Changes between Initial Version and Version 1 of ネットワークのハードウエアアドレスを取得する

Timestamp:

Nov 9, 2016, 9:56:02 AM (7 years ago)

Author:

admin

Comment:

--

ネットワークのハードウエアアドレスを取得する

@@ +1 @@
+
+ネットワークのハードウエアアドレスを取得する
+{{{
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#if defined(SIOCGARP)
+# include <net/if_arp.h>
+#endif
+
+#if defined __linux__
+# define HAVE_INET_NTOP 1
+#elif defined __CYGWIN__
+# define HAVE_INET_NTOP 1
+#else
+# define HAVE_INET_NTOP 1
+# define HAVE_SOCKADDR_SA_LEN 1
+#endif
+
+
+static
+const char *
+my_sockaddr_in_ntop(const struct sockaddr_in *sin)
+{
+#if HAVE_INET_NTOP
+  static char buf[INET6_ADDRSTRLEN];
+  return inet_ntop(sin->sin_family, &(sin->sin_addr), buf, sizeof(buf));
+#else
+  return inet_ntoa(sin->sin_addr);
+#endif
+}
+
+static
+const char *
+#if defined(SIOCGIFHWADDR)
+my_inet_ntop_mac(const struct ifreq *ifr)  /* linux & cygwin */
+{
+  const unsigned char *p = (const unsigned char *)ifr->ifr_hwaddr.sa_data;
+#elif defined(SIOCGARP)
+my_inet_ntop_mac(const struct arpreq *arp)
+{
+  const unsigned char *p = (const unsigned char *)arp->arp_ha.sa_data;
+#else
+# error not supported...
+#endif
+  static char buf[65];
+  
+  sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X",
+                p[0],p[1],p[2],p[3],p[4],p[5]
+         );
+  return buf;
+}
+
+
+int
+main(void)
+{
+  char  buf[16384];
+  struct ifconf ifc;
+  int i, numnic, fd;
+  int rc;
+  
+  fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (fd == -1) {
+    fprintf(stderr, "socket err\n");
+    exit(1);
+  }
+  memset(buf, 0, sizeof(buf));
+  memset(&ifc, 0, sizeof(ifc));
+  ifc.ifc_req = (struct ifreq *)buf;
+  ifc.ifc_len = sizeof(buf);
+  errno = 0;
+  rc = ioctl(fd, SIOCGIFCONF, &ifc);
+  if (rc == -1 || errno == EINVAL) {
+    fprintf(stderr, "ioctl SIOCGIFCONF err\n");
+    exit(1);
+  }
+  
+  for(i=0, numnic=0; i<ifc.ifc_len; ) {
+    struct ifreq  *ifr;
+#if defined(SIOCGIFHWADDR)
+    struct ifreq req;
+#elif defined(SIOCGARP)
+    struct arpreq req;
+#endif
+    
+    ifr = (struct ifreq *)(buf + i);
+    switch (ifr->ifr_addr.sa_family) {
+      case AF_INET:
+        printf("%3d \"%s\" ", numnic, ifr->ifr_name);
+        printf("AF_INET %s", my_sockaddr_in_ntop((struct sockaddr_in *)&ifr->ifr_addr));
+#if defined(SIOCGIFHWADDR)
+        memcpy(&req, ifr, sizeof(req));
+        rc = ioctl(fd, SIOCGIFHWADDR, &req);  /* linux */
+#elif defined(SIOCGARP)
+        memset(&req, 0, sizeof(req));
+        memcpy(&req.arp_pa, &ifr->ifr_addr, sizeof(struct sockaddr_in));
+        rc = ioctl(fd, SIOCGARP, &req);
+#else
+# error not supported...
+#endif
+        if (rc >= 0) {
+          printf("  %s", my_inet_ntop_mac(&req));
+        }
+        printf("\n");
+        break;
+    default:
+        printf("%3d \"%s\" family=%d\n", numnic, ifr->ifr_name, ifr->ifr_addr.sa_family);
+      break;
+    }
+    ++numnic;
+#if HAVE_SOCKADDR_SA_LEN
+    i += ifr->ifr_addr.sa_len <= sizeof(struct sockaddr) ?
+      sizeof(struct ifreq) :
+      sizeof(struct ifreq) - sizeof(struct sockaddr) + ifr->ifr_addr.sa_len;
+#else
+    i += sizeof(struct ifreq);
+#endif
+  }
+  
+  return 0;
+}
+
+}}}