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 GMID_STRING	"gmid " VERSION
54 #define GMID_VERSION	"gmid/" VERSION
55 
56 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
57 
58 #define SUCCESS		20
59 #define TEMP_REDIRECT	30
60 #define TEMP_FAILURE	40
61 #define CGI_ERROR	42
62 #define PROXY_ERROR	43
63 #define NOT_FOUND	51
64 #define PROXY_REFUSED	53
65 #define BAD_REQUEST	59
66 #define CLIENT_CERT_REQ	60
67 #define CERT_NOT_AUTH	61
68 
69 /* maximum hostname and label length, +1 for the NUL-terminator */
70 #define DOMAIN_NAME_LEN	(253+1)
71 #define LABEL_LEN	(63+1)
72 
73 #define FCGI_MAX	32
74 #define PROC_MAX	16
75 
76 struct iri {
77 	char		*schema;
78 	char		*host;
79 	char		*port;
80 	uint16_t	 port_no;
81 	char		*path;
82 	char		*query;
83 	char		*fragment;
84 };
85 
86 struct parser {
87 	char		*iri;
88 	struct iri	*parsed;
89 	const char	*err;
90 };
91 
92 struct fcgi {
93 	int		 id;
94 	char		*path;
95 	char		*port;
96 	char		*prog;
97 };
98 extern struct fcgi fcgi[FCGI_MAX];
99 
100 TAILQ_HEAD(proxyhead, proxy);
101 struct proxy {
102 	char		*match_proto;
103 	char		*match_host;
104 	const char	*match_port;
105 
106 	char		*host;
107 	const char	*port;
108 	int		 notls;
109 	uint32_t	 protocols;
110 	int		 noverifyname;
111 	uint8_t		*cert;
112 	size_t		 certlen;
113 	uint8_t		*key;
114 	size_t		 keylen;
115 	X509_STORE	*reqca;
116 
117 	TAILQ_ENTRY(proxy) proxies;
118 };
119 
120 TAILQ_HEAD(lochead, location);
121 struct location {
122 	const char	*match;
123 	const char	*lang;
124 	const char	*default_mime;
125 	const char	*index;
126 	int		 auto_index; /* 0 auto, -1 off, 1 on */
127 	int		 block_code;
128 	const char	*block_fmt;
129 	int		 strip;
130 	X509_STORE	*reqca;
131 	int		 disable_log;
132 	int		 fcgi;
133 
134 	const char	*dir;
135 	int		 dirfd;
136 
137 	TAILQ_ENTRY(location) locations;
138 };
139 
140 TAILQ_HEAD(envhead, envlist);
141 struct envlist {
142 	char		*name;
143 	char		*value;
144 	TAILQ_ENTRY(envlist) envs;
145 };
146 
147 TAILQ_HEAD(aliashead, alist);
148 struct alist {
149 	char		*alias;
150 	TAILQ_ENTRY(alist) aliases;
151 };
152 
153 extern TAILQ_HEAD(vhosthead, vhost) hosts;
154 struct vhost {
155 	const char	*domain;
156 	const char	*cert;
157 	const char	*key;
158 	const char	*ocsp;
159 	const char	*cgi;
160 	const char	*entrypoint;
161 
162 	TAILQ_ENTRY(vhost) vhosts;
163 
164 	/*
165 	 * the first location rule is always '*' and holds the default
166 	 * settings for the vhost, then follows the "real" location
167 	 * rules as specified in the configuration.
