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8b4a9693 PF |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright (C) 2013 Intel Corporation. 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 | ||
20 | #include <errno.h> | |
8b4a9693 PF |
21 | #include <sys/socket.h> |
22 | #include <string.h> | |
23 | #include <linux/if_packet.h> | |
76253e73 | 24 | #include <linux/if_infiniband.h> |
8b4a9693 | 25 | #include <net/ethernet.h> |
7429b07f | 26 | #include <net/if_arp.h> |
8b4a9693 | 27 | #include <stdio.h> |
bc29e507 | 28 | #include <linux/filter.h> |
8b4a9693 PF |
29 | |
30 | #include "socket-util.h" | |
31 | ||
32 | #include "dhcp-internal.h" | |
33 | ||
76253e73 DW |
34 | static int _bind_raw_socket(int ifindex, union sockaddr_union *link, |
35 | uint32_t xid, const uint8_t *mac_addr, | |
36 | size_t mac_addr_len, | |
37 | const uint8_t *bcast_addr, | |
38 | const struct ether_addr *eth_mac, | |
39 | uint16_t arp_type, uint8_t dhcp_hlen) { | |
bc29e507 | 40 | struct sock_filter filter[] = { |
088b6ba2 LP |
41 | BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */ |
42 | BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(DHCPPacket), 1, 0), /* packet >= DHCPPacket ? */ | |
43 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
44 | BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.protocol)), /* A <- IP protocol */ | |
45 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 1, 0), /* IP protocol == UDP ? */ | |
46 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
47 | BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.frag_off)), /* A <- Flags */ | |
48 | BPF_STMT(BPF_ALU + BPF_AND + BPF_K, 0x20), /* A <- A & 0x20 (More Fragments bit) */ | |
49 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ | |
50 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
51 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, ip.frag_off)), /* A <- Flags + Fragment offset */ | |
52 | BPF_STMT(BPF_ALU + BPF_AND + BPF_K, 0x1fff), /* A <- A & 0x1fff (Fragment offset) */ | |
53 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ | |
54 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
55 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, udp.dest)), /* A <- UDP destination port */ | |
56 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_PORT_CLIENT, 1, 0), /* UDP destination port == DHCP client port ? */ | |
57 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
58 | BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.op)), /* A <- DHCP op */ | |
59 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, BOOTREPLY, 1, 0), /* op == BOOTREPLY ? */ | |
60 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
61 | BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.htype)), /* A <- DHCP header type */ | |
76253e73 | 62 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, arp_type, 1, 0), /* header type == arp_type ? */ |
088b6ba2 | 63 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ |
e2acdb6b | 64 | BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.hlen)), /* A <- MAC address length */ |
76253e73 | 65 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, dhcp_hlen, 1, 0), /* address length == dhcp_hlen ? */ |
088b6ba2 LP |
66 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ |
67 | BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.xid)), /* A <- client identifier */ | |
68 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, xid, 1, 0), /* client identifier == xid ? */ | |
69 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
76253e73 | 70 | BPF_STMT(BPF_LD + BPF_IMM, htobe32(*((unsigned int *) eth_mac))), /* A <- 4 bytes of client's MAC */ |
088b6ba2 LP |
71 | BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */ |
72 | BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr)), /* A <- 4 bytes of MAC from dhcp.chaddr */ | |
73 | BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */ | |
74 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ | |
75 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
76253e73 | 76 | BPF_STMT(BPF_LD + BPF_IMM, htobe16(*((unsigned short *) (((char *) eth_mac) + 4)))), /* A <- remainder of client's MAC */ |
088b6ba2 LP |
77 | BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */ |
78 | BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr) + 4), /* A <- remainder of MAC from dhcp.chaddr */ | |
79 | BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */ | |
80 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ | |
81 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
82 | BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.magic)), /* A <- DHCP magic cookie */ | |
83 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_MAGIC_COOKIE, 1, 0), /* cookie == DHCP magic cookie ? */ | |
84 | BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ | |
85 | BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */ | |
bc29e507 TG |
86 | }; |
87 | struct sock_fprog fprog = { | |
088b6ba2 LP |
88 | .len = ELEMENTSOF(filter), |
89 | .filter = filter | |
bc29e507 | 90 | }; |
c3d2994b | 91 | _cleanup_close_ int s = -1; |
fef0e0f3 | 92 | int r, on = 1; |
8b4a9693 | 93 | |
