http 304: client-option to force-disable cache

an extremely brutish workaround for issues such as #110 where
browsers receive an HTTP 304 and misinterpret as HTTP 200

option `--no304=1` adds the button `no304` to the controlpanel
which can be enabled to force-disable caching in that browser

the button is default-disabled; by specifying `--no304=2`
instead of `--no304=1` the button becomes default-enabled

can also always be enabled by accessing `/?setck=no304=y`

copyparty/__main__.py

@@ -1461,6 +1461,7 @@ def add_ui(ap, retry):
     ap2.add_argument("--pb-url", metavar="URL", type=u, default="https://github.com/9001/copyparty", help="powered-by link; disable with \033[33m-np\033[0m")
     ap2.add_argument("--ver", action="store_true", help="show version on the control panel (incompatible with \033[33m-nb\033[0m)")
     ap2.add_argument("--k304", metavar="NUM", type=int, default=0, help="configure the option to enable/disable k304 on the controlpanel (workaround for buggy reverse-proxies); [\033[32m0\033[0m] = hidden and default-off, [\033[32m1\033[0m] = visible and default-off, [\033[32m2\033[0m] = visible and default-on")
+    ap2.add_argument("--no304", metavar="NUM", type=int, default=0, help="configure the option to enable/disable no304 on the controlpanel (workaround for buggy caching in browsers); [\033[32m0\033[0m] = hidden and default-off, [\033[32m1\033[0m] = visible and default-off, [\033[32m2\033[0m] = visible and default-on")
     ap2.add_argument("--md-sbf", metavar="FLAGS", type=u, default="downloads forms popups scripts top-navigation-by-user-activation", help="list of capabilities to ALLOW for README.md docs (volflag=md_sbf); see https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#attr-sandbox")
     ap2.add_argument("--lg-sbf", metavar="FLAGS", type=u, default="downloads forms popups scripts top-navigation-by-user-activation", help="list of capabilities to ALLOW for prologue/epilogue docs  (volflag=lg_sbf)")
     ap2.add_argument("--no-sb-md", action="store_true", help="don't sandbox README/PREADME.md documents (volflags: no_sb_md | sb_md)")

copyparty/httpcli.py

@@ -125,6 +125,8 @@ _ = (argparse, threading)
 
 NO_CACHE = {"Cache-Control": "no-cache"}
 
+ALL_COOKIES = "k304 no304 js idxh dots cppwd cppws".split()
+
 H_CONN_KEEPALIVE = "Connection: Keep-Alive"
 H_CONN_CLOSE = "Connection: Close"
 
@@ -795,6 +797,10 @@ class HttpCli(object):
         k304 = self.cookies.get("k304")
         return k304 == "y" or (self.args.k304 == 2 and k304 != "n")
 
+    def no304(self) -> bool:
+        no304 = self.cookies.get("no304")
+        return no304 == "y" or (self.args.no304 == 2 and no304 != "n")
+
     def _build_html_head(self, maybe_html: Any, kv: dict[str, Any]) -> None:
         html = str(maybe_html)
         is_jinja = html[:2] in "%@%"
@@ -1199,9 +1205,6 @@ class HttpCli(object):
             if "ups" in self.uparam:
                 return self.tx_ups()
 
-            if "k304" in self.uparam:
-                return self.set_k304()
-
             if "setck" in self.uparam:
                 return self.setck()
 
@@ -3428,6 +3431,9 @@ class HttpCli(object):
         if do_send and c_lastmod:
             t = "sending body due to If-Modified-Since cli(%s) file(%s)"
             self.log(t % (c_lastmod, file_lastmod), 6)
+        elif not do_send and self.no304():
+            do_send = True
+            self.log("sending body due to no304")
 
         return file_lastmod, do_send, True
 
@@ -4460,7 +4466,9 @@ class HttpCli(object):
             dbwt=vs["dbwt"],
             url_suf=suf,
             k304=self.k304(),
+            no304=self.no304(),
             k304vis=self.args.k304 > 0,
+            no304vis=self.args.no304 > 0,
             ver=S_VERSION if self.args.ver else "",
             chpw=self.args.chpw and self.uname != "*",
             ahttps="" if self.is_https else "https://" + self.host + self.req,
@@ -4468,29 +4476,21 @@ class HttpCli(object):
         self.reply(html.encode("utf-8"))
         return True
 
