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_VERSION	"gmid/1.7"
42 
43 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
44 
45 #define SUCCESS		20
46 #define TEMP_REDIRECT	30
47 #define TEMP_FAILURE	40
48 #define CGI_ERROR	42
49 #define NOT_FOUND	51
50 #define PROXY_REFUSED	53
51 #define BAD_REQUEST	59
52 #define CLIENT_CERT_REQ	60
53 #define CERT_NOT_AUTH	61
54 
55 #define MAX_USERS	64
56 
57 /* maximum hostname and label length, +1 for the NUL-terminator */
58 #define DOMAIN_NAME_LEN	(253+1)
59 #define LABEL_LEN	(63+1)
60 
61 #define FCGI_MAX	32
62 #define PROC_MAX	16
63 
64 struct fcgi {
65 	int		 id;
66 	char		*path;
67 	char		*port;
68 	char		*prog;
69 	int		 fd;
70 	struct event	 e;
71 
72 #define FCGI_OFF	0
73 #define FCGI_INFLIGHT	1
74 #define FCGI_READY	2
75 	int		 s;
76 };
77 extern struct fcgi fcgi[FCGI_MAX];
78 
79 TAILQ_HEAD(lochead, location);
80 struct location {
81 	const char	*match;
82 	const char	*lang;
83 	const char	*default_mime;
84 	const char	*index;
85 	int		 auto_index; /* 0 auto, -1 off, 1 on */
86 	int		 block_code;
87 	const char	*block_fmt;
88 	int		 strip;
89 	X509_STORE	*reqca;
90 	int		 disable_log;
91 	int		 fcgi;
92 
93 	const char	*dir;
94 	int		 dirfd;
95 
96 	TAILQ_ENTRY(location) locations;
97 };
98 
99 TAILQ_HEAD(envhead, envlist);
100 struct envlist {
101 	char		*name;
102 	char		*value;
103 	TAILQ_ENTRY(envlist) envs;
104 };
105 
106 TAILQ_HEAD(aliashead, alist);
107 struct alist {
108 	char		*alias;
109 	TAILQ_ENTRY(alist) aliases;
110 };
111 
112 extern TAILQ_HEAD(vhosthead, vhost) hosts;
113 struct vhost {
114 	const char	*domain;
115 	const char	*cert;
116 	const char	*key;
117 	const char	*cgi;
118 	const char	*entrypoint;
119 
120 	TAILQ_ENTRY(vhost) vhosts;
121 
122 	/* the first location rule is always '*' and holds the default
123 	 * settings for the vhost, then follows the "real" location
124 	 * rules as specified in the configuration. */
125 	struct lochead	 locations;
126 
127 	struct envhead	 env;
128 	struct aliashead aliases;
129 };
130 
131 struct etm {			/* extension to mime */
132 	const char	*mime;
133 	const char	*ext;
134 };
135 
136 struct mime {
137 	struct etm	*t;
138 	size_t		len;
139 	size_t		cap;
140 };
141 
142 struct conf {
143 	/* from command line */
144 	int		 foreground;
145 	int		 verbose;
146 
147 	/* in the config */
148 	int		 port;
149 	int		 ipv6;
150 	uint32_t	 protos;
151 	struct mime	 mime;
152 	char		*chroot;
153 	char		*user;
154 	int		 prefork;
155 };
156 
157 extern const char *config_path;
158 extern struct conf conf;
159 
160 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
161 
162 extern int servpipes[PROC_MAX];
163 
164 struct iri {
165 	char		*schema;
166 	char		*host;
167 	char		*port;
168 	uint16_t	 port_no;
169 	char		*path;
170 	char		*query;
171 	char		*fragment;
172 };
173 
174 struct parser {
175 	char		*iri;
176 	struct iri	*parsed;
177 	const char	*err;
178 };
179 
180 struct mbuf {
181 	size_t			len;
182 	size_t			off;
183 	TAILQ_ENTRY(mbuf)	mbufs;
184 	char			data[];
185 };
186 TAILQ_HEAD(mbufhead, mbuf);
187 
188 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
189 
190 typedef void (*statefn)(int, short, void*);
191 
192 /*
193  * DFA: handle_handshake is the initial state, close_conn the final.
