1 /*
2  * Copyright (c) 2020, 2021, 2022, 2023 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 #define TLS_CERT_HASH_SIZE	128
86 
87 /* forward declaration */
88 struct privsep;
89 struct privsep_proc;
90 
91 struct iri {
92 	char		*schema;
93 	char		*host;
94 	char		*port;
95 	uint16_t	 port_no;
96 	char		*path;
97 	char		*query;
98 	char		*fragment;
99 };
100 
101 struct parser {
102 	char		*iri;
103 	struct iri	*parsed;
104 	const char	*err;
105 };
106 
107 struct conf;
108 TAILQ_HEAD(addrhead, address);
109 struct address {
110 	int			 ai_flags;
111 	int			 ai_family;
112 	int			 ai_socktype;
113 	int			 ai_protocol;
114 	struct sockaddr_storage	 ss;
115 	socklen_t		 slen;
116 	int16_t			 port;
117 
118 	/* used in the server */
119 	struct conf		*conf;
120 	int			 sock;
121 	struct event		 evsock; /* set if sock != -1 */
122 	struct tls		*ctx;
123 
124 	TAILQ_ENTRY(address)	 addrs;
125 };
126 
127 TAILQ_HEAD(fcgihead, fcgi);
128 struct fcgi {
129 	int		 id;
130 	char		 path[PATH_MAX];
131 	char		 port[32];
132 	TAILQ_ENTRY(fcgi) fcgi;
133 };
134 
135 TAILQ_HEAD(proxyhead, proxy);
136 struct proxy {
137 	char		 match_proto[32];
138 	char		 match_host[HOST_NAME_MAX + 1];
139 	char		 match_port[32];
140 
141 	char		 host[HOST_NAME_MAX + 1];
142 	char		 port[32];
143 	char		 sni[HOST_NAME_MAX];
144 	int		 notls;
145 	uint32_t	 protocols;
146 	int		 noverifyname;
147 	char		*cert_path;
148 	uint8_t		*cert;
149 	size_t		 certlen;
150 	char		*key_path;
151 	uint8_t		*key;
152 	size_t		 keylen;
153 	char		*reqca_path;
154 	X509_STORE	*reqca;
155 
156 	TAILQ_ENTRY(proxy) proxies;
157 };
158 
159 TAILQ_HEAD(lochead, location);
160 struct location {
161 	char		 match[128];
162 	char		 lang[32];
163 	char		 default_mime[MEDIATYPE_TYPEMAX];
164 	char		 index[PATH_MAX];
165 	int		 auto_index; /* 0 auto, -1 off, 1 on */
166 	int		 block_code;
167 	char		 block_fmt[GEMINI_URL_LEN];
168 	int		 strip;
169 	char		*reqca_path;
170 	X509_STORE	*reqca;
171 	int		 disable_log;
172 	int		 fcgi;
173 
174 	char		 dir[PATH_MAX];
175 	int		 dirfd;
176 
177 	TAILQ_ENTRY(location) locations;
178 };
179 
180 TAILQ_HEAD(envhead, envlist);
181 struct envlist {
182 	char		 name[FCGI_NAME_MAX];
183 	char		 value[FCGI_VAL_MAX];
184 	TAILQ_ENTRY(envlist) envs;
185 };
186 
187 TAILQ_HEAD(aliashead, alist);
188 struct alist {
189 	char		alias[HOST_NAME_MAX + 1];
190 	TAILQ_ENTRY(alist) aliases;
191 };
192 
193 TAILQ_HEAD(vhosthead, vhost);
194 struct vhost {
195 	char		 domain[HOST_NAME_MAX + 1];
196 	char		*cert_path;
197 	char		*key_path;
198 	char		*ocsp_path;
199 
200 	uint8_t		*cert;
201 	size_t		 certlen;
202 
203 	uint8_t		*key;
204 	size_t		 keylen;
205 
206 	uint8_t		*ocsp;
207 	size_t		 ocsplen;
208 
209 	TAILQ_ENTRY(vhost) vhosts;
210 
211 	struct addrhead	 addrs;
212 
213 	/*
214 	 * the first location rule is always '*' and holds the default
215 	 * settings for the vhost, then follows the "real" location
216 	 * rules as specified in the configuration.
