httpd.c

ENC28J60 System HTTP

/*
,-----------------------------------------------------------------------------------------.
| net/httpd
|-----------------------------------------------------------------------------------------
| this file implements a very basic http server
| - support for HTTP POST 
| - support for http basic auuth (all /adm/.. file acces must be authorized)
|
| KNOWN PROBLEMS:
| - somehow quick&dirty implementation ! sorry for that ;)
| - uses some dirty hacks (content length detection etc)
| - very big routines without function calls for memory/flash/speed reasons
| - not really documented :-\
| - http authorization does not work if browser request is split into two packets ! (-> always not authorized)
| - httpd_add_prog* only use 16bit as data offset ! -> biggest filesize in avr flash is 65k!!!
|
| Author   : {{removed according to contest rules}}
|            -> circuitcellar.com avr design contest 2006
|            -> Entry #AT2616
|
|-----------------------------------------------------------------------------------------
| License:
| This program is free software; you can redistribute it and/or modify it under
| the terms of the GNU General Public License as published by the Free Software
| Foundation; either version 2 of the License, or (at your option) any later
| version.
| This program is distributed in the hope that it will be useful, but
|
| WITHOUT ANY WARRANTY;
|
| without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
| PURPOSE. See the GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License along with
| this program; if not, write to the Free Software Foundation, Inc., 51
| Franklin St, Fifth Floor, Boston, MA 02110, USA
|
| http://www.gnu.de/gpl-ger.html
`-----------------------------------------------------------------------------------------*/

#include "httpd.h"

//ACTIVATE DEBUG by editing this file:
#include "debug.h"

///FIXME: include the .c file here !
///       without this sizeof() does not work !! -> is there another way to do this ?!
#include "httpd_data.c"


struct httpd_conn_struct {
	unsigned char state;
	unsigned char substate;
	unsigned int  file_id;
	unsigned long  seq_offset;
	unsigned int  data_ptr;
	unsigned long data_position;
};

struct httpd_conn_struct httpd_conn[TCP_SOCKET_COUNT];

//initialise connection table
void httpd_init(void){
	for(unsigned char c=0; c<TCP_SOCKET_COUNT; c++){
		httpd_cleanup_conn(c);
	}
}

//initialise/cleanup http conn
void httpd_cleanup_conn(unsigned char i){
	if (i<TCP_SOCKET_COUNT){
		httpd_conn[i].state = HTTPD_STATE_IDLE;
		httpd_conn[i].data_position = 0;
	}
}

//return: how many data bytes should be transferred ?
unsigned int httpd_data_in(unsigned char *buffer, unsigned int datapos, unsigned int datalen, unsigned char socketnum, unsigned char *appstate){
	unsigned int pos;
	unsigned char file_name[8+6+1];
	unsigned char file_ext[3+1];
	unsigned char f;
	unsigned int ret;
	unsigned long offset;
	unsigned char authorized;

	pos = 0;

	#if HTTPD_DEBUG2
	softuart_puts_progmem("HTTP: SEQ-SEQ_OFFSET_DATA = ");
	softuart_put_uint16((tcp_sockets[socketnum].seq-httpd_conn[socketnum].seq_offset)&0xFFFF);
	softuart_puts_progmem("\r\n");
	#endif

  //initialise filename:
	for (f=0; f<8+6+1; f++)
		file_name[f] = 0;
	for (f=0; f<3+1; f++)
		file_ext[f] = 0;

	switch(httpd_conn[socketnum].state){
		case(HTTPD_STATE_IDLE):
		//case(HTTPD_STATE_IDLE_r):
		//case(HTTPD_STATE_IDLE_rn):
		//case(HTTPD_STATE_IDLE_rnr):
		//case(HTTPD_STATE_IDLE_rnrn):
			//new request, scan for GET/POST:
			if ((buffer[datapos + 0] == 'G') && 
			    (buffer[datapos + 1] == 'E') && 
			    (buffer[datapos + 2] == 'T')){
				//get request !
				pos = datapos + 3;
				
				f = 0;

