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