xref: /titanic_41/usr/src/uts/common/inet/ip_impl.h (revision 890e8ff10cfc85bc7d33064a9a30c3e8477b4813)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	_INET_IP_IMPL_H
27 #define	_INET_IP_IMPL_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 /*
32  * IP implementation private declarations.  These interfaces are
33  * used to build the IP module and are not meant to be accessed
34  * by any modules except IP itself.  They are undocumented and are
35  * subject to change without notice.
36  */
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 #ifdef _KERNEL
43 
44 #define	IP_MOD_ID		5701
45 
46 #ifdef	_BIG_ENDIAN
47 #define	IP_HDR_CSUM_TTL_ADJUST	256
48 #define	IP_TCP_CSUM_COMP	IPPROTO_TCP
49 #define	IP_UDP_CSUM_COMP	IPPROTO_UDP
50 #else
51 #define	IP_HDR_CSUM_TTL_ADJUST	1
52 #define	IP_TCP_CSUM_COMP	(IPPROTO_TCP << 8)
53 #define	IP_UDP_CSUM_COMP	(IPPROTO_UDP << 8)
54 #endif
55 
56 #define	TCP_CHECKSUM_OFFSET	16
57 #define	TCP_CHECKSUM_SIZE	2
58 
59 #define	UDP_CHECKSUM_OFFSET	6
60 #define	UDP_CHECKSUM_SIZE	2
61 
62 #define	IPH_TCPH_CHECKSUMP(ipha, hlen)	\
63 	((uint16_t *)(((uchar_t *)(ipha)) + ((hlen) + TCP_CHECKSUM_OFFSET)))
64 
65 #define	IPH_UDPH_CHECKSUMP(ipha, hlen)	\
66 	((uint16_t *)(((uchar_t *)(ipha)) + ((hlen) + UDP_CHECKSUM_OFFSET)))
67 
68 #define	ILL_HCKSUM_CAPABLE(ill)		\
69 	(((ill)->ill_capabilities & ILL_CAPAB_HCKSUM) != 0)
70 /*
71  * Macro that performs software checksum calculation on the IP header.
72  */
73 #define	IP_HDR_CKSUM(ipha, sum, v_hlen_tos_len, ttl_protocol) {		\
74 	(sum) += (ttl_protocol) + (ipha)->ipha_ident +			\
75 	    ((v_hlen_tos_len) >> 16) +					\
76 	    ((v_hlen_tos_len) & 0xFFFF) +				\
77 	    (ipha)->ipha_fragment_offset_and_flags;			\
78 	(sum) = (((sum) & 0xFFFF) + ((sum) >> 16));			\
79 	(sum) = ~((sum) + ((sum) >> 16));				\
80 	(ipha)->ipha_hdr_checksum = (uint16_t)(sum);			\
81 }
82 
83 #define	IS_IP_HDR_HWCKSUM(ipsec, mp, ill)				\
84 	((!ipsec) && (DB_CKSUMFLAGS(mp) & HCK_IPV4_HDRCKSUM) &&		\
85 	ILL_HCKSUM_CAPABLE(ill) && dohwcksum)
86 
87 /*
88  * This macro acts as a wrapper around IP_CKSUM_XMIT_FAST, and it performs
89  * several checks on the IRE and ILL (among other things) in order to see
90  * whether or not hardware checksum offload is allowed for the outgoing
91  * packet.  It assumes that the caller has held a reference to the IRE.
