From f1bc71203597feaf212fba89ad3e72a2a13f5607 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Tue, 7 Jul 2009 11:04:26 -0700 Subject: [PATCH] net: use new reflect interface (CL 31107) R=r DELTA=186 (55 added, 8 deleted, 123 changed) OCL=31117 CL=31287 --- src/pkg/net/dnsclient.go | 8 +- src/pkg/net/dnsmsg.go | 297 +++++++++++++++++++++++---------------- 2 files changed, 176 insertions(+), 129 deletions(-) diff --git a/src/pkg/net/dnsclient.go b/src/pkg/net/dnsclient.go index 57cf15c921..7e82855a17 100644 --- a/src/pkg/net/dnsclient.go +++ b/src/pkg/net/dnsclient.go @@ -113,16 +113,16 @@ Cname: for i := 0; i < len(dns.answer); i++ { rr := dns.answer[i]; h := rr.Header(); - if h.class == _DNS_ClassINET && h.name == name { - switch h.rrtype { + if h.Class == _DNS_ClassINET && h.Name == name { + switch h.Rrtype { case _DNS_TypeA: n := len(addrs); - a := rr.(*_DNS_RR_A).a; + a := rr.(*_DNS_RR_A).A; addrs = addrs[0:n+1]; addrs[n] = IPv4(byte(a>>24), byte(a>>16), byte(a>>8), byte(a)).String(); case _DNS_TypeCNAME: // redirect to cname - name = rr.(*_DNS_RR_CNAME).cname; + name = rr.(*_DNS_RR_CNAME).Cname; continue Cname } } diff --git a/src/pkg/net/dnsmsg.go b/src/pkg/net/dnsmsg.go index 728e89821d..c7fb07f6db 100644 --- a/src/pkg/net/dnsmsg.go +++ b/src/pkg/net/dnsmsg.go @@ -34,7 +34,7 @@ import ( // Wire constants. const ( - // valid _DNS_RR_Header.rrtype and _DNS_Question.qtype + // valid _DNS_RR_Header.Rrtype and _DNS_Question.qtype _DNS_TypeA = 1; _DNS_TypeNS = 2; _DNS_TypeMD = 3; @@ -76,13 +76,13 @@ const ( // The wire format for the DNS packet header. type __DNS_Header struct { - id uint16; - bits uint16; - qdcount, ancount, nscount, arcount uint16; + Id uint16; + Bits uint16; + Qdcount, Ancount, Nscount, Arcount uint16; } const ( - // __DNS_Header.bits + // __DNS_Header.Bits _QR = 1<<15; // query/response (response=1) _AA = 1<<10; // authoritative _TC = 1<<9; // truncated @@ -92,20 +92,20 @@ const ( // DNS queries. type _DNS_Question struct { - name string "domain-name"; // "domain-name" specifies encoding; see packers below - qtype uint16; - qclass uint16; + Name string "domain-name"; // "domain-name" specifies encoding; see packers below + Qtype uint16; + Qclass uint16; } // DNS responses (resource records). // There are many types of messages, // but they all share the same header. type _DNS_RR_Header struct { - name string "domain-name"; - rrtype uint16; - class uint16; - ttl uint32; - rdlength uint16; // length of data after header + Name string "domain-name"; + Rrtype uint16; + Class uint16; + Ttl uint32; + Rdlength uint16; // length of data after header } func (h *_DNS_RR_Header) Header() *_DNS_RR_Header { @@ -120,74 +120,123 @@ type _DNS_RR interface { // Specific DNS RR formats for each query type. type _DNS_RR_CNAME struct { - _DNS_RR_Header; - cname string "domain-name"; + Hdr _DNS_RR_Header; + Cname string "domain-name"; +} + +func (rr *_DNS_RR_CNAME) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_HINFO struct { - _DNS_RR_Header; - cpu string; - os string; + Hdr _DNS_RR_Header; + Cpu string; + Os string; +} + +func (rr *_DNS_RR_HINFO) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_MB struct { - _DNS_RR_Header; - mb string "domain-name"; + Hdr _DNS_RR_Header; + Mb string "domain-name"; +} + +func (rr *_DNS_RR_MB) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_MG struct { - _DNS_RR_Header; - mg string "domain-name"; + Hdr _DNS_RR_Header; + Mg string "domain-name"; +} + +func (rr *_DNS_RR_MG) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_MINFO struct { - _DNS_RR_Header; - rmail string "domain-name"; - email string "domain-name"; + Hdr _DNS_RR_Header; + Rmail string "domain-name"; + Email string "domain-name"; +} + +func (rr *_DNS_RR_MINFO) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_MR struct { - _DNS_RR_Header; - mr string "domain-name"; + Hdr _DNS_RR_Header; + Mr string "domain-name"; +} + +func (rr *_DNS_RR_MR) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_MX struct { - _DNS_RR_Header; - pref uint16; - mx string "domain-name"; + Hdr _DNS_RR_Header; + Pref uint16; + Mx string "domain-name"; +} + +func (rr *_DNS_RR_MX) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_NS struct { - _DNS_RR_Header; - ns string "domain-name"; + Hdr _DNS_RR_Header; + Ns string "domain-name"; +} + +func (rr *_DNS_RR_NS) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_PTR struct { - _DNS_RR_Header; - ptr string "domain-name"; + Hdr _DNS_RR_Header; + Ptr string "domain-name"; +} + +func (rr *_DNS_RR_PTR) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_SOA struct { - _DNS_RR_Header; - ns string "domain-name"; - mbox string "domain-name"; - serial uint32; - refresh uint32; - retry uint32; - expire uint32; - minttl uint32; + Hdr _DNS_RR_Header; + Ns string "domain-name"; + Mbox string "domain-name"; + Serial uint32; + Refresh uint32; + Retry uint32; + Expire uint32; + Minttl uint32; +} + +func (rr *_DNS_RR_SOA) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_TXT struct { - _DNS_RR_Header; - txt string; // not domain name + Hdr _DNS_RR_Header; + Txt string; // not domain name +} + +func (rr *_DNS_RR_TXT) Header() *_DNS_RR_Header { + return &rr.Hdr; } type _DNS_RR_A struct { - _DNS_RR_Header; - a uint32 "ipv4"; + Hdr _DNS_RR_Header; + A uint32 "ipv4"; } +func (rr *_DNS_RR_A) Header() *_DNS_RR_Header { + return &rr.Hdr; +} + + // Packing and unpacking. // @@ -316,28 +365,28 @@ Loop: return s, off1, true } +// TODO(rsc): Move into generic library? // Pack a reflect.StructValue into msg. Struct members can only be uint16, uint32, string, // and other (often anonymous) structs. -func packStructValue(val reflect.StructValue, msg []byte, off int) (off1 int, ok bool) { - for i := 0; i < val.Len(); i++ { - fld := val.Field(i); - name, typ, tag, xxx := val.Type().(reflect.StructType).Field(i); - switch fld.Kind() { +func packStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int, ok bool) { + for i := 0; i < val.NumField(); i++ { + f := val.Type().(*reflect.StructType).Field(i); + switch fv := val.Field(i).(type) { default: - fmt.Fprintf(os.Stderr, "net: dns: unknown packing type %v", fld.Type()); + fmt.Fprintf(os.Stderr, "net: dns: unknown packing type %v", f.Type); return len(msg), false; - case reflect.StructKind: - off, ok = packStructValue(fld.(reflect.StructValue), msg, off); - case reflect.Uint16Kind: - i := fld.(reflect.Uint16Value).Get(); + case *reflect.StructValue: + off, ok = packStructValue(fv, msg, off); + case *reflect.Uint16Value: + i := fv.Get(); if off+2 > len(msg) { return len(msg), false } msg[off] = byte(i>>8); msg[off+1] = byte(i); off += 2; - case reflect.Uint32Kind: - i := fld.(reflect.Uint32Value).Get(); + case *reflect.Uint32Value: + i := fv.Get(); if off+4 > len(msg) { return len(msg), false } @@ -346,13 +395,13 @@ func packStructValue(val reflect.StructValue, msg []byte, off int) (off1 int, ok msg[off+2] = byte(i>>8); msg[off+4] = byte(i); off += 4; - case reflect.StringKind: + case *reflect.StringValue: // There are multiple string encodings. // The tag distinguishes ordinary strings from domain names. - s := fld.(reflect.StringValue).Get(); - switch tag { + s := fv.Get(); + switch f.Tag { default: - fmt.Fprintf(os.Stderr, "net: dns: unknown string tag %v", tag); + fmt.Fprintf(os.Stderr, "net: dns: unknown string tag %v", f.Tag); return len(msg), false; case "domain-name": off, ok = packDomainName(s, msg, off); @@ -376,43 +425,46 @@ func packStructValue(val reflect.StructValue, msg []byte, off int) (off1 int, ok return off, true } +func structValue(any interface{}) *reflect.StructValue { + return reflect.NewValue(any).