File size: 3,382 Bytes
8059bf0 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | package responseheaders
import (
"net/http"
"strings"
"github.com/Wei-Shaw/sub2api/internal/config"
)
// defaultAllowed 定义允许透传的响应头白名单
// 注意：以下头部由 Go HTTP 包自动处理，不应手动设置：
// - content-length: 由 ResponseWriter 根据实际写入数据自动设置
// - transfer-encoding: 由 HTTP 库根据需要自动添加/移除
// - connection: 由 HTTP 库管理连接复用
var defaultAllowed = map[string]struct{}{
"content-type": {},
"content-encoding": {},
"content-language": {},
"cache-control": {},
"etag": {},
"last-modified": {},
"expires": {},
"vary": {},
"date": {},
"x-request-id": {},
"x-ratelimit-limit-requests": {},
"x-ratelimit-limit-tokens": {},
"x-ratelimit-remaining-requests": {},
"x-ratelimit-remaining-tokens": {},
"x-ratelimit-reset-requests": {},
"x-ratelimit-reset-tokens": {},
"retry-after": {},
"location": {},
"www-authenticate": {},
}
// hopByHopHeaders 是跳过的 hop-by-hop 头部，这些头部由 HTTP 库自动处理
var hopByHopHeaders = map[string]struct{}{
"content-length": {},
"transfer-encoding": {},
"connection": {},
}
type CompiledHeaderFilter struct {
allowed map[string]struct{}
forceRemove map[string]struct{}
}
var defaultCompiledHeaderFilter = CompileHeaderFilter(config.ResponseHeaderConfig{})
func CompileHeaderFilter(cfg config.ResponseHeaderConfig) *CompiledHeaderFilter {
allowed := make(map[string]struct{}, len(defaultAllowed)+len(cfg.AdditionalAllowed))
for key := range defaultAllowed {
allowed[key] = struct{}{}
}
// 关闭时只使用默认白名单，additional/force_remove 不生效
if cfg.Enabled {
for _, key := range cfg.AdditionalAllowed {
normalized := strings.ToLower(strings.TrimSpace(key))
if normalized == "" {
continue
}
allowed[normalized] = struct{}{}
}
}
forceRemove := map[string]struct{}{}
if cfg.Enabled {
forceRemove = make(map[string]struct{}, len(cfg.ForceRemove))
for _, key := range cfg.ForceRemove {
normalized := strings.ToLower(strings.TrimSpace(key))
if normalized == "" {
continue
}
forceRemove[normalized] = struct{}{}
}
}
return &CompiledHeaderFilter{
allowed: allowed,
forceRemove: forceRemove,
}
}
func FilterHeaders(src http.Header, filter *CompiledHeaderFilter) http.Header {
if filter == nil {
filter = defaultCompiledHeaderFilter
}
filtered := make(http.Header, len(src))
for key, values := range src {
lower := strings.ToLower(key)
if _, blocked := filter.forceRemove[lower]; blocked {
continue
}
if _, ok := filter.allowed[lower]; !ok {
continue
}
// 跳过 hop-by-hop 头部，这些由 HTTP 库自动处理
if _, isHopByHop := hopByHopHeaders[lower]; isHopByHop {
continue
}
for _, value := range values {
filtered.Add(key, value)
}
}
return filtered
}
func WriteFilteredHeaders(dst http.Header, src http.Header, filter *CompiledHeaderFilter) {
filtered := FilterHeaders(src, filter)
for key, values := range filtered {
for _, value := range values {
dst.Add(key, value)
}
}
}
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