_mark *mark = nla_data(a);

			if (!mark->mask) {
				OVS_NLERR(log, "ct_mark mask cannot be 0");
				return -EINVAL;
			}
			info->mark = *mark;
			break;
		}
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
		case OVS_CT_ATTR_LABELS: {
			struct md_labels *labels = nla_data(a);

			if (!labels_nonzero(&labels->mask)) {
				OVS_NLERR(log, "ct_labels mask cannot be 0");
				return -EINVAL;
			}
			info->labels = *labels;
			break;
		}
#endif
		case OVS_CT_ATTR_HELPER:
			*helper = nla_data(a);
			if (!memchr(*helper, '\0', nla_len(a))) {
				OVS_NLERR(log, "Invalid conntrack helper");
				return -EINVAL;
			}
			break;
#ifdef CONFIG_NF_NAT_NEEDED
		case OVS_CT_ATTR_NAT: {
			int err = parse_nat(a, info, log);

			if (err)
				return err;
			break;
		}
#endif
		case OVS_CT_ATTR_EVENTMASK:
			info->have_eventmask = true;
			info->eventmask = nla_get_u32(a);
			break;

		default:
			OVS_NLERR(log, "Unknown conntrack attr (%d)",
				  type);
			return -EINVAL;
		}
	}

#ifdef CONFIG_NF_CONNTRACK_MARK
	if (!info->commit && info->mark.mask) {
		OVS_NLERR(log,
			  "Setting conntrack mark requires 'commit' flag.");
		return -EINVAL;
	}
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
	if (!info->commit && labels_nonzero(&info->labels.mask)) {
		OVS_NLERR(log,
			  "Setting conntrack labels requires 'commit' flag.");
		return -EINVAL;
	}
#endif
	if (rem > 0) {
		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
		return -EINVAL;
	}

	return 0;
}

bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
{
	if (attr == OVS_KEY_ATTR_CT_STATE)
		return true;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
	    attr == OVS_KEY_ATTR_CT_ZONE)
		return true;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
	    attr == OVS_KEY_ATTR_CT_MARK)
		return true;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
	    attr == OVS_KEY_ATTR_CT_LABELS) {
		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

		return ovs_net->xt_label;
	}

	return false;
}

int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
		       const struct sw_flow_key *key,
		       struct sw_flow_actions **sfa,  bool log)
{
	struct ovs_conntrack_info ct_info;
	const char *helper = NULL;
	u16 family;
	int err;

	family = key_to_nfproto(key);
	if (family == NFPROTO_UNSPEC) {
		OVS_NLERR(log, "ct family unspecified");
		return -EINVAL;
	}

	memset(&ct_info, 0, sizeof(ct_info));
	ct_info.family = family;

	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
			NF_CT_DEFAULT_ZONE_DIR, 0);

	err = parse_ct(attr, &ct_info, &helper, log);
	if (err)
		return err;

	/* Set up template for tracking connections in specific zones. */
	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
	if (!ct_info.ct) {
		OVS_NLERR(log, "Failed to allocate conntrack template");
		return -ENOMEM;
	}
	if (helper) {
		err = ovs_ct_add_helper(&ct_info, helper, key, log);
		if (err)
			goto err_free_ct;
	}

	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
				 sizeof(ct_info), log);
	if (err)
		goto err_free_ct;

	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
	nf_conntrack_get(&ct_info.ct->ct_general);
	return 0;
err_free_ct:
	__ovs_ct_free_action(&ct_info);
	return err;
}

#ifdef CONFIG_NF_NAT_NEEDED
static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
			       struct sk_buff *skb)
{
	struct nlattr *start;

	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
	if (!start)
		return false;

	if (info->nat & OVS_CT_SRC_NAT) {
		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
			return false;
	} else if (info->nat & OVS_CT_DST_NAT) {
		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
			return false;
	} else {
		goto out;
	}