(*reflect.PtrValue).Elem().(*reflect.StructValue); +} + func packStruct(any interface{}, msg []byte, off int) (off1 int, ok bool) { - val := reflect.NewValue(any).(reflect.PtrValue).Sub().(reflect.StructValue); - off, ok = packStructValue(val, msg, off); + off, ok = packStructValue(structValue(any), msg, off); return off, ok } +// TODO(rsc): Move into generic library? // Unpack a reflect.StructValue from msg. // Same restrictions as packStructValue. -func unpackStructValue(val reflect.StructValue, msg []byte, off int) (off1 int, ok bool) { - for i := 0; i < val.Len(); i++ { - name, typ, tag, xxx := val.Type().(reflect.StructType).Field(i); - fld := val.Field(i); - switch fld.Kind() { +func unpackStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int, ok bool) { + for i := 0; i < val.NumField(); i++ { + f := val.Type().(*reflect.StructType).Field(i); + switch fv := val.Field(i).(type) { default: - fmt.Fprintf(os.Stderr, "net: dns: unknown packing type %v", fld.Type()); + fmt.Fprintf(os.Stderr, "net: dns: unknown packing type %v", f.Type); return len(msg), false; - case reflect.StructKind: - off, ok = unpackStructValue(fld.(reflect.StructValue), msg, off); - case reflect.Uint16Kind: + case *reflect.StructValue: + off, ok = unpackStructValue(fv, msg, off); + case *reflect.Uint16Value: if off+2 > len(msg) { return len(msg), false } i := uint16(msg[off])<<8 | uint16(msg[off+1]); - fld.(reflect.Uint16Value).Set(i); + fv.Set(i); off += 2; - case reflect.Uint32Kind: + case *reflect.Uint32Value: if off+4 > len(msg) { return len(msg), false } i := uint32(msg[off])<<24 | uint32(msg[off+1])<<16 | uint32(msg[off+2])<<8 | uint32(msg[off+3]); - fld.(reflect.Uint32Value).Set(i); + fv.Set(i); off += 4; - case reflect.StringKind: + case *reflect.StringValue: var s string; - switch tag { + switch f.Tag { default: - fmt.Fprintf(os.Stderr, "net: dns: unknown string tag %v", tag); + fmt.Fprintf(os.Stderr, "net: dns: unknown string tag %v", f.Tag); return len(msg), false; case "domain-name": s, off, ok = unpackDomainName(msg, off); @@ -432,15 +484,14 @@ func unpackStructValue(val reflect.StructValue, msg []byte, off int) (off1 int, off += n; s = string(b); } - fld.(reflect.StringValue).Set(s); + fv.Set(s); } } return off, true } func unpackStruct(any interface{}, msg []byte, off int) (off1 int, ok bool) { - val := reflect.NewValue(any).(reflect.PtrValue).Sub().(reflect.StructValue); - off, ok = unpackStructValue(val, msg, off); + off, ok = unpackStructValue(structValue(any), msg, off); return off, ok } @@ -448,26 +499,24 @@ func unpackStruct(any interface{}, msg []byte, off int) (off1 int, ok bool) { // Doesn't care about the string tag "domain-name", // but does look for an "ipv4" tag on uint32 variables, // printing them as IP addresses. -func printStructValue(val reflect.StructValue) string { +func printStructValue(val *reflect.StructValue) string { s := "{"; - for i := 0; i < val.Len(); i++ { + for i := 0; i < val.NumField(); i++ { if i > 0 { s += ", "; } - name, typ, tag, xxx := val.Type().(reflect.StructType).Field(i); - fld := val.Field(i); - if name != "" && name != "?" { // BUG? Shouldn't the reflect library hide "?" ? - s += name + "="; + f := val.Type().(*reflect.StructType).Field(i); + if !f.Anonymous { + s += f.Name + "="; } - kind := fld.Kind(); - switch { - case kind == reflect.StructKind: - s += printStructValue(fld.(reflect.StructValue)); - case kind == reflect.Uint32Kind && tag == "ipv4": - i := fld.(reflect.Uint32Value).Get(); + fval := val.Field(i); + if fv, ok := fval.