netfilter: nat: remove l4proto->unique_tuple
authorFlorian Westphal <fw@strlen.de>
Thu, 13 Dec 2018 15:01:29 +0000 (16:01 +0100)
committerPablo Neira Ayuso <pablo@netfilter.org>
Mon, 17 Dec 2018 22:33:04 +0000 (23:33 +0100)
fold remaining users (icmp, icmpv6, gre) into nf_nat_l4proto_unique_tuple.
The static-save of old incarnation of resolved key in gre and icmp is
removed as well, just use the prandom based offset like the others.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
include/net/netfilter/nf_nat_l4proto.h
net/ipv4/netfilter/nf_nat_proto_gre.c
net/ipv4/netfilter/nf_nat_proto_icmp.c
net/ipv6/netfilter/nf_nat_proto_icmpv6.c
net/netfilter/nf_nat_core.c
net/netfilter/nf_nat_proto_unknown.c

index 96f0794..4a0e4f0 100644 (file)
@@ -27,17 +27,6 @@ struct nf_nat_l4proto {
                         const union nf_conntrack_man_proto *min,
                         const union nf_conntrack_man_proto *max);
 
-       /* Alter the per-proto part of the tuple (depending on
-        * maniptype), to give a unique tuple in the given range if
-        * possible.  Per-protocol part of tuple is initialized to the
-        * incoming packet.
-        */
-       void (*unique_tuple)(const struct nf_nat_l3proto *l3proto,
-                            struct nf_conntrack_tuple *tuple,
-                            const struct nf_nat_range2 *range,
-                            enum nf_nat_manip_type maniptype,
-                            const struct nf_conn *ct);
-
        int (*nlattr_to_range)(struct nlattr *tb[],
                               struct nf_nat_range2 *range);
 };
index 00fda63..a04ff76 100644 (file)
@@ -37,49 +37,6 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
 MODULE_DESCRIPTION("Netfilter NAT protocol helper module for GRE");
 
-/* generate unique tuple ... */
-static void
-gre_unique_tuple(const struct nf_nat_l3proto *l3proto,
-                struct nf_conntrack_tuple *tuple,
-                const struct nf_nat_range2 *range,
-                enum nf_nat_manip_type maniptype,
-                const struct nf_conn *ct)
-{
-       static u_int16_t key;
-       __be16 *keyptr;
-       unsigned int min, i, range_size;
-
-       /* If there is no master conntrack we are not PPTP,
-          do not change tuples */
-       if (!ct->master)
-               return;
-
-       if (maniptype == NF_NAT_MANIP_SRC)
-               keyptr = &tuple->src.u.gre.key;
-       else
-               keyptr = &tuple->dst.u.gre.key;
-
-       if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
-               pr_debug("%p: NATing GRE PPTP\n", ct);
-               min = 1;
-               range_size = 0xffff;
-       } else {
-               min = ntohs(range->min_proto.gre.key);
-               range_size = ntohs(range->max_proto.gre.key) - min + 1;
-       }
-
-       pr_debug("min = %u, range_size = %u\n", min, range_size);
-
-       for (i = 0; ; ++key) {
-               *keyptr = htons(min + key % range_size);
-               if (++i == range_size || !nf_nat_used_tuple(tuple, ct))
-                       return;
-       }
-
-       pr_debug("%p: no NAT mapping\n", ct);
-       return;
-}
-
 /* manipulate a GRE packet according to maniptype */
 static bool
 gre_manip_pkt(struct sk_buff *skb,
@@ -124,7 +81,6 @@ static const struct nf_nat_l4proto gre = {
        .l4proto                = IPPROTO_GRE,
        .manip_pkt              = gre_manip_pkt,
        .in_range               = nf_nat_l4proto_in_range,
-       .unique_tuple           = gre_unique_tuple,
 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
        .nlattr_to_range        = nf_nat_l4proto_nlattr_to_range,
 #endif
index 6d7cf1d..70d7fab 100644 (file)
@@ -27,32 +27,6 @@ icmp_in_range(const struct nf_conntrack_tuple *tuple,
               ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
 }
 
