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