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 #define MAX_USERS	64
69 
70 /* maximum hostname and label length, +1 for the NUL-terminator */
71 #define DOMAIN_NAME_LEN	(253+1)
72 #define LABEL_LEN	(63+1)
73 
74 #define FCGI_MAX	32
75 #define PROC_MAX	16
76 
77 struct fcgi {
78 	int		 id;
79 	char		*path;
80 	char		*port;
81 	char		*prog;
82 	int		 fd;
83 
84 	struct bufferevent *bev;
85 
86 	/* number of pending clients */
87 	int		 pending;
88 
89 #define FCGI_OFF	0
90 #define FCGI_INFLIGHT	1
91 #define FCGI_READY	2
92 	int		 s;
93 };
94 extern struct fcgi fcgi[FCGI_MAX];
95 
96 TAILQ_HEAD(lochead, location);
97 struct location {
98 	const char	*match;
99 	const char	*lang;
100 	const char	*default_mime;
101 	const char	*index;
102 	int		 auto_index; /* 0 auto, -1 off, 1 on */
103 	int		 block_code;
104 	const char	*block_fmt;
105 	int		 strip;
106 	X509_STORE	*reqca;
107 	int		 disable_log;
108 	int		 fcgi;
109 
110 	const char	*dir;
111 	int		 dirfd;
112 
113 	TAILQ_ENTRY(location) locations;
114 };
115 
116 TAILQ_HEAD(envhead, envlist);
117 struct envlist {
118 	char		*name;
119 	char		*value;
120 	TAILQ_ENTRY(envlist) envs;
121 };
122 
123 TAILQ_HEAD(aliashead, alist);
124 struct alist {
125 	char		*alias;
126 	TAILQ_ENTRY(alist) aliases;
127 };
128 
129 extern TAILQ_HEAD(vhosthead, vhost) hosts;
130 struct vhost {
131 	const char	*domain;
132 	const char	*cert;
133 	const char	*key;
134 	const char	*cgi;
135 	const char	*entrypoint;
136 
137 	TAILQ_ENTRY(vhost) vhosts;
138 
139 	/*
140 	 * the first location rule is always '*' and holds the default
141 	 * settings for the vhost, then follows the "real" location
142 	 * rules as specified in the configuration.
143 	 */
144 	struct lochead	 locations;
145 
146 	struct envhead	 env;
147 	struct envhead	 params;
148 	struct aliashead aliases;
149 };
150 
151 struct etm {			/* extension to mime */
152 	const char	*mime;
153 	const char	*ext;
154 };
155 
156 struct mime {
157 	struct etm	*t;
158 	size_t		len;
159 	size_t		cap;
160 };
161 
162 struct conf {
163 	/* from command line */
164 	int		 foreground;
165 	int		 verbose;
166 
167 	/* in the config */
168 	int		 port;
169 	int		 ipv6;
170 	uint32_t	 protos;
171 	struct mime	 mime;
172 	char		*chroot;
173 	char		*user;
174 	int		 prefork;
175 };
176 
177 extern const char *config_path;
178 extern struct conf conf;
179 
180 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
181 
182 extern int servpipes[PROC_MAX];
183 
184 struct iri {
185 	char		*schema;
186 	char		*host;
187 	char		*port;
188 	uint16_t	 port_no;
189 	char		*path;
190 	char		*query;
191 	char		*fragment;
192 };
193 
194 struct parser {
195 	char		*iri;
196 	struct iri	*parsed;
197 	const char	*err;
198 };
199 
200 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
201 
202 enum {
203 	REQUEST_UNDECIDED,
204 	REQUEST_FILE,
205 	REQUEST_DIR,
206 	REQUEST_CGI,
207 	REQUEST_FCGI,
208 	REQUEST_DONE,
209 };
210 
211 #define IS_INTERNAL_REQUEST(x)	((x) != REQUEST_CGI && (x) != REQUEST_FCGI)
212 
213 struct client {
214 	int		 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 	char		*header;
227 
228 	int		 code;
229 	const char	*meta;
230 	int		 fd, pfd;
231 	struct dirent	**dir;
232 	int		 dirlen, diroff;
233 	int		 fcgi;
234 
235 	/* big enough to store STATUS + SPACE + META + CRLF */
236 	char		 sbuf[1029];
237 	ssize_t		 len, off;
238 
239 	struct sockaddr_storage	 addr;
240 	struct vhost	*host;	/* host they're talking to */
241 	size_t		 loc;	/* location matched */
242 };
243 
244 extern struct client clients[MAX_USERS];
245 
246 struct cgireq {
247 	char		buf[GEMINI_URL_LEN];
248 
249 	size_t		iri_schema_off;
250 	size_t		iri_host_off;
251 	size_t		iri_port_off;
252 	size_t		iri_path_off;
253 	size_t		iri_query_off;
254 	size_t		iri_fragment_off;
255 	int		iri_portno;
256 
257 	char		spath[PATH_MAX+1];
258 	char		relpath[PATH_MAX+1];
259 	char		addr[NI_MAXHOST+1];
260 
261 	/* AFAIK there isn't an upper limit for these two fields. */
262 	char		subject[64+1];
263 	char		issuer[64+1];
264 
265 	char		hash[128+1];
266 	char		version[8];
267 	char		cipher[32];
268 	int		cipher_strength;
269 	time_t		notbefore;
270 	time_t		notafter;
271 
272 	size_t		host_off;
273 	size_t		loc_off;
274 };
275 
276 enum {
277 	FILE_EXISTS,
278 	FILE_EXECUTABLE,
279 	FILE_DIRECTORY,
280 	FILE_MISSING,
281 };
282 
283 enum imsg_type {
284 	IMSG_CGI_REQ,
285 	IMSG_CGI_RES,
286 	IMSG_FCGI_REQ,
287 	IMSG_FCGI_FD,
288 	IMSG_LOG,
289 	IMSG_LOG_REQUEST,
290 	IMSG_LOG_TYPE,
291 	IMSG_QUIT,
292 };
293 
294 /* gmid.c */
295 char		*data_dir(void);
296 void		 load_local_cert(const char*, const char*);
297 void		 load_vhosts(void);
298 int		 make_socket(int, int);
299 void		 setup_tls(void);
300 void		 init_config(void);
301 void		 free_config(void);
302 void		 drop_priv(void);
303 
304 void		 yyerror(const char*, ...);
305 void		 parse_conf(const char*);
306 int		 cmdline_symset(char *);
307 
308 /* log.c */
309 void		 fatal(const char*, ...)
