void dot_so_finder(char *filename) {
int file_fd;
char *file_map;
char *ptr;
char *prev;
off_t size;
struct stat file_stat;
file_fd = open(filename, O_RDONLY);
fstat(file_fd, &file_stat);
file_map = mmap(0, file_stat.st_size, PROT_READ, MAP_PRIVATE, file_fd, 0);
ptr = file_map;
prev = ptr;
size = file_stat.st_size;
while ((ptr = memmem(ptr, size, lib_ending, strlen(lib_ending))) != NULL) {
if (ptr >= file_map + file_stat.st_size)
break;
if (char_is_valid(ptr - 1))
get_full_lib_name(ptr);
size -= ptr - prev;
prev = ptr;
ptr++; /* Advance pointer one character to ensure we don't keep looping
over the same ".so" instance over and over again */
}
munmap(file_map, file_stat.st_size);
close(file_fd);
}
int charset_is_valid(char *s)
{
for (; s && *s && char_is_valid(*s); s++);
return !s || !*s;
}
void get_full_lib_name(char *found_lib) {
char *ptr, *peek;
char full_name[256] = {0};
long len;
int num_chars;
int i;
ptr = found_lib;
peek = ptr - 1;
/* if there's a false-positive in finding matching ".so", but it isn't ever referencing
* a library, it's probably just instructions that slipped through the cracks. In this case
* we will rewind the pointer that's searching for "lib" or "egl" MAX_LIB_NAME (default 50)
* times, in which we will bail out citing that it was probably a false-positive
*/
for (num_chars = 0; num_chars <= MAX_LIB_NAME; num_chars++) {
if (!strncmp(ptr, egl_beginning, strlen(egl_beginning)) || !strncmp(ptr, lib_beginning, strlen(lib_beginning))) {
peek = ptr - 1;
/* the peek below would fall victim to a file which is looking directly for
* "/system/lib/lib_whatever.so", because it would now point to lib/lib_whatever.so
* which is not what what we want, so take the first pick if the peek character is '/'
*/
if (*peek == '/') {
for (i = 0; blob_directories[i]; i++) {
if (!strncmp(peek, blob_directories[i], strlen(blob_directories[i]))) {
peek += strlen(blob_directories[i]);
ptr = peek;
break;
}
}
break;
}
/* some libraries are called "libmmcamera_wavelet_lib.so", in which the pointer will
* rewind to the first "lib" and then will pass it over to the check_emulator_for_lib
* method, which will in turn bark about a missing "lib.so", so we will rewind the pointer
* some extra times until it encounters an invalid character using the char_is_valid
* function and if it ends up finding another instance of "lib", picks that *that* one, not
* the original one, so we will get the entire library name of "libmmcamera_wavelet_lib.so"
* and not just "lib.so" which would have been chosen if not for the peek.
*/
while (char_is_valid(peek) && *peek--) {
if (!strncmp(peek, lib_beginning, strlen(lib_beginning))) {
#ifdef DEBUG
printf("Possible lib_lib.so! %s\n", peek);
#endif
ptr = peek;
}
}
break;
}
if (num_chars == MAX_LIB_NAME) {
#ifdef DEBUG
printf("Character limit exceeded! Full string was:\n");
for (num_chars = 0; num_chars < MAX_LIB_NAME + strlen(lib_beginning); num_chars++) {
printf("%c", *ptr);
ptr++;
}
printf("\n");
#endif
return;
}
ptr--;
peek--;
}
len = (long)(found_lib + strlen(lib_beginning)) - (long)ptr;
strncpy(full_name, ptr, len);
check_emulator_for_lib(full_name);
}
