gophernicus/gophernicus.h

/*
 * Gophernicus - Copyright (c) 2009-2018 Kim Holviala <kimholviala@fastmail.com>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _GOPHERNICUS_H
#define _GOPHERNICUS_H


/*
 * Ignore useless snprintf() format truncation warnings on GCC 7+
 */
#if __GNUC__ >= 7
#pragma GCC diagnostic ignored "-Wformat-truncation"
#endif


/*
 * Features
 */
#undef  ENABLE_STRICT_RFC1436	/* Follow RFC1436 to the letter */
#undef  ENABLE_AUTOHIDING	/* Hide manually listed resources from generated menus */
#define ENABLE_HAPROXY1		/* Autodetect HAproxy/Stunnel proxy protocol v1 */


/*
 * Platform configuration
 */

/* Defaults should fit standard POSIX systems */
#define HAVE_IPv4		/* IPv4 should work anywhere */
#define HAVE_IPv6		/* Requires modern POSIX */
#define HAVE_PASSWD		/* For systems with passwd-like userdb */
#define PASSWD_MIN_UID 100	/* Minimum allowed UID for ~userdirs */
#define HAVE_LOCALES		/* setlocale() and friends */
#define HAVE_SHMEM		/* Shared memory support */
#define HAVE_UNAME		/* uname() */
#define HAVE_POPEN		/* popen() */
#undef  HAVE_STRLCPY		/* strlcpy() from OpenBSD */
#undef  HAVE_SENDFILE		/* sendfile() in Linux & others */
/* #undef  HAVE_LIBWRAP		   autodetected, don't enable here */

/* Linux */
#ifdef __linux
#undef  PASSWD_MIN_UID
#define PASSWD_MIN_UID 500
#define _FILE_OFFSET_BITS 64
#endif

/* Embedded Linux with uClibc */
#ifdef __UCLIBC__
#undef HAVE_SHMEM
#undef HAVE_PASSWD
#endif

/* Haiku */
#ifdef __HAIKU__
#undef HAVE_SHMEM
#undef HAVE_PASSWD
#endif

/* OpenBSD */
#ifdef __OpenBSD__
#define HAVE_STRLCPY
#endif

/* MacOS */
#if defined(__APPLE__)
#if __MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_10
#define HAVE_STRLCPY
#endif
#endif

/* AIX */
#if defined(_AIX)
#define _LARGE_FILES 1
#endif

/* Add other OS-specific defines here */

/*
 * Include headers
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <string.h>
#include <libgen.h>
#include <time.h>
#include <syslog.h>
#include <errno.h>
#include <pwd.h>
#include <limits.h>

#ifdef HAVE_SENDFILE
#include <sys/sendfile.h>
#include <fcntl.h>
#endif

#ifdef HAVE_LOCALES
#include <locale.h>
#endif

#ifdef HAVE_SHMEM
#include <sys/ipc.h>
#include <sys/shm.h>
#else
#define shm_state void
#endif

#if defined(HAVE_IPv4) || defined(HAVE_IPv6)
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#endif

#ifdef HAVE_UNAME
#include <sys/utsname.h>
#endif

#if !defined(HAVE_STRLCPY)
size_t strlcpy(char *dst, const char *src, size_t siz);
size_t strlcat(char *dst, const char *src, size_t siz);
#endif

#ifdef HAVE_LIBWRAP
#include <tcpd.h>
#endif

/*
 * Compile-time configuration
 */

/* Common stuff */
#define CRLF		"\r\n"
#define EMPTY		""
#define PARENT		".."
#define ROOT		"/"

#define FALSE		0
#define TRUE		1

#define QUIT		1
#define OK		0
#define ERROR		-1

#define MATCH		0
#define WRAP_DENIED	0


/* Gopher filetypes */
#define TYPE_TEXT	'0'
#define TYPE_MENU	'1'
#define TYPE_ERROR	'3'
#define TYPE_GZIP	'5'
#define TYPE_QUERY	'7'
#define TYPE_BINARY	'9'
#define TYPE_GIF	'g'
#define TYPE_HTML	'h'
#define TYPE_INFO	'i'
#define TYPE_IMAGE	'I'
#define TYPE_MIME	'M'
#define TYPE_DOC	'd'
#define TYPE_TITLE	'!'

