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 * The maximum hash table size for queues. This value must be a power 81 * of 2. 82 */ 83 #define DN_MAX_HASH_SIZE 65536 84 85 /* 86 * A heap entry is made of a key and a pointer to the actual 87 * object stored in the heap. 88 * The heap is an array of dn_heap_entry entries, dynamically allocated. 89 * Current size is "size", with "elements" actually in use. 90 * The heap normally supports only ordered insert and extract from the top. 91 * If we want to extract an object from the middle of the heap, we 92 * have to know where the object itself is located in the heap (or we 93 * need to scan the whole array). To this purpose, an object has a 94 * field (int) which contains the index of the object itself into the 95 * heap. When the object is moved, the field must also be updated. 96 * The offset of the index in the object is stored in the 'offset' 97 * field in the heap descriptor. The assumption is that this offset 98 * is non-zero if we want to support extract from the middle. 99 */ 100 struct dn_heap_entry { 101 dn_key key ; /* sorting key. Topmost element is smallest one */ 102 void *object ; /* object pointer */ 103 } ; 104 105 struct dn_heap { 106 int size ; 107 int elements ; 108 int offset ; /* XXX if > 0 this is the offset of direct ptr to obj */ 109 struct dn_heap_entry *p ; /* really an array of "size" entries */ 110 } ; 111 112 #ifdef _KERNEL 113 /* 114 * Packets processed by dummynet have an mbuf tag associated with 115 * them that carries their dummynet state. This is used within 116 * the dummynet code as well as outside when checking for special 117 * processing requirements. 118 */ 119 struct dn_pkt_tag { 120 struct ip_fw *rule; /* matching rule */ 121 int dn_dir; /* action when packet comes out. */ 122 #define DN_TO_IP_OUT 1 123 #define DN_TO_IP_IN 2 124 #define DN_TO_BDG_FWD 3 125 #define DN_TO_ETH_DEMUX 4 126 #define DN_TO_ETH_OUT 5 127 128 dn_key output_time; /* when the pkt is due for delivery */ 129 struct ifnet *ifp; /* interface, for ip_output */ 130 int flags ; /* flags, for ip_output (IPv6 ?) */ 131 }; 132 #endif /* _KERNEL */ 133 134 /* 135 * Overall structure of dummynet (with WF2Q+): 136 137 In dummynet, packets are selected with the firewall rules, and passed 138 to two different objects: PIPE or QUEUE. 139 140 A QUEUE is just a queue with configurable size and queue management 141 policy. It is also associated with a mask (to discriminate among 142 different flows), a weight (used to give different shares of the 143 bandwidth to different flows) and a "pipe", which essentially 144 supplies the transmit clock for all queues associated with that 145 pipe. 146 147 A PIPE emulates a fixed-bandwidth link, whose bandwidth is 148 configurable. The "clock" for a pipe can come from either an 149 internal timer, or from the transmit interrupt of an interface. 150 A pipe is also associated with one (or more, if masks are used) 151 queue, where all packets for that pipe are stored. 152 153 The bandwidth available on the pipe is shared by the queues 154 associated with that pipe (only one in case the packet is sent 155 to a PIPE) according to the WF2Q+ scheduling algorithm and the 156 configured weights. 157 158 In general, incoming packets are stored in the appropriate queue, 159 which is then placed into one of a few heaps managed by a scheduler 160 to decide when the packet should be extracted. 161 The scheduler (a function called dummynet()) is run at every timer 162 tick, and grabs queues from the head of the heaps when they are 163 ready for processing. 