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1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1993
3  *      The Regents of the University of California.
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  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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  *
30  */
31 
32 #ifndef _USER_MBUF_H_
33 #define _USER_MBUF_H_
34 
35 /* __Userspace__ header file for mbufs */
36 #include <stdio.h>
37 #if !defined(SCTP_SIMPLE_ALLOCATOR)
38 #include "umem.h"
39 #endif
40 #include "user_malloc.h"
41 #include "netinet/sctp_os_userspace.h"
42 
43 #define USING_MBUF_CONSTRUCTOR 0
44 
45 /* For Linux */
46 #ifndef MSIZE
47 #define MSIZE 256
48 /* #define MSIZE 1024 */
49 #endif
50 #ifndef MCLBYTES
51 #define MCLBYTES 2048
52 #endif
53 
54 struct mbuf * m_gethdr(int how, short type);
55 struct mbuf * m_get(int how, short type);
56 struct mbuf * m_free(struct mbuf *m);
57 void m_clget(struct mbuf *m, int how);
58 struct mbuf * m_getm2(struct mbuf *m, int len, int how, short type, int flags, int allonebuf);
59 struct mbuf *m_uiotombuf(struct uio *uio, int how, int len, int align, int flags);
60 u_int m_length(struct mbuf *m0, struct mbuf **last);
61 struct mbuf *m_last(struct mbuf *m);
62 
63 /* mbuf initialization function */
64 void mbuf_initialize(void *);
65 
66 #define	M_MOVE_PKTHDR(to, from)	m_move_pkthdr((to), (from))
67 #define	MGET(m, how, type)	((m) = m_get((how), (type)))
68 #define	MGETHDR(m, how, type)	((m) = m_gethdr((how), (type)))
69 #define	MCLGET(m, how)		m_clget((m), (how))
70 
71 
72 #define M_HDR_PAD ((sizeof(intptr_t)==4) ? 2 : 6) /* modified for __Userspace__ */
73 
74 /* Length to m_copy to copy all. */
75 #define	M_COPYALL	1000000000
76 
77 /* umem_cache_t is defined in user_include/umem.h as
78  * typedef struct umem_cache umem_cache_t;
79  * Note:umem_zone_t is a pointer.
80  */
81 #if defined(SCTP_SIMPLE_ALLOCATOR)
82 typedef size_t sctp_zone_t;
83 #else
84 typedef umem_cache_t *sctp_zone_t;
85 #endif
86 
87 extern sctp_zone_t zone_mbuf;
88 extern sctp_zone_t zone_clust;
89 extern sctp_zone_t zone_ext_refcnt;
90 
91 /*-
92  * Macros for type conversion:
93  * mtod(m, t)	-- Convert mbuf pointer to data pointer of correct type.
94  * dtom(x)	-- Convert data pointer within mbuf to mbuf pointer (XXX).
95  */
96 #define	mtod(m, t)	((t)((m)->m_data))
97 #define	dtom(x)		((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1)))
98 
99 struct mb_args {
100 	int	flags;	/* Flags for mbuf being allocated */
101 	short	type;	/* Type of mbuf being allocated */
102 };
103 
104 struct clust_args {
105 	struct mbuf * parent_mbuf;
106 };
107 
108 struct mbuf *    m_split(struct mbuf *, int, int);
109 void             m_cat(struct mbuf *m, struct mbuf *n);
110 void		 m_adj(struct mbuf *, int);
111 void  mb_free_ext(struct mbuf *);
112 void  m_freem(struct mbuf *);
113 struct m_tag	*m_tag_alloc(uint32_t, int, int, int);
114 struct mbuf	*m_copym(struct mbuf *, int, int, int);
115 void		 m_copyback(struct mbuf *, int, int, caddr_t);
116 struct mbuf	*m_pullup(struct mbuf *, int);
117 struct mbuf	*m_pulldown(struct mbuf *, int off, int len, int *offp);
118 int		 m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
119 struct m_tag	*m_tag_copy(struct m_tag *, int);
120 int		 m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
121 struct mbuf	*m_prepend(struct mbuf *, int, int);
122 void		 m_copydata(const struct mbuf *, int, int, caddr_t);
123 
124 #define MBUF_MEM_NAME "mbuf"
125 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
126 #define	MBUF_EXTREFCNT_MEM_NAME	"mbuf_ext_refcnt"
127 
128 #define	MT_NOINIT	255	/* Not a type but a flag to allocate
129 				   a non-initialized mbuf */
130 
131 /*
132  * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
133  * An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in
134  * sys/param.h), which has no additional overhead and is used instead of the
135  * internal data area; this is done when at least MINCLSIZE of data must be
136  * stored.  Additionally, it is possible to allocate a separate buffer
137  * externally and attach it to the mbuf in a way similar to that of mbuf
138  * clusters.
