netcam.c

motion motion

/*
 *      netcam.c
 *
 *      Module for handling network cameras.
 *
 *      This code was inspired by the original netcam.c module
 *      written by Jeroen Vreeken and enhanced by several Motion
 *      project contributors, particularly Angel Carpintero and
 *      Christopher Price.
 *
 *      Copyright 2005, William M. Brack
 *      This software is distributed under the GNU Public license
 *      Version 2.  See also the file 'COPYING'.
 *
 *
 *      When a netcam has been configured, instead of using the routines
 *      within video.c (which handle a CCTV-type camera) the routines
 *      within this module are used.  There are only four entry points -
 *      one for "starting up" the camera (netcam_start), for "fetching a
 *      picture" from it (netcam_next), one for cleanup at the end of a
 *      run (netcam_cleanup), and a utility routine for receiving data
 *      from the camera (netcam_recv).
 *
 *      Two quite different types of netcams are handled.  The simplest
 *      one is the type which supplies a single JPEG frame each time it
 *      is accessed.  The other type is one which supplies an mjpeg
 *      stream of data.
 *
 *      For each of these cameras, the routine taking care of the netcam
 *      will start up a completely separate thread (which I call the "camera
 *      handler thread" within subsequent comments).  For a streaming camera,
 *      this handler will receive the mjpeg stream of data from the camera,
 *      and save the latest complete image when it begins to work on the next
 *      one.  For the non-streaming version, this handler will be "triggered"
 *      (signalled) whenever the main motion-loop asks for a new image, and
 *      will start to fetch the next image at that time.  For either type,
 *      the most recent image received from the camera will be returned to
 *      motion.
 */
#include "motion.h"

#include <netdb.h>
#include <netinet/in.h>
#include <regex.h>                  /* For parsing of the URL */
//#include <stdio.h>
//#include <stdlib.h>
//#include <string.h>
#include <sys/socket.h>
//#include <sys/types.h>

#include "netcam_ftp.h"

#define CONNECT_TIMEOUT        10   /* timeout on remote connection attempt */
#define READ_TIMEOUT            5   /* default timeout on recv requests */
#define POLLING_TIMEOUT  READ_TIMEOUT /* file polling timeout [s] */
#define POLLING_TIME  500*1000*1000 /* file polling time quantum [ns] (500ms) */
#define MAX_HEADER_RETRIES      5   /* Max tries to find a header record */
#define MINVAL(x, y) ((x) < (y) ? (x) : (y))

/*
 * The macro NETCAM_DEBUG is for development testing of this module.
 * The macro SETUP is to assure that "configuration-setup" type messages
 * are also printed when NETCAM_DEBUG is set.  Set the following #if to
 * 1 to enable it, or 0 (normal setting) to disable it.
 */
#define SETUP    ((cnt->conf.setup_mode) || (debug_level >= CAMERA_INFO))


tfile_context *file_new_context(void);
void file_free_context(tfile_context* ctxt);

/* These strings are used for the HTTP connection */
static const char    *connect_req;

static const char    *connect_req_http10 = "GET %s HTTP/1.0\r\n"
                      "Host: %s\r\n"
                      "User-Agent: Motion-netcam/" VERSION "\r\n";

static const char    *connect_req_http11 = "GET %s HTTP/1.1\r\n"
                      "Host: %s\r\n"
                      "User-Agent: Motion-netcam/" VERSION "\r\n";

static const char    *connect_req_close = "Connection: close\r\n";

static const char    *connect_req_keepalive = "Connection: Keep-Alive\r\n";

static const char    *connect_auth_req = "Authorization: Basic %s\r\n";

