| 1 |
/* Database file handling routines. |
| 2 |
* |
| 3 |
* IRC Services is copyright (c) 1996-2009 Andrew Church. |
| 4 |
* E-mail: <achurch@achurch.org> |
| 5 |
* Parts written by Andrew Kempe and others. |
| 6 |
* This program is free but copyrighted software; see the file GPL.txt for |
| 7 |
* details. |
| 8 |
*/ |
| 9 |
|
| 10 |
#include "services.h" |
| 11 |
#ifndef CONVERT_DB |
| 12 |
# include "modules.h" |
| 13 |
#endif |
| 14 |
#include <fcntl.h> |
| 15 |
|
| 16 |
#include "fileutil.h" |
| 17 |
|
| 18 |
/*************************************************************************/ |
| 19 |
/*************************************************************************/ |
| 20 |
|
| 21 |
/* Return the version number of the file. Return -1 if there is no version |
| 22 |
* number or the number doesn't make sense (i.e. less than 1). |
| 23 |
*/ |
| 24 |
|
| 25 |
int32 get_file_version(dbFILE *f) |
| 26 |
{ |
| 27 |
FILE *fp = f->fp; |
| 28 |
int version = fgetc(fp)<<24 | fgetc(fp)<<16 | fgetc(fp)<<8 | fgetc(fp); |
| 29 |
if (ferror(fp)) { |
| 30 |
#ifndef CONVERT_DB |
| 31 |
module_log_perror("Error reading version number on %s", f->filename); |
| 32 |
#endif |
| 33 |
return -1; |
| 34 |
} else if (feof(fp)) { |
| 35 |
#ifndef CONVERT_DB |
| 36 |
module_log("Error reading version number on %s: End of file detected", |
| 37 |
f->filename); |
| 38 |
#endif |
| 39 |
return -1; |
| 40 |
} else if (version < 1) { |
| 41 |
#ifndef CONVERT_DB |
| 42 |
module_log("Invalid version number (%d) on %s", version, f->filename); |
| 43 |
#endif |
| 44 |
return -1; |
| 45 |
} |
| 46 |
return version; |
| 47 |
} |
| 48 |
|
| 49 |
/*************************************************************************/ |
| 50 |
|
| 51 |
/* Write the version number to the file. Return 0 on success, -1 on |
| 52 |
* failure. |
| 53 |
*/ |
| 54 |
|
| 55 |
int write_file_version(dbFILE *f, int32 filever) |
| 56 |
{ |
| 57 |
FILE *fp = f->fp; |
| 58 |
if ( |
| 59 |
fputc(filever>>24 & 0xFF, fp) < 0 || |
| 60 |
fputc(filever>>16 & 0xFF, fp) < 0 || |
| 61 |
fputc(filever>> 8 & 0xFF, fp) < 0 || |
| 62 |
fputc(filever & 0xFF, fp) < 0 |
| 63 |
) { |
| 64 |
#ifndef CONVERT_DB |
| 65 |
module_log_perror("Error writing version number on %s", f->filename); |
| 66 |
#endif |
| 67 |
return -1; |
| 68 |
} |
| 69 |
return 0; |
| 70 |
} |
| 71 |
|
| 72 |
/*************************************************************************/ |
| 73 |
/*************************************************************************/ |
| 74 |
|
| 75 |
/* Helper functions for open_db(). */ |
| 76 |
|
| 77 |
static dbFILE *open_db_read(const char *filename) |
| 78 |
{ |
| 79 |
dbFILE *f; |
| 80 |
FILE *fp; |
| 81 |
|
| 82 |
f = smalloc(sizeof(*f)); |
| 83 |
*f->tempname = 0; |
| 84 |
strbcpy(f->filename, filename); |
| 85 |
f->mode = 'r'; |
| 86 |
fp = fopen(f->filename, "rb"); |
| 87 |
if (!fp) { |
| 88 |
int errno_save = errno; |
| 89 |
#ifndef CONVERT_DB |
| 90 |
if (errno != ENOENT) |
| 91 |
module_log_perror("Can't read database file %s", f->filename); |
| 92 |
#endif |
| 93 |
free(f); |
| 94 |
errno = errno_save; |
| 95 |
return NULL; |
| 96 |
} |
| 97 |
f->fp = fp; |
| 98 |
return f; |
| 99 |
} |
| 100 |
|
| 101 |
/************************************/ |
| 102 |
|
| 103 |
static dbFILE *open_db_write(const char *filename, int32 filever) |
| 104 |
{ |
| 105 |
dbFILE *f; |
| 106 |
