shotgun/lib/ar.c

   1 #include <fcntl.h>
   2 #include <string.h>
   3 #include <strings.h>
   4 #include <sys/types.h>
   5 #include <sys/uio.h>
   6 #include <unistd.h>
   7
   8 #include "shotgun/lib/shotgun.h"
   9 #include "shotgun/lib/ar.h"
  10
  11 static int ar_validate(int fd) {
  12   char data[8];
  13   long bytes;
  14
  15   bzero(data, 8);
  16
  17   bytes = read(fd, data, 8);
  18
  19   if(bytes != 8 || strncmp(data, "!<arch>\n", 8)) {
  20     return FALSE;
  21   }
  22
  23   return TRUE;
  24 }
  25
  26 static char *ar_file_name(int fd, char *name, long *size) {
  27   long bytes, length;
  28   char *ptr;
  29
  30   if(strncmp(name, "#1/", 3) != 0) {
  31     ptr = strchr(name, ' ');
  32     *ptr = (char)0;
  33     return strdup(name);
  34   } else {
  35     length = atoi(name + 3);
  36
  37     ptr = (char *)calloc(length, sizeof(char));
  38     if(ptr == NULL) return NULL;
  39
  40     bytes = read(fd, ptr, length);
  41
  42     if(bytes != length) {
  43       free(ptr);
  44       return NULL;
  45     }
  46
  47     *size -= length;
  48
  49     return ptr;
  50   }
  51 }
  52
  53 /*
  54  * Retrieves each file from from ar(5) archive +path+ and processes it with
  55  * +callback+.
  56  */
  57 int ar_each_file(machine m, const char *path, int(*callback)(machine, char *, uint8_t *, long)) {
  58   int err;
  59   long bytes, size;
  60   char *name, data_size[11], name_data[17];
  61   uint8_t *data;
  62   int fd;
  63   int ret = TRUE;
  64
  65   bzero(data_size, 11);
  66   bzero(name_data, 17);
  67
  68   fd = open(path, O_RDONLY);
  69
  70   if(fd == -1) {
  71     return FALSE;
  72   }
  73
  74   if(!ar_validate(fd)) {
  75     return FALSE;
  76   }
  77
  78   for(;;) {
  79     bytes = read(fd, name_data, 16);
  80     if(bytes == 0) { /* end of file */
  81       break;
  82     } else if(bytes != 16) {
  83       ret = FALSE;
  84       break;
  85     }
  86
  87     err = lseek(fd, 32, SEEK_CUR); /* mtime, uid, gid, mode */
  88     if(err < 0) {
  89       ret = FALSE;
  90       break;
  91     }
  92
  93     bytes = read(fd, data_size, 10);
  94     if(bytes != 10) {
  95       ret = FALSE;
  96       break;
  97     }
  98
  99     size = atoi(data_size);
 100
 101     err = lseek(fd, 2, SEEK_CUR);
 102     if(err < 0) {
 103       ret = FALSE;
 104       break;
 105     }
 106
 107     name = ar_file_name(fd, name_data, &size);
 108
 109     data = (uint8_t *)calloc(size, sizeof(uint8_t));
 110     if(data == NULL) {
 111       ret = FALSE;
 112       break;
 113     }
 114
 115     bytes = read(fd, data, size);
 116     if(bytes != size) {
 117       free(data);
 118       ret = FALSE;
 119       break;
 120     }
 121
 122     ret = callback(m, name, data, bytes);
 123
 124     free(data);
 125
 126     if(!RTEST(ret)) {
 127       break;
 128     }
 129
 130     if(size % 2 == 1) {
 131       lseek(fd, 1, SEEK_CUR);
 132       if(err < 0) {
 133         ret = FALSE;
 134         break;
 135       }
 136     }
 137   }
 138
 139   close(fd);
 140
 141   return ret;
 142 }
 143