+ implement (two lines) the kernel side of 'lookup dscp N' to use the

  dscp as a search key in table lookups;

+ (re)implement a sysctl variable to control the expire frequency of
  pipes and queues when they become empty;

+ add 'queue number' as optional part of the flow_id. This can be
  enabled with the command

        queue X config mask queue ...

  and makes it possible to support priority-based schedulers, where
  packets should be grouped according to the priority and not some
  fields in the 5-tuple.
  This is implemented as follows:
  - redefine a field in the ipfw_flow_id (in sys/netinet/ip_fw.h) but
    without changing the size or shape of the structure, so there are
    no ABI changes. On passing, also document how other fields are
    used, and remove some useless assignments in ip_fw2.c

  - implement small changes in the userland code to set/read the field;

  - revise the functions in ip_dummynet.c to manipulate masks so they
    also handle the additional field;

There are no ABI changes in this commit.

1 files changed, 9 insertions, 6 deletions

diff --git a/sys/netinet/ip_fw.h b/sys/netinet/ip_fw.h
index d357f18..cf5d8d0 100644
--- a/sys/netinet/ip_fw.h
+++ b/sys/netinet/ip_fw.h
@@ -487,24 +487,27 @@ struct ip_fw {
 #define RULESIZE(rule)  (sizeof(struct ip_fw) + \
 	((struct ip_fw *)(rule))->cmd_len * 4 - 4)
 
-#if 1 // moved to in.h
+#if 1 // should be moved to in.h
 /*
  * This structure is used as a flow mask and a flow id for various
  * parts of the code.
+ * addr_type is used in userland and kernel to mark the address type.
+ * fib is used in the kernel to record the fib in use.
+ * _flags is used in the kernel to store tcp flags for dynamic rules.
  */
 struct ipfw_flow_id {
 	uint32_t	dst_ip;
 	uint32_t	src_ip;
 	uint16_t	dst_port;
 	uint16_t	src_port;
-	uint8_t	fib;
-	uint8_t	proto;
-	uint8_t	flags;	/* protocol-specific flags */
-	uint8_t		addr_type; /* 4 = ipv4, 6 = ipv6, 1=ether ? */
+	uint8_t		fib;
+	uint8_t		proto;
+	uint8_t		_flags;	/* protocol-specific flags */
+	uint8_t		addr_type; /* 4=ip4, 6=ip6, 1=ether ? */
 	struct in6_addr dst_ip6;
 	struct in6_addr src_ip6;
 	uint32_t	flow_id6;
-	uint32_t	frag_id6;
+	uint32_t	extra; /* queue/pipe or frag_id */
 };
 #endif