为什么我会收到一条警告说"赋值从整数中生成没有强制转换的指针"？

Question

这是我在混杂模式下从以太网接收原始数据包的代码.编译时我在代码行中收到警告

logfile=open("sniff_data.bin",O_CREAT|O_APPEND|O_TRUNC,0777);

警告:赋值使整数指针没有强制转换[默认情况下启用].我在谷歌检查但无法找到解决方案.任何人都可以告诉我解决方案,我哪里出错了？

void ProcessPacket(unsigned char* , int);
void print_ip_header(unsigned char* , int);
void print_tcp_packet(unsigned char * , int );
void print_udp_packet(unsigned char * , int );
void print_icmp_packet(unsigned char* , int );
void PrintData (unsigned char* , int);

FILE *logfile;
struct sockaddr_in source,dest;
int i,j;

int main()
{
    int saddr_size,data_size;
    struct sockaddr saddr;
    gopromiscous();
    unsigned char *buffer = (unsigned char *) malloc(1024);  

    logfile=open("sniff_data.bin",O_CREAT|O_APPEND|O_TRUNC,0777);  

    if(logfile==NULL)
    {
        printf("Unable to create sniff_data file.");
    }
    printf("\n Starting..\n");

    int sock_raw = socket( AF_PACKET , SOCK_RAW , htons(ETH_P_ALL)) ;
    setsockopt(sock_raw , SOL_SOCKET , SO_BINDTODEVICE , "eth0" , strlen("eth0")+ 1 );

    if(sock_raw < 0)
    {

        perror("Socket Error");
        return 1;
    }
    int count=30; 
    while(count>=0)
    { 
        count--;
        saddr_size = sizeof saddr;
        //Receive a packet
        data_size = recvfrom(sock_raw , buffer , 1024, 0 , &saddr , 
          (socklen_t*)&saddr_size);
        if(data_size <0 )
        {
            printf("Recvfrom error , failed to get packets\n");
            return 1;
        }

        fwrite(buffer, data_size, 1, logfile);    

    }

    fclose(logfile);
    close(sock_raw);
    printf("\n");
    printf(" Finished\n\n");
    return 0;
}


int gopromiscous()
  {

    int fd;
    struct ifreq eth;

    fd = socket(AF_INET, SOCK_PACKET, htons(0x800));

    strcpy(eth.ifr_name, "eth0");

    ioctl(fd, SIOCGIFFLAGS, &eth);

    eth.ifr_flags |= IFF_PROMISC;

    ioctl(fd, SIOCSIFFLAGS, &eth);

    printf("\n Entered Promiscuous Mode Successfully\n");

 }

Answer 1

从男人2开

    int open(const char *path, int oflag, ...);

打开返回一个int(文件描述符),而不是一个FILE*.因此警告,以及您的代码无法工作的原因.

您可能希望将FILE*更改为int,并使用write(2)和close(2)而不是fwrite和flcose

或者使用fopen(3)