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_dispatch_imsg(int, short, void*);
41 
42 static struct event		 imsgev;
43 static struct imsgbuf		*ibuf;
44 
45 static char	bookmark_file[PATH_MAX];
46 static char	known_hosts_file[PATH_MAX];
47 
48 static imsg_handlerfn *handlers[] = {
49 	[IMSG_GET] = handle_get,
50 	[IMSG_QUIT] = handle_quit,
51 	[IMSG_BOOKMARK_PAGE] = handle_bookmark_page,
52 	[IMSG_SAVE_CERT] = handle_save_cert,
53 };
54 
55 static void __attribute__((__noreturn__))
56 die(void)
57 {
58 	abort(); 		/* TODO */
59 }
60 
61 static void
62 serve_bookmarks(uint32_t peerid)
63 {
64 	const char	*t;
65 	char		 buf[BUFSIZ];
66 	size_t		 r;
67 	FILE		*f;
68 
69 	if ((f = fopen(bookmark_file, "r")) == NULL) {
70 		t = "# error\n\nCan't open bookmarks\n";
71 		imsg_compose(ibuf, IMSG_BUF, peerid, 0, -1, t, strlen(t));
72 		imsg_compose(ibuf, IMSG_EOF, peerid, 0, -1, NULL, 0);
73 		imsg_flush(ibuf);
74 		return;
75 	}
76 
77 	for (;;) {
78 		r = fread(buf, 1, sizeof(buf), f);
79 		imsg_compose(ibuf, IMSG_BUF, peerid, 0, -1, buf, r);
80 		imsg_flush(ibuf);
81 		if (r != sizeof(buf))
82 			break;
83 	}
84 
85 	imsg_compose(ibuf, IMSG_EOF, peerid, 0, -1, NULL, 0);
86 	imsg_flush(ibuf);
87 
88 	fclose(f);
89 }
90 
91 static void
92 handle_get(struct imsg *imsg, size_t datalen)
93 {
94 	char		*data;
95 	const char	*p;
96 
97 	data = imsg->data;
98 
99 	if (data[datalen-1] != '\0')
100 		die();
101 
102 	if (!strcmp(data, "about:new")) {
103 		imsg_compose(ibuf, IMSG_BUF, imsg->hdr.peerid, 0, -1,
104 		    about_new, strlen(about_new));
105 		imsg_compose(ibuf, IMSG_EOF, imsg->hdr.peerid, 0, -1, NULL, 0);
106 		imsg_flush(ibuf);
107 	} else if (!strcmp(data, "about:bookmarks")) {
108 		serve_bookmarks(imsg->hdr.peerid);
109 	} else {
110 		p = "# not found!\n";
111 		imsg_compose(ibuf, IMSG_BUF, imsg->hdr.peerid, 0, -1, p, strlen(p));
112 		imsg_compose(ibuf, IMSG_EOF, imsg->hdr.peerid, 0, -1, NULL, 0);
113 		imsg_flush(ibuf);
114 	}
115 }
116 
117 static void
118 handle_quit(struct imsg *imsg, size_t datalen)
119 {
120 	event_loopbreak();
121 }
122 
123 static void
124 handle_bookmark_page(struct imsg *imsg, size_t datalen)
125 {
126 	char	*data;
127 	int	 res;
128 	FILE	*f;
129 
130 	data = imsg->data;
131 	if (data[datalen-1] != '\0')
132 		die();
133 
134 	if ((f = fopen(bookmark_file, "a")) == NULL) {
135 		res = errno;
136 		goto end;
137 	}
138 	fprintf(f, "=> %s\n", data);
139 	fclose(f);
140 
141 	res = 0;
142 end:
143 	imsg_compose(ibuf, IMSG_BOOKMARK_OK, 0, 0, -1, &res, sizeof(res));
144 	imsg_flush(ibuf);
145 }
146 
147 static void
148 handle_save_cert(struct imsg *imsg, size_t datalen)
149 {
150 	struct tofu_entry	 e;
151 	FILE			*f;
152 	int			 res;
153 
154 	/* TODO: traverse the file to avoid duplications? */
