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 <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <time.h>
33 #include <tls.h>
34 #include <unistd.h>
35 
36 #include <openssl/x509.h>
37 
38 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
39 
40 #define SUCCESS		20
41 #define TEMP_REDIRECT	30
42 #define TEMP_FAILURE	40
43 #define CGI_ERROR	42
44 #define NOT_FOUND	51
45 #define PROXY_REFUSED	53
46 #define BAD_REQUEST	59
47 #define CLIENT_CERT_REQ	60
48 #define CERT_NOT_AUTH	61
49 
50 #define MAX_USERS	64
51 
52 #define HOSTSLEN	64
53 #define LOCLEN		32
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 struct location {
60 	const char	*match;
61 	const char	*lang;
62 	const char	*default_mime;
63 	const char	*index;
64 	int		 auto_index; /* 0 auto, -1 off, 1 on */
65 	int		 block_code;
66 	const char	*block_fmt;
67 	int		 strip;
68 	X509_STORE	*reqca;
69 	int		 disable_log;
70 };
71 
72 struct vhost {
73 	const char	*domain;
74 	const char	*cert;
75 	const char	*key;
76 	const char	*dir;
77 	const char	*cgi;
78 	const char	*entrypoint;
79 	int		 dirfd;
80 
81 	/* the first location rule is always '*' and holds the default
82 	 * settings for the vhost, from locations[1] onwards there are
83 	 * the "real" location rules specified in the configuration. */
84 	struct location	 locations[LOCLEN];
85 };
86 
87 extern struct vhost hosts[HOSTSLEN];
88 
89 struct etm {			/* extension to mime */
90 	const char	*mime;
91 	const char	*ext;
92 };
93 
94 struct mime {
95 	struct etm	*t;
96 	size_t		len;
97 	size_t		cap;
98 };
99 
100 struct conf {
101 	/* from command line */
102 	int		 foreground;
103 	int		 verbose;
104 
105 	/* in the config */
106 	int		 port;
107 	int		 ipv6;
108 	uint32_t	 protos;
109 	struct mime	 mime;
110 	char		*chroot;
111 	char		*user;
112 	int		 prefork;
113 };
114 
115 extern const char *config_path;
116 extern struct conf conf;
117 extern int exfd;
118 
119 extern volatile sig_atomic_t hupped;
120 
121 struct iri {
122 	char		*schema;
123 	char		*host;
124 	char		*port;
125 	uint16_t	 port_no;
126 	char		*path;
127 	char		*query;
128 	char		*fragment;
129 };
130 
131 struct parser {
132 	char		*iri;
133 	struct iri	*parsed;
134 	const char	*err;
135 };
136 
137 struct client;
138 
139 typedef void (*statefn)(int, short, void*);
140 
141 /*
142  * DFA: handle_handshake is the initial state, close_conn the final.
143  * Sometimes we have an enter_* function to handle the state switch.
144  *
145  * handle_handshake -> handle_open_conn
146  * handle_handshake -> close_conn		// on err
147  *
148  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
149  * handle_open_conn -> handle_dirlist		// ...same
150  * handle_open_conn -> send_file		// ...same
151  * handle_open_conn -> start_reply		// on error
152  *
153  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
154  * handle_cgi_reply -> start_reply	// on error
155  *
156  * handle_cgi -> close_conn
157  *
158  * handle_dirlist -> send_directory_listing
159  * handle_dirlist -> close_conn			// on error
160  *
161  * send_directory_listing -> close_conn
162  *
163  * send_file -> close_conn
164  */
165 struct client {
166 	struct tls	*ctx;
167 	char		 req[GEMINI_URL_LEN];
168 	struct iri	 iri;
169 	char		 domain[DOMAIN_NAME_LEN];
170 	statefn		 next;
171 	int		 code;
172 	const char	*meta;
173 	int		 fd, pfd;
174 	DIR		*dir;
175 	char		 sbuf[1024];
176 	ssize_t		 len, off;
177 	struct sockaddr_storage	 addr;
178 	struct vhost	*host;	/* host she's talking to */
179 };
180 
181 enum {
182 	FILE_EXISTS,
183 	FILE_EXECUTABLE,
184 	FILE_DIRECTORY,
185 	FILE_MISSING,
186 };
187 
188 /* gmid.c */
189 void		 sig_handler(int);
190 void		 mkdirs(const char*);
191 char		*data_dir(void);
192 void		 load_local_cert(const char*, const char*);
193 void		 load_vhosts(void);
194 int		 make_socket(int, int);
195 void		 setup_tls(void);
196 void		 init_config(void);
197 void		 free_config(void);
198 void		 drop_priv(void);
199 
200 /* provided by lex/yacc */
201 extern FILE *yyin;
202 extern int yylineno;
203 extern int yyparse(void);
204 extern int yylex(void);
205 
206 void		 yyerror(const char*, ...);
207 int		 parse_portno(const char*);
208 void		 parse_conf(const char*);
209 
210 /* log.c */
211 void		 fatal(const char*, ...)
212 	__attribute__((format (printf, 1, 2)))
213 	__attribute__((__noreturn__));
214 
215 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
216 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
217 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
218 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
219 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
220 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
221 void		 log_request(struct client*, char*, size_t);
222 void		 logger_init(void);
223 
224 /* mime.c */
225 void		 init_mime(struct mime*);
226 void		 add_mime(struct mime*, const char*, const char*);
227 void		 load_default_mime(struct mime*);
228 const char	*mime(struct vhost*, const char*);
229 
230 /* server.c */
231 const char	*vhost_lang(struct vhost*, const char*);
232 const char	*vhost_default_mime(struct vhost*, const char*);
233 const char	*vhost_index(struct vhost*, const char*);
234 int		 vhost_auto_index(struct vhost*, const char*);
235 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
236 int		 vhost_strip(struct vhost*, const char*);
237 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
238 int		 vhost_disable_log(struct vhost*, const char*);
239 void		 mark_nonblock(int);
240 void		 loop(struct tls*, int, int);
241 
242 /* ex.c */
243 int		 send_string(int, const char*);
244 int		 recv_string(int, char**);
245 int		 send_iri(int, struct iri*);
246 int		 recv_iri(int, struct iri*);
247 void		 free_recvd_iri(struct iri*);
248 int		 send_vhost(int, struct vhost*);
249 int		 recv_vhost(int, struct vhost**);
250 int		 send_time(int, time_t);
251 int		 recv_time(int, time_t*);
252 int		 send_fd(int, int);
253 int		 recv_fd(int);
254 int		 executor_main(void);
255 
256 /* sandbox.c */
257 void		 sandbox(void);
258 
259 /* utf8.c */
260 int		 valid_multibyte_utf8(struct parser*);
261 char		*utf8_nth(char*, size_t);
262 
263 /* iri.c */
264 int		 parse_iri(char*, struct iri*, const char**);
265 int		 trim_req_iri(char*, const char **);
266 int		 serialize_iri(struct iri*, char*, size_t);
267 char		*pct_decode_str(char *);
268 
269 /* puny.c */
270 int		 puny_decode(const char*, char*, size_t, const char**);
271 
272 /* utils.c */
273 void		 block_signals(void);
274 void		 unblock_signals(void);
275 int		 starts_with(const char*, const char*);
276 int		 ends_with(const char*, const char*);
277 ssize_t		 filesize(int);
278 char		*absolutify_path(const char*);
279 char		*xstrdup(const char*);
280 void		 gen_certificate(const char*, const char*, const char*);
281 X509_STORE	*load_ca(const char*);
282 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
283 
284 #endif