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 #include "iri.h"
54 
55 #define VERSION_STR(n)	n " " VERSION
56 #define GEMEXP_STRING	VERSION_STR("gemexp")
57 #define GG_STRING	VERSION_STR("gg")
58 #define GMID_STRING	VERSION_STR("gmid")
59 
60 #define GMID_VERSION	"gmid/" VERSION
61 
62 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
63 
64 #define SUCCESS		20
65 #define TEMP_REDIRECT	30
66 #define TEMP_FAILURE	40
67 #define CGI_ERROR	42
68 #define PROXY_ERROR	43
69 #define NOT_FOUND	51
70 #define PROXY_REFUSED	53
71 #define BAD_REQUEST	59
72 #define CLIENT_CERT_REQ	60
73 #define CERT_NOT_AUTH	61
74 
75 /* maximum hostname and label length, +1 for the NUL-terminator */
76 #define DOMAIN_NAME_LEN	(253+1)
77 #define LABEL_LEN	(63+1)
78 
79 #define MEDIATYPE_NAMEMAX	128	/* file name extension */
80 #define MEDIATYPE_TYPEMAX	128	/* length of type/subtype */
81 
82 #define FCGI_NAME_MAX		511
83 #define FCGI_VAL_MAX		511
84 
85 #define PROC_MAX_INSTANCES	16
86 
87 #define TLS_CERT_HASH_SIZE	128
88 
89 /* forward declaration */
90 struct privsep;
91 struct privsep_proc;
92 
93 enum log_format {
94 	LOG_FORMAT_CONDENSED,
95 	LOG_FORMAT_COMMON,
96 	LOG_FORMAT_COMBINED,
97 	LOG_FORMAT_LEGACY,
98 };
99 
100 struct parser {
101 	char		*iri;
102 	struct iri	*parsed;
103 	const char	*err;
104 };
105 
106 struct conf;
107 TAILQ_HEAD(addrhead, address);
108 struct address {
109 	int			 ai_flags;
110 	int			 ai_family;
111 	int			 ai_socktype;
112 	int			 ai_protocol;
113 	struct sockaddr_storage	 ss;
114 	socklen_t		 slen;
115 	int16_t			 port;
116 
117 	/* used in the server */
118 	struct conf		*conf;
119 	int			 sock;
120 	struct event		 evsock; /* set if sock != -1 */
121 	struct tls		*ctx;
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(envhead, envlist);
135 struct envlist {
136 	char		 name[FCGI_NAME_MAX];
137 	char		 value[FCGI_VAL_MAX];
138 	TAILQ_ENTRY(envlist) envs;
139 };
140 
141 TAILQ_HEAD(aliashead, alist);
142 struct alist {
143 	char		alias[HOST_NAME_MAX + 1];
144 	TAILQ_ENTRY(alist) aliases;
145 };
146 
147 TAILQ_HEAD(proxyhead, proxy);
148 struct proxy {
149 	char		 match_proto[32];
150 	char		 match_host[HOST_NAME_MAX + 1];
151 	char		 match_port[32];
152 
153 	char		 host[HOST_NAME_MAX + 1];
154 	char		 port[32];
155 	char		 sni[HOST_NAME_MAX];
156 	int		 notls;
157 	uint32_t	 protocols;
158 	int		 noverifyname;
159 	char		*cert_path;
160 	uint8_t		*cert;
161 	size_t		 certlen;
162 	char		*key_path;
163 	uint8_t		*key;
164 	size_t		 keylen;
165 	char		*reqca_path;
166 	X509_STORE	*reqca;
167 
168 	TAILQ_ENTRY(proxy) proxies;
169 };
170 
171 TAILQ_HEAD(lochead, location);
172 struct location {
173 	char		 match[128];
174 	char		 lang[32];
175 	char		 default_mime[MEDIATYPE_TYPEMAX];
176 	char		 index[PATH_MAX];
177 	int		 auto_index; /* 0 auto, -1 off, 1 on */
178 	int		 block_code;
179 	char		 block_fmt[GEMINI_URL_LEN];
180 	int		 strip;
181 	char		*reqca_path;
182 	X509_STORE	*reqca;
183 	int		 disable_log;
184 	int		 fcgi;
185 	int		 nofcgi;
186 	int		 fcgi_strip;
187 	struct envhead	 params;
188 
189 	char		 dir[PATH_MAX];
190 	int		 dirfd;
191 
192 	TAILQ_ENTRY(location) locations;
193 };
194 
195 TAILQ_HEAD(vhosthead, vhost);
196 struct vhost {
197 	char		 domain[HOST_NAME_MAX + 1];
198 	char		*cert_path;
199 	char		*key_path;
200 	char		*ocsp_path;
201 
202 	uint8_t		*cert;
203 	size_t		 certlen;
204 
205 	uint8_t		*key;
206 	size_t		 keylen;
207 
208 	uint8_t		*ocsp;
209 	size_t		 ocsplen;
210 
211 	TAILQ_ENTRY(vhost) vhosts;
212 
213 	struct addrhead	 addrs;
214 
215 	/*
216 	 * the first location rule is always '*' and holds the default
217 	 * settings for the vhost, then follows the "real" location
218 	 * rules as specified in the configuration.
