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 * $FreeBSD$ 28 */ 29 30 #ifndef _IP_DUMMYNET_H 31 #define _IP_DUMMYNET_H 32 33 /* 34 * Definition of dummynet data structures. In the structures, I decided 35 * not to use the macros in <sys/queue.h> in the hope of making the code 36 * easier to port to other architectures. The type of lists and queue we 37 * use here is pretty simple anyways. 38 */ 39 40 /* 41 * We start with a heap, which is used in the scheduler to decide when 42 * to transmit packets etc. 43 * 44 * The key for the heap is used for two different values: 45 * 46 * 1. timer ticks- max 10K/second, so 32 bits are enough; 47 * 48 * 2. virtual times. These increase in steps of len/x, where len is the 49 * packet length, and x is either the weight of the flow, or the 50 * sum of all weights. 51 * If we limit to max 1000 flows and a max weight of 100, then 52 * x needs 17 bits. The packet size is 16 bits, so we can easily 53 * overflow if we do not allow errors. 54 * So we use a key "dn_key" which is 64 bits. Some macros are used to 55 * compare key values and handle wraparounds. 56 * MAX64 returns the largest of two key values. 57 * MY_M is used as a shift count when doing fixed point arithmetic 58 * (a better name would be useful...). 59 */ 60 typedef u_int64_t dn_key ; /* sorting key */ 61 #define DN_KEY_LT(a,b) ((int64_t)((a)-(b)) < 0) 62 #define DN_KEY_LEQ(a,b) ((int64_t)((a)-(b)) <= 0) 63 #define DN_KEY_GT(a,b) ((int64_t)((a)-(b)) > 0) 64 #define DN_KEY_GEQ(a,b) ((int64_t)((a)-(b)) >= 0) 65 #define MAX64(x,y) (( (int64_t) ( (y)-(x) )) > 0 ) ? (y) : (x) 66 #define MY_M 16 /* number of left shift to obtain a larger precision */ 67 68 /* 69 * XXX With this scaling, max 1000 flows, max weight 100, 1Gbit/s, the 70 * virtual time wraps every 15 days. 71 */ 72 73 /* 74 * The OFFSET_OF macro is used to return the offset of a field within 75 * a structure. It is used by the heap management routines. 76 */ 77 #define OFFSET_OF(type, field) ((int)&( ((type *)0)->field) ) 78 79 /* 80 * A heap entry is made of a key and a pointer to the actual 81 * object stored in the heap. 82 * The heap is an array of dn_heap_entry entries, dynamically allocated. 83 * Current size is "size", with "elements" actually in use. 84 * The heap normally supports only ordered insert and extract from the top. 85 * If we want to extract an object from the middle of the heap, we 86 * have to know where the object itself is located in the heap (or we 87 * need to scan the whole array). To this purpose, an object has a 88 * field (int) which contains the index of the object itself into the 89 * heap. When the object is moved, the field must also be updated. 90 * The offset of the index in the object is stored in the 'offset' 91 * field in the heap descriptor. The assumption is that this offset 92 * is non-zero if we want to support extract from the middle. 93 */ 94 struct dn_heap_entry { 95 dn_key key ; /* sorting key. Topmost element is smallest one */ 96 void *object ; /* object pointer */ 97 } ; 98 99 struct dn_heap { 100 int size ; 101 int elements ; 102 int offset ; /* XXX if > 0 this is the offset of direct ptr to obj */ 103 struct dn_heap_entry *p ; /* really an array of "size" entries */ 104 } ; 105 106 /* 107 * MT_DUMMYNET is a new (fake) mbuf type that is prepended to the 108 * packet when it comes out of a pipe. The definition 109 * ought to go in /sys/sys/mbuf.h but here it is less intrusive. 110 */ 111 112 #define MT_DUMMYNET MT_CONTROL 113 114 /* 115 * struct dn_pkt identifies a packet in the dummynet queue. The 116 * first part is really an m_hdr for implementation purposes, and some 117 * fields are saved there. When passing the packet back to the ip_input/ 118 * ip_output()/bdg_forward, the struct is prepended to the mbuf chain with type 119 * MT_DUMMYNET, and contains the pointer to the matching rule. 120 * 121 * Note: there is no real need to make this structure contain an m_hdr, 122 * in the future this should be changed to a normal data structure. 123 */ 124 struct dn_pkt { 125 struct m_hdr hdr ; 126 #define dn_next hdr.mh_nextpkt /* next element in queue */ 127 #define DN_NEXT(x) (struct dn_pkt *)(x)->dn_next 128 #define dn_m hdr.mh_next /* packet to be forwarded */ 129 #define dn_dir hdr.mh_flags /* action when pkt extracted from a queue */ 130 #define DN_TO_IP_OUT 1 131 #define DN_TO_IP_IN 2 132 #define DN_TO_BDG_FWD 3 133 134 dn_key output_time; /* when the pkt is due for delivery */ 135 struct ifnet *ifp; /* interface, for ip_output */ 136 struct sockaddr_in *dn_dst ; 137 struct route ro; /* route, for ip_output. MUST COPY */ 138 int flags ; /* flags, for ip_output (IPv6 ?) */ 139 }; 140 141 /* 142 * Overall structure of dummynet (with WF2Q+): 143 144 In dummynet, packets are selected with the firewall rules, and passed 145 to two different objects: PIPE or QUEUE. 