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