Code cleanups

Code cleanups

[Jan Engelhardt]

Hi,


the next patch pack is mostly about cleanups, and there is one
commit for improving debug a little.
Pull URL will be posted once the previous request has been
merged, but I am already posting them now for review.



The following changes since commit e3eaa9910b380530cfd2c0670fcd3f627674da8a:
  Jan Engelhardt (1):
        netfilter: xtables: generate initial table on-demand

are available in the git repository at:

  . master2

Jan Engelhardt (6):
      netfilter: iptables: remove unused function arguments
      netfilter: reduce NF_HOOK by one argument
      netfilter: get rid of the grossness in netfilter.h
      netfilter: xtables: print details on size mismatch
      netfilter: xtables: constify args in compat copying functions
      netfilter: xtables: add const qualifiers

 include/linux/netfilter.h            |   55 +++++++++++---------
 include/linux/netfilter/x_tables.h   |   12 ++--
 net/bridge/netfilter/ebtables.c      |   59 ++++++++++++----------
 net/ipv4/netfilter/arp_tables.c      |   73 +++++++++++++++------------
 net/ipv4/netfilter/ip_tables.c       |   92 +++++++++++++++++++---------------
 net/ipv4/netfilter/ipt_ULOG.c        |    4 +-
 net/ipv4/netfilter/iptable_mangle.c  |   10 +---
 net/ipv6/netfilter/ip6_tables.c      |   92 ++++++++++++++++++---------------
 net/ipv6/netfilter/ip6table_mangle.c |   10 +---
 net/netfilter/x_tables.c             |   16 ++++--
 net/netfilter/xt_hashlimit.c         |    4 +-
 net/netfilter/xt_limit.c             |    4 +-
 12 files changed, 233 insertions(+), 198 deletions(-)

[PATCH 1/6] netfilter: iptables: remove unused function arguments

[Jan Engelhardt]

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 net/ipv4/netfilter/iptable_mangle.c  |   10 +++-------
 net/ipv6/netfilter/ip6table_mangle.c |   10 +++-------
 2 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index 58d7097..78c62c8 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -36,11 +36,7 @@ static const struct xt_table packet_mangler = {
 };
 
 static unsigned int
-ipt_local_hook(unsigned int hook,
-		   struct sk_buff *skb,
-		   const struct net_device *in,
-		   const struct net_device *out,
-		   int (*okfn)(struct sk_buff *))
+ipt_mangle_out(struct sk_buff *skb, const struct net_device *out)
 {
 	unsigned int ret;
 	const struct iphdr *iph;
@@ -60,7 +56,7 @@ ipt_local_hook(unsigned int hook,
 	daddr = iph->daddr;
 	tos = iph->tos;
 
-	ret = ipt_do_table(skb, hook, in, out,
+	ret = ipt_do_table(skb, NF_INET_LOCAL_OUT, NULL, out,
 			   dev_net(out)->ipv4.iptable_mangle);
 	/* Reroute for ANY change. */
 	if (ret != NF_DROP && ret != NF_STOLEN && ret != NF_QUEUE) {
@@ -86,7 +82,7 @@ iptable_mangle_hook(unsigned int hook,
 		     int (*okfn)(struct sk_buff *))
 {
 	if (hook == NF_INET_LOCAL_OUT)
-		return ipt_local_hook(hook, skb, in, out, okfn);
+		return ipt_mangle_out(skb, out);
 
 	/* PREROUTING/INPUT/FORWARD: */
 	return ipt_do_table(skb, hook, in, out,
diff --git a/net/ipv6/netfilter/ip6table_mangle.c b/net/ipv6/netfilter/ip6table_mangle.c
index dc803b7..e530038 100644
--- a/net/ipv6/netfilter/ip6table_mangle.c
+++ b/net/ipv6/netfilter/ip6table_mangle.c
@@ -30,12 +30,8 @@ static const struct xt_table packet_mangler = {
 };
 
 static unsigned int
-ip6t_local_out_hook(unsigned int hook,
-		   struct sk_buff *skb,
-		   const struct net_device *out,
-		   int (*okfn)(struct sk_buff *))
+ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out)
 {
-
 	unsigned int ret;
 	struct in6_addr saddr, daddr;
 	u_int8_t hop_limit;
@@ -60,7 +56,7 @@ ip6t_local_out_hook(unsigned int hook,
 	/* flowlabel and prio (includes version, which shouldn't change either */
 	flowlabel = *((u_int32_t *)ipv6_hdr(skb));
 
-	ret = ip6t_do_table(skb, hook, NULL, out,
+	ret = ip6t_do_table(skb, NF_INET_LOCAL_OUT, NULL, out,
 			    dev_net(out)->ipv6.ip6table_mangle);
 
 	if (ret != NF_DROP && ret != NF_STOLEN &&
@@ -80,7 +76,7 @@ ip6table_mangle_hook(unsigned int hook, struct sk_buff *skb,
 		     int (*okfn)(struct sk_buff *))
 {
 	if (hook == NF_INET_LOCAL_OUT)
-		return ip6t_local_out_hook(hook, skb, out, okfn);
+		return ip6t_mangle_out(skb, out);
 
 	/* INPUT/FORWARD */
 	return ip6t_do_table(skb, hook, in, out,
-- 
1.6.6.1

[PATCH 2/6] netfilter: reduce NF_HOOK by one argument

[Jan Engelhardt]

No changes in vmlinux filesize.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 include/linux/netfilter.h |   14 +++++---------
 1 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 78f33d2..2f22816 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -163,11 +163,8 @@ static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
 				 struct sk_buff *skb,
 				 struct net_device *indev,
 				 struct net_device *outdev,
-				 int (*okfn)(struct sk_buff *), int thresh,
-				 int cond)
+				 int (*okfn)(struct sk_buff *), int thresh)
 {
-	if (!cond)
-		return 1;
 #ifndef CONFIG_NETFILTER_DEBUG
 	if (list_empty(&nf_hooks[pf][hook]))
 		return 1;
@@ -179,7 +176,7 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
 			  struct net_device *indev, struct net_device *outdev,
 			  int (*okfn)(struct sk_buff *))
 {
-	return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN, 1);
+	return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
 }
                    
 /* Activate hook; either okfn or kfree_skb called, unless a hook
@@ -206,13 +203,13 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
 
 #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh)	       \
 ({int __ret;								       \
-if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh, 1)) == 1)\
+if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh)) == 1)\
 	__ret = (okfn)(skb);						       \
 __ret;})
 
 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)		       \
 ({int __ret;								       \
-if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
+if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
 	__ret = (okfn)(skb);						       \
 __ret;})
 
@@ -328,8 +325,7 @@ static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
 				 struct sk_buff *skb,
 				 struct net_device *indev,
 				 struct net_device *outdev,
-				 int (*okfn)(struct sk_buff *), int thresh,
-				 int cond)
+				 int (*okfn)(struct sk_buff *), int thresh)
 {
 	return okfn(skb);
 }
-- 
1.6.6.1

[PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Jan Engelhardt]

GCC is now smart enough to follow the inline trail correctly.
vmlinux size remain the same.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 include/linux/netfilter.h |   45 ++++++++++++++++++++++++++++-----------------
 1 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 2f22816..7007945 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -196,25 +196,36 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
    coders :)
 */
 
-/* This is gross, but inline doesn't cut it for avoiding the function
-   call in fast path: gcc doesn't inline (needs value tracking?). --RR */
-
-/* HX: It's slightly less gross now. */
-
-#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh)	       \
-({int __ret;								       \
-if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh)) == 1)\
-	__ret = (okfn)(skb);						       \
-__ret;})
+static inline int
+NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+	       struct net_device *in, struct net_device *out,
+	       int (*okfn)(struct sk_buff *), int thresh)
+{
+	int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
+	if (ret == 1)
+		ret = okfn(skb);
+	return ret;
+}
 
-#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)		       \
-({int __ret;								       \
-if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
-	__ret = (okfn)(skb);						       \
-__ret;})
+static inline int
+NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+	     struct net_device *in, struct net_device *out,
+	     int (*okfn)(struct sk_buff *), bool cond)
+{
+	int ret = 1;
+	if (cond ||
+	    (ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN) == 1))
+		ret = okfn(skb);
+	return ret;
+}
 
-#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
-	NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
+static inline int
+NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+	struct net_device *in, struct net_device *out,
+	int (*okfn)(struct sk_buff *))
+{
+	return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
+}
 
 /* Call setsockopt() */
 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
-- 
1.6.6.1

Re: [PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Patrick McHardy]

Jan Engelhardt wrote:
> GCC is now smart enough to follow the inline trail correctly.
> vmlinux size remain the same.

Which one? The kernel currently supports 3.2+.

Re: [PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Jan Engelhardt]

On Wednesday 2010-02-10 18:44, Patrick McHardy wrote:

>Jan Engelhardt wrote:
>> GCC is now smart enough to follow the inline trail correctly.
>> vmlinux size remain the same.
>
>Which one? The kernel currently supports 3.2+.

