Thread: [Redbutton-devel] SF.net SVN: redbutton: [5] redbutton-download/trunk

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Revision: 5
Author:   skilvington
Date:     2006-03-01 08:05:30 -0800 (Wed, 01 Mar 2006)
ViewCVS:  http://svn.sourceforge.net/redbutton/?rev=5&view=rev

Log Message:
-----------
allow rb-download to listen for commands from rb-browser

Modified Paths:
--------------
    redbutton-download/trunk/Makefile
    redbutton-download/trunk/TODO
    redbutton-download/trunk/rb-download.c
    redbutton-download/trunk/utils.c
    redbutton-download/trunk/utils.h

Added Paths:
-----------
    redbutton-download/trunk/command.c
    redbutton-download/trunk/command.h
    redbutton-download/trunk/listen.c
    redbutton-download/trunk/listen.h
Modified: redbutton-download/trunk/Makefile
===================================================================

--- redbutton-download/trunk/Makefile	2006-03-01 10:26:41 UTC (rev 4)
+++ redbutton-download/trunk/Makefile	2006-03-01 16:05:30 UTC (rev 5)
@@ -4,6 +4,8 @@
 OBJS=	rb-download.o	\
 	list.o		\
 	findmheg.o	\
+	listen.o	\
+	command.o	\
 	assoc.o		\
 	carousel.o	\
 	module.o	\

Modified: redbutton-download/trunk/TODO
===================================================================
--- redbutton-download/trunk/TODO	2006-03-01 10:26:41 UTC (rev 4)
+++ redbutton-download/trunk/TODO	2006-03-01 16:05:30 UTC (rev 5)
@@ -1,3 +1,5 @@
+replace TRUE/FALSE with stdbool
+
 work out why this happened on BBC1 once:
 read: Value too large for defined data type
 Unable to read PID

Added: redbutton-download/trunk/command.c
===================================================================
--- redbutton-download/trunk/command.c	                        (rev 0)
+++ redbutton-download/trunk/command.c	2006-03-01 16:05:30 UTC (rev 5)
@@ -0,0 +1,185 @@
+/*
+ * command.c
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include "command.h"
+#include "utils.h"
+
+/* max number of args that can be passed to a command (arbitrary) */
+#define ARGV_MAX	10
+
+/* the commands */
+bool cmd_file(struct listen_data *, int, int, char **);
+bool cmd_help(struct listen_data *, int, int, char **);
+bool cmd_quit(struct listen_data *, int, int, char **);
+
+static struct
+{
+	char *name;
+	char *args;
+	bool (*proc)(struct listen_data *, int, int, char **);
+	char *help;
+} command[] =
+{
+	{ "exit", "",			cmd_quit,	"Kill the programme" },
+	{ "file", "<ContentReference>",	cmd_file,	"Retrieve the given file from the carousel" },
+	{ "help", "",			cmd_help,	"List available commands" },
+	{ "quit", "",			cmd_quit,	"Kill the programme" },
+	{ NULL, NULL, NULL, NULL }
+};
+
+/*
+ * process the given command
+ * return true if we should quit the programme
+ */
+
+bool
+process_command(struct listen_data *listen_data, int client_sock, char *cmd)
+{
+	int argc;
+	char *argv[ARGV_MAX];
+	char term;
+	unsigned int cmd_len;
+	int i;
+
+	/* chop it into words, complicated by quoting */
+	argc = 0;
+	while(argc < ARGV_MAX && *cmd != '\0')
+	{
+		argv[argc++] = cmd;
+		/* do we need to find the next space, or the next quote */
+		if(*cmd == '\'' || *cmd == '"')
+		{
+			term = *cmd;
+			/* remove/skip the opening quote */
+			argv[argc-1] ++;
+			cmd ++;
+		}
+		else
+		{
+			/* stop at the next space */
+			term = ' ';
+		}
+		/* find the next terminating character */
+		while(*cmd != term && *cmd != '\0')
+			cmd ++;
+		/* if this is not the end, skip to the start of the next word */
+		if(*cmd != '\0')
+		{
+			/* terminate the last word */
+			*cmd = '\0';
+			/* move onto the next non-space character */
+			cmd = skip_ws(cmd + 1);
+		}
+	}
+
+	cmd_len = strlen(argv[0]);
+	for(i=0; command[i].name != NULL; i++)
+	{
+		if(strncmp(argv[0], command[i].name, cmd_len) == 0)
+			return (command[i].proc)(listen_data, client_sock, argc, argv);
+	}
+
+	write_string(client_sock, "500 Unrecognised command\n");
+
+	return false;
+}
+
+/*
+ * the commands
+ * listen_data is global data needed by listener commands
+ * client_sock is where any response data should go
+ * argc is the number of arguments passed to it
+ * argv[0] is the command name (or the abreviation the user used)
+ * return true if we should quit the programme
+ */
+
+/*
+ * file <ContentReference>
+ * send the given file down client_sock
+ * ContentReference should be absolute, ie start with "~//"
+ */
+
+bool
+cmd_file(struct listen_data *listen_data, int client_sock, int argc, char *argv[])
+{
+	char *filename;
+	FILE *file;
+	size_t nread;
+	char buff[1024 * 8];
+
+	if(argc != 2)
+	{
+		write_string(client_sock, "500 Syntax: file <ContentReference>\n");
+		return false;
+	}
+
+	filename = argv[1];
+
+	/* is ContentReference absolute */
+	if(strlen(filename) < 3 || strncmp(filename, "~//", 3) != 0)
+	{
+		write_string(client_sock, "500 ContentReference is not absolute\n");
+		return false;
+	}
+
+	/* strip off the ~// prefix */
+	filename += 3;
+
+	if((file = fopen(filename, "r")) == NULL)
+	{
+		write_string(client_sock, "404 Not found\n");
+		return false;
+	}
+
+	write_string(client_sock, "200 OK\n");
+
+	do
+	{
+		nread = fread(buff, 1, sizeof(buff), file);
+		write_all(client_sock, buff, nread);
+	}
+	while(nread == sizeof(buff));
+
+	fclose(file);
+
+	return false;
+}
+
+/*
+ * help
+ */
+
+bool
+cmd_help(struct listen_data *listen_data, int client_sock, int argc, char *argv[])
+{
+	int i;
+	char name_args[64];
+	char help_line[128];
+
+	write_string(client_sock, "200 OK\n");
+
+	for(i=0; command[i].name != NULL; i++)
+	{
+		snprintf(name_args, sizeof(name_args), "%s %s", command[i].name, command[i].args);
+		snprintf(help_line, sizeof(help_line), "%-30s %s\n", name_args, command[i].help);
+		write_string(client_sock, help_line);
+	}
+
+	return false;
+}
+
+/*
+ * quit
+ */
+
+bool
+cmd_quit(struct listen_data *listen_data, int client_sock, int argc, char *argv[])
+{
+	return true;
+}
+

