ioam: manycast using iOAM and SR (VPP-628)

Change-Id: I6d2afda991d771fb4a89fc3f6544f8e940a9b9f0
Signed-off-by: Shwetha Bhandari <shwethab@cisco.com>

5 files changed, 172 insertions, 78 deletions

diff --git a/src/vnet/fib/fib_entry.h b/src/vnet/fib/fib_entry.h
index f258b755741..9dfb8127124 100644
--- a/src/vnet/fib/fib_entry.h
+++ b/src/vnet/fib/fib_entry.h
@@ -188,9 +188,14 @@ typedef enum fib_entry_attribute_t_ {
      */
     FIB_ENTRY_ATTRIBUTE_LOCAL,
     /**
+     * The prefix/address exempted from loose uRPF check
+     * To be used with caution
+     */
+    FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT,
+    /**
      * Marker. add new entries before this one.
      */
-    FIB_ENTRY_ATTRIBUTE_LAST = FIB_ENTRY_ATTRIBUTE_LOCAL,
+    FIB_ENTRY_ATTRIBUTE_LAST = FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT,
 } fib_entry_attribute_t;
 
 /**
@@ -205,6 +210,7 @@ typedef enum fib_entry_attribute_t_ {
     [FIB_ENTRY_ATTRIBUTE_DROP]      = "drop",		\
     [FIB_ENTRY_ATTRIBUTE_EXCLUSIVE] = "exclusive",      \
     [FIB_ENTRY_ATTRIBUTE_LOCAL]     = "local",		\
+    [FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT] = "uRPF-exempt"   \
 }
 
 #define FOR_EACH_FIB_ATTRIBUTE(_item)			\
@@ -220,6 +226,7 @@ typedef enum fib_entry_flag_t_ {
     FIB_ENTRY_FLAG_EXCLUSIVE = (1 << FIB_ENTRY_ATTRIBUTE_EXCLUSIVE),
     FIB_ENTRY_FLAG_LOCAL     = (1 << FIB_ENTRY_ATTRIBUTE_LOCAL),
     FIB_ENTRY_FLAG_IMPORT    = (1 << FIB_ENTRY_ATTRIBUTE_IMPORT),
+    FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT = (1 << FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT),
 } __attribute__((packed)) fib_entry_flag_t;
 
 /**
diff --git a/src/vnet/fib/fib_entry_src.c b/src/vnet/fib/fib_entry_src.c
index 6f5b7fee485..feb232df7f1 100644
--- a/src/vnet/fib/fib_entry_src.c
+++ b/src/vnet/fib/fib_entry_src.c
@@ -446,8 +446,9 @@ fib_entry_src_mk_lb (fib_entry_t *fib_entry,
      */
     index_t ui = fib_path_list_get_urpf(esrc->fes_pl);
 
-    if (fib_entry_is_sourced(fib_entry_get_index(fib_entry),
-			     FIB_SOURCE_URPF_EXEMPT) &&
+    if ((fib_entry_is_sourced(fib_entry_get_index(fib_entry),
+			      FIB_SOURCE_URPF_EXEMPT) ||
+	 (esrc->fes_entry_flags & FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT))&&
 	(0 == fib_urpf_check_size(ui)))
     {
 	/*
diff --git a/src/vnet/ip/ip6.h b/src/vnet/ip/ip6.h
index 2615fbfab02..cf40fbb37aa 100644
--- a/src/vnet/ip/ip6.h
+++ b/src/vnet/ip/ip6.h
@@ -474,6 +474,84 @@ ip6_compute_flow_hash (const ip6_header_t * ip,
   return (u32) c;
 }
 
