commit a3e4d56b6d9bcfca48f3d8c8f1e526e95b0c2f64
from: Thomas Adam <thomas.adam22@gmail.com>
date: Sat May 25 00:52:40 2024 UTC

tls: guard against faulty gemini servers

Some gemini servers have faulty TLS handling, such as:

  gg: tls_close: EOF without close notify

In such cases, telescope will receive that error and naturally assume
there was a problem and stop processing.  However, in the case of there
still being legitimate content read from the request, this should still
be displayed, rather than ignored.

This change therefore detects this condition and adds a status of 'W' to
telescope's modeline to indicate that the information presented is from
a faulty gemini server and could be truncated and hence display oddly.

commit - 5cf5039df1f7526a79b6067417efe594e9c685bd
commit + a3e4d56b6d9bcfca48f3d8c8f1e526e95b0c2f64
blob - 7b3309eb7c60b587980e11a74ce5e00de7724c73
blob + 51d8a65fcb5359ea11f7ba67630934522cd5c7e6
--- imsgev.h
+++ imsgev.h
@@ -28,6 +28,7 @@ enum imsg_type {
 	IMSG_ERR,
 	IMSG_CHECK_CERT,
 	IMSG_CERT_STATUS,
+	IMSG_FAULTY_GEMSERVER,
 	IMSG_REPLY,		/* reply code (int) + meta string */
 	IMSG_PROCEED,
 	IMSG_STOP,
blob - c892b6b9639d0a5658a1aff25591beebb10294d4
blob + 024d7a5796113050461798068c61a5727e1c96dd
--- net.c
+++ net.c
@@ -472,9 +472,9 @@ net_ev(int fd, int ev, void *d)
 
 	if (ev & EV_READ) {
 		read = bufio_read(&req->bio);
-		if (read == -1 && errno != EAGAIN) {			
-			close_with_errf(req, "Read error");
-			return;
+		if (read == -1 && errno != EAGAIN) {
+			req->eof = 1;
+			net_send_ui(IMSG_FAULTY_GEMSERVER, req->id, NULL, 0);
 		}
 		if (read == 0)
 			req->eof = 1;
blob - e54a1de144252e239ec403f04af538d4a2638175
blob + 0ab6bdcd5603e3fd5e515711da30ba7edfbac905
--- telescope.1
+++ telescope.1
@@ -76,11 +76,18 @@ It contains the current page and optionally a side win
 .Pp
 The modeline is the second to last row of the screen.
 It shows some information about the page: a spinner when the page is
-loading, the trust level, whether a client certificate is in use, the
-document type, the scroll offset and the URL.
+loading, the trust level, whether a client certificate is in use, a
+warning indicator for faulty Gemini servers, document type, the
+scroll offset and the URL.
 When a client certificate is in use, a
 .Sq C
 character is showed.
+Some Gemini servers have buggy TLS handling but some information might
+still be available.
+This information could be truncated.
+In those circumstances, a
+.Sq W
+character is shown.
 .Pp
 The echoarea is usually the last line of the screen.
 Messages are often showed there, and link addresses too.
blob - 3b5c0156989123d3b9cf4cb87275d5dcf65c95fd
blob + 51793ce48e26b6d9b70a334e18db68748d725d94
--- telescope.c
+++ telescope.c
@@ -517,6 +517,16 @@ handle_dispatch_imsg(int fd, int event, void *data)
 				ui_on_download_refresh();
 			}
 			break;
+		case IMSG_FAULTY_GEMSERVER:
+			if ((tab = tab_by_id(imsg_get_id(&imsg))) == NULL &&
+			    ((d = download_by_id(imsg_get_id(&imsg)))) == NULL)
+				return;
+
+			if (tab) {
+				tab->faulty_gemserver = 1;
+				ui_on_tab_refresh(tab);
+			}
+			break;
 		case IMSG_EOF:
 			if ((tab = tab_by_id(imsg_get_id(&imsg))) == NULL &&
 			    ((d = download_by_id(imsg_get_id(&imsg)))) == NULL)
@@ -714,6 +724,7 @@ make_request(struct tab *tab, struct get_req *req, int
 
 	stop_tab(tab);
 	tab->id = tab_new_id();
+	tab->faulty_gemserver = 0;
 	req->proto = proto;
 
 	if (r != NULL) {
blob - c510cc27deff21895a2b1771955e9edbb4ff39b8
blob + 2a6e252eb25b696d48f5c82bda10a0cdacbd0123
--- telescope.h
+++ telescope.h
@@ -165,6 +165,7 @@ struct tab {
 
 	char			*cert;
 	enum trust_state	 trust;
+	int			 faulty_gemserver;
 	const char		*client_cert;
 	int			 client_cert_temp;
 	struct proxy		*proxy;
blob - 6ec9314b6ce98bc82f7a80268211c1c4012e5d32
blob + d7c77490d1fef81b810f1a8aec2d0729c548baf8
--- ui.c
+++ ui.c
@@ -846,10 +846,11 @@ redraw_modeline(struct tab *tab)
 	wattr_on(modeline, modeline_face.background, NULL);
 	wmove(modeline, 0, 0);
 
-	wprintw(modeline, "-%c%c%c %s ",
+	wprintw(modeline, "-%c%c%c%c %s ",
 	    spin[tab->loading_anim_step],
 	    trust_status_char(tab->trust),
 	    tab->client_cert ? 'C' : '-',
+	    tab->faulty_gemserver ? 'W' : '-',
 	    mode == NULL ? "(none)" : mode);
 
 	pct = (buffer->line_off + buffer->curs_y) * 100.0