2 * Copyright (c) 1998-2002 Luigi Rizzo, Universita` di Pisa
3 * Portions Copyright (c) 2000 Akamba Corp.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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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
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 1.9 2007/10/25 13:13:18 sephe Exp $
31 #ifndef _IP_DUMMYNET_H
32 #define _IP_DUMMYNET_H
35 * Definition of dummynet data structures. In the structures, I decided
36 * not to use the macros in <sys/queue.h> in the hope of making the code
37 * easier to port to other architectures. The type of lists and queue we
38 * use here is pretty simple anyways.
42 * We start with a heap, which is used in the scheduler to decide when
43 * to transmit packets etc.
45 * The key for the heap is used for two different values:
47 * 1. timer ticks- max 10K/second, so 32 bits are enough;
49 * 2. virtual times. These increase in steps of len/x, where len is the
50 * packet length, and x is either the weight of the flow, or the
52 * If we limit to max 1000 flows and a max weight of 100, then
53 * x needs 17 bits. The packet size is 16 bits, so we can easily
54 * overflow if we do not allow errors.
55 * So we use a key "dn_key" which is 64 bits. Some macros are used to
56 * compare key values and handle wraparounds.
57 * MAX64 returns the largest of two key values.
58 * MY_M is used as a shift count when doing fixed point arithmetic
59 * (a better name would be useful...).
61 typedef uint64_t dn_key; /* sorting key */
62 #define DN_KEY_LT(a,b) ((int64_t)((a)-(b)) < 0)
63 #define DN_KEY_LEQ(a,b) ((int64_t)((a)-(b)) <= 0)
64 #define DN_KEY_GT(a,b) ((int64_t)((a)-(b)) > 0)
65 #define DN_KEY_GEQ(a,b) ((int64_t)((a)-(b)) >= 0)
66 #define MAX64(x,y) (((int64_t)((y) - (x))) > 0) ? (y) : (x)
67 #define MY_M 16 /* number of left shift to obtain a larger precision */
70 * XXX With this scaling, max 1000 flows, max weight 100, 1Gbit/s, the
71 * virtual time wraps every 15 days.
75 * The maximum hash table size for queues. This value must be a power
78 #define DN_MAX_HASH_SIZE 65536
81 * A heap entry is made of a key and a pointer to the actual
82 * object stored in the heap.
83 * The heap is an array of dn_heap_entry entries, dynamically allocated.
84 * Current size is "size", with "elements" actually in use.
85 * The heap normally supports only ordered insert and extract from the top.
86 * If we want to extract an object from the middle of the heap, we
87 * have to know where the object itself is located in the heap (or we
88 * need to scan the whole array). To this purpose, an object has a
89 * field (int) which contains the index of the object itself into the
90 * heap. When the object is moved, the field must also be updated.
91 * The offset of the index in the object is stored in the 'offset'
92 * field in the heap descriptor. The assumption is that this offset
93 * is non-zero if we want to support extract from the middle.
95 struct dn_heap_entry {
96 dn_key key; /* sorting key. Topmost element is smallest one */
97 void *object; /* object pointer */
103 int offset; /* XXX if > 0 this is the offset of direct ptr to obj */
104 struct dn_heap_entry *p; /* really an array of "size" entries */
107 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
110 * struct dn_pkt identifies a packet in the dummynet queue, but
111 * is also used to tag packets passed back to the various destinations
112 * (ip_input(), ip_output() and so on).
113 * It is a tag(PACKET_TAG_DUMMYNET) associated with the actual mbuf.
117 struct dn_pkt *dn_next;
119 struct ip_fw *rule; /* matching rule */
120 int dn_dir; /* action when packet comes out. */
121 #define DN_TO_IP_OUT 1
122 #define DN_TO_IP_IN 2
123 #define DN_TO_ETH_DEMUX 4
124 #define DN_TO_ETH_OUT 5
126 dn_key output_time; /* when the pkt is due for delivery */
127 struct ifnet *ifp; /* interface, for ip_output */
128 struct sockaddr_in *dn_dst;
129 struct route ro; /* route, for ip_output. MUST COPY */
130 int flags; /* flags, for ip_output (IPv6 ?) */
136 * Overall structure of dummynet (with WF2Q+):
138 * In dummynet, packets are selected with the firewall rules, and passed
139 * to two different objects: PIPE or QUEUE.
