netfilter: xtables: add const qualifiers

This should make it easier to remove redundant arguments later.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

1 files changed, 48 insertions, 40 deletions

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 3ff4fd50e96e..4185099c2943 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)
 {