1 /* MDB Tools - A library for reading MS Access database file
2  * Copyright (C) 2000 Brian Bruns
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Library General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Library General Public License for more details.
13  *
14  * You should have received a copy of the GNU Library General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17  * Boston, MA  02110-1301, USA.
18  */
19 
20 #include "mdbtools.h"
21 
22 #ifdef DMALLOC
23 #include "dmalloc.h"
24 #endif
25 
26 
mdb_col_comparer(MdbColumn ** a,MdbColumn ** b)27 static gint mdb_col_comparer(MdbColumn **a, MdbColumn **b)
28 {
29 	if ((*a)->col_num > (*b)->col_num)
30 		return 1;
31 	else if ((*a)->col_num < (*b)->col_num)
32 		return -1;
33 	else
34 		return 0;
35 }
36 
mdb_col_needs_size(int col_type)37 unsigned char mdb_col_needs_size(int col_type)
38 {
39 	if (col_type == MDB_TEXT) {
40 		return TRUE;
41 	} else {
42 		return FALSE;
43 	}
44 }
45 
mdb_alloc_tabledef(MdbCatalogEntry * entry)46 MdbTableDef *mdb_alloc_tabledef(MdbCatalogEntry *entry)
47 {
48 	MdbTableDef *table;
49 
50 	table = (MdbTableDef *) g_malloc0(sizeof(MdbTableDef));
51 	table->entry=entry;
52 	strcpy(table->name, entry->object_name);
53 
54 	return table;
55 }
mdb_free_tabledef(MdbTableDef * table)56 void mdb_free_tabledef(MdbTableDef *table)
57 {
58 	if (!table) return;
59 	if (table->is_temp_table) {
60 		unsigned int i;
61 		/* Temp table pages are being stored in memory */
62 		for (i=0; i<table->temp_table_pages->len; i++)
63 			g_free(g_ptr_array_index(table->temp_table_pages,i));
64 		g_ptr_array_free(table->temp_table_pages, TRUE);
65 		/* Temp tables use dummy entries */
66 		g_free(table->entry);
67 	}
68 	mdb_free_columns(table->columns);
69 	mdb_free_indices(table->indices);
70 	g_free(table->usage_map);
71 	g_free(table->free_usage_map);
72 	g_free(table);
73 }
mdb_read_table(MdbCatalogEntry * entry)74 MdbTableDef *mdb_read_table(MdbCatalogEntry *entry)
75 {
76 	MdbTableDef *table;
77 	MdbHandle *mdb = entry->mdb;
78 	MdbFormatConstants *fmt = mdb->fmt;
79 	int len, row_start, pg_row;
80 	void *buf, *pg_buf = mdb->pg_buf;
81 
82 	mdb_read_pg(mdb, entry->table_pg);
83 	if (mdb_get_byte(pg_buf, 0) != 0x02)  /* not a valid table def page */
84 		return NULL;
85 	table = mdb_alloc_tabledef(entry);
86 
87 	len = mdb_get_int16(pg_buf, 8);
88 
89 	table->num_rows = mdb_get_int32(pg_buf, fmt->tab_num_rows_offset);
90 	table->num_var_cols = mdb_get_int16(pg_buf, fmt->tab_num_cols_offset-2);
91 	table->num_cols = mdb_get_int16(pg_buf, fmt->tab_num_cols_offset);
92 	table->num_idxs = mdb_get_int32(pg_buf, fmt->tab_num_idxs_offset);
93 	table->num_real_idxs = mdb_get_int32(pg_buf, fmt->tab_num_ridxs_offset);
94 
95 	/* grab a copy of the usage map */
96 	pg_row = mdb_get_int32(pg_buf, fmt->tab_usage_map_offset);
97 	mdb_find_pg_row(mdb, pg_row, &buf, &row_start, &(table->map_sz));
98 	table->usage_map = g_memdup(buf + row_start, table->map_sz);