(*reflect.StructValue); ok { + s += printStructValue(fv); + } else if fv, ok := fval.(*reflect.Uint32Value); ok && f.Tag == "ipv4" { + i := fv.Get(); s += IPv4(byte(i>>24), byte(i>>16), byte(i>>8), byte(i)).String(); - default: - s += fmt.Sprint(fld.Interface()) + } else { + s += fmt.Sprint(fval.Interface()) } } s += "}"; @@ -475,9 +524,7 @@ func printStructValue(val reflect.StructValue) string { } func printStruct(any interface{}) string { - val := reflect.NewValue(any).(reflect.PtrValue).Sub().(reflect.StructValue); - s := printStructValue(val); - return s + return printStructValue(structValue(any)); } // Resource record packer. @@ -494,7 +541,7 @@ func packRR(rr _DNS_RR, msg []byte, off int) (off2 int, ok bool) { return len(msg), false } // pack a third time; redo header with correct data length - rr.Header().rdlength = uint16(off2 - off1); + rr.Header().Rdlength = uint16(off2 - off1); packStruct(rr.Header(), msg, off); return off2, true } @@ -507,11 +554,11 @@ func unpackRR(msg []byte, off int) (rr _DNS_RR, off1 int, ok bool) { if off, ok = unpackStruct(&h, msg, off); !ok { return nil, len(msg), false } - end := off+int(h.rdlength); + end := off+int(h.Rdlength); // make an rr of that type and re-unpack. // again inefficient but doesn't need to be fast. - mk, known := rr_mk[int(h.rrtype)]; + mk, known := rr_mk[int(h.Rrtype)]; if !known { return &h, end, true } @@ -551,22 +598,22 @@ func (dns *_DNS_Msg) Pack() (msg []byte, ok bool) { var dh __DNS_Header; // Convert convenient _DNS_Msg into wire-like __DNS_Header. - dh.id = dns.id; - dh.bits = uint16(dns.opcode)<<11 | uint16(dns.rcode); + dh.Id = dns.id; + dh.Bits = uint16(dns.opcode)<<11 | uint16(dns.rcode); if dns.recursion_available { - dh.bits |= _RA; + dh.Bits |= _RA; } if dns.recursion_desired { - dh.bits |= _RD; + dh.Bits |= _RD; } if dns.truncated { - dh.bits |= _TC; + dh.Bits |= _TC; } if dns.authoritative { - dh.bits |= _AA; + dh.Bits |= _AA; } if dns.response { - dh.bits |= _QR; + dh.Bits |= _QR; } // Prepare variable sized arrays. @@ -575,10 +622,10 @@ func (dns *_DNS_Msg) Pack() (msg []byte, ok bool) { ns := dns.ns; extra := dns.extra; - dh.qdcount = uint16(len(question)); - dh.ancount = uint16(len(answer)); - dh.nscount = uint16(len(ns)); - dh.arcount = uint16(len(extra)); + dh.Qdcount = uint16(len(question)); + dh.Ancount = uint16(len(answer)); + dh.Nscount = uint16(len(ns)); + dh.Arcount = uint16(len(extra)); // Could work harder to calculate message size, // but this is far more than we need and not @@ -614,20 +661,20 @@ func (dns *_DNS_Msg) Unpack(msg []byte) bool { if off, ok = unpackStruct(&dh, msg, off); !ok { return false } - dns.id = dh.id; - dns.response = (dh.bits & _QR) != 0; - dns.opcode = int(dh.bits >> 11) & 0xF; - dns.authoritative = (dh.bits & _AA) != 0; - dns.truncated = (dh.bits & _TC) != 0; - dns.recursion_desired = (dh.bits & _RD) != 0; - dns.recursion_available = (dh.bits & _RA) != 0; - dns.rcode = int(dh.bits & 0xF); + dns.id = dh.Id; + dns.response = (dh.Bits & _QR) != 0; + dns.opcode = int(dh.Bits >> 11) & 0xF; + dns.authoritative = (dh.Bits & _AA) != 0; + dns.truncated = (dh.Bits & _TC) != 0; + dns.recursion_desired = (dh.Bits & _RD) != 0; + dns.recursion_available = (dh.Bits & _RA) != 0; + dns.rcode = int(dh.Bits & 0xF); // Arrays. - dns.question = make([]_DNS_Question, dh.qdcount); - dns.answer = make([]_DNS_RR, dh.ancount); - dns.ns = make([]_DNS_RR, dh.nscount); - dns.extra = make([]_DNS_RR, dh.arcount); + dns.question = make([]_DNS_Question, dh.Qdcount); + dns.answer = make([]_DNS_RR, dh.Ancount); + dns.ns = make([]_DNS_RR, dh.Nscount); + dns.extra = make([]_DNS_RR, dh.Arcount); for i := 0; i < len(dns.question); i++ { off, ok = unpackStruct(&dns.question[i], msg, off);