contrib/sendmail-8.13.4/libsm/findfp.c

   1 /*
   2  * Copyright (c) 2000-2002 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Chris Torek.
   9  *
  10  * By using this file, you agree to the terms and conditions set
  11  * forth in the LICENSE file which can be found at the top level of
  12  * the sendmail distribution.
  13  */
  14
  15 #include <sm/gen.h>
  16 SM_RCSID("@(#)$Id: findfp.c,v 1.66 2002/02/20 02:40:24 ca Exp $")
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19 #include <sys/param.h>
  20 #include <errno.h>
  21 #include <string.h>
  22 #include <syslog.h>
  23 #include <sm/io.h>
  24 #include <sm/assert.h>
  25 #include <sm/heap.h>
  26 #include <sm/string.h>
  27 #include <sm/conf.h>
  28 #include "local.h"
  29 #include "glue.h"
  30
  31 bool    Sm_IO_DidInit;  /* IO system has been initialized? */
  32
  33 const char SmFileMagic[] = "sm_file";
  34
  35 /* An open type to map to fopen()-like behavior */
  36 SM_FILE_T SmFtStdio_def =
  37     {SmFileMagic, 0, 0, 0, (SMRW|SMFBF), -1, {0, 0}, 0, 0, 0,
  38         sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,
  39         sm_stdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,
  40         SM_TIME_BLOCK, "stdio" };
  41
  42 /* An open type to map to fdopen()-like behavior */
  43 SM_FILE_T SmFtStdiofd_def =
  44     {SmFileMagic, 0, 0, 0, (SMRW|SMFBF), -1, {0, 0}, 0, 0, 0,
  45         sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,
  46         sm_stdfdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,
  47         SM_TIME_BLOCK, "stdiofd" };
  48
  49 /* A string file type */
  50 SM_FILE_T SmFtString_def =
  51     {SmFileMagic, 0, 0, 0, (SMRW|SMNBF), -1, {0, 0}, 0, 0, 0,
  52         sm_strclose, sm_strread, sm_strseek, sm_strwrite,
  53         sm_stropen, sm_strsetinfo, sm_strgetinfo, SM_TIME_FOREVER,
  54         SM_TIME_BLOCK, "string" };
  55
  56 #if 0
  57 /* A file type for syslog communications */
  58 SM_FILE_T SmFtSyslog_def =
  59     {SmFileMagic, 0, 0, 0, (SMRW|SMNBF), -1, {0, 0}, 0, 0, 0,
  60         sm_syslogclose, sm_syslogread, sm_syslogseek, sm_syslogwrite,
  61         sm_syslogopen, sm_syslogsetinfo, sm_sysloggetinfo, SM_TIME_FOREVER,
  62         SM_TIME_BLOCK, "syslog" };
  63 #endif /* 0 */
  64
  65 #define NDYNAMIC 10             /* add ten more whenever necessary */
  66
  67 #define smio(flags, file, name)                                         \
  68     {SmFileMagic, 0, 0, 0, flags, file, {0}, 0, SmIoF+file, 0,          \
  69         sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,               \
  70         sm_stdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,      \
  71         SM_TIME_BLOCK, name}
  72
  73 /* sm_magic p r w flags file bf lbfsize cookie ival */
  74 #define smstd(flags, file, name)                                        \
  75     {SmFileMagic, 0, 0, 0, flags, -1, {0}, 0, 0, file,                  \
  76         sm_stdioclose, sm_stdioread, sm_stdioseek, sm_stdiowrite,       \
  77         sm_stdioopen, sm_stdiosetinfo, sm_stdiogetinfo, SM_TIME_FOREVER,\
  78         SM_TIME_BLOCK, name}
  79
  80 /* A file type for interfacing to stdio FILE* streams. */
  81 SM_FILE_T SmFtRealStdio_def = smstd(SMRW|SMNBF, -1, "realstdio");
  82
  83                                 /* the usual - (stdin + stdout + stderr) */
  84 static SM_FILE_T usual[SM_IO_OPEN_MAX - 3];
  85 static struct sm_glue smuglue = { 0, SM_IO_OPEN_MAX - 3, usual };
  86
  87 /* List of builtin automagically already open file pointers */
  88 SM_FILE_T SmIoF[6] =
  89 {
  90         smio(SMRD|SMLBF, SMIOIN_FILENO, "smioin"),      /* smioin */
  91         smio(SMWR|SMLBF, SMIOOUT_FILENO, "smioout"),    /* smioout */
  92         smio(SMWR|SMNBF, SMIOERR_FILENO, "smioerr"),    /* smioerr */
  93         smstd(SMRD|SMNBF, SMIOIN_FILENO, "smiostdin"),  /* smiostdin */
  94         smstd(SMWR|SMNBF, SMIOOUT_FILENO, "smiostdout"),/* smiostdout */
  95         smstd(SMWR|SMNBF, SMIOERR_FILENO, "smiostderr") /* smiostderr */
  96 };
  97
  98 /* Structure containing list of currently open file pointers */
  99 struct sm_glue smglue = { &smuglue, 3, SmIoF };
 100
 101 /*
 102 **  SM_MOREGLUE -- adds more space for open file pointers
 103 **
 104 **      Parameters:
 105 **              n -- number of new spaces for file pointers
 106 **
 107 **      Returns:
 108 **              Raises an exception if no more memory.