Added: redbutton-download/trunk/command.h
===================================================================
--- redbutton-download/trunk/command.h	                        (rev 0)
+++ redbutton-download/trunk/command.h	2006-03-01 16:05:30 UTC (rev 5)
@@ -0,0 +1,12 @@
+/*
+ * command.h
+ */
+
+#ifndef __COMMAND_H__
+#define __COMMAND_H__
+
+#include "listen.h"
+
+bool process_command(struct listen_data *, int, char *);
+
+#endif

Added: redbutton-download/trunk/listen.c
===================================================================
--- redbutton-download/trunk/listen.c	                        (rev 0)
+++ redbutton-download/trunk/listen.c	2006-03-01 16:05:30 UTC (rev 5)
@@ -0,0 +1,249 @@
+/*
+ * listen.c
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "command.h"
+#include "utils.h"
+
+/* listen() backlog, 5 is max for BSD apparently */
+#define BACKLOG		5
+
+/* internal functions */
+static int get_host_addr(char *, struct in_addr *);
+
+static bool handle_connection(struct listen_data *, int, struct sockaddr_in *);
+static void dead_child(int);
+
+/*
+ * extract the IP addr and port number from a string in one of these forms:
+ * host:port
+ * ip-addr:port
+ * host
+ * ip-addr
+ * port
+ * if the string is NULL, or the host or the port are not defined in the string,
+ * the corresponding param passed to this routine is not changed
+ * ip and port are both returned in network byte order
+ * returns -1 on error (can't resolve host name)
+ */
+
+int
+parse_addr(char *str, struct in_addr *ip, in_port_t *port)
+{
+	char *p;
+	int ishost;
+
+	/* easy case */
+	if(str == NULL)
+		return 0;
+
+	if((p = strchr(str, ':')) != NULL)
+	{
+		/* its either host:port or ip:port */
+		*(p++) = '\0';
+		if(get_host_addr(str, ip) < 0)
+			return -1;
+		*port = htons(atoi(p));
+		/* reconstruct the string */
+		*(--p) = ':';
+	}
+	else
+	{
+		/* its either host, ip, or port */
+		/* all digits => a port number */
+		ishost = 0;
+		for(p=str; *p && !ishost; p++)
+			ishost = !isdigit(*p);
+		if(ishost)
+		{
+			if(get_host_addr(str, ip) < 0)
+				return -1;
+		}
+		else
+		{
+			*port = htons(atoi(str));
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * puts the IP address associated with the given host into output buffer
+ * host can be a.b.c.d or a host name
+ * returns 0 if successful, -1 on error
+ */
+
+static int
+get_host_addr(char *host, struct in_addr *output)
+{
+	struct hostent *he;
+	int error = 0;
+
+	if(((he = gethostbyname(host)) != NULL) && (he->h_addrtype == AF_INET))
+		memcpy(output, he->h_addr, sizeof(struct in_addr));
+	else
+		error = -1;
+
+	return error;
+}
+
+/*
+ * start a process to listen on the given interface for commands from a remote rb-browser
+ */
+
+void
+start_listener(struct listen_data *listen_data)
+{
+	struct sigaction action;
+	pid_t child;
+	int sockopt;
+	int listen_sock;
+	int accept_sock;
+	fd_set read_fds;
+	socklen_t addr_len;
+	struct sockaddr_in client_addr;
+	bool quit;
+
+	/*
+	 * fork:
+	 * the parent listens for commands,
+	 * the child returns and downloads the carousel
+	 */
+
+	/* don't let our children become zombies */
+	action.sa_handler = dead_child;
+	sigemptyset(&action.sa_mask);
