Cross Reference: /freebsd-11.0-release/share/man/man9/altq.9

altq.9 (133265)	altq.9 (133386)
1.\" $FreeBSD: head/share/man/man9/altq.9 133265 2004-08-07 12:35:56Z mlaier $
2.\" $NetBSD: altq.9,v 1.8 2002/05/28 11:41:45 wiz Exp $ 3.\" $OpenBSD: altq.9,v 1.4 2001/07/12 12:41:42 itojun Exp $ 4.\" 5.\" Copyright (C) 2004 Max Laier. All rights reserved. 6.\" Copyright (C) 2001 7.\" Sony Computer Science Laboratories Inc. All rights reserved. 8.\" 9.\" Redistribution and use in source and binary forms, with or without --- 12 unchanged lines hidden (view full) --- 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\"	1.\" $NetBSD: altq.9,v 1.8 2002/05/28 11:41:45 wiz Exp $ 2.\" $OpenBSD: altq.9,v 1.4 2001/07/12 12:41:42 itojun Exp $ 3.\" 4.\" Copyright (C) 2004 Max Laier. All rights reserved. 5.\" Copyright (C) 2001 6.\" Sony Computer Science Laboratories Inc. All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without --- 12 unchanged lines hidden (view full) --- 21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27.\" SUCH DAMAGE. 28.\"
	29.\" $FreeBSD: head/share/man/man9/altq.9 133386 2004-08-09 15:58:39Z mlaier $ 30.\"
30.Dd August 7, 2004 31.Dt ALTQ 9 32.Os 33.\" 34.Sh NAME 35.Nm ALTQ 36.Nd kernel interfaces for manipulating output queues on network interfaces 37.Sh SYNOPSIS 38.In sys/types.h 39.In sys/socket.h 40.In net/if.h 41.In net/if_var.h 42.\" 43.Ss Enqueue macros 44.Fn IFQ_ENQUEUE "struct ifaltq ifq" "struct mbuf m" "int error" 45.Fn IFQ_HANDOFF "struct ifnet ifp" "struct mbuf m" "int error"	31.Dd August 7, 2004 32.Dt ALTQ 9 33.Os 34.\" 35.Sh NAME 36.Nm ALTQ 37.Nd kernel interfaces for manipulating output queues on network interfaces 38.Sh SYNOPSIS 39.In sys/types.h 40.In sys/socket.h 41.In net/if.h 42.In net/if_var.h 43.\" 44.Ss Enqueue macros 45.Fn IFQ_ENQUEUE "struct ifaltq ifq" "struct mbuf m" "int error" 46.Fn IFQ_HANDOFF "struct ifnet ifp" "struct mbuf m" "int error"
46.Fn IFQ_HANDOFF_ADJ "struct ifnet ifp" "struct mbuf m" "int adjust" "int error"	47.Fo IFQ_HANDOFF_ADJ 48.Fa "struct ifnet ifp" "struct mbuf m" "int adjust" "int error" 49.Fc
47.\" 48.Ss Dequeue macros 49.Fn IFQ_DEQUEUE "struct ifaltq ifq" "struct mbuf m" 50.Fn IFQ_POLL_NOLOCK "struct ifaltq ifq" "struct mbuf m" 51.Fn IFQ_PURGE "struct ifaltq ifq" 52.Fn IFQ_IS_EMPTY "struct ifaltq ifq" 53.\" 54.Ss Driver managed dequeue macros --- 15 unchanged lines hidden (view full) --- 70interfaces. 71.Nm 72introduces new macros to manipulate output queues. 73The output queue macros are used to abstract queue operations and not to 74touch the internal fields of the output queue structure. 75The macros are independent from the 76.Nm 77implementation, and compatible with the traditional	50.\" 51.Ss Dequeue macros 52.Fn IFQ_DEQUEUE "struct ifaltq ifq" "struct mbuf m" 53.Fn IFQ_POLL_NOLOCK "struct ifaltq ifq" "struct mbuf m" 54.Fn IFQ_PURGE "struct ifaltq ifq" 55.Fn IFQ_IS_EMPTY "struct ifaltq ifq" 56.\" 57.Ss Driver managed dequeue macros --- 15 unchanged lines hidden (view full) --- 73interfaces. 74.Nm 75introduces new macros to manipulate output queues. 76The output queue macros are used to abstract queue operations and not to 77touch the internal fields of the output queue structure. 78The macros are independent from the 79.Nm 80implementation, and compatible with the traditional
78.Dv ifqueue	81.Vt ifqueue
79macros for ease of transition. 80.Pp 81.Fn IFQ_ENQUEUE , 82.Fn IFQ_HANDOFF 83and 84.Fn IFQ_HANDOFF_ADJ 85enqueue a packet 86.Fa m 87to the queue 88.Fa ifq . 89The underlying queuing discipline may discard the packet.	82macros for ease of transition. 83.Pp 84.Fn IFQ_ENQUEUE , 85.Fn IFQ_HANDOFF 86and 87.Fn IFQ_HANDOFF_ADJ 88enqueue a packet 89.Fa m 90to the queue 91.Fa ifq . 92The underlying queuing discipline may discard the packet.
	93The
90.Fa error	94.Fa error
91is set to 0 on success, or 92.Dv ENOBUFS	95argument is set to 0 on success, or 96.Er ENOBUFS
93if the packet is discarded.	97if the packet is discarded.
	98The packet pointed to by
94.Fa m	99.Fa m
95will be freed by the device driver on success or by the queuing discipline on 96failure so that the caller should not touch	100will be freed by the device driver on success, or by the queuing discipline on 101failure, so the caller should not touch
97.Fa m 98after enqueuing. 99.Fn IFQ_HANDOFF 100and 101.Fn IFQ_HANDOFF_ADJ 102combine the enqueue operation with statistic generation and call 103.Fn if_start 104upon successful enqueue to initiate the actual send. --- 10 unchanged lines hidden (view full) --- 115The caller must always check 116.Fa m 117since a non-empty queue could return 118.Dv NULL 119under rate-limiting. 120.Pp 121.Fn IFQ_POLL_NOLOCK 122returns the next packet without removing it from the queue.	102.Fa m 103after enqueuing. 104.Fn IFQ_HANDOFF 105and 106.Fn IFQ_HANDOFF_ADJ 107combine the enqueue operation with statistic generation and call 108.Fn if_start 109upon successful enqueue to initiate the actual send. --- 10 unchanged lines hidden (view full) --- 120The caller must always check 121.Fa m 122since a non-empty queue could return 123.Dv NULL 124under rate-limiting. 125.Pp 126.Fn IFQ_POLL_NOLOCK 127returns the next packet without removing it from the queue.
123The caller must hold the queue mutex when calling to	128The caller must hold the queue mutex when calling
124.Fn IFQ_POLL_NOLOCK 125in order to guarantee that a subsequent call to 126.Fn IFQ_DEQUEUE_NOLOCK 127dequeues the same packet. 128.Pp	129.Fn IFQ_POLL_NOLOCK 130in order to guarantee that a subsequent call to 131.Fn IFQ_DEQUEUE_NOLOCK 132dequeues the same packet. 133.Pp
129.Fn IFQ_XXX_NOLOCK 130variants - if available - always assume that the caller holds the queue mutex.	134.Fn IFQ__NOLOCK 135*variants (if available) always assume that the caller holds the queue mutex.
131They can be grabbed with 132.Fn IFQ_LOCK 133and released with 134.Fn IFQ_UNLOCK . 135.Pp 136.Fn IFQ_PURGE 137discards all the packets in the queue. 138The purge operation is needed since a non-work conserving queue cannot be --- 4 unchanged lines hidden (view full) --- 143Note that 144.Fn IFQ_DEQUEUE 145could still return 146.Dv NULL 147if the queuing discipline is non-work conserving. 148.Pp 149.Fn IFQ_DRV_DEQUEUE 150moves up to	136They can be grabbed with 137.Fn IFQ_LOCK 138and released with 139.Fn IFQ_UNLOCK . 140.Pp 141.Fn IFQ_PURGE 142discards all the packets in the queue. 143The purge operation is needed since a non-work conserving queue cannot be --- 4 unchanged lines hidden (view full) --- 148Note that 149.Fn IFQ_DEQUEUE 150could still return 151.Dv NULL 152if the queuing discipline is non-work conserving. 153.Pp 154.Fn IFQ_DRV_DEQUEUE 155moves up to
151.Va ifq->ifq_drv_maxlen	156.Fa ifq->ifq_drv_maxlen
152packets from the queue to the	157packets from the queue to the
153.Ql driver managed	158.Dq "driver managed"
154queue and returns the first one via 155.Fa m . 156As for 157.Fn IFQ_DEQUEUE , 158.Fa m 159can be 160.Dv NULL 161even for a non-empty queue. 162Subsequent calls to 163.Fn IFQ_DRV_DEQUEUE 164pass the packets from the	159queue and returns the first one via 160.Fa m . 161As for 162.Fn IFQ_DEQUEUE , 163.Fa m 164can be 165.Dv NULL 166even for a non-empty queue. 167Subsequent calls to 168.Fn IFQ_DRV_DEQUEUE 169pass the packets from the
