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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 caddyfile
import (
"bytes"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"go.uber.org/zap"
"github.com/caddyserver/caddy/v2"
)
// Parse parses the input just enough to group tokens, in
// order, by server block. No further parsing is performed.
// Server blocks are returned in the order in which they appear.
// Directives that do not appear in validDirectives will cause
// an error. If you do not want to check for valid directives,
// pass in nil instead.
//
// Environment variables in {$ENVIRONMENT_VARIABLE} notation
// will be replaced before parsing begins.
func Parse(filename string, input []byte) ([]ServerBlock, error) {
// unfortunately, we must copy the input because parsing must
// remain a read-only operation, but we have to expand environment
// variables before we parse, which changes the underlying array (#4422)
inputCopy := make([]byte, len(input))
copy(inputCopy, input)
tokens, err := allTokens(filename, inputCopy)
if err != nil {
return nil, err
}
p := parser{
Dispenser: NewDispenser(tokens),
importGraph: importGraph{
nodes: make(map[string]bool),
edges: make(adjacency),
},
}
return p.parseAll()
}
// allTokens lexes the entire input, but does not parse it.
// It returns all the tokens from the input, unstructured
// and in order. It may mutate input as it expands env vars.
func allTokens(filename string, input []byte) ([]Token, error) {
return Tokenize(replaceEnvVars(input), filename)
}
// replaceEnvVars replaces all occurrences of environment variables.
// It mutates the underlying array and returns the updated slice.
func replaceEnvVars(input []byte) []byte {
var offset int
for {
begin := bytes.Index(input[offset:], spanOpen)
if begin < 0 {
break
}
begin += offset // make beginning relative to input, not offset
end := bytes.Index(input[begin+len(spanOpen):], spanClose)
if end < 0 {
break
}
end += begin + len(spanOpen) // make end relative to input, not begin
// get the name; if there is no name, skip it
envString := input[begin+len(spanOpen) : end]
if len(envString) == 0 {
offset = end + len(spanClose)
continue
}
// split the string into a key and an optional default
envParts := strings.SplitN(string(envString), envVarDefaultDelimiter, 2)
// do a lookup for the env var, replace with the default if not found
envVarValue, found := os.LookupEnv(envParts[0])
if !found && len(envParts) == 2 {
envVarValue = envParts[1]
}
// get the value of the environment variable
// note that this causes one-level deep chaining
envVarBytes := []byte(envVarValue)
// splice in the value
input = append(input[:begin],
append(envVarBytes, input[end+len(spanClose):]...)...)
// continue at the end of the replacement
offset = begin + len(envVarBytes)
}
return input
}
type parser struct {
*Dispenser
block ServerBlock // current server block being parsed
eof bool // if we encounter a valid EOF in a hard place
definedSnippets map[string][]Token
nesting int
importGraph importGraph
}
func (p *parser) parseAll() ([]ServerBlock, error) {
var blocks []ServerBlock
for p.Next() {
err := p.parseOne()
if err != nil {
return blocks, err
}
if len(p.block.Keys) > 0 || len(p.block.Segments) > 0 {
blocks = append(blocks, p.block)
}
if p.nesting > 0 {
return blocks, p.EOFErr()
}
}
return blocks, nil
}
func (p *parser) parseOne() error {
p.block = ServerBlock{}
return p.begin()
}
func (p *parser) begin() error {
if len(p.tokens) == 0 {
return nil
}
err := p.addresses()
if err != nil {
return err
}
if p.eof {
// this happens if the Caddyfile consists of only
// a line of addresses and nothing else
return nil
}
if ok, name := p.isNamedRoute(); ok {
// we just need a dummy leading token to ease parsing later
nameToken := p.Token()
nameToken.Text = name
// named routes only have one key, the route name
p.block.Keys = []Token{nameToken}
p.block.IsNamedRoute = true
// get all the tokens from the block, including the braces
tokens, err := p.blockTokens(true)
if err != nil {
return err
}
tokens = append([]Token{nameToken}, tokens...)
p.block.Segments = []Segment{tokens}
return nil
}
if ok, name := p.isSnippet(); ok {
if p.definedSnippets == nil {
p.definedSnippets = map[string][]Token{}
}
if _, found := p.definedSnippets[name]; found {
return p.Errf("redeclaration of previously declared snippet %s", name)
}
// consume all tokens til matched close brace
tokens, err := p.blockTokens(false)
if err != nil {
return err
}
// Just as we need to track which file the token comes from, we need to
// keep track of which snippet the token comes from. This is helpful
// in tracking import cycles across files/snippets by namespacing them.
