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