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Diffstat (limited to 'i/pc104/initrd/conf/busybox/networking/udhcp/arpping.c')
-rw-r--r--i/pc104/initrd/conf/busybox/networking/udhcp/arpping.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/i/pc104/initrd/conf/busybox/networking/udhcp/arpping.c b/i/pc104/initrd/conf/busybox/networking/udhcp/arpping.c
new file mode 100644
index 0000000..f78fd3f
--- /dev/null
+++ b/i/pc104/initrd/conf/busybox/networking/udhcp/arpping.c
@@ -0,0 +1,114 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * arpping.c
+ *
+ * Mostly stolen from: dhcpcd - DHCP client daemon
+ * by Yoichi Hariguchi <yoichi@fore.com>
+ */
+
+#include <netinet/if_ether.h>
+#include <net/if_arp.h>
+
+#include "common.h"
+#include "dhcpd.h"
+
+
+struct arpMsg {
+ /* Ethernet header */
+ uint8_t h_dest[6]; /* destination ether addr */
+ uint8_t h_source[6]; /* source ether addr */
+ uint16_t h_proto; /* packet type ID field */
+
+ /* ARP packet */
+ uint16_t htype; /* hardware type (must be ARPHRD_ETHER) */
+ uint16_t ptype; /* protocol type (must be ETH_P_IP) */
+ uint8_t hlen; /* hardware address length (must be 6) */
+ uint8_t plen; /* protocol address length (must be 4) */
+ uint16_t operation; /* ARP opcode */
+ uint8_t sHaddr[6]; /* sender's hardware address */
+ uint8_t sInaddr[4]; /* sender's IP address */
+ uint8_t tHaddr[6]; /* target's hardware address */
+ uint8_t tInaddr[4]; /* target's IP address */
+ uint8_t pad[18]; /* pad for min. Ethernet payload (60 bytes) */
+} ATTRIBUTE_PACKED;
+
+/* args: yiaddr - what IP to ping
+ * ip - our ip
+ * mac - our arp address
+ * interface - interface to use
+ * retn: 1 addr free
+ * 0 addr used
+ * -1 error
+ */
+
+/* FIXME: match response against chaddr */
+int arpping(uint32_t yiaddr, uint32_t ip, uint8_t *mac, char *interface)
+{
+ int timeout = 2;
+ int s; /* socket */
+ int rv = 1; /* return value */
+ struct sockaddr addr; /* for interface name */
+ struct arpMsg arp;
+ fd_set fdset;
+ struct timeval tm;
+ time_t prevTime;
+
+
+ s = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP));
+ if (s == -1) {
+ bb_perror_msg(bb_msg_can_not_create_raw_socket);
+ return -1;
+ }
+
+ if (setsockopt_broadcast(s) == -1) {
+ bb_perror_msg("cannot setsocketopt on raw socket");
+ close(s);
+ return -1;
+ }
+
+ /* send arp request */
+ memset(&arp, 0, sizeof(arp));
+ memcpy(arp.h_dest, MAC_BCAST_ADDR, 6); /* MAC DA */
+ memcpy(arp.h_source, mac, 6); /* MAC SA */
+ arp.h_proto = htons(ETH_P_ARP); /* protocol type (Ethernet) */
+ arp.htype = htons(ARPHRD_ETHER); /* hardware type */
+ arp.ptype = htons(ETH_P_IP); /* protocol type (ARP message) */
+ arp.hlen = 6; /* hardware address length */
+ arp.plen = 4; /* protocol address length */
+ arp.operation = htons(ARPOP_REQUEST); /* ARP op code */
+ memcpy(arp.sInaddr, &ip, sizeof(ip)); /* source IP address */
+ memcpy(arp.sHaddr, mac, 6); /* source hardware address */
+ memcpy(arp.tInaddr, &yiaddr, sizeof(yiaddr)); /* target IP address */
+
+ memset(&addr, 0, sizeof(addr));
+ strcpy(addr.sa_data, interface);
+ if (sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0)
+ rv = 0;
+
+ /* wait arp reply, and check it */
+ tm.tv_usec = 0;
+ prevTime = uptime();
+ while (timeout > 0) {
+ FD_ZERO(&fdset);
+ FD_SET(s, &fdset);
+ tm.tv_sec = timeout;
+ if (select(s + 1, &fdset, (fd_set *) NULL, (fd_set *) NULL, &tm) < 0) {
+ bb_perror_msg("error on ARPING request");
+ if (errno != EINTR) rv = 0;
+ } else if (FD_ISSET(s, &fdset)) {
+ if (recv(s, &arp, sizeof(arp), 0) < 0 ) rv = 0;
+ if (arp.operation == htons(ARPOP_REPLY) &&
+ memcmp(arp.tHaddr, mac, 6) == 0 &&
+ *((uint32_t *) arp.sInaddr) == yiaddr) {
+ DEBUG("Valid arp reply received for this address");
+ rv = 0;
+ break;
+ }
+ }
+ timeout -= uptime() - prevTime;
+ prevTime = uptime();
+ }
+ close(s);
+ DEBUG("%salid arp replies for this address", rv ? "No v" : "V");
+ return rv;
+}