217 	 */
218 	struct lochead	 locations;
219 
220 	struct envhead	 params;
221 	struct aliashead aliases;
222 	struct proxyhead proxies;
223 };
224 
225 struct etm {			/* extension to mime */
226 	char	 mime[MEDIATYPE_TYPEMAX];
227 	char	 ext[MEDIATYPE_NAMEMAX];
228 };
229 
230 struct mime {
231 	struct etm	*t;
232 	size_t		 len;
233 	size_t		 cap;
234 };
235 
236 TAILQ_HEAD(pkihead, pki);
237 struct pki {
238 	char		*hash;
239 	EVP_PKEY	*pkey;
240 	TAILQ_ENTRY(pki) pkis;
241 };
242 
243 struct conf {
244 	struct privsep	*ps;
245 	uint32_t	 protos;
246 	struct mime	 mime;
247 	char		 chroot[PATH_MAX];
248 	char		 user[LOGIN_NAME_MAX];
249 	int		 prefork;
250 	int		 reload;
251 	int		 use_privsep_crypto;
252 
253 	struct fcgihead	 fcgi;
254 	struct vhosthead hosts;
255 	struct pkihead	 pkis;
256 	struct addrhead	 addrs;
257 };
258 
259 extern const char *config_path;
260 
261 extern int servpipes[PROC_MAX_INSTANCES];
262 extern int privsep_process;
263 
264 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
265 
266 enum {
267 	REQUEST_UNDECIDED,
268 	REQUEST_FILE,
269 	REQUEST_DIR,
270 	REQUEST_FCGI,
271 	REQUEST_PROXY,
272 	REQUEST_DONE,
273 };
274 
275 struct client {
276 	struct conf	*conf;
277 	struct address	*addr;
278 	uint32_t	 id;
279 	struct tls	*ctx;
280 	char		*req;
281 	size_t		 reqlen;
282 	struct iri	 iri;
283 	char		 domain[DOMAIN_NAME_LEN];
284 
285 	struct bufferevent *bev;
286 
287 	int		 type;
288 
289 	struct bufferevent *cgibev;
290 
291 	struct proxy	*proxy;
292 	struct bufferevent *proxybev;
293 	struct tls	*proxyctx;
294 	int		 proxyevset;
295 	struct event	 proxyev;
296 
297 	char		*header;
298 
299 	int		 code;
300 	const char	*meta;
301 	int		 fd, pfd;
302 	struct dirent	**dir;
303 	int		 dirlen, diroff;
304 
305 	/* big enough to store STATUS + SPACE + META + CRLF */
306 	char		 sbuf[1029];
307 	ssize_t		 len, off;
308 
309 	struct sockaddr_storage	 raddr;
310 	socklen_t		 raddrlen;
311 
312 	struct vhost	*host;	/* host they're talking to */
313 	size_t		 loc;	/* location matched */
314 
315 	SPLAY_ENTRY(client) entry;
316 };
317 SPLAY_HEAD(client_tree_id, client);
318 extern struct client_tree_id clients;
319 
320 struct connreq {
321 	char	host[NI_MAXHOST];
322 	char	port[NI_MAXSERV];
323 	int	flag;
324 };
325 
326 enum {
327 	FILE_EXISTS,
328 	FILE_DIRECTORY,
329 	FILE_MISSING,
330 };
331 
332 enum imsg_type {
333 	IMSG_FCGI_REQ,
334 	IMSG_FCGI_FD,
335 	IMSG_CONN_REQ,
336 	IMSG_CONN_FD,
337 	IMSG_LOG,
338 	IMSG_LOG_REQUEST,
339 	IMSG_LOG_TYPE,
340 
341 	IMSG_RECONF_START,	/* 7 */
342 	IMSG_RECONF_MIME,
343 	IMSG_RECONF_PROTOS,
344 	IMSG_RECONF_SOCK,
345 	IMSG_RECONF_FCGI,
346 	IMSG_RECONF_HOST,
347 	IMSG_RECONF_CERT,
348 	IMSG_RECONF_KEY,
349 	IMSG_RECONF_OCSP,
350 	IMSG_RECONF_HOST_ADDR,
351 	IMSG_RECONF_LOC,
352 	IMSG_RECONF_ENV,
353 	IMSG_RECONF_ALIAS,
354 	IMSG_RECONF_PROXY,
355 	IMSG_RECONF_PROXY_CERT,
356 	IMSG_RECONF_PROXY_KEY,
357 	IMSG_RECONF_END,
358 	IMSG_RECONF_DONE,
359 
360 	IMSG_CRYPTO_RSA_PRIVENC,
361 	IMSG_CRYPTO_RSA_PRIVDEC,
362 	IMSG_CRYPTO_ECDSA_SIGN,
363 
364 	IMSG_CTL_PROCFD,
365 };
366 
367 /* gmid.c */
368 char		*data_dir(void);
369 void		 load_local_cert(struct vhost*, const char*, const char*);
370 
371 /* gmid.c / ge.c */
372 void		 log_request(struct client *, char *, size_t);
373 
374 /* config.c */
375 struct conf	*config_new(void);
376 void		 config_purge(struct conf *);
377 int		 config_send(struct conf *);
378 int		 config_recv(struct conf *, struct imsg *);
379 
380 /* crypto.c */
381 void		 crypto(struct privsep *, struct privsep_proc *);
382 void		 crypto_engine_init(struct conf *);
383 