 109 **              Otherwise, returns a pointer to new spaces.
 110 */
 111
 112 static struct sm_glue *sm_moreglue_x __P((int));
 113 static SM_FILE_T empty;
 114
 115 static struct sm_glue *
 116 sm_moreglue_x(n)
 117         register int n;
 118 {
 119         register struct sm_glue *g;
 120         register SM_FILE_T *p;
 121
 122         g = (struct sm_glue *) sm_pmalloc_x(sizeof(*g) + SM_ALIGN_BITS +
 123                                             n * sizeof(SM_FILE_T));
 124         p = (SM_FILE_T *) SM_ALIGN(g + 1);
 125         g->gl_next = NULL;
 126         g->gl_niobs = n;
 127         g->gl_iobs = p;
 128         while (--n >= 0)
 129                 *p++ = empty;
 130         return g;
 131 }
 132
 133 /*
 134 **  SM_FP -- allocate and initialize an SM_FILE structure
 135 **
 136 **      Parameters:
 137 **              t -- file type requested to be opened.
 138 **              flags -- control flags for file type behavior
 139 **              oldfp -- file pointer to reuse if available (optional)
 140 **
 141 **      Returns:
 142 **              Raises exception on memory exhaustion.
 143 **              Aborts if type is invalid.
 144 **              Otherwise, returns file pointer for requested file type.
 145 */
 146
 147 SM_FILE_T *
 148 sm_fp(t, flags, oldfp)
 149         const SM_FILE_T *t;
 150         const int flags;
 151         SM_FILE_T *oldfp;
 152 {
 153         register SM_FILE_T *fp;
 154         register int n;
 155         register struct sm_glue *g;
 156
 157         SM_REQUIRE(t->f_open && t->f_close && (t->f_read || t->f_write));
 158
 159         if (!Sm_IO_DidInit)
 160                 sm_init();
 161
 162         if (oldfp != NULL)
 163         {
 164                 fp = oldfp;
 165                 goto found; /* for opening reusing an 'fp' */
 166         }
 167
 168         for (g = &smglue;; g = g->gl_next)
 169         {
 170                 for (fp = g->gl_iobs, n = g->gl_niobs; --n >= 0; fp++)
 171                         if (fp->sm_magic == NULL)
 172                                 goto found;
 173                 if (g->gl_next == NULL)
 174                         g->gl_next = sm_moreglue_x(NDYNAMIC);
 175         }
 176 found:
 177         fp->sm_magic = SmFileMagic; /* 'fp' now valid and in-use */
 178         fp->f_p = NULL;         /* no current pointer */
 179         fp->f_w = 0;            /* nothing to write */
 180         fp->f_r = 0;            /* nothing to read */
 181         fp->f_flags = flags;
 182         fp->f_file = -1;                /* no file */
 183         fp->f_bf.smb_base = NULL;       /* no buffer */
 184         fp->f_bf.smb_size = 0;  /* no buffer size with no buffer */
 185         fp->f_lbfsize = 0;      /* not line buffered */
 186         fp->f_flushfp = NULL;   /* no associated flush file */
 187
 188         fp->f_cookie = fp;      /* default: *open* overrides cookie setting */
 189         fp->f_close = t->f_close;       /* assign close function */
 190         fp->f_read = t->f_read;         /* assign read function */
 191         fp->f_seek = t->f_seek;         /* assign seek function */
 192         fp->f_write = t->f_write;       /* assign write function */
 193         fp->f_open = t->f_open;         /* assign open function */
 194         fp->f_setinfo = t->f_setinfo;   /* assign setinfo function */
 195         fp->f_getinfo = t->f_getinfo;   /* assign getinfo function */
 196         fp->f_type = t->f_type;         /* file type */
 197
 198         fp->f_ub.smb_base = NULL;       /* no ungetc buffer */
 199         fp->f_ub.smb_size = 0;          /* no size for no ungetc buffer */
 200
 201         if (fp->f_timeout == SM_TIME_DEFAULT)
 202                 fp->f_timeout = SM_TIME_FOREVER;
 203         else
 204                 fp->f_timeout = t->f_timeout; /* traditional behavior */
 205         fp->f_timeoutstate = SM_TIME_BLOCK; /* by default */
 206
 207         return fp;
 208 }
 209
 210 /*
 211 **  SM_CLEANUP -- cleanup function when exit called.
