94 lines
2.1 KiB
C
94 lines
2.1 KiB
C
/*
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* addrs_ioctl.c:
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*
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* Provides the get_addrs_ioctl() function for use on systems that
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* support a simple socket ioctl for acquiring low-level ethernet
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* information about interfaces.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include "iftop.h"
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/*
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* This function identifies the IP address and ethernet address for the requested
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* interface
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*
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* This function returns -1 on catastrophic failure, or a bitwise OR of the
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* following values:
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*
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* 1 - Was able to get the ethernet address
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* 2 - Was able to get the IP address
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*
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* This function should return 3 if all information was found
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*/
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int
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get_addrs_ioctl(char *interface, char if_hw_addr[], struct in_addr *if_ip_addr)
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{
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int s;
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struct ifreq ifr = {};
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int got_hw_addr = 0;
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int got_ip_addr = 0;
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/* -- */
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s = socket(PF_INET, SOCK_DGRAM, 0); /* any sort of IP socket will do */
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if (s == -1) {
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perror("socket");
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return -1;
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}
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fprintf(stderr,"if: %s\n", interface);
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memset(if_hw_addr, 0, 6);
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strncpy(ifr.ifr_name, interface, IFNAMSIZ);
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#ifdef SIOCGIFHWADDR
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if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0) {
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fprintf(stderr, "Error getting hardware address for interface: %s\n", interface);
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perror("ioctl(SIOCGIFHWADDR)");
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close(s);
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return -1;
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}
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else {
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memcpy(if_hw_addr, ifr.ifr_hwaddr.sa_data, 6);
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got_hw_addr = 1;
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}
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#else
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fprintf(stderr, "Cannot obtain hardware address on this platform\n");
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#endif
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/* Get the IP address of the interface */
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#ifdef SIOCGIFADDR
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(*(struct sockaddr_in *) &ifr.ifr_addr).sin_family = AF_INET;
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if (ioctl(s, SIOCGIFADDR, &ifr) < 0) {
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fprintf(stderr, "Error getting IP address for interface: %s\n", interface);
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perror("ioctl(SIOCGIFADDR)");
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close(s);
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return -1;
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}
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else {
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memcpy(if_ip_addr, &((*(struct sockaddr_in *) &ifr.ifr_addr).sin_addr), sizeof(struct in_addr));
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got_ip_addr = 2;
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}
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#else
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fprintf(stderr, "Cannot obtain IP address on this platform\n");
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#endif
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close(s);
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return got_hw_addr + got_ip_addr;
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}
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