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 <event.h>
30 #include <limits.h>
31 #include <netdb.h>
32 #include <signal.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <time.h>
36 #include <tls.h>
37 #include <unistd.h>
38 
39 #include <openssl/x509.h>
40 
41 #define GMID_STRING	"gmid " VERSION
42 #define GMID_VERSION	"gmid/" VERSION
43 
44 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
45 
46 #define SUCCESS		20
47 #define TEMP_REDIRECT	30
48 #define TEMP_FAILURE	40
49 #define CGI_ERROR	42
50 #define NOT_FOUND	51
51 #define PROXY_REFUSED	53
52 #define BAD_REQUEST	59
53 #define CLIENT_CERT_REQ	60
54 #define CERT_NOT_AUTH	61
55 
56 #define MAX_USERS	64
57 
58 /* maximum hostname and label length, +1 for the NUL-terminator */
59 #define DOMAIN_NAME_LEN	(253+1)
60 #define LABEL_LEN	(63+1)
61 
62 #define FCGI_MAX	32
63 #define PROC_MAX	16
64 
65 struct fcgi {
66 	int		 id;
67 	char		*path;
68 	char		*port;
69 	char		*prog;
70 	int		 fd;
71 
72 	struct bufferevent *bev;
73 
74 	/* number of pending clients */
75 	int		 pending;
76 
77 #define FCGI_OFF	0
78 #define FCGI_INFLIGHT	1
79 #define FCGI_READY	2
80 	int		 s;
81 };
82 extern struct fcgi fcgi[FCGI_MAX];
83 
84 TAILQ_HEAD(lochead, location);
85 struct location {
86 	const char	*match;
87 	const char	*lang;
88 	const char	*default_mime;
89 	const char	*index;
90 	int		 auto_index; /* 0 auto, -1 off, 1 on */
91 	int		 block_code;
92 	const char	*block_fmt;
93 	int		 strip;
94 	X509_STORE	*reqca;
95 	int		 disable_log;
96 	int		 fcgi;
97 
98 	const char	*dir;
99 	int		 dirfd;
100 
101 	TAILQ_ENTRY(location) locations;
102 };
103 
104 TAILQ_HEAD(envhead, envlist);
105 struct envlist {
106 	char		*name;
107 	char		*value;
108 	TAILQ_ENTRY(envlist) envs;
109 };
110 
111 TAILQ_HEAD(aliashead, alist);
112 struct alist {
113 	char		*alias;
114 	TAILQ_ENTRY(alist) aliases;
115 };
116 
117 extern TAILQ_HEAD(vhosthead, vhost) hosts;
118 struct vhost {
119 	const char	*domain;
120 	const char	*cert;
121 	const char	*key;
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 struct mbuf {
189 	size_t			len;
190 	size_t			off;
191 	TAILQ_ENTRY(mbuf)	mbufs;
192 	char			data[];
193 };
194 TAILQ_HEAD(mbufhead, mbuf);
195 
196 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
197 
198 typedef void (*statefn)(int, short, void*);
199 
200 /*
201  * DFA: handle_handshake is the initial state, close_conn the final.
202  * Sometimes we have an enter_* function to handle the state switch.
203  *
204  * handle_handshake -> handle_open_conn
205  * handle_handshake -> close_conn		// on err
206  *
207  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
208  * handle_open_conn -> send_fcgi_req		// via apply_fastcgi, IMSG_FCGI_FD
209  * handle_open_conn -> handle_dirlist		// ...same
210  * handle_open_conn -> send_file		// ...same
211  * handle_open_conn -> start_reply		// on error
212  *
213  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
214  * handle_cgi_reply -> start_reply	// on error
215  *
216  * handle_cgi -> close_conn
217  *
218  * send_fcgi_req -> copy_mbuf		// via handle_fcgi
219  * handle_fcgi -> close_all		// on error
220  * copy_mbuf -> close_conn		// on success/error
221  *
222  * handle_dirlist -> send_directory_listing
223  * handle_dirlist -> close_conn			// on error
224  *
225  * send_directory_listing -> close_conn
226  *
227  * send_file -> close_conn
228  */
229 struct client {
230 	int		 id;
231 	struct tls	*ctx;
232 	char		 req[GEMINI_URL_LEN];
233 	struct iri	 iri;
234 	char		 domain[DOMAIN_NAME_LEN];
235 
236 	/*
237 	 * start_reply uses this to know what function call after the
238 	 * reply.  It's also used as sentinel value in fastcgi to know
239 	 * if the server has closed the request.
