Revert "netfilter: xtables: compute exact size needed for jumpstack"

This reverts commit 98d1bd802cdbc8f56868fae51edec13e86b59515.

mark_source_chains will not re-visit chains, so

*filter
:INPUT ACCEPT [365:25776]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [217:45832]
:t1 - [0:0]
:t2 - [0:0]
:t3 - [0:0]
:t4 - [0:0]
-A t1 -i lo -j t2
-A t2 -i lo -j t3
-A t3 -i lo -j t4
# -A INPUT -j t4
# -A INPUT -j t3
# -A INPUT -j t2
-A INPUT -j t1
COMMIT

Will compute a chain depth of 2 if the comments are removed.
Revert back to counting the number of chains for the time being.

Reported-by: Cong Wang <cwang@twopensource.com>
Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index c416cb3..8f87fc3 100644 (file)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -367,13 +367,10 @@ 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.
- *
- * Keeps track of largest call depth seen and stores it in newinfo->stacksize.
  */
-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 calldepth, max_calldepth = 0;
        unsigned int hook;
 
        /* No recursion; use packet counter to save back ptrs (reset
@@ -389,7 +386,6 @@ static int mark_source_chains(struct xt_table_info *newinfo,
 
                /* Set initial back pointer. */
                e->counters.pcnt = pos;
-               calldepth = 0;
 
                for (;;) {
                        const struct xt_standard_target *t
@@ -444,8 +440,6 @@ static int mark_source_chains(struct xt_table_info *newinfo,
                                        (entry0 + pos + size);
                                e->counters.pcnt = pos;
                                pos += size;
-                               if (calldepth > 0)
-                                       --calldepth;
                        } else {
                                int newpos = t->verdict;
 
@@ -460,10 +454,6 @@ static int mark_source_chains(struct xt_table_info *newinfo,
                                                return 0;
                                        }
 
-                                       if (entry0 + newpos != arpt_next_entry(e) &&
-                                           ++calldepth > max_calldepth)
-                                               max_calldepth = calldepth;
-
                                        /* This a jump; chase it. */
                                        duprintf("Jump rule %u -> %u\n",
                                                 pos, newpos);
@@ -480,7 +470,6 @@ static int mark_source_chains(struct xt_table_info *newinfo,
                next:
                duprintf("Finished chain %u\n", hook);
        }
-       newinfo->stacksize = max_calldepth;
        return 1;
 }
 
@@ -670,6 +659,9 @@ static int translate_table(struct xt_table_info *newinfo, void *entry0,
                if (ret != 0)
                        break;
                ++i;
+               if (strcmp(arpt_get_target(iter)->u.user.name,
+                   XT_ERROR_TARGET) == 0)
+                       ++newinfo->stacksize;
        }
        duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
        if (ret != 0)
@@ -1442,6 +1434,9 @@ static int translate_compat_table(const char *name,
                        break;
                }
                ++i;
+               if (strcmp(arpt_get_target(iter1)->u.user.name,
+                   XT_ERROR_TARGET) == 0)
+                       ++newinfo->stacksize;
        }
        if (ret) {
                /*

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 787f99e..b0a86e7 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -443,15 +443,11 @@ 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.
- *
- * Keeps track of largest call depth seen and stores it in newinfo->stacksize.
- */
+   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 calldepth, max_calldepth = 0;
        unsigned int hook;
 
        /* No recursion; use packet counter to save back ptrs (reset
@@ -465,7 +461,6 @@ mark_source_chains(struct xt_table_info *newinfo,
 
                /* Set initial back pointer. */
                e->counters.pcnt = pos;
-               calldepth = 0;
 
                for (;;) {
                        const struct xt_standard_target *t
@@ -527,9 +522,6 @@ mark_source_chains(struct xt_table_info *newinfo,
                                        (entry0 + pos + size);
                                e->counters.pcnt = pos;
                                pos += size;
-                               WARN_ON_ONCE(calldepth == 0);
-                               if (calldepth > 0)
-                                       --calldepth;
                        } else {
                                int newpos = t->verdict;
 