-rw-r--r-- 1 jengelh users 12659677 Feb 10 21:58 linux-gcc33/vmlinux.o.before
-rw-r--r-- 1 jengelh users 12659557 Feb 10 22:00 linux-gcc33/vmlinux.o
-rw-r--r-- 1 jengelh users 12874092 Feb 10 21:58 linux-gcc41/vmlinux.o.before
-rw-r--r-- 1 jengelh users 12874005 Feb 10 22:01 linux-gcc41/vmlinux.o
-rw-r--r-- 1 jengelh users 12986285 Feb 10 21:58 linux-gcc43/vmlinux.o.before
-rw-r--r-- 1 jengelh users 12986236 Feb 10 22:02 linux-gcc43/vmlinux.o
-rw-r--r-- 1 jengelh users 12915901 Feb 10 21:58 linux-gcc44/vmlinux.o.before
-rw-r--r-- 1 jengelh users 12915884 Feb 10 22:03 linux-gcc44/vmlinux.o
-rw-r--r-- 1 jengelh users 12946544 Feb 10 21:58 linux-gcc45/vmlinux.o.before
-rw-r--r-- 1 jengelh users 12946520 Feb 10 22:04 linux-gcc45/vmlinux.o

Re: [PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Patrick McHardy]

Jan Engelhardt wrote:
> On Wednesday 2010-02-10 18:44, Patrick McHardy wrote:
> 
>> Jan Engelhardt wrote:
>>> GCC is now smart enough to follow the inline trail correctly.
>>> vmlinux size remain the same.
>> Which one? The kernel currently supports 3.2+.
> 
> -rw-r--r-- 1 jengelh users 12659677 Feb 10 21:58 linux-gcc33/vmlinux.o.before
> -rw-r--r-- 1 jengelh users 12659557 Feb 10 22:00 linux-gcc33/vmlinux.o
> -rw-r--r-- 1 jengelh users 12874092 Feb 10 21:58 linux-gcc41/vmlinux.o.before
> -rw-r--r-- 1 jengelh users 12874005 Feb 10 22:01 linux-gcc41/vmlinux.o
> -rw-r--r-- 1 jengelh users 12986285 Feb 10 21:58 linux-gcc43/vmlinux.o.before
> -rw-r--r-- 1 jengelh users 12986236 Feb 10 22:02 linux-gcc43/vmlinux.o
> -rw-r--r-- 1 jengelh users 12915901 Feb 10 21:58 linux-gcc44/vmlinux.o.before
> -rw-r--r-- 1 jengelh users 12915884 Feb 10 22:03 linux-gcc44/vmlinux.o
> -rw-r--r-- 1 jengelh users 12946544 Feb 10 21:58 linux-gcc45/vmlinux.o.before
> -rw-r--r-- 1 jengelh users 12946520 Feb 10 22:04 linux-gcc45/vmlinux.o
> 

Thanks, this looks fine.

[PATCH 4/6] netfilter: xtables: print details on size mismatch

[Jan Engelhardt]

Print which revision has been used and which size are which
(kernel/user) for easier debugging.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 net/netfilter/x_tables.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index dc2e05c..760ea3e 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -366,8 +366,10 @@ int xt_check_match(struct xt_mtchk_param *par,
 		 * ebt_among is exempt from centralized matchsize checking
 		 * because it uses a dynamic-size data set.
 		 */
-		pr_err("%s_tables: %s match: invalid size %Zu != %u\n",
+		pr_err("%s_tables: %s.%u match: invalid size "
+		       "(kernel) %zu != (user) %u\n",
 		       xt_prefix[par->family], par->match->name,
+		       par->match->revision,
 		       XT_ALIGN(par->match->matchsize), size);
 		return -EINVAL;
 	}
@@ -516,8 +518,10 @@ int xt_check_target(struct xt_tgchk_param *par,
 		    unsigned int size, u_int8_t proto, bool inv_proto)
 {
 	if (XT_ALIGN(par->target->targetsize) != size) {
-		pr_err("%s_tables: %s target: invalid size %Zu != %u\n",
+		pr_err("%s_tables: %s.%u target: invalid size "
+		       "(kernel) %zu != (user) %u\n",
 		       xt_prefix[par->family], par->target->name,
+		       par->target->revision,
 		       XT_ALIGN(par->target->targetsize), size);
 		return -EINVAL;
 	}
-- 
1.6.6.1

[PATCH 5/6] netfilter: xtables: constify args in compat copying functions

[Jan Engelhardt]

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 include/linux/netfilter/x_tables.h |   12 ++++++------
 net/ipv4/netfilter/arp_tables.c    |    4 ++--
 net/ipv4/netfilter/ip_tables.c     |    4 ++--
 net/ipv4/netfilter/ipt_ULOG.c      |    4 ++--
 net/ipv6/netfilter/ip6_tables.c    |    4 ++--
 net/netfilter/x_tables.c           |    8 ++++----
 net/netfilter/xt_hashlimit.c       |    4 ++--
 net/netfilter/xt_limit.c           |    4 ++--
 8 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index fdd3342..3d39e6e 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -287,8 +287,8 @@ struct xt_match {
 	void (*destroy)(const struct xt_mtdtor_param *);
 #ifdef CONFIG_COMPAT
 	/* Called when userspace align differs from kernel space one */
-	void (*compat_from_user)(void *dst, void *src);
-	int (*compat_to_user)(void __user *dst, void *src);
+	void (*compat_from_user)(void *dst, const void *src);
+	int (*compat_to_user)(void __user *dst, const void *src);
 #endif
 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
 	struct module *me;
@@ -329,8 +329,8 @@ struct xt_target {
 	void (*destroy)(const struct xt_tgdtor_param *);
 #ifdef CONFIG_COMPAT
 	/* Called when userspace align differs from kernel space one */
-	void (*compat_from_user)(void *dst, void *src);
-	int (*compat_to_user)(void __user *dst, void *src);
+	void (*compat_from_user)(void *dst, const void *src);
+	int (*compat_to_user)(void __user *dst, const void *src);
 #endif
 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
 	struct module *me;
@@ -592,13 +592,13 @@ extern short xt_compat_calc_jump(u_int8_t af, unsigned int offset);
 extern int xt_compat_match_offset(const struct xt_match *match);
 extern int xt_compat_match_from_user(struct xt_entry_match *m,
 				     void **dstptr, unsigned int *size);
-extern int xt_compat_match_to_user(struct xt_entry_match *m,
+extern int xt_compat_match_to_user(const struct xt_entry_match *m,
 				   void __user **dstptr, unsigned int *size);
 
 extern int xt_compat_target_offset(const struct xt_target *target);
 extern void xt_compat_target_from_user(struct xt_entry_target *t,
 				       void **dstptr, unsigned int *size);
-extern int xt_compat_target_to_user(struct xt_entry_target *t,
+extern int xt_compat_target_to_user(const struct xt_entry_target *t,
 				    void __user **dstptr, unsigned int *size);
 
 #endif /* CONFIG_COMPAT */
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 72723ea..2303dc9 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -842,7 +842,7 @@ static int copy_entries_to_user(unsigned int total_size,
 }
 
 #ifdef CONFIG_COMPAT
-static void compat_standard_from_user(void *dst, void *src)
+static void compat_standard_from_user(void *dst, const void *src)
 {
 	int v = *(compat_int_t *)src;
 
@@ -851,7 +851,7 @@ static void compat_standard_from_user(void *dst, void *src)
 	memcpy(dst, &v, sizeof(v));
 }
 
-static int compat_standard_to_user(void __user *dst, void *src)
+static int compat_standard_to_user(void __user *dst, const void *src)
 {
 	compat_int_t cv = *(int *)src;
 
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 2057b1b..2a4f745 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1047,7 +1047,7 @@ copy_entries_to_user(unsigned int total_size,
 }
 
 #ifdef CONFIG_COMPAT
-static void compat_standard_from_user(void *dst, void *src)
+static void compat_standard_from_user(void *dst, const void *src)
 {
 	int v = *(compat_int_t *)src;
 
@@ -1056,7 +1056,7 @@ static void compat_standard_from_user(void *dst, void *src)
 	memcpy(dst, &v, sizeof(v));
 }
 
-static int compat_standard_to_user(void __user *dst, void *src)
+static int compat_standard_to_user(void __user *dst, const void *src)
 {
 	compat_int_t cv = *(int *)src;
 
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 399061c..09a5d3f 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -338,7 +338,7 @@ struct compat_ipt_ulog_info {
 	char		prefix[ULOG_PREFIX_LEN];
 };
 
-static void ulog_tg_compat_from_user(void *dst, void *src)
+static void ulog_tg_compat_from_user(void *dst, const void *src)
 {
 	const struct compat_ipt_ulog_info *cl = src;
 	struct ipt_ulog_info l = {
@@ -351,7 +351,7 @@ static void ulog_tg_compat_from_user(void *dst, void *src)
 	memcpy(dst, &l, sizeof(l));
 }
 
-static int ulog_tg_compat_to_user(void __user *dst, void *src)
+static int ulog_tg_compat_to_user(void __user *dst, const void *src)
 {
 	const struct ipt_ulog_info *l = src;
 	struct compat_ipt_ulog_info cl = {
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index dcd7825..3ff4fd5 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1079,7 +1079,7 @@ copy_entries_to_user(unsigned int total_size,
 }
 
 #ifdef CONFIG_COMPAT
-static void compat_standard_from_user(void *dst, void *src)
+static void compat_standard_from_user(void *dst, const void *src)
 {
 	int v = *(compat_int_t *)src;
 
@@ -1088,7 +1088,7 @@ static void compat_standard_from_user(void *dst, void *src)
 	memcpy(dst, &v, sizeof(v));
 }
 
-static int compat_standard_to_user(void __user *dst, void *src)
+static int compat_standard_to_user(void __user *dst, const void *src)
 {
 	compat_int_t cv = *(int *)src;
 
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 760ea3e..2120ab7 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -485,8 +485,8 @@ int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
 }
 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
 
