1 /*
2  * Copyright (c) 2020, 2021, 2022 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 #ifndef GMID_H
18 #define GMID_H
19 
20 #include "config.h"
21 
22 #include <sys/socket.h>
23 #include <sys/types.h>
24 
25 #include <arpa/inet.h>
26 #include <netinet/in.h>
27 
28 #include <dirent.h>
29 #include <limits.h>
30 #include <netdb.h>
31 #include <signal.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <time.h>
35 #include <tls.h>
36 #include <unistd.h>
37 
38 #include <openssl/x509.h>
39 
40 #if HAVE_EVENT2
41 # include <event2/event.h>
42 # include <event2/event_compat.h>
43 # include <event2/event_struct.h>
44 # include <event2/buffer.h>
45 # include <event2/buffer_compat.h>
46 # include <event2/bufferevent.h>
47 # include <event2/bufferevent_struct.h>
48 # include <event2/bufferevent_compat.h>
49 #else
50 # include <event.h>
51 #endif
52 
53 #define VERSION_STR(n)	n " " VERSION
54 #define GE_STRING	VERSION_STR("ge")
55 #define GG_STRING	VERSION_STR("gg")
56 #define GMID_STRING	VERSION_STR("gmid")
57 
58 #define GMID_VERSION	"gmid/" VERSION
59 
60 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
61 
62 #define SUCCESS		20
63 #define TEMP_REDIRECT	30
64 #define TEMP_FAILURE	40
65 #define CGI_ERROR	42
66 #define PROXY_ERROR	43
67 #define NOT_FOUND	51
68 #define PROXY_REFUSED	53
69 #define BAD_REQUEST	59
70 #define CLIENT_CERT_REQ	60
71 #define CERT_NOT_AUTH	61
72 
73 /* maximum hostname and label length, +1 for the NUL-terminator */
74 #define DOMAIN_NAME_LEN	(253+1)
75 #define LABEL_LEN	(63+1)
76 
77 #define MEDIATYPE_NAMEMAX	128	/* file name extension */
78 #define MEDIATYPE_TYPEMAX	128	/* length of type/subtype */
79 
80 #define FCGI_NAME_MAX		511
81 #define FCGI_VAL_MAX		511
82 
83 #define PROC_MAX_INSTANCES	16
84 
85 /* forward declaration */
86 struct privsep;
87 struct privsep_proc;
88 
89 struct iri {
90 	char		*schema;
91 	char		*host;
92 	char		*port;
93 	uint16_t	 port_no;
94 	char		*path;
95 	char		*query;
96 	char		*fragment;
97 };
98 
99 struct parser {
100 	char		*iri;
101 	struct iri	*parsed;
102 	const char	*err;
103 };
104 
105 TAILQ_HEAD(fcgihead, fcgi);
106 struct fcgi {
107 	int		 id;
108 	char		 path[PATH_MAX];
109 	char		 port[32];
110 	TAILQ_ENTRY(fcgi) fcgi;
111 };
112 
113 TAILQ_HEAD(proxyhead, proxy);
114 struct proxy {
115 	char		 match_proto[32];
116 	char		 match_host[HOST_NAME_MAX + 1];
117 	char		 match_port[32];
118 
119 	char		 host[HOST_NAME_MAX + 1];
120 	char		 port[32];
121 	char		 sni[HOST_NAME_MAX];
122 	int		 notls;
123 	uint32_t	 protocols;
124 	int		 noverifyname;
125 	char		*cert_path;
126 	uint8_t		*cert;
127 	size_t		 certlen;
128 	char		*key_path;
129 	uint8_t		*key;
130 	size_t		 keylen;
131 	char		*reqca_path;
132 	X509_STORE	*reqca;
133 
134 	TAILQ_ENTRY(proxy) proxies;
135 };
136 
137 TAILQ_HEAD(lochead, location);
138 struct location {
139 	char		 match[128];
140 	char		 lang[32];
141 	char		 default_mime[MEDIATYPE_TYPEMAX];
142 	char		 index[PATH_MAX];
143 	int		 auto_index; /* 0 auto, -1 off, 1 on */
144 	int		 block_code;
145 	char		 block_fmt[GEMINI_URL_LEN];
146 	int		 strip;
147 	char		*reqca_path;
148 	X509_STORE	*reqca;
149 	int		 disable_log;
150 	int		 fcgi;
151 
152 	char		 dir[PATH_MAX];
153 	int		 dirfd;
154 
155 	TAILQ_ENTRY(location) locations;
156 };
157 
158 TAILQ_HEAD(envhead, envlist);
159 struct envlist {
160 	char		 name[FCGI_NAME_MAX];
161 	char		 value[FCGI_VAL_MAX];
162 	TAILQ_ENTRY(envlist) envs;
163 };
164 
165 TAILQ_HEAD(aliashead, alist);
166 struct alist {
167 	char		alias[HOST_NAME_MAX + 1];
168 	TAILQ_ENTRY(alist) aliases;
169 };
170 
171 TAILQ_HEAD(vhosthead, vhost);
172 struct vhost {
173 	char		 domain[HOST_NAME_MAX + 1];
174 	char		*cert_path;
175 	char		*key_path;
176 	char		*ocsp_path;
177 
178 	uint8_t		*cert;
179 	size_t		 certlen;
180 
181 	uint8_t		*key;
182 	size_t		 keylen;
183 
184 	uint8_t		*ocsp;
185 	size_t		 ocsplen;
186 
187 	TAILQ_ENTRY(vhost) vhosts;
188 
189 	/*
190 	 * the first location rule is always '*' and holds the default
191 	 * settings for the vhost, then follows the "real" location
192 	 * rules as specified in the configuration.
