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1.1 root 1: /*
2: * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
3: * All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This product includes software developed by the University of
16: * California, Berkeley and its contributors.
17: * 4. Neither the name of the University nor the names of its contributors
18: * may be used to endorse or promote products derived from this software
19: * without specific prior written permission.
20: *
21: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31: * SUCH DAMAGE.
32: *
33: * @(#)mbuf.h 7.14 (Berkeley) 12/5/90
34: */
35:
36: #ifndef M_WAITOK
37: #include "malloc.h"
38: #endif
39:
40: /*
41: * Mbufs are of a single size, MSIZE (machine/machparam.h), which
42: * includes overhead. An mbuf may add a single "mbuf cluster" of size
43: * MCLBYTES (also in machine/machparam.h), which has no additional overhead
44: * and is used instead of the internal data area; this is done when
45: * at least MINCLSIZE of data must be stored.
46: */
47:
48: #define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */
49: #define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */
50:
51: #define MINCLSIZE (MHLEN + MLEN) /* smallest amount to put in cluster */
52: #define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */
53:
54: /*
55: * Macros for type conversion
56: * mtod(m,t) - convert mbuf pointer to data pointer of correct type
57: * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX)
58: * mtocl(x) - convert pointer within cluster to cluster index #
59: * cltom(x) - convert cluster # to ptr to beginning of cluster
60: */
61: #define mtod(m,t) ((t)((m)->m_data))
62: #define dtom(x) ((struct mbuf *)((int)(x) & ~(MSIZE-1)))
63: #define mtocl(x) (((u_int)(x) - (u_int)mbutl) >> MCLSHIFT)
64: #define cltom(x) ((caddr_t)((u_int)mbutl + ((u_int)(x) >> MCLSHIFT)))
65:
66: /* header at beginning of each mbuf: */
67: struct m_hdr {
68: struct mbuf *mh_next; /* next buffer in chain */
69: struct mbuf *mh_nextpkt; /* next chain in queue/record */
70: int mh_len; /* amount of data in this mbuf */
71: caddr_t mh_data; /* location of data */
72: short mh_type; /* type of data in this mbuf */
73: short mh_flags; /* flags; see below */
74: };
75:
76: /* record/packet header in first mbuf of chain; valid if M_PKTHDR set */
77: struct pkthdr {
78: int len; /* total packet length */
79: struct ifnet *rcvif; /* rcv interface */
80: };
81:
82: /* description of external storage mapped into mbuf, valid if M_EXT set */
83: struct m_ext {
84: caddr_t ext_buf; /* start of buffer */
85: void (*ext_free)(); /* free routine if not the usual */
86: u_int ext_size; /* size of buffer, for ext_free */
87: };
88:
89: struct mbuf {
90: struct m_hdr m_hdr;
91: union {
92: struct {
93: struct pkthdr MH_pkthdr; /* M_PKTHDR set */
94: union {
95: struct m_ext MH_ext; /* M_EXT set */
96: char MH_databuf[MHLEN];
97: } MH_dat;
98: } MH;
99: char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */
100: } M_dat;
101: };
102: #define m_next m_hdr.mh_next
103: #define m_len m_hdr.mh_len
104: #define m_data m_hdr.mh_data
105: #define m_type m_hdr.mh_type
106: #define m_flags m_hdr.mh_flags
107: #define m_nextpkt m_hdr.mh_nextpkt
108: #define m_act m_nextpkt
109: #define m_pkthdr M_dat.MH.MH_pkthdr
110: #define m_ext M_dat.MH.MH_dat.MH_ext
111: #define m_pktdat M_dat.MH.MH_dat.MH_databuf
112: #define m_dat M_dat.M_databuf
113:
114: /* mbuf flags */
115: #define M_EXT 0x0001 /* has associated external storage */
116: #define M_PKTHDR 0x0002 /* start of record */
117: #define M_EOR 0x0004 /* end of record */
118:
119: /* mbuf pkthdr flags, also in m_flags */
120: #define M_BCAST 0x0100 /* send/received as link-level broadcast */
121: #define M_MCAST 0x0200 /* send/received as link-level multicast */
122:
123: /* flags copied when copying m_pkthdr */
124: #define M_COPYFLAGS (M_PKTHDR|M_EOR|M_BCAST|M_MCAST)
125:
126: /* mbuf types */
127: #define MT_FREE 0 /* should be on free list */
128: #define MT_DATA 1 /* dynamic (data) allocation */
129: #define MT_HEADER 2 /* packet header */
130: #define MT_SOCKET 3 /* socket structure */
131: #define MT_PCB 4 /* protocol control block */
132: #define MT_RTABLE 5 /* routing tables */
133: #define MT_HTABLE 6 /* IMP host tables */
134: #define MT_ATABLE 7 /* address resolution tables */
135: #define MT_SONAME 8 /* socket name */
136: #define MT_SOOPTS 10 /* socket options */
137: #define MT_FTABLE 11 /* fragment reassembly header */
138: #define MT_RIGHTS 12 /* access rights */
139: #define MT_IFADDR 13 /* interface address */
140: #define MT_CONTROL 14 /* extra-data protocol message */
141: #define MT_OOBDATA 15 /* expedited data */
142:
143: /* flags to m_get/MGET */
144: #define M_DONTWAIT M_NOWAIT
145: #define M_WAIT M_WAITOK
146:
147: /*
148: * mbuf allocation/deallocation macros:
149: *
150: * MGET(struct mbuf *m, int how, int type)
151: * allocates an mbuf and initializes it to contain internal data.