141 * A QUEUE is just a queue with configurable size and queue management
142 * policy. It is also associated with a mask (to discriminate among
143 * different flows), a weight (used to give different shares of the
144 * bandwidth to different flows) and a "pipe", which essentially
145 * supplies the transmit clock for all queues associated with that
148 * A PIPE emulates a fixed-bandwidth link, whose bandwidth is
149 * configurable. The "clock" for a pipe can come from either an
150 * internal timer, or from the transmit interrupt of an interface.
151 * A pipe is also associated with one (or more, if masks are used)
152 * queue, where all packets for that pipe are stored.
154 * The bandwidth available on the pipe is shared by the queues
155 * associated with that pipe (only one in case the packet is sent
156 * to a PIPE) according to the WF2Q+ scheduling algorithm and the
157 * configured weights.
159 * In general, incoming packets are stored in the appropriate queue,
160 * which is then placed into one of a few heaps managed by a scheduler
161 * to decide when the packet should be extracted.
162 * The scheduler (a function called dummynet()) is run at every timer
163 * tick, and grabs queues from the head of the heaps when they are
164 * ready for processing.
166 * There are three data structures definining a pipe and associated queues:
168 * + dn_pipe, which contains the main configuration parameters related
169 * to delay and bandwidth;
170 * + dn_flow_set, which contains WF2Q+ configuration, flow
171 * masks, plr and RED configuration;
172 * + dn_flow_queue, which is the per-flow queue (containing the packets)
174 * Multiple dn_flow_set can be linked to the same pipe, and multiple
175 * dn_flow_queue can be linked to the same dn_flow_set.
176 * All data structures are linked in a linear list which is used for
177 * housekeeping purposes.
179 * During configuration, we create and initialize the dn_flow_set
180 * and dn_pipe structures (a dn_pipe also contains a dn_flow_set).
182 * At runtime: packets are sent to the appropriate dn_flow_set (either
183 * WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows),
184 * which in turn dispatches them to the appropriate dn_flow_queue
185 * (created dynamically according to the masks).
187 * The transmit clock for fixed rate flows (ready_event()) selects the
188 * dn_flow_queue to be used to transmit the next packet. For WF2Q,
189 * wfq_ready_event() extract a pipe which in turn selects the right
190 * flow using a number of heaps defined into the pipe itself.
194 * per flow queue. This contains the flow identifier, the queue
195 * of packets, counters, and parameters used to support both RED and
198 * A dn_flow_queue is created and initialized whenever a packet for
199 * a new flow arrives.
201 struct dn_flow_queue {
202 struct dn_flow_queue *next;
203 struct ipfw_flow_id id;
205 struct dn_pkt *head, *tail; /* queue of packets */
208 u_long numbytes; /* credit for transmission (dynamic queues) */
210 uint64_t tot_pkts; /* statistics counters */
214 int hash_slot; /* debugging/diagnostic */
217 int avg; /* average queue length est. (scaled) */
218 int count; /* arrivals since last RED drop */
219 int random; /* random value (scaled) */
220 uint32_t q_time; /* start of queue idle time */
223 struct dn_flow_set *fs; /* parent flow set */
224 int heap_pos; /* position (index) of struct in heap */
225 dn_key sched_time; /* current time when queue enters ready_heap */
227 dn_key S, F; /* start time, finish time */
229 * Setting F < S means the timestamp is invalid. We only need
230 * to test this when the queue is empty.
235 * flow_set descriptor. Contains the "template" parameters for the
236 * queue configuration, and pointers to the hash table of dn_flow_queue's.
238 * The hash table is an array of lists -- we identify the slot by
239 * hashing the flow-id, then scan the list looking for a match.
240 * The size of the hash table (buckets) is configurable on a per-queue
243 * A dn_flow_set is created whenever a new queue or pipe is created (in the
244 * latter case, the structure is located inside the struct dn_pipe).
