xref: /dragonfly/sys/net/dummynet/ip_dummynet.h (revision 6b5c5d0d)
1 /*
2  * Copyright (c) 1998-2002 Luigi Rizzo, Universita` di Pisa
3  * Portions Copyright (c) 2000 Akamba Corp.
4  * All rights reserved
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD: src/sys/netinet/ip_dummynet.h,v 1.10.2.9 2003/05/13 09:31:06 maxim Exp $
28  * $DragonFly: src/sys/net/dummynet/ip_dummynet.h,v 1.18 2007/11/18 13:00:28 sephe Exp $
29  */
30 
31 #ifndef _IP_DUMMYNET_H
32 #define _IP_DUMMYNET_H
33 
34 /*
35  * We start with a heap, which is used in the scheduler to decide when to
36  * transmit packets etc.
37  *
38  * The key for the heap is used for two different values:
39  *
40  * 1. Timer ticks- max 10K/second, so 32 bits are enough;
41  *
42  * 2. Virtual times.  These increase in steps of len/x, where len is the
43  *    packet length, and x is either the weight of the flow, or the sum
44  *    of all weights.
45  *    If we limit to max 1000 flows and a max weight of 100, then x needs
46  *    17 bits.  The packet size is 16 bits, so we can easily overflow if
47  *    we do not allow errors.
48  *
49  * So we use a key "dn_key" which is 64 bits.
50  *
51  * MY_M is used as a shift count when doing fixed point arithmetic
52  * (a better name would be useful...).
53  */
54 typedef uint64_t	dn_key;	/* sorting key */
55 
56 /*
57  * Number of left shift to obtain a larger precision
58  *
59  * XXX With this scaling, max 1000 flows, max weight 100, 1Gbit/s, the
60  * virtual time wraps every 15 days.
61  */
62 #define MY_M		16
63 
64 #ifdef _KERNEL
65 
66 /*
67  * A heap entry is made of a key and a pointer to the actual object stored
68  * in the heap.
69  *
70  * The heap is an array of dn_heap_entry entries, dynamically allocated.
71  * Current size is "size", with "elements" actually in use.
72  *
73  * The heap normally supports only ordered insert and extract from the top.
74  * If we want to extract an object from the middle of the heap, we have to
75  * know where the object itself is located in the heap (or we need to scan
76  * the whole array).  To this purpose, an object has a field (int) which
77  * contains the index of the object itself into the heap.  When the object
78  * is moved, the field must also be updated.  The offset of the index in the
79  * object is stored in the 'offset' field in the heap descriptor.  The
80  * assumption is that this offset is non-zero if we want to support extract
81  * from the middle.
82  */
83 struct dn_heap_entry {
84     dn_key key;		/* sorting key.  Topmost element is smallest one */
85     void *object;	/* object pointer */
86 };
87 
88 struct dn_heap {
89     int size;
90     int elements;
91     int offset; /* XXX if > 0 this is the offset of direct ptr to obj */
92     struct dn_heap_entry *p;	/* really an array of "size" entries */
93 };
94 
95 struct dn_flow_id {
96     uint16_t fid_type;	/* ETHERTYPE_ */
97     uint16_t pad;
98     union {
99 	struct {
100 	    uint32_t dst_ip;
101 	    uint32_t src_ip;
102 	    uint16_t dst_port;
103 	    uint16_t src_port;
104 	    uint8_t proto;
105 	    uint8_t flags;
106 	} inet;
107     } fid_u;
108 #define fid_dst_ip	fid_u.inet.dst_ip
109 #define fid_src_ip	fid_u.inet.src_ip
110 #define fid_dst_port	fid_u.inet.dst_port
111 #define fid_src_port	fid_u.inet.src_port
112 #define fid_proto	fid_u.inet.proto
113 #define fid_flags	fid_u.inet.flags
114 };
115 
116 typedef void	(*ip_dn_unref_priv_t)(void *);
117 
118 /*
119  * struct dn_pkt identifies a packet in the dummynet queue, but is also used
120  * to tag packets passed back to the various destinations (ip_input(),
121  * ip_output() and so on).
122  *
123  * It is a tag (PACKET_TAG_DUMMYNET) associated with the actual mbuf.