-int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
-			    unsigned int *size)
+int xt_compat_match_to_user(const struct xt_entry_match *m,
+			    void __user **dstptr, unsigned int *size)
 {
 	const struct xt_match *match = m->u.kernel.match;
 	struct compat_xt_entry_match __user *cm = *dstptr;
@@ -588,8 +588,8 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
 }
 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
 
-int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
-			     unsigned int *size)
+int xt_compat_target_to_user(const struct xt_entry_target *t,
+			     void __user **dstptr, unsigned int *size)
 {
 	const struct xt_target *target = t->u.kernel.target;
 	struct compat_xt_entry_target __user *ct = *dstptr;
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 017c959..e47fb80 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -775,7 +775,7 @@ struct compat_xt_hashlimit_info {
 	compat_uptr_t master;
 };
 
-static void hashlimit_mt_compat_from_user(void *dst, void *src)
+static void hashlimit_mt_compat_from_user(void *dst, const void *src)
 {
 	int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
 
@@ -783,7 +783,7 @@ static void hashlimit_mt_compat_from_user(void *dst, void *src)
 	memset(dst + off, 0, sizeof(struct compat_xt_hashlimit_info) - off);
 }
 
-static int hashlimit_mt_compat_to_user(void __user *dst, void *src)
+static int hashlimit_mt_compat_to_user(void __user *dst, const void *src)
 {
 	int off = offsetof(struct compat_xt_hashlimit_info, hinfo);
 
diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
index 2773be6..a0ca533 100644
--- a/net/netfilter/xt_limit.c
+++ b/net/netfilter/xt_limit.c
@@ -148,7 +148,7 @@ struct compat_xt_rateinfo {
 
 /* To keep the full "prev" timestamp, the upper 32 bits are stored in the
  * master pointer, which does not need to be preserved. */
-static void limit_mt_compat_from_user(void *dst, void *src)
+static void limit_mt_compat_from_user(void *dst, const void *src)
 {
 	const struct compat_xt_rateinfo *cm = src;
 	struct xt_rateinfo m = {
@@ -162,7 +162,7 @@ static void limit_mt_compat_from_user(void *dst, void *src)
 	memcpy(dst, &m, sizeof(m));
 }
 
-static int limit_mt_compat_to_user(void __user *dst, void *src)
+static int limit_mt_compat_to_user(void __user *dst, const void *src)
 {
 	const struct xt_rateinfo *m = src;
 	struct compat_xt_rateinfo cm = {
-- 
1.6.6.1

[PATCH 6/6] netfilter: xtables: add const qualifiers

[Jan Engelhardt]

This should make it easier to remove redundant arguments later.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 net/bridge/netfilter/ebtables.c |   59 ++++++++++++++------------
 net/ipv4/netfilter/arp_tables.c |   69 +++++++++++++++++-------------
 net/ipv4/netfilter/ip_tables.c  |   88 +++++++++++++++++++++-----------------
 net/ipv6/netfilter/ip6_tables.c |   88 +++++++++++++++++++++------------------
 4 files changed, 168 insertions(+), 136 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 208f4e3..bcdf02d 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -82,7 +82,8 @@ static inline int ebt_do_match (struct ebt_entry_match *m,
 	return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
 }
 
-static inline int ebt_dev_check(char *entry, const struct net_device *device)
+static inline int
+ebt_dev_check(const char *entry, const struct net_device *device)
 {
 	int i = 0;
 	const char *devname;
@@ -100,8 +101,9 @@ static inline int ebt_dev_check(char *entry, const struct net_device *device)
 
 #define FWINV2(bool,invflg) ((bool) ^ !!(e->invflags & invflg))
 /* process standard matches */
-static inline int ebt_basic_match(struct ebt_entry *e, struct ethhdr *h,
-   const struct net_device *in, const struct net_device *out)
+static inline int
+ebt_basic_match(const struct ebt_entry *e, const struct ethhdr *h,
+                const struct net_device *in, const struct net_device *out)
 {
 	int verdict, i;
 
@@ -156,12 +158,12 @@ unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb,
 	int i, nentries;
 	struct ebt_entry *point;
 	struct ebt_counter *counter_base, *cb_base;
-	struct ebt_entry_target *t;
+	const struct ebt_entry_target *t;
 	int verdict, sp = 0;
 	struct ebt_chainstack *cs;
 	struct ebt_entries *chaininfo;
-	char *base;
-	struct ebt_table_info *private;
+	const char *base;
+	const struct ebt_table_info *private;
 	bool hotdrop = false;
 	struct xt_match_param mtpar;
 	struct xt_target_param tgpar;
@@ -395,7 +397,7 @@ ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
 	return 0;
 }
 
-static int ebt_verify_pointers(struct ebt_replace *repl,
+static int ebt_verify_pointers(const struct ebt_replace *repl,
 			       struct ebt_table_info *newinfo)
 {
 	unsigned int limit = repl->entries_size;
@@ -466,8 +468,8 @@ static int ebt_verify_pointers(struct ebt_replace *repl,
  * to parse the userspace data
  */
 static inline int
-ebt_check_entry_size_and_hooks(struct ebt_entry *e,
-   struct ebt_table_info *newinfo,
+ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
+   const struct ebt_table_info *newinfo,
    unsigned int *n, unsigned int *cnt,
    unsigned int *totalcnt, unsigned int *udc_cnt)
 {
@@ -622,9 +624,8 @@ ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
 }
 
 static inline int
-ebt_check_entry(struct ebt_entry *e,
-   struct net *net,
-   struct ebt_table_info *newinfo,
+ebt_check_entry(struct ebt_entry *e, struct net *net,
+   const struct ebt_table_info *newinfo,
    const char *name, unsigned int *cnt,
    struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
 {
@@ -743,12 +744,12 @@ cleanup_matches:
  * the hook mask for udc tells us from which base chains the udc can be
  * accessed. This mask is a parameter to the check() functions of the extensions
  */
-static int check_chainloops(struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
+static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
    unsigned int udc_cnt, unsigned int hooknr, char *base)
 {
 	int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
-	struct ebt_entry *e = (struct ebt_entry *)chain->data;
-	struct ebt_entry_target *t;
+	const struct ebt_entry *e = (struct ebt_entry *)chain->data;
+	const struct ebt_entry_target *t;
 
 	while (pos < nentries || chain_nr != -1) {
 		/* end of udc, go back one 'recursion' step */
@@ -814,7 +815,7 @@ letscontinue:
 }
 
 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
-static int translate_table(struct net *net, char *name,
+static int translate_table(struct net *net, const char *name,
 			   struct ebt_table_info *newinfo)
 {
 	unsigned int i, j, k, udc_cnt;
@@ -934,7 +935,7 @@ static int translate_table(struct net *net, char *name,
 }
 
 /* called under write_lock */
-static void get_counters(struct ebt_counter *oldcounters,
+static void get_counters(const struct ebt_counter *oldcounters,
    struct ebt_counter *counters, unsigned int nentries)
 {
 	int i, cpu;
@@ -957,7 +958,8 @@ static void get_counters(struct ebt_counter *oldcounters,
 }
 
 /* replace the table */
-static int do_replace(struct net *net, void __user *user, unsigned int len)
+static int do_replace(struct net *net, const void __user *user,
+		      unsigned int len)
 {
 	int ret, i, countersize;
 	struct ebt_table_info *newinfo;
@@ -1237,7 +1239,8 @@ void ebt_unregister_table(struct net *net, struct ebt_table *table)
 }
 
 /* userspace just supplied us with counters */
-static int update_counters(struct net *net, void __user *user, unsigned int len)
+static int update_counters(struct net *net, const void __user *user,
+			   unsigned int len)
 {
 	int i, ret;
 	struct ebt_counter *tmp;
@@ -1292,8 +1295,8 @@ free_tmp:
 	return ret;
 }
 
-static inline int ebt_make_matchname(struct ebt_entry_match *m,
-   char *base, char __user *ubase)
+static inline int ebt_make_matchname(const struct ebt_entry_match *m,
+    const char *base, char __user *ubase)
 {
 	char __user *hlp = ubase + ((char *)m - base);
 	if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN))
@@ -1301,8 +1304,8 @@ static inline int ebt_make_matchname(struct ebt_entry_match *m,
 	return 0;
 }
 
-static inline int ebt_make_watchername(struct ebt_entry_watcher *w,
-   char *base, char __user *ubase)
+static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
+    const char *base, char __user *ubase)
 {
 	char __user *hlp = ubase + ((char *)w - base);
 	if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN))
@@ -1310,11 +1313,12 @@ static inline int ebt_make_watchername(struct ebt_entry_watcher *w,
 	return 0;
 }
 
-static inline int ebt_make_names(struct ebt_entry *e, char *base, char __user *ubase)
+static inline int
+ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase)
 {
 	int ret;
 	char __user *hlp;
-	struct ebt_entry_target *t;
+	const struct ebt_entry_target *t;
 
 	if (e->bitmask == 0)
 		return 0;
@@ -1335,10 +1339,11 @@ static inline int ebt_make_names(struct ebt_entry *e, char *base, char __user *u
 
 /* called with ebt_mutex locked */
 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
-   int *len, int cmd)
+    const int *len, int cmd)
 {
 	struct ebt_replace tmp;
-	struct ebt_counter *counterstmp, *oldcounters;
+	struct ebt_counter *counterstmp;
+	const struct ebt_counter *oldcounters;
 	unsigned int entries_size, nentries;
 	char *entries;
 
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 2303dc9..4db5c1e 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -233,7 +233,14 @@ arpt_error(struct sk_buff *skb, const struct xt_target_param *par)
 	return NF_DROP;
 }
 