	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
		    info->family == NFPROTO_IPV4) {
			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
					    info->range.min_addr.ip) ||
			    (info->range.max_addr.ip
			     != info->range.min_addr.ip &&
			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
					      info->range.max_addr.ip))))
				return false;
		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
			   info->family == NFPROTO_IPV6) {
			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
					     &info->range.min_addr.in6) ||
			    (memcmp(&info->range.max_addr.in6,
				    &info->range.min_addr.in6,
				    sizeof(info->range.max_addr.in6)) &&
			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
					       &info->range.max_addr.in6))))
				return false;
		} else {
			return false;
		}
	}
	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
			 ntohs(info->range.min_proto.all)) ||
	     (info->range.max_proto.all != info->range.min_proto.all &&
	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
			  ntohs(info->range.max_proto.all)))))
		return false;

	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
		return false;
	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
		return false;
	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
		return false;
out:
	nla_nest_end(skb, start);

	return true;
}
#endif

int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
			  struct sk_buff *skb)
{
	struct nlattr *start;

	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
	if (!start)
		return -EMSGSIZE;

	if (ct_info->commit && nla_put_flag(skb, ct_info->force
					    ? OVS_CT_ATTR_FORCE_COMMIT
					    : OVS_CT_ATTR_COMMIT))
		return -EMSGSIZE;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
		return -EMSGSIZE;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
		    &ct_info->mark))
		return -EMSGSIZE;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
	    labels_nonzero(&ct_info->labels.mask) &&
	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
		    &ct_info->labels))
		return -EMSGSIZE;
	if (ct_info->helper) {
		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
				   ct_info->helper->name))
			return -EMSGSIZE;
	}
	if (ct_info->have_eventmask &&
	    nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
		return -EMSGSIZE;

#ifdef CONFIG_NF_NAT_NEEDED
	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
		return -EMSGSIZE;
#endif
	nla_nest_end(skb, start);

	return 0;
}

void ovs_ct_free_action(const struct nlattr *a)
{
	struct ovs_conntrack_info *ct_info = nla_data(a);

	__ovs_ct_free_action(ct_info);
}

static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
{
	if (ct_info->helper)
		nf_conntrack_helper_put(ct_info->helper);
	if (ct_info->ct)
		nf_ct_tmpl_free(ct_info->ct);
}

#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
{
	int i, err;

	ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
					 GFP_KERNEL);
	if (!ovs_net->ct_limit_info)
		return -ENOMEM;

	ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
	ovs_net->ct_limit_info->limits =
		kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
			      GFP_KERNEL);
	if (!ovs_net->ct_limit_info->limits) {
		kfree(ovs_net->ct_limit_info);
		return -ENOMEM;
	}

	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
		INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);

	ovs_net->ct_limit_info->data =
		nf_conncount_init(net, NFPROTO_INET, sizeof(u32));

	if (IS_ERR(ovs_net->ct_limit_info->data)) {
		err = PTR_ERR(ovs_net->ct_limit_info->data);
		kfree(ovs_net->ct_limit_info->limits);
		kfree(ovs_net->ct_limit_info);
		pr_err("openvswitch: failed to init nf_conncount %d\n", err);
		return err;
	}
	return 0;
}

static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
{
	const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
	int i;

	nf_conncount_destroy(net, NFPROTO_INET, info->data);
	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
		struct hlist_head *head = &info->limits[i];
		struct ovs_ct_limit *ct_limit;

		hlist_for_each_entry_rcu(ct_limit, head, hlist_node)
			kfree_rcu(ct_limit, rcu);
	}
	kfree(ovs_net->ct_limit_info->limits);
	kfree(ovs_net->ct_limit_info);
}

static struct sk_buff *
ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
			     struct ovs_header **ovs_reply_header)
{
	struct ovs_header *ovs_header = info->userhdr;
	struct sk_buff *skb;

	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (!skb)
		return ERR_PTR(-ENOMEM);

	*ovs_reply_header = genlmsg_put(skb, info->snd_portid,
					info->snd_seq,
					&dp_ct_limit_genl_family, 0, cmd);

	if (!*ovs_reply_header) {
		nlmsg_free(skb);
		return ERR_PTR(-EMSGSIZE);
	}
	(*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;

	return skb;
}

static bool check_zone_id(int zone_id, u16 *pzone)
{
	if (zone_id >= 0 && zone_id <= 65535) {
		*pzone = (u16)zone_id;
		return true;
	}
	return false;
}

static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
				       struct ovs_ct_limit_info *info)
{
	struct ovs_zone_limit *zone_limit;
	int rem;
	u16 zone;

	rem = NLA_ALIGN(nla_len(nla_zone_limit));
	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);