165.Ql driver managed	170.Dq "driver managed"
166queue without obtaining the queue mutex. 167It is the responsibility of the caller to protect against concurrent access. 168Enabling 169.Nm 170for a given queue sets 171.Va ifq_drv_maxlen	171queue without obtaining the queue mutex. 172It is the responsibility of the caller to protect against concurrent access. 173Enabling 174.Nm 175for a given queue sets 176.Va ifq_drv_maxlen
172to 173.Dv 0 174as the 175.Ql bulk dequeue	177to 0 as the 178.Dq "bulk dequeue"
176performed by 177.Fn IFQ_DRV_DEQUEUE 178for higher values of 179.Va ifq_drv_maxlen 180is adverse to	179performed by 180.Fn IFQ_DRV_DEQUEUE 181for higher values of 182.Va ifq_drv_maxlen 183is adverse to
181.Sy ALTQ's	184.Nm ALTQ Ns 's
182internal timing. 183Note that a driver must not mix	185internal timing. 186Note that a driver must not mix
184.Fn IFQ_DRV_XXX	187.Fn IFQ_DRV_*
185macros with the default dequeue macros as the default macros do not look at the	188macros with the default dequeue macros as the default macros do not look at the
186.Ql driver managed	189.Dq "driver managed"
187queue which might lead to an mbuf leak. 188.Pp 189.Fn IFQ_DRV_PREPEND 190prepends 191.Fa m 192to the	190queue which might lead to an mbuf leak. 191.Pp 192.Fn IFQ_DRV_PREPEND 193prepends 194.Fa m 195to the
193.Ql driver managed	196.Dq "driver managed"
194queue from where it will be obtained with the next call to 195.Fn IFQ_DRV_DEQUEUE . 196.Pp 197.Fn IFQ_DRV_PURGE 198flushes all packets in the	197queue from where it will be obtained with the next call to 198.Fn IFQ_DRV_DEQUEUE . 199.Pp 200.Fn IFQ_DRV_PURGE 201flushes all packets in the
199.Ql driver managed	202.Dq "driver managed"
200queue and calls to 201.Fn IFQ_PURGE 202afterwards. 203.Pp 204.Fn IFQ_DRV_IS_EMPTY 205checks for packets in the	203queue and calls to 204.Fn IFQ_PURGE 205afterwards. 206.Pp 207.Fn IFQ_DRV_IS_EMPTY 208checks for packets in the
206.Ql driver managed 207part of the queue. If it is empty it forwards to	209.Dq "driver managed" 210part of the queue. 211If it is empty, it forwards to
208.Fn IFQ_IS_EMPTY . 209.Pp	212.Fn IFQ_IS_EMPTY . 213.Pp
210.Pp
211.Fn IFQ_SET_MAXLEN 212sets the queue length limit to the default FIFO queue.	214.Fn IFQ_SET_MAXLEN 215sets the queue length limit to the default FIFO queue.
213.Va ifaltq.ifq_drv_maxlen 214controls the length limit of the 215.Ql driver managed	216The 217.Va ifq_drv_maxlen 218member of the 219.Vt ifaltq 220structure controls the length limit of the 221.Dq "driver managed"
216queue. 217.Pp 218.Fn IFQ_INC_LEN 219and 220.Fn IFQ_DEC_LEN 221increment or decrement the current queue length in packets. 222This is mostly for internal purposes. 223.Pp 224.Fn IFQ_INC_DROPS	222queue. 223.Pp 224.Fn IFQ_INC_LEN 225and 226.Fn IFQ_DEC_LEN 227increment or decrement the current queue length in packets. 228This is mostly for internal purposes. 229.Pp 230.Fn IFQ_INC_DROPS
225increments the drop counter and is equal to	231increments the drop counter and is identical to
226.Fn IF_DROP .	232.Fn IF_DROP .
227It is defined for naming consistency.	233It is defined for naming consistency only.
228.Pp 229.Fn IFQ_SET_READY	234.Pp 235.Fn IFQ_SET_READY
230sets a flag to indicate this driver is converted to use the new macros.	236sets a flag to indicate that a driver was converted to use the new macros.
231.Nm 232can be enabled only on interfaces with this flag. 233.Sh COMPATIBILITY	237.Nm 238can be enabled only on interfaces with this flag. 239.Sh COMPATIBILITY
234.Ss ifaltq structure	240.Ss Vt ifaltq Ss structure
235In order to keep compatibility with the existing code, the new 236output queue structure	241In order to keep compatibility with the existing code, the new 242output queue structure
237.Dv ifaltq	243.Vt ifaltq
238has the same fields. 239The traditional	244has the same fields. 245The traditional
240.Fn IF_XXX	246.Fn IF_*
241macros and the code directly referencing the fields within	247macros and the code directly referencing the fields within
242.Dv if_snd	248.Va if_snd
243still work with	249still work with
244.Dv ifaltq .	250.Vt ifaltq .
245.Bd -literal 246 ##old-style## ##new-style## 247 \| 248 struct ifqueue { \| struct ifaltq { 249 struct mbuf ifq_head; \| struct mbuf ifq_head; 250 struct mbuf ifq_tail; \| struct mbuf ifq_tail; 251 int ifq_len; \| int ifq_len; 252 int ifq_maxlen; \| int ifq_maxlen; 253 int ifq_drops; \| int ifq_drops; 254 }; \| /* driver queue fields / 255* \| ...... 256 \| /* altq related fields / 257* \| ...... 258 \| }; 259 \| 260.Ed 261The new structure replaces	251.Bd -literal 252 ##old-style## ##new-style## 253 \| 254 struct ifqueue { \| struct ifaltq { 255 struct mbuf ifq_head; \| struct mbuf ifq_head; 256 struct mbuf ifq_tail; \| struct mbuf ifq_tail; 257 int ifq_len; \| int ifq_len; 258 int ifq_maxlen; \| int ifq_maxlen; 259 int ifq_drops; \| int ifq_drops; 260 }; \| /* driver queue fields / 261* \| ...... 262 \| /* altq related fields / 263* \| ...... 264 \| }; 265 \| 266.Ed 267The new structure replaces
262.Dv struct ifqueue	268.Vt "struct ifqueue"
263in	269in
264.Dv struct ifnet .	270.Vt "struct ifnet" .
265.Bd -literal 266 ##old-style## ##new-style## 267 \| 268 struct ifnet { \| struct ifnet { 269 .... \| .... 270 \| 271 struct ifqueue if_snd; \| struct ifaltq if_snd; 272 \| 273 .... \| .... 274 }; \| }; 275 \| 276.Ed 277The (simplified) new	271.Bd -literal 272 ##old-style## ##new-style## 273 \| 274 struct ifnet { \| struct ifnet { 275 .... \| .... 276 \| 277 struct ifqueue if_snd; \| struct ifaltq if_snd; 278 \| 279 .... \| .... 280 }; \| }; 281 \| 282.Ed 283The (simplified) new
278.Fn IFQ_XXX 279macros looks like:	284.Fn IFQ_* 285macros look like:
280.Bd -literal 281 #define IFQ_DEQUEUE(ifq, m) \e 282 if (ALTQ_IS_ENABLED((ifq)) \e 283 ALTQ_DEQUEUE((ifq), (m)); \e 284 else \e 285 IF_DEQUEUE((ifq), (m)); 286.Ed 287.Ss Enqueue operation --- 14 unchanged lines hidden (view full) --- 302 IF_ENQUEUE((ifq), (m)); \e 303 (error) = 0; \e 304 } \e 305} while (0) 306.Ed 307.Pp 308.Fn IFQ_ENQUEUE 309does the following:	286.Bd -literal 287 #define IFQ_DEQUEUE(ifq, m) \e 288 if (ALTQ_IS_ENABLED((ifq)) \e 289 ALTQ_DEQUEUE((ifq), (m)); \e 290 else \e 291 IF_DEQUEUE((ifq), (m)); 292.Ed 293.Ss Enqueue operation --- 14 unchanged lines hidden (view full) --- 308 IF_ENQUEUE((ifq), (m)); \e 309 (error) = 0; \e 310 } \e 311} while (0) 312.Ed 313.Pp 314.Fn IFQ_ENQUEUE 315does the following:
	316.Pp
310.Bl -hyphen -compact 311.It	317.Bl -hyphen -compact 318.It
312queue a packet	319queue a packet,
313.It	320.It
314drop (and free) a packet if the enqueue operation fails	321drop (and free) a packet if the enqueue operation fails.
315.El	322.El
	323.Pp
316If the enqueue operation fails, 317.Fa error 318is set to	324If the enqueue operation fails, 325.Fa error 326is set to
319.Dv ENOBUFS . 320.Fa mbuf 321is freed by the queuing discipline.	327.Er ENOBUFS . 328The 329.Fa m 330mbuf is freed by the queuing discipline.
