1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 /*
18  * Handles the data in ~/.telescope
19  *
20  * TODO: add some form of locking on the files
21  */
22 
23 #include "telescope.h"
24 
25 #include <sys/stat.h>
26 
27 #include <errno.h>
28 #include <limits.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33 
34 static void		 die(void) __attribute__((__noreturn__));
35 static void		 serve_bookmarks(uint32_t);
36 static void		 handle_get(struct imsg*, size_t);
37 static void		 handle_quit(struct imsg*, size_t);
38 static void		 handle_bookmark_page(struct imsg*, size_t);
39 static void		 handle_save_cert(struct imsg*, size_t);
40 static void		 handle_session_start(struct imsg*, size_t);
41 static void		 handle_session_tab(struct imsg*, size_t);
42 static void		 handle_session_end(struct imsg*, size_t);
43 static void		 handle_dispatch_imsg(int, short, void*);
44 
45 static struct event		 imsgev;
46 static struct imsgbuf		*ibuf;
47 
48 static FILE			*session;
49 
50 static char	bookmark_file[PATH_MAX];
51 static char	known_hosts_file[PATH_MAX];
52 static char	session_file[PATH_MAX];
53 
54 static imsg_handlerfn *handlers[] = {
55 	[IMSG_GET] = handle_get,
56 	[IMSG_QUIT] = handle_quit,
57 	[IMSG_BOOKMARK_PAGE] = handle_bookmark_page,
58 	[IMSG_SAVE_CERT] = handle_save_cert,
59 	[IMSG_SESSION_START] = handle_session_start,
60 	[IMSG_SESSION_TAB] = handle_session_tab,
61 	[IMSG_SESSION_END] = handle_session_end,
62 };
63 
64 static void __attribute__((__noreturn__))
65 die(void)
66 {
67 	abort(); 		/* TODO */
68 }
69 
70 static void
71 serve_bookmarks(uint32_t peerid)
72 {
73 	const char	*t;
74 	char		 buf[BUFSIZ];
75 	size_t		 r;
76 	FILE		*f;
77 
78 	if ((f = fopen(bookmark_file, "r")) == NULL) {
79 		t = "# Bookmarks\n\n"
80 		    "No bookmarks yet!\n"
81 		    "Create ~/.telescope/bookmarks.gmi or use `bookmark-page'.\n";
82 		imsg_compose(ibuf, IMSG_BUF, peerid, 0, -1, t, strlen(t));
83 		imsg_compose(ibuf, IMSG_EOF, peerid, 0, -1, NULL, 0);
84 		imsg_flush(ibuf);
85 		return;
86 	}
87 
88 	for (;;) {
89 		r = fread(buf, 1, sizeof(buf), f);
90 		imsg_compose(ibuf, IMSG_BUF, peerid, 0, -1, buf, r);
91 		imsg_flush(ibuf);
92 		if (r != sizeof(buf))
93 			break;
94 	}
95 
96 	imsg_compose(ibuf, IMSG_EOF, peerid, 0, -1, NULL, 0);
97 	imsg_flush(ibuf);
98 
99 	fclose(f);
100 }
101 
102 static void
103 handle_get(struct imsg *imsg, size_t datalen)
104 {
105 	char		*data;
106 	const char	*p;
107 
108 	data = imsg->data;
109 
110 	if (data[datalen-1] != '\0')
111 		die();
112 
113 	if (!strcmp(data, "about:new")) {
114 		imsg_compose(ibuf, IMSG_BUF, imsg->hdr.peerid, 0, -1,
115 		    about_new, strlen(about_new));
116 		imsg_compose(ibuf, IMSG_EOF, imsg->hdr.peerid, 0, -1, NULL, 0);
117 		imsg_flush(ibuf);
118 	} else if (!strcmp(data, "about:bookmarks")) {
119 		serve_bookmarks(imsg->hdr.peerid);
120 	} else {
121 		p = "# not found!\n";
122 		imsg_compose(ibuf, IMSG_BUF, imsg->hdr.peerid, 0, -1, p, strlen(p));
123 		imsg_compose(ibuf, IMSG_EOF, imsg->hdr.peerid, 0, -1, NULL, 0);
124 		imsg_flush(ibuf);
125 	}
126 }
127 
128 static void
129 handle_quit(struct imsg *imsg, size_t datalen)
130 {
131 	event_loopbreak();
132 }
133 
134 static void
135 handle_bookmark_page(struct imsg *imsg, size_t datalen)
136 {
137 	char	*data;
138 	int	 res;
139 	FILE	*f;
140 
141 	data = imsg->data;
142 	if (data[datalen-1] != '\0')
143 		die();
144 
145 	if ((f = fopen(bookmark_file, "a")) == NULL) {
146 		res = errno;
147 		goto end;
148 	}
149 	fprintf(f, "=> %s\n", data);
150 	fclose(f);
151 
152 	res = 0;
153 end:
154 	imsg_compose(ibuf, IMSG_BOOKMARK_OK, 0, 0, -1, &res, sizeof(res));
155 	imsg_flush(ibuf);
156 }
157 
158 static void
159 handle_save_cert(struct imsg *imsg, size_t datalen)
160 {
161 	struct tofu_entry	 e;
162 	FILE			*f;
163 	int			 res;
164 
165 	/* TODO: traverse the file to avoid duplications? */
166 
167 	if (datalen != sizeof(e))
168 		die();
169 	memcpy(&e, imsg->data, datalen);
170 