99 	if (mdb_get_option(MDB_DEBUG_USAGE))
100 		buffer_dump(buf, row_start, row_start+table->map_sz-1);
101 	mdb_debug(MDB_DEBUG_USAGE,"usage map found on page %ld row %d start %d len %d",
102 		pg_row >> 8, pg_row & 0xff, row_start, table->map_sz);
103 
104 	/* grab a copy of the free space page map */
105 	pg_row = mdb_get_int32(pg_buf, fmt->tab_free_map_offset);
106 	mdb_find_pg_row(mdb, pg_row, &buf, &row_start, &(table->freemap_sz));
107 	table->free_usage_map = g_memdup(buf + row_start, table->freemap_sz);
108 	mdb_debug(MDB_DEBUG_USAGE,"free map found on page %ld row %d start %d len %d\n",
109 		pg_row >> 8, pg_row & 0xff, row_start, table->freemap_sz);
110 
111 	table->first_data_pg = mdb_get_int16(pg_buf, fmt->tab_first_dpg_offset);
112 
113 	return table;
114 }
mdb_read_table_by_name(MdbHandle * mdb,gchar * table_name,int obj_type)115 MdbTableDef *mdb_read_table_by_name(MdbHandle *mdb, gchar *table_name, int obj_type)
116 {
117 	unsigned int i;
118 	MdbCatalogEntry *entry;
119 
120 	mdb_read_catalog(mdb, obj_type);
121 
122 	for (i=0; i<mdb->num_catalog; i++) {
123 		entry = g_ptr_array_index(mdb->catalog, i);
124 		if (!strcasecmp(entry->object_name, table_name))
125 			return mdb_read_table(entry);
126 	}
127 
128 	return NULL;
129 }
130 
131 /*
132 ** read the next page if offset is > pg_size
133 ** return true if page was read
134 */
135 int
read_pg_if(MdbHandle * mdb,int * cur_pos,int offset)136 read_pg_if(MdbHandle *mdb, int *cur_pos, int offset)
137 {
138 	if (*cur_pos + offset >= mdb->fmt->pg_size) {
139 		mdb_read_pg(mdb, mdb_get_int32(mdb->pg_buf,4));
140 		*cur_pos = 8 - (mdb->fmt->pg_size - (*cur_pos));
141 		return 1;
142 	}
143 	return 0;
144 }
145 guint32
read_pg_if_32(MdbHandle * mdb,int * cur_pos)146 read_pg_if_32(MdbHandle *mdb, int *cur_pos)
147 {
148 	unsigned char c[4];
149 	int i, rc = 0;
150 
151 	for (i=0;i<4;i++) {
152 		rc += read_pg_if(mdb, cur_pos, i);
153 		c[i] = mdb->pg_buf[(*cur_pos) + i];
154 	}
155 	return mdb_get_int32(c, 0);
156 }
157 guint16
read_pg_if_16(MdbHandle * mdb,int * cur_pos)158 read_pg_if_16(MdbHandle *mdb, int *cur_pos)
159 {
160 	unsigned char low_byte, high_byte;
161 	int rc = 0;
162 
163 	rc += read_pg_if(mdb, cur_pos, 0);
164 	low_byte = mdb->pg_buf[*cur_pos];
165 	rc += read_pg_if(mdb, cur_pos, 1);
166 	high_byte = mdb->pg_buf[(*cur_pos) + 1];
167 
168 	return (high_byte * 256 + low_byte);
169 }
170 guint16
read_pg_if_n(MdbHandle * mdb,unsigned char * buf,int * cur_pos,int len)171 read_pg_if_n(MdbHandle *mdb, unsigned char *buf, int *cur_pos, int len)
172 {
173 	if (*cur_pos + len < mdb->fmt->pg_size) {
174 		memcpy(buf, &mdb->pg_buf[*cur_pos], len);
175 		return 0;
176 	} else {
177 		int half = mdb->fmt->pg_size - *cur_pos;
178 		memcpy(buf, &mdb->pg_buf[*cur_pos], half);
179 		mdb_read_pg(mdb, mdb_get_int32(mdb->pg_buf,4));
180 		memcpy(buf + half, &mdb->pg_buf[8], len - half);
181 		*cur_pos = 8 - half;
182 		return 1;
183 	}
184 }
185 