// Without this, we end up with false-positives in cycle-detection.
for k, v := range tokens {
v.snippetName = name
tokens[k] = v
}
p.definedSnippets[name] = tokens
// empty block keys so we don't save this block as a real server.
p.block.Keys = nil
return nil
}
return p.blockContents()
}
func (p *parser) addresses() error {
var expectingAnother bool
for {
value := p.Val()
token := p.Token()
// special case: import directive replaces tokens during parse-time
if value == "import" && p.isNewLine() {
err := p.doImport(0)
if err != nil {
return err
}
continue
}
// Open brace definitely indicates end of addresses
if value == "{" {
if expectingAnother {
return p.Errf("Expected another address but had '%s' - check for extra comma", value)
}
// Mark this server block as being defined with braces.
// This is used to provide a better error message when
// the user may have tried to define two server blocks
// without having used braces, which are required in
// that case.
p.block.HasBraces = true
break
}
// Users commonly forget to place a space between the address and the '{'
if strings.HasSuffix(value, "{") {
return p.Errf("Site addresses cannot end with a curly brace: '%s' - put a space between the token and the brace", value)
}
if value != "" { // empty token possible if user typed ""
// Trailing comma indicates another address will follow, which
// may possibly be on the next line
if value[len(value)-1] == ',' {
value = value[:len(value)-1]
expectingAnother = true
} else {
expectingAnother = false // but we may still see another one on this line
}
// If there's a comma here, it's probably because they didn't use a space
// between their two domains, e.g. "foo.com,bar.com", which would not be
// parsed as two separate site addresses.
if strings.Contains(value, ",") {
return p.Errf("Site addresses cannot contain a comma ',': '%s' - put a space after the comma to separate site addresses", value)
}
token.Text = value
p.block.Keys = append(p.block.Keys, token)
}
// Advance token and possibly break out of loop or return error
hasNext := p.Next()
if expectingAnother && !hasNext {
return p.EOFErr()
}
if !hasNext {
p.eof = true
break // EOF
}
if !expectingAnother && p.isNewLine() {
break
}
}
return nil
}
func (p *parser) blockContents() error {
errOpenCurlyBrace := p.openCurlyBrace()
if errOpenCurlyBrace != nil {
// single-server configs don't need curly braces
p.cursor--
}
err := p.directives()
if err != nil {
return err
}
// only look for close curly brace if there was an opening
if errOpenCurlyBrace == nil {
err = p.closeCurlyBrace()
if err != nil {
return err
}
}
return nil
}
// directives parses through all the lines for directives
// and it expects the next token to be the first
// directive. It goes until EOF or closing curly brace
// which ends the server block.
func (p *parser) directives() error {
for p.Next() {
// end of server block
if p.Val() == "}" {
// p.nesting has already been decremented
break
}
// special case: import directive replaces tokens during parse-time
if p.Val() == "import" {
err := p.doImport(1)
if err != nil {
return err
}
p.cursor-- // cursor is advanced when we continue, so roll back one more
continue
}
// normal case: parse a directive as a new segment
// (a "segment" is a line which starts with a directive
// and which ends at the end of the line or at the end of
// the block that is opened at the end of the line)
if err := p.directive(); err != nil {
return err
}
}
return nil
}
// doImport swaps out the import directive and its argument
// (a total of 2 tokens) with the tokens in the specified file
// or globbing pattern. When the function returns, the cursor
// is on the token before where the import directive was. In
// other words, call Next() to access the first token that was
// imported.
