usr.sbin/resident/resident.c

   1 /*
   2  * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com>
   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
  27 #include <sys/param.h>
  28 #include <sys/wait.h>
  29 #include <sys/stat.h>
  30 #include <sys/resident.h>
  31 #include <sys/sysctl.h>
  32
  33 #include <machine/elf.h>
  34 #include <a.out.h>
  35 #include <dlfcn.h>
  36 #include <err.h>
  37 #include <fcntl.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41 #include <string.h>
  42 #include <errno.h>
  43
  44 static void
  45 usage(void)
  46 {
  47         fprintf(stderr, "usage: resident [-l] [-f] [-x id] [-d] [-R] program ...\n");
  48         exit(1);
  49 }
  50
  51 static int
  52 list_residents(void)
  53 {
  54         const char *mib = "vm.resident";
  55         struct xresident *buf;
  56         size_t res_count, res_total, i;
  57         int error;
  58
  59         /* get the number of resident binaries */
  60         error = sysctlbyname(mib, NULL, &res_count, NULL, 0);
  61         if (error != 0) {
  62                 perror("sysctl: vm.resident");
  63                 goto done;
  64         }
  65
  66         if (res_count == 0) {
  67                 printf("no resident binaries to list\n");
  68                 goto done;
  69         }
  70
  71         /* allocate memory for the list of binaries */
  72         res_total = sizeof(*buf) * res_count;
  73         if ((buf = malloc(res_total)) != NULL) {
  74                 /* retrieve entries via sysctl */
  75                 error = sysctlbyname(mib, buf, &res_total, NULL, 0);
  76                 if (error != 0) {
  77                         perror("sysctl: vm.resident");
  78                         goto done;
  79                 }
  80         } else {
  81                 perror("malloc");
  82                 goto done;
  83         }
  84
  85         /* print the list of retrieved resident binary */
  86         printf("%-4s\t%-15s\t%-12s\t%-30s\n","Id", "Size", "Address", "Executable");
  87         for (i = 0; i < res_count; ++i) {
  88                 printf("%-4d\t%-15jd\t0x%-12x\t%-30s\n",
  89                         buf[i].res_id,
  90                         (intmax_t)buf[i].res_stat.st_size,
  91                         (int)buf[i].res_entry_addr,
  92                         buf[i].res_file);
  93         }
  94
  95         /* free back the memory */
  96         free(buf);
  97
  98 done:
  99         return error;
 100 }
 101
 102 int
 103 main(int argc, char *argv[])
 104 {
 105         int     rval;
 106         int     c;
 107         int     doreg = 1;
 108         int     force = 0;
 109
 110         while ((c = getopt(argc, argv, "Rdflx:")) != -1) {
 111                 switch (c) {
 112                 case 'f':
 113                         force = 1;
 114                         break;
 115                 case 'l':
 116                         rval = list_residents();
 117                         if (rval < 0)
 118                                 exit(EXIT_FAILURE);
 119                         else
 120                                 exit(EXIT_SUCCESS);
 121                 case 'd':
 122                         doreg = 0;
 123                         break;
 124                 case 'x':
 125                 case 'R':
 126                         if (c == 'R')
 127                             c = exec_sys_unregister(-2);
 128                         else
 129                             c = exec_sys_unregister(strtol(optarg, NULL, 0));
 130                         if (c < 0)
 131                             printf("unregister: %s\n", strerror(errno));
 132                         else
 133                             printf("unregister: success\n");
 134                         exit(0);
 135                 default:
 136                         usage();
 137                         /*NOTREACHED*/
 138                 }
 139         }
 140         argc -= optind;
 141         argv += optind;
 142
 143         if (argc <= 0) {
 144                 usage();
 145                 /*NOTREACHED*/
 146         }
 147
 148         /* ld-elf.so magic */
 149         if (doreg) {
 150             if (setenv("LD_RESIDENT_REGISTER_NOW", "yes", 1) == -1)
 151                         err(1, "setenv failed");
 152         } else {
 153             if (setenv("LD_RESIDENT_UNREGISTER_NOW", "yes", 1) == -1)
 154                         err(1, "setenv failed");
 155         }
 156
 157         rval = 0;
 158         for ( ;  argc > 0;  argc--, argv++) {
 159                 int     fd;
 160                 union {
 161                         struct exec aout;
 162                         Elf_Ehdr elf;
 163                 } hdr;
 164                 int     n;
 165                 int     status;
 166                 int     file_ok;
 167                 int     is_shlib;
 168
 169                 if (force)
 170                         goto force_target;
 171
 172                 if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
 173                         warn("%s", *argv);
 174                         rval |= 1;
 175                         continue;
 176                 }
 177                 if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
 178                         warn("%s: can't read program header", *argv);
 179                         close(fd);
