Stream Server

**ch4** · 06-09-2009

I'm trying to make a stream server.
This first attempt sends a mp3 file to the media that request http://127.0.0.1:7000/test.mp3
The only that server does is to read and print the whole request(blue code), send the answer (red code) and finally stream the file(green code).
Server runs once.

Here is the list with my problems-questions :
1) Is something missing from my code ?

2) Why after the end of server's execution i have to wait a minute(or less) for another one ? I get this error "Address already in use"

3) Why media-player/browser sometimes open the file and sometimes not. (I mean that, i run server and i request through firefox the file and i get it. The next execution will not work and server won't stream file)

4) How can i achieve a real streaming because this one just loads the file to media-player/browser and after stores or play it.

*This is not the final code but as i test network C for first time i want to learn by testing.

Thanks in advance

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>

#define BACKLOG SOMAXCONN
#define BUFSIZE 1024

int main(void)
{
 char buffer[BUFSIZE];
 int socketFd;
 int newSocketFd;
 int port=7000;

 int res;
 
 FILE *stream;

 struct sockaddr_in server;
 struct sockaddr_in client;

 struct hostent *rem;

 socklen_t clientLength;


        //Create socket
        socketFd = socket(PF_INET,SOCK_STREAM,0);
        if (socketFd == -1)
        {
          fprintf(stderr,"Error creating socket : ");
          perror("");

          return -1;
        }

        //Binding the above socket
        server.sin_family = PF_INET;
        server.sin_addr.s_addr = htonl(INADDR_ANY);
        server.sin_port = htons(port);

        res = bind(socketFd,(struct sockaddr *)&server,sizeof(struct sockaddr_in));
        if(res < 0)
        {
          fprintf(stderr,"Error binding socket : ");
          perror("");

          close(socketFd);

          return -1;
        }

        //Listening for connections
        res = listen(socketFd,BACKLOG);
        if(res < 0)
        {
          fprintf(stderr,"Error listening socket : ");
          perror("");

          close(socketFd);

          return -1;
        }

        printf("Server ready to accept clients\n");

        clientLength = sizeof(struct sockaddr_in);
        newSocketFd = accept(socketFd, (struct sockaddr *)&client, &clientLength);
        if(newSocketFd < 0)
        {
          fprintf(stderr,"Fail to accept connection : ");
          perror("");
        }

        printf("Connection established\n");

        recv(newSocketFd,buffer,BUFSIZE,0);  printf("%s",buffer);

        send(newSocketFd,"HTTP/1.0 200 OK\r\n",18,1);
        send(newSocketFd,"Sever: musicstreamer v1.0\r\n",28,1);
        send(newSocketFd,"Connection: close\r\n",20,1);
        send(newSocketFd,"Content-Type: audio/mpeg\r\n\r\n",26,1);

        stream = fopen("test.mp3","rb");
        while(fread(buffer,1,1,stream) > 0)
          send(newSocketFd,buffer,1,0);
        fclose(stream);

        close(newSocketFd);
        close(socketFd);



 return 0;
}

**itCbitC** · 06-09-2009

For starters clear the local variables server and client so they won't contain garbage values, as in

Code:

struct sockaddr_in server = {0};
struct sockaddr_in client = {0};

**brewbuck** · 06-09-2009

Originally Posted by ch4

Why after the end of server's execution i have to wait a minute(or less) for another one ? I get this error "Address already in use"

Make the following change.

Code:

        //Binding the above socket
        server.sin_family = PF_INET;
        server.sin_addr.s_addr = htonl(INADDR_ANY);
        server.sin_port = htons(port);

        int reuse = 1;
        setsockopt(socketFd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
        res = bind(socketFd,(struct sockaddr *)&server,sizeof(struct sockaddr_in));

(Of course, the declaration of reuse needs to be higher)

**ch4** · 06-10-2009

Originally Posted by itCbitC

For starters clear the local variables server and client so they won't contain garbage values, as in

Code:

struct sockaddr_in server = {0};
struct sockaddr_in client = {0};

Originally Posted by brewbuck

Make the following change.

Code:

        //Binding the above socket
        server.sin_family = PF_INET;
        server.sin_addr.s_addr = htonl(INADDR_ANY);
        server.sin_port = htons(port);

        int reuse = 1;
        setsockopt(socketFd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
        res = bind(socketFd,(struct sockaddr *)&server,sizeof(struct sockaddr_in));

(Of course, the declaration of reuse needs to be higher)

Thank you, both helped.

Any ideas for the rest problems ?

**bithub** · 06-10-2009

Why are you sending the HTTP header out-of-band, and the HTTP content in-band? That doesn't seem right.

**brewbuck** · 06-10-2009

Originally Posted by bithub

Why are you sending the HTTP header out-of-band, and the HTTP content in-band? That doesn't seem right.

It definitely isn't. HTTP protocol does not use OOB signaling anywhere. In fact, I'm not aware of any widely-used protocol that does.

**ch4** · 06-10-2009

Originally Posted by bithub

Why are you sending the HTTP header out-of-band, and the HTTP content in-band? That doesn't seem right.