92  */
93 #define	IP_CKSUM_XMIT(ill, ire, mp, ihp, up, proto, start, end,		\
94 	    max_frag, ipsec_len, pseudo) {				\
95 	uint32_t _hck_flags;						\
96 	/*								\
97 	 * We offload checksum calculation to hardware when IPsec isn't	\
98 	 * present and if fragmentation isn't required.  We also check	\
99 	 * if M_DATA fastpath is safe to be used on the	corresponding	\
100 	 * IRE; this check is performed without grabbing ire_lock but	\
101 	 * instead by holding a reference to it.  This is sufficient	\
102 	 * for IRE_CACHE; for IRE_BROADCAST on non-Ethernet links, the	\
103 	 * DL_NOTE_FASTPATH_FLUSH indication could come up from the	\
104 	 * driver and trigger the IRE (hence fp_mp) deletion.  This is	\
105 	 * why only IRE_CACHE type is eligible for offload.		\
106 	 *								\
107 	 * The presense of IP options also forces the network stack to	\
108 	 * calculate the checksum in software.  This is because:	\
109 	 *								\
110 	 * Wrap around: certain partial-checksum NICs (eri, ce) limit	\
111 	 * the size of "start offset" width to 6-bit.  This effectively	\
112 	 * sets the largest value of the offset to 64-bytes, starting	\
113 	 * from the MAC header.  When the cumulative MAC and IP headers	\
114 	 * exceed such limit, the offset will wrap around.  This causes	\
115 	 * the checksum to be calculated at the wrong place.		\
116 	 *								\
117 	 * IPv4 source routing: none of the full-checksum capable NICs	\
118 	 * is capable of correctly handling the	IPv4 source-routing	\
119 	 * option for purposes of calculating the pseudo-header; the	\
120 	 * actual destination is different from the destination in the	\
121 	 * header which is that of the next-hop.  (This case may not be	\
122 	 * true for NICs which can parse IPv6 extension headers, but	\
123 	 * we choose to simplify the implementation by not offloading	\
124 	 * checksum when they are present.)				\
125 	 *								\
126 	 */								\
127 	if ((ill) != NULL && ILL_HCKSUM_CAPABLE(ill) &&			\
128 	    !((ire)->ire_flags & RTF_MULTIRT) &&			\
129 	    (!((ire)->ire_type & (IRE_BROADCAST|IRE_MIPRTUN)) ||	\
130 	    (ill)->ill_type == IFT_ETHER) &&				\
131 	    (ipsec_len) == 0 &&						\
132 	    (((ire)->ire_ipversion == IPV4_VERSION &&			\
133 	    (start) == IP_SIMPLE_HDR_LENGTH &&				\
134 	    (ire)->ire_fp_mp != NULL &&					\
135 	    MBLKHEAD(mp) >= MBLKL((ire)->ire_fp_mp)) ||			\
136 	    ((ire)->ire_ipversion == IPV6_VERSION &&			\
137 	    (start) == IPV6_HDR_LEN &&					\
138 	    (ire)->ire_nce->nce_fp_mp != NULL &&			\
139 	    MBLKHEAD(mp) >= MBLKL((ire)->ire_nce->nce_fp_mp))) &&	\
140 	    (max_frag) >= (uint_t)((end) + (ipsec_len)) &&		\
141 	    dohwcksum) {						\
142 		_hck_flags = (ill)->ill_hcksum_capab->ill_hcksum_txflags; \
143 	} else {							\
144 		_hck_flags = 0;						\
145 	}								\
146 	IP_CKSUM_XMIT_FAST((ire)->ire_ipversion, _hck_flags, mp, ihp,	\
147 	    up, proto, start, end, pseudo);				\
148 }
149 
150 /*
151  * Based on the device capabilities, this macro either marks an outgoing
152  * packet with hardware checksum offload information or calculate the
153  * checksum in software.  If the latter is performed, the checksum field
154  * of the dblk is cleared; otherwise it will be non-zero and contain the
155  * necessary flag(s) for the driver.
