Add support for source-specific IPv6 routes to BIRD core

This patch adds support for source-specific IPv6 routes to BIRD core.
This is based on Dean Luga's original patch, with the review comments
addressed. SADR support is added to network address parsing in confbase.Y
and to the kernel protocol on Linux.

Currently there is no way to mix source-specific and non-source-specific
routes (i.e., SADR tables cannot be connected to non-SADR tables).

Thanks to Toke Hoiland-Jorgensen for the original patch.
Minor changes by Ondrej Santiago Zajicek.

1 files changed, 81 insertions, 9 deletions

diff --git a/lib/net.h b/lib/net.h
index 69f00641..ad4000fd 100644
--- a/lib/net.h
+++ b/lib/net.h
@@ -21,8 +21,9 @@
 #define NET_ROA6	6
 #define NET_FLOW4	7
 #define NET_FLOW6	8
-#define NET_MPLS	9
-#define NET_MAX		10
+#define NET_IP6_SADR	9
+#define NET_MPLS	10
+#define NET_MAX		11
 
 #define NB_IP4		(1 << NET_IP4)
 #define NB_IP6		(1 << NET_IP6)
@@ -32,12 +33,13 @@
 #define NB_ROA6		(1 << NET_ROA6)
 #define NB_FLOW4	(1 << NET_FLOW4)
 #define NB_FLOW6	(1 << NET_FLOW6)
+#define NB_IP6_SADR	(1 << NET_IP6_SADR)
 #define NB_MPLS		(1 << NET_MPLS)
 
 #define NB_IP		(NB_IP4 | NB_IP6)
 #define NB_VPN		(NB_VPN4 | NB_VPN6)
 #define NB_FLOW		(NB_FLOW4 | NB_FLOW6)
-#define NB_DEST		(NB_IP | NB_VPN | NB_MPLS)
+#define NB_DEST		(NB_IP | NB_IP6_SADR | NB_VPN | NB_MPLS)
 #define NB_ANY		0xffffffff
 
 
@@ -121,6 +123,15 @@ typedef struct net_addr_mpls {
   u32 label;
 } net_addr_mpls;
 
+typedef struct net_addr_ip6_sadr {
+  u8 type;
+  u8 dst_pxlen;
+  u16 length;
+  ip6_addr dst_prefix;
+  s32 src_pxlen; /* s32 to avoid padding */
+  ip6_addr src_prefix;
+} net_addr_ip6_sadr;
+
 typedef union net_addr_union {
   net_addr n;
   net_addr_ip4 ip4;
@@ -131,6 +142,7 @@ typedef union net_addr_union {
   net_addr_roa6 roa6;
   net_addr_flow4 flow4;
   net_addr_flow6 flow6;
+  net_addr_ip6_sadr ip6_sadr;
   net_addr_mpls mpls;
 } net_addr_union;
 
@@ -167,6 +179,9 @@ extern const u16 net_max_text_length[];
 #define NET_ADDR_FLOW6(prefix,pxlen,dlen) \
   ((net_addr_flow6) { NET_FLOW6, pxlen, sizeof(net_addr_ip6) + dlen, prefix })
 
+#define NET_ADDR_IP6_SADR(dst_prefix,dst_pxlen,src_prefix,src_pxlen) \
+  ((net_addr_ip6_sadr) { NET_IP6_SADR, dst_pxlen, sizeof(net_addr_ip6_sadr), dst_prefix, src_pxlen, src_prefix })
+
 #define NET_ADDR_MPLS(label) \
   ((net_addr_mpls) { NET_MPLS, 20, sizeof(net_addr_mpls), label })
 
@@ -189,6 +204,9 @@ static inline void net_fill_roa4(net_addr *a, ip4_addr prefix, uint pxlen, uint
 static inline void net_fill_roa6(net_addr *a, ip6_addr prefix, uint pxlen, uint max_pxlen, u32 asn)
 { *(net_addr_roa6 *)a = NET_ADDR_ROA6(prefix, pxlen, max_pxlen, asn); }
 
+static inline void net_fill_ip6_sadr(net_addr *a, ip6_addr dst_prefix, uint dst_pxlen, ip6_addr src_prefix, uint src_pxlen)
+{ *(net_addr_ip6_sadr *)a = NET_ADDR_IP6_SADR(dst_prefix, dst_pxlen, src_prefix, src_pxlen); }
+
 static inline void net_fill_mpls(net_addr *a, u32 label)
 { *(net_addr_mpls *)a = NET_ADDR_MPLS(label); }
 