+/* ip6_locate_header
+ *
+ * This function is to search for the header specified by the protocol number
+ * in find_hdr_type.
+ * This is used to locate a specific IPv6 extension header
+ * or to find transport layer header.
+ *   1. If the find_hdr_type < 0 then it finds and returns the protocol number and
+ *   offset stored in *offset of the transport or ESP header in the chain if
+ *   found.
+ *   2. If a header with find_hdr_type > 0 protocol number is found then the
+ *      offset is stored in *offset and protocol number of the header is
+ *      returned.
+ *   3. If find_hdr_type is not found or packet is malformed or
+ *      it is a non-first fragment -1 is returned.
+ */
+always_inline int
+ip6_locate_header (vlib_buffer_t * p0,
+		   ip6_header_t * ip0, int find_hdr_type, u32 * offset)
+{
+  u8 next_proto = ip0->protocol;
+  u8 *next_header;
+  u8 done = 0;
+  u32 cur_offset;
+  u8 *temp_nxthdr = 0;
+  u32 exthdr_len = 0;
+
+  next_header = ip6_next_header (ip0);
+  cur_offset = sizeof (ip6_header_t);
+  while (1)
+    {
+      done = (next_proto == find_hdr_type);
+      if (PREDICT_FALSE
+	  (next_header >=
+	   (u8 *) vlib_buffer_get_current (p0) + p0->current_length))
+	{
+	  //A malicious packet could set an extension header with a too big size
+	  return (-1);
+	}
+      if (done)
+	break;
+      if ((!ip6_ext_hdr (next_proto)) || next_proto == IP_PROTOCOL_IP6_NONXT)
+	{
+	  if (find_hdr_type < 0)
+	    break;
+	  return -1;
+	}
+      if (next_proto == IP_PROTOCOL_IPV6_FRAGMENTATION)
+	{
+	  ip6_frag_hdr_t *frag_hdr = (ip6_frag_hdr_t *) next_header;
+	  u16 frag_off = ip6_frag_hdr_offset (frag_hdr);
+	  /* Non first fragment return -1 */
+	  if (frag_off)
+	    return (-1);
+	  exthdr_len = sizeof (ip6_frag_hdr_t);
+	  temp_nxthdr = next_header + exthdr_len;
+	}
+      else if (next_proto == IP_PROTOCOL_IPSEC_AH)
+	{
+	  exthdr_len =
+	    ip6_ext_authhdr_len (((ip6_ext_header_t *) next_header));
+	  temp_nxthdr = next_header + exthdr_len;
+	}
+      else
+	{
+	  exthdr_len =
+	    ip6_ext_header_len (((ip6_ext_header_t *) next_header));
+	  temp_nxthdr = next_header + exthdr_len;
+	}
+      next_proto = ((ip6_ext_header_t *) next_header)->next_hdr;
+      next_header = temp_nxthdr;
+      cur_offset += exthdr_len;
+    }
+
+  *offset = cur_offset;
+  return (next_proto);
+}
+
+u8 *format_ip6_hop_by_hop_ext_hdr (u8 * s, va_list * args);
 /*
  * Hop-by-Hop handling
  */
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index 6f77c6dd69d..2388a30e7ed 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -1236,80 +1236,6 @@ ip6_tcp_udp_icmp_validate_checksum (vlib_main_t * vm, vlib_buffer_t * p0)
   return p0->flags;
 }
 
-/* ip6_locate_header
- *
- * This function is to search for the header specified by the find_hdr number.
- *   1. If the find_hdr < 0 then it finds and returns the protocol number and
- *   offset stored in *offset of the transport or ESP header in the chain if
- *   found.
- *   2. If a header with find_hdr > 0 protocol number is found then the
- *      offset is stored in *offset and protocol number of the header is
- *      returned.
- *   3. If find_hdr header is not found or packet is malformed or
- *      it is a non-first fragment -1 is returned.
- */
-always_inline int
-ip6_locate_header (vlib_buffer_t * p0,
-		   ip6_header_t * ip0, int find_hdr, u32 * offset)
-{
-  u8 next_proto = ip0->protocol;
-  u8 *next_header;
-  u8 done = 0;
-  u32 cur_offset;
-  u8 *temp_nxthdr = 0;
-  u32 exthdr_len = 0;
-
-  next_header = ip6_next_header (ip0);
-  cur_offset = sizeof (ip6_header_t);
-  while (1)
-    {
-      done = (next_proto == find_hdr);
-      if (PREDICT_FALSE
-	  (next_header >=
-	   (u8 *) vlib_buffer_get_current (p0) + p0->current_length))
-	{
-	  //A malicious packet could set an extension header with a too big size
-	  return (-1);
-	}
-      if (done)
-	break;
-      if ((!ip6_ext_hdr (next_proto)) || next_proto == IP_PROTOCOL_IP6_NONXT)
-	{
-	  if (find_hdr < 0)
-	    break;
-	  return -1;
-	}
-      if (next_proto == IP_PROTOCOL_IPV6_FRAGMENTATION)
-	{
-	  ip6_frag_hdr_t *frag_hdr = (ip6_frag_hdr_t *) next_header;
-	  u16 frag_off = ip6_frag_hdr_offset (frag_hdr);
-	  /* Non first fragment return -1 */
-	  if (frag_off)
-	    return (-1);
-	  exthdr_len = sizeof (ip6_frag_hdr_t);
-	  temp_nxthdr = next_header + exthdr_len;
-	}
-      else if (next_proto == IP_PROTOCOL_IPSEC_AH)
-	{
-	  exthdr_len =
-	    ip6_ext_authhdr_len (((ip6_ext_header_t *) next_header));
-	  temp_nxthdr = next_header + exthdr_len;
-	}
-      else
-	{
-	  exthdr_len =
-	    ip6_ext_header_len (((ip6_ext_header_t *) next_header));
-	  temp_nxthdr = next_header + exthdr_len;
-	}
-      next_proto = ((ip6_ext_header_t *) next_header)->next_hdr;
-      next_header = temp_nxthdr;
-      cur_offset += exthdr_len;
-    }
-
-  *offset = cur_offset;
-  return (next_proto);
-}
-
 /**
  * @brief returns number of links on which src is reachable.
  */
@@ -2413,6 +2339,50 @@ static char *ip6_hop_by_hop_error_strings[] = {
 #undef _
 };
 