/*
 * The following three routines (netcam_url_match, netcam_url_parse and
 * netcam_url_free are for 'parsing' (i.e. separating into the relevant
 * components) the URL provided by the user.  They make use of regular
 * expressions (which is outside the scope of this module, so detailed
 * comments are not provided).  netcam_url_parse is called from netcam_start,
 * and puts the "broken-up" components of the URL into the "url" element of
 * the netcam_context structure.
 *
 * Note that the routines are not "very clever", but they work sufficiently
 * well for the limited requirements of this module.  The expression:
 *   (http)://(((.*):(.*))@)?([^/:]|[-.a-z0-9]+)(:([0-9]+))?($|(/[^:]*))
 * requires
 *   1) a string which begins with 'http', followed by '://'
 *   2) optionally a '@' which is preceded by two strings
 *      (with 0 or more characters each) separated by a ':'
 *      [this is for an optional username:password]
 *   3) a string comprising alpha-numerics, '-' and '.' characters
 *      [this is for the hostname]
 *   4) optionally a ':' followed by one or more numeric characters
 *      [this is for an optional port number]
 *   5) finally, either an end of line or a series of segments,
 *      each of which begins with a '/', and contains anything
 *      except a ':'
 */

/**
 * netcam_url_match
 *
 *      Finds the matched part of a regular expression
 *
 * Parameters:
 *
 *      m          A structure containing the regular expression to be used
 *      input      The input string
 *
 * Returns:        The string which was matched
 *
 */
static char *netcam_url_match(regmatch_t m, const char *input)
{
	char *match = NULL;
	int len;

	if (m.rm_so != -1) {
		len = m.rm_eo - m.rm_so;

		if ((match = (char *) malloc(len + 1)) != NULL) {
			strncpy(match, input + m.rm_so, len);
			match[len] = '\0';
		}
	}

	return (match);
}

/**
 * netcam_url_parse
 *
 *      parses a string containing a URL into it's components
 *
 * Parameters:
 *      parse_url          A structure which will receive the results
 *                         of the parsing
 *      text_url           The input string containing the URL
 *
 * Returns:                Nothing
 *
 */
static void netcam_url_parse(struct url_t *parse_url, const char *text_url)
{
	char *s;
	int i;
	const char *re = "(http|ftp)://(((.*):(.*))@)?"
	                 "([^/:]|[-.a-z0-9]+)(:([0-9]+))?($|(/[^:]*))";
	regex_t pattbuf;
	regmatch_t matches[10];

	if( !strncmp( text_url, "file", 4 ) ) 
		re = "(file)://(((.*):(.*))@)?"
		     "([^/:]|[-.a-z0-9]*)(:([0-9]*))?($|(/[^:][/-_.a-z0-9]+))";

	if (debug_level > CAMERA_DEBUG)
		motion_log(-1, 0, "Entry netcam_url_parse data %s", text_url );

	memset(parse_url, 0, sizeof(struct url_t));
	/*
	 * regcomp compiles regular expressions into a form that is
	 * suitable for regexec searches
	 * regexec matches the URL string against the regular expression
	 * and returns an array of pointers to strings matching each match
	 * within (). The results that we need are finally placed in parse_url
	 */
	if (!regcomp(&pattbuf, re, REG_EXTENDED | REG_ICASE)) {
		if (regexec(&pattbuf, text_url, 10, matches, 0) != REG_NOMATCH) {
			for (i = 0; i < 10; i++) {
				if ((s = netcam_url_match(matches[i], text_url)) != NULL) {
					if (debug_level > CAMERA_DEBUG)
						motion_log(-1, 0, "Parse case %d data %s", i, s );
					switch (i) {
						case 1:
							parse_url->service = s;
							break;
						case 3:
							parse_url->userpass = s;
							break;
						case 6:
							parse_url->host = s;
							break;
						case 8:
							parse_url->port = atoi(s);
							free(s);
							break;
						case 9:
							parse_url->path = s;
							break;
						/* other components ignored */
						default:
							free(s);
							break;
					}
				}
			}
		}
	}
	if ((!parse_url->port) && (parse_url->service)){
		if (!strcmp(parse_url->service, "http"))
			parse_url->port = 80;
		else if (!strcmp(parse_url->service, "ftp"))
			parse_url->port = 21;
	}