@@ -222,6 +240,16 @@ static inline void net_fill_flow6(net_addr *a, ip6_addr prefix, uint pxlen, byte
   memcpy(f->data, data, dlen);
 }
 
+/* Make NET_IP6_SADR from NET_IP6, assuming there is enough space */
+static inline void net_make_ip6_sadr(net_addr *a)
+{
+  net_addr_ip6_sadr *n = (void *) a;
+  n->type = NET_IP6_SADR;
+  n->length = sizeof(net_addr_ip6_sadr);
+  n->src_pxlen = 0;
+  n->src_prefix = IP6_NONE;
+}
+
 static inline int net_val_match(u8 type, u32 mask)
 { return !!((1 << type) & mask); }
 
@@ -261,6 +289,7 @@ static inline ip_addr net_prefix(const net_addr *a)
   case NET_VPN6:
   case NET_ROA6:
   case NET_FLOW6:
+  case NET_IP6_SADR:
     return ipa_from_ip6(net6_prefix(a));
 
   case NET_MPLS:
@@ -328,6 +357,9 @@ static inline int net_equal_flow4(const net_addr_flow4 *a, const net_addr_flow4
 static inline int net_equal_flow6(const net_addr_flow6 *a, const net_addr_flow6 *b)
 { return net_equal((const net_addr *) a, (const net_addr *) b); }
 
+static inline int net_equal_ip6_sadr(const net_addr_ip6_sadr *a, const net_addr_ip6_sadr *b)
+{ return !memcmp(a, b, sizeof(net_addr_ip6_sadr)); }
+
 static inline int net_equal_mpls(const net_addr_mpls *a, const net_addr_mpls *b)
 { return !memcmp(a, b, sizeof(net_addr_mpls)); }
 
@@ -338,6 +370,12 @@ static inline int net_equal_prefix_roa4(const net_addr_roa4 *a, const net_addr_r
 static inline int net_equal_prefix_roa6(const net_addr_roa6 *a, const net_addr_roa6 *b)
 { return ip6_equal(a->prefix, b->prefix) && (a->pxlen == b->pxlen); }
 
+static inline int net_equal_dst_ip6_sadr(const net_addr_ip6_sadr *a, const net_addr_ip6_sadr *b)
+{ return ip6_equal(a->dst_prefix, b->dst_prefix) && (a->dst_pxlen == b->dst_pxlen); }
+
+static inline int net_equal_src_ip6_sadr(const net_addr_ip6_sadr *a, const net_addr_ip6_sadr *b)
+{ return ip6_equal(a->src_prefix, b->src_prefix) && (a->src_pxlen == b->src_pxlen); }
+
 
 static inline int net_zero_ip4(const net_addr_ip4 *a)
 { return !a->pxlen && ip4_zero(a->prefix); }
@@ -391,6 +429,13 @@ static inline int net_compare_flow4(const net_addr_flow4 *a, const net_addr_flow
 static inline int net_compare_flow6(const net_addr_flow6 *a, const net_addr_flow6 *b)
 { return ip6_compare(a->prefix, b->prefix) ?: uint_cmp(a->pxlen, b->pxlen) ?: uint_cmp(a->length, b->length) ?: memcmp(a->data, b->data, a->length - sizeof(net_addr_flow6)); }
 
+static inline int net_compare_ip6_sadr(const net_addr_ip6_sadr *a, const net_addr_ip6_sadr *b)
+{
+  return
+    ip6_compare(a->dst_prefix, b->dst_prefix) ?: uint_cmp(a->dst_pxlen, b->dst_pxlen) ?:
+    ip6_compare(a->src_prefix, b->src_prefix) ?: uint_cmp(a->src_pxlen, b->src_pxlen);
+}
+
 static inline int net_compare_mpls(const net_addr_mpls *a, const net_addr_mpls *b)
 { return uint_cmp(a->label, b->label); }
 
@@ -424,6 +469,9 @@ static inline void net_copy_flow4(net_addr_flow4 *dst, const net_addr_flow4 *src
 static inline void net_copy_flow6(net_addr_flow6 *dst, const net_addr_flow6 *src)
 { memcpy(dst, src, src->length); }
 
+static inline void net_copy_ip6_sadr(net_addr_ip6_sadr *dst, const net_addr_ip6_sadr *src)
+{ memcpy(dst, src, sizeof(net_addr_ip6_sadr)); }
+
 static inline void net_copy_mpls(net_addr_mpls *dst, const net_addr_mpls *src)
 { memcpy(dst, src, sizeof(net_addr_mpls)); }
 