-static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
+static inline const struct arpt_entry_target *
+arpt_get_target_c(const struct arpt_entry *e)
+{
+	return arpt_get_target((struct arpt_entry *)e);
+}
+
+static inline struct arpt_entry *
+get_entry(const void *base, unsigned int offset)
 {
 	return (struct arpt_entry *)(base + offset);
 }
@@ -280,7 +287,7 @@ unsigned int arpt_do_table(struct sk_buff *skb,
 
 	arp = arp_hdr(skb);
 	do {
-		struct arpt_entry_target *t;
+		const struct arpt_entry_target *t;
 		int hdr_len;
 
 		if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
@@ -292,7 +299,7 @@ unsigned int arpt_do_table(struct sk_buff *skb,
 			(2 * skb->dev->addr_len);
 		ADD_COUNTER(e->counters, hdr_len, 1);
 
-		t = arpt_get_target(e);
+		t = arpt_get_target_c(e);
 
 		/* Standard target? */
 		if (!t->u.kernel.target->target) {
@@ -358,7 +365,7 @@ static inline bool unconditional(const struct arpt_arp *arp)
 /* Figures out from what hook each rule can be called: returns 0 if
  * there are loops.  Puts hook bitmask in comefrom.
  */
-static int mark_source_chains(struct xt_table_info *newinfo,
+static int mark_source_chains(const struct xt_table_info *newinfo,
 			      unsigned int valid_hooks, void *entry0)
 {
 	unsigned int hook;
@@ -379,7 +386,7 @@ static int mark_source_chains(struct xt_table_info *newinfo,
 
 		for (;;) {
 			const struct arpt_standard_target *t
-				= (void *)arpt_get_target(e);
+				= (void *)arpt_get_target_c(e);
 			int visited = e->comefrom & (1 << hook);
 
 			if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
@@ -463,7 +470,7 @@ static int mark_source_chains(struct xt_table_info *newinfo,
 	return 1;
 }
 
-static inline int check_entry(struct arpt_entry *e, const char *name)
+static inline int check_entry(const struct arpt_entry *e, const char *name)
 {
 	const struct arpt_entry_target *t;
 
@@ -475,7 +482,7 @@ static inline int check_entry(struct arpt_entry *e, const char *name)
 	if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset)
 		return -EINVAL;
 
-	t = arpt_get_target(e);
+	t = arpt_get_target_c(e);
 	if (e->target_offset + t->u.target_size > e->next_offset)
 		return -EINVAL;
 
@@ -540,14 +547,14 @@ out:
 	return ret;
 }
 
-static bool check_underflow(struct arpt_entry *e)
+static bool check_underflow(const struct arpt_entry *e)
 {
 	const struct arpt_entry_target *t;
 	unsigned int verdict;
 
 	if (!unconditional(&e->arp))
 		return false;
-	t = arpt_get_target(e);
+	t = arpt_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 		return false;
 	verdict = ((struct arpt_standard_target *)t)->verdict;
@@ -557,8 +564,8 @@ static bool check_underflow(struct arpt_entry *e)
 
 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
 					     struct xt_table_info *newinfo,
-					     unsigned char *base,
-					     unsigned char *limit,
+					     const unsigned char *base,
+					     const unsigned char *limit,
 					     const unsigned int *hook_entries,
 					     const unsigned int *underflows,
 					     unsigned int valid_hooks,
@@ -768,11 +775,11 @@ static void get_counters(const struct xt_table_info *t,
 	local_bh_enable();
 }
 
-static struct xt_counters *alloc_counters(struct xt_table *table)
+static struct xt_counters *alloc_counters(const struct xt_table *table)
 {
 	unsigned int countersize;
 	struct xt_counters *counters;
-	struct xt_table_info *private = table->private;
+	const struct xt_table_info *private = table->private;
 
 	/* We need atomic snapshot of counters: rest doesn't change
 	 * (other than comefrom, which userspace doesn't care
@@ -790,11 +797,11 @@ static struct xt_counters *alloc_counters(struct xt_table *table)
 }
 
 static int copy_entries_to_user(unsigned int total_size,
-				struct xt_table *table,
+				const struct xt_table *table,
 				void __user *userptr)
 {
 	unsigned int off, num;
-	struct arpt_entry *e;
+	const struct arpt_entry *e;
 	struct xt_counters *counters;
 	struct xt_table_info *private = table->private;
 	int ret = 0;
@@ -814,7 +821,7 @@ static int copy_entries_to_user(unsigned int total_size,
 	/* FIXME: use iterator macros --RR */
 	/* ... then go back and fix counters and names */
 	for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
-		struct arpt_entry_target *t;
+		const struct arpt_entry_target *t;
 
 		e = (struct arpt_entry *)(loc_cpu_entry + off);
 		if (copy_to_user(userptr + off
@@ -825,7 +832,7 @@ static int copy_entries_to_user(unsigned int total_size,
 			goto free_counters;
 		}
 
-		t = arpt_get_target(e);
+		t = arpt_get_target_c(e);
 		if (copy_to_user(userptr + off + e->target_offset
 				 + offsetof(struct arpt_entry_target,
 					    u.user.name),
@@ -860,18 +867,18 @@ static int compat_standard_to_user(void __user *dst, const void *src)
 	return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
 }
 
-static int compat_calc_entry(struct arpt_entry *e,
+static int compat_calc_entry(const struct arpt_entry *e,
 			     const struct xt_table_info *info,
-			     void *base, struct xt_table_info *newinfo)
+			     const void *base, struct xt_table_info *newinfo)
 {
-	struct arpt_entry_target *t;
+	const struct arpt_entry_target *t;
 	unsigned int entry_offset;
 	int off, i, ret;
 
 	off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
 	entry_offset = (void *)e - base;
 
-	t = arpt_get_target(e);
+	t = arpt_get_target_c(e);
 	off += xt_compat_target_offset(t->u.kernel.target);
 	newinfo->size -= off;
 	ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
@@ -907,7 +914,8 @@ static int compat_table_info(const struct xt_table_info *info,
 }
 #endif
 
-static int get_info(struct net *net, void __user *user, int *len, int compat)
+static int get_info(struct net *net, void __user *user,
+                    const int *len, int compat)
 {
 	char name[ARPT_TABLE_MAXNAMELEN];
 	struct xt_table *t;
@@ -966,7 +974,7 @@ static int get_info(struct net *net, void __user *user, int *len, int compat)
 }
 
 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
-		       int *len)
+		       const int *len)
 {
 	int ret;
 	struct arpt_get_entries get;
@@ -1080,7 +1088,8 @@ static int __do_replace(struct net *net, const char *name,
 	return ret;
 }
 
-static int do_replace(struct net *net, void __user *user, unsigned int len)
+static int do_replace(struct net *net, const void __user *user,
+                      unsigned int len)
 {
 	int ret;
 	struct arpt_replace tmp;
@@ -1140,8 +1149,8 @@ add_counter_to_entry(struct arpt_entry *e,
 	return 0;
 }
 
-static int do_add_counters(struct net *net, void __user *user, unsigned int len,
-			   int compat)
+static int do_add_counters(struct net *net, const void __user *user,
+			   unsigned int len, int compat)
 {
 	unsigned int i, curcpu;
 	struct xt_counters_info tmp;
@@ -1245,10 +1254,10 @@ static inline int
 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 				  struct xt_table_info *newinfo,
 				  unsigned int *size,
-				  unsigned char *base,
-				  unsigned char *limit,
-				  unsigned int *hook_entries,
-				  unsigned int *underflows,
+				  const unsigned char *base,
+				  const unsigned char *limit,
+				  const unsigned int *hook_entries,
+				  const unsigned int *underflows,
 				  unsigned int *i,
 				  const char *name)
 {
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 2a4f745..e94c18b 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -176,7 +176,7 @@ ipt_error(struct sk_buff *skb, const struct xt_target_param *par)
 
 /* Performance critical - called for every packet */
 static inline bool
-do_match(struct ipt_entry_match *m, const struct sk_buff *skb,
+do_match(const struct ipt_entry_match *m, const struct sk_buff *skb,
 	 struct xt_match_param *par)
 {
 	par->match     = m->u.kernel.match;
@@ -191,7 +191,7 @@ do_match(struct ipt_entry_match *m, const struct sk_buff *skb,
 
 /* Performance critical */
 static inline struct ipt_entry *
-get_entry(void *base, unsigned int offset)
+get_entry(const void *base, unsigned int offset)
 {
 	return (struct ipt_entry *)(base + offset);
 }
@@ -206,6 +206,13 @@ static inline bool unconditional(const struct ipt_ip *ip)
 #undef FWINV
 }
 
+/* for const-correctness */
+static inline const struct ipt_entry_target *
+ipt_get_target_c(const struct ipt_entry *e)
+{
+	return ipt_get_target((struct ipt_entry *)e);
+}
+
 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 static const char *const hooknames[] = {
@@ -240,11 +247,11 @@ static struct nf_loginfo trace_loginfo = {
 
 /* Mildly perf critical (only if packet tracing is on) */
 static inline int
-get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
+get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
 		      const char *hookname, const char **chainname,
 		      const char **comment, unsigned int *rulenum)
 {
-	struct ipt_standard_target *t = (void *)ipt_get_target(s);
+	const struct ipt_standard_target *t = (void *)ipt_get_target_c(s);
 
 	if (strcmp(t->target.u.kernel.target->name, IPT_ERROR_TARGET) == 0) {
 		/* Head of user chain: ERROR target with chainname */
@@ -270,15 +277,15 @@ get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
 	return 0;
 }
 