func (p *parser) doImport(nesting int) error {
// syntax checks
if !p.NextArg() {
return p.ArgErr()
}
importPattern := p.Val()
if importPattern == "" {
return p.Err("Import requires a non-empty filepath")
}
// grab remaining args as placeholder replacements
args := p.RemainingArgs()
// set up a replacer for non-variadic args replacement
repl := makeArgsReplacer(args)
// splice out the import directive and its arguments
// (2 tokens, plus the length of args)
tokensBefore := p.tokens[:p.cursor-1-len(args)]
tokensAfter := p.tokens[p.cursor+1:]
var importedTokens []Token
var nodes []string
// first check snippets. That is a simple, non-recursive replacement
if p.definedSnippets != nil && p.definedSnippets[importPattern] != nil {
importedTokens = p.definedSnippets[importPattern]
if len(importedTokens) > 0 {
// just grab the first one
nodes = append(nodes, fmt.Sprintf("%s:%s", importedTokens[0].File, importedTokens[0].snippetName))
}
} else {
// make path relative to the file of the _token_ being processed rather
// than current working directory (issue #867) and then use glob to get
// list of matching filenames
absFile, err := filepath.Abs(p.Dispenser.File())
if err != nil {
return p.Errf("Failed to get absolute path of file: %s: %v", p.Dispenser.File(), err)
}
var matches []string
var globPattern string
if !filepath.IsAbs(importPattern) {
globPattern = filepath.Join(filepath.Dir(absFile), importPattern)
} else {
globPattern = importPattern
}
if strings.Count(globPattern, "*") > 1 || strings.Count(globPattern, "?") > 1 ||
(strings.Contains(globPattern, "[") && strings.Contains(globPattern, "]")) {
// See issue #2096 - a pattern with many glob expansions can hang for too long
return p.Errf("Glob pattern may only contain one wildcard (*), but has others: %s", globPattern)
}
matches, err = filepath.Glob(globPattern)
if err != nil {
return p.Errf("Failed to use import pattern %s: %v", importPattern, err)
}
if len(matches) == 0 {
if strings.ContainsAny(globPattern, "*?[]") {
caddy.Log().Warn("No files matching import glob pattern", zap.String("pattern", importPattern))
} else {
return p.Errf("File to import not found: %s", importPattern)
}
} else {
// See issue #5295 - should skip any files that start with a . when iterating over them.
sep := string(filepath.Separator)
segGlobPattern := strings.Split(globPattern, sep)
if strings.HasPrefix(segGlobPattern[len(segGlobPattern)-1], "*") {
var tmpMatches []string
for _, m := range matches {
seg := strings.Split(m, sep)
if !strings.HasPrefix(seg[len(seg)-1], ".") {
tmpMatches = append(tmpMatches, m)
}
}
matches = tmpMatches
}
}
// collect all the imported tokens
for _, importFile := range matches {
newTokens, err := p.doSingleImport(importFile)
if err != nil {
return err
}
importedTokens = append(importedTokens, newTokens...)
}
nodes = matches
}
nodeName := p.File()
if p.Token().snippetName != "" {
nodeName += fmt.Sprintf(":%s", p.Token().snippetName)
}
p.importGraph.addNode(nodeName)
p.importGraph.addNodes(nodes)
if err := p.importGraph.addEdges(nodeName, nodes); err != nil {
p.importGraph.removeNodes(nodes)
return err
}
// copy the tokens so we don't overwrite p.definedSnippets
tokensCopy := make([]Token, 0, len(importedTokens))
var (
maybeSnippet bool
maybeSnippetId bool
index int
)
// run the argument replacer on the tokens
// golang for range slice return a copy of value
// similarly, append also copy value
for i, token := range importedTokens {
// update the token's imports to refer to import directive filename, line number and snippet name if there is one
if token.snippetName != "" {
token.imports = append(token.imports, fmt.Sprintf("%s:%d (import %s)", p.File(), p.Line(), token.snippetName))
} else {
token.imports = append(token.imports, fmt.Sprintf("%s:%d (import)", p.File(), p.Line()))
}
// naive way of determine snippets, as snippets definition can only follow name + block
// format, won't check for nesting correctness or any other error, that's what parser does.
