netfilter: ipset: Use netlink callback dump args only

Instead of cb->data, use callback dump args only and introduce symbolic
names instead of plain numbers at accessing the argument members.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

5 files changed, 68 insertions, 54 deletions

diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h
index 7967516adc0d..c7174b816674 100644
--- a/include/linux/netfilter/ipset/ip_set.h
+++ b/include/linux/netfilter/ipset/ip_set.h
@@ -316,6 +316,16 @@ ip_set_init_counter(struct ip_set_counter *counter,
                 atomic64_set(&(counter)->packets, (long long)(ext->packets));
 }
 
+/* Netlink CB args */
+enum {
+        IPSET_CB_NET = 0,
+        IPSET_CB_DUMP,
+        IPSET_CB_INDEX,
+        IPSET_CB_ARG0,
+        IPSET_CB_ARG1,
+        IPSET_CB_ARG2,
+};
+
 /* register and unregister set references */
 extern ip_set_id_t ip_set_get_byname(struct net *net,
                                      const char *name, struct ip_set **set);
diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h b/net/netfilter/ipset/ip_set_bitmap_gen.h
index a13e15be7911..f2c7d83dc23f 100644
--- a/net/netfilter/ipset/ip_set_bitmap_gen.h
+++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
@@ -198,13 +198,14 @@ mtype_list(const struct ip_set *set,
         struct mtype *map = set->data;
         struct nlattr *adt, *nested;
         void *x;
-        u32 id, first = cb->args[2];
+        u32 id, first = cb->args[IPSET_CB_ARG0];
 
         adt = ipset_nest_start(skb, IPSET_ATTR_ADT);
         if (!adt)
                 return -EMSGSIZE;
-        for (; cb->args[2] < map->elements; cb->args[2]++) {
-                id = cb->args[2];
+        for (; cb->args[IPSET_CB_ARG0] < map->elements;
+             cb->args[IPSET_CB_ARG0]++) {
+                id = cb->args[IPSET_CB_ARG0];
                 x = get_ext(set, map, id);
                 if (!test_bit(id, map->members) ||
                     (SET_WITH_TIMEOUT(set) &&
@@ -231,14 +232,14 @@ mtype_list(const struct ip_set *set,
         ipset_nest_end(skb, adt);
 
         /* Set listing finished */
-        cb->args[2] = 0;
+        cb->args[IPSET_CB_ARG0] = 0;
 
         return 0;
 
 nla_put_failure:
         nla_nest_cancel(skb, nested);
         if (unlikely(id == first)) {
-                cb->args[2] = 0;
+                cb->args[IPSET_CB_ARG0] = 0;
                 return -EMSGSIZE;
         }
         ipset_nest_end(skb, adt);
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index dc9284bdd2dd..bac7e01df67f 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1182,10 +1182,12 @@ ip_set_swap(struct sock *ctnl, struct sk_buff *skb,
 static int
 ip_set_dump_done(struct netlink_callback *cb)
 {
-        struct ip_set_net *inst = (struct ip_set_net *)cb->data;
-        if (cb->args[2]) {
-                pr_debug("release set %s\n", nfnl_set(inst, cb->args[1])->name);
-                __ip_set_put_byindex(inst, (ip_set_id_t) cb->args[1]);
+        struct ip_set_net *inst = (struct ip_set_net *)cb->args[IPSET_CB_NET];
+        if (cb->args[IPSET_CB_ARG0]) {
+                pr_debug("release set %s\n",
+                         nfnl_set(inst, cb->args[IPSET_CB_INDEX])->name);
+                __ip_set_put_byindex(inst,
+                        (ip_set_id_t) cb->args[IPSET_CB_INDEX]);
         }
         return 0;
 }
@@ -1203,7 +1205,7 @@ dump_attrs(struct nlmsghdr *nlh)
 }
 
 static int
-dump_init(struct netlink_callback *cb)
+dump_init(struct netlink_callback *cb, struct ip_set_net *inst)
 {
         struct nlmsghdr *nlh = nlmsg_hdr(cb->skb);
         int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
@@ -1211,15 +1213,15 @@ dump_init(struct netlink_callback *cb)
         struct nlattr *attr = (void *)nlh + min_len;
         u32 dump_type;
         ip_set_id_t index;
-        struct ip_set_net *inst = (struct ip_set_net *)cb->data;
 
         /* Second pass, so parser can't fail */
         nla_parse(cda, IPSET_ATTR_CMD_MAX,
                   attr, nlh->nlmsg_len - min_len, ip_set_setname_policy);
 
-        /* cb->args[0] : dump single set/all sets
-         *         [1] : set index
-         *         [..]: type specific
+        /* cb->args[IPSET_CB_NET]:      net namespace
+         *         [IPSET_CB_DUMP]:     dump single set/all sets
+         *         [IPSET_CB_INDEX]:    set index
+         *         [IPSET_CB_ARG0]:     type specific
          */
 
         if (cda[IPSET_ATTR_SETNAME]) {
@@ -1231,7 +1233,7 @@ dump_init(struct netlink_callback *cb)
                         return -ENOENT;
 
                 dump_type = DUMP_ONE;
-                cb->args[1] = index;
+                cb->args[IPSET_CB_INDEX] = index;
         } else
                 dump_type = DUMP_ALL;
 
@@ -1239,7 +1241,8 @@ dump_init(struct netlink_callback *cb)
                 u32 f = ip_set_get_h32(cda[IPSET_ATTR_FLAGS]);
                 dump_type |= (f << 16);
         }
-        cb->args[0] = dump_type;
+        cb->args[IPSET_CB_NET] = (unsigned long)inst;
+        cb->args[IPSET_CB_DUMP] = dump_type;
 
         return 0;
 }
@@ -1251,12 +1254,12 @@ ip_set_dump_start(struct sk_buff *skb, struct netlink_callback *cb)
         struct ip_set *set = NULL;
         struct nlmsghdr *nlh = NULL;
         unsigned int flags = NETLINK_CB(cb->skb).portid ? NLM_F_MULTI : 0;
+        struct ip_set_net *inst = ip_set_pernet(sock_net(skb->sk));
         u32 dump_type, dump_flags;
         int ret = 0;
-        struct ip_set_net *inst = (struct ip_set_net *)cb->data;
 
-        if (!cb->args[0]) {
-                ret = dump_init(cb);
+        if (!cb->args[IPSET_CB_DUMP]) {
+                ret = dump_init(cb, inst);
                 if (ret < 0) {
                         nlh = nlmsg_hdr(cb->skb);
                         /* We have to create and send the error message
@@ -1267,17 +1270,18 @@ ip_set_dump_start(struct sk_buff *skb, struct netlink_callback *cb)
                 }
         }
 
-        if (cb->args[1] >= inst->ip_set_max)
+        if (cb->args[IPSET_CB_INDEX] >= inst->ip_set_max)
                 goto out;
 
-        dump_type = DUMP_TYPE(cb->args[0]);
-        dump_flags = DUMP_FLAGS(cb->args[0]);
+        dump_type = DUMP_TYPE(cb->args[IPSET_CB_DUMP]);
+        dump_flags = DUMP_FLAGS(cb->args[IPSET_CB_DUMP]);