int fd; |
| 107 |
|
| 108 |
f = smalloc(sizeof(*f)); |
| 109 |
*f->tempname = 0; |
| 110 |
strbcpy(f->filename, filename); |
| 111 |
filename = f->filename; |
| 112 |
f->mode = 'w'; |
| 113 |
|
| 114 |
snprintf(f->tempname, sizeof(f->tempname), "%s.new", filename); |
| 115 |
if (!*f->tempname || strcmp(f->tempname, filename) == 0) { |
| 116 |
#ifndef CONVERT_DB |
| 117 |
module_log("Opening database file %s for write: Filename too long", |
| 118 |
filename); |
| 119 |
#endif |
| 120 |
free(f); |
| 121 |
errno = ENAMETOOLONG; |
| 122 |
return NULL; |
| 123 |
} |
| 124 |
remove(f->tempname); |
| 125 |
/* Use open() to avoid people sneaking a new file in under us */ |
| 126 |
fd = open(f->tempname, O_WRONLY | O_CREAT | O_EXCL, 0666); |
| 127 |
if (fd >= 0) |
| 128 |
f->fp = fdopen(fd, "wb"); |
| 129 |
if (!f->fp || write_file_version(f, filever) < 0) { |
| 130 |
int errno_save = errno; |
| 131 |
#ifndef CONVERT_DB |
| 132 |
static int walloped = 0; |
| 133 |
if (!walloped) { |
| 134 |
walloped++; |
| 135 |
wallops(NULL, "Can't create temporary database file %s", |
| 136 |
f->tempname); |
| 137 |
} |
| 138 |
errno = errno_save; |
| 139 |
module_log_perror("Can't create temporary database file %s", |
| 140 |
f->tempname); |
| 141 |
#endif |
| 142 |
if (f->fp) |
| 143 |
fclose(f->fp); |
| 144 |
remove(f->tempname); |
| 145 |
errno = errno_save; |
| 146 |
return NULL; |
| 147 |
} |
| 148 |
return f; |
| 149 |
} |
| 150 |
|
| 151 |
/*************************************************************************/ |
| 152 |
|
| 153 |
/* Open a database file for reading (*mode == 'r') or writing (*mode == 'w'). |
| 154 |
* Return the stream pointer, or NULL on error. When opening for write, the |
| 155 |
* file actually opened is a temporary file, which will be renamed to the |
| 156 |
* original file on close. |
| 157 |
* |
| 158 |
* `version' is only used when opening a file for writing, and indicates the |
| 159 |
* version number to write to the file. |
| 160 |
*/ |
| 161 |
|
| 162 |
dbFILE *open_db(const char *filename, const char *mode, int32 version) |
| 163 |
{ |
| 164 |
if (*mode == 'r') { |
| 165 |
return open_db_read(filename); |
| 166 |
} else if (*mode == 'w') { |
| 167 |
return open_db_write(filename, version); |
| 168 |
} else { |
| 169 |
errno = EINVAL; |
| 170 |
return NULL; |
| 171 |
} |
| 172 |
} |
| 173 |
|
| 174 |
/*************************************************************************/ |
| 175 |
|
| 176 |
/* Close a database file. If the file was opened for write, moves the new |
| 177 |
* file over the old one, and logs/wallops an error message if the rename() |
| 178 |
* fails. |
| 179 |
*/ |
| 180 |
|
| 181 |
int close_db(dbFILE *f) |
| 182 |
{ |
| 183 |
int res; |
| 184 |
if (!f->fp) { |
| 185 |
errno = EINVAL; |
| 186 |
return -1; |
| 187 |
} |
| 188 |
res = fclose(f->fp); |
| 189 |
f->fp = NULL; |
| 190 |
if (res != 0) |
| 191 |
return -1; |
| 192 |
if (f->mode=='w' && *f->tempname && strcmp(f->tempname,f->filename)!=0) { |
| 193 |
if (rename(f->tempname, f->filename) < 0) { |
| 194 |
#ifndef CONVERT_DB |
| 195 |
int errno_save = errno; |
| 196 |
wallops(NULL, "Unable to move new data to database file %s;" |
| 197 |
" new data NOT saved.", f->filename); |
| 198 |
errno = errno_save; |
| 199 |
module_log_perror("Unable to move new data to database file %s;" |
| 200 |
" new data NOT saved.", f->filename); |