156  */
157 #define	IP_CKSUM_XMIT_FAST(ipver, hck_flags, mp, ihp, up, proto, start,	\
158 	    end, pseudo) {						\
159 	uint32_t _sum;							\
160 	/*								\
161 	 * Underlying interface supports hardware checksum offload for	\
162 	 * the payload; leave the payload checksum for the hardware to	\
163 	 * calculate.  N.B: We only need to set up checksum info on the	\
164 	 * first mblk.							\
165 	 */								\
166 	DB_CKSUMFLAGS(mp) = 0;						\
167 	if (((ipver) == IPV4_VERSION &&					\
168 	    ((hck_flags) & HCKSUM_INET_FULL_V4)) ||			\
169 	    ((ipver) == IPV6_VERSION &&					\
170 	    ((hck_flags) & HCKSUM_INET_FULL_V6))) {			\
171 		/*							\
172 		 * Hardware calculates pseudo-header, header and the	\
173 		 * payload checksums, so clear the checksum field in	\
174 		 * the protocol header.					\
175 		 */							\
176 		*(up) = 0;						\
177 		DB_CKSUMFLAGS(mp) |= HCK_FULLCKSUM;			\
178 	} else if ((hck_flags) & HCKSUM_INET_PARTIAL)  {		\
179 		/*							\
180 		 * Partial checksum offload has been enabled.  Fill	\
181 		 * the checksum field in the protocl header with the	\
182 		 * pseudo-header checksum value.			\
183 		 */							\
184 		_sum = ((proto) == IPPROTO_UDP) ?			\
185 		    IP_UDP_CSUM_COMP : IP_TCP_CSUM_COMP;		\
186 		_sum += *(up) + (pseudo);				\
187 		_sum = (_sum & 0xFFFF) + (_sum >> 16);			\
188 		*(up) = (_sum & 0xFFFF) + (_sum >> 16);			\
189 		/*							\
190 		 * Offsets are relative to beginning of IP header.	\
191 		 */							\
192 		DB_CKSUMSTART(mp) = (start);				\
193 		DB_CKSUMSTUFF(mp) = ((proto) == IPPROTO_UDP) ?		\
194 		    (start) + UDP_CHECKSUM_OFFSET :			\
195 		    (start) + TCP_CHECKSUM_OFFSET;			\
196 		DB_CKSUMEND(mp) = (end);				\
197 		DB_CKSUMFLAGS(mp) |= HCK_PARTIALCKSUM;			\
198 	} else {							\
199 		/*							\
200 		 * Software checksumming.				\
201 		 */							\
202 		_sum = ((proto) == IPPROTO_UDP) ?			\
203 		    IP_UDP_CSUM_COMP : IP_TCP_CSUM_COMP;		\
204 		_sum += (pseudo);					\
205 		_sum = IP_CSUM(mp, start, _sum);			\
206 		*(up) = (uint16_t)(_sum ? _sum : ~_sum);		\
207 	}								\
208 	/*								\
209 	 * Hardware supports IP header checksum offload; clear the	\
210 	 * contents of IP header checksum field as expected by NIC.	\
211 	 * Do this only if we offloaded either full or partial sum.	\
212 	 */								\
213 	if ((ipver) == IPV4_VERSION && DB_CKSUMFLAGS(mp) != 0 &&	\
214 	    ((hck_flags) & HCKSUM_IPHDRCKSUM)) {			\
215 		DB_CKSUMFLAGS(mp) |= HCK_IPV4_HDRCKSUM;			\
216 		((ipha_t *)(ihp))->ipha_hdr_checksum = 0;		\
217 	}								\
218 }
219 
220 /*
221  * Macro to inspect the checksum of a fully-reassembled incoming datagram.
222  */
223 #define	IP_CKSUM_RECV_REASS(hck_flags, off, pseudo, sum, err) {		\
224 	(err) = B_FALSE;						\
225 	if ((hck_flags) & HCK_FULLCKSUM) {				\
226 		/*							\
227 		 * The sum of all fragment checksums should		\
228 		 * result in -0 (0xFFFF) or otherwise invalid.		\
229 		 */							\
230 		if ((sum) != 0xFFFF)					\
231 			(err) = B_TRUE;					\
232 	} else if ((hck_flags) & HCK_PARTIALCKSUM) {			\
233 		(sum) += (pseudo);					\
234 		(sum) = ((sum) & 0xFFFF) + ((sum) >> 16);		\
235 		(sum) = ((sum) & 0xFFFF) + ((sum) >> 16);		\
236 		if (~(sum) & 0xFFFF)					\
237 			(err) = B_TRUE;					\
238 	} else if (((sum) = IP_CSUM(mp, off, pseudo)) != 0) {		\
239 		(err) = B_TRUE;						\
240 	}								\
241 }
242 
243 /*
244  * This macro inspects an incoming packet to see if the checksum value
245  * contained in it is valid; if the hardware has provided the information,
246  * the value is verified, otherwise it performs software checksumming.
247  * The checksum value is returned to caller.
