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Commit | Line | Data |
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5c1d3fc9 UTL |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright (C) 2014 Axis Communications AB. All rights reserved. | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
298f77c6 TG |
20 | #include <linux/filter.h> |
21 | ||
5c1d3fc9 UTL |
22 | #include "util.h" |
23 | #include "ipv4ll-internal.h" | |
24 | ||
25 | int arp_network_send_raw_socket(int fd, const union sockaddr_union *link, | |
26 | const struct ether_arp *arp) { | |
c3d2994b TG |
27 | int r; |
28 | ||
5c1d3fc9 UTL |
29 | assert(arp); |
30 | assert(link); | |
31 | assert(fd >= 0); | |
32 | ||
c3d2994b TG |
33 | r = sendto(fd, arp, sizeof(struct ether_arp), 0, &link->sa, sizeof(link->ll)); |
34 | if (r < 0) | |
5c1d3fc9 UTL |
35 | return -errno; |
36 | ||
37 | return 0; | |
38 | } | |
39 | ||
088b6ba2 LP |
40 | int arp_network_bind_raw_socket(int ifindex, union sockaddr_union *link) { |
41 | ||
42 | static const struct sock_filter filter[] = { | |
43 | BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */ | |
44 | BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(struct ether_arp), 1, 0), /* packet >= arp packet ? */ | |
45 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
46 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_hrd)), /* A <- header */ | |
47 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPHRD_ETHER, 1, 0), /* header == ethernet ? */ | |
48 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
49 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_pro)), /* A <- protocol */ | |
50 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 1, 0), /* protocol == IP ? */ | |
51 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
52 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_op)), /* A <- operation */ | |
53 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REQUEST, 0, 1), /* protocol == request ? */ | |
54 | BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */ | |
55 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REPLY, 0, 1), /* protocol == reply ? */ | |
56 | BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */ | |
57 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
298f77c6 TG |
58 | }; |
59 | struct sock_fprog fprog = { | |
088b6ba2 LP |
60 | .len = ELEMENTSOF(filter), |
61 | .filter = (struct sock_filter*) filter | |
298f77c6 | 62 | }; |
c3d2994b TG |
63 | _cleanup_close_ int s = -1; |
64 | int r; | |
5c1d3fc9 | 65 | |
088b6ba2 | 66 | assert(ifindex > 0); |
5c1d3fc9 UTL |
67 | assert(link); |
68 | ||
bcf3ce7b | 69 | s = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); |
5c1d3fc9 UTL |
70 | if (s < 0) |
71 | return -errno; | |
72 | ||
c3d2994b TG |
73 | r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog)); |
74 | if (r < 0) | |
298f77c6 | 75 | return -errno; |
298f77c6 | 76 | |
5c1d3fc9 | 77 | link->ll.sll_family = AF_PACKET; |
5c1d3fc9 | 78 | link->ll.sll_protocol = htons(ETH_P_ARP); |
088b6ba2 | 79 | link->ll.sll_ifindex = ifindex; |
5c1d3fc9 | 80 | link->ll.sll_halen = ETH_ALEN; |
463b73e2 | 81 | memset(link->ll.sll_addr, 0xff, ETH_ALEN); |
5c1d3fc9 | 82 | |
c3d2994b TG |
83 | r = bind(s, &link->sa, sizeof(link->ll)); |
84 | if (r < 0) | |
5c1d3fc9 | 85 | return -errno; |
5c1d3fc9 | 86 | |
c3d2994b TG |
87 | r = s; |
88 | s = -1; | |
89 | ||
90 | return r; | |
5c1d3fc9 | 91 | } |