				//find start of requested url
				while(buffer[pos] == ' ')
					pos++;

				while((buffer[pos] != ' ')  && (buffer[pos] != '\r') && (buffer[pos] != '\n')  && (buffer[pos] != '?') && (pos<datapos+datalen)){
					//read requested file,
					//read filename:
					file_name[f] = buffer[pos];

					//read file extension:
					/*if (!((file_ext[2] == ' ') || (file_ext[2] == '?'))){
						file_ext[0] = file_ext[1];
						file_ext[1] = file_ext[2];
						file_ext[2] = buffer[pos];
					}*/
					if (buffer[pos] == '.'){
						file_ext[0] = buffer[pos+1];
						file_ext[1] = buffer[pos+2];
						file_ext[2] = buffer[pos+3];
						file_name[f] = 0;
						break;
					}

					if (file_name[f] == '.')
						file_name[f] = 0;
					
					if (f<8+6)
						f++;
	
					//remove first /
					if (file_name[0] == '/')
						f=0;

					pos++;
				}
				//if (file_name[f]=='.')
				//	file_name[f] = 0;

				#if HTTPD_DEBUG
				softuart_puts_progmem("HTTP: GET <");				
				for(f=0;f<8+6 && file_name[f];f++)
					softuart_putc(file_name[f]);
				softuart_putc('.');
				for(f=0;f<3 && file_ext[f];f++)
					softuart_putc(file_ext[f]);
				softuart_puts_progmem(">.\r\n");
				#endif

				//set file id:
				if (file_name[0] == '/' || string_compare_progmem("index", file_name)){
					///show index
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_INDEX;
					file_ext[0] = 'h'; //->html
				}else if ( string_compare_progmem("site/cam", file_name)){
					///show webcam pic
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SITE_CAM;
				}else if ( string_compare_progmem("site/temp", file_name)){
					///show templog site
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SITE_TEMP;
				}else if ( string_compare_progmem("site/io", file_name)){
					///show io site
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SITE_IO;
				}else if ( string_compare_progmem("site/ficon", file_name)){
					///show file icon
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SITE_FILE_ICON_PIC;
				}else if ( string_compare_progmem("graph_0", file_name)){
					///show tempgraph (use eeprom data)
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_GRAPH0;
				}else if ( string_compare_progmem("fs/ls", file_name)){
					///show dataflash file list
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_FS_LS;
				}else if ( string_compare_progmem("cam/pic", file_name)){
					///show webcam image
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_CAM_PIC;
				}else if ( string_compare_progmem("cam/busy", file_name)){
					///show webcam busy image
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_CAM_BUSY;
				}else if ( string_compare_progmem("site/servo", file_name)){
					///show servo page
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SERVO_OK;
				}else if ( string_compare_progmem_noeof("servo_", file_name)){
					///show/set servo pos
					//parse number & set servopos (use uint16 parser)
					//if you want to show servopos without moving use servo_999.bmp for example
					if (string_buffer_to_uint16(&file_name[6])<256)
						servo_set_pos(string_buffer_to_uint16(&file_name[6])&0xFF);
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SERVO_POS;
				}else if ( string_compare_progmem_noeof("set/", file_name)){
					///show port image
					if(file_name[7] == '1'){
						httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SET_IO_1_PIC;
						port_set_portbit(file_name[4], file_name[5], 1);
					}else{
						httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_SET_IO_0_PIC;
						port_set_portbit(file_name[4], file_name[5], 0);
					}
				//deprecated
				//}else if ( string_compare_progmem_noeof("fs/f", file_name)){
				//	///show dataflash file with id given (fs/f1234 -> file 1234 !):
				//	httpd_conn[socketnum].file_id = 0xFF + string_buffer_to_uint16(&file_name[4]);
				}else if ( string_compare_progmem_noeof("fs/", file_name)){
					///try to find dataflash file with the given name:
					httpd_conn[socketnum].file_id = 0xFF + filesystem_search_file(&file_name[3], &file_ext[0]);
					httpd_conn[socketnum].data_ptr = 0; 
					if (httpd_conn[socketnum].file_id == 0xFF)
						httpd_conn[socketnum].file_id = HTTPD_STATE_IDLE; ///no file found !
				}else if ( string_compare_progmem("adm/up", file_name)){
					///show upload form
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_UP;
				}else if ( string_compare_progmem_noeof("adm/rm/", file_name)){
					///try to find dataflash file with the given name:
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_REMOVED;
				}else if ( string_compare_progmem("adm/mkfs", file_name)){
					///format filesystem question
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_MKFS;
				}else if ( string_compare_progmem("adm/mkfs2", file_name)){
					///format filesystem exec!
					httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_MKFS2;
				}else{
					///FILE not found -> 404 err
					httpd_conn[socketnum].file_id = HTTPD_STATE_IDLE;
				}
				//initialise substate
				httpd_conn[socketnum].substate = HTTPD_SUBSTATE_NONE;
			}else if ((buffer[datapos + 0] == 'P') && 
					(buffer[datapos + 1] == 'O') && 
					(buffer[datapos + 2] == 'S') && 
					(buffer[datapos + 3] == 'T')){
				//QUICK HACK (TEST!)
				httpd_conn[socketnum].file_id = HTTPD_STATE_FILE_POST;

