chat_client.cc
#define _GNU_SOURCE 1 //为了在poll.h中得到POLLRDHUP标志位的定义
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <poll.h>
#include <fcntl.h>
#define BUFFER_SIZE 64
int main(int argc, char* argv[]){
if(argc < 2){
printf("usage: %s ip port\n", basename(argv[0]));
return 1;
}
const char* ip = argv[1];
int port = atoi(argv[2]);
struct sockaddr_in server_address;
bzero(&server_address, sizeof(server_address));
server_address.sin_family = AF_INET;
inet_pton(AF_INET, ip, &server_address.sin_addr);
server_address.sin_port = htons(port);
int sockfd = socket(PF_INET, SOCK_STREAM, 0);
assert(sockfd >= 0);
if(connect(sockfd, (struct sockaddr*)&server_address, sizeof(server_address)) < 0){
printf("connection failed\n");
close(sockfd);
return 1;
}
pollfd fds[2];
fds[0].fd = 0;
fds[0].events = POLLIN;
fds[0].revents = 0;
fds[1].fd = sockfd;
fds[1].events = POLLIN | POLLRDHUP;
fds[1].revents = 0;
char read_buf[BUFFER_SIZE];
int pipefd[2];
int ret = pipe(pipefd);
assert(ret != -1);
while(1){
ret = poll(fds, 2, -1);
if(ret < 0){
printf("poll failure\n");
break;
}
if(fds[1].revents & POLLRDHUP){
printf("server close the connection\n");
break;
}
else if(fds[1].revents & POLLIN){
memset(read_buf, '\0', BUFFER_SIZE);
recv(fds[1].fd, read_buf, BUFFER_SIZE-1, 0);
printf("%s\n",read_buf);
}
if(fds[0].revents & POLLIN){
ret = splice(0, NULL, pipefd[1], NULL, 32768, SPLICE_F_MORE | SPLICE_F_MOVE);
ret = splice(pipefd[0], NULL, sockfd, NULL, 32768, SPLICE_F_MORE | SPLICE_F_MOVE);
}
}
close(sockfd);
return 0;
}
chat_server.cc
#define _GUN_SOURCE 1
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <poll.h>
#define USER_LIMIT 5
#define BUFFER_SIZE 64
#define FD_LIMIT 65535
struct client_data{
sockaddr_in address;
char* write_buf;
char buf[BUFFER_SIZE];
};
int setnonblocking(int fd){
int old_option = fcntl(fd, F_GETFL);
int new_option = old_option | O_NONBLOCK;
fcntl(fd, F_SETFL, new_option);
return old_option;
}
int main(int argc, char* argv[]){
if(argc <= 2){
printf("usage: %s ip port\n", basename(argv[0]));
return 1;
}
const char* ip = argv[1];
int port = atoi(argv[2]);
struct sockaddr_in server_address;
bzero(&server_address, sizeof(server_address));
server_address.sin_family = AF_INET;
inet_pton(AF_INET, ip, &server_address.sin_addr);
server_address.sin_port = htons(port);
int listenfd = socket(PF_INET, SOCK_STREAM, 0);
assert(listenfd >= 0);
int ret = bind(listenfd, (struct sockaddr*)&server_address, sizeof(server_address));
assert(ret != -1);
ret = listen(listenfd, USER_LIMIT);
assert(ret != -1);
client_data* users = new client_data[FD_LIMIT];
pollfd fds[USER_LIMIT+1];
int user_counter = 0;
for(int i = 1; i <= USER_LIMIT; i++){
fds[i].fd = -1;
fds[i].events = 0;
}
fds[0].fd = listenfd;
fds[0].events = POLLIN | POLLERR;
fds[0].revents = 0;
while(1){
ret = poll(fds, user_counter+1, -1);
if(ret < 0){
printf("poll failure\n");
break;
}
for(int i = 0; i < user_counter+1; ++i){
if((fds[i].fd == listenfd) && (fds[i].revents & POLLIN)){
struct sockaddr_in client_address;
socklen_t client_addrlength = sizeof(client_address);
int connfd = accept(listenfd, (struct sockaddr*)&client_address, &client_addrlength);
if(connfd < 0){
printf("errno is: %d", errno);
continue;
}
if(user_counter >= USER_LIMIT){
const char* info = "too many user\n";
printf("%s", info);
send(connfd, info, strlen(info), 0);
close(connfd);
continue;
}
user_counter++;
users[connfd].address = client_address;
setnonblocking(connfd);
fds[user_counter].fd = connfd;
fds[user_counter].events = POLLIN | POLLRDHUP | POLLERR;
fds[user_counter].revents = 0;
printf("comes a new user, now have %d users\n", user_counter);
}
else if(fds[i].revents & POLLERR){
printf("get an error from %d\n", fds[i].fd);
char errors[100];
memset(errors, '\0', 100);
socklen_t length = sizeof(errors);
if(getsockopt(fds[i].fd, SOL_SOCKET, SO_ERROR, &errors, &length) < 0){
printf("get socket option failure\n");
}
continue;
}
else if(fds[i].revents & POLLRDHUP){
users[fds[i].fd] = users[fds[user_counter].fd];
close(fds[i].fd);
fds[i] = fds[user_counter];
user_counter--;
printf("a client left\n");
}
else if(fds[i].revents & POLLIN){
int connfd = fds[i].fd;
memset(users[connfd].buf, '\0', BUFFER_SIZE);
ret = recv(connfd, users[connfd].buf, BUFFER_SIZE-1, 0);
printf("get %d bytes of client data %s from %d\n", ret, users[connfd].buf, connfd);
if(ret < 0){
if(errno != EAGAIN){
close(connfd);
users[fds[i].fd] = users[fds[user_counter].fd];
fds[i] = fds[user_counter];
i--;
user_counter--;
}
}
else if(ret == 0){}
else{
for(int j = 1; j <= user_counter; ++j){
if(fds[j].fd == connfd)continue;
fds[j].events &= ~POLLIN;
fds[j].events |= POLLOUT;
users[fds[j].fd].write_buf = users[connfd].buf;
}
}
}
else if(fds[i].revents & POLLOUT){
int connfd = fds[i].fd;
if(!users[connfd].write_buf){
continue;
}
ret = send(connfd,users[connfd].write_buf,strlen(users[connfd].write_buf),0);
users[connfd].write_buf = NULL;
fds[i].events &= ~POLLOUT;
fds[i].events |= POLLIN;
}
}
}
delete []users;
close(listenfd);
return 0;
}