TCP concurrent web server for the introduction of network hackers
TCP concurrent web server for the introduction of network hackers
The TCP concurrent server was originally intended to be written after TCP programming for getting started with network hackers, but because the code was a bit long, I wrote a separate article
Note:
Because the browser sends a lot of data, the recv_buf as the acceptance buffer of this server should be larger, at least 512 bytes, and 1024 bytes is recommended
If the reception is not complete, under no circumstances can you upload the web page to the browser. This bug stuck me all night, so I remember it very clearly.
The parameters passed to the thread when creating the thread pay attention to the value of the write connection socket, which is first converted to type (void*)
Pthread_create (& pth,NULL,msg_echo, (void *) connfd)
And then switch back to the int type in the thread
Int connfd = (int) arg
Cannot write an address to prevent the value of connfd from changing too fast when there are multiple requests at the same time, before the subthread takes the address out.
1. Header file
# include
# include
# include
# include
# include
# include
# include
# include
# include
/ / the child thread processes the browser's web page request
Void * msg_echo (void * arg)
{
Int connfd = (int) arg
Int ret_read=0
Int ret_recv=0
Char recv_buf [1024] = ""
Char read_buf [1024] = ""
Char send_buf [1024] = ""
Int fd
Char filename [50] = "html/"
/ / request returned successfully
Char head [] = "HTTP/1.1 200 OK\ r\ n"\
"Content-Type: text/html\ r\ n"\
"\ r\ n"
/ / request failed and returned
Char err [] = "HTTP/1.1 404 Not Found\ r\ n"\
"Content-Type: text/html\ r\ n"\
"\ r\ n"\
"File not found"
Printf ("connfd=%d\ n", connfd)
/ / receive request data
Ret_recv = recv (connfd,recv_buf,sizeof (recv_buf), 0)
Printf ("ret_recv:%d\ n", ret_recv)
/ / read the web page file name
Sscanf (recv_buf+4, "% [^]", (filename + 5))
Printf ("filename:%s\ n", filename)
/ / Open the web file
Fd = open (filename, O_RDONLY)
If (fd
< 0) { perror("open"); send(connfd, err, strlen(err), 0); close(connfd); return NULL; } //将网页文件发给浏览器 send(connfd,head,strlen(head),0); while((ret_read = read(fd,read_buf,sizeof(read_buf)))>0)
{
/ / printf ("% s\ n", read_buf)
Send (connfd,read_buf,ret_read,0)
}
Close (connfd)
Close (fd)
}
2.main function
Int main (int argc, char * argv [])
{
Unsigned int port=8000;// setting Port
If (argc > 1) / / Ports can be specified
{
Port = atoi (argv [1])
}
Int sockfd
Struct sockaddr_in my_addr
/ / structure
Memset (& my_addr,0,sizeof (my_addr))
My_addr.sin_family = AF_INET
My_addr.sin_port = htons (port)
My_addr.sin_addr.s_addr = htonl (INADDR_ANY)
/ / socket
Sockfd = socket (AF_INET, SOCK_STREAM, 0)
If (sockfd < 0)
{
Perror ("socket")
Exit (- 1)
}
/ / bind port
Int err = bind (sockfd, (struct sockaddr*) & my_addr,sizeof (my_addr))
If (err! = 0)
{
Perror ("bind")
Close (sockfd)
Exit (- 1)
}
/ / listening port
Err = listen (sockfd,10)
If (err! = 0)
{
Perror ("listen")
Close (sockfd)
Exit (- 1)
}
Printf ("listen at% d\ n", port)
/ / Multithreading processes connection requests
While (1)
{
Int connfd;// connection socket
Struct sockaddr_in client_addr
Char cli_ IP [inet _ ADDRSTRLEN] = ""
Socklen_t cliaddr_len = sizeof (client_addr)
/ / accept the request
Connfd = accept (sockfd, (struct sockaddr *) & client_addr,&cliaddr_len)
If (connfd < 0)
{
Perror ("accept")
}
/ / output connector information
Inet_ntop (AF_INET,&client_addr.sin_addr,cli_ip,INET_ADDRSTRLEN)
Printf ("accepted--ip:%s port:%d\ n", cli_ip,ntohs (client_addr.sin_port))
/ / create thread
Pthread_t pth
Pthread_create (& pth,NULL,msg_echo, (void *) connfd)
Pthread_detach (pth)
}
Close (sockfd)
Return 0
}