 180                         rval |= 1;
 181                         continue;
 182                 }
 183
 184                 file_ok = 1;
 185                 is_shlib = 0;
 186                 if ((size_t)n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
 187                         /* a.out file */
 188                         if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
 189 #if 1 /* Compatibility */
 190                             || hdr.aout.a_entry < __LDPGSZ
 191 #endif
 192                                 ) {
 193                                 warnx("%s: not a dynamic executable", *argv);
 194                                 file_ok = 0;
 195                         }
 196                 } else if ((size_t)n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
 197                         Elf_Ehdr ehdr;
 198                         Elf_Phdr phdr;
 199                         int dynamic = 0, i;
 200
 201                         if (lseek(fd, 0, SEEK_SET) == -1 ||
 202                             read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
 203                             lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
 204                            ) {
 205                                 warnx("%s: can't read program header", *argv);
 206                                 file_ok = 0;
 207                         } else {
 208                                 for (i = 0; i < ehdr.e_phnum; i++) {
 209                                         if (read(fd, &phdr, ehdr.e_phentsize)
 210                                            != sizeof phdr) {
 211                                                 warnx("%s: can't read program header",
 212                                                     *argv);
 213                                                 file_ok = 0;
 214                                                 break;
 215                                         }
 216                                         if (phdr.p_type == PT_DYNAMIC)
 217                                                 dynamic = 1;
 218                                 }
 219                         }
 220                         if (!dynamic) {
 221                                 warnx("%s: not a dynamic executable", *argv);
 222                                 file_ok = 0;
 223                         } else if (hdr.elf.e_type == ET_DYN) {
 224                                 if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
 225                                         is_shlib = 1;
 226                                 } else {
 227                                         warnx("%s: not a FreeBSD ELF shared "
 228                                               "object", *argv);
 229                                         file_ok = 0;
 230                                 }
 231                         }
 232                 } else {
 233                         warnx("%s: not a dynamic executable", *argv);
 234                         file_ok = 0;
 235                 }
 236                 close(fd);
 237                 if (!file_ok) {
 238                         rval |= 1;
 239                         continue;
 240                 }
 241
 242                 if (is_shlib) {
 243                         rval |= 1;
 244                         warnx("%s: resident not supported on shared libraries.", *argv);
 245                         continue;
 246                 }
 247
 248 force_target:
 249                 fflush(stdout);
 250
 251                 switch (fork()) {
 252                 case -1:
 253                         err(1, "fork");
 254                         break;
 255                 default:
 256                         if (wait(&status) <= 0) {
 257                                 warn("wait");
 258                                 rval |= 1;
 259                         } else if (WIFSIGNALED(status)) {
 260                                 fprintf(stderr, "%s: signal %d\n",
 261                                                 *argv, WTERMSIG(status));
 262                                 rval |= 1;
 263                         } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
 264                                 switch(WEXITSTATUS(status)) {
 265                                 case ENOENT:
 266                                     fprintf(stderr, "%s: entry not found\n",
 267                                         *argv);
 268                                     break;
 269                                 case EEXIST:
 270                                     fprintf(stderr, "%s: binary already resident\n",
 271                                         *argv);
 272                                     break;
 273                                 default:
 274                                     fprintf(stderr, "%s: exit status %s\n",
 275                                                 *argv, strerror(WEXITSTATUS(status)));
 276                                 }
 277                                 rval |= 1;
 278                         } else {
 279                         }
 280                         break;
 281                 case 0:
 282                         execl(*argv, *argv, NULL);
 283                         warn("%s", *argv);
 284                         _exit(1);
 285                 }
 286         }
 287
 288         return rval;
 289 }