--- /dev/null
+--- a/include/linux/netfilter_ipv4/ip_tables.h
++++ b/include/linux/netfilter_ipv4/ip_tables.h
+@@ -93,6 +93,7 @@ struct ipt_ip {
+ #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
+ #define IPT_F_GOTO 0x02 /* Set if jump is a goto */
+ #define IPT_F_MASK 0x03 /* All possible flag bits mask. */
++#define IPT_F_NO_DEF_MATCH 0x80 /* Internal: no default match rules present */
+
+ /* Values for "inv" field in struct ipt_ip. */
+ #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -90,6 +90,9 @@ ip_packet_match(const struct iphdr *ip,
+
+ #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
+
++ if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
++ return true;
++
+ if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+ IPT_INV_SRCIP) ||
+ FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+@@ -143,6 +146,26 @@ ip_packet_match(const struct iphdr *ip,
+ return true;
+ }
+
++static void
++ip_checkdefault(struct ipt_ip *ip)
++{
++ static const char iface_mask[IFNAMSIZ] = {};
++
++ if (ip->invflags || ip->flags & IPT_F_FRAG)
++ return;
++
++ if (memcmp(ip->iniface_mask, iface_mask, IFNAMSIZ) != 0)
++ return;
++
++ if (memcmp(ip->outiface_mask, iface_mask, IFNAMSIZ) != 0)
++ return;
++
++ if (ip->proto)
++ return;
++
++ ip->flags |= IPT_F_NO_DEF_MATCH;
++}
++
+ static bool
+ ip_checkentry(const struct ipt_ip *ip)
+ {
+@@ -566,7 +589,7 @@ static void cleanup_match(struct xt_entr
+ }
+
+ static int
+-check_entry(const struct ipt_entry *e, const char *name)
++check_entry(struct ipt_entry *e, const char *name)
+ {
+ const struct xt_entry_target *t;
+
+@@ -575,6 +598,8 @@ check_entry(const struct ipt_entry *e, c
+ return -EINVAL;
+ }
+
++ ip_checkdefault(&e->ip);
++
+ if (e->target_offset + sizeof(struct xt_entry_target) >
+ e->next_offset)
+ return -EINVAL;
+@@ -936,6 +961,7 @@ copy_entries_to_user(unsigned int total_
+ const struct xt_table_info *private = table->private;
+ int ret = 0;
+ const void *loc_cpu_entry;
++ u8 flags;
+
+ counters = alloc_counters(table);
+ if (IS_ERR(counters))
+@@ -967,6 +993,14 @@ copy_entries_to_user(unsigned int total_
+ goto free_counters;
+ }
+
++ flags = e->ip.flags & IPT_F_MASK;
++ if (copy_to_user(userptr + off
++ + offsetof(struct ipt_entry, ip.flags),
++ &flags, sizeof(flags)) != 0) {
++ ret = -EFAULT;
++ goto free_counters;
++ }
++
+ for (i = sizeof(struct ipt_entry);
+ i < e->target_offset;
+ i += m->u.match_size) {
--- /dev/null
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -316,6 +316,33 @@ 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,
+@@ -339,6 +366,23 @@ ipt_do_table(struct sk_buff *skb,
+ ip = ip_hdr(skb);
+ indev = in ? in->name : nulldevname;
+ outdev = out ? out->name : nulldevname;
++
++ IP_NF_ASSERT(table->valid_hooks & (1 << hook));
++ xt_info_rdlock_bh();
++ private = table->private;
++ cpu = smp_processor_id();
++ table_base = private->entries[cpu];
++ jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
++ stackptr = per_cpu_ptr(private->stackptr, cpu);
++ origptr = *stackptr;
++
++ e = get_entry(table_base, private->hook_entry[hook]);
++ if (ipt_handle_default_rule(e, &verdict)) {
++ ADD_COUNTER(e->counters, skb->len, 1);
++ xt_info_rdunlock_bh();
++ return verdict;
++ }
++
+ /* 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
+@@ -353,17 +397,6 @@ ipt_do_table(struct sk_buff *skb,
+ acpar.family = NFPROTO_IPV4;
+ acpar.hooknum = hook;
+
+- IP_NF_ASSERT(table->valid_hooks & (1 << hook));
+- xt_info_rdlock_bh();
+- private = table->private;
+- cpu = smp_processor_id();
+- table_base = private->entries[cpu];
+- jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
+- stackptr = per_cpu_ptr(private->stackptr, cpu);
+- origptr = *stackptr;
+-
+- e = get_entry(table_base, private->hook_entry[hook]);
+-
+ pr_debug("Entering %s(hook %u); sp at %u (UF %p)\n",
+ table->name, hook, origptr,
+ get_entry(table_base, private->underflow[hook]));
--- /dev/null
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -93,9 +93,11 @@ ip_packet_match(const struct iphdr *ip,
+ if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
+ return true;
+
+- if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
++ if (FWINV(ipinfo->smsk.s_addr &&
++ (ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+ IPT_INV_SRCIP) ||
+- FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
++ FWINV(ipinfo->smsk.s_addr &&
++ (ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+ IPT_INV_DSTIP)) {
+ dprintf("Source or dest mismatch.\n");
+
--- /dev/null
+--- a/net/netfilter/nf_conntrack_proto_tcp.c
++++ b/net/netfilter/nf_conntrack_proto_tcp.c
+@@ -29,6 +29,9 @@
+ #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
+ #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
+
++/* Do not check the TCP window for incoming packets */
++static int nf_ct_tcp_no_window_check __read_mostly = 1;
++
+ /* "Be conservative in what you do,
+ be liberal in what you accept from others."