	while (rem >= sizeof(*zone_limit)) {
		if (unlikely(zone_limit->zone_id ==
				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
			ovs_lock();
			info->default_limit = zone_limit->limit;
			ovs_unlock();
		} else if (unlikely(!check_zone_id(
				zone_limit->zone_id, &zone))) {
			OVS_NLERR(true, "zone id is out of range");
		} else {
			struct ovs_ct_limit *ct_limit;

			ct_limit = kmalloc(sizeof(*ct_limit), GFP_KERNEL);
			if (!ct_limit)
				return -ENOMEM;

			ct_limit->zone = zone;
			ct_limit->limit = zone_limit->limit;

			ovs_lock();
			ct_limit_set(info, ct_limit);
			ovs_unlock();
		}
		rem -= NLA_ALIGN(sizeof(*zone_limit));
		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
				NLA_ALIGN(sizeof(*zone_limit)));
	}

	if (rem)
		OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);

	return 0;
}

static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
				       struct ovs_ct_limit_info *info)
{
	struct ovs_zone_limit *zone_limit;
	int rem;
	u16 zone;

	rem = NLA_ALIGN(nla_len(nla_zone_limit));
	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);

	while (rem >= sizeof(*zone_limit)) {
		if (unlikely(zone_limit->zone_id ==
				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
			ovs_lock();
			info->default_limit = OVS_CT_LIMIT_DEFAULT;
			ovs_unlock();
		} else if (unlikely(!check_zone_id(
				zone_limit->zone_id, &zone))) {
			OVS_NLERR(true, "zone id is out of range");
		} else {
			ovs_lock();
			ct_limit_del(info, zone);
			ovs_unlock();
		}
		rem -= NLA_ALIGN(sizeof(*zone_limit));
		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
				NLA_ALIGN(sizeof(*zone_limit)));
	}

	if (rem)
		OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);

	return 0;
}

static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
					  struct sk_buff *reply)
{
	struct ovs_zone_limit zone_limit;
	int err;

	zone_limit.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE;
	zone_limit.limit = info->default_limit;
	err = nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
	if (err)
		return err;

	return 0;
}

static int __ovs_ct_limit_get_zone_limit(struct net *net,
					 struct nf_conncount_data *data,
					 u16 zone_id, u32 limit,
					 struct sk_buff *reply)
{
	struct nf_conntrack_zone ct_zone;
	struct ovs_zone_limit zone_limit;
	u32 conncount_key = zone_id;

	zone_limit.zone_id = zone_id;
	zone_limit.limit = limit;
	nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);

	zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
					      &ct_zone);
	return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
}

static int ovs_ct_limit_get_zone_limit(struct net *net,
				       struct nlattr *nla_zone_limit,
				       struct ovs_ct_limit_info *info,
				       struct sk_buff *reply)
{
	struct ovs_zone_limit *zone_limit;
	int rem, err;
	u32 limit;
	u16 zone;

	rem = NLA_ALIGN(nla_len(nla_zone_limit));
	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);

	while (rem >= sizeof(*zone_limit)) {
		if (unlikely(zone_limit->zone_id ==
				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
			err = ovs_ct_limit_get_default_limit(info, reply);
			if (err)
				return err;
		} else if (unlikely(!check_zone_id(zone_limit->zone_id,
							&zone))) {
			OVS_NLERR(true, "zone id is out of range");
		} else {
			rcu_read_lock();
			limit = ct_limit_get(info, zone);
			rcu_read_unlock();

			err = __ovs_ct_limit_get_zone_limit(
				net, info->data, zone, limit, reply);
			if (err)
				return err;
		}
		rem -= NLA_ALIGN(sizeof(*zone_limit));
		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
				NLA_ALIGN(sizeof(*zone_limit)));
	}

	if (rem)
		OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);

	return 0;
}

static int ovs_ct_limit_get_all_zone_limit(struct net *net,
					   struct ovs_ct_limit_info *info,
					   struct sk_buff *reply)
{
	struct ovs_ct_limit *ct_limit;
	struct hlist_head *head;
	int i, err = 0;

	err = ovs_ct_limit_get_default_limit(info, reply);
	if (err)
		return err;

	rcu_read_lock();
	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
		head = &info->limits[i];
		hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
			err = __ovs_ct_limit_get_zone_limit(net, info->data,
				ct_limit->zone, ct_limit->limit, reply);
			if (err)
				goto exit_err;
		}
	}

exit_err:
	rcu_read_unlock();
	return err;
}

static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr **a = info->attrs;
	struct sk_buff *reply;
	struct ovs_header *ovs_reply_header;
	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
	int err;

