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 /* large enough to hold a copy of a gemini URL and still have extra room */
43 #define PATHBUF		2048
44 
45 #define SUCCESS		20
46 #define TEMP_REDIRECT	30
47 #define TEMP_FAILURE	40
48 #define NOT_FOUND	51
49 #define PROXY_REFUSED	53
50 #define BAD_REQUEST	59
51 
52 #define MAX_USERS	64
53 
54 #define HOSTSLEN	64
55 #define LOCLEN		32
56 
57 #define LOGE(c, fmt, ...) logs(LOG_ERR,     c, fmt, __VA_ARGS__)
58 #define LOGW(c, fmt, ...) logs(LOG_WARNING, c, fmt, __VA_ARGS__)
59 #define LOGN(c, fmt, ...) logs(LOG_NOTICE,  c, fmt, __VA_ARGS__)
60 #define LOGI(c, fmt, ...) logs(LOG_INFO,    c, fmt, __VA_ARGS__)
61 #define LOGD(c, fmt, ...) logs(LOG_DEBUG,   c, fmt, __VA_ARGS__)
62 
63 struct location {
64 	char		*match;
65 	char		*lang;
66 	char		*default_mime;
67 	char		*index;
68 	int		 auto_index; /* 0 auto, -1 off, 1 on */
69 };
70 
71 struct vhost {
72 	const char	*domain;
73 	const char	*cert;
74 	const char	*key;
75 	const char	*dir;
76 	const char	*cgi;
77 	int		 dirfd;
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 	int		 foreground;
96 	int		 port;
97 	int		 ipv6;
98 	uint32_t	 protos;
99 	struct mime	 mime;
100 	char		*chroot;
101 	char		*user;
102 };
103 
104 extern struct conf conf;
105 extern int exfd;
106 
107 struct iri {
108 	char		*schema;
109 	char		*host;
110 	char		*port;
111 	uint16_t	 port_no;
112 	char		*path;
113 	char		*query;
114 	char		*fragment;
115 };
116 
117 struct parser {
118 	char		*iri;
119 	struct iri	*parsed;
120 	const char	*err;
121 };
122 
123 enum {
124 	S_HANDSHAKE,
125 	S_OPEN,
126 	S_INITIALIZING,
127 	S_SENDING_FILE,
128 	S_SENDING_DIR,
129 	S_SENDING_CGI,
130 	S_CLOSING,
131 };
132 
133 struct client {
134 	struct tls	*ctx;
135 	char		 req[GEMINI_URL_LEN];
136 	struct iri	 iri;
137 	int		 state, next;
138 	int		 code;
139 	const char	*meta;
140 	int		 fd, waiting_on_child;
141 	char		 sbuf[1024];	  /* static buffer */
142 	void		*buf, *i;	  /* mmap buffer */
143 	ssize_t		 len, off;	  /* mmap/static buffer  */
144 	DIR		*dir;
145 	struct sockaddr_storage	 addr;
146 	struct vhost	*host;	/* host she's talking to */
147 };
148 
149 enum {
150 	FILE_EXISTS,
151 	FILE_EXECUTABLE,
152 	FILE_DIRECTORY,
153 	FILE_MISSING,
154 };
155 
156 /* gmid.c */
157 
158 __attribute__((format (printf, 1, 2)))
159 __attribute__((__noreturn__))
160 void fatal(const char*, ...);
161 
162 __attribute__((format (printf, 3, 4)))
163 void logs(int, struct client*, const char*, ...);
164 void log_request(struct client*, char*, size_t);
165 
166 void		 sig_handler(int);
167 int		 starts_with(const char*, const char*);
168 int		 ends_with(const char*, const char*);
169 ssize_t		 filesize(int);
170 char		*absolutify_path(const char*);
171 void		 yyerror(const char*);
172 int		 parse_portno(const char*);
173 void		 parse_conf(const char*);
174 void		 load_vhosts(void);
175 int		 make_socket(int, int);
176 void		 setup_tls(void);
177 int		 listener_main(void);
178 void		 init_config(void);
179 void		 drop_priv(void);
180 void		 usage(const char*);
181 
182 /* provided by lex/yacc */
183 extern FILE *yyin;
184 extern int yylineno;
185 extern int yyparse(void);
186 extern int yylex(void);
187 
188 /* mime.c */
189 void		 init_mime(struct mime*);
190 void		 add_mime(struct mime*, const char*, const char*);
191 void		 load_default_mime(struct mime*);
192 const char	*mime(struct vhost*, const char*);
193 
194 /* server.c */
195 const char	*vhost_lang(struct vhost*, const char*);
196 const char	*vhost_default_mime(struct vhost*, const char*);
197 const char	*vhost_index(struct vhost*, const char*);
198 int		 vhost_auto_index(struct vhost*, const char*);
199 int		 check_path(struct client*, const char*, int*);
200 void		 open_file(struct pollfd*, struct client*);
201 void		 load_file(struct pollfd*, struct client*);
202 void		 check_for_cgi(char *, char*, struct pollfd*, struct client*);
203 void		 mark_nonblock(int);
204 void		 handle_handshake(struct pollfd*, struct client*);
205 void		 handle_open_conn(struct pollfd*, struct client*);
206 void		 start_reply(struct pollfd*, struct client*, int, const char*);
207 void		 start_cgi(const char*, const char*, const char*, struct pollfd*, struct client*);
208 void		 send_file(struct pollfd*, struct client*);
209 void		 open_dir(struct pollfd*, struct client*);
210 void		 redirect_canonical_dir(struct pollfd*, struct client*);
211 int		 read_next_dir_entry(struct client*);
212 void		 send_directory_listing(struct pollfd*, struct client*);
213 void		 cgi_poll_on_child(struct pollfd*, struct client*);
214 void		 cgi_poll_on_client(struct pollfd*, struct client*);
215 void		 handle_cgi(struct pollfd*, struct client*);
216 void		 close_conn(struct pollfd*, struct client*);
217 void		 do_accept(int, struct tls*, struct pollfd*, struct client*);
218 void		 handle(struct pollfd*, struct client*);
219 void		 loop(struct tls*, int, int);
220 
221 /* ex.c */
222 int		 send_string(int, const char*);
223 int		 recv_string(int, char**);
224 int		 send_vhost(int, struct vhost*);
225 int		 recv_vhost(int, struct vhost**);
226 int		 send_fd(int, int);
227 int		 recv_fd(int);
228 int		 executor_main(int);
229 
230 /* sandbox.c */
231 void		 sandbox(void);
232 
233 /* utf8.c */
234 int		 valid_multibyte_utf8(struct parser*);
235 
236 /* iri.c */
237 int		 parse_iri(char*, struct iri*, const char**);
238 int		 trim_req_iri(char*);
239 
240 #endif