+u8 *
+format_ip6_hop_by_hop_ext_hdr (u8 * s, va_list * args)
+{
+  ip6_hop_by_hop_header_t *hbh0 = va_arg (*args, ip6_hop_by_hop_header_t *);
+  int total_len = va_arg (*args, int);
+  ip6_hop_by_hop_option_t *opt0, *limit0;
+  ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
+  u8 type0;
+
+  s = format (s, "IP6_HOP_BY_HOP: next protocol %d len %d total %d",
+	      hbh0->protocol, (hbh0->length + 1) << 3, total_len);
+
+  opt0 = (ip6_hop_by_hop_option_t *) (hbh0 + 1);
+  limit0 = (ip6_hop_by_hop_option_t *) ((u8 *) hbh0 + total_len);
+
+  while (opt0 < limit0)
+    {
+      type0 = opt0->type;
+      switch (type0)
+	{
+	case 0:		/* Pad, just stop */
+	  opt0 = (ip6_hop_by_hop_option_t *) ((u8 *) opt0 + 1);
+	  break;
+
+	default:
+	  if (hm->trace[type0])
+	    {
+	      s = (*hm->trace[type0]) (s, opt0);
+	    }
+	  else
+	    {
+	      s =
+		format (s, "\n    unrecognized option %d length %d", type0,
+			opt0->length);
+	    }
+	  opt0 =
+	    (ip6_hop_by_hop_option_t *) (((u8 *) opt0) + opt0->length +
+					 sizeof (ip6_hop_by_hop_option_t));
+	  break;
+	}
+    }
+  return s;
+}
+
 static u8 *
 format_ip6_hop_by_hop_trace (u8 * s, va_list * args)
 {
diff --git a/src/vnet/sr/sr.h b/src/vnet/sr/sr.h
index eb781e4bcee..1545a84f38b 100755
--- a/src/vnet/sr/sr.h
+++ b/src/vnet/sr/sr.h
@@ -83,7 +83,6 @@ typedef struct
   ip6_address_t bsid;			/**< BindingSID (key) */
 
   u8 type;					/**< Type (default is 0) */
-
   /* SR Policy specific DPO                                                                               */
   /* IF Type = DEFAULT Then Load Balancer DPO among SID lists     */
   /* IF Type = SPRAY then Spray DPO with all SID lists                    */
@@ -290,6 +289,45 @@ sr_steering_policy (int is_del, ip6_address_t * bsid, u32 sr_policy_index,
 		    u32 table_id, ip46_address_t * prefix, u32 mask_width,
 		    u32 sw_if_index, u8 traffic_type);
 
+/**
+ * @brief SR rewrite string computation for SRH insertion (inline)
+ *
+ * @param sl is a vector of IPv6 addresses composing the Segment List
+ *
+ * @return precomputed rewrite string for SRH insertion
+ */
+static inline u8 *
+ip6_compute_rewrite_string_insert (ip6_address_t * sl)
+{
+  ip6_sr_header_t *srh;
+  ip6_address_t *addrp, *this_address;
+  u32 header_length = 0;
+  u8 *rs = NULL;
+
+  header_length = 0;
+  header_length += sizeof (ip6_sr_header_t);
+  header_length += (vec_len (sl) + 1) * sizeof (ip6_address_t);
+
+  vec_validate (rs, header_length - 1);
+
+  srh = (ip6_sr_header_t *) rs;
+  srh->type = ROUTING_HEADER_TYPE_SR;
+  srh->segments_left = vec_len (sl);
+  srh->first_segment = vec_len (sl);
+  srh->length = ((sizeof (ip6_sr_header_t) +
+		  ((vec_len (sl) + 1) * sizeof (ip6_address_t))) / 8) - 1;
+  srh->flags = 0x00;
+  srh->reserved = 0x0000;
+  addrp = srh->segments + vec_len (sl);
+  vec_foreach (this_address, sl)
+  {
+    clib_memcpy (addrp->as_u8, this_address->as_u8, sizeof (ip6_address_t));
+    addrp--;
+  }
+  return rs;
+}
+
+
 #endif /* included_vnet_sr_h */
 
 /*