kernel: add linux 5.10 support

[openwrt/openwrt.git] / target / linux / generic / pending-5.10 / 611-netfilter_match_bypass_default_table.patch

diff --git a/target/linux/generic/pending-5.10/611-netfilter_match_bypass_default_table.patch b/target/linux/generic/pending-5.10/611-netfilter_match_bypass_default_table.patch
new file mode 100644 (file)
index 0000000..1792534
--- /dev/null
+++ b/target/linux/generic/pending-5.10/611-netfilter_match_bypass_default_table.patch
@@ -0,0 +1,106 @@
+From: Felix Fietkau <nbd@nbd.name>
+Subject: netfilter: match bypass default table
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+ net/ipv4/netfilter/ip_tables.c | 79 +++++++++++++++++++++++++++++++-----------
+ 1 file changed, 58 insertions(+), 21 deletions(-)
+
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -246,6 +246,33 @@ struct ipt_entry *ipt_next_entry(const s
+       return (void *)entry + entry->next_offset;
+ }
+ 
++static bool
++ipt_handle_default_rule(struct ipt_entry *e, unsigned int *verdict)
++{
++      struct xt_entry_target *t;
++      struct xt_standard_target *st;
++
++      if (e->target_offset != sizeof(struct ipt_entry))
++              return false;
++
++      if (!(e->ip.flags & IPT_F_NO_DEF_MATCH))
++              return false;
++
++      t = ipt_get_target(e);
++      if (t->u.kernel.target->target)
++              return false;
++
++      st = (struct xt_standard_target *) t;
++      if (st->verdict == XT_RETURN)
++              return false;
++
++      if (st->verdict >= 0)
++              return false;
++
++      *verdict = (unsigned)(-st->verdict) - 1;
++      return true;
++}
++
+ /* Returns one of the generic firewall policies, like NF_ACCEPT. */
+ unsigned int
+ ipt_do_table(struct sk_buff *skb,
+@@ -266,27 +293,28 @@ ipt_do_table(struct sk_buff *skb,
+       unsigned int addend;
+ 
+       /* Initialization */
++      WARN_ON(!(table->valid_hooks & (1 << hook)));
++      local_bh_disable();
++      private = rcu_access_pointer(table->private);
++      cpu        = smp_processor_id();
++      table_base = private->entries;
++
++      e = get_entry(table_base, private->hook_entry[hook]);
++      if (ipt_handle_default_rule(e, &verdict)) {
++              struct xt_counters *counter;
++
++              counter = xt_get_this_cpu_counter(&e->counters);
++              ADD_COUNTER(*counter, skb->len, 1);
++              local_bh_enable();
++              return verdict;
++      }
++
+       stackidx = 0;
+       ip = ip_hdr(skb);
+       indev = state->in ? state->in->name : nulldevname;
+       outdev = state->out ? state->out->name : nulldevname;
+-      /* We handle fragments by dealing with the first fragment as
+-       * if it was a normal packet.  All other fragments are treated
+-       * normally, except that they will NEVER match rules that ask
+-       * things we don't know, ie. tcp syn flag or ports).  If the
+-       * rule is also a fragment-specific rule, non-fragments won't
+-       * match it. */
+-      acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
+-      acpar.thoff   = ip_hdrlen(skb);
+-      acpar.hotdrop = false;
+-      acpar.state   = state;
+ 
+-      WARN_ON(!(table->valid_hooks & (1 << hook)));
+-      local_bh_disable();
+       addend = xt_write_recseq_begin();
+-      private = rcu_access_pointer(table->private);
+-      cpu        = smp_processor_id();
+-      table_base = private->entries;
+       jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];
+ 
+       /* Switch to alternate jumpstack if we're being invoked via TEE.
+@@ -299,7 +327,16 @@ ipt_do_table(struct sk_buff *skb,
+       if (static_key_false(&xt_tee_enabled))
+               jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
+ 
+-      e = get_entry(table_base, private->hook_entry[hook]);
++      /* We handle fragments by dealing with the first fragment as
++       * if it was a normal packet.  All other fragments are treated
++       * normally, except that they will NEVER match rules that ask
++       * things we don't know, ie. tcp syn flag or ports).  If the
++       * rule is also a fragment-specific rule, non-fragments won't
++       * match it. */
++      acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
++      acpar.thoff   = ip_hdrlen(skb);
++      acpar.hotdrop = false;
++      acpar.state   = state;
+ 
+       do {
+               const struct xt_entry_target *t;