if !maybeSnippet && nesting == 0 {
// first of the line
if i == 0 || isNextOnNewLine(tokensCopy[i-1], token) {
index = 0
} else {
index++
}
if index == 0 && len(token.Text) >= 3 && strings.HasPrefix(token.Text, "(") && strings.HasSuffix(token.Text, ")") {
maybeSnippetId = true
}
}
switch token.Text {
case "{":
nesting++
if index == 1 && maybeSnippetId && nesting == 1 {
maybeSnippet = true
maybeSnippetId = false
}
case "}":
nesting--
if nesting == 0 && maybeSnippet {
maybeSnippet = false
}
}
if maybeSnippet {
tokensCopy = append(tokensCopy, token)
continue
}
foundVariadic, startIndex, endIndex := parseVariadic(token, len(args))
if foundVariadic {
for _, arg := range args[startIndex:endIndex] {
token.Text = arg
tokensCopy = append(tokensCopy, token)
}
} else {
token.Text = repl.ReplaceKnown(token.Text, "")
tokensCopy = append(tokensCopy, token)
}
}
// splice the imported tokens in the place of the import statement
// and rewind cursor so Next() will land on first imported token
p.tokens = append(tokensBefore, append(tokensCopy, tokensAfter...)...)
p.cursor -= len(args) + 1
return nil
}
// doSingleImport lexes the individual file at importFile and returns
// its tokens or an error, if any.
func (p *parser) doSingleImport(importFile string) ([]Token, error) {
file, err := os.Open(importFile)
if err != nil {
return nil, p.Errf("Could not import %s: %v", importFile, err)
}
defer file.Close()
if info, err := file.Stat(); err != nil {
return nil, p.Errf("Could not import %s: %v", importFile, err)
} else if info.IsDir() {
return nil, p.Errf("Could not import %s: is a directory", importFile)
}
input, err := io.ReadAll(file)
if err != nil {
return nil, p.Errf("Could not read imported file %s: %v", importFile, err)
}
// only warning in case of empty files
if len(input) == 0 || len(strings.TrimSpace(string(input))) == 0 {
caddy.Log().Warn("Import file is empty", zap.String("file", importFile))
return []Token{}, nil
}
importedTokens, err := allTokens(importFile, input)
if err != nil {
return nil, p.Errf("Could not read tokens while importing %s: %v", importFile, err)
}
// Tack the file path onto these tokens so errors show the imported file's name
// (we use full, absolute path to avoid bugs: issue #1892)
filename, err := filepath.Abs(importFile)
if err != nil {
return nil, p.Errf("Failed to get absolute path of file: %s: %v", importFile, err)
}
for i := 0; i < len(importedTokens); i++ {
importedTokens[i].File = filename
}
return importedTokens, nil
}
// directive collects tokens until the directive's scope
// closes (either end of line or end of curly brace block).
// It expects the currently-loaded token to be a directive
// (or } that ends a server block). The collected tokens
// are loaded into the current server block for later use
// by directive setup functions.
func (p *parser) directive() error {
// a segment is a list of tokens associated with this directive
var segment Segment
// the directive itself is appended as a relevant token
segment = append(segment, p.Token())
for p.Next() {
if p.Val() == "{" {
p.nesting++
if !p.isNextOnNewLine() && p.Token().wasQuoted == 0 {
return p.Err("Unexpected next token after '{' on same line")
}
if p.isNewLine() {
return p.Err("Unexpected '{' on a new line; did you mean to place the '{' on the previous line?")