@@ -456,6 +504,9 @@ static inline u32 net_hash_flow4(const net_addr_flow4 *n)
 static inline u32 net_hash_flow6(const net_addr_flow6 *n)
 { return ip6_hash(n->prefix) ^ ((u32) n->pxlen << 26); }
 
+static inline u32 net_hash_ip6_sadr(const net_addr_ip6_sadr *n)
+{ return net_hash_ip6((net_addr_ip6 *) n); }
+
 static inline u32 net_hash_mpls(const net_addr_mpls *n)
 { return n->label; }
 
@@ -508,6 +559,9 @@ static inline int net_validate_flow6(const net_addr_flow6 *n)
 static inline int net_validate_mpls(const net_addr_mpls *n)
 { return n->label < (1 << 20); }
 
+static inline int net_validate_ip6_sadr(const net_addr_ip6_sadr *n)
+{ return net_validate_px6(n->dst_prefix, n->dst_pxlen) && net_validate_px6(n->src_prefix, n->src_pxlen); }
+
 int net_validate(const net_addr *N);
 
 
@@ -523,6 +577,12 @@ static inline void net_normalize_vpn4(net_addr_vpn4 *n)
 static inline void net_normalize_vpn6(net_addr_vpn6 *n)
 { net_normalize_ip6((net_addr_ip6 *) n); }
 
+static inline void net_normalize_ip6_sadr(net_addr_ip6_sadr *n)
+{
+  n->dst_prefix = ip6_and(n->dst_prefix, ip6_mkmask(n->dst_pxlen));
+  n->src_prefix = ip6_and(n->src_prefix, ip6_mkmask(n->src_pxlen));
+}
+
 void net_normalize(net_addr *N);
 
 
@@ -530,17 +590,29 @@ int net_classify(const net_addr *N);
 int net_format(const net_addr *N, char *buf, int buflen);
 int rd_format(const u64 rd, char *buf, int buflen);
 
-static inline int ipa_in_net_ip4(ip4_addr a, const net_addr_ip4 *n)
-{ return ip4_zero(ip4_and(ip4_xor(a, n->prefix), ip4_mkmask(n->pxlen))); }
+static inline int ipa_in_px4(ip4_addr a, ip4_addr prefix, uint pxlen)
+{ return ip4_zero(ip4_and(ip4_xor(a, prefix), ip4_mkmask(pxlen))); }
 
-static inline int net_in_net_ip4(const net_addr_ip4 *a, const net_addr_ip4 *b)
-{ return (a->pxlen >= b->pxlen) && ipa_in_net_ip4(a->prefix, b); }
+static inline int ipa_in_px6(ip6_addr a, ip6_addr prefix, uint pxlen)
+{ return ip6_zero(ip6_and(ip6_xor(a, prefix), ip6_mkmask(pxlen))); }
+
+static inline int ipa_in_net_ip4(ip4_addr a, const net_addr_ip4 *n)
+{ return ipa_in_px4(a, n->prefix, n->pxlen); }
 
 static inline int ipa_in_net_ip6(ip6_addr a, const net_addr_ip6 *n)
-{ return ip6_zero(ip6_and(ip6_xor(a, n->prefix), ip6_mkmask(n->pxlen))); }
+{ return ipa_in_px6(a, n->prefix, n->pxlen); }
+
+static inline int net_in_net_ip4(const net_addr_ip4 *a, const net_addr_ip4 *b)
+{ return (a->pxlen >= b->pxlen) && ipa_in_px4(a->prefix, b->prefix, b->pxlen); }
 
 static inline int net_in_net_ip6(const net_addr_ip6 *a, const net_addr_ip6 *b)
-{ return (a->pxlen >= b->pxlen) && ipa_in_net_ip6(a->prefix, b); }
+{ return (a->pxlen >= b->pxlen) && ipa_in_px6(a->prefix, b->prefix, b->pxlen); }
+
+static inline int net_in_net_dst_ip6_sadr(const net_addr_ip6_sadr *a, const net_addr_ip6_sadr *b)
+{ return (a->dst_pxlen >= b->dst_pxlen) && ipa_in_px6(a->dst_prefix, b->dst_prefix, b->dst_pxlen); }
+
+static inline int net_in_net_src_ip6_sadr(const net_addr_ip6_sadr *a, const net_addr_ip6_sadr *b)
+{ return (a->src_pxlen >= b->src_pxlen) && ipa_in_px6(a->src_prefix, b->src_prefix, b->src_pxlen); }
 
 int ipa_in_netX(const ip_addr A, const net_addr *N);
 int net_in_netX(const net_addr *A, const net_addr *N);