lib/roken/test-auxval.c

   1 /*
   2  * Copyright (c) 1999 - 2004 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include <sys/types.h>
  37 #include <sys/stat.h>
  38 #include <err.h>
  39 #include <fcntl.h>
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43 #include "roken.h"
  44 #include "getauxval.h"
  45
  46 static void
  47 check_secure_getenv(char **env)
  48 {
  49     size_t i;
  50     char *v;
  51
  52     for (i = 0; env[i] != NULL; i++) {
  53         if (strchr(env[i], '=') == NULL)
  54             continue;
  55         if ((v = strdup(env[i])) == NULL)
  56             err(1, "could not allocate copy of %s", env[i]);
  57         *strchr(v, '=') = '\0';
  58         if (issuid() && rk_secure_getenv(v) != NULL)
  59             err(1, "rk_secure_getenv() returned non-NULL when issuid()!");
  60         if (!issuid() && rk_secure_getenv(v) == NULL)
  61             err(1, "rk_secure_getenv() returned NULL when !issuid()");
  62         free(v);
  63         return;
  64     }
  65 }
  66
  67 static void
  68 inject_suid(int suid)
  69 {
  70 #if defined(AT_SECURE) || (defined(AT_EUID) && defined(AT_RUID) && defined(AT_EGID) && defined(AT_RGID))
  71     auxv_t e;
  72 #ifdef AT_SECURE
  73     unsigned long secure = suid ? 1 : 0;
  74 #endif
  75 #if defined(AT_EUID) && defined(AT_RUID) && defined(AT_EGID) && defined(AT_RGID)
  76     unsigned long eid = suid ? 0 : 1000;
  77
  78     /* Inject real UID and GID */
  79     e.a_un.a_val = 1000;
  80     e.a_type = AT_UID;
  81     if ((errno = rk_injectauxv(&e)) != 0)
  82         err(1, "rk_injectauxv(AT_RUID) failed");
  83     e.a_type = AT_GID;
  84     if ((errno = rk_injectauxv(&e)) != 0)
  85         err(1, "rk_injectauxv(AT_RGID) failed");
  86
  87     /* Inject effective UID and GID */
  88     e.a_un.a_val = eid;
  89     e.a_type = AT_EUID;
  90     if ((errno = rk_injectauxv(&e)) != 0)
  91         err(1, "rk_injectauxv(AT_EUID) failed");
  92     e.a_type = AT_EGID;
  93     if ((errno = rk_injectauxv(&e)) != 0)
  94         err(1, "rk_injectauxv(AT_RGID) failed");
  95 #endif
  96
  97 #ifdef AT_SECURE
  98     e.a_un.a_val = secure;
  99     e.a_type = AT_SECURE;
 100     if ((errno = rk_injectauxv(&e)) != 0)
 101         err(1, "rk_injectauxv(AT_SECURE) failed");
 102 #endif
 103
 104     return;
 105 #else
 106     warnx("No ELF auxv types to inject");
 107 #endif
 108 }
 109
 110 static
 111 unsigned long
 112 getprocauxval(unsigned long type)
 113 {
 114     const auxv_t *e;
 115
 116     if ((e = rk_getauxv(type)) == NULL) {
 117         errno = ENOENT;
 118         return 0;
 119     }
 120     return e->a_un.a_val;
 121 }
 122
 123 /* returns 1 if auxval type is handled specially by libc */
 124 static int
 125 is_special_auxv_p(long type)
 126 {
 127 #ifdef AT_HWCAP
 128     if (type == AT_HWCAP)
 129         return 1;
 130 #endif
 131 #ifdef AT_HWCAP2
 132     if (type == AT_HWCAP2)
 133         return 1;
 134 #endif
 135
 136     return 0;
 137 }
 138
 139 int
 140 main(int argc, char **argv, char **env)
 141 {
 142     unsigned long max_t = 0;
 143     unsigned long a[2];
 144     unsigned long v;
 145     ssize_t bytes;
 146     int am_suid = issuid();
 147     int fd;
 148
 149     (void) argc;
 150     (void) argv;
 151
 152     if (getuid() == geteuid() && getgid() == getegid()) {
 153         if (issuid())
 154             errx(1, "issuid() false positive?  Check AT_SECURE?");
 155     } else {
 156         if (!issuid())
 157             errx(1, "issuid() did not detect set-uid-ness!");
 158     }
 159
 160     if ((fd = open("/proc/self/auxv", O_RDONLY)) == -1)
 161         return 0;
 162
 163     /*
 164      * Check that for every ELF auxv entry in /proc/self/auxv we
 165      * find the correct answer from the rk_get*auxval() functions.
 166      */
 167     do {
 168         bytes = read(fd, a, sizeof(a));
 169         if (bytes != sizeof(a)) {
 170             if (bytes == -1)
 171                 err(1, "Error reading from /proc/self/auxv");
 172             if (bytes == 0)
 173                 warnx("Did not see terminator in /proc/self/auxv");
 174             else
 175                 warnx("Partial entry in /proc/self/auxv or test interrupted");
 176             (void) close(fd);
 177             return 1;
 178         }
 179         if (a[0] > max_t)
 180             max_t = a[0];
 181         if (a[0] == 0) {
 182             if (a[1] != 0)
 183                 warnx("AT_NULL with non-zero value %lu?!", a[1]);
 184             continue;
 185         } else if (is_special_auxv_p(a[0]))
 186             continue;
 187
 188         errno = EACCES;
 189
 190         if ((v = rk_getauxval(a[0])) != a[1])
 191             errx(1, "rk_getauxval(%lu) should have been %lu, was %lu",
 192                  a[0], a[1], v);
 193         if (errno != EACCES)
 194             errx(1, "rk_getauxval(%lu) did not preserve errno", a[0]);
 195
 196         if ((v = getprocauxval(a[0])) != a[1])
 197             errx(1, "rk_getauxval(%lu) should have been %lu, was %lu",
 198                  a[0], a[1], v);
 199         if (errno != EACCES)
 200             errx(1, "rk_getauxv(%lu) did not preserve errno", a[0]);
 201
 202         printf("auxv type %lu -> %lu\n", a[0], a[1]);
 203     } while (a[0] != 0 || a[1] != 0);
 204
 205     (void) close(fd);
 206     if (max_t == 0) {
 207         warnx("No entries in /proc/self/auxv or it is not available on this "
 208               "system or this program is linked statically; cannot test "
 209               "rk_getauxval()");
 210         return 0;
 211     }
 212
 213     errno = EACCES;
 214     if ((v = rk_getauxval(max_t + 1)) != 0)
 215         errx(1, "rk_getauxval((max_type_seen = %lu) + 1) should have been "
 216              "0, was %lu", max_t, v);
 217     if (errno != ENOENT)
 218         errx(1, "rk_getauxval((max_type_seen = %lu) + 1) did not set "
 219              "errno = ENOENT!", max_t);
 220
 221     errno = EACCES;
 222     if ((v = getprocauxval(max_t + 1)) != 0)
 223         errx(1, "rk_getauxv((max_type_seen = %lu) + 1) should have been "
 224              "0, was %lu", max_t, v);
 225     if (errno != ENOENT)
 226         errx(1, "rk_getauxv((max_type_seen = %lu) + 1) did not set "
 227              "errno = ENOENT!", max_t);
 228
 229     check_secure_getenv(env);
 230     inject_suid(!am_suid);
 231     if ((am_suid && issuid()) || (!am_suid && !issuid()))
 232         errx(1, "rk_injectprocauxv() failed");
 233     check_secure_getenv(env);
 234
 235     return 0;
 236 }