+	action.sa_flags = 0;
+	if(sigaction(SIGCHLD, &action, NULL) < 0)
+		fatal("signal: SIGCHLD: %s", strerror(errno));
+
+	/* if we can't fork it's probably best to kill ourselves*/
+	if((child = fork()) < 0)
+		fatal("fork: %s", strerror(errno));
+	/* child returns */
+	else if(child == 0)
+		return;
+	/* parent continues */
+
+	/* listen on the given ip:port */
+	printf("Listening on %s:%u\n", inet_ntoa(listen_data->addr.sin_addr), ntohs(listen_data->addr.sin_port));
+
+	if((listen_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		fatal("socket: %s", strerror(errno));
+
+	/* in case someones already using it */
+	sockopt = 1;
+	if(setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, &sockopt, sizeof(sockopt)) < 0)
+		fatal("setsockopt: SO_REUSEADDR: %s", strerror(errno));
+
+	if(bind(listen_sock, (struct sockaddr *) &listen_data->addr, sizeof(struct sockaddr_in)) < 0)
+		fatal("bind: %s", strerror(errno));
+
+	if(listen(listen_sock, BACKLOG) < 0)
+		fatal("listen: %s", strerror(errno));
+
+	/* listen for connections */
+	while(true)
+	{
+		FD_ZERO(&read_fds);
+		FD_SET(listen_sock, &read_fds);
+		if(select(listen_sock + 1, &read_fds, NULL, NULL, NULL) < 0)
+		{
+			/* could have been interupted by SIGCHLD */
+			if(errno != EINTR)
+				error("select: %s", strerror(errno));
+			continue;
+		}
+		/* check select didnt fuck up */
+		if(!FD_ISSET(listen_sock, &read_fds))
+			continue;
+		addr_len = sizeof(client_addr);
+		if((accept_sock = accept(listen_sock, (struct sockaddr *) &client_addr, &addr_len)) < 0)
+		{
+			/* we get ECONNABORTED in Linux if we're being SYN scanned */
+			error("accept: %s", strerror(errno));
+			continue;
+		}
+		/* fork off a child to handle it */
+		if((child = fork()) < 0)
+		{
+			/* if we can't fork it's probably best to kill ourselves*/
+			fatal("fork: %s", strerror(errno));
+		}
+		else if(child == 0)
+		{
+			/* child */
+			close(listen_sock);
+			quit = handle_connection(listen_data, accept_sock, &client_addr);
+			close(accept_sock);
+/* TODO */
+if(quit) printf("QUIT!!!\n");
+			exit(EXIT_SUCCESS);
+		}
+		else
+		{
+			/* parent */
+			close(accept_sock);
+		}
+	}
+
+	/* we never get here */
+	close(listen_sock);
+
+	return;
+}
+
+/*
+ * handle a connection from a remote rb-browser
+ */
+
+static bool
+handle_connection(struct listen_data *listen_data, int client_sock, struct sockaddr_in *client_addr)
+{
+	char cmd[1024];
+	ssize_t nread;
+	bool quit = false;
+
+	printf("Connection from %s:%d\n", inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port));
+
+	/* read the command from the client */
+	if((nread = read(client_sock, cmd, sizeof(cmd)-1)) > 0)
+	{
+		/* \0 terminate the buffer */
+		cmd[nread] = '\0';
+		/* strip off an trailing \n (only needed when testing with telnet etc) */
+		nread --;
+		while(nread > 0 && (cmd[nread] == '\n' || cmd[nread] == '\r'))
+			cmd[nread--] = '\0';
+		/* process the command */
+		quit = process_command(listen_data, client_sock, cmd);
+	}
+
+	printf("Connection from %s:%d closed\n", inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port));
+
+	return quit;
+}
+
+static void
+dead_child(int signo)
+{
+	if(signo == SIGCHLD)
+		wait(NULL);
+
+	return;
+}