322The caller should not touch mbuf after calling 323.Fn IFQ_ENQUEUE 324so that the caller may need to copy	331The caller should not touch mbuf after calling 332.Fn IFQ_ENQUEUE 333so that the caller may need to copy
325.Fa m_pkthdr.len	334.Va m_pkthdr.len
326or	335or
327.Fa m_flags	336.Va m_flags
328field beforehand for statistics. 329.Fn IFQ_HANDOFF 330and 331.Fn IFQ_HANDOFF_ADJ 332can be used if only default interface statistics and an immediate call to 333.Fn if_start 334are desired. 335The caller should not use --- 6 unchanged lines hidden (view full) --- 342.Bd -literal 343 ##old-style## ##new-style## 344 \| 345 int \| int 346 ether_output(ifp, m0, dst, rt0) \| ether_output(ifp, m0, dst, rt0) 347 { \| { 348 ...... \| ...... 349 \|	337field beforehand for statistics. 338.Fn IFQ_HANDOFF 339and 340.Fn IFQ_HANDOFF_ADJ 341can be used if only default interface statistics and an immediate call to 342.Fn if_start 343are desired. 344The caller should not use --- 6 unchanged lines hidden (view full) --- 351.Bd -literal 352 ##old-style## ##new-style## 353 \| 354 int \| int 355 ether_output(ifp, m0, dst, rt0) \| ether_output(ifp, m0, dst, rt0) 356 { \| { 357 ...... \| ...... 358 \|
350 \| mflags = m-\[Gt]m_flags; 351* \| len = m-\*[Gt]m_pkthdr.len;	359 \| mflags = m->m_flags; 360 \| len = m->m_pkthdr.len;
352 s = splimp(); \| s = splimp();	361 s = splimp(); \| s = splimp();
353 if (IF_QFULL(\[Am]ifp-\[Gt]if_snd)) { \| IFQ_ENQUEUE(\[Am]ifp-\[Gt]if_snd, m,	362 if (IF_QFULL(&ifp->if_snd)) { \| IFQ_ENQUEUE(&ifp->if_snd, m,
354 \| error);	363 \| error);
355 IF_DROP(\[Am]ifp-\[Gt]if_snd); \| if (error != 0) {	364 IF_DROP(&ifp->if_snd); \| if (error != 0) {
356 splx(s); \| splx(s); 357 senderr(ENOBUFS); \| return (error); 358 } \| }	365 splx(s); \| splx(s); 366 senderr(ENOBUFS); \| return (error); 367 } \| }
359 IF_ENQUEUE(\[Am]ifp-\[Gt]if_snd, m); \| 360 ifp-\[Gt]if_obytes += \| ifp-\[Gt]if_obytes += len; 361 m-\[Gt]m_pkthdr.len; \| 362* if (m-\[Gt]m_flags \[Am] M_MCAST) \| if (mflags \[Am] M_MCAST) 363* ifp-\[Gt]if_omcasts++; \| ifp-\[Gt]if_omcasts++;	368 IF_ENQUEUE(&ifp->if_snd, m); \| 369 ifp->if_obytes += \| ifp->if_obytes += len; 370 m->m_pkthdr.len; \| 371 if (m->m_flags & M_MCAST) \| if (mflags & M_MCAST) 372 ifp->if_omcasts++; \| ifp->if_omcasts++;
364 \|	373 \|
365 if ((ifp-\[Gt]if_flags \[Am] IFF_OACTIVE) \| if ((ifp-\[Gt]if_flags \[Am] IFF_OACTIVE)	374 if ((ifp->if_flags & IFF_OACTIVE) \| if ((ifp->if_flags & IFF_OACTIVE)
366 == 0) \| == 0)	375 == 0) \| == 0)
367 (ifp-\[Gt]if_start)(ifp); \| (ifp-\[Gt]if_start)(ifp);	376 (ifp->if_start)(ifp); \| (ifp->if_start)(ifp);
368 splx(s); \| splx(s); 369 return (error); \| return (error); 370 \| 371 bad: \| bad: 372 if (m) \| if (m) 373 m_freem(m); \| m_freem(m); 374 return (error); \| return (error); 375 } \| } 376 \| 377.Ed 378.Sh HOW TO CONVERT THE EXISTING DRIVERS 379First, make sure the corresponding 380.Fn if_output 381is already converted to the new style. 382.Pp 383Look for	377 splx(s); \| splx(s); 378 return (error); \| return (error); 379 \| 380 bad: \| bad: 381 if (m) \| if (m) 382 m_freem(m); \| m_freem(m); 383 return (error); \| return (error); 384 } \| } 385 \| 386.Ed 387.Sh HOW TO CONVERT THE EXISTING DRIVERS 388First, make sure the corresponding 389.Fn if_output 390is already converted to the new style. 391.Pp 392Look for
384.Fa if_snd	393.Va if_snd
385in the driver. 386Probably, you need to make changes to the lines that include	394in the driver. 395Probably, you need to make changes to the lines that include
387.Fa if_snd .	396.Va if_snd .
388.Ss Empty check operation 389If the code checks	397.Ss Empty check operation 398If the code checks
390.Fa ifq_head	399.Va ifq_head
391to see whether the queue is empty or not, use 392.Fn IFQ_IS_EMPTY . 393.Bd -literal 394 ##old-style## ##new-style## 395 \|	400to see whether the queue is empty or not, use 401.Fn IFQ_IS_EMPTY . 402.Bd -literal 403 ##old-style## ##new-style## 404 \|
396 if (ifp-\[Gt]if_snd.ifq_head != NULL) \| if (!IFQ_IS_EMPTY(\[Am]ifp-\*[Gt]if_snd))	405 if (ifp->if_snd.ifq_head != NULL) \| if (!IFQ_IS_EMPTY(&ifp->if_snd))
397 \| 398.Ed 399.Fn IFQ_IS_EMPTY	406 \| 407.Ed 408.Fn IFQ_IS_EMPTY
400checks only if there is any packet stored in the queue.	409only checks if there is any packet stored in the queue.
401Note that even when 402.Fn IFQ_IS_EMPTY 403is 404.Dv FALSE , 405.Fn IFQ_DEQUEUE 406could still return 407.Dv NULL 408if the queue is under rate-limiting. --- 11 unchanged lines hidden (view full) --- 420.Dv FALSE , 421.Fn IFQ_DEQUEUE 422could return 423.Dv NULL 424due to rate-limiting. 425.Bd -literal 426 ##old-style## ##new-style## 427 \|	410Note that even when 411.Fn IFQ_IS_EMPTY 412is 413.Dv FALSE , 414.Fn IFQ_DEQUEUE 415could still return 416.Dv NULL 417if the queue is under rate-limiting. --- 11 unchanged lines hidden (view full) --- 429.Dv FALSE , 430.Fn IFQ_DEQUEUE 431could return 432.Dv NULL 433due to rate-limiting. 434.Bd -literal 435 ##old-style## ##new-style## 436 \|
428 IF_DEQUEUE(\[Am]ifp-\[Gt]if_snd, m); \| IFQ_DEQUEUE(\[Am]ifp-\[Gt]if_snd, m);	437 IF_DEQUEUE(&ifp->if_snd, m); \| IFQ_DEQUEUE(&ifp->if_snd, m);
429 \| if (m == NULL) 430 \| return; 431 \| 432.Ed 433A driver is supposed to call 434.Fn if_start 435from transmission complete interrupts in order to trigger the next dequeue. 436.Ss Poll-and-dequeue operation 437If the code polls the packet at the head of the queue and actually uses 438the packet before dequeuing it, use 439.Fn IFQ_POLL_NOLOCK 440and 441.Fn IFQ_DEQUEUE_NOLOCK . 442.Bd -literal 443 ##old-style## ##new-style## 444 \|	438 \| if (m == NULL) 439 \| return; 440 \| 441.Ed 442A driver is supposed to call 443.Fn if_start 444from transmission complete interrupts in order to trigger the next dequeue. 445.Ss Poll-and-dequeue operation 446If the code polls the packet at the head of the queue and actually uses 447the packet before dequeuing it, use 448.Fn IFQ_POLL_NOLOCK 449and 450.Fn IFQ_DEQUEUE_NOLOCK . 451.Bd -literal 452 ##old-style## ##new-style## 453 \|
445 \| IFQ_LOCK(\[Am]ifp-\[Gt]if_snd); 446 m = ifp-\[Gt]if_snd.ifq_head; \| IFQ_POLL_NOLOCK(\[Am]ifp-\*[Gt]if_snd, m);	454 \| IFQ_LOCK(&ifp->if_snd); 455 m = ifp->if_snd.ifq_head; \| IFQ_POLL_NOLOCK(&ifp->if_snd, m);
447 if (m != NULL) { \| if (m != NULL) { 448 \| 449 /* use m to get resources / \| / use m to get resources / 450* if (something goes wrong) \| if (something goes wrong)	456 if (m != NULL) { \| if (m != NULL) { 457 \| 458 /* use m to get resources / \| / use m to get resources / 459* if (something goes wrong) \| if (something goes wrong)
451 \| IFQ_UNLOCK(\[Am]ifp-\[Gt]if_snd);	460 \| IFQ_UNLOCK(&ifp->if_snd);
452 return; \| return; 453 \|	461 return; \| return; 462 \|
454 IF_DEQUEUE(\[Am]ifp-\[Gt]if_snd, m); \| IFQ_DEQUEUE_NOLOCK(\[Am]ifp-\[Gt]if_snd, m); 455 \| IFQ_UNLOCK(\[Am]ifp-\[Gt]if_snd);	463 IF_DEQUEUE(&ifp->if_snd, m); \| IFQ_DEQUEUE_NOLOCK(&ifp->if_snd, m); 464 \| IFQ_UNLOCK(&ifp->if_snd);