124  */
125 struct dn_pkt {
126     struct mbuf *dn_m;
127     TAILQ_ENTRY(dn_pkt) dn_next;
128 
129     void *dn_priv;
130     ip_dn_unref_priv_t dn_unref_priv;
131 
132     uint32_t dn_flags;		/* action when packet comes out. */
133 #define DN_FLAGS_IS_PIPE	0x10
134 #define DN_FLAGS_DIR_MASK	0x0f
135 #define DN_TO_IP_OUT		1
136 #define DN_TO_IP_IN		2
137 #define DN_TO_ETH_DEMUX		4
138 #define DN_TO_ETH_OUT		5
139 #define DN_TO_MAX		6
140 
141     dn_key output_time;		/* when the pkt is due for delivery */
142     struct ifnet *ifp;		/* interface, for ip_output */
143     struct sockaddr_in *dn_dst;
144     struct route ro;		/* route, for ip_output. MUST COPY */
145     int flags;			/* flags, for ip_output (IPv6 ?) */
146 
147     u_short pipe_nr;		/* pipe/flow_set number */
148     u_short pad;
149 
150     struct dn_flow_id id;	/* flow id */
151     int cpuid;			/* target cpu, for IP_OUT/ETH_DEMUX/ETH_OUT */
152 };
153 TAILQ_HEAD(dn_pkt_queue, dn_pkt);
154 
155 /*
156  * Overall structure of dummynet (with WF2Q+):
157  *
158  * In dummynet, packets are selected with the firewall rules, and passed to
159  * two different objects: PIPE or QUEUE.
160  *
161  * A QUEUE is just a queue with configurable size and queue management policy.
162  * It is also associated with a mask (to discriminate among different flows),
163  * a weight (used to give different shares of the bandwidth to different flows)
164  * and a "pipe", which essentially supplies the transmit clock for all queues
165  * associated with that pipe.
166  *
167  * A PIPE emulates a fixed-bandwidth link, whose bandwidth is configurable.
168  * The "clock" for a pipe comes from an internal timer.  A pipe is also
169  * associated with one (or more, if masks are used) queue, where all packets
170  * for that pipe are stored.
171  *
172  * The bandwidth available on the pipe is shared by the queues associated with
173  * that pipe (only one in case the packet is sent to a PIPE) according to the
174  * WF2Q+ scheduling algorithm and the configured weights.
175  *
176  * In general, incoming packets are stored in the appropriate queue, which is
177  * then placed into one of a few heaps managed by a scheduler to decide when
178  * the packet should be extracted.  The scheduler (a function called dummynet())
179  * is run at every timer tick, and grabs queues from the head of the heaps when
180  * they are ready for processing.
181  *
182  * There are three data structures definining a pipe and associated queues:
183  *
184  *  + dn_pipe, which contains the main configuration parameters related to
185  *    delay and bandwidth;
186  *  + dn_flow_set, which contains WF2Q+ configuration, flow masks, plr and
187  *    RED configuration;
188  *  + dn_flow_queue, which is the per-flow queue (containing the packets)
189  *
190  * Multiple dn_flow_set can be linked to the same pipe, and multiple
191  * dn_flow_queue can be linked to the same dn_flow_set.
192  * All data structures are linked in a linear list which is used for
193  * housekeeping purposes.
194  *
195  * During configuration, we create and initialize the dn_flow_set and dn_pipe
196  * structures (a dn_pipe also contains a dn_flow_set).
197  *
198  * At runtime: packets are sent to the appropriate dn_flow_set (either WFQ
199  * ones, or the one embedded in the dn_pipe for fixed-rate flows), which in
200  * turn dispatches them to the appropriate dn_flow_queue (created dynamically
201  * according to the masks).
202  *
203  * The transmit clock for fixed rate flows (ready_event()) selects the
204  * dn_flow_queue to be used to transmit the next packet. For WF2Q,
205  * wfq_ready_event() extract a pipe which in turn selects the right flow using
206  * a number of heaps defined into the pipe itself.
207  */
208 
209 /*
210  * Per flow queue.  This contains the flow identifier, the queue of packets,
211  * counters, and parameters used to support both RED and WF2Q+.
212  *
213  * A dn_flow_queue is created and initialized whenever a packet for a new
214  * flow arrives.
215  */
216 struct dn_flow_queue {
217     struct dn_flow_id id;
218     LIST_ENTRY(dn_flow_queue) q_link;
219 
220     struct dn_pkt_queue queue;	/* queue of packets */
221     u_int len;
222     u_int len_bytes;
223     u_long numbytes;		/* credit for transmission (dynamic queues) */
224 
225     uint64_t tot_pkts;		/* statistics counters */
226     uint64_t tot_bytes;
227     uint32_t drops;
228 
229     int hash_slot;		/* debugging/diagnostic */
230 
231     /* RED parameters */
232     int avg;			/* average queue length est. (scaled) */
233     int count;			/* arrivals since last RED drop */
234     int random;			/* random value (scaled) */
235     uint32_t q_time;		/* start of queue idle time */
236 
237     /* WF2Q+ support */
238     struct dn_flow_set *fs;	/* parent flow set */
239     int heap_pos;		/* position (index) of struct in heap */
240     dn_key sched_time;		/* current time when queue enters ready_heap */
241 
242     dn_key S, F;		/* start time, finish time */
243     /*
244      * Setting F < S means the timestamp is invalid. We only need
245      * to test this when the queue is empty.