194  * Sometimes we have an enter_* function to handle the state switch.
195  *
196  * handle_handshake -> handle_open_conn
197  * handle_handshake -> close_conn		// on err
198  *
199  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
200  * handle_open_conn -> send_fcgi_req		// via apply_fastcgi, IMSG_FCGI_FD
201  * handle_open_conn -> handle_dirlist		// ...same
202  * handle_open_conn -> send_file		// ...same
203  * handle_open_conn -> start_reply		// on error
204  *
205  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
206  * handle_cgi_reply -> start_reply	// on error
207  *
208  * handle_cgi -> close_conn
209  *
210  * send_fcgi_req -> copy_mbuf		// via handle_fcgi
211  * handle_fcgi -> close_all		// on error
212  * copy_mbuf -> close_conn		// on success/error
213  *
214  * handle_dirlist -> send_directory_listing
215  * handle_dirlist -> close_conn			// on error
216  *
217  * send_directory_listing -> close_conn
218  *
219  * send_file -> close_conn
220  */
221 struct client {
222 	int		 id;
223 	struct tls	*ctx;
224 	char		 req[GEMINI_URL_LEN];
225 	struct iri	 iri;
226 	char		 domain[DOMAIN_NAME_LEN];
227 
228 	/*
229 	 * start_reply uses this to know what function call after the
230 	 * reply.  It's also used as sentinel value in fastcgi to know
231 	 * if the server has closed the request.
232 	 */
233 	statefn		 next;
234 
235 	int		 code;
236 	const char	*meta;
237 	int		 fd, pfd;
238 	struct dirent	**dir;
239 	int		 dirlen, diroff;
240 	int		 fcgi;
241 
242 	/* big enough to store STATUS + SPACE + META + CRLF */
243 	char		 sbuf[1029];
244 	ssize_t		 len, off;
245 
246 	struct mbufhead	 mbufhead;
247 
248 	struct sockaddr_storage	 addr;
249 	struct vhost	*host;	/* host they're talking to */
250 	size_t		 loc;	/* location matched */
251 };
252 
253 extern struct client clients[MAX_USERS];
254 
255 struct cgireq {
256 	char		buf[GEMINI_URL_LEN];
257 
258 	size_t		iri_schema_off;
259 	size_t		iri_host_off;
260 	size_t		iri_port_off;
261 	size_t		iri_path_off;
262 	size_t		iri_query_off;
263 	size_t		iri_fragment_off;
264 	int		iri_portno;
265 
266 	char		spath[PATH_MAX+1];
267 	char		relpath[PATH_MAX+1];
268 	char		addr[NI_MAXHOST+1];
269 
270 	/* AFAIK there isn't an upper limit for these two fields. */
271 	char		subject[64+1];
272 	char		issuer[64+1];
273 
274 	char		hash[128+1];
275 	char		version[8];
276 	char		cipher[32];
277 	int		cipher_strength;
278 	time_t		notbefore;
279 	time_t		notafter;
280 
281 	size_t		host_off;
282 	size_t		loc_off;
283 };
284 
285 enum {
286 	FILE_EXISTS,
287 	FILE_EXECUTABLE,
288 	FILE_DIRECTORY,
289 	FILE_MISSING,
290 };
291 
292 enum imsg_type {
293 	IMSG_CGI_REQ,
294 	IMSG_CGI_RES,
295 	IMSG_FCGI_REQ,
296 	IMSG_FCGI_FD,
297 	IMSG_LOG,
298 	IMSG_QUIT,
299 };
300 
301 /* gmid.c */
302 char		*data_dir(void);
303 void		 load_local_cert(const char*, const char*);
304 void		 load_vhosts(void);
305 int		 make_socket(int, int);
306 void		 setup_tls(void);
307 void		 init_config(void);
308 void		 free_config(void);
309 void		 drop_priv(void);
310 
311 /* provided by lex/yacc */
312 extern FILE *yyin;
313 extern int yylineno;
314 extern int yyparse(void);
315 extern int yylex(void);
316 
317 void		 yyerror(const char*, ...);
318 int		 parse_portno(const char*);
319 void		 parse_conf(const char*);
320 
321 /* log.c */
322 void		 fatal(const char*, ...)
