1 /*
2  * Copyright (c) 2020 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 TAILQ_HEAD(lochead, location);
101 struct location {
102 	const char	*match;
103 	const char	*lang;
104 	const char	*default_mime;
105 	const char	*index;
106 	int		 auto_index; /* 0 auto, -1 off, 1 on */
107 	int		 block_code;
108 	const char	*block_fmt;
109 	int		 strip;
110 	X509_STORE	*reqca;
111 	int		 disable_log;
112 	int		 fcgi;
113 
114 	char		*proxy_host;
115 	const char	*proxy_port;
116 
117 	const char	*dir;
118 	int		 dirfd;
119 
120 	TAILQ_ENTRY(location) locations;
121 };
122 
123 TAILQ_HEAD(envhead, envlist);
124 struct envlist {
125 	char		*name;
126 	char		*value;
127 	TAILQ_ENTRY(envlist) envs;
128 };
129 
130 TAILQ_HEAD(aliashead, alist);
131 struct alist {
132 	char		*alias;
133 	TAILQ_ENTRY(alist) aliases;
134 };
135 
136 extern TAILQ_HEAD(vhosthead, vhost) hosts;
137 struct vhost {
138 	const char	*domain;
139 	const char	*cert;
140 	const char	*key;
141 	const char	*ocsp;
142 	const char	*cgi;
143 	const char	*entrypoint;
144 
145 	TAILQ_ENTRY(vhost) vhosts;
146 
147 	/*
148 	 * the first location rule is always '*' and holds the default
149 	 * settings for the vhost, then follows the "real" location
150 	 * rules as specified in the configuration.
151 	 */
152 	struct lochead	 locations;
153 
154 	struct envhead	 env;
155 	struct envhead	 params;
156 	struct aliashead aliases;
157 };
158 
159 struct etm {			/* extension to mime */
160 	const char	*mime;
161 	const char	*ext;
162 };
163 
164 struct mime {
165 	struct etm	*t;
166 	size_t		len;
167 	size_t		cap;
168 };
169 
170 struct conf {
171 	/* from command line */
172 	int		 foreground;
173 	int		 verbose;
174 
175 	/* in the config */
176 	int		 port;
177 	int		 ipv6;
178 	uint32_t	 protos;
179 	struct mime	 mime;
180 	char		*chroot;
181 	char		*user;
182 	int		 prefork;
183 };
184 
185 extern const char *config_path;
186 extern struct conf conf;
187 
188 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
189 
190 extern int servpipes[PROC_MAX];
191 
192 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
193 
194 enum {
195 	REQUEST_UNDECIDED,
196 	REQUEST_FILE,
197 	REQUEST_DIR,
198 	REQUEST_CGI,
199 	REQUEST_FCGI,
200 	REQUEST_PROXY,
201 	REQUEST_DONE,
202 };
203 
204 #define IS_INTERNAL_REQUEST(x) \
205 	((x) != REQUEST_CGI && \
206 	 (x) != REQUEST_FCGI && \
207 	 (x) != REQUEST_PROXY)
208 
209 struct client {
210 	uint32_t	 id;
211 	struct tls	*ctx;
212 	char		*req;
213 	struct iri	 iri;
214 	char		 domain[DOMAIN_NAME_LEN];
215 
216 	struct bufferevent *bev;
217 
218 	int		 type;
219 
220 	struct bufferevent *cgibev;
221 
222 	struct bufferevent *proxybev;
223 	struct tls	*proxyctx;
224 	struct event	 proxyev;
225 
226 	char		*header;
227 
228 	int		 code;
229 	const char	*meta;
230 	int		 fd, pfd;
231 	struct dirent	**dir;
232 	int		 dirlen, diroff;
233 
234 	/* big enough to store STATUS + SPACE + META + CRLF */
235 	char		 sbuf[1029];
236 	ssize_t		 len, off;
237 
238 	struct sockaddr_storage	 addr;
239 	struct vhost	*host;	/* host they're talking to */
240 	size_t		 loc;	/* location matched */
241 
242 	SPLAY_ENTRY(client) entry;
243 };
244 SPLAY_HEAD(client_tree_id, client);
245 extern struct client_tree_id clients;
246 
247 struct cgireq {
248 	char		buf[GEMINI_URL_LEN];
249 
250 	size_t		iri_schema_off;
251 	size_t		iri_host_off;
252 	size_t		iri_port_off;
253 	size_t		iri_path_off;
254 	size_t		iri_query_off;
255 	size_t		iri_fragment_off;
256 	int		iri_portno;
257 
258 	char		spath[PATH_MAX+1];
259 	char		relpath[PATH_MAX+1];
260 	char		addr[NI_MAXHOST+1];
261 
262 	/* AFAIK there isn't an upper limit for these two fields. */
263 	char		subject[64+1];
264 	char		issuer[64+1];
265 
266 	char		hash[128+1];
267 	char		version[8];
268 	char		cipher[32];
269 	int		cipher_strength;
270 	time_t		notbefore;
271 	time_t		notafter;
272 
273 	size_t		host_off;
274 	size_t		loc_off;
275 };
276 
277 struct connreq {
278 	char	host[NI_MAXHOST];
279 	char	port[NI_MAXSERV];
280 	int	flag;
281 };
282 
283 enum {
284 	FILE_EXISTS,
285 	FILE_EXECUTABLE,
286 	FILE_DIRECTORY,
287 	FILE_MISSING,
288 };
289 
290 enum imsg_type {
291 	IMSG_CGI_REQ,
292 	IMSG_CGI_RES,
293 	IMSG_FCGI_REQ,
294 	IMSG_FCGI_FD,
295 	IMSG_CONN_REQ,
296 	IMSG_CONN_FD,
297 	IMSG_LOG,
298 	IMSG_LOG_REQUEST,
299 	IMSG_LOG_TYPE,
300 	IMSG_QUIT,
301 };
302 
303 /* gmid.c */
304 char		*data_dir(void);
305 void		 load_local_cert(const char*, const char*);
306 void		 load_vhosts(void);
307 int		 make_socket(int, int);
308 void		 setup_tls(void);
309 void		 init_config(void);
310 void		 free_config(void);
311 void		 drop_priv(void);
312 
313 void		 yyerror(const char*, ...);
314 void		 parse_conf(const char*);
315 void		 print_conf(void);
316 int		 cmdline_symset(char *);
317 
318 /* log.c */
319 void		 fatal(const char*, ...)