				string_progmem_to_buffer(PSTR("adm/"), file_name,4);

				//initialise substate
				httpd_conn[socketnum].substate = HTTPD_SUBSTATE_NONE;
			}

			//find the content length!
			//use a quick & dirty method for this !!!
			//-> we search for *th: <number> 
			//   (instead of content-length:)
			//
			// we do this because to minimize the following problem:
			// clen detection DOES NOT work when the header is 
			// split into multiple packets & the packetborder
			// is anywhere between th: <number> !! FIXME!
			if (httpd_conn[socketnum].file_id == 0xFE){
				pos = datapos;
				//pos+4 because len("th: ") is 4 (fixme: number might be outside packetlen!)
				while (pos+4<datapos+datalen){
					if (string_compare_progmem_noeof("th: ", &buffer[pos])){
						//next is the number ! 
						//parse it !
						httpd_conn[socketnum].data_position = string_buffer_to_uint32(&buffer[pos+4]);
						break;
					}
					pos++;
				}
			}

			///search for authorization key
			authorized = 0;
			if (string_compare_progmem_noeof("adm/", file_name)){
				//accessing admin zone, search for auth!
				#if HTTPD_DEBUG_AUTH
				softuart_puts_progmem("HTTPD: auth required! [");
				#endif
				pos = datapos;
				
				while(pos<datapos+datalen){
					//speedup, check first letter
					if (buffer[pos] == 'A'){
						//if match, call whole function match
						if (string_compare_progmem_noeof("Authorization: Basic ", &buffer[pos])){
							//got it ! now buf[pos+21]-... has auth string!
							unsigned char len;
							unsigned char *pwbuff = &buffer[pos+21];

							//maximum pw len 100
							for(len=0; len < 100; len++){ 
								//check buf < '0' is ok because of base64... \r\n & space are smaller ;)
								if (pwbuff[len]<'0')
									break;
								#if HTTPD_DEBUG_AUTH
								softuart_putc(pwbuff[len]);
								#endif
							}
							//len--;
							
							//base64 decode, after this the decoded string is in buffer[pos+21]...
							base64_decode(&pwbuff[0], len);

							#if HTTPD_DEBUG_AUTH
							softuart_puts_progmem("], decoded [");
							for(len=0; len < 100; len++){
								if (pwbuff[len]==0)	
									break;
								softuart_putc(pwbuff[len]);
							}
							softuart_puts_progmem("] auth? ");
							#endif

							if (string_compare_progmem(HTTPD_ADMIN_AUTH_LOGIN":"HTTPD_ADMIN_AUTH_PASS, &pwbuff[0])){
								//auth passed !!
								authorized = 1;
							}
							#if HTTPD_DEBUG_AUTH
							softuart_put_uint8(authorized);
							softuart_putnewline();
							#endif

							break;
						}
					}
					pos++;
				}
				//check if there was a file remove request
				if (authorized && (httpd_conn[socketnum].file_id == HTTPD_STATE_FILE_REMOVED)){
					httpd_conn[socketnum].file_id = 0xFF + string_buffer_to_uint16(&file_name[7]);