1 files changed, 350 insertions, 0 deletions
diff --git a/caddyconfig/httpcaddyfile/addresses.go b/caddyconfig/httpcaddyfile/addresses.go
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+++ b/caddyconfig/httpcaddyfile/addresses.go
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+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package httpcaddyfile
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"github.com/mholt/certmagic"
+)
+
+// mapAddressToServerBlocks returns a map of listener address to list of server
+// blocks that will be served on that address. To do this, each server block is
+// expanded so that each one is considered individually, although keys of a
+// server block that share the same address stay grouped together so the config
+// isn't repeated unnecessarily. For example, this Caddyfile:
+//
+// 	example.com {
+// 		bind 127.0.0.1
+// 	}
+// 	www.example.com, example.net/path, localhost:9999 {
+// 		bind 127.0.0.1 1.2.3.4
+// 	}
+//
+// has two server blocks to start with. But expressed in this Caddyfile are
+// actually 4 listener addresses: 127.0.0.1:443, 1.2.3.4:443, 127.0.0.1:9999,
+// and 127.0.0.1:9999. This is because the bind directive is applied to each
+// key of its server block (specifying the host part), and each key may have
+// a different port. And we definitely need to be sure that a site which is
+// bound to be served on a specific interface is not served on others just
+// beceause that is more convenient: it would be a potential security risk
+// if the difference between interfaces means private vs. public.
+//
+// So what this function does for the example above is iterate each server
+// block, and for each server block, iterate its keys. For the first, it
+// finds one key (example.com) and determines its listener address
+// (127.0.0.1:443 - because of 'bind' and automatic HTTPS). It then adds
+// the listener address to the map value returned by this function, with
+// the first server block as one of its associations.
+//
+// It then iterates each key on the second server block and associates them
+// with one or more listener addresses. Indeed, each key in this block has
+// two listener addresses because of the 'bind' directive. Once we know
+// which addresses serve which keys, we can create a new server block for
+// each address containing the contents of the server block and only those
+// specific keys of the server block which use that address.
+//
+// It is possible and even likely that some keys in the returned map have
+// the exact same list of server blocks (i.e. they are identical). This
+// happens when multiple hosts are declared with a 'bind' directive and
+// the resulting listener addresses are not shared by any other server
+// block (or the other server blocks are exactly identical in their token
+// contents). This happens with our example above because 1.2.3.4:443
+// and 1.2.3.4:9999 are used exclusively with the second server block. This
+// repetition may be undesirable, so call consolidateAddrMappings() to map
+// multiple addresses to the same lists of server blocks (a many:many mapping).
+// (Doing this is essentially a map-reduce technique.)
+func (st *ServerType) mapAddressToServerBlocks(originalServerBlocks []caddyfile.ServerBlock) (map[string][]caddyfile.ServerBlock, error) {
+	sbmap := make(map[string][]caddyfile.ServerBlock)
+
+	for i, sblock := range originalServerBlocks {
+		// within a server block, we need to map all the listener addresses
+		// implied by the server block to the keys of the server block which
+		// will be served by them; this has the effect of treating each
+		// key of a server block as its own, but without having to repeat its
+		// contents in cases where multiple keys really can be served together
+		addrToKeys := make(map[string][]string)
+		for j, key := range sblock.Keys {
+			// a key can have multiple listener addresses if there are multiple
+			// arguments to the 'bind' directive (although they will all have
+			// the same port, since the port is defined by the key or is implicit
+			// through automatic HTTPS)
+			addrs, err := st.listenerAddrsForServerBlockKey(sblock, key)
+			if err != nil {
+				return nil, fmt.Errorf("server block %d, key %d (%s): determining listener address: %v", i, j, key, err)
+			}
+
+			// associate this key with each listener address it is served on
+			for _, addr := range addrs {
+				addrToKeys[addr] = append(addrToKeys[addr], key)
+			}
+		}
+
+		// now that we know which addresses serve which keys of this
+		// server block, we iterate that mapping and create a list of
+		// new server blocks for each address where the keys of the
+		// server block are only the ones which use the address; but
+		// the contents (tokens) are of course the same
+		for addr, keys := range addrToKeys {
+			sbmap[addr] = append(sbmap[addr], caddyfile.ServerBlock{
+				Keys:   keys,
+				Tokens: sblock.Tokens,
+			})
+		}
+	}
+
+	return sbmap, nil
+}
+
+// consolidateAddrMappings eliminates repetition of identical server blocks in a mapping of
+// single listener addresses to lists of server blocks. Since multiple addresses may serve
+// identical sites (server block contents), this function turns a 1:many mapping into a
+// many:many mapping. Server block contents (tokens) must be exactly identical so that
+// reflect.DeepEqual returns true in order for the addresses to be combined. Identical
+// entries are deleted from the addrToServerBlocks map. Essentially, each pairing (each
+// association from multiple addresses to multiple server blocks; i.e. each element of
+// the returned slice) becomes a server definition in the output JSON.
