pd.if.org Git - zpackage/blob - elf/elftype.c

   1 #define _POSIX_C_SOURCE 200112L
   2 #include <sys/types.h>
   3 #include <sys/stat.h>
   4 #include <fcntl.h>
   5 #include <unistd.h>
   6 #include <limits.h>
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include "elf.h"
  11
  12 #define RELOCATABLE 0x1
  13 #define EXECUTABLE  0x2
  14 #define DYNAMIC     0x4
  15 #define CORE        0x8
  16 #define SYMLINKS    0x10
  17
  18 int readline(FILE *f, char *fn);
  19 int checkfile(char *fn, unsigned int want, int perr);
  20
  21 int errors = 0;
  22 int zeroterm = 0;
  23
  24 int main(int ac, char **av) {
  25         int option;
  26         unsigned int want = 0;
  27         int printtype = 0;
  28         int printname = 0;
  29         int verbose = 0;
  30         int perr = 0;
  31         FILE *list = 0;
  32         char fn[PATH_MAX];
  33
  34         while ((option = getopt(ac, av, "vtnredclap0f:")) != -1) {
  35                 switch (option) {
  36                         case 'r': want |= RELOCATABLE; break;
  37                         case 'e': want |= EXECUTABLE; break;
  38                         case 'd': want |= DYNAMIC; break;
  39                         case 'c': want |= CORE; break;
  40                         case 'l': want |= SYMLINKS; break;
  41                         case 'a': want = (RELOCATABLE|EXECUTABLE|DYNAMIC|CORE); break;
  42                         case 't': printtype++; break;
  43                         case 'n': printname++; break;
  44                         case 'v': verbose++; break;
  45                         case 'p': perr++; break;
  46                         case '0': zeroterm = 1; break;
  47                         case 'f':
  48                                   if (optarg[0] == '-' && optarg[1] == 0) {
  49                                           list = stdin;
  50                                   } else {
  51                                           list = fopen(optarg, "r");
  52                                   }
  53                                   break;
  54                         default:
  55                                   exit(1);
  56                                   break;
  57                 }
  58         }
  59
  60         if (!want) want = (RELOCATABLE|EXECUTABLE|DYNAMIC|CORE);
  61
  62         if (list) {
  63                 int type;
  64                 perr = 0;
  65                 while (readline(list, fn)) {
  66                         if ((type = checkfile(fn, want, perr)) & want) {
  67                                 if (printtype) {
  68                                         switch (type) {
  69                                                 case RELOCATABLE:
  70                                                         printf("relocatable "); break;
  71                                                 case EXECUTABLE:
  72                                                         printf("executable "); break;
  73                                                 case DYNAMIC:
  74                                                         printf("dynamic "); break;
  75                                                 case CORE:
  76                                                         printf("core "); break;
  77                                                 default:
  78                                                         printf("notelf "); break;
  79                                         }
  80                                 }
  81                                 printf("%s\n", fn);
  82                         }
  83                 }
  84         } else {
  85                 int type;
  86                 char *fn;
  87
  88                 fn = av[optind];
  89                 if (verbose) fprintf(stderr, "checking %s\n", av[optind]);
  90                 type = checkfile(fn,want,perr);
  91
  92                 if (printtype) {
  93                         switch (type) {
  94                                 case RELOCATABLE:
  95                                         printf("relocatable"); break;
  96                                 case EXECUTABLE:
  97                                         printf("executable"); break;
  98                                 case DYNAMIC:
  99                                         printf("dynamic"); break;
 100                                 case CORE:
 101                                         printf("core"); break;
 102                                 default:
 103                                         printf("notelf"); break;
 104                         }
 105                 }
 106
 107                 if (printname) {
 108                         printf("%s%s", printtype ? " " : "", fn);
 109                 }
 110                 if (printtype || printname) printf("\n");
 111
 112                 return type & want ? 0 : 1;
 113         }
 114         return errors ? 1 : 0;
 115 }
 116
 117 int readline(FILE *f, char *fn) {
 118         int ch;
 119         int i = 0;
 120
 121         do {
 122                 ch = fgetc(f);
 123                 switch (ch) {
 124                         case EOF: break;
 125                         case 0:
 126                                   if (i == 0) continue;
 127                                   break;
 128                         case '\n':
 129                                   if (!zeroterm) {
 130                                           if (i == 0) continue;
 131                                           break;
 132                                   }
 133                         default:
 134                                   fn[i++] = ch;
 135                                   continue;
 136                 }
 137                 if (i >= PATH_MAX) {
 138                         /* TODO print an error */
 139                         return 0;
 140                 }
 141                 fn[i] = 0;
 142                 return i;
 143         } while (ch != EOF);
 144         return 0;
 145 }
 146
 147 int checkfile(char *fn, unsigned int want, int perr) {
 148         Elf64_Ehdr hdr;
 149         int fd, bytes;
 150         int endian = 0;
 151         struct stat st;
 152
 153         if (want & SYMLINKS) {
 154                 lstat(fn, &st);
 155         } else {
 156                 stat(fn, &st);
 157         }
 158         if (!S_ISREG(st.st_mode)) {
 159                 return 0;
 160         }
 161
 162         fd = open(fn, O_RDONLY);
 163         if (fd == -1) {
 164                 perror("elfcheck");
 165                 errors++;
 166                 return 0;
 167         }
 168         bytes = read(fd, &hdr, sizeof hdr);
 169         close(fd);
 170         if ((size_t)bytes < sizeof hdr) {
 171                 if (perr) fprintf(stderr, "could not read full elf header (wanted %zu got %d bytes)\n", sizeof hdr, bytes);
 172                 return 0;
 173         }
 174         if (hdr.e_ident[EI_MAG0] != ELFMAG0
 175                         || hdr.e_ident[EI_MAG1] != ELFMAG1
 176                         || hdr.e_ident[EI_MAG2] != ELFMAG2
 177                         || hdr.e_ident[EI_MAG3] != ELFMAG3
 178            ) {
 179                 if (perr) fprintf(stderr, "elf header magic wrong\n");
 180                 return 0;
 181         }
 182         switch (hdr.e_ident[EI_CLASS]) {
 183                 case ELFCLASS64:
 184                 case ELFCLASS32:
 185                 case ELFCLASSNONE:
 186                         break;
 187                 default:
 188                         if (perr) fprintf(stderr, "elf header unknown class\n");
 189                         return 0;
 190         }
 191
 192         endian = hdr.e_ident[EI_DATA];
 193         switch (endian) {
 194                 case ELFDATA2LSB: break;
 195                 case ELFDATA2MSB: break;
 196                                   /* TODO swap endian if needed */
 197                 default:
 198                         if (perr) fprintf(stderr, "elf header unknown endian\n");
 199                         return 0;
 200         }
 201
 202         switch (hdr.e_type) {
 203                 case ET_REL: return RELOCATABLE;
 204                 case ET_EXEC: return EXECUTABLE;
 205                 case ET_DYN: return DYNAMIC;
 206                 case ET_CORE: return CORE;
 207                 case ET_NONE:
 208                 default:
 209                         if (perr) fprintf(stderr, "unknown %s\n", fn);
 210                         return 0;
 211         }
 212
 213         return 0;
 214 }