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 <stdio.h>
29 #include <stdlib.h>
30 #include <syslog.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 NOT_FOUND	51
46 #define PROXY_REFUSED	53
47 #define BAD_REQUEST	59
48 
49 #define MAX_USERS	64
50 
51 #define HOSTSLEN	64
52 #define LOCLEN		32
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 LOGE(c, fmt, ...) logs(LOG_ERR,     c, fmt, __VA_ARGS__)
59 #define LOGW(c, fmt, ...) logs(LOG_WARNING, c, fmt, __VA_ARGS__)
60 #define LOGN(c, fmt, ...) logs(LOG_NOTICE,  c, fmt, __VA_ARGS__)
61 #define LOGI(c, fmt, ...) logs(LOG_INFO,    c, fmt, __VA_ARGS__)
62 #define LOGD(c, fmt, ...) logs(LOG_DEBUG,   c, fmt, __VA_ARGS__)
63 
64 struct location {
65 	const char	*match;
66 	const char	*lang;
67 	const char	*default_mime;
68 	const char	*index;
69 	int		 auto_index; /* 0 auto, -1 off, 1 on */
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 	int		 dirfd;
79 
80 	/* the first location rule is always '*' and holds the default
81 	 * settings for the vhost, from locations[1] onwards there are
82 	 * the "real" location rules specified in the configuration. */
83 	struct location	 locations[LOCLEN];
84 };
85 
86 extern struct vhost hosts[HOSTSLEN];
87 
88 struct etm {			/* extension to mime */
89 	const char	*mime;
90 	const char	*ext;
91 };
92 
93 struct mime {
94 	struct etm	*t;
95 	size_t		len;
96 	size_t		cap;
97 };
98 
99 struct conf {
100 	int		 port;
101 	int		 ipv6;
102 	uint32_t	 protos;
103 	struct mime	 mime;
104 	char		*chroot;
105 	char		*user;
106 };
107 
108 extern struct conf conf;
109 extern int exfd;
110 
111 struct iri {
112 	char		*schema;
113 	char		*host;
114 	char		*port;
115 	uint16_t	 port_no;
116 	char		*path;
117 	char		*query;
118 	char		*fragment;
119 };
120 
121 struct parser {
122 	char		*iri;
123 	struct iri	*parsed;
124 	const char	*err;
125 };
126 
127 enum {
128 	S_HANDSHAKE,
129 	S_OPEN,
130 	S_INITIALIZING,
131 	S_SENDING_FILE,
132 	S_SENDING_DIR,
133 	S_SENDING_CGI,
134 	S_CLOSING,
135 };
136 
137 struct client {
138 	struct tls	*ctx;
139 	char		 req[GEMINI_URL_LEN];
140 	struct iri	 iri;
141 	char		 domain[DOMAIN_NAME_LEN];
142 	int		 state, next;
143 	int		 code;
144 	const char	*meta;
145 	int		 fd, waiting_on_child;
146 	char		 sbuf[1024];	  /* static buffer */
147 	void		*buf, *i;	  /* mmap buffer */
148 	ssize_t		 len, off;	  /* mmap/static buffer  */
149 	DIR		*dir;
150 	struct sockaddr_storage	 addr;
151 	struct vhost	*host;	/* host she's talking to */
152 };
153 
154 enum {
155 	FILE_EXISTS,
156 	FILE_EXECUTABLE,
157 	FILE_DIRECTORY,
158 	FILE_MISSING,
159 };
160 
161 /* gmid.c */
162 __attribute__((format (printf, 1, 2)))
163 __attribute__((__noreturn__))
164 void fatal(const char*, ...);
165 
166 __attribute__((format (printf, 3, 4)))
167 void logs(int, struct client*, const char*, ...);
168 void log_request(struct client*, char*, size_t);
169 
170 void		 sig_handler(int);
171 void		 gen_certificate(const char*, const char*, const char*);
172 void		 mkdirs(const char*);
173 char		*data_dir(void);
174 void		 load_local_cert(const char*, const char*);
175 void		 load_vhosts(void);
176 int		 make_socket(int, int);
177 void		 setup_tls(void);
178 int		 listener_main(void);
179 void		 init_config(void);
180 void		 drop_priv(void);
181 void		 usage(const char*);
182 
183 /* provided by lex/yacc */
184 extern FILE *yyin;
185 extern int yylineno;
186 extern int yyparse(void);
187 extern int yylex(void);
188 
189 void		 yyerror(const char*);
190 int		 parse_portno(const char*);
191 void		 parse_conf(const char*);
192 
193 /* mime.c */
194 void		 init_mime(struct mime*);
195 void		 add_mime(struct mime*, const char*, const char*);
196 void		 load_default_mime(struct mime*);
197 const char	*mime(struct vhost*, const char*);
198 
199 /* server.c */
200 const char	*vhost_lang(struct vhost*, const char*);
201 const char	*vhost_default_mime(struct vhost*, const char*);
202 const char	*vhost_index(struct vhost*, const char*);
203 int		 vhost_auto_index(struct vhost*, const char*);
204 int		 check_path(struct client*, const char*, int*);
205 void		 open_file(struct pollfd*, struct client*);
206 void		 load_file(struct pollfd*, struct client*);
207 void		 check_for_cgi(char *, char*, struct pollfd*, struct client*);
208 void		 mark_nonblock(int);
209 void		 handle_handshake(struct pollfd*, struct client*);
210 void		 handle_open_conn(struct pollfd*, struct client*);
211 void		 start_reply(struct pollfd*, struct client*, int, const char*);
212 void		 start_cgi(const char*, const char*, const char*, struct pollfd*, struct client*);
213 void		 send_file(struct pollfd*, struct client*);
214 void		 open_dir(struct pollfd*, struct client*);
215 void		 redirect_canonical_dir(struct pollfd*, struct client*);
216 int		 read_next_dir_entry(struct client*);
217 void		 send_directory_listing(struct pollfd*, struct client*);
218 void		 cgi_poll_on_child(struct pollfd*, struct client*);
219 void		 cgi_poll_on_client(struct pollfd*, struct client*);
220 void		 handle_cgi(struct pollfd*, struct client*);
221 void		 close_conn(struct pollfd*, struct client*);
222 void		 do_accept(int, struct tls*, struct pollfd*, struct client*);
223 void		 handle(struct pollfd*, struct client*);
224 void		 loop(struct tls*, int, int);
225 
226 /* ex.c */
227 int		 send_string(int, const char*);
228 int		 recv_string(int, char**);
229 int		 send_vhost(int, struct vhost*);
230 int		 recv_vhost(int, struct vhost**);
231 int		 send_fd(int, int);
232 int		 recv_fd(int);
233 int		 executor_main(int);
234 
235 /* sandbox.c */
236 void		 sandbox(void);
237 
238 /* utf8.c */
239 int		 valid_multibyte_utf8(struct parser*);
240 char		*utf8_nth(char*, size_t);
241 
242 /* iri.c */
243 int		 parse_iri(char*, struct iri*, const char**);
244 int		 trim_req_iri(char*, const char **);
245 
246 /* puny.c */
247 int		 puny_decode(const char*, char*, size_t, const char**);
248 
249 /* utils.c */
250 int		 starts_with(const char*, const char*);
251 int		 ends_with(const char*, const char*);
252 ssize_t		 filesize(int);
253 
254 #endif