-    def set_k304(self) -> bool:
-        v = self.uparam["k304"].lower()
-        if v in "yn":
-            dur = 86400 * 299
-        else:
-            dur = 0
-            v = "x"
-
-        ck = gencookie("k304", v, self.args.R, False, dur)
-        self.out_headerlist.append(("Set-Cookie", ck))
-        self.redirect("", "?h#cc")
-        return True
-
     def setck(self) -> bool:
         k, v = self.uparam["setck"].split("=", 1)
-        t = 0 if v == "" else 86400 * 299
+        t = 0 if v in ("", "x") else 86400 * 299
         ck = gencookie(k, v, self.args.R, False, t)
         self.out_headerlist.append(("Set-Cookie", ck))
+        if "cc" in self.ouparam:
+            self.redirect("", "?h#cc")
+        else:
             self.reply(b"o7\n")
         return True
 
     def set_cfg_reset(self) -> bool:
-        for k in ("k304", "js", "idxh", "dots", "cppwd", "cppws"):
+        for k in ALL_COOKIES:
+            if k not in self.cookies:
+                continue
             cookie = gencookie(k, "x", self.args.R, False)
             self.out_headerlist.append(("Set-Cookie", cookie))
 

copyparty/web/splash.html

@@ -129,11 +129,20 @@
 
 			{% if k304 or k304vis %}
 			{% if k304 %}
-			<li><a id="h" href="{{ r }}/?k304=n">disable k304</a> (currently enabled)
+			<li><a id="h" href="{{ r }}/?cc&setck=k304=n">disable k304</a> (currently enabled)
 			{%- else %}
-			<li><a id="i" href="{{ r }}/?k304=y" class="r">enable k304</a> (currently disabled)
+			<li><a id="i" href="{{ r }}/?cc&setck=k304=y" class="r">enable k304</a> (currently disabled)
 			{% endif %}
-			<blockquote id="j">enabling this will disconnect your client on every HTTP 304, which can prevent some buggy proxies from getting stuck (suddenly not loading pages), <em>but</em> it will also make things slower in general</blockquote></li>
+			<blockquote id="j">enabling k304 will disconnect your client on every HTTP 304, which can prevent some buggy proxies from getting stuck (suddenly not loading pages), <em>but</em> it will also make things slower in general</blockquote></li>
+			{% endif %}
+
+			{% if no304 or no304vis %}
+			{% if no304 %}
+			<li><a id="ab" href="{{ r }}/?cc&setck=no304=n">disable no304</a> (currently enabled)
+			{%- else %}
+			<li><a id="ac" href="{{ r }}/?cc&setck=no304=y" class="r">enable no304</a> (currently disabled)
+			{% endif %}
+			<blockquote id="ad">enabling no304 will disable all caching; try this if k304 wasn't enough. This will waste a huge amount of network traffic!</blockquote></li>
 			{% endif %}
 
