netfilter: xtables: replace XT_ENTRY_ITERATE macro

The macro is replaced by a list.h-like foreach loop. This makes
the code much more inspectable.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 104 insertions, 56 deletions

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 4185099c2943..23926e38d36b 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -318,6 +318,7 @@ static void trace_packet(const struct sk_buff *skb,
         const void *table_base;
         const struct ip6t_entry *root;
         const char *hookname, *chainname, *comment;
+        const struct ip6t_entry *iter;
         unsigned int rulenum = 0;
 
         table_base = private->entries[smp_processor_id()];
@@ -326,10 +327,10 @@ static void trace_packet(const struct sk_buff *skb,
         hookname = chainname = hooknames[hook];
         comment = comments[NF_IP6_TRACE_COMMENT_RULE];
 
-        IP6T_ENTRY_ITERATE(root,
-                           private->size - private->hook_entry[hook],
-                           get_chainname_rulenum,
-                           e, hookname, &chainname, &comment, &rulenum);
+        xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
+                if (get_chainname_rulenum(iter, e, hookname,
+                    &chainname, &comment, &rulenum) != 0)
+                        break;
 
         nf_log_packet(AF_INET6, hook, skb, in, out, &trace_loginfo,
                       "TRACE: %s:%s:%s:%u ",
@@ -857,8 +858,9 @@ translate_table(struct net *net,
                 const unsigned int *hook_entries,
                 const unsigned int *underflows)
 {
+        struct ip6t_entry *iter;
         unsigned int i;
-        int ret;
+        int ret = 0;
 
         newinfo->size = size;
         newinfo->number = number;
@@ -872,12 +874,13 @@ translate_table(struct net *net,
         duprintf("translate_table: size %u\n", newinfo->size);
         i = 0;
         /* Walk through entries, checking offsets. */
-        ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
-                                check_entry_size_and_hooks,
-                                newinfo,
-                                entry0,
-                                entry0 + size,
-                                hook_entries, underflows, valid_hooks, &i);
+        xt_entry_foreach(iter, entry0, newinfo->size) {
+                ret = check_entry_size_and_hooks(iter, newinfo, entry0,
+                      entry0 + size, hook_entries, underflows,
+                      valid_hooks, &i);
+                if (ret != 0)
+                        break;
+        }
         if (ret != 0)
                 return ret;
 
@@ -909,12 +912,16 @@ translate_table(struct net *net,
 
         /* Finally, each sanity check must pass */
         i = 0;
-        ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
-                                find_check_entry, net, name, size, &i);
+        xt_entry_foreach(iter, entry0, newinfo->size) {
+                ret = find_check_entry(iter, net, name, size, &i);
+                if (ret != 0)
+                        break;
+        }
 
         if (ret != 0) {
-                IP6T_ENTRY_ITERATE(entry0, newinfo->size,
-                                   cleanup_entry, net, &i);
+                xt_entry_foreach(iter, entry0, newinfo->size)
+                        if (cleanup_entry(iter, net, &i) != 0)
+                                break;
                 return ret;
         }
 
@@ -954,6 +961,7 @@ static void
 get_counters(const struct xt_table_info *t,
              struct xt_counters counters[])
 {
+        struct ip6t_entry *iter;
         unsigned int cpu;
         unsigned int i;
         unsigned int curcpu;
@@ -969,22 +977,18 @@ get_counters(const struct xt_table_info *t,
         curcpu = smp_processor_id();
 
         i = 0;
-        IP6T_ENTRY_ITERATE(t->entries[curcpu],
-                           t->size,
-                           set_entry_to_counter,
-                           counters,
-                           &i);
+        xt_entry_foreach(iter, t->entries[curcpu], t->size)
+                if (set_entry_to_counter(iter, counters, &i) != 0)
+                        break;
 
         for_each_possible_cpu(cpu) {
                 if (cpu == curcpu)
                         continue;
                 i = 0;
                 xt_info_wrlock(cpu);
-                IP6T_ENTRY_ITERATE(t->entries[cpu],
-                                  t->size,
-                                  add_entry_to_counter,
-                                  counters,
-                                  &i);
+                xt_entry_foreach(iter, t->entries[cpu], t->size)
+                        if (add_entry_to_counter(iter, counters, &i) != 0)
+                                break;
                 xt_info_wrunlock(cpu);
         }
         local_bh_enable();
@@ -1142,7 +1146,9 @@ static int compat_calc_entry(const struct ip6t_entry *e,
 static int compat_table_info(const struct xt_table_info *info,
                              struct xt_table_info *newinfo)
 {
+        struct ip6t_entry *iter;
         void *loc_cpu_entry;
+        int ret = 0;
 