456 \| 457 /* kick the hardware / \| / kick the hardware / 458* } \| } 459 \| 460.Ed 461It is guaranteed that 462.Fn IFQ_DEQUEUE_NOLOCK 463under the same lock as a previous 464.Fn IFQ_POLL_NOLOCK 465returns the same packet. 466Note that they need to be guarded by 467.Fn IFQ_LOCK .	465 \| 466 /* kick the hardware / \| / kick the hardware / 467* } \| } 468 \| 469.Ed 470It is guaranteed that 471.Fn IFQ_DEQUEUE_NOLOCK 472under the same lock as a previous 473.Fn IFQ_POLL_NOLOCK 474returns the same packet. 475Note that they need to be guarded by 476.Fn IFQ_LOCK .
468.Ss Eliminating IF_PREPEND	477.Ss Eliminating Fn IF_PREPEND
469If the code uses 470.Fn IF_PREPEND , 471you have to eliminate it unless you can use a	478If the code uses 479.Fn IF_PREPEND , 480you have to eliminate it unless you can use a
472.Ql driver managed 473queue which allows use of	481.Dq "driver managed" 482queue which allows the use of
474.Fn IFQ_DRV_PREPEND 475as a substitute.	483.Fn IFQ_DRV_PREPEND 484as a substitute.
476A common use of	485A common usage of
477.Fn IF_PREPEND 478is to cancel the previous dequeue operation. 479You have to convert the logic into poll-and-dequeue. 480.Bd -literal 481 ##old-style## ##new-style## 482 \|	486.Fn IF_PREPEND 487is to cancel the previous dequeue operation. 488You have to convert the logic into poll-and-dequeue. 489.Bd -literal 490 ##old-style## ##new-style## 491 \|
483 \| IFQ_LOCK(\[Am]ifp-\[Gt]if_snd); 484 IF_DEQUEUE(\[Am]ifp-\[Gt]if_snd, m); \| IFQ_POLL_NOLOCK(\[Am]ifp-\[Gt]if_snd, m);	492 \| IFQ_LOCK(&ifp->if_snd); 493 IF_DEQUEUE(&ifp->if_snd, m); \| IFQ_POLL_NOLOCK(&ifp->if_snd, m);
485 if (m != NULL) { \| if (m != NULL) { 486 \| 487 if (something_goes_wrong) { \| if (something_goes_wrong) {	494 if (m != NULL) { \| if (m != NULL) { 495 \| 496 if (something_goes_wrong) { \| if (something_goes_wrong) {
488 IF_PREPEND(\[Am]ifp-\[Gt]if_snd, m); \| IFQ_UNLOCK(\[Am]ifp-\[Gt]if_snd);	497 IF_PREPEND(&ifp->if_snd, m); \| IFQ_UNLOCK(&ifp->if_snd);
489 return; \| return; 490 } \| } 491 \| 492 \| /* at this point, the driver 493 \| * is committed to send this 494 \| * packet. 495 \| */	498 return; \| return; 499 } \| } 500 \| 501 \| /* at this point, the driver 502 \| * is committed to send this 503 \| * packet. 504 \| */
496 \| IFQ_DEQUEUE_NOLOCK(\[Am]ifp-\[Gt]if_snd, m); 497 \| IFQ_UNLOCK(\[Am]ifp-\[Gt]if_snd);	505 \| IFQ_DEQUEUE_NOLOCK(&ifp->if_snd, m); 506 \| IFQ_UNLOCK(&ifp->if_snd);
498 \| 499 /* kick the hardware / \| / kick the hardware / 500* } \| } 501 \| 502.Ed 503.Ss Purge operation 504Use 505.Fn IFQ_PURGE 506to empty the queue. 507Note that a non-work conserving queue cannot be emptied by a dequeue loop. 508.Bd -literal 509 ##old-style## ##new-style## 510 \|	507 \| 508 /* kick the hardware / \| / kick the hardware / 509* } \| } 510 \| 511.Ed 512.Ss Purge operation 513Use 514.Fn IFQ_PURGE 515to empty the queue. 516Note that a non-work conserving queue cannot be emptied by a dequeue loop. 517.Bd -literal 518 ##old-style## ##new-style## 519 \|
511 while (ifp-\[Gt]if_snd.ifq_head != NULL) {\| IFQ_PURGE(\[Am]ifp-\[Gt]if_snd); 512* IF_DEQUEUE(\[Am]ifp-\[Gt]if_snd, m); \|	520 while (ifp->if_snd.ifq_head != NULL) {\| IFQ_PURGE(&ifp->if_snd); 521 IF_DEQUEUE(&ifp->if_snd, m); \|
513 m_freem(m); \| 514 } \| 515 \| 516.Ed 517.Ss Conversion using a driver managed queue 518Convert	522 m_freem(m); \| 523 } \| 524 \| 525.Ed 526.Ss Conversion using a driver managed queue 527Convert
519.Fn IF_XXX	528.Fn IF_*
520macros to their equivalent	529macros to their equivalent
521.Fn IFQ_DRV_XXX	530.Fn IFQ_DRV_*
522and employ 523.Fn IFQ_DRV_IS_EMPTY	531and employ 532.Fn IFQ_DRV_IS_EMPTY
524where appropriate	533where appropriate.
525.Bd -literal 526 ##old-style## ##new-style## 527 \|	534.Bd -literal 535 ##old-style## ##new-style## 536 \|
528 if (ifp-\[Gt]if_snd.ifq_head != NULL) \| if (!IFQ_DRV_IS_EMPTY(\[Am]ifp-\*[Gt]if_snd))	537 if (ifp->if_snd.ifq_head != NULL) \| if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
529 \| 530.Ed 531Make sure that calls to 532.Fn IFQ_DRV_DEQUEUE , 533.Fn IFQ_DRV_PREPEND 534and 535.Fn IFQ_DRV_PURGE 536are protected with a mutex of some kind. 537Setting 538.Dv IFF_NEEDSGIANT 539in 540.Va if_flags 541might also be appropriate. 542.Ss Attach routine 543Use 544.Fn IFQ_SET_MAXLEN 545to set	538 \| 539.Ed 540Make sure that calls to 541.Fn IFQ_DRV_DEQUEUE , 542.Fn IFQ_DRV_PREPEND 543and 544.Fn IFQ_DRV_PURGE 545are protected with a mutex of some kind. 546Setting 547.Dv IFF_NEEDSGIANT 548in 549.Va if_flags 550might also be appropriate. 551.Ss Attach routine 552Use 553.Fn IFQ_SET_MAXLEN 554to set
546.Fa ifq_maxlen	555.Va ifq_maxlen
547to 548.Fa len . 549Initialize 550.Va ifq_drv_maxlen 551with a sensible value if you plan to use the	556to 557.Fa len . 558Initialize 559.Va ifq_drv_maxlen 560with a sensible value if you plan to use the
552.Fn IFQ_DRV_XXX	561.Fn IFQ_DRV_*
553macros. 554Add 555.Fn IFQ_SET_READY 556to show this driver is converted to the new style. 557(This is used to distinguish new-style drivers.) 558.Bd -literal 559 ##old-style## ##new-style## 560 \|	562macros. 563Add 564.Fn IFQ_SET_READY 565to show this driver is converted to the new style. 566(This is used to distinguish new-style drivers.) 567.Bd -literal 568 ##old-style## ##new-style## 569 \|
561 ifp-\[Gt]if_snd.ifq_maxlen = qsize; \| IFQ_SET_MAXLEN(\[Am]ifp-\[Gt]if_snd, qsize); 562* \| ifp-\[Gt]if_snd.ifq_drv_maxlen = qsize; 563* \| IFQ_SET_READY(\[Am]ifp-\[Gt]if_snd);	570 ifp->if_snd.ifq_maxlen = qsize; \| IFQ_SET_MAXLEN(&ifp->if_snd, qsize); 571 \| ifp->if_snd.ifq_drv_maxlen = qsize; 572 \| IFQ_SET_READY(&ifp->if_snd);
564 if_attach(ifp); \| if_attach(ifp); 565 \| 566.Ed 567.Ss Other issues 568The new macros for statistics: 569.Bd -literal 570 ##old-style## ##new-style## 571 \|	573 if_attach(ifp); \| if_attach(ifp); 574 \| 575.Ed 576.Ss Other issues 577The new macros for statistics: 578.Bd -literal 579 ##old-style## ##new-style## 580 \|
572 IF_DROP(\[Am]ifp-\[Gt]if_snd); \| IFQ_INC_DROPS(\[Am]ifp-\[Gt]if_snd);	581 IF_DROP(&ifp->if_snd); \| IFQ_INC_DROPS(&ifp->if_snd);
573 \|	582 \|
574 ifp-\[Gt]if_snd.ifq_len++; \| IFQ_INC_LEN(\[Am]ifp-\*[Gt]if_snd);	583 ifp->if_snd.ifq_len++; \| IFQ_INC_LEN(&ifp->if_snd);
575 \|	584 \|
576 ifp-\[Gt]if_snd.ifq_len--; \| IFQ_DEC_LEN(\[Am]ifp-\*[Gt]if_snd);	585 ifp->if_snd.ifq_len--; \| IFQ_DEC_LEN(&ifp->if_snd);
577 \| 578.Ed 579.Sh QUEUING DISCIPLINES 580Queuing disciplines need to maintain 581.Fa ifq_len	586 \| 587.Ed 588.Sh QUEUING DISCIPLINES 589Queuing disciplines need to maintain 590.Fa ifq_len
582.Po 583used by 584.Fn IFQ_IS_EMPTY 585.Pc . 586Queuing disciplines also need to guarantee the same mbuf is returned if	591(used by 592.Fn IFQ_IS_EMPTY ) . 593Queuing disciplines also need to guarantee that the same mbuf is returned if
587.Fn IFQ_DEQUEUE 588is called immediately after 589.Fn IFQ_POLL . 590.Sh SEE ALSO 591.Xr pf 4 ,	594.Fn IFQ_DEQUEUE 595is called immediately after 596.Fn IFQ_POLL . 597.Sh SEE ALSO 598.Xr pf 4 ,
592.Xr pf.conf 5	599.Xr pf.conf 5 ,
593.Xr pfctl 8 594.Sh HISTORY 595The 596.Nm 597system first appeared in March 1997.	600.Xr pfctl 8 601.Sh HISTORY 602The 603.Nm 604system first appeared in March 1997.

