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, int quiet);
  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 quiet = 0;
  28         int printtype = 0;
  29         int printname = 0;
  30         int verbose = 0;
  31         int perr = 0;
  32         FILE *list = 0;
  33         char fn[PATH_MAX];
  34
  35         while ((option = getopt(ac, av, "vtnredclaqp0f:")) != -1) {
  36                 switch (option) {
  37                         case 'r': want |= RELOCATABLE; break;
  38                         case 'e': want |= EXECUTABLE; break;
  39                         case 'd': want |= DYNAMIC; break;
  40                         case 'c': want |= CORE; break;
  41                         case 'l': want |= SYMLINKS; break;
  42                         case 'a': want = (RELOCATABLE|EXECUTABLE|DYNAMIC|CORE); break;
  43                         case 'q': quiet++; break;
  44                         case 't': printtype++; break;
  45                         case 'n': printname++; break;
  46                         case 'v': verbose++; break;
  47                         case 'p': perr++; break;
  48                         case '0': zeroterm = 1; break;
  49                         case 'f':
  50                                   if (optarg[0] == '-' && optarg[1] == 0) {
  51                                           fprintf(stderr, "opening stdin\n");
  52                                           list = stdin;
  53                                   } else {
  54                                           list = fopen(optarg, "r");
  55                                   }
  56                                   break;
  57                         default:
  58                                   exit(1);
  59                                   break;
  60                 }
  61         }
  62
  63         if (!want) want = (RELOCATABLE|EXECUTABLE|DYNAMIC|CORE);
  64
  65         if (list) {
  66                 quiet = 2;
  67                 perr = 0;
  68                 while (readline(list, fn)) {
  69                         if (checkfile(fn, want,perr,quiet)) {
  70                                 printf("%s\n", fn);
  71                         }
  72                 }
  73         } else {
  74                 int type;
  75                 char *fn;
  76
  77                 fn = av[optind];
  78                 if (verbose) fprintf(stderr, "checking %s\n", av[optind]);
  79                 type = checkfile(fn,want,perr,quiet);
  80
  81                 if (printtype) {
  82                         switch (type) {
  83                                 case RELOCATABLE:
  84                                         printf("relocatable"); break;
  85                                 case EXECUTABLE:
  86                                         printf("executable"); break;
  87                                 case DYNAMIC:
  88                                         printf("dynamic"); break;
  89                                 case CORE:
  90                                         printf("core"); break;
  91                                 default:
  92                                         printf("notelf"); break;
  93                         }
  94                 }
  95
  96                 if (printname) {
  97                         printf("%s%s", printtype ? " " : "", fn);
  98                 }
  99                 if (printtype || printname) printf("\n");
 100
 101                 return type & want ? 0 : 1;
 102         }
 103         return errors ? 1 : 0;
 104 }
 105
 106 int readline(FILE *f, char *fn) {
 107         int ch;
 108         int i = 0;
 109
 110         do {
 111                 ch = fgetc(f);
 112                 switch (ch) {
 113                         case EOF: break;
 114                         case 0:
 115                                   if (i == 0) continue;
 116                                   break;
 117                         case '\n':
 118                                   if (!zeroterm) {
 119                                           if (i == 0) continue;
 120                                           break;
 121                                   }
 122                         default:
 123                                   fn[i++] = ch;
 124                                   continue;
 125                 }
 126                 if (i >= PATH_MAX) {
 127                         /* TODO print an error */
 128                         return 0;
 129                 }
 130                 fn[i] = 0;
 131                 return i;
 132         } while (ch != EOF);
 133         return 0;
 134 }
 135
 136 int checkfile(char *fn, unsigned int want, int perr, int quiet) {
 137         Elf64_Ehdr hdr;
 138         int fd, bytes;
 139         int endian = 0;
 140         struct stat st;
 141
 142         if (want & SYMLINKS) {
 143                 lstat(fn, &st);
 144         } else {
 145                 stat(fn, &st);
 146         }
 147         if (!S_ISREG(st.st_mode)) {
 148                 return 0;
 149         }
 150
 151         fd = open(fn, O_RDONLY);
 152         if (fd == -1) {
 153                 perror("elfcheck");
 154                 errors++;
 155                 return 0;
 156         }
 157         bytes = read(fd, &hdr, sizeof hdr);
 158         close(fd);
 159         if (bytes < sizeof hdr) {
 160                 if (perr) fprintf(stderr, "could not read full elf header (wanted %zu got %d bytes)\n", sizeof hdr, bytes);
 161                 return 0;
 162         }
 163         if (hdr.e_ident[EI_MAG0] != ELFMAG0
 164                         || hdr.e_ident[EI_MAG1] != ELFMAG1
 165                         || hdr.e_ident[EI_MAG2] != ELFMAG2
 166                         || hdr.e_ident[EI_MAG3] != ELFMAG3
 167            ) {
 168                 if (perr) fprintf(stderr, "elf header magic wrong\n");
 169                 return 0;
 170         }
 171         switch (hdr.e_ident[EI_CLASS]) {
 172                 case ELFCLASS64:
 173                 case ELFCLASS32:
 174                 case ELFCLASSNONE:
 175                         break;
 176                 default:
 177                         if (perr) fprintf(stderr, "elf header unknown class\n");
 178                         return 0;
 179         }
 180
 181         endian = hdr.e_ident[EI_DATA];
 182         switch (endian) {
 183                 case ELFDATA2LSB: break;
 184                 case ELFDATA2MSB: break;
 185                                   /* TODO swap endian if needed */
 186                 default:
 187                         if (perr) fprintf(stderr, "elf header unknown endian\n");
 188                         return 0;
 189         }
 190
 191         switch (hdr.e_type) {
 192                 case ET_REL: return RELOCATABLE;
 193                 case ET_EXEC: return EXECUTABLE;
 194                 case ET_DYN: return DYNAMIC;
 195                 case ET_CORE: return CORE;
 196                 case ET_NONE:
 197                 default:
 198                         if (perr) fprintf(stderr, "unknown %s\n", fn);
 199                         return 0;
 200         }
 201
 202         return 0;
 203 }