1 /*
2 * dhcpcd - DHCP client daemon
3 * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/types.h>
28 #include <sys/ioctl.h>
29 #include <sys/socket.h>
30
31 #include <net/if.h>
32 #include <netinet/in_systm.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
35
36 #ifdef __linux__
37 # include <asm/types.h> /* needed for 2.4 kernels for the below header */
38 # include <linux/filter.h>
39 # include <netpacket/packet.h>
40 # define bpf_insn sock_filter
41 # define BPF_SKIPTYPE
42 # define BPF_ETHCOOK -ETH_HLEN
43 # define BPF_WHOLEPACKET 0x0fffffff /* work around buggy LPF filters */
44 #endif
45
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <time.h>
52 #include <unistd.h>
53
54 #include "config.h"
55 #include "common.h"
56 #include "dhcp.h"
57 #include "net.h"
58 #include "bpf-filter.h"
59
60 /* Broadcast address for IPoIB */
61 static const uint8_t ipv4_bcast_addr[] = {
62 0x00, 0xff, 0xff, 0xff,
63 0xff, 0x12, 0x40, 0x1b, 0x00, 0x00, 0x00, 0x00,
64 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff
65 };
66
67 int
open_socket(struct interface * iface,int protocol)68 open_socket(struct interface *iface, int protocol)
69 {
70 int s;
71 union sockunion {
72 struct sockaddr sa;
73 struct sockaddr_in sin;
74 struct sockaddr_ll sll;
75 struct sockaddr_storage ss;
76 } su;
77 struct sock_fprog pf;
78 int *fd;
79
80 if ((s = socket(PF_PACKET, SOCK_DGRAM, htons(protocol))) == -1)
81 return -1;
82
83 memset(&su, 0, sizeof(su));
84 su.sll.sll_family = PF_PACKET;
85 su.sll.sll_protocol = htons(protocol);
86 if (!(su.sll.sll_ifindex = if_nametoindex(iface->name))) {
87 errno = ENOENT;
88 goto eexit;
89 }
90 /* Install the DHCP filter */
91 memset(&pf, 0, sizeof(pf));
92 if (protocol == ETHERTYPE_ARP) {
93 pf.filter = UNCONST(arp_bpf_filter);
94 pf.len = arp_bpf_filter_len;
95 } else {
96 pf.filter = UNCONST(dhcp_bpf_filter);
97 pf.len = dhcp_bpf_filter_len;
98 }
99 if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &pf, sizeof(pf)) != 0)
100 goto eexit;
101 if (set_cloexec(s) == -1)
102 goto eexit;
103 if (set_nonblock(s) == -1)
104 goto eexit;
105 if (bind(s, &su.sa, sizeof(su)) == -1)
106 goto eexit;
107 if (protocol == ETHERTYPE_ARP)
108 fd = &iface->arp_fd;
109 else
110 fd = &iface->raw_fd;
111 if (*fd != -1)
112 close(*fd);
113 *fd = s;
114 return s;
115
116 eexit:
117 close(s);
118 return -1;
119 }
120
121 ssize_t
send_raw_packet(const struct interface * iface,int protocol,const void * data,ssize_t len)122 send_raw_packet(const struct interface *iface, int protocol,
123 const void *data, ssize_t len)
124 {
125 union sockunion {
126 struct sockaddr sa;
127 struct sockaddr_ll sll;
128 struct sockaddr_storage ss;
129 } su;
130 int fd;
131
132 memset(&su, 0, sizeof(su));
133 su.sll.sll_family = AF_PACKET;
134 su.sll.sll_protocol = htons(protocol);
135 if (!(su.sll.sll_ifindex = if_nametoindex(iface->name))) {
136 errno = ENOENT;
137 return -1;
138 }
139 su.sll.sll_hatype = htons(iface->family);
140 su.sll.sll_halen = iface->hwlen;
141 if (iface->family == ARPHRD_INFINIBAND)
142 memcpy(&su.sll.sll_addr,
143 &ipv4_bcast_addr, sizeof(ipv4_bcast_addr));
144 else
145 memset(&su.sll.sll_addr, 0xff, iface->hwlen);
146 if (protocol == ETHERTYPE_ARP)
147 fd = iface->arp_fd;
148 else
149 fd = iface->raw_fd;
150
151 return sendto(fd, data, len, 0, &su.sa, sizeof(su));
152 }
153
154 ssize_t
get_raw_packet(struct interface * iface,int protocol,void * data,ssize_t len)155 get_raw_packet(struct interface *iface, int protocol, void *data, ssize_t len)
156 {
157 ssize_t bytes;
158 int fd = -1;
159
160 if (protocol == ETHERTYPE_ARP)
161 fd = iface->arp_fd;
162 else
163 fd = iface->raw_fd;
164 bytes = read(fd, data, len);
165 if (bytes == -1)
166 return errno == EAGAIN ? 0 : -1;
167 return bytes;
168 }
169