acl: perform a sanity check of ACL rules before creating ACL

Adding acl with incorrect arguments like 1.1.1.1/24 (instead of 1.1.1.0/24)
don't cause a disaster, but doesn't match either, as some might expect.

Add an explicit sanity check which returns an error.

Type: fix

Change-Id: Id1601f4b9c9887d3e7e70aac419d1f1de0c0e012
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/src/plugins/acl/acl.c b/src/plugins/acl/acl.c
index 6b120563c9b..dc9caa66177 100644
--- a/src/plugins/acl/acl.c
+++ b/src/plugins/acl/acl.c
@@ -408,6 +408,50 @@ validate_and_reset_acl_counters (acl_main_t * am, u32 acl_index)
 }
 
 static int
+acl_api_ip4_invalid_prefix (void *ip4_pref_raw, u8 ip4_prefix_len)
+{
+  ip4_address_t ip4_addr;
+  ip4_address_t ip4_mask;
+  ip4_address_t ip4_masked_addr;
+
+  memcpy (&ip4_addr, ip4_pref_raw, sizeof (ip4_addr));
+  ip4_preflen_to_mask (ip4_prefix_len, &ip4_mask);
+  ip4_masked_addr.as_u32 = ip4_addr.as_u32 & ip4_mask.as_u32;
+  int ret = (ip4_masked_addr.as_u32 != ip4_addr.as_u32);
+  if (ret)
+    {
+      clib_warning
+	("inconsistent addr %U for prefix len %d; (%U when masked)",
+	 format_ip4_address, ip4_pref_raw, ip4_prefix_len, format_ip4_address,
+	 &ip4_masked_addr);
+    }
+  return ret;
+}
+
+static int
+acl_api_ip6_invalid_prefix (void *ip6_pref_raw, u8 ip6_prefix_len)
+{
+  ip6_address_t ip6_addr;
+  ip6_address_t ip6_mask;
+  ip6_address_t ip6_masked_addr;
+
+  memcpy (&ip6_addr, ip6_pref_raw, sizeof (ip6_addr));
+  ip6_preflen_to_mask (ip6_prefix_len, &ip6_mask);
+  ip6_masked_addr.as_u64[0] = ip6_addr.as_u64[0] & ip6_mask.as_u64[0];
+  ip6_masked_addr.as_u64[1] = ip6_addr.as_u64[1] & ip6_mask.as_u64[1];
+  int ret = ((ip6_masked_addr.as_u64[0] != ip6_addr.as_u64[0])
+	     || (ip6_masked_addr.as_u64[1] != ip6_addr.as_u64[1]));
+  if (ret)
+    {
+      clib_warning
+	("inconsistent addr %U for prefix len %d; (%U when masked)",
+	 format_ip6_address, ip6_pref_raw, ip6_prefix_len, format_ip6_address,
+	 &ip6_masked_addr);
+    }
+  return ret;
+}
+
+static int
 acl_add_list (u32 count, vl_api_acl_rule_t rules[],
 	      u32 * acl_list_index, u8 * tag)
 {
@@ -421,6 +465,43 @@ acl_add_list (u32 count, vl_api_acl_rule_t rules[],
     clib_warning ("API dbg: acl_add_list index %d tag %s", *acl_list_index,
 		  tag);
 
+  /* check if what they request is consistent */
+  for (i = 0; i < count; i++)
+    {
+      if (rules[i].is_ipv6)
+	{
+	  if (rules[i].src_ip_prefix_len > 128)
+	    return VNET_API_ERROR_INVALID_VALUE;
+	  if (rules[i].dst_ip_prefix_len > 128)
+	    return VNET_API_ERROR_INVALID_VALUE;
+	  if (acl_api_ip6_invalid_prefix
+	      (&rules[i].src_ip_addr, rules[i].src_ip_prefix_len))
+	    return VNET_API_ERROR_INVALID_SRC_ADDRESS;
+	  if (acl_api_ip6_invalid_prefix
+	      (&rules[i].dst_ip_addr, rules[i].dst_ip_prefix_len))
+	    return VNET_API_ERROR_INVALID_DST_ADDRESS;
+	}
+      else
+	{
+	  if (rules[i].src_ip_prefix_len > 32)
+	    return VNET_API_ERROR_INVALID_VALUE;
+	  if (rules[i].dst_ip_prefix_len > 32)
+	    return VNET_API_ERROR_INVALID_VALUE;
+	  if (acl_api_ip4_invalid_prefix
+	      (&rules[i].src_ip_addr, rules[i].src_ip_prefix_len))
+	    return VNET_API_ERROR_INVALID_SRC_ADDRESS;
+	  if (acl_api_ip4_invalid_prefix
+	      (&rules[i].dst_ip_addr, rules[i].dst_ip_prefix_len))
+	    return VNET_API_ERROR_INVALID_DST_ADDRESS;
+	}
+      if (ntohs (rules[i].srcport_or_icmptype_first) >
+	  ntohs (rules[i].srcport_or_icmptype_last))
+	return VNET_API_ERROR_INVALID_VALUE_2;
+      if (ntohs (rules[i].dstport_or_icmpcode_first) >
+	  ntohs (rules[i].dstport_or_icmpcode_last))
+	return VNET_API_ERROR_INVALID_VALUE_2;
+    }
+
   if (*acl_list_index != ~0)
     {
       /* They supplied some number, let's see if this ACL exists */