         if (!newinfo || !info)
                 return -EINVAL;
@@ -1151,9 +1157,12 @@ static int compat_table_info(const struct xt_table_info *info,
         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
         newinfo->initial_entries = 0;
         loc_cpu_entry = info->entries[raw_smp_processor_id()];
-        return IP6T_ENTRY_ITERATE(loc_cpu_entry, info->size,
-                                  compat_calc_entry, info, loc_cpu_entry,
-                                  newinfo);
+        xt_entry_foreach(iter, loc_cpu_entry, info->size) {
+                ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
+                if (ret != 0)
+                        break;
+        }
+        return ret;
 }
 #endif
 
@@ -1267,6 +1276,7 @@ __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
         struct xt_table_info *oldinfo;
         struct xt_counters *counters;
         const void *loc_cpu_old_entry;
+        struct ip6t_entry *iter;
 
         ret = 0;
         counters = vmalloc_node(num_counters * sizeof(struct xt_counters),
@@ -1310,8 +1320,10 @@ __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
 
         /* Decrease module usage counts and free resource */
         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
-        IP6T_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
-                           net, NULL);
+        xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
+                if (cleanup_entry(iter, net, NULL) != 0)
+                        break;
+
         xt_free_table_info(oldinfo);
         if (copy_to_user(counters_ptr, counters,
                          sizeof(struct xt_counters) * num_counters) != 0)
@@ -1336,6 +1348,7 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
         struct ip6t_replace tmp;
         struct xt_table_info *newinfo;
         void *loc_cpu_entry;
+        struct ip6t_entry *iter;
 
         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
                 return -EFAULT;
@@ -1371,7 +1384,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
         return 0;
 
  free_newinfo_untrans:
-        IP6T_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, net, NULL);
+        xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
+                if (cleanup_entry(iter, net, NULL) != 0)
+                        break;
  free_newinfo:
         xt_free_table_info(newinfo);
         return ret;
@@ -1405,6 +1420,7 @@ do_add_counters(struct net *net, const void __user *user, unsigned int len,
         const struct xt_table_info *private;
         int ret = 0;
         const void *loc_cpu_entry;
+        struct ip6t_entry *iter;
 #ifdef CONFIG_COMPAT
         struct compat_xt_counters_info compat_tmp;
 
@@ -1463,11 +1479,9 @@ do_add_counters(struct net *net, const void __user *user, unsigned int len,
         curcpu = smp_processor_id();
         xt_info_wrlock(curcpu);
         loc_cpu_entry = private->entries[curcpu];
-        IP6T_ENTRY_ITERATE(loc_cpu_entry,
-                          private->size,
-                          add_counter_to_entry,
-                          paddc,
-                          &i);
+        xt_entry_foreach(iter, loc_cpu_entry, private->size)
+                if (add_counter_to_entry(iter, paddc, &i) != 0)
+                        break;
         xt_info_wrunlock(curcpu);
 
  unlock_up_free:
@@ -1753,8 +1767,10 @@ translate_compat_table(struct net *net,
         unsigned int i, j;
         struct xt_table_info *newinfo, *info;
         void *pos, *entry0, *entry1;
+        struct compat_ip6t_entry *iter0;
+        struct ip6t_entry *iter1;
         unsigned int size;
-        int ret;
+        int ret = 0;
 
         info = *pinfo;
         entry0 = *pentry0;
@@ -1771,11 +1787,13 @@ translate_compat_table(struct net *net,
         j = 0;
         xt_compat_lock(AF_INET6);
         /* Walk through entries, checking offsets. */
-        ret = COMPAT_IP6T_ENTRY_ITERATE(entry0, total_size,
-                                        check_compat_entry_size_and_hooks,
-                                        info, &size, entry0,
-                                        entry0 + total_size,
-                                        hook_entries, underflows, &j, name);
+        xt_entry_foreach(iter0, entry0, total_size) {
+                ret = check_compat_entry_size_and_hooks(iter0, info, &size,
+                      entry0, entry0 + total_size, hook_entries, underflows,
+                      &j, name);
+                if (ret != 0)
+                        break;
+        }
         if (ret != 0)
                 goto out_unlock;
 
