У меня есть небольшая программа, которая отправляет и получает данные с сервера и клиента, и наоборот.
Все работает нормально, но я не вижу полученные сообщения с обеих сторон, и это всегда 0 байтов. Это не дает никакой ошибки компиляции, но не работает так, как я хотел.
Можете ли вы взглянуть на это, где я делаю неправильно?
Спасибо
// клиент
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
int main(int argc, char* argv[])
{
int sockfd;
struct addrinfo hints, *servinfo, *p;
int rv;
int numbytes;
char* hostname = "localhost";
char* server = "localhost";
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
if ((rv = getaddrinfo(hostname, "5000", &hints, &servinfo)) != 0)
{
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 0;
}
// loop through all the results and make a socket
for(p = servinfo; p != NULL; p = p->ai_next)
{
if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1)
{
perror("client: socket");
continue;
}
if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1)
{
close(sockfd);
perror("client: connect");
continue;
}
break;
}
if (p == NULL)
{
fprintf(stderr, "client: failed to bind socket\n");
return 2;
}
char message[] = "hi";
if ((numbytes = send(sockfd, message, 2, 0)) == -1)
{
perror("client: send");
exit(1);
}
int numbytesRecv;
char buf[100];
if ((numbytesRecv = recv(sockfd, buf, 99, 0)) == -1)
{
perror("client: recv");
exit(1);
}
freeaddrinfo(servinfo);
printf("client: sent %d bytes to %s\n", numbytes, server);
printf("client: received %d bytes from %s\n", numbytesRecv, server);
buf[numbytesRecv] = '\0';
printf("client: message received is %s\n",buf);
close(sockfd);
return 0;
}
// сервер
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#define MYPORT "5000" // the port users will be connecting to
#define MAXBUFLEN 100
// get sockaddr, IPv4 or IPv6:
void *get_in_addr(struct sockaddr *sa)
{
if (sa->sa_family == AF_INET) {
return &(((struct sockaddr_in*)sa)->sin_addr);
}
return &(((struct sockaddr_in6*)sa)->sin6_addr);
}
int main(void)
{
int sockfdTCP;
struct addrinfo hintsTCP, *servinfoTCP, *pTCP;
int rv;
int numbytes;
struct sockaddr_storage their_addr;
char buf[MAXBUFLEN];
size_t addr_len;
char s[INET6_ADDRSTRLEN];
memset(&hintsTCP, 0, sizeof hintsTCP);
hintsTCP.ai_family = AF_UNSPEC;
hintsTCP.ai_socktype = SOCK_STREAM;
hintsTCP.ai_flags = AI_PASSIVE;
if ((rv = getaddrinfo(NULL, MYPORT, &hintsTCP, &servinfoTCP)) != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 1;
}
// loop through all the results and bind to the first we can for TCP socket
for(pTCP = servinfoTCP; pTCP != NULL; pTCP = pTCP->ai_next)
{
if ((sockfdTCP = socket(pTCP->ai_family, pTCP->ai_socktype,pTCP->ai_protocol)) == -1)
{
perror("listener: socket");
continue;
}
if (bind(sockfdTCP, pTCP->ai_addr, pTCP->ai_addrlen) == -1)
{
close(sockfdTCP);
perror("listener: bind");
continue;
}
break;
}
if (pTCP == NULL)
{
fprintf(stderr, "listener: failed to bind socket\n");
return 2;
}
freeaddrinfo(servinfoTCP);
printf("listener: waiting to recvfrom...\n");
addr_len = sizeof their_addr;
const int BACKLOG = 10;
if (listen(sockfdTCP, BACKLOG) == -1) {
perror("listen");
exit(1);
}
socklen_t sin_size;
int new_fd;
sin_size = sizeof their_addr;
new_fd = accept(sockfdTCP, (struct sockaddr *)&their_addr, &sin_size);
printf("I am here\n");
if (new_fd == -1)
{
perror("accept");
}
if ((numbytes = recv(new_fd, buf, MAXBUFLEN, 0) == -1))
{
perror("recv");
exit(1);
}
char* msg = " hi i am server";
int numbytesSend;
if ((numbytesSend = send(new_fd, msg,strlen(msg), 0) == -1))
{
perror("recv");
exit(1);
}
inet_ntop(their_addr.ss_family,get_in_addr((struct sockaddr *)&their_addr), s, sizeof s);
printf("server: got connection from %s\n", s);
printf("listener: packet is %d bytes long\n", numbytes);
buf[numbytes] = '\0';
printf("listener: packet contains : %s\n", buf);
close(sockfdTCP);
close(new_fd);
return 0;
}
// выходной клиент
./clientTCP
client: sent 2 bytes to localhost
client: received 0 bytes from localhost
client: message received is
// сервер вывода
./serverTCP
listener: waiting to recvfrom...
I am here
server: got connection from 127.0.0.1
listener: packet is 0 bytes long
listener: packet contains :