Added: redbutton-download/trunk/listen.h
===================================================================
--- redbutton-download/trunk/listen.h	                        (rev 0)
+++ redbutton-download/trunk/listen.h	2006-03-01 16:05:30 UTC (rev 5)
@@ -0,0 +1,19 @@
+/*
+ * listen.h
+ */
+
+#ifndef __LISTEN_H__
+#define __LISTEN_H__
+
+#include <netinet/in.h>
+
+struct listen_data
+{
+	struct sockaddr_in addr;	/* ip:port to listen on */
+};
+
+int parse_addr(char *, struct in_addr *, in_port_t *);
+
+void start_listener(struct listen_data *);
+
+#endif

Modified: redbutton-download/trunk/rb-download.c
===================================================================
--- redbutton-download/trunk/rb-download.c	2006-03-01 10:26:41 UTC (rev 4)
+++ redbutton-download/trunk/rb-download.c	2006-03-01 16:05:30 UTC (rev 5)
@@ -1,5 +1,5 @@
 /*
- * rb-download [-d <demux_device>] [-b <base_dir>] [-t <timeout>] [-c <carousel_id>] [<service_id>]
+ * rb-download [-d <demux_device>] [-b <base_dir>] [-t <timeout>] [-l[<listen-addr>]] [-c <carousel_id>] [<service_id>]
  *
  * Download the DVB Object Carousel for the given channel onto the local hard disc
  * files will be stored under the current dir if no -b option is given
@@ -7,6 +7,17 @@
  * if no service_id is given, a list of possible channels (and their service_id) is printed
  * the carousel ID is normally read from the PMT, use -c to explicitly set it
  *
+ * the default timeout is 10 seconds
+ * if no DSMCC data is read after this time, it is assumed none is being broadcast
+ *
+ * if -l is given, rb-download listens on the network for commands from a remote rb-browser
+ * the default IP to listen on is 0.0.0.0 (ie all interfaces), the default TCP port is 10101
+ * listen-addr should be given in the form "host:port", where host defaults to 0.0.0.0 and port defaults to 10101
+ * eg, to listen on a different port, do "-l8080"
+ * to only listen on the loop back, do "-l127.0.0.1" or on a different port too, do "-l127.0.0.1:8080"
+ * NOTE: because -l may or may not take an argument, you must not put a space between the -l and the value
+ * (otherwise, "rb-download -l 1234", is ambiguous - listen on port 1234 or use service_id 1234?)
+ *
  * the file structure will be:
  * ./services/<service_id>
  * this is a symlink to the root of the carousel
@@ -17,7 +28,7 @@
  */
 
 /*
- * Copyright (C) 2005, Simon Kilvington
+ * Copyright (C) 2005, 2006, Simon Kilvington
  *
  * 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
@@ -39,11 +50,14 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <stdbool.h>
 #include <errno.h>
+#include <netinet/in.h>
 
 #include "list.h"
 #include "findmheg.h"
 #include "carousel.h"
+#include "listen.h"
 #include "utils.h"
 
 /* DVB demux device */
@@ -52,6 +66,10 @@
 /* seconds before we assume no DSMCC data is available on this PID */
 #define DEFAULT_TIMEOUT	10
 
+/* default listen address */
+#define DEFAULT_LISTEN_ADDR	INADDR_ANY
+#define DEFAULT_LISTEN_PORT	10101
+
 void usage(char *);
 
 int
@@ -60,12 +78,14 @@
 	char *prog_name = argv[0];
 	char *device = DEFAULT_DEVICE;
 	unsigned int timeout = DEFAULT_TIMEOUT;
+	bool listen = false;
+	struct listen_data listen_data;
 	int carousel_id = -1;
 	uint16_t service_id;
 	struct carousel *car;
 	int arg;
 
