Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(314)

Unified Diff: net/dns/dns_query.cc

Issue 8762001: Isolates generic DnsClient from AsyncHostResolver. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src
Patch Set: applied review Created 9 years ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
Index: net/dns/dns_query.cc
diff --git a/net/dns/dns_query.cc b/net/dns/dns_query.cc
index 788d653a304cab9a1297920cc6108cc4b206836c..6ddd152cab3620141e326b739dede340a07b8656 100644
--- a/net/dns/dns_query.cc
+++ b/net/dns/dns_query.cc
@@ -6,91 +6,78 @@
#include <limits>
+#include "net/base/big_endian.h"
#include "net/base/dns_util.h"
#include "net/base/io_buffer.h"
+#include "net/base/sys_byteorder.h"
+#include "net/dns/dns_protocol.h"
namespace net {
-namespace {
-
-void PackUint16BE(char buf[2], uint16 v) {
- buf[0] = v >> 8;
- buf[1] = v & 0xff;
-}
-
-uint16 UnpackUint16BE(char buf[2]) {
- return static_cast<uint8>(buf[0]) << 8 | static_cast<uint8>(buf[1]);
-}
-
-} // namespace
-
// DNS query consists of a 12-byte header followed by a question section.
// For details, see RFC 1035 section 4.1.1. This header template sets RD
// bit, which directs the name server to pursue query recursively, and sets
-// the QDCOUNT to 1, meaning the question section has a single entry. The
-// first two bytes of the header form a 16-bit random query ID to be copied
-// in the corresponding reply by the name server -- randomized during
-// DnsQuery construction.
-static const char kHeader[] = {0x00, 0x00, 0x01, 0x00, 0x00, 0x01,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-static const size_t kHeaderSize = arraysize(kHeader);
-
-DnsQuery::DnsQuery(const std::string& qname,
- uint16 qtype,
- const RandIntCallback& rand_int_cb)
- : qname_size_(qname.size()),
- rand_int_cb_(rand_int_cb) {
- DCHECK(DnsResponseBuffer(reinterpret_cast<const uint8*>(qname.c_str()),
- qname.size()).DNSName(NULL));
- DCHECK(qtype == kDNS_A || qtype == kDNS_AAAA);
-
- io_buffer_ = new IOBufferWithSize(kHeaderSize + question_size());
-
- int byte_offset = 0;
- char* buffer_head = io_buffer_->data();
- memcpy(&buffer_head[byte_offset], kHeader, kHeaderSize);
- byte_offset += kHeaderSize;
- memcpy(&buffer_head[byte_offset], &qname[0], qname_size_);
- byte_offset += qname_size_;
- PackUint16BE(&buffer_head[byte_offset], qtype);
- byte_offset += sizeof(qtype);
- PackUint16BE(&buffer_head[byte_offset], kClassIN);
- RandomizeId();
+// the QDCOUNT to 1, meaning the question section has a single entry.
+DnsQuery::DnsQuery(uint16 id, const base::StringPiece& qname, uint16 qtype)
+ : qname_size_(qname.size()) {
+ DCHECK(!DNSDomainToString(qname).empty());
+ // QNAME + QTYPE + QCLASS
+ size_t question_size = qname_size_ + sizeof(uint16) + sizeof(uint16);
+ io_buffer_ = new IOBufferWithSize(sizeof(dns_protocol::Header) +
+ question_size);
+ dns_protocol::Header* header =
+ reinterpret_cast<dns_protocol::Header*>(io_buffer_->data());
+ memset(header, 0, sizeof(dns_protocol::Header));
+ header->id = htons(id);
+ header->flags[0] = 0x1; // RD bit
+ header->qdcount = htons(1);
+
+ // Write question section after the header.
+ BigEndianWriter writer(reinterpret_cast<char*>(header + 1), question_size);
+ writer.WriteBytes(qname.data(), qname.size());
+ writer.WriteU16(qtype);
+ writer.WriteU16(dns_protocol::kClassIN);
}
DnsQuery::~DnsQuery() {
}
-uint16 DnsQuery::id() const {
- return UnpackUint16BE(&io_buffer_->data()[0]);
+DnsQuery* DnsQuery::CloneWithNewId(uint16 id) const {
+ return new DnsQuery(*this, id);
}
-uint16 DnsQuery::qtype() const {
- return UnpackUint16BE(&io_buffer_->data()[kHeaderSize + qname_size_]);
-}
-
-DnsQuery* DnsQuery::CloneWithNewId() const {
- return new DnsQuery(qname(), qtype(), rand_int_cb_);
+uint16 DnsQuery::id() const {
+ const dns_protocol::Header* h =
mmenke 2011/12/06 20:43:01 nit: Rename variable to header or something.
szym 2011/12/06 21:06:43 Done. (I thought I caught all of them.)
+ reinterpret_cast<const dns_protocol::Header*>(io_buffer_->data());
+ return ntohs(h->id);
}
-size_t DnsQuery::question_size() const {
- return qname_size_ // QNAME
- + sizeof(uint16) // QTYPE
- + sizeof(uint16); // QCLASS
+base::StringPiece DnsQuery::qname() const {
+ return base::StringPiece(io_buffer_->data() + sizeof(dns_protocol::Header),
+ qname_size_);
}
-const char* DnsQuery::question_data() const {
- return &io_buffer_->data()[kHeaderSize];
+uint16 DnsQuery::qtype() const {
+ uint16 type;
+ ReadBigEndian<uint16>(io_buffer_->data() +
+ sizeof(dns_protocol::Header) +
+ qname_size_, &type);
+ return type;
}
-const std::string DnsQuery::qname() const {
- return std::string(question_data(), qname_size_);
+base::StringPiece DnsQuery::question() const {
+ return base::StringPiece(io_buffer_->data() + sizeof(dns_protocol::Header),
+ qname_size_ + sizeof(uint16) + sizeof(uint16));
}
-void DnsQuery::RandomizeId() {
- PackUint16BE(&io_buffer_->data()[0], rand_int_cb_.Run(
- std::numeric_limits<uint16>::min(),
- std::numeric_limits<uint16>::max()));
+DnsQuery::DnsQuery(const DnsQuery& orig, uint16 id) {
+ qname_size_ = orig.qname_size_;
+ io_buffer_ = new IOBufferWithSize(orig.io_buffer()->size());
+ memcpy(io_buffer_.get()->data(), orig.io_buffer()->data(),
+ io_buffer_.get()->size());
+ dns_protocol::Header* header =
+ reinterpret_cast<dns_protocol::Header*>(io_buffer_->data());
+ header->id = htons(id);
}
} // namespace net

Powered by Google App Engine
This is Rietveld 408576698