From 5ca4bd5d9018bb7572f10825e1ca431444601be7 Mon Sep 17 00:00:00 2001 From: "Ondrej Zajicek (work)" Date: Wed, 26 Apr 2017 17:13:45 +0200 Subject: Flowspec: Max tcp mask length is 12 bits --- lib/flowspec.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'lib/flowspec.c') diff --git a/lib/flowspec.c b/lib/flowspec.c index 764b648e..0b863ed9 100644 --- a/lib/flowspec.c +++ b/lib/flowspec.c @@ -259,7 +259,8 @@ static const char* flow_validated_state_str_[] = { [FLOW_ST_BAD_TYPE_ORDER] = "Bad component order", [FLOW_ST_AND_BIT_SHOULD_BE_UNSET] = "The AND-bit should be unset", [FLOW_ST_ZERO_BIT_SHOULD_BE_UNSED] = "The Zero-bit should be unset", - [FLOW_ST_DEST_PREFIX_REQUIRED] = "Destination prefix is required to define", + [FLOW_ST_DEST_PREFIX_REQUIRED] = "Destination prefix is missing", + [FLOW_ST_INVALID_TCP_FLAGS] = "TCP flags exceeding 0xfff", [FLOW_ST_CANNOT_USE_DONT_FRAGMENT] = "Cannot use Don't fragment flag in IPv6 flow" }; @@ -332,8 +333,11 @@ flow_check_cf_bmk_values(struct flow_builder *fb, u8 neg, u32 val, u32 mask) if (neg && !(val == 0 || val == mask)) cf_error("For negation, value must be zero or bitmask"); - if (fb->this_type == FLOW_TYPE_FRAGMENT && fb->ipv6 && (mask & 0x01)) - cf_error("Invalid mask 0x%x. Bit 0 must be 0", mask); + if ((fb->this_type == FLOW_TYPE_TCP_FLAGS) && (mask & 0xf000)) + cf_error("Invalid mask 0x%x, must not exceed 0xfff", mask); + + if ((fb->this_type == FLOW_TYPE_FRAGMENT) && fb->ipv6 && (mask & 0x01)) + cf_error("Invalid mask 0x%x, bit 0 must be 0", mask); if (val & ~mask) cf_error("Value 0x%x outside bitmask 0x%x", val, mask); @@ -456,15 +460,20 @@ flow_validate(const byte *nlri, uint len, int ipv6) return FLOW_ST_ZERO_BIT_SHOULD_BE_UNSED; } - /* Bit-7 must be 0 [draft-ietf-idr-flow-spec-v6] */ - if (ipv6 && type == FLOW_TYPE_FRAGMENT && (*(pos+1) & 0x01)) - return FLOW_ST_CANNOT_USE_DONT_FRAGMENT; - /* XXX: Could be a fragment component encoded in 2-bytes? */ - /* Value length of operator */ uint len = get_value_length(pos); if (len > flow_max_value_length(type, ipv6)) return FLOW_ST_EXCEED_MAX_VALUE_LENGTH; + + /* TCP Flags component must not check highest nibble (just 12 valid bits) */ + if ((type == FLOW_TYPE_TCP_FLAGS) && (len == 2) && (pos[1] & 0xf0)) + return FLOW_ST_INVALID_TCP_FLAGS; + + /* Bit-7 must be 0 [draft-ietf-idr-flow-spec-v6] */ + if ((type == FLOW_TYPE_FRAGMENT) && ipv6 && (pos[1] & 0x01)) + return FLOW_ST_CANNOT_USE_DONT_FRAGMENT; + /* XXX: Could be a fragment component encoded in 2-bytes? */ + pos += 1+len; if (pos > end && !last) -- cgit v1.2.3