+func (st *ServerType) consolidateAddrMappings(addrToServerBlocks map[string][]caddyfile.ServerBlock) []sbAddrAssociation {
+	var sbaddrs []sbAddrAssociation
+	for addr, sblocks := range addrToServerBlocks {
+		// we start with knowing that at least this address
+		// maps to these server blocks
+		a := sbAddrAssociation{
+			addresses:    []string{addr},
+			serverBlocks: sblocks,
+		}
+
+		// now find other addresses that map to identical
+		// server blocks and add them to our list of
+		// addresses, while removing them from the map
+		for otherAddr, otherSblocks := range addrToServerBlocks {
+			if addr == otherAddr {
+				continue
+			}
+			if reflect.DeepEqual(sblocks, otherSblocks) {
+				a.addresses = append(a.addresses, otherAddr)
+				delete(addrToServerBlocks, otherAddr)
+			}
+		}
+
+		sbaddrs = append(sbaddrs, a)
+	}
+	return sbaddrs
+}
+
+func (st *ServerType) listenerAddrsForServerBlockKey(sblock caddyfile.ServerBlock, key string) ([]string, error) {
+	addr, err := standardizeAddress(key)
+	if err != nil {
+		return nil, fmt.Errorf("parsing key: %v", err)
+	}
+
+	lnPort := defaultPort
+	if addr.Port != "" {
+		// port explicitly defined
+		lnPort = addr.Port
+	} else if certmagic.HostQualifies(addr.Host) {
+		// automatic HTTPS
+		lnPort = strconv.Itoa(certmagic.HTTPSPort)
+	}
+
+	// the bind directive specifies hosts, but is optional
+	var lnHosts []string
+	for i, token := range sblock.Tokens["bind"] {
+		if i == 0 {
+			continue
+		}
+		lnHosts = append(lnHosts, token.Text)
+	}
+	if len(lnHosts) == 0 {
+		lnHosts = []string{""}
+	}
+
+	// use a map to prevent duplication
+	listeners := make(map[string]struct{})
+	for _, host := range lnHosts {
+		listeners[net.JoinHostPort(host, lnPort)] = struct{}{}
+	}
+
+	// now turn map into list
+	var listenersList []string
+	for lnStr := range listeners {
+		listenersList = append(listenersList, lnStr)
+	}
+	// sort.Strings(listenersList) // TODO: is sorting necessary?
+
+	return listenersList, nil
+}
+
+// Address represents a site address. It contains
+// the original input value, and the component
+// parts of an address. The component parts may be
+// updated to the correct values as setup proceeds,
+// but the original value should never be changed.
+//
+// The Host field must be in a normalized form.
+type Address struct {
+	Original, Scheme, Host, Port, Path string
+}
+
+// String returns a human-friendly print of the address.
