git.zerfleddert.de Git - rsbs2/blob - extract.c

   1 #include <sys/stat.h>
   2 #include <sys/types.h>
   3 #include <limits.h>
   4 #include <fcntl.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <strings.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10 #include <errno.h>
  11 #include <libgen.h>
  12 #include "rsb-lz.h"
  13 #include "extract.h"
  14
  15 struct file_entry* get_next_file(unsigned char *fw, int len)
  16 {
  17         static unsigned char *pos;
  18         static unsigned char *end;
  19         static struct file_entry fent;
  20         int name_length;
  21
  22         if (fw != NULL && len != 0) {
  23                 pos = fw + 0x28;
  24
  25 #if 0
  26                 printf("Start of filesystem: 0x%08x\n", *((unsigned int*)pos));
  27 #endif
  28                 pos = fw + *((unsigned int*)pos);
  29                 end = fw + len;
  30         }
  31
  32         fent.unknown = *pos;
  33         pos++;
  34
  35         name_length = *((unsigned int*)pos);
  36         pos += 4;
  37
  38         fent.length = *((unsigned int*)pos);
  39         pos += 4;
  40
  41         if ((fent.length > (end - pos)) ||
  42             (name_length > (end - pos))) {
  43 #if 0
  44                 printf("EOF reached\n");
  45 #endif
  46                 return NULL;
  47         }
  48
  49         fent.name = (char*)pos;
  50         pos += name_length;
  51
  52         fent.start = pos;
  53         pos += fent.length;
  54
  55         return &fent;
  56 }
  57
  58 void extract_files(unsigned char *fw, int len)
  59 {
  60         struct file_entry *fent;
  61
  62         fent = get_next_file(fw, len);
  63
  64         while (fent) {
  65                 printf("%s: unknown: 0x%02x, length: %d",
  66                         fent->name, fent->unknown, fent->length);
  67
  68                 if (fent->length > 0) {
  69                         write_file(fent->name, fent->start, fent->length);
  70                         if (*((unsigned int*)fent->start) == LZ_MAGIC) {
  71                                 char *lzname;
  72
  73                                 if ((lzname = strdup(fent->name)) == NULL) {
  74                                         perror("strdup");
  75                                         exit(1);
  76                                 }
  77
  78                                 if (!strcmp(lzname + strlen(lzname) - 4 , ".lz")) {
  79                                         fprintf(stderr, "Ugh, can't derive filename...\n");
  80                                         exit(1);
  81                                 }
  82                                 lzname[strlen(lzname) - 3] = 0x00;
  83
  84                                 printf("%s: packed file found", lzname);
  85
  86                                 extract_lz_file(fent->start, (unsigned char*)lzname);
  87                                 free(lzname);
  88                         } else if (!strcmp(fent->name, "firmware")) {
  89                                 unsigned char *lzpos;
  90                                 char lzname[128];
  91
  92                                 bzero(lzname, sizeof(lzname));
  93                                 strcpy(lzname, "firmware.");
  94
  95                                 lzpos = fent->start + *((unsigned int*)(fent->start + 0x20));
  96                                 memcpy(lzname + strlen(lzname), lzpos - 4, 4);
  97                                 lzpos += 4;
  98                                 if (*((unsigned int*)(lzpos)) == LZ_MAGIC) {
  99                                         printf("%s: compressed firmware part found", lzname);
 100                                         extract_lz_file(lzpos, (unsigned char*)lzname);
 101                                 }
 102                         }
 103                 }
 104                 fent = get_next_file(NULL, 0);
 105         }
 106 }
 107
 108 void mkdir_p(char *dir)
 109 {
 110         char *copy, *parent;
 111
 112         if ((dir == NULL) || (!strcmp(dir, ".")))
 113                 return;
 114
 115         if ((copy = strdup(dir)) == NULL) {
 116                 perror("strdup");
 117                 exit(1);
 118         }
 119         parent = dirname(copy);
 120         mkdir_p(parent);
 121
 122         errno = 0;
 123         if (mkdir(dir, 0755) == -1) {
 124                 if (errno != EEXIST) {
 125                         fprintf(stderr, "%s: ", dir);
 126                         perror("mkdir");
 127                         exit(1);
 128                 }
 129         }
 130         free(copy);
 131 }
 132
 133 void write_file(char *fname, unsigned char *buf, int len)
 134 {
 135         char filename[PATH_MAX];
 136         char *filename_c, *dirn;
 137         int fd;
 138         int remaining;
 139         int ret;
 140
 141         strcpy(filename, "extracted/");
 142         strcat(filename, fname);
 143
 144         if ((filename_c = strdup(filename)) == NULL) {
 145                 perror("strdup");
 146                 exit(1);
 147         }
 148         dirn = dirname(filename_c);
 149         mkdir_p(dirn);
 150         free(filename_c);
 151
 152         if ((fd = open(filename, O_WRONLY|O_CREAT, 0644)) == -1) {
 153                 fprintf(stderr, "%s: ", filename);
 154                 perror("open");
 155                 exit(1);
 156         }
 157
 158         remaining = len;
 159
 160         while(remaining) {
 161                 ret = write(fd, buf + (len - remaining), remaining);
 162                 if (ret < 0) {
 163                         perror("write");
 164                         exit(1);
 165                 }
 166                 remaining -= ret;
 167         }
 168
 169         printf(", %s written.\n", filename);
 170
 171         close(fd);
 172 }