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 <sys/socket.h>
21 #include <sys/types.h>
22 
23 #include <arpa/inet.h>
24 #include <netinet/in.h>
25 
26 #include <dirent.h>
27 #include <signal.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <time.h>
31 #include <tls.h>
32 #include <unistd.h>
33 
34 #include "config.h"
35 
36 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
37 
38 #define SUCCESS		20
39 #define TEMP_REDIRECT	30
40 #define TEMP_FAILURE	40
41 #define CGI_ERROR	42
42 #define NOT_FOUND	51
43 #define PROXY_REFUSED	53
44 #define BAD_REQUEST	59
45 
46 #define MAX_USERS	64
47 
48 #define HOSTSLEN	64
49 #define LOCLEN		32
50 
51 /* maximum hostname and label length, +1 for the NUL-terminator */
52 #define DOMAIN_NAME_LEN	(253+1)
53 #define LABEL_LEN	(63+1)
54 
55 struct location {
56 	const char	*match;
57 	const char	*lang;
58 	const char	*default_mime;
59 	const char	*index;
60 	int		 auto_index; /* 0 auto, -1 off, 1 on */
61 	int		 block_code;
62 	const char	*block_fmt;
63 	int		 strip;
64 };
65 
66 struct vhost {
67 	const char	*domain;
68 	const char	*cert;
69 	const char	*key;
70 	const char	*dir;
71 	const char	*cgi;
72 	const char	*entrypoint;
73 	int		 dirfd;
74 
75 	/* the first location rule is always '*' and holds the default
76 	 * settings for the vhost, from locations[1] onwards there are
77 	 * the "real" location rules specified in the configuration. */
78 	struct location	 locations[LOCLEN];
79 };
80 
81 extern struct vhost hosts[HOSTSLEN];
82 
83 struct etm {			/* extension to mime */
84 	const char	*mime;
85 	const char	*ext;
86 };
87 
88 struct mime {
89 	struct etm	*t;
90 	size_t		len;
91 	size_t		cap;
92 };
93 
94 struct conf {
95 	/* from command line */
96 	int		 foreground;
97 	int		 verbose;
98 
99 	/* in the config */
100 	int		 port;
101 	int		 ipv6;
102 	uint32_t	 protos;
103 	struct mime	 mime;
104 	char		*chroot;
105 	char		*user;
106 	int		 prefork;
107 };
108 
109 extern struct conf conf;
110 extern int exfd;
111 
112 extern volatile sig_atomic_t hupped;
113 
114 struct iri {
115 	char		*schema;
116 	char		*host;
117 	char		*port;
118 	uint16_t	 port_no;
119 	char		*path;
120 	char		*query;
121 	char		*fragment;
122 };
123 
124 struct parser {
125 	char		*iri;
126 	struct iri	*parsed;
127 	const char	*err;
128 };
129 
130 struct client;
131 
132 typedef void (*statefn)(int, short, void*);
133 
134 /*
135  * DFA: handle_handshake is the initial state, close_conn the final.
136  * Sometimes we have an enter_* function to handle the state switch.
