netfilter: xtables: change xt_match.checkentry return type

Restore function signatures from bool to int so that we can report
memory allocation failures or similar using -ENOMEM rather than
always having to pass -EINVAL back.

This semantic patch may not be too precise (checking for functions
that use xt_mtchk_param rather than functions referenced by
xt_match.checkentry), but reviewed, it produced the intended result.

// <smpl>
@@
type bool;
identifier check, par;
@@
-bool check
+int check
 (struct xt_mtchk_param *par) { ... }
// </smpl>

Signed-off-by: Jan Engelhardt <[email protected]>

net/ipv6/netfilter/ip6_tables.c

@@ -2209,7 +2209,7 @@ icmp6_match(const struct sk_buff *skb, const struct xt_match_param *par)
 }
 
 /* Called when user tries to insert an entry of this type. */
-static bool icmp6_checkentry(const struct xt_mtchk_param *par)
+static int icmp6_checkentry(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_icmp *icmpinfo = par->matchinfo;
 

net/ipv6/netfilter/ip6t_ah.c

@@ -87,7 +87,7 @@ static bool ah_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 		!(ahinfo->hdrres && ah->reserved);
 }
 
-static bool ah_mt6_check(const struct xt_mtchk_param *par)
+static int ah_mt6_check(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_ah *ahinfo = par->matchinfo;
 

net/ipv6/netfilter/ip6t_frag.c

@@ -102,7 +102,7 @@ frag_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 		  (ntohs(fh->frag_off) & IP6_MF));
 }
 
-static bool frag_mt6_check(const struct xt_mtchk_param *par)
+static int frag_mt6_check(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_frag *fraginfo = par->matchinfo;
 

net/ipv6/netfilter/ip6t_hbh.c

@@ -164,7 +164,7 @@ hbh_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 	return false;
 }
 
-static bool hbh_mt6_check(const struct xt_mtchk_param *par)
+static int hbh_mt6_check(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_opts *optsinfo = par->matchinfo;
 

net/ipv6/netfilter/ip6t_ipv6header.c

@@ -118,7 +118,7 @@ ipv6header_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 	}
 }
 
-static bool ipv6header_mt6_check(const struct xt_mtchk_param *par)
+static int ipv6header_mt6_check(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_ipv6header_info *info = par->matchinfo;
 

net/ipv6/netfilter/ip6t_mh.c

@@ -62,7 +62,7 @@ static bool mh_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 			  !!(mhinfo->invflags & IP6T_MH_INV_TYPE));
 }
 
-static bool mh_mt6_check(const struct xt_mtchk_param *par)
+static int mh_mt6_check(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_mh *mhinfo = par->matchinfo;
 

net/ipv6/netfilter/ip6t_rt.c

@@ -183,7 +183,7 @@ static bool rt_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 	return false;
 }
 
-static bool rt_mt6_check(const struct xt_mtchk_param *par)
+static int rt_mt6_check(const struct xt_mtchk_param *par)
 {
 	const struct ip6t_rt *rtinfo = par->matchinfo;