BUGFIX: Content-Type, Nil Raw Body Edge Case, Links

FIXES:
* There was an edge case where a raw body for HTML would potentially
  result in a nil byte slice exception. This has been fixed.
  (I don't even know if it was possible, I just made sure it wasn't.)
* The links browser is now explicitly returned as HTML and properly
  detected as a "browser".
* Hyperlinks for links, w3m added to Usage page.
* Content-Type is now always set correctly; there were cases where it
  was improperly returning e.g. text/plain for JSON.

README.adoc

@@ -0,0 +1,20 @@
+= ClientInfo
+r00t^2 <brent.saner@gmail.com>
+Last rendered {localdatetime}
+:doctype: book
+:docinfo: shared
+:data-uri:
+:imagesdir: images
+:sectlinks:
+:sectnums:
+:sectnumlevels: 7
+:toc: preamble
+:toc2: left
+:idprefix:
+:toclevels: 7
+//:toclevels: 4
+:source-highlighter: rouge
+:docinfo: shared
+
+== DOCS
+**TODO!**

TODO

@@ -1,3 +1,7 @@
 - suggest browser, OS alternatives (again)
-- link to ipinfo.io for client IP (again)
+- implement ipinfo.io equiv. myself?
--- or just implement myself
+- also link to https://www.useragentstring.com/
+-- or maybe https://www.whatsmyua.info/
+-- see https://www.useragentstring.com/pages/api.php
+- note that though lynx and elinks are "graphical", links is considered text. w3m is considered graphical.
+- fix the text/plain issue for the json (et. al.) renderer

server/consts.go

@@ -79,10 +79,15 @@ var (
 		mediaJSON: json.MarshalIndent,
 		mediaXML:  xml.MarshalIndent,
 	}
+	// valid MIMEs.
 	okAcceptMime []string = []string{
 		mediaJSON,
 		mediaXML,
 		mediaYAML,
 		mediaHTML,
 	}
+	// These are actually HTML.
+	htmlOverride map[string]bool = map[string]bool{
+		"Links": true,
+	}
 )

server/funcs_server.go

@@ -19,6 +19,7 @@ import (
 	sysd "github.com/coreos/go-systemd/daemon"
 	"github.com/davecgh/go-spew/spew"
 	`github.com/goccy/go-yaml`
+	`r00t2.io/clientinfo/version`
 	"r00t2.io/goutils/multierr"
 )
 
@@ -280,6 +281,8 @@ func (s *Server) handleDefault(resp http.ResponseWriter, req *http.Request) {
 
 	s.log.Debug("server.Server.handleDefault: Handling request:\n%s", spew.Sdump(req))
 
+	resp.Header().Set("ClientInfo-Version", version.Ver.Short())
+
 	page = &Page{
 		Info: &R00tInfo{
 			Client:  nil,
@@ -327,6 +330,9 @@ func (s *Server) handleDefault(resp http.ResponseWriter, req *http.Request) {
 				http.Error(resp, fmt.Sprintf("ERROR: Failed to parse 'User-Agent' '%s'", ua), http.StatusInternalServerError)
 				return
 			}
+			if parsedUA.Name != nil && htmlOverride[*parsedUA.Name] {
+				parsedUA.IsDesktop = true
+			}
 			page.Info.Client = append(page.Info.Client, parsedUA)
 		}
 	}
@@ -470,6 +476,7 @@ func (s *Server) handleAbout(resp http.ResponseWriter, req *http.Request) {
 
 	s.log.Debug("server.Server.handleAbout: Handling request:\n%s", spew.Sdump(req))
 
+	resp.Header().Set("ClientInfo-Version", version.Ver.Short())
 	resp.Header().Set("Content-Type", "text/html; charset=utf-8")
 
 	if err = tpl.ExecuteTemplate(resp, "about", renderPage); err != nil {
@@ -495,7 +502,9 @@ func (s *Server) handleUsage(resp http.ResponseWriter, req *http.Request) {
 
 	s.log.Debug("server.Server.handleUsage: Handling request:\n%s", spew.Sdump(req))
 
+	resp.Header().Set("ClientInfo-Version", version.Ver.Short())
 	resp.Header().Set("Content-Type", "text/html; charset=utf-8")
+
 	if err = tpl.ExecuteTemplate(resp, "usage", renderPage); err != nil {
 		s.log.Err("server.Server.handleAbout: Failed to execute template for '%s': %v", req.RemoteAddr, err)
 		http.Error(resp, "ERROR: Failed to render HTML", http.StatusInternalServerError)
@@ -511,6 +520,8 @@ func (s *Server) renderJSON(page *Page, resp http.ResponseWriter) (err error) {
 
 	var b []byte
 
+	resp.Header().Set("Content-Type", "application/json")
+
 	if page.DoIndent {
 		if b, err = json.MarshalIndent(page.Info, "", page.Indent); err != nil {
 			s.log.Err("server.Server.renderJSON: Failed to render to indented JSON: %v", err)
@@ -561,10 +572,14 @@ func (s *Server) renderHTML(page *Page, resp http.ResponseWriter) (err error) {
 				s.log.Err("server.Server.renderHTML: Failed to render to '%s': %v", *page.RawFmt, err)
 			}
 		}
-		page.Raw = new(string)
+		if b != nil {
-		*page.Raw = string(b)
+			page.Raw = new(string)
+			*page.Raw = string(b)
+		}
 	}
 
+	resp.Header().Set("Content-Type", "text/html; charset=utf-8")
+
 	if err = tpl.ExecuteTemplate(resp, "index", page); err != nil {
 		s.log.Err("server.Server.renderHTML: Failed to render template: %v", err)
 		http.Error(resp, "ERROR: Failed to render HTML", http.StatusInternalServerError)
@@ -591,6 +606,9 @@ func (s *Server) renderXML(page *Page, resp http.ResponseWriter) (err error) {
 			return
 		}
 	}
+
+	resp.Header().Set("Content-Type", "application/xml; charset=utf-8")
+
 	if _, err = resp.Write(b); err != nil {
 		s.log.Err("server.Server.renderXML: Failed to send XML: %v", err)
 		return
@@ -609,6 +627,8 @@ func (s *Server) renderYML(page *Page, resp http.ResponseWriter) (err error) {
 		return
 	}
 
+	resp.Header().Set("Content-Type", "application/yaml")
+
 	if _, err = resp.Write(b); err != nil {
 		s.log.Err("server.Server.renderJSON: Failed to send JSON: %v", err)
 		return

server/tpl/usage.html.tpl

@@ -46,8 +46,8 @@ Accept: text/html
 						</pre>
 					</p>
 
-					Note that <a href="https://lynx.invisible-island.net/">Lynx</a> and <a href="http://elinks.or.cz/">Elinks</a> are considered "graphical"
+					Note that <a href="http://links.twibright.com/">Links</a>a>, <a href="https://lynx.invisible-island.net/">Lynx</a>, <a href="http://elinks.or.cz/">Elinks</a>,
-					browsers by this program as they are HTML-centric.
+					and <a href="https://w3m.sourceforge.net/">W3M</a> are considered "graphical" browsers by this program as they are HTML-centric.
 				</p>
 				<p id="usage_params_mod">
 					The following parameters control/modify behavior.<a href="#usage_params_mod">{{ $linkico }}</a>