I've already fixed that, but i didn't update it.

I try to send to the client a m3u list by changing to "Content-Type: audio/x-mpegurl"
and this one

Code:

        url_encode("http://127.0.0.1:7000/test.mp3\n",buffer,BUFSIZE,1);
        send(newSocketFd,buffer,strlen(buffer),0);

and it's working fine.

Based on something i read, my server sends bytes of mp3 faster than client can read and client may not receive all of them. So i want to re-send the lost bytes, but here is my new problem. Send functions returns the number of bytes sent but is this enough to be sure that all gone well ?

**bithub** · 06-10-2009

but is this enough to be sure that all gone well ?

Yes. There should not be any "lost" bytes with the TCP protocol.

**Cactus_Hugger** · 06-10-2009

You should be checking the return value from send(), which will tell you how much is sent. Also, change your reading loop so that you're not reading/sending 1 byte at a time. Read a fair chunk out of that file (1K or better), send that, then repeat. Doing single byte read/sends is going to waste an incredible amount of CPU time compared... worst - if during that read, the previous byte actually gets sent, then you're sending 1 byte at a time... which is terrible. Read as much as you can, and send as much as you have available to send. (But try to minimize the amount of data you actually have to send.)

**ch4** · 06-11-2009

Update v1.0

but streaming is still a problem. Would my router be the problem ?
I run my server on another machine (ubuntu 8.4) and i got "pipe broken" in firefox.

I also run it using as client wget and it works fine, so i can't see where is the problem.
Firefox's plugin, totem, my code ????

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>
#include <fcntl.h>

#include "url_codec.h"

#define BACKLOG SOMAXCONN
#define BUFSIZE 1024


int serveClient(void);
int sendAll(int socket, const void *buffer,int len,int flags);


int main(void)
{
 char buffer[BUFSIZE];
 int socketFd;
 int newSocketFd;
 int port=7000;

 int res,reuseAddr;
 
 //FILE *stream;
 int stream;

 struct sockaddr_in server = {0};
 struct sockaddr_in client = {0};

 struct hostent *rem;

 socklen_t clientLength;


        //Create socket
        socketFd = socket(PF_INET,SOCK_STREAM,0);
        if (socketFd == -1)
        {
          fprintf(stderr,"Error creating socket : ");
          perror("");

          return -1;
        }

        //Prepare options of socket
        server.sin_family = PF_INET;
        server.sin_addr.s_addr = htonl(INADDR_ANY);
        server.sin_port = htons(port);
        reuseAddr = 1;

        setsockopt(socketFd,SOL_SOCKET,SO_REUSEADDR,&reuseAddr,sizeof(int));

        //Binding the above socket
        res = bind(socketFd,(struct sockaddr *)&server,sizeof(struct sockaddr_in));
        if(res < 0)
        {
          fprintf(stderr,"Error binding socket : ");
          perror("");

          close(socketFd);

          return -1;
        }

        //Listening for connections
        res = listen(socketFd,BACKLOG);
        if(res < 0)
        {
          fprintf(stderr,"Error listening socket : ");
          perror("");

          close(socketFd);

          return -1;
        }

        printf("Server ready to accept clients\n");

        clientLength = sizeof(struct sockaddr_in);
        newSocketFd = accept(socketFd, (struct sockaddr *)&client, &clientLength);
        if(newSocketFd < 0)
        {
          fprintf(stderr,"Fail to accept connection : ");
          perror("");
        }

        printf("Connection established\n");

        strcpy(buffer,"\0");
        while(strstr(buffer,"\r\n\r\n") == NULL)
        {
          recv(newSocketFd,buffer,5,0);
          printf("%s",buffer);
        }

        strcpy(buffer,"\0");
        strcpy(buffer,"HTTP/1.0 200 OK\r\n");                   puts(buffer);
        sendAll(newSocketFd,buffer,strlen(buffer),0);

        strcpy(buffer,"Sever: musicstreamer v1.0\r\n");         puts(buffer);
        sendAll(newSocketFd,buffer,strlen(buffer),0);

        strcpy(buffer,"Connection: close\r\n");                 puts(buffer);
        sendAll(newSocketFd,buffer,strlen(buffer),0);

        strcpy(buffer,"Content-Type: audio/mpeg\r\n\r\n");      puts(buffer);
        sendAll(newSocketFd,buffer,strlen(buffer),0);

        stream = open("test.mp3",O_RDONLY);
        if(stream < 0) perror("");

        while(read(stream,buffer,1) > 0)
        {
          sendAll(newSocketFd,buffer,1,0);
        }
        close(stream);

        close(newSocketFd);
        close(socketFd);


 return 0;
}

int sendAll(int socket, const void *buffer,int len,int flags)
{
 int bytesSent=0;

        bytesSent += send(socket,buffer,len,flags);
        while(bytesSent < len)
        {
          bytesSent += send(socket,buffer+bytesSent,len-bytesSent,flags);
        }

 return 1;
}

I'll fix byte rate later thanks Cactus Hugger

**brewbuck** · 06-11-2009

Originally Posted by ch4

Update v1.0

but streaming is still a problem. Would my router be the problem ?
I run my server on another machine (ubuntu 8.4) and i got "pipe broken" in firefox.

