along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include <linux/filter.h>
+
#include "util.h"
#include "ipv4ll-internal.h"
int arp_network_send_raw_socket(int fd, const union sockaddr_union *link,
const struct ether_arp *arp) {
+ int r;
+
assert(arp);
assert(link);
assert(fd >= 0);
- if (sendto(fd, arp, sizeof(struct ether_arp), 0, &link->sa, sizeof(link->ll)) < 0)
+ r = sendto(fd, arp, sizeof(struct ether_arp), 0, &link->sa, sizeof(link->ll));
+ if (r < 0)
return -errno;
return 0;
}
int arp_network_bind_raw_socket(int index, union sockaddr_union *link) {
- int s;
+ struct sock_filter filter[] = {
+ BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */
+ BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(struct ether_arp), 1, 0), /* packet >= arp packet ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_hrd)), /* A <- header */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPHRD_ETHER, 1, 0), /* header == ethernet ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_pro)), /* A <- protocol */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 1, 0), /* protocol == IP ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_op)), /* A <- operation */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REQUEST, 0, 1), /* protocol == request ? */
+ BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REPLY, 0, 1), /* protocol == reply ? */
+ BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ };
+ struct sock_fprog fprog = {
+ .len = ELEMENTSOF(filter),
+ .filter = filter
+ };
+ _cleanup_close_ int s = -1;
+ int r;
assert(index > 0);
assert(link);
if (s < 0)
return -errno;
+ r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog));
+ if (r < 0)
+ return -errno;
+
link->ll.sll_family = AF_PACKET;
link->ll.sll_protocol = htons(ETH_P_ARP);
link->ll.sll_ifindex = index;
link->ll.sll_halen = ETH_ALEN;
memset(link->ll.sll_addr, 0xff, ETH_ALEN);
- if (bind(s, &link->sa, sizeof(link->ll)) < 0) {
- safe_close(s);
+ r = bind(s, &link->sa, sizeof(link->ll));
+ if (r < 0)
return -errno;
- }
- return s;
+ r = s;
+ s = -1;
+
+ return r;
}