Support for per-SELinux-type split property spaces

jni/setpropex.c

@@ -94,34 +94,36 @@ static int read_mapinfo(FILE *fp, mapinfo* mi)
  return 0;
 }
 
-static mapinfo *search_maps(int pid, const char* perm, const char* name)
+static mapinfo *load_maps(int pid)
 {
  char tmp[128];
  FILE *fp;
- mapinfo *mi;
+ mapinfo *mi, *last, *ret;
 
  sprintf(tmp, "/proc/%d/maps", pid);
  fp = fopen(tmp, "r");
  if(fp == 0) {
- LOGE("search_maps: unable to open maps file: %s", strerror(errno));
- return 0;
+ LOGE("load_maps: unable to open maps file: %s", strerror(errno));
+ return NULL;
  }
-
- mi = calloc(1, sizeof(mapinfo) + 16);
 
+ ret = NULL;
+ last = NULL;
+ mi = malloc(sizeof(mapinfo));
+ memset(mi, 0, sizeof(mapinfo));
  while(!read_mapinfo(fp, mi)) {
- LOGD("search_maps: %"PRIxPTR" %s %s", mi->start, mi->perm, mi->name);
- if(!strcmp(mi->perm, perm) && !strcmp(mi->name, name)){
- fclose(fp);
- mi->pid = pid;
- return mi;
- }
+ LOGD("load_maps: %"PRIxPTR" %s %s", mi->start, mi->perm, mi->name);
+ mi->pid = pid;
+ if (ret == NULL) ret = mi;
+ if (last != NULL) last->next = mi;
+ last = mi;
+ mi = malloc(sizeof(mapinfo));
+ memset(mi, 0, sizeof(mapinfo));
  }
 
- LOGD("search_maps: map \"%s\" not found!", name);
  fclose(fp);
  free(mi);
- return 0;
+ return ret;
 }
 
 static void dump_region(int fd, uintptr_t start, uintptr_t end, char* mem)
@@ -220,8 +222,7 @@ static int property_set_ex(const char *name, const char *value, int mem, mapinfo
 
  return 0;
  }
- else
- LOGE("didn't find the property!");
+
  return -1;
 }
 
@@ -236,20 +237,6 @@ static int setpropex(int init_pid, int argc, char *argv[])
  return 1;
  }
 
- /* try several different strategies to find the property area in init */
- mi = search_maps(init_pid, "rw-s", "/dev/__properties__");
- if(!mi)
- mi = search_maps(init_pid, "rw-s", "/dev/__properties__ (deleted)");
- if(!mi)
- mi = search_maps(init_pid, "rwxs", "/dev/__properties__ (deleted)");
- if(!mi)
- mi = search_maps(init_pid, "rwxs", "/dev/ashmem/system_properties (deleted)");
- if(!mi) {
- LOGE("didn't find mapinfo!");
- return 1;
- }
- LOGD("map found @ %"PRIxPTR" %"PRIxPTR" %s %s", mi->start, mi->end, mi->perm, mi->name);
-
  /* open it up, so we can read a copy */
  sprintf(tmp, "/proc/%d/mem", init_pid);
  int mem = open(tmp, O_RDONLY);
@@ -258,35 +245,59 @@ static int setpropex(int init_pid, int argc, char *argv[])
  goto error2;
  }
 
- pa_size = mi->end - mi->start;
- pa_data_size = pa_size - sizeof(prop_area);
+ mi = load_maps(init_pid);
+ while(mi != NULL) {
+ if (
+ /* try several different strategies to find the property area in init */
+ (!strcmp(mi->perm, "rw-s") && !strcmp(mi->name, "/dev/__properties__")) ||
+ (!strcmp(mi->perm, "rw-s") && !strcmp(mi->name, "/dev/__properties__ (deleted)")) ||
+ (!strcmp(mi->perm, "rwxs") && !strcmp(mi->name, "/dev/__properties__ (deleted)")) ||
+ (!strcmp(mi->perm, "rwxs") && !strcmp(mi->name, "/dev/ashmem/system_properties (deleted)")) ||
+
+ /* property spaces split per SELinux type */
+ (!strcmp(mi->perm, "rw-s") && !strncmp(mi->name, "/dev/__properties__/u", strlen("/dev/__properties__/u")))
+ ) {
+ LOGD("map found @ %"PRIxPTR" %"PRIxPTR" %s %s", mi->start, mi->end, mi->perm, mi->name);
+
+ pa_size = mi->end - mi->start;
+ pa_data_size = pa_size - sizeof(prop_area);
+
+ /* allocate memory for our copy */
+ void *p = malloc(pa_size);
+ if(p == 0) {
+ LOGE("unable to allocate memory for our copy of the property area");
+ goto error1;
+ }
+
+ /* got it, read the data and set it for the system_property code */
+ dump_region(mem, mi->start, mi->end, p);
+ __system_property_area__ = p;
+
+ /* detect old versions of android and use the correct implementation
+ * accordingly */
+ if (__system_property_area__->version == PROP_AREA_VERSION_COMPAT)
+ compat_mode = true;
+
+ /* set the property */
+ ret = property_set_ex(argv[1], argv[2], mem, mi);
+
+ /* clean up */
+ free(p);
+
+ if (ret == 0)
+ break;
+ }
 
- /* allocate memory for our copy */
- void *p = malloc(pa_size);
- if(p == 0) {
- LOGE("unable to allocate memory for our copy of the property area");
- goto error1;
+ mi = mi->next;
  }
 
- /* got it, read the data and set it for the system_property code */
- dump_region(mem, mi->start, mi->end, p);
- __system_property_area__ = p;
-
- /* detect old versions of android and use the correct implementation
- * accordingly */
- if (__system_property_area__->version == PROP_AREA_VERSION_COMPAT)
- compat_mode = true;
-
- /* set the property */
- ret = property_set_ex(argv[1], argv[2], mem, mi);
-
- /* clean up */
- free(p);
+ if(ret == -1){
+ LOGE("didn't find the property!");
+ }
 
 error1:
  close(mem);
 error2:
- free(mi);
  if(ret == 0){
  return 0;
  }