219 	 */
220 	struct lochead	 locations;
221 
222 	struct aliashead aliases;
223 	struct proxyhead proxies;
224 };
225 
226 struct etm {			/* extension to mime */
227 	char	 mime[MEDIATYPE_TYPEMAX];
228 	char	 ext[MEDIATYPE_NAMEMAX];
229 };
230 
231 struct mime {
232 	struct etm	*t;
233 	size_t		 len;
234 	size_t		 cap;
235 };
236 
237 TAILQ_HEAD(pkihead, pki);
238 struct pki {
239 	char		*hash;
240 	EVP_PKEY	*pkey;
241 	TAILQ_ENTRY(pki) pkis;
242 };
243 
244 struct conf {
245 	struct privsep	*ps;
246 	uint32_t	 protos;
247 	struct mime	 mime;
248 	char		 chroot[PATH_MAX];
249 	char		 user[LOGIN_NAME_MAX];
250 	int		 prefork;
251 	int		 reload;
252 	int		 log_syslog;
253 	int		 log_facility;
254 	char		*log_access;
255 	enum log_format	 log_format;
256 	int		 use_privsep_crypto;
257 	int		 conftest;
258 
259 	struct fcgihead	 fcgi;
260 	struct vhosthead hosts;
261 	struct pkihead	 pkis;
262 	struct addrhead	 addrs;
263 };
264 
265 extern const char *config_path;
266 
267 extern int servpipes[PROC_MAX_INSTANCES];
268 extern int privsep_process;
269 
270 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
271 
272 enum {
273 	REQUEST_UNDECIDED,
274 	REQUEST_FILE,
275 	REQUEST_DIR,
276 	REQUEST_FCGI,
277 	REQUEST_PROXY,
278 	REQUEST_DONE,
279 };
280 
281 struct client {
282 	struct conf	*conf;
283 	struct address	*addr;
284 	uint32_t	 id;
285 	struct tls	*ctx;
286 	char		*req;
287 	size_t		 reqlen;
288 	struct iri	 iri;
289 	char		 domain[DOMAIN_NAME_LEN];
290 	char		 rhost[NI_MAXHOST];
291 	char		 rserv[NI_MAXSERV];
292 
293 	struct bufferevent *bev;
294 
295 	int		 type;
296 
297 	struct bufferevent *cgibev;
298 
299 	struct proxy	*proxy;
300 	struct bufferevent *proxybev;
301 	struct tls	*proxyctx;
302 	int		 proxyevset;
303 	struct event	 proxyev;
304 
305 	char		*header;
306 
307 	int		 code;
308 	const char	*meta;
309 	int		 fd, pfd;
310 	struct dirent	**dir;
311 	int		 dirlen, diroff;
312 
313 	/* big enough to store STATUS + SPACE + META + CRLF */
314 	char		 sbuf[1029];
315 	size_t		 soff;
316 
317 	struct sockaddr_storage	 raddr;
318 	socklen_t		 raddrlen;
319 
320 	struct vhost	*host;	/* host they're talking to */
321 	size_t		 loc;	/* location matched */
322 
323 	SPLAY_ENTRY(client) entry;
324 };
325 SPLAY_HEAD(client_tree_id, client);
326 extern struct client_tree_id clients;
327 
328 struct connreq {
329 	char	host[NI_MAXHOST];
330 	char	port[NI_MAXSERV];
331 	int	flag;
332 };
333 
334 enum imsg_type {
335 	IMSG_LOG_REQUEST,
336 	IMSG_LOG_ACCESS,
337 	IMSG_LOG_SYSLOG,
338 	IMSG_LOG_FACILITY,
339 
340 	IMSG_RECONF_START,
341 	IMSG_RECONF_LOG_FMT,
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 *, int, const char *);
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 int		 config_test(struct conf *);
380 
381 /* crypto.c */
382 void		 crypto(struct privsep *, struct privsep_proc *);
383 void		 crypto_engine_init(struct conf *);
384 
385 /* parse.y */
386 void		 yyerror(const char*, ...);
387 int		 parse_conf(struct conf *, const char*);
388 int		 cmdline_symset(char *);
389 
390 /* mime.c */
391 void		 init_mime(struct mime*);
392 int		 add_mime(struct mime*, const char*, const char*);
393 int		 load_default_mime(struct mime*);
394 void		 sort_mime(struct mime *);
395 const char	*mime(struct conf *, struct vhost*, const char*);
396 void		 free_mime(struct mime *);
397 
398 /* server.c */
399 extern int	shutting_down;
400 const char	*vhost_lang(struct vhost*, const char*);
401 const char	*vhost_default_mime(struct vhost*, const char*);
402 const char	*vhost_index(struct vhost*, const char*);
403 int		 vhost_auto_index(struct vhost*, const char*);
404 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
405 struct location	*vhost_fastcgi(struct vhost*, const char*);
406 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
407 int		 vhost_strip(struct vhost*, const char*);
408 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
409 int		 vhost_disable_log(struct vhost*, const char*);
410 
411 void		 mark_nonblock(int);
412 void		 client_write(struct bufferevent *, void *);
413 int		 start_reply(struct client*, int, const char*);
414 void		 client_close(struct client *);
415 void		 server_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 *, struct location *);
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 /* logger.c */
446 void		 logger(struct privsep *, struct privsep_proc *);
447 
448 /* proxy.c */
449 int		 proxy_init(struct client *);
450 
451 /* puny.c */
452 int		 puny_decode(const char*, char*, size_t, const char**);
453 
454 /* utils.c */
455 const char	*strip_path(const char *, int);
456 int		 ends_with(const char*, const char*);
457 char		*absolutify_path(const char*);
458 char		*xstrdup(const char*);
459 void		*xcalloc(size_t, size_t);
460 void		 gencert(const char *, const char *, const char *, int);
461 X509_STORE	*load_ca(uint8_t *, size_t);
462 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
463 void		 ssl_error(const char *);
464 char		*ssl_pubkey_hash(const uint8_t *, size_t);
465 EVP_PKEY	*ssl_load_pkey(const uint8_t *, size_t);
466 struct vhost	*new_vhost(void);
467 struct location	*new_location(void);
468 struct proxy	*new_proxy(void);
469 
470 #endif