1.\" $FreeBSD: head/share/man/man9/altq.9 133265 2004-08-07 12:35:56Z mlaier $

2.\" $NetBSD: altq.9,v 1.8 2002/05/28 11:41:45 wiz Exp $
3.\" $OpenBSD: altq.9,v 1.4 2001/07/12 12:41:42 itojun Exp $
4.\"
5.\" Copyright (C) 2004 Max Laier. All rights reserved.
6.\" Copyright (C) 2001
7.\" Sony Computer Science Laboratories Inc. All rights reserved.
8.\"
9.\" Redistribution and use in source and binary forms, with or without

--- 12 unchanged lines hidden (view full) ---

22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28.\" SUCH DAMAGE.
29.\"

1.\" $NetBSD: altq.9,v 1.8 2002/05/28 11:41:45 wiz Exp $
2.\" $OpenBSD: altq.9,v 1.4 2001/07/12 12:41:42 itojun Exp $
3.\"
4.\" Copyright (C) 2004 Max Laier. All rights reserved.
5.\" Copyright (C) 2001
6.\" Sony Computer Science Laboratories Inc. All rights reserved.
7.\"
8.\" Redistribution and use in source and binary forms, with or without

--- 12 unchanged lines hidden (view full) ---

21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27.\" SUCH DAMAGE.
28.\"

29.\" $FreeBSD: head/share/man/man9/altq.9 133386 2004-08-09 15:58:39Z mlaier $
30.\"

30.Dd August 7, 2004
31.Dt ALTQ 9
32.Os
33.\"
34.Sh NAME
35.Nm ALTQ
36.Nd kernel interfaces for manipulating output queues on network interfaces
37.Sh SYNOPSIS
38.In sys/types.h
39.In sys/socket.h
40.In net/if.h
41.In net/if_var.h
42.\"
43.Ss Enqueue macros
44.Fn IFQ_ENQUEUE "struct ifaltq *ifq" "struct mbuf *m" "int error"
45.Fn IFQ_HANDOFF "struct ifnet *ifp" "struct mbuf *m" "int error"

31.Dd August 7, 2004
32.Dt ALTQ 9
33.Os
34.\"
35.Sh NAME
36.Nm ALTQ
37.Nd kernel interfaces for manipulating output queues on network interfaces
38.Sh SYNOPSIS
39.In sys/types.h
40.In sys/socket.h
41.In net/if.h
42.In net/if_var.h
43.\"
44.Ss Enqueue macros
45.Fn IFQ_ENQUEUE "struct ifaltq *ifq" "struct mbuf *m" "int error"
46.Fn IFQ_HANDOFF "struct ifnet *ifp" "struct mbuf *m" "int error"

46.Fn IFQ_HANDOFF_ADJ "struct ifnet *ifp" "struct mbuf *m" "int adjust" "int error"

47.Fo IFQ_HANDOFF_ADJ
48.Fa "struct ifnet *ifp" "struct mbuf *m" "int adjust" "int error"
49.Fc

47.\"
48.Ss Dequeue macros
49.Fn IFQ_DEQUEUE "struct ifaltq *ifq" "struct mbuf *m"
50.Fn IFQ_POLL_NOLOCK "struct ifaltq *ifq" "struct mbuf *m"
51.Fn IFQ_PURGE "struct ifaltq *ifq"
52.Fn IFQ_IS_EMPTY "struct ifaltq *ifq"
53.\"
54.Ss Driver managed dequeue macros

--- 15 unchanged lines hidden (view full) ---

70interfaces.
71.Nm
72introduces new macros to manipulate output queues.
73The output queue macros are used to abstract queue operations and not to
74touch the internal fields of the output queue structure.
75The macros are independent from the
76.Nm
77implementation, and compatible with the traditional

50.\"
51.Ss Dequeue macros
52.Fn IFQ_DEQUEUE "struct ifaltq *ifq" "struct mbuf *m"
53.Fn IFQ_POLL_NOLOCK "struct ifaltq *ifq" "struct mbuf *m"
54.Fn IFQ_PURGE "struct ifaltq *ifq"
55.Fn IFQ_IS_EMPTY "struct ifaltq *ifq"
56.\"
57.Ss Driver managed dequeue macros

--- 15 unchanged lines hidden (view full) ---

73interfaces.
74.Nm
75introduces new macros to manipulate output queues.
76The output queue macros are used to abstract queue operations and not to
77touch the internal fields of the output queue structure.
78The macros are independent from the
79.Nm
80implementation, and compatible with the traditional

78.Dv ifqueue

81.Vt ifqueue

79macros for ease of transition.
80.Pp
81.Fn IFQ_ENQUEUE ,
82.Fn IFQ_HANDOFF
83and
84.Fn IFQ_HANDOFF_ADJ
85enqueue a packet
86.Fa m
87to the queue
88.Fa ifq .
89The underlying queuing discipline may discard the packet.

82macros for ease of transition.
83.Pp
84.Fn IFQ_ENQUEUE ,
85.Fn IFQ_HANDOFF
86and
87.Fn IFQ_HANDOFF_ADJ
88enqueue a packet
89.Fa m
90to the queue
91.Fa ifq .
92The underlying queuing discipline may discard the packet.

93The

90.Fa error

94.Fa error

91is set to 0 on success, or
92.Dv ENOBUFS

95argument is set to 0 on success, or
96.Er ENOBUFS

93if the packet is discarded.

97if the packet is discarded.

98The packet pointed to by

94.Fa m

99.Fa m

95will be freed by the device driver on success or by the queuing discipline on
96failure so that the caller should not touch

100will be freed by the device driver on success, or by the queuing discipline on
101failure, so the caller should not touch

97.Fa m
98after enqueuing.
99.Fn IFQ_HANDOFF
100and
101.Fn IFQ_HANDOFF_ADJ
102combine the enqueue operation with statistic generation and call
103.Fn if_start
104upon successful enqueue to initiate the actual send.

--- 10 unchanged lines hidden (view full) ---

115The caller must always check
116.Fa m
117since a non-empty queue could return
118.Dv NULL
119under rate-limiting.
120.Pp
121.Fn IFQ_POLL_NOLOCK
122returns the next packet without removing it from the queue.

102.Fa m
103after enqueuing.
104.Fn IFQ_HANDOFF
105and
106.Fn IFQ_HANDOFF_ADJ
107combine the enqueue operation with statistic generation and call
108.Fn if_start
109upon successful enqueue to initiate the actual send.

--- 10 unchanged lines hidden (view full) ---

120The caller must always check
121.Fa m
122since a non-empty queue could return
123.Dv NULL
124under rate-limiting.
125.Pp
126.Fn IFQ_POLL_NOLOCK
127returns the next packet without removing it from the queue.

123The caller must hold the queue mutex when calling to

128The caller must hold the queue mutex when calling

124.Fn IFQ_POLL_NOLOCK
125in order to guarantee that a subsequent call to
126.Fn IFQ_DEQUEUE_NOLOCK
127dequeues the same packet.
128.Pp

129.Fn IFQ_POLL_NOLOCK
130in order to guarantee that a subsequent call to
131.Fn IFQ_DEQUEUE_NOLOCK
132dequeues the same packet.
133.Pp

129.Fn IFQ_XXX_NOLOCK
130variants - if available - always assume that the caller holds the queue mutex.

134.Fn IFQ_*_NOLOCK
135variants (if available) always assume that the caller holds the queue mutex.

131They can be grabbed with
132.Fn IFQ_LOCK
133and released with
134.Fn IFQ_UNLOCK .
135.Pp
136.Fn IFQ_PURGE
137discards all the packets in the queue.
138The purge operation is needed since a non-work conserving queue cannot be

--- 4 unchanged lines hidden (view full) ---

143Note that
144.Fn IFQ_DEQUEUE
145could still return
146.Dv NULL
147if the queuing discipline is non-work conserving.
148.Pp
149.Fn IFQ_DRV_DEQUEUE
150moves up to

136They can be grabbed with
137.Fn IFQ_LOCK
138and released with
139.Fn IFQ_UNLOCK .
140.Pp
141.Fn IFQ_PURGE
142discards all the packets in the queue.
143The purge operation is needed since a non-work conserving queue cannot be

--- 4 unchanged lines hidden (view full) ---

148Note that
149.Fn IFQ_DEQUEUE
150could still return
151.Dv NULL
152if the queuing discipline is non-work conserving.
153.Pp
154.Fn IFQ_DRV_DEQUEUE
155moves up to

151.Va ifq->ifq_drv_maxlen

156.Fa ifq->ifq_drv_maxlen

152packets from the queue to the

157packets from the queue to the

153.Ql driver managed

158.Dq "driver managed"

154queue and returns the first one via
155.Fa m .
156As for
157.Fn IFQ_DEQUEUE ,
158.Fa m
159can be
160.Dv NULL
161even for a non-empty queue.
162Subsequent calls to
163.Fn IFQ_DRV_DEQUEUE
164pass the packets from the