146 147 A QUEUE is just a queue with configurable size and queue management 148 policy. It is also associated with a mask (to discriminate among 149 different flows), a weight (used to give different shares of the 150 bandwidth to different flows) and a "pipe", which essentially 151 supplies the transmit clock for all queues associated with that 152 pipe. 153 154 A PIPE emulates a fixed-bandwidth link, whose bandwidth is 155 configurable. The "clock" for a pipe can come from either an 156 internal timer, or from the transmit interrupt of an interface. 157 A pipe is also associated with one (or more, if masks are used) 158 queue, where all packets for that pipe are stored. 159 160 The bandwidth available on the pipe is shared by the queues 161 associated with that pipe (only one in case the packet is sent 162 to a PIPE) according to the WF2Q+ scheduling algorithm and the 163 configured weights. 164 165 In general, incoming packets are stored in the appropriate queue, 166 which is then placed into one of a few heaps managed by a scheduler 167 to decide when the packet should be extracted. 168 The scheduler (a function called dummynet()) is run at every timer 169 tick, and grabs queues from the head of the heaps when they are 170 ready for processing. 171 172 There are three data structures definining a pipe and associated queues: 173 174 + dn_pipe, which contains the main configuration parameters related 175 to delay and bandwidth; 176 + dn_flow_set, which contains WF2Q+ configuration, flow 177 masks, plr and RED configuration; 178 + dn_flow_queue, which is the per-flow queue (containing the packets) 179 180 Multiple dn_flow_set can be linked to the same pipe, and multiple 181 dn_flow_queue can be linked to the same dn_flow_set. 182 All data structures are linked in a linear list which is used for 183 housekeeping purposes. 184 185 During configuration, we create and initialize the dn_flow_set 186 and dn_pipe structures (a dn_pipe also contains a dn_flow_set). 187 188 At runtime: packets are sent to the appropriate dn_flow_set (either 189 WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows), 190 which in turn dispatches them to the appropriate dn_flow_queue 191 (created dynamically according to the masks). 192 193 The transmit clock for fixed rate flows (ready_event()) selects the 194 dn_flow_queue to be used to transmit the next packet. For WF2Q, 195 wfq_ready_event() extract a pipe which in turn selects the right 196 flow using a number of heaps defined into the pipe itself. 197 198 * 199 */ 200 201 /* 202 * per flow queue. This contains the flow identifier, the queue 203 * of packets, counters, and parameters used to support both RED and 204 * WF2Q+. 205 * 206 * A dn_flow_queue is created and initialized whenever a packet for 207 * a new flow arrives. 208 */ 209 struct dn_flow_queue { 210 struct dn_flow_queue *next ; 211 struct ipfw_flow_id id ; 212 213 struct dn_pkt *head, *tail ; /* queue of packets */ 214 u_int len ; 215 u_int len_bytes ; 216 long numbytes ; /* credit for transmission (dynamic queues) */ 217 218 u_int64_t tot_pkts ; /* statistics counters */ 219 u_int64_t tot_bytes ; 220 u_int32_t drops ; 221 222 int hash_slot ; /* debugging/diagnostic */ 223 224 /* RED parameters */ 225 int avg ; /* average queue length est. (scaled) */ 226 int count ; /* arrivals since last RED drop */ 227 int random ; /* random value (scaled) */ 228 u_int32_t q_time ; /* start of queue idle time */ 229 230 /* WF2Q+ support */ 231 struct dn_flow_set *fs ; /* parent flow set */ 232 int heap_pos ; /* position (index) of struct in heap */ 233 dn_key sched_time ; /* current time when queue enters ready_heap */ 234 235 dn_key S,F ; /* start time, finish time */ 236 /* 237 * Setting F < S means the timestamp is invalid. We only need 238 * to test this when the queue is empty. 239 */ 240 } ; 241 242 /* 243 * flow_set descriptor. Contains the "template" parameters for the 244 * queue configuration, and pointers to the hash table of dn_flow_queue's. 245 * 246 * The hash table is an array of lists -- we identify the slot by 247 * hashing the flow-id, then scan the list looking for a match. 