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Filename : VSEV.C

/* vsev - version 7 nodelist processor */
/* Written by Paul Edwards and released to the public domain */

/* The version 7 nodelist is normally comprised as follows:
1. NODEX.DAT - the complete nodelist data file.
2. NODEX.NDX - an index into nodex.dat. The index entries
are all address-based. After using the index, you will
obtain an offset, which can be used to access nodex.dat.
3. SYSOP.NDX - another index into nodex.dat, this time by
sysop name. The name used for the index is
"surname, firstname". Although the names are stored in
mixed case, they are ordered case-insensitive. */


/* This module has only one external function - vsevGetInfo
It requires a pointer to a VSEV structure, which should
be empty. The second parameter is the name of the V7
data file. The third parameter is the offset. You are
expected to have used one of the indexes to have retrieved
the proper offset before retrieving the data.

The function returns 0 on success, non-zero on failure. If
the call was successful, then via the passed VSEV data
structure, you will now have access to the following
information:

zone, net, node, point, hub, cost, fee, flags, modem, phone,
password, board, sysop, misc, baud.


Note that on return from this function, the board name,
sysop name and misc info will be both unpacked and converted
into mixed case. Internally, the data in the v7 nodelist data
file is packed by converting everything to uppercase and then
compressing it by compressing 3 bytes into 2. Presumably
someone thought that the space advantages of making an abortion
like this was worth it, and not just a gigantic wank. */


#include
#include
#include

#include "vsev.h"

static void vsevActual(VSEV *vsev);
static void vsevActual2(VSEV *vsev);
static void processPack(VSEV *vsev);
static void unpack(unsigned char *one, unsigned char *two, int len);
static void mixstr(unsigned char *str);

int vsevGetInfo(VSEV *vsev, char *dataFile, long offset)
{
vsev->error = 0;
vsev->fp = fopen(dataFile, "rb");
if (vsev->fp == NULL)
{
vsev->error = 1;
}
else
{
if (fseek(vsev->fp, offset, SEEK_SET) != 0)
{
vsev->error = 1;
}
else
{
vsevActual(vsev);
}
}
fclose(vsev->fp);
if (vsev->error)
{
return (1);
}
else
{
return (0);
}
}

static void vsevActual(VSEV *vsev)
{
fread(&vsev->zone, sizeof vsev->zone, 1, vsev->fp);
fread(&vsev->net, sizeof vsev->net, 1, vsev->fp);
fread(&vsev->node, sizeof vsev->node, 1, vsev->fp);
fread(&vsev->hub, sizeof vsev->hub, 1, vsev->fp);
fread(&vsev->cost, sizeof vsev->cost, 1, vsev->fp);
fread(&vsev->fee, sizeof vsev->fee, 1, vsev->fp);
fread(&vsev->flags, sizeof vsev->flags, 1, vsev->fp);
fread(&vsev->modem, sizeof vsev->modem, 1, vsev->fp);
fread(&vsev->phoneLen, sizeof vsev->phoneLen, 1, vsev->fp);
fread(&vsev->passwordLen, sizeof vsev->passwordLen, 1, vsev->fp);
fread(&vsev->boardLen, sizeof vsev->boardLen, 1, vsev->fp);
fread(&vsev->sysopLen, sizeof vsev->sysopLen, 1, vsev->fp);
fread(&vsev->miscLen, sizeof vsev->miscLen, 1, vsev->fp);
fread(&vsev->packLen, sizeof vsev->packLen, 1, vsev->fp);
fread(&vsev->baud, sizeof vsev->baud, 1, vsev->fp);
if (feof(vsev->fp) || ferror(vsev->fp))
{
vsev->error = 1;
}
else
{
vsevActual2(vsev);
}
return;
}

static void vsevActual2(VSEV *vsev)
{
if ((vsev->flags & 0x1000U) != 0)
{
vsev->point = vsev->hub;
vsev->hub = vsev->node;
}
else
{
vsev->point = 0;
}
fread(vsev->phone, vsev->phoneLen, 1, vsev->fp);
fread(vsev->password, vsev->passwordLen, 1, vsev->fp);
fread(vsev->packData, sizeof vsev->packData, 1, vsev->fp);
if (feof(vsev->fp) || ferror(vsev->fp))
{
vsev->error = 1;
}
else
{
processPack(vsev);
}
return;
}

static void processPack(VSEV *vsev)
{
int x;
int offset = 0;

vsev->packData[vsev->packLen] = '\0'; /* just in case */
unpack(vsev->unpackData, vsev->packData, vsev->packLen);
x = vsev->boardLen;
if (x > 100) x = 100;
memcpy(vsev->board, vsev->unpackData + offset, x);
vsev->board[x] = '\0';
offset += vsev->boardLen;
mixstr(vsev->board);
x = vsev->sysopLen;
if (x > 100) x = 100;
memcpy(vsev->sysop, vsev->unpackData + offset, x);
vsev->sysop[x] = '\0';
offset += vsev->sysopLen;
mixstr(vsev->sysop);
x = vsev->miscLen;
if (x > 100) x = 100;
memcpy(vsev->misc, vsev->unpackData + offset, x);
vsev->misc[x] = '\0';
offset += vsev->miscLen;
mixstr(vsev->misc);
return;
}

static void unpack(unsigned char *one, unsigned char *two, int len)
{
int x;
int y;
char *code = " EANROSTILCHBDMUGPKYWFVJXZQ-'0123456789";
unsigned int i;

for (x = 0, y = 0; x < len; x += 2, y += 3)
{
i = two[x] | (two[x+1] << 8);
one[y+2] = code[(size_t)(i%40)];
i /= 40;
one[y+1] = code[(size_t)(i%40)];
i /= 40;
one[y] = code[(size_t)(i%40)];
}
one[y] = '\0';
return;
}

static void mixstr(unsigned char *str)
{
int upper = 1;

while (*str != '\0')
{
if (upper)
{
*str = (unsigned char)toupper(*str);
}
else
{
*str = (unsigned char)tolower(*str);
}
if (isalpha(*str))
{
upper = 0;
}
else
{
upper = 1;
}
str++;
}
return;
}