152: *
153: * MGETHDR(struct mbuf *m, int how, int type)
154: * allocates an mbuf and initializes it to contain a packet header
155: * and internal data.
156: */
157: #define MGET(m, how, type) { \
158: MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \
159: if (m) { \
160: (m)->m_type = (type); \
161: mbstat.m_mtypes[type]++; \
162: (m)->m_next = (struct mbuf *)NULL; \
163: (m)->m_nextpkt = (struct mbuf *)NULL; \
164: (m)->m_data = (m)->m_dat; \
165: (m)->m_flags = 0; \
166: } else \
167: (m) = m_retry((how), (type)); \
168: }
169:
170: #define MGETHDR(m, how, type) { \
171: MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \
172: if (m) { \
173: (m)->m_type = (type); \
174: mbstat.m_mtypes[type]++; \
175: (m)->m_next = (struct mbuf *)NULL; \
176: (m)->m_nextpkt = (struct mbuf *)NULL; \
177: (m)->m_data = (m)->m_pktdat; \
178: (m)->m_flags = M_PKTHDR; \
179: } else \
180: (m) = m_retryhdr((how), (type)); \
181: }
182:
183: /*
184: * Mbuf cluster macros.
185: * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster.
186: * MCLGET adds such clusters to a normal mbuf;
187: * the flag M_EXT is set upon success.
188: * MCLFREE releases a reference to a cluster allocated by MCLALLOC,
189: * freeing the cluster if the reference count has reached 0.
190: *
191: * Normal mbuf clusters are normally treated as character arrays
192: * after allocation, but use the first word of the buffer as a free list
193: * pointer while on the free list.
194: */
195: union mcluster {
196: union mcluster *mcl_next;
197: char mcl_buf[MCLBYTES];
198: };
199:
200: #define MCLALLOC(p, how) \
201: { int ms = splimp(); \
202: if (mclfree == 0) \
203: (void)m_clalloc(1, (how)); \
204: if ((p) = (caddr_t)mclfree) { \
205: ++mclrefcnt[mtocl(p)]; \
206: mbstat.m_clfree--; \
207: mclfree = ((union mcluster *)(p))->mcl_next; \
208: } \
209: splx(ms); \
210: }
211:
212: #define MCLGET(m, how) \
213: { MCLALLOC((m)->m_ext.ext_buf, (how)); \
214: if ((m)->m_ext.ext_buf != NULL) { \
215: (m)->m_data = (m)->m_ext.ext_buf; \
216: (m)->m_flags |= M_EXT; \
217: (m)->m_ext.ext_size = MCLBYTES; \
218: } \
219: }
220:
221: #define MCLFREE(p) \
222: { int ms = splimp(); \
223: if (--mclrefcnt[mtocl(p)] == 0) { \
224: ((union mcluster *)(p))->mcl_next = mclfree; \
225: mclfree = (union mcluster *)(p); \
226: mbstat.m_clfree++; \
227: } \
228: splx(ms); \
229: }
230:
231: /*
232: * MFREE(struct mbuf *m, struct mbuf *n)
233: * Free a single mbuf and associated external storage.
234: * Place the successor, if any, in n.
235: */
236: #ifdef notyet
237: #define MFREE(m, n) \
238: { mbstat.m_mtypes[(m)->m_type]--; \
239: if ((m)->m_flags & M_EXT) { \
240: if ((m)->m_ext.ext_free) \
241: (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \
242: (m)->m_ext.ext_size); \
243: else \
244: MCLFREE((m)->m_ext.ext_buf); \
245: } \
246: (n) = (m)->m_next; \
247: FREE((m), mbtypes[(m)->m_type]); \
248: }
249: #else /* notyet */
250: #define MFREE(m, nn) \
251: { mbstat.m_mtypes[(m)->m_type]--; \
252: if ((m)->m_flags & M_EXT) { \
253: MCLFREE((m)->m_ext.ext_buf); \
254: } \
255: (nn) = (m)->m_next; \
256: FREE((m), mbtypes[(m)->m_type]); \
257: }
258: #endif
259:
260: /*
261: * Copy mbuf pkthdr from from to to.
262: * from must have M_PKTHDR set, and to must be empty.