168 	 */
169 	struct lochead	 locations;
170 
171 	struct envhead	 env;
172 	struct envhead	 params;
173 	struct aliashead aliases;
174 	struct proxyhead proxies;
175 };
176 
177 struct etm {			/* extension to mime */
178 	const char	*mime;
179 	const char	*ext;
180 };
181 
182 struct mime {
183 	struct etm	*t;
184 	size_t		len;
185 	size_t		cap;
186 };
187 
188 struct conf {
189 	/* from command line */
190 	int		 foreground;
191 	int		 verbose;
192 
193 	/* in the config */
194 	int		 port;
195 	int		 ipv6;
196 	uint32_t	 protos;
197 	struct mime	 mime;
198 	char		*chroot;
199 	char		*user;
200 	int		 prefork;
201 };
202 
203 extern const char *config_path;
204 extern struct conf conf;
205 
206 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
207 
208 extern int servpipes[PROC_MAX];
209 
210 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
211 
212 enum {
213 	REQUEST_UNDECIDED,
214 	REQUEST_FILE,
215 	REQUEST_DIR,
216 	REQUEST_CGI,
217 	REQUEST_FCGI,
218 	REQUEST_PROXY,
219 	REQUEST_DONE,
220 };
221 
222 #define IS_INTERNAL_REQUEST(x) \
223 	((x) != REQUEST_CGI && \
224 	 (x) != REQUEST_FCGI && \
225 	 (x) != REQUEST_PROXY)
226 
227 struct client {
228 	uint32_t	 id;
229 	struct tls	*ctx;
230 	char		*req;
231 	struct iri	 iri;
232 	char		 domain[DOMAIN_NAME_LEN];
233 
234 	struct bufferevent *bev;
235 
236 	int		 type;
237 
238 	struct bufferevent *cgibev;
239 
240 	struct proxy	*proxy;
241 	struct bufferevent *proxybev;
242 	struct tls	*proxyctx;
243 	int		 proxyevset;
244 	struct event	 proxyev;
245 
246 	char		*header;
247 
248 	int		 code;
249 	const char	*meta;
250 	int		 fd, pfd;
251 	struct dirent	**dir;
252 	int		 dirlen, diroff;
253 
254 	/* big enough to store STATUS + SPACE + META + CRLF */
255 	char		 sbuf[1029];
256 	ssize_t		 len, off;
257 
258 	struct sockaddr_storage	 addr;
259 	struct vhost	*host;	/* host they're talking to */
260 	size_t		 loc;	/* location matched */
261 
262 	SPLAY_ENTRY(client) entry;
263 };
264 SPLAY_HEAD(client_tree_id, client);
265 extern struct client_tree_id clients;
266 
267 struct cgireq {
268 	char		buf[GEMINI_URL_LEN];
269 
270 	size_t		iri_schema_off;
271 	size_t		iri_host_off;
272 	size_t		iri_port_off;
273 	size_t		iri_path_off;
274 	size_t		iri_query_off;
275 	size_t		iri_fragment_off;
276 	int		iri_portno;
277 
278 	char		spath[PATH_MAX+1];
279 	char		relpath[PATH_MAX+1];
280 	char		addr[NI_MAXHOST+1];
281 
282 	/* AFAIK there isn't an upper limit for these two fields. */
283 	char		subject[64+1];
284 	char		issuer[64+1];
285 
286 	char		hash[128+1];
287 	char		version[8];
288 	char		cipher[32];
289 	int		cipher_strength;
290 	time_t		notbefore;
291 	time_t		notafter;
292 
293 	size_t		host_off;
294 	size_t		loc_off;
295 };
296 
297 struct connreq {
298 	char	host[NI_MAXHOST];
299 	char	port[NI_MAXSERV];
300 	int	flag;
301 };
302 
303 enum {
304 	FILE_EXISTS,
305 	FILE_EXECUTABLE,
306 	FILE_DIRECTORY,
307 	FILE_MISSING,
308 };
309 
310 enum imsg_type {
311 	IMSG_CGI_REQ,
312 	IMSG_CGI_RES,
313 	IMSG_FCGI_REQ,
314 	IMSG_FCGI_FD,
315 	IMSG_CONN_REQ,
316 	IMSG_CONN_FD,
317 	IMSG_LOG,
318 	IMSG_LOG_REQUEST,
319 	IMSG_LOG_TYPE,
320 	IMSG_QUIT,
321 };
322 
323 /* gmid.c */
324 char		*data_dir(void);
325 void		 load_local_cert(const char*, const char*);
326 void		 load_vhosts(void);
327 int		 make_socket(int, int);
328 void		 setup_tls(void);
329 void		 init_config(void);
330 void		 free_config(void);
331 void		 drop_priv(void);
332 
333 void		 yyerror(const char*, ...);
334 void		 parse_conf(const char*);
335 void		 print_conf(void);
336 int		 cmdline_symset(char *);
337 
338 /* log.c */
339 void		 fatal(const char*, ...)
