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 NOT_FOUND	51
63 #define PROXY_REFUSED	53
64 #define BAD_REQUEST	59
65 #define CLIENT_CERT_REQ	60
66 #define CERT_NOT_AUTH	61
67 
68 /* maximum hostname and label length, +1 for the NUL-terminator */
69 #define DOMAIN_NAME_LEN	(253+1)
70 #define LABEL_LEN	(63+1)
71 
72 #define FCGI_MAX	32
73 #define PROC_MAX	16
74 
75 struct fcgi {
76 	int		 id;
77 	char		*path;
78 	char		*port;
79 	char		*prog;
80 };
81 extern struct fcgi fcgi[FCGI_MAX];
82 
83 TAILQ_HEAD(lochead, location);
84 struct location {
85 	const char	*match;
86 	const char	*lang;
87 	const char	*default_mime;
88 	const char	*index;
89 	int		 auto_index; /* 0 auto, -1 off, 1 on */
90 	int		 block_code;
91 	const char	*block_fmt;
92 	int		 strip;
93 	X509_STORE	*reqca;
94 	int		 disable_log;
95 	int		 fcgi;
96 
97 	const char	*dir;
98 	int		 dirfd;
99 
100 	TAILQ_ENTRY(location) locations;
101 };
102 
103 TAILQ_HEAD(envhead, envlist);
104 struct envlist {
105 	char		*name;
106 	char		*value;
107 	TAILQ_ENTRY(envlist) envs;
108 };
109 
110 TAILQ_HEAD(aliashead, alist);
111 struct alist {
112 	char		*alias;
113 	TAILQ_ENTRY(alist) aliases;
114 };
115 
116 extern TAILQ_HEAD(vhosthead, vhost) hosts;
117 struct vhost {
118 	const char	*domain;
119 	const char	*cert;
120 	const char	*key;
121 	const char	*ocsp;
122 	const char	*cgi;
123 	const char	*entrypoint;
124 
125 	TAILQ_ENTRY(vhost) vhosts;
126 
127 	/*
128 	 * the first location rule is always '*' and holds the default
129 	 * settings for the vhost, then follows the "real" location
130 	 * rules as specified in the configuration.
131 	 */
132 	struct lochead	 locations;
133 
134 	struct envhead	 env;
135 	struct envhead	 params;
136 	struct aliashead aliases;
137 };
138 
139 struct etm {			/* extension to mime */
140 	const char	*mime;
141 	const char	*ext;
142 };
143 
144 struct mime {
145 	struct etm	*t;
146 	size_t		len;
147 	size_t		cap;
148 };
149 
150 struct conf {
151 	/* from command line */
152 	int		 foreground;
153 	int		 verbose;
154 
155 	/* in the config */
156 	int		 port;
157 	int		 ipv6;
158 	uint32_t	 protos;
159 	struct mime	 mime;
160 	char		*chroot;
161 	char		*user;
162 	int		 prefork;
163 };
164 
165 extern const char *config_path;
166 extern struct conf conf;
167 
168 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
169 
170 extern int servpipes[PROC_MAX];
171 
172 struct iri {
173 	char		*schema;
174 	char		*host;
175 	char		*port;
176 	uint16_t	 port_no;
177 	char		*path;
178 	char		*query;
179 	char		*fragment;
180 };
181 
182 struct parser {
183 	char		*iri;
184 	struct iri	*parsed;
185 	const char	*err;
186 };
187 
188 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
189 
190 enum {
191 	REQUEST_UNDECIDED,
192 	REQUEST_FILE,
193 	REQUEST_DIR,
194 	REQUEST_CGI,
195 	REQUEST_FCGI,
196 	REQUEST_DONE,
197 };
198 
199 #define IS_INTERNAL_REQUEST(x)	((x) != REQUEST_CGI && (x) != REQUEST_FCGI)
200 
201 struct client {
202 	uint32_t	 id;
203 	struct tls	*ctx;
204 	char		*req;
205 	struct iri	 iri;
206 	char		 domain[DOMAIN_NAME_LEN];
207 
208 	struct bufferevent *bev;
209 
210 	int		 type;
211 
212 	struct bufferevent *cgibev;
213 
214 	char		*header;
215 
216 	int		 code;
217 	const char	*meta;
218 	int		 fd, pfd;
219 	struct dirent	**dir;
220 	int		 dirlen, diroff;
221 
222 	/* big enough to store STATUS + SPACE + META + CRLF */
223 	char		 sbuf[1029];
224 	ssize_t		 len, off;
225 
226 	struct sockaddr_storage	 addr;
227 	struct vhost	*host;	/* host they're talking to */
228 	size_t		 loc;	/* location matched */
229 
230 	SPLAY_ENTRY(client) entry;
231 };
232 SPLAY_HEAD(client_tree_id, client);
233 extern struct client_tree_id clients;
234 
235 struct cgireq {
236 	char		buf[GEMINI_URL_LEN];
237 
238 	size_t		iri_schema_off;
239 	size_t		iri_host_off;
240 	size_t		iri_port_off;
241 	size_t		iri_path_off;
242 	size_t		iri_query_off;
243 	size_t		iri_fragment_off;
244 	int		iri_portno;
245 
246 	char		spath[PATH_MAX+1];
247 	char		relpath[PATH_MAX+1];
248 	char		addr[NI_MAXHOST+1];
249 
250 	/* AFAIK there isn't an upper limit for these two fields. */
251 	char		subject[64+1];
252 	char		issuer[64+1];
253 
254 	char		hash[128+1];
255 	char		version[8];
256 	char		cipher[32];
257 	int		cipher_strength;
258 	time_t		notbefore;
259 	time_t		notafter;
260 
261 	size_t		host_off;
262 	size_t		loc_off;
263 };
264 
265 enum {
266 	FILE_EXISTS,
267 	FILE_EXECUTABLE,
268 	FILE_DIRECTORY,
269 	FILE_MISSING,
270 };
271 
272 enum imsg_type {
273 	IMSG_CGI_REQ,
274 	IMSG_CGI_RES,
275 	IMSG_FCGI_REQ,
276 	IMSG_FCGI_FD,
277 	IMSG_LOG,
278 	IMSG_LOG_REQUEST,
279 	IMSG_LOG_TYPE,
280 	IMSG_QUIT,
281 };
282 
283 /* gmid.c */
284 char		*data_dir(void);
285 void		 load_local_cert(const char*, const char*);
286 void		 load_vhosts(void);
287 int		 make_socket(int, int);
288 void		 setup_tls(void);
289 void		 init_config(void);
290 void		 free_config(void);
291 void		 drop_priv(void);
292 
293 void		 yyerror(const char*, ...);
294 void		 parse_conf(const char*);
295 void		 print_conf(void);
296 int		 cmdline_symset(char *);
297 
298 /* log.c */
299 void		 fatal(const char*, ...)