320 	__attribute__((format (printf, 1, 2)))
321 	__attribute__((__noreturn__));
322 
323 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
324 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
325 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
326 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
327 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
328 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
329 void		 log_request(struct client*, char*, size_t);
330 int		 logger_main(int, struct imsgbuf*);
331 
332 /* mime.c */
333 void		 init_mime(struct mime*);
334 void		 add_mime(struct mime*, const char*, const char*);
335 void		 load_default_mime(struct mime*);
336 const char	*mime(struct vhost*, const char*);
337 
338 /* server.c */
339 extern int	shutting_down;
340 const char	*vhost_lang(struct vhost*, const char*);
341 const char	*vhost_default_mime(struct vhost*, const char*);
342 const char	*vhost_index(struct vhost*, const char*);
343 int		 vhost_auto_index(struct vhost*, const char*);
344 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
345 struct location	*vhost_reverse_proxy(struct vhost *, const char *);
346 int		 vhost_fastcgi(struct vhost*, const char*);
347 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
348 int		 vhost_strip(struct vhost*, const char*);
349 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
350 int		 vhost_disable_log(struct vhost*, const char*);
351 
352 void		 mark_nonblock(int);
353 void		 client_write(struct bufferevent *, void *);
354 void		 start_reply(struct client*, int, const char*);
355 void		 client_close(struct client *);
356 struct client	*try_client_by_id(int);
357 void		 loop(struct tls*, int, int, struct imsgbuf*);
358 
359 int		 client_tree_cmp(struct client *, struct client *);
360 SPLAY_PROTOTYPE(client_tree_id, client, entry, client_tree_cmp);
361 
362 /* dirs.c */
363 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
364 		    int(*)(const struct dirent**, const struct dirent**));
365 int		 select_non_dot(const struct dirent*);
366 int		 select_non_dotdot(const struct dirent*);
367 
368 /* ex.c */
369 int		 send_string(int, const char*);
370 int		 recv_string(int, char**);
371 int		 send_iri(int, struct iri*);
372 int		 recv_iri(int, struct iri*);
373 void		 free_recvd_iri(struct iri*);
374 int		 send_vhost(int, struct vhost*);
375 int		 recv_vhost(int, struct vhost**);
376 int		 send_time(int, time_t);
377 int		 recv_time(int, time_t*);
378 int		 send_fd(int, int);
379 int		 recv_fd(int);
380 int		 executor_main(struct imsgbuf*);
381 
382 /* fcgi.c */
383 void		 fcgi_read(struct bufferevent *, void *);
384 void		 fcgi_write(struct bufferevent *, void *);
385 void		 fcgi_error(struct bufferevent *, short, void *);
386 void		 fcgi_req(struct client *);
387 
388 /* sandbox.c */
389 void		 sandbox_server_process(void);
390 void		 sandbox_executor_process(void);
391 void		 sandbox_logger_process(void);
392 
393 /* utf8.c */
394 int		 valid_multibyte_utf8(struct parser*);
395 char		*utf8_nth(char*, size_t);
396 
397 /* iri.c */
398 int		 parse_iri(char*, struct iri*, const char**);
399 int		 serialize_iri(struct iri*, char*, size_t);
400 char		*pct_decode_str(char *);
401 
402 /* proxy.c */
403 int		 proxy_init(struct client *);
404 
405 /* puny.c */
406 int		 puny_decode(const char*, char*, size_t, const char**);
407 
408 /* utils.c */
409 void		 block_signals(void);
410 void		 unblock_signals(void);
411 int		 starts_with(const char*, const char*);
412 int		 ends_with(const char*, const char*);
413 ssize_t		 filesize(int);
414 char		*absolutify_path(const char*);
415 char		*xstrdup(const char*);
416 void		*xcalloc(size_t, size_t);
417 void		 gen_certificate(const char*, const char*, const char*);
418 X509_STORE	*load_ca(const char*);
419 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
420 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
421 
422 #endif