diff options
Diffstat (limited to 'networking/udhcp')
| -rw-r--r-- | networking/udhcp/socket.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/networking/udhcp/socket.c b/networking/udhcp/socket.c index 0ed7ad1..39f1cec 100644 --- a/networking/udhcp/socket.c +++ b/networking/udhcp/socket.c @@ -36,42 +36,45 @@ int FAST_FUNC udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) { + /* char buffer instead of bona-fide struct avoids aliasing warning */ + char ifr_buf[sizeof(struct ifreq)]; + struct ifreq *const ifr = (void *)ifr_buf; + int fd; - struct ifreq ifr; struct sockaddr_in *our_ip; - memset(&ifr, 0, sizeof(ifr)); + memset(ifr, 0, sizeof(*ifr)); fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW); - ifr.ifr_addr.sa_family = AF_INET; - strncpy_IFNAMSIZ(ifr.ifr_name, interface); + ifr->ifr_addr.sa_family = AF_INET; + strncpy_IFNAMSIZ(ifr->ifr_name, interface); if (nip) { - if (ioctl_or_perror(fd, SIOCGIFADDR, &ifr, + if (ioctl_or_perror(fd, SIOCGIFADDR, ifr, "is interface %s up and configured?", interface) ) { close(fd); return -1; } - our_ip = (struct sockaddr_in *) &ifr.ifr_addr; + our_ip = (struct sockaddr_in *) &ifr->ifr_addr; *nip = our_ip->sin_addr.s_addr; log1("IP %s", inet_ntoa(our_ip->sin_addr)); } if (ifindex) { - if (ioctl_or_warn(fd, SIOCGIFINDEX, &ifr) != 0) { + if (ioctl_or_warn(fd, SIOCGIFINDEX, ifr) != 0) { close(fd); return -1; } - log1("Adapter index %d", ifr.ifr_ifindex); - *ifindex = ifr.ifr_ifindex; + log1("Adapter index %d", ifr->ifr_ifindex); + *ifindex = ifr->ifr_ifindex; } if (mac) { - if (ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr) != 0) { + if (ioctl_or_warn(fd, SIOCGIFHWADDR, ifr) != 0) { close(fd); return -1; } - memcpy(mac, ifr.ifr_hwaddr.sa_data, 6); + memcpy(mac, ifr->ifr_hwaddr.sa_data, 6); log1("MAC %02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); } |