	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
					     &ovs_reply_header);
	if (IS_ERR(reply))
		return PTR_ERR(reply);

	if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
		err = -EINVAL;
		goto exit_err;
	}

	err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
					  ct_limit_info);
	if (err)
		goto exit_err;

	static_branch_enable(&ovs_ct_limit_enabled);

	genlmsg_end(reply, ovs_reply_header);
	return genlmsg_reply(reply, info);

exit_err:
	nlmsg_free(reply);
	return err;
}

static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr **a = info->attrs;
	struct sk_buff *reply;
	struct ovs_header *ovs_reply_header;
	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
	int err;

	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
					     &ovs_reply_header);
	if (IS_ERR(reply))
		return PTR_ERR(reply);

	if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
		err = -EINVAL;
		goto exit_err;
	}

	err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
					  ct_limit_info);
	if (err)
		goto exit_err;

	genlmsg_end(reply, ovs_reply_header);
	return genlmsg_reply(reply, info);

exit_err:
	nlmsg_free(reply);
	return err;
}

static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr **a = info->attrs;
	struct nlattr *nla_reply;
	struct sk_buff *reply;
	struct ovs_header *ovs_reply_header;
	struct net *net = sock_net(skb->sk);
	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
	int err;

	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
					     &ovs_reply_header);
	if (IS_ERR(reply))
		return PTR_ERR(reply);

	nla_reply = nla_nest_start(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);

	if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
		err = ovs_ct_limit_get_zone_limit(
			net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
			reply);
		if (err)
			goto exit_err;
	} else {
		err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
						      reply);
		if (err)
			goto exit_err;
	}

	nla_nest_end(reply, nla_reply);
	genlmsg_end(reply, ovs_reply_header);
	return genlmsg_reply(reply, info);

exit_err:
	nlmsg_free(reply);
	return err;
}

static struct genl_ops ct_limit_genl_ops[] = {
	{ .cmd = OVS_CT_LIMIT_CMD_SET,
		.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
					   * privilege. */
		.policy = ct_limit_policy,
		.doit = ovs_ct_limit_cmd_set,
	},
	{ .cmd = OVS_CT_LIMIT_CMD_DEL,
		.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
					   * privilege. */
		.policy = ct_limit_policy,
		.doit = ovs_ct_limit_cmd_del,
	},
	{ .cmd = OVS_CT_LIMIT_CMD_GET,
		.flags = 0,		  /* OK for unprivileged users. */
		.policy = ct_limit_policy,
		.doit = ovs_ct_limit_cmd_get,
	},
};

static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
	.name = OVS_CT_LIMIT_MCGROUP,
};

struct genl_family dp_ct_limit_genl_family __ro_after_init = {
	.hdrsize = sizeof(struct ovs_header),
	.name = OVS_CT_LIMIT_FAMILY,
	.version = OVS_CT_LIMIT_VERSION,
	.maxattr = OVS_CT_LIMIT_ATTR_MAX,
	.netnsok = true,
	.parallel_ops = true,
	.ops = ct_limit_genl_ops,
	.n_ops = ARRAY_SIZE(ct_limit_genl_ops),
	.mcgrps = &ovs_ct_limit_multicast_group,
	.n_mcgrps = 1,
	.module = THIS_MODULE,
};
#endif

int ovs_ct_init(struct net *net)
{
	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

	if (nf_connlabels_get(net, n_bits - 1)) {
		ovs_net->xt_label = false;
		OVS_NLERR(true, "Failed to set connlabel length");
	} else {
		ovs_net->xt_label = true;
	}

#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
	return ovs_ct_limit_init(net, ovs_net);
#else
	return 0;
#endif
}

void ovs_ct_exit(struct net *net)
{
	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
	ovs_ct_limit_exit(net, ovs_net);
#endif

	if (ovs_net->xt_label)
		nf_connlabels_put(net);
}