193 	 */
194 	struct lochead	 locations;
195 
196 	struct envhead	 params;
197 	struct aliashead aliases;
198 	struct proxyhead proxies;
199 };
200 
201 struct etm {			/* extension to mime */
202 	char	 mime[MEDIATYPE_TYPEMAX];
203 	char	 ext[MEDIATYPE_NAMEMAX];
204 };
205 
206 struct mime {
207 	struct etm	*t;
208 	size_t		 len;
209 	size_t		 cap;
210 };
211 
212 struct conf {
213 	struct privsep	*ps;
214 	int		 port;
215 	int		 ipv6;
216 	uint32_t	 protos;
217 	struct mime	 mime;
218 	char		 chroot[PATH_MAX];
219 	char		 user[LOGIN_NAME_MAX];
220 	int		 prefork;
221 	int		 reload;
222 
223 	int		 sock4;
224 	struct event	 evsock4;
225 	int		 sock6;
226 	struct event	 evsock6;
227 
228 	struct fcgihead	 fcgi;
229 	struct vhosthead hosts;
230 };
231 
232 extern const char *config_path;
233 
234 extern int servpipes[PROC_MAX_INSTANCES];
235 extern int privsep_process;
236 
237 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
238 
239 enum {
240 	REQUEST_UNDECIDED,
241 	REQUEST_FILE,
242 	REQUEST_DIR,
243 	REQUEST_FCGI,
244 	REQUEST_PROXY,
245 	REQUEST_DONE,
246 };
247 
248 struct client {
249 	struct conf	*conf;
250 	uint32_t	 id;
251 	struct tls	*ctx;
252 	char		*req;
253 	size_t		 reqlen;
254 	struct iri	 iri;
255 	char		 domain[DOMAIN_NAME_LEN];
256 
257 	struct bufferevent *bev;
258 
259 	int		 type;
260 
261 	struct bufferevent *cgibev;
262 
263 	struct proxy	*proxy;
264 	struct bufferevent *proxybev;
265 	struct tls	*proxyctx;
266 	int		 proxyevset;
267 	struct event	 proxyev;
268 
269 	char		*header;
270 
271 	int		 code;
272 	const char	*meta;
273 	int		 fd, pfd;
274 	struct dirent	**dir;
275 	int		 dirlen, diroff;
276 
277 	/* big enough to store STATUS + SPACE + META + CRLF */
278 	char		 sbuf[1029];
279 	ssize_t		 len, off;
280 
281 	struct sockaddr_storage	 addr;
282 	struct vhost	*host;	/* host they're talking to */
283 	size_t		 loc;	/* location matched */
284 
285 	SPLAY_ENTRY(client) entry;
286 };
287 SPLAY_HEAD(client_tree_id, client);
288 extern struct client_tree_id clients;
289 
290 struct connreq {
291 	char	host[NI_MAXHOST];
292 	char	port[NI_MAXSERV];
293 	int	flag;
294 };
295 
296 enum {
297 	FILE_EXISTS,
298 	FILE_DIRECTORY,
299 	FILE_MISSING,
300 };
301 
302 enum imsg_type {
303 	IMSG_FCGI_REQ,
304 	IMSG_FCGI_FD,
305 	IMSG_CONN_REQ,
306 	IMSG_CONN_FD,
307 	IMSG_LOG,
308 	IMSG_LOG_REQUEST,
309 	IMSG_LOG_TYPE,
310 
311 	IMSG_RECONF_START,	/* 7 */
312 	IMSG_RECONF_MIME,
313 	IMSG_RECONF_PROTOS,
314 	IMSG_RECONF_PORT,
315 	IMSG_RECONF_SOCK4,
316 	IMSG_RECONF_SOCK6,
317 	IMSG_RECONF_FCGI,
318 	IMSG_RECONF_HOST,
319 	IMSG_RECONF_CERT,
320 	IMSG_RECONF_KEY,
321 	IMSG_RECONF_OCSP,
322 	IMSG_RECONF_LOC,
323 	IMSG_RECONF_ENV,
324 	IMSG_RECONF_ALIAS,
325 	IMSG_RECONF_PROXY,
326 	IMSG_RECONF_PROXY_CERT,
327 	IMSG_RECONF_PROXY_KEY,
328 	IMSG_RECONF_END,
329 	IMSG_RECONF_DONE,
330 
331 	IMSG_CTL_PROCFD,
332 };
333 
334 /* gmid.c */
335 char		*data_dir(void);
336 void		 load_local_cert(struct vhost*, const char*, const char*);
337 
338 /* gmid.c / ge.c */
339 void		 log_request(struct client *, char *, size_t);
340 
341 /* config.c */
342 struct conf	*config_new(void);
343 void		 config_purge(struct conf *);
344 int		 config_send(struct conf *);
345 int		 config_recv(struct conf *, struct imsg *);
346 
347 /* parse.y */
348 void		 yyerror(const char*, ...);
349 int		 parse_conf(struct conf *, const char*);
