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 GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
42 
43 #define SUCCESS		20
44 #define TEMP_REDIRECT	30
45 #define TEMP_FAILURE	40
46 #define CGI_ERROR	42
47 #define NOT_FOUND	51
48 #define PROXY_REFUSED	53
49 #define BAD_REQUEST	59
50 #define CLIENT_CERT_REQ	60
51 #define CERT_NOT_AUTH	61
52 
53 #define MAX_USERS	64
54 
55 /* maximum hostname and label length, +1 for the NUL-terminator */
56 #define DOMAIN_NAME_LEN	(253+1)
57 #define LABEL_LEN	(63+1)
58 
59 #define FCGI_MAX	32
60 #define PROC_MAX	16
61 
62 struct fcgi {
63 	int		 id;
64 	char		*path;
65 	char		*port;
66 	char		*prog;
67 	int		 fd;
68 	struct event	 e;
69 
70 #define FCGI_OFF	0
71 #define FCGI_INFLIGHT	1
72 #define FCGI_READY	2
73 	int		 s;
74 };
75 extern struct fcgi fcgi[FCGI_MAX];
76 
77 TAILQ_HEAD(lochead, location);
78 struct location {
79 	const char	*match;
80 	const char	*lang;
81 	const char	*default_mime;
82 	const char	*index;
83 	int		 auto_index; /* 0 auto, -1 off, 1 on */
84 	int		 block_code;
85 	const char	*block_fmt;
86 	int		 strip;
87 	X509_STORE	*reqca;
88 	int		 disable_log;
89 	int		 fcgi;
90 
91 	const char	*dir;
92 	int		 dirfd;
93 
94 	TAILQ_ENTRY(location) locations;
95 };
96 
97 TAILQ_HEAD(envhead, envlist);
98 struct envlist {
99 	char		*name;
100 	char		*value;
101 	TAILQ_ENTRY(envlist) envs;
102 };
103 
104 TAILQ_HEAD(aliashead, alist);
105 struct alist {
106 	char		*alias;
107 	TAILQ_ENTRY(alist) aliases;
108 };
109 
110 extern TAILQ_HEAD(vhosthead, vhost) hosts;
111 struct vhost {
112 	const char	*domain;
113 	const char	*cert;
114 	const char	*key;
115 	const char	*cgi;
116 	const char	*entrypoint;
117 
118 	TAILQ_ENTRY(vhost) vhosts;
119 
120 	/* the first location rule is always '*' and holds the default
121 	 * settings for the vhost, then follows the "real" location
122 	 * rules as specified in the configuration. */
123 	struct lochead	 locations;
124 
125 	struct envhead	 env;
126 	struct aliashead aliases;
127 };
128 
129 struct etm {			/* extension to mime */
130 	const char	*mime;
131 	const char	*ext;
132 };
133 
134 struct mime {
135 	struct etm	*t;
136 	size_t		len;
137 	size_t		cap;
138 };
139 
140 struct conf {
141 	/* from command line */
142 	int		 foreground;
143 	int		 verbose;
144 
145 	/* in the config */
146 	int		 port;
147 	int		 ipv6;
148 	uint32_t	 protos;
149 	struct mime	 mime;
150 	char		*chroot;
151 	char		*user;
152 	int		 prefork;
153 };
154 
155 extern const char *config_path;
156 extern struct conf conf;
157 
158 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
159 
160 extern int servpipes[PROC_MAX];
161 
162 struct iri {
163 	char		*schema;
164 	char		*host;
165 	char		*port;
166 	uint16_t	 port_no;
167 	char		*path;
168 	char		*query;
169 	char		*fragment;
170 };
171 
172 struct parser {
173 	char		*iri;
174 	struct iri	*parsed;
175 	const char	*err;
176 };
177 
178 struct mbuf {
179 	size_t			len;
180 	size_t			off;
181 	TAILQ_ENTRY(mbuf)	mbufs;
182 	char			data[];
183 };
184 TAILQ_HEAD(mbufhead, mbuf);
185 
186 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
187 
188 typedef void (*statefn)(int, short, void*);
189 
190 /*
191  * DFA: handle_handshake is the initial state, close_conn the final.