384 /* parse.y */
385 void		 yyerror(const char*, ...);
386 int		 parse_conf(struct conf *, const char*);
387 int		 cmdline_symset(char *);
388 
389 /* mime.c */
390 void		 init_mime(struct mime*);
391 int		 add_mime(struct mime*, const char*, const char*);
392 int		 load_default_mime(struct mime*);
393 void		 sort_mime(struct mime *);
394 const char	*mime(struct conf *, struct vhost*, const char*);
395 void		 free_mime(struct mime *);
396 
397 /* server.c */
398 extern int	shutting_down;
399 const char	*vhost_lang(struct vhost*, const char*);
400 const char	*vhost_default_mime(struct vhost*, const char*);
401 const char	*vhost_index(struct vhost*, const char*);
402 int		 vhost_auto_index(struct vhost*, const char*);
403 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
404 int		 vhost_fastcgi(struct vhost*, const char*);
405 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
406 int		 vhost_strip(struct vhost*, const char*);
407 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
408 int		 vhost_disable_log(struct vhost*, const char*);
409 
410 void		 mark_nonblock(int);
411 void		 client_write(struct bufferevent *, void *);
412 void		 start_reply(struct client*, int, const char*);
413 void		 client_close(struct client *);
414 struct client	*client_by_id(int);
415 void		 do_accept(int, short, void *);
416 void		 server_init(struct privsep *, struct privsep_proc *, void *);
417 int		 server_configure_done(struct conf *);
418 void		 server(struct privsep *ps, struct privsep_proc *);
419 
420 int		 client_tree_cmp(struct client *, struct client *);
421 SPLAY_PROTOTYPE(client_tree_id, client, entry, client_tree_cmp);
422 
423 /* dirs.c */
424 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
425 		    int(*)(const struct dirent**, const struct dirent**));
426 int		 select_non_dot(const struct dirent*);
427 int		 select_non_dotdot(const struct dirent*);
428 
429 /* fcgi.c */
430 void		 fcgi_read(struct bufferevent *, void *);
431 void		 fcgi_write(struct bufferevent *, void *);
432 void		 fcgi_error(struct bufferevent *, short, void *);
433 void		 fcgi_req(struct client *);
434 
435 /* sandbox.c */
436 void		 sandbox_main_process(void);
437 void		 sandbox_server_process(void);
438 void		 sandbox_crypto_process(void);
439 void		 sandbox_logger_process(void);
440 
441 /* utf8.c */
442 int		 valid_multibyte_utf8(struct parser*);
443 char		*utf8_nth(char*, size_t);
444 
445 /* iri.c */
446 int		 parse_iri(char*, struct iri*, const char**);
447 int		 serialize_iri(struct iri*, char*, size_t);
448 int		 encode_path(char *, size_t, const char *);
449 char		*pct_decode_str(char *);
450 
451 /* logger.c */
452 void		 logger(struct privsep *, struct privsep_proc *);
453 
454 /* proxy.c */
455 int		 proxy_init(struct client *);
456 
457 /* puny.c */
458 int		 puny_decode(const char*, char*, size_t, const char**);
459 
460 /* utils.c */
461 void		 block_signals(void);
462 void		 unblock_signals(void);
463 int		 starts_with(const char*, const char*);
464 int		 ends_with(const char*, const char*);
465 ssize_t		 filesize(int);
466 char		*absolutify_path(const char*);
467 char		*xstrdup(const char*);
468 void		*xcalloc(size_t, size_t);
469 void		 gen_certificate(const char*, const char*, const char*);
470 X509_STORE	*load_ca(uint8_t *, size_t);
471 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
472 void		 ssl_error(const char *);
473 char		*ssl_pubkey_hash(const uint8_t *, size_t);
474 EVP_PKEY	*ssl_load_pkey(const uint8_t *, size_t);
475 struct vhost	*new_vhost(void);
476 struct location	*new_location(void);
477 struct proxy	*new_proxy(void);
478 
479 #endif