--- a/include/linux/netfilter_ipv4/ip_tables.h +++ b/include/linux/netfilter_ipv4/ip_tables.h @@ -62,6 +62,7 @@ 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 @@ -88,6 +88,9 @@ 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, @@ -138,13 +141,35 @@ ip_packet_match(const struct iphdr *ip, return false; } +#undef FWINV return true; } static bool -ip_checkentry(const struct ipt_ip *ip) +ip_checkentry(struct ipt_ip *ip) { - if (ip->flags & ~IPT_F_MASK) { +#define FWINV(bool, invflg) ((bool) || (ip->invflags & (invflg))) + + if (FWINV(ip->smsk.s_addr, IPT_INV_SRCIP) || + FWINV(ip->dmsk.s_addr, IPT_INV_DSTIP)) + goto has_match_rules; + + if (FWINV(!!((const unsigned long *)ip->iniface_mask)[0], + IPT_INV_VIA_IN) || + FWINV(!!((const unsigned long *)ip->outiface_mask)[0], + IPT_INV_VIA_OUT)) + goto has_match_rules; + + if (FWINV(ip->proto, IPT_INV_PROTO)) + goto has_match_rules; + + if (FWINV(ip->flags&IPT_F_FRAG, IPT_INV_FRAG)) + goto has_match_rules; + + ip->flags |= IPT_F_NO_DEF_MATCH; + +has_match_rules: + if (ip->flags & ~(IPT_F_MASK|IPT_F_NO_DEF_MATCH)) { duprintf("Unknown flag bits set: %08X\n", ip->flags & ~IPT_F_MASK); return false; @@ -154,6 +179,8 @@ ip_checkentry(const struct ipt_ip *ip) ip->invflags & ~IPT_INV_MASK); return false; } + +#undef FWINV return true; } @@ -196,7 +223,6 @@ static inline bool unconditional(const s static const struct ipt_ip uncond; return memcmp(ip, &uncond, sizeof(uncond)) == 0; -#undef FWINV } #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ @@ -321,8 +347,28 @@ ipt_do_table(struct sk_buff *skb, struct xt_match_param mtpar; struct xt_target_param tgpar; - /* Initialization */ ip = ip_hdr(skb); + + IP_NF_ASSERT(table->valid_hooks & (1 << hook)); + xt_info_rdlock_bh(); + private = table->private; + table_base = private->entries[smp_processor_id()]; + e = get_entry(table_base, private->hook_entry[hook]); + + if (e->target_offset <= sizeof(struct ipt_entry) && + (e->ip.flags & IPT_F_NO_DEF_MATCH)) { + struct ipt_entry_target *t = ipt_get_target(e); + if (!t->u.kernel.target->target) { + int v = ((struct ipt_standard_target *)t)->verdict; + if ((v < 0) && (v != IPT_RETURN)) { + ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1); + xt_info_rdunlock_bh(); + return (unsigned)(-v) - 1; + } + } + } + + /* Initialization */ indev = in ? in->name : nulldevname; outdev = out ? out->name : nulldevname; /* We handle fragments by dealing with the first fragment as @@ -339,13 +385,6 @@ ipt_do_table(struct sk_buff *skb, mtpar.family = tgpar.family = NFPROTO_IPV4; mtpar.hooknum = tgpar.hooknum = hook; - IP_NF_ASSERT(table->valid_hooks & (1 << hook)); - xt_info_rdlock_bh(); - private = table->private; - table_base = private->entries[smp_processor_id()]; - - e = get_entry(table_base, private->hook_entry[hook]); - /* For return from builtin chain */ back = get_entry(table_base, private->underflow[hook]); @@ -992,6 +1031,7 @@ copy_entries_to_user(unsigned int total_ unsigned int i; const struct ipt_entry_match *m; const struct ipt_entry_target *t; + u8 flags; e = (struct ipt_entry *)(loc_cpu_entry + off); if (copy_to_user(userptr + off @@ -1001,6 +1041,14 @@ copy_entries_to_user(unsigned int total_ ret = -EFAULT; goto free_counters; } + + flags = e->ip.flags & ~IPT_F_NO_DEF_MATCH; + 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;