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 struct client;
128 
129 typedef void (*statefn)(struct pollfd*, struct client*);
130 
131 struct client {
132 	struct tls	*ctx;
133 	char		 req[GEMINI_URL_LEN];
134 	struct iri	 iri;
135 	char		 domain[DOMAIN_NAME_LEN];
136 	statefn		 state, next;
137 	int		 code;
138 	const char	*meta;
139 	int		 fd, waiting_on_child;
140 	char		 sbuf[1024];	  /* static buffer */
141 	void		*buf, *i;	  /* mmap buffer */
142 	ssize_t		 len, off;	  /* mmap/static buffer  */
143 	DIR		*dir;
144 	struct sockaddr_storage	 addr;
145 	struct vhost	*host;	/* host she's talking to */
146 };
147 
148 enum {
149 	FILE_EXISTS,
150 	FILE_EXECUTABLE,
151 	FILE_DIRECTORY,
152 	FILE_MISSING,
153 };
154 
155 /* gmid.c */
156 __attribute__((format (printf, 1, 2)))
157 __attribute__((__noreturn__))
158 void fatal(const char*, ...);
159 
160 __attribute__((format (printf, 3, 4)))
161 void logs(int, struct client*, const char*, ...);
162 void log_request(struct client*, char*, size_t);
163 
164 void		 sig_handler(int);
165 void		 gen_certificate(const char*, const char*, const char*);
166 void		 mkdirs(const char*);
167 char		*data_dir(void);
168 void		 load_local_cert(const char*, const char*);
169 void		 load_vhosts(void);
170 int		 make_socket(int, int);
171 void		 setup_tls(void);
172 int		 listener_main(void);
173 void		 init_config(void);
174 void		 drop_priv(void);
175 void		 usage(const char*);
176 
177 /* provided by lex/yacc */
178 extern FILE *yyin;
179 extern int yylineno;
180 extern int yyparse(void);
181 extern int yylex(void);
182 
183 void		 yyerror(const char*);
184 int		 parse_portno(const char*);
185 void		 parse_conf(const char*);
186 
187 /* mime.c */
188 void		 init_mime(struct mime*);
189 void		 add_mime(struct mime*, const char*, const char*);
190 void		 load_default_mime(struct mime*);
191 const char	*mime(struct vhost*, const char*);
192 
193 /* server.c */
194 const char	*vhost_lang(struct vhost*, const char*);
195 const char	*vhost_default_mime(struct vhost*, const char*);
196 const char	*vhost_index(struct vhost*, const char*);
197 int		 vhost_auto_index(struct vhost*, const char*);
198 int		 check_path(struct client*, const char*, int*);
199 void		 open_file(struct pollfd*, struct client*);
200 void		 load_file(struct pollfd*, struct client*);
201 void		 check_for_cgi(struct pollfd*, struct client*);
202 void		 mark_nonblock(int);
203 void		 handle_handshake(struct pollfd*, struct client*);
204 void		 handle_open_conn(struct pollfd*, struct client*);
205 void		 start_reply(struct pollfd*, struct client*, int, const char*);
206 void		 handle_start_reply(struct pollfd*, struct client*);
207 void		 start_cgi(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		 loop(struct tls*, int, int);
219 
220 /* ex.c */
221 int		 send_string(int, const char*);
222 int		 recv_string(int, char**);
223 int		 send_iri(int, struct iri*);
224 int		 recv_iri(int, struct iri*);
225 void		 free_recvd_iri(struct iri*);
226 int		 send_vhost(int, struct vhost*);
227 int		 recv_vhost(int, struct vhost**);
228 int		 send_fd(int, int);
229 int		 recv_fd(int);
230 int		 executor_main(int);
231 
232 /* sandbox.c */
233 void		 sandbox(void);
234 
235 /* utf8.c */
236 int		 valid_multibyte_utf8(struct parser*);
237 char		*utf8_nth(char*, size_t);
238 
239 /* iri.c */
240 int		 parse_iri(char*, struct iri*, const char**);
241 int		 trim_req_iri(char*, const char **);
242 int		 serialize_iri(struct iri*, char*, size_t);
243 
244 /* puny.c */
245 int		 puny_decode(const char*, char*, size_t, const char**);
246 
247 /* utils.c */
248 int		 starts_with(const char*, const char*);
249 int		 ends_with(const char*, const char*);
250 ssize_t		 filesize(int);
251 char		*absolutify_path(const char*);
252 
253 #endif