248  */
249 #define	IP_CKSUM_RECV(hck_flags, sum, cksum_start, ulph_off, mp, mp1, err) { \
250 	int32_t _len;							\
251 									\
252 	(err) = B_FALSE;						\
253 	if ((hck_flags) & HCK_FULLCKSUM) {				\
254 		/*							\
255 		 * Full checksum has been computed by the hardware	\
256 		 * and has been attached.  If the driver wants us to	\
257 		 * verify the correctness of the attached value, in	\
258 		 * order to protect against faulty hardware, compare	\
259 		 * it against -0 (0xFFFF) to see if it's valid.		\
260 		 */							\
261 		(sum) = DB_CKSUM16(mp);					\
262 		if (!((hck_flags) & HCK_FULLCKSUM_OK) && (sum) != 0xFFFF) \
263 			(err) = B_TRUE;					\
264 	} else if (((hck_flags) & HCK_PARTIALCKSUM) &&			\
265 	    ((mp1) == NULL || (mp1)->b_cont == NULL) &&			\
266 	    (ulph_off) >= DB_CKSUMSTART(mp) &&				\
267 	    ((_len = (ulph_off) - DB_CKSUMSTART(mp)) & 1) == 0) {	\
268 		uint32_t _adj;						\
269 		/*							\
270 		 * Partial checksum has been calculated by hardware	\
271 		 * and attached to the packet; in addition, any		\
272 		 * prepended extraneous data is even byte aligned,	\
273 		 * and there are at most two mblks associated with	\
274 		 * the packet.  If any such data exists, we adjust	\
275 		 * the checksum; also take care any postpended data.	\
276 		 */							\
277 		IP_ADJCKSUM_PARTIAL(cksum_start, mp, mp1, _len, _adj);	\
278 		/*							\
279 		 * One's complement subtract extraneous checksum	\
280 		 */							\
281 		(sum) += DB_CKSUM16(mp);				\
282 		if (_adj >= (sum))					\
283 			(sum) = ~(_adj - (sum)) & 0xFFFF;		\
284 		else							\
285 			(sum) -= _adj;					\
286 		(sum) = ((sum) & 0xFFFF) + ((int)(sum) >> 16);		\
287 		(sum) = ((sum) & 0xFFFF) + ((int)(sum) >> 16);		\
288 		if (~(sum) & 0xFFFF)					\
289 			(err) = B_TRUE;					\
290 	} else if (((sum) = IP_CSUM(mp, ulph_off, sum)) != 0) {		\
291 		(err) = B_TRUE;						\
292 	}								\
293 }
294 
295 /*
296  * Macro to adjust a given checksum value depending on any prepended
297  * or postpended data on the packet.  It expects the start offset to
298  * begin at an even boundary and that the packet consists of at most
299  * two mblks.
300  */
301 #define	IP_ADJCKSUM_PARTIAL(cksum_start, mp, mp1, len, adj) {		\
302 	/*								\
303 	 * Prepended extraneous data; adjust checksum.			\
304 	 */								\
305 	if ((len) > 0)							\
306 		(adj) = IP_BCSUM_PARTIAL(cksum_start, len, 0);		\
307 	else								\
308 		(adj) = 0;						\
309 	/*								\
310 	 * len is now the total length of mblk(s)			\
311 	 */								\
312 	(len) = MBLKL(mp);						\
313 	if ((mp1) == NULL)						\
314 		(mp1) = (mp);						\
315 	else								\
316 		(len) += MBLKL(mp1);					\
317 	/*								\
318 	 * Postpended extraneous data; adjust checksum.			\
319 	 */								\
320 	if (((len) = (DB_CKSUMEND(mp) - len)) > 0) {			\
321 		uint32_t _pad;						\
322 									\
323 		_pad = IP_BCSUM_PARTIAL((mp1)->b_wptr, len, 0);		\
324 		/*							\
325 		 * If the postpended extraneous data was odd		\
326 		 * byte aligned, swap resulting checksum bytes.		\
327 		 */							\
328 		if ((uintptr_t)(mp1)->b_wptr & 1)			\
329 			(adj) += ((_pad << 8) & 0xFFFF) | (_pad >> 8);	\
330 		else							\
331 			(adj) += _pad;					\
332 		(adj) = ((adj) & 0xFFFF) + ((int)(adj) >> 16);		\
333 	}								\
334 }
335 
336 #define	ILL_MDT_CAPABLE(ill)		\
337 	(((ill)->ill_capabilities & ILL_CAPAB_MDT) != 0)
338 
339 /*
340  * ioctl identifier and structure for Multidata Transmit update
341  * private M_CTL communication from IP to ULP.
