diff options
Diffstat (limited to 'vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/client.go')
| -rw-r--r-- | vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/client.go | 467 |
1 files changed, 0 insertions, 467 deletions
diff --git a/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/client.go b/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/client.go deleted file mode 100644 index 301dab9c1..000000000 --- a/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/client.go +++ /dev/null @@ -1,467 +0,0 @@ -package dns - -// A client implementation. - -import ( - "bytes" - "crypto/tls" - "encoding/binary" - "io" - "net" - "time" -) - -const dnsTimeout time.Duration = 2 * time.Second -const tcpIdleTimeout time.Duration = 8 * time.Second - -// A Conn represents a connection to a DNS server. -type Conn struct { - net.Conn // a net.Conn holding the connection - UDPSize uint16 // minimum receive buffer for UDP messages - TsigSecret map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be fully qualified - rtt time.Duration - t time.Time - tsigRequestMAC string -} - -// A Client defines parameters for a DNS client. -type Client struct { - Net string // if "tcp" or "tcp-tls" (DNS over TLS) a TCP query will be initiated, otherwise an UDP one (default is "" for UDP) - UDPSize uint16 // minimum receive buffer for UDP messages - TLSConfig *tls.Config // TLS connection configuration - Timeout time.Duration // a cumulative timeout for dial, write and read, defaults to 0 (disabled) - overrides DialTimeout, ReadTimeout and WriteTimeout when non-zero - DialTimeout time.Duration // net.DialTimeout, defaults to 2 seconds - overridden by Timeout when that value is non-zero - ReadTimeout time.Duration // net.Conn.SetReadTimeout value for connections, defaults to 2 seconds - overridden by Timeout when that value is non-zero - WriteTimeout time.Duration // net.Conn.SetWriteTimeout value for connections, defaults to 2 seconds - overridden by Timeout when that value is non-zero - TsigSecret map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be fully qualified - SingleInflight bool // if true suppress multiple outstanding queries for the same Qname, Qtype and Qclass - group singleflight -} - -// Exchange performs a synchronous UDP query. It sends the message m to the address -// contained in a and waits for a reply. Exchange does not retry a failed query, nor -// will it fall back to TCP in case of truncation. -// See client.Exchange for more information on setting larger buffer sizes. -func Exchange(m *Msg, a string) (r *Msg, err error) { - var co *Conn - co, err = DialTimeout("udp", a, dnsTimeout) - if err != nil { - return nil, err - } - - defer co.Close() - - opt := m.IsEdns0() - // If EDNS0 is used use that for size. - if opt != nil && opt.UDPSize() >= MinMsgSize { - co.UDPSize = opt.UDPSize() - } - - co.SetWriteDeadline(time.Now().Add(dnsTimeout)) - if err = co.WriteMsg(m); err != nil { - return nil, err - } - - co.SetReadDeadline(time.Now().Add(dnsTimeout)) - r, err = co.ReadMsg() - if err == nil && r.Id != m.Id { - err = ErrId - } - return r, err -} - -// ExchangeConn performs a synchronous query. It sends the message m via the connection -// c and waits for a reply. The connection c is not closed by ExchangeConn. -// This function is going away, but can easily be mimicked: -// -// co := &dns.Conn{Conn: c} // c is your net.Conn -// co.WriteMsg(m) -// in, _ := co.ReadMsg() -// co.Close() -// -func ExchangeConn(c net.Conn, m *Msg) (r *Msg, err error) { - println("dns: this function is deprecated") - co := new(Conn) - co.Conn = c - if err = co.WriteMsg(m); err != nil { - return nil, err - } - r, err = co.ReadMsg() - if err == nil && r.Id != m.Id { - err = ErrId - } - return r, err -} - -// Exchange performs a synchronous query. It sends the message m to the address -// contained in a and waits for a reply. Basic use pattern with a *dns.Client: -// -// c := new(dns.Client) -// in, rtt, err := c.Exchange(message, "127.0.0.1:53") -// -// Exchange does not retry a failed query, nor will it fall back to TCP in -// case of truncation. -// It is up to the caller to create a message that allows for larger responses to be -// returned. Specifically this means