eliminate aliasing warnings in traceroute.c and udhcp/socket.c
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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]);
}