我已經寫了最簡單的原始套接字示例通過RAW套接字發送數據從一個應用程序到另一個protcol no = 5(未被標準協議使用)。沒有正確的數據正在接收原始套接字
這裏是我的代碼:
發件人
void sendRawData(char sendString[])
{
int sock;
struct sockaddr_in server_addr;
struct hostent *host; //hostent predefined structure use to store info about host host = (struct hostent *) gethostbyname(server);//gethostbyname returns a pointer to hostent
if ((sock = socket(AF_INET, SOCK_RAW, 5)) == -1)
{
perror("socket");
exit(1);
}
//destination address structure
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(NOT_REQ); // NOT_REQ is 2000 but for SOCK_RAW sockets, it should be useless.
server_addr.sin_addr = *((struct in_addr *)host->h_addr); //host->h_addr gives address of host
bzero(&(server_addr.sin_zero),8);
sendto(sock, sendString, strlen(sendString), 0,(struct sockaddr *)&server_addr, sizeof(struct sockaddr));
//sendto() function shall send a message through a connectionless-mode socket.
printf("\nFORWARD REQUEST : '%s' has been forwarded to server\n",sendString);
close(sock);
}
reciever
int main(int argc, char **argv){
int sock = 0, len, addr_len;
char rec_buff[5000];
struct sockaddr_in address,
server_addr_udp,
client_addr;
if ((sock = socket(AF_INET, SOCK_RAW, 5)) == -1) //Creating a UDP Socket
{
perror("Socket");
exit(1);
}
server_addr_udp.sin_family = AF_INET;
server_addr_udp.sin_port = htons(2004); // again it should be useless
server_addr_udp.sin_addr.s_addr = INADDR_ANY;
bzero(&(server_addr_udp.sin_zero),8);
addr_len = sizeof(struct sockaddr);
if (bind(sock,(struct sockaddr *)&server_addr_udp, sizeof(struct sockaddr)) == -1)//Binding UDP socket
{
perror("Bind");
exit(1);
}
len = recvfrom(sock, rec_buff,5000,0,(struct sockaddr *)&client_addr, &addr_len);
printf("ip = %s, port = %d\n", inet_ntoa(client_addr.sin_addr),ntohs(client_addr.sin_port));
printf("%s\n", rec_buff);
main(0, NULL);
return 0;
}
什麼,我觀察是在接收端,我收到了不正確的數據。 如果我更改套接字類型SOCK_DGRAM和協議= IPPROTO_UDP,那麼一切工作完美。 我的意圖是使用自定義協議號(5),因爲世界上的每個數據包都不需要是UDP/TCP數據包。
有人能指教我哪裏出錯了。
輸出
ip = 127.0.0.1, port = 0
E
我推薦開始檢查'len'(你的讀取字節數)以及'sendto'實際發送的字節數。也請擺脫那些討厭的'bzero's。 – SergeyA
我打印由sendto和recv來重新調整的值。 FORWARD REQUEST:'你好,我是發件人'已被轉發到服務器,rc = 18(由sendto返回的值是正確的) 在接收方:它是38. –