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