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 * struct dn_pkt identifies a packet in the dummynet queue, but 108 * is also used to tag packets passed back to the various destinations 109 * (ip_input(), ip_output(), bdg_forward() and so on). 110 * As such the first part of the structure must be a struct m_hdr, 111 * followed by dummynet-specific parameters. The m_hdr must be 112 * initialized with 113 * mh_type = MT_TAG; 114 * mh_flags = PACKET_TYPE_DUMMYNET; 115 * mh_next = <pointer to the actual mbuf> 116 * 117 * mh_nextpkt, mh_data are free for dummynet use (mh_nextpkt is used to 118 * build a linked list of packets in a dummynet queue). 119 */ 120 struct dn_pkt { 121 struct m_hdr hdr ; 122 #define DN_NEXT(x) (struct dn_pkt *)(x)->hdr.mh_nextpkt 123 #define dn_m hdr.mh_next /* packet to be forwarded */ 124 125 struct ip_fw *rule; /* matching rule */ 126 int dn_dir; /* action when packet comes out. */ 127 #define DN_TO_IP_OUT 1 128 #define DN_TO_IP_IN 2 129 #define DN_TO_BDG_FWD 3 130 #define DN_TO_ETH_DEMUX 4 131 #define DN_TO_ETH_OUT 5 132 133 dn_key output_time; /* when the pkt is due for delivery */ 134 struct ifnet *ifp; /* interface, for ip_output */ 135 struct sockaddr_in *dn_dst ; 136 struct route ro; /* route, for ip_output. MUST COPY */ 137 int flags ; /* flags, for ip_output (IPv6 ?) */ 138 }; 139 140 /* 141 * Overall structure of dummynet (with WF2Q+): 142 143 In dummynet, packets are selected with the firewall rules, and passed 144 to two different objects: PIPE or QUEUE. 145 146 A QUEUE is just a queue with configurable size and queue management 147 policy. It is also associated with a mask (to discriminate among 148 different flows), a weight (used to give different shares of the 149 bandwidth to different flows) and a "pipe", which essentially 150 supplies the transmit clock for all queues associated with that 151 pipe. 152 153 A PIPE emulates a fixed-bandwidth link, whose bandwidth is 154 configurable. The "clock" for a pipe can come from either an 155 internal timer, or from the transmit interrupt of an interface. 156 A pipe is also associated with one (or more, if masks are used) 157 queue, where all packets for that pipe are stored. 158 159 The bandwidth available on the pipe is shared by the queues 160 associated with that pipe (only one in case the packet is sent 161 to a PIPE) according to the WF2Q+ scheduling algorithm and the 162 configured weights. 163 164 In general, incoming packets are stored in the appropriate queue, 165 which is then placed into one of a few heaps managed by a scheduler 166 to decide when the packet should be extracted. 167 The scheduler (a function called dummynet()) is run at every timer 168 tick, and grabs queues from the head of the heaps when they are 169 ready for processing. 170 171 There are three data structures definining a pipe and associated queues: 172 173 + dn_pipe, which contains the main configuration parameters related 174 to delay and bandwidth; 175 + dn_flow_set, which contains WF2Q+ configuration, flow 176 masks, plr and RED configuration; 177 + dn_flow_queue, which is the per-flow queue (containing the packets) 178 179 Multiple dn_flow_set can be linked to the same pipe, and multiple 180 dn_flow_queue can be linked to the same dn_flow_set. 181 All data structures are linked in a linear list which is used for 182 housekeeping purposes. 183 184 During configuration, we create and initialize the dn_flow_set 185 and dn_pipe structures (a dn_pipe also contains a dn_flow_set). 186 187 At runtime: packets are sent to the appropriate dn_flow_set (either 188 WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows), 189 which in turn dispatches them to the appropriate dn_flow_queue 190 (created dynamically according to the masks). 191 192 The transmit clock for fixed rate flows (ready_event()) selects the 193 dn_flow_queue to be used to transmit the next packet. For WF2Q, 194 wfq_ready_event() extract a pipe which in turn selects the right 195 flow using a number of heaps defined into the pipe itself. 196 197 * 198 */ 199 200 /* 201 * per flow queue. This contains the flow identifier, the queue 202 * of packets, counters, and parameters used to support both RED and 203 * WF2Q+. 204 * 205 * A dn_flow_queue is created and initialized whenever a packet for 206 * a new flow arrives. 207 */ 208 struct dn_flow_queue { 209 struct dn_flow_queue *next ; 210 struct ipfw_flow_id id ; 211 212 struct dn_pkt *head, *tail ; /* queue of packets */ 213 u_int len ; 214 u_int len_bytes ; 215 long numbytes ; /* credit for transmission (dynamic queues) */ 216 217 u_int64_t tot_pkts ; /* statistics counters */ 218 u_int64_t tot_bytes ; 219 u_int32_t drops ; 220 221 int hash_slot ; /* debugging/diagnostic */ 222 223 /* RED parameters */ 224 int avg ; /* average queue length est. (scaled) */ 225 int count ; /* arrivals since last RED drop */ 226 int random ; /* random value (scaled) */ 227 u_int32_t q_time ; /* start of queue idle time */ 228 229 /* WF2Q+ support */ 230 struct dn_flow_set *fs ; /* parent flow set */ 231 int heap_pos ; /* position (index) of struct in heap */ 232 dn_key sched_time ; /* current time when queue enters ready_heap */ 233 234 dn_key S,F ; /* start time, finish time */ 235 /* 236 * Setting F < S means the timestamp is invalid. We only need 237 * to test this when the queue is empty. 238 */ 239 } ; 240 241 /* 242 * flow_set descriptor. Contains the "template" parameters for the 243 * queue configuration, and pointers to the hash table of dn_flow_queue's. 244 * 245 * The hash table is an array of lists -- we identify the slot by 246 * hashing the flow-id, then scan the list looking for a match. 247 * The size of the hash table (buckets) is configurable on a per-queue 248 * basis. 249 * 250 * A dn_flow_set is created whenever a new queue or pipe is created (in the 251 * latter case, the structure is located inside the struct dn_pipe). 252 */ 253 struct dn_flow_set { 254 struct dn_flow_set *next; /* next flow set in all_flow_sets list */ 255 256 u_short fs_nr ; /* flow_set number */ 257 u_short flags_fs; 258 #define DN_HAVE_FLOW_MASK 0x0001 259 #define DN_IS_RED 0x0002 260 #define DN_IS_GENTLE_RED 0x0004 261 #define DN_QSIZE_IS_BYTES 0x0008 /* queue size is measured in bytes */ 262 #define DN_NOERROR 0x0010 /* do not report ENOBUFS on drops */ 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(struct mbuf *m, int pipe_nr, int dir, 353 struct ip_fw_args *fwa); 354 extern ip_dn_ctl_t *ip_dn_ctl_ptr; 355 extern ip_dn_ruledel_t *ip_dn_ruledel_ptr; 356 extern ip_dn_io_t *ip_dn_io_ptr; 357 #define DUMMYNET_LOADED (ip_dn_io_ptr != NULL) 358 #endif 359 360 #endif /* _IP_DUMMYNET_H */ 361