246      */
247 };
248 LIST_HEAD(dn_flowqueue_head, dn_flow_queue);
249 
250 /*
251  * flow_set descriptor.  Contains the "template" parameters for the queue
252  * configuration, and pointers to the hash table of dn_flow_queue's.
253  *
254  * The hash table is an array of lists -- we identify the slot by hashing
255  * the flow-id, then scan the list looking for a match.
256  * The size of the hash table (buckets) is configurable on a per-queue basis.
257  *
258  * A dn_flow_set is created whenever a new queue or pipe is created (in the
259  * latter case, the structure is located inside the struct dn_pipe).
260  */
261 struct dn_flow_set {
262     u_short fs_nr;		/* flow_set number */
263     u_short flags_fs;		/* see 'Flow set flags' */
264 
265     LIST_ENTRY(dn_flow_set) fs_link;
266 
267     struct dn_pipe *pipe;	/* pointer to parent pipe */
268     u_short parent_nr;		/* parent pipe#, 0 if local to a pipe */
269 
270     int weight;			/* WFQ queue weight */
271     int qsize;			/* queue size in slots or bytes */
272     int plr;			/* pkt loss rate (2^31-1 means 100%) */
273 
274     struct dn_flow_id flow_mask;
275 
276     /* hash table of queues onto this flow_set */
277     int rq_size;		/* number of slots */
278     int rq_elements;		/* active elements */
279     struct dn_flowqueue_head *rq;/* array of rq_size entries */
280 
281     uint32_t last_expired;	/* do not expire too frequently */
282     int backlogged;		/* #active queues for this flowset */
283 
284     /* RED parameters */
285     int w_q;			/* queue weight (scaled) */
286     int max_th;			/* maximum threshold for queue (scaled) */
287     int min_th;			/* minimum threshold for queue (scaled) */
288     int max_p;			/* maximum value for p_b (scaled) */
289     u_int c_1;			/* max_p/(max_th-min_th) (scaled) */
290     u_int c_2;			/* max_p*min_th/(max_th-min_th) (scaled) */
291     u_int c_3;			/* for GRED, (1-max_p)/max_th (scaled) */
292     u_int c_4;			/* for GRED, 1 - 2*max_p (scaled) */
293     u_int *w_q_lookup;		/* lookup table for computing (1-w_q)^t */
294     u_int lookup_depth;		/* depth of lookup table */
295     int lookup_step;		/* granularity inside the lookup table */
296     int lookup_weight;		/* equal to (1-w_q)^t / (1-w_q)^(t+1) */
297     int avg_pkt_size;		/* medium packet size */
298     int max_pkt_size;		/* max packet size */
299 };
300 LIST_HEAD(dn_flowset_head, dn_flow_set);
301 
302 /*
303  * Pipe descriptor. Contains global parameters, delay-line queue, and the
304  * flow_set used for fixed-rate queues.
305  *
306  * For WF2Q+ support it also has 3 heaps holding dn_flow_queue:
307  *  + not_eligible_heap, for queues whose start time is higher than the
308  *    virtual time. Sorted by start time.
309  *  + scheduler_heap, for queues eligible for scheduling.  Sorted by finish
310  *    time.
311  *  + idle_heap, all flows that are idle and can be removed.  We do that on
312  *    each tick so we do not slow down too much operations during forwarding.