 			<li><a id="k" href="{{ r }}/?reset" class="r" onclick="localStorage.clear();return true">reset client settings</a></li>

copyparty/web/splash.js

@@ -34,6 +34,9 @@ var Ls = {
 		"ta2": "gjenta for å bekrefte nytt passord:",
 		"ta3": "fant en skrivefeil; vennligst prøv igjen",
 		"aa1": "innkommende:",
+		"ab1": "skru av no304",
+		"ac1": "skru på no304",
+		"ad1": "no304 stopper all bruk av cache. Hvis ikke k304 var nok, prøv denne. Vil mangedoble dataforbruk!",
 	},
 	"eng": {
 		"d2": "shows the state of all active threads",
@@ -80,6 +83,9 @@ var Ls = {
 		"ta2": "重复以确认新密码：",
 		"ta3": "发现拼写错误；请重试",
 		"aa1": "正在接收的文件：", //m
+		"ab1": "关闭 k304",
+		"ac1": "开启 k304",
+		"ad1": "启用 no304 将禁用所有缓存；如果 k304 不够，可以尝试此选项。这将消耗大量的网络流量！", //m
 	}
 };
 

scripts/tl.js

@@ -54,7 +54,7 @@ var tl_cpanel = {
 		"cc1": "other stuff:",
 		"h1": "disable k304",  // TLNote: "j1" explains what k304 is
 		"i1": "enable k304",
-		"j1": "enabling this will disconnect your client on every HTTP 304, which can prevent some buggy proxies from getting stuck (suddenly not loading pages), <em>but</em> it will also make things slower in general",
+		"j1": "enabling k304 will disconnect your client on every HTTP 304, which can prevent some buggy proxies from getting stuck (suddenly not loading pages), <em>but</em> it will also make things slower in general",
 		"k1": "reset client settings",
 		"l1": "login for more:",
 		"m1": "welcome back,",  // TLNote: "welcome back, USERNAME"
@@ -76,6 +76,9 @@ var tl_cpanel = {
 		"ta2": "repeat to confirm new password:",
 		"ta3": "found a typo; please try again",
 		"aa1": "incoming files:",
+		"ab1": "disable no304",
+		"ac1": "enable no304",
+		"ad1": "enabling no304 will disable all caching; try this if k304 wasn't enough. This will waste a huge amount of network traffic!",
 	},
 };
 

scripts/tl.py

@@ -89,7 +89,7 @@ var tl_cpanel = {{
 		"cc1": "other stuff:",
 		"h1": "disable k304",  // TLNote: "j1" explains what k304 is
 		"i1": "enable k304",
-		"j1": "enabling this will disconnect your client on every HTTP 304, which can prevent some buggy proxies from getting stuck (suddenly not loading pages), <em>but</em> it will also make things slower in general",
+		"j1": "enabling k304 will disconnect your client on every HTTP 304, which can prevent some buggy proxies from getting stuck (suddenly not loading pages), <em>but</em> it will also make things slower in general",
 		"k1": "reset client settings",
 		"l1": "login for more:",
 		"m1": "welcome back,",  // TLNote: "welcome back, USERNAME"
@@ -111,6 +111,9 @@ var tl_cpanel = {{
 		"ta2": "repeat to confirm new password:",
 		"ta3": "found a typo; please try again",
 		"aa1": "incoming files:",
+		"ab1": "disable no304",
+		"ac1": "enable no304",
+		"ad1": "enabling no304 will disable all caching; try this if k304 wasn't enough. This will waste a huge amount of network traffic!",
 	}},
 }};
 

tests/util.py

@@ -137,7 +137,7 @@ class Cfg(Namespace):
         ex = "au_vol mtab_age reg_cap s_thead s_tbody th_convt"
         ka.update(**{k: 9 for k in ex.split()})
 
-        ex = "db_act k304 loris re_maxage rproxy rsp_jtr rsp_slp s_wr_slp snap_wri theme themes turbo"
+        ex = "db_act k304 loris no304 re_maxage rproxy rsp_jtr rsp_slp s_wr_slp snap_wri theme themes turbo"
         ka.update(**{k: 0 for k in ex.split()})
 
         ex = "ah_alg bname chpw_db doctitle df exit favico idp_h_usr ipa html_head lg_sbf log_fk md_sbf name og_desc og_site og_th og_title og_title_a og_title_v og_title_i shr tcolor textfiles unlist vname xff_src R RS SR"