socket programming question, closing sockets...
I have been provided a client and server code and asked to run them. THe server just echos what the client tells him. I need to fix whats wrong with the code. I have noticed that if i close the client and then the server the socket opened by the client remains open
This is what netstat tells me when both have been closed:
tcp 0 0 192.168.2.7:3000 192.168.2.7:52186 TIME_WAIT
This is the connection for the client.
I dont know if im reading this right but i have used tcpdump and noticed that the server tells teh client he is closing and the client acks it, shouldnt the client close the socket then?
This is the client code:
Code:
char buf[LINELEN+1]; /* buffer for one line of text */
int s, n; /* socket descriptor, read count*/
int outchars, inchars; /* characters sent and received */
s = connectTCP ("localhost", "echo");
/* don't even think of using other function than fgets for this */
while (fgets(buf, LINELEN+1, stdin))
{
buf[LINELEN] = '\0'; /* insure line null-terminated */
outchars = strlen(buf);
(void) write(s, buf, outchars);
/* read it back */
for (inchars = 0; inchars < outchars; inchars+=n )
{
n = read(s, &buf[inchars], outchars - inchars);
if (n < 0)
errexit("socket read failed: %s\n",
strerror(errno));
}
fputs(buf, stdout);
}
this is how connectTCP configures the socket:
Code:
struct hostent *phe; /* pointer to host information entry */
struct servent *pse; /* pointer to service information entry */
struct protoent *ppe; /* pointer to protocol information entry*/
struct sockaddr_in sin; /* an Internet endpoint address */
int s, type; /* socket descriptor and socket type */
// int no_nagle= 1;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
/* Map service name to port number */
if ( pse = getservbyname(service, transport) )
sin.sin_port = pse->s_port;
else if ( (sin.sin_port = htons((u_short)atoi(service))) == 0 )
errexit("can't get \"%s\" service entry\n", service);
/* Map host name to IP address, allowing for dotted decimal */
if ( phe = gethostbyname(host) )
memcpy(&sin.sin_addr, phe->h_addr, phe->h_length);
else if ( (sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE )
errexit("can't get \"%s\" host entry\n", host);
/* Map transport protocol name to protocol number */
if ( (ppe = getprotobyname(transport)) == 0)
errexit("can't get \"%s\" protocol entry\n", transport);
/* Use protocol to choose a socket type */
if (strcmp(transport, "udp") == 0)
type = SOCK_DGRAM;
else
type = SOCK_STREAM;
/* Allocate a socket */
s = socket(PF_INET, type, ppe->p_proto);
if (s < 0)
errexit("can't create socket: %s\n", strerror(errno));
// if (setsockopt(s,SOL_TCP,TCP_NODELAY,&no_nagle, sizeof(no_nagle)) != 0)
// errexit("setsockopt: no pude deshabilitar Nagle");
/* Connect the socket */
if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0)
errexit("can't connect to %s.%s: %s\n", host, service,
strerror(errno));
return s;
tx!