-static void trace_packet(struct sk_buff *skb,
+static void trace_packet(const struct sk_buff *skb,
 			 unsigned int hook,
 			 const struct net_device *in,
 			 const struct net_device *out,
 			 const char *tablename,
-			 struct xt_table_info *private,
-			 struct ipt_entry *e)
+			 const struct xt_table_info *private,
+			 const struct ipt_entry *e)
 {
-	void *table_base;
+	const void *table_base;
 	const struct ipt_entry *root;
 	const char *hookname, *chainname, *comment;
 	unsigned int rulenum = 0;
@@ -322,9 +329,9 @@ ipt_do_table(struct sk_buff *skb,
 	/* Initializing verdict to NF_DROP keeps gcc happy. */
 	unsigned int verdict = NF_DROP;
 	const char *indev, *outdev;
-	void *table_base;
+	const void *table_base;
 	struct ipt_entry *e, *back;
-	struct xt_table_info *private;
+	const struct xt_table_info *private;
 	struct xt_match_param mtpar;
 	struct xt_target_param tgpar;
 
@@ -357,7 +364,7 @@ ipt_do_table(struct sk_buff *skb,
 	back = get_entry(table_base, private->underflow[hook]);
 
 	do {
-		struct ipt_entry_target *t;
+		const struct ipt_entry_target *t;
 
 		IP_NF_ASSERT(e);
 		IP_NF_ASSERT(back);
@@ -450,7 +457,7 @@ ipt_do_table(struct sk_buff *skb,
 /* Figures out from what hook each rule can be called: returns 0 if
    there are loops.  Puts hook bitmask in comefrom. */
 static int
-mark_source_chains(struct xt_table_info *newinfo,
+mark_source_chains(const struct xt_table_info *newinfo,
 		   unsigned int valid_hooks, void *entry0)
 {
 	unsigned int hook;
@@ -468,8 +475,8 @@ mark_source_chains(struct xt_table_info *newinfo,
 		e->counters.pcnt = pos;
 
 		for (;;) {
-			struct ipt_standard_target *t
-				= (void *)ipt_get_target(e);
+			const struct ipt_standard_target *t
+				= (void *)ipt_get_target_c(e);
 			int visited = e->comefrom & (1 << hook);
 
 			if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
@@ -578,9 +585,9 @@ cleanup_match(struct ipt_entry_match *m, struct net *net, unsigned int *i)
 }
 
 static int
-check_entry(struct ipt_entry *e, const char *name)
+check_entry(const struct ipt_entry *e, const char *name)
 {
-	struct ipt_entry_target *t;
+	const struct ipt_entry_target *t;
 
 	if (!ip_checkentry(&e->ip)) {
 		duprintf("ip_tables: ip check failed %p %s.\n", e, name);
@@ -591,7 +598,7 @@ check_entry(struct ipt_entry *e, const char *name)
 	    e->next_offset)
 		return -EINVAL;
 
-	t = ipt_get_target(e);
+	t = ipt_get_target_c(e);
 	if (e->target_offset + t->u.target_size > e->next_offset)
 		return -EINVAL;
 
@@ -718,14 +725,14 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
 	return ret;
 }
 
-static bool check_underflow(struct ipt_entry *e)
+static bool check_underflow(const struct ipt_entry *e)
 {
 	const struct ipt_entry_target *t;
 	unsigned int verdict;
 
 	if (!unconditional(&e->ip))
 		return false;
-	t = ipt_get_target(e);
+	t = ipt_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 		return false;
 	verdict = ((struct ipt_standard_target *)t)->verdict;
@@ -736,8 +743,8 @@ static bool check_underflow(struct ipt_entry *e)
 static int
 check_entry_size_and_hooks(struct ipt_entry *e,
 			   struct xt_table_info *newinfo,
-			   unsigned char *base,
-			   unsigned char *limit,
+			   const unsigned char *base,
+			   const unsigned char *limit,
 			   const unsigned int *hook_entries,
 			   const unsigned int *underflows,
 			   unsigned int valid_hooks,
@@ -952,11 +959,11 @@ get_counters(const struct xt_table_info *t,
 	local_bh_enable();
 }
 
-static struct xt_counters * alloc_counters(struct xt_table *table)
+static struct xt_counters *alloc_counters(const struct xt_table *table)
 {
 	unsigned int countersize;
 	struct xt_counters *counters;
-	struct xt_table_info *private = table->private;
+	const struct xt_table_info *private = table->private;
 
 	/* We need atomic snapshot of counters: rest doesn't change
 	   (other than comefrom, which userspace doesn't care
@@ -974,11 +981,11 @@ static struct xt_counters * alloc_counters(struct xt_table *table)
 
 static int
 copy_entries_to_user(unsigned int total_size,
-		     struct xt_table *table,
+		     const struct xt_table *table,
 		     void __user *userptr)
 {
 	unsigned int off, num;
-	struct ipt_entry *e;
+	const struct ipt_entry *e;
 	struct xt_counters *counters;
 	const struct xt_table_info *private = table->private;
 	int ret = 0;
@@ -1030,7 +1037,7 @@ copy_entries_to_user(unsigned int total_size,
 			}
 		}
 
-		t = ipt_get_target(e);
+		t = ipt_get_target_c(e);
 		if (copy_to_user(userptr + off + e->target_offset
 				 + offsetof(struct ipt_entry_target,
 					    u.user.name),
@@ -1066,24 +1073,24 @@ static int compat_standard_to_user(void __user *dst, const void *src)
 }
 
 static inline int
-compat_calc_match(struct ipt_entry_match *m, int *size)
+compat_calc_match(const struct ipt_entry_match *m, int *size)
 {
 	*size += xt_compat_match_offset(m->u.kernel.match);
 	return 0;
 }
 
-static int compat_calc_entry(struct ipt_entry *e,
+static int compat_calc_entry(const struct ipt_entry *e,
 			     const struct xt_table_info *info,
-			     void *base, struct xt_table_info *newinfo)
+			     const void *base, struct xt_table_info *newinfo)
 {
-	struct ipt_entry_target *t;
+	const struct ipt_entry_target *t;
 	unsigned int entry_offset;
 	int off, i, ret;
 
 	off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
 	entry_offset = (void *)e - base;
 	IPT_MATCH_ITERATE(e, compat_calc_match, &off);
-	t = ipt_get_target(e);
+	t = ipt_get_target_c(e);
 	off += xt_compat_target_offset(t->u.kernel.target);
 	newinfo->size -= off;
 	ret = xt_compat_add_offset(AF_INET, entry_offset, off);
@@ -1119,7 +1126,8 @@ static int compat_table_info(const struct xt_table_info *info,
 }
 #endif
 
-static int get_info(struct net *net, void __user *user, int *len, int compat)
+static int get_info(struct net *net, void __user *user,
+                    const int *len, int compat)
 {
 	char name[IPT_TABLE_MAXNAMELEN];
 	struct xt_table *t;
@@ -1179,7 +1187,8 @@ static int get_info(struct net *net, void __user *user, int *len, int compat)
 }
 
 static int
-get_entries(struct net *net, struct ipt_get_entries __user *uptr, int *len)
+get_entries(struct net *net, struct ipt_get_entries __user *uptr,
+	    const int *len)
 {
 	int ret;
 	struct ipt_get_entries get;
@@ -1289,7 +1298,7 @@ __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
 }
 
 static int
-do_replace(struct net *net, void __user *user, unsigned int len)
+do_replace(struct net *net, const void __user *user, unsigned int len)
 {
 	int ret;
 	struct ipt_replace tmp;
@@ -1350,7 +1359,8 @@ add_counter_to_entry(struct ipt_entry *e,
 }
 
 static int
-do_add_counters(struct net *net, void __user *user, unsigned int len, int compat)
+do_add_counters(struct net *net, const void __user *user,
+                unsigned int len, int compat)
 {
 	unsigned int i, curcpu;
 	struct xt_counters_info tmp;
@@ -1546,10 +1556,10 @@ static int
 check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 				  struct xt_table_info *newinfo,
 				  unsigned int *size,
-				  unsigned char *base,
-				  unsigned char *limit,
-				  unsigned int *hook_entries,
-				  unsigned int *underflows,
+				  const unsigned char *base,
+				  const unsigned char *limit,
+				  const unsigned int *hook_entries,
+				  const unsigned int *underflows,
 				  unsigned int *i,
 				  const char *name)
 {
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 3ff4fd5..4185099 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -208,7 +208,7 @@ ip6t_error(struct sk_buff *skb, const struct xt_target_param *par)
 
 /* Performance critical - called for every packet */
 static inline bool
-do_match(struct ip6t_entry_match *m, const struct sk_buff *skb,
+do_match(const struct ip6t_entry_match *m, const struct sk_buff *skb,
 	 struct xt_match_param *par)
 {
 	par->match     = m->u.kernel.match;
@@ -222,7 +222,7 @@ do_match(struct ip6t_entry_match *m, const struct sk_buff *skb,
 }
 
 static inline struct ip6t_entry *
-get_entry(void *base, unsigned int offset)
+get_entry(const void *base, unsigned int offset)
 {
 	return (struct ip6t_entry *)(base + offset);
 }
@@ -236,6 +236,12 @@ static inline bool unconditional(const struct ip6t_ip6 *ipv6)
 	return memcmp(ipv6, &uncond, sizeof(uncond)) == 0;
 }
 
+static inline const struct ip6t_entry_target *
+ip6t_get_target_c(const struct ip6t_entry *e)
+{
+	return ip6t_get_target((struct ip6t_entry *)e);
+}
+
 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 /* This cries for unification! */
@@ -271,11 +277,11 @@ static struct nf_loginfo trace_loginfo = {
 
