/*
* dhcpcd - DHCP client daemon
* Copyright (c) 2006-2013 Roy Marples <roy@marples.name>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifdef __linux__
# include <asm/types.h> /* needed for 2.4 kernels for the below header */
# include <linux/filter.h>
# include <linux/if_packet.h>
# define bpf_insn sock_filter
# define BPF_SKIPTYPE
# define BPF_ETHCOOK -ETH_HLEN
# define BPF_WHOLEPACKET 0x0fffffff /* work around buggy LPF filters */
#endif
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "config.h"
#include "common.h"
#include "dhcp.h"
#include "ipv4.h"
#include "bpf-filter.h"
/* Broadcast address for IPoIB */
static const uint8_t ipv4_bcast_addr[] = {
0x00, 0xff, 0xff, 0xff,
0xff, 0x12, 0x40, 0x1b, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff
};
#ifdef INET
int
ipv4_opensocket(struct interface *ifp, int protocol)
{
int s;
union sockunion {
struct sockaddr sa;
struct sockaddr_in sin;
struct sockaddr_ll sll;
struct sockaddr_storage ss;
} su;
struct sock_fprog pf;
#ifdef PACKET_AUXDATA
int n;
#endif
if ((s = socket(PF_PACKET, SOCK_DGRAM, htons(protocol))) == -1)
return -1;
memset(&su, 0, sizeof(su));
su.sll.sll_family = PF_PACKET;
su.sll.sll_protocol = htons(protocol);
su.sll.sll_ifindex = ifp->index;
/* Install the DHCP filter */
memset(&pf, 0, sizeof(pf));
if (protocol == ETHERTYPE_ARP) {
pf.filter = UNCONST(arp_bpf_filter);
pf.len = arp_bpf_filter_len;
} else {
pf.filter = UNCONST(dhcp_bpf_filter);
pf.len = dhcp_bpf_filter_len;
}
if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &pf, sizeof(pf)) != 0)
goto eexit;
#ifdef PACKET_AUXDATA
n = 1;
if (setsockopt(s, SOL_PACKET, PACKET_AUXDATA, &n, sizeof(n)) != 0) {
if (errno != ENOPROTOOPT)
goto eexit;
}
#endif
if (set_cloexec(s) == -1)
goto eexit;
if (set_nonblock(s) == -1)
goto eexit;
if (bind(s, &su.sa, sizeof(su)) == -1)
goto eexit;
return s;
eexit:
close(s);
return -1;
}
ssize_t
ipv4_sendrawpacket(const struct interface *ifp, int protocol,
const void *data, ssize_t len)
{
const struct dhcp_state *state;
union sockunion {
struct sockaddr sa;
struct sockaddr_ll sll;
struct sockaddr_storage ss;
} su;
int fd;
memset(&su, 0, sizeof(su));
su.sll.sll_family = AF_PACKET;
su.sll.sll_protocol = htons(protocol);
su.sll.sll_ifindex = ifp->index;
su.sll.sll_hatype = htons(ifp->family);
su.sll.sll_halen = ifp->hwlen;
if (ifp->family == ARPHRD_INFINIBAND)
memcpy(&su.sll.sll_addr,
&ipv4_bcast_addr, sizeof(ipv4_bcast_addr));
else
memset(&su.sll.sll_addr, 0xff, ifp->hwlen);
state = D_CSTATE(ifp);
if (protocol == ETHERTYPE_ARP)
fd = state->arp_fd;
else
fd = state->raw_fd;
return sendto(fd, data, len, 0, &su.sa, sizeof(su));
}
ssize_t
ipv4_getrawpacket(struct interface *ifp, int protocol,
void *data, ssize_t len, int *partialcsum)
{
struct iovec iov = {
.iov_base = data,
.iov_len = len,
};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
};
struct dhcp_state *state;
#ifdef PACKET_AUXDATA
unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
struct cmsghdr *cmsg;
struct tpacket_auxdata *aux;
#endif
ssize_t bytes;
int fd = -1;
#ifdef PACKET_AUXDATA
msg.msg_control = cmsgbuf;
msg.msg_controllen = sizeof(cmsgbuf);
#endif
state = D_STATE(ifp);
if (protocol == ETHERTYPE_ARP)
fd = state->arp_fd;
else
fd = state->raw_fd;
bytes = recvmsg(fd, &msg, 0);
if (bytes == -1)
return errno == EAGAIN ? 0 : -1;
if (partialcsum != NULL) {
*partialcsum = 0;
#ifdef PACKET_AUXDATA
for (cmsg = CMSG_FIRSTHDR(&msg);
cmsg;
cmsg = CMSG_NXTHDR(&msg, cmsg))
{
if (cmsg->cmsg_level == SOL_PACKET &&
cmsg->cmsg_type == PACKET_AUXDATA) {
aux = (void *)CMSG_DATA(cmsg);
*partialcsum = aux->tp_status &
TP_STATUS_CSUMNOTREADY;
}
}
#endif
}
return bytes;
}
#endif
