1 /*
2  * Copyright (c) 2020, 2021, 2022 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 struct proxy {
101 	char		*host;
102 	const char	*port;
103 	int		 notls;
104 	uint32_t	 protocols;
105 	int		 noverifyname;
106 	uint8_t		*cert;
107 	size_t		 certlen;
108 	uint8_t		*key;
109 	size_t		 keylen;
110 };
111 
112 TAILQ_HEAD(lochead, location);
113 struct location {
114 	const char	*match;
115 	const char	*lang;
116 	const char	*default_mime;
117 	const char	*index;
118 	int		 auto_index; /* 0 auto, -1 off, 1 on */
119 	int		 block_code;
120 	const char	*block_fmt;
121 	int		 strip;
122 	X509_STORE	*reqca;
123 	int		 disable_log;
124 	int		 fcgi;
125 
126 	const char	*dir;
127 	int		 dirfd;
128 
129 	TAILQ_ENTRY(location) locations;
130 };
131 
132 TAILQ_HEAD(envhead, envlist);
133 struct envlist {
134 	char		*name;
135 	char		*value;
136 	TAILQ_ENTRY(envlist) envs;
137 };
138 
139 TAILQ_HEAD(aliashead, alist);
140 struct alist {
141 	char		*alias;
142 	TAILQ_ENTRY(alist) aliases;
143 };
144 
145 extern TAILQ_HEAD(vhosthead, vhost) hosts;
146 struct vhost {
147 	const char	*domain;
148 	const char	*cert;
149 	const char	*key;
150 	const char	*ocsp;
151 	const char	*cgi;
152 	const char	*entrypoint;
153 
154 	TAILQ_ENTRY(vhost) vhosts;
155 
156 	/*
157 	 * the first location rule is always '*' and holds the default
158 	 * settings for the vhost, then follows the "real" location
159 	 * rules as specified in the configuration.
160 	 */
161 	struct lochead	 locations;
162 
163 	struct envhead	 env;
164 	struct envhead	 params;
165 	struct aliashead aliases;
166 	struct proxy	 proxy;
167 };
168 
169 struct etm {			/* extension to mime */
170 	const char	*mime;
171 	const char	*ext;
172 };
173 
174 struct mime {
175 	struct etm	*t;
176 	size_t		len;
177 	size_t		cap;
178 };
179 
180 struct conf {
181 	/* from command line */
182 	int		 foreground;
183 	int		 verbose;
184 
185 	/* in the config */
186 	int		 port;
187 	int		 ipv6;
188 	uint32_t	 protos;
189 	struct mime	 mime;
190 	char		*chroot;
191 	char		*user;
192 	int		 prefork;
193 };
194 
195 extern const char *config_path;
196 extern struct conf conf;
197 
198 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
199 
200 extern int servpipes[PROC_MAX];
201 
202 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
203 
204 enum {
205 	REQUEST_UNDECIDED,
206 	REQUEST_FILE,
207 	REQUEST_DIR,
208 	REQUEST_CGI,
209 	REQUEST_FCGI,
210 	REQUEST_PROXY,
211 	REQUEST_DONE,
212 };
213 
214 #define IS_INTERNAL_REQUEST(x) \
215 	((x) != REQUEST_CGI && \
216 	 (x) != REQUEST_FCGI && \
217 	 (x) != REQUEST_PROXY)
218 
219 struct client {
220 	uint32_t	 id;
221 	struct tls	*ctx;
222 	char		*req;
223 	struct iri	 iri;
224 	char		 domain[DOMAIN_NAME_LEN];
225 
226 	struct bufferevent *bev;
227 
228 	int		 type;
229 
230 	struct bufferevent *cgibev;
231 
232 	struct bufferevent *proxybev;
233 	struct tls	*proxyctx;
234 	struct event	 proxyev;
235 
236 	char		*header;
237 
238 	int		 code;
239 	const char	*meta;
240 	int		 fd, pfd;
241 	struct dirent	**dir;
242 	int		 dirlen, diroff;
243 
244 	/* big enough to store STATUS + SPACE + META + CRLF */
245 	char		 sbuf[1029];
246 	ssize_t		 len, off;
247 
248 	struct sockaddr_storage	 addr;
249 	struct vhost	*host;	/* host they're talking to */
250 	size_t		 loc;	/* location matched */
251 
252 	SPLAY_ENTRY(client) entry;
253 };
254 SPLAY_HEAD(client_tree_id, client);
255 extern struct client_tree_id clients;
256 
257 struct cgireq {
258 	char		buf[GEMINI_URL_LEN];
259 
260 	size_t		iri_schema_off;
261 	size_t		iri_host_off;
262 	size_t		iri_port_off;
263 	size_t		iri_path_off;
264 	size_t		iri_query_off;
265 	size_t		iri_fragment_off;
266 	int		iri_portno;
267 
268 	char		spath[PATH_MAX+1];
269 	char		relpath[PATH_MAX+1];
270 	char		addr[NI_MAXHOST+1];
271 
272 	/* AFAIK there isn't an upper limit for these two fields. */
273 	char		subject[64+1];
274 	char		issuer[64+1];
275 
276 	char		hash[128+1];
277 	char		version[8];
278 	char		cipher[32];
279 	int		cipher_strength;
280 	time_t		notbefore;
281 	time_t		notafter;
282 
283 	size_t		host_off;
284 	size_t		loc_off;
285 };
286 
287 struct connreq {
288 	char	host[NI_MAXHOST];
289 	char	port[NI_MAXSERV];
290 	int	flag;
291 };
292 
293 enum {
294 	FILE_EXISTS,
295 	FILE_EXECUTABLE,
296 	FILE_DIRECTORY,
297 	FILE_MISSING,
298 };
299 
300 enum imsg_type {
301 	IMSG_CGI_REQ,
302 	IMSG_CGI_RES,
303 	IMSG_FCGI_REQ,
304 	IMSG_FCGI_FD,
305 	IMSG_CONN_REQ,
306 	IMSG_CONN_FD,
307 	IMSG_LOG,
308 	IMSG_LOG_REQUEST,
309 	IMSG_LOG_TYPE,
310 	IMSG_QUIT,
311 };
312 
313 /* gmid.c */
314 char		*data_dir(void);
315 void		 load_local_cert(const char*, const char*);
316 void		 load_vhosts(void);
317 int		 make_socket(int, int);
318 void		 setup_tls(void);
319 void		 init_config(void);
320 void		 free_config(void);
321 void		 drop_priv(void);
322 
323 void		 yyerror(const char*, ...);
324 void		 parse_conf(const char*);
325 void		 print_conf(void);
326 int		 cmdline_symset(char *);
327 
328 /* log.c */
329 void		 fatal(const char*, ...)
