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$FreeBSD: release/9.1.0/sys/netgraph/NOTES 198448 2009-10-24 18:49:17Z ru $ Development ideas.. Archie's suggestions... :-) - There should be a new malloc type: M_NETGRAPH [DONE] - all mallocs/frees now changed to use this.. JRE - might further split them out some time. - Use MALLOC and FREE macros instead of direct function calls [DONE] - They allow conditional compilation which keeps statistics & counters on various memory allocation (or so it seems) - Now tend to have NG_FREE_XX() macros. they allow better debugging - In struct ng_mesg: at least make "header" into "hdr", if not getting rid of it altogether. It doesn't seem necessary and makes all my C code lines too long. - I understand.. one thought however.. consider.. if char data[0] were not legal, so that data[1] needed to be used instead, then the only way to get the size of the header would be sizeof(msg.header) as sizeof(msg) would include the dummy following bytes. this is a portability issue and I hope it will be ported eventually :) - Baloney! you can use sizeof(msg) - 1 then.. or just make it a macro, then its always portable: #ifdef __GNU_C__ #define NG_MSG_HDR_SIZE (sizeof(struct ng_message)) #else #define NG_MSG_HDR_SIZE (sizeof(struct ng_message) - 1) #endif - inertia rules :-b - Have a user level program to print out and manipulate nodes, etc. - [DONE] see ngctl, nghook - "Netgraph global" flags to turn on tracing, etc. - ngctl needs to be rewritten using libnetgraph. Also it needs a command to list all existing nodes (in case you don't know the name of what you're looking for). [DONE] - Need a way to get a list of ALL nodes. [DONE] - see NGM_LISTNODES - Enhance "netstat" to display all netgraph nodes -- or at least all netgraph socket nodes. [DONE] - BUG FIX: bind() on a socket should neither require nor allow a colon character at the end of the name. Note ngctl allows you to do it either way! [DONE] (I think) - bind on a control socket has been disabled it was a bad idea. - Need to implement passing meta information through socket nodes using sendmsg() and recvmsg(). - Stuff needing to be added to manual: - Awareness of SPL level, use ng_queue*() functions when necessary. - Malloc all memory with type M_NETGRAPH. -DONE - Write code so it can be an LKM or built into the kernel.. this means be careful with things like #ifdef INET. - All nodes assume that all data mbufs have the M_PKTHDR flag set! The ng_send_data() and related functions should have an #ifdef DIAGNOSTIC check to check this assumption for every mbuf. -DONE with INVARIANTS. Framework should test this more. - More generally, netgraph code should make liberal use of the #ifdef DIAGNOSTIC definition. -INVARIANTS. - Since data and messages are sent functionally, programmers need to watch out for infinite feedback loops. Should ng_base.c detect this automatically? - I've been thinking about this. each node could have a 'colour' which is set to the colour of the packet as you pass through. hitting a node already of your colour would abort. Each packet has another (incremented) colour. -new 'item' type can hold a hopcount... NEW in 2001 All piggyback responses have gone away. use the node ID in the return address field for quick response delivery. Every node has a queue, plus there is a list of nodes that have queued work. Extensive use of Mutexes. Getting in shape for SMP. Messages and data are deliverd in a new form. An Item now has all information needed to queue such a request and deliver it later, so it is now the basis of all data transfer since any transfer may need to be queued.