map: Prevent output destinations overlap with Caddyfile shorthands (#4657)

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Francis Lavoie 2022-05-06 12:25:31 -04:00 committed by GitHub
parent f6900fcf53
commit f7be0ee101
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2 changed files with 61 additions and 28 deletions

View file

@ -88,34 +88,10 @@ func (st ServerType) Setup(inputServerBlocks []caddyfile.ServerBlock,
return nil, warnings, err
}
// replace shorthand placeholders (which are
// convenient when writing a Caddyfile) with
// their actual placeholder identifiers or
// variable names
replacer := strings.NewReplacer(
"{dir}", "{http.request.uri.path.dir}",
"{file}", "{http.request.uri.path.file}",
"{host}", "{http.request.host}",
"{hostport}", "{http.request.hostport}",
"{port}", "{http.request.port}",
"{method}", "{http.request.method}",
"{path}", "{http.request.uri.path}",
"{query}", "{http.request.uri.query}",
"{remote}", "{http.request.remote}",
"{remote_host}", "{http.request.remote.host}",
"{remote_port}", "{http.request.remote.port}",
"{scheme}", "{http.request.scheme}",
"{uri}", "{http.request.uri}",
"{tls_cipher}", "{http.request.tls.cipher_suite}",
"{tls_version}", "{http.request.tls.version}",
"{tls_client_fingerprint}", "{http.request.tls.client.fingerprint}",
"{tls_client_issuer}", "{http.request.tls.client.issuer}",
"{tls_client_serial}", "{http.request.tls.client.serial}",
"{tls_client_subject}", "{http.request.tls.client.subject}",
"{tls_client_certificate_pem}", "{http.request.tls.client.certificate_pem}",
"{tls_client_certificate_der_base64}", "{http.request.tls.client.certificate_der_base64}",
"{upstream_hostport}", "{http.reverse_proxy.upstream.hostport}",
)
// replace shorthand placeholders (which are convenient
// when writing a Caddyfile) with their actual placeholder
// identifiers or variable names
replacer := strings.NewReplacer(placeholderShorthands()...)
// these are placeholders that allow a user-defined final
// parameters, but we still want to provide a shorthand
@ -1265,6 +1241,58 @@ func encodeMatcherSet(matchers map[string]caddyhttp.RequestMatcher) (caddy.Modul
return msEncoded, nil
}
// placeholderShorthands returns a slice of old-new string pairs,
// where the left of the pair is a placeholder shorthand that may
// be used in the Caddyfile, and the right is the replacement.
func placeholderShorthands() []string {
return []string{
"{dir}", "{http.request.uri.path.dir}",
"{file}", "{http.request.uri.path.file}",
"{host}", "{http.request.host}",
"{hostport}", "{http.request.hostport}",
"{port}", "{http.request.port}",
"{method}", "{http.request.method}",
"{path}", "{http.request.uri.path}",
"{query}", "{http.request.uri.query}",
"{remote}", "{http.request.remote}",
"{remote_host}", "{http.request.remote.host}",
"{remote_port}", "{http.request.remote.port}",
"{scheme}", "{http.request.scheme}",
"{uri}", "{http.request.uri}",
"{tls_cipher}", "{http.request.tls.cipher_suite}",
"{tls_version}", "{http.request.tls.version}",
"{tls_client_fingerprint}", "{http.request.tls.client.fingerprint}",
"{tls_client_issuer}", "{http.request.tls.client.issuer}",
"{tls_client_serial}", "{http.request.tls.client.serial}",
"{tls_client_subject}", "{http.request.tls.client.subject}",
"{tls_client_certificate_pem}", "{http.request.tls.client.certificate_pem}",
"{tls_client_certificate_der_base64}", "{http.request.tls.client.certificate_der_base64}",
"{upstream_hostport}", "{http.reverse_proxy.upstream.hostport}",
}
}
// WasReplacedPlaceholderShorthand checks if a token string was
// likely a replaced shorthand of the known Caddyfile placeholder
// replacement outputs. Useful to prevent some user-defined map
// output destinations from overlapping with one of the
// predefined shorthands.
func WasReplacedPlaceholderShorthand(token string) string {
prev := ""
for i, item := range placeholderShorthands() {
// only look at every 2nd item, which is the replacement
if i%2 == 0 {
prev = item
continue
}
if strings.Trim(token, "{}") == strings.Trim(item, "{}") {
// we return the original shorthand so it
// can be used for an error message
return prev
}
}
return ""
}
// tryInt tries to convert val to an integer. If it fails,
// it downgrades the error to a warning and returns 0.
func tryInt(val interface{}, warnings *[]caddyconfig.Warning) int {

View file

@ -56,6 +56,11 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
if len(handler.Destinations) == 0 {
return nil, h.Err("missing destination argument(s)")
}
for _, dest := range handler.Destinations {
if shorthand := httpcaddyfile.WasReplacedPlaceholderShorthand(dest); shorthand != "" {
return nil, h.Errf("destination %s conflicts with a Caddyfile placeholder shorthand", shorthand)
}
}
// mappings
for h.NextBlock(0) {