323 	__attribute__((format (printf, 1, 2)))
324 	__attribute__((__noreturn__));
325 
326 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
327 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
328 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
329 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
330 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
331 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
332 void		 log_request(struct client*, char*, size_t);
333 int		 logger_main(int, struct imsgbuf*);
334 
335 /* mime.c */
336 void		 init_mime(struct mime*);
337 void		 add_mime(struct mime*, const char*, const char*);
338 void		 load_default_mime(struct mime*);
339 const char	*mime(struct vhost*, const char*);
340 
341 /* server.c */
342 const char	*vhost_lang(struct vhost*, const char*);
343 const char	*vhost_default_mime(struct vhost*, const char*);
344 const char	*vhost_index(struct vhost*, const char*);
345 int		 vhost_auto_index(struct vhost*, const char*);
346 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
347 int		 vhost_fastcgi(struct vhost*, const char*);
348 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
349 int		 vhost_strip(struct vhost*, const char*);
350 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
351 int		 vhost_disable_log(struct vhost*, const char*);
352 
353 void		 mark_nonblock(int);
354 void		 start_reply(struct client*, int, const char*);
355 void		 close_conn(int, short, void*);
356 struct client	*try_client_by_id(int);
357 void		 loop(struct tls*, int, int, struct imsgbuf*);
358 
359 /* dirs.c */
360 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
361 		    int(*)(const struct dirent**, const struct dirent**));
362 int		 select_non_dot(const struct dirent*);
363 int		 select_non_dotdot(const struct dirent*);
364 
365 /* ex.c */
366 int		 send_string(int, const char*);
367 int		 recv_string(int, char**);
368 int		 send_iri(int, struct iri*);
369 int		 recv_iri(int, struct iri*);
370 void		 free_recvd_iri(struct iri*);
371 int		 send_vhost(int, struct vhost*);
372 int		 recv_vhost(int, struct vhost**);
373 int		 send_time(int, time_t);
374 int		 recv_time(int, time_t*);
375 int		 send_fd(int, int);
376 int		 recv_fd(int);
377 int		 executor_main(struct imsgbuf*);
378 
379 /* fcgi.c */
380 void		 handle_fcgi(int, short, void*);
381 void		 send_fcgi_req(struct fcgi*, struct client*);
382 
383 /* sandbox.c */
384 void		 sandbox_server_process(void);
385 void		 sandbox_executor_process(void);
386 void		 sandbox_logger_process(void);
387 
388 /* utf8.c */
389 int		 valid_multibyte_utf8(struct parser*);
390 char		*utf8_nth(char*, size_t);
391 
392 /* iri.c */
393 int		 parse_iri(char*, struct iri*, const char**);
394 int		 trim_req_iri(char*, const char **);
395 int		 serialize_iri(struct iri*, char*, size_t);
396 char		*pct_decode_str(char *);
397 
398 /* puny.c */
399 int		 puny_decode(const char*, char*, size_t, const char**);
400 
401 /* utils.c */
402 void		 block_signals(void);
403 void		 unblock_signals(void);
404 int		 starts_with(const char*, const char*);
405 int		 ends_with(const char*, const char*);
406 ssize_t		 filesize(int);
407 char		*absolutify_path(const char*);
408 char		*xstrdup(const char*);
409 void		*xcalloc(size_t, size_t);
410 void		 gen_certificate(const char*, const char*, const char*);
411 X509_STORE	*load_ca(const char*);
412 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
413 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
414 
415 #endif