 212 **
 213 **      This function is registered via atexit().
 214 **
 215 **      Parameters:
 216 **              none
 217 **
 218 **      Returns:
 219 **              nothing.
 220 **
 221 **      Side Effects:
 222 **              flushes open files before they are forced closed
 223 */
 224
 225 void
 226 sm_cleanup()
 227 {
 228         int timeout = SM_TIME_DEFAULT;
 229
 230         (void) sm_fwalk(sm_flush, &timeout); /* `cheating' */
 231 }
 232
 233 /*
 234 **  SM_INIT -- called whenever sm_io's internal variables must be set up.
 235 **
 236 **      Parameters:
 237 **              none
 238 **
 239 **      Returns:
 240 **              none
 241 **
 242 **      Side Effects:
 243 **              Registers sm_cleanup() using atexit().
 244 */
 245
 246 void
 247 sm_init()
 248 {
 249         if (Sm_IO_DidInit)      /* paranoia */
 250                 return;
 251
 252         /* more paranoia: initialize pointers in a static variable */
 253         empty.f_type = NULL;
 254         empty.sm_magic = NULL;
 255
 256         /* make sure we clean up on exit */
 257         atexit(sm_cleanup);             /* conservative */
 258         Sm_IO_DidInit = true;
 259 }
 260
 261 /*
 262 **  SM_IO_SETINFO -- change info for an open file type (fp)
 263 **
 264 **      The generic SM_IO_WHAT_VECTORS is auto supplied for all file types.
 265 **      If the request is to set info other than SM_IO_WHAT_VECTORS then
 266 **      the request is passed on to the file type's specific setinfo vector.
 267 **      WARNING: this is working on an active/open file type.
 268 **
 269 **      Parameters:
 270 **              fp -- file to make the setting on
 271 **              what -- type of information to set
 272 **              valp -- structure to obtain info from
 273 **
 274 **      Returns:
 275 **              0 on success
 276 **              -1 on error and sets errno:
 277 **                      - when what != SM_IO_WHAT_VECTORS and setinfo vector
 278 **                              not set
 279 **                      - when vectored setinfo returns -1
 280 */
 281
 282 int
 283 sm_io_setinfo(fp, what, valp)
 284         SM_FILE_T *fp;
 285         int what;
 286         void *valp;
 287 {
 288         SM_FILE_T *v = (SM_FILE_T *) valp;
 289
 290         SM_REQUIRE_ISA(fp, SmFileMagic);
 291         switch (what)
 292         {
 293           case SM_IO_WHAT_VECTORS:
 294
 295                 /*
 296                 **  This is the "generic" available for all.
 297                 **  This allows the function vectors to be replaced
 298                 **  while the file type is active.
