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