159queue and returns the first one via
160.Fa m .
161As for
162.Fn IFQ_DEQUEUE ,
163.Fa m
164can be
165.Dv NULL
166even for a non-empty queue.
167Subsequent calls to
168.Fn IFQ_DRV_DEQUEUE
169pass the packets from the

165.Ql driver managed

170.Dq "driver managed"

166queue without obtaining the queue mutex.
167It is the responsibility of the caller to protect against concurrent access.
168Enabling
169.Nm
170for a given queue sets
171.Va ifq_drv_maxlen

171queue without obtaining the queue mutex.
172It is the responsibility of the caller to protect against concurrent access.
173Enabling
174.Nm
175for a given queue sets
176.Va ifq_drv_maxlen

172to
173.Dv 0
174as the
175.Ql bulk dequeue

177to 0 as the
178.Dq "bulk dequeue"

176performed by
177.Fn IFQ_DRV_DEQUEUE
178for higher values of
179.Va ifq_drv_maxlen
180is adverse to

179performed by
180.Fn IFQ_DRV_DEQUEUE
181for higher values of
182.Va ifq_drv_maxlen
183is adverse to

181.Sy ALTQ's

184.Nm ALTQ Ns 's

182internal timing.
183Note that a driver must not mix

185internal timing.
186Note that a driver must not mix

184.Fn IFQ_DRV_XXX

187.Fn IFQ_DRV_*

185macros with the default dequeue macros as the default macros do not look at the

188macros with the default dequeue macros as the default macros do not look at the

186.Ql driver managed

189.Dq "driver managed"

187queue which might lead to an mbuf leak.
188.Pp
189.Fn IFQ_DRV_PREPEND
190prepends
191.Fa m
192to the

190queue which might lead to an mbuf leak.
191.Pp
192.Fn IFQ_DRV_PREPEND
193prepends
194.Fa m
195to the

193.Ql driver managed

196.Dq "driver managed"

194queue from where it will be obtained with the next call to
195.Fn IFQ_DRV_DEQUEUE .
196.Pp
197.Fn IFQ_DRV_PURGE
198flushes all packets in the

197queue from where it will be obtained with the next call to
198.Fn IFQ_DRV_DEQUEUE .
199.Pp
200.Fn IFQ_DRV_PURGE
201flushes all packets in the

199.Ql driver managed

202.Dq "driver managed"

200queue and calls to
201.Fn IFQ_PURGE
202afterwards.
203.Pp
204.Fn IFQ_DRV_IS_EMPTY
205checks for packets in the

203queue and calls to
204.Fn IFQ_PURGE
205afterwards.
206.Pp
207.Fn IFQ_DRV_IS_EMPTY
208checks for packets in the

206.Ql driver managed
207part of the queue. If it is empty it forwards to

209.Dq "driver managed"
210part of the queue.
211If it is empty, it forwards to

208.Fn IFQ_IS_EMPTY .
209.Pp

212.Fn IFQ_IS_EMPTY .
213.Pp

210.Pp

211.Fn IFQ_SET_MAXLEN
212sets the queue length limit to the default FIFO queue.

214.Fn IFQ_SET_MAXLEN
215sets the queue length limit to the default FIFO queue.

213.Va ifaltq.ifq_drv_maxlen
214controls the length limit of the
215.Ql driver managed

216The
217.Va ifq_drv_maxlen
218member of the
219.Vt ifaltq
220structure controls the length limit of the
221.Dq "driver managed"

216queue.
217.Pp
218.Fn IFQ_INC_LEN
219and
220.Fn IFQ_DEC_LEN
221increment or decrement the current queue length in packets.
222This is mostly for internal purposes.
223.Pp
224.Fn IFQ_INC_DROPS

222queue.
223.Pp
224.Fn IFQ_INC_LEN
225and
226.Fn IFQ_DEC_LEN
227increment or decrement the current queue length in packets.
228This is mostly for internal purposes.
229.Pp
230.Fn IFQ_INC_DROPS

225increments the drop counter and is equal to

231increments the drop counter and is identical to

226.Fn IF_DROP .

232.Fn IF_DROP .

227It is defined for naming consistency.

233It is defined for naming consistency only.

228.Pp
229.Fn IFQ_SET_READY

234.Pp
235.Fn IFQ_SET_READY

230sets a flag to indicate this driver is converted to use the new macros.

236sets a flag to indicate that a driver was converted to use the new macros.

231.Nm
232can be enabled only on interfaces with this flag.
233.Sh COMPATIBILITY

237.Nm
238can be enabled only on interfaces with this flag.
239.Sh COMPATIBILITY

234.Ss ifaltq structure

240.Ss Vt ifaltq Ss structure

235In order to keep compatibility with the existing code, the new
236output queue structure

241In order to keep compatibility with the existing code, the new
242output queue structure

237.Dv ifaltq

243.Vt ifaltq

238has the same fields.
239The traditional

244has the same fields.
245The traditional

240.Fn IF_XXX

246.Fn IF_*

241macros and the code directly referencing the fields within

247macros and the code directly referencing the fields within

242.Dv if_snd

248.Va if_snd

243still work with

249still work with

244.Dv ifaltq .

250.Vt ifaltq .

245.Bd -literal
246 ##old-style## ##new-style##
247 |
248 struct ifqueue { | struct ifaltq {
249 struct mbuf *ifq_head; | struct mbuf *ifq_head;
250 struct mbuf *ifq_tail; | struct mbuf *ifq_tail;
251 int ifq_len; | int ifq_len;
252 int ifq_maxlen; | int ifq_maxlen;
253 int ifq_drops; | int ifq_drops;
254 }; | /* driver queue fields */
255 | ......
256 | /* altq related fields */
257 | ......
258 | };
259 |
260.Ed
261The new structure replaces

251.Bd -literal
252 ##old-style## ##new-style##
253 |
254 struct ifqueue { | struct ifaltq {
255 struct mbuf *ifq_head; | struct mbuf *ifq_head;
256 struct mbuf *ifq_tail; | struct mbuf *ifq_tail;
257 int ifq_len; | int ifq_len;
258 int ifq_maxlen; | int ifq_maxlen;
259 int ifq_drops; | int ifq_drops;
260 }; | /* driver queue fields */
261 | ......
262 | /* altq related fields */
263 | ......
264 | };
265 |
266.Ed
267The new structure replaces

262.Dv struct ifqueue

268.Vt "struct ifqueue"

263in

269in

264.Dv struct ifnet .

270.Vt "struct ifnet" .

265.Bd -literal
266 ##old-style## ##new-style##
267 |
268 struct ifnet { | struct ifnet {
269 .... | ....
270 |
271 struct ifqueue if_snd; | struct ifaltq if_snd;
272 |
273 .... | ....
274 }; | };
275 |
276.Ed
277The (simplified) new

271.Bd -literal
272 ##old-style## ##new-style##
273 |
274 struct ifnet { | struct ifnet {
275 .... | ....
276 |
277 struct ifqueue if_snd; | struct ifaltq if_snd;
278 |
279 .... | ....
280 }; | };
281 |
282.Ed
283The (simplified) new

278.Fn IFQ_XXX
279macros looks like:

284.Fn IFQ_*
285macros look like:

280.Bd -literal
281 #define IFQ_DEQUEUE(ifq, m) \e
282 if (ALTQ_IS_ENABLED((ifq)) \e
283 ALTQ_DEQUEUE((ifq), (m)); \e
284 else \e
285 IF_DEQUEUE((ifq), (m));
286.Ed
287.Ss Enqueue operation

--- 14 unchanged lines hidden (view full) ---

302 IF_ENQUEUE((ifq), (m)); \e
303 (error) = 0; \e
304 } \e
305} while (0)
306.Ed
307.Pp
308.Fn IFQ_ENQUEUE
309does the following:

286.Bd -literal
287 #define IFQ_DEQUEUE(ifq, m) \e
288 if (ALTQ_IS_ENABLED((ifq)) \e
289 ALTQ_DEQUEUE((ifq), (m)); \e
290 else \e
291 IF_DEQUEUE((ifq), (m));
292.Ed
293.Ss Enqueue operation

--- 14 unchanged lines hidden (view full) ---

308 IF_ENQUEUE((ifq), (m)); \e
309 (error) = 0; \e
310 } \e
311} while (0)
312.Ed
313.Pp
314.Fn IFQ_ENQUEUE
315does the following:

316.Pp

310.Bl -hyphen -compact
311.It

317.Bl -hyphen -compact
318.It

312queue a packet

319queue a packet,

313.It

320.It

314drop (and free) a packet if the enqueue operation fails

321drop (and free) a packet if the enqueue operation fails.

315.El

322.El

323.Pp

316If the enqueue operation fails,
317.Fa error
318is set to

324If the enqueue operation fails,
325.Fa error
326is set to

319.Dv ENOBUFS .
320.Fa mbuf
321is freed by the queuing discipline.

327.Er ENOBUFS .
328The
329.Fa m
330mbuf is freed by the queuing discipline.