| 201 |
#endif |
| 202 |
remove(f->tempname); |
| 203 |
} |
| 204 |
} |
| 205 |
free(f); |
| 206 |
return 0; |
| 207 |
} |
| 208 |
|
| 209 |
/*************************************************************************/ |
| 210 |
|
| 211 |
/* Restore the database file to its condition before open_db(). This is |
| 212 |
* identical to close_db() for files open for reading; however, for files |
| 213 |
* open for writing, we discard the new temporary file instead of renaming |
| 214 |
* it over the old file. The value of errno is preserved. |
| 215 |
*/ |
| 216 |
|
| 217 |
void restore_db(dbFILE *f) |
| 218 |
{ |
| 219 |
int errno_orig = errno; |
| 220 |
if (f->fp) |
| 221 |
fclose(f->fp); |
| 222 |
if (f->mode == 'w' && *f->tempname) |
| 223 |
remove(f->tempname); |
| 224 |
free(f); |
| 225 |
errno = errno_orig; |
| 226 |
} |
| 227 |
|
| 228 |
/*************************************************************************/ |
| 229 |
/*************************************************************************/ |
| 230 |
|
| 231 |
/* Read and write 2- and 4-byte quantities, pointers, and strings. All |
| 232 |
* multibyte values are stored in big-endian order (most significant byte |
| 233 |
* first). A pointer is stored as a byte, either 0 if NULL or 1 if not, |
| 234 |
* and read pointers are returned as either (void *)0 or (void *)1. A |
| 235 |
* string is stored with a 2-byte unsigned length (including the trailing |
| 236 |
* \0) first; a length of 0 indicates that the string pointer is NULL. |
| 237 |
* Written strings are truncated silently at 65534 bytes, and are always |
| 238 |
* null-terminated. |
| 239 |
* |
| 240 |
* All routines return -1 on error, 0 otherwise. |
| 241 |
*/ |
| 242 |
|
| 243 |
/*************************************************************************/ |
| 244 |
|
| 245 |
int read_int8(int8 *ret, dbFILE *f) |
| 246 |
{ |
| 247 |
int c = fgetc(f->fp); |
| 248 |
if (c == EOF) |
| 249 |
return -1; |
| 250 |
*ret = c; |
| 251 |
return 0; |
| 252 |
} |
| 253 |
|
| 254 |
/* Alternative version of read_int8() to avoid GCC's pointer signedness |
| 255 |
* warnings when reading into an unsigned variable: */ |
| 256 |
int read_uint8(uint8 *ret, dbFILE *f) { |
| 257 |
return read_int8((int8 *)ret, f); |
| 258 |
} |
| 259 |
|
| 260 |
int write_int8(int8 val, dbFILE *f) |
| 261 |
{ |
| 262 |
if (fputc(val, f->fp) == EOF) |
| 263 |
return -1; |
| 264 |
return 0; |
| 265 |
} |
| 266 |
|
| 267 |
/*************************************************************************/ |
| 268 |
|
| 269 |
/* These are inline to help out {read,write}_string. */ |
| 270 |
|
| 271 |
inline int read_int16(int16 *ret, dbFILE *f) |
| 272 |
{ |
| 273 |
int c1, c2; |
| 274 |
|
| 275 |
c1 = fgetc(f->fp); |
| 276 |
c2 = fgetc(f->fp); |
| 277 |
if (c2 == EOF) |
| 278 |
return -1; |
| 279 |
*ret = c1<<8 | c2; |
| 280 |
return 0; |
| 281 |
} |
| 282 |
|
| 283 |
inline int read_uint16(uint16 *ret, dbFILE *f) { |
| 284 |
return read_int16((int16 *)ret, f); |
| 285 |
} |
| 286 |
|
| 287 |
inline int write_int16(int16 val, dbFILE *f) |
| 288 |
{ |
| 289 |
fputc((val>>8), f->fp); |
| 290 |
if (fputc(val, f->fp) == EOF) |
| 291 |
return -1; |
| 292 |
return 0; |
| 293 |
} |
| 294 |
|
| 295 |
/*************************************************************************/ |
| 296 |
|
| 297 |
int read_int32(int32 *ret, dbFILE *f) |
| 298 |
{ |
| 299 |