330 	__attribute__((format (printf, 1, 2)))
331 	__attribute__((__noreturn__));
332 
333 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
334 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
335 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
336 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
337 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
338 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
339 void		 log_request(struct client*, char*, size_t);
340 int		 logger_main(int, struct imsgbuf*);
341 
342 /* mime.c */
343 void		 init_mime(struct mime*);
344 void		 add_mime(struct mime*, const char*, const char*);
345 void		 load_default_mime(struct mime*);
346 const char	*mime(struct vhost*, const char*);
347 
348 /* server.c */
349 extern int	shutting_down;
350 const char	*vhost_lang(struct vhost*, const char*);
351 const char	*vhost_default_mime(struct vhost*, const char*);
352 const char	*vhost_index(struct vhost*, const char*);
353 int		 vhost_auto_index(struct vhost*, const char*);
354 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
355 int		 vhost_fastcgi(struct vhost*, const char*);
356 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
357 int		 vhost_strip(struct vhost*, const char*);
358 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
359 int		 vhost_disable_log(struct vhost*, const char*);
360 
361 void		 mark_nonblock(int);
362 void		 client_write(struct bufferevent *, void *);
363 void		 start_reply(struct client*, int, const char*);
364 void		 client_close(struct client *);
365 struct client	*try_client_by_id(int);
366 void		 loop(struct tls*, int, int, struct imsgbuf*);
367 
368 int		 client_tree_cmp(struct client *, struct client *);
369 SPLAY_PROTOTYPE(client_tree_id, client, entry, client_tree_cmp);
370 
371 /* dirs.c */
372 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
373 		    int(*)(const struct dirent**, const struct dirent**));
374 int		 select_non_dot(const struct dirent*);
375 int		 select_non_dotdot(const struct dirent*);
376 
377 /* ex.c */
378 int		 send_string(int, const char*);
379 int		 recv_string(int, char**);
380 int		 send_iri(int, struct iri*);
381 int		 recv_iri(int, struct iri*);
382 void		 free_recvd_iri(struct iri*);
383 int		 send_vhost(int, struct vhost*);
384 int		 recv_vhost(int, struct vhost**);
385 int		 send_time(int, time_t);
386 int		 recv_time(int, time_t*);
387 int		 send_fd(int, int);
388 int		 recv_fd(int);
389 int		 executor_main(struct imsgbuf*);
390 
391 /* fcgi.c */
392 void		 fcgi_read(struct bufferevent *, void *);
393 void		 fcgi_write(struct bufferevent *, void *);
394 void		 fcgi_error(struct bufferevent *, short, void *);
395 void		 fcgi_req(struct client *);
396 
397 /* sandbox.c */
398 void		 sandbox_server_process(void);
399 void		 sandbox_executor_process(void);
400 void		 sandbox_logger_process(void);
401 
402 /* utf8.c */
403 int		 valid_multibyte_utf8(struct parser*);
404 char		*utf8_nth(char*, size_t);
405 
406 /* iri.c */
407 int		 parse_iri(char*, struct iri*, const char**);
408 int		 serialize_iri(struct iri*, char*, size_t);
409 char		*pct_decode_str(char *);
410 
411 /* proxy.c */
412 int		 proxy_init(struct client *);
413 
414 /* puny.c */
415 int		 puny_decode(const char*, char*, size_t, const char**);
416 
417 /* utils.c */
418 void		 block_signals(void);
419 void		 unblock_signals(void);
420 int		 starts_with(const char*, const char*);
421 int		 ends_with(const char*, const char*);
422 ssize_t		 filesize(int);
423 char		*absolutify_path(const char*);
424 char		*xstrdup(const char*);
425 void		*xcalloc(size_t, size_t);
426 void		 gen_certificate(const char*, const char*, const char*);
427 X509_STORE	*load_ca(const char*);
428 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
429 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
430 
431 #endif