310 	__attribute__((format (printf, 1, 2)))
311 	__attribute__((__noreturn__));
312 
313 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
314 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
315 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
316 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
317 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
318 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
319 void		 log_request(struct client*, char*, size_t);
320 int		 logger_main(int, struct imsgbuf*);
321 
322 /* mime.c */
323 void		 init_mime(struct mime*);
324 void		 add_mime(struct mime*, const char*, const char*);
325 void		 load_default_mime(struct mime*);
326 const char	*mime(struct vhost*, const char*);
327 
328 /* server.c */
329 extern int	shutting_down;
330 const char	*vhost_lang(struct vhost*, const char*);
331 const char	*vhost_default_mime(struct vhost*, const char*);
332 const char	*vhost_index(struct vhost*, const char*);
333 int		 vhost_auto_index(struct vhost*, const char*);
334 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
335 int		 vhost_fastcgi(struct vhost*, const char*);
336 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
337 int		 vhost_strip(struct vhost*, const char*);
338 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
339 int		 vhost_disable_log(struct vhost*, const char*);
340 
341 void		 mark_nonblock(int);
342 void		 client_write(struct bufferevent *, void *);
343 void		 start_reply(struct client*, int, const char*);
344 void		 client_close(struct client *);
345 struct client	*try_client_by_id(int);
346 void		 loop(struct tls*, int, int, struct imsgbuf*);
347 
348 /* dirs.c */
349 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
350 		    int(*)(const struct dirent**, const struct dirent**));
351 int		 select_non_dot(const struct dirent*);
352 int		 select_non_dotdot(const struct dirent*);
353 
354 /* ex.c */
355 int		 send_string(int, const char*);
356 int		 recv_string(int, char**);
357 int		 send_iri(int, struct iri*);
358 int		 recv_iri(int, struct iri*);
359 void		 free_recvd_iri(struct iri*);
360 int		 send_vhost(int, struct vhost*);
361 int		 recv_vhost(int, struct vhost**);
362 int		 send_time(int, time_t);
363 int		 recv_time(int, time_t*);
364 int		 send_fd(int, int);
365 int		 recv_fd(int);
366 int		 executor_main(struct imsgbuf*);
367 
368 /* fcgi.c */
369 void		 fcgi_abort_request(struct client *);
370 void		 fcgi_close_backend(struct fcgi *);
371 void		 fcgi_read(struct bufferevent *, void *);
372 void		 fcgi_write(struct bufferevent *, void *);
373 void		 fcgi_error(struct bufferevent *, short, void *);
374 void		 fcgi_req(struct fcgi *, struct client *);
375 
376 /* sandbox.c */
377 void		 sandbox_server_process(void);
378 void		 sandbox_executor_process(void);
379 void		 sandbox_logger_process(void);
380 
381 /* utf8.c */
382 int		 valid_multibyte_utf8(struct parser*);
383 char		*utf8_nth(char*, size_t);
384 
385 /* iri.c */
386 int		 parse_iri(char*, struct iri*, const char**);
387 int		 serialize_iri(struct iri*, char*, size_t);
388 char		*pct_decode_str(char *);
389 
390 /* puny.c */
391 int		 puny_decode(const char*, char*, size_t, const char**);
392 
393 /* utils.c */
394 void		 block_signals(void);
395 void		 unblock_signals(void);
396 int		 starts_with(const char*, const char*);
397 int		 ends_with(const char*, const char*);
398 ssize_t		 filesize(int);
399 char		*absolutify_path(const char*);
400 char		*xstrdup(const char*);
401 void		*xcalloc(size_t, size_t);
402 void		 gen_certificate(const char*, const char*, const char*);
403 X509_STORE	*load_ca(const char*);
404 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
405 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
406 
407 #endif