192  * Sometimes we have an enter_* function to handle the state switch.
193  *
194  * handle_handshake -> handle_open_conn
195  * handle_handshake -> close_conn		// on err
196  *
197  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
198  * handle_open_conn -> send_fcgi_req		// via apply_fastcgi, IMSG_FCGI_FD
199  * handle_open_conn -> handle_dirlist		// ...same
200  * handle_open_conn -> send_file		// ...same
201  * handle_open_conn -> start_reply		// on error
202  *
203  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
204  * handle_cgi_reply -> start_reply	// on error
205  *
206  * handle_cgi -> close_conn
207  *
208  * send_fcgi_req -> copy_mbuf		// via handle_fcgi
209  * handle_fcgi -> close_all		// on error
210  * copy_mbuf -> close_conn		// on success/error
211  *
212  * handle_dirlist -> send_directory_listing
213  * handle_dirlist -> close_conn			// on error
214  *
215  * send_directory_listing -> close_conn
216  *
217  * send_file -> close_conn
218  */
219 struct client {
220 	int		 id;
221 	struct tls	*ctx;
222 	char		 req[GEMINI_URL_LEN];
223 	struct iri	 iri;
224 	char		 domain[DOMAIN_NAME_LEN];
225 
226 	/*
227 	 * start_reply uses this to know what function call after the
228 	 * reply.  It's also used as sentinel value in fastcgi to know
229 	 * if the server has closed the request.
230 	 */
231 	statefn		 next;
232 
233 	int		 code;
234 	const char	*meta;
235 	int		 fd, pfd;
236 	struct dirent	**dir;
237 	int		 dirlen, diroff;
238 	int		 fcgi;
239 
240 	/* big enough to store STATUS + SPACE + META + CRLF */
241 	char		 sbuf[1029];
242 	ssize_t		 len, off;
243 
244 	struct mbufhead	 mbufhead;
245 
246 	struct sockaddr_storage	 addr;
247 	struct vhost	*host;	/* host they're talking to */
248 };
249 
250 extern struct client clients[MAX_USERS];
251 
252 struct cgireq {
253 	char		buf[GEMINI_URL_LEN];
254 
255 	size_t		iri_schema_off;
256 	size_t		iri_host_off;
257 	size_t		iri_port_off;
258 	size_t		iri_path_off;
259 	size_t		iri_query_off;
260 	size_t		iri_fragment_off;
261 	int		iri_portno;
262 
263 	char		spath[PATH_MAX+1];
264 	char		relpath[PATH_MAX+1];
265 	char		addr[NI_MAXHOST+1];
266 
267 	/* AFAIK there isn't an upper limit for these two fields. */
268 	char		subject[64+1];
269 	char		issuer[64+1];
270 
271 	char		hash[128+1];
272 	char		version[8];
273 	char		cipher[32];
274 	int		cipher_strength;
275 	time_t		notbefore;
276 	time_t		notafter;
277 
278 	size_t		host_off;
279 	size_t		loc_off;
280 };
281 
282 enum {
283 	FILE_EXISTS,
284 	FILE_EXECUTABLE,
285 	FILE_DIRECTORY,
286 	FILE_MISSING,
287 };
288 
289 enum imsg_type {
290 	IMSG_CGI_REQ,
291 	IMSG_CGI_RES,
292 	IMSG_FCGI_REQ,
293 	IMSG_FCGI_FD,
294 	IMSG_LOG,
295 	IMSG_QUIT,
296 };
297 
298 /* gmid.c */
299 char		*data_dir(void);
300 void		 load_local_cert(const char*, const char*);
301 void		 load_vhosts(void);
302 int		 make_socket(int, int);
303 void		 setup_tls(void);
304 void		 init_config(void);
305 void		 free_config(void);
306 void		 drop_priv(void);
307 
308 /* provided by lex/yacc */
309 extern FILE *yyin;
310 extern int yylineno;
311 extern int yyparse(void);
312 extern int yylex(void);
313 
314 void		 yyerror(const char*, ...);
315 int		 parse_portno(const char*);
316 void		 parse_conf(const char*);
317 
318 /* log.c */
319 void		 fatal(const char*, ...)
