send() and recv() through a TCP socket

[moroccanplaya]

cant read the html file is there any suggestions ?

listen(sockfd,5);
        clilen = sizeof(cli_addr);
        newsockfd = accept(sockfd,(struct sockaddr *) &cli_addr, &clilen);
 
        if(newsockfd < 0) error("eror on accept");
        bzero(buffer,256);
        FILE* open;
        open =fopen("/home/rocco/www/home.hml","r"); 
        n = recv(newsockfd,open,255,0);
 
        if(n< 0) error("error reading from socket");
        printf("here is the message: %s\n", buffer);
        n = send(newsockfd,open, 18,0);
        if(n<0) error("writing to socket");
        close(newsockfd);
        close(sockfd);
        return 0;
 
 

[Banfa]

The way you are calling send is just wrong, passing it the file pointer is not going to work. You will need to read data from the file (fread) and then write it to the socket using send.

Also you are assuming that send will send all the data that you request it sends but send does not guarantee that, it guarantees to send at least 1 byte.

I suggest you read Beej's Guide to Network Programming

[moroccanplaya]

so i have to put it in a loop?

 
 
    open_ptr = fopen("/home/rocco/www/home.html","r");
    if(open_ptr == NULL){
    printf("ERROR OPENING FILE"); 
    }
    while(1)
 
    {
    int bytes_read = fread(buffer,1,sizeof buffer,open_ptr);
    if(bytes_read == 0)
    break;
 
    if(bytes_read < 0){
    printf("error");
    }
    void *p = buffer; 
    while(bytes_read > 0) {
    int bytes_written = fwrite(new_sock,buffer + bytes_written, bytes_read);
 
    if(bytes_written <= 0){
    printf("error"); 
    }
    bytes_read = recv(new_sock,open_ptr,255,0);
    int bytes_sent = send(new_sock,bytes_read,sizeof(bytes_read),0);
 
 
 
 
 

[Banfa]

From line 19 onwards that code makes no sense, you have not even managed (attempted?) to get the right types of variable in the right places in the function calls for fwrite, recv and send and it is not at all clear why you think you need to call fwrite.

Try the examples given in section 6 of Beej's Guide to Network Programming, compile them make the work and understand how/why they work.

[moroccanplaya]

i have created the socket, checked if the socket is ok, binded the socket, checked if the binding is ok, listen for connection, checked if the listning is ok, and accept connection and check if the accepting is ok.

#include<stdio.h>
#include<stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
 
#define PEND 10
 
 
int main(int argc, char *argv[])
{
    /* listen on listen_fd, new connection on new_fd */
    int listen_fd, new_fd;
    /* my address information, address where I run this program */
    struct sockaddr_in my_addr;
    /* remote address information */
    struct sockaddr_in there_addr;
    int size;
    int port;
 
 
 
    if (argc < 2) 
{
             printf(stderr,"ERROR, no port provided\n");
             exit(1)
}
 
 
    lisen_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(sockfd == -1)
{
          perror("socket error!");
           exit(1);
}
 
    else
      printf("socket is OK\n");
 
      /* pass port through command line */
      port = atoi(argv[1]);
      /* host byte order */
    my_addr.sin_family = AF_INET;
    /* network byte order */
    my_addr.sin_port = htons(port);
    /* use my IP address */
    my_addr.sin_addr.s_addr = INADDR_ANY;    
 
    memset(&(my_addr.sin_zero), 0, 8);
 
    if(bind(listen_fd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1)
{
      perror("bind error!");
       exit(1);
}
 
    else
    printf("bind is OK...\n");
 
    if(listen(listen_fd, PEND) == -1)
{
 
      perror("listen error!");
       exit(1);
}
 
    else
    printf("listen is OK...\n");
 
    size = sizeof(struct sockaddr_in);
    new_fd = accept(listen_fd, (struct sockaddr *)&there_addr, &size);
 
    if(new_fd == -1)
    perror("accept error!");
 
    else
      printf("accept is OK...\n");
 
       close(new_fd);
    close(listen_fd);
    return 0;
}
 
 
 
 
 

now i want to send my html file thats on my filesystem through the socket and i do not know how to go about that. i know i have to accept read then write but i do not know how to put that in practice.

[moroccanplaya]

i have created the socket, checked if the socket is ok, binded the socket, checked if the binding is ok, listen for connection, checked if the listning is ok, and accept connection and check if the accepting is ok.

