#include <string.h>
#include <linux/if_packet.h>
#include <net/ethernet.h>
+#include <net/if_arp.h>
#include <stdio.h>
#include <unistd.h>
+#include <linux/filter.h>
#include "socket-util.h"
#include "dhcp-internal.h"
-int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link)
-{
- int s, one = 1;
+int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link,
+ uint32_t xid) {
+ struct sock_filter filter[] = {
+ BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */
+ BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(DHCPPacket), 1, 0), /* packet >= DHCPPacket ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.protocol)), /* A <- IP protocol */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 1, 0), /* IP protocol == UDP ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, udp.dest)), /* A <- UDP destination port */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_PORT_CLIENT, 1, 0), /* UDP destination port == DHCP client port ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.op)), /* A <- DHCP op */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, BOOTREPLY, 1, 0), /* op == BOOTREPLY ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.htype)), /* A <- DHCP header type */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPHRD_ETHER, 1, 0), /* header type == ARPHRD_ETHER ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.hlen)), /* A <- mac address length */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHER_ADDR_LEN, 1, 0), /* address length == ETHER_ADDR_LEN ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.xid)), /* A <- client identifier */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, xid, 1, 0), /* client identifier == xid ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ /* TODO: match chaddr */
+ BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.magic)), /* A <- DHCP magic cookie */
+ BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_MAGIC_COOKIE, 1, 0), /* cookie == DHCP magic cookie ? */
+ BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */
+ BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */
+ };
+ struct sock_fprog fprog = {
+ .len = ELEMENTSOF(filter),
+ .filter = filter
+ };
+ _cleanup_close_ int s = -1;
+ int r, on = 1;
assert(index > 0);
assert(link);
if (s < 0)
return -errno;
+ r = setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &on, sizeof(on));
+ if (r < 0)
+ return -errno;
+
+ r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog));
+ if (r < 0)
+ return -errno;
+
link->ll.sll_family = AF_PACKET;
link->ll.sll_protocol = htons(ETH_P_IP);
link->ll.sll_ifindex = index;
link->ll.sll_halen = ETH_ALEN;
memset(link->ll.sll_addr, 0xff, ETH_ALEN);
- if (setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one)) < 0)
+ r = bind(s, &link->sa, sizeof(link->ll));
+ if (r < 0)
return -errno;
- if (bind(s, &link->sa, sizeof(link->ll)) < 0) {
- safe_close(s);
- return -errno;
- }
+ r = s;
+ s = -1;
- return s;
+ return r;
}
-int dhcp_network_bind_udp_socket(int index, be32_t address, uint16_t port)
-{
- int s;
+int dhcp_network_bind_udp_socket(be32_t address, uint16_t port) {
union sockaddr_union src = {
.in.sin_family = AF_INET,
.in.sin_port = htobe16(port),
.in.sin_addr.s_addr = address,
};
+ _cleanup_close_ int s = -1;
+ int r, tos = IPTOS_CLASS_CS6;
s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
if (s < 0)
return -errno;
- if (bind(s, &src.sa, sizeof(src.in)) < 0) {
- safe_close(s);
+ r = setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
+ if (r < 0)
return -errno;
+
+ if (address == INADDR_ANY) {
+ int on = 1;
+
+ r = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+ if (r < 0)
+ return -errno;
+
+ r = setsockopt(s, IPPROTO_IP, IP_PKTINFO, &on, sizeof(on));
+ if (r < 0)
+ return -errno;
}
- return s;
+ r = bind(s, &src.sa, sizeof(src.in));
+ if (r < 0)
+ return -errno;
+
+ r = s;
+ s = -1;
+
+ return r;
}
int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
- const void *packet, size_t len)
-{
+ const void *packet, size_t len) {
+ int r;
+
assert(link);
assert(packet);
assert(len);
- if (sendto(s, packet, len, 0, &link->sa, sizeof(link->ll)) < 0)
+ r = sendto(s, packet, len, 0, &link->sa, sizeof(link->ll));
+ if (r < 0)
return -errno;
return 0;
}
int dhcp_network_send_udp_socket(int s, be32_t address, uint16_t port,
- const void *packet, size_t len)
-{
+ const void *packet, size_t len) {
union sockaddr_union dest = {
.in.sin_family = AF_INET,
.in.sin_port = htobe16(port),
.in.sin_addr.s_addr = address,
};
+ int r;
+
+ assert(s >= 0);
+ assert(packet);
+ assert(len);
- if (sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)) < 0)
+ r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in));
+ if (r < 0)
return -errno;
return 0;
~ianmdlvl / elogind.git / blobdiff