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 <arpa/inet.h>
21 #include <netinet/in.h>
22 
23 #include <poll.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <syslog.h>
27 #include <tls.h>
28 #include <unistd.h>
29 
30 #ifndef __OpenBSD__
31 # define pledge(a, b) 0
32 # define unveil(a, b) 0
33 #endif
34 
35 #ifndef INFTIM
36 # define INFTIM -1
37 #endif
38 
39 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
40 
41 /* large enough to hold a copy of a gemini URL and still have extra room */
42 #define PATHBUF		2048
43 
44 #define SUCCESS		20
45 #define TEMP_FAILURE	40
46 #define NOT_FOUND	51
47 #define BAD_REQUEST	59
48 
49 #ifndef MAX_USERS
50 #define MAX_USERS	64
51 #endif
52 
53 #define SAFE_SETENV(var, val) do {		\
54 		const char *_tmp = (val);	\
55 		if (_tmp == NULL)		\
56 			_tmp = "";		\
57 		setenv((var), _tmp, 1);		\
58 	} while(0)
59 
60 #define LOG(priority, c, fmt, ...)					\
61 	do {								\
62 		char buf[INET_ADDRSTRLEN];				\
63 		if (inet_ntop((c)->af, &(c)->addr,			\
64 		    buf, sizeof(buf)) == NULL)				\
65 			FATAL("inet_ntop: %s", strerror(errno));	\
66 		if (foreground)						\
67 			fprintf(stderr,					\
68 			    "%s " fmt "\n", buf, __VA_ARGS__);		\
69 		else							\
70 			syslog((priority) | LOG_DAEMON,			\
71 			    "%s " fmt, buf, __VA_ARGS__);		\
72 	} while (0)
73 
74 #define LOGE(c, fmt, ...) LOG(LOG_ERR,    c, fmt, __VA_ARGS__)
75 #define LOGN(c, fmt, ...) LOG(LOG_NOTICE, c, fmt, __VA_ARGS__)
76 #define LOGI(c, fmt, ...) LOG(LOG_INFO,   c, fmt, __VA_ARGS__)
77 #define LOGD(c, fmt, ...) LOG(LOG_DEBUG,  c, fmt, __VA_ARGS__)
78 
79 #define FATAL(fmt, ...)							\
80 	do {								\
81 		if (foreground)						\
82 			fprintf(stderr, fmt "\n", __VA_ARGS__);		\
83 		else							\
84 			syslog(LOG_DAEMON | LOG_CRIT,			\
85 			    fmt, __VA_ARGS__);				\
86 		exit(1);						\
87 	} while (0)
88 
89 enum {
90 	S_OPEN,
91 	S_INITIALIZING,
92 	S_SENDING,
93 	S_CLOSING,
94 };
95 
96 struct client {
97 	struct tls	*ctx;
98 	int		 state;
99 	int		 code;
100 	const char	*meta;
101 	int		 fd, waiting_on_child;
102 	pid_t		 child;
103 	char		 sbuf[1024];	  /* static buffer */
104 	void		*buf, *i;	  /* mmap buffer */
105 	ssize_t		 len, off;	  /* mmap/static buffer  */
106 	int		 af;
107 	struct in_addr	 addr;
108 };
109 
110 struct uri {
111 	char		*schema;
112 	char		*host;
113 	char		*port;
114 	uint16_t	 port_no;
115 	char		*path;
116 	char		*query;
117 	char		*fragment;
118 };
119 
120 struct parser {
121 	char		*uri;
122 	struct uri	*parsed;
123 	const char	*err;
124 };
125 
126 enum {
127 	FILE_EXISTS,
128 	FILE_EXECUTABLE,
129 	FILE_DIRECTORY,
130 	FILE_MISSING,
131 };
132 
133 /* gmid.c */
134 void		 sig_handler(int);
135 int		 starts_with(const char*, const char*);
136 
137 int		 start_reply(struct pollfd*, struct client*, int, const char*);
138 ssize_t		 filesize(int);
139 const char	*path_ext(const char*);
140 const char	*mime(const char*);
141 int		 check_path(struct client*, const char*, int*);
142 int		 check_for_cgi(char *, char*, struct pollfd*, struct client*);
143 int		 open_file(char*, char*, struct pollfd*, struct client*);
144 int		 start_cgi(const char*, const char*, const char*, struct pollfd*, struct client*);
145 void		 cgi_poll_on_child(struct pollfd*, struct client*);
146 void		 cgi_poll_on_client(struct pollfd*, struct client*);
147 void		 handle_cgi(struct pollfd*, struct client*);
148 void		 send_file(char*, char*, struct pollfd*, struct client*);
149 void		 send_dir(char*, struct pollfd*, struct client*);
150 void		 handle(struct pollfd*, struct client*);
151 
152 void		 mark_nonblock(int);
153 int		 make_soket(int);
154 void		 do_accept(int, struct tls*, struct pollfd*, struct client*);
155 void		 goodbye(struct pollfd*, struct client*);
156 void		 loop(struct tls*, int);
157 
158 void		 usage(const char*);
159 
160 /* utf8.c */
161 int		 valid_multibyte_utf8(struct parser*);
162 
163 /* uri.c */
164 int		 parse_uri(char*, struct uri*, const char**);
165 int		 trim_req_uri(char*);
166 
167 #endif