164 165 There are three data structures definining a pipe and associated queues: 166 167 + dn_pipe, which contains the main configuration parameters related 168 to delay and bandwidth; 169 + dn_flow_set, which contains WF2Q+ configuration, flow 170 masks, plr and RED configuration; 171 + dn_flow_queue, which is the per-flow queue (containing the packets) 172 173 Multiple dn_flow_set can be linked to the same pipe, and multiple 174 dn_flow_queue can be linked to the same dn_flow_set. 175 All data structures are linked in a linear list which is used for 176 housekeeping purposes. 177 178 During configuration, we create and initialize the dn_flow_set 179 and dn_pipe structures (a dn_pipe also contains a dn_flow_set). 180 181 At runtime: packets are sent to the appropriate dn_flow_set (either 182 WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows), 183 which in turn dispatches them to the appropriate dn_flow_queue 184 (created dynamically according to the masks). 185 186 The transmit clock for fixed rate flows (ready_event()) selects the 187 dn_flow_queue to be used to transmit the next packet. For WF2Q, 188 wfq_ready_event() extract a pipe which in turn selects the right 189 flow using a number of heaps defined into the pipe itself. 190 191 * 192 */ 193 194 /* 195 * per flow queue. This contains the flow identifier, the queue 196 * of packets, counters, and parameters used to support both RED and 197 * WF2Q+. 198 * 199 * A dn_flow_queue is created and initialized whenever a packet for 200 * a new flow arrives. 201 */ 202 struct dn_flow_queue { 203 struct dn_flow_queue *next ; 204 struct ipfw_flow_id id ; 205 206 struct mbuf *head, *tail ; /* queue of packets */ 207 u_int len ; 208 u_int len_bytes ; 209 u_long numbytes ; /* credit for transmission (dynamic queues) */ 210 211 u_int64_t tot_pkts ; /* statistics counters */ 212 u_int64_t tot_bytes ; 213 u_int32_t drops ; 214 215 int hash_slot ; /* debugging/diagnostic */ 216 217 /* RED parameters */ 218 int avg ; /* average queue length est. (scaled) */ 219 int count ; /* arrivals since last RED drop */ 220 int random ; /* random value (scaled) */ 221 u_int32_t q_time ; /* start of queue idle time */ 222 223 /* WF2Q+ support */ 224 struct dn_flow_set *fs ; /* parent flow set */ 225 int heap_pos ; /* position (index) of struct in heap */ 226 dn_key sched_time ; /* current time when queue enters ready_heap */ 227 228 dn_key S,F ; /* start time, finish time */ 229 /* 230 * Setting F < S means the timestamp is invalid. We only need 231 * to test this when the queue is empty. 232 */ 233 } ; 234 235 /* 236 * flow_set descriptor. Contains the "template" parameters for the 237 * queue configuration, and pointers to the hash table of dn_flow_queue's. 238 * 239 * The hash table is an array of lists -- we identify the slot by 240 * hashing the flow-id, then scan the list looking for a match. 241 * The size of the hash table (buckets) is configurable on a per-queue 242 * basis. 243 * 244 * A dn_flow_set is created whenever a new queue or pipe is created (in the 245 * latter case, the structure is located inside the struct dn_pipe). 246 */ 247 struct dn_flow_set { 248 struct dn_flow_set *next; /* next flow set in all_flow_sets list */ 249 250 u_short fs_nr ; /* flow_set number */ 251 u_short flags_fs; 252 #define DN_HAVE_FLOW_MASK 0x0001 253 #define DN_IS_RED 0x0002 254 #define DN_IS_GENTLE_RED 0x0004 255 #define DN_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */ 256 #define DN_NOERROR 0x0010 /* do not report ENOBUFS on drops */ 257 #define DN_IS_PIPE 0x4000 258 #define DN_IS_QUEUE 0x8000 259 260 struct dn_pipe *pipe ; /* pointer to parent pipe */ 261 u_short parent_nr ; /* parent pipe#, 0 if local to a pipe */ 262 263 int weight ; /* WFQ queue weight */ 264 int qsize ; /* queue size in slots or bytes */ 265 int plr ; /* pkt loss rate (2^31-1 means 100%) */ 266 267 struct