mdb_append_column(GPtrArray * columns,MdbColumn * in_col)186 void mdb_append_column(GPtrArray *columns, MdbColumn *in_col)
187 {
188 	g_ptr_array_add(columns, g_memdup(in_col,sizeof(MdbColumn)));
189 }
mdb_free_columns(GPtrArray * columns)190 void mdb_free_columns(GPtrArray *columns)
191 {
192 	unsigned int i;
193 
194 	if (!columns) return;
195 	for (i=0; i<columns->len; i++)
196 		g_free (g_ptr_array_index(columns, i));
197 	g_ptr_array_free(columns, TRUE);
198 }
mdb_read_columns(MdbTableDef * table)199 GPtrArray *mdb_read_columns(MdbTableDef *table)
200 {
201 	MdbHandle *mdb = table->entry->mdb;
202 	MdbFormatConstants *fmt = mdb->fmt;
203 	MdbColumn *pcol;
204 	unsigned char *col;
205 	unsigned int i;
206 	int cur_pos, name_sz;
207 
208 	table->columns = g_ptr_array_new();
209 
210 	col = (unsigned char *) g_malloc(fmt->tab_col_entry_size);
211 
212 	cur_pos = fmt->tab_cols_start_offset +
213 		(table->num_real_idxs * fmt->tab_ridx_entry_size);
214 
215 	/* new code based on patch submitted by Tim Nelson 2000.09.27 */
216 
217 	/*
218 	** column attributes
219 	*/
220 	for (i=0;i<table->num_cols;i++) {
221 #ifdef MDB_DEBUG
222 	/* printf("column %d\n", i);
223 	buffer_dump(mdb->pg_buf, cur_pos ,cur_pos + 18); */
224 #endif
225 		read_pg_if_n(mdb, col, &cur_pos, fmt->tab_col_entry_size);
226 		cur_pos += fmt->tab_col_entry_size;
227 		pcol = (MdbColumn *) g_malloc0(sizeof(MdbColumn));
228 
229 		pcol->col_type = col[0];
230 
231 		// col_num_offset == 1 or 5
232 		pcol->col_num = col[fmt->col_num_offset];
233 
234 		//fprintf(stdout,"----- column %d -----\n",pcol->col_num);
235 		// col_var == 3 or 7
236 		pcol->var_col_num = mdb_get_int16(col, fmt->tab_col_offset_var);
237 		//fprintf(stdout,"var column pos %d\n",pcol->var_col_num);
238 
239 		// col_var == 5 or 9
240 		pcol->row_col_num = mdb_get_int16(col, fmt->tab_row_col_num_offset);
241 		//fprintf(stdout,"row column num %d\n",pcol->row_col_num);
242 
243 		/* FIXME: can this be right in Jet3 and Jet4? */
244 		if (pcol->col_type == MDB_NUMERIC) {
245 			pcol->col_prec = col[11];
246 			pcol->col_scale = col[12];
247 		}
248 
249 		// col_fixed_offset == 13 or 15
250 		pcol->is_fixed = col[fmt->col_fixed_offset] & 0x01 ? 1 : 0;
251 
252 		// col_fixed_offset == 13 or 15
253 		pcol->fixed_offset = mdb_get_int16(col, fmt->tab_col_offset_fixed);
254 		//fprintf(stdout,"fixed column offset %d\n",pcol->fixed_offset);
255 		//fprintf(stdout,"col type %s\n",pcol->is_fixed ? "fixed" : "variable");
256 
257 		if (pcol->col_type != MDB_BOOL) {
258 			// col_size_offset == 16 or 23
259 			pcol->col_size = mdb_get_int16(col, fmt->col_size_offset);
260 		} else {
261 			pcol->col_size=0;
262 		}
263 
264 		g_ptr_array_add(table->columns, pcol);
265 	}
266 
267 	g_free (col);
268 
269 	/*
270 	** column names - ordered the same as the column attributes table
271 	*/
272 	for (i=0;i<table->num_cols;i++) {
273 		unsigned char *tmp_buf;
274 		pcol = g_ptr_array_index(table->columns, i);