320 	__attribute__((format (printf, 1, 2)))
321 	__attribute__((__noreturn__));
322 
323 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
324 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
325 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
326 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
327 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
328 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
329 void		 log_request(struct client*, char*, size_t);
330 int		 logger_main(int, struct imsgbuf*);
331 
332 /* mime.c */
333 void		 init_mime(struct mime*);
334 void		 add_mime(struct mime*, const char*, const char*);
335 void		 load_default_mime(struct mime*);
336 const char	*mime(struct vhost*, const char*);
337 
338 /* server.c */
339 const char	*vhost_lang(struct vhost*, const char*);
340 const char	*vhost_default_mime(struct vhost*, const char*);
341 const char	*vhost_index(struct vhost*, const char*);
342 int		 vhost_auto_index(struct vhost*, const char*);
343 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
344 int		 vhost_fastcgi(struct vhost*, const char*);
345 int		 vhost_dirfd(struct vhost*, const char*);
346 int		 vhost_strip(struct vhost*, const char*);
347 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
348 int		 vhost_disable_log(struct vhost*, const char*);
349 
350 void		 mark_nonblock(int);
351 void		 start_reply(struct client*, int, const char*);
352 void		 close_conn(int, short, void*);
353 struct client	*try_client_by_id(int);
354 void		 loop(struct tls*, int, int, struct imsgbuf*);
355 
356 /* dirs.c */
357 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
358 		    int(*)(const struct dirent**, const struct dirent**));
359 int		 select_non_dot(const struct dirent*);
360 int		 select_non_dotdot(const struct dirent*);
361 
362 /* ex.c */
363 int		 send_string(int, const char*);
364 int		 recv_string(int, char**);
365 int		 send_iri(int, struct iri*);
366 int		 recv_iri(int, struct iri*);
367 void		 free_recvd_iri(struct iri*);
368 int		 send_vhost(int, struct vhost*);
369 int		 recv_vhost(int, struct vhost**);
370 int		 send_time(int, time_t);
371 int		 recv_time(int, time_t*);
372 int		 send_fd(int, int);
373 int		 recv_fd(int);
374 int		 executor_main(struct imsgbuf*);
375 
376 /* fcgi.c */
377 void		 handle_fcgi(int, short, void*);
378 void		 send_fcgi_req(struct fcgi*, struct client*);
379 
380 /* sandbox.c */
381 void		 sandbox_server_process(void);
382 void		 sandbox_executor_process(void);
383 void		 sandbox_logger_process(void);
384 
385 /* utf8.c */
386 int		 valid_multibyte_utf8(struct parser*);
387 char		*utf8_nth(char*, size_t);
388 
389 /* iri.c */
390 int		 parse_iri(char*, struct iri*, const char**);
391 int		 trim_req_iri(char*, const char **);
392 int		 serialize_iri(struct iri*, char*, size_t);
393 char		*pct_decode_str(char *);
394 
395 /* puny.c */
396 int		 puny_decode(const char*, char*, size_t, const char**);
397 
398 /* utils.c */
399 void		 block_signals(void);
400 void		 unblock_signals(void);
401 int		 starts_with(const char*, const char*);
402 int		 ends_with(const char*, const char*);
403 ssize_t		 filesize(int);
404 char		*absolutify_path(const char*);
405 char		*xstrdup(const char*);
406 void		*xcalloc(size_t, size_t);
407 void		 gen_certificate(const char*, const char*, const char*);
408 X509_STORE	*load_ca(const char*);
409 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
410 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
411 
412 #endif