342  */
343 #define	MDT_IOC_INFO_UPDATE	(('M' << 8) + 1020)
344 
345 typedef struct ip_mdt_info_s {
346 	uint_t	mdt_info_id;	/* MDT_IOC_INFO_UPDATE */
347 	ill_mdt_capab_t	mdt_capab; /* ILL MDT capabilities */
348 } ip_mdt_info_t;
349 
350 /*
351  * Macro that determines whether or not a given ILL is allowed for MDT.
352  */
353 #define	ILL_MDT_USABLE(ill)						\
354 	(ILL_MDT_CAPABLE(ill) &&					\
355 	ill->ill_mdt_capab != NULL &&					\
356 	ill->ill_mdt_capab->ill_mdt_version == MDT_VERSION_2 &&		\
357 	ill->ill_mdt_capab->ill_mdt_on != 0)
358 
359 /*
360  * Macro that determines whether or not a given CONN may be considered
361  * for fast path prior to proceeding further with Multidata.
362  */
363 #define	CONN_IS_MD_FASTPATH(connp)	\
364 	((connp)->conn_dontroute == 0 &&	/* SO_DONTROUTE */	\
365 	!((connp)->conn_nexthop_set) &&		/* IP_NEXTHOP */	\
366 	(connp)->conn_nofailover_ill == NULL &&	/* IPIF_NOFAILOVER */	\
367 	(connp)->conn_xmit_if_ill == NULL &&	/* IP_XMIT_IF */	\
368 	(connp)->conn_outgoing_pill == NULL &&	/* IP{V6}_BOUND_PIF */	\
369 	(connp)->conn_outgoing_ill == NULL)	/* IP{V6}_BOUND_IF */
370 
371 /* Definitons for fragmenting IP packets using MDT. */
372 
373 /*
374  * Smaller and private version of pdescinfo_t used specifically for IP,
375  * which allows for only a single payload span per packet.
376  */
377 typedef struct ip_pdescinfo_s PDESCINFO_STRUCT(2)	ip_pdescinfo_t;
378 
379 /*
380  * Macro version of ip_can_frag_mdt() which avoids the function call if we
381  * only examine a single message block.
382  */
383 #define	IP_CAN_FRAG_MDT(mp, hdr_len, len)			\
384 	(((mp)->b_cont == NULL) ?				\
385 	(MBLKL(mp) >= ((hdr_len) + ip_wput_frag_mdt_min)) :	\
386 	ip_can_frag_mdt((mp), (hdr_len), (len)))
387 
388 /*
389  * Macro that determines whether or not a given IPC requires
390  * outbound IPSEC processing.
391  */
392 #define	CONN_IPSEC_OUT_ENCAPSULATED(connp)	\
393 	((connp)->conn_out_enforce_policy ||	\
394 	((connp)->conn_latch != NULL &&		\
395 	(connp)->conn_latch->ipl_out_policy != NULL))
396 
397 /*
398  * These are used by the synchronous streams code in tcp and udp.
399  * When we set the flags for a wakeup from a synchronous stream we
400  * always set RSLEEP in sd_wakeq, even if we have a read thread waiting
401  * to do the io. This is in case the read thread gets interrupted
402  * before completing the io. The RSLEEP flag in sd_wakeq is used to
403  * indicate that there is data available at the synchronous barrier.
404  * The assumption is that subsequent functions calls through rwnext()
405  * will reset sd_wakeq appropriately.
