sd-ipv4ll: filter out unwanted ARP packets in the kernel

We currently process every ARP packet, but we should only care about the ones
relating to our IP address.

Also rename ipv4ll helpers to apr-utils.[ch], and rework the helpers a bit.

1 files changed, 0 insertions, 91 deletions

diff --git a/src/libsystemd-network/ipv4ll-network.c b/src/libsystemd-network/ipv4ll-network.c
deleted file mode 100644
index 93ffed408f..0000000000
--- a/src/libsystemd-network/ipv4ll-network.c
+++ /dev/null
@@ -1,91 +0,0 @@
-/***
-  This file is part of systemd.
-
-  Copyright (C) 2014 Axis Communications AB. All rights reserved.
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  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);
-
-        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 ifindex, union sockaddr_union *link) {
-
-        static const 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 = (struct sock_filter*) filter
-        };
-        _cleanup_close_ int s = -1;
-        int r;
-
-        assert(ifindex > 0);
-        assert(link);
-
-        s = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
-        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 = ifindex;
-        link->ll.sll_halen = ETH_ALEN;
-        memset(link->ll.sll_addr, 0xff, ETH_ALEN);
-
-        r = bind(s, &link->sa, sizeof(link->ll));
-        if (r < 0)
-                return -errno;
-
-        r = s;
-        s = -1;
-
-        return r;
-}