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