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 1.7"
42 #define GMID_VERSION	"gmid/1.7"
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 	struct event	 e;
72 
73 	/* number of pending clients */
74 	int		 pending;
75 
76 #define FCGI_OFF	0
77 #define FCGI_INFLIGHT	1
78 #define FCGI_READY	2
79 	int		 s;
80 };
81 extern struct fcgi fcgi[FCGI_MAX];
82 
83 TAILQ_HEAD(lochead, location);
84 struct location {
85 	const char	*match;
86 	const char	*lang;
87 	const char	*default_mime;
88 	const char	*index;
89 	int		 auto_index; /* 0 auto, -1 off, 1 on */
90 	int		 block_code;
91 	const char	*block_fmt;
92 	int		 strip;
93 	X509_STORE	*reqca;
94 	int		 disable_log;
95 	int		 fcgi;
96 
97 	const char	*dir;
98 	int		 dirfd;
99 
100 	TAILQ_ENTRY(location) locations;
101 };
102 
103 TAILQ_HEAD(envhead, envlist);
104 struct envlist {
105 	char		*name;
106 	char		*value;
107 	TAILQ_ENTRY(envlist) envs;
108 };
109 
110 TAILQ_HEAD(aliashead, alist);
111 struct alist {
112 	char		*alias;
113 	TAILQ_ENTRY(alist) aliases;
114 };
115 
116 extern TAILQ_HEAD(vhosthead, vhost) hosts;
117 struct vhost {
118 	const char	*domain;
119 	const char	*cert;
120 	const char	*key;
121 	const char	*cgi;
122 	const char	*entrypoint;
123 
124 	TAILQ_ENTRY(vhost) vhosts;
125 
126 	/* the first location rule is always '*' and holds the default
127 	 * settings for the vhost, then follows the "real" location
128 	 * rules as specified in the configuration. */
129 	struct lochead	 locations;
130 
131 	struct envhead	 env;
132 	struct envhead	 params;
133 	struct aliashead aliases;
134 };
135 
136 struct etm {			/* extension to mime */
137 	const char	*mime;
138 	const char	*ext;
139 };
140 
141 struct mime {
142 	struct etm	*t;
143 	size_t		len;
144 	size_t		cap;
145 };
146 
147 struct conf {
148 	/* from command line */
149 	int		 foreground;
150 	int		 verbose;
151 
152 	/* in the config */
153 	int		 port;
154 	int		 ipv6;
155 	uint32_t	 protos;
156 	struct mime	 mime;
157 	char		*chroot;
158 	char		*user;
159 	int		 prefork;
160 };
161 
162 extern const char *config_path;
163 extern struct conf conf;
164 
165 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
166 
167 extern int servpipes[PROC_MAX];
168 
169 struct iri {
170 	char		*schema;
171 	char		*host;
172 	char		*port;
173 	uint16_t	 port_no;
174 	char		*path;
175 	char		*query;
176 	char		*fragment;
177 };
178 
179 struct parser {
180 	char		*iri;
181 	struct iri	*parsed;
182 	const char	*err;
183 };
184 
185 struct mbuf {
186 	size_t			len;
187 	size_t			off;
188 	TAILQ_ENTRY(mbuf)	mbufs;
189 	char			data[];
190 };
191 TAILQ_HEAD(mbufhead, mbuf);
192 
193 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
194 
195 typedef void (*statefn)(int, short, void*);
196 
197 /*
198  * DFA: handle_handshake is the initial state, close_conn the final.
199  * Sometimes we have an enter_* function to handle the state switch.
200  *
201  * handle_handshake -> handle_open_conn
202  * handle_handshake -> close_conn		// on err
203  *
204  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
205  * handle_open_conn -> send_fcgi_req		// via apply_fastcgi, IMSG_FCGI_FD
206  * handle_open_conn -> handle_dirlist		// ...same
207  * handle_open_conn -> send_file		// ...same
208  * handle_open_conn -> start_reply		// on error
209  *
210  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
211  * handle_cgi_reply -> start_reply	// on error
212  *
213  * handle_cgi -> close_conn
214  *
215  * send_fcgi_req -> copy_mbuf		// via handle_fcgi
216  * handle_fcgi -> close_all		// on error
217  * copy_mbuf -> close_conn		// on success/error
218  *
219  * handle_dirlist -> send_directory_listing
220  * handle_dirlist -> close_conn			// on error
221  *
222  * send_directory_listing -> close_conn
223  *
224  * send_file -> close_conn
225  */
226 struct client {
227 	int		 id;
228 	struct tls	*ctx;
229 	char		 req[GEMINI_URL_LEN];
230 	struct iri	 iri;
231 	char		 domain[DOMAIN_NAME_LEN];
232 
233 	/*
234 	 * start_reply uses this to know what function call after the
235 	 * reply.  It's also used as sentinel value in fastcgi to know
236 	 * if the server has closed the request.
