micro_httpd

/* micro_httpd - really small HTTP server**** Copyright ?1999,2005 by Jef Poskanzer <[e-mail]>.** All rights reserved.**** Redistribution and use in source and binary forms, with or without** modification, are permitted provided that the following conditions** are met:** 1. Redistributions of source code must retain the above copyright**    notice, this list of conditions and the following disclaimer.** 2. 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 AUTHOR 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 AUTHOR OR CONTRIBUTORS 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.*/#include <stdlib.h>#include <unistd.h>#include <stdio.h>#include <string.h>#include <dirent.h>#include <ctype.h>#include <time.h>#include <sys/types.h>#include <sys/stat.h>#define SERVER_NAME "micro_httpd"#define SERVER_URL "http://www.acme.com/software/micro_httpd/"#define PROTOCOL "HTTP/1.0"#define RFC1123FMT "%a, %d %b %Y %H:%M:%S GMT"/* Forwards. */static void file_details( char* dir, char* name );static void send_error( int status, char* title, char* extra_header, char* text );static void send_headers( int status, char* title, char* extra_header, char* mime_type, off_t length, time_t mod );static char* get_mime_type( char* name );static void strdecode( char* to, char* from );static int hexit( char c );static void strencode( char* to, size_t tosize, const char* from );intmain( int argc, char** argv )    {    char line[10000], method[10000], path[10000], protocol[10000], idx[20000], location[20000];    char* file;    size_t len;    int ich;    struct stat sb;    FILE* fp;    struct dirent **dl;    int i, n;    if ( argc != 2 )send_error( 500, "Internal Error", (char*) 0, "Config error - no dir specified." );    if ( chdir( argv[1] ) < 0 )send_error( 500, "Internal Error", (char*) 0, "Config error - couldn't chdir()." );    if ( fgets( line, sizeof(line), stdin ) == (char*) 0 )send_error( 400, "Bad Request", (char*) 0, "No request found." );    if ( sscanf( line, "%[^ ] %[^ ] %[^ ]", method, path, protocol ) != 3 )send_error( 400, "Bad Request", (char*) 0, "Can't parse request." );    while ( fgets( line, sizeof(line), stdin ) != (char*) 0 ){if ( strcmp( line, "\n" ) == 0 || strcmp( line, "\r\n" ) == 0 )    break;}    if ( strcasecmp( method, "get" ) != 0 )send_error( 501, "Not Implemented", (char*) 0, "That method is not implemented." );    if ( path[0] != '/' )send_error( 400, "Bad Request", (char*) 0, "Bad filename." );    file = &(path[1]);    strdecode( file, file );    if ( file[0] == '\0' )file = "./";    len = strlen( file );    if ( file[0] == '/' || strcmp( file, ".." ) == 0 || strncmp( file, "../", 3 ) == 0 || strstr( file, "/../" ) != (char*) 0 || strcmp( &(file[len-3]), "/.." ) == 0 )send_error( 400, "Bad Request", (char*) 0, "Illegal filename." );    if ( stat( file, &sb ) < 0 )send_error( 404, "Not Found", (char*) 0, "File not found." );    if ( S_ISDIR( sb.st_mode ) ){if ( file[len-1] != '/' )    {    (void) snprintf(location, sizeof(location), "Location: %s/", path );    send_error( 302, "Found", location, "Directories must end with a slash." );    }(void) snprintf( idx, sizeof(idx), "%sindex.html", file );if ( stat( idx, &sb ) >= 0 )    {    file = idx;    goto do_file;    }send_headers( 200, "Ok", (char*) 0, "text/html", -1, sb.st_mtime );(void) printf( "\<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">\n\<html>\n\  <head>\n\    <meta http-equiv=\"Content-type\" content=\"text/html;charset=UTF-8\">\n\    <title>Index of %s</title>\n\  </head>\n\  <body bgcolor=\"#99cc99\">\n\    <h4>Index of %s</h4>\n\    <pre>\n", file, file );n = scandir( file, &dl, NULL, alphasort );if ( n < 0 )    perror( "scandir" );else    for ( i = 0; i < n; ++i )file_details( file, dl[i]->d_name );(void) printf( "\    </pre>\n\    <hr>\n\    <address><a href=\"%s\">%s</a></address>\n\  </body>\n\</html>\n", SERVER_URL, SERVER_NAME );}    else{do_file:fp = fopen( file, "r" );if ( fp == (FILE*) 0 )    send_error( 403, "Forbidden", (char*) 0, "File is protected." );send_headers( 200, "Ok", (char*) 0, get_mime_type( file ), sb.st_size, sb.st_mtime );while ( ( ich = getc( fp ) ) != EOF )    putchar( ich );}    (void) fflush( stdout );    exit( 0 );    }static voidfile_details( char* dir, char* name )    {    static char encoded_name[1000];    static char path[2000];    struct stat sb;    char timestr[16];    strencode( encoded_name, sizeof(encoded_name), name );    (void) snprintf( path, sizeof(path), "%s/%s", dir, name );    if ( lstat( path, &sb ) < 0 )(void) printf( "<a href=\"%s\">%-32.32s</a>    ???