-	while((arg = getopt(argc, argv, "d:b:t:c:")) != EOF)
+	while((arg = getopt(argc, argv, "d:b:t:l::c:")) != EOF)
 	{
 		switch(arg)
 		{
@@ -82,6 +102,16 @@
 			timeout = strtoul(optarg, NULL, 0);
 			break;
 
+		case 'l':
+			listen = true;
+			/* default values */
+			listen_data.addr.sin_addr.s_addr = htonl(DEFAULT_LISTEN_ADDR);
+			listen_data.addr.sin_port = htons(DEFAULT_LISTEN_PORT);
+			/* optarg is NULL if no value is given, parse_addr can't fail with NULL */
+			if(parse_addr(optarg, &listen_data.addr.sin_addr, &listen_data.addr.sin_port) < 0)
+				fatal("Unable to resolve host %s", optarg);
+			break;
+
 		case 'c':
 			carousel_id = strtoul(optarg, NULL, 0);
 			break;
@@ -101,6 +131,8 @@
 		service_id = strtoul(argv[optind], NULL, 0);
 		car = find_mheg(device, timeout, service_id, carousel_id);
 		printf("Carousel ID=%u\n", car->carousel_id);
+		if(listen)
+			start_listener(&listen_data);
 		load_carousel(car);
 	}
 	else
@@ -114,6 +146,11 @@
 void
 usage(char *prog_name)
 {
-	fatal("Usage: %s [-d <demux_device>] [-b <base_dir>] [-t <timeout>] [-c carousel_id] [<service_id>]", prog_name);
+	fatal("Usage: %s [-d <demux_device>] "
+			"[-b <base_dir>] "
+			"[-t <timeout>] "
+			"[-l[<listen-addr>]] "
+			"[-c carousel_id] "
+			"[<service_id>]", prog_name);
 }
 

Modified: redbutton-download/trunk/utils.c
===================================================================
--- redbutton-download/trunk/utils.c	2006-03-01 10:26:41 UTC (rev 4)
+++ redbutton-download/trunk/utils.c	2006-03-01 16:05:30 UTC (rev 5)
@@ -20,13 +20,76 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
+#include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <string.h>
 #include <ctype.h>
+#include <errno.h>
 
 #include "utils.h"
 
+/*
+ * write the given string (ie upto \0) to the given fd
+ */
+
+void
+write_string(int fd, const char *str)
+{
+	write_all(fd, str, strlen(str));
+
+	return;
+}
+
+/*
+ * guarantee writing count bytes from buf to fd
+ * W. Richard Stevens
+ */
+
+void
+write_all(int fd, const void *buf, size_t count)
+{
+	size_t nwritten;
+	const char *buf_ptr;
+
+	buf_ptr = buf;
+	while(count > 0)
+	{
+		if((nwritten = write(fd, buf_ptr, count)) < 0)
+		{
+			if(errno == EINTR || errno == EAGAIN)
+				nwritten = 0;
+			else
+				fatal("write: %s\n", strerror(errno));
+		}
+		count -= nwritten;
+		buf_ptr += nwritten;
+	}
+
+	return;
+}
+
+/*
+ * move str to the next non-white space character (or the end of the string)
+ */
+
+char *
+skip_ws(char *str)
+{
+	if(str == NULL)
+		return NULL;
+
+	while(*str != '\0' && isspace((int) *str))
+		str ++;
+
+	return str;
+}
+
+/*
+ * returns a single ASCII char for the values 0-15
+ */
+
 char
 hex_digit(uint8_t val)
 {

Modified: redbutton-download/trunk/utils.h
===================================================================
--- redbutton-download/trunk/utils.h	2006-03-01 10:26:41 UTC (rev 4)
+++ redbutton-download/trunk/utils.h	2006-03-01 16:05:30 UTC (rev 5)
@@ -36,6 +36,11 @@
 #define MAX(a, b)	((a) > (b) ? (a) : (b))
 #endif
 
+void write_string(int, const char *);
+void write_all(int, const void *, size_t);
+
+char *skip_ws(char *);
+
 char hex_digit(uint8_t);
 
 void *safe_malloc(size_t);



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Thread: [Redbutton-devel] SF.net SVN: redbutton: [5] redbutton-download/trunk

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