adding an EDNS0 OPT RR that will advertise a larger -// buffer, see SetEdns0. Messages without an OPT RR will fallback to the historic limit -// of 512 bytes. -func (c *Client) Exchange(m *Msg, a string) (r *Msg, rtt time.Duration, err error) { - if !c.SingleInflight { - return c.exchange(m, a) - } - // This adds a bunch of garbage, TODO(miek). - t := "nop" - if t1, ok := TypeToString[m.Question[0].Qtype]; ok { - t = t1 - } - cl := "nop" - if cl1, ok := ClassToString[m.Question[0].Qclass]; ok { - cl = cl1 - } - r, rtt, err, shared := c.group.Do(m.Question[0].Name+t+cl, func() (*Msg, time.Duration, error) { - return c.exchange(m, a) - }) - if r != nil && shared { - r = r.Copy() - } - if err != nil { - return r, rtt, err - } - return r, rtt, nil -} - -func (c *Client) dialTimeout() time.Duration { - if c.Timeout != 0 { - return c.Timeout - } - if c.DialTimeout != 0 { - return c.DialTimeout - } - return dnsTimeout -} - -func (c *Client) readTimeout() time.Duration { - if c.ReadTimeout != 0 { - return c.ReadTimeout - } - return dnsTimeout -} - -func (c *Client) writeTimeout() time.Duration { - if c.WriteTimeout != 0 { - return c.WriteTimeout - } - return dnsTimeout -} - -func (c *Client) exchange(m *Msg, a string) (r *Msg, rtt time.Duration, err error) { - var co *Conn - network := "udp" - tls := false - - switch c.Net { - case "tcp-tls": - network = "tcp" - tls = true - case "tcp4-tls": - network = "tcp4" - tls = true - case "tcp6-tls": - network = "tcp6" - tls = true - default: - if c.Net != "" { - network = c.Net - } - } - - var deadline time.Time - if c.Timeout != 0 { - deadline = time.Now().Add(c.Timeout) - } - - if tls { - co, err = DialTimeoutWithTLS(network, a, c.TLSConfig, c.dialTimeout()) - } else { - co, err = DialTimeout(network, a, c.dialTimeout()) - } - - if err != nil { - return nil, 0, err - } - defer co.Close() - - opt := m.IsEdns0() - // If EDNS0 is used use that for size. - if opt != nil && opt.UDPSize() >= MinMsgSize { - co.UDPSize = opt.UDPSize() - } - // Otherwise use the client's configured UDP size. - if opt == nil && c.UDPSize >= MinMsgSize { - co.UDPSize = c.UDPSize - } - - co.TsigSecret = c.TsigSecret - co.SetWriteDeadline(deadlineOrTimeout(deadline, c.writeTimeout())) - if err = co.WriteMsg(m); err != nil { - return nil, 0, err - } - - co.SetReadDeadline(deadlineOrTimeout(deadline, c.readTimeout())) - r, err = co.ReadMsg() - if err == nil && r.Id != m.Id { - err = ErrId - } - return r, co.rtt, err -} - -// ReadMsg reads a message from the connection co. -// If the received message contains a TSIG record the transaction -// signature is verified. -func (co *Conn) ReadMsg() (*Msg, error) { - p, err := co.ReadMsgHeader(nil) - if err != nil { - return nil, err - } - - m := new(Msg) - if err := m.Unpack(p); err != nil { - // If ErrTruncated was returned, we still want to allow the user to use - // the message, but naively they can just check err if they don't want - // to use a truncated message - if err == ErrTruncated { - return m, err - } - return nil, err - } - if t := m.IsTsig(); t != nil { - if _, ok := co.TsigSecret[t.Hdr.Name]; !ok { - return m, ErrSecret - } - // Need to work on the original message p, as that was used to calculate the tsig. - err = TsigVerify(p, co.TsigSecret[t.Hdr.Name], co.tsigRequestMAC, false) - } - return m, err -} - -// ReadMsgHeader reads a DNS message, parses and populates hdr (when hdr is not nil). -// Returns message as a byte slice to be parsed with Msg.Unpack later on. -// Note that error handling on the message body is not possible as only the header is parsed. -func (co *Conn) ReadMsgHeader(hdr *Header) ([]byte, error) { - var ( - p []byte - n int - err error - ) - - switch t := co.Conn.(type) { - case *net.TCPConn, *tls.Conn: - r := t.