workbench/network/stacks/AROSTCP/netlib/_chkufb.c

   1 /* $Id$
   2  *
   3  *      _chkufb.c - return struct ufb * from a file handle (SAS/C)
   4  *
   5  *      Copyright © 1994 AmiTCP/IP Group,
   6  *                       Network Solutions Development Inc.
   7  *                       All rights reserved.
   8  */
   9
  10 #include <ios1.h>
  11 #include <stdlib.h>
  12 #include <errno.h>
  13 #include <bsdsocket.h>
  14 #include <sys/cdefs.h>
  15 #include <amitcp/socketbasetags.h>
  16 #include <syslog.h>
  17
  18 extern unsigned long __fmask;
  19 extern int (*__closefunc)(int);
  20
  21 long ASM fdCallback(REG(d0) int fd, REG(d1) int action);
  22
  23 /*
  24  * The initializator priority is just above the standard I/O, so that this
  25  * will be called after the standard I/O is initialized
  26  */
  27 long __stdargs
  28 _STI_510_install_AmiTCP_callback(void)
  29 {
  30   if (SocketBaseTags(SBTM_SETVAL(SBTC_FDCALLBACK), &fdCallback, TAG_END)) {
  31     syslog(LOG_ERR, "Cannot install fdCallback!");
  32 #if __VERSION__ > 6 || __REVISION__ > 3
  33     return 1;
  34 #else
  35     exit(20);
  36 #endif
  37   }
  38
  39   /*
  40    * Set up __closefunc (which is used at stdio cleanup)
  41    */
  42   __closefunc = __close;
  43
  44   /*
  45    * Set default file mask to UNIX style
  46    */
  47   __fmask = 0644;
  48
  49   return 0;
  50 }
  51
  52 long ASM SAVEDS
  53 fdCallback(REG(d0) int fd, REG(d1) int action)
  54 {
  55   struct UFB *ufb;
  56   int fd2;
  57
  58 #ifdef DEBUG
  59   syslog(LOG_INFO, "fdCallback(fd: %d, action: %d)", fd, action);
  60 #endif
  61
  62   switch (action) {
  63   case FDCB_FREE:
  64     ufb = __chkufb(fd);
  65     if (ufb == NULL)
  66       return EBADF;
  67
  68     if (!(ufb->ufbflg & UFB_SOCK) && ufb->ufbflg != 0) {
  69 #ifdef DEBUG
  70       syslog(LOG_ERR, "fdCallback: fd (%d) is not a socket!", fd);
  71 #endif
  72       return ENOTSOCK;
  73     }
  74
  75     ufb->ufbflg = 0;
  76     return 0;
  77
  78   case FDCB_ALLOC:
  79     do {
  80       ufb = __allocufb(&fd2);
  81       if (ufb == NULL)
  82         return ENOMEM;
  83 #ifdef DEBUG
  84       if (fd2 > fd) {
  85         syslog(LOG_ERR, "fdCallback: fd2(%d) > fd(%d)!", fd2, fd);
  86         return EINVAL;
  87       }
  88 #endif
  89       ufb->ufbflg = UFB_SOCK | UFB_WA | UFB_RA; /* read/write socket */
  90       ufb->ufbfh = NULL; /* no file handle */
  91       ufb->ufbfn = NULL; /* no name */
  92     } while (fd2 < fd);
  93     return 0;
  94
  95   case FDCB_CHECK:
  96     ufb = __chkufb(fd);
  97     if (ufb != NULL && ufb->ufbflg != 0)
  98       return EBADF;
  99
 100     return 0;
 101
 102   default:
 103 #ifdef DEBUG
 104     syslog(LOG_ERR, "fdCallback: invalid action.");
 105 #endif
 106     return EINVAL;
 107   }
 108 }
 109
 110
 111 struct UFB *
 112 __chkufb(int fd)
 113 {
 114   struct UFB *ufb;
 115
 116   /* a single element cache */
 117   static struct UFB *last_ufb = NULL;
 118   static int         last_fd = -1;
 119
 120   _OSERR = 0;
 121
 122   if ((unsigned int)fd >= __nufbs) { /* unsigned cast checks for (fd < 0) */
 123     errno = EBADF;
 124     return NULL;
 125   }
 126
 127   /*
 128    * Check the cache first
 129    */
 130   if (fd == last_fd)
 131     return last_ufb;
 132
 133   last_fd = fd; /* update cache */
 134   ufb = __ufbs;
 135   while (fd > 0 && ufb != NULL) {
 136     fd--;
 137     ufb = ufb->ufbnxt;
 138   }
 139   last_ufb = ufb; /* update cache */
 140
 141   if (ufb == NULL) {
 142     last_fd = -1; /* invalidate cache */
 143     errno = EIO;
 144     return NULL;
 145   }
 146   else
 147     return ufb;
 148 }