clone-shim/examples/echo/echo.c

80 lines
1.7 KiB
C
Raw Normal View History

2022-03-01 11:29:21 +00:00
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#define BUF_SIZE 1024
int connection_listener(int, int);
int request_handler(int);
int main(int argc, char **argv) {
if (argc < 2) {
fprintf(stderr, "usage: %s SUBCOMMAND...\n", argv[0]);
return -1;
}
if (strcmp(argv[1], "connection_listener") == 0) {
if (argc != 4) {
fprintf(stderr, "usage: %s connection_listener SERVER_FD WRITE_PIPE_FD\n",
argv[0]);
return -1;
}
return connection_listener(atoi(argv[2]), atoi(argv[3]));
} else if (strcmp(argv[1], "request_handler") == 0) {
if (argc != 3) {
fprintf(stderr, "usage: %s request_handler CLIENT_FD\n", argv[0]);
return -1;
}
return request_handler(atoi(argv[2]));
}
fprintf(stderr, "unrecognised subcommand\n");
return -1;
}
int connection_listener(int server_fd, int write_pipe) {
while (1) {
struct sockaddr_in client;
socklen_t client_len = sizeof(client);
int client_fd = accept(server_fd, (struct sockaddr *)&client, &client_len);
if (client_fd < 0) {
perror("accept");
}
write(write_pipe, &client_fd, sizeof(client_fd));
fprintf(stderr, "sent client_fd: %d\n", client_fd);
}
return 0;
}
int request_handler(int client_fd) {
char buf[BUF_SIZE];
while (1) {
int read = recv(client_fd, buf, BUF_SIZE, 0);
if (read < 0) {
perror("recv");
return read;
}
if (!read) {
fprintf(stderr, "connection terminated\n");
return 0;
}
if (send(client_fd, buf, read, 0) < 0) {
perror("send");
return -1;
}
}
return 0;
}