-static void
-icmp_unique_tuple(const struct nf_nat_l3proto *l3proto,
-                 struct nf_conntrack_tuple *tuple,
-                 const struct nf_nat_range2 *range,
-                 enum nf_nat_manip_type maniptype,
-                 const struct nf_conn *ct)
-{
-       static u_int16_t id;
-       unsigned int range_size;
-       unsigned int i;
-
-       range_size = ntohs(range->max_proto.icmp.id) -
-                    ntohs(range->min_proto.icmp.id) + 1;
-       /* If no range specified... */
-       if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED))
-               range_size = 0xFFFF;
-
-       for (i = 0; ; ++id) {
-               tuple->src.u.icmp.id = htons(ntohs(range->min_proto.icmp.id) +
-                                            (id % range_size));
-               if (++i == range_size || !nf_nat_used_tuple(tuple, ct))
-                       return;
-       }
-       return;
-}
-
 static bool
 icmp_manip_pkt(struct sk_buff *skb,
               const struct nf_nat_l3proto *l3proto,
@@ -76,7 +50,6 @@ const struct nf_nat_l4proto nf_nat_l4proto_icmp = {
        .l4proto                = IPPROTO_ICMP,
        .manip_pkt              = icmp_manip_pkt,
        .in_range               = icmp_in_range,
-       .unique_tuple           = icmp_unique_tuple,
 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
        .nlattr_to_range        = nf_nat_l4proto_nlattr_to_range,
 #endif
index d9bf42b..491361b 100644 (file)
@@ -29,31 +29,6 @@ icmpv6_in_range(const struct nf_conntrack_tuple *tuple,
               ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
 }
 
-static void
-icmpv6_unique_tuple(const struct nf_nat_l3proto *l3proto,
-                   struct nf_conntrack_tuple *tuple,
-                   const struct nf_nat_range2 *range,
-                   enum nf_nat_manip_type maniptype,
-                   const struct nf_conn *ct)
-{
-       static u16 id;
-       unsigned int range_size;
-       unsigned int i;
-
-       range_size = ntohs(range->max_proto.icmp.id) -
-                    ntohs(range->min_proto.icmp.id) + 1;
-
-       if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED))
-               range_size = 0xffff;
-
-       for (i = 0; ; ++id) {
-               tuple->src.u.icmp.id = htons(ntohs(range->min_proto.icmp.id) +
-                                            (id % range_size));
-               if (++i == range_size || !nf_nat_used_tuple(tuple, ct))
-                       return;
-       }
-}
-
 static bool
 icmpv6_manip_pkt(struct sk_buff *skb,
                 const struct nf_nat_l3proto *l3proto,
@@ -83,7 +58,6 @@ const struct nf_nat_l4proto nf_nat_l4proto_icmpv6 = {
        .l4proto                = IPPROTO_ICMPV6,
        .manip_pkt              = icmpv6_manip_pkt,
        .in_range               = icmpv6_in_range,
-       .unique_tuple           = icmpv6_unique_tuple,
 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
        .nlattr_to_range        = nf_nat_l4proto_nlattr_to_range,
 #endif
index 0c0f012..763a92e 100644 (file)
@@ -310,20 +310,65 @@ find_best_ips_proto(const struct nf_conntrack_zone *zone,
        }
 }
 
+/* Alter the per-proto part of the tuple (depending on maniptype), to
+ * give a unique tuple in the given range if possible.
+ *
+ * Per-protocol part of tuple is initialized to the incoming packet.
+ */
 static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
                                        const struct nf_nat_range2 *range,
                                        enum nf_nat_manip_type maniptype,
                                        const struct nf_conn *ct)
 {
        unsigned int range_size, min, max, i, attempts;
-       __be16 *portptr;
+       __be16 *keyptr;
        u16 off;
        static const unsigned int max_attempts = 128;
 
