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 struct sockaddr_in *dn_dst ; 131 struct route ro; /* route, for ip_output. MUST COPY */ 132 int flags ; /* flags, for ip_output (IPv6 ?) */ 133 }; 134 #endif /* _KERNEL */ 135 136 /* 137 * Overall structure of dummynet (with WF2Q+): 138 139 In dummynet, packets are selected with the firewall rules, and passed 140 to two different objects: PIPE or QUEUE. 141 142 A QUEUE is just a queue with configurable size and queue management 143 policy. It is also associated with a mask (to discriminate among 144 different flows), a weight (used to give different shares of the 145 bandwidth to different flows) and a "pipe", which essentially 146 supplies the transmit clock for all queues associated with that 147 pipe. 148 149 A PIPE emulates a fixed-bandwidth link, whose bandwidth is 150 configurable. The "clock" for a pipe can come from either an 151 internal timer, or from the transmit interrupt of an interface. 152 A pipe is also associated with one (or more, if masks are used) 153 queue, where all packets for that pipe are stored. 154 155 The bandwidth available on the pipe is shared by the queues 156 associated with that pipe (only one in case the packet is sent 157 to a PIPE) according to the WF2Q+ scheduling algorithm and the 158 configured weights. 159 160 In general, incoming packets are stored in the appropriate queue, 161 which is then placed into one of a few heaps managed by a scheduler 162 to decide when the packet should be extracted. 163 The scheduler (a function called dummynet()) is run at every timer 164 tick, and grabs queues from the head of the heaps when they are 165 ready for processing. 166 167 There are three data structures definining a pipe and associated queues: 168 169 + dn_pipe, which contains the main configuration parameters related 170 to delay and bandwidth; 171 + dn_flow_set, which contains WF2Q+ configuration, flow 172 masks, plr and RED configuration; 173 + dn_flow_queue, which is the per-flow queue (containing the packets) 174 175 Multiple dn_flow_set can be linked to the same pipe, and multiple 176 dn_flow_queue can be linked to the same dn_flow_set. 177 All data structures are linked in a linear list which is used for 178 housekeeping purposes. 179 180 During configuration, we create and initialize the dn_flow_set 181 and dn_pipe structures (a dn_pipe also contains a dn_flow_set). 182 183 At runtime: packets are sent to the appropriate dn_flow_set (either 184 WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows), 185 which in turn dispatches them to the appropriate dn_flow_queue 186 (created dynamically according to the masks). 187 188 The transmit clock for fixed rate flows (ready_event()) selects the 189 dn_flow_queue to be used to transmit the next packet. For WF2Q, 190 wfq_ready_event() extract a pipe which in turn selects the right 191 flow using a number of heaps defined into the pipe itself. 192 193 * 194 */ 195 196 /* 197 * per flow queue. This contains the flow identifier, the queue 198 * of packets, counters, and parameters used to support both RED and 199 * WF2Q+. 200 * 201 * A dn_flow_queue is created and initialized whenever a packet for 202 * a new flow arrives. 203 */ 204 struct dn_flow_queue { 205 struct dn_flow_queue *next ; 206 struct ipfw_flow_id id ; 207 208 struct mbuf *head, *tail ; /* queue of packets */ 209 u_int len ; 210 u_int len_bytes ; 211 u_long numbytes ; /* credit for transmission (dynamic queues) */ 212 213 u_int64_t tot_pkts ; /* statistics counters */ 214 u_int64_t tot_bytes ; 215 u_int32_t drops ; 216 217 int hash_slot ; /* debugging/diagnostic */ 218 219 /* RED parameters */ 220 int avg ; /* average queue length est. (scaled) */ 221 int count ; /* arrivals since last RED drop */ 222 int random ; /* random value (scaled) */ 223 u_int32_t q_time ; /* start of queue idle time */ 224 225 /* WF2Q+ support */ 226 struct dn_flow_set *fs ; /* parent flow set */ 227 int heap_pos ; /* position (index) of struct in heap */ 228 dn_key sched_time ; /* current time when queue enters ready_heap */ 229 230 dn_key S,F ; /* start time, finish time */ 231 /* 232 * Setting F < S means the timestamp is invalid. We only need 233 * to test this when the queue is empty. 234 */ 235 } ; 236 237 /* 238 * flow_set descriptor. Contains the "template" parameters for the 239 * queue configuration, and pointers to the hash table of dn_flow_queue's. 240 * 241 * The hash table is an array of lists -- we identify the slot by 242 * hashing the flow-id, then scan the list looking for a match. 243 * The size of the hash table (buckets) is configurable on a per-queue 244 * basis. 245 * 246 * A dn_flow_set is created whenever a new queue or pipe is created (in the 247 * latter case, the structure is located inside the struct dn_pipe). 