139  */
140 #define	MLEN		((int)(MSIZE - sizeof(struct m_hdr)))	/* normal data len */
141 #define	MHLEN		((int)(MLEN - sizeof(struct pkthdr)))	/* data len w/pkthdr */
142 #define	MINCLSIZE	((int)(MHLEN + 1))	/* smallest amount to put in cluster */
143 #define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */
144 
145 
146 /*
147  * Header present at the beginning of every mbuf.
148  */
149 struct m_hdr {
150 	struct mbuf	*mh_next;	/* next buffer in chain */
151 	struct mbuf	*mh_nextpkt;	/* next chain in queue/record */
152 	caddr_t		 mh_data;	/* location of data */
153 	int		 mh_len;	/* amount of data in this mbuf */
154 	int		 mh_flags;	/* flags; see below */
155 	short		 mh_type;	/* type of data in this mbuf */
156 	uint8_t          pad[M_HDR_PAD];/* word align                  */
157 };
158 
159 /*
160  * Packet tag structure (see below for details).
161  */
162 struct m_tag {
163 	SLIST_ENTRY(m_tag)	m_tag_link;	/* List of packet tags */
164 	uint16_t		m_tag_id;	/* Tag ID */
165 	uint16_t		m_tag_len;	/* Length of data */
166 	uint32_t		m_tag_cookie;	/* ABI/Module ID */
167 	void			(*m_tag_free)(struct m_tag *);
168 };
169 
170 /*
171  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
172  */
173 struct pkthdr {
174 	struct ifnet	*rcvif;		/* rcv interface */
175 	/* variables for ip and tcp reassembly */
176 	void		*header;	/* pointer to packet header */
177 	int		 len;		/* total packet length */
178 	/* variables for hardware checksum */
179 	int		 csum_flags;	/* flags regarding checksum */
180 	int		 csum_data;	/* data field used by csum routines */
181 	uint16_t	 tso_segsz;	/* TSO segment size */
182 	uint16_t	 ether_vtag;	/* Ethernet 802.1p+q vlan tag */
183 	SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
184 };
185 
186 /*
187  * Description of external storage mapped into mbuf; valid only if M_EXT is
188  * set.
189  */
190 struct m_ext {
191 	caddr_t		 ext_buf;	/* start of buffer */
192 	void		(*ext_free)	/* free routine if not the usual */
193 			    (void *, void *);
194 	void		*ext_args;	/* optional argument pointer */
195 	u_int		 ext_size;	/* size of buffer, for ext_free */
196 	volatile u_int	*ref_cnt;	/* pointer to ref count info */
197 	int		 ext_type;	/* type of external storage */
198 };
199 
200 
201 /*
202  * The core of the mbuf object along with some shortcut defined for practical
203  * purposes.
204  */
205 struct mbuf {
206 	struct m_hdr	m_hdr;
207 	union {
208 		struct {
209 			struct pkthdr	MH_pkthdr;	/* M_PKTHDR set */
210 			union {
211 				struct m_ext	MH_ext;	/* M_EXT set */
212 				char		MH_databuf[MHLEN];
213 			} MH_dat;
214 		} MH;
215 		char	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
216 	} M_dat;
217 };
218 
219 #define	m_next		m_hdr.mh_next
220 #define	m_len		m_hdr.mh_len
221 #define	m_data		m_hdr.mh_data
222 #define	m_type		m_hdr.mh_type
223 #define	m_flags		m_hdr.mh_flags
224 #define	m_nextpkt	m_hdr.mh_nextpkt
225 #define	m_act		m_nextpkt
226 #define	m_pkthdr	M_dat.MH.MH_pkthdr
227 #define	m_ext		M_dat.MH.MH_dat.MH_ext
228 #define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
229 #define	m_dat		M_dat.M_databuf
230 
231 
232 /*
233  * mbuf flags.
