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 <limits.h>
30 #include <netdb.h>
31 #include <signal.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <time.h>
35 #include <tls.h>
36 #include <unistd.h>
37 
38 #include <openssl/x509.h>
39 
40 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
41 
42 #define SUCCESS		20
43 #define TEMP_REDIRECT	30
44 #define TEMP_FAILURE	40
45 #define CGI_ERROR	42
46 #define NOT_FOUND	51
47 #define PROXY_REFUSED	53
48 #define BAD_REQUEST	59
49 #define CLIENT_CERT_REQ	60
50 #define CERT_NOT_AUTH	61
51 
52 #define MAX_USERS	64
53 
54 /* maximum hostname and label length, +1 for the NUL-terminator */
55 #define DOMAIN_NAME_LEN	(253+1)
56 #define LABEL_LEN	(63+1)
57 
58 #define PROC_MAX	16
59 
60 TAILQ_HEAD(lochead, location);
61 struct location {
62 	const char	*match;
63 	const char	*lang;
64 	const char	*default_mime;
65 	const char	*index;
66 	int		 auto_index; /* 0 auto, -1 off, 1 on */
67 	int		 block_code;
68 	const char	*block_fmt;
69 	int		 strip;
70 	X509_STORE	*reqca;
71 	int		 disable_log;
72 
73 	const char	*dir;
74 	int		 dirfd;
75 
76 	TAILQ_ENTRY(location) locations;
77 };
78 
79 TAILQ_HEAD(envhead, envlist);
80 struct envlist {
81 	char		*name;
82 	char		*value;
83 	TAILQ_ENTRY(envlist) envs;
84 };
85 
86 TAILQ_HEAD(aliashead, alist);
87 struct alist {
88 	char		*alias;
89 	TAILQ_ENTRY(alist) aliases;
90 };
91 
92 extern TAILQ_HEAD(vhosthead, vhost) hosts;
93 struct vhost {
94 	const char	*domain;
95 	const char	*cert;
96 	const char	*key;
97 	const char	*cgi;
98 	const char	*entrypoint;
99 
100 	TAILQ_ENTRY(vhost) vhosts;
101 
102 	/* the first location rule is always '*' and holds the default
103 	 * settings for the vhost, then follows the "real" location
104 	 * rules as specified in the configuration. */
105 	struct lochead	 locations;
106 
107 	struct envhead	 env;
108 	struct aliashead aliases;
109 };
110 
111 struct etm {			/* extension to mime */
112 	const char	*mime;
113 	const char	*ext;
114 };
115 
116 struct mime {
117 	struct etm	*t;
118 	size_t		len;
119 	size_t		cap;
120 };
121 
122 struct conf {
123 	/* from command line */
124 	int		 foreground;
125 	int		 verbose;
126 
127 	/* in the config */
128 	int		 port;
129 	int		 ipv6;
130 	uint32_t	 protos;
131 	struct mime	 mime;
132 	char		*chroot;
133 	char		*user;
134 	int		 prefork;
135 };
136 
137 extern const char *config_path;
138 extern struct conf conf;
139 
140 extern struct imsgbuf logibuf, exibuf, servibuf[PROC_MAX];
141 
142 extern int servpipes[PROC_MAX];
143 
144 struct iri {
145 	char		*schema;
146 	char		*host;
147 	char		*port;
148 	uint16_t	 port_no;
149 	char		*path;
150 	char		*query;
151 	char		*fragment;
152 };
153 
154 struct parser {
155 	char		*iri;
156 	struct iri	*parsed;
157 	const char	*err;
158 };
159 
160 struct client;
161 
162 typedef void (imsg_handlerfn)(struct imsgbuf*, struct imsg*, size_t);
163 
164 typedef void (*statefn)(int, short, void*);
165 
166 /*
167  * DFA: handle_handshake is the initial state, close_conn the final.
168  * Sometimes we have an enter_* function to handle the state switch.
