Android系统file_contexts二进制与文本转换工具

Posted 2020-10-27 lyuyangly

  1 #ifdef _WIN32
  2     #define __USE_MINGW_ANSI_STDIO 1
  3 #endif
  4 
  5 #include <stdio.h>
  6 #include <stdlib.h>
  7 #include <string.h>
  8 #include <errno.h>
  9 #include <fcntl.h>
 10 #ifdef HAS_STDINT_H
 11     #include <stdint.h>
 12 #endif
 13 #ifdef unix
 14     #include <unistd.h>
 15     #include <sys/types.h>
 16     #include <sys/stat.h>
 17 #else
 18     #include <direct.h>
 19     #include <io.h>
 20 #endif
 21 
 22 #define MAGIC 0xF97CFF8A
 23 
 24 #define S_IFMT      00170000
 25 #define S_IFSOCK    0140000
 26 #define S_IFLNK        0120000
 27 #define S_IFREG        0100000
 28 #define S_IFBLK        0060000
 29 #define S_IFDIR        0040000
 30 #define S_IFCHR        0020000
 31 #define S_IFIFO        0010000
 32 #define S_ISUID        0004000
 33 #define S_ISGID        0002000
 34 #define S_ISVTX        0001000
 35 
 36 #define S_ISLNK(m)    (((m) & S_IFMT) == S_IFLNK)
 37 #define S_ISREG(m)    (((m) & S_IFMT) == S_IFREG)
 38 #define S_ISDIR(m)    (((m) & S_IFMT) == S_IFDIR)
 39 #define S_ISCHR(m)    (((m) & S_IFMT) == S_IFCHR)
 40 #define S_ISBLK(m)    (((m) & S_IFMT) == S_IFBLK)
 41 #define S_ISFIFO(m)    (((m) & S_IFMT) == S_IFIFO)
 42 #define S_ISSOCK(m)    (((m) & S_IFMT) == S_IFSOCK)
 43 
 44 char *mode_to_string(unsigned int mode)
 45 {
 46     if (S_ISBLK(mode))
 47         return "-b";
 48     else if (S_ISCHR(mode))
 49         return "-c";
 50     else if (S_ISDIR(mode))
 51         return "-d";
 52     else if (S_ISFIFO(mode))
 53         return "-p";
 54     else if (S_ISLNK(mode))
 55         return "-l";
 56     else if (S_ISSOCK(mode))
 57         return "-s";
 58     else if (S_ISREG(mode))
 59         return "--";
 60     else
 61         return "";
 62 }
 63 
 64 int main(int argc, char *argv[])
 65 {
 66     unsigned int selinux_vers;
 67     unsigned int nothing;
 68     unsigned int i;
 69     unsigned int steams;
 70     unsigned int num_of_regex;
 71 
 72     char steam[256];
 73     char src[512];
 74     char context[512];
 75 
 76     FILE *fp = NULL;
 77     FILE *fpout = NULL;
 78 
 79     if (argc != 3) {
 80         printf("usage: %s BINARY_FILE OUTPUT_TEXT_FILE\n", argv[0]);
 81         printf("e.g: %s file_contexts.bin file_contexts\n", argv[0]);
 82         return 1;
 83     }
 84 
 85     if ((fp = fopen(argv[1], "rb")) == NULL) {
 86         printf("Unable to open %s : ", argv[1]);
 87         perror("");
 88         return 1;
 89     }
 90     fread(&nothing, 1, 4, fp);
 91     if (nothing != MAGIC) {
 92         printf("%s is not a binary!\n", argv[1]);
 93         if (fp) fclose(fp);
 94         return 1;
 95     }
 96 
 97     fread(&nothing, 1, 4, fp);
 98   selinux_vers = nothing;
 99     fread(&nothing, 1, 4, fp);
100     fseek(fp, (unsigned int)ftell(fp) + nothing, SEEK_SET);
101 
102     fread(&nothing, 1, 4, fp);
103     //printf("num of steams: 0x%x\n", nothing);
104 
105     for (i=0; i<nothing; ++i) {
106         fread(&steams, 1, 4, fp);
107       fread(steam, 1, steams+1, fp);
108         //printf("%s\n", steam);
109     }
110 
111     fread(&num_of_regex, 1, 4, fp);
112     //printf("num of regex: 0x%x\n", num_of_regex);
113 
114     if ((fpout = fopen(argv[2], "wb")) == NULL) {
115         printf("unable to open %s for write!\n", argv[2]);
116         if (fp) fclose(fp);
117         return 1;
118     }
119 
120   //printf("selinux version: %d\n", selinux_vers);
121   fprintf(fpout, "#context version %d\n", selinux_vers);
122 
123     for (i=0; i<num_of_regex; ++i) {
124         fread(&nothing, 1, 4, fp);
125       fread(context, 1, nothing, fp);
126     fread(&nothing, 1, 4, fp);
127     fread(src, 1, nothing, fp);
128         //printf("%s %s\n", src, context);
129         fread(&nothing, 1, 4, fp);
130         fprintf(fpout, "%s\t%s\t%s\n", src, mode_to_string(nothing), context);
131       fseek(fp, (unsigned int)ftell(fp) + 12, SEEK_SET);
132         fread(&nothing, 1, 4, fp);
133     fseek(fp, (unsigned int)ftell(fp) + nothing, SEEK_SET);
134         fread(&nothing, 1 , 4, fp);
135     fread(&nothing, 1 , 4, fp);
136     fseek(fp, (unsigned int)ftell(fp) + nothing - 4, SEEK_SET);
137     }
138 
139     if (fp) fclose(fp);
140     if (fpout) fclose(fpout);
141 
142     return 0;
143 }