240 	 */
241 	statefn		 next;
242 
243 	int		 code;
244 	const char	*meta;
245 	int		 fd, pfd;
246 	struct dirent	**dir;
247 	int		 dirlen, diroff;
248 	int		 fcgi;
249 
250 	/* big enough to store STATUS + SPACE + META + CRLF */
251 	char		 sbuf[1029];
252 	ssize_t		 len, off;
253 
254 	struct mbufhead	 mbufhead;
255 
256 	struct sockaddr_storage	 addr;
257 	struct vhost	*host;	/* host they're talking to */
258 	size_t		 loc;	/* location matched */
259 };
260 
261 extern struct client clients[MAX_USERS];
262 
263 struct cgireq {
264 	char		buf[GEMINI_URL_LEN];
265 
266 	size_t		iri_schema_off;
267 	size_t		iri_host_off;
268 	size_t		iri_port_off;
269 	size_t		iri_path_off;
270 	size_t		iri_query_off;
271 	size_t		iri_fragment_off;
272 	int		iri_portno;
273 
274 	char		spath[PATH_MAX+1];
275 	char		relpath[PATH_MAX+1];
276 	char		addr[NI_MAXHOST+1];
277 
278 	/* AFAIK there isn't an upper limit for these two fields. */
279 	char		subject[64+1];
280 	char		issuer[64+1];
281 
282 	char		hash[128+1];
283 	char		version[8];
284 	char		cipher[32];
285 	int		cipher_strength;
286 	time_t		notbefore;
287 	time_t		notafter;
288 
289 	size_t		host_off;
290 	size_t		loc_off;
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_LOG,
306 	IMSG_LOG_REQUEST,
307 	IMSG_LOG_TYPE,
308 	IMSG_QUIT,
309 };
310 
311 /* gmid.c */
312 char		*data_dir(void);
313 void		 load_local_cert(const char*, const char*);
314 void		 load_vhosts(void);
315 int		 make_socket(int, int);
316 void		 setup_tls(void);
317 void		 init_config(void);
318 void		 free_config(void);
319 void		 drop_priv(void);
320 
321 void		 yyerror(const char*, ...);
322 void		 parse_conf(const char*);
323 int		 cmdline_symset(char *);
324 
325 /* log.c */
326 void		 fatal(const char*, ...)
327 	__attribute__((format (printf, 1, 2)))
328 	__attribute__((__noreturn__));
329 
330 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
331 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
332 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
333 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
334 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
335 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
336 void		 log_request(struct client*, char*, size_t);
337 int		 logger_main(int, struct imsgbuf*);
338 
339 /* mime.c */
340 void		 init_mime(struct mime*);
341 void		 add_mime(struct mime*, const char*, const char*);
342 void		 load_default_mime(struct mime*);
343 const char	*mime(struct vhost*, const char*);
344 
345 /* server.c */
346 extern int	shutting_down;
347 const char	*vhost_lang(struct vhost*, const char*);
348 const char	*vhost_default_mime(struct vhost*, const char*);
349 const char	*vhost_index(struct vhost*, const char*);
350 int		 vhost_auto_index(struct vhost*, const char*);
351 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
352 int		 vhost_fastcgi(struct vhost*, const char*);
353 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
354 int		 vhost_strip(struct vhost*, const char*);
355 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
356 int		 vhost_disable_log(struct vhost*, const char*);
357 
358 void		 mark_nonblock(int);
359 void		 start_reply(struct client*, int, const char*);
360 void		 close_conn(int, short, void*);
361 struct client	*try_client_by_id(int);
362 void		 loop(struct tls*, int, int, struct imsgbuf*);
363 
364 /* dirs.c */
365 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
366 		    int(*)(const struct dirent**, const struct dirent**));
367 int		 select_non_dot(const struct dirent*);
368 int		 select_non_dotdot(const struct dirent*);
369 
370 /* ex.c */
371 int		 send_string(int, const char*);
372 int		 recv_string(int, char**);
373 int		 send_iri(int, struct iri*);
374 int		 recv_iri(int, struct iri*);
375 void		 free_recvd_iri(struct iri*);
376 int		 send_vhost(int, struct vhost*);
377 int		 recv_vhost(int, struct vhost**);
378 int		 send_time(int, time_t);
379 int		 recv_time(int, time_t*);
380 int		 send_fd(int, int);
381 int		 recv_fd(int);
382 int		 executor_main(struct imsgbuf*);
383 
384 /* fcgi.c */
385 void		 fcgi_close_backend(struct fcgi *);
386 void		 fcgi_read(struct bufferevent *, void *);
387 void		 fcgi_write(struct bufferevent *, void *);
388 void		 fcgi_error(struct bufferevent *, short, void *);
389 void		 fcgi_req(struct fcgi *, struct client *);
390 
391 /* sandbox.c */
392 void		 sandbox_server_process(void);
393 void		 sandbox_executor_process(void);
394 void		 sandbox_logger_process(void);
395 
396 /* utf8.c */
397 int		 valid_multibyte_utf8(struct parser*);
398 char		*utf8_nth(char*, size_t);
399 
400 /* iri.c */
401 int		 parse_iri(char*, struct iri*, const char**);
402 int		 trim_req_iri(char*, const char **);
403 int		 serialize_iri(struct iri*, char*, size_t);
404 char		*pct_decode_str(char *);
405 
406 /* puny.c */
407 int		 puny_decode(const char*, char*, size_t, const char**);
408 
409 /* utils.c */
410 void		 block_signals(void);
411 void		 unblock_signals(void);
412 int		 starts_with(const char*, const char*);
413 int		 ends_with(const char*, const char*);
414 ssize_t		 filesize(int);
415 char		*absolutify_path(const char*);
416 char		*xstrdup(const char*);
417 void		*xcalloc(size_t, size_t);
418 void		 gen_certificate(const char*, const char*, const char*);
419 X509_STORE	*load_ca(const char*);
420 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
421 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
422 
423 #endif