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 #define DN_TO_ETH_DEMUX 4 134 #define DN_TO_ETH_OUT 5 135 136 dn_key output_time; /* when the pkt is due for delivery */ 137 struct ifnet *ifp; /* interface, for ip_output */ 138 struct sockaddr_in *dn_dst ; 139 struct route ro; /* route, for ip_output. MUST COPY */ 140 int flags ; /* flags, for ip_output (IPv6 ?) */ 141 }; 142 143 /* 144 * Overall structure of dummynet (with WF2Q+): 145 146 In dummynet, packets are selected with the firewall rules, and passed 147 to two different objects: PIPE or QUEUE. 148 149 A QUEUE is just a queue with configurable size and queue management 150 policy. It is also associated with a mask (to discriminate among 151 different flows), a weight (used to give different shares of the 152 bandwidth to different flows) and a "pipe", which essentially 153 supplies the transmit clock for all queues associated with that 154 pipe. 155 156 A PIPE emulates a fixed-bandwidth link, whose bandwidth is 157 configurable. The "clock" for a pipe can come from either an 158 internal timer, or from the transmit interrupt of an interface. 159 A pipe is also associated with one (or more, if masks are used) 160 queue, where all packets for that pipe are stored. 161 162 The bandwidth available on the pipe is shared by the queues 163 associated with that pipe (only one in case the packet is sent 164 to a PIPE) according to the WF2Q+ scheduling algorithm and the 165 configured weights. 166 167 In general, incoming packets are stored in the appropriate queue, 168 which is then placed into one of a few heaps managed by a scheduler 169 to decide when the packet should be extracted. 170 The scheduler (a function called dummynet()) is run at every timer 171 tick, and grabs queues from the head of the heaps when they are 172 ready for processing. 173 174 There are three data structures definining a pipe and associated queues: 175 176 + dn_pipe, which contains the main configuration parameters related 177 to delay and bandwidth; 178 + dn_flow_set, which contains WF2Q+ configuration, flow 179 masks, plr and RED configuration; 180 + dn_flow_queue, which is the per-flow queue (containing the packets) 181 182 Multiple dn_flow_set can be linked to the same pipe, and multiple 183 dn_flow_queue can be linked to the same dn_flow_set. 184 All data structures are linked in a linear list which is used for 185 housekeeping purposes. 186 187 During configuration, we create and initialize the dn_flow_set 188 and dn_pipe structures (a dn_pipe also contains a dn_flow_set). 189 190 At runtime: packets are sent to the appropriate dn_flow_set (either 191 WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows), 192 which in turn dispatches them to the appropriate dn_flow_queue 193 (created dynamically according to the masks). 194 195 The transmit clock for fixed rate flows (ready_event()) selects the 196 dn_flow_queue to be used to transmit the next packet. For WF2Q, 197 wfq_ready_event() extract a pipe which in turn selects the right 198 flow using a number of heaps defined into the pipe itself. 199 200 * 201 */ 202 203 /* 204 * per flow queue. This contains the flow identifier, the queue 205 * of packets, counters, and parameters used to support both RED and 206 * WF2Q+. 207 * 208 * A dn_flow_queue is created and initialized whenever a packet for 209 * a new flow arrives. 210 */ 211 struct dn_flow_queue { 212 struct dn_flow_queue *next ; 213 struct ipfw_flow_id id ; 214 215 struct dn_pkt *head, *tail ; /* queue of packets */ 216 u_int len ; 217 u_int len_bytes ; 218 long numbytes ; /* credit for transmission (dynamic queues) */ 219 220 u_int64_t tot_pkts ; /* statistics counters */ 221 u_int64_t tot_bytes ; 222 u_int32_t drops ; 223 224 int hash_slot ; /* debugging/diagnostic */ 225 226 /* RED parameters */ 227 int avg ; /* average queue length est. (scaled) */ 228 int count ; /* arrivals since last RED drop */ 229 int random ; /* random value (scaled) */ 230 u_int32_t q_time ; /* start of queue idle time */ 231 232 /* WF2Q+ support */ 233 struct dn_flow_set *fs ; /* parent flow set */ 234 int heap_pos ; /* position (index) of struct in heap */ 235 dn_key sched_time ; /* current time when queue enters ready_heap */ 236 237 dn_key S,F ; /* start time, finish time */ 238 /* 239 * Setting F < S means the timestamp is invalid. We only need 240 * to test this when the queue is empty. 241 */ 242 } ; 243 244 /* 245 * flow_set descriptor. Contains the "template" parameters for the 246 * queue configuration, and pointers to the hash table of dn_flow_queue's. 247 * 248 * The hash table is an array of lists -- we identify the slot by 249 * hashing the flow-id, then scan the list looking for a match. 