137  *
138  * handle_handshake -> handle_open_conn
139  * handle_handshake -> close_conn		// on err
140  *
141  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
142  * handle_open_conn -> handle_dirlist		// ...same
143  * handle_open_conn -> send_file		// ...same
144  * handle_open_conn -> start_reply		// on error
145  *
146  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
147  * handle_cgi_reply -> start_reply	// on error
148  *
149  * handle_cgi -> close_conn
150  *
151  * handle_dirlist -> send_directory_listing
152  * handle_dirlist -> close_conn			// on error
153  *
154  * send_directory_listing -> close_conn
155  *
156  * send_file -> close_conn
157  */
158 struct client {
159 	struct tls	*ctx;
160 	char		 req[GEMINI_URL_LEN];
161 	struct iri	 iri;
162 	char		 domain[DOMAIN_NAME_LEN];
163 	statefn		 next;
164 	int		 code;
165 	const char	*meta;
166 	int		 fd, pfd;
167 	DIR		*dir;
168 	char		 sbuf[1024];	  /* static buffer */
169 	void		*buf, *i;	  /* mmap buffer */
170 	ssize_t		 len, off;	  /* mmap/static buffer  */
171 	struct sockaddr_storage	 addr;
172 	struct vhost	*host;	/* host she's talking to */
173 };
174 
175 enum {
176 	FILE_EXISTS,
177 	FILE_EXECUTABLE,
178 	FILE_DIRECTORY,
179 	FILE_MISSING,
180 };
181 
182 /* gmid.c */
183 void		 sig_handler(int);
184 void		 mkdirs(const char*);
185 char		*data_dir(void);
186 void		 load_local_cert(const char*, const char*);
187 void		 load_vhosts(void);
188 int		 make_socket(int, int);
189 void		 setup_tls(void);
190 void		 init_config(void);
191 void		 free_config(void);
192 void		 drop_priv(void);
193 
194 /* provided by lex/yacc */
195 extern FILE *yyin;
196 extern int yylineno;
197 extern int yyparse(void);
198 extern int yylex(void);
199 
200 void		 yyerror(const char*, ...);
201 int		 parse_portno(const char*);
202 void		 parse_conf(const char*);
203 
204 /* log.c */
205 void		 fatal(const char*, ...)
206 	__attribute__((format (printf, 1, 2)))
207 	__attribute__((__noreturn__));
208 
209 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
210 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
211 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
212 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
213 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
214 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
215 void		 log_request(struct client*, char*, size_t);
216 
217 /* mime.c */
218 void		 init_mime(struct mime*);
219 void		 add_mime(struct mime*, const char*, const char*);
220 void		 load_default_mime(struct mime*);
221 const char	*mime(struct vhost*, const char*);
222 
223 /* server.c */
224 const char	*vhost_lang(struct vhost*, const char*);
225 const char	*vhost_default_mime(struct vhost*, const char*);
226 const char	*vhost_index(struct vhost*, const char*);
227 int		 vhost_auto_index(struct vhost*, const char*);
228 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
229 int		 vhost_strip(struct vhost*, const char*);
230 void		 mark_nonblock(int);
231 void		 loop(struct tls*, int, int);
232 
233 /* ex.c */
234 int		 send_string(int, const char*);
235 int		 recv_string(int, char**);
236 int		 send_iri(int, struct iri*);
237 int		 recv_iri(int, struct iri*);
238 void		 free_recvd_iri(struct iri*);
239 int		 send_vhost(int, struct vhost*);
240 int		 recv_vhost(int, struct vhost**);
241 int		 send_time(int, time_t);
242 int		 recv_time(int, time_t*);
243 int		 send_fd(int, int);
244 int		 recv_fd(int);
245 int		 executor_main(void);
246 
247 /* sandbox.c */
248 void		 sandbox(void);
249 
250 /* utf8.c */
251 int		 valid_multibyte_utf8(struct parser*);
252 char		*utf8_nth(char*, size_t);
253 
254 /* iri.c */
255 int		 parse_iri(char*, struct iri*, const char**);
256 int		 trim_req_iri(char*, const char **);
257 int		 serialize_iri(struct iri*, char*, size_t);
258 char		*pct_decode_str(char *);
259 
260 /* puny.c */
261 int		 puny_decode(const char*, char*, size_t, const char**);
262 
263 /* utils.c */
264 void		 block_signals(void);
265 void		 unblock_signals(void);
266 int		 starts_with(const char*, const char*);
267 int		 ends_with(const char*, const char*);
268 ssize_t		 filesize(int);
269 char		*absolutify_path(const char*);
270 char		*xstrdup(const char*);
271 void		 gen_certificate(const char*, const char*, const char*);
272 
273 #endif