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