| 1 | /* |
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| 2 | * |
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| 3 | * Copyright (C) 1988, 1989 by the Massachusetts Institute of Technology |
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| 4 | * Developed by the MIT Student Information Processing Board (SIPB). |
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| 5 | * For copying information, see the file mit-copyright.h in this release. |
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| 6 | * |
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| 7 | */ |
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| 8 | /* |
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| 9 | * |
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| 10 | * $Id: tnet.c,v 1.7 1999-02-08 14:47:13 danw Exp $ |
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| 11 | * |
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| 12 | * tnet.c -- procedures to have tfiles go over the net. |
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| 13 | * |
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| 14 | * |
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| 15 | */ |
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| 16 | #ifndef lint |
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| 17 | static char rcsid_tnet_c[] = |
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| 18 | "$Id: tnet.c,v 1.7 1999-02-08 14:47:13 danw Exp $"; |
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| 19 | #endif /* lint */ |
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| 20 | |
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| 21 | #define min(A, B) ((A) < (B) ? (A) : (B)) |
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| 22 | #define NIL 0 |
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| 23 | |
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| 24 | #define SUCCESS 1 |
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| 25 | #define TFILE_BLK 500 |
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| 26 | |
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| 27 | #include <stdio.h> |
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| 28 | #include "usp.h" |
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| 29 | #include <discuss/tfile.h> |
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| 30 | #include <errno.h> |
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| 31 | |
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| 32 | |
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| 33 | extern int errno; |
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| 34 | |
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| 35 | /* |
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| 36 | * |
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| 37 | * tnet () -- This is the handler procedure, that handles tfile requests. |
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| 38 | * |
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| 39 | */ |
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| 40 | int tnet (op, infop, info, argp, argn, result) |
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| 41 | int op, *info, argn, *result; |
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| 42 | char **infop, *argp; |
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| 43 | { |
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| 44 | USPStream *us; |
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| 45 | USPCardinal bt; |
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| 46 | unsigned numread; |
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| 47 | |
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| 48 | *result = 0; /* optimist */ |
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| 49 | us = (USPStream *) *infop; |
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| 50 | |
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| 51 | switch (op) { |
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| 52 | case TFOPEN: /* argp is pointer to modes */ |
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| 53 | if (*argp == 'r') { /* reading */ |
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| 54 | if (USP_rcv_blk(us, &bt) != SUCCESS) { |
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| 55 | *result = errno; |
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| 56 | return (-1); |
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| 57 | } |
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| 58 | if (bt != TFILE_BLK) { |
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| 59 | *result = EBADF; |
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| 60 | return (-1); |
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| 61 | } |
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| 62 | *info = 1; |
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| 63 | } else { |
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| 64 | if (USP_begin_block (us, TFILE_BLK) != SUCCESS) { |
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| 65 | *result = errno; |
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| 66 | return (-1); |
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| 67 | } |
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| 68 | *info = -1; |
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| 69 | } |
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| 70 | return (0); |
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| 71 | |
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| 72 | case TFCLOSE: |
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| 73 | if (*info > 0) |
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| 74 | USP_flush_block(us); |
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| 75 | else |
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| 76 | USP_end_block(us); |
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| 77 | return (0); |
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| 78 | |
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| 79 | case TFREAD: |
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| 80 | if (USP_get_byte_block(us, argp, argn, &numread) != SUCCESS) { |
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| 81 | *result = errno; |
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| 82 | return (-1); |
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| 83 | } |
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| 84 | return(numread); |
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| 85 | |
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| 86 | case TFWRITE: |
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| 87 | if (USP_put_byte_block(us, argp, argn) != SUCCESS) { |
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| 88 | *result = errno; |
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| 89 | return (-1); |
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| 90 | } |
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| 91 | return (argn); |
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| 92 | |
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| 93 | case TFDESTROY: |
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| 94 | return (0); |
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| 95 | |
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| 96 | default: |
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| 97 | *result = EBADF; |
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| 98 | return (-1); |
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| 99 | } |
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| 100 | } |
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| 101 | |
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| 102 | /* |
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| 103 | * |
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| 104 | * net_tfile (tfs, us) |
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| 105 | * |
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| 106 | */ |
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| 107 | tfile net_tfile (tfs, us) |
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| 108 | int tfs; |
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| 109 | USPStream *us; |
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| 110 | { |
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| 111 | return (tcreate (tfs, (char *)us, 0, tnet)); |
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| 112 | } |
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