406  */
407 #define	STR_WAKEUP_CLEAR(stp) {						\
408 	mutex_enter(&stp->sd_lock);					\
409 	stp->sd_wakeq &= ~RSLEEP;					\
410 	mutex_exit(&stp->sd_lock);					\
411 }
412 
413 #define	STR_WAKEUP_SET(stp) {						\
414 	mutex_enter(&stp->sd_lock);					\
415 	if (stp->sd_flag & RSLEEP) {					\
416 		stp->sd_flag &= ~RSLEEP;				\
417 		cv_broadcast(&_RD(stp->sd_wrq)->q_wait);		\
418 	}								\
419 	stp->sd_wakeq |= RSLEEP;					\
420 	mutex_exit(&stp->sd_lock);					\
421 }
422 
423 #define	STR_SENDSIG(stp) {						\
424 	int _events;							\
425 	mutex_enter(&stp->sd_lock);					\
426 	if ((_events = stp->sd_sigflags & (S_INPUT | S_RDNORM)) != 0)	\
427 		strsendsig(stp->sd_siglist, _events, 0, 0);		\
428 	if (stp->sd_rput_opt & SR_POLLIN) {				\
429 		stp->sd_rput_opt &= ~SR_POLLIN;				\
430 		mutex_exit(&stp->sd_lock);				\
431 		pollwakeup(&stp->sd_pollist, POLLIN | POLLRDNORM);	\
432 	} else {							\
433 		mutex_exit(&stp->sd_lock);				\
434 	}								\
435 }
436 
437 #define	CONN_UDP_SYNCSTR(connp)						\
438 	(IPCL_IS_UDP(connp) && (connp)->conn_udp->udp_direct_sockfs)
439 
440 /*
441  * Macro that checks whether or not a particular UDP conn is
442  * flow-controlling on the read-side.  If udp module is directly
443  * above ip, check to see if the drain queue is full; note here
444  * that we check this without any lock protection because this
445  * is a coarse granularity inbound flow-control.  If the module
446  * above ip is not udp, then use canputnext to determine the
447  * flow-control.
448  *
449  * Note that these checks are done after the conn is found in
450  * the UDP fanout table.  A UDP conn in that table may have its
451  * IPCL_UDP bit cleared from the conn_flags when the application
452  * pops the udp module without issuing an unbind; in this case
453  * IP will still receive packets for the conn and deliver it
454  * upstream via putnext.  This is the reason why we have to test
455  * against IPCL_UDP.
456  */
457 #define	CONN_UDP_FLOWCTLD(connp)					\
458 	((CONN_UDP_SYNCSTR(connp) &&					\
459 	(connp)->conn_udp->udp_drain_qfull) ||				\
460 	(!CONN_UDP_SYNCSTR(connp) && !canputnext((connp)->conn_rq)))
461 
462 /*
463  * Macro that delivers a given message upstream; if udp module
464  * is directly above ip, the message is passed directly into
465  * the stream-less entry point.  Otherwise putnext is used.
466  */
467 #define	CONN_UDP_RECV(connp, mp) {					\
468 	if (IPCL_IS_UDP(connp))						\
469 		udp_conn_recv(connp, mp);				\
470 	else								\
471 		putnext((connp)->conn_rq, mp);				\
472 }
473 
474 #define	ILL_DLS_CAPABLE(ill)	\
475 	(((ill)->ill_capabilities &		\
476 	(ILL_CAPAB_POLL|ILL_CAPAB_SOFT_RING)) != 0)
477 
478 /*
479  * Macro that hands off one or more messages directly to DLD
480  * when the interface is marked with ILL_CAPAB_POLL.
481  */
482 #define	IP_DLS_ILL_TX(ill, mp) {					\
483 	ill_dls_capab_t *ill_dls = ill->ill_dls_capab;		\
484 	ASSERT(ILL_DLS_CAPABLE(ill));					\
485 	ASSERT(ill_dls != NULL);					\
486 	ASSERT(ill_dls->ill_tx != NULL);				\
487 	ASSERT(ill_dls->ill_tx_handle != NULL);			\
488 	ill_dls->ill_tx(ill_dls->ill_tx_handle, mp);			\
489 }
490 
491 extern int	ip_wput_frag_mdt_min;
492 extern boolean_t ip_can_frag_mdt(mblk_t *, ssize_t, ssize_t);
493 
494 #endif	/* _KERNEL */
495 
496 #ifdef	__cplusplus
497 }
498 #endif
499 
500 #endif	/* _INET_IP_IMPL_H */
501