+ If it's non-zero, we mark only out of window RST segments as INVALID. */
+@@ -524,6 +527,9 @@ static bool tcp_in_window(const struct n
+ s16 receiver_offset;
+ bool res;
+
++ if (nf_ct_tcp_no_window_check)
++ return true;
++
+ /*
+ * Get the required data from the packet.
+ */
+@@ -1321,6 +1327,13 @@ static struct ctl_table tcp_sysctl_table
+ .proc_handler = proc_dointvec,
+ },
+ {
++ .procname = "nf_conntrack_tcp_no_window_check",
++ .data = &nf_ct_tcp_no_window_check,
++ .maxlen = sizeof(unsigned int),
++ .mode = 0644,
++ .proc_handler = proc_dointvec,
++ },
++ {
+ .procname = "nf_conntrack_tcp_be_liberal",
+ .data = &nf_ct_tcp_be_liberal,
+ .maxlen = sizeof(unsigned int),
--- /dev/null
+--- a/include/linux/netfilter_ipv4/ip_tables.h
++++ b/include/linux/netfilter_ipv4/ip_tables.h
+@@ -93,6 +93,7 @@ struct ipt_ip {
+ #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
+ #define IPT_F_GOTO 0x02 /* Set if jump is a goto */
+ #define IPT_F_MASK 0x03 /* All possible flag bits mask. */
++#define IPT_F_NO_DEF_MATCH 0x80 /* Internal: no default match rules present */
+
+ /* Values for "inv" field in struct ipt_ip. */
+ #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -81,6 +81,9 @@ ip_packet_match(const struct iphdr *ip,
+
+ #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
+
++ if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
++ return true;
++
+ if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+ IPT_INV_SRCIP) ||
+ FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+@@ -134,6 +137,26 @@ ip_packet_match(const struct iphdr *ip,
+ return true;
+ }
+
++static void
++ip_checkdefault(struct ipt_ip *ip)
++{
++ static const char iface_mask[IFNAMSIZ] = {};
++
++ if (ip->invflags || ip->flags & IPT_F_FRAG)
++ return;
++
++ if (memcmp(ip->iniface_mask, iface_mask, IFNAMSIZ) != 0)
++ return;
++
++ if (memcmp(ip->outiface_mask, iface_mask, IFNAMSIZ) != 0)
++ return;
++
++ if (ip->proto)
++ return;
++
++ ip->flags |= IPT_F_NO_DEF_MATCH;
++}
++
+ static bool
+ ip_checkentry(const struct ipt_ip *ip)
+ {
+@@ -561,7 +584,7 @@ static void cleanup_match(struct xt_entr
+ }
+
+ static int
+-check_entry(const struct ipt_entry *e, const char *name)
++check_entry(struct ipt_entry *e, const char *name)
+ {
+ const struct xt_entry_target *t;
+
+@@ -570,6 +593,8 @@ check_entry(const struct ipt_entry *e, c
+ return -EINVAL;
+ }
+
++ ip_checkdefault(&e->ip);
++
+ if (e->target_offset + sizeof(struct xt_entry_target) >
+ e->next_offset)
+ return -EINVAL;
+@@ -931,6 +956,7 @@ copy_entries_to_user(unsigned int total_
+ const struct xt_table_info *private = table->private;
+ int ret = 0;
+ const void *loc_cpu_entry;
++ u8 flags;
+
+ counters = alloc_counters(table);
+ if (IS_ERR(counters))
+@@ -962,6 +988,14 @@ copy_entries_to_user(unsigned int total_
+ goto free_counters;
+ }
+
++ flags = e->ip.flags & IPT_F_MASK;
++ if (copy_to_user(userptr + off
++ + offsetof(struct ipt_entry, ip.flags),
++ &flags, sizeof(flags)) != 0) {
++ ret = -EFAULT;
++ goto free_counters;
++ }
++
+ for (i = sizeof(struct ipt_entry);
+ i < e->target_offset;
+ i += m->u.match_size) {
--- /dev/null
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -307,6 +307,33 @@ 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,