 /* Mildly perf critical (only if packet tracing is on) */
 static inline int
-get_chainname_rulenum(struct ip6t_entry *s, struct ip6t_entry *e,
+get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
 		      const char *hookname, const char **chainname,
 		      const char **comment, unsigned int *rulenum)
 {
-	struct ip6t_standard_target *t = (void *)ip6t_get_target(s);
+	const struct ip6t_standard_target *t = (void *)ip6t_get_target_c(s);
 
 	if (strcmp(t->target.u.kernel.target->name, IP6T_ERROR_TARGET) == 0) {
 		/* Head of user chain: ERROR target with chainname */
@@ -301,15 +307,15 @@ get_chainname_rulenum(struct ip6t_entry *s, struct ip6t_entry *e,
 	return 0;
 }
 
-static void trace_packet(struct sk_buff *skb,
+static void trace_packet(const struct sk_buff *skb,
 			 unsigned int hook,
 			 const struct net_device *in,
 			 const struct net_device *out,
 			 const char *tablename,
-			 struct xt_table_info *private,
-			 struct ip6t_entry *e)
+			 const struct xt_table_info *private,
+			 const struct ip6t_entry *e)
 {
-	void *table_base;
+	const void *table_base;
 	const struct ip6t_entry *root;
 	const char *hookname, *chainname, *comment;
 	unsigned int rulenum = 0;
@@ -352,9 +358,9 @@ ip6t_do_table(struct sk_buff *skb,
 	/* Initializing verdict to NF_DROP keeps gcc happy. */
 	unsigned int verdict = NF_DROP;
 	const char *indev, *outdev;
-	void *table_base;
+	const void *table_base;
 	struct ip6t_entry *e, *back;
-	struct xt_table_info *private;
+	const struct xt_table_info *private;
 	struct xt_match_param mtpar;
 	struct xt_target_param tgpar;
 
@@ -385,7 +391,7 @@ ip6t_do_table(struct sk_buff *skb,
 	back = get_entry(table_base, private->underflow[hook]);
 
 	do {
-		struct ip6t_entry_target *t;
+		const struct ip6t_entry_target *t;
 
 		IP_NF_ASSERT(e);
 		IP_NF_ASSERT(back);
@@ -400,7 +406,7 @@ ip6t_do_table(struct sk_buff *skb,
 			    ntohs(ipv6_hdr(skb)->payload_len) +
 			    sizeof(struct ipv6hdr), 1);
 
-		t = ip6t_get_target(e);
+		t = ip6t_get_target_c(e);
 		IP_NF_ASSERT(t->u.kernel.target);
 
 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
@@ -482,7 +488,7 @@ ip6t_do_table(struct sk_buff *skb,
 /* Figures out from what hook each rule can be called: returns 0 if
    there are loops.  Puts hook bitmask in comefrom. */
 static int
-mark_source_chains(struct xt_table_info *newinfo,
+mark_source_chains(const struct xt_table_info *newinfo,
 		   unsigned int valid_hooks, void *entry0)
 {
 	unsigned int hook;
@@ -500,8 +506,8 @@ mark_source_chains(struct xt_table_info *newinfo,
 		e->counters.pcnt = pos;
 
 		for (;;) {
-			struct ip6t_standard_target *t
-				= (void *)ip6t_get_target(e);
+			const struct ip6t_standard_target *t
+				= (void *)ip6t_get_target_c(e);
 			int visited = e->comefrom & (1 << hook);
 
 			if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
@@ -610,9 +616,9 @@ cleanup_match(struct ip6t_entry_match *m, struct net *net, unsigned int *i)
 }
 
 static int
-check_entry(struct ip6t_entry *e, const char *name)
+check_entry(const struct ip6t_entry *e, const char *name)
 {
-	struct ip6t_entry_target *t;
+	const struct ip6t_entry_target *t;
 
 	if (!ip6_checkentry(&e->ipv6)) {
 		duprintf("ip_tables: ip check failed %p %s.\n", e, name);
@@ -623,7 +629,7 @@ check_entry(struct ip6t_entry *e, const char *name)
 	    e->next_offset)
 		return -EINVAL;
 
-	t = ip6t_get_target(e);
+	t = ip6t_get_target_c(e);
 	if (e->target_offset + t->u.target_size > e->next_offset)
 		return -EINVAL;
 
@@ -750,14 +756,14 @@ find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
 	return ret;
 }
 
-static bool check_underflow(struct ip6t_entry *e)
+static bool check_underflow(const struct ip6t_entry *e)
 {
 	const struct ip6t_entry_target *t;
 	unsigned int verdict;
 
 	if (!unconditional(&e->ipv6))
 		return false;
-	t = ip6t_get_target(e);
+	t = ip6t_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 		return false;
 	verdict = ((struct ip6t_standard_target *)t)->verdict;
@@ -768,8 +774,8 @@ static bool check_underflow(struct ip6t_entry *e)
 static int
 check_entry_size_and_hooks(struct ip6t_entry *e,
 			   struct xt_table_info *newinfo,
-			   unsigned char *base,
-			   unsigned char *limit,
+			   const unsigned char *base,
+			   const unsigned char *limit,
 			   const unsigned int *hook_entries,
 			   const unsigned int *underflows,
 			   unsigned int valid_hooks,
@@ -984,11 +990,11 @@ get_counters(const struct xt_table_info *t,
 	local_bh_enable();
 }
 
-static struct xt_counters *alloc_counters(struct xt_table *table)
+static struct xt_counters *alloc_counters(const struct xt_table *table)
 {
 	unsigned int countersize;
 	struct xt_counters *counters;
-	struct xt_table_info *private = table->private;
+	const struct xt_table_info *private = table->private;
 
 	/* We need atomic snapshot of counters: rest doesn't change
 	   (other than comefrom, which userspace doesn't care
@@ -1006,11 +1012,11 @@ static struct xt_counters *alloc_counters(struct xt_table *table)
 
 static int
 copy_entries_to_user(unsigned int total_size,
-		     struct xt_table *table,
+		     const struct xt_table *table,
 		     void __user *userptr)
 {
 	unsigned int off, num;
-	struct ip6t_entry *e;
+	const struct ip6t_entry *e;
 	struct xt_counters *counters;
 	const struct xt_table_info *private = table->private;
 	int ret = 0;
@@ -1062,7 +1068,7 @@ copy_entries_to_user(unsigned int total_size,
 			}
 		}
 
-		t = ip6t_get_target(e);
+		t = ip6t_get_target_c(e);
 		if (copy_to_user(userptr + off + e->target_offset
 				 + offsetof(struct ip6t_entry_target,
 					    u.user.name),
@@ -1098,24 +1104,24 @@ static int compat_standard_to_user(void __user *dst, const void *src)
 }
 
 static inline int
-compat_calc_match(struct ip6t_entry_match *m, int *size)
+compat_calc_match(const struct ip6t_entry_match *m, int *size)
 {
 	*size += xt_compat_match_offset(m->u.kernel.match);
 	return 0;
 }
 
-static int compat_calc_entry(struct ip6t_entry *e,
+static int compat_calc_entry(const struct ip6t_entry *e,
 			     const struct xt_table_info *info,
-			     void *base, struct xt_table_info *newinfo)
+			     const void *base, struct xt_table_info *newinfo)
 {
-	struct ip6t_entry_target *t;
+	const struct ip6t_entry_target *t;
 	unsigned int entry_offset;
 	int off, i, ret;
 
 	off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
 	entry_offset = (void *)e - base;
 	IP6T_MATCH_ITERATE(e, compat_calc_match, &off);
-	t = ip6t_get_target(e);
+	t = ip6t_get_target_c(e);
 	off += xt_compat_target_offset(t->u.kernel.target);
 	newinfo->size -= off;
 	ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
@@ -1151,7 +1157,8 @@ static int compat_table_info(const struct xt_table_info *info,
 }
 #endif
 
-static int get_info(struct net *net, void __user *user, int *len, int compat)
+static int get_info(struct net *net, void __user *user,
+                    const int *len, int compat)
 {
 	char name[IP6T_TABLE_MAXNAMELEN];
 	struct xt_table *t;
@@ -1211,7 +1218,8 @@ static int get_info(struct net *net, void __user *user, int *len, int compat)
 }
 
 static int
-get_entries(struct net *net, struct ip6t_get_entries __user *uptr, int *len)
+get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
+            const int *len)
 {
 	int ret;
 	struct ip6t_get_entries get;
@@ -1322,7 +1330,7 @@ __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
 }
 
 static int
-do_replace(struct net *net, void __user *user, unsigned int len)
+do_replace(struct net *net, const void __user *user, unsigned int len)
 {
 	int ret;
 	struct ip6t_replace tmp;
@@ -1383,7 +1391,7 @@ add_counter_to_entry(struct ip6t_entry *e,
 }
 
 static int
-do_add_counters(struct net *net, void __user *user, unsigned int len,
+do_add_counters(struct net *net, const void __user *user, unsigned int len,
 		int compat)
 {
 	unsigned int i, curcpu;
@@ -1582,10 +1590,10 @@ static int
 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
 				  struct xt_table_info *newinfo,
 				  unsigned int *size,
-				  unsigned char *base,
-				  unsigned char *limit,
-				  unsigned int *hook_entries,
-				  unsigned int *underflows,
+				  const unsigned char *base,
+				  const unsigned char *limit,
+				  const unsigned int *hook_entries,
+				  const unsigned int *underflows,
 				  unsigned int *i,
 				  const char *name)
 {
-- 
1.6.6.1

Re: [PATCH 6/6] netfilter: xtables: add const qualifiers

[Patrick McHardy]

Jan Engelhardt wrote:
> +static inline const struct ip6t_entry_target *
> +ip6t_get_target_c(const struct ip6t_entry *e)
> +{
> +	return ip6t_get_target((struct ip6t_entry *)e);
> +}
> +

I would prefer a macro over these get_target_c functions.

