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 <errno.h>
26 #include <limits.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <unistd.h>
31 
32 static void		 die(void) __attribute__((__noreturn__));
33 static void		 serve_bookmarks(uint32_t);
34 static void		 handle_get(struct imsg*, size_t);
35 static void		 handle_quit(struct imsg*, size_t);
36 static void		 handle_bookmark_page(struct imsg*, size_t);
37 static void		 handle_save_cert(struct imsg*, size_t);
38 static void		 handle_dispatch_imsg(int, short, void*);
39 
40 static struct event		 imsgev;
41 static struct imsgbuf		*ibuf;
42 
43 static char	bookmark_file[PATH_MAX];
44 static char	known_hosts_file[PATH_MAX];
45 
46 static imsg_handlerfn *handlers[] = {
47 	[IMSG_GET] = handle_get,
48 	[IMSG_QUIT] = handle_quit,
49 	[IMSG_BOOKMARK_PAGE] = handle_bookmark_page,
50 	[IMSG_SAVE_CERT] = handle_save_cert,
51 };
52 
53 static void __attribute__((__noreturn__))
54 die(void)
55 {
56 	abort(); 		/* TODO */
57 }
58 
59 static void
60 serve_bookmarks(uint32_t peerid)
61 {
62 	const char	*t;
63 	char		 buf[BUFSIZ];
64 	size_t		 r;
65 	FILE		*f;
66 
67 	if ((f = fopen(bookmark_file, "r")) == NULL) {
68 		t = "# error\n\nCan't open bookmarks\n";
69 		imsg_compose(ibuf, IMSG_BUF, peerid, 0, -1, t, strlen(t));
70 		imsg_compose(ibuf, IMSG_EOF, peerid, 0, -1, NULL, 0);
71 		imsg_flush(ibuf);
72 		return;
73 	}
74 
75 	for (;;) {
76 		r = fread(buf, 1, sizeof(buf), f);
77 		imsg_compose(ibuf, IMSG_BUF, peerid, 0, -1, buf, r);
78 		imsg_flush(ibuf);
79 		if (r != sizeof(buf))
80 			break;
81 	}
82 
83 	imsg_compose(ibuf, IMSG_EOF, peerid, 0, -1, NULL, 0);
84 	imsg_flush(ibuf);
85 
86 	fclose(f);
87 }
88 
89 static void
90 handle_get(struct imsg *imsg, size_t datalen)
91 {
92 	char		*data;
93 	const char	*p;
94 
95 	data = imsg->data;
96 
97 	if (data[datalen-1] != '\0')
98 		die();
99 
100 	if (!strcmp(data, "about:new")) {
101 		imsg_compose(ibuf, IMSG_BUF, imsg->hdr.peerid, 0, -1,
102 		    about_new, strlen(about_new));
103 		imsg_compose(ibuf, IMSG_EOF, imsg->hdr.peerid, 0, -1, NULL, 0);
104 		imsg_flush(ibuf);
105 	} else if (!strcmp(data, "about:bookmarks")) {
106 		serve_bookmarks(imsg->hdr.peerid);
107 	} else {
108 		p = "# not found!\n";
109 		imsg_compose(ibuf, IMSG_BUF, imsg->hdr.peerid, 0, -1, p, strlen(p));
110 		imsg_compose(ibuf, IMSG_EOF, imsg->hdr.peerid, 0, -1, NULL, 0);
111 		imsg_flush(ibuf);
112 	}
113 }
114 
115 static void
116 handle_quit(struct imsg *imsg, size_t datalen)
117 {
118 	event_loopbreak();
119 }
120 
121 static void
122 handle_bookmark_page(struct imsg *imsg, size_t datalen)
123 {
124 	char	*data;
125 	int	 res;
126 	FILE	*f;
127 
128 	data = imsg->data;
129 	if (data[datalen-1] != '\0')
130 		die();
131 
132 	if ((f = fopen(bookmark_file, "a")) == NULL) {
133 		res = errno;
134 		goto end;
135 	}
136 	fprintf(f, "=> %s\n", data);
137 	fclose(f);
138 
139 	res = 0;
140 end:
