moved Buffer to dns_util as DnsResponseBuffer

net/base/dnsrr_resolver.cc

Index: net/base/dnsrr_resolver.cc
diff --git a/net/base/dnsrr_resolver.cc b/net/base/dnsrr_resolver.cc
index b07df697693818fd6525c05bea1a36371d5416eb..454a9fe7d685c056e95d8cec4a94d32c4a2ae002 100644
--- a/net/base/dnsrr_resolver.cc
+++ b/net/base/dnsrr_resolver.cc
@@ -400,142 +400,6 @@ class RRResolverWorker {
   DISALLOW_COPY_AND_ASSIGN(RRResolverWorker);
 };
 
-
-// A Buffer is used for walking over a DNS packet.
-class Buffer {
- public:
-  Buffer(const uint8* p, unsigned len)
-      : p_(p),
-        packet_(p),
-        len_(len),
-        packet_len_(len) {
-  }
-
-  bool U8(uint8* v) {
-    if (len_ < 1)
-      return false;
-    *v = *p_;
-    p_++;
-    len_--;
-    return true;
-  }
-
-  bool U16(uint16* v) {
-    if (len_ < 2)
-      return false;
-    *v = static_cast<uint16>(p_[0]) << 8 |
-         static_cast<uint16>(p_[1]);
-    p_ += 2;
-    len_ -= 2;
-    return true;
-  }
-
-  bool U32(uint32* v) {
-    if (len_ < 4)
-      return false;
-    *v = static_cast<uint32>(p_[0]) << 24 |
-         static_cast<uint32>(p_[1]) << 16 |
-         static_cast<uint32>(p_[2]) << 8 |
-         static_cast<uint32>(p_[3]);
-    p_ += 4;
-    len_ -= 4;
-    return true;
-  }
-
-  bool Skip(unsigned n) {
-    if (len_ < n)
-      return false;
-    p_ += n;
-    len_ -= n;
-    return true;
-  }
-
-  bool Block(base::StringPiece* out, unsigned len) {
-    if (len_ < len)
-      return false;
-    *out = base::StringPiece(reinterpret_cast<const char*>(p_), len);
-    p_ += len;
-    len_ -= len;
-    return true;
-  }
-
-  // DNSName parses a (possibly compressed) DNS name from the packet. If |name|
-  // is not NULL, then the name is written into it. See RFC 1035 section 4.1.4.
-  bool DNSName(std::string* name) {
-    unsigned jumps = 0;
-    const uint8* p = p_;
-    unsigned len = len_;
-
-    if (name)
-      name->clear();
-
-    for (;;) {
-      if (len < 1)
-        return false;
-      uint8 d = *p;
-      p++;
-      len--;
-
-      // The two couple of bits of the length give the type of the length. It's
-      // either a direct length or a pointer to the remainder of the name.
-      if ((d & 0xc0) == 0xc0) {
-        // This limit matches the depth limit in djbdns.
-        if (jumps > 100)
-          return false;
-        if (len < 1)
-          return false;
-        uint16 offset = static_cast<uint16>(d) << 8 |
-                        static_cast<uint16>(p[0]);
-        offset &= 0x3ff;
-        p++;
-        len--;
-
-        if (jumps == 0) {
-          p_ = p;
-          len_ = len;
-        }
-        jumps++;
-
-        if (offset >= packet_len_)
-          return false;
-        p = &packet_[offset];
-        len = packet_len_ - offset;
-      } else if ((d & 0xc0) == 0) {
-        uint8 label_len = d;
-        if (len < label_len)
-          return false;
-        if (name && label_len) {
-          if (!name->empty())
-            name->append(".");
-          name->append(reinterpret_cast<const char*>(p), label_len);
-        }
-        p += label_len;
-        len -= label_len;
-
-        if (jumps == 0) {
-          p_ = p;
-          len_ = len;
-        }
-
-        if (label_len == 0)
-          break;
-      } else {
-        return false;
-      }
-    }
-
-    return true;
-  }
-
- private:
-  const uint8* p_;
-  const uint8* const packet_;
-  unsigned len_;
-  const unsigned packet_len_;
-
-  DISALLOW_COPY_AND_ASSIGN(Buffer);
-};
-
 bool RRResponse::HasExpired(const base::Time current_time) const {
   const base::TimeDelta delta(base::TimeDelta::FromSeconds(ttl));
   const base::Time expiry = fetch_time + delta;
@@ -554,7 +418,7 @@ bool RRResponse::ParseFromResponse(const uint8* p, unsigned len,
 
   // RFC 1035 section 4.4.1
   uint8 flags2;
-  Buffer buf(p, len);
+  DnsResponseBuffer buf(p, len);
   if (!buf.Skip(2) ||  // skip id
       !buf.Skip(1) ||  // skip first flags byte
       !buf.U8(&flags2)) {