237 	 */
238 	statefn		 next;
239 
240 	int		 code;
241 	const char	*meta;
242 	int		 fd, pfd;
243 	struct dirent	**dir;
244 	int		 dirlen, diroff;
245 	int		 fcgi;
246 
247 	/* big enough to store STATUS + SPACE + META + CRLF */
248 	char		 sbuf[1029];
249 	ssize_t		 len, off;
250 
251 	struct mbufhead	 mbufhead;
252 
253 	struct sockaddr_storage	 addr;
254 	struct vhost	*host;	/* host they're talking to */
255 	size_t		 loc;	/* location matched */
256 };
257 
258 extern struct client clients[MAX_USERS];
259 
260 struct cgireq {
261 	char		buf[GEMINI_URL_LEN];
262 
263 	size_t		iri_schema_off;
264 	size_t		iri_host_off;
265 	size_t		iri_port_off;
266 	size_t		iri_path_off;
267 	size_t		iri_query_off;
268 	size_t		iri_fragment_off;
269 	int		iri_portno;
270 
271 	char		spath[PATH_MAX+1];
272 	char		relpath[PATH_MAX+1];
273 	char		addr[NI_MAXHOST+1];
274 
275 	/* AFAIK there isn't an upper limit for these two fields. */
276 	char		subject[64+1];
277 	char		issuer[64+1];
278 
279 	char		hash[128+1];
280 	char		version[8];
281 	char		cipher[32];
282 	int		cipher_strength;
283 	time_t		notbefore;
284 	time_t		notafter;
285 
286 	size_t		host_off;
287 	size_t		loc_off;
288 };
289 
290 enum {
291 	FILE_EXISTS,
292 	FILE_EXECUTABLE,
293 	FILE_DIRECTORY,
294 	FILE_MISSING,
295 };
296 
297 enum imsg_type {
298 	IMSG_CGI_REQ,
299 	IMSG_CGI_RES,
300 	IMSG_FCGI_REQ,
301 	IMSG_FCGI_FD,
302 	IMSG_LOG,
303 	IMSG_LOG_TYPE,
304 	IMSG_QUIT,
305 };
306 
307 /* gmid.c */
308 char		*data_dir(void);
309 void		 load_local_cert(const char*, const char*);
310 void		 load_vhosts(void);
311 int		 make_socket(int, int);
312 void		 setup_tls(void);
313 void		 init_config(void);
314 void		 free_config(void);
315 void		 drop_priv(void);
316 
317 void		 yyerror(const char*, ...);
318 int		 parse_portno(const char*);
319 void		 parse_conf(const char*);
320 int		 cmdline_symset(char *);
321 
322 /* log.c */
323 void		 fatal(const char*, ...)
324 	__attribute__((format (printf, 1, 2)))
325 	__attribute__((__noreturn__));
326 
327 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
328 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
329 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
330 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
331 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
332 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
333 void		 log_request(struct client*, char*, size_t);
334 int		 logger_main(int, struct imsgbuf*);
335 
336 /* mime.c */
337 void		 init_mime(struct mime*);
338 void		 add_mime(struct mime*, const char*, const char*);
339 void		 load_default_mime(struct mime*);
340 const char	*mime(struct vhost*, const char*);
341 
342 /* server.c */
343 extern int	shutting_down;
344 const char	*vhost_lang(struct vhost*, const char*);
345 const char	*vhost_default_mime(struct vhost*, const char*);
346 const char	*vhost_index(struct vhost*, const char*);
347 int		 vhost_auto_index(struct vhost*, const char*);
348 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
349 int		 vhost_fastcgi(struct vhost*, const char*);
350 int		 vhost_dirfd(struct vhost*, const char*, size_t*);
351 int		 vhost_strip(struct vhost*, const char*);
352 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
353 int		 vhost_disable_log(struct vhost*, const char*);
354 
355 void		 mark_nonblock(int);
356 void		 start_reply(struct client*, int, const char*);
357 void		 close_conn(int, short, void*);
358 struct client	*try_client_by_id(int);
359 void		 loop(struct tls*, int, int, struct imsgbuf*);
360 
361 /* dirs.c */
362 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
363 		    int(*)(const struct dirent**, const struct dirent**));
364 int		 select_non_dot(const struct dirent*);
365 int		 select_non_dotdot(const struct dirent*);
366 
367 /* ex.c */
368 int		 send_string(int, const char*);
369 int		 recv_string(int, char**);
370 int		 send_iri(int, struct iri*);
371 int		 recv_iri(int, struct iri*);
372 void		 free_recvd_iri(struct iri*);
373 int		 send_vhost(int, struct vhost*);
374 int		 recv_vhost(int, struct vhost**);
375 int		 send_time(int, time_t);
376 int		 recv_time(int, time_t*);
377 int		 send_fd(int, int);
378 int		 recv_fd(int);
379 int		 executor_main(struct imsgbuf*);
380 
381 /* fcgi.c */
382 void		 fcgi_close_backend(struct fcgi *);
383 void		 handle_fcgi(int, short, void*);
384 void		 send_fcgi_req(struct fcgi*, struct client*);
385 
386 /* sandbox.c */
387 void		 sandbox_server_process(void);
388 void		 sandbox_executor_process(void);
389 void		 sandbox_logger_process(void);
390 
391 /* utf8.c */
392 int		 valid_multibyte_utf8(struct parser*);
393 char		*utf8_nth(char*, size_t);
394 
395 /* iri.c */
396 int		 parse_iri(char*, struct iri*, const char**);
397 int		 trim_req_iri(char*, const char **);
398 int		 serialize_iri(struct iri*, char*, size_t);
399 char		*pct_decode_str(char *);
400 
401 /* puny.c */
402 int		 puny_decode(const char*, char*, size_t, const char**);
403 
404 /* utils.c */
405 void		 block_signals(void);
406 void		 unblock_signals(void);
407 int		 starts_with(const char*, const char*);
408 int		 ends_with(const char*, const char*);
409 ssize_t		 filesize(int);
410 char		*absolutify_path(const char*);
411 char		*xstrdup(const char*);
412 void		*xcalloc(size_t, size_t);
413 void		 gen_certificate(const char*, const char*, const char*);
414 X509_STORE	*load_ca(const char*);
415 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
416 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
417 
418 #endif