155 
156 	if (datalen != sizeof(e))
157 		die();
158 	memcpy(&e, imsg->data, datalen);
159 
160 	if ((f = fopen(known_hosts_file, "a")) == NULL) {
161 		res = errno;
162 		goto end;
163 	}
164 	fprintf(f, "%s %s %d\n", e.domain, e.hash, e.verified);
165 	fclose(f);
166 
167 	res = 0;
168 end:
169 	imsg_compose(ibuf, IMSG_SAVE_CERT_OK, imsg->hdr.peerid, 0, -1,
170 	    &res, sizeof(res));
171 	imsg_flush(ibuf);
172 }
173 
174 static void
175 handle_dispatch_imsg(int fd, short ev, void *d)
176 {
177 	struct imsgbuf	*ibuf = d;
178 	dispatch_imsg(ibuf, handlers, sizeof(handlers));
179 }
180 
181 int
182 fs_init(void)
183 {
184 	char	dir[PATH_MAX];
185 
186 	strlcpy(dir, getenv("HOME"), sizeof(dir));
187 	strlcat(dir, "/.telescope", sizeof(dir));
188 	mkdir(dir, 0700);
189 
190 	strlcpy(bookmark_file, getenv("HOME"), sizeof(bookmark_file));
191 	strlcat(bookmark_file, "/.telescope/bookmarks.gmi", sizeof(bookmark_file));
192 
193 	strlcpy(known_hosts_file, getenv("HOME"), sizeof(known_hosts_file));
194 	strlcat(known_hosts_file, "/.telescope/known_hosts", sizeof(known_hosts_file));
195 
196 	return 1;
197 }
198 
199 int
200 fs_main(struct imsgbuf *b)
201 {
202 	ibuf = b;
203 
204 	event_init();
205 
206 	event_set(&imsgev, ibuf->fd, EV_READ | EV_PERSIST, handle_dispatch_imsg, ibuf);
207 	event_add(&imsgev, NULL);
208 
209 	sandbox_fs_process();
210 
211 	event_dispatch();
212 	return 0;
213 }
214 
215 
216 
217 int
218 load_certs(struct ohash *h)
219 {
220 	char		*p, *last, *el, *line = NULL;
221 	const char	*errstr;
222 	int		 i;
223 	size_t		 linesize = 0;
224 	ssize_t		 linelen;
225 	FILE		*f;
226 	struct tofu_entry *e;
227 
228 	if ((f = fopen(known_hosts_file, "r")) == NULL)
229 		return 0;
230 
231 	while ((linelen = getline(&line, &linesize, f)) != -1) {
232 		if ((e = calloc(1, sizeof(*e))) == NULL)
233 			abort();
234 
235 		i = 0;
236                 for ((p = strtok_r(line, " ", &last)); p;
237 		    (p = strtok_r(NULL, " ", &last))) {
238 			if (*p == '\n') {
239 				free(e);
240 				break;
241 			}
242 
243 			switch (i) {
244 			case 0:
245 				strlcpy(e->domain, p, sizeof(e->domain));
246 				break;
247 			case 1:
248 				strlcpy(e->hash, p, sizeof(e->hash));
249 				break;
250 			case 2:
251 				if ((el = strchr(p, '\n')) == NULL)
252 					abort();
253 				*el = '\0';
254 
255 				/* 0 <= verified <= 1 */
256 				e->verified = strtonum(p, -1, 2, &errstr);
257 				if (errstr != NULL)
258 					errx(1, "verification for %s is %s: %s",
259 					    e->domain, errstr, p);
260 				break;
261 			default:
262 				abort();
263 			}
264 			i++;
265 		}
266 
267 		if (i != 0 && i != 3)
268 			abort();
269 
270 		if (i != 0)
271 			telescope_ohash_insert(h, e);
272 	}
273 
274 	free(line);
275 	return ferror(f);
276 }