4.3BSD - /usr/src/sys/h/mbuf.h

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)mbuf.h	7.1 (Berkeley) 6/4/86
   7:  */
   8: 
   9: /*
  10:  * Constants related to memory allocator.
  11:  */
  12: #define MSIZE       128         /* size of an mbuf */
  13: 
  14: #define MMINOFF     12          /* mbuf header length */
  15: #define MTAIL       4
  16: #define MMAXOFF     (MSIZE-MTAIL)       /* offset where data ends */
  17: #define MLEN        (MSIZE-MMINOFF-MTAIL)   /* mbuf data length */
  18: #define NMBCLUSTERS 256
  19: #define NMBPCL      (CLBYTES/MSIZE)     /* # mbufs per cluster */
  20: 
  21: /*
  22:  * Macros for type conversion
  23:  */
  24: 
  25: /* network cluster number to virtual address, and back */
  26: #define cltom(x) ((struct mbuf *)((int)mbutl + ((x) << CLSHIFT)))
  27: #define mtocl(x) (((int)x - (int)mbutl) >> CLSHIFT)
  28: 
  29: /* address in mbuf to mbuf head */
  30: #define dtom(x)     ((struct mbuf *)((int)x & ~(MSIZE-1)))
  31: 
  32: /* mbuf head, to typed data */
  33: #define mtod(x,t)   ((t)((int)(x) + (x)->m_off))
  34: 
  35: struct mbuf {
  36:     struct  mbuf *m_next;       /* next buffer in chain */
  37:     u_long  m_off;          /* offset of data */
  38:     short   m_len;          /* amount of data in this mbuf */
  39:     short   m_type;         /* mbuf type (0 == free) */
  40:     u_char  m_dat[MLEN];        /* data storage */
  41:     struct  mbuf *m_act;        /* link in higher-level mbuf list */
  42: };
  43: 
  44: /* mbuf types */
  45: #define MT_FREE     0   /* should be on free list */
  46: #define MT_DATA     1   /* dynamic (data) allocation */
  47: #define MT_HEADER   2   /* packet header */
  48: #define MT_SOCKET   3   /* socket structure */
  49: #define MT_PCB      4   /* protocol control block */
  50: #define MT_RTABLE   5   /* routing tables */
  51: #define MT_HTABLE   6   /* IMP host tables */
  52: #define MT_ATABLE   7   /* address resolution tables */
  53: #define MT_SONAME   8   /* socket name */
  54: #define MT_ZOMBIE   9   /* zombie proc status */
  55: #define MT_SOOPTS   10  /* socket options */
  56: #define MT_FTABLE   11  /* fragment reassembly header */
  57: #define MT_RIGHTS   12  /* access rights */
  58: #define MT_IFADDR   13  /* interface address */
  59: 
  60: /* flags to m_get */
  61: #define M_DONTWAIT  0
  62: #define M_WAIT      1
  63: 
  64: /* flags to m_pgalloc */
  65: #define MPG_MBUFS   0       /* put new mbufs on free list */
  66: #define MPG_CLUSTERS    1       /* put new clusters on free list */
  67: #define MPG_SPACE   2       /* don't free; caller wants space */
  68: 
  69: /* length to m_copy to copy all */
  70: #define M_COPYALL   1000000000
  71: 
  72: /*
  73:  * m_pullup will pull up additional length if convenient;
  74:  * should be enough to hold headers of second-level and higher protocols.
  75:  */
  76: #define MPULL_EXTRA 32
  77: 
  78: #define MGET(m, i, t) \
  79:     { int ms = splimp(); \
  80:       if ((m)=mfree) \
  81:         { if ((m)->m_type != MT_FREE) panic("mget"); (m)->m_type = t; \
  82:           mbstat.m_mtypes[MT_FREE]--; mbstat.m_mtypes[t]++; \
  83:           mfree = (m)->m_next; (m)->m_next = 0; \
  84:           (m)->m_off = MMINOFF; } \
  85:       else \
  86:         (m) = m_more(i, t); \
  87:       splx(ms); }
  88: /*
  89:  * Mbuf page cluster macros.
  90:  * MCLALLOC allocates mbuf page clusters.
  91:  * Note that it works only with a count of 1 at the moment.
  92:  * MCLGET adds such clusters to a normal mbuf.
  93:  * m->m_len is set to CLBYTES upon success.
  94:  * MCLFREE frees clusters allocated by MCLALLOC.
  95:  */
  96: #define MCLALLOC(m, i) \
  97:     { int ms = splimp(); \
  98:       if ((m)=mclfree) \
  99:          {++mclrefcnt[mtocl(m)];mbstat.m_clfree--;mclfree = (m)->m_next;} \
 100:       splx(ms); }
 101: #define M_HASCL(m)  ((m)->m_off >= MSIZE)
 102: #define MTOCL(m)    ((struct mbuf *)(mtod((m), int)&~CLOFSET))
 103: 
 104: #define MCLGET(m) \
 105:     { struct mbuf *p; \
 106:       if (mclfree == 0) \
 107:         (void)m_clalloc(1, MPG_CLUSTERS, M_DONTWAIT); \
 108:       MCLALLOC(p, 1); \
 109:       if (p) { \
 110:         (m)->m_off = (int)p - (int)(m); \
 111:         (m)->m_len = CLBYTES; \
 112:       } \
 113:     }
 114: #define MCLFREE(m) { \
 115:     if (--mclrefcnt[mtocl(m)] == 0) \
 116:         { (m)->m_next = mclfree;mclfree = (m);mbstat.m_clfree++;} \
 117:     }
 118: #define MFREE(m, n) \
 119:     { int ms = splimp(); \
 120:       if ((m)->m_type == MT_FREE) panic("mfree"); \
 121:       mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[MT_FREE]++; \
 122:       (m)->m_type = MT_FREE; \
 123:       if (M_HASCL(m)) { \
 124:         (n) = MTOCL(m); \
 125:         MCLFREE(n); \
 126:       } \
 127:       (n) = (m)->m_next; (m)->m_next = mfree; \
 128:       (m)->m_off = 0; (m)->m_act = 0; mfree = (m); \
 129:       splx(ms); \
 130:       if (m_want) { \
 131:           m_want = 0; \
 132:           wakeup((caddr_t)&mfree); \
 133:       } \
 134:     }
 135: 
 136: /*
 137:  * Mbuf statistics.
 138:  */
 139: struct mbstat {
 140:     short   m_mbufs;    /* mbufs obtained from page pool */
 141:     short   m_clusters; /* clusters obtained from page pool */
 142:     short   m_clfree;   /* free clusters */
 143:     short   m_drops;    /* times failed to find space */
 144:     short   m_mtypes[256];  /* type specific mbuf allocations */
 145: };
 146: 
 147: #ifdef  KERNEL
 148: extern  struct mbuf mbutl[];        /* virtual address of net free mem */
 149: extern  struct pte Mbmap[];     /* page tables to map Netutl */
 150: struct  mbstat mbstat;
 151: int nmbclusters;
 152: struct  mbuf *mfree, *mclfree;
 153: char    mclrefcnt[NMBCLUSTERS + 1];
 154: int m_want;
 155: struct  mbuf *m_get(),*m_getclr(),*m_free(),*m_more(),*m_copy(),*m_pullup();
 156: caddr_t m_clalloc();
 157: #endif

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