248 */ 249 struct dn_flow_set { 250 struct dn_flow_set *next; /* next flow set in all_flow_sets list */ 251 252 u_short fs_nr ; /* flow_set number */ 253 u_short flags_fs; 254 #define DN_HAVE_FLOW_MASK 0x0001 255 #define DN_IS_RED 0x0002 256 #define DN_IS_GENTLE_RED 0x0004 257 #define DN_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */ 258 #define DN_NOERROR 0x0010 /* do not report ENOBUFS on drops */ 259 #define DN_IS_PIPE 0x4000 260 #define DN_IS_QUEUE 0x8000 261 262 struct dn_pipe *pipe ; /* pointer to parent pipe */ 263 u_short parent_nr ; /* parent pipe#, 0 if local to a pipe */ 264 265 int weight ; /* WFQ queue weight */ 266 int qsize ; /* queue size in slots or bytes */ 267 int plr ; /* pkt loss rate (2^31-1 means 100%) */ 268 269 struct ipfw_flow_id flow_mask ; 270 271 /* hash table of queues onto this flow_set */ 272 int rq_size ; /* number of slots */ 273 int rq_elements ; /* active elements */ 274 struct dn_flow_queue **rq; /* array of rq_size entries */ 275 276 u_int32_t last_expired ; /* do not expire too frequently */ 277 int backlogged ; /* #active queues for this flowset */ 278 279 /* RED parameters */ 280 #define SCALE_RED 16 281 #define SCALE(x) ( (x) << SCALE_RED ) 282 #define SCALE_VAL(x) ( (x) >> SCALE_RED ) 283 #define SCALE_MUL(x,y) ( ( (x) * (y) ) >> SCALE_RED ) 284 int w_q ; /* queue weight (scaled) */ 285 int max_th ; /* maximum threshold for queue (scaled) */ 286 int min_th ; /* minimum threshold for queue (scaled) */ 287 int max_p ; /* maximum value for p_b (scaled) */ 288 u_int c_1 ; /* max_p/(max_th-min_th) (scaled) */ 289 u_int c_2 ; /* max_p*min_th/(max_th-min_th) (scaled) */ 290 u_int c_3 ; /* for GRED, (1-max_p)/max_th (scaled) */ 291 u_int c_4 ; /* for GRED, 1 - 2*max_p (scaled) */ 292 u_int * w_q_lookup ; /* lookup table for computing (1-w_q)^t */ 293 u_int lookup_depth ; /* depth of lookup table */ 294 int lookup_step ; /* granularity inside the lookup table */ 295 int lookup_weight ; /* equal to (1-w_q)^t / (1-w_q)^(t+1) */ 296 int avg_pkt_size ; /* medium packet size */ 297 int max_pkt_size ; /* max packet size */ 298 } ; 299 300 /* 301 * Pipe descriptor. Contains global parameters, delay-line queue, 302 * and the flow_set used for fixed-rate queues. 303 * 304 * For WF2Q+ support it also has 3 heaps holding dn_flow_queue: 305 * not_eligible_heap, for queues whose start time is higher 306 * than the virtual time. Sorted by start time. 307 * scheduler_heap, for queues eligible for scheduling. Sorted by 308 * finish time. 309 * idle_heap, all flows that are idle and can be removed. We 310 * do that on each tick so we do not slow down too much 311 * operations during forwarding. 312 * 313 */ 314 struct dn_pipe { /* a pipe */ 315 struct dn_pipe *next ; 316 317 int pipe_nr ; /* number */ 318 int bandwidth; /* really, bytes/tick. */ 319 int delay ; /* really, ticks */ 320 321 struct mbuf *head, *tail ; /* packets in delay line */ 322 323 /* WF2Q+ */ 324 struct dn_heap scheduler_heap ; /* top extract - key Finish time*/ 325 struct dn_heap not_eligible_heap; /* top extract- key Start time */ 326 struct dn_heap idle_heap ; /* random extract - key Start=Finish time */ 327 328 dn_key V ; /* virtual time */ 329 int sum; /* sum of weights of all active sessions */ 330 int numbytes; /* bits I can transmit (more or less). */ 331 332 dn_key sched_time ; /* time pipe was scheduled in ready_heap */ 333 334 /* 335 * When the tx clock come from an interface (if_name[0] != '\0'), its name 336 * is stored below, whereas the ifp is filled when the rule is configured. 337 */ 338 char if_name[IFNAMSIZ]; 339 struct ifnet *ifp ; 340 int ready ; /* set if ifp != NULL and we got a signal from it */ 341 342 struct dn_flow_set fs ; /* used with fixed-rate flows */ 343 }; 344 345 #ifdef _KERNEL 346 typedef int ip_dn_ctl_t(struct sockopt *); /* raw_ip.c */ 347 typedef void ip_dn_ruledel_t(void *); /* ip_fw.c */ 348 typedef int ip_dn_io_t(struct mbuf *m, int pipe_nr, int dir, 349 struct ip_fw_args *fwa); 350 extern ip_dn_ctl_t *ip_dn_ctl_ptr; 351 extern ip_dn_ruledel_t *ip_dn_ruledel_ptr; 352 extern ip_dn_io_t *ip_dn_io_ptr; 353 #define DUMMYNET_LOADED (ip_dn_io_ptr != NULL) 354 355 /* 356 * Return the IPFW rule associated with the dummynet tag; if any. 357 * Make sure that the dummynet tag is not reused by lower layers. 358 */ 359 static __inline struct ip_fw * 360 ip_dn_claim_rule(struct mbuf *m) 361 { 362 struct m_tag *mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 363 if (mtag != NULL) { 364 mtag->m_tag_id = PACKET_TAG_NONE; 365 return (((struct dn_pkt_tag *)(mtag+1))->rule); 366 } else 367 return (NULL); 368 } 369 #endif 370 #endif /* _IP_DUMMYNET_H */ 371