141 	imsg_compose(ibuf, IMSG_BOOKMARK_OK, 0, 0, -1, &res, sizeof(res));
142 	imsg_flush(ibuf);
143 }
144 
145 static void
146 handle_save_cert(struct imsg *imsg, size_t datalen)
147 {
148 	struct tofu_entry	 e;
149 	FILE			*f;
150 	int			 res;
151 
152 	/* TODO: traverse the file to avoid duplications? */
153 
154 	if (datalen != sizeof(e))
155 		die();
156 	memcpy(&e, imsg->data, datalen);
157 
158 	if ((f = fopen(known_hosts_file, "a")) == NULL) {
159 		res = errno;
160 		goto end;
161 	}
162 	fprintf(f, "%s %s %d\n", e.domain, e.hash, e.verified);
163 	fclose(f);
164 
165 	res = 0;
166 end:
167 	imsg_compose(ibuf, IMSG_SAVE_CERT_OK, imsg->hdr.peerid, 0, -1,
168 	    &res, sizeof(res));
169 	imsg_flush(ibuf);
170 }
171 
172 static void
173 handle_dispatch_imsg(int fd, short ev, void *d)
174 {
175 	struct imsgbuf	*ibuf = d;
176 	dispatch_imsg(ibuf, handlers, sizeof(handlers));
177 }
178 
179 int
180 fs_init(void)
181 {
182 	/* TODO: mkdir(~/.telescope) and touch bookmarks.gmi/known_hosts? */
183 
184 	strlcpy(bookmark_file, getenv("HOME"), sizeof(bookmark_file));
185 	strlcat(bookmark_file, "/.telescope/bookmarks.gmi", sizeof(bookmark_file));
186 
187 	strlcpy(known_hosts_file, getenv("HOME"), sizeof(known_hosts_file));
188 	strlcat(known_hosts_file, "/.telescope/known_hosts", sizeof(known_hosts_file));
189 
190 	return 1;
191 }
192 
193 int
194 fs_main(struct imsgbuf *b)
195 {
196 	ibuf = b;
197 
198 	event_init();
199 
200 	event_set(&imsgev, ibuf->fd, EV_READ | EV_PERSIST, handle_dispatch_imsg, ibuf);
201 	event_add(&imsgev, NULL);
202 
203 	sandbox_fs_process();
204 
205 	event_dispatch();
206 	return 0;
207 }
208 
209 
210 
211 int
212 load_certs(struct ohash *h)
213 {
214 	char		*p, *last, *errstr, *el, *line = NULL;
215 	int		 i;
216 	size_t		 linesize = 0;
217 	ssize_t		 linelen;
218 	FILE		*f;
219 	struct tofu_entry *e;
220 
221 	if ((f = fopen(known_hosts_file, "r")) == NULL)
222 		return 0;
223 
224 	while ((linelen = getline(&line, &linesize, f)) != -1) {
225 		if ((e = calloc(1, sizeof(*e))) == NULL)
226 			abort();
227 
228 		i = 0;
229                 for ((p = strtok_r(line, " ", &last)); p;
230 		    (p = strtok_r(NULL, " ", &last))) {
231 			if (*p == '\n') {
232 				free(e);
233 				break;
234 			}
235 
236 			switch (i) {
237 			case 0:
238 				strlcpy(e->domain, p, sizeof(e->domain));
239 				break;
240 			case 1:
241 				strlcpy(e->hash, p, sizeof(e->hash));
242 				break;
243 			case 2:
244 				if ((el = strchr(p, '\n')) == NULL)
245 					abort();
246 				*el = '\0';
247 
248 				/* 0 <= verified <= 1 */
249 				e->verified = strtonum(p, -1, 2, &errstr);
250 				if (errstr != NULL)
251 					errx(1, "verification for %s is %s: %s",
252 					    e->domain, errstr, p);
253 				break;
254 			default:
255 				abort();
256 			}
257 			i++;
258 		}
259 
260 		if (i != 0 && i != 3)
261 			abort();
262 
263 		if (i != 0)
264 			telescope_ohash_insert(h, e);
265 	}
266 
267 	free(line);
268 	return ferror(f);
269 }