@@ -1816,9 +1834,12 @@ translate_compat_table(struct net *net,
         entry1 = newinfo->entries[raw_smp_processor_id()];
         pos = entry1;
         size = total_size;
-        ret = COMPAT_IP6T_ENTRY_ITERATE(entry0, total_size,
-                                        compat_copy_entry_from_user,
-                                        &pos, &size, name, newinfo, entry1);
+        xt_entry_foreach(iter0, entry0, total_size) {
+                ret = compat_copy_entry_from_user(iter0, &pos,
+                      &size, name, newinfo, entry1);
+                if (ret != 0)
+                        break;
+        }
         xt_compat_flush_offsets(AF_INET6);
         xt_compat_unlock(AF_INET6);
         if (ret)
@@ -1829,13 +1850,28 @@ translate_compat_table(struct net *net,
                 goto free_newinfo;
 
         i = 0;
-        ret = IP6T_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
-                                 net, name, &i);
+        xt_entry_foreach(iter1, entry1, newinfo->size) {
+                ret = compat_check_entry(iter1, net, name, &i);
+                if (ret != 0)
+                        break;
+        }
         if (ret) {
+                /*
+                 * The first i matches need cleanup_entry (calls ->destroy)
+                 * because they had called ->check already. The other j-i
+                 * entries need only release.
+                 */
+                int skip = i;
                 j -= i;
-                COMPAT_IP6T_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
-                                                   compat_release_entry, &j);
-                IP6T_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, net, &i);
+                xt_entry_foreach(iter0, entry0, newinfo->size) {
+                        if (skip-- > 0)
+                                continue;
+                        if (compat_release_entry(iter0, &j) != 0)
+                                break;
+                }
+                xt_entry_foreach(iter1, entry1, newinfo->size)
+                        if (cleanup_entry(iter1, net, &i) != 0)
+                                break;
                 xt_free_table_info(newinfo);
                 return ret;
         }
@@ -1853,7 +1889,9 @@ translate_compat_table(struct net *net,
 free_newinfo:
         xt_free_table_info(newinfo);
 out:
-        COMPAT_IP6T_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
+        xt_entry_foreach(iter0, entry0, total_size)
+                if (compat_release_entry(iter0, &j) != 0)
+                        break;
         return ret;
 out_unlock:
         xt_compat_flush_offsets(AF_INET6);
@@ -1868,6 +1906,7 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
         struct compat_ip6t_replace tmp;
         struct xt_table_info *newinfo;
         void *loc_cpu_entry;
+        struct ip6t_entry *iter;
 
         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
                 return -EFAULT;
@@ -1906,7 +1945,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
         return 0;
 
  free_newinfo_untrans:
-        IP6T_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, net, NULL);
+        xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
+                if (cleanup_entry(iter, net, NULL) != 0)
+                        break;
  free_newinfo:
         xt_free_table_info(newinfo);
         return ret;
@@ -1955,6 +1996,7 @@ compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
         int ret = 0;
         const void *loc_cpu_entry;
         unsigned int i = 0;
+        struct ip6t_entry *iter;
 
         counters = alloc_counters(table);
         if (IS_ERR(counters))
@@ -1967,9 +2009,12 @@ compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
         loc_cpu_entry = private->entries[raw_smp_processor_id()];
         pos = userptr;
         size = total_size;
-        ret = IP6T_ENTRY_ITERATE(loc_cpu_entry, total_size,
-                                 compat_copy_entry_to_user,
-                                 &pos, &size, counters, &i);
+        xt_entry_foreach(iter, loc_cpu_entry, total_size) {
+                ret = compat_copy_entry_to_user(iter, &pos,
+                      &size, counters, &i);
+                if (ret != 0)
+                        break;
+        }
 
         vfree(counters);
         return ret;
@@ -2169,12 +2214,15 @@ void ip6t_unregister_table(struct net *net, struct xt_table *table)
         struct xt_table_info *private;
         void *loc_cpu_entry;
         struct module *table_owner = table->me;
+        struct ip6t_entry *iter;
 
         private = xt_unregister_table(table);
 
         /* Decrease module usage counts and free resources */
         loc_cpu_entry = private->entries[raw_smp_processor_id()];
-        IP6T_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, net, NULL);
+        xt_entry_foreach(iter, loc_cpu_entry, private->size)
+                if (cleanup_entry(iter, net, NULL) != 0)
+                        break;
         if (private->number > private->initial_entries)
                 module_put(table_owner);
         xt_free_table_info(private);