Re: [PATCH 6/6] netfilter: xtables: add const qualifiers

[Jan Engelhardt]

On Thursday 2010-02-11 10:00, Patrick McHardy wrote:

>Jan Engelhardt wrote:
>> +static inline const struct ip6t_entry_target *
>> +ip6t_get_target_c(const struct ip6t_entry *e)
>> +{
>> +	return ip6t_get_target((struct ip6t_entry *)e);
>> +}
>> +
>
>I would prefer a macro over these get_target_c functions.

Why so?

Re: [PATCH 6/6] netfilter: xtables: add const qualifiers

[Patrick McHardy]

Jan Engelhardt wrote:
> On Thursday 2010-02-11 10:00, Patrick McHardy wrote:
> 
>> Jan Engelhardt wrote:
>>> +static inline const struct ip6t_entry_target *
>>> +ip6t_get_target_c(const struct ip6t_entry *e)
>>> +{
>>> +	return ip6t_get_target((struct ip6t_entry *)e);
>>> +}
>>> +
>> I would prefer a macro over these get_target_c functions.
> 
> Why so?

Because it avoids having a function for const and one for non-const.

Re: [PATCH 6/6] netfilter: xtables: add const qualifiers

[Jan Engelhardt]

On Thursday 2010-02-11 17:06, Patrick McHardy wrote:

>Jan Engelhardt wrote:
>> On Thursday 2010-02-11 10:00, Patrick McHardy wrote:
>> 
>>> Jan Engelhardt wrote:
>>>> +static inline const struct ip6t_entry_target *
>>>> +ip6t_get_target_c(const struct ip6t_entry *e)
>>>> +{
>>>> +	return ip6t_get_target((struct ip6t_entry *)e);
>>>> +}
>>>> +
>>> I would prefer a macro over these get_target_c functions.
>> 
>> Why so?
>
>Because it avoids having a function for const and one for non-const.

Well, I need two. One that returns const and one that does not;
ip6t_get_target_c is signaturally-incompatible with ip6t_get_target.
FWIW, the function is removed later on anyway ("remove remaining xt1 
code").

Re: [PATCH 6/6] netfilter: xtables: add const qualifiers

[Patrick McHardy]

Jan Engelhardt wrote:
> On Thursday 2010-02-11 17:06, Patrick McHardy wrote:
> 
>> Jan Engelhardt wrote:
>>> On Thursday 2010-02-11 10:00, Patrick McHardy wrote:
>>>
>>>> Jan Engelhardt wrote:
>>>>> +static inline const struct ip6t_entry_target *
>>>>> +ip6t_get_target_c(const struct ip6t_entry *e)
>>>>> +{
>>>>> +	return ip6t_get_target((struct ip6t_entry *)e);
>>>>> +}
>>>>> +
>>>> I would prefer a macro over these get_target_c functions.
>>> Why so?
>> Because it avoids having a function for const and one for non-const.
> 
> Well, I need two. One that returns const and one that does not;
> ip6t_get_target_c is signaturally-incompatible with ip6t_get_target.

Yes, but you wouldn't if you'd use a macro.

#define ip6t_get_target(e)	((void *)e + e->target_offset)

> FWIW, the function is removed later on anyway ("remove remaining xt1 
> code").

This is patch 6/6, what do you mean with "later"?

Re: [PATCH 6/6] netfilter: xtables: add const qualifiers

[Jan Engelhardt]

On Thursday 2010-02-11 17:27, Patrick McHardy wrote:
>>>>> I would prefer a macro over these get_target_c functions.
>>>> Why so?
>>> Because it avoids having a function for const and one for non-const.
>> 
>> Well, I need two. One that returns const and one that does not;
>> ip6t_get_target_c is signaturally-incompatible with ip6t_get_target.
>
>Yes, but you wouldn't if you'd use a macro.
>
>#define ip6t_get_target(e)	((void *)e + e->target_offset)

That would remove the const from a const e, which is what I
expressly wanted to avoid because it's already a little hairy.

>> FWIW, the function is removed later on anyway ("remove remaining xt1 
>> code").
>
>This is patch 6/6, what do you mean with "later"?

Patch 094/103 from the original submission
http://markmail.org/browse/org.kernel.vger.netfilter-devel/2009-08
that I am trying to push to you all the time :)

Re: Code cleanups

[Jan Engelhardt]

On Wednesday 2010-02-10 18:39, Jan Engelhardt wrote:

>the next patch pack is mostly about cleanups, and there is one
>commit for improving debug a little.
>Pull URL will be posted once the previous request has been
>merged, but I am already posting them now for review.
>
>The following changes since commit e3eaa9910b380530cfd2c0670fcd3f627674da8a:
>are available in the git repository at:


	git://dev.medozas.de/linux master



> include/linux/netfilter.h            |   55 +++++++++++---------
> include/linux/netfilter/x_tables.h   |   12 ++--
> net/bridge/netfilter/ebtables.c      |   59 ++++++++++++----------
> net/ipv4/netfilter/arp_tables.c      |   73 +++++++++++++++------------
> net/ipv4/netfilter/ip_tables.c       |   92 +++++++++++++++++++---------------
> net/ipv4/netfilter/ipt_ULOG.c        |    4 +-
> net/ipv4/netfilter/iptable_mangle.c  |   10 +---
> net/ipv6/netfilter/ip6_tables.c      |   92 ++++++++++++++++++---------------
> net/ipv6/netfilter/ip6table_mangle.c |   10 +---
> net/netfilter/x_tables.c             |   16 ++++--
> net/netfilter/xt_hashlimit.c         |    4 +-
> net/netfilter/xt_limit.c             |    4 +-
> 12 files changed, 233 insertions(+), 198 deletions(-)

Re: Code cleanups

[Patrick McHardy]

Jan Engelhardt wrote:
> On Wednesday 2010-02-10 18:39, Jan Engelhardt wrote:
> 
>> the next patch pack is mostly about cleanups, and there is one
>> commit for improving debug a little.
>> Pull URL will be posted once the previous request has been
>> merged, but I am already posting them now for review.
>>
>> The following changes since commit e3eaa9910b380530cfd2c0670fcd3f627674da8a:
>> are available in the git repository at:
> 
> 
> 	git://dev.medozas.de/linux master

This doesn't apply cleanly anymore due to the mangle table
fixes from Alexey.

Re: Code cleanups

[Jan Engelhardt]

On Monday 2010-02-15 16:34, Patrick McHardy wrote:
>> 
>>> the next patch pack is mostly about cleanups, and there is one
>>> commit for improving debug a little.
>>> Pull URL will be posted once the previous request has been
>>> merged, but I am already posting them now for review.
>>>
>>> The following changes since commit e3eaa9910b380530cfd2c0670fcd3f627674da8a:
>>> are available in the git repository at:
>> 
>> 	git://dev.medozas.de/linux master
>
>This doesn't apply cleanly anymore due to the mangle table
>fixes from Alexey.


Rebased, see below.


The following changes since commit 98e6d2d5ee26bf56850a10eb64139c68fb09ba19:
  Jan Engelhardt (1):
        netfilter: xt_recent: inform user when hitcount is too large

are available in the git repository at:

  git://dev.medozas.de/linux master-d5d1baa

Jan Engelhardt (6):
      netfilter: iptables: remove unused function arguments
      netfilter: reduce NF_HOOK by one argument
      netfilter: get rid of the grossness in netfilter.h
      netfilter: xtables: print details on size mismatch
      netfilter: xtables: constify args in compat copying functions
      netfilter: xtables: add const qualifiers

 include/linux/netfilter.h            |   55 +++++++++++---------
 include/linux/netfilter/x_tables.h   |   12 ++--
 net/bridge/netfilter/ebtables.c      |   59 ++++++++++++----------
 net/ipv4/netfilter/arp_tables.c      |   73 +++++++++++++++------------
 net/ipv4/netfilter/ip_tables.c       |   92 +++++++++++++++++++---------------
 net/ipv4/netfilter/ipt_ULOG.c        |    4 +-
 net/ipv4/netfilter/iptable_mangle.c  |   10 +---
 net/ipv6/netfilter/ip6_tables.c      |   92 ++++++++++++++++++---------------
 net/ipv6/netfilter/ip6table_mangle.c |   10 +---
 net/netfilter/x_tables.c             |   16 ++++--
 net/netfilter/xt_hashlimit.c         |    4 +-
 net/netfilter/xt_limit.c             |    4 +-
 12 files changed, 233 insertions(+), 198 deletions(-)