300 	__attribute__((format (printf, 1, 2)))
301 	__attribute__((__noreturn__));
302 
303 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
304 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
305 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
306 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
307 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
308 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
309 void		 log_request(struct client*, char*, size_t);
310 int		 logger_main(int, struct imsgbuf*);
311 
312 /* mime.c */
313 void		 init_mime(struct mime*);
314 void		 add_mime(struct mime*, const char*, const char*);
315 void		 load_default_mime(struct mime*);
316 const char	*mime(struct vhost*, const char*);
317 
318 /* server.c */
319 extern int	shutting_down;
320 const char	*vhost_lang(struct vhost*, const char*);
321 const char	*vhost_default_mime(struct vhost*, const char*);
322 const char	*vhost_index(struct vhost*, const char*);
323 int		 vhost_auto_index(struct vhost*, const char*);
324 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
325 int		 vhost_fastcgi(struct vhost*, const char*);
326 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
327 int		 vhost_strip(struct vhost*, const char*);
328 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
329 int		 vhost_disable_log(struct vhost*, const char*);
330 
331 void		 mark_nonblock(int);
332 void		 client_write(struct bufferevent *, void *);
333 void		 start_reply(struct client*, int, const char*);
334 void		 client_close(struct client *);
335 struct client	*try_client_by_id(int);
336 void		 loop(struct tls*, int, int, struct imsgbuf*);
337 
338 int		 client_tree_cmp(struct client *, struct client *);
339 SPLAY_PROTOTYPE(client_tree_id, client, entry, client_tree_cmp);
340 
341 /* dirs.c */
342 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
343 		    int(*)(const struct dirent**, const struct dirent**));
344 int		 select_non_dot(const struct dirent*);
345 int		 select_non_dotdot(const struct dirent*);
346 
347 /* ex.c */
348 int		 send_string(int, const char*);
349 int		 recv_string(int, char**);
350 int		 send_iri(int, struct iri*);
351 int		 recv_iri(int, struct iri*);
352 void		 free_recvd_iri(struct iri*);
353 int		 send_vhost(int, struct vhost*);
354 int		 recv_vhost(int, struct vhost**);
355 int		 send_time(int, time_t);
356 int		 recv_time(int, time_t*);
357 int		 send_fd(int, int);
358 int		 recv_fd(int);
359 int		 executor_main(struct imsgbuf*);
360 
361 /* fcgi.c */
362 void		 fcgi_read(struct bufferevent *, void *);
363 void		 fcgi_write(struct bufferevent *, void *);
364 void		 fcgi_error(struct bufferevent *, short, void *);
365 void		 fcgi_req(struct client *);
366 
367 /* sandbox.c */
368 void		 sandbox_server_process(void);
369 void		 sandbox_executor_process(void);
370 void		 sandbox_logger_process(void);
371 
372 /* utf8.c */
373 int		 valid_multibyte_utf8(struct parser*);
374 char		*utf8_nth(char*, size_t);
375 
376 /* iri.c */
377 int		 parse_iri(char*, struct iri*, const char**);
378 int		 serialize_iri(struct iri*, char*, size_t);
379 char		*pct_decode_str(char *);
380 
381 /* puny.c */
382 int		 puny_decode(const char*, char*, size_t, const char**);
383 
384 /* utils.c */
385 void		 block_signals(void);
386 void		 unblock_signals(void);
387 int		 starts_with(const char*, const char*);
388 int		 ends_with(const char*, const char*);
389 ssize_t		 filesize(int);
390 char		*absolutify_path(const char*);
391 char		*xstrdup(const char*);
392 void		*xcalloc(size_t, size_t);
393 void		 gen_certificate(const char*, const char*, const char*);
394 X509_STORE	*load_ca(const char*);
395 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
396 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
397 
398 #endif