	regfree(&pattbuf);
}

/**
 * netcam_url_free
 *
 *      General cleanup of the URL structure, called from netcam_cleanup.
 *
 * Parameters:
 *
 *      parse_url       Structure containing the parsed data
 *
 * Returns:             Nothing
 *
 */
static void netcam_url_free(struct url_t *parse_url)
{
	if (parse_url->service) {
		free(parse_url->service);
		parse_url->service = NULL;
	}

	if (parse_url->userpass) {
		free(parse_url->userpass);
		parse_url->userpass = NULL;
	}

	if (parse_url->host) {
		free(parse_url->host);
		parse_url->host = NULL;
	}

	if (parse_url->path) {
		free(parse_url->path);
		parse_url->path = NULL;
	}
}

/**
 * check_quote
 *
 *      Checks a string to see if it's quoted, and if so removes the
 *      quotes.
 *
 * Parameters:
 *
 *      str             Pointer to a string
 *
 * Returns:             Nothing, but updates the target if necessary
 *
 */
static void check_quote(char *str)
{
	int len;
	char ch;

	ch = *str;

	if ((ch == '"') || (ch == '\'')) {
		len = strlen(str) - 1;
		if (str[len] == ch) {
			memmove(str, str+1, len-1);
			str[len-1] = 0;
		}
	}
}

/**
 * netcam_check_content_length
 *
 * 	Analyse an HTTP-header line to see if it is a Content-length
 *
 * Parameters:
 *
 *      header          Pointer to a string containing the header line
 *
 * Returns:
 *      -1              Not a Content-length line
 *      >=0             Value of Content-length field
 *
 */
static long netcam_check_content_length(char *header)
{
	long length=-1;	/* note this is a long, not an int */

	if (!header_process(header, "Content-Length", header_extract_number, &length)) {
		/*
		 * Some netcams deliver some bad-format data, but if
		 * we were able to recognize the header section and the
		 * number we might as well try to use it.
		 */
		if (length > 0)
			return length;
		return -1;
	}

	return length;
}

/**
 * netcam_check_keepalive
 *
 * 	Analyse an HTTP-header line to see if it is a Keep-Alive.
 *
 * Parameters:
 *
 *      header          Pointer to a string containing the header line
 *
 * Returns:
 *      -1              Not a Keep-Alive line
 *      1               Is a Keep-Alive line
 *
 */
static int netcam_check_keepalive(char *header)
{
	char *content_type = NULL;

	if (!header_process(header, "Keep-Alive", http_process_type, &content_type))
		return -1;

	/* We do not detect the second field or other case mixes at present. */

	if (content_type) 
		free(content_type);

	return 1;
}

/**
 * netcam_check_close
 *
 * 	Analyse an HTTP-header line to see if it is a Connection: close
 *
 * Parameters:
 *
 *      header          Pointer to a string containing the header line
 *
 * Returns:
 *      -1              Not a Connection: close
 *      1               Is a Connection: close
 *
 */
static int netcam_check_close(char *header)
{
	char *type = NULL;
	int ret=-1;

	if (!header_process(header, "Connection", http_process_type, &type))
		return -1;
	
	if (!strcmp(type, "close")) /* strcmp returns 0 for match */
		ret=1;
	
	if (type) 
		free(type);

	return ret;
}

/**
 * netcam_check_content_type
 *
 * 	Analyse an HTTP-header line to see if it is a Content-type
 *
 * Parameters:
 *
 *      header          Pointer to a string containing the header line
 *
 * Returns:
 *      -1              Not a Content-type line
 *      0               Content-type not recognized
 *      1               image/jpeg
 *      2               multipart/x-mixed-replace or multipart/mixed
 *
 */
static int netcam_check_content_type(char *header)
{
	char *content_type = NULL;
	int ret;

	if (!header_process(header, "Content-type", http_process_type, &content_type))
		return -1;

	if (!strcmp(content_type, "image/jpeg")) {
		ret = 1;
	} else if (!strcmp(content_type, "multipart/x-mixed-replace") ||
	           !strcmp(content_type, "multipart/mixed")) {
		ret = 2;
	} else
		ret = 0;

	if (content_type)
		free(content_type);

	return ret;
}


/**
 * netcam_read_next_header