Backward compatibility for licenses and certificates

Certificates and offline licenses are stored in security level
specific directories in klp. When devices transition from jb-mr2,
their persistent information has to be ported to these directories.

bug:10366036

Merge of https://widevine-internal-review.googlesource.com/#/c/7310/
from the widevine CDM repo

Change-Id: I70b4a79dc5b69bda7fc3a4b92fdcde7ef8b41836

libwvdrmengine/cdm/src/file_store.cpp

@@ -6,8 +6,10 @@
 
 #include <dirent.h>
 #include <errno.h>
-#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/sendfile.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <stdio.h>
 #include <unistd.h>
 
@@ -175,18 +177,80 @@ bool File::Remove(const std::string& path) {
   }
 }
 
+bool File::Copy(const std::string& src, const std::string& dest) {
+  struct stat stat_buf;
+  if (stat(src.c_str(), &stat_buf)) {
+    LOGV("File::Copy: file %s does not exist: %d", src.c_str(), errno);
+    return false;
+  }
+
+  int fd_src = open(src.c_str(), O_RDONLY);
+  if (fd_src < 0) {
+    LOGV("File::Copy: unable to open file %s: %d", src.c_str(), errno);
+    return false;
+  }
+
+  int fd_dest = open(dest.c_str(), O_WRONLY|O_CREAT, stat_buf.st_mode);
+  if (fd_dest < 0) {
+    LOGV("File::Copy: unable to open file %s: %d", dest.c_str(), errno);
+    close(fd_src);
+    return false;
+  }
+
+  off_t offset = 0;
+  bool sts = true;
+  if (sendfile(fd_dest, fd_src, &offset, stat_buf.st_size) < 0) {
+    LOGV("File::Copy: unable to copy %s to %s: %d", src.c_str(), dest.c_str(),
+         errno);
+    sts = false;
+  }
+
+  close(fd_src);
+  close(fd_dest);
+  return sts;
+}
+
+bool File::List(const std::string& path, std::vector<std::string>* files) {
+  if (NULL == files) {
+    LOGV("File::List: files destination not provided");
+    return false;
+  }
+
+  if (!Exists(path)) {
+    LOGV("File::List: path %s does not exist: %d", path.c_str(), errno);
+    return false;
+  }
+
+  DIR* dir;
+  if ((dir = opendir(path.c_str())) == NULL) {
+    LOGW("File::List: unable to open directory %s: %d", path.c_str(), errno);
+    return false;
+  }
+
+  struct dirent* entry;
+  while ((entry = readdir(dir)) != NULL) {
+    if (strcmp(entry->d_name, kCurrentDirectory) &&
+        (strcmp(entry->d_name, kParentDirectory))) {
+      files->push_back(entry->d_name);
+    }
+  }
+  closedir(dir);
+
+  return true;
+}
+
 bool File::CreateDirectory(std::string path) {
   size_t size = path.size();
-  if ((size == 1) && (path[0] == '/')) return true;
+  if ((size == 1) && (path[0] == kPathDelimiter[0])) return true;
 
   if (size <= 1) return false;
 
-  if (path.at(size - 1) == '/') {
+  if (path.at(size - 1) == kPathDelimiter[0]) {
     --size;
     path.resize(size);
   }
 
-  size_t pos = path.find('/', 1);
+  size_t pos = path.find(kPathDelimiter[0], 1);
   while (pos < size) {
     path.at(pos) = '\0';
     if (mkdir(path.c_str(), 0775) != 0) {
@@ -195,8 +259,8 @@ bool File::CreateDirectory(std::string path) {
         return false;
       }
     }
-    path.at(pos) = '/';
-    pos = path.find('/', pos + 1);
+    path.at(pos) = kPathDelimiter[0];
+    pos = path.find(kPathDelimiter[0], pos + 1);
   }
   if (mkdir(path.c_str(), 0775) != 0) {
     if (errno != EEXIST) {