void cria_server_tcp(int porto)
{
struct sockaddr_in serveraddr, clientaddr;
int fd_listen = cria_socket_tcp();
int max_clientes = 20; //numero maximo de clientes em espera
int addrlen;
int *memset_r;
int bind_r;
int listen_r;
memset_r=memset((void*)&serveraddr, (int)'void cria_server_tcp(int porto)
{
struct sockaddr_in serveraddr, clientaddr;
int fd_listen = cria_socket_tcp();
int max_clientes = 20; //numero maximo de clientes em espera
int addrlen;
int *memset_r;
int bind_r;
int listen_r;
memset_r=memset((void*)&serveraddr, (int)'%pre%', sizeof(serveraddr));
if(memset_r==NULL){
printf("Erro no memset para cliente (TCP).\n");
exit(EXIT_FAILURE);
}
serveraddr.sin_family= AF_INET;
serveraddr.sin_addr.s_addr=htonl(INADDR_ANY);
serveraddr.sin_port=htons((u_short)porto);
bind_r=bind(fd_listen, (struct sockaddr*)&serveraddr, sizeof(serveraddr));
if(bind_r == -1){
printf("Erro no bind ao cliente (TCP).\n");
exit(EXIT_FAILURE);
}
if(listen(fd_listen, max_clientes) < 0){
printf("Erro a abrir socket para ouvir cliente (TCP).\n");
exit(EXIT_FAILURE);
}
addrlen = sizeof(clientaddr);
int fd;
int n=0, len=0, maxlen=MAX_LEN;
char buffer[MAX_LEN];
char *auxbuffer = buffer;
char msg[MAX_LEN];
fd_set read_set;
struct timeval timeout;
int check_select;
char ler[MAX_LEN];
fd = accept(fd_listen, (struct sockaddr*)&clientaddr, &addrlen);
if(fd == -1){
printf("Erro a aceitar dados do cliente (TCP).\n");
exit(EXIT_FAILURE);
}
timeout.tv_sec = 100; /* timeout (secs.) */
timeout.tv_usec = 0; /* 0 microseconds */
//corre indefinidamente
while(1){
FD_ZERO(&read_set);
FD_SET(0, &read_set);
FD_SET(fd, &read_set);
check_select = select(fd + 1, &read_set, NULL, NULL, &timeout);
if(check_select != 0 && check_select != -1)
{
if(FD_ISSET(fd, &read_set))
{
n = recv(fd, buffer, maxlen, 0);
//printf("%d\n", n);
/*auxbuffer += n;
maxlen -= n;
len += n;*/
printf("Mensagem recebida: '%s'\n", buffer);
send(fd, msg, strlen(buffer), 0);
printf("entrei\n");
}
if(FD_ISSET(0, &read_set))
{
scanf("%s", ler);
ler[strlen(ler)] = '%pre%';
read_stdin(ler, &fd);
}
}
//corre enquanto a sessão do cliente estiver aberta
/*while((n = recv(fd, auxbuffer, maxlen, 0)) > 0){
auxbuffer += n;
maxlen -= n;
len += n;
printf("Mensagem recebida: '%s'\n", buffer);
send(fd, buffer, strlen(buffer), 0);
}*/
}
close(fd);
close(fd_listen);
}
', sizeof(serveraddr));
if(memset_r==NULL){
printf("Erro no memset para cliente (TCP).\n");
exit(EXIT_FAILURE);
}
serveraddr.sin_family= AF_INET;
serveraddr.sin_addr.s_addr=htonl(INADDR_ANY);
serveraddr.sin_port=htons((u_short)porto);
bind_r=bind(fd_listen, (struct sockaddr*)&serveraddr, sizeof(serveraddr));
if(bind_r == -1){
printf("Erro no bind ao cliente (TCP).\n");
exit(EXIT_FAILURE);
}
if(listen(fd_listen, max_clientes) < 0){
printf("Erro a abrir socket para ouvir cliente (TCP).\n");
exit(EXIT_FAILURE);
}
addrlen = sizeof(clientaddr);
int fd;
int n=0, len=0, maxlen=MAX_LEN;
char buffer[MAX_LEN];
char *auxbuffer = buffer;
char msg[MAX_LEN];
fd_set read_set;
struct timeval timeout;
int check_select;
char ler[MAX_LEN];
fd = accept(fd_listen, (struct sockaddr*)&clientaddr, &addrlen);
if(fd == -1){
printf("Erro a aceitar dados do cliente (TCP).\n");
exit(EXIT_FAILURE);
}
timeout.tv_sec = 100; /* timeout (secs.) */
timeout.tv_usec = 0; /* 0 microseconds */
//corre indefinidamente
while(1){
FD_ZERO(&read_set);
FD_SET(0, &read_set);
FD_SET(fd, &read_set);
check_select = select(fd + 1, &read_set, NULL, NULL, &timeout);
if(check_select != 0 && check_select != -1)
{
if(FD_ISSET(fd, &read_set))
{
n = recv(fd, buffer, maxlen, 0);
//printf("%d\n", n);
/*auxbuffer += n;
maxlen -= n;
len += n;*/
printf("Mensagem recebida: '%s'\n", buffer);
send(fd, msg, strlen(buffer), 0);
printf("entrei\n");
}
if(FD_ISSET(0, &read_set))
{
scanf("%s", ler);
ler[strlen(ler)] = '%pre%';
read_stdin(ler, &fd);
}
}
//corre enquanto a sessão do cliente estiver aberta
/*while((n = recv(fd, auxbuffer, maxlen, 0)) > 0){
auxbuffer += n;
maxlen -= n;
len += n;
printf("Mensagem recebida: '%s'\n", buffer);
send(fd, buffer, strlen(buffer), 0);
}*/
}
close(fd);
close(fd_listen);
}
TCP server with select () does not work because printf shows 3x msg and msg comes with garbage at the end and it finishes automatically
0
asked by anonymous 30.03.2018 / 01:15
1 answer
0
An error can be seen from the face: you are receiving buffered data using recv (), but it is using buffer in printf () as if it were a string ending in 0, and recv () does not guarantee this. A simple solution is put
buffer[n] = 'buffer[n] = '%pre%';
';
shortly after recv (). You should also make the buffer size equal to (MAX_LEN + 1) to fit this zero in case recv () has received MAX_LEN octets.
Another thing: a connection is flagged as closed when recv () returns zero, ie receives zero characters. It seems to me that you are not dealing with this case.
30.03.2018 / 04:12