Modify data_reduction_proxy_header to support tamper detection logic.

components/data_reduction_proxy/common/data_reduction_proxy_headers.cc

Index: components/data_reduction_proxy/common/data_reduction_proxy_headers.cc
diff --git a/components/data_reduction_proxy/common/data_reduction_proxy_headers.cc b/components/data_reduction_proxy/common/data_reduction_proxy_headers.cc
index e48afc366876e3aed082e133548044b45713a1f2..4a50ad2f8749be342faa7f37d6ecf0d523b962e3 100644
--- a/components/data_reduction_proxy/common/data_reduction_proxy_headers.cc
+++ b/components/data_reduction_proxy/common/data_reduction_proxy_headers.cc
@@ -23,10 +23,35 @@ namespace data_reduction_proxy {
 const char* kDataReductionProxyViaValues[] = {"Chrome-Compression-Proxy",
                                               "Chrome Compression Proxy"};
 
+bool GetDataReductionProxyActionValue(
+    const net::HttpResponseHeaders* headers,
+    const std::string& action_prefix,
+    std::string* action_value) {
+  DCHECK(action_prefix.size());
+  void* iter = NULL;
+  std::string value;
+  std::string name = "chrome-proxy";
+
+  while (headers->EnumerateHeader(&iter, name, &value)) {
+    if (value.size() > action_prefix.size()) {
+      if (LowerCaseEqualsASCII(value.begin(),
+                               value.begin() + action_prefix.size(),
+                               action_prefix.c_str()) &&
+          value[action_prefix.size()] == '=') {
+        if (action_value)
+          *action_value = value.substr(action_prefix.size() + 1);
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 bool GetDataReductionProxyBypassDuration(

[bolian, 2014/07/14 22:42:43]

why doesn't this one call GetDataReductionProxyActionValue?

[xingx, 2014/07/14 22:51:08]

Need to discuss with Ben: my function (above) returns the first matched string;
his function (below) returns the first matched, integer-convertable string.

     const net::HttpResponseHeaders* headers,
     const std::string& action_prefix,
     base::TimeDelta* duration) {
+  DCHECK(action_prefix.size());
   void* iter = NULL;
   std::string value;
   std::string name = "chrome-proxy";
@@ -35,10 +60,12 @@ bool GetDataReductionProxyBypassDuration(
     if (value.size() > action_prefix.size()) {
       if (LowerCaseEqualsASCII(value.begin(),
                                value.begin() + action_prefix.size(),
-                               action_prefix.c_str())) {
+                               action_prefix.c_str()) &&
+          value[action_prefix.size()] == '=') {
         int64 seconds;
         if (!base::StringToInt64(
-                StringPiece(value.begin() + action_prefix.size(), value.end()),
+                StringPiece(value.begin() + action_prefix.size() + 1,
+                            value.end()),
                 &seconds) || seconds < 0) {
           continue;  // In case there is a well formed instruction.
         }
@@ -66,14 +93,14 @@ bool GetDataReductionProxyInfo(const net::HttpResponseHeaders* headers,
   // 'block' takes precedence over 'bypass', so look for it first.
   // TODO(bengr): Reduce checks for 'block' and 'bypass' to a single loop.
   if (GetDataReductionProxyBypassDuration(
-      headers, "block=", &proxy_info->bypass_duration)) {
+      headers, "block", &proxy_info->bypass_duration)) {
     proxy_info->bypass_all = true;
     return true;
   }
 
   // Next, look for 'bypass'.
   if (GetDataReductionProxyBypassDuration(
-      headers, "bypass=", &proxy_info->bypass_duration)) {
+      headers, "bypass", &proxy_info->bypass_duration)) {
     return true;
   }
   return false;