247 struct dn_flow_set *next; /* next flow set in all_flow_sets list */
249 u_short fs_nr; /* flow_set number */
251 #define DN_HAVE_FLOW_MASK 0x0001
252 #define DN_IS_RED 0x0002
253 #define DN_IS_GENTLE_RED 0x0004
254 #define DN_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */
255 #define DN_NOERROR 0x0010 /* do not report ENOBUFS on drops */
256 #define DN_IS_PIPE 0x4000
257 #define DN_IS_QUEUE 0x8000
259 struct dn_pipe *pipe; /* pointer to parent pipe */
260 u_short parent_nr; /* parent pipe#, 0 if local to a pipe */
262 int weight; /* WFQ queue weight */
263 int qsize; /* queue size in slots or bytes */
264 int plr; /* pkt loss rate (2^31-1 means 100%) */
266 struct ipfw_flow_id flow_mask;
268 /* hash table of queues onto this flow_set */
269 int rq_size; /* number of slots */
270 int rq_elements; /* active elements */
271 struct dn_flow_queue **rq; /* array of rq_size entries */
273 uint32_t last_expired; /* do not expire too frequently */
274 int backlogged; /* #active queues for this flowset */
278 #define SCALE(x) ((x) << SCALE_RED)
279 #define SCALE_VAL(x) ((x) >> SCALE_RED)
280 #define SCALE_MUL(x, y) (((x) * (y)) >> SCALE_RED)
281 int w_q; /* queue weight (scaled) */
282 int max_th; /* maximum threshold for queue (scaled) */
283 int min_th; /* minimum threshold for queue (scaled) */
284 int max_p; /* maximum value for p_b (scaled) */
285 u_int c_1; /* max_p/(max_th-min_th) (scaled) */
286 u_int c_2; /* max_p*min_th/(max_th-min_th) (scaled) */
287 u_int c_3; /* for GRED, (1-max_p)/max_th (scaled) */
288 u_int c_4; /* for GRED, 1 - 2*max_p (scaled) */
289 u_int *w_q_lookup; /* lookup table for computing (1-w_q)^t */
290 u_int lookup_depth; /* depth of lookup table */
291 int lookup_step; /* granularity inside the lookup table */
292 int lookup_weight; /* equal to (1-w_q)^t / (1-w_q)^(t+1) */
293 int avg_pkt_size; /* medium packet size */
294 int max_pkt_size; /* max packet size */
298 * Pipe descriptor. Contains global parameters, delay-line queue,
299 * and the flow_set used for fixed-rate queues.
301 * For WF2Q+ support it also has 3 heaps holding dn_flow_queue:
302 * not_eligible_heap, for queues whose start time is higher
303 * than the virtual time. Sorted by start time.
304 * scheduler_heap, for queues eligible for scheduling. Sorted by
306 * idle_heap, all flows that are idle and can be removed. We
307 * do that on each tick so we do not slow down too much
308 * operations during forwarding.
311 struct dn_pipe { /* a pipe */
312 struct dn_pipe *next;
314 int pipe_nr; /* number */
315 int bandwidth; /* really, bytes/tick. */
316 int delay; /* really, ticks */
318 struct dn_pkt *head, *tail; /* packets in delay line */
321 struct dn_heap scheduler_heap; /* top extract - key Finish time*/
322 struct dn_heap not_eligible_heap; /* top extract- key Start time */
323 struct dn_heap idle_heap; /* random extract - key Start=Finish time */
325 dn_key V; /* virtual time */
326 int sum; /* sum of weights of all active sessions */
327 int numbytes; /* bits I can transmit (more or less). */
329 dn_key sched_time; /* time pipe was scheduled in ready_heap */
332 * When the tx clock come from an interface (if_name[0] != '\0'), its name
333 * is stored below, whereas the ifp is filled when the rule is configured.
335 char if_name[IFNAMSIZ];
337 int ready; /* set if ifp != NULL and we got a signal from it */
339 struct dn_flow_set fs; /* used with fixed-rate flows */
343 typedef int ip_dn_ctl_t(struct sockopt *); /* raw_ip.c */
344 typedef void ip_dn_ruledel_t(void *); /* ip_fw2.c */
345 typedef int ip_dn_io_t(struct mbuf *m, int pipe_nr, int dir,
346 struct ip_fw_args *fwa);
347 extern ip_dn_ctl_t *ip_dn_ctl_ptr;
348 extern ip_dn_ruledel_t *ip_dn_ruledel_ptr;
349 extern ip_dn_io_t *ip_dn_io_ptr;
350 #define DUMMYNET_LOADED (ip_dn_io_ptr != NULL)
353 #endif /* !_IP_DUMMYNET_H */