sbin/kldconfig/kldconfig.c

   1 /*
   2  * Copyright (c) 2001 Peter Pentchev
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sbin/kldconfig/kldconfig.c,v 1.3.2.1 2001/08/01 05:52:36 obrien Exp $
  27  * $DragonFly: src/sbin/kldconfig/kldconfig.c,v 1.4 2007/11/25 18:10:07 swildner Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/types.h>
  32 #include <sys/queue.h>
  33 #include <sys/sysctl.h>
  34
  35 #include <err.h>
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42
  43 #if defined(__FreeBSD_version)
  44 #if __FreeBSD_version < 500000
  45 #define NEED_SLASHTERM
  46 #endif /* < 500000 */
  47 #else  /* defined(__FreeBSD_version) */
  48 /* just in case.. */
  49 #define NEED_SLASHTERM
  50 #endif /* defined(__FreeBSD_version) */
  51
  52 /* the default sysctl name */
  53 #define PATHCTL "kern.module_path"
  54
  55 /* queue structure for the module path broken down into components */
  56 TAILQ_HEAD(pathhead, pathentry);
  57 struct pathentry {
  58         char                    *path;
  59         TAILQ_ENTRY(pathentry)  next;
  60 };
  61
  62 /* the Management Information Base entries for the search path sysctl */
  63 static int       mib[5];
  64 static size_t    miblen;
  65 /* the sysctl name, defaults to PATHCTL */
  66 static char     *pathctl;
  67 /* the sysctl value - the current module search path */
  68 static char     *modpath;
  69 /* flag whether user actions require changing the sysctl value */
  70 static int       changed;
  71
  72 /* Top-level path management functions */
  73 static void      addpath(struct pathhead *, char *, int, int);
  74 static void      rempath(struct pathhead *, char *, int, int);
  75 static void      showpath(struct pathhead *);
  76
  77 /* Low-level path management functions */
  78 static char     *qstring(struct pathhead *);
  79
  80 /* sysctl-related functions */
  81 static void      getmib(void);
  82 static void      getpath(void);
  83 static void      parsepath(struct pathhead *, char *, int);
  84 static void      setpath(struct pathhead *);
  85
  86 static void      usage(void);
  87
  88 /* Get the MIB entry for our sysctl */
  89 static void
  90 getmib(void)
  91 {
  92
  93         /* have we already fetched it? */
  94         if (miblen != 0)
  95                 return;
  96
  97         miblen = sizeof(mib) / sizeof(mib[0]);
  98         if (sysctlnametomib(pathctl, mib, &miblen) != 0)
  99                 err(1, "sysctlnametomib(%s)", pathctl);
 100 }
 101
 102 /* Get the current module search path */
 103 static void
 104 getpath(void)
 105 {
 106         char *path;
 107         size_t sz;
 108
 109         if (modpath != NULL) {
 110                 free(modpath);
 111                 modpath = NULL;
 112         }
 113
 114         if (miblen == 0)
 115                 getmib();
 116         if (sysctl(mib, miblen, NULL, &sz, NULL, 0) == -1)
 117                 err(1, "getting path: sysctl(%s) - size only", pathctl);
 118         if ((path = malloc(sz + 1)) == NULL) {
 119                 errno = ENOMEM;
 120                 err(1, "allocating %lu bytes for the path",
 121                     (unsigned long)sz+1);
 122         }
 123         if (sysctl(mib, miblen, path, &sz, NULL, 0) == -1)
 124                 err(1, "getting path: sysctl(%s)", pathctl);
 125         modpath = path;
 126 }
 127
 128 /* Set the module search path after changing it */
 129 static void
 130 setpath(struct pathhead *pathq)
 131 {
 132         char *newpath;
 133
 134         if (miblen == 0)
 135                 getmib();
 136         if ((newpath = qstring(pathq)) == NULL) {
 137                 errno = ENOMEM;
 138                 err(1, "building path string");
 139         }
 140         if (sysctl(mib, miblen, NULL, NULL, newpath, strlen(newpath)+1) == -1)
 141                 err(1, "setting path: sysctl(%s)", pathctl);
 142
 143         if (modpath)
 144                 free(modpath);
 145         modpath = newpath;
 146 }
 147
 148 /* Add/insert a new component to the module search path */
 149 static void
 150 addpath(struct pathhead *pathq, char *path, int force, int insert)
 151 {
 152         struct pathentry *pe, *pskip;
 153         char pathbuf[MAXPATHLEN+1];
 154         size_t len;
 155         static unsigned added = 0;
 156         unsigned i;
 157
 158         /*
 159          * If the path exists, use it; otherwise, take the user-specified
 160          * path at face value - may be a removed directory.
 161          */
 162         if (realpath(path, pathbuf) == NULL)
 163                 strlcpy(pathbuf, path, sizeof(pathbuf));
 164
 165         len = strlen(pathbuf);
 166 #ifdef NEED_SLASHTERM
 167         /* slash-terminate, because the kernel linker said so. */
 168         if ((len == 0) || (pathbuf[len-1] != '/')) {
 169                 if (len == sizeof(pathbuf) - 1)
 170                         errx(1, "path too long: %s", pathbuf);
 171                 pathbuf[len] = '/';
 172         }
 173 #else  /* NEED_SLASHTERM */
 174         /* remove a terminating slash if present */
 175         if ((len > 0) && (pathbuf[len-1] == '/'))
 176                 pathbuf[--len] = '\0';
 177 #endif /* NEED_SLASHTERM */
 178
 179         /* is it already in there? */
 180         TAILQ_FOREACH(pe, pathq, next)
 181                 if (!strcmp(pe->path, pathbuf))
 182                         break;
 183         if (pe != NULL) {
 184                 if (force)
 185                         return;
 186                 errx(1, "already in the module search path: %s", pathbuf);
 187         }
 188
 189         /* OK, allocate and add it. */
 190         if (((pe = malloc(sizeof(*pe))) == NULL) ||
 191             ((pe->path = strdup(pathbuf)) == NULL)) {
 192                 errno = ENOMEM;
 193                 err(1, "allocating path component");
 194         }
 195         if (!insert) {
 196                 TAILQ_INSERT_TAIL(pathq, pe, next);
 197         } else {
 198                 for (i = 0, pskip = TAILQ_FIRST(pathq); i < added; i++)
 199                         pskip = TAILQ_NEXT(pskip, next);
 200                 if (pskip != NULL)
 201                         TAILQ_INSERT_BEFORE(pskip, pe, next);
 202                 else
 203                         TAILQ_INSERT_TAIL(pathq, pe, next);
 204                 added++;
 205         }
 206         changed = 1;
 207 }
 208
 209 /* Remove a path component from the module search path */
 210 static void
 211 rempath(struct pathhead *pathq, char *path, int force, int insert __unused)
 212 {
 213         char pathbuf[MAXPATHLEN+1];
 214         struct pathentry *pe;
 215         size_t len;
 216
 217         /* same logic as in addpath() */
 218         if (realpath(path, pathbuf) == NULL)
 219                 strlcpy(pathbuf, path, sizeof(pathbuf));
 220
 221         len = strlen(pathbuf);
 222 #ifdef NEED_SLASHTERM
 223         /* slash-terminate, because the kernel linker said so. */
 224         if ((len == 0) || (pathbuf[len-1] != '/')) {
 225                 if (len == sizeof(pathbuf) - 1)
 226                         errx(1, "path too long: %s", pathbuf);
 227                 pathbuf[len] = '/';
 228         }
 229 #else  /* NEED_SLASHTERM */
 230         /* remove a terminating slash if present */
 231         if ((len > 0) && (pathbuf[len-1] == '/'))
 232                 pathbuf[--len] = '\0';
 233 #endif /* NEED_SLASHTERM */
 234
 235         /* Is it in there? */
 236         TAILQ_FOREACH(pe, pathq, next)
 237                 if (!strcmp(pe->path, pathbuf))
 238                         break;
 239         if (pe == NULL) {
 240                 if (force)
 241                         return;
 242                 errx(1, "not in module search path: %s", pathbuf);
 243         }
 244
 245         /* OK, remove it now.. */
 246         TAILQ_REMOVE(pathq, pe, next);
 247         changed = 1;
 248 }
 249
 250 /* Display the retrieved module search path */
 251 static void
 252 showpath(struct pathhead *pathq)
 253 {
 254         char *s;
 255
 256         if ((s = qstring(pathq)) == NULL) {
 257                 errno = ENOMEM;
 258                 err(1, "building path string");
 259         }
 260         printf("%s\n", s);
 261         free(s);
 262 }
 263
 264 /* Break a string down into path components, store them into a queue */
 265 static void
 266 parsepath(struct pathhead *pathq, char *path, int uniq)
 267 {
 268         char *p;
 269         struct pathentry *pe;
 270
 271         while ((p = strsep(&path, ";")) != NULL)
 272                 if (!uniq) {
 273                         if (((pe = malloc(sizeof(*pe))) == NULL) ||
 274                             ((pe->path = strdup(p)) == NULL)) {
 275                                 errno = ENOMEM;
 276                                 err(1, "allocating path element");
 277                         }
 278                         TAILQ_INSERT_TAIL(pathq, pe, next);
 279                 } else {
 280                         addpath(pathq, p, 1, 0);
 281                 }
 282 }
 283
 284 /* Recreate a path string from a components queue */
 285 static char *
 286 qstring(struct pathhead *pathq)
 287 {
 288         char *s, *p;
 289         struct pathentry *pe;
 290
 291         s = strdup("");
 292         TAILQ_FOREACH(pe, pathq, next) {
 293                 asprintf(&p, "%s%s%s",
 294                     s, pe->path, (TAILQ_NEXT(pe, next) != NULL? ";": ""));
 295                 free(s);
 296                 if (p == NULL)
 297                         return (NULL);
 298                 s = p;
 299         }
 300
 301         return (s);
 302 }
 303
 304 /* Usage message */
 305 static void
 306 usage(void)
 307 {
 308
 309         fprintf(stderr, "%s\n%s\n",
 310             "usage:\tkldconfig [-dfimnUv] [-S sysctlname] [path..]",
 311             "\tkldconfig -r");
 312         exit(1);
 313 }
 314
 315 /* Main function */
 316 int
 317 main(int argc, char *argv[])
 318 {
 319         /* getopt() iterator */
 320         int c;
 321         /* iterator over argv[] path components */
 322         int i;
 323         /* Command-line flags: */
 324         /* "-f" - no diagnostic messages */
 325         int fflag;
 326         /* "-i" - insert before the first element */
 327         int iflag;
 328         /* "-m" - merge into the existing path, do not replace it */
 329         int mflag;
 330         /* "-n" - do not actually set the new module path */
 331         int nflag;
 332         /* "-r" - print out the current search path */
 333         int rflag;
 334         /* "-U" - remove duplicate values from the path */
 335         int uniqflag;
 336         /* "-v" - verbose operation (currently a no-op) */
 337         int vflag;
 338         /* The higher-level function to call - add/remove */
 339         void (*act)(struct pathhead *, char *, int, int);
 340         /* The original path */
 341         char *origpath;
 342         /* The module search path broken down into components */
 343         struct pathhead pathq;
 344
 345         fflag = iflag = mflag = nflag = rflag = uniqflag = vflag = 0;
 346         act = addpath;
 347         origpath = NULL;
 348         if ((pathctl = strdup(PATHCTL)) == NULL) {
 349                 /* this is just too paranoid ;) */
 350                 errno = ENOMEM;
 351                 err(1, "initializing sysctl name %s", PATHCTL);
 352         }
 353
 354         /* If no arguments and no options are specified, force '-m' */
 355         if (argc == 1)
 356                 mflag = 1;
 357
 358         while ((c = getopt(argc, argv, "dfimnrS:Uv")) != -1)
 359                 switch (c) {
 360                         case 'd':
 361                                 if (iflag || mflag)
 362                                         usage();
 363                                 act = rempath;
 364                                 break;
 365                         case 'f':
 366                                 fflag = 1;
 367                                 break;
 368                         case 'i':
 369                                 if (act != addpath)
 370                                         usage();
 371                                 iflag = 1;
 372                                 break;
 373                         case 'm':
 374                                 if (act != addpath)
 375                                         usage();
 376                                 mflag = 1;
 377                                 break;
 378                         case 'n':
 379                                 nflag = 1;
 380                                 break;
 381                         case 'r':
 382                                 rflag = 1;
 383                                 break;
 384                         case 'S':
 385                                 free(pathctl);
 386                                 if ((pathctl = strdup(optarg)) == NULL) {
 387                                         errno = ENOMEM;
 388                                         err(1, "sysctl name %s", optarg);
 389                                 }
 390                                 break;
 391                         case 'U':
 392                                 uniqflag = 1;
 393                                 break;
 394                         case 'v':
 395                                 vflag++;
 396                                 break;
 397                         default:
 398                                 usage();
 399                 }
 400
 401         argc -= optind;
 402         argv += optind;
 403
 404         /* The '-r' flag cannot be used when paths are also specified */
 405         if (rflag && (argc > 0))
 406                 usage();
 407
 408         TAILQ_INIT(&pathq);
 409
 410         /* Retrieve and store the path from the sysctl value */
 411         getpath();
 412         if ((origpath = strdup(modpath)) == NULL) {
 413                 errno = ENOMEM;
 414                 err(1, "saving the original search path");
 415         }
 416
 417         /*
 418          * Break down the path into the components queue if:
 419          * - we are NOT adding paths, OR
 420          * - the 'merge' flag is specified, OR
 421          * - the 'print only' flag is specified, OR
 422          * - the 'unique' flag is specified.
 423          */
 424         if ((act != addpath) || mflag || rflag || uniqflag)
 425                 parsepath(&pathq, modpath, uniqflag);
 426         else if (modpath[0] != '\0')
 427                 changed = 1;
 428
 429         /* Process the path arguments */
 430         for (i = 0; i < argc; i++)
 431                 act(&pathq, argv[i], fflag, iflag);
 432
 433         if (changed && !nflag)
 434                 setpath(&pathq);
 435
 436         if (rflag || (changed && vflag)) {
 437                 if (changed && (vflag > 1))
 438                         printf("%s -> ", origpath);
 439                 showpath(&pathq);
 440         }
 441
 442         return (0);
 443 }