1 /* 2 * dhcpcd - DHCP client daemon 3 * Copyright 2006-2008 Roy Marples <roy (at) 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 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 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 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