340 	__attribute__((format (printf, 1, 2)))
341 	__attribute__((__noreturn__));
342 
343 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
344 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
345 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
346 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
347 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
348 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
349 void		 log_request(struct client*, char*, size_t);
350 int		 logger_main(int, struct imsgbuf*);
351 
352 /* mime.c */
353 void		 init_mime(struct mime*);
354 void		 add_mime(struct mime*, const char*, const char*);
355 void		 load_default_mime(struct mime*);
356 const char	*mime(struct vhost*, const char*);
357 
358 /* server.c */
359 extern int	shutting_down;
360 const char	*vhost_lang(struct vhost*, const char*);
361 const char	*vhost_default_mime(struct vhost*, const char*);
362 const char	*vhost_index(struct vhost*, const char*);
363 int		 vhost_auto_index(struct vhost*, const char*);
364 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
365 int		 vhost_fastcgi(struct vhost*, const char*);
366 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
367 int		 vhost_strip(struct vhost*, const char*);
368 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
369 int		 vhost_disable_log(struct vhost*, const char*);
370 
371 void		 mark_nonblock(int);
372 void		 client_write(struct bufferevent *, void *);
373 void		 start_reply(struct client*, int, const char*);
374 void		 client_close(struct client *);
375 struct client	*try_client_by_id(int);
376 void		 loop(struct tls*, int, int, struct imsgbuf*);
377 
378 int		 client_tree_cmp(struct client *, struct client *);
379 SPLAY_PROTOTYPE(client_tree_id, client, entry, client_tree_cmp);
380 
381 /* dirs.c */
382 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
383 		    int(*)(const struct dirent**, const struct dirent**));
384 int		 select_non_dot(const struct dirent*);
385 int		 select_non_dotdot(const struct dirent*);
386 
387 /* ex.c */
388 int		 send_string(int, const char*);
389 int		 recv_string(int, char**);
390 int		 send_iri(int, struct iri*);
391 int		 recv_iri(int, struct iri*);
392 void		 free_recvd_iri(struct iri*);
393 int		 send_vhost(int, struct vhost*);
394 int		 recv_vhost(int, struct vhost**);
395 int		 send_time(int, time_t);
396 int		 recv_time(int, time_t*);
397 int		 send_fd(int, int);
398 int		 recv_fd(int);
399 int		 executor_main(struct imsgbuf*);
400 
401 /* fcgi.c */
402 void		 fcgi_read(struct bufferevent *, void *);
403 void		 fcgi_write(struct bufferevent *, void *);
404 void		 fcgi_error(struct bufferevent *, short, void *);
405 void		 fcgi_req(struct client *);
406 
407 /* sandbox.c */
408 void		 sandbox_server_process(void);
409 void		 sandbox_executor_process(void);
410 void		 sandbox_logger_process(void);
411 
412 /* utf8.c */
413 int		 valid_multibyte_utf8(struct parser*);
414 char		*utf8_nth(char*, size_t);
415 
416 /* iri.c */
417 int		 parse_iri(char*, struct iri*, const char**);
418 int		 serialize_iri(struct iri*, char*, size_t);
419 char		*pct_decode_str(char *);
420 
421 /* proxy.c */
422 int		 proxy_init(struct client *);
423 
424 /* puny.c */
425 int		 puny_decode(const char*, char*, size_t, const char**);
426 
427 /* utils.c */
428 void		 block_signals(void);
429 void		 unblock_signals(void);
430 int		 starts_with(const char*, const char*);
431 int		 ends_with(const char*, const char*);
432 ssize_t		 filesize(int);
433 char		*absolutify_path(const char*);
434 char		*xstrdup(const char*);
435 void		*xcalloc(size_t, size_t);
436 void		 gen_certificate(const char*, const char*, const char*);
437 X509_STORE	*load_ca(const char*);
438 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
439 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
440 
441 #endif