+func (a Address) String() string {
+	if a.Host == "" && a.Port == "" {
+		return ""
+	}
+	scheme := a.Scheme
+	if scheme == "" {
+		if a.Port == strconv.Itoa(certmagic.HTTPSPort) {
+			scheme = "https"
+		} else {
+			scheme = "http"
+		}
+	}
+	s := scheme
+	if s != "" {
+		s += "://"
+	}
+	if a.Port != "" &&
+		((scheme == "https" && a.Port != strconv.Itoa(caddyhttp.DefaultHTTPSPort)) ||
+			(scheme == "http" && a.Port != strconv.Itoa(caddyhttp.DefaultHTTPPort))) {
+		s += net.JoinHostPort(a.Host, a.Port)
+	} else {
+		s += a.Host
+	}
+	if a.Path != "" {
+		s += a.Path
+	}
+	return s
+}
+
+// VHost returns a sensible concatenation of Host:Port/Path from a.
+// It's basically the a.Original but without the scheme.
+func (a Address) VHost() string {
+	if idx := strings.Index(a.Original, "://"); idx > -1 {
+		return a.Original[idx+3:]
+	}
+	return a.Original
+}
+
+// Normalize normalizes URL: turn scheme and host names into lower case
+func (a Address) Normalize() Address {
+	path := a.Path
+	if !caseSensitivePath {
+		path = strings.ToLower(path)
+	}
+
+	// ensure host is normalized if it's an IP address
+	host := a.Host
+	if ip := net.ParseIP(host); ip != nil {
+		host = ip.String()
+	}
+
+	return Address{
+		Original: a.Original,
+		Scheme:   strings.ToLower(a.Scheme),
+		Host:     strings.ToLower(host),
+		Port:     a.Port,
+		Path:     path,
+	}
+}
+
+// Key is similar to String, just replaces scheme and host values with modified values.
+// Unlike String it doesn't add anything default (scheme, port, etc)
+func (a Address) Key() string {
+	res := ""
+	if a.Scheme != "" {
+		res += a.Scheme + "://"
+	}
+	if a.Host != "" {
+		res += a.Host
+	}
+	if a.Port != "" {
+		if strings.HasPrefix(a.Original[len(res):], ":"+a.Port) {
+			// insert port only if the original has its own explicit port
+			res += ":" + a.Port
+		}
+	}
+	if a.Path != "" {
+		res += a.Path
+	}
+	return res
+}
+
+// standardizeAddress parses an address string into a structured format with separate
+// scheme, host, port, and path portions, as well as the original input string.
+func standardizeAddress(str string) (Address, error) {
+	httpPort, httpsPort := strconv.Itoa(certmagic.HTTPPort), strconv.Itoa(certmagic.HTTPSPort)
+
+	input := str
+
+	// Split input into components (prepend with // to assert host by default)
+	if !strings.Contains(str, "//") && !strings.HasPrefix(str, "/") {
+		str = "//" + str
+	}
+	u, err := url.Parse(str)
+	if err != nil {
+		return Address{}, err
+	}
+
+	// separate host and port
+	host, port, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		host, port, err = net.SplitHostPort(u.Host + ":")
+		if err != nil {
+			host = u.Host
+		}
+	}
+
+	// see if we can set port based off scheme
+	if port == "" {
+		if u.Scheme == "http" {
+			port = httpPort
+		} else if u.Scheme == "https" {
+			port = httpsPort
+		}
+	}
+
+	// repeated or conflicting scheme is confusing, so error
+	if u.Scheme != "" && (port == "http" || port == "https") {
+		return Address{}, fmt.Errorf("[%s] scheme specified twice in address", input)
+	}
+
+	// error if scheme and port combination violate convention
+	if (u.Scheme == "http" && port == httpsPort) || (u.Scheme == "https" && port == httpPort) {
+		return Address{}, fmt.Errorf("[%s] scheme and port violate convention", input)
+	}
+
+	// standardize http and https ports to their respective port numbers
+	if port == "http" {
+		u.Scheme = "http"
+		port = httpPort
+	} else if port == "https" {
+		u.Scheme = "https"
+		port = httpsPort
+	}
+
+	return Address{Original: input, Scheme: u.Scheme, Host: host, Port: port, Path: u.Path}, err
+}
+
+const (
+	defaultPort       = "2015"
+	caseSensitivePath = false
+)