313  */
314 struct dn_pipe {		/* a pipe */
315     int pipe_nr;		/* number */
316     int bandwidth;		/* really, bytes/tick. */
317     int delay;			/* really, ticks */
318 
319     struct dn_pkt_queue p_queue;/* packets in delay line */
320     LIST_ENTRY(dn_pipe) p_link;
321 
322     /* WF2Q+ */
323     struct dn_heap scheduler_heap; /* top extract - key Finish time*/
324     struct dn_heap not_eligible_heap; /* top extract- key Start time */
325     struct dn_heap idle_heap;	/* random extract - key Start=Finish time */
326 
327     dn_key V;			/* virtual time */
328     int sum;			/* sum of weights of all active sessions */
329     int numbytes;		/* bits I can transmit (more or less). */
330 
331     dn_key sched_time;		/* time pipe was scheduled in ready_heap */
332 
333     struct dn_flow_set fs;	/* used with fixed-rate flows */
334 };
335 LIST_HEAD(dn_pipe_head, dn_pipe);
336 
337 struct dn_sopt {
338 	int	dn_sopt_name;
339 	void	*dn_sopt_arg;
340 	size_t	dn_sopt_arglen;
341 };
342 
343 typedef int	ip_dn_ctl_t(struct dn_sopt *);
344 typedef int	ip_dn_io_t(struct mbuf *);
345 
346 extern ip_dn_ctl_t	*ip_dn_ctl_ptr;
347 extern ip_dn_io_t	*ip_dn_io_ptr;
348 
349 void	ip_dn_queue(struct mbuf *);
350 void	ip_dn_packet_free(struct dn_pkt *);
351 void	ip_dn_packet_redispatch(struct dn_pkt *);
352 int	ip_dn_sockopt(struct sockopt *);
353 
354 #define	DUMMYNET_LOADED	(ip_dn_io_ptr != NULL)
355 
356 #endif	/* _KERNEL */
357 
358 struct dn_ioc_flowid {
359     uint16_t type;	/* ETHERTYPE_ */
360     uint16_t pad;
361     union {
362 	struct {
363 	    uint32_t dst_ip;
364 	    uint32_t src_ip;
365 	    uint16_t dst_port;
366 	    uint16_t src_port;
367 	    uint8_t proto;
368 	    uint8_t flags;
369 	} ip;
370 	uint8_t pad[64];
371     } u;
372 };
373 
374 struct dn_ioc_flowqueue {
375     u_int len;
376     u_int len_bytes;
377 
378     uint64_t tot_pkts;
379     uint64_t tot_bytes;
380     uint32_t drops;
381 
382     int hash_slot;		/* debugging/diagnostic */
383     dn_key S;			/* virtual start time */
384     dn_key F;			/* virtual finish time */
385 
386     struct dn_ioc_flowid id;
387     uint8_t reserved[16];
388 };
389 
390 struct dn_ioc_flowset {
391     u_short fs_type;		/* DN_IS_{QUEUE,PIPE}, MUST be first */
392 
393     u_short fs_nr;		/* flow_set number */
394     u_short flags_fs;		/* see 'Flow set flags' */
395     u_short parent_nr;		/* parent pipe#, 0 if local to a pipe */
396 
397     int weight;			/* WFQ queue weight */
398     int qsize;			/* queue size in slots or bytes */
399     int plr;			/* pkt loss rate (2^31-1 means 100%) */
400 
401     /* Hash table information */
402     int rq_size;		/* number of slots */
403     int rq_elements;		/* active elements */
404 
405     /* RED parameters */
406     int w_q;			/* queue weight (scaled) */
407     int max_th;			/* maximum threshold for queue (scaled) */
408     int min_th;			/* minimum threshold for queue (scaled) */
409     int max_p;			/* maximum value for p_b (scaled) */
410     int lookup_step;		/* granularity inside the lookup table */
411     int lookup_weight;		/* equal to (1-w_q)^t / (1-w_q)^(t+1) */
412 
413     struct dn_ioc_flowid flow_mask;
414     uint8_t reserved[16];
415 };
416 
417 struct dn_ioc_pipe {
418     struct dn_ioc_flowset fs;	/* MUST be first */
419 
420     int pipe_nr;		/* pipe number */
421     int bandwidth;		/* bit/second */
422     int delay;			/* milliseconds */
423 
424     dn_key V;			/* virtual time */
425 
426     uint8_t reserved[16];
427 };
428 
429 /*
430  * Flow set flags
431  */
432 #define DN_HAVE_FLOW_MASK	0x0001
433 #define DN_IS_RED		0x0002
434 #define DN_IS_GENTLE_RED	0x0004
435 #define DN_QSIZE_IS_BYTES	0x0008	/* queue size is measured in bytes */
436 #define DN_NOERROR		0x0010	/* do not report ENOBUFS on drops */
437 #define DN_IS_PIPE		0x4000
438 #define DN_IS_QUEUE		0x8000
439 
440 /*
441  * Macros for RED
442  */
443 #define SCALE_RED		16
444 #define SCALE(x)		((x) << SCALE_RED)
445 #define SCALE_VAL(x)		((x) >> SCALE_RED)
446 #define SCALE_MUL(x, y)		(((x) * (y)) >> SCALE_RED)
447 
448 /*
449  * Maximum pipe number
450  */
451 #define DN_PIPE_NR_MAX		65536
452 
453 #endif /* !_IP_DUMMYNET_H */
454