169  *
170  * handle_handshake -> handle_open_conn
171  * handle_handshake -> close_conn		// on err
172  *
173  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
174  * handle_open_conn -> handle_dirlist		// ...same
175  * handle_open_conn -> send_file		// ...same
176  * handle_open_conn -> start_reply		// on error
177  *
178  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
179  * handle_cgi_reply -> start_reply	// on error
180  *
181  * handle_cgi -> close_conn
182  *
183  * handle_dirlist -> send_directory_listing
184  * handle_dirlist -> close_conn			// on error
185  *
186  * send_directory_listing -> close_conn
187  *
188  * send_file -> close_conn
189  */
190 struct client {
191 	int		 id;
192 	struct tls	*ctx;
193 	char		 req[GEMINI_URL_LEN];
194 	struct iri	 iri;
195 	char		 domain[DOMAIN_NAME_LEN];
196 	statefn		 next;
197 	int		 code;
198 	const char	*meta;
199 	int		 fd, pfd;
200 	struct dirent	**dir;
201 	int		 dirlen, diroff;
202 
203 	/* big enough to store STATUS + SPACE + META + CRLF */
204 	char		 sbuf[1029];
205 	ssize_t		 len, off;
206 
207 	struct sockaddr_storage	 addr;
208 	struct vhost	*host;	/* host they're talking to */
209 };
210 
211 struct cgireq {
212 	char		buf[GEMINI_URL_LEN];
213 
214 	size_t		iri_schema_off;
215 	size_t		iri_host_off;
216 	size_t		iri_port_off;
217 	size_t		iri_path_off;
218 	size_t		iri_query_off;
219 	size_t		iri_fragment_off;
220 	int		iri_portno;
221 
222 	char		spath[PATH_MAX+1];
223 	char		relpath[PATH_MAX+1];
224 	char		addr[NI_MAXHOST+1];
225 
226 	/* AFAIK there isn't an upper limit for these two fields. */
227 	char		subject[64+1];
228 	char		issuer[64+1];
229 
230 	char		hash[128+1];
231 	char		version[8];
232 	char		cipher[32];
233 	int		cipher_strength;
234 	time_t		notbefore;
235 	time_t		notafter;
236 
237 	size_t		host_off;
238 	size_t		loc_off;
239 };
240 
241 enum {
242 	FILE_EXISTS,
243 	FILE_EXECUTABLE,
244 	FILE_DIRECTORY,
245 	FILE_MISSING,
246 };
247 
248 enum imsg_type {
249 	IMSG_CGI_REQ,
250 	IMSG_CGI_RES,
251 	IMSG_LOG,
252 	IMSG_QUIT,
253 };
254 
255 /* gmid.c */
256 char		*data_dir(void);
257 void		 load_local_cert(const char*, const char*);
258 void		 load_vhosts(void);
259 int		 make_socket(int, int);
260 void		 setup_tls(void);
261 void		 init_config(void);
262 void		 free_config(void);
263 void		 drop_priv(void);
264 
265 /* provided by lex/yacc */
266 extern FILE *yyin;
267 extern int yylineno;
268 extern int yyparse(void);
269 extern int yylex(void);
270 
271 void		 yyerror(const char*, ...);
272 int		 parse_portno(const char*);
273 void		 parse_conf(const char*);
274 
275 /* log.c */
276 void		 fatal(const char*, ...)
277 	__attribute__((format (printf, 1, 2)))
278 	__attribute__((__noreturn__));
279 
280 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
281 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
282 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
283 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
284 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
285 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
286 void		 log_request(struct client*, char*, size_t);
287 int		 logger_main(int, struct imsgbuf*);
288 
289 /* mime.c */
290 void		 init_mime(struct mime*);
291 void		 add_mime(struct mime*, const char*, const char*);
292 void		 load_default_mime(struct mime*);
293 const char	*mime(struct vhost*, const char*);
294 
295 /* server.c */
296 const char	*vhost_lang(struct vhost*, const char*);
297 const char	*vhost_default_mime(struct vhost*, const char*);
298 const char	*vhost_index(struct vhost*, const char*);
299 int		 vhost_auto_index(struct vhost*, const char*);
300 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
301 int		 vhost_strip(struct vhost*, const char*);
302 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
303 int		 vhost_disable_log(struct vhost*, const char*);
304 void		 mark_nonblock(int);
305 void		 loop(struct tls*, int, int, struct imsgbuf*);
306 
307 /* dirs.c */
308 int		 scandir_fd(int, struct dirent***, int(*)(const struct dirent*),
309 		    int(*)(const struct dirent**, const struct dirent**));
310 int		 select_non_dot(const struct dirent*);
311 int		 select_non_dotdot(const struct dirent*);
312 
313 /* ex.c */
314 int		 send_string(int, const char*);
315 int		 recv_string(int, char**);
316 int		 send_iri(int, struct iri*);
317 int		 recv_iri(int, struct iri*);
318 void		 free_recvd_iri(struct iri*);
319 int		 send_vhost(int, struct vhost*);
320 int		 recv_vhost(int, struct vhost**);
321 int		 send_time(int, time_t);
322 int		 recv_time(int, time_t*);
323 int		 send_fd(int, int);
324 int		 recv_fd(int);
325 int		 executor_main(struct imsgbuf*);
326 
327 /* sandbox.c */
328 void		 sandbox_server_process(void);
329 void		 sandbox_executor_process(void);
330 void		 sandbox_logger_process(void);
331 
332 /* utf8.c */
333 int		 valid_multibyte_utf8(struct parser*);
334 char		*utf8_nth(char*, size_t);
335 
336 /* iri.c */
337 int		 parse_iri(char*, struct iri*, const char**);
338 int		 trim_req_iri(char*, const char **);
339 int		 serialize_iri(struct iri*, char*, size_t);
340 char		*pct_decode_str(char *);
341 
342 /* puny.c */
343 int		 puny_decode(const char*, char*, size_t, const char**);
344 
345 /* utils.c */
346 void		 block_signals(void);
347 void		 unblock_signals(void);
348 int		 starts_with(const char*, const char*);
349 int		 ends_with(const char*, const char*);
350 ssize_t		 filesize(int);
351 char		*absolutify_path(const char*);
352 char		*xstrdup(const char*);
353 void		*xcalloc(size_t, size_t);
354 void		 gen_certificate(const char*, const char*, const char*);
355 X509_STORE	*load_ca(const char*);
356 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
357 void		 dispatch_imsg(struct imsgbuf*, imsg_handlerfn**, size_t);
358 
359 #endif