From 8f9140b705011eea9a7344466362662f3106cd69 Mon Sep 17 00:00:00 2001
From: "Gerasimos (Makis) Maropoulos" <kataras2006@hotmail.com>
Date: Mon, 7 Jun 2021 15:33:19 +0300
Subject: [PATCH] New Context.FormFiles method

---
 HISTORY.md           |  1 +
 context/context.go   | 47 +++++++++++++++++++++++++++++++++++++++++++-
 core/netutil/addr.go | 23 ++++++++++++++++++++++
 3 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/HISTORY.md b/HISTORY.md
index 2a694e9a..6b9230e0 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -396,6 +396,7 @@ var dirOpts = iris.DirOptions{
 
 ## New Context Methods
 
+- `Context.FormFiles(key string, before ...func(*Context, *multipart.FileHeader) bool) (files []multipart.File, headers []*multipart.FileHeader, err error)` method.
 - `Context.ReadURL(ptr interface{}) error` shortcut of `ReadParams` and `ReadQuery`. Binds URL dynamic path parameters and URL query parameters to the given "ptr" pointer of a struct value.
 - `Context.SetUser(User)` and `Context.User() User` to store and retrieve an authenticated client. Read more [here](https://github.com/iris-contrib/middleware/issues/63).
 - `Context.SetLogoutFunc(fn interface{}, persistenceArgs ...interface{})` and `Logout(args ...interface{}) error` methods to allow different kind of auth middlewares to be able to set a "logout" a user/client feature with a single function, the route handler may not be aware of the implementation of the authentication used.
diff --git a/context/context.go b/context/context.go
index 1fed82ae..29907a07 100644
--- a/context/context.go
+++ b/context/context.go
@@ -1943,6 +1943,51 @@ func (ctx *Context) FormFile(key string) (multipart.File, *multipart.FileHeader,
 	return ctx.request.FormFile(key)
 }
 
+// FormFiles same as FormFile but may return multiple file inputs based on a key, e.g. "files[]".
+func (ctx *Context) FormFiles(key string, before ...func(*Context, *multipart.FileHeader) bool) (files []multipart.File, headers []*multipart.FileHeader, err error) {
+	err = ctx.request.ParseMultipartForm(ctx.app.ConfigurationReadOnly().GetPostMaxMemory())
+	if err != nil {
+		return
+	}
+
+	if ctx.request.MultipartForm != nil {
+		fhs := ctx.request.MultipartForm.File
+		if n := len(fhs); n > 0 {
+			files = make([]multipart.File, 0, n)
+			headers = make([]*multipart.FileHeader, 0, n)
+
+		innerLoop:
+			for _, header := range fhs[key] {
+				// Fix an issue that net/http has,
+				// an attacker can push a filename
+				// which could lead to override existing system files
+				// by ../../$header.
+				// Reported by Frank through security reports.
+				header.Filename = strings.ReplaceAll(header.Filename, "../", "")
+				header.Filename = strings.ReplaceAll(header.Filename, "..\\", "")
+
+				for _, b := range before {
+					if !b(ctx, header) {
+						continue innerLoop
+					}
+				}
+
+				file, fErr := header.Open()
+				if fErr != nil { // exit on first error but return the succeed.
+					return files, headers, fErr
+				}
+
+				files = append(files, file)
+				headers = append(headers, header)
+			}
+		}
+
+		return
+	}
+
+	return nil, nil, http.ErrMissingFile
+}
+
 // UploadFormFiles uploads any received file(s) from the client
 // to the system physical location "destDirectory".
 //
@@ -1967,7 +2012,7 @@ func (ctx *Context) FormFile(key string) (multipart.File, *multipart.FileHeader,
 // the `WithPostMaxMemory` configurator or by `SetMaxRequestBodySize` or
 // by the `LimitRequestBodySize` middleware (depends the use case).
 //
-// See `FormFile` to a more controlled way to receive a file.
+// See `FormFile` and `FormFiles` to a more controlled way to receive a file.
 //
 // Example: https://github.com/kataras/iris/tree/master/_examples/file-server/upload-files
 func (ctx *Context) UploadFormFiles(destDirectory string, before ...func(*Context, *multipart.FileHeader) bool) (uploaded []*multipart.FileHeader, n int64, err error) {
diff --git a/core/netutil/addr.go b/core/netutil/addr.go
index 12db4e74..47ecdf3b 100644
--- a/core/netutil/addr.go
+++ b/core/netutil/addr.go
@@ -98,6 +98,29 @@ var IsLoopbackHost = func(requestHost string) bool {
 	return valid
 }
 
+/*
+func isLoopbackHostGoVersion(host string) bool {
+	ip := net.ParseIP(host)
+	if ip != nil {
+		return ip.IsLoopback()
+	}
+
+	// Host is not an ip, perform lookup.
+	addrs, err := net.LookupHost(host)
+	if err != nil {
+		return false
+	}
+
+	for _, addr := range addrs {
+		if !net.ParseIP(addr).IsLoopback() {
+			return false
+		}
+	}
+
+	return true
+}
+*/
+
 const (
 	// defaultServerHostname returns the default hostname which is "localhost"
 	defaultServerHostname = "localhost"