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                         fprintf(stderr, "checking %s\n", fn);
  70                         if (checkfile(fn, want,perr,quiet)) {
  71                                 printf("%s\n", fn);
  72                         }
  73                 }
  74         } else {
  75                 int type;
  76                 char *fn;
  77
  78                 fn = av[optind];
  79                 if (verbose) fprintf(stderr, "checking %s\n", av[optind]);
  80                 type = checkfile(fn,want,perr,quiet);
  81
  82                 if (printtype) {
  83                         switch (type) {
  84                                 case RELOCATABLE:
  85                                         printf("relocatable"); break;
  86                                 case EXECUTABLE:
  87                                         printf("executable"); break;
  88                                 case DYNAMIC:
  89                                         printf("dynamic"); break;
  90                                 case CORE:
  91                                         printf("core"); break;
  92                                 default:
  93                                         printf("notelf"); break;
  94                         }
  95                 }
  96
  97                 if (printname) {
  98                         printf("%s%s", printtype ? " " : "", fn);
  99                 }
 100                 if (printtype || printname) printf("\n");
 101
 102                 return type & want ? 0 : 1;
 103         }
 104         return errors ? 1 : 0;
 105 }
 106
 107 int readline(FILE *f, char *fn) {
 108         int ch;
 109         int i = 0;
 110
 111         do {
 112                 ch = fgetc(f);
 113                 switch (ch) {
 114                         case EOF: break;
 115                         case 0:
 116                                   if (i == 0) continue;
 117                                   break;
 118                         case '\n':
 119                                   if (!zeroterm) {
 120                                           if (i == 0) continue;
 121                                           break;
 122                                   }
 123                         default:
 124                                   fn[i++] = ch;
 125                                   continue;
 126                 }
 127                 if (i >= PATH_MAX) {
 128                         /* TODO print an error */
 129                         return 0;
 130                 }
 131                 fn[i] = 0;
 132                 return i;
 133         } while (ch != EOF);
 134         return 0;
 135 }
 136
 137 int checkfile(char *fn, unsigned int want, int perr, int quiet) {
 138         Elf64_Ehdr hdr;
 139         int fd, bytes;
 140         int endian = 0;
 141         struct stat st;
 142
 143         if (want & SYMLINKS) {
 144                 lstat(fn, &st);
 145         } else {
 146                 stat(fn, &st);
 147         }
 148         if (!S_ISREG(st.st_mode)) {
 149                 return 0;
 150         }
 151
 152         fd = open(fn, O_RDONLY);
 153         if (fd == -1) {
 154                 perror("elfcheck");
 155                 errors++;
 156                 return 0;
 157         }
 158         bytes = read(fd, &hdr, sizeof hdr);
 159         close(fd);
 160         if (bytes < sizeof hdr) {
 161                 if (perr) fprintf(stderr, "could not read full elf header (wanted %zu got %d bytes)\n", sizeof hdr, bytes);
 162                 return 0;
 163         }
 164         if (hdr.e_ident[EI_MAG0] != ELFMAG0
 165                         || hdr.e_ident[EI_MAG1] != ELFMAG1
 166                         || hdr.e_ident[EI_MAG2] != ELFMAG2
 167                         || hdr.e_ident[EI_MAG3] != ELFMAG3
 168            ) {
 169                 if (perr) fprintf(stderr, "elf header magic wrong\n");
 170                 return 0;
 171         }
 172         switch (hdr.e_ident[EI_CLASS]) {
 173                 case ELFCLASS64:
 174                 case ELFCLASS32:
 175                 case ELFCLASSNONE:
 176                         break;
 177                 default:
 178                         if (perr) fprintf(stderr, "elf header unknown class\n");
 179                         return 0;
 180         }
 181
 182         endian = hdr.e_ident[EI_DATA];
 183         switch (endian) {
 184                 case ELFDATA2LSB: break;
 185                 case ELFDATA2MSB: break;
 186                                   /* TODO swap endian if needed */
 187                 default:
 188                         if (perr) fprintf(stderr, "elf header unknown endian\n");
 189                         return 0;
 190         }
 191
 192         switch (hdr.e_type) {
 193                 case ET_REL: return RELOCATABLE;
 194                 case ET_EXEC: return EXECUTABLE;
 195                 case ET_DYN: return DYNAMIC;
 196                 case ET_CORE: return CORE;
 197                 case ET_NONE:
 198                 default:
 199                         if (perr) fprintf(stderr, "unknown %s\n", fn);
 200                         return 0;
 201         }
 202
 203         return 0;
 204 }