322The caller should not touch mbuf after calling
323.Fn IFQ_ENQUEUE
324so that the caller may need to copy

331The caller should not touch mbuf after calling
332.Fn IFQ_ENQUEUE
333so that the caller may need to copy

325.Fa m_pkthdr.len

334.Va m_pkthdr.len

326or

335or

327.Fa m_flags

336.Va m_flags

328field beforehand for statistics.
329.Fn IFQ_HANDOFF
330and
331.Fn IFQ_HANDOFF_ADJ
332can be used if only default interface statistics and an immediate call to
333.Fn if_start
334are desired.
335The caller should not use

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342.Bd -literal
343 ##old-style## ##new-style##
344 |
345 int | int
346 ether_output(ifp, m0, dst, rt0) | ether_output(ifp, m0, dst, rt0)
347 { | {
348 ...... | ......
349 |

337field beforehand for statistics.
338.Fn IFQ_HANDOFF
339and
340.Fn IFQ_HANDOFF_ADJ
341can be used if only default interface statistics and an immediate call to
342.Fn if_start
343are desired.
344The caller should not use

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351.Bd -literal
352 ##old-style## ##new-style##
353 |
354 int | int
355 ether_output(ifp, m0, dst, rt0) | ether_output(ifp, m0, dst, rt0)
356 { | {
357 ...... | ......
358 |

350 | mflags = m-\*[Gt]m_flags;
351 | len = m-\*[Gt]m_pkthdr.len;

359 | mflags = m->m_flags;
360 | len = m->m_pkthdr.len;

352 s = splimp(); | s = splimp();

361 s = splimp(); | s = splimp();

353 if (IF_QFULL(\*[Am]ifp-\*[Gt]if_snd)) { | IFQ_ENQUEUE(\*[Am]ifp-\*[Gt]if_snd, m,

362 if (IF_QFULL(&ifp->if_snd)) { | IFQ_ENQUEUE(&ifp->if_snd, m,

354 | error);

363 | error);

355 IF_DROP(\*[Am]ifp-\*[Gt]if_snd); | if (error != 0) {

364 IF_DROP(&ifp->if_snd); | if (error != 0) {

356 splx(s); | splx(s);
357 senderr(ENOBUFS); | return (error);
358 } | }

365 splx(s); | splx(s);
366 senderr(ENOBUFS); | return (error);
367 } | }

359 IF_ENQUEUE(\*[Am]ifp-\*[Gt]if_snd, m); |
360 ifp-\*[Gt]if_obytes += | ifp-\*[Gt]if_obytes += len;
361 m-\*[Gt]m_pkthdr.len; |
362 if (m-\*[Gt]m_flags \*[Am] M_MCAST) | if (mflags \*[Am] M_MCAST)
363 ifp-\*[Gt]if_omcasts++; | ifp-\*[Gt]if_omcasts++;

364 |

373 |

365 if ((ifp-\*[Gt]if_flags \*[Am] IFF_OACTIVE) | if ((ifp-\*[Gt]if_flags \*[Am] IFF_OACTIVE)

374 if ((ifp->if_flags & IFF_OACTIVE) | if ((ifp->if_flags & IFF_OACTIVE)

366 == 0) | == 0)

375 == 0) | == 0)

367 (*ifp-\*[Gt]if_start)(ifp); | (*ifp-\*[Gt]if_start)(ifp);

376 (*ifp->if_start)(ifp); | (*ifp->if_start)(ifp);

368 splx(s); | splx(s);
369 return (error); | return (error);
370 |
371 bad: | bad:
372 if (m) | if (m)
373 m_freem(m); | m_freem(m);
374 return (error); | return (error);
375 } | }
376 |
377.Ed
378.Sh HOW TO CONVERT THE EXISTING DRIVERS
379First, make sure the corresponding
380.Fn if_output
381is already converted to the new style.
382.Pp
383Look for

377 splx(s); | splx(s);
378 return (error); | return (error);
379 |
380 bad: | bad:
381 if (m) | if (m)
382 m_freem(m); | m_freem(m);
383 return (error); | return (error);
384 } | }
385 |
386.Ed
387.Sh HOW TO CONVERT THE EXISTING DRIVERS
388First, make sure the corresponding
389.Fn if_output
390is already converted to the new style.
391.Pp
392Look for

384.Fa if_snd

393.Va if_snd

385in the driver.
386Probably, you need to make changes to the lines that include

394in the driver.
395Probably, you need to make changes to the lines that include

387.Fa if_snd .

396.Va if_snd .

388.Ss Empty check operation
389If the code checks

397.Ss Empty check operation
398If the code checks

390.Fa ifq_head

399.Va ifq_head

391to see whether the queue is empty or not, use
392.Fn IFQ_IS_EMPTY .
393.Bd -literal
394 ##old-style## ##new-style##
395 |

400to see whether the queue is empty or not, use
401.Fn IFQ_IS_EMPTY .
402.Bd -literal
403 ##old-style## ##new-style##
404 |

396 if (ifp-\*[Gt]if_snd.ifq_head != NULL) | if (!IFQ_IS_EMPTY(\*[Am]ifp-\*[Gt]if_snd))

405 if (ifp->if_snd.ifq_head != NULL) | if (!IFQ_IS_EMPTY(&ifp->if_snd))

397 |
398.Ed
399.Fn IFQ_IS_EMPTY

406 |
407.Ed
408.Fn IFQ_IS_EMPTY

400checks only if there is any packet stored in the queue.

409only checks if there is any packet stored in the queue.

401Note that even when
402.Fn IFQ_IS_EMPTY
403is
404.Dv FALSE ,
405.Fn IFQ_DEQUEUE
406could still return
407.Dv NULL
408if the queue is under rate-limiting.

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420.Dv FALSE ,
421.Fn IFQ_DEQUEUE
422could return
423.Dv NULL
424due to rate-limiting.
425.Bd -literal
426 ##old-style## ##new-style##
427 |

410Note that even when
411.Fn IFQ_IS_EMPTY
412is
413.Dv FALSE ,
414.Fn IFQ_DEQUEUE
415could still return
416.Dv NULL
417if the queue is under rate-limiting.

--- 11 unchanged lines hidden (view full) ---

429.Dv FALSE ,
430.Fn IFQ_DEQUEUE
431could return
432.Dv NULL
433due to rate-limiting.
434.Bd -literal
435 ##old-style## ##new-style##
436 |

428 IF_DEQUEUE(\*[Am]ifp-\*[Gt]if_snd, m); | IFQ_DEQUEUE(\*[Am]ifp-\*[Gt]if_snd, m);

437 IF_DEQUEUE(&ifp->if_snd, m); | IFQ_DEQUEUE(&ifp->if_snd, m);

429 | if (m == NULL)
430 | return;
431 |
432.Ed
433A driver is supposed to call
434.Fn if_start
435from transmission complete interrupts in order to trigger the next dequeue.
436.Ss Poll-and-dequeue operation
437If the code polls the packet at the head of the queue and actually uses
438the packet before dequeuing it, use
439.Fn IFQ_POLL_NOLOCK
440and
441.Fn IFQ_DEQUEUE_NOLOCK .
442.Bd -literal
443 ##old-style## ##new-style##
444 |

438 | if (m == NULL)
439 | return;
440 |
441.Ed
442A driver is supposed to call
443.Fn if_start
444from transmission complete interrupts in order to trigger the next dequeue.
445.Ss Poll-and-dequeue operation
446If the code polls the packet at the head of the queue and actually uses
447the packet before dequeuing it, use
448.Fn IFQ_POLL_NOLOCK
449and
450.Fn IFQ_DEQUEUE_NOLOCK .
451.Bd -literal
452 ##old-style## ##new-style##
453 |

445 | IFQ_LOCK(\*[Am]ifp-\*[Gt]if_snd);
446 m = ifp-\*[Gt]if_snd.ifq_head; | IFQ_POLL_NOLOCK(\*[Am]ifp-\*[Gt]if_snd, m);

454 | IFQ_LOCK(&ifp->if_snd);
455 m = ifp->if_snd.ifq_head; | IFQ_POLL_NOLOCK(&ifp->if_snd, m);

447 if (m != NULL) { | if (m != NULL) {
448 |
449 /* use m to get resources */ | /* use m to get resources */
450 if (something goes wrong) | if (something goes wrong)

456 if (m != NULL) { | if (m != NULL) {
457 |
458 /* use m to get resources */ | /* use m to get resources */
459 if (something goes wrong) | if (something goes wrong)

451 | IFQ_UNLOCK(\*[Am]ifp-\*[Gt]if_snd);

460 | IFQ_UNLOCK(&ifp->if_snd);

452 return; | return;
453 |

461 return; | return;
462 |

454 IF_DEQUEUE(\*[Am]ifp-\*[Gt]if_snd, m); | IFQ_DEQUEUE_NOLOCK(\*[Am]ifp-\*[Gt]if_snd, m);
455 | IFQ_UNLOCK(\*[Am]ifp-\*[Gt]if_snd);

463 IF_DEQUEUE(&ifp->if_snd, m); | IFQ_DEQUEUE_NOLOCK(&ifp->if_snd, m);
464 | IFQ_UNLOCK(&ifp->if_snd);

456 |
457 /* kick the hardware */ | /* kick the hardware */
458 } | }
459 |
460.Ed
461It is guaranteed that
462.Fn IFQ_DEQUEUE_NOLOCK
463under the same lock as a previous
464.Fn IFQ_POLL_NOLOCK
465returns the same packet.
466Note that they need to be guarded by
467.Fn IFQ_LOCK .

465 |
466 /* kick the hardware */ | /* kick the hardware */
467 } | }
468 |
469.Ed
470It is guaranteed that
471.Fn IFQ_DEQUEUE_NOLOCK
472under the same lock as a previous
473.Fn IFQ_POLL_NOLOCK
474returns the same packet.
475Note that they need to be guarded by
476.Fn IFQ_LOCK .

