linux c flash安全策略

Posted 2020-06-16

flash的socket安全策略机制默认端口为843,需要服务器在这个端口响应请求并返回信息；代码如下：

#include<stdio.h>
#include<string.h>
#include<errno.h>
#include<unistd.h>
#include<event.h>

void accept_cb(int fd, short events, void* arg);
void socket_read_cb(int fd, short events, void *arg);
int tcp_server_init(int port, int listen_num);

int main(int argc, char** argv)
{

  int listener = tcp_server_init(843, 10);
  if( listener == -1 )
  {
    perror(" tcp_server_init error ");
    return -1;
  }

  struct event_base* base = event_base_new();

  //添加监听客户端请求连接事件
  struct event* ev_listen = event_new(base, listener, EV_READ | EV_PERSIST, accept_cb, base);
  event_add(ev_listen, NULL);

  event_base_dispatch(base);
  return 0;
}

void accept_cb(int fd, short events, void* arg)
{
  evutil_socket_t sockfd;

  struct sockaddr_in client;
  socklen_t len;

  sockfd = accept(fd, (struct sockaddr*)&client, &len );
  evutil_make_socket_nonblocking(sockfd);

  printf("accept a client %d\n", sockfd);

  struct event_base* base = (struct event_base*)arg;

  //仅仅是为了动态创建一个event结构体
  struct event *ev = event_new(NULL, -1, 0, NULL, NULL);
  //将动态创建的结构体作为event的回调参数
  event_assign(ev, base, sockfd, EV_READ | EV_PERSIST, socket_read_cb, (void*)ev);

  event_add(ev, NULL);
}


void socket_read_cb(int fd, short events, void *arg)
{
  char msg[4096];
  struct event *ev = (struct event*)arg;
  int len = read(fd, msg, sizeof(msg) - 1);
  msg[len] = ‘\0‘;  

  char *reply_msg = "<?xml version=\"1.0\"?><cross-domain-policy><site-control permitted-cross-domain-policies=\"all\"/><allow-access-from domain=\"*\" to-ports=\"*\"/></cross-domain-policy>";
  if(strcmp(msg, "<policy-file-request/>") == 0){
    printf("recv the client msg: %s\r\n", msg);  
    printf("%s\r\n", reply_msg);
 
    write(fd, reply_msg, strlen(reply_msg) );
    
    close(event_get_fd(ev));
    event_free(ev);
    return ;
  }
 
  if( len <= 0 )
  {
    printf("some error happen when read\n");
    close(event_get_fd(ev));
    event_free(ev);
    return ;
  }
}

typedef struct sockaddr SA;
int tcp_server_init(int port, int listen_num)
{
  int errno_save;
  evutil_socket_t listener;

  listener = socket(AF_INET, SOCK_STREAM, 0);
  if( listener == -1 )
    return -1;

  //允许多次绑定同一个地址。要用在socket和bind之间
  evutil_make_listen_socket_reuseable(listener);

  struct sockaddr_in sin;
  sin.sin_family = AF_INET;
  sin.sin_addr.s_addr = 0;
  sin.sin_port = htons(port);

  if(bind(listener, (SA*)&sin, sizeof(sin)) < 0 )
    goto error;

  if(listen(listener, listen_num) < 0)
    goto error;


  //跨平台统一接口，将套接字设置为非阻塞状态
  evutil_make_socket_nonblocking(listener);

  return listener;

  error:
    errno_save = errno;
    evutil_closesocket(listener);
    errno = errno_save;

    return -1;
}

2.编译后执行就ok!

gcc -Wall  -I/usr/local/include event.c -L/usr/local/lib -levent

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