234  */
235 #define	M_EXT		0x0001	/* has associated external storage */
236 #define	M_PKTHDR	0x0002	/* start of record */
237 #define	M_EOR		0x0004	/* end of record */
238 #define	M_RDONLY	0x0008	/* associated data is marked read-only */
239 #define	M_PROTO1	0x0010	/* protocol-specific */
240 #define	M_PROTO2	0x0020	/* protocol-specific */
241 #define	M_PROTO3	0x0040	/* protocol-specific */
242 #define	M_PROTO4	0x0080	/* protocol-specific */
243 #define	M_PROTO5	0x0100	/* protocol-specific */
244 #define	M_FREELIST	0x8000	/* mbuf is on the free list */
245 
246 
247 /*
248  * Flags copied when copying m_pkthdr.
249  */
250 #define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_RDONLY|M_PROTO1|M_PROTO1|M_PROTO2|\
251 			    M_PROTO3|M_PROTO4|M_PROTO5|\
252 			    M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG|\
253 			    M_VLANTAG|M_PROMISC)
254 
255 
256 /*
257  * mbuf pkthdr flags (also stored in m_flags).
258  */
259 #define	M_BCAST		0x0200	/* send/received as link-level broadcast */
260 #define	M_MCAST		0x0400	/* send/received as link-level multicast */
261 #define	M_FRAG		0x0800	/* packet is a fragment of a larger packet */
262 #define	M_FIRSTFRAG	0x1000	/* packet is first fragment */
263 #define	M_LASTFRAG	0x2000	/* packet is last fragment */
264 #define	M_VLANTAG	0x10000	/* ether_vtag is valid */
265 #define	M_PROMISC	0x20000	/* packet was not for us */
266 #define	M_NOFREE	0x40000	/* do not free mbuf - it is embedded in the cluster */
267 
268 
269 /*
270  * External buffer types: identify ext_buf type.
271  */
272 #define	EXT_CLUSTER	1	/* mbuf cluster */
273 #define	EXT_SFBUF	2	/* sendfile(2)'s sf_bufs */
274 #define	EXT_JUMBOP	3	/* jumbo cluster 4096 bytes */
275 #define	EXT_JUMBO9	4	/* jumbo cluster 9216 bytes */
276 #define	EXT_JUMBO16	5	/* jumbo cluster 16184 bytes */
277 #define	EXT_PACKET	6	/* mbuf+cluster from packet zone */
278 #define	EXT_MBUF	7	/* external mbuf reference (M_IOVEC) */
279 #define	EXT_NET_DRV	100	/* custom ext_buf provided by net driver(s) */
280 #define	EXT_MOD_TYPE	200	/* custom module's ext_buf type */
281 #define	EXT_DISPOSABLE	300	/* can throw this buffer away w/page flipping */
282 #define	EXT_EXTREF	400	/* has externally maintained ref_cnt ptr */
283 
284 
285 /*
286  * mbuf types.
287  */
288 #define	MT_NOTMBUF	0	/* USED INTERNALLY ONLY! Object is not mbuf */
289 #define	MT_DATA		1	/* dynamic (data) allocation */
290 #define	MT_HEADER	MT_DATA	/* packet header, use M_PKTHDR instead */
291 #define	MT_SONAME	8	/* socket name */
292 #define	MT_CONTROL	14	/* extra-data protocol message */
293 #define	MT_OOBDATA	15	/* expedited data  */
294 #define	MT_NTYPES	16	/* number of mbuf types for mbtypes[] */
295 
296 #define	MT_NOINIT	255	/* Not a type but a flag to allocate
297 				   a non-initialized mbuf */
298 
299 /*
300  * __Userspace__ flags like M_NOWAIT are defined in malloc.h
301  * Flags like these are used in functions like uma_zalloc()
302  * but don't have an equivalent in userland umem
303  * Flags specifying how an allocation should be made.
304  *
305  * The flag to use is as follows:
306  * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation.
307  * - M_WAIT or M_WAITOK or M_TRYWAIT from wherever it is safe to block.