250 * The size of the hash table (buckets) is configurable on a per-queue 251 * basis. 252 * 253 * A dn_flow_set is created whenever a new queue or pipe is created (in the 254 * latter case, the structure is located inside the struct dn_pipe). 255 */ 256 struct dn_flow_set { 257 struct dn_flow_set *next; /* next flow set in all_flow_sets list */ 258 259 u_short fs_nr ; /* flow_set number */ 260 u_short flags_fs; 261 #define DN_HAVE_FLOW_MASK 0x0001 262 #define DN_IS_RED 0x0002 263 #define DN_IS_GENTLE_RED 0x0004 264 #define DN_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */ 265 #define DN_IS_PIPE 0x4000 266 #define DN_IS_QUEUE 0x8000 267 268 struct dn_pipe *pipe ; /* pointer to parent pipe */ 269 u_short parent_nr ; /* parent pipe#, 0 if local to a pipe */ 270 271 int weight ; /* WFQ queue weight */ 272 int qsize ; /* queue size in slots or bytes */ 273 int plr ; /* pkt loss rate (2^31-1 means 100%) */ 274 275 struct ipfw_flow_id flow_mask ; 276 277 /* hash table of queues onto this flow_set */ 278 int rq_size ; /* number of slots */ 279 int rq_elements ; /* active elements */ 280 struct dn_flow_queue **rq; /* array of rq_size entries */ 281 282 u_int32_t last_expired ; /* do not expire too frequently */ 283 int backlogged ; /* #active queues for this flowset */ 284 285 /* RED parameters */ 286 #define SCALE_RED 16 287 #define SCALE(x) ( (x) << SCALE_RED ) 288 #define SCALE_VAL(x) ( (x) >> SCALE_RED ) 289 #define SCALE_MUL(x,y) ( ( (x) * (y) ) >> SCALE_RED ) 290 int w_q ; /* queue weight (scaled) */ 291 int max_th ; /* maximum threshold for queue (scaled) */ 292 int min_th ; /* minimum threshold for queue (scaled) */ 293 int max_p ; /* maximum value for p_b (scaled) */ 294 u_int c_1 ; /* max_p/(max_th-min_th) (scaled) */ 295 u_int c_2 ; /* max_p*min_th/(max_th-min_th) (scaled) */ 296 u_int c_3 ; /* for GRED, (1-max_p)/max_th (scaled) */ 297 u_int c_4 ; /* for GRED, 1 - 2*max_p (scaled) */ 298 u_int * w_q_lookup ; /* lookup table for computing (1-w_q)^t */ 299 u_int lookup_depth ; /* depth of lookup table */ 300 int lookup_step ; /* granularity inside the lookup table */ 301 int lookup_weight ; /* equal to (1-w_q)^t / (1-w_q)^(t+1) */ 302 int avg_pkt_size ; /* medium packet size */ 303 int max_pkt_size ; /* max packet size */ 304 } ; 305 306 /* 307 * Pipe descriptor. Contains global parameters, delay-line queue, 308 * and the flow_set used for fixed-rate queues. 309 * 310 * For WF2Q+ support it also has 3 heaps holding dn_flow_queue: 311 * not_eligible_heap, for queues whose start time is higher 312 * than the virtual time. Sorted by start time. 313 * scheduler_heap, for queues eligible for scheduling. Sorted by 314 * finish time. 315 * idle_heap, all flows that are idle and can be removed. We 316 * do that on each tick so we do not slow down too much 317 * operations during forwarding. 318 * 319 */ 320 struct dn_pipe { /* a pipe */ 321 struct dn_pipe *next ; 322 323 int pipe_nr ; /* number */ 324 int bandwidth; /* really, bytes/tick. */ 325 int delay ; /* really, ticks */ 326 327 struct dn_pkt *head, *tail ; /* packets in delay line */ 328 329 /* WF2Q+ */ 330 struct dn_heap scheduler_heap ; /* top extract - key Finish time*/ 331 struct dn_heap not_eligible_heap; /* top extract- key Start time */ 332 struct dn_heap idle_heap ; /* random extract - key Start=Finish time */ 333 334 dn_key V ; /* virtual time */ 335 int sum; /* sum of weights of all active sessions */ 336 int numbytes; /* bits I can transmit (more or less). */ 337 338 dn_key sched_time ; /* time pipe was scheduled in ready_heap */ 339 340 /* 341 * When the tx clock come from an interface (if_name[0] != '\0'), its name 342 * is stored below, whereas the ifp is filled when the rule is configured. 343 */ 344 char if_name[16]; 345 struct ifnet *ifp ; 346 int ready ; /* set if ifp != NULL and we got a signal from it */ 347 348 struct dn_flow_set fs ; /* used with fixed-rate flows */ 349 }; 350 351 #ifdef _KERNEL 352 typedef int ip_dn_ctl_t(struct sockopt *); /* raw_ip.c */ 353 typedef void ip_dn_ruledel_t(void *); /* ip_fw.c */ 354 typedef int ip_dn_io_t(int pipe, int dir, struct mbuf *m, 355 struct ifnet *ifp, struct route *ro, struct sockaddr_in * dst, 356 struct ip_fw *rule, int flags); /* ip_{in,out}put.c, bridge.c */ 357 extern ip_dn_ctl_t *ip_dn_ctl_ptr; 358 extern ip_dn_ruledel_t *ip_dn_ruledel_ptr; 359 extern ip_dn_io_t *ip_dn_io_ptr; 360 #define DUMMYNET_LOADED (ip_dn_io_ptr != NULL) 361 #endif 362 363 #endif /* _IP_DUMMYNET_H */ 364