| 1 | #define _GNU_SOURCE |
| 2 | #include <net/if.h> |
| 3 | #include <sys/socket.h> |
| 4 | #include <sys/ioctl.h> |
| 5 | #include <string.h> |
| 6 | #include <errno.h> |
| 7 | #include "syscall.h" |
| 8 | |
| 9 | char *if_indextoname(unsigned index, char *name) |
| 10 | { |
| 11 | struct ifreq ifr; |
| 12 | int fd, r; |
| 13 | |
| 14 | if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) return 0; |
| 15 | ifr.ifr_ifindex = index; |
| 16 | r = ioctl(fd, SIOCGIFNAME, &ifr); |
| 17 | __syscall(SYS_close, fd); |
| 18 | if (r < 0) { |
| 19 | if (errno == ENODEV) errno = ENXIO; |
| 20 | return 0; |
| 21 | } |
| 22 | return strncpy(name, ifr.ifr_name, IF_NAMESIZE); |
| 23 | } |