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