@@ -543,14 +535,9 @@ mark_source_chains(struct xt_table_info *newinfo,
                                                                newpos);
                                                return 0;
                                        }
-                                       if (entry0 + newpos != ipt_next_entry(e) &&
-                                           !(e->ip.flags & IPT_F_GOTO) &&
-                                           ++calldepth > max_calldepth)
-                                               max_calldepth = calldepth;
-
                                        /* This a jump; chase it. */
-                                       duprintf("Jump rule %u -> %u, calldepth %d\n",
-                                                pos, newpos, calldepth);
+                                       duprintf("Jump rule %u -> %u\n",
+                                                pos, newpos);
                                } else {
                                        /* ... this is a fallthru */
                                        newpos = pos + e->next_offset;
@@ -564,7 +551,6 @@ mark_source_chains(struct xt_table_info *newinfo,
                next:
                duprintf("Finished chain %u\n", hook);
        }
-       newinfo->stacksize = max_calldepth;
        return 1;
 }
 
@@ -844,6 +830,9 @@ translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
                if (ret != 0)
                        return ret;
                ++i;
+               if (strcmp(ipt_get_target(iter)->u.user.name,
+                   XT_ERROR_TARGET) == 0)
+                       ++newinfo->stacksize;
        }
 
        if (i != repl->num_entries) {
@@ -1759,6 +1748,9 @@ translate_compat_table(struct net *net,
                if (ret != 0)
                        break;
                ++i;
+               if (strcmp(ipt_get_target(iter1)->u.user.name,
+                   XT_ERROR_TARGET) == 0)
+                       ++newinfo->stacksize;
        }
        if (ret) {
                /*

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 4e21f80..0771991 100644 (file)
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -455,15 +455,11 @@ 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.
- *
- * Keeps track of largest call depth seen and stores it in newinfo->stacksize.
- */
+   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 calldepth, max_calldepth = 0;
        unsigned int hook;
 
        /* No recursion; use packet counter to save back ptrs (reset
@@ -477,7 +473,6 @@ mark_source_chains(struct xt_table_info *newinfo,
 
                /* Set initial back pointer. */
                e->counters.pcnt = pos;
-               calldepth = 0;
 
                for (;;) {
                        const struct xt_standard_target *t
@@ -539,8 +534,6 @@ mark_source_chains(struct xt_table_info *newinfo,
                                        (entry0 + pos + size);
                                e->counters.pcnt = pos;
                                pos += size;
-                               if (calldepth > 0)
-                                       --calldepth;
                        } else {
                                int newpos = t->verdict;
 
@@ -554,11 +547,6 @@ mark_source_chains(struct xt_table_info *newinfo,
                                                                newpos);
                                                return 0;
                                        }
-                                       if (entry0 + newpos != ip6t_next_entry(e) &&
-                                           !(e->ipv6.flags & IP6T_F_GOTO) &&
-                                           ++calldepth > max_calldepth)
-                                               max_calldepth = calldepth;
-
                                        /* This a jump; chase it. */
                                        duprintf("Jump rule %u -> %u\n",
                                                 pos, newpos);
@@ -575,7 +563,6 @@ mark_source_chains(struct xt_table_info *newinfo,
                next:
                duprintf("Finished chain %u\n", hook);
        }
-       newinfo->stacksize = max_calldepth;
        return 1;
 }
 
@@ -855,6 +842,9 @@ translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
                if (ret != 0)
                        return ret;
                ++i;
+               if (strcmp(ip6t_get_target(iter)->u.user.name,
+                   XT_ERROR_TARGET) == 0)
+                       ++newinfo->stacksize;
        }
 
        if (i != repl->num_entries) {
@@ -1767,6 +1757,9 @@ translate_compat_table(struct net *net,
                if (ret != 0)
                        break;
                ++i;
+               if (strcmp(ip6t_get_target(iter1)->u.user.name,
+                   XT_ERROR_TARGET) == 0)
+                       ++newinfo->stacksize;
        }
        if (ret) {
                /*