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

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This reverts commit 98d1bd802c.

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>
This commit is contained in:
Florian Westphal 2015-08-26 23:20:51 +02:00 committed by Pablo Neira Ayuso
parent 1b383bf912
commit 98dbbfc3f1
3 changed files with 25 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
net/ipv4/netfilter/arp_tables.c
View File

@ -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) {
/*

28
net/ipv4/netfilter/ip_tables.c
View File

@ -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) {
/*

23
net/ipv6/netfilter/ip6_tables.c
View File

@ -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) {
/*