+@@ -331,6 +358,25 @@ ipt_do_table(struct sk_buff *skb,
+ ip = ip_hdr(skb);
+ indev = in ? in->name : nulldevname;
+ outdev = out ? out->name : nulldevname;
++
++ IP_NF_ASSERT(table->valid_hooks & (1 << hook));
++ local_bh_disable();
++ addend = xt_write_recseq_begin();
++ private = table->private;
++ cpu = smp_processor_id();
++ table_base = private->entries[cpu];
++ jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
++ stackptr = per_cpu_ptr(private->stackptr, cpu);
++ origptr = *stackptr;
++
++ e = get_entry(table_base, private->hook_entry[hook]);
++ if (ipt_handle_default_rule(e, &verdict)) {
++ ADD_COUNTER(e->counters, skb->len, 1);
++ xt_write_recseq_end(addend);
++ local_bh_enable();
++ return verdict;
++ }
++
+ /* 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
+@@ -345,18 +391,6 @@ ipt_do_table(struct sk_buff *skb,
+ acpar.family = NFPROTO_IPV4;
+ acpar.hooknum = hook;
+
+- IP_NF_ASSERT(table->valid_hooks & (1 << hook));
+- local_bh_disable();
+- addend = xt_write_recseq_begin();
+- private = table->private;
+- cpu = smp_processor_id();
+- table_base = private->entries[cpu];
+- jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
+- stackptr = per_cpu_ptr(private->stackptr, cpu);
+- origptr = *stackptr;
+-
+- e = get_entry(table_base, private->hook_entry[hook]);
+-
+ pr_debug("Entering %s(hook %u); sp at %u (UF %p)\n",
+ table->name, hook, origptr,
+ get_entry(table_base, private->underflow[hook]));
--- /dev/null
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -84,9 +84,11 @@ ip_packet_match(const struct iphdr *ip,
+ if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
+ return true;
+
+- if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
++ if (FWINV(ipinfo->smsk.s_addr &&
++ (ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+ IPT_INV_SRCIP) ||
+- FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
++ FWINV(ipinfo->smsk.s_addr &&
++ (ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+ IPT_INV_DSTIP)) {
+ dprintf("Source or dest mismatch.\n");
+
--- /dev/null
+--- a/net/netfilter/nf_conntrack_proto_tcp.c
++++ b/net/netfilter/nf_conntrack_proto_tcp.c
+@@ -29,6 +29,9 @@
+ #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
+ #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
+
++/* Do not check the TCP window for incoming packets */
++static int nf_ct_tcp_no_window_check __read_mostly = 1;
++
+ /* "Be conservative in what you do,
+ be liberal in what you accept from others."
+ If it's non-zero, we mark only out of window RST segments as INVALID. */
+@@ -524,6 +527,9 @@ static bool tcp_in_window(const struct n
+ s16 receiver_offset;
+ bool res;
+
++ if (nf_ct_tcp_no_window_check)
++ return true;
++
+ /*
+ * Get the required data from the packet.
+ */
+@@ -1321,6 +1327,13 @@ static struct ctl_table tcp_sysctl_table
+ .proc_handler = proc_dointvec,
+ },
+ {
++ .procname = "nf_conntrack_tcp_no_window_check",
++ .data = &nf_ct_tcp_no_window_check,
++ .maxlen = sizeof(unsigned int),
++ .mode = 0644,
++ .proc_handler = proc_dointvec,
++ },
++ {
+ .procname = "nf_conntrack_tcp_be_liberal",
+ .data = &nf_ct_tcp_be_liberal,
+ .maxlen = sizeof(unsigned int),
projects / openwrt / staging / xback.git / commitdiff