(io.Reader) - - // First two bytes specify the length of the entire message. - l, err := tcpMsgLen(r) - if err != nil { - return nil, err - } - p = make([]byte, l) - n, err = tcpRead(r, p) - co.rtt = time.Since(co.t) - default: - if co.UDPSize > MinMsgSize { - p = make([]byte, co.UDPSize) - } else { - p = make([]byte, MinMsgSize) - } - n, err = co.Read(p) - co.rtt = time.Since(co.t) - } - - if err != nil { - return nil, err - } else if n < headerSize { - return nil, ErrShortRead - } - - p = p[:n] - if hdr != nil { - dh, _, err := unpackMsgHdr(p, 0) - if err != nil { - return nil, err - } - *hdr = dh - } - return p, err -} - -// tcpMsgLen is a helper func to read first two bytes of stream as uint16 packet length. -func tcpMsgLen(t io.Reader) (int, error) { - p := []byte{0, 0} - n, err := t.Read(p) - if err != nil { - return 0, err - } - - // As seen with my local router/switch, retursn 1 byte on the above read, - // resulting a a ShortRead. Just write it out (instead of loop) and read the - // other byte. - if n == 1 { - n1, err := t.Read(p[1:]) - if err != nil { - return 0, err - } - n += n1 - } - - if n != 2 { - return 0, ErrShortRead - } - l := binary.BigEndian.Uint16(p) - if l == 0 { - return 0, ErrShortRead - } - return int(l), nil -} - -// tcpRead calls TCPConn.Read enough times to fill allocated buffer. -func tcpRead(t io.Reader, p []byte) (int, error) { - n, err := t.Read(p) - if err != nil { - return n, err - } - for n < len(p) { - j, err := t.Read(p[n:]) - if err != nil { - return n, err - } - n += j - } - return n, err -} - -// Read implements the net.Conn read method. -func (co *Conn) Read(p []byte) (n int, err error) { - if co.Conn == nil { - return 0, ErrConnEmpty - } - if len(p) < 2 { - return 0, io.ErrShortBuffer - } - switch t := co.Conn.(type) { - case *net.TCPConn, *tls.Conn: - r := t.(io.Reader) - - l, err := tcpMsgLen(r) - if err != nil { - return 0, err - } - if l > len(p) { - return int(l), io.ErrShortBuffer - } - return tcpRead(r, p[:l]) - } - // UDP connection - n, err = co.Conn.Read(p) - if err != nil { - return n, err - } - return n, err -} - -// WriteMsg sends a message through the connection co. -// If the message m contains a TSIG record the transaction -// signature is calculated. -func (co *Conn) WriteMsg(m *Msg) (err error) { - var out []byte - if t := m.IsTsig(); t != nil { - mac := "" - if _, ok := co.TsigSecret[t.Hdr.Name]; !ok { - return ErrSecret - } - out, mac, err = TsigGenerate(m, co.TsigSecret[t.Hdr.Name], co.tsigRequestMAC, false) - // Set for the next read, although only used in zone transfers - co.tsigRequestMAC = mac - } else { - out, err = m.Pack() - } - if err != nil { - return err - } - co.t = time.Now() - if _, err = co.Write(out); err != nil { - return err - } - return nil -} - -// Write implements the net.Conn Write method. -func (co *Conn) Write(p []byte) (n int, err error) { - switch t := co.Conn.(type) { - case *net.TCPConn, *tls.Conn: - w := t.(io.Writer) - - lp := len(p) - if lp < 2 { - return 0, io.ErrShortBuffer - } - if lp > MaxMsgSize { - return 0, &Error{err: "message too large"} - } - l := make([]byte, 2, lp+2) - binary.BigEndian.PutUint16(l, uint16(lp)) - p = append(l, p...) - n, err := io.Copy(w, bytes.NewReader(p)) - return int(n), err - } - n, err = co.Conn.Write(p) - return n, err -} - -// Dial connects to the address on the named network. -func Dial(network, address string) (conn *Conn, err error) { - conn = new(Conn) - conn.Conn, err = net.Dial(network, address) - if err != nil { - return nil, err - } - return conn, nil -} - -// DialTimeout acts like Dial but takes a timeout. -func DialTimeout(network, address string, timeout time.Duration) (conn *Conn, err error) { - conn = new(Conn) - conn.Conn, err = net.DialTimeout(network, address, timeout) - if err != nil { - return nil, err - } - return conn, nil -} - -// DialWithTLS connects to the address on the named network with TLS. -func DialWithTLS(network, address string, tlsConfig *tls.Config) (conn *Conn, err error) { - conn = new(Conn) - conn.Conn, err = tls.Dial(network, address, tlsConfig) - if err != nil { - return nil, err - } - return conn, nil -} - -// DialTimeoutWithTLS acts like DialWithTLS but takes a timeout. -func DialTimeoutWithTLS(network, address string, tlsConfig *tls.Config, timeout time.Duration) (conn *Conn, err error) { - var dialer net.Dialer - dialer.Timeout = timeout - - conn = new(Conn) - conn.Conn, err = tls.DialWithDialer(&dialer, network, address, tlsConfig) - if err != nil { - return nil, err - } - return conn, nil -} - -func deadlineOrTimeout(deadline time.Time, timeout time.Duration) time.Time { - if deadline.IsZero() { - return time.Now().Add(timeout) - } - return deadline -} |