308  *
309  * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and
310  * if we cannot allocate immediately we may return NULL, whereas
311  * M_WAIT/M_WAITOK/M_TRYWAIT means that if we cannot allocate resources we
312  * will block until they are available, and thus never return NULL.
313  *
314  * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT.
315  */
316 #define	MBTOM(how)	(how)
317 
318 void		 m_tag_delete(struct mbuf *, struct m_tag *);
319 void		 m_tag_delete_chain(struct mbuf *, struct m_tag *);
320 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
321 void		 m_tag_free_default(struct m_tag *);
322 
323 extern int max_linkhdr;    /* Largest link-level header */
324 extern int max_protohdr; /* Size of largest protocol layer header. See user_mbuf.c */
325 
326 /*
327  * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
328  * be both the local data payload, or an external buffer area, depending on
329  * whether M_EXT is set).
330  */
331 #define	M_WRITABLE(m)	(!((m)->m_flags & M_RDONLY) &&			\
332 			 (!(((m)->m_flags & M_EXT)) ||			\
333 			 (*((m)->m_ext.ref_cnt) == 1)) )		\
334 
335 
336 /*
337  * Compute the amount of space available before the current start of data in
338  * an mbuf.
339  *
340  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
341  * of checking writability of the mbuf data area rests solely with the caller.
342  */
343 #define	M_LEADINGSPACE(m)						\
344 	(((m)->m_flags & M_EXT) ?					\
345 	    (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):	\
346 	    ((m)->m_flags & M_PKTHDR)? (m)->m_data - (m)->m_pktdat :	\
347 	    (m)->m_data - (m)->m_dat)
348 
349 /*
350  * Compute the amount of space available after the end of data in an mbuf.
351  *
352  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
353  * of checking writability of the mbuf data area rests solely with the caller.
354  */
355 #define	M_TRAILINGSPACE(m)						\
356 	(((m)->m_flags & M_EXT) ?					\
357 	    (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size	\
358 		- ((m)->m_data + (m)->m_len) : 0) :			\
359 	    &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
360 
361 
362 
363 /*
364  * Arrange to prepend space of size plen to mbuf m.  If a new mbuf must be
365  * allocated, how specifies whether to wait.  If the allocation fails, the
366  * original mbuf chain is freed and m is set to NULL.
367  */
368 #define	M_PREPEND(m, plen, how) do {					\
369 	struct mbuf **_mmp = &(m);					\
370 	struct mbuf *_mm = *_mmp;					\
371 	int _mplen = (plen);						\
372 	int __mhow = (how);						\
373 									\
374 	if (M_LEADINGSPACE(_mm) >= _mplen) {				\
375 		_mm->m_data -= _mplen;					\
376 		_mm->m_len += _mplen;					\
377 	} else								\
378 		_mm = m_prepend(_mm, _mplen, __mhow);			\
379 	if (_mm != NULL && _mm->m_flags & M_PKTHDR)			\
380 		_mm->m_pkthdr.len += _mplen;				\
381 	*_mmp = _mm;							\
382 } while (0)
383 
384 /*
385  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
386  * object of the specified size at the end of the mbuf, longword aligned.
387  */
388 #define	M_ALIGN(m, len) do {						\
389         KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)),                     \
390                 ("%s: M_ALIGN not normal mbuf", __func__));             \
391         KASSERT((m)->m_data == (m)->m_dat,                              \
392                 ("%s: M_ALIGN not a virgin mbuf", __func__));           \
393 	(m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);		\
394 } while (0)
395 
396 /*
397  * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
398  * M_DUP/MOVE_PKTHDR.
399  */
400 #define	MH_ALIGN(m, len) do {						\
401         KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT),     \
402                 ("%s: MH_ALIGN not PKTHDR mbuf", __func__));            \
403         KASSERT((m)->m_data == (m)->m_pktdat,                           \
404                 ("%s: MH_ALIGN not a virgin mbuf", __func__));          \
405 	(m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);		\
406 } while (0)
407 
408 #define M_SIZE(m)						\
409 		(((m)->m_flags & M_EXT) ? (m)->m_ext.ext_size :	\
410 		((m)->m_flags & M_PKTHDR) ? MHLEN :		\
411 		MLEN)
412 
413 #endif
414