350 void		 print_conf(void);
351 int		 cmdline_symset(char *);
352 
353 /* mime.c */
354 void		 init_mime(struct mime*);
355 int		 add_mime(struct mime*, const char*, const char*);
356 int		 load_default_mime(struct mime*);
357 void		 sort_mime(struct mime *);
358 const char	*mime(struct conf *, struct vhost*, const char*);
359 void		 free_mime(struct mime *);
360 
361 /* server.c */
362 extern int	shutting_down;
363 const char	*vhost_lang(struct vhost*, const char*);
364 const char	*vhost_default_mime(struct vhost*, const char*);
365 const char	*vhost_index(struct vhost*, const char*);
366 int		 vhost_auto_index(struct vhost*, const char*);
367 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
368 int		 vhost_fastcgi(struct vhost*, const char*);
369 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
370 int		 vhost_strip(struct vhost*, const char*);
371 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
372 int		 vhost_disable_log(struct vhost*, const char*);
373 
374 void		 mark_nonblock(int);
375 void		 client_write(struct bufferevent *, void *);
376 void		 start_reply(struct client*, int, const char*);
377 void		 client_close(struct client *);
378 struct client	*client_by_id(int);
379 void		 do_accept(int, short, void *);
380 void		 server_init(struct privsep *, struct privsep_proc *, void *);
381 int		 server_configure_done(struct conf *);
382 void		 server(struct privsep *ps, struct privsep_proc *);
383 
384 int		 client_tree_cmp(struct client *, struct client *);
385 SPLAY_PROTOTYPE(client_tree_id, client, entry, client_tree_cmp);
386 
387 /* dirs.c */
388 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
389 		    int(*)(const struct dirent**, const struct dirent**));
390 int		 select_non_dot(const struct dirent*);
391 int		 select_non_dotdot(const struct dirent*);
392 
393 /* fcgi.c */
394 void		 fcgi_read(struct bufferevent *, void *);
395 void		 fcgi_write(struct bufferevent *, void *);
396 void		 fcgi_error(struct bufferevent *, short, void *);
397 void		 fcgi_req(struct client *);
398 
399 /* sandbox.c */
400 void		 sandbox_main_process(void);
401 void		 sandbox_server_process(void);
402 void		 sandbox_logger_process(void);
403 
404 /* utf8.c */
405 int		 valid_multibyte_utf8(struct parser*);
406 char		*utf8_nth(char*, size_t);
407 
408 /* iri.c */
409 int		 parse_iri(char*, struct iri*, const char**);
410 int		 serialize_iri(struct iri*, char*, size_t);
411 int		 encode_path(char *, size_t, const char *);
412 char		*pct_decode_str(char *);
413 
414 /* logger.c */
415 void		 logger(struct privsep *, struct privsep_proc *);
416 
417 /* proxy.c */
418 int		 proxy_init(struct client *);
419 
420 /* puny.c */
421 int		 puny_decode(const char*, char*, size_t, const char**);
422 
423 /* utils.c */
424 void		 block_signals(void);
425 void		 unblock_signals(void);
426 int		 starts_with(const char*, const char*);
427 int		 ends_with(const char*, const char*);
428 ssize_t		 filesize(int);
429 char		*absolutify_path(const char*);
430 char		*xstrdup(const char*);
431 void		*xcalloc(size_t, size_t);
432 void		 gen_certificate(const char*, const char*, const char*);
433 X509_STORE	*load_ca(int);
434 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
435 struct vhost	*new_vhost(void);
436 struct location	*new_location(void);
437 struct proxy	*new_proxy(void);
438 
439 #endif