-       if (maniptype == NF_NAT_MANIP_SRC)
-               portptr = &tuple->src.u.all;
-       else
-               portptr = &tuple->dst.u.all;
+       switch (tuple->dst.protonum) {
+       case IPPROTO_ICMP: /* fallthrough */
+       case IPPROTO_ICMPV6:
+               /* id is same for either direction... */
+               keyptr = &tuple->src.u.icmp.id;
+               min = range->min_proto.icmp.id;
+               range_size = ntohs(range->max_proto.icmp.id) -
+                            ntohs(range->min_proto.icmp.id) + 1;
+               goto find_free_id;
+#if IS_ENABLED(CONFIG_NF_CT_PROTO_GRE)
+       case IPPROTO_GRE:
+               /* If there is no master conntrack we are not PPTP,
+                  do not change tuples */
+               if (!ct->master)
+                       return;
+
+               if (maniptype == NF_NAT_MANIP_SRC)
+                       keyptr = &tuple->src.u.gre.key;
+               else
+                       keyptr = &tuple->dst.u.gre.key;
+
+               if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
+                       min = 1;
+                       range_size = 65535;
+               } else {
+                       min = ntohs(range->min_proto.gre.key);
+                       range_size = ntohs(range->max_proto.gre.key) - min + 1;
+               }
+               goto find_free_id;
+#endif
+       case IPPROTO_UDP:       /* fallthrough */
+       case IPPROTO_UDPLITE:   /* fallthrough */
+       case IPPROTO_TCP:       /* fallthrough */
+       case IPPROTO_SCTP:      /* fallthrough */
+       case IPPROTO_DCCP:      /* fallthrough */
+               if (maniptype == NF_NAT_MANIP_SRC)
+                       keyptr = &tuple->src.u.all;
+               else
+                       keyptr = &tuple->dst.u.all;
+
+               break;
+       default:
+               return;
+       }
 
        /* If no range specified... */
        if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
@@ -331,9 +376,9 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
                if (maniptype == NF_NAT_MANIP_DST)
                        return;
 
-               if (ntohs(*portptr) < 1024) {
+               if (ntohs(*keyptr) < 1024) {
                        /* Loose convention: >> 512 is credential passing */
-                       if (ntohs(*portptr) < 512) {
+                       if (ntohs(*keyptr) < 512) {
                                min = 1;
                                range_size = 511 - min + 1;
                        } else {
@@ -352,8 +397,9 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
                range_size = max - min + 1;
        }
 
+find_free_id:
        if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
-               off = (ntohs(*portptr) - ntohs(range->base_proto.all));
+               off = (ntohs(*keyptr) - ntohs(range->base_proto.all));
        else
                off = prandom_u32();
 
@@ -369,7 +415,7 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
         */
 another_round:
        for (i = 0; i < attempts; i++, off++) {
-               *portptr = htons(min + off % range_size);
+               *keyptr = htons(min + off % range_size);
                if (!nf_nat_used_tuple(tuple, ct))
                        return;
        }
@@ -454,10 +500,7 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple,
        }
 
        /* Last chance: get protocol to try to obtain unique tuple. */
-       if (l4proto->unique_tuple)
-               l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
-       else
-               nf_nat_l4proto_unique_tuple(tuple, range, maniptype, ct);
+       nf_nat_l4proto_unique_tuple(tuple, range, maniptype, ct);
 out:
        rcu_read_unlock();
 }
index c5db3e2..16b6678 100644 (file)
@@ -25,18 +25,6 @@ static bool unknown_in_range(const struct nf_conntrack_tuple *tuple,
        return true;
 }
 
-static void unknown_unique_tuple(const struct nf_nat_l3proto *l3proto,
-                                struct nf_conntrack_tuple *tuple,
-                                const struct nf_nat_range2 *range,
-                                enum nf_nat_manip_type maniptype,
-                                const struct nf_conn *ct)
-{
-       /* Sorry: we can't help you; if it's not unique, we can't frob
-        * anything.
-        */
-       return;
-}
-
 static bool
 unknown_manip_pkt(struct sk_buff *skb,
                  const struct nf_nat_l3proto *l3proto,
@@ -50,5 +38,4 @@ unknown_manip_pkt(struct sk_buff *skb,
 const struct nf_nat_l4proto nf_nat_l4proto_unknown = {
        .manip_pkt              = unknown_manip_pkt,
        .in_range               = unknown_in_range,
-       .unique_tuple           = unknown_unique_tuple,
 };