int c1, c2, c3, c4; |
| 300 |
|
| 301 |
c1 = fgetc(f->fp); |
| 302 |
c2 = fgetc(f->fp); |
| 303 |
c3 = fgetc(f->fp); |
| 304 |
c4 = fgetc(f->fp); |
| 305 |
if (c4 == EOF) |
| 306 |
return -1; |
| 307 |
*ret = c1<<24 | c2<<16 | c3<<8 | c4; |
| 308 |
return 0; |
| 309 |
} |
| 310 |
|
| 311 |
int read_uint32(uint32 *ret, dbFILE *f) { |
| 312 |
return read_int32((int32 *)ret, f); |
| 313 |
} |
| 314 |
|
| 315 |
int write_int32(int32 val, dbFILE *f) |
| 316 |
{ |
| 317 |
fputc((val>>24), f->fp); |
| 318 |
fputc((val>>16), f->fp); |
| 319 |
fputc((val>> 8), f->fp); |
| 320 |
if (fputc((val & 0xFF), f->fp) == EOF) |
| 321 |
return -1; |
| 322 |
return 0; |
| 323 |
} |
| 324 |
|
| 325 |
/*************************************************************************/ |
| 326 |
|
| 327 |
int read_time(time_t *ret, dbFILE *f) |
| 328 |
{ |
| 329 |
int32 high, low; |
| 330 |
if (read_int32(&high, f) < 0 || read_int32(&low, f) < 0) |
| 331 |
return -1; |
| 332 |
#if SIZEOF_TIME_T > 4 |
| 333 |
*ret = (time_t)high << 32 | (time_t)low; |
| 334 |
#else |
| 335 |
*ret = low; |
| 336 |
#endif |
| 337 |
return 0; |
| 338 |
} |
| 339 |
|
| 340 |
int write_time(time_t val, dbFILE *f) |
| 341 |
{ |
| 342 |
#if SIZEOF_TIME_T > 4 |
| 343 |
if (write_int32(val>>32, f) < 0 |
| 344 |
|| write_int32(val & (time_t)0xFFFFFFFF, f) < 0) |
| 345 |
#else |
| 346 |
if (write_int32(0, f) < 0 || write_int32(val, f) < 0) |
| 347 |
#endif |
| 348 |
return -1; |
| 349 |
return 0; |
| 350 |
} |
| 351 |
|
| 352 |
/*************************************************************************/ |
| 353 |
|
| 354 |
int read_ptr(void **ret, dbFILE *f) |
| 355 |
{ |
| 356 |
int c; |
| 357 |
|
| 358 |
c = fgetc(f->fp); |
| 359 |
if (c == EOF) |
| 360 |
return -1; |
| 361 |
*ret = (c ? (void *)1 : (void *)0); |
| 362 |
return 0; |
| 363 |
} |
| 364 |
|
| 365 |
int write_ptr(const void *ptr, dbFILE *f) |
| 366 |
{ |
| 367 |
if (fputc(ptr ? 1 : 0, f->fp) == EOF) |
| 368 |
return -1; |
| 369 |
return 0; |
| 370 |
} |
| 371 |
|
| 372 |
/*************************************************************************/ |
| 373 |
|
| 374 |
int read_string(char **ret, dbFILE *f) |
| 375 |
{ |
| 376 |
char *s; |
| 377 |
uint16 len; |
| 378 |
|
| 379 |
if (read_uint16(&len, f) < 0) |
| 380 |
return -1; |
| 381 |
if (len == 0) { |
| 382 |
*ret = NULL; |
| 383 |
return 0; |
| 384 |
} |
| 385 |
s = smalloc(len); |
| 386 |
if (len != fread(s, 1, len, f->fp)) { |
| 387 |
free(s); |
| 388 |
return -1; |
| 389 |
} |
| 390 |
*ret = s; |
| 391 |
return 0; |
| 392 |
} |
| 393 |
|
| 394 |
int write_string(const char *s, dbFILE *f) |
| 395 |
{ |
| 396 |
uint32 len; |
| 397 |
|
| 398 |
if (!s) |
| 399 |
return write_int16(0, f); |
| 400 |
len = strlen(s); |
| 401 |
if (len > 65534) |
| 402 |
len = 65534; |
| 403 |
if (write_int16((uint16)(len+1), f) < 0) |
| 404 |
return -1; |
| 405 |
if (fwrite(s, 1, len, f->fp) != len) |
| 406 |
return -1; |
| 407 |
if (fputc(0, f->fp) == EOF) |
| 408 |
return -1; |
| 409 |
return 0; |
| 410 |
} |
| 411 |
|
| 412 |
/*************************************************************************/ |
| 413 |
|
| 414 |
/* |
| 415 |
* Local variables: |
| 416 |
* c-file-style: "stroustrup" |
| 417 |
* c-file-offsets: ((case-label . *) (statement-case-intro . *)) |
| 418 |
* indent-tabs-mode: nil |
| 419 |
* End: |
| 420 |
* |
| 421 |
* vim: expandtab shiftwidth=4: |
| 422 |
*/ |