171 	if ((f = fopen(known_hosts_file, "a")) == NULL) {
172 		res = errno;
173 		goto end;
174 	}
175 	fprintf(f, "%s %s %d\n", e.domain, e.hash, e.verified);
176 	fclose(f);
177 
178 	res = 0;
179 end:
180 	imsg_compose(ibuf, IMSG_SAVE_CERT_OK, imsg->hdr.peerid, 0, -1,
181 	    &res, sizeof(res));
182 	imsg_flush(ibuf);
183 }
184 
185 static void
186 handle_session_start(struct imsg *imsg, size_t datalen)
187 {
188 	if (datalen != 0)
189 		die();
190 
191 	if ((session = fopen(session_file, "w")) == NULL)
192 		die();
193 }
194 
195 static void
196 handle_session_tab(struct imsg *imsg, size_t datalen)
197 {
198 	if (session == NULL)
199 		die();
200 
201 	if (datalen == 0)
202 		die();
203 
204 	/* skip the NUL-terminator */
205         fwrite(imsg->data, 1, datalen-1, session);
206 
207 	fprintf(session, "\n");
208 }
209 
210 static void
211 handle_session_end(struct imsg *imsg, size_t datalen)
212 {
213 	if (session == NULL)
214 		die();
215 	fclose(session);
216 	session = NULL;
217 }
218 
219 static void
220 handle_dispatch_imsg(int fd, short ev, void *d)
221 {
222 	struct imsgbuf	*ibuf = d;
223 	dispatch_imsg(ibuf, handlers, sizeof(handlers));
224 }
225 
226 int
227 fs_init(void)
228 {
229 	char	dir[PATH_MAX];
230 
231 	strlcpy(dir, getenv("HOME"), sizeof(dir));
232 	strlcat(dir, "/.telescope", sizeof(dir));
233 	mkdir(dir, 0700);
234 
235 	strlcpy(bookmark_file, getenv("HOME"), sizeof(bookmark_file));
236 	strlcat(bookmark_file, "/.telescope/bookmarks.gmi", sizeof(bookmark_file));
237 
238 	strlcpy(known_hosts_file, getenv("HOME"), sizeof(known_hosts_file));
239 	strlcat(known_hosts_file, "/.telescope/known_hosts", sizeof(known_hosts_file));
240 
241 	strlcpy(session_file, getenv("HOME"), sizeof(session_file));
242 	strlcat(session_file, "/.telescope/session", sizeof(session_file));
243 
244 	return 1;
245 }
246 
247 int
248 fs_main(struct imsgbuf *b)
249 {
250 	ibuf = b;
251 
252 	event_init();
253 
254 	event_set(&imsgev, ibuf->fd, EV_READ | EV_PERSIST, handle_dispatch_imsg, ibuf);
255 	event_add(&imsgev, NULL);
256 
257 	sandbox_fs_process();
258 
259 	event_dispatch();
260 	return 0;
261 }
262 
263 
264 
265 int
266 load_certs(struct ohash *h)
267 {
268 	char		*p, *last, *el, *line = NULL;
269 	const char	*errstr;
270 	int		 i;
271 	size_t		 linesize = 0;
272 	ssize_t		 linelen;
273 	FILE		*f;
274 	struct tofu_entry *e;
275 
276 	if ((f = fopen(known_hosts_file, "r")) == NULL)
277 		return 0;
278 
279 	while ((linelen = getline(&line, &linesize, f)) != -1) {
280 		if ((e = calloc(1, sizeof(*e))) == NULL)
281 			abort();
282 
283 		i = 0;
284                 for ((p = strtok_r(line, " ", &last)); p;
285 		    (p = strtok_r(NULL, " ", &last))) {
286 			if (*p == '\n') {
287 				free(e);
288 				break;
289 			}
290 
291 			switch (i) {
292 			case 0:
293 				strlcpy(e->domain, p, sizeof(e->domain));
294 				break;
295 			case 1:
296 				strlcpy(e->hash, p, sizeof(e->hash));
297 				break;
298 			case 2:
299 				if ((el = strchr(p, '\n')) == NULL)
300 					abort();
301 				*el = '\0';
302 
303 				/* 0 <= verified <= 1 */
304 				e->verified = strtonum(p, -1, 2, &errstr);
305 				if (errstr != NULL)
306 					errx(1, "verification for %s is %s: %s",
307 					    e->domain, errstr, p);
308 				break;
309 			default:
310 				abort();
311 			}
312 			i++;
313 		}
314 
315 		if (i != 0 && i != 3)
316 			abort();
317 
318 		if (i != 0)
319 			telescope_ohash_insert(h, e);
320 	}
321 
322 	free(line);
323 	return ferror(f);
324 }
325 
326 int
327 load_last_session(void (*cb)(const char*))
328 {
329 	char	*nl, *line = NULL;
330 	int	 e;
331 	size_t	 linesize = 0;
332 	ssize_t	 linelen;
333 	FILE	*session;
334 
335 	if ((session = fopen(session_file, "r")) == NULL)
336 		return 0;
337 
338 	while ((linelen = getline(&line, &linesize, session)) != -1) {
339                 if ((nl = strchr(line, '\n')) != NULL)
340 			*nl = '\0';
341 		cb(line);
342 	}
343 
344 	free(line);
345 	e = ferror(session);
346 	fclose(session);
347 
348 	return !e;
349 }