263: */
264: #define M_COPY_PKTHDR(to, from) { \
265: (to)->m_pkthdr = (from)->m_pkthdr; \
266: (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \
267: (to)->m_data = (to)->m_pktdat; \
268: }
269:
270: /*
271: * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
272: * an object of the specified size at the end of the mbuf, longword aligned.
273: */
274: #define M_ALIGN(m, len) \
275: { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); }
276: /*
277: * As above, for mbufs allocated with m_gethdr/MGETHDR
278: * or initialized by M_COPY_PKTHDR.
279: */
280: #define MH_ALIGN(m, len) \
281: { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); }
282:
283: /*
284: * Compute the amount of space available
285: * before the current start of data in an mbuf.
286: */
287: #define M_LEADINGSPACE(m) \
288: ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \
289: (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
290: (m)->m_data - (m)->m_dat)
291:
292: /*
293: * Compute the amount of space available
294: * after the end of data in an mbuf.
295: */
296: #define M_TRAILINGSPACE(m) \
297: ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \
298: ((m)->m_data + (m)->m_len) : \
299: &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
300:
301: /*
302: * Arrange to prepend space of size plen to mbuf m.
303: * If a new mbuf must be allocated, how specifies whether to wait.
304: * If how is M_DONTWAIT and allocation fails, the original mbuf chain
305: * is freed and m is set to NULL.
306: */
307: #define M_PREPEND(m, plen, how) { \
308: if (M_LEADINGSPACE(m) >= (plen)) { \
309: (m)->m_data -= (plen); \
310: (m)->m_len += (plen); \
311: } else \
312: (m) = m_prepend((m), (plen), (how)); \
313: if ((m) && (m)->m_flags & M_PKTHDR) \
314: (m)->m_pkthdr.len += (plen); \
315: }
316:
317: /* change mbuf to new type */
318: #define MCHTYPE(m, t) { \
319: mbstat.m_mtypes[(m)->m_type]--; \
320: mbstat.m_mtypes[t]++; \
321: (m)->m_type = t;\
322: }
323:
324: /* length to m_copy to copy all */
325: #define M_COPYALL 1000000000
326:
327: /* compatiblity with 4.3 */
328: #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
329:
330: /*
331: * Mbuf statistics.
332: */
333: struct mbstat {
334: u_long m_mbufs; /* mbufs obtained from page pool */
335: u_long m_clusters; /* clusters obtained from page pool */
336: u_long m_spare; /* spare field */
337: u_long m_clfree; /* free clusters */
338: u_long m_drops; /* times failed to find space */
339: u_long m_wait; /* times waited for space */
340: u_long m_drain; /* times drained protocols for space */
341: u_short m_mtypes[256]; /* type specific mbuf allocations */
342: };
343:
344: #ifdef KERNEL
345: extern struct mbuf *mbutl; /* virtual address of mclusters */
346: extern char *mclrefcnt; /* cluster reference counts */
347: struct mbstat mbstat;
348: int nmbclusters;
349: union mcluster *mclfree;
350: int max_linkhdr; /* largest link-level header */
351: int max_protohdr; /* largest protocol header */
352: int max_hdr; /* largest link+protocol header */
353: int max_datalen; /* MHLEN - max_hdr */
354: struct mbuf *m_get(), *m_gethdr(), *m_getclr(), *m_retry(), *m_retryhdr();
355: struct mbuf *m_free(), *m_copym(), *m_pullup(), *m_prepend();
356: int m_clalloc();
357: extern int mbtypes[]; /* XXX */
358:
359: #ifdef MBTYPES
360: int mbtypes[] = { /* XXX */
361: M_FREE, /* MT_FREE 0 /* should be on free list */
362: M_MBUF, /* MT_DATA 1 /* dynamic (data) allocation */
363: M_MBUF, /* MT_HEADER 2 /* packet header */
364: M_SOCKET, /* MT_SOCKET 3 /* socket structure */
365: M_PCB, /* MT_PCB 4 /* protocol control block */
366: M_RTABLE, /* MT_RTABLE 5 /* routing tables */
367: M_HTABLE, /* MT_HTABLE 6 /* IMP host tables */
368: 0, /* MT_ATABLE 7 /* address resolution tables */
369: M_MBUF, /* MT_SONAME 8 /* socket name */
370: 0, /* 9 */
371: M_SOOPTS, /* MT_SOOPTS 10 /* socket options */
372: M_FTABLE, /* MT_FTABLE 11 /* fragment reassembly header */
373: M_MBUF, /* MT_RIGHTS 12 /* access rights */
374: M_IFADDR, /* MT_IFADDR 13 /* interface address */
375: M_MBUF, /* MT_CONTROL 14 /* extra-data protocol message */
376: M_MBUF, /* MT_OOBDATA 15 /* expedited data */
377: #ifdef DATAKIT
378: 25, 26, 27, 28, 29, 30, 31, 32 /* datakit ugliness */
379: #endif
380: };
381: #endif
382: #endif
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