088b6ba2 | 94 | assert(ifindex > 0); |
23f30ed3 TG |
95 | assert(link); |
96 | ||
66a67eff | 97 | s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); |
8b4a9693 PF |
98 | if (s < 0) |
99 | return -errno; | |
100 | ||
088b6ba2 | 101 | r = setsockopt(s, SOL_PACKET, PACKET_AUXDATA, &on, sizeof(on)); |
c3d2994b TG |
102 | if (r < 0) |
103 | return -errno; | |
104 | ||
105 | r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog)); | |
106 | if (r < 0) | |
107 | return -errno; | |
108 | ||
8c00042c PF |
109 | link->ll.sll_family = AF_PACKET; |
110 | link->ll.sll_protocol = htons(ETH_P_IP); | |
088b6ba2 | 111 | link->ll.sll_ifindex = ifindex; |
76253e73 DW |
112 | link->ll.sll_hatype = htons(arp_type); |
113 | link->ll.sll_halen = mac_addr_len; | |
114 | memcpy(link->ll.sll_addr, bcast_addr, mac_addr_len); | |
8b4a9693 | 115 | |
c3d2994b TG |
116 | r = bind(s, &link->sa, sizeof(link->ll)); |
117 | if (r < 0) | |
bc29e507 | 118 | return -errno; |
bc29e507 | 119 | |
c3d2994b TG |
120 | r = s; |
121 | s = -1; | |
8b4a9693 | 122 | |
c3d2994b | 123 | return r; |
8c00042c PF |
124 | } |
125 | ||
76253e73 DW |
126 | int dhcp_network_bind_raw_socket(int ifindex, union sockaddr_union *link, |
127 | uint32_t xid, const uint8_t *mac_addr, | |
128 | size_t mac_addr_len, uint16_t arp_type) { | |
129 | static const uint8_t eth_bcast[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; | |
130 | /* Default broadcast address for IPoIB */ | |
131 | static const uint8_t ib_bcast[] = { | |
132 | 0x00, 0xff, 0xff, 0xff, 0xff, 0x12, 0x40, 0x1b, | |
133 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
134 | 0xff, 0xff, 0xff, 0xff | |
135 | }; | |
136 | struct ether_addr eth_mac = { { 0, 0, 0, 0, 0, 0 } }; | |
137 | const uint8_t *bcast_addr = NULL; | |
138 | uint8_t dhcp_hlen = 0; | |
139 | ||
140 | assert_return(mac_addr_len > 0, -EINVAL); | |
141 | ||
142 | if (arp_type == ARPHRD_ETHER) { | |
143 | assert_return(mac_addr_len == ETH_ALEN, -EINVAL); | |
144 | memcpy(ð_mac, mac_addr, ETH_ALEN); | |
145 | bcast_addr = eth_bcast; | |
146 | dhcp_hlen = ETH_ALEN; | |
147 | } else if (arp_type == ARPHRD_INFINIBAND) { | |
148 | assert_return(mac_addr_len == INFINIBAND_ALEN, -EINVAL); | |
149 | bcast_addr = ib_bcast; | |
150 | } else | |
151 | return -EINVAL; | |
152 | ||
153 | return _bind_raw_socket(ifindex, link, xid, mac_addr, mac_addr_len, | |
154 | bcast_addr, ð_mac, arp_type, dhcp_hlen); | |
155 | } | |
156 | ||
c3d2994b | 157 | int dhcp_network_bind_udp_socket(be32_t address, uint16_t port) { |
234fc2df PF |
158 | union sockaddr_union src = { |
159 | .in.sin_family = AF_INET, | |
080ab276 TG |
160 | .in.sin_port = htobe16(port), |
161 | .in.sin_addr.s_addr = address, | |
234fc2df | 162 | }; |
c3d2994b | 163 | _cleanup_close_ int s = -1; |
076adf01 | 164 | int r, on = 1, tos = IPTOS_CLASS_CS6; |
234fc2df PF |
165 | |
166 | s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); | |
167 | if (s < 0) | |
168 | return -errno; | |
169 | ||
c3d2994b TG |
170 | r = setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); |
171 | if (r < 0) | |
85923f79 | 172 | return -errno; |
b44cd882 | 173 | |
076adf01 TG |
174 | r = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); |
175 | if (r < 0) | |
176 | return -errno; | |
fef0e0f3 | 177 | |
076adf01 | 178 | if (address == INADDR_ANY) { |
fef0e0f3 TG |
179 | r = setsockopt(s, IPPROTO_IP, IP_PKTINFO, &on, sizeof(on)); |
180 | if (r < 0) | |
181 | return -errno; | |
d6bd972d TG |
182 | |
183 | r = setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)); | |
184 | if (r < 0) | |
185 | return -errno; | |
076adf01 TG |
186 | } else { |
187 | r = setsockopt(s, IPPROTO_IP, IP_FREEBIND, &on, sizeof(on)); | |
188 | if (r < 0) | |
189 | return -errno; | |
fef0e0f3 | 190 | } |
85923f79 | 191 | |
c3d2994b TG |
192 | r = bind(s, &src.sa, sizeof(src.in)); |
193 | if (r < 0) | |
234fc2df | 194 | return -errno; |
234fc2df | 195 | |
c3d2994b TG |
196 | r = s; |
197 | s = -1; | |
198 | ||
199 | return r; | |
234fc2df PF |
200 | } |
201 | ||
8c00042c | 202 | int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link, |
c3d2994b TG |
203 | const void *packet, size_t len) { |
204 | int r; | |
205 | ||
23f30ed3 TG |
206 | assert(link); |
207 | assert(packet); | |
208 | assert(len); | |
209 | ||
c3d2994b TG |
210 | r = sendto(s, packet, len, 0, &link->sa, sizeof(link->ll)); |
211 | if (r < 0) | |
1c8035a8 | 212 | return -errno; |
8b4a9693 | 213 | |
1c8035a8 | 214 | return 0; |
8b4a9693 | 215 | } |
234fc2df | 216 | |
080ab276 | 217 | int dhcp_network_send_udp_socket(int s, be32_t address, uint16_t port, |
c3d2994b | 218 | const void *packet, size_t len) { |
234fc2df PF |
219 | union sockaddr_union dest = { |
220 | .in.sin_family = AF_INET, | |
080ab276 TG |
221 | .in.sin_port = htobe16(port), |
222 | .in.sin_addr.s_addr = address, | |
234fc2df | 223 | }; |
c3d2994b TG |
224 | int r; |
225 | ||
226 | assert(s >= 0); | |
227 | assert(packet); | |
228 | assert(len); | |
234fc2df | 229 | |
c3d2994b TG |
230 | r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)); |
231 | if (r < 0) | |
234fc2df PF |
232 | return -errno; |
233 | ||
234 | return 0; | |
235 | } |