468.Ss Eliminating IF_PREPEND

477.Ss Eliminating Fn IF_PREPEND

469If the code uses
470.Fn IF_PREPEND ,
471you have to eliminate it unless you can use a

478If the code uses
479.Fn IF_PREPEND ,
480you have to eliminate it unless you can use a

472.Ql driver managed
473queue which allows use of

481.Dq "driver managed"
482queue which allows the use of

474.Fn IFQ_DRV_PREPEND
475as a substitute.

483.Fn IFQ_DRV_PREPEND
484as a substitute.

476A common use of

485A common usage of

477.Fn IF_PREPEND
478is to cancel the previous dequeue operation.
479You have to convert the logic into poll-and-dequeue.
480.Bd -literal
481 ##old-style## ##new-style##
482 |

486.Fn IF_PREPEND
487is to cancel the previous dequeue operation.
488You have to convert the logic into poll-and-dequeue.
489.Bd -literal
490 ##old-style## ##new-style##
491 |

483 | IFQ_LOCK(\*[Am]ifp-\*[Gt]if_snd);
484 IF_DEQUEUE(\*[Am]ifp-\*[Gt]if_snd, m); | IFQ_POLL_NOLOCK(\*[Am]ifp-\*[Gt]if_snd, m);

492 | IFQ_LOCK(&ifp->if_snd);
493 IF_DEQUEUE(&ifp->if_snd, m); | IFQ_POLL_NOLOCK(&ifp->if_snd, m);

485 if (m != NULL) { | if (m != NULL) {
486 |
487 if (something_goes_wrong) { | if (something_goes_wrong) {

494 if (m != NULL) { | if (m != NULL) {
495 |
496 if (something_goes_wrong) { | if (something_goes_wrong) {

488 IF_PREPEND(\*[Am]ifp-\*[Gt]if_snd, m); | IFQ_UNLOCK(\*[Am]ifp-\*[Gt]if_snd);

497 IF_PREPEND(&ifp->if_snd, m); | IFQ_UNLOCK(&ifp->if_snd);

489 return; | return;
490 } | }
491 |
492 | /* at this point, the driver
493 | * is committed to send this
494 | * packet.
495 | */

498 return; | return;
499 } | }
500 |
501 | /* at this point, the driver
502 | * is committed to send this
503 | * packet.
504 | */

496 | IFQ_DEQUEUE_NOLOCK(\*[Am]ifp-\*[Gt]if_snd, m);
497 | IFQ_UNLOCK(\*[Am]ifp-\*[Gt]if_snd);

505 | IFQ_DEQUEUE_NOLOCK(&ifp->if_snd, m);
506 | IFQ_UNLOCK(&ifp->if_snd);

498 |
499 /* kick the hardware */ | /* kick the hardware */
500 } | }
501 |
502.Ed
503.Ss Purge operation
504Use
505.Fn IFQ_PURGE
506to empty the queue.
507Note that a non-work conserving queue cannot be emptied by a dequeue loop.
508.Bd -literal
509 ##old-style## ##new-style##
510 |

507 |
508 /* kick the hardware */ | /* kick the hardware */
509 } | }
510 |
511.Ed
512.Ss Purge operation
513Use
514.Fn IFQ_PURGE
515to empty the queue.
516Note that a non-work conserving queue cannot be emptied by a dequeue loop.
517.Bd -literal
518 ##old-style## ##new-style##
519 |

511 while (ifp-\*[Gt]if_snd.ifq_head != NULL) {| IFQ_PURGE(\*[Am]ifp-\*[Gt]if_snd);
512 IF_DEQUEUE(\*[Am]ifp-\*[Gt]if_snd, m); |

520 while (ifp->if_snd.ifq_head != NULL) {| IFQ_PURGE(&ifp->if_snd);
521 IF_DEQUEUE(&ifp->if_snd, m); |

513 m_freem(m); |
514 } |
515 |
516.Ed
517.Ss Conversion using a driver managed queue
518Convert

522 m_freem(m); |
523 } |
524 |
525.Ed
526.Ss Conversion using a driver managed queue
527Convert

519.Fn IF_XXX

528.Fn IF_*

520macros to their equivalent

529macros to their equivalent

521.Fn IFQ_DRV_XXX

530.Fn IFQ_DRV_*

522and employ
523.Fn IFQ_DRV_IS_EMPTY

531and employ
532.Fn IFQ_DRV_IS_EMPTY

524where appropriate

533where appropriate.

525.Bd -literal
526 ##old-style## ##new-style##
527 |

534.Bd -literal
535 ##old-style## ##new-style##
536 |

528 if (ifp-\*[Gt]if_snd.ifq_head != NULL) | if (!IFQ_DRV_IS_EMPTY(\*[Am]ifp-\*[Gt]if_snd))

537 if (ifp->if_snd.ifq_head != NULL) | if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))

529 |
530.Ed
531Make sure that calls to
532.Fn IFQ_DRV_DEQUEUE ,
533.Fn IFQ_DRV_PREPEND
534and
535.Fn IFQ_DRV_PURGE
536are protected with a mutex of some kind.
537Setting
538.Dv IFF_NEEDSGIANT
539in
540.Va if_flags
541might also be appropriate.
542.Ss Attach routine
543Use
544.Fn IFQ_SET_MAXLEN
545to set

538 |
539.Ed
540Make sure that calls to
541.Fn IFQ_DRV_DEQUEUE ,
542.Fn IFQ_DRV_PREPEND
543and
544.Fn IFQ_DRV_PURGE
545are protected with a mutex of some kind.
546Setting
547.Dv IFF_NEEDSGIANT
548in
549.Va if_flags
550might also be appropriate.
551.Ss Attach routine
552Use
553.Fn IFQ_SET_MAXLEN
554to set

546.Fa ifq_maxlen

555.Va ifq_maxlen

547to
548.Fa len .
549Initialize
550.Va ifq_drv_maxlen
551with a sensible value if you plan to use the

556to
557.Fa len .
558Initialize
559.Va ifq_drv_maxlen
560with a sensible value if you plan to use the

552.Fn IFQ_DRV_XXX

561.Fn IFQ_DRV_*

553macros.
554Add
555.Fn IFQ_SET_READY
556to show this driver is converted to the new style.
557(This is used to distinguish new-style drivers.)
558.Bd -literal
559 ##old-style## ##new-style##
560 |

562macros.
563Add
564.Fn IFQ_SET_READY
565to show this driver is converted to the new style.
566(This is used to distinguish new-style drivers.)
567.Bd -literal
568 ##old-style## ##new-style##
569 |

561 ifp-\*[Gt]if_snd.ifq_maxlen = qsize; | IFQ_SET_MAXLEN(\*[Am]ifp-\*[Gt]if_snd, qsize);
562 | ifp-\*[Gt]if_snd.ifq_drv_maxlen = qsize;
563 | IFQ_SET_READY(\*[Am]ifp-\*[Gt]if_snd);

570 ifp->if_snd.ifq_maxlen = qsize; | IFQ_SET_MAXLEN(&ifp->if_snd, qsize);
571 | ifp->if_snd.ifq_drv_maxlen = qsize;
572 | IFQ_SET_READY(&ifp->if_snd);

564 if_attach(ifp); | if_attach(ifp);
565 |
566.Ed
567.Ss Other issues
568The new macros for statistics:
569.Bd -literal
570 ##old-style## ##new-style##
571 |

573 if_attach(ifp); | if_attach(ifp);
574 |
575.Ed
576.Ss Other issues
577The new macros for statistics:
578.Bd -literal
579 ##old-style## ##new-style##
580 |

572 IF_DROP(\*[Am]ifp-\*[Gt]if_snd); | IFQ_INC_DROPS(\*[Am]ifp-\*[Gt]if_snd);

581 IF_DROP(&ifp->if_snd); | IFQ_INC_DROPS(&ifp->if_snd);

573 |

582 |

574 ifp-\*[Gt]if_snd.ifq_len++; | IFQ_INC_LEN(\*[Am]ifp-\*[Gt]if_snd);

583 ifp->if_snd.ifq_len++; | IFQ_INC_LEN(&ifp->if_snd);

575 |

584 |

576 ifp-\*[Gt]if_snd.ifq_len--; | IFQ_DEC_LEN(\*[Am]ifp-\*[Gt]if_snd);

585 ifp->if_snd.ifq_len--; | IFQ_DEC_LEN(&ifp->if_snd);

577 |
578.Ed
579.Sh QUEUING DISCIPLINES
580Queuing disciplines need to maintain
581.Fa ifq_len

586 |
587.Ed
588.Sh QUEUING DISCIPLINES
589Queuing disciplines need to maintain
590.Fa ifq_len

582.Po
583used by
584.Fn IFQ_IS_EMPTY
585.Pc .
586Queuing disciplines also need to guarantee the same mbuf is returned if

591(used by
592.Fn IFQ_IS_EMPTY ) .
593Queuing disciplines also need to guarantee that the same mbuf is returned if

587.Fn IFQ_DEQUEUE
588is called immediately after
589.Fn IFQ_POLL .
590.Sh SEE ALSO
591.Xr pf 4 ,

594.Fn IFQ_DEQUEUE
595is called immediately after
596.Fn IFQ_POLL .
597.Sh SEE ALSO
598.Xr pf 4 ,

592.Xr pf.conf 5

599.Xr pf.conf 5 ,