 299                 */
 300
 301                 fp->f_close = v->f_close;
 302                 fp->f_read = v->f_read;
 303                 fp->f_seek = v->f_seek;
 304                 fp->f_write = v->f_write;
 305                 fp->f_open = v->f_open;
 306                 fp->f_setinfo = v->f_setinfo;
 307                 fp->f_getinfo = v->f_getinfo;
 308                 sm_free(fp->f_type);
 309                 fp->f_type = sm_strdup_x(v->f_type);
 310                 return 0;
 311           case SM_IO_WHAT_TIMEOUT:
 312                 fp->f_timeout = *((int *)valp);
 313                 return 0;
 314         }
 315
 316         /* Otherwise the vector will check it out */
 317         if (fp->f_setinfo == NULL)
 318         {
 319                 errno = EINVAL;
 320                 return -1;
 321         }
 322         else
 323                 return (*fp->f_setinfo)(fp, what, valp);
 324 }
 325
 326 /*
 327 **  SM_IO_GETINFO -- get information for an active file type (fp)
 328 **
 329 **  This function supplies for all file types the answers for the
 330 **              three requests SM_IO_WHAT_VECTORS, SM_IO_WHAT_TYPE and
 331 **              SM_IO_WHAT_ISTYPE. Other requests are handled by the getinfo
 332 **              vector if available for the open file type.
 333 **      SM_IO_WHAT_VECTORS returns information for the file pointer vectors.
 334 **      SM_IO_WHAT_TYPE returns the type identifier for the file pointer
 335 **      SM_IO_WHAT_ISTYPE returns >0 if the passed in type matches the
 336 **              file pointer's type.
 337 **      SM_IO_IS_READABLE returns 1 if there is data available for reading,
 338 **              0 otherwise.
 339 **
 340 **      Parameters:
 341 **              fp -- file pointer for active file type
 342 **              what -- type of information request
 343 **              valp -- structure to place obtained info into
 344 **
 345 **      Returns:
 346 **              -1 on error and sets errno:
 347 **                      - when valp==NULL and request expects otherwise
 348 **                      - when request is not SM_IO_WHAT_VECTORS and not
 349 **                              SM_IO_WHAT_TYPE and not SM_IO_WHAT_ISTYPE
 350 **                              and getinfo vector is NULL
 351 **                      - when getinfo type vector returns -1
 352 **              >=0 on success
 353 */
 354
 355 int
 356 sm_io_getinfo(fp, what, valp)
 357         SM_FILE_T *fp;
 358         int what;
 359         void *valp;
 360 {
 361         SM_FILE_T *v = (SM_FILE_T *) valp;
 362
 363         SM_REQUIRE_ISA(fp, SmFileMagic);
 364
 365         switch (what)
 366         {
 367           case SM_IO_WHAT_VECTORS:
 368
 369                 /* This is the "generic" available for all */
 370                 v->f_close = fp->f_close;
 371                 v->f_read = fp->f_read;
 372                 v->f_seek = fp->f_seek;
 373                 v->f_write = fp->f_write;
 374                 v->f_open = fp->f_open;
 375                 v->f_setinfo = fp->f_setinfo;
 376                 v->f_getinfo = fp->f_getinfo;
 377                 v->f_type = fp->f_type;
 378                 return 0;
 379
 380           case SM_IO_WHAT_TYPE:
 381                 if (valp == NULL)
 382                 {
 383                         errno = EINVAL;
 384                         return -1;
 385                 }
 386                 valp = sm_strdup_x(fp->f_type);
 387                 return 0;
 388
 389           case SM_IO_WHAT_ISTYPE:
 390                 if (valp == NULL)
 391                 {
 392                         errno = EINVAL;
 393                         return -1;
 394                 }
 395                 return strcmp(fp->f_type, valp) == 0;
 396
 397           case SM_IO_IS_READABLE:
 398
 399                 /* if there is data in the buffer, it must be readable */
 400                 if (fp->f_r > 0)
 401                         return 1;
 402
 403                 /* otherwise query the underlying file */
 404                 break;
 405
 406            case SM_IO_WHAT_TIMEOUT:
 407                 *((int *) valp) = fp->f_timeout;
 408                 return 0;
 409
 410           case SM_IO_WHAT_FD:
 411                 if (fp->f_file > -1)
 412                         return fp->f_file;
 413
 414                 /* try the file type specific getinfo to see if it knows */
 415                 break;
 416         }
 417
 418         /* Otherwise the vector will check it out */
 419         if (fp->f_getinfo == NULL)
 420         {
 421                 errno = EINVAL;
 422                 return -1;
 423         }
 424         return (*fp->f_getinfo)(fp, what, valp);
 425 }