248 * The size of the hash table (buckets) is configurable on a per-queue 249 * basis. 250 * 251 * A dn_flow_set is created whenever a new queue or pipe is created (in the 252 * latter case, the structure is located inside the struct dn_pipe). 253 */ 254 struct dn_flow_set { 255 struct dn_flow_set *next; /* next flow set in all_flow_sets list */ 256 257 u_short fs_nr ; /* flow_set number */ 258 u_short flags_fs; 259 #define DN_HAVE_FLOW_MASK 0x0001 260 #define DN_IS_RED 0x0002 261 #define DN_IS_GENTLE_RED 0x0004 262 #define DN_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */ 263 #define DN_IS_PIPE 0x4000 264 #define DN_IS_QUEUE 0x8000 265 266 struct dn_pipe *pipe ; /* pointer to parent pipe */ 267 u_short parent_nr ; /* parent pipe#, 0 if local to a pipe */ 268 269 int weight ; /* WFQ queue weight */ 270 int qsize ; /* queue size in slots or bytes */ 271 int plr ; /* pkt loss rate (2^31-1 means 100%) */ 272 273 struct ipfw_flow_id flow_mask ; 274 275 /* hash table of queues onto this flow_set */ 276 int rq_size ; /* number of slots */ 277 int rq_elements ; /* active elements */ 278 struct dn_flow_queue **rq; /* array of rq_size entries */ 279 280 u_int32_t last_expired ; /* do not expire too frequently */ 281 int backlogged ; /* #active queues for this flowset */ 282 283 /* RED parameters */ 284 #define SCALE_RED 16 285 #define SCALE(x) ( (x) << SCALE_RED ) 286 #define SCALE_VAL(x) ( (x) >> SCALE_RED ) 287 #define SCALE_MUL(x,y) ( ( (x) * (y) ) >> SCALE_RED ) 288 int w_q ; /* queue weight (scaled) */ 289 int max_th ; /* maximum threshold for queue (scaled) */ 290 int min_th ; /* minimum threshold for queue (scaled) */ 291 int max_p ; /* maximum value for p_b (scaled) */ 292 u_int c_1 ; /* max_p/(max_th-min_th) (scaled) */ 293 u_int c_2 ; /* max_p*min_th/(max_th-min_th) (scaled) */ 294 u_int c_3 ; /* for GRED, (1-max_p)/max_th (scaled) */ 295 u_int c_4 ; /* for GRED, 1 - 2*max_p (scaled) */ 296 u_int * w_q_lookup ; /* lookup table for computing (1-w_q)^t */ 297 u_int lookup_depth ; /* depth of lookup table */ 298 int lookup_step ; /* granularity inside the lookup table */ 299 int lookup_weight ; /* equal to (1-w_q)^t / (1-w_q)^(t+1) */ 300 int avg_pkt_size ; /* medium packet size */ 301 int max_pkt_size ; /* max packet size */ 302 } ; 303 304 /* 305 * Pipe descriptor. Contains global parameters, delay-line queue, 306 * and the flow_set used for fixed-rate queues. 307 * 308 * For WF2Q+ support it also has 3 heaps holding dn_flow_queue: 309 * not_eligible_heap, for queues whose start time is higher 310 * than the virtual time. Sorted by start time. 311 * scheduler_heap, for queues eligible for scheduling. Sorted by 312 * finish time. 313 * idle_heap, all flows that are idle and can be removed. We 314 * do that on each tick so we do not slow down too much 315 * operations during forwarding. 316 * 317 */ 318 struct dn_pipe { /* a pipe */ 319 struct dn_pipe *next ; 320 321 int pipe_nr ; /* number */ 322 int bandwidth; /* really, bytes/tick. */ 323 int delay ; /* really, ticks */ 324 325 struct dn_pkt *head, *tail ; /* packets in delay line */ 326 327 /* WF2Q+ */ 328 struct dn_heap scheduler_heap ; /* top extract - key Finish time*/ 329 struct dn_heap not_eligible_heap; /* top extract- key Start time */ 330 struct dn_heap idle_heap ; /* random extract - key Start=Finish time */ 331 332 dn_key V ; /* virtual time */ 333 int sum; /* sum of weights of all active sessions */ 334 int numbytes; /* bits I can transmit (more or less). */ 335 336 dn_key sched_time ; /* time pipe was scheduled in ready_heap */ 337 338 /* 339 * When the tx clock come from an interface (if_name[0] != '\0'), its name 340 * is stored below, whereas the ifp is filled when the rule is configured. 341 */ 342 char if_name[16]; 343 struct ifnet *ifp ; 344 int ready ; /* set if ifp != NULL and we got a signal from it */ 345 346 struct dn_flow_set fs ; /* used with fixed-rate flows */ 347 }; 348 349 #ifdef _KERNEL 350 typedef int ip_dn_ctl_t(struct sockopt *); /* raw_ip.c */ 351 typedef void ip_dn_ruledel_t(void *); /* ip_fw.c */ 352 typedef int ip_dn_io_t(int pipe, int dir, struct mbuf *m, 353 struct ifnet *ifp, struct route *ro, struct sockaddr_in * dst, 354 struct ip_fw *rule, int flags); /* ip_{in,out}put.c, bridge.c */ 355 extern ip_dn_ctl_t *ip_dn_ctl_ptr; 356 extern ip_dn_ruledel_t *ip_dn_ruledel_ptr; 357 extern ip_dn_io_t *ip_dn_io_ptr; 358 #define DUMMYNET_LOADED (ip_dn_io_ptr != NULL) 359 #endif 360 361 #endif /* _IP_DUMMYNET_H */ 362