}
} else if p.Val() == "{}" {
if p.isNextOnNewLine() && p.Token().wasQuoted == 0 {
return p.Err("Unexpected '{}' at end of line")
}
} else if p.isNewLine() && p.nesting == 0 {
p.cursor-- // read too far
break
} else if p.Val() == "}" && p.nesting > 0 {
p.nesting--
} else if p.Val() == "}" && p.nesting == 0 {
return p.Err("Unexpected '}' because no matching opening brace")
} else if p.Val() == "import" && p.isNewLine() {
if err := p.doImport(1); err != nil {
return err
}
p.cursor-- // cursor is advanced when we continue, so roll back one more
continue
}
segment = append(segment, p.Token())
}
p.block.Segments = append(p.block.Segments, segment)
if p.nesting > 0 {
return p.EOFErr()
}
return nil
}
// openCurlyBrace expects the current token to be an
// opening curly brace. This acts like an assertion
// because it returns an error if the token is not
// a opening curly brace. It does NOT advance the token.
func (p *parser) openCurlyBrace() error {
if p.Val() != "{" {
return p.SyntaxErr("{")
}
return nil
}
// closeCurlyBrace expects the current token to be
// a closing curly brace. This acts like an assertion
// because it returns an error if the token is not
// a closing curly brace. It does NOT advance the token.
func (p *parser) closeCurlyBrace() error {
if p.Val() != "}" {
return p.SyntaxErr("}")
}
return nil
}
func (p *parser) isNamedRoute() (bool, string) {
keys := p.block.Keys
// A named route block is a single key with parens, prefixed with &.
if len(keys) == 1 && strings.HasPrefix(keys[0].Text, "&(") && strings.HasSuffix(keys[0].Text, ")") {
return true, strings.TrimSuffix(keys[0].Text[2:], ")")
}
return false, ""
}
func (p *parser) isSnippet() (bool, string) {
keys := p.block.Keys
// A snippet block is a single key with parens. Nothing else qualifies.
if len(keys) == 1 && strings.HasPrefix(keys[0].Text, "(") && strings.HasSuffix(keys[0].Text, ")") {
return true, strings.TrimSuffix(keys[0].Text[1:], ")")
}
return false, ""
}
// read and store everything in a block for later replay.
func (p *parser) blockTokens(retainCurlies bool) ([]Token, error) {
// block must have curlies.
err := p.openCurlyBrace()
if err != nil {
return nil, err
}
nesting := 1 // count our own nesting
tokens := []Token{}
if retainCurlies {
tokens = append(tokens, p.Token())
}
for p.Next() {
if p.Val() == "}" {
nesting--
if nesting == 0 {
if retainCurlies {
tokens = append(tokens, p.Token())
}
break
}
}
if p.Val() == "{" {
nesting++
}
tokens = append(tokens, p.tokens[p.cursor])
}
// make sure we're matched up
if nesting != 0 {
return nil, p.SyntaxErr("}")
}
return tokens, nil
}
// ServerBlock associates any number of keys from the
// head of the server block with tokens, which are
// grouped by segments.
type ServerBlock struct {
HasBraces bool
Keys []Token
Segments []Segment
IsNamedRoute bool
}
func (sb ServerBlock) GetKeysText() []string {
res := []string{}
for _, k := range sb.Keys {
res = append(res, k.Text)
}
return res
}
// DispenseDirective returns a dispenser that contains
// all the tokens in the server block.
func (sb ServerBlock) DispenseDirective(dir string) *Dispenser {
var tokens []Token
for _, seg := range sb.Segments {
if len(seg) > 0 && seg[0].Text == dir {
tokens = append(tokens, seg...)
}
}
return NewDispenser(tokens)
}
// Segment is a list of tokens which begins with a directive
// and ends at the end of the directive (either at the end of
// the line, or at the end of a block it opens).
type Segment []Token
// Directive returns the directive name for the segment.
// The directive name is the text of the first token.
func (s Segment) Directive() string {
if len(s) > 0 {
return s[0].Text
}
return ""
}
// spanOpen and spanClose are used to bound spans that
// contain the name of an environment variable.
var (
spanOpen, spanClose = []byte{'{', '$'}, []byte{'}'}
envVarDefaultDelimiter = ":"
)
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