/* Protocols */
#define PROTO_GOPHER	'g'
#define PROTO_HTTP	'h'

/* Charsets */
#define AUTO		0
#define US_ASCII	1
#define ISO_8859_1	2
#define UTF_8		3

/* HTTP protocol stuff for logging */
#define HTTP_OK		200
#define HTTP_404	404
#define HTTP_DATE	"%d/%b/%Y:%T %z"
#define HTTP_USERAGENT	"Unknown gopher client"

/* Defaults for settings */
#define DEFAULT_HOST		"localhost"
#define DEFAULT_PORT		70
#define DEFAULT_TLS_PORT	0
#define DEFAULT_TYPE		TYPE_TEXT
#define DEFAULT_MAP		"gophermap"
#define DEFAULT_TAG		"gophertag"
#define DEFAULT_CGI		"/cgi-bin/"
#define DEFAULT_USERDIR		"public_gopher"
#define DEFAULT_WIDTH		76
#define DEFAULT_CHARSET		US_ASCII
#define MIN_WIDTH		33
#define MAX_WIDTH		200
#define UNKNOWN_ADDR		"unknown"

/* Session defaults */
#define DEFAULT_SESSION_TIMEOUT		1800
#define DEFAULT_SESSION_MAX_KBYTES	4194304
#define DEFAULT_SESSION_MAX_HITS	4096

/* Dummy values for gopher protocol */
#define DUMMY_SELECTOR	"null"
#define DUMMY_HOST	"null.host\t1"

/* Safe $PATH for exec() */
#ifdef __HAIKU__
#define SAFE_PATH	"/boot/common/bin:/bin"
#else
#define SAFE_PATH	"/usr/bin:/bin"
#endif

/* Special requests */
#define SERVER_STATUS	"/server-status"
#define CAPS_TXT	"/caps.txt"

/* Error messages */
#define ERR_ACCESS	"Access denied!"
#define ERR_NOTFOUND	"File or directory not found!"

#define ERROR_HOST	"error.host\t1"
#define ERROR_PREFIX	"Error: "

/* Strings */
#define SERVER_SOFTWARE	"Gophernicus"
#define SERVER_SOFTWARE_FULL SERVER_SOFTWARE "/" VERSION " (%s)"

#define HEADER_FORMAT	"[%s]"
#define FOOTER_FORMAT	"Gophered by Gophernicus/" VERSION " on %s"

#define UNITS		"KB", "MB", "GB", "TB", "PB", NULL
#define DATE_FORMAT	"%Y-%b-%d %H:%M"	/* See man 3 strftime */
#define DATE_WIDTH	17
#define DATE_LOCALE 	"POSIX"

#define USERDIR_FORMAT	"~%s", pwd->pw_name	/* See man 3 getpwent */
#define VHOST_FORMAT	"gopher://%s/"

/* ISO-8859-1 to US-ASCII look-alike conversion table */
#define ASCII \
	"E?,f..++^%S<??Z?" \
	"?''\"\"*--~?s>??zY" \
	" !c_*Y|$\"C?<?-R-" \
	"??23'u?*,1?>????" \
	"AAAAAAACEEEEIIII" \
	"DNOOOOO*OUUUUYTB" \
	"aaaaaaaceeeeiiii" \
	"dnooooo/ouuuuyty"

#define UNKNOWN '?'

/* Sizes & maximums */
#define BUFSIZE		1024	/* Default size for string buffers */
#define MAX_HIDDEN	32	/* Maximum number of hidden files */
#define MAX_FILETYPES	128	/* Maximum number of suffix to filetype mappings */
#define MAX_FILTERS	16	/* Maximum number of file filters */
#define MAX_SDIRENT	1024	/* Maximum number of files per directory to handle */
#define MAX_REWRITE	32	/* Maximum number of selector rewrite options */

/* Struct for file suffix -> gopher filetype mapping */
typedef struct {
	char suffix[15];
	char type;
} ftype;

/* Struct for selector rewriting */
typedef struct {
	char match[BUFSIZE];
	char replace[BUFSIZE];
} srewrite;

/* Struct for keeping the current options & state */
typedef struct {

	/* Request */
	char req_selector[BUFSIZE];
	char req_realpath[BUFSIZE];
	char req_query_string[BUFSIZE];
	char req_search[BUFSIZE];
	char req_referrer[BUFSIZE];
	char req_local_addr[64];
	char req_remote_addr[64];
	char req_filetype;
	char req_protocol;
	off_t req_filesize;