\n", encoded_name, name );    else{(void) strftime( timestr, sizeof(timestr), "%d%b%Y %H:%M", localtime( &sb.st_mtime ) );(void) printf( "<a href=\"%s\">%-32.32s</a>    %15s %14lld\n", encoded_name, name, timestr, (long long) sb.st_size );}    }static voidsend_error( int status, char* title, char* extra_header, char* text )    {    send_headers( status, title, extra_header, "text/html", -1, -1 );    (void) printf( "\<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">\n\<html>\n\  <head>\n\    <meta http-equiv=\"Content-type\" content=\"text/html;charset=UTF-8\">\n\    <title>%d %s</title>\n\  </head>\n\  <body bgcolor=\"#cc9999\">\n\    <h4>%d %s</h4>\n", status, title, status, title );    (void) printf( "%s\n", text );    (void) printf( "\    <hr>\n\    <address><a href=\"%s\">%s</a></address>\n\  </body>\n\</html>\n", SERVER_URL, SERVER_NAME );    (void) fflush( stdout );    exit( 1 );    }static voidsend_headers( int status, char* title, char* extra_header, char* mime_type, off_t length, time_t mod )    {    time_t now;    char timebuf[100];    (void) printf( "%s %d %s\015\012", PROTOCOL, status, title );    (void) printf( "Server: %s\015\012", SERVER_NAME );    now = time( (time_t*) 0 );    (void) strftime( timebuf, sizeof(timebuf), RFC1123FMT, gmtime( &now ) );    (void) printf( "Date: %s\015\012", timebuf );    if ( extra_header != (char*) 0 )(void) printf( "%s\015\012", extra_header );    if ( mime_type != (char*) 0 )(void) printf( "Content-Type: %s\015\012", mime_type );    if ( length >= 0 )(void) printf( "Content-Length: %lld\015\012", (long long) length );    if ( mod != (time_t) -1 ){(void) strftime( timebuf, sizeof(timebuf), RFC1123FMT, gmtime( &mod ) );(void) printf( "Last-Modified: %s\015\012", timebuf );}    (void) printf( "Connection: close\015\012" );    (void) printf( "\015\012" );    }static char*get_mime_type( char* name )    {    char* dot;    dot = strrchr( name, '.' );    if ( dot == (char*) 0 )return "text/plain; charset=UTF-8";    if ( strcmp( dot, ".html" ) == 0 || strcmp( dot, ".htm" ) == 0 )return "text/html; charset=UTF-8";    if ( strcmp( dot, ".xhtml" ) == 0 || strcmp( dot, ".xht" ) == 0 )return "application/xhtml+xml; charset=UTF-8";    if ( strcmp( dot, ".jpg" ) == 0 || strcmp( dot, ".jpeg" ) == 0 )return "image/jpeg";    if ( strcmp( dot, ".gif" ) == 0 )return "image/gif";    if ( strcmp( dot, ".png" ) == 0 )return "image/png";    if ( strcmp( dot, ".css" ) == 0 )return "text/css";    if ( strcmp( dot, ".xml" ) == 0 || strcmp( dot, ".xsl" ) == 0 )return "text/xml; charset=UTF-8";    if ( strcmp( dot, ".au" ) == 0 )return "audio/basic";    if ( strcmp( dot, ".wav" ) == 0 )return "audio/wav";    if ( strcmp( dot, ".avi" ) == 0 )return "video/x-msvideo";    if ( strcmp( dot, ".mov" ) == 0 || strcmp( dot, ".qt" ) == 0 )return "video/quicktime";    if ( strcmp( dot, ".mpeg" ) == 0 || strcmp( dot, ".mpe" ) == 0 )return "video/mpeg";    if ( strcmp( dot, ".vrml" ) == 0 || strcmp( dot, ".wrl" ) == 0 )return "model/vrml";    if ( strcmp( dot, ".midi" ) == 0 || strcmp( dot, ".mid" ) == 0 )return "audio/midi";    if ( strcmp( dot, ".mp3" ) == 0 )return "audio/mpeg";    if ( strcmp( dot, ".ogg" ) == 0 )return "application/ogg";    if ( strcmp( dot, ".pac" ) == 0 )return "application/x-ns-proxy-autoconfig";    return "text/plain; charset=UTF-8";    }static voidstrdecode( char* to, char* from )    {    for ( ; *from != '\0'; ++to, ++from ){if ( from[0] == '%' && isxdigit( from[1] ) && isxdigit( from[2] ) )    {    *to = hexit( from[1] ) * 16 + hexit( from[2] );    from += 2;    }else    *to = *from;}    *to = '\0';    }static inthexit( char c )    {    if ( c >= '0' && c <= '9' )return c - '0';    if ( c >= 'a' && c <= 'f' )return c - 'a' + 10;    if ( c >= 'A' && c <= 'F' )return c - 'A' + 10;    return 0;/* shouldn't happen, we're guarded by isxdigit() */    }static voidstrencode( char* to, size_t tosize, const char* from )    {    int tolen;    for ( tolen = 0; *from != '\0' && tolen + 4 < tosize; ++from ){if ( isalnum(*from) || strchr( "/_.-~", *from ) != (char*) 0 )    {    *to = *from;    ++to;    ++tolen;    }else    {    (void) sprintf( to, "%%%02x", (int) *from & 0xff );    to += 3;    tolen += 3;    }}    *to = '\0';    }