That happens when one side shuts down the receiving end of their connection, and the other end tries to send() to it. The host which tried to send() to a closed socket gets a SIGPIPE. You can turn that off if you want with various socket options (or are they ioctls? I don't remember).

In other words, your server closed the connection too early, and the client tried to write something to a closed connection.

**Cactus_Hugger** · 06-11-2009

Code:

        strcpy(buffer,"\0");
        while(strstr(buffer,"\r\n\r\n") == NULL)
        {
          recv(newSocketFd,buffer,5,0);
          printf("%s",buffer);
        }

You have a possible buffer overflow here. If recv() actually does get 5 bytes, they will not be null-terminated, and strstr() is going to read past the end of buffer, unless there is a null. You're probably getting lucky, since in 1024 bytes, there probably is a null, but: add one in.

Further, say you get "\r\n\r" in one recv(), and "\n" in the next -- you've missed the "\r\n\r\n".

Finally, don't recv() 5 bytes at a time. recv() as much as you can at a time. recv() BUFSIZE-1, add a null terminator. Look for a "\r\n\r\n", if you see it, we're done. If not, then move the last 3 bytes to the front of the buffer, and repeat. Like so:

Code:

// used is a size_t, holding how much of our buffer is in use.
used = 0;
while(1)
{
	// Go get some data. ret is an int.
	ret = recv(newSocketFd, buffer + used, BUFSIZE - 1 - used, 0);
	if(ret < 0)
	{
		fprintf(stderr, "Error in recv'ing headers.\n");
		// Close down sockets...
		// ...I'm lazy. Don't you be.
		return 1;
	}
	else if(ret == 0)
	{
		fprintf(stderr, "Connection closed?\n");
		// Ditto above comment...
		return 1;
	}
	// Null-terminate the buffer.
	buffer[ret + used] = 0;
	used += ret;
	// Go look for the \r\n\r\n
	if(strstr(buffer, "\r\n\r\n") != NULL)
		break;
	// Didn't find it.
	if(used > BUFSIZE / 2)
	{
		// The buffer is more than half-full. Let's empty it.
		// The last three characters could be \r\n\r, so keep them around.
		memcpy(buffer, buffer + used - 3, 3);
		used = 3;
	}
}

And I'm sitll poking you about sending 1 byte at a time, but I see your note. :-)

Finally, in sendAll() (good job with that function, btw.), check to make sure send isn't returning an error.

**ch4** · 06-12-2009

Solved !!!! It's working

The problem was my router, so i change the address to access my server, from 127.0.0.1 to 0.0.0.0

Thanks Cactus, i appreciate your help.

PS : @Cactus take a look a the red code.
According to wget with previous code streaming last 12-16 secs, now just 0.3

Code:

        stream = fopen("test.mp3","rb");
        if(stream == NULL)
        {
          close(newSocketFd);
          perror("");

          return -1;
        }

        res = stat("test.mp3",&fileInfo);
        if(res < 0)
        {
          fprintf(stderr,"Cannot access file\n");
          perror("");

          fclose(stream);
          close(newSocketFd);
          close(socketFd);

          return -1;
        }

        //Calculate byterate
        byterate = BUFSIZE;
        while(fileInfo.st_size % byterate != 0)
          byterate--;

        //Now stream file
        while(fread(buffer,1,byterate,stream) > 0)
        {
          if(sendAll(newSocketFd,buffer,byterate,0) == 0)
          {
            fprintf(stderr,"Fail to transmit file\n");

            break;
          }
        }
        fclose(stream);

        close(newSocketFd);
        close(socketFd);


 return 0;
}

int sendAll(int socket, const void *buffer,int len,int flags)
{
 int bytesSent;
 int ret_bytes;


        //Try to sent the package
        ret_bytes = send(socket,buffer,len,flags);
        if(ret_bytes < 0)
          return 0;

        //Increase bytes that sent
        bytesSent = ret_bytes;

        //Try to resend the whole package (if necessary)
        while(bytesSent < len)
        {
          ret_bytes = send(socket,buffer+bytesSent,len-bytesSent,flags);
          if(ret_bytes < 0)
            return 0;

          bytesSent += ret_bytes;
        }


 return 1;
}

**Cactus_Hugger** · 06-12-2009

The code in red is ew. If I feed you a large file whose filesize is prime, then it's going to read 1 byte at a time, and performance will suffer. First, lower performance is bad, but lower performance on files whose filesize is prime is just strange.

You're worrying about a read only partially filling the buffer, judging by your code. This is good, but wrong approach. Just read a nice, round number, such as a multiple of 512 (which BUFSIZE is) as this size is nice for most disk. (But is situation dependent, and won't mean beans if you're reading off a network/memory/compressed file/etc.) Then check the return value from fread(), and send() however many bytes fread() says it read, so that when you get that last chunk of data, it'll handle it.

**ch4** · 06-13-2009

Right. I haven't thought about primes.
Your way is much more faster than mine, so I'll keep yours.

Thank you one more time.

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