And the second run would be


The following changes since commit d5d1baa15f5b05e9110403724d5dc72d6d541e04:
  Jan Engelhardt (1):
        netfilter: xtables: add const qualifiers

are available in the git repository at:

  git://dev.medozas.de/linux master

Jan Engelhardt (6):
      netfilter: xtables: replace XT_ENTRY_ITERATE macro
      netfilter: xtables: optimize call flow around xt_entry_foreach
      netfilter: xtables: replace XT_MATCH_ITERATE macro
      netfilter: xtables: optimize call flow around xt_ematch_foreach
      netfilter: xtables: reduce arguments to translate_table
      netfilter: xtables2: make ip_tables reentrant

 include/linux/netfilter/x_tables.h        |   24 ++
 include/linux/netfilter_arp/arp_tables.h  |   10 +-
 include/linux/netfilter_ipv4/ip_tables.h  |   15 +-
 include/linux/netfilter_ipv6/ip6_tables.h |   14 +-
 net/ipv4/netfilter/arp_tables.c           |  307 ++++++++----------
 net/ipv4/netfilter/ip_tables.c            |  501 ++++++++++++++---------------
 net/ipv6/netfilter/ip6_tables.c           |  492 ++++++++++++++---------------
 net/netfilter/x_tables.c                  |   79 +++++
 net/netfilter/xt_TCPMSS.c                 |   12 +-
 9 files changed, 741 insertions(+), 713 deletions(-)

Re: Code cleanups

[Patrick McHardy]

Jan Engelhardt wrote:
> On Monday 2010-02-15 16:34, Patrick McHardy wrote:
>>>> the next patch pack is mostly about cleanups, and there is one
>>>> commit for improving debug a little.
>>>> Pull URL will be posted once the previous request has been
>>>> merged, but I am already posting them now for review.
>>>>
>>>> The following changes since commit e3eaa9910b380530cfd2c0670fcd3f627674da8a:
>>>> are available in the git repository at:
>>> 	git://dev.medozas.de/linux master
>> This doesn't apply cleanly anymore due to the mangle table
>> fixes from Alexey.
> 
> 
> Rebased, see below.
> 
> 
> The following changes since commit 98e6d2d5ee26bf56850a10eb64139c68fb09ba19:
>   Jan Engelhardt (1):
>         netfilter: xt_recent: inform user when hitcount is too large
> 
> are available in the git repository at:
> 
>   git://dev.medozas.de/linux master-d5d1baa
> 
> Jan Engelhardt (6):
>       netfilter: iptables: remove unused function arguments
>       netfilter: reduce NF_HOOK by one argument
>       netfilter: get rid of the grossness in netfilter.h
>       netfilter: xtables: print details on size mismatch
>       netfilter: xtables: constify args in compat copying functions
>       netfilter: xtables: add const qualifiers


Pulled and pushed out again, thanks.

> And the second run would be
> 
> 
> The following changes since commit d5d1baa15f5b05e9110403724d5dc72d6d541e04:
>   Jan Engelhardt (1):
>         netfilter: xtables: add const qualifiers
> 
> are available in the git repository at:
> 
>   git://dev.medozas.de/linux master
> 
> Jan Engelhardt (6):
>       netfilter: xtables: replace XT_ENTRY_ITERATE macro
>       netfilter: xtables: optimize call flow around xt_entry_foreach
>       netfilter: xtables: replace XT_MATCH_ITERATE macro
>       netfilter: xtables: optimize call flow around xt_ematch_foreach
>       netfilter: xtables: reduce arguments to translate_table
>       netfilter: xtables2: make ip_tables reentrant

These will have to wait until I can review them. This won't happen
today since I want to get the first batch of patches out previously.

Xtables cleanup patches

[Jan Engelhardt]

I am posting here already the next round of pullable patches
(that I originally wanted to get in _much_ faster) for review.

This block is mostly cleanups, simplifications. It might be worth
testing these together with the previous set if there are concerns
about speed.

-----
The following changes since commit 7891b6c280d01d52be5ecefe0db79d4b1f671a1e:
  Jan Engelhardt (1):
        netfilter: xtables: generate initial table on-demand

are available in the git repository at:

  git://dev.medozas.de/linux next

Jan Engelhardt (6):
      netfilter: iptables: remove unused function arguments
      netfilter: reduce NF_HOOK by one argument
      netfilter: get rid of the grossness in netfilter.h
      netfilter: xtables: print details on size mismatch
      netfilter: xtables: constify args in compat copying functions
      netfilter: xtables: add const qualifiers

 include/linux/netfilter.h            |   55 +++++++++++---------
 include/linux/netfilter/x_tables.h   |   12 ++--
 net/bridge/netfilter/ebtables.c      |   56 +++++++++++---------
 net/ipv4/netfilter/arp_tables.c      |   73 +++++++++++++++------------
 net/ipv4/netfilter/ip_tables.c       |   92 +++++++++++++++++++---------------
 net/ipv4/netfilter/ipt_ULOG.c        |    4 +-
 net/ipv4/netfilter/iptable_mangle.c  |   10 +---
 net/ipv6/netfilter/ip6_tables.c      |   92 ++++++++++++++++++---------------
 net/ipv6/netfilter/ip6table_mangle.c |   10 +---
 net/netfilter/x_tables.c             |   16 ++++--
 net/netfilter/xt_hashlimit.c         |    4 +-
 net/netfilter/xt_limit.c             |    4 +-
 12 files changed, 232 insertions(+), 196 deletions(-)

[PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Jan Engelhardt]

GCC is now smart enough to follow the inline trail correctly.
vmlinux size remain the same.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 include/linux/netfilter.h |   45 ++++++++++++++++++++++++++++-----------------
 1 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index d02dc03..bea0e0c 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -196,25 +196,36 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
    coders :)
 */
 
-/* This is gross, but inline doesn't cut it for avoiding the function
-   call in fast path: gcc doesn't inline (needs value tracking?). --RR */
-
-/* HX: It's slightly less gross now. */
-
-#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh)	       \
-({int __ret;								       \
-if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh)) == 1)\
-	__ret = (okfn)(skb);						       \
-__ret;})
+static inline int
+NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+	       struct net_device *in, struct net_device *out,
+	       int (*okfn)(struct sk_buff *), int thresh)
+{
+	int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
+	if (ret == 1)
+		ret = okfn(skb);
+	return ret;
+}
 
-#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)		       \
-({int __ret;								       \
-if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
-	__ret = (okfn)(skb);						       \
-__ret;})
+static inline int
+NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+	     struct net_device *in, struct net_device *out,
+	     int (*okfn)(struct sk_buff *), bool cond)
+{
+	int ret = 1;
+	if (cond ||
+	    (ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN) == 1))
+		ret = okfn(skb);
+	return ret;
+}
 
-#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
-	NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
+static inline int
+NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+	struct net_device *in, struct net_device *out,
+	int (*okfn)(struct sk_buff *))
+{
+	return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
+}
 
 /* Call setsockopt() */
 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
-- 
1.6.5.2

Re: [PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Changli Gao]

On Wed, Nov 4, 2009 at 2:04 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
>
> -#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)                \
> -({int __ret;                                                                  \
> -if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
> -       __ret = (okfn)(skb);                                                   \
> -__ret;})
This code isn't the same as the linus tree's. And has a risk about
uninitialized variable __ret.

#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)                 \
({int __ret;                                                                   \
if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn,
INT_MIN, cond)) == 1)\
        __ret = (okfn)(skb);                                                   \
__ret;})

/**
 *      nf_hook_thresh - call a netfilter hook
 *
 *      Returns 1 if the hook has allowed the packet to pass.  The function
 *      okfn must be invoked by the caller in this case.  Any other return
 *      value indicates the packet has been consumed by the hook.
 */
static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
                                 struct sk_buff *skb,
                                 struct net_device *indev,
                                 struct net_device *outdev,
                                 int (*okfn)(struct sk_buff *), int thresh,
                                 int cond)
{
        if (!cond)
                return 1;
#ifndef CONFIG_NETFILTER_DEBUG
        if (list_empty(&nf_hooks[pf][hook]))
                return 1;
#endif
        return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
}


> +static inline int
> +NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
> +            struct net_device *in, struct net_device *out,
> +            int (*okfn)(struct sk_buff *), bool cond)
> +{
> +       int ret = 1;
> +       if (cond ||
> +           (ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN) == 1))
> +               ret = okfn(skb);
> +       return ret;
> +}

The fact is: no matter the cond value, okfn(skb) should always be
called, and hf_hook_thresh() should be called only when cond is true.
So the code will be.

if (cond) {
   if (ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1)
       ret = okfn(skb);
} else {
    ret = okfn(skb);
}

-- 
Regards，
Changli Gao(xiaosuo@gmail.com)
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Re: [PATCH 3/6] netfilter: get rid of the grossness in netfilter.h

[Jan Engelhardt]

On Wednesday 2009-11-04 08:59, Changli Gao wrote:

>On Wed, Nov 4, 2009 at 2:04 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
>>
>> -#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)                \
>> -({int __ret;                                                                  \
>> -if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
>> -       __ret = (okfn)(skb);                                                   \
>> -__ret;})
>This code isn't the same as the linus tree's.

It sure is:

        git diff mdz/next~6..mdz/next include/linux/netfilter.h

=> no output, hence the same.

>And has a risk about uninitialized variable __ret.
>
>#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)                 \
>({int __ret;                                                                   \
>if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn,
>INT_MIN, cond)) == 1)\
>        __ret = (okfn)(skb);                                                   \
>__ret;})

No uninitialized variable either there.

>The fact is: no matter the cond value, okfn(skb) should always be
>called, and hf_hook_thresh() should be called only when cond is true.

Yes, thank you for noticing. I will have that fixed up:

Subject: augment a3dc8cdef7c00d0340a0e6bc80211ce81b665f3b
---
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index d02dc03..6854000 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -209,7 +209,7 @@ __ret;})
 
 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)		       \
 ({int __ret;								       \
-if ((cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
+if (!(cond) || (__ret = nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN)) == 1)\
 	__ret = (okfn)(skb);						       \
 __ret;})
 
-- 
# Created with git-export-patch
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