#include<stdio.h>
#include<stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
 
#define PEND 10
 
 
int main(int argc, char *argv[])
{
    /* listen on listen_fd, new connection on new_fd */
    int listen_fd, new_fd;
    /* my address information, address where I run this program */
    struct sockaddr_in my_addr;
    /* remote address information */
    struct sockaddr_in there_addr;
    int size;
    int port;
 
 
 
    if (argc < 2) 
{
             printf(stderr,"ERROR, no port provided\n");
             exit(1)
}
 
 
    lisen_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(sockfd == -1)
{
          perror("socket error!");
           exit(1);
}
 
    else
      printf("socket is OK\n");
 
      /* pass port through command line */
      port = atoi(argv[1]);
      /* host byte order */
    my_addr.sin_family = AF_INET;
    /* network byte order */
    my_addr.sin_port = htons(port);
    /* use my IP address */
    my_addr.sin_addr.s_addr = INADDR_ANY;    
 
    memset(&(my_addr.sin_zero), 0, 8);
 
    if(bind(listen_fd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1)
{
      perror("bind error!");
       exit(1);
}
 
    else
    printf("bind is OK...\n");
 
    if(listen(listen_fd, PEND) == -1)
{
 
      perror("listen error!");
       exit(1);
}
 
    else
    printf("listen is OK...\n");
 
    size = sizeof(struct sockaddr_in);
    new_fd = accept(listen_fd, (struct sockaddr *)&there_addr, &size);
 
    if(new_fd == -1)
    perror("accept error!");
 
    else
      printf("accept is OK...\n");
 
       close(new_fd);
    close(listen_fd);
    return 0;
}
 
 
 
 
 

now i want to send my html file thats on my filesystem through the socket and i do not know how to go about that. i know i have to accept read then write but i do not know how to put that in practice.

[moroccanplaya]

i can send a message but i dont kno how to send a file ?

    char *msg = "GET %s HTTP/1.0\r\nHOST:%s \r\n\r\n";
    int len; 
    int bytes_sent;
    len = strlen(msg);
 
 
 
     while(len != bytes_sent)
{
 
        bytes_sent = send(new_fd,msg,len,0);
} 
       close(new_fd);
    close(listen_fd);
    return 0;
}

[Banfa]

You send a properly formatted http protocol message, that is you send the appropriate and required headers with a CR LF sequence at the end of each header. After the last header you send 2 CR LF sequences and then you send the contents of the file.

As I have told you already a number of times this is basic http protocol which you can easily read up on by doing a web-search or you could start in wikipedia which has quite a good article.

[moroccanplaya]

hi i have read up on the protocol but still getting nowhere i still cant find how to write a file to the socket heres how far i got

 
 
    char *msg = "HTTP/1.0 200 OK\n Content-Type: text/html\n Content-Length: 1354\n\n<html><body><h1>new website!</h1></body></html>";
 
 
 
    int len; 
    int bytes_sent;
    len = strlen(msg);
 
 
 
     while(len != bytes_sent)
{
 
        bytes_sent = send(new_fd,msg,len,0);
} 
       close(new_fd);
    close(listen_fd);
    return 0;
}
 
 
 

[Banfa]

You haven't read and understood the HTTP protocol: the end of line is CR LF not just LF as you have in your string.

You have read and understood (or just plain copied) the socket programming guide I linked to, you send loop will fail if a partial send happens.

Send a file is easy, open the file, read the data from the file, write the data to the socket, close the file.

[Banfa]

You haven't read and understood the HTTP protocol: the end of line is CR LF not just LF as you have in your string.

You haven't read and understood (or just plain copied) the socket programming guide I linked to, your send loop will fail if a partial send happens.

Send a file is easy, open the file, read the data from the file, write the data to the socket, close the file.

[moroccanplaya]

 
    FILE *fp=fopen("/home/index.html","r");
    int len;
    char buffer1[1000];
 
    while((len = fread(buffer1, sizeof(buffer1),1,fp))>0)
    {
 
        send(new_fd, buffer1,sizeof(buffer1), 0);
 

[moroccanplaya]

i have read beej's guide to programming, tcp/ip sockets in c practical guide and read the on wiki about the http protocol i guess im missing a lot here

[Banfa]

You don't want to send the sizeof buffer1, you want to send the number of bytes you have read.

You say you have read Beej's guide, try comparing your while send loop to the while send loop in that guide.