275 
276 		if (IS_JET4(mdb)) {
277 			name_sz = read_pg_if_16(mdb, &cur_pos);
278 			cur_pos += 2;
279 		} else if (IS_JET3(mdb)) {
280 			read_pg_if(mdb, &cur_pos, 0);
281 			name_sz = mdb->pg_buf[cur_pos];
282 			cur_pos++;
283 		} else {
284 			fprintf(stderr,"Unknown MDB version\n");
285 			continue;
286 		}
287 		tmp_buf = (unsigned char *) g_malloc(name_sz);
288 		read_pg_if_n(mdb, tmp_buf, &cur_pos, name_sz);
289 		mdb_unicode2ascii(mdb, tmp_buf, name_sz, pcol->name, MDB_MAX_OBJ_NAME);
290 		g_free(tmp_buf);
291 		cur_pos += name_sz;
292 
293 	}
294 
295 	/* Sort the columns by col_num */
296 	g_ptr_array_sort(table->columns, (GCompareFunc)mdb_col_comparer);
297 
298 	table->index_start = cur_pos;
299 	return table->columns;
300 }
301 
mdb_table_dump(MdbCatalogEntry * entry)302 void mdb_table_dump(MdbCatalogEntry *entry)
303 {
304 MdbTableDef *table;
305 MdbColumn *col;
306 int coln;
307 MdbIndex *idx;
308 MdbHandle *mdb = entry->mdb;
309 unsigned int i, bitn;
310 guint32 pgnum;
311 
312 	table = mdb_read_table(entry);
313 	fprintf(stdout,"definition page     = %lu\n",entry->table_pg);
314 	fprintf(stdout,"number of datarows  = %d\n",table->num_rows);
315 	fprintf(stdout,"number of columns   = %d\n",table->num_cols);
316 	fprintf(stdout,"number of indices   = %d\n",table->num_real_idxs);
317 
318 	mdb_read_columns(table);
319 	mdb_read_indices(table);
320 
321 	for (i=0;i<table->num_cols;i++) {
322 		col = g_ptr_array_index(table->columns,i);
323 
324 		fprintf(stdout,"column %d Name: %-20s Type: %s(%d)\n",
325 			i, col->name,
326 			mdb_get_coltype_string(mdb->default_backend, col->col_type),
327 			col->col_size);
328 	}
329 
330 	for (i=0;i<table->num_idxs;i++) {
331 		idx = g_ptr_array_index (table->indices, i);
332 		mdb_index_dump(table, idx);
333 	}
334 	if (table->usage_map) {
335 		printf("pages reserved by this object\n");
336 		printf("usage map pg %" G_GUINT32_FORMAT "\n",
337 			table->map_base_pg);
338 		printf("free map pg %" G_GUINT32_FORMAT "\n",
339 			table->freemap_base_pg);
340 		pgnum = mdb_get_int32(table->usage_map,1);
341 		/* the first 5 bytes of the usage map mean something */
342 		coln = 0;
343 		for (i=5;i<table->map_sz;i++) {
344 			for (bitn=0;bitn<8;bitn++) {
345 				if (table->usage_map[i] & 1 << bitn) {
346 					coln++;
347 					printf("%6" G_GUINT32_FORMAT, pgnum);
348 					if (coln==10) {
349 						printf("\n");
350 						coln = 0;
351 					} else {
352 						printf(" ");
353 					}
354 				}
355 				pgnum++;
356 			}
357 		}
358 		printf("\n");
359 	}
360 }
361 
mdb_is_user_table(MdbCatalogEntry * entry)362 int mdb_is_user_table(MdbCatalogEntry *entry)
363 {
364 	return ((entry->object_type == MDB_TABLE)
365 	 && !(entry->flags & 0x80000002)) ? 1 : 0;
366 }
mdb_is_system_table(MdbCatalogEntry * entry)367 int mdb_is_system_table(MdbCatalogEntry *entry)
368 {
369 	return ((entry->object_type == MDB_TABLE)
370 	 && (entry->flags & 0x80000002)) ? 1 : 0;
371 }
372