	/* Output */
	int out_width;
	int out_charset;

	/* Settings */
	char server_description[64];
	char server_location[64];
	char server_platform[64];
	char server_admin[64];
	char server_root[256];
	char server_host_default[64];
	char server_host[64];
	int  server_port;
	int  server_tls_port;

	char default_filetype;
	char map_file[64];
	char tag_file[64];
	char cgi_file[64];
	char user_dir[64];
	char log_file[256];

	char hidden[MAX_HIDDEN][256];
	int hidden_count;

	ftype filetype[MAX_FILETYPES];
	int filetype_count;
	char filter_dir[64];

	srewrite rewrite[MAX_REWRITE];
	int rewrite_count;

	/* Session */
	int session_timeout;
	int session_max_kbytes;
	int session_max_hits;
	int session_id;

	/* Feature options */
	char opt_parent;
	char opt_header;
	char opt_footer;
	char opt_date;
	char opt_syslog;
	char opt_magic;
	char opt_iconv;
	char opt_vhost;
	char opt_query;
	char opt_caps;
	char opt_status;
	char opt_shm;
	char opt_root;
	char opt_proxy;
	char debug;
} state;

/* Shared memory for session & accounting data */
#ifdef HAVE_SHMEM

#define SHM_KEY		0xbeeb0008	/* Unique identifier + struct version */
#define SHM_MODE	0600		/* Access mode for the shared memory */
#define SHM_SESSIONS	256		/* Max amount of user sessions to track */

typedef struct {
	long hits;
	long kbytes;

	time_t req_atime;
	char req_selector[128];
	char req_remote_addr[64];
	char req_filetype;
	int session_id;

	char server_host[64];
	int  server_port;
} shm_session;

typedef struct {
	time_t start_time;
	long hits;
	long kbytes;
	char server_platform[64];
	char server_description[64];
	shm_session session[SHM_SESSIONS];
} shm_state;

#endif

/* Struct for directory sorting */
typedef struct {
	char	name[128];	/* Should be 256 but we're saving stack space */
	mode_t	mode;
	uid_t	uid;
	gid_t	gid;
	off_t	size;
	time_t	mtime;
} sdirent;


/* File suffix to gopher filetype mappings */
#define FILETYPES \
	"txt","0","pl","0","py","0","sh","0","tcl","0","c","0","cpp","0", "h","0","log","0", \
	"conf","0","php","0","php3","0", \
	"map","1","menu","1", \
	"hqx","4", \
	"Z","5","gz","5","tgz","5","tar","5","zip","5","bz2","5","rar","5","sea","5", \
	"q","7","qry","7", \
	"iso","9","so","9","o","9","rtf","9","ttf","9","bin","9", \
	"ics","c","ical","c", \
	"gif","g", \
	"html","h","htm","h","xhtml","h","css","h","swf","h","rdf","h","rss","h","xml","h", \
	"jpg","I","jpeg","I","png","I","bmp","I","svg","I","tif","I","tiff","I", \
	"ico","I","xbm","I","xpm","I","pcx","I", \
	"mbox","M", \
	"pdf","d","ps","d","doc","d","ppt","d","xls","d","xlsx","d","docx","d","pptx","d", \
	"mp3","s","wav","s","mid","s","wma","s","flac","s","ogg","s","aiff","s","aac","s", \
	"avi",";","mp4",";","mpg",";","mov",";","qt",";","asf",";","mpv",";","m4v",";","webm",";","ogv",";", \
	NULL, NULL

/*
 * Useful macros
 */
#define strclear(str) str[0] = '\0';
#define sstrlcpy(dest, src) strlcpy(dest, src, sizeof(dest))
#define sstrlcat(dest, src) strlcat(dest, src, sizeof(dest))
#define sstrncmp(s1, s2) strncmp(s1, s2, sizeof(s2) - 1)
#define sstrncasecmp(s1, s2) strncasecmp(s1, s2, sizeof(s2) - 1)
#define sstrniconv(charset, out, in) strniconv(charset, out, in, sizeof(out))
#define max(a,b) (((a) > (b)) ? (a) : (b))
#define min(a,b) (((a) < (b)) ? (a) : (b))

/*
 * Include generated headers
 */
#include "functions.h"
#include "files.h"

#endif