ipfw_flow_id flow_mask ; 268 269 /* hash table of queues onto this flow_set */ 270 int rq_size ; /* number of slots */ 271 int rq_elements ; /* active elements */ 272 struct dn_flow_queue **rq; /* array of rq_size entries */ 273 274 u_int32_t last_expired ; /* do not expire too frequently */ 275 int backlogged ; /* #active queues for this flowset */ 276 277 /* RED parameters */ 278 #define SCALE_RED 16 279 #define SCALE(x) ( (x) << SCALE_RED ) 280 #define SCALE_VAL(x) ( (x) >> SCALE_RED ) 281 #define SCALE_MUL(x,y) ( ( (x) * (y) ) >> SCALE_RED ) 282 int w_q ; /* queue weight (scaled) */ 283 int max_th ; /* maximum threshold for queue (scaled) */ 284 int min_th ; /* minimum threshold for queue (scaled) */ 285 int max_p ; /* maximum value for p_b (scaled) */ 286 u_int c_1 ; /* max_p/(max_th-min_th) (scaled) */ 287 u_int c_2 ; /* max_p*min_th/(max_th-min_th) (scaled) */ 288 u_int c_3 ; /* for GRED, (1-max_p)/max_th (scaled) */ 289 u_int c_4 ; /* for GRED, 1 - 2*max_p (scaled) */ 290 u_int * w_q_lookup ; /* lookup table for computing (1-w_q)^t */ 291 u_int lookup_depth ; /* depth of lookup table */ 292 int lookup_step ; /* granularity inside the lookup table */ 293 int lookup_weight ; /* equal to (1-w_q)^t / (1-w_q)^(t+1) */ 294 int avg_pkt_size ; /* medium packet size */ 295 int max_pkt_size ; /* max packet size */ 296 } ; 297 298 /* 299 * Pipe descriptor. Contains global parameters, delay-line queue, 300 * and the flow_set used for fixed-rate queues. 301 * 302 * For WF2Q+ support it also has 3 heaps holding dn_flow_queue: 303 * not_eligible_heap, for queues whose start time is higher 304 * than the virtual time. Sorted by start time. 305 * scheduler_heap, for queues eligible for scheduling. Sorted by 306 * finish time. 307 * idle_heap, all flows that are idle and can be removed. We 308 * do that on each tick so we do not slow down too much 309 * operations during forwarding. 310 * 311 */ 312 struct dn_pipe { /* a pipe */ 313 struct dn_pipe *next ; 314 315 int pipe_nr ; /* number */ 316 int bandwidth; /* really, bytes/tick. */ 317 int delay ; /* really, ticks */ 318 319 struct mbuf *head, *tail ; /* packets in delay line */ 320 321 /* WF2Q+ */ 322 struct dn_heap scheduler_heap ; /* top extract - key Finish time*/ 323 struct dn_heap not_eligible_heap; /* top extract- key Start time */ 324 struct dn_heap idle_heap ; /* random extract - key Start=Finish time */ 325 326 dn_key V ; /* virtual time */ 327 int sum; /* sum of weights of all active sessions */ 328 int numbytes; /* bits I can transmit (more or less). */ 329 330 dn_key sched_time ; /* time pipe was scheduled in ready_heap */ 331 332 /* 333 * When the tx clock come from an interface (if_name[0] != '\0'), its name 334 * is stored below, whereas the ifp is filled when the rule is configured. 335 */ 336 char if_name[IFNAMSIZ]; 337 struct ifnet *ifp ; 338 int ready ; /* set if ifp != NULL and we got a signal from it */ 339 340 struct dn_flow_set fs ; /* used with fixed-rate flows */ 341 }; 342 343 #ifdef _KERNEL 344 typedef int ip_dn_ctl_t(struct sockopt *); /* raw_ip.c */ 345 typedef void ip_dn_ruledel_t(void *); /* ip_fw.c */ 346 typedef int ip_dn_io_t(struct mbuf *m, int dir, 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) 351 352 /* 353 * Return the IPFW rule associated with the dummynet tag; if any. 354 * Make sure that the dummynet tag is not reused by lower layers. 355 */ 356 static __inline struct ip_fw * 357 ip_dn_claim_rule(struct mbuf *m) 358 { 359 struct m_tag *mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 360 if (mtag != NULL) { 361 mtag->m_tag_id = PACKET_TAG_NONE; 362 return (((struct dn_pkt_tag *)(mtag+1))->rule); 363 } else 364 return (NULL); 365 } 366 #endif 367 #endif /* _IP_DUMMYNET_H */ 368