套接字權限ubuntu

Question

您好我是Linux新手，並且有一個與套接字相關的項目。我現在面臨的問題是，當我運行的代碼輸入的eth0我的路由器的for interface和IP地址即 ./mycode eth0 192.168.1.1它給出了一個錯誤

您沒有權限在該設備上捕捉（插座：不允許的操作）

我從一個鏈接了的代碼是：

#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <pcap.h> 
#include <arpa/inet.h> 
#include <net/if.h> 
#include <net/ethernet.h> 
#include <netinet/if_ether.h> 
#include <sys/ioctl.h> 

int main(int argc,const char* argv[]) { 
    // Get interface name and target IP address from command line. 
    if (argc<2) { 
     fprintf(stderr,"usage: send_arp <interface> <ipv4-address>\n"); 
     exit(1); 
    } 
    const char* if_name=argv[1]; 
    const char* target_ip_string=argv[2]; 

    // Construct Ethernet header (except for source MAC address). 
    // (Destination set to broadcast address, FF:FF:FF:FF:FF:FF.) 
    struct ether_header header; 
    header.ether_type=htons(ETH_P_ARP); 
    memset(header.ether_dhost,0xff,sizeof(header.ether_dhost)); 

    // Construct ARP request (except for MAC and IP addresses). 
    struct ether_arp req; 
    req.arp_hrd=htons(ARPHRD_ETHER); 
    req.arp_pro=htons(ETH_P_IP); 
    req.arp_hln=ETHER_ADDR_LEN; 
    req.arp_pln=sizeof(in_addr_t); 
    req.arp_op=htons(ARPOP_REQUEST); 
    memset(&req.arp_tha,0,sizeof(req.arp_tha)); 

    // Convert target IP address from string, copy into ARP request. 
    struct in_addr target_ip_addr={0}; 
    if (!inet_aton(target_ip_string,&target_ip_addr)) { 
     fprintf(stderr,"%s is not a valid IP address",target_ip_string); 
     exit(1); 
    } 
    memcpy(&req.arp_tpa,&target_ip_addr.s_addr,sizeof(req.arp_tpa)); 

    // Write the interface name to an ifreq structure, 
    // for obtaining the source MAC and IP addresses. 
    struct ifreq ifr; 
    size_t if_name_len=strlen(if_name); 
    if (if_name_len<sizeof(ifr.ifr_name)) { 
     memcpy(ifr.ifr_name,if_name,if_name_len); 
     ifr.ifr_name[if_name_len]=0; 
    } else { 
     fprintf(stderr,"interface name is too long"); 
     exit(1); 
    } 

    // Open an IPv4-family socket for use when calling ioctl. 
    int fd=socket(AF_INET,SOCK_DGRAM,0); 
    if (fd==-1) { 
     perror(0); 
     exit(1); 
    } 

    // Obtain the source IP address, copy into ARP request 
    if (ioctl(fd,SIOCGIFADDR,&ifr)==-1) { 
     perror(0); 
     close(fd); 
     exit(1); 
    } 
    struct sockaddr_in* source_ip_addr = (struct sockaddr_in*)&ifr.ifr_addr; 
    memcpy(&req.arp_spa,&source_ip_addr->sin_addr.s_addr,sizeof(req.arp_spa)); 

    // Obtain the source MAC address, copy into Ethernet header and ARP request. 
    if (ioctl(fd,SIOCGIFHWADDR,&ifr)==-1) { 
     perror(0); 
     close(fd); 
     exit(1); 
    } 
    if (ifr.ifr_hwaddr.sa_family!=ARPHRD_ETHER) { 
     fprintf(stderr,"not an Ethernet interface"); 
     close(fd); 
     exit(1); 
    } 
    const unsigned char* source_mac_addr=(unsigned char*)ifr.ifr_hwaddr.sa_data; 
    memcpy(header.ether_shost,source_mac_addr,sizeof(header.ether_shost)); 
    memcpy(&req.arp_sha,source_mac_addr,sizeof(req.arp_sha)); 
    close(fd); 

    // Combine the Ethernet header and ARP request into a contiguous block. 
    unsigned char frame[sizeof(struct ether_header)+sizeof(struct ether_arp)]; 
    memcpy(frame,&header,sizeof(struct ether_header)); 
    memcpy(frame+sizeof(struct ether_header),&req,sizeof(struct ether_arp)); 

    // Open a PCAP packet capture descriptor for the specified interface. 
    char pcap_errbuf[PCAP_ERRBUF_SIZE]; 
    pcap_errbuf[0]='\0'; 
    pcap_t* pcap=pcap_open_live(if_name,96,0,0,pcap_errbuf); 
    if (pcap_errbuf[0]!='\0') { 
     fprintf(stderr,"%s\n",pcap_errbuf); 
    } 
    if (!pcap) { 
     exit(1); 
    } 

    // Write the Ethernet frame to the interface. 
    if (pcap_inject(pcap,frame,sizeof(frame))==-1) { 
     pcap_perror(pcap,0); 
     pcap_close(pcap); 
     exit(1); 
    } 

    // Close the PCAP descriptor. 
    pcap_close(pcap); 
    return 0; 
} 

Answer 1

你需要root權限做到這一點。嘗試以root身份運行程序。