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hwdb: Add accelerometer orientation quirk for the PoV TAB-P1006W-232-3G
[thirdparty/systemd.git] / src / libsystemd-network / arp-util.c
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53e1b683 1/* SPDX-License-Identifier: LGPL-2.1+ */
996d1697 2/***
810adae9 3 Copyright © 2014 Axis Communications AB. All rights reserved.
996d1697
TG		 4***/
5
6#include <linux/filter.h>
7#include <arpa/inet.h>
8
996d1697 9#include "arp-util.h"
3ffd4af2 10#include "fd-util.h"
f11cba74 11#include "unaligned.h"
3ffd4af2 12#include "util.h"
996d1697
TG		 13
14int arp_network_bind_raw_socket(int ifindex, be32_t address, const struct ether_addr *eth_mac) {
15 struct sock_filter filter[] = {
16 BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */
17 BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(struct ether_arp), 1, 0), /* packet >= arp packet ? */
18 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
19 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_hrd)), /* A <- header */
20 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPHRD_ETHER, 1, 0), /* header == ethernet ? */
21 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
22 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_pro)), /* A <- protocol */
23 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 1, 0), /* protocol == IP ? */
24 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
25 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_hln)), /* A <- hardware address length */
26 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, sizeof(struct ether_addr), 1, 0), /* length == sizeof(ether_addr)? */
27 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
28 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_pln)), /* A <- protocol address length */
29 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, sizeof(struct in_addr), 1, 0), /* length == sizeof(in_addr) ? */
30 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
31 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, ea_hdr.ar_op)), /* A <- operation */
32 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REQUEST, 2, 0), /* protocol == request ? */
33 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REPLY, 1, 0), /* protocol == reply ? */
34 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
35 /* Sender Hardware Address must be different from our own */
6afe9046 36 BPF_STMT(BPF_LD + BPF_IMM, unaligned_read_be32(&eth_mac->ether_addr_octet[0])),/* A <- 4 bytes of client's MAC */
996d1697
TG		 37 BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */
38 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(struct ether_arp, arp_sha)), /* A <- 4 bytes of SHA */
39 BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */
40 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 0, 6), /* A == 0 ? */
6afe9046 41 BPF_STMT(BPF_LD + BPF_IMM, unaligned_read_be16(&eth_mac->ether_addr_octet[4])),/* A <- remainder of client's MAC */
996d1697
TG		 42 BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */
43 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(struct ether_arp, arp_sha) + 4), /* A <- remainder of SHA */
44 BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */
45 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 0, 1), /* A == 0 ? */
46 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
13e785f7 47 /* Sender Protocol Address or Target Protocol Address must be equal to the one we care about */
996d1697
TG		 48 BPF_STMT(BPF_LD + BPF_IMM, htobe32(address)), /* A <- clients IP */
49 BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */
50 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(struct ether_arp, arp_spa)), /* A <- SPA */
51 BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* X xor A */
52 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 0, 1), /* A == 0 ? */
53 BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */
54 BPF_STMT(BPF_LD + BPF_IMM, htobe32(address)), /* A <- clients IP */
55 BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */
56 BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(struct ether_arp, arp_tpa)), /* A <- TPA */
57 BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* X xor A */
58 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 0, 1), /* A == 0 ? */
59 BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */
60 BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
61 };
62 struct sock_fprog fprog = {
63 .len = ELEMENTSOF(filter),
64 .filter = (struct sock_filter*) filter
65 };
66 union sockaddr_union link = {
67 .ll.sll_family = AF_PACKET,
8e38570e 68 .ll.sll_protocol = htobe16(ETH_P_ARP),
996d1697
TG		 69 .ll.sll_ifindex = ifindex,
70 .ll.sll_halen = ETH_ALEN,
71 .ll.sll_addr = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
72 };
73 _cleanup_close_ int s = -1;
74 int r;
75
76 assert(ifindex > 0);
77
78 s = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
79 if (s < 0)
80 return -errno;
81
82 r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog));
83 if (r < 0)
84 return -errno;
85
86 r = bind(s, &link.sa, sizeof(link.ll));
87 if (r < 0)
88 return -errno;
89
c10d6bdb 90 return TAKE_FD(s);
996d1697
TG		 91}
92
93static int arp_send_packet(int fd, int ifindex,
94 be32_t pa, const struct ether_addr *ha,
95 bool announce) {
96 union sockaddr_union link = {
97 .ll.sll_family = AF_PACKET,
8e38570e 98 .ll.sll_protocol = htobe16(ETH_P_ARP),
996d1697
TG		 99 .ll.sll_ifindex = ifindex,
100 .ll.sll_halen = ETH_ALEN,
101 .ll.sll_addr = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
102 };
103 struct ether_arp arp = {
8e38570e
LP		 104 .ea_hdr.ar_hrd = htobe16(ARPHRD_ETHER), /* HTYPE */
105 .ea_hdr.ar_pro = htobe16(ETHERTYPE_IP), /* PTYPE */
996d1697
TG		 106 .ea_hdr.ar_hln = ETH_ALEN, /* HLEN */
107 .ea_hdr.ar_pln = sizeof(be32_t), /* PLEN */
8e38570e 108 .ea_hdr.ar_op = htobe16(ARPOP_REQUEST), /* REQUEST */
996d1697
TG		 109 };
110 int r;
111
112 assert(fd >= 0);
113 assert(pa != 0);
114 assert(ha);
115
116 memcpy(&arp.arp_sha, ha, ETH_ALEN);
117 memcpy(&arp.arp_tpa, &pa, sizeof(pa));
118
119 if (announce)
120 memcpy(&arp.arp_spa, &pa, sizeof(pa));
121
122 r = sendto(fd, &arp, sizeof(struct ether_arp), 0, &link.sa, sizeof(link.ll));
123 if (r < 0)
124 return -errno;
125
126 return 0;
127}
128
129int arp_send_probe(int fd, int ifindex,
130 be32_t pa, const struct ether_addr *ha) {
131 return arp_send_packet(fd, ifindex, pa, ha, false);
132}
133
134int arp_send_announcement(int fd, int ifindex,
135 be32_t pa, const struct ether_addr *ha) {
136 return arp_send_packet(fd, ifindex, pa, ha, true);
137}
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