make shadow records really work

[unix-history] / usr / src / usr.bin / cap_mkdb / cap_mkdb.c

/*-
* Copyright (c) 1992 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1992 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)cap_mkdb.c  5.5 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>

#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void     db_build __P((char **));
void     dounlink __P((void));
void     usage __P((void));

DB *capdbp;
int verbose;
char *capdb, *capname, buf[8 * 1024];

/*
* Mkcapdb creates a capability hash database for quick retrieval of capability
* records.  The database contains 2 types of entries: records and references
* marked by the first byte in the data.  A record entry contains the actual
* capability record whereas a reference contains the name (key) under which
* the correct record is stored.
*/
int
main(argc, argv)
       int argc;
       char *argv[];
{
       int c;

       capname = NULL;
       while ((c = getopt(argc, argv, "f:v")) != EOF) {
               switch(c) {
               case 'f':
                       capname = optarg;
                       break;
               case 'v':
                       verbose = 1;
                       break;
               case '?':
               default:
                       usage();
               }
       }
       argc -= optind;
       argv += optind;

       if (*argv == NULL)
               usage();

       /*
        * The database file is the first argument if no name is specified.
        * Make arrangements to unlink it if exit badly.
        */
       (void)snprintf(buf, sizeof(buf), "%s.db", capname ? capname : *argv);
       if ((capname = strdup(buf)) == NULL)
               err(1, "");
       if ((capdbp = dbopen(capname,
           O_CREAT | O_TRUNC | O_RDWR, DEFFILEMODE, DB_HASH, NULL)) == NULL)
               err(1, "%s", buf);

       if (atexit(dounlink))
               err(1, "atexit");

       db_build(argv);

       if (capdbp->close(capdbp) < 0)
               err(1, "%s", capname);
       capname = NULL;
       exit(0);
}

void
dounlink()
{
       if (capname != NULL)
               (void)unlink(capname);
}

/*
* Any changes to these definitions should be made also in the getcap(3)
* library routines.
*/
#define RECOK   (char)0
#define TCERR   (char)1
#define SHADOW  (char)2

/*
* Db_build() builds the name and capabilty databases according to the
* details above.
*/
void
db_build(ifiles)
       char **ifiles;
{
       DBT key, data;
       recno_t reccnt;
       size_t len, bplen;
       int st;
       char *bp, *p, *t;

       data.data = NULL;
       key.data = NULL;
       for (reccnt = 0, bplen = 0; (st = cgetnext(&bp, ifiles)) > 0;) {

               /*
                * Allocate enough memory to store record, terminating
                * NULL and one extra byte.
                */
               len = strlen(bp);
               if (bplen <= len + 2) {
                       bplen += MAX(256, len + 2);
                       if ((data.data = realloc(data.data, bplen)) == NULL)
                               err(1, "");
               }

               /* First byte of stored record indicates error. */
               ((char *)(data.data))[0] = st == 2 ? TCERR : RECOK;

               /* Create the stored record. */
               memmove(&((u_char *)(data.data))[1], bp, len + 1);
               data.size = len + 2;

               /* Store record under name field. */
               if ((p = strchr(bp, ':')) == NULL) {
                       warn("no name field: %.*s", MIN(len, 20), bp);
                       continue;
               }
               key.data = bp;
               key.size = p - bp;

               switch(capdbp->put(capdbp, &key, &data, R_NOOVERWRITE)) {
               case -1:
                       err(1, "put");
                       /* NOTREACHED */
               case 1:
                       warnx("ignored duplicate: %.*s",
                           key.size, (char *)key.data);
                       continue;
               }
               ++reccnt;

               /* If only one name, ignore the rest. */
               if ((p = strchr(bp, '|')) == NULL)
                       continue;

               /* The rest of the names reference the entire name. */
               ((char *)(data.data))[0] = SHADOW;
               memmove(&((u_char *)(data.data))[1], key.data, key.size);
               data.size = key.size + 1;

               /* Store references for other names. */
               for (p = t = bp;; ++p) {
                       if (p > t && (*p == ':' || *p == '|')) {
                               key.size = p - t;
                               key.data = t;
                               switch(capdbp->put(capdbp,
                                   &key, &data, R_NOOVERWRITE)) {
                               case -1:
                                       err(1, "put");
                                       /* NOTREACHED */
                               case 1:
                                       warnx("ignored duplicate: %.*s",
                                           key.size, (char *)key.data);
                               }
                               t = p + 1;
                       }
                       if (*p == ':')
                               break;
               }
       }

       switch(st) {
       case -1:
               err(1, "file argument");
               /* NOTREACHED */
       case -2:
               errx(1, "potential reference loop detected");
               /* NOTREACHED */
       }

       if (verbose)
               (void)printf("cap_mkdb: %d capability records\n", reccnt);
}

void
usage()
{
       (void)fprintf(stderr,
           "usage: cap_mkdb [-v] [-f outfile] file1 [file2 ...]\n");
       exit(1);
}