On 07/14/2016, 10:15 AM, Jiri Slaby wrote: > From: Florian Westphal <[email protected]> > > 3.12-stable review patch. If anyone has any objections, please let me know. > > =============== > > commit 36472341017529e2b12573093cc0f68719300997 upstream.
I am now dropping this one. 3.12.62 will be released without that patch. After the performance issue is resolved, it will be requeued. > When we see a jump also check that the offset gets us to beginning of > a rule (an ipt_entry). > > The extra overhead is negible, even with absurd cases. > > 300k custom rules, 300k jumps to 'next' user chain: > [ plus one jump from INPUT to first userchain ]: > > Before: > real 0m24.874s > user 0m7.532s > sys 0m16.076s > > After: > real 0m27.464s > user 0m7.436s > sys 0m18.840s > > Signed-off-by: Florian Westphal <[email protected]> > Signed-off-by: Pablo Neira Ayuso <[email protected]> > Signed-off-by: Jiri Slaby <[email protected]> > --- > net/ipv4/netfilter/arp_tables.c | 17 +++++++++++++++++ > net/ipv4/netfilter/ip_tables.c | 17 +++++++++++++++++ > net/ipv6/netfilter/ip6_tables.c | 17 +++++++++++++++++ > 3 files changed, 51 insertions(+) > > diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c > index 7460b7bef3ab..473ec559ce7b 100644 > --- a/net/ipv4/netfilter/arp_tables.c > +++ b/net/ipv4/netfilter/arp_tables.c > @@ -358,6 +358,19 @@ static inline bool unconditional(const struct arpt_entry > *e) > memcmp(&e->arp, &uncond, sizeof(uncond)) == 0; > } > > +static bool find_jump_target(const struct xt_table_info *t, > + const void *entry0, > + const struct arpt_entry *target) > +{ > + struct arpt_entry *iter; > + > + xt_entry_foreach(iter, entry0, t->size) { > + if (iter == target) > + return true; > + } > + return false; > +} > + > /* Figures out from what hook each rule can be called: returns 0 if > * there are loops. Puts hook bitmask in comefrom. > */ > @@ -451,6 +464,10 @@ static int mark_source_chains(const struct xt_table_info > *newinfo, > /* This a jump; chase it. */ > duprintf("Jump rule %u -> %u\n", > pos, newpos); > + e = (struct arpt_entry *) > + (entry0 + newpos); > + if (!find_jump_target(newinfo, entry0, > e)) > + return 0; > } else { > /* ... this is a fallthru */ > newpos = pos + e->next_offset; > diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c > index 8fc22eed9603..dba9d8070d07 100644 > --- a/net/ipv4/netfilter/ip_tables.c > +++ b/net/ipv4/netfilter/ip_tables.c > @@ -434,6 +434,19 @@ ipt_do_table(struct sk_buff *skb, > #endif > } > > +static bool find_jump_target(const struct xt_table_info *t, > + const void *entry0, > + const struct ipt_entry *target) > +{ > + struct ipt_entry *iter; > + > + xt_entry_foreach(iter, entry0, t->size) { > + if (iter == target) > + return true; > + } > + return false; > +} > + > /* Figures out from what hook each rule can be called: returns 0 if > there are loops. Puts hook bitmask in comefrom. */ > static int > @@ -531,6 +544,10 @@ mark_source_chains(const struct xt_table_info *newinfo, > /* This a jump; chase it. */ > duprintf("Jump rule %u -> %u\n", > pos, newpos); > + e = (struct ipt_entry *) > + (entry0 + newpos); > + if (!find_jump_target(newinfo, entry0, > e)) > + return 0; > } else { > /* ... this is a fallthru */ > newpos = pos + e->next_offset; > diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c > index 63f7876c4f29..97a8d2525c26 100644 > --- a/net/ipv6/netfilter/ip6_tables.c > +++ b/net/ipv6/netfilter/ip6_tables.c > @@ -444,6 +444,19 @@ ip6t_do_table(struct sk_buff *skb, > #endif > } > > +static bool find_jump_target(const struct xt_table_info *t, > + const void *entry0, > + const struct ip6t_entry *target) > +{ > + struct ip6t_entry *iter; > + > + xt_entry_foreach(iter, entry0, t->size) { > + if (iter == target) > + return true; > + } > + return false; > +} > + > /* Figures out from what hook each rule can be called: returns 0 if > there are loops. Puts hook bitmask in comefrom. */ > static int > @@ -541,6 +554,10 @@ mark_source_chains(const struct xt_table_info *newinfo, > /* This a jump; chase it. */ > duprintf("Jump rule %u -> %u\n", > pos, newpos); > + e = (struct ip6t_entry *) > + (entry0 + newpos